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See detailLiquidity risk in capital markets
Busch, Thomas UL

Doctoral thesis (2013)

This thesis focuses on liquidity risk in capital markets. The main aim is to help practitioners to better understand and manage liquidity risk by analyzing the following three topics: modeling ... [more ▼]

This thesis focuses on liquidity risk in capital markets. The main aim is to help practitioners to better understand and manage liquidity risk by analyzing the following three topics: modeling correlations in a Liquidity Adjusted VaR (L − VaR) (Chapter Three), impact of regulatory interventions on stock liquidity (Chapter Four) and liquidity commonality and option prices (Chapter Five). The first topic focuses on an appropriate way to measure expected stock losses by considering liquidity risk (see Chapter Three). The need for a new measure, which also includes stock liquidity, is based on the concern of investors only being able to sell stock at a huge discount or not at all. In reaction, various papers with new methodologies have been published, including the liquidity adjusted Value at Risk (L − VaR) models proposed by Bangia et al. (1998) and Ernst et al. (2012). Based on their approach, we analyze different ways to extend these models and to optimize performance. This is done using advanced conditional volatility models like AR − GARCH and AR − GJR models and by considering correlations between spread and return data. The new model is called correlation and liquidity adjusted VaR (CL – VaR) and shows (based on a five-year observation period) better performance compared to the models by Bangia et al. (1998) and Ernst et al. (2012). The models are calculated and back-tested using unique data called Xetra Liquidity Measure (XLM) provided by Deutsche Börse. The collapse of Lehman Brothers in 2008 marked the beginning of a financial crisis affecting the entire world of finance. This period is characterized by increasing fear of further defaults by corporations (including banks) or even by countries. In reaction, investors began shifting their assets to more stable and secure investments and this resulted in stock market crashes. Various interventions were made by government institutions to restore stability. The target of the second topic is to analyze the impact of these interventions on liquidity (measured by volume-weighted bid-ask spreads) and market reaction (measured by returns) at the announcement date (see Chapter Four). In the event, we study abnormal changes of stocks listed on the Dax. The interventions which we consider are published by the Federal Reserve Bank (FED) in the form of a crisis time-line. Here they are further combined to the following categories: bank liability guarantees, liquidity and rescue interventions, unconventional monetary policy and other market intervention. The results show that, for example, the market reacts positively to liquidity and rescue interventions, whereas bank liability guarantees reduce liquidity. In addition, we show that international events have a significant impact on the domestic market in a "spillover effect". By analyzing the spreads of different traded volumes, an asymmetric increase can be detected at the announcement date. The last topic focuses on the link between equity and option markets (see Chapter Five). There we analyze, on one hand, the link between stock market liquidity and option prices and, on the other hand, the impact of liquidity commonality in equity and option markets. We can show that systematic liquidity (rather than idiosyncratic liquidity) gives a better explanation of changes in “at-the-money” implied volatility. This effect was especially strong during the financial crisis in 2008. Another result is that liquidity risk of higher traded stock volumes is not properly reflected in the option price. This can result in higher hedging costs, as mentioned by Certin et al. (2006). To shed more light into liquidity commonality within the stock market we calculate the LiqCom measure as mentioned by Chordia et al. (2000). The results show a continuously changing liquidity commonality which decreases with increasing traded volume. This is because the market maker focuses for bigger stock positions more on the idiosyncratic liquidity risks while for smaller stock positions the systematic liquidity risk is more important. We confirmed our findings with a robustness check. [less ▲]

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See detailImpact des glucocorticoïdes plasmatiques sur la maturation et le fonctionnement de l'inhibition spinale GABAergique
Zell, Vivien UL

Doctoral thesis (2013)

Glucocorticoids (GC) such as corticosterone (CORT) in rats are synthetized following stress and HPA axis activation and are part of organisms response to homeostasis perturbations. Furthermore, GC can ... [more ▼]

Glucocorticoids (GC) such as corticosterone (CORT) in rats are synthetized following stress and HPA axis activation and are part of organisms response to homeostasis perturbations. Furthermore, GC can also alter pain perception. [less ▲]

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See detailEnforced privacy: from practice to theory
Dong, Naipeng UL

Doctoral thesis (2013)

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See detailPaysages silencieux dans le roman réaliste (1850-1900)
Thiltges, Sébastian UL

