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Earth observation (EO) is a prerequisite for sustainable land use management, and the open-data Landsat mission is at the forefront of this development. However, increasing data volumes have led to a "digital-divide", and consequently, it is key to develop methods that account for the most data-intensive processing steps, then used for the generation and provision of analysis-ready, standardized, higher-level (Level 2 and Level 3) baseline products for enhanced uptake in environmental monitoring systems. Accordingly, the overarching research task of this dissertation was to develop such a framework with a special emphasis on the yet under-researched drylands of Southern Africa. A fully automatic and memory-resident radiometric preprocessing streamline (Level 2) was implemented. The method was applied to the complete Angolan, Zambian, Zimbabwean, Botswanan, and Namibian Landsat record, amounting 58,731 images with a total data volume of nearly 15 TB. Cloud/shadow detection capabilities were improved for drylands. An integrated correction of atmospheric, topographic and bidirectional effects was implemented, based on radiative theory with corrections for multiple scatterings, and adjacency effects, as well as including a multilayered toolset for estimating aerosol optical depth over persistent dark targets or by falling back on a spatio-temporal climatology. Topographic and bidirectional effects were reduced with a semi-empirical C-correction and a global set of correction parameters, respectively. Gridding and reprojection were already included to facilitate easy and efficient further processing. The selection of phenologically similar observations is a key monitoring requirement for multi-temporal analyses, and hence, the generation of Level 3 products that realize phenological normalization on the pixel-level was pursued. As a prerequisite, coarse resolution Land Surface Phenology (LSP) was derived in a first step, then spatially refined by fusing it with a small number of Level 2 images. For this purpose, a novel data fusion technique was developed, wherein a focal filter based approach employs multi-scale and source prediction proxies. Phenologically normalized composites (Level 3) were generated by coupling the target day (i.e. the main compositing criterion) to the input LSP. The approach was demonstrated by generating peak, end and minimum of season composites, and by comparing these with static composites (fixed target day). It was shown that the phenological normalization accounts for terrain- and land cover class-induced LSP differences, and the use of Level 2 inputs enables a wide range of monitoring options, among them the detection of within state processes like forest degradation. In summary, the developed preprocessing framework is capable of generating several analysis-ready baseline EO satellite products. These datasets can be used for regional case studies, but may also be directly integrated into more operational monitoring systems " e.g. in support of the Reducing Emissions from Deforestation and Forest Degradation (REDD) incentive. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of Trier University's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink.
Psychiatric/Behavioral disorders/traits are usually polygenic in nature, where a particular phenotype is the manifestation of multiple genes. However, the existence of large families with numerous members who are affected by these disorders/traits steers us towards a Mendelian (or monogenic) possibility, where the phenotype is caused by a single gene. In order to better understand the genetic architecture of general psychiatric/behavioral disorders/traits, this thesis investigates large pedigrees that display a Mendelian pattern for attention-deficit/hyperactivity disorder, schizophrenia and bipolar disorder. Numerous challenges in the field of psychiatric and behavioral sciences have impeded the genetic investigation of such disorders/traits. Examples include frequent cross-disorders, genetic heterogeneity across subjects as well as the use of diagnostic tools that can be subjective at times. To overcome these challenges, this thesis investigates large multi-generational pedigrees, which comprise a significant number of members who exhibit specific psychiatric/behavioral phenotypes. These pedigrees provide high-resolution experimental setups that can dissect the genetic complexities of psychiatric/behavioral disorders/traits. This thesis adopts a classical two-stage genetic approach to investigate the various psychiatric/behavioral disorders/traits in large pedigrees. The classical two-stage genetic approach is commonly used by many human geneticists to study a wide spectrum of human physiological disorders but is only being applied to the field of psychiatric and behavioral genetics recently. Through the study of large pedigrees, this thesis discovers the genomic regions that may play a causative role in the expression of certain psychiatric/behavioral disorders/traits within the vast genome.
Primary focal hyperhidrosis (PFH, OMIM %144110) is a genetically influenced condition characterised by excessive sweating. Prevalence varies between 1.0–6.1% in the general population, dependent on ethnicity. The aetiology of PFH remains unclear but an autosomal dominant mode of inheritance, incomplete penetrance and variable phenotypes have been reported. In our study, nine pedigrees (50 affected, 53 non-affected individuals) were included. Clinical characterisation was performed at the German Hyperhidrosis Centre, Munich, by using physiological and psychological questionnaires. Genome-wide parametric linkage analysis with GeneHunter was performed based on the Illumina genome-wide SNP arrays. Haplotypes were constructed using easyLINKAGE and visualised via HaploPainter. Whole-exome sequencing (WES) with 100x coverage in 31 selected members (24 affected, 7 non-affected) from our pedigrees was achieved by next generation sequencing. We identified four genome-wide significant loci, 1q41-1q42.3, 2p14-2p13.3, 2q21.2-2q23.3 and 15q26.3-15q26.3 for PFH. Three pedigrees map to a shared locus at 2q21.2-2q23.3, with a genome-wide significant LOD score of 3.45. The chromosomal region identified here overlaps with a locus at chromosome 2q22.1-2q31.1 reported previously. Three families support 1q41-1q42.3 (LOD = 3.69), two families share a region identical by descent at 2p14-2p13.3 (LOD = 3.15) and another two families at 15q26.3 (LOD = 3.01). Thus, our results point to considerable genetic heterogeneity. WES did not reveal any causative variants, suggesting that variants or mutations located outside the coding regions might be involved in the molecular pathogenesis of PFH. We suggest a strategy based on whole-genome or targeted next generation sequencing to identify causative genes or variants for PFH.
Geographic ranges of species and their determinants are of great interest in the field of biogeography and are often studied in terms of the species" ecological niches. In this context, the range of a species is defined by the accessibility of an area, abiotic factors and biotic interactions, which affect a species" distributions with different intensities across spatial scales. Parapatry describes a distributional pattern in which the ranges of two species meet along sharp range limits with narrow contact zones. Such parapatric range limits are determined by changing abiotic conditions along sharp environmental gradients or can result from interspecific resource competition. However, it has been shown that often the interplay of abiotic conditions and species interactions determine parapatry. The geographic ranges of the land salamanders, Salamandra salamandra and S. atra, narrowly overlap in the European Alps with only few syntopic localities and to date, the cause of parapatry is unknown. The goal of this thesis was thus to identify the importance of abiotic and biotic factors for their parapatric range limits at different spatial scales. On a broad spatial scale, the role of climate for the parapatric range limits of the species was investigated within three contact zones in Switzerland. Climatic conditions at species" records were analysed and species distribution modelling techniques were used to explore the species" climatic niches and to quantify the interspecific niche overlap. Furthermore, it was tested whether the parapatric range limit coincides with a strong climatic gradient. The results revealed distinct niches for the species as well as the presence of strong climatic gradients which could explain the parapatric range limits of the species. Yet, there was a moderate interspecific niche overlap in all contact zones indicating that the species may co-occur and interact with each other in areas where they both find adequate conditions. Comparison among contact zones revealed geographic variation in the species" niches as well as in the climatic conditions at their records suggesting that the species can occur in a much wider range of conditions than they actually do. These findings imply that climate represents a main factor for the species" parapatric range limits. Yet, interspecific niche overlap and the geographic variation provide indirect evidence that interspecific interaction may also affect their spatial distribution. To test whether competition restricts the species" ranges on the habitat scale and to understand local syntopic co-occurrence of the salamanders within their contact zones, site-occupancy modelling was used. This approach allowed to find the habitat predictors that best explain the species" local distribution. While the slope of the site positively affected the occupancy probability of S. salamandra, no tested predictor explained that of S. atra. Also, there was no effect of the occurrence of one species on the occupancy probability of the other providing no evidence for competition. Should competition occur, it does not lead to spatial segregation of the species on this scale. Because biotic interactions most significantly affect the ranges of species on small spatial scales, the microhabitat conditions at locations of the species within syntopic contact zones were compared and a null model analysis was applied to determine their niche overlap. Resource selection probability function models were used to assess those attributes that affect the species" habitat selections. The results revealed species-specific microhabitat preferences related to leaf litter cover, tree number and that the species were active at different temperatures as well as times of the day. The high degree of diurnal activity of S. atra may be due to its preference of forest floor microhabitats that long remain suitable during daytime. Besides, there was a great niche overlap for shelters indicating that the species may compete for this resource. Differential habitat selection and the use of the available shelters at different times of the day may minimize species interactions and allow their local co-occurrence within contact zones. To identify whether the potential infection with the pathogenic chytrid fungus could serve as an alternative biotic explanation for the range margins of S. atra, several populations throughout its range were screened for infection. Since the occurrence of this pathogen was detected mostly at lower altitudes of the Alps, it may confine the range of S. atra to higher elevations. Because chytrid was not detected in any of the samples, the pathogen unlikely plays a role in determining its range limits. Overall, these findings underline the complexity of mechanisms that determine the range margins of parapatric species and provide an important basis for subsequent studies regarding the determinants of the parapatric distribution of the two salamander species.
In this thesis, we mainly investigate geometric properties of optimal codebooks for random elements $X$ in a seperable Banach space $E$. Here, for a natural number $ N $ and a random element $X$ , an $N$-optimal codebook is an $ N $-subset in the underlying Banach space $E$ which gives a best approximation to $ X $ in an average sense. We focus on two types of geometric properties: The global growth behaviour (growing in $N$) for a sequence of $N$-optimal codebooks is described by the maximal (quantization) radius and a so-called quantization ball. For many distributions, such as central-symmetric distributions on $R^d$ as well as Gaussian distributions on general Banach spaces, we are able to estimate the asymptotics of the quantization radius as well as the quantization ball. Furthermore, we investigate local properties of optimal codebooks, in particular the local quantization error and the weights of the Voronoi cells induced by an optimal codebook. In the finite-dimensional setting, we are able to proof for many interesting distributions classical conjectures on the asymptotic behaviour of those properties. Finally, we propose a method to construct sequences of asymptotically optimal codebooks for random elements in infinite dimensional Banach spaces and apply this method to construct codebooks for stochastic processes, such as fractional Brownian Motions.
Recent non-comparative studies diverge in their assessments of the extent to which German and Japanese post-Cold War foreign policies are characterized by continuity or change. While the majority of analyses on Germany find overall continuity in policies and guiding principles, prominent works on Japan see the country undergoing drastic and fundamental change. Using an explicitly comparative framework for analysis based on a role theoretical approach, this study reevaluates the question of change and continuity in the two countries" regional foreign policies, focusing on the time period from 1990 to 2010. Through a qualitative content analysis of key foreign policy speeches, this dissertation traces and compares German and Japanese national role conceptions (NRCs) by identifying policymakers" perceived duties and responsibilities of their country in international politics. Furthermore, it investigates actual foreign policy behavior in two case studies about German and Japanese policies on missile defense and on textbook disputes. The dissertation examines whether the NRCs identified in the content analysis are useful to understand and explain each country- particular conduct. Both qualitative content analysis and case studies demonstrate the influence of normative and ideational variables in foreign policymaking. Incremental adaptations in foreign policy preferences can be found in Germany as well as Japan, but they are anchored in established normative guidelines and represent attempts to harmonize existing preferences with the conditions of the post-Cold War era. The dissertation argues that scholars have overstated and misconstrued the changes underway by asserting that Japan is undergoing a sweeping transformation in its foreign policy.
GIS – what can and what can’t it say about social relations in adaptation to urban flood risk?
(2017)
Urban flooding cannot be avoided entirely and in all areas, particularly in coastal cities. Therefore adaptation to the growing risk is necessary. Geographical Information Systems (GIS) based knowledge on risk informs location-based approach to adaptation to climate risk. It allows managing city- wide coordination of adaptation measures, reducing adverse impacts of local strategies on neighbouring areas to the minimum. Quantitative assessments dominate GIS applications in flood risk management, for instance to demonstrate the distribution of people and assets in a flood prone area. Qualitative, participatory approaches to GIS are on the rise but have not been applied in the context of flooding yet. The overarching research question of this working paper is: what can GIS, and what can it not say about relationships / social relations in adaptation to urban flood risk? The use of GIS in risk mapping has exposed environmental injustices. Applications of GIS further allow model- ling future flood risk in function of demographic and land use changes, and combining it with decision support systems (DSS). While such GIS applications provide invaluable information for urban planners steering adaptation they however fall short on revealing the social relations that shape individual and household adaptation decisions. The relevance of networked social relations in adaptation to flood risk has been demonstrated in case studies, and extensively in the literature on organizational learning and adaptation to change. The purpose of this literature review is to identify the type of social relations that shape adaptive capacities towards urban flood risk which can- not be identified in a conventional GIS application.
Globalization and Divergence: Dynamics of Dissensus in Non-Dominant Cinema Cultures of South India
(2002)
Based on her field studies between 1999 and 2003 in the South Indian State Kerala, the author critically reflects about Habermas's concept of the (bourgeois) public sphere, and also about later critiques of Habermas (eg. Eley). Schulze adds the new dimensions of human emotionality and humane ethics to the discussion of today's public (spheres) and civil societies which are part of globalising modernisations. It is poor and marginalized women's strongly felt compassion and love practised in their daily lives, which Schulze focusses on: these Marginalized ethics of the 'Good life' do sharply contrast the dominant societies' value systems; these latters consequently don't provide to the Marginaliezed a 'model'. However, Kerala, which is widely refered to as a development model - particularly with respect to the situation/ education of its women - is thus analysed by the author as a historically and culturally specific kind of 'modernity', which follows are rather violent and aggressive path of development in consonance with the general ruling anti-human/ nature philosophy of 'globalization'. Schulze's tool in her field work is 'participatory action research' and also her 'empathic camera' (camcoder). She mixed with local women who had organized themselves in women's groups with the urge to truly represent themSelves and their own ethics and goals in life - without the usual intervention of men/ of nationalist politics ruling Kerala's public sphere(s). In the course of Schulze and the local women groups becoming acquainted with each other, the scholar and the Marginalized felt the desire to support each other in their respective struggles for empowerment and for being respected as a human being. The author finally understood the fallacy and cynicism which lies in applying as a scholar the term 'women in Kerala' as if there wasn't the day to day particular violence which women of dalit ('untouchable'), or of adivasi (indigenous) background experience. Women's lives are moulded by networks of violence which are inherent to Kerala's castes, classes, and ethnicities, parallel to the basic oppression which women face because they are women. A group of dalit women in Kerala became particularly close companions in Schulze's quest for unravelling seemingly contradictory facts: Kerala's official claim to provide to women and other persons who were generally discriminated against in the larger Indian context, a supportive social and educational environment, on the one hand, and on the other hand the comparatively high number of suicides among Keralite women (and men), and the absence of women in what appears as Kerala's public sphere and 'civil society'. In several analytical steps which always centre around the experiences and feelings of the many poor and marginalized women, their life-worlds, their daily life philosophies, their views, voices, their ethics, dreams, Schulze unfolds these Marginalized visions, and tries to interpret them on their own terms. In this manner not only the mainstream society's propaganda about the 'Kerala development model' is demystified, but also to the reader insights become possible into a totally different set of ethics held by these women. They transgress notions of competition, of the 'necessary' monetarisation of all spheres of human life and of nature, of caste, religious, or gender conflicts. By means of 13 small video films the women together with Schulze showed and reflected upon their philosophy of an empowered 'Good life'.
The Hadamard product of two holomorphic functions which is defined via a convolution integral constitutes a generalization of the Hadamard product of two power series which is obtained by pointwise multiplying their coefficients. Based on the integral representation mentioned above, an associative law for this convolution is shown. The main purpose of this thesis is the examination of the linear and continuous Hadamard convolution operators. These operators map between spaces of holomorphic functions and send - with a fixed function phi - a function f to the convolution of phi and f. The transposed operator is computed and turns out to be a Hadamard convolution operator, too, mapping between spaces of germs of holomorphic functions. The kernel of Hadamard convolution operators is investigated and necessary and sufficient conditions for those operators to be injective or to have dense range are given. In case that the domain of holomorphy of the function phi allows a Mellin transform of phi, certain (generalized) monomials are identified as eigenfunctions of the corresponding operator. By means of this result and some extract of the theory of growth of entire functions, further propositions concerning the injectivity, the denseness of the range or the surjectivity of Hadamard convolution operators are shown. The relationship between Hadamard convolution operators, operators which are defined via the convolution with an analytic functional and differential operators of infinite order is investigated and the results which are obtained in the thesis are put into the research context. The thesis ends with an application of the results to the approximation of holomorphic functions by lacunary polynomials. On the one hand, the question under which conditions lacunary polynomials are dense in the space of all holomorphic functions is investigated and on the other hand, the rate of approximation is considered. In this context, a result corresponding to the Bernstein-Walsh theorem is formulated.
We are living in a connected world, surrounded by interwoven technical systems. Since they pervade more and more aspects of our everyday lives, a thorough understanding of the structure and dynamics of these systems is becoming increasingly important. However - rather than being blueprinted and constructed at the drawing board - many technical infrastructures like for example the Internet's global router network, the World Wide Web, large scale Peer-to-Peer systems or the power grid - evolve in a distributed fashion, beyond the control of a central instance and influenced by various surrounding conditions and interdependencies. Hence, due to this increase in complexity, making statements about the structure and behavior of tomorrow's networked systems is becoming increasingly complicated. A number of failures has shown that complex structures can emerge unintentionally that resemble those which can be observed in biological, physical and social systems. In this dissertation, we investigate how such complex phenomena can be controlled and actively used. For this, we review methodologies stemming from the field of random and complex networks, which are being used for the study of natural, social and technical systems, thus delivering insights into their structure and dynamics. A particularly interesting finding is the fact that the efficiency, dependability and adaptivity of natural systems can be related to rather simple local interactions between a large number of elements. We review a number of interesting findings about the formation of complex structures and collective dynamics and investigate how these are applicable in the design and operation of large scale networked computing systems. A particular focus of this dissertation are applications of principles and methods stemming from the study of complex networks in distributed computing systems that are based on overlay networks. Here we argue how the fact that the (virtual) connectivity in such systems is alterable and widely independent from physical limitations facilitates a design that is based on analogies between complex network structures and phenomena studied in statistical physics. Based on results about the properties of scale-free networks, we present a simple membership protocol by which scale-free overlay networks with adjustable degree distribution exponent can be created in a distributed fashion. With this protocol we further exemplify how phase transition phenomena - as occurring frequently in the domain of statistical physics - can actively be used to quickly adapt macroscopic statistical network parameters which are known to massively influence the stability and performance of networked systems. In the case considered in this dissertation, the adaptation of the degree distribution exponent of a random, scale-free overlay allows - within critical regions - a change of relevant structural and dynamical properties. As such, the proposed scheme allows to make sound statements about the relation between the local behavior of individual nodes and large scale properties of the resulting complex network structures. For systems in which the degree distribution exponent cannot easily be derived for example from local protocol parameters, we further present a distributed, probabilistic mechanism which can be used to monitor a network's degree distribution exponent and thus to reason about important structural qualities. Finally, the dissertation shifts its focus towards the study of complex, non-linear dynamics in networked systems. We consider a message-based protocol which - based on the Kuramoto model for coupled oscillators - achieves a stable, global synchronization of periodic heartbeat events. The protocol's performance and stability is evaluated in different network topologies. We further argue that - based on existing findings about the interrelation between spectral network properties and the dynamics of coupled oscillators - the proposed protocol allows to monitor structural properties of networked computing systems. An important aspect of this dissertation is its interdisciplinary approach towards a sensible and constructive handling of complex structures and collective dynamics in networked systems. The associated investigation of distributed systems from the perspective of non-linear dynamics and statistical physics highlights interesting parallels both to biological and physical systems. This foreshadows systems whose structures and dynamics can be analyzed and understood in the conceptual frameworks of statistical physics and complex systems.
Repeatedly encountering a stimulus biases the observer’s affective response and evaluation of the stimuli. Here we provide evidence for a causal link between mere exposure to fictitious news reports and subsequent voting behavior. In four pre-registered online experiments, participants browsed through newspaper webpages and were tacitly exposed to names of fictitious politicians. Exposure predicted voting behavior in a subsequent mock election, with a consistent preference for frequent over infrequent names, except when news items were decidedly negative. Follow-up analyses indicated that mere media presence fuels implicit personality theories regarding a candidate’s vigor in political contexts. News outlets should therefore be mindful to cover political candidates as evenly as possible.