Doctoral thesis (2013)

En Europe et depuis le romantisme, les arts et la littérature font apparaître le paysage silencieux comme une représentation esthétique, une création culturelle ou un espace reflétant une expérience ... [more ▼]

En Europe et depuis le romantisme, les arts et la littérature font apparaître le paysage silencieux comme une représentation esthétique, une création culturelle ou un espace reflétant une expérience singulière de communion avec la nature. D’une part, le paysage, qui se définit à partir du point de vue du sujet, est par essence subjectif. D’autre part, le silence paysager, dans son acception générale d’absence de bruit ou de son, est un phénomène théorique, non définissable et non mesurable objectivement. En réaction à ce qu’il dénonce comme une projection lyrique de la subjectivité humaine sur le monde contemplé, le réalisme propose l’exploration scientifique de la nature observée et vise une pratique descriptive basée de prime abord sur la représentation objective du paysage. Au silence romantique, dans lequel tout est langage, s’oppose un silence réaliste, musellement du créateur et constat du mutisme et de l’indifférence du monde environnant. Les influences de la science et du positivisme ont métamorphosé le regard de l’être humain sur le monde sensible et ont ouvert de nouveaux mondes qu’explorent les romanciers. Simultanément, la disparition de la figure humaine dans l’art paysager témoigne du bouleversement épistémique qui engendre une nouvelle révolution copernicienne dans laquelle l’homme n’est plus le centre du monde et de la connaissance. Le détournement réaliste du topos romantique est problématique en ce qu’il refuse la représentation subjective de la nature, qui pourtant s’est avérée être un modèle efficace, tout en butant sur l’impossible représentation objective d’un motif insaisissable. De ce double échec constitutif de la modernité du réalisme naît une poétique descriptive du paysage qui offre une vision nouvelle du monde, basée non seulement sur le positivisme et le déterminisme, mais également sur la contingence du monde, témoignant d’un certain scepticisme envers les signes. Dans le sillage de ces évolutions esthétiques et poétiques, le regard et l’horizon du lecteur sur le roman se transforment également. La description du paysage silencieux constitue un espace textuel dans lequel le sens est perpétuellement mis en suspens. Les analogies entre l’écoute du paysage et l’écoute du texte romanesque, entre le paysage silencieux et la lecture silencieuse, permettent de définir une phénoménologie de la description réaliste du paysage silencieux. La construction d’un paysage polysensoriel ainsi que l’association du paysage et du silence, deux concepts pluridisciplinaires, soulignent l’importance de la perception et mettent en exergue la figure de l’interprétant. Le lecteur reconnaît et comprend la référentialité de la description littéraire réaliste, tout en faisant l’expérience, au sein du silence de la page, de la face sonore du signifiant poétique. De la description du paysage silencieux se dégagent un modèle heuristique et un enseignement de lecture, tant au niveau diégétique – les personnages ou le narrateur tentant de percer le silence du paysage – que textuel – le lecteur déchiffrant la signifiance de la description romanesque. [less ▲]

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See detailNetwork analysis to model diseases and cellular reprogramming for therapeutic intervention
Crespo, Isaac UL

Doctoral thesis (2013)

Applications of network analysis to the study of disease can be divided into two main categories: disease description, including characterisation, diagnosis and prognosis; and disease treatment, including ... [more ▼]

Applications of network analysis to the study of disease can be divided into two main categories: disease description, including characterisation, diagnosis and prognosis; and disease treatment, including drug target discovery and cellular reprogramming, together with its applications to regenerative medicine. In this dissertation, I will critically discuss some research projects on which I have been working during my PhD program. In correspondence with the two aforementioned categories, these projects can be broken down into two different blocks of content, with the common goal of acquiring insights into the study of disease. In the first block of contents, corresponding with Chapter 2, I will explain and discuss novel strategies for network-based analysis and modelling which have been applied for disease description and characterisation in different case-studies, namely the metabolic syndrome, prion disease and the epithelial to mesenchymal transition in breast cancer. Indeed, these projects exploited the evolutionary conservation of motifs of regulatory interactions and consistency between computed and experimentally validated expression so as to reconstruct dynamical models and create a network-based characterisation of the corresponding systems. With regards the second block of content, corresponding with Chapter 3, I explain and discuss novel computational methods which have been developed during my PhD program to address the task of the artificial induction of cellular reprogramming; something with a wealth of potential applications when it comes to the creation of disease models and in the field of regenerative medicine. Within the general conclusion discussion focuses on the fact that, although the methodology explained in this work was developed in the context of disease study, one may find the application of some of these ideas and strategies fitting for other problems. Indeed, the same principles applied to detect driver genes capable of changing the cell phenotype when perturbed can also be applied to control biological living systems for basic research or industrial purposes. These principles could also be potentially extended to higher level systems than the cellular level (tissue or cell population level). [less ▲]

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See detailDevelopment of adhesives constitutive material laws for the assessment of bonded steel to glass partial composite beams
Dias, Vincent UL

Doctoral thesis (2013)

Glass products are widely employed in transparent facade and roof structures as tertiary non-structural elements despite their large in-plane compressive resistances. To structurally implement them in ... [more ▼]

Glass products are widely employed in transparent facade and roof structures as tertiary non-structural elements despite their large in-plane compressive resistances. To structurally implement them in building, tensile stresses must be consequently reduced or avoided. The later requirements would be fulfilled by realizing composite steel to glass connection, whose principal difficulty would arose from the connection mean which should be sufficiently rigid to transfer shear forces and sufficiently soft to not alter the glazing. Two possible jointing methods were envisaged and investigated to accomplish this assembly and overcome this problem, i.e. a linear adhesive bonding of the steel and glass parts and a mixed mechanical-adhesive connection. In consequence, two potential adhesives were selected, a silicone elastomer and a UV-curing acrylic thermoset. A lack of knowledge with regards to their mechanical properties implied the conduction of several series of quasi-static, cyclic and long-term relaxation tests. The possible influence of external parameters, such as temperature, humidity or UV-radiation, on their uniaxial tension/compression and shear behaviours was evaluated with the help of statistical methods applied on the results of Taguchi design of experiments tables. With the invariance of the silicone properties, a new hyperelastic quasi-incompressible constitutive material law accounting for the quasi-static and post Mullins effect behaviour was developed and validated with finite element analyzes of the small-scale experimental tests. The UV-acrylic was however found strongly dependent on the loading rate and one-dimensional models were suggested to describe the quasi-static tension and shear behaviour under specific rates. In reason of the poor long-term properties of the UV-acrylic, only the silicone was regarded for the construction of the two types of composite beams. Pre-evaluations issued from numerical simulations including the developed material law accommodated perfectly with theoretical data and approached the large-scale tests results by considering the manufacturing operations conducted on the steel beam. [less ▲]

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See detailAttack-defense trees
Schweitzer, Patrick UL

Doctoral thesis (2013)

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See detailTowards the Formal Verification of Model Transformations: An Application to Kermeta
Amrani, Moussa UL

Doctoral thesis (2013)

Model-Driven Engineering (MDE) is becoming a popular engineering methodology for developing large-scale software applications, using models and transformations as primary principles. MDE is now being ... [more ▼]