The human brain is characterised by two apparently symmetrical cerebral hemispheres. However, the functions attributed to each half of the brain are very distinct with a relative specialisation of the left hemisphere for language processing. Most laterality research has been performed on a behavioural level, using techniques such as visual half-field presentation. The visual half-field technique involves the presentation of stimuli in the left or right visual field for a very short time (about 200 ms). During the presentation of lateralized stimuli, the gaze of the participants is fixated on a centrally presented fixation cross. This technique takes advantage of the anatomy of the visual pathway as the temporal hemiretinae project ipsilateral, while the nasal hemiretinae project contralateral. Thus, stimuli presented in the left or right visual field are initially processed in the contralateral hemisphere. Language organisation can also be directly investigated using functional magnetic resonance imaging (fMRI). Both behavioural and neuroimaging studies showed that about 95% of right-handed men have a left hemispheric specialisation for language. In contrast, data on language organisation in women are ambiguous. It is supposed that this ambivalent picture might be associated with changes in gonadal steroid levels in blood during the menstrual cycle. However, gonadal steroid effects are complex and their role in functional cerebral lateralization is still open to discussion. The aim of this PhD project was to investigate, using fMRI: (1) the processing of linguistic information initially received in the specialised, non-specialised or both hemispheres; (2) linking the associated brain activation pattern with progesterone levels during the menstrual cycle. Firstly, brain activation was measured in 16 right-handed, healthy males during processing of different components of language (orthography, phonology and semantics) after reception in the left, right or both hemispheres. Secondly, to investigate changes in language organisation during the menstrual cycle, we conducted an event-related fMRI study during semantic and phonological processing also using visual half-field and central presentation of linguistic stimuli. Our results revealed higher BOLD signal intensity change in the visual cortex contralateral to the visual field of stimulus presentation compared to the ipsilateral visual cortex reflecting the crossing of visual pathways. We also found support for the hypothesis that the superiority of word recognition in the left VWFA is the result of a reduced activity in the right VWFA under left hemispheric control. Further, linguistic information received in the subdominant RH, is interhemispheric transferred to the left hemisphere for phonological processing. Semantic processing in contrast occurs in the specialised and in the non-specialised hemisphere. For the group of women, data analysis revealed that during semantic processing, salivary progesterone levels correlated positively with brain activity of the left superior frontal gyrus, left middle and inferior occipital gyri and bilateral fusiform gyrus. In contrast, the brain activation pattern for phonological processing did not change significantly across the menstrual cycle. In conclusion, the effect of serum progesterone levels on brain activity is task and region specific.
Today, usage of complex circuit designs in computers, in multimedia applications and communication devices is widespread and still increasing. At the same time, due to Moore's Law we do not expect to see an end in the growth of the complexity of digital circuits. The decreasing ability of common validation techniques -- like simulation -- to assure correctness of a circuit design enlarges the need for formal verification techniques. Formal verification delivers a mathematical proof that a given implementation of a design fulfills its specification. One of the basic and during the last years widely used data structure in formal verification are the so called Ordered Binary Decision Diagrams (OBDDs) introduced by R. Bryant in 1986. The topic of this thesis is integration of structural high-level information in the OBDD-based formal verification of sequential systems. This work consist of three major parts, covering different layers of formal verification applications: At the application layer, an assertion checking methodology, integrated in the verification flow of the high-level design and verification tool Protocol Compiler is presented. At the algorithmic layer, new approaches for partitioning of transition relations of complex finite state machines, that significantly improve the performance of OBDD-based sequential verification are introduced. Finally, at the data structure level, dynamic variable reordering techniques that drastically reduce the time required for reordering without a trade-off in OBDD-size are described. Overall, this work demonstrates how a tighter integration of applications by using structural information can significantly improve the efficiency of formal verification applications in an industrial setting.
In Beloved, Jazz and Paradise, Toni Morrison negotiates ways of individual and collective identity formation through figurations of space and trauma. In geographical spaces that are public and private, open and closed, inclusive and exclusive, space of the past and spaces of the present, Morrison writes discursive spaces in which to create individual and communal African American history and identity, based on the traumatic hi-stories at the core of the Black American experience: the Middle Passage, slavery, Jim Crow and the Civil Rights Movement, just to name a few. In the three novels, Toni Morrison subscribes to a postmodern notion of space and place, presenting it as relative to the individual- frame of mind. Places are used as metonymies for the protagonists" traumatized minds and their different ways of dealing with trauma. Trauma that is not worked through and transcended is presented by Morrison as impacting the protagonists- ability to fashion a home out of a vast and often hostile space. The physical and mental space of Morrison- protagonists is occupied by historical traumata that disables the protagonists to find a place in the present without revisiting the places of their troubled past. While this burdens their lives, it also opens up a historical and metahistorical discourse that allows the revision of mainstream historiography to include minority histories of oppression and trauma. Morrison reconfigures the American historical landscape by emphasizing the subjectivity of any history and offering alternatives to historical grand narratives through her historiographic metafiction. All three novels explore the possibility of reconciliation between past trauma and present life. Doing so requires Morrison to send her protagonists on strenuous journeys through time and space in order to visit the past trauma that keeps them from making a home in the here and now. The protagonists venture back to the primal scenes that bear major significance for their lives but have been suppressed for being too painful to remember. Their pain thus awakens anew, but out of it grow the possibility of a life in the present and the hope for a future. The pasts Morrison thus digs up serve as anchors to situate the African American place in the American historical landscape. Those primal places have a geographical as well as a historical and psychological quality, as places in Morrison- novels are often used as metonymies for the protagonists" traumatized minds, containing the memory of the traumatic past. By spatializing time, Morrison makes history accessible to a communal working through, thus countering the modernist impulse to treat memory as a private faculty embedded in the individual- psyche. This makes it difficult, for African Americans with individual recollections of slavery and racist oppression for example, to use traumatic memory as the basis for a common sense of identity. Morrison uses spatialized time as a forum to discover this basis, to allow for the establishment of a common historical bond. At the same time, she warns against instrumentalizing a common history to exclude those who do not share it. Any history, for Morrison, should be open and flexible enough to accommodate different perspectives. Essentially, Morrison suggests that western historiography is a discursive construct. By allowing, in all three novels, a polyphonic weaving of different equal histories to destablize a single, authoritative, hegemonic historiography, Morrison gives African Americans the power to construct her own past, her own present, and thereby claim back her identity. Moreover, Morrison destabilizes the duality of private space and public space that has long served to distinguish subjective individual memory from objective communal history and thus to legitimize certain accounts of history at the expense of others. The gendered as well as the racial other, by virtue of being excluded from the public sphere, have been excluded from their own historicization. By opening up the private sphere of personal trauma and loss, Morrison spatializes personal memory in a way that it forms a parallel public sphere in which African Americans may negotiate their historicity, move out of the timelessness of the private into the historicized public. By opening up the traditionally private sphere of the home to the public and turning it into a deeply political place, Morrison redefines home in a way that it does not necessarily conform to the classic view of a closed-off shelter but rather a transient place with flexible boundaries that allows for the formation of liberated individual and communal identities out of (hi)stories of pain and trauma.
This paper tested the ability of Mandarin learners of German, whose native language has lexical tone, to imitate pitch accent contrasts in German, an intonation language. In intonation languages, pitch accents do not convey lexical information; also, pitch accents are sparser than lexical tones as they only associate with prominent words in the utterance. We compared two kinds of German pitch-accent contrasts: (1) a “non-merger” contrast, which Mandarin listeners perceive as different and (2) a “merger” contrast, which sounds more similar to Mandarin listeners. Speakers of a tone language are generally very sensitive to pitch. Hypothesis 1 (H1) therefore stated that Mandarin learners produce the two kinds of contrasts similarly to native German speakers. However, the documented sensitivity to tonal contrasts, at the expense of processing phrase-level intonational contrasts, may generally hinder target-like production of intonational pitch accents in the L2 (Hypothesis 2, H2). Finally, cross-linguistic influence (CLI) predicts a difference in the realization of these two contrasts as well as improvement with higher proficiency (Hypothesis 3, H3). We used a delayed imitation paradigm, which is well-suited for assessing L2-phonetics and -phonology because it does not necessitate access to intonational meaning. We investigated the imitation of three kinds of accents, which were associated with the sentence-final noun in short wh-questions (e.g., Wer malt denn Mandalas, lit: “Who draws PRT mandalas?” “Who likes drawing mandalas?”). In Experiment 1, 28 native speakers of Mandarin participated (14 low- and 14 high-proficient). The learners’ productions of the two kinds of contrasts were analyzed using General Additive Mixed Models to evaluate differences in pitch accent contrasts over time, in comparison to the productions of native German participants from an earlier study in our lab. Results showed a more pronounced realization of the non-merger contrast compared to German natives and a less distinct realization of the merger contrast, with beneficial effects of proficiency, lending support to H3. Experiment 2 tested low-proficient Italian learners of German (whose L1 is an intonation language) to contextualize the Mandarin data and further investigate CLI. Italian learners realized the non-merger contrast more target-like than Mandarin learners, lending additional support to CLI (H3).
For decades, academics and practitioners aim to understand whether and how (economic) events affect firm value. Optimally, these events occur exogenously, i.e. suddenly and unexpectedly, so that an accurate evaluation of the effects on firm value can be conducted. However, recent studies show that even the evaluation of exogenous events is often prone to many challenges that can lead to diverse interpretations, resulting in heated debates. Recently, there have been intense debates in particular on the impact of takeover defenses and of Covid-19 on firm value. The announcements of takeover defenses and the propagation of Covid-19 are exogenous events that occur worldwide and are economically important, but have been insufficiently examined. By answering open research questions, this dissertation aims to provide a greater understanding about the heterogeneous effects that exogenous events such as the announcements of takeover defenses and the propagation of Covid-19 have on firm value. In addition, this dissertation analyzes the influence of certain firm characteristics on the effects of these two exogenous events and identifies influencing factors that explain contradictory results in the existing literature and thus can reconcile different views.
Human behavior in regard to financial issues has long been explained in the light of the efficient market hypothesis. Following the strict interpretation of this theory, investors in the financial markets take into account that all relevant information is already included in the market price of an asset. Accordingly, information from the past does not affect future prices as all information is instantly incorporated. However, focussing on the actual behavior of humans, our empirical results indicate that the existing market conditions influence the behavior of stock market investors.
In the introductory chapter, we describe the difficulties of the efficient markets hypothesis in explaining the behavior of investors within a strictly rational frame. In the second chapter, we show that investors do consider the previous market development for their upcoming investment decisions. First, stock market patterns with predominantly positive days trigger significantly more trades than patterns with negative days. And second, after recent upward movements, investors sell proportionally more stocks than they buy. In the third chapter, we expound a theoretical framework that connects investment-related triggers of arousal, such as the performance of own stocks and the general market environment, with investors’ risk appetite in the decision-making processes. Our model predicts that aroused investors accept higher risks by holding stocks longer in comparison to their less aroused peers. In the fourth chapter, we show how two extreme market environments, the bull and the bear market, affect the disposition effect and especially learning to avoid this behavioral bias. Investors are subject to the bias in each market phase but with a far stronger propensity during the bear market. However, we show that investors also make the greatest progress in avoiding the disposition effect during this period.
These results suggest that future studies about investors’ behavior in the financial markets should consider the market environment as an important determinant.
The present work explores how theories of motivation can be used to enhance video game research. Currently, Flow-Theory and Self-Determination Theory are the most common approaches in the field of Human-Computer Interaction. The dissertation provides an in-depth look into Motive Disposition Theory and how to utilize it to explain interindividual differences in motivation. Different players have different preferences and make different choices when playing games, and not every player experiences the same outcomes when playing the same game. I provide a short overview of the current state of the research on motivation to play video games. Next, Motive Disposition Theory is applied in the context of digital games in four different research papers, featuring seven studies, totaling 1197 participants. The constructs of explicit and implicit motives are explained in detail while focusing on the two social motives (i.e., affiliation and power). As dependent variables, behaviour, preferences, choices, and experiences are used in different game environments (i.e., Minecraft, League of Legends, and Pokémon). The four papers are followed by a general discussion about the seven studies and Motive Disposition Theory in general. Finally, a short overview is provided about other theories of motivation and how they could be used to further our understanding of the motivation to play digital games in the future. This thesis proposes that 1) Motive Disposition Theory represents a valuable approach to understand individual motivations within the context of digital games; 2) there is a variety of motivational theories that can and should be utilized by researchers in the field of Human-Computer Interaction to broaden the currently one-sided perspective on human motivation; 3) researchers should aim to align their choice of motivational theory with their research goals by choosing the theory that best describes the phenomenon in question and by carefully adjusting each study design to the theoretical assumptions of that theory.
Advances in eye tracking technology have enabled the development of interactive experimental setups to study social attention. Since these setups differ substantially from the eye tracker manufacturer’s test conditions, validation is essential with regard to the quality of gaze data and other factors potentially threatening the validity of this signal. In this study, we evaluated the impact of accuracy and areas of interest (AOIs) size on the classification of simulated gaze (fixation) data. We defined AOIs of different sizes using the Limited-Radius Voronoi-Tessellation (LRVT) method, and simulated gaze data for facial target points with varying accuracy. As hypothesized, we found that accuracy and AOI size had strong effects on gaze classification. In addition, these effects were not independent and differed in falsely classified gaze inside AOIs (Type I errors; false alarms) and falsely classified gaze outside the predefined AOIs (Type II errors; misses). Our results indicate that smaller AOIs generally minimize false classifications as long as accuracy is good enough. For studies with lower accuracy, Type II errors can still be compensated to some extent by using larger AOIs, but at the cost of more probable Type I errors. Proper estimation of accuracy is therefore essential for making informed decisions regarding the size of AOIs in eye tracking research.
Hybrid Modelling in general, describes the combination of at least two different methods to solve one specific task. As far as this work is concerned, Hybrid Models describe an approach to combine sophisticated, well-studied mathematical methods with Deep Neural Networks to solve parameter estimation tasks. To combine these two methods, the data structure of artifi- cially generated acceleration data of an approximate vehicle model, the Quarter-Car-Model, is exploited. Acceleration of individual components within a coupled dynamical system, can be described as a second order ordinary differential equation, including velocity and dis- placement of coupled states, scaled by spring - and damping-coefficient of the system. An appropriate numerical integration scheme can then be used to simulate discrete acceleration profiles of the Quarter-Car-Model with a random variation of the parameters of the system. Given explicit knowledge about the data structure, one can then investigate under which con- ditions it is possible to estimate the parameters of the dynamical system for a set of randomly generated data samples. We test, if Neural Networks are capable to solve parameter estima- tion problems in general, or if they can be used to solve several sub-tasks, which support a state-of-the-art parameter estimation method. Hybrid Models are presented for parameter estimation under uncertainties, including for instance measurement noise or incompleteness of measurements, which combine knowledge about the data structure and several Neural Networks for robust parameter estimation within a dynamical system.
Hydrodynamic processes play a fundamental role in the distribution of salt within mangrove-fringed estuaries and mangrove forests. In this thesis, two hydrodynamic processes and their ecological implications were examined. (1) Passive Irrigation and Functional Morphology of Crustacean Burrows in Rhizophora-forests. The mangrove Rhizophora excludes more than 90% of the seawater salt at water intake at the roots. By means of conductivity methods and resin casting, it was found that crustacean burrows play a key role in the removal of excess salt from the root zone. Salt diffuses from the roots into the burrows, and is efficiently flushed from the burrows by rainwater infiltration and tidal irrigation. The burrows contribute significantly to favourable conditions for the growth of Rhizophora trees. (2) Trapping of Mangrove Propagules due to Density-driven Secondary Circulation in Tropical Estuaries. In North East Australian estuaries, mangrove propagules are drifted upstream by density-driven axial surface convergences. Propagules accumulate in hydrodynamic traps upstream from suitable habitat, where they are trapped at least for the entire tropical dry season. Axial convergences may provide an efficient barrier for propagule exchange across estuaries. In such estuaries, mangrove populations can be regarded as floristically isolated, not unlike island communities, even though the populations lie on a continuous coastline. This effect may contribute to the disjunct distribution observed in some mangrove species. The outcomes of this work contribute to the understanding of the importance of salt as a growth and habitat-restricting factor in the mangrove environment.
The subject of this thesis is hypercyclic, mixing, and chaotic C0-semigroups on Banach spaces. After introducing the relevant notions and giving some examples the so called hypercyclicity criterion and its relation with weak mixing is treated. Some new equivalent formulations of the criterion are given which are used to derive a very short proof of the well-known fact that a C0-semigroup is weakly mixing if and only if each of its operators is. Moreover, it is proved that under some "regularity conditions" each hypercyclic C0-semigroup is weakly mixing. Furthermore, it is shown that for a hypercyclic C0-semigroup there is always a dense set of hypercyclic vectors having infinitely differentiable trajectories. Chaotic C0-semigroups are also considered. It is proved that they are always weakly mixing and that in certain cases chaoticity is already implied by the existence of a single periodic point. Moreover, it is shown that strongly elliptic differential operators on bounded C^1-domains never generate chaotic C0-semigroups. A thorough investigation of transitivity, weak mixing, and mixing of weighted compositioin operators follows and complete characterisations of these properties are derived. These results are then used to completely characterise hypercyclicity, weak mixing, and mixing of C0-semigroups generated by first order partial differential operators. Moreover, a characterisation of chaos for these C0-semigroups is attained. All these results are achieved on spaces of p-integrable functions as well as on spaces of continuous functions and illustrated by various concrete examples.
Hypothalamic-pituitary-adrenal (HPA) axis-related genetic variants influence the stress response
(2019)
The physiological stress system includes the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary system (SAM). Parameters representing these systems such as cortisol, blood pressure or heart rate define the physiological reaction in response to a stressor. The main objective of the studies described in this thesis was to understand the role of the HPA-related genetic factors in these two systems. Genetic factors represent one of the components causing individual variations in physiological stress parameters. Five genes involved in the functioning of the HPA axis regarding stress responses are examined in this thesis. They are: corticotropin-releasing hormone (CRH), the glucocorticoid receptor (GR), the mineralocorticoid receptor (MR), the 5-hydroxytryptamine-transporter-linked polymorphic region (5-HTTLPR) in the serotonin transporter (5-HTT) and the brain-derived neurotrophic factor (BDNF) gene. Two hundred thirty-two healthy participants were genotyped. The influence of genetic factors on physiological parameters, such as post-awakening cortisol and blood pressure was assessed, as well as the influence of genetic factors on stress reactivity in response to a socially evaluated cold pressor test (SeCPT). Three studies tested the HPA-related genes each on three different levels. The first study examined the influences of genotypes and haplotypes of these five genes on physiological as well as psychological stress indicators (Chapter 2). The second study examined the effects of GR variants (genotypes and haplotypes) and promoter methylation level on both the SAM system and the HPA axis stress reactivity (Chapter 3). The third study comprised the characterization of CRH promoter haplotypes in an in-vitro study and the association of the CRH promoter with stress indicators in vivo (Chapter 4).
Computer simulation has become established in a two-fold way: As a tool for planning, analyzing, and optimizing complex systems but also as a method for the scientific instigation of theories and thus for the generation of knowledge. Generated results often serve as a basis for investment decisions, e.g., road construction and factory planning, or provide evidence for scientific theory-building processes. To ensure the generation of credible and reproducible results, it is indispensable to conduct systematic and methodologically sound simulation studies. A variety of procedure models exist that structure and predetermine the process of a study. As a result, experimenters are often required to repetitively but thoroughly carry out a large number of experiments. Moreover, the process is not sufficiently specified and many important design decisions still have to be made by the experimenter, which might result in an unintentional bias of the results.
To facilitate the conducting of simulation studies and to improve both replicability and reproducibility of the generated results, this thesis proposes a procedure model for carrying out Hypothesis-Driven Simulation Studies, an approach that assists the experimenter during the design, execution, and analysis of simulation experiments. In contrast to existing approaches, a formally specified hypothesis becomes the key element of the study so that each step of the study can be adapted and executed to directly contribute to the verification of the hypothesis. To this end, the FITS language is presented, which enables the specification of hypotheses as assumptions regarding the influence specific input values have on the observable behavior of the model. The proposed procedure model systematically designs relevant simulation experiments, runs, and iterations that must be executed to provide evidence for the verification of the hypothesis. Generated outputs are then aggregated for each defined performance measure to allow for the application of statistical hypothesis testing approaches. Hence, the proposed assistance only requires the experimenter to provide an executable simulation model and a corresponding hypothesis to conduct a sound simulation study. With respect to the implementation of the proposed assistance system, this thesis presents an abstract architecture and provides formal specifications of all required services.
To evaluate the concept of Hypothesis-Driven Simulation Studies, two case studies are presented from the manufacturing domain. The introduced approach is applied to a NetLogo simulation model of a four-tiered supply chain. Two scenarios as well as corresponding assumptions about the model behavior are presented to investigate conditions for the occurrence of the bullwhip effect. Starting from the formal specification of the hypothesis, each step of a Hypothesis-Driven Simulation Study is presented in detail, with specific design decisions outlined, and generated inter- mediate data as well as final results illustrated. With respect to the comparability of the results, a conventional simulation study is conducted which serves as reference data. The approach that is proposed in this thesis is beneficial for both practitioners and scientists. The presented assistance system allows for a more effortless and simplified execution of simulation experiments while the efficient generation of credible results is ensured.