Model-Driven Engineering (MDE) is becoming a popular engineering methodology for developing large-scale software applications, using models and transformations as primary principles. MDE is now being successfully applied to domain-specific languages (DSLs), which target a narrow subject domain like process management, telecommunication, product lines, smartphone applications among others, providing experts high-level and intuitive notations very close to their problem domain. More recently, MDE has been applied to safety-critical applications, where failure may have dramatic consequences, either in terms of economic, ecologic or human losses. These recent application domains call for more robust and more practical approaches for ensuring the correctness of models and model transformations. Testing is the most common technique used in MDE for ensuring the correctness of model transformations, a recurrent, yet unsolved problem in MDE. But testing suffers from the so-called coverage problem, which is unacceptable when safety is at stake. Rather, exhaustive coverage is required in this application domain, which means that transformation designers need to use formal analysis methods and tools to meet this requirement. Unfortunately, two factors seem to limit the use of such methods in an engineer’s daily life. First, a methodological factor, because MDE engineers rarely possess the effective knowledge for deploying formal analysis techniques in their daily life developments. Second, a practical factor, because DSLs do not necessarily have a formal explicit semantics, which is a necessary enabler for exhaustive analysis. In this thesis, we contribute to the problem of formal analysis of model transformations regarding each perspective. On the conceptual side, we propose a methodological framework for engineering verified model transformations based on current best practices. For that purpose, we identify three important dimensions: (i) the transformation being built; (ii) the properties of interest ensuring the transformation’s correctness; and finally, (iii) the verification technique that allows proving these properties with minimal effort. Finding which techniques are better suited for which kind of properties is the concern of the Computer-Aided Verification community. Consequently in this thesis, we focus on studying the relationship between transformations and properties. Our methodological framework introduces two novel notions. A transformation intent gathers all transformations sharing the same purpose, abstracting from the way the transformation is expressed. A property class captures under the same denomination all properties sharing the same form, abstracting away from their underlying property languages. The framework consists of mapping each intent with its characteristic set of property classes, meaning that for proving the correctness of a particular transformation obeying this intent, one has to prove properties of these specific classes. We illustrate the use and utility of our framework through the detailed description of five common intents in MDE, and their application to a case study drawn from the automative software domain, consisting of a chain of more than thirty transformations. On a more practical side, we study the problem of verifying DSLs whose behaviour is expressed with Kermeta. Kermeta is an object-oriented transformation framework aligned with Object Management Group standard specification MOF (Meta-Object Facility). It can be used for defining metamodels and models, as well as their behaviour. Kermeta lacks a formal semantics: we first specify such a semantics, and then choose an appropriate verification domain for handling the analysis one is interested in. Since the semantics is defined at the level of Kermeta’s transformation language itself, our work presents two interesting features: first, any DSL whose behaviour is defined using Kermeta (more precisely, any transformation defined with Kermeta) enjoys a de facto formal underground for free; second, it is easier to define appropriate abstractions for targeting specific analysis for this full-fledged semantics than defining specific semantics for each possible kind of analysis. To illustrate this point, we have selected Maude, a powerful rewriting system based on algebraic specifications equipped with model-checking and theorem-proving capabilities. Maude was chosen because its underlying formalism is close to the mathematical tools we use for specifying the formal semantics, reducing the implementation gap and consequently limiting the possible implementation mistakes. We validate our approach by illustrating behavioural properties of small, yet representative DSLs from the literature. [less ▲]

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See detailDerived D-Geometry and Field Theory
Bonavolonta, Giuseppe UL

Doctoral thesis (2013)

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See detailThe relationship between intelligence and health in Luxembourg
Wrulich, Marius UL

Doctoral thesis (2013)

Even though the general health and life expectancies of Western societies have been consistently rising throughout the 20th century, socioeconomic health inequalities continue to persist. Individuals from ... [more ▼]