The dissertation includes three published articles on which the development of a theoretical model of motivational and self-regulatory determinants of the intention to comprehensively search for health information is based. The first article focuses on building a solid theoretical foundation as to the nature of a comprehensive search for health information and enabling its integration into a broader conceptual framework. Based on subjective source perceptions, a taxonomy of health information sources was developed. The aim of this taxonomy was to identify most fundamental source characteristics to provide a point of reference when it comes to relating to the target objects of a comprehensive search. Three basic source characteristics were identified: expertise, interaction and accessibility. The second article reports on the development and evaluation of an instrument measuring the goals individuals have when seeking health information: the ‘Goals Associated with Health Information Seeking’ (GAINS) questionnaire. Two goal categories (coping focus and regulatory focus) were theoretically derived, based on which four goals (understanding, action planning, hope and reassurance) were classified. The final version of the questionnaire comprised four scales representing the goals, with four items per scale (sixteen items in total). The psychometric properties of the GAINS were analyzed in three independent samples, and the questionnaire was found to be reliable and sufficiently valid as well as suitable for a patient sample. It was concluded that the GAINS makes it possible to evaluate goals of health information seeking (HIS) which are likely to inform the intention building on how to organize the search for health information. The third article describes the final development and a first empirical evaluation of a model of motivational and self-regulatory determinants of an intentionally comprehensive search for health information. Based on the insights and implications of the previous two articles and an additional rigorous theoretical investigation, the model included approach and avoidance motivation, emotion regulation, HIS self-efficacy, problem and emotion focused coping goals and the intention to seek comprehensively (as outcome variable). The model was analyzed via structural equation modeling in a sample of university students. Model fit was good and hypotheses with regard to specific direct and indirect effects were confirmed. Last, the findings of all three articles are synthesized, the final model is presented and discussed with regard to its strengths and weaknesses, and implications for further research are determined.
In recent decades, Border Studies have gained importance and have seen a noticeable increase in development. This manifests itself in an increased institutionalization, a differentiation of the areas of research interest and a conceptual reorientation that is interested in examining processes. So far, however, little attention has been paid to questions about (inter)disciplinary self-perception and methodological foundations of Border Studies and the associated consequences for research activities. This thematic issue addresses these desiderata and brings together articles that deal with their (inter)disciplinary foundations as well as method(olog)ical and practical research questions. The authors also provide sound insights into a disparate field of work, disclose practical research strategies, and present methodologically sophisticated systematizations.
Legalisation cannot be fully explained by interest politics. If that were the case, the attitudes towards legalisation would be expected to be based on objective interests and actual policies in France and Germany would be expected to be more similar. Nor can it be explained by institutional agency, because there are no hints that states struggle with different normative traditions. Rather, political actors seek to make use of the structures that already exist to guar-antee legitimacy for their actions. If the main concern of governmental actors really is to accumulate legitimacy, as stated in the introduction, then politicians have a good starting position in the case of legalisation of illegal foreigners. Citizens" negative attitudes towards legalisation cannot be explained by imagined labour market competition; income effects play only a secondary role. The most important explanatory factor is the educational level of each individual. Objective interests do not trigger attitudes towards legalisation, but rather a basic men-tal predisposition for or against illegal immigrants who are eligible for legalisation. Politics concerning amnesties are thus not tied to an objectively given structure like the socio-economic composition of the electorate, but are open for political discretion. Attitudes on legalising illegal immigrants can be regarded as being mediated by beliefs and perceptions, which can be used by political agents or altered by political developments. However, politicians must adhere to a national frame of legitimating strategies that cannot be neglected without consequences. It was evident in the cross-country comparison of political debates that there are national systems of reference that provide patterns of interpretation. Legalisation is seen and incorporated into immigration policy in a very specific way that differs from one country to the next. In both countries investigated in this study, there are fundamental debates about which basic principles apply to legalisation and which of these should be held in higher esteem: a legal system able to work, humanitarian rights, practical considerations, etc. The results suggest that legalisation is "technicized" in France by describing it as an unusual but possible pragmatic instrument for the adjustment of the inefficient rule of law. In Germany, however, legalisation is discussed at a more normative level. Proponents of conservative immigration policies regard it as a substantial infringement on the rule of law, so that even defenders of a humanitarian solution for illegal immigrants are not able to challenge this view without significant political harm. But the arguments brought to bear in the debate on legalisation are not necessarily sound because they are not irrefutable facts, but instruments to generate legitimacy, and there are enough possibilities for arguing and persuading because socio-economic factors play a minor role. One of the most important arguments, the alleged pull effect of legalisation, has been subjected to an empirical investigation. In the political debate, it does not make any dif-ference whether this is true or not, insofar as it is not contested by incontrovertible findings. In reality, the results suggest that amnesties indeed exert a small attracting influence on illegal immigration, which has been contested by immigration friendly politicians in the French par-liament. The effect, however, is not large; therefore, some conservative politicians may put too much stress on this argument. Moreover, one can see legalisation as an instrument to restore legitimacy that has slipped away from immigration politics because of a high number of illegally residing foreigners. This aspect explains some of the peculiarities in the French debate on legalisation, e.g. the idea that the coherence of the law is secured by creating exceptional rules for legalising illegal immigrants. It has become clear that the politics of legalisation are susceptible to manipulation by introducing certain interpretations into the political debate, which become predominant and supersede other views. In this study, there are no signs of a systematic misuse of this constellation by any certain actor. However, the history of immigration policy is full of examples of symbolic politics in which a certain measure has been initiated while the actors are totally aware of its lack of effect. Legalisation has escaped this fate so far because it is a specific instrument that is the result of neglecting populist mechanisms rather than an ex-ample of a superficial measure. This result does not apply to policies concerning illegal immi-gration in general, both with regard to concealing a lack of control and flexing the state- muscles.
The main objective of the present thesis was to investigate whether antibody effects observed in earlier in vitro studies can translate into the protection against chemical carcinogenesis in vivo as the basis of an immunoprophylactic approach against carcinogens. As model for chemical carcinogenesis, we selected B[a]P the prototype polycyclic aromatic hydrocarbon (PAH), an environmental pollutant emanating from both natural and anthropogenic sources. Many in vivo models conveniently use high doses of carcinogens mostly given as single bolus, which provides simple surrogate readouts, but poorly reflects chronic exposure to the low concentrations found in the environment. In addition, these concentrations cannot be matched with equimolar antibody concentrations obtained by immunisation. However, low B[a]P concentrations do not permit to directly measure chemical carcinogenesis. Therefore, in the present thesis, the pharmacokinetic, metabolism and B[a]P mediated immunotoxicity were chosen as experimental read-outs. B[a]P conjugate vaccines based on ovalbumin, tetanus toxoid and diphtheria toxoid (DT) as carrier proteins were developed to actively immunise mice against B[a]P. B[a]P-DT conjugate induced the most robust immune response. The antibodies reacted not only with B[a]P but also with the proximate carcinogen 7,8-diol-B[a]P. Antibodies modulated the bioavailability of B[a]P and its metabolic activation in a dose-dependent manner by sequestration in the blood. In order to further improve the vaccination, we replaced the protein carrier by promiscuous T-helper cell epitopes to induce higher antibody titer with increased specificity for the B[a]P hapten. We hypothesised that a reduction of B cell binding sites on the carrier, compared to whole protein carrier, should favour the activation of B cells recognising the hapten instead of the carrier protein. An internal processing of the carrier and cleavage of the B[a]P-BA and subsequent presentation of the carrier peptide by MHC II molecules to T cell receptor should induce a B cell dependent immune response by activating B cells capable to recognise B[a]P. We demonstrated that a vaccination against B[a]P using promiscuous T-helper cell epitopes as a carrier is feasible and some tested peptide conjugates were more immunogenic as whole protein conjugates with increased specificity. We showed that vaccination against B[a]P reduces immunotoxicity. B[a]P suppressed the proliferative response of both T and B cells after a sub-acute administration, an effect that was completely reversed by vaccination. In immunized mice the immunotoxic effect of B[a]P on IFN-γ, Il-12, TNF-ï¡ production and B cell activation was restored. In addition, specific antibodies inhibited the induction of Cyp1a1 by B[a]P in lymphocytes and Cyp1b1 in the liver, enzymes that are known to convert the procarcinogen B[a]P to the ultimate DNA-adduct forming metabolite, a major risk factor of chemical carcinogenesis. In order to replace Freund adjuvant and to improve the immunisation strategy in terms of antibody quantity and quality, several adjuvants that are potentially compatible with their use in humans were tested. In combination with Freund adjuvant, the conjugate-vaccine induced high levels of B[a]P-specific antibodies. We showed that all adjuvants tested induced specific antibodies against B[a]P and 7,8-diol-B[a]P, its carcinogenic metabolite. The highest antibody levels were obtained with Quil A, MF-59 and Alum. Biological activity in terms of enhanced retention of B[a]P was confirmed in mice immunised with Quil A, Montanide, Alum and MF-59. Our findings demonstrate that a vaccination against B[a]P is feasible in combination with adjuvants licensed in humans. Based on these results and with the current understanding of the mechanisms of chemical carcinogenesis of the ubiquitous carcinogen B[a]P and of the effects of specific antibodies, an immunoprophylactic approach against chemical carcinogenesis is absolutely warranted. Nevertheless, the direct effects of B[a]P-specific antibodies on the different stages of carcinogenesis (e.g. adduct formation) and whether these effects may translate into long-term protective effect against tumourigenesis needs to be proven in further experiments.
Early life adversity (ELA) poses a high risk for developing major health problems in adulthood including cardiovascular and infectious diseases and mental illness. However, the fact that ELA-associated disorders first become manifest many years after exposure raises questions about the mechanisms underlying their etiology. This thesis focuses on the impact of ELA on startle reflexivity, physiological stress reactivity and immunology in adulthood.
The first experiment investigated the impact of parental divorce on affective processing. A special block design of the affective startle modulation paradigm revealed blunted startle responsiveness during presentation of aversive stimuli in participants with experience of parental divorce. Nurture context potentiated startle in these participants suggesting that visual cues of childhood-related content activates protective behavioral responses. The findings provide evidence for the view that parental divorce leads to altered processing of affective context information in early adulthood.
A second investigation was conducted to examine the link between aging of the immune system and long-term consequences of ELA. In a cohort of healthy young adults, who were institutionalized early in life and subsequently adopted, higher levels of T cell senescence were observed compared to parent-reared controls. Furthermore, the results suggest that ELA increases the risk of cytomegalovirus infection in early childhood, thereby mediating the effect of ELA on T cell-specific immunosenescence.
The third study addresses the effect of ELA on stress reactivity. An extended version of the Cold Pressor Test combined with a cognitive challenging task revealed blunted endocrine response in adults with a history of adoption while cardiovascular stress reactivity was similar to control participants. This pattern of response separation may best be explained by selective enhancement of central feedback-sensitivity to glucocorticoids resulting from ELA, in spite of preserved cardiovascular/autonomic stress reactivity.
In this thesis, three studies investigating the impact of stress on the protective startle eye blink reflex are reported. In the first study a decrease in prepulse inhibition of the startle reflex was observed after intravenous low dose cortisol application. In the second study a decrease in reflex magnitude of the startle reflex was observed after pharmacological suppression of endogenous cortisol production. In the third study, a higher reflex magnitude of the startle reflex was observed at reduced arterial and central venous blood pressure. These results can be interpreted in terms of an adaption to hostile environments.
Background: Increasing exposure to engineered inorganic nanoparticles takes actually place in both terrestric and aquatic ecosystems worldwide. Although we already know harmful effects of AgNP on the soil bacterial community, information about the impact of the factors functionalization, concentration, exposure time, and soil texture on the AgNP effect expression are still rare. Hence, in this study, three soils of different grain size were exposed for up to 90 days to bare and functionalized AgNP in concentrations ranging from 0.01 to 1.00 mg/kg soil dry weight. Effects on soil microbial community were quantified by various biological parameters, including 16S rRNA gene, photometric, and fluorescence analyses.
Results: Multivariate data analysis revealed significant effects of AgNP exposure for all factors and factor combinations investigated. Analysis of individual factors (silver species, concentration, exposure time, soil texture) in the unifactorial ANOVA explained the largest part of the variance compared to the error variance. In depth analysis of factor combinations revealed even better explanation of variance. For the biological parameters assessed in this study, the matching of soil texture and silver species, and the matching of soil texture and exposure time were the two most relevant factor combinations. The factor AgNP concentration contributed to a lower extent to the effect expression compared to silver species, exposure time and physico–chemical composition of soil.
Conclusions: The factors functionalization, concentration, exposure time, and soil texture significantly impacted the effect expression of AgNP on the soil microbial community. Especially long-term exposure scenarios are strongly needed for the reliable environmental impact assessment of AgNP exposure in various soil types.
Allocating scarce resources efficiently is a major task in mechanism design. One of the most fundamental problems in mechanism design theory is the problem of selling a single indivisible item to bidders with private valuations for the item. In this setting, the classic Vickrey auction of~\citet{vickrey1961} describes a simple mechanism to implement a social welfare maximizing allocation.
The Vickrey auction for a single item asks every buyer to report its valuation and allocates the item to the highest bidder for a price of the second highest bid. This auction features some desirable properties, e.g., buyers cannot benefit from misreporting their true value for the item (incentive compatibility) and the auction can be executed in polynomial time.
However, when there is more than one item for sale and buyers' valuations for sets of items are not additive or the set of feasible allocations is constrained, then constructing mechanisms that implement efficient allocations and have polynomial runtime might be very challenging. Consider a single seller selling $n\in \N$ heterogeneous indivisible items to several bidders. The Vickrey-Clarke-Groves auction generalizes the idea of the Vickrey auction to this multi-item setting. Naturally, every bidder has an intrinsic value for every subset of items. As in in the Vickrey auction, bidders report their valuations (Now, for every subset of items!). Then, the auctioneer computes a social welfare maximizing allocation according to the submitted bids and charges buyers the social cost of their winning that is incurred by the rest of the buyers. (This is the analogue to charging the second highest bid to the winning bidder in the single item Vickrey auction.) It turns out that the Vickrey-Clarke-Groves auction is also incentive compatible but it poses some problems: In fact, say for $n=40$, bidders would have to submit $2^{40}-1$ values (one value for each nonempty subset of the ground set) in total. Thus, asking every bidder for its valuation might be impossible due to time complexity issues. Therefore, even though the Vickrey-Clarke-Groves auction implements a social welfare maximizing allocation in this multi-item setting it might be impractical and there is need for alternative approaches to implement social welfare maximizing allocations.
This dissertation represents the results of three independent research papers all of them tackling the problem of implementing efficient allocations in different combinatorial settings.
Energy transition strategies in Germany have led to an expansion of energy crop cultivation in landscape, with silage maize as most valuable feedstock. The changes in the traditional cropping systems, with increasing shares of maize, raised concerns about the sustainability of agricultural feedstock production regarding threats to soil health. However, spatially explicit data about silage maize cultivation are missing; thus, implications for soil cannot be estimated in a precise way. With this study, we firstly aimed to track the fields cultivated with maize based on remote sensing data. Secondly, available soil data were target-specifically processed to determine the site-specific vulnerability of the soils for erosion and compaction. The generated, spatially-explicit data served as basis for a differentiated analysis of the development of the agricultural biogas sector, associated maize cultivation and its implications for soil health. In the study area, located in a low mountain range region in Western Germany, the number and capacity of biogas producing units increased by 25 installations and 10,163 kW from 2009 to 2016. The remote sensing-based classification approach showed that the maize cultivation area was expanded by 16% from 7305 to 8447 hectares. Thus, maize cultivation accounted for about 20% of the arable land use; however, with distinct local differences. Significant shares of about 30% of the maize cultivation was done on fields that show at least high potentials for soil erosion exceeding 25 t soil ha−1 a−1. Furthermore, about 10% of the maize cultivation was done on fields that pedogenetically show an elevated risk for soil compaction. In order to reach more sustainable cultivation systems of feedstock for anaerobic digestion, changes in cultivated crops and management strategies are urgently required, particularly against first signs of climate change. The presented approach can regionally be modified in order to develop site-adapted, sustainable bioenergy cropping systems.
There is a lot of evidence for the impact of acute glucocorticoid treatment on hippocampus-dependent explicit learning and memory (memory for facts and events). But there have been few studies, investigating the effect of glucocorticoids on implicit learning and memory. We conducted three studies with different methodology to investigate the effect of glucocorticoids on different forms of implicit learning. In Study 1, we investigated the effect of cortisol depletion on short-term habituation in 49 healthy subjects. 25 participants received oral metyrapone (1500 mg) to suppress endogenous cortisol production, while 24 controls received oral placebo. Eye blink electromyogram (EMG) responses to 105 dB acoustic startle stimuli were assessed. Effective endogenous cortisol suppression had no effect on short-term habituation of the startle reflex, but startle eye blink responses were significantly increased in the metyrapone group. The latter findings are in line with previous human studies, which have shown that excess cortisol, sufficient to fully occupy central nervous system (CNS) corticosteroid receptors, may reduce startle eye blink. This effect may be mediated by CNS mechanisms controlling cortisol feedback. In Study 2, we investigated delay or trace eyeblink conditioning in a patient group with a relative hypocortisolism (30 patients with fibromyaligia syndrome/FMS) compared to 20 healthy control subjects. Conditioned eyeblink response probability was assessed by EMG. Morning cortisol levels, ratings of depression, anxiety and psychosomatic complaints as well as general symptomatology and psychological distress were assessed. As compared to healthy controls FMS patients showed lower morning cortisol levels, and trace eyeblink conditioning was facilitated whereas delay eyeblink conditioning was reduced. Cortisol measures correlate significantly only with trace eyeblink conditioning. Our results are in line with studies of pharmacologically induced hyper- and hypocortisolism, which affected trace eyeblink conditioning. We suggest that endocrine mechanisms affecting hippocampus-mediated forms of associative learning may play a role in the generation of symptoms in these patients.rnIn Study 3, we investigated the effect of excess cortisol on implicit sequence learning in healthy subjects. Oral cortisol (30 mg) was given to 29 participants, whereas 31 control subjects received placebo. All volunteers performed a 5-choice serial reaction time task (SRTT). The reaction speed of every button-press was determined and difference-scores were calculated as a proof of learning. Compared to the control group, we found a delayed learning in the cortisol group at the very beginning of the task. This study is the first human investigation, indicating impaired implicit memory function after exogenous administration of the stress hormone cortisol. Our findings support a previous neuroimaging study, which suggested that the medial temporal lobe (including the hippocampus) is also active in implicit sequence learning, but our results may also depend on the engagement of other brain structures.
There is no longer any doubt about the general effectiveness of psychotherapy. However, up to 40% of patients do not respond to treatment. Despite efforts to develop new treatments, overall effectiveness has not improved. Consequently, practice-oriented research has emerged to make research results more relevant to practitioners. Within this context, patient-focused research (PFR) focuses on the question of whether a particular treatment works for a specific patient. Finally, PFR gave rise to the precision mental health research movement that is trying to tailor treatments to individual patients by making data-driven and algorithm-based predictions. These predictions are intended to support therapists in their clinical decisions, such as the selection of treatment strategies and adaptation of treatment. The present work summarizes three studies that aim to generate different prediction models for treatment personalization that can be applied to practice. The goal of Study I was to develop a model for dropout prediction using data assessed prior to the first session (N = 2543). The usefulness of various machine learning (ML) algorithms and ensembles was assessed. The best model was an ensemble utilizing random forest and nearest neighbor modeling. It significantly outperformed generalized linear modeling, correctly identifying 63.4% of all cases and uncovering seven key predictors. The findings illustrated the potential of ML to enhance dropout predictions, but also highlighted that not all ML algorithms are equally suitable for this purpose. Study II utilized Study I’s findings to enhance the prediction of dropout rates. Data from the initial two sessions and observer ratings of therapist interventions and skills were employed to develop a model using an elastic net (EN) algorithm. The findings demonstrated that the model was significantly more effective at predicting dropout when using observer ratings with a Cohen’s d of up to .65 and more effective than the model in Study I, despite the smaller sample (N = 259). These results indicated that generating models could be improved by employing various data sources, which provide better foundations for model development. Finally, Study III generated a model to predict therapy outcome after a sudden gain (SG) in order to identify crucial predictors of the upward spiral. EN was used to generate the model using data from 794 cases that experienced a SG. A control group of the same size was also used to quantify and relativize the identified predictors by their general influence on therapy outcomes. The results indicated that there are seven key predictors that have varying effect sizes on therapy outcome, with Cohen's d ranging from 1.08 to 12.48. The findings suggested that a directive approach is more likely to lead to better outcomes after an SG, and that alliance ruptures can be effectively compensated for. However, these effects
were reversed in the control group. The results of the three studies are discussed regarding their usefulness to support clinical decision-making and their implications for the implementation of precision mental health.