Even though the general health and life expectancies of Western societies have been consistently rising throughout the 20th century, socioeconomic health inequalities continue to persist. Individuals from lower socioeconomic groups have substantially worse health and an increased mortality risk compared to individuals from higher socioeconomic groups. As external factors such as material resources cannot fully account for these health inequalities, personal factors such as intellectual abilities have been suggested as additional important explanatory factors. The research field concerned with the effects of intelligence on different health outcomes is called cognitive epidemiology. Results from this field of research have now established that childhood intelligence is an important predictor of different health outcomes in adulthood. Specifically, children with higher intelligence exhibit a lower mortality risk and enjoy better health in adulthood compared to children with lower childhood intelligence. Despite these findings, several open research questions remain: (1) Almost all previous studies on the relation between childhood intelligence and adult health have been conducted in English-speaking or Scandinavian countries. Can these findings be generalized to countries with different cultural backgrounds, health-care systems, or levels of social mobility? Specifically, Luxembourg offers universal access to quality health care, which may compensate for some of the effects of individual differences in intelligence on health, and as a result, intelligence may lose its impact. (2) Physical health is a multidimensional concept with three distinct subdimensions: a physical subdimension (e.g., presence of diagnosed diseases, number of doctor visits in a certain time period), a subjective subdimension (e.g., satisfaction with one’s own health), and a (social-)functional subdimension (e.g., unimpaired participation in social and occupational activities or performing household tasks). Most previous studies on the relation between intelligence and health outcomes have focused on the physical health subdimension. Hence, considerably less is known about the effects of intelligence on the functional and subjective subdimensions. This issue is of particular importance as childhood intelligence may be differentially related to different aspects of adult health. (3) It remains unclear whether different facets of childhood intelligence (e.g., general, fluid, or crystallized intelligence) predict adult health equally well, as most studies on the topic have used only global measures of childhood intelligence to predict later health. However, investigating different facets of childhood intelligence as predictors of adult health would provide insights into which facets of intelligence are important in personal health management and could be targeted by interventions. (4) Despite considerable evidence that has emphasized the relevance of education and further indicators of subsequent socioeconomic status (SES) as potential mediators between childhood intelligence and later health outcomes, previous research has yielded inconsistent results regarding the extent to which these relations are mediated. Some studies have reported pronounced mediation via education and subsequent SES, yet others have reported little or no mediation. However, knowing and understanding which mediational mechanisms underlie the intelligence-health relation and the extent to which they mediate this relation are crucial for applying findings from cognitive epidemiology to public health. (5) As is the case for studies on intelligence and health outcomes, most studies on the relation between intelligence and mortality risk have been conducted in English-speaking or Scandinavian countries. Thus, it remains unclear whether the results of these studies can be generalized to Luxembourg. Further, there is controversy about whether the effect of intelligence on mortality exists across the entire range of intelligence scores or whether individuals at the lower end of the intelligence distribution constitute a risk group with a particularly high mortality risk. Identifying potential risk groups is crucial for determining which groups should be targeted by interventions to reduce inequalities in health and mortality risk. The present Ph.D. thesis addressed these five research questions with three distinctive studies. Study I investigated whether childhood intelligence would predict adult physical, functional, and subjective health 40 years later even when controlling for the effects of childhood SES. Study I also investigated whether a global measure of childhood general intelligence or whether more specific facets such as fluid and crystallized intelligence would better predict adult health. Study II investigated whether and the extent to which educational attainment and SES in adulthood would mediate the effects of childhood intelligence on the three adult health dimensions. Study III investigated whether childhood intelligence would predict adult mortality risk when controlling for childhood SES and whether individuals at the lower end of the intelligence distribution would constitute a risk group with a particularly high mortality risk. All three studies were embedded in the general framework of the Luxembourgish MAGRIP project. This large-scale longitudinal study comprised two waves of measurement over a 40-year period. In the first wave of measurement in 1968, detailed intelligence and socioeconomic data were collected on a randomly selected nationally representative sample comprising 2,824 students at the end of their primary education (M = 11.9 years; SD = 0.6 years; 50.1% male). In the second wave conducted 40 years later, 745 participants (M = 51.7 years, SD = 0.6 years; 46.7% male) provided data on their educational careers, adult SES, and functional, subjective, and physical health. In addition, the mortality rate was established for the participants in the first wave of MAGRIP: 166 participants (69.9% male) had died. The results of the three studies demonstrated that childhood intelligence, particularly childhood fluid intelligence, showed a significant association with adult health: Lower childhood intelligence scores were associated with worse health outcomes on all three dimensions of physical, functional, and subjective health in adulthood, even when controlling for childhood SES. These effects were entirely mediated via educational attainment and adult SES, with educational attainment playing a crucial role in these mediational processes. Further, childhood intelligence showed a significant association with adult mortality such that lower childhood intelligence scores were associated with an increased mortality risk. This effect was particularly strong among men at the lower end of the intelligence distribution. These results suggest that even high-quality public health care cannot fully offset the cumulative effects of childhood intelligence on adult health. Intelligence may thus be an important explanatory factor for socioeconomic inequalities in health. Promising means for reducing these socioeconomic health inequalities consist of interventions that are designed to improve childhood intelligence, to improve environments for childhood physical and intellectual development, and to make public health care and preventive measures or treatments accessible to adults with lower intellectual abilities. [less ▲]

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See detailThe impact of childhood intelligence on subjective well-being in adulthood
Chmiel, Magda UL

Doctoral thesis (2013)

Detailed reference viewed: 64 (13 UL)
See detailGame-theory and Logic for Non-repudiation Protocols and Attack Analysis
Melissen, Matthijs UL

Doctoral thesis (2013)

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See detailModelling Metabolic Interactions in the Legume-Rhizobia Symbiosis
Pfau, Thomas UL

Doctoral thesis (2013)

With the emergence of “omics” techniques, it has become essential to develop tools to utilise the vast amount of data produced by these methods. Genome-scale metabolic models represent the mathematical ... [more ▼]