This thesis is focused on improving the knowledge on a group of threatened species, the European cave salamanders (genus Hydromantes). There are three main sections gathering studies dealing with different topics: Ecology (first part), Life traits (second part) and Monitoring methodologies (third part). First part starts with the study of the response of Hydromantes to the variation of climatic conditions, analysing 15 different localities throughout a full year (CHAPTER I; published in PEERJ in August 2015). After that, the focus moves on identify which is the operative temperature that these salamander experience, including how their body respond to variation of environmental temperature. This study was conducted using one of the most advanced tool, an infrared thermocamera, which gave the opportunity to perform detailed observation on salamanders body (CHAPTER II; published in JOURNAL OF THERMAL BIOLOGY in June 2016). In the next chapter we use the previous results to analyse the ecological niche of all eight Hydromantes species. The study mostly underlines the mismatch between macro- and microscale analysis of ecological niche, showing a weak conservatism of ecological niches within the evolution of species (CHAPTER III; unpublished manuscript). We then focus only on hybrids, which occur within the natural distribution of mainland species. Here, we analyse if the ecological niche of hybrids shows divergences from those of parental species, thus evaluating the power of hybrids adaptation (CHAPTER IV; unpublished manuscript). Considering that hybrids may represent a potential threat for parental species (in terms of genetic erosion and competition), we produced the first ecological study on an allochthonous mixed population of Hydromantes, analysing population structure, ecological requirements and diet. The interest on this particular population mostly comes by the fact that its members are coming from all three mainland Hydromantes species, and thus it may represent a potential source of new hybrids (CHAPTER V; accepted in AMPHIBIA-REPTILIA in October 2017). The focus than moves on how bioclimatic parameters affect species within their distributional range. Using as model species the microendemic H. flavus, we analyse the relationship between environmental suitability and local abundance of the species, also focusing on all intermediate dynamics which provide useful information on spatial variation of individual fitness (CHAPTER VI; submitted to SCIENTIFIC REPORTS in November 2017). The first part ends with an analysis of the interaction between Hydromantes and Batracobdella algira leeches, the only known ectoparasite for European cave salamanders. Considering that the effect of leeches on their hosts is potentially detrimental, we investigated if these ectoparasites may represent a further threat for Hydromantes (CHAPTER VII; submitted to INTERNATIONAL JOURNAL FOR PARASITOLOGY: PARASITES AND WILDLIFE in November 2017). The second part is related to the reproduction of Hydromantes. In the first study we perform analyses on the breeding behaviour of several females belonging to a single population, identifying differences and similarities occurring in cohorting females (CHAPTER VIII; published in NORTH-WESTERN JOURNAL OF ZOOLOGY in December 2015). In the second study we gather information from all Hydromantes species, analysing size and development of breeding females, and identifying a relationship between breeding time and climatic conditions (CHAPTER IX; submitted to SALAMANDRA in June 2017). In the last part of this thesis, we analyse two potential methods for monitoring Hydromantes populations. In the first study we evaluate the efficiency of the marking method involving Alpha tags (CHAPTER X; published in SALAMANDRA in October 2017). In the second study we focus on evaluating N-mixtures models as a methodology for estimating abundance in wild populations (CHAPTER XI; submitted to BIODIVERSITY & CONSERVATION in October 2017).
Hardware bugs can be extremely expensive, financially. Because microprocessors and integrated circuits have become omnipresent in our daily live and also because of their continously growing complexity, research is driven towards methods and tools that are supposed to provide higher reliability of hardware designs and their implementations. Over the last decade Ordered Binary Decision Diagrams (OBDDs) have been well proven to serve as a data structure for the representation of combinatorial or sequential circuits. Their conciseness and their efficient algorithmic properties are responsible for their huge success in formal verification. But, due to Shannon's counting argument, OBDDs can not always guarantee the concise representation of a given design. In this thesis, Parity Ordered Binary Decision Diagrams are presented, which are a true extension of OBDDs. In addition to the regular branching nodes of an OBDD, functional nodes representing a parity operation are integrated into the data structure, thus resulting in Parity-OBDDs. Parity-OBDDs are more powerful than OBDDs are, but, they are no longer a canonical representation. Besides theoretical aspects of Parity-OBDDs, algorithms for their efficient manipulation are the main focus of this thesis. Furthermore, an analysis on the factors that influence the Parity-OBDD representation size gives way for the development of heuristic algorithms for their minimization. The results of these analyses as well as the efficiency of the data structure are also supported by experiments. Finally, the algorithmic concept of Parity-OBDDs is extended to Mod-p-Decision Diagrams (Mod-p-DDs) for the representation of functions that are defined over an arbitrary finite domain.
Today, almost every modern computing device is equipped with multicore processors capable of efficient concurrent and parallel execution of threads. This processor feature can be leveraged by concurrent programming, which is a challenge for software developers for two reasons: first, it introduces a paradigm shift that requires a new way of thinking. Second, it can lead to issues that are unique to concurrent programs due to the non-deterministic, interleaved execution of threads. Consequently, the debugging of concurrency and related performance issues is a rather difficult and often tedious task. Developers still lack on thread-aware programming tools that facilitate the understanding of concurrent programs. Ideally, these tools should be part of their daily working environment, which typically includes an Integrated Development Environment (IDE). In particular, the way source code is visually presented in traditional source-code editors does not convey much information on whether the source code is executed concurrently or in parallel in the first place.
With this dissertation, we pursue the main goal of facilitating and supporting the understanding and debugging of concurrent programs. To this end, we formulate and utilize a visualization paradigm that particularly includes the display of interactive glyph-based visualizations embedded in the source-code editor close to their corresponding artifacts (in-situ).
To facilitate the implementation of visualizations that comply with our paradigm as plugins for IDEs, we designed, implemented and evaluated a programming framework called CodeSparks. After presenting the design goals and the architecture of the framework, we demonstrate its versatility with a total of fourteen plugins realized by different developers using the CodeSparks framework (CodeSparks plugins). With focus group interviews, we empirically investigated how developers of the CodeSparks plugins experienced working with the framework. Based on the plugins, deliberate design decisions and the interview results, we discuss to what extent we achieved our design goals. We found that the framework is largely target programming-language independent and that it supports the development of plugins for a wide range of source-code-related tasks while hiding most of the details of the underlying plugin development API.
In addition, we applied our visualization paradigm to thread-related runtime data from concurrent programs to foster the awareness of source code being executed concurrently or in parallel. As a result, we developed and designed two in-situ thread visualizations, namely ThreadRadar and ThreadFork, with the latter building on the former. Both thread visualizations are based on a debugging approach, which combines statistical profiling, thread-aware runtime metrics, clustering of threads on the basis of these metrics, and finally interactive glyph-based in-situ visualizations. To address scalability issues of the ThreadRadar in terms of space required and the number of displayable thread clusters, we designed a revised thread visualization. This revision also involved the question of how many thread clusters k should be computed in the first place. To this end, we conducted experiments with the clustering of threads for artifacts from a corpus of concurrent Java programs that include real-world Java applications and concurrency bugs. We found that the maximum k on the one hand and the optimal k according to four cluster validation indices on the other hand rarely exceed three. However, occasionally thread clusterings with k > 3 are available and also optimal. Consequently, we revised both the clustering strategy and the visualization as parts of our debugging approach, which resulted in the ThreadFork visualization. Both in-situ thread visualizations, including their additional features that support the exploration of the thread data, are implemented in a tool called CodeSparks-JPT, i.e., as a CodeSparks plugin for IntelliJ IDEA.
With various empirical studies, including anecdotal usage scenarios, a usability test, web surveys, hands-on sessions, questionnaires and interviews, we investigated quality aspects of the in-situ thread visualizations and their corresponding tools. First, by a demonstration study, we illustrated the usefulness of the ThreadRadar visualization in investigating and fixing concurrency bugs and a performance bug. This was confirmed by a subsequent usability test and interview, which also provided formative feedback. Second, we investigated the interpretability and readability of the ThreadFork glyphs as well as the effectiveness of the ThreadFork visualization through anonymous web surveys. While we have found that the ThreadFork glyphs are correctly interpreted and readable, it remains unproven that the ThreadFork visualization effectively facilitates understanding the dynamic behavior of threads that concurrently executed portions of source code. Moreover, the overall usability of CodeSparks-JPT is perceived as "OK, but not acceptable" as the tool has issues with its learnability and memorability. However, all other usability aspects of CodeSparks-JPT that were examined are perceived as "above average" or "good".
Our work supports software-engineering researchers and practitioners in flexibly and swiftly developing novel glyph-based visualizations that are embedded in the source-code editor. Moreover, we provide in-situ thread visualizations that foster the awareness of source code being executed concurrently or in parallel. These in-situ thread visualizations can, for instance, be adapted, extended and used to analyze other use cases or to replicate the results. Through empirical studies, we have gradually shaped the design of the in-situ thread visualizations through data-driven decisions, and evaluated several quality aspects of the in-situ thread visualizations and the corresponding tools for their utility in understanding and debugging concurrent programs.
Influence of Ozone and Drought on Tree Growth under Field Conditions in a 22 Year Time Series
(2022)
Studying the effect of surface ozone (O3) and water stress on tree growth is important for planning sustainable forest management and forest ecology. In the present study, a 22-year long time series (1998–2019) on basal area increment (BAI) and fructification severity of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H.Karst.) at five forest sites in Western Germany (Rhineland Palatinate) was investigated to evaluate how it correlates with drought and stomatal O3 fluxes (PODY) with an hourly threshold of uptake (Y) to represent the detoxification capacity of trees (POD1, with Y = 1 nmol O3 m−2 s−1). Between 1998 and 2019, POD1 declined over time by on average 0.31 mmol m−2 year−1. The BAI showed no significant trend at all sites, except in Leisel where a slight decline was observed over time (−0.37 cm2 per year, p < 0.05). A random forest analysis showed that the soil water content and daytime O3 mean concentration were the best predictors of BAI at all sites. The highest mean score of fructification was observed during the dry years, while low level or no fructification was observed in most humid years. Combined effects of drought and O3 pollution mostly influence tree growth decline for European beech and Norway spruce.
In my paper I will talk about the mutual influences between the female spectators and the programming practices of Imperial Germany- cinema. I will focus on the period of the transition from the short film programme of the "cinema of attractions" to the dominance of the long feature film, i.e. from 1906-1918. I will ask questions how the presence of women in the cinema (the place where they first entered the public sphere) influenced the practice of programming. So I will deal with the relatively new topic of the programme (and its structural changes) as a mode of exhibition and I will try to connect this to the role the female audience played in shaping this format: how does the female audience affect the changes of the programme patterns, the modification of genres and their meaning within the structure of the programme and does it finally bring about a change in the mode of reception. And on the other hand how does the cinematographical programme represent and influence the female identity, and women- wishes and needs. One must ask for the reasons why the early cinema, that was characterised by diversity concerning class, gender and cultural issues and that built a kind of alternative public sphere, was displaced by an institutionalised, state monitored and nationalised German cinema. Taking into account that this change of film forms was not a teleological evolution, "gender" might be a more useful and insightful category than "class" is to explain the changes of the programme and the essence of early cinema. First I am going to present the main ideas of my project, then I"ll talk about the composition of the audience and the relation between audience and program, after that I"ll make some remarks on the reform movement and what the reformers thought about women in the cinema and about the programming practices, and as a last part, we"ll have a look at what actually happened in the cinema and at the program of the year 1911/1912 and how this program catered to the interests of the female audience. I"ll conclude with a short outlook on the changes that occurred during WW I.
Institutional and cultural determinants of speed of government responses during COVID-19 pandemic
(2021)
This article examines institutional and cultural determinants of the speed of government responses during the COVID-19 pandemic. We define the speed as the marginal rate of stringency index change. Based on cross-country data, we find that collectivism is associated with higher speed of government response. We also find a moderating role of trust in government, i.e., the association of individualism-collectivism on speed is stronger in countries with higher levels of trust in government. We do not find significant predictive power of democracy, media freedom and power distance on the speed of government responses.
Floods are hydrological extremes that have enormous environmental, social and economic consequences.The objective of this thesis was a contribution to the implementation of a processing chain that integrates remote sensing information into hydraulic models. Specifically, the aim was to improve water elevation and discharge simulations by assimilating microwave remote sensing-derived flood information into hydraulic models. The first component of the proposed processing chain is represented by a fully automated flood mapping algorithm that enables the automated, objective, and reliable flood extent extraction from Synthetic Aperture Radar images, providing accurate results in both rural and urban regions. The method operates with minimum data requirements and is efficient in terms of computational time. The map obtained with the developed algorithm is still subject to uncertainties, both introduced by the flood mapping algorithm and inherent in the image itself. In this work, particular attention was given to image uncertainty deriving from speckle. By bootstrapping the original satellite image pixels, several synthetic images were generated and provided as input to the developed flood mapping algorithm. From the analysis performed on the mapping products, speckle uncertainty can be considered as a negligible component of the total uncertainty. In the final step of the proposed processing chain real event water elevations, obtained from satellite observations, were assimilated in a hydraulic model with an adapted version of the Particle Filter, modified to work with non-Gaussian distribution of observations. To deal with model structure error and possibly biased observations, a global and a local weight variant of the Particle Filter were tested. The variant to be preferred depends on the level of confidence that is attributed to the observations or to the model. This study also highlighted the complementarity of remote sensing derived and in-situ data sets. An accurate binary flood map represents an invaluable product for different end users. However, deriving from this binary map additional hydraulic information, such as water elevations, is a way of enhancing the value of the product itself. The derived data can be assimilated into hydraulic models that will fill the gaps where, for technical reasons, Earth Observation data cannot provide information, also enabling a more accurate and reliable prediction of flooded areas.
Despite significant advances in terms of the adoption of formal Intellectual Property Rights (IPR) protection, enforcement of and compliance with IPR regulations remains a contested issue in one of the world's major contemporary economies—China. The present review seeks to offer insights into possible reasons for this discrepancy as well as possible paths of future development by reviewing prior literature on IPR in China. Specifically, it focuses on the public's perspective, which is a crucial determinant of the effectiveness of any IPR regime. It uncovers possible differences with public perspectives in other countries and points to mechanisms (e.g., political, economic, cultural, and institutional) that may foster transitions over time in both formal IPR regulation and in the public perception of and compliance with IPR in China. On this basis, the review advances suggestions for future research in order to improve scholars' understanding of the public's perspective of IPR in China, its antecedents and implications.
Interaction between the Hypothalamic-Pituitary-Adrenal Axis and the Circadian Clock System in Humans
(2017)
Rotation of the Earth creates day and night cycles of 24 h. The endogenous circadian clocks sense these light/dark rhythms and the master pacemaker situated in the suprachiasmatic nucleus of the hypothalamus entrains the physical activities according to this information. The circadian machinery is built from the transcriptional/translational feedback loops generating the oscillations in all nucleated cells of the body. In addition, unexpected environmental changes, called stressors, also challenge living systems. A response to these stimuli is provided immediately via the autonomic-nervous system and slowly via the hypothalamus"pituitary"adrenal (HPA) axis. When the HPA axis is activated, circulating glucocorticoids are elevated and regulate organ activities in order to maintain survival of the organism. Both the clock and the stress systems are essential for continuity and interact with each other to keep internal homeostasis. The physiological interactions between the HPA axis and the circadian clock system are mainly addressed in animal studies, which focus on the effects of stress and circadian disturbances on cardiovascular, psychiatric and metabolic disorders. Although these studies give opportunity to test in whole body, apply unwelcome techniques, control and manipulate the parameters at the high level, generalization of the results to humans is still a debate. On the other hand, studies established with cell lines cannot really reflect the conditions occurring in a living organism. Thus, human studies are absolutely necessary to investigate mechanisms involved in stress and circadian responses. The studies presented in this thesis were intended to determine the effects of cortisol as an end-product of the HPA axis on PERIOD (PER1, PER2 and PER3) transcripts as circadian clock genes in healthy humans. The expression levels of PERIOD genes were measured under baseline conditions and after stress in whole blood. The results demonstrated here have given better understanding of transcriptional programming regulated by pulsatile cortisol at standard conditions and short-term effects of cortisol increase on circadian clocks after acute stress. These findings also draw attention to inter-individual variations in stress response as well as non-circadian functions of PERIOD genes in the periphery, which need to be examined in details in the future.
Subject of this publication is torture as an interrogational instrument in criminal proceedings from a legal history point of view. Thereby, the author makes a distinction between torturing the accused on the one hand and, on the other hand, torture as an instrument to force a witness' incriminating testimony against third parties (in German: Zeugenfolter), torture as a means to avert dangers (lifesaving torture), torture as an additional cruelty to the accused's punishment (in German: Straffolter), and corporal punlishment for lying in a court. Only the first manifestation, namely torturing the accused intending to extort his confession, is the real subject of this paper.
Subject of this publication is torture as an interrogational instrument in criminal proceedings from a legal history point of view. Thereby, the paper at hand is the continuation of Volume I (published in 2014, number 68 of the Legal Policy Forum).
Volume II covers the following historical periods: Late Middle Ages and Early Modern Age; the latter ending with the 18th century as the so called Century of Enlightenment, being the actual beginning of the Modern Age in criminal law and criminal procedure law.
The paper ends with critical remarks against the predominant view that the torture's reign of terror in the former inquisitionsprozess merely was the inevitable consequence of the unreasonable kaw on evidence applicable at that time.
During pregnancy every eighth woman is treated with glucocorticoids. Glucocorticoids inhibit cell division but are assumed to accelerate the differentiation of cells. In this review animal models for the development of the human fetal and neonatal hypothalamic-pituitary-adrenal (HPA) axis are investigated. It is possible to show that during pregnancy in humans, as in most of the here-investigated animal models, a stress hyporesponsive period (SHRP) is present. In this period, the fetus is facing reduced glucocorticoid concentrations, by low or absent fetal glucocorticoid synthesis and by reduced exposure to maternal glucocorticoids. During that phase, sensitive maturational processes in the brain are assumed, which could be inhibited by high glucocorticoid concentrations. In the SHRP, species-specific maximal brain growth spurt and neurogenesis of the somatosensory cortex take place. The latter is critical for the development of social and communication skills and the secure attachment of mother and child. Glucocorticoid treatment during pregnancy needs to be further investigated especially during this vulnerable SHRP. The hypothalamus and the pituitary stimulate the adrenal glucocorticoid production. On the other hand, glucocorticoids can inhibit the synthesis of corticotropin-releasing hormone (CRH) in the hypothalamus and of adrenocorticotropic hormone (ACTH) in the pituitary. Alterations in this negative feedback are assumed among others in the development of fibromyalgia, diabetes and factors of the metabolic syndrome. In this work it is shown that the fetal cortisol surge at the end of gestation is at least partially due to reduced glucocorticoid negative feedback. It is also assumed that androgens are involved in the control of fetal glucocorticoid synthesis. Glucocorticoids seem to prevent masculinization of the female fetus by androgens during the sexual gonadal development. In this work a negative interaction of glucocorticoids and androgens is detectable.
This thesis contributes to the economic literature on India and specifically focuses on investment project (IP) location choice. I study three topics that naturally arise in sequence: geographic concentration of investment projects, the determinants of the location choices, and the impact these choices have on project success.
In Chapter 2, I provide the analysis of geographic concentration of IPs. I find that investments were concentrated over the period of observation (1996–2015), although the degree of concentration was decreasing. Additionally, I analyze different subsamples of the data set by ownership (Indian private, Indian public and foreign) and project status (completed or dropped). Foreign projects in all industries are more concentrated than private and public, while for the latter categories I identify only minor differences in concentration levels. Additionally, I find that the location patterns of completed and dropped investments are similar to that of the overall distribution and the distributions of their respective industries with completed IPs being somewhat more concentrated.
In Chapter 3, I study the determinants of project location choices with the focus on an important highway upgrade, the Golden Quadrilateral (GQ). In line with the existing literature, the GQ construction is connected to higher levels of investment in the affected non-nodal GQ districts in 2002–2016. I also provide suggestive evidence on changes in firm behavior after the GQ construction: Firms located in the non-nodal GQ districts became less likely to invest in their neighbor districts after the GQ completion compared to firms located in districts unaffected by the GQ construction.
Finally, in Chapter 4, I investigate the characteristics of IPs that may contribute to discontinuation of their implementation by comparing completed investments to dropped ones, defined as abandoned, shelved, and stalled investments as identified on the date of the data download. Controlling for local and business cycle conditions, as well as various investor and project characteristics, I show that projects located in close proximity to the investor offices (i.e., in the same district) are more likely to achieve the completion stage than more remote projects.
By rodent studies it has been shown that the mineralocorticoid receptor (MR) is a candidate gene for the investigation of cognitive functions comparable to human executive function. The present work addresses the question if polymorphisms in the MR gene can act as a "probe" to explain a part of the interindividual variance of human executive functions. For this purpose, 72 healthy young participants were assigned to four equally sized groups, concerning their particular MR genotype for two common MR polymorphisms. They were investigated in an electroencephalogram (EEG) test session, accomplishing two cognitive tests while delivering saliva samples for subsequent cortisol measures. The two tests chosen for the assessment of executive functions were the Attention Network Task (ANT) and a modified version of the Wisconsin Card Sorting Test (WCST).Chapter 1 of the present work reports of the rational bases for the empirical approach, which were built up on a broad theoretical background presented in Chapter 2. In the third chapter, the investigation and results of the statistical analysis for behavioral data (i.e. reaction times, accuracy/error rates) are presented. No association with MR polymorphisms was found for the reaction times of both tests. For the accuracy rate, differences between genotype groups were found for ANT and WCST, indicating an association of MR polymorphisms and accuracy in the Alertness and Executive Control network of the ANT and during the detection of an intradimensional shift in the WCST. Data acquisition and the results for EEG data analyses are presented in Chapter 4. The results show that groups differing for MR genotype show different activity over prefrontal motor areas during the process of answering to the ANT. Those group differences again were prominent for the Alertness and Executive Control network. A tendency for further significant group differences was found for activity on frontopolar positions in extradimensional rule switching. Chapter 5 summarizes the findings for the analysis of salivary free cortisol, showing a tendency for an association between MR polymorphisms and a mildly stimulated Hypothalamus-pituitary-adrenal (HPA) axis during the test situation. The results of the different measures are integrated and discussed in Chapter 6 within the scope of novel findings in investigating the functionality of the chosen MR polymorphisms. Finally, Chapter 7 gives an outlook on the methodology and constraints of future research strategies to further describe the role of the MR in human cognitive function.
Redox-driven biogeochemical cycling of iron plays an integral role in the complex process network of ecosystems, such as carbon cycling, the fate of nutrients and greenhouse gas emissions. We investigate Fe-(hydr)oxide (trans)formation pathways from rhyolitic tephra in acidic topsoils of South Patagonian Andosols to evaluate the ecological relevance of terrestrial iron cycling for this sensitive fjord ecosystem. Using bulk geochemical analyses combined with micrometer-scale-measurements on individual soil aggregates and tephra pumice, we document biotic and abiotic pathways of Fe released from the glassy tephra matrix and titanomagnetite phenocrysts. During successive redox cycles that are controlled by frequent hydrological perturbations under hyper-humid climate, (trans)formations of ferrihydrite-organic matter coprecipitates, maghemite and hematite are closely linked to tephra weathering and organic matter turnover. These Fe-(hydr)oxides nucleate after glass dissolution and complexation with organic ligands, through maghemitization or dissolution-(re)crystallization processes from metastable precursors. Ultimately, hematite represents the most thermodynamically stable Fe-(hydr)oxide formed under these conditions and physically accumulates at redox interfaces, whereas the ferrihydrite coprecipitates represent a so far underappreciated terrestrial source of bio-available iron for fjord bioproductivity. The insights into Fe-(hydr)oxide (trans)formation in Andosols have implications for a better understanding of biogeochemical cycling of iron in this unique Patagonian fjord ecosystem.
At any given moment, our senses are assaulted with a flood of information from the environment around us. We need to pick our way through all this information in order to be able to effectively respond to that what is relevant to us. In most cases we are usually able to select information relevant to our intentions from what is not relevant. However, what happens to the information that is not relevant to us? Is this irrelevant information completely ignored so that it does not affect our actions? The literature suggests that even though we mayrnignore an irrelevant stimulus, it may still interfere with our actions. One of the ways in which irrelevant stimuli can affect actions is by retrieving a response with which it was associated. An irrelevant stimulus that is presented in close temporal contiguity with a relevant stimulus can be associated with the response made to the relevant stimulus " an observation termed distractor-response binding (Rothermund, Wentura, & De Houwer, 2005). The studies presented in this work take a closer look at such distractor-response bindings, and therncircumstances in which they occur. Specifically, the study reported in chapter 6 examined whether only an exact repetition of the distractor can retrieve the response with which it was associated, or whether even similar distractors may cause retrieval. The results suggested that even repeating a similar distractor caused retrieval, albeit less than an exact repetition. In chapter 7, the existence of bindings between a distractor and a response were tested beyond arnperceptual level, to see whether they exist at an (abstract) conceptual level. Similar to perceptual repetition, distractor-based retrieval of the response was observed for the repetition of concepts. The study reported in chapter 8 of this work examined the influence of attention on the feature-response binding of irrelevant features. The results pointed towards a stronger binding effects when attention was directed towards the irrelevant feature compared to whenrnit was not. The study in chapter 9 presented here looked at the processes underlying distractor-based retrieval and distractor inhibition. The data suggest that motor processes underlie distractor-based retrieval and cognitive process underlie distractor inhibition. Finally, the findings of all four studies are also discussed in the context of learning.
Entrepreneurship has become an essential phenomenon all over the world because it is a major driving force behind the economic growth and development of a country. It is widely accepted that entrepreneurship development in a country creates new jobs, pro-motes healthy competition through innovation, and benefits the social well being of individuals and societies. The policymakers in both developed and developing countries focus on entrepreneurship because it helps to alleviate impediments to economic development and social welfare. Therefore, policymakers and academic researchers consider the promotion of entrepreneurship as essential for the economy and research-based support is needed for further development of entrepreneurship activities.
The impact of entrepreneurial activities on economic and social development also varies from country to country. The effect of entrepreneurial activities on economic and social development also varies from country to country because the level of entrepreneur-ship activities also varies from one region to another or one country to another. To under-stand these variations, policymakers have investigated the determinants of entrepreneur-ship at different levels, such as the individual, industry, and country levels. Moreover, entrepreneurship behavior is influenced by various personal and environmental level factors. However, these personal-level factors cannot be separated from the surrounding environment.
The link between religion and entrepreneurship is well established and can be traced back to Weber (1930). Researchers have analyzed the relationship between religion and entrepreneurship from various perspectives, and the research related to religion and entrepreneurship is diversified and scattered across disciplines. This dissertation tries to explain the link between religion and entrepreneurship, specifically Islamic religion and entrepreneurship. Technically this dissertation comprises three parts. The first part of this dissertation consists of two chapters that discuss the definition and theories of entrepreneurship (Chapter 2) and the theoretical relationship between religion and entrepreneur-ship (Chapter 3).
The second part of this dissertation (Chapter 4) provides an overview of the field with a purpose to gain a better understanding of the field’s current state of knowledge to bridge the different views and perspectives. In order to provide an overview of the field, a systematic literature search leading to a descriptive overview of the field based on 270 articles published in 163 journals Subsequently, bibliometric methods are used to identify thematic clusters, the most influential authors and articles, and how they are connected.
The third part of this dissertation (Chapter 5) empirically evaluates the influence of Islamic values and Islamic religious practices on entrepreneurship intentions within the Islamic community. Using the theory of planned behavior as a theoretical lens, we also take into account that the relationship between religion and entrepreneurial intentions can be mediated by individual’s attitude towards entrepreneurship. A self-administrative questionnaire was used to collect the responses from a sample of 1895 Pakistani university students. A structured equation modeling was adopted to perform a nuanced assessment of the relationship between Islamic values and practices and entrepreneurship intentions and to account for mediating effect of attitude towards entrepreneurship.
The research on religion and entrepreneurship has increased sharply during the last years and is scattered across various academic disciplines and fields. The analysis identifies and characterize the most important publications, journals, and authors in the area and map the analyzed religions and regions. The comprehensive overview of previous studies allows us to identify research gaps and derive avenues for future research in a substantiated way. Moreover, this dissertation helps the research scholars to understand the field in its entirety, identify relevant articles, and to uncover parallels and differences across religions and regions. Besides, the study reveals a lack of empirical research related to specific religions and specific regions. Therefore, scholars can take these regions and religions into consideration when conducting empirical research.
Furthermore, the empirical analysis about the influence of Islamic religious values and Islamic religious practices show that Islamic values served as a guiding principle in shaping people’s attitudes towards entrepreneurship in an Islamic community; they had an indirect influence on entrepreneurship intention through attitude. Similarly, the relationship between Islamic religious practices and the entrepreneurship intentions of students was fully mediated by the attitude towards entrepreneurship. Furthermore, this dissertation contributes to prior research on entrepreneurship in Islamic communities by applying a more fine-grained approach to capture the link between religion and entrepreneurship. Moreover, it contributes to the literature on entrepreneurship intentions by showing that the influence of religion on entrepreneurship intentions is mainly due to religious values and practices, which shape the attitude towards entrepreneurship and thereby influence entrepreneurship intentions in religious communities. The entrepreneur-ship research has put a higher emphasis on assessing the influence of a diverse set of con-textual factors. This dissertation introduces Islamic values and Islamic religious practices as critical contextual factors that shape entrepreneurship in countries that are characterized by the Islamic religion.
Issues in Price Measurement
(2022)
This thesis focuses on the issues in price measurement and consists of three chapters. Due to outdated weighting information, a Laspeyres-based consumer price index (CPI) is prone to accumulating upward bias. Therefore, chapter 1 introduces and examines simple and transparent revision approaches that retrospectively address the source of the bias. They provide a consistent long-run time series of the CPI and require no additional information. Furthermore, a coherent decomposition of the bias into the contributions of individual product groups is developed. In a case study, the approaches are applied to a Laspeyres-based CPI. The empirical results confirm the theoretical predictions. The proposed revision approaches are adoptable not only to most national CPIs but also to other price-level measures such as the producer price index or the import and export price indices.
Chapter 2 is dedicated to the measurement of import and export price indices. Such indices are complicated by the impact of exchange rates. These indices are usually also compiled by some Laspeyres type index. Therefore, substitution bias is an issue. The terms of trade (ratio of export and import price index) are therefore also likely to be distorted. The underlying substitution bias accumulates over time. The present article applies a simple and transparent retroactive correction approach that addresses the source of the substitution bias and produces meaningful long-run time series of import and export price levels and, therefore, of the terms of trade. Furthermore, an empirical case study is conducted that demonstrates the efficacy and versatility of the correction approach.
Chapter 3 leaves the field of index revision and studies another issue in price measurement, namely, the economic evaluation of digital products in monetary terms that have zero market prices. This chapter explores different methods of economic valuation and pricing of free digital products and proposes an alternative way to calculate the economic value and a shadow price of free digital products: the Usage Cost Model (UCM). The goal of the chapter is, first of all, to formulate a theoretical framework and incorporate an alternative measure of the value of free digital products. However, an empirical application is also made to show the work of the theoretical model. Some conclusions on applicability are drawn at the end of the chapter.
The present study covers the period from the late-ninth to the early-sixteenth centuries. Within this period, the late-thirteenth to mid-fourteenth centuries marked the decisive turning point, shaped more by attitudes and actions among the Christian majority than among Jewish agents. Our findings indicate an intensification of anti-Jewish tendencies, rooted in religious developments in Western Christendom. According to circumstances, however, these tendencies had a very varying impact across time and space. The frequent religious and ecclesiastical reform movements of Western Europe offer cases in point. In the 'German' Empire north of the Alps the monastic reforms of Saint Maximin and Gorze were by no means confined to the realm of monasticism; they were essential for shaping the historical circumstances in which the foundations of Ashkenazic Judaism were laid in the tenth and early-eleventh centuries. The concept of 'honor' was used by leading ecclesiastics such as bishop Rudiger of Speyer in 1084 to justify the settlement of Jews, but also by civic authorities such as those of Regensburg later on. It is significant for the long-term tendency, therefore, that the late-medieval expulsions from cities like Trier, Cologne, and Regensburg were eventually also legitimized by reference to the idea of honor.
Digital technologies have become central to social interaction and accessing goods and services. Development strategies and approaches to governance have increasingly deployed self-labelled ‘smart’ technologies and systems at various spatial scales, often promoted as rectifying social and geographic inequalities and increasing economic and environmental efficiencies. These have also been accompanied with similarly digitalized commercial and non-profit offers, particularly within the sharing economy. Concern has grown, however, over possible inequalities linked to their introduction. In this paper we critically analyse the role of sharing economies’ contribution to more inclusive, socially equitable
and spatially just transitions. Conceptually, this paper brings together literature on sharing economies, smart urbanism
and just transitions. Drawing on an explorative database of sharing initiatives within the cross-border region of Luxembourg and Germany, we discuss aspects of sustainability as they relate to distributive justice through spatial accessibility, intended benefits, and their operationalization. The regional analysis shows the diversity of sharing models, how they are appropriated in different ways and how intent and operationalization matter in terms of potential benefits.
Results emphasize the need for more fine-grained, qualitative research revealing who is, and is not, participating and
benefitting from sharing economies.
We study planned changes in protective routines after the COVID-19 pandemic: in a survey in Germany among >650 respondents, we find that the majority plans to use face masks in certain situations even after the end of the pandemic. We observe that this willingness is strongly related to the perception that there is something to be learned from East Asians’ handling of pandemics, even when controlling for perceived protection by wearing masks. Given strong empirical evidence that face masks help prevent the spread of respiratory diseases and given the considerable estimated health and economic costs of such diseases even pre-Corona, this would be a very positive side effect of the current crisis.
Knowledge acquisition comprises various processes. Each of those has its dedicated research domain. Two examples are the relations between knowledge types and the influences of person-related variables. Furthermore, the transfer of knowledge is another crucial domain in educational research. I investigated these three processes through secondary analyses in this dissertation. Secondary analyses comply with the broadness of each field and yield the possibility of more general interpretations. The dissertation includes three meta-analyses: The first meta-analysis reports findings on the predictive relations between conceptual and procedural knowledge in mathematics in a cross-lagged panel model. The second meta-analysis focuses on the mediating effects of motivational constructs on the relationship between prior knowledge and knowledge after learning. The third meta-analysis deals with the effect of instructional methods in transfer interventions on knowledge transfer in school students. These three studies provide insights into the determinants and processes of knowledge acquisition and transfer. Knowledge types are interrelated; motivation mediates the relation between prior and later knowledge, and interventions influence knowledge transfer. The results are discussed by examining six key insights that build upon the three studies. Additionally, practical implications, as well as methodological and content-related ideas for further research, are provided.
The ability to acquire knowledge helps humans to cope with the demands of the environment. Supporting knowledge acquisition processes is among the main goals of education. Empirical research in educational psychology has identified several processes mediated through that prior knowledge affects learning. However, the majority of studies investigated cognitive mechanisms mediating between prior knowledge and learning and neglected that motivational processes might also mediate the influence. In addition, the impact of successful knowledge acquisition on patients’ health has not been comprehensively studied. This dissertation aims at closing knowledge gaps on these topics with the use of three studies. The first study is a meta-analysis that examined motivation as a mediator of individual differences in knowledge before and after learning. The second study investigated in greater detail the extent to which motivation mediated the influence of prior knowledge on knowledge gains in a sample of university students. The third study is a second-order meta-analysis synthesizing the results of previous meta-analyses on the effects of patient education on several health outcomes. The findings of this dissertation show that (a) motivation mediates individual differences in knowledge before and after learning; (b) interest and academic self-concept stabilize individual differences in knowledge more than academic self-efficacy, intrinsic motivation, and extrinsic motivation; (c) test-oriented instruction closes knowledge gaps between students; (d) students’ motivation can be independent of prior knowledge in high aptitude students; (e) knowledge acquisition affects motivational and health-related outcomes; and (f) evidence on prior knowledge and motivation can help develop effective interventions in patient education. The results of the dissertation provide insights into prerequisites, processes, and outcomes of knowledge acquisition. Future research should address covariates of learning and environmental impacts for a better understanding of knowledge acquisition processes.
This doctoral thesis examines intergenerational knowledge, its antecedents as well as how participation in intergenerational knowledge transfer is related to the performance evaluation of employees. To answer these questions, this doctoral thesis builds on a literature review and quantitative research methods. A systematic literature study shows that empirical evidence on intergenerational knowledge transfer is limited. Building on prior literature, effects of various antecedents at the interpersonal and organizational level regarding their effects on intergenerational and intragenerational knowledge transfer are postulated. By questioning 444 trainees and trainers, this doctoral thesis also demonstrates that interpersonal antecedents impact how trainees participate in intergenerational knowledge transfer with their trainers. Thereby, the results of this study provide support that interpersonal antecedents are relevant for intergenerational knowledge transfer, yet, also emphasize the implications attached to the assigned roles in knowledge transfer (i.e., whether one is a trainee or trainer). Moreover, the results of an experimental vignette study reveal that participation in intergenerational knowledge transfer is linked to the performance evaluation of employees, yet, is susceptible to whether the employee is sharing or seeking knowledge. Overall, this doctoral thesis provides insights into this topic by covering a multitude of antecedents of intergenerational knowledge transfer, as well as how participation in intergenerational knowledge transfer may be associated with the performance evaluation of employees.
The main research question of this thesis was to set up a framework to allow for the identification of land use changes in drylands and reveal their underlying drivers. The concept of describing land cover change processes in a framework of global change syndrome was introduced by Schellnhuber et al. (1997). In a first step the syndrome approach was implemented for semi-natural areas of the Iberian Peninsula based on time series analysis of the MEDOKADS archive. In the subsequent study the approach was expanded and adapted to other land cover strata. Furthermore, results of an analysis of the relationship of annual NDVI and rainfall data were incorporated to designate areas that show a significant relationship indicating that at least a part of the variability found in NDVI time series was caused by precipitation. Additionally, a first step was taken towards the integration of socio-economic data into the analysis; population density changes between 1961 and 2008 were utilized to support the identification of processes related to land abandonment accompanied by cessation of agricultural practices on the one hand and urbanization on the other. The main findings of the studies comprise three major land cover change processes caused by human interaction: (i) shrub and woody vegetation encroachment in the wake of land abandonment of marginal areas, (ii) intensification of non-irrigated and irrigated, intensively used fertile regions and (iii) urbanization trends along the coastline caused by migration and the increase of mass tourism. Land abandonment of cultivated fields and the give-up of grazing areas in marginal mountainous areas often lead to the encroachment of shrubs and woody vegetation in the course of succession or reforestation. Whereas this cover change has positive effects concerning soil stabilization and carbon sequestration the increase of biomass involves also negative consequences for ecosystem goods and services; these include decreased water yield as a result of increased evapotranspiration, increasing fire risk, decreasing biodiversity due to landscape homogenization and loss of aesthetic value. Arable land in intensively used fertile zones of Spain was further intensified including the expansion of irrigated arable land. The intensification of agriculture has also generated land abandonment in these areas because less people are needed in the agricultural labour sector due to mechanization. Urbanization effects due to migration and the growth of the tourism sector were mapped along the eastern Mediterranean coast. Urban sprawl was only partly detectable by means of the MEDOKADS archive as the changes of urbanization are often too subtle to be detected by data with a spatial resolution of 1 km-². This is in line with a comparison of a Landsat TM time series and the NOAA AVHRR archive for a study area in the Greece that showed that small scale changes cannot be detected based on this approach, even though they might be of high relevance for local management of resources. This underlines the fact that land degradation processes are multi-scale problems and that data of several spatial and temporal scales are mandatory to build a comprehensive dryland observation system. Further land cover processes related to a decrease of greenness did not play an important role in the observation period. Thus, only few patches were identified, suggesting that no large-scale land degradation processes are taking place in the sense of decline of primary productivity after disturbances. Nevertheless, the land cover processes detected impact ecosystem functioning and using the example of shrub encroachment, bear risks for the provision of goods and services which can be valued as land degradation in the sense of a decline of important ecosystem goods and services. This risk is not only confined to the affected ecosystem itself but can also impact adjacent ecosystems due to inter-linkages. In drylands water availability is of major importance and the management of water resources is an important political issue. In view of climate change this topic will become even more important because aridity in Spain did increase within the last decades and is likely to further do so. In addition, the land cover changes detected by the syndrome approach could even augment water scarcity problems. Whereas the water yield of marginal areas, which often serve as headwaters of rivers, decreases with increasing biomass, water demand of agriculture and tourism is not expected to decline. In this context it will be of major importance to evaluate the trade-offs between different land uses and to take decisions that maintain the future functioning of the ecosystems for human well-being.
Digital libraries have become a central aspect of our live. They provide us with an immediate access to an amount of data which has been unthinkable in the past. Support of computers and the ability to aggregate data from different libraries enables small projects to maintain large digital collections on various topics. A central aspect of digital libraries is the metadata -- the information that describes the objects in the collection. Metadata are digital and can be processed and studied automatically. In recent years, several studies considered different aspects of metadata. Many studies focus on finding defects in the data. Specifically, locating errors related to the handling of personal names has drawn attention. In most cases the studies concentrate on the most recent metadata of a collection. For example, they look for errors in the collection at day X. This is a reasonable approach for many applications. However, to answer questions such as when the errors were added to the collection we need to consider the history of the metadata itself. In this work, we study how the history of metadata can be used to improve the understanding of a digital library. To this goal, we consider how digital libraries handle and store their metadata. Based in this information we develop a taxonomy to describe available historical data which means data on how the metadata records changed over time. We develop a system that identifies changes to metadata over time and groups them in semantically related blocks. We found that historical meta data is often unavailable. However, we were able to apply our system on a set of large real-world collections. A central part of this work is the identification and analysis of changes to metadata which corrected a defect in the collection. These corrections are the accumulated effort to ensure data quality of a digital library. In this work, we present a system that automatically extracts corrections of defects from the set of all modifications. We present test collections containing more than 100,000 test cases which we created by extracting defects and their corrections from DBLP. This collections can be used to evaluate automatic approaches for error detection. Furthermore, we use these collections to study properties of defects. We will concentrate on defects related to the person name problem. We show that many defects occur in situations where very little context information is available. This has major implications for automatic defect detection. We also show that properties of defects depend on the digital library in which they occur. We also discuss briefly how corrected defects can be used to detect hidden or future defects. Besides the study of defects, we show that historical metadata can be used to study the development of a digital library over time. In this work, we present different studies as example how historical metadata can be used. At first we describe the development of the DBLP collection over a period of 15 years. Specifically, we study how the coverage of different computer science sub fields changed over time. We show that DBLP evolved from a specialized project to a collection that encompasses most parts of computer science. In another study we analyze the impact of user emails to defect corrections in DBLP. We show that these emails trigger a significant amount of error corrections. Based on these data we can draw conclusions on why users report a defective entry in DBLP.