With the emergence of “omics” techniques, it has become essential to develop tools to utilise the vast amount of data produced by these methods. Genome-scale metabolic models represent the mathematical essence of metabolism and can easily be linked to the data from omics sources. Such models can be used for various analyses, including the investigation of metabolic responses to changing environmental conditions. Legumes are known for their ability to form a nitrogen-fixing symbiosis with rhizobia, a vital process that provides the biosphere with the majority of its nitrogen content. In the present thesis, a genome-scale metabolic model for the legume Medicago truncatula was reconstructed, based on the annotated genome sequence and the MedicCyc database. A novel approach was employed to define the compartmentalisation of the plant’s metabolism. The model was used to calculate the biosynthetic costs of biomass precursors (e.g. amino acids, sugars, fatty acids, nucleotides), and its capability to produce biomass in experimentally observed ratios was demonstrated using flux balance analysis. Further investigation was carried out into how the biosynthesis fluxes and costs change with respect to different nitrogen sources. The precise charge balancing of all reactions in the model allowed the investigation of the effects of charge transport over the cellular membrane. The simulations showed a good agreement with experimental data in using different sources of nitrogen (ammonium and nitrate) to minimise the charge transport of the membrane. To allow the investigation of the symbiotic relationship, two rhizobial models were used. The first model, for Sinorhizobium meliloti, was reconstructed from the MetaCyc database (MC-model); the second model was a recently published model for S. meliloti specialised for symbiotic nitrogen fixation (SNF-model). Combined models were created for both rhizobial networks using a specialised nodule submodel of the plant model. Potential interactions were extracted from the literature and investigated, with the analysis suggesting that oxygen availability is the main limitation factor in symbiotic nitrogen fixation. Within the analysis the SNF-model appeared to be too restricted and lacking the potential for sufficient nitrogen fixation; therefore, further analysis was carried out using the MC-model, upon which it was observed that the availability of oxygen can also influence how nitrogen is supplied to the plant. At high oxygen concentrations ammonia is the primary form of nitrogen supplied by the rhizobium. However, the simulations, in accordance with experimental data, show that at lower concentrations of oxygen, alanine takes precedence. The findings also support the concept of amino acid cycling as a potential way to improve nitrogen fixation. The more flexible MetaCyc based model has allowed other potential genetic engineering approaches for higher nitrogen fixation yields to be proposed. [less ▲]

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See detailZum Tragverhalten von Verbunddecken mit Holzleichtbeton im Hochbau
May, Andreas UL

Doctoral thesis (2013)

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See detailZUM TRAGVERHALTEN VON VERBUNDDECKEN MIT HOLZLEICHTBETON IM HOCHBAU
May, Andreas UL

Doctoral thesis (2013)

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See detailMolecular Eco-Systems Biology of Lipid Accumulating Microbial Communities in Biological Wastewater Treatment Plants
Roume, Hugo UL

Doctoral thesis (2013)

Biological wastewater treatment is based on the use of microorganisms capable of intense metabolic activity that results in the removal of a large proportion of organic and inorganic contaminants. Given ... [more ▼]

Biological wastewater treatment is based on the use of microorganisms capable of intense metabolic activity that results in the removal of a large proportion of organic and inorganic contaminants. Given copious amounts of energy-dense organic molecules such as lipids accumulated by the microbial biomass, chemical energy may be directly harnessed from this for biofuel production. Here, lipid accumulating organism (LAO)-enriched microbial communities were studied using a molecular eco-systems biology approach. This involved the development of necessary methodologies including a new comprehensive biomolecular extraction method, yielding high-quality DNA, RNA, proteins and metabolites, as well as bioinformatic approaches for integrating and analysing the derived high-throughput genomic, transcriptomic, proteomic and metabolomic data. At the inception of the project, a full-scale wastewater treatment plant (WWTP) system with a strong presence of LAOs especially during winter months, i.e. the Schifflange WWTP (Esch-sur-Alzette, Luxembourg), was identified and selected for further study. 16S rRNA amplicon sequencing highlighted the presence of ubiquitous lipid accumulating bacteria closely related to Candidatus Microthrix parvicella which increase in abundance from autumn to winter over other highly abundant community members belonging to Alkanindiges spp. and Acinetobacter spp. In order to elucidate compositional, genetic and functional differences between autumn and winter LAO communities, a comparative integrative omic analysis was carried out on rationally selected autumn and winter LAO community samples. The results from metabolomic/lipidomic analyses between intra- and extracellular compartments support previous models of uptake of unprocessed long chain fatty acids (LCFAs) from the wastewater environment and their storage as triacyglycerols within LAOs. Furthermore, a tailored computational framework for the integration of multi-omic datasets into reconstructed community-wide metabolic networks and models was developed. The resulting networks provide overviews of functional capacity of the sampled LAO communities by incorporating gene copy numbers, transcript levels and protein frequency across the two studied environmental conditions. The identification of genes overexpressed, strongly associated with a specific season and/or possessing a high clustering coefficient suggests the existence of keystone genes, analogous to keystone species in species interaction networks. Examples of such keystone genes in the context of the LAO communities include genes coding for proteins involved in nitrogen and glycerolipid metabolism. The existence of such keystone genes opens up exciting possibilities for prediction and control strategies of microbial communities at the dawn of the field of Eco-Systems Biology. [less ▲]