Up-to-date information about the type and spatial distribution of forests is an essential element in both sustainable forest management and environmental monitoring and modelling. The OpenStreetMap (OSM) database contains vast amounts of spatial information on natural features, including forests (landuse=forest). The OSM data model includes describing tags for its contents, i.e., leaf type for forest areas (i.e., leaf_type=broadleaved). Although the leaf type tag is common, the vast majority of forest areas are tagged with the leaf type mixed, amounting to a total area of 87% of landuse=forests from the OSM database. These areas comprise an important information source to derive and update forest type maps. In order to leverage this information content, a methodology for stratification of leaf types inside these areas has been developed using image segmentation on aerial imagery and subsequent classification of leaf types. The presented methodology achieves an overall classification accuracy of 85% for the leaf types needleleaved and broadleaved in the selected forest areas. The resulting stratification demonstrates that through approaches, such as that presented, the derivation of forest type maps from OSM would be feasible with an extended and improved methodology. It also suggests an improved methodology might be able to provide updates of leaf type to the OSM database with contributor participation.
Global human population growth is associated with many problems, such asrnfood and water provision, political conflicts, spread of diseases, and environmental destruction. The mitigation of these problems is mirrored in several global conventions and programs, some of which, however, are conflicting. Here, we discuss the conflicts between biodiversity conservation and disease eradication. Numerous health programs aim at eradicating pathogens, and many focus on the eradication of vectors, such as mosquitos or other parasites. As a case study, we focus on the "Pan African Tsetse and Trypanosomiasis Eradication Campaign," which aims at eradicating a pathogen (Trypanosoma) as well as its vector, the entire group of tsetse flies (Glossinidae). As the distribution of tsetse flies largely overlaps with the African hotspots of freshwater biodiversity, we argue for a strong consideration of environmental issues when applying vector control measures, especially the aerial applications of insecticides.rnFurthermore, we want to stimulate discussions on the value of speciesrnand whether full eradication of a pathogen or vector is justified at all. Finally, we call for a stronger harmonization of international conventions. Proper environmental impact assessments need to be conducted before control or eradication programs are carried out to minimize negative effects on biodiversity.
The development of our society contributed to increased occurrence of emerging substances (pesticides, pharmaceuticals, personal care products, etc.) in wastewater. Because of their potential hazard on ecosystems and humans, Wastewater Treatment Plants (WWTPs) need to adapt to better remove these compounds. Technology or policy development should however comply with sustainable development, e.g. based on Life Cycle Assessment (LCA) metrics. Nevertheless, the reliability or consistency of LCA results can sometimes be debatable. The main objective of this work was to explore how LCA can better support the implementation of innovative wastewater treatment options, in particular including removal benefits. The method was applied to support solutions for pharmaceuticals elimination from wastewater, regarding: (i) UV technology design, (ii) choice of advanced technology and (iii) centralized or decentralized treatment policy. The assessment approach followed by previous authors based on net impacts calculation seemed very promising to consider both environmental effects induced by treatment plant operation and environmental benefits obtained from pollutants removal. It was therefore applied to compare UV configuration types. LCA outcomes were consistent with degradation kinetics analysis. For the comparison of advanced technologies and policy scenarios, the common practice (net impacts based on EDIP method) was compared to other assessments, to better consider elimination benefits. First, USEtox consensus was applied for the avoided (eco)toxicity impacts, in combination with the recent method ReCiPe for generated impacts. Then, an eco-efficiency indicator (EFI) was developed to weigh the treatment efforts (generated impacts based on EDIP and ReCiPe methods) by the average removal efficiency (overcoming (eco)toxicity uncertainty issues). In total, the four types of comparative assessment showed the same trends: (i) ozonation and activated carbon perform better than UV irradiation, and (ii) no clear advantage distinguished between policy scenarios. It cannot be however concluded that advanced treatment of pharmaceuticals is not necessary because other criteria should be considered (risk assessment, bacterial resistance, etc.) and large uncertainties were embedded in calculations. Indeed, a significant part of this work was dedicated to the discussion of uncertainty and limitations of the LCA outcomes. At the inventory level, it was difficult to model technology operation at development stage. For impact assessment, the newly developed characterization factors for pharmaceuticals (eco)toxicity showed large uncertainties, mainly due to the lack of data and quality for toxicity tests. The use of information made available under REACH framework to develop CFs for detergent ingredients tried to cope with this issue but the benefits were limited due to the mismatch of information between REACH and USEtox method. The highlighted uncertainties were treated with sensitivity analyses to understand their effects on LCA results. This research work finally presents perspectives on the use of transparently generated data (technology inventory and (eco)toxicity factors) and further development of EFI indicator. Also, an accent is made on increasing the reliability of LCA outcomes, in particular through the implementation of advanced techniques for uncertainty management. To conclude, innovative technology/product development (e.g. based on circular economy approach) needs the involvement of all types of actors and the support from sustainability metrics.
This dissertation focusses on research into the personality construct of action vs. state orientation. Derived from the Personality-Systems-Interaction Theory (PSI Theory), state orientation is defined as a low ability to self-regulate emotions and associated with many adverse consequences – especially under stress. Because of the high prevalence of state orientation, it is a very important topic to investigate factors that help state-oriented people to buffer these adverse consequences. Action orientation, in contrast, is defined as a high ability to self-regulate own emotions in a very specific way: through accessing the self. The present dissertation demonstrates this theme in five studies, using a total of N = 1251 participants with a wide age range, encompassing different populations (students, non-student population (people from the coaching and therapy sector), applying different operationalisations to investigate self-access as a mediator or an outcome variable. Furthermore, it is tested whether the popular technique of mindfulness - that is advertised as a potent remedy for bringing people closer to the self -really works for everybody. The findings show that the presumed remedy is rather harmful for state-oriented individuals. Finally, an attempt to ameliorate these alienating effects, the present dissertation attempts to find theory-driven, and easy-to-apply solution how mindfulness exercises can be adapted.
Flexibility and spatial mobility of labour are central characteristics of modern societies which contribute not only to higher overall economic growth but also to a reduction of interregional employment disparities. For these reasons, there is the political will in many countries to expand labour market areas, resulting especially in an overall increase in commuting. The picture of the various, unintended long-term consequences of commuting on individuals is, however, relatively unclear. Therefore, in recent years, the journey to work has gained high attention especially in the study of health and well-being. Empirical analyses based on longitudinal as well as European data on how commuting may affect health and well-being are nevertheless rare. The principle aim of this thesis is, thus, to address this question with regard to Germany using data from the Socio-Economic Panel. Chapter 2 empirically investigates the causal impact of commuting on absence from work due to sickness-related reasons. Whereas an exogenous change in commuting distance does not affect the number of absence days of those individuals who commute short distances to work, it increases the number of absence days of those employees who commute middle (25 " 49 kilometres) or long distances (50 kilometres and more). Moreover, our results highlight that commuting may deteriorate an individual- health. However, this effect is not sufficient to explain the observed impact of commuting on absence from work. Chapter 3 explores the relationship between commuting distance and height-adjusted weight and sheds some light on the mechanisms through which commuting might affect individual body weight. We find no evidence that commuting leads to excess weight. Compensating health behaviour of commuters, especially healthy dietary habits, could explain the non-relationship of commuting and height-adjusted weight. In Chapter 4, a multivariate probit approach is used to estimate recursive systems of equations for commuting and health-related behaviours. Controlling for potential endogeneity of commuting, the results show that long distance commutes significantly decrease the propensity to engage in health-related activities. Furthermore, unobservable individual heterogeneity can influence both the decision to commute and healthy lifestyle choices. Chapter 5 investigates the relationship between commuting and several cognitive and affective components of subjective well-being. The results suggest that commuting is related to lower levels of satisfaction with family life and leisure time which can largely be ascribed to changes in daily time use patterns, influenced by the work commute.
Background: The growing production and use of engineered AgNP in industry and private households make increasing concentrations of AgNP in the environment unavoidable. Although we already know the harmful effects of AgNP on pivotal bacterial driven soil functions, information about the impact of silver nanoparticles (AgNP) on the soil bacterial community structure is rare. Hence, the aim of this study was to reveal the long-term effects of AgNP on major soil bacterial phyla in a loamy soil. The study was conducted as a laboratory incubation experiment over a period of 1 year using a loamy soil and AgNP concentrations ranging from 0.01 to 1 mg AgNP/kg soil. Effects were quantified using the taxon-specific 16S rRNA qPCR.
Results: The short-term exposure of AgNP at environmentally relevant concentration of 0.01 mg AgNP/kg caused significant positive effects on Acidobacteria (44.0%), Actinobacteria (21.1%) and Bacteroidetes (14.6%), whereas beta-Proteobacteria population was minimized by 14.2% relative to the control (p ≤ 0.05). After 1 year of exposure to 0.01 mg AgNP/kg diminished Acidobacteria (p = 0.007), Bacteroidetes (p = 0.005) and beta-Proteobacteria (p = 0.000) by 14.5, 10.1 and 13.9%, respectively. Actino- and alpha-Proteobacteria were statistically unaffected by AgNP treatments after 1-year exposure. Furthermore, a statistically significant regression and correlation analysis between silver toxicity and exposure time confirmed loamy soils as a sink for silver nanoparticles and their concomitant silver ions.
Conclusions: Even very low concentrations of AgNP may cause disadvantages for the autotrophic ammonia oxidation (nitrification), the organic carbon transformation and the chitin degradation in soils by exerting harmful effects on the liable bacterial phyla.
Long-Term Memory Updating: The Reset-of-Encoding Hypothesis in List-Method Directed Forgetting
(2017)
People- memory for new information can be enhanced by cuing them to forget older information, as is shown in list-method directed forgetting (LMDF). In this task, people are cued to forget a previously studied list of items (list 1) and to learn a new list of items (list 2) instead. Such cuing typically enhances memory for the list 2 items and reduces memory for the list 1 items, which reflects effective long-term memory updating. This review focuses on the reset-of-encoding (ROE) hypothesis as a theoretical explanation of the list 2 enhancement effect in LMDF. The ROE hypothesis is based on the finding that encoding efficacy typically decreases with number of encoded items and assumes that providing a forget cue after study of some items (e.g., list 1) resets the encoding process and makes encoding of subsequent items (e.g., early list 2 items) as effective as encoding of previously studied (e.g., early list 1) items. The review provides an overview of current evidence for the ROE hypothesis. The evidence arose from recent behavioral, neuroscientific, and modeling studies that examined LMDF on both an item and a list level basis. The findings support the view that ROE plays a critical role for the list 2 enhancement effect in LMDF. Alternative explanations of the effect and the generalizability of ROE to other experimental tasks are discussed.
Food waste is the origin of major social and environmental issues. In industrial societies, domestic households are the biggest contributors to this problem. But why do people waste food although they buy and value it? Answering this question is mandatory to design effective interventions against food waste. So far, however, many interventions have not been based on theoretical knowledge. Integrating food waste literature and ambivalence research, we propose that domestic food waste can be understood via the concept of ambivalence—the simultaneous presence of positive and negative associations towards the same attitude object. In support of this notion, we demonstrated in three pre-registered experiments that people experienced ambivalence towards non-perishable food products with expired best before dates. The experience of ambivalence was in turn associated with an increased willingness to waste food. However, two informational interventions aiming to prevent people from experiencing ambivalence did not work as intended (Experiment 3). We hope that the outlined conceptualization inspires theory-driven research on why and when people dispose of food and on how to design effective interventions.
This thesis considers the general task of computing a partition of a set of given objects such that each set of the partition has a cardinality of at least a fixed number k. Among such kinds of partitions, which we call k-clusters, the objective is to find the k-cluster which minimises a certain cost derived from a given pairwise difference between objects which end up the same set. As a first step, this thesis introduces a general problem, denoted by (||.||,f)-k-cluster, which models the task to find a k-cluster of minimum cost given by an objective function computed with respect to specific choices for the cost functions f and ||.||. In particular this thesis considers three different choices for f and also three different choices for ||.|| which results in a total of nine different variants of the general problem. Especially with the idea to use the concept of parameterised approximation, we first investigate the role of the lower bound on the cluster cardinalities and find that k is not a suitable parameter, due to remaining NP-hardness even for the restriction to the constant 3. The reductions presented to show this hardness yield the even stronger result which states that polynomial time approximations with some constant performance ratio for any of the nine variants of (||.||,f)-k-cluster require a restriction to instances for which the pairwise distance on the objects satisfies the triangle inequality. For this restriction to what we informally refer to as metric instances, constant-factor approximation algorithms for eight of the nine variants of (||.||,f)-k-cluster are presented. While two of these algorithms yield the provably best approximation ratio (assuming P!=NP), others can only guarantee a performance which depends on the lower bound k. With the positive effect of the triangle inequality and applications to facility location in mind, we discuss the further restriction to the setting where the given objects are points in the Euclidean metric space. Considering the effect of computational hardness caused by high dimensionality of the input for other related problems (curse of dimensionality) we check if this is also the source of intractability for (||.||,f)-k-cluster. Remaining NP-hardness for restriction to small constant dimensionality however disproves this theory. We then use parameterisation to develop approximation algorithms for (||.||,f)-k-cluster without restriction to metric instances. In particular, we discuss structural parameters which reflect how much the given input differs from a metric. This idea results in parameterised approximation algorithms with parameters such as the number of conflicts (our name for pairs of objects for which the triangle inequality is violated) or the number of conflict vertices (objects involved in a conflict). The performance ratios of these parameterised approximations are in most cases identical to those of the approximations for metric instances. This shows that for most variants of (||.||,f)-k-cluster efficient and reasonable solutions are also possible for non-metric instances.
The study at hand deals with madness as it is represented in English Canadian fiction. The topic seemed most interesting and fruitful for analysis due to the fact that as the ways madness has been defined, understood, described, judged and handled differ quite profoundly from society to society, from era to era, as the language, ideas and associations surrounding insanity are both strongly culture-relative and shifting, madness as a theme of myth and literature has always been a excellent vehicle to mirror the assumptions and arguments, the aspirations and nostalgia, the beliefs and values, hopes and fears of its age and society. Thus, while the overall intent of this study is to elucidate some discernible patterns of structure and style which accompany the use of madness in Canadian literature, to investigate the varying sorts of portrayal and the conventions of presentation, to interpret the use of madness as literary devices and to highlight the different statements which are made, the continuity, variation, and changes in the theme of madness provide an informing principle in terms of certain Canadian experiences and perceptions. By examining madness as it represents itself in Canadian literature and considering the respective explorations of the deranged mind within their historical context, I hope to demonstrate that literary interpretations of madness both reflect and question cultural, political, religious and psychological assumptions of their times and that certain symptoms or usages are characteristic of certain periods. Such an approach, it is hoped, might not only contribute towards an assessment of the wealth of associations which surround madness and the ambivalence with which it is viewed, but also shed some light on the Canadian imagination. As such this study can be considered not only as a history of literary madness, but a history of Canadian society and the Canadian mind.
In recent years, the establishment of new makerspaces in Germany has increased significantly. The underlying phenomenon of the Maker Movement is a cultural and technological movement focused on making physical and digital products using open source principles, collaborative production, and individual empowerment. Because of its potential to democratize the innovation and production process, empower individuals and communities, and enable innovators to solve problems at the local level, the Maker Movement has received considerable attention in recent years. Despite numerous indicators, little is known about the phenomenon and its individual members, especially in Germany. Initial research suggests that the Maker Movement holds great potential for innovation and entrepreneurship. However, there is still a gap in understanding how Makers discover, evaluate and exploit entrepreneurial opportunities. Moreover, there is still controversy - both among policy makers and within the maker community itself - about the impact the maker movement has and can have on innovation and entrepreneurship in the future. This dissertation uses a mixed-methods approach to explore these questions. In addition to a quantitative analysis of maker characteristics, the results show that social impact, market size, and property rights have significant effects on the evaluation of entrepreneurial opportunities. The findings within this dissertation expand research in the field of the Maker Movement and offer multiple implications for practice. This dissertation provides the first quantitative data on makers in makerspaces in Germany, their characteristics and motivations. In particular, the relationship between the Maker Movement and entrepreneurship is explored in depth for the first time. This is complemented by the presentation of different identity profiles of the individuals involved. In this way, policy-makers can develop a better understanding of the movement, its personalities and values, and consider them in initiatives and formats.
Service innovation has increasingly gained acknowledgement to contribute to economic growth and well-being. Despite this increased relevance in practice, service innovation is a developing research field. To advance literature on service innovation, this work analyzes with a qualitative study how firms manage service innovation activities in their organization differently. In addition, it evaluates the influence of top management commitment and corporate service innovativeness on service innovation capabilities of a firm and their implications for firm-level performance by conducting a quantitative study. Accordingly, the main overall research questions of this dissertation are: 1.) How and why do firms manage service innovation activities in their organization differently? 2.) What influence do top management commitment and corporate service innovativeness have on service innovation capabilities of a firm and what are the implications for firm-level performance? To respond to the first research question the way firms manage service innovation activities in their organization is investigated and by whom and how service innovations are developed. Moreover, it is examined why firms implement their service innovation activities differently. To achieve this a qualitative empirical study is conducted which included 22 semi-structured interviews with 15 firms in the sectors of construction, financial services, IT services, and logistics. Addressing the second research question, the aim is to improve the understanding about factors that enhance firm-level performance through service innovations. Deploying a dynamic capabilities perspective, a quantitative study is performed which underlines the importance of service innovation capabilities. More specifically, a theoretical framework is developed that proposes a positive relationship of top management commitment and corporate service innovativeness with service innovation capabilities and a positive relationship between service innovation capabilities and the firm-level performance indicators market performance, competitive advantage, and efficiency. A survey with double respondents from 87 companies from the sectors construction, financial services, IT services, and logistics was conducted to test the proposed theoretical framework by applying partial least squares structural equation modeling (PLS-SEM).
Matching problems with additional resource constraints are generalizations of the classical matching problem. The focus of this work is on matching problems with two types of additional resource constraints: The couple constrained matching problem and the level constrained matching problem. The first one is a matching problem which has imposed a set of additional equality constraints. Each constraint demands that for a given pair of edges either both edges are in the matching or none of them is in the matching. The second one is a matching problem which has imposed a single equality constraint. This constraint demands that an exact number of edges in the matching are so-called on-level edges. In a bipartite graph with fixed indices of the nodes, these are the edges with end-nodes that have the same index. As a central result concerning the couple constrained matching problem we prove that this problem is NP-hard, even on bipartite cycle graphs. Concerning the complexity of the level constrained perfect matching problem we show that it is polynomially equivalent to three other combinatorial optimization problems from the literature. For different combinations of fixed and variable parameters of one of these problems, the restricted perfect matching problem, we investigate their effect on the complexity of the problem. Further, the complexity of the assignment problem with an additional equality constraint is investigated. In a central part of this work we bring couple constraints into connection with a level constraint. We introduce the couple and level constrained matching problem with on-level couples, which is a matching problem with a special case of couple constraints together with a level constraint imposed on it. We prove that the decision version of this problem is NP-complete. This shows that the level constraint can be sufficient for making a polynomially solvable problem NP-hard when being imposed on that problem. This work also deals with the polyhedral structure of resource constrained matching problems. For the polytope corresponding to the relaxation of the level constrained perfect matching problem we develop a characterization of its non-integral vertices. We prove that for any given non-integral vertex of the polytope a corresponding inequality which separates this vertex from the convex hull of integral points can be found in polynomial time. Regarding the calculation of solutions of resource constrained matching problems, two new algorithms are presented. We develop a polynomial approximation algorithm for the level constrained matching problem on level graphs, which returns solutions whose size is at most one less than the size of an optimal solution. We then describe the Objective Branching Algorithm, a new algorithm for exactly solving the perfect matching problem with an additional equality constraint. The algorithm makes use of the fact that the weighted perfect matching problem without an additional side constraint is polynomially solvable. In the Appendix, experimental results of an implementation of the Objective Branching Algorithm are listed.
This work is concerned with the numerical solution of optimization problems that arise in the context of ground water modeling. Both ground water hydraulic and quality management problems are considered. The considered problems are discretized problems of optimal control that are governed by discretized partial differential equations. Aspects of special interest in this work are inaccurate function evaluations and the ensuing numerical treatment within an optimization algorithm. Methods for noisy functions are appropriate for the considered practical application. Also, block preconditioners are constructed and analyzed that exploit the structure of the underlying linear system. Specifically, KKT systems are considered, and the preconditioners are tested for use within Krylov subspace methods. The project was financed by the foundation Stiftung Rheinland-Pfalz für Innovation and carried out in joint work with TGU GmbH, a company of consulting engineers for ground water and water resources.
Even though in most cases time is a good metric to measure costs of algorithms, there are cases where theoretical worst-case time and experimental running time do not match. Since modern CPUs feature an innate memory hierarchy, the location of data is another factor to consider. When most operations of an algorithm are executed on data which is already in the CPU cache, the running time is significantly faster than algorithms where most operations have to load the data from the memory. The topic of this thesis is a new metric to measure costs of algorithms called memory distance—which can be seen as an abstraction of the just mentioned aspect. We will show that there are simple algorithms which show a discrepancy between measured running time and theoretical time but not between measured time and memory distance. Moreover we will show that in some cases it is sufficient to optimize the input of an algorithm with regard to memory distance (while treating the algorithm as a black box) to improve running times. Further we show the relation between worst-case time, memory distance and space and sketch how to define "the usual" memory distance complexity classes.
Exposure to fine and ultra-fine environmental particles is still a problem of concern in many industrialized parts of the world and the intensified use of nanotechnology may further increase exposure to small particles. Since many years air pollution is recognized as a critical problem in western countries, which led to rigorous regulation of air quality and the introduction of strict guidelines. However, the upper thresholds for particulates in ambient air recommended by the world health organization are often exceeded several times in newly industrialized countries. Such high levels of air pollution have the potential to induce adverse effects on human health. The response triggered by air pollutants is not limited to local effects of the respiratory system but is often systemic, resulting in endothelial dysfunction or atherosclerotic malady. The link between air pollution and cardiovascular disease is now accepted by the scientific community but the underlying mechanisms responsible for the pro-atherogenic potential still need to be unraveled in detail. Based on the results from in- vivo and in vitro studies the production of reactive oxygen species due to exposure to particles is the most important mechanism to explain the observed adverse effects. However, the doses that were applied in many in vivo and in vitro studies are far beyond the range of what humans are exposed to and there is the need for more realistic exposure studies. Complex in vitro coculture systems may be valuable tools to study particle-induced processes and to extrapolate effects of particles on the lung. One of the objectives of this PhD thesis was the establishment and further improvement of a complex coculture system initially described by Alfaro-Moreno et al. [1]. The system is composed of an alveolar type-II cell line (A549), differentiated macrophage-like cells (THP-1), mast cells (HMC-1) and endothelial cells (EA.hy 926), seeded in a 3D-orientation on a microporous membrane to mimic the cell response of the alveolar surface in vitro in conjunction with native aerosol exposure (VitrocellTM chamber). The tetraculture system was carefully characterized to ensure its performance and repeatability of results. The spatial distribution of the cells in the tetraculture was analyzed by confocal laser scanning microscopy (CLSM), showing a confluent layer of endothelial and epithelial cells on both sides of the Transwellâ„¢. Macrophage-like cells and mast cells can be found on top of the epithelial cells. The latter cells formed colonies under submerged conditions, which disappeared at the air-liquid-interface (ALI). The VitrocellTM aerosol exposure system was not significantly influencing the viability. Using this system, cells were exposed to an aerosol of 50 nm SiO2-Rhodamine nanoparticles (NPs) in PBS. The distribution of the NPs in the tetraculture after exposure was evaluated by CLSM. Fluorescence from internalized particles was detected in CD11b-positive THP-1 cells only. Furthermore, all cell lines were found to be able to respond to xenobiotic model compounds, such as benzo[a]pyrene (B[a]P) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) with the upregulation of CYP1 mRNA. With this tetraculture system the response of the endothelial part of the alveolar barrier was studied in- vitro in a still realistic exposure scenario representing the conditions for a polluted situation without direct exposure of endothelial cells. After exposure to diesel exhaust particulate matter (DEPM) the expression of different anti-oxidant target genes and inflammatory genes such as NAD(P)H dehydrogenase quinone 1 (NQO1), superoxide dismutase 1 (SOD1) and heme oxygenase 1 (HMOX1), as well as the nuclear translocation nuclear factor erythroid-derived 2 (Nrf2) was evaluated. In addition, the potential of DEPM to induce the upregulation of CYP1A1 mRNA in the endothelium was analyzed. DEPM exposure led not to an upregulation of the anti-oxidant or inflammatory target genes, but to clear nuclear translocation of Nrf2. The endothelial cells responded to the DEPM treatment also with the upregulation of CYP1A1 mRNA and nuclear translocation of the aryl hydrocarbon receptor (AhR). Overall, DEPM triggered a response in the endothelial cells after indirect exposure of the tetraculture system to low doses of DEPM, underlining the sensitivity of ALI exposure systems. The use of the tetraculture together with the native aerosol exposure equipment may finally lead to a more realistic judgment regarding the hazard of new compounds and/or new nano-scaled materials in the future. For the first time, it was possible to study the response of the endothelial cells of the alveolar barrier in vitro in a realistic exposure scenario avoiding direct exposure of endothelial cells to high amounts of particulates.
Survey data can be viewed as incomplete or partially missing from a variety of perspectives and there are different ways of dealing with this kind of data in the prediction and the estimation of economic quantities. In this thesis, we present two selected research contexts in which the prediction or estimation of economic quantities is examined under incomplete survey data.
These contexts are first the investigation of composite estimators in the German Microcensus (Chapters 3 and 4) and second extensions of multivariate Fay-Herriot (MFH) models (Chapters 5 and 6), which are applied to small area problems.
Composite estimators are estimation methods that take into account the sample overlap in rotating panel surveys such as the German Microcensus in order to stabilise the estimation of the statistics of interest (e.g. employment statistics). Due to the partial sample overlaps, information from previous samples is only available for some of the respondents, so the data are partially missing.
MFH models are model-based estimation methods that work with aggregated survey data in order to obtain more precise estimation results for small area problems compared to classical estimation methods. In these models, several variables of interest are modelled simultaneously. The survey estimates of these variables, which are used as input in the MFH models, are often partially missing. If the domains of interest are not explicitly accounted for in a sampling design, the sizes of the samples allocated to them can, by chance, be small. As a result, it can happen that either no estimates can be calculated at all or that the estimated values are not published by statistical offices because their variances are too large.
Industrial companies mainly aim for increasing their profit. That is why they intend to reduce production costs without sacrificing the quality. Furthermore, in the context of the 2020 energy targets, energy efficiency plays a crucial role. Mathematical modeling, simulation and optimization tools can contribute to the achievement of these industrial and environmental goals. For the process of white wine fermentation, there exists a huge potential for saving energy. In this thesis mathematical modeling, simulation and optimization tools are customized to the needs of this biochemical process and applied to it. Two different models are derived that represent the process as it can be observed in real experiments. One model takes the growth, division and death behavior of the single yeast cell into account. This is modeled by a partial integro-differential equation and additional multiple ordinary integro-differential equations showing the development of the other substrates involved. The other model, described by ordinary differential equations, represents the growth and death behavior of the yeast concentration and development of the other substrates involved. The more detailed model is investigated analytically and numerically. Thereby existence and uniqueness of solutions are studied and the process is simulated. These investigations initiate a discussion regarding the value of the additional benefit of this model compared to the simpler one. For optimization, the process is described by the less detailed model. The process is identified by a parameter and state estimation problem. The energy and quality targets are formulated in the objective function of an optimal control or model predictive control problem controlling the fermentation temperature. This means that cooling during the process of wine fermentation is controlled. Parameter and state estimation with nonlinear economic model predictive control is applied in two experiments. For the first experiment, the optimization problems are solved by multiple shooting with a backward differentiation formula method for the discretization of the problem and a sequential quadratic programming method with a line search strategy and a Broyden-Fletcher-Goldfarb-Shanno update for the solution of the constrained nonlinear optimization problems. Different rounding strategies are applied to the resulting post-fermentation control profile. Furthermore, a quality assurance test is performed. The outcomes of this experiment are remarkable energy savings and tasty wine. For the next experiment, some modifications are made, and the optimization problems are solved by using direct transcription via orthogonal collocation on finite elements for the discretization and an interior-point filter line-search method for the solution of the constrained nonlinear optimization problems. The second experiment verifies the results of the first experiment. This means that by the use of this novel control strategy energy conservation is ensured and production costs are reduced. From now on tasty white wine can be produced at a lower price and with a clearer conscience at the same time.
Monetary Policy During Times of Crisis - Frictions and Non-Linearities in the Transmission Mechanism
(2017)
For a long time it was believed that monetary policy would be able to maintain price stability and foster economic growth during all phases of the business cycle. The era of the Great Moderation, often also called the Volcker-Greenspan period, beginning in the mid 1980s was characterized by a decline in volatility of output growth and inflation among the industrialized countries. The term itself is first used by Stock and Watson (2003). Economist have long studied what triggered the decline in volatility and pointed out several main factors. An important research strand points out structural changes in the economy, such as a decline of volatility in the goods producing sector through better inventory controls and developments in the financial sector and government spending (McConnell2000, Blanchard2001, Stock2003, Kim2004, Davis2008). While many believed that monetary policy was only 'lucky' in terms of their reaction towards inflation and exogenous shocks (Stock2003, Primiceri2005, Sims2006, Gambetti2008), others reveal a more complex picture of the story. Rule based monetary policy (Taylor1993) that incorporates inflation targeting (Svensson1999) has been identified as a major source of inflation stabilization by increasing transparency (Clarida2000, Davis2008, Benati2009, Coibion2011). Apart from that, the mechanics of monetary policy transmission have changed. Giannone et al. (2008) compare the pre-Great Moderation era with the Great Modertation and find that the economies reaction towards monetary shocks has decreased. This finding is supported by Boivin et al. (2011). Similar to this, Herrera and Pesavento (2009) show that monetary policy during the Volcker-Greenspan period was very effective in dampening the effects of exogenous oil price shocks on the economy, while this cannot be found for the period thereafter. Yet, the subprime crisis unexpectedly hit worldwide economies and ended the era of Great Moderation. Financial deregulation and innovation has given banks opportunities for excessive risk taking, weakened financial stability (Crotty2009, Calomiris2009) and led to the build-up of credit-driven asset price bubbles (SchularickTaylor2012). The Federal Reserve (FED), that was thought to be the omnipotent conductor of price stability and economic growth during the Great Moderation, failed at preventing a harsh crisis. Even more, it did intensify the bubble with low interest rates following the Dotcom crisis of the early 2000s and misjudged the impact of its interventions (Taylor2009, Obstfeld2009). New results give a more detailed explanation on the question of latitude for monetary policy raised by Bernanke and suggest the existence of non-linearities in the transmission of monetary policy. Weise (1999), Garcia and Schaller (2002), Lo and Piger (2005), Mishkin (2009), Neuenkirch (2013) and Jannsen et al. (2015) find that monetary policy is more potent during times of financial distress and recessions. Its effectiveness during 'normal times' is much weaker or even insignificant. This prompts the question if these non-linearities limit central banks ability to lean against bubbles and financial imbalances (White2009, Walsh2009, Boivin2010, Mishkin2011).
The argan woodlands of South Morocco represent an open-canopy dryland forest with traditional silvopastoral usage that includes browsing by goats, sheep and camels, oil production as well as agricultural use. In the past, these forests have undergone extensive clearing, but are now protected by the state. However, the remaining argan woodlands are still under pressure from intensive grazing and illegal firewood collection. Although the argan-forest area seems to be overall decreasing due to large forest clearings for intensive agriculture, little quantitative data is available on the dynamics and overall state of the remaining argan forest. To determine how the argan woodlands in the High Atlas and the Anti-Atlas had changed in tree-crown cover from 1972 to 2018 we used historical black and white HEXAGON satellite images as well as recent WorldView satellite images (see Part A of our study). Because tree shadows can oftentimes not be separated from the tree crown on panchromatic satellite images, individual trees were mapped in three size categories to determine if trees were unchanged, had decreased/increased in crown size or had disappeared or newly grown. The current state of the argan trees was evaluated by mapping tree architectures in the field. Tree-cover changes varied highly between the test sites. Trees that remained unchanged between 1972 and 2018 were in the majority, while tree mortality and tree establishment were nearly even. Small unchanged trees made up 48.4% of all remaining trees, of these 51% showed degraded tree architectures. 40% of small (re-) grown trees were so overbrowsed that they only appeared as bushes, while medium (3–7 m crown diameter) and large trees (>7 m) showed less degraded trees regardless if they had changed or not. Approaches like grazing exclusion or cereal cultivation lead to a positive influence on tree architecture and less tree-cover decrease. Although the woodland was found to be mostly unchanged 1972–2018, the analysis of tree architecture reveals that a lot of (mostly small) trees remained stable but in a degraded state. This stability might be the result of the small trees’ high degradation status and shows the heavy pressure on the argan forest.
Arctic and Antarctic polynya systems are of high research interest since extensive new ice formation takes place in these regions. The monitoring of polynyas and the ice production is crucial with respect to the changing sea-ice regime. The thin-ice thickness (TIT) distribution within polynyas controls the amount of heat that is released to the atmosphere and has therefore an impact on the ice-production rates. This thesis presents an improved method to retrieve thermal-infrared thin-ice thickness distributions within polynyas. TIT with a spatial resolution of 1 km × 1 km is calculated using the MODIS ice-surface temperature and atmospheric model variables within the Laptev Sea polynya for the winter periods 2007/08 and 2008/09. The improvement of the algorithm is focused on the surface-energy flux parameterizations. Furthermore, a thorough sensitivity analysis is applied to quantify the uncertainty in the thin-ice thickness results. An absolute mean uncertainty of -±4.7 cm for ice below 20 cm of thickness is calculated. Furthermore, advantages and drawbacks using different atmospheric data sets are investigated. Daily MODIS TIT composites are computed to fill the data gaps arising from clouds and shortwave radiation. The resulting maps cover on average 70 % of the Laptev Sea polynya. An intercomparison of MODIS and AMSR-E polynya data indicates that the spatial resolution issue is essential for accurately deriving polynya characteristics. Monthly fast-ice masks are generated using the daily TIT composites. These fast-ice masks are implemented into the coupled sea-ice/ocean model FESOM. An evaluation of FESOM sea-ice concentrations is performed with the result that a prescribed high-resolution fast-ice mask is necessary regarding the accurate polynya location. However, for a more realistic simulation of other small-scale sea-ice features further model improvements are required. The retrieval of daily high-resolution MODIS TIT composites is an important step towards a more precise monitoring of thin sea ice and sea-ice production. Future work will address a combined remote sensing " model assimilation method to simulate fully-covered thin-ice thickness maps that enable the retrieval of accurate ice production values.
The midcingulate cortex has become the focus of scientific interest as it has been associated with a wide range of attentional phenomena. This survey found evidence indicating the relevance of gender and handedness for measures of regional cortical morphology. Although gender was associated with structural variations concerning the neuroanatomy of the midcingulum bundle as well, handedness did not emerge in the analyses of white matter characteristics as significant factor. Hemispheric differences were found at the level of both gray and white matter. Turning to the functional implications of neuroanatomical variations and comparing subjects with a pronounced and a low degree of midcingulate folding, which indicates differential expansions of cytoarchitectural areas, behavioral and electrophysiological differences in the processing of interference became evident. A high degree of leftward midcingulate fissurization was associated with better behavioral performance, presumably caused by a more effective conflict-monitoring system triggering fast and automatic attentional filtering mechanisms. Subjects exhibiting a lower degree of midcingulate fissurization rather seem to rely on more effortful control processes. These results carry implications not only concerning neuronal representations of individual differences in attentional processes, but might also be of relevance for the refinement of models for mental disorders.
Background
The morphology of anuran larvae is suggested to differ between species with tadpoles living in standing (lentic) and running (lotic) waters. To explore which character combinations within the general tadpole morphospace are associated with these habitats, we studied categorical and metric larval data of 123 (one third of which from lotic environments) Madagascan anurans.
Results
Using univariate and multivariate statistics, we found that certain combinations of fin height, body musculature and eye size prevail either in larvae from lentic or lotic environments.
Conclusion
Evidence for adaptation to lotic conditions in larvae of Madagascan anurans is presented. While lentic tadpoles typically show narrow to moderate oral discs, small to medium sized eyes, convex or moderately low fins and non-robust tail muscles, tadpoles from lotic environments typically show moderate to broad oral discs, medium to big sized eyes, low fins and a robust tail muscle.
Objective: Attunement is a novel measure of nonverbal synchrony reflecting the duration of the present moment shared by two interaction partners. This study examined its association with early change in outpatient psychotherapy.
Methods: Automated video analysis based on motion energy analysis (MEA) and cross-correlation of the movement time-series of patient and therapist was conducted to calculate movement synchrony for N = 161 outpatients. Movement-based attunement was defined as the range of connected time lags with significant synchrony. Latent change classes in the HSCL-11 were identified with growth mixture modeling (GMM) and predicted by pre-treatment covariates and attunement using multilevel multinomial regression.
Results: GMM identified four latent classes: high impairment, no change (Class 1); high impairment, early response (Class 2); moderate impairment (Class 3); and low impairment (Class 4). Class 2 showed the strongest attunement, the largest early response, and the best outcome. Stronger attunement was associated with a higher likelihood of membership in Class 2 (b = 0.313, p = .007), Class 3 (b = 0.251, p = .033), and Class 4 (b = 0.275, p = .043) compared to Class 1. For highly impaired patients, the probability of no early change (Class 1) decreased and the probability of early response (Class 2) increased as a function of attunement.
Conclusions: Among patients with high impairment, stronger patient-therapist attunement was associated with early response, which predicted a better treatment outcome. Video-based assessment of attunement might provide new information for therapists not available from self-report questionnaires and support therapists in their clinical decision-making.
In recent decades, the Arctic has been undergoing a wide range of fast environmental changes. The sea ice covering the Arctic Ocean not only reacts rapidly to these changes, but also influences and alters the physical properties of the atmospheric boundary layer and the underlying ocean on various scales. In that regard, polynyas, i.e. regions of open water and thin ice within thernclosed pack ice, play a key role as being regions of enhanced atmosphere-ice-ocean interactions and extensive new ice formation during winter. A precise long-term monitoring and increased efforts to employ long-term and high-resolution satellite data is therefore of high interest for the polar scientific community. The retrieval of thin-ice thickness (TIT) fields from thermal infrared satellite data and atmospheric reanalysis, utilizing a one-dimensional energy balance model, allows for the estimation of the heat loss to the atmosphere and hence, ice-production rates. However, an extended application of this approach is inherently connected with severe challenges that originate predominantly from the disturbing influence of clouds and necessary simplifications in the model set-up, which all need to be carefully considered and compensated for. The presented thesis addresses these challenges and demonstrates the applicability of thermal infrared TIT distributions for a long-term polynya monitoring, as well as an accurate estimation of ice production in Arctic polynyas at a relatively high spatial resolution. Being written in a cumulative style, the thesis is subdivided into three parts that show the consequent evolution and improvement of the TIT retrieval, based on two regional studies (Storfjorden and North Water (NOW) polynya) and a final large-scale, pan-Arctic study. The first study on the Storfjorden polynya, situated in the Svalbard archipelago, represents the first long-term investigation on spatial and temporal polynya characteristics that is solely based on daily TIT fields derived from MODIS thermal infrared satellite data and ECMWF ERA-Interim atmospheric reanalysis data. Typical quantities such as polynya area (POLA), the TIT distribution, frequencies of polynya events as well as the total ice production are derived and compared to previous remote sensing and modeling studies. The study includes a first basic approach that aims for a compensation of cloud-induced gaps in daily TIT composites. This coverage-correction (CC) is a mathematically simple upscaling procedure that depends solely on the daily percentage of available MODIS coverage and yields daily POLA with an error-margin of 5 to 6 %. The NOW polynya in northern Baffin Bay is the main focus region of the second study, which follows two main goals. First, a new statistics-based cloud interpolation scheme (Spatial Feature Reconstruction - SFR) as well as additional cloud-screening procedures are successfully adapted and implemented in the TIT retrieval for usage in Arctic polynya regions. For a 13-yr period, results on polynya characteristics are compared to the CC approach. Furthermore, an investigation on highly variable ice-bridge dynamics in Nares Strait is presented. Second, an analysis of decadal changes of the NOW polynya is carried out, as the additional use of a suite of passive microwave sensors leads to an extended record of 37 consecutive winter seasons, thereby enabling detailed inter-sensor comparisons. In the final study, the SFR-interpolated daily TIT composites are used to infer spatial and temporal characteristics of 17 circumpolar polynya regions in the Arctic for 2002/2003 to 2014/2015. All polynya regions combined cover an average thin-ice area of 226.6 -± 36.1 x 10-³ km-² during winter (November to March) and yield an average total wintertime accumulated ice production of about 1811 -± 293 km-³. Regional differences in derived ice production trends are noticeable. The Laptev Sea on the Siberian shelf is presented as a focus region, as frequently appearing polynyas along the fast-ice edge promote high rates of new ice production. New affirming results on a distinct relation to sea-ice area export rates and hence, the Transpolar Drift, are shown. This new high-resolution pan-Arctic data set can be further utilized and build upon in a variety of atmospheric and oceanographic applications, while still offering room for further improvements such as incorporating high-resolution atmospheric data sets and an optimized lead-detection.