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See detailDirect and Indirect Measures of Learning in Visual Search
Reuter, Robert UL

Doctoral thesis (2013)

In this thesis, we will explore direct and indirect measures of learning in a visual search task commonly called contextual cueing. In the first part, we present a review of the scientific literature on ... [more ▼]

In this thesis, we will explore direct and indirect measures of learning in a visual search task commonly called contextual cueing. In the first part, we present a review of the scientific literature on contextual cueing, in order to give the readers of this thesis a better general idea of existing evidence and open questions within this relatively new research field. The aims of our own experimental studies presented in the succeeding chapters are the following ones: (1) to replicate and extend the findings described in the various papers by Marvin Chun and various colleagues on contextual cueing of visual attention; (2) to explore the nature of memory representations underlying the observed learning effects, especially whether learning is actually implicit and whether memory representations are distinctive, episodic and instance-based or rather distributed, continuous and graded; (3) to extend the study of contextual cueing to more realistic visual stimuli, in order to test its robustness across various situations and validate its adaptive value in ecologically sound conditions; and (4) to investigate whether such knowledge about the association between visual contexts and “meaningful” locations can be (automatically) transferred to other tasks, namely a change detection task. In a first series of four experiments, we tried to replicate the documented contextual cueing effect using a wide range of various direct measures of learning (tasks that are supposed to be related to explicit knowledge) and we systematically varied the distinctiveness of context configurations to study its effect on both direct and indirect measures of learning. We also ran a series of neural network simulations (briefly described in the general discussion of this thesis), based on a very simple association-learning mechanism, that not only account for the observed contextual cueing effect, but also yield rather specific predictions about future experimental data: contextual cueing effects should also be observed when repetitions of context configurations are not perfect, i.e., the networks were able to react to slightly distorted versions of repeating contexts in a similar way than they did to completely identical contexts. Human participants, we conjectured, should therefore (if the simple connectionist model captures some relevant aspects of the contextual cueing effect) become faster at detecting targets surrounded by context configurations that are only partially identical from trial to trial compared to those trials where the context configurations were randomly generated. These predictions were tested in a second series of experiments using pseudo-repeated context configurations, where some distractor items were either displaced from trial to trial or their orientation changed, while conserving their global layout. In a third series of experiments, we used more realistic images of natural landscapes as background contexts to establish the robustness of the contextual cueing effect as well as its ecological relevance claimed by Chun and colleagues. We furthermore added a second task to these experiments to study whether the acquired knowledge about the background-target location associations would (automatically) transfer to another visual search task, namely a change detection task. If participants have learned that certain locations of the repeated images are “important”, since they contain the target item to look for, then changes occurring at those specific locations should lead to less “change blindness” than changes occurring at other irrelevant locations. We used two different types of instructions to introduce this second task after the visual search task, where we either stressed the link between the two tasks, i.e., telling them that remembering the “important” locations for each image could be used to find the changes faster, or we simply told them to perform the second task without any reference to the first one. We will close this thesis with a general discussion, combining findings based on our review of the existing research literature and findings based on our own experimental explorations of the contextual cueing effect. By this we will discuss the implications of our empirical studies for the scientific investigation of contextual cueing and implicit learning, in terms of theoretical, empirical and methodological issues. [less ▲]

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See detailHigher Lie and Leibniz algebras
Khudaverdyan, David UL

Doctoral thesis (2013)