Optimal control problems are optimization problems governed by ordinary or partial differential equations (PDEs). A general formulation is given byrn \min_{(y,u)} J(y,u) with subject to e(y,u)=0, assuming that e_y^{-1} exists and consists of the three main elements: 1. The cost functional J that models the purpose of the control on the system. 2. The definition of a control function u that represents the influence of the environment of the systems. 3. The set of differential equations e(y,u) modeling the controlled system, represented by the state function y:=y(u) which depends on u. These kind of problems are well investigated and arise in many fields of application, for example robot control, control of biological processes, test drive simulation and shape and topology optimization. In this thesis, an academic model problem of the form \min_{(y,u)} J(y,u):=\min_{(y,u)}\frac{1}{2}\|y-y_d\|^2_{L^2(\Omega)}+\frac{\alpha}{2}\|u\|^2_{L^2(\Omega)} subject to -\div(A\grad y)+cy=f+u in \Omega, y=0 on \partial\Omega and u\in U_{ad} is considered. The objective is tracking type with a given target function y_d and a regularization term with parameter \alpha. The control function u takes effect on the whole domain \Omega. The underlying partial differential equation is assumed to be uniformly elliptic. This problem belongs to the class of linear-quadratic elliptic control problems with distributed control. The existence and uniqueness of an optimal solution for problems of this type is well-known and in a first step, following the paradigm 'first optimize, then discretize', the necessary and sufficient optimality conditions are derived by means of the adjoint equation which ends in a characterization of the optimal solution in form of an optimality system. In a second step, the occurring differential operators are approximated by finite differences and the hence resulting discretized optimality system is solved with a collective smoothing multigrid method (CSMG). In general, there are several optimization methods for solving the optimal control problem: an application of the implicit function theorem leads to so-called black-box approaches where the PDE-constrained optimization problem is transformed into an unconstrained optimization problem and the reduced gradient for these reduced functional is computed via the adjoint approach. Another possibilities are Quasi-Newton methods, which approximate the Hessian by a low-rank update based on gradient evaluations, Krylov-Newton methods or (reduced) SQP methods. The use of multigrid methods for optimization purposes is motivated by its optimal computational complexity, i.e. the number of required computer iterations scales linearly with the number of unknowns and the rate of convergence, which is independent of the grid size. Originally multigrid methods are a class of algorithms for solving linear systems arising from the discretization of partial differential equations. The main part of this thesis is devoted to the investigation of the implementability and the efficiency of the CSMG on commodity graphics cards. GPUs (graphic processing units) are designed for highly parallelizable graphics computations and possess many cores of SIMD-architecture, which are able to outperform the CPU regarding to computational power and memory bandwidth. Here they are considered as prototype for prospective multi-core computers with several hundred of cores. When using GPUs as streamprocessors, two major problems arise: data have to be transferred from the CPU main memory to the GPU main memory, which can be quite slow and the limited size of the GPU main memory. Furthermore, only when the streamprocessors are fully used to capacity, a remarkable speed-up comparing to a CPU is achieved. Therefore, new algorithms for the solution of optimal control problems are designed in this thesis. To this end, a nonoverlapping domain decomposition method is introduced which allows the exploitation of the computational power of many GPUs resp. CPUs in parallel. This algorithm is based on preliminary work for elliptic problems and enhanced for the application to optimal control problems. For the domain decomposition into two subdomains the linear system for the unknowns on the interface is solved with a Schur complement method by using a discrete approximation of the Steklov-Poincare operator. For the academic optimal control problem, the arising capacitance matrix can be inverted analytically. On this basis, two different algorithms for the nonoverlapping domain decomposition for the case of many subdomains are proposed in this thesis: on the one hand, a recursive approach and on the other hand a simultaneous approach. Numerical test compare the performance of the CSMG for the one domain case and the two approaches for the multi-domain case on a GPU and CPU for different variants.
Background
In light of the current biodiversity crisis, DNA barcoding is developing into an essential tool to quantify state shifts in global ecosystems. Current barcoding protocols often rely on short amplicon sequences, which yield accurate identification of biological entities in a community but provide limited phylogenetic resolution across broad taxonomic scales. However, the phylogenetic structure of communities is an essential component of biodiversity. Consequently, a barcoding approach is required that unites robust taxonomic assignment power and high phylogenetic utility. A possible solution is offered by sequencing long ribosomal DNA (rDNA) amplicons on the MinION platform (Oxford Nanopore Technologies).
Findings
Using a dataset of various animal and plant species, with a focus on arthropods, we assemble a pipeline for long rDNA barcode analysis and introduce a new software (MiniBar) to demultiplex dual indexed Nanopore reads. We find excellent phylogenetic and taxonomic resolution offered by long rDNA sequences across broad taxonomic scales. We highlight the simplicity of our approach by field barcoding with a miniaturized, mobile laboratory in a remote rainforest. We also test the utility of long rDNA amplicons for analysis of community diversity through metabarcoding and find that they recover highly skewed diversity estimates.
Conclusions
Sequencing dual indexed, long rDNA amplicons on the MinION platform is a straightforward, cost-effective, portable, and universal approach for eukaryote DNA barcoding. Although bulk community analyses using long-amplicon approaches may introduce biases, the long rDNA amplicons approach signifies a powerful tool for enabling the accurate recovery of taxonomic and phylogenetic diversity across biological communities.
Mental processes are filters which intervene in the literary presentation of nature. This article will take you on a journey through literary landscapes, starting from Joseph Furphy and end-ing with Gerald Murnane. It will try to show the development of Australian literary landscape depiction. The investigation of this extensive topic will show that the perception of the Aus-tralian landscape as foreign and threatening is a coded expression of the protagonists" crisis of identity due to their estrangement from European cultural roots. Only a feeling of being at home enables the characters to perceive landscapes in a positive way and allows the author to depict intimate and familiar views of nature. This topic will be investigated with a range of novels to reveal the development of this theme from the turn of the nineteenth century (the time of Furphy- novel Such is Life) up to the present (i.e. novels by Malouf, Foster, Hall, Murnane).
1.The Discursive Construction of Black Masculinity: Intersections of Race, Gender, and Sexuality
1.1.The Plight of Black Men: A History of Lynchings and Castrations
1.2.The Discursive Construction of the Black Man as Otherrn
1.3.Black Corporeality and the Scopic Regime of Racism
2. Ralph Ellison's 'Invisible man'
2.1.Invisible Black Men: Between Emasculation and Hypermasculinityrn
2.2.Transcending Invisibility
During the last decade, anatomic and physiological neuroscience research has yielded extensive information on the physiological regulators of short-term satiety, visceral and interoceptive sensation. Distinct neural circuits regulate the elements of food ingestion physiologically. The general aim of the current studies is to elucidate the peripheral neural pathways to the brain in healthy subjects to establish the groundwork for the study of the pathophysiology of bulimia nervosa (BN). We aimed to define the central activation pattern during non-nutritive gastric distension in humans, and aimed to define the cognitive responses to this mechanical gastric distension. We estimated regional cerebral blood flow with 15O-water positron emission tomography during intragastric balloon inflation and deflation in 18 healthy young women of normal weight. The contrast between inflated minus deflated in the exploratory analysis revealed activation in more than 20 brain regions. The analysis confirmed several well known areas in the central nervous system that contribute to visceral processing: the inferior frontal cortex, representing a zone of convergence for food related stimuli; the insula and operculum referred to as "visceral cortex"; the anterior cingulate gyrus (and insula), processing affective information; and the brainstem, a site of vagal relay for visceral afferent stimuli. Brain activation in the left ventrolateral prefrontal cortex was reproducible. This area is well known for higher cognitive processing, especially reward-related stimuli. The ventrolateral prefrontal cortex with the insular regions may provide a link between the affective and rewarding components of eating and disordered eating as observed in BN and binge-eating obesity. Gastric distension caused a significant rapid, reversible, and reproducible increase in the feelings of fullness, sleepiness, and gastric discomfort as well as a significant rapid, reversible, and reproducible decrease in the feeling of hunger. We showed that mechanical activation of the neurocircuitry involved in meal termination led to the described phenomena. The current brain activation studies of non-painful, proximal gastric distension could provide groundwork in the field of abnormal eating behavior by suggesting a link between visceral sensation and abnormal eating patterns. A potential treatment for disordered eating and obesity could alter the conscious and unconscious perception and interoceptive awareness of gastric distension contributing to meal termination.
The aim of the thesis was to investigate the role of the immune system in fibromyalgia (FM), as part of a dynamic co-regulation between different bodily systems. FM is a chronic musculoskeletal disorder characterized by widespread pain and specific tender points, combined with other symptoms including fatigue, sleep disturbances, morning stiffness and anxiety. The main goal of the work was to identify possible dysregulation of peripheral immune and endocrine parameters in patients with FM compared to matched healthy controls. Moreover, the possible relation between symptom complaints and the specific parameters measured was also evaluated. A first approach was to investigate possible differences between FM patients and controls in the expression of cytokines, as they have been implicated in the occurrence of several of the symptoms associated with FM. Furthermore, adhesion molecules which are involved in cell-to-cell communication and immune cell trafficking were also studied. The latter are known to be regulated by both cytokines and glucocorticoids (GCs) and their expression is often found altered in patients with immune dysregulation. It was expected that subjects with FM would have an increased production of proinflammatory cytokines and/or a reduced antiinflammatory cytokine production and that certain cytokines and/or adhesion molecules would be differently regulated by dexamethasone (DEX). Unstimulated blood was used in the analysis of adhesion molecule expression by flow cytometry while stimulated whole blood cell cultures were used in cytokine flow cytometry assays. Peripheral blood mononuclear cells (PBMCs) were also cultured and the supernatants collected to determine the concentration of cytokines by biochip protein array. In addition, serum samples were used in enzyme-linked immunosorbent assays (ELISA) for quantification of soluble adhesion molecules. L-selectin was found elevated on monocytes and neutrophils of FM patients. A bias toward lower IL-4 levels was observed in FM patients. Based on studies showing differences in glucocorticoid receptor (GR) affinity and disturbances associated with loss of hypothalamic-pituitary-adrenal (HPA) axis resiliency in FM, it was hypothesized whether FM would be associated with abnormalities in glucocorticoid sensitivity. Total plasma cortisol and salivary free cortisol were quantified by ELISA and time-resolved fluorescence immunoassay, respectively. GR sensitivity through DEX inhibition of IL-6, in stimulated whole blood, was evaluated after cytokine quantification by ELISA. The corticosteroid receptors, GR alpha and mineralocorticoid receptor (MR), as well as the glucocorticoid-induced leucine zipper (GILZ) and the FK506 binding protein 5 mRNA expression were assessed in PBMCs by real-time reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, sequencing of RT-PCR products and/or genomic DNA was used for mutational analysis of the corticosteroid receptors. We observed lower basal plasma cortisol levels (borderline statistical significance) and a lower expression of corticosteroid receptors and GILZ in FM patients when compared to healthy controls. The minor allele of the MR single nucleotide polymorphism (SNP) rs5522 was found more often in FM patients than in controls. In addition, female carriers of this SNP seemed to have reduced salivary cortisol responses to a strong psychological stressor (Trier Social Stress Test) compared to non-carriers. FM patient carriers of an MR intronic SNP (rs17484245), before exon 3, were associated with significantly higher scores of depression symptoms compared to patient non-carriers. The thesis includes also a comprehensive analysis of the complexity of GR regulation and the role of alternative mRNA splicing. It focuses on the differential expression of the untranslated GR first exons, their high sequence homology among different species and how genetic determinants, without apparent relevance, may have implications in health and disease. In FM patients, GR exon 1-C expression was found lower and a significant difference was observed when comparing GR 1-C expression between antidepressant-free and patients who had taken antidepressants until two weeks before sample collection. In summary, the study shows a slight disturbance of some components of the innate immune system of FM patients and suggests an enhanced adhesion and possible recruitment of leukocytes to inflammatory sites. The reduced expression of corticosteroid receptors and possibly the reduced MR function may be associated with an impaired function of the HPA axis in these patients. A hyporesponsiveness of the HPA axis under stress or disturbances of the stress response could make these patients more vulnerable to cytokines and inflammation which, compounded by lower antiinflammatory mediators, may sustain some of the symptoms that contribute to the clinical picture of FM.
Background and rationale: Changing working conditions demand adaptation, resulting in higher stress levels in employees. In consequence, decreased productivity, increasing rates of sick leave, and cases of early retirement result in higher direct, indirect, and intangible costs. Aims of the Research Project: The aim of the study was to test the usefulness of a novel translational diagnostic tool, Neuropattern, for early detection, prevention, and personalized treatment of stress-related disorders. The trial was designed as a pilot study with a wait list control group. Materials and Methods: In this study, 70 employees of the Forestry Department Rhineland-Palatinate, Germany, were enrolled. Subjects were block-randomized according to the functional group of their career field, and either underwent Neuropattern diagnostics immediately, or after a waiting period of three months. After the diagnostic assessment, their physicians received the Neuropattern Medical Report, including the diagnostic results and treatment recommendations. Participants were informed by the Neuropattern Patient Report, and were eligible to an individualized Neuropattern Online Counseling account. Results: The application of Neuropattern diagnostics significantly improved mental health and health-related behavior, reduced perceived stress, emotional exhaustion, overcommitment and possibly, presenteeism. Additionally, Neuropattern sensitively detected functional changes in stress physiology at an early stage, thus allowing timely personalized interventions to prevent and treat stress pathology. Conclusion: The present study encouraged the application of Neuropattern diagnostics to early intervention in non-clinical populations. However, further research is required to determine the best operating conditions.
Many NP-hard optimization problems that originate from classical graph theory, such as the maximum stable set problem and the maximum clique problem, have been extensively studied over the past decades and involve the choice of a subset of edges or vertices. There usually exist combinatorial methods that can be applied to solve them directly in the graph.
The most simple method is to enumerate feasible solutions and select the best. It is not surprising that this method is very slow oftentimes, so the task is to cleverly discard fruitless search space during the search. An alternative method to solve graph problems is to formulate integer linear programs, such that their solution yields an optimal solution to the original optimization problem in the graph. In order to solve integer linear programs, one can start with relaxing the integer constraints and then try to find inequalities for cutting off fractional extreme points. In the best case, it would be possible to describe the convex hull of the feasible region of the integer linear program with a set of inequalities. In general, giving a complete description of this convex hull is out of reach, even if it has a polynomial number of facets. Thus, one tries to strengthen the (weak) relaxation of the integer linear program best possible via strong inequalities that are valid for the convex hull of feasible integer points.
Many classes of valid inequalities are of exponential size. For instance, a graph can have exponentially many odd cycles in general and therefore the number of odd cycle inequalities for the maximum stable set problem is exponential. It is sometimes possible to check in polynomial time if some given point violates any of the exponentially many inequalities. This is indeed the case for the odd cycle inequalities for the maximum stable set problem. If a polynomial time separation algorithm is known, there exists a formulation of polynomial size that contains a given point if and only if it does not violate one of the (potentially exponentially many) inequalities. This thesis can be divided into two parts. The first part is the main part and it contains various new results. We present new extended formulations for several optimization problems, i.e. the maximum stable set problem, the nonconvex quadratic program with box
constraints and the p-median problem. In the second part we modify a very fast algorithm for finding a maximum clique in very large sparse graphs. We suggest and compare three alternative versions of this algorithm to the original version and compare their strengths and weaknesses.
No Longer Printing the Legend: The Aporia of Heteronormativity in the American Western (1903-1969)
(2023)
This study critically investigates the U.S.-American Western and its construction of sexuality and gender, revealing that the heteronormative matrix that is upheld and defended in the genre is consistently preceded by the exploration of alternative sexualities and ways to think gender beyond the binary. The endeavor to naturalize heterosexuality seems to be baked in the formula of the U.S.-Western. However, as I show in this study, this endeavor relies on an aporia, because the U.S.-Western can only ever attempt to naturalize gender by constructing it first, hence inevitably and simultaneously construct evidence that supports the opposite: the unnaturalness and contingency of gender and sexuality.
My study relies on the works of Raewyn Connell, Pierre Bourdieu, and Judith Butler, and amalgamates in its methodology established approaches from film and literary studies (i.e., close readings) with a Foucaultian understanding of discourse and discourse analysis, which allows me to relate individual texts to cultural, socio-political and economical contexts that invariably informed the production and reception of any filmic text. In an analysis of 14 U.S.-Westerns (excluding three excursions) that appeared between 1903 and 1969 I give ample and minute narrative and film-aesthetical evidence to reveal the complex and contradictory construction of gender and sexuality in the U.S.-Western, aiming to reveal both the normative power of those categories and its structural instability and inconsistency.
This study proofs that the Western up until 1969 did not find a stable pattern to represent the gender binary. The U.S.-Western is not necessarily always looking to confirm or stabilize governing constructs of (gendered) power. However, it without fail explores and negotiates its legitimacy. Heterosexuality and male hegemony are never natural, self-evident, incontestable, or preordained. Quite conversely: the U.S.-Western repeatedly – and in a surprisingly diverse and versatile way – reveals the illogical constructedness of the heteronormative matrix.
My study therefore offers a fresh perspective on the genre and shows that the critical exploration and negotiation of the legitimacy of heteronormativity as a way to organize society is constitutive for the U.S.-Western. It is the inquiry – not necessarily the affirmation – of the legitimacy of this model that gives the U.S.-Western its ideological currency and significance as an artifact of U.S.-American popular culture.
Nonlocal operators are used in a wide variety of models and applications due to many natural phenomena being driven by nonlocal dynamics. Nonlocal operators are integral operators allowing for interactions between two distinct points in space. The nonlocal models investigated in this thesis involve kernels that are assumed to have a finite range of nonlocal interactions. Kernels of this type are used in nonlocal elasticity and convection-diffusion models as well as finance and image analysis. Also within the mathematical theory they arouse great interest, as they are asymptotically related to fractional and classical differential equations.
The results in this thesis can be grouped according to the following three aspects: modeling and analysis, discretization and optimization.
Mathematical models demonstrate their true usefulness when put into numerical practice. For computational purposes, it is important that the support of the kernel is clearly determined. Therefore nonlocal interactions are typically assumed to occur within an Euclidean ball of finite radius. In this thesis we consider more general interaction sets including norm induced balls as special cases and extend established results about well-posedness and asymptotic limits.
The discretization of integral equations is a challenging endeavor. Especially kernels which are truncated by Euclidean balls require carefully designed quadrature rules for the implementation of efficient finite element codes. In this thesis we investigate the computational benefits of polyhedral interaction sets as well as geometrically approximated interaction sets. In addition to that we outline the computational advantages of sufficiently structured problem settings.
Shape optimization methods have been proven useful for identifying interfaces in models governed by partial differential equations. Here we consider a class of shape optimization problems constrained by nonlocal equations which involve interface-dependent kernels. We derive the shape derivative associated to the nonlocal system model and solve the problem by established numerical techniques.
In this psycho-neuro-endocrine study the molecular basis of different variants of steroid receptors as well as highly conserved non steroidal receptors was investigated. These nuclear receptors (NRs) are important key regulators of a wide variety of different physiological and pathophysiological challenges ranging from inflammation and stress to complex behaviour and disease. NRs control gene transcription in a ligand dependent manner and are embedded in the huge interaction network of the neuroendocrine and immune system. Two receptors, the glucocorticoid receptor (GR) and the chicken ovalbumin upstream promoter-transcription factorII (Coup-TFII), both expressed in the immune and nervous system, were investigated regarding possible splice variants and their implication in the control of gene transcription. Both NRs are known to interact and modulate each other- target gene regulation. This study could be shown that both NRs have different splice variants that are expressed in a tissue specific manner. The different 5-´alternative transcript variants of the human GR were in silico identified in other species and evidence for a highly conserved and tightly controlled function was provided. Investigations of the N-terminal transactivation domain of the GR showed a deletion suggesting an altered glucocorticoid-dependent transactivation profile. The newly identified alternative transcript variant of Coup-TFII leads to a DNA binding deficient Coup-TFII isoform that is highly expressed in the brain. This Coup-TFII isoform alters Coup-TFII target gene expression and is suggested to interact with GR via its ligand binding domain resulting in an impaired GR target gene regulation in the nervous system. In this thesis it was demonstrated that NR variants are important for the understanding of the enormous regulatory potential of this receptor family and have to be taken into account for the development of therapeutic strategies for complex diseases such as stress related and neurodegenerative disorders.