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See detailIl principio di proporzionalità nella disciplina del mandato d'arresto europeo
Marletta, Angelo UL

Doctoral thesis (2013)

This thesis deals with a current issue in the enforcement of the European Arrest Warrant. Surrender procedures were originally «designed with major criminals in mind», but in an increasing number of cases ... [more ▼]

This thesis deals with a current issue in the enforcement of the European Arrest Warrant. Surrender procedures were originally «designed with major criminals in mind», but in an increasing number of cases they involved minor offences and “trivial cases”. This has caused a great concern about keeping the mutual trust in the Area of freedom, security and justice. In 2011 a Report of the European Commission stressed the importance of the respect of proportionality principle in this highly sensitive field of EU law. This essay analyzes the possibility of applying the proportionality check to the European Arrest Warrant in a fundamental rights perspective. Specific attention is paid to the European Charter of Fundamental Rights and to the Art. 52 par. 1, as a binding constitutional norm establishing the proportionality principle for the whole EU legal order. [less ▲]

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See detailEntwicklungskindheit als Beobachtungsprojekt. Ethnographische Studien zu den Praktiken der Entwicklungsbeobachtung in kindermedizinischen Untersuchungen
Bollig, Sabine UL

Doctoral thesis (2013)

Diese publikationsbasierte Dissertationsschrift bündelt neun bereits veröffentlichte ethnographische und methodologische Studien zu den Praktiken der entwicklungsbezogenen Beobachtung von Kindern in ... [more ▼]

Diese publikationsbasierte Dissertationsschrift bündelt neun bereits veröffentlichte ethnographische und methodologische Studien zu den Praktiken der entwicklungsbezogenen Beobachtung von Kindern in Kindervorsorge‐ und Schuleingangsuntersuchungen. Den gemeinsamen Bezugspunkt finden die vorgelegten Studien in der Frage, wie in diesen medizinischen Beobachtungspraxen ‚Entwicklungskindheit‘ formiert wird. Unter ‚Entwicklungskindheit’ wird eine über das Entwicklungskonzept aufgespannte Konfigurierung von Kindheit gefasst, die nicht nur bestimmte Bilder von Kindern erzeugt, sondern auch die Unterscheidung zwischen Kindern und Erwachsenen bzw. Kindern und ihren Eltern normiert und relational reguliert. Insofern ist die ‚Entwicklungskindheit‘ als eine epistemische wie praktische Form ‚generationalen Ordnens‘ zu verstehen. An der Schnittstelle von erziehungswissenschaftlicher Kindheitsforschung, Medizin‐ und Präventionssoziologie wird mit diesem Bezugspunkt dann sowohl die Frage formulierbar, wie im Vollzug der Kindervorsorge‐ und Schuleingangsuntersuchungen deren ‚einheimischen‘ Entwicklungskonzepte ‚praktiziert‘ werden, als auch wie in diese Darstellungspraxis Ansatzpunkte für die ‚pädagogische Ordnung der Familie‘ eingewoben sind.Auf einer methodologischen Ebene wurde dieses Forschungsprogramm über einen praxistheoretische Modellierung der ‚Praktiken der Entwicklungsbeobachtung‘ konzeptualisiert und mit den Methoden der praxisanalytisch ausgerichteten Ethnographie realisiert. Gegenstandstheoretisch werden über die verschiedenen empirischen Studien hinweg vier Dimensionen dieser Praktiken der Entwicklungsbeobachtung ausdifferenziert: Beobachterkollektive, Beobachteroptionen, Beobachterprogramme und Beobachtungsbühnen. Die ethnographischen Studien zeigen auf, das im Vollzug der Kindervorsorge‐ und Schuleingangsuntersuchungen ‚Entwicklung‘ in dreifacher Weise als ein hybrides Beobachtungsobjekt konstituiert wird: erstens, da sich in den verteilten Praktiken der Entwicklungsbeobachtung sehr heterogene ‚Partizipanden‘ der entwicklungsdiagnostischen Praxis kollektivieren um Entwicklung als zeitlichen, sozialen, biologischen und räumlichen Prozess sichtbar zu mache und als ‚normale‘ oder ‚abweichende‘ Entwicklung beurteilen zu können. ‚Hybrid‘ auch zweitens, weil das Beobachtungsobjekt ‚Entwicklung‘ zwar an Kindern erarbeitet wird, gleichzeitig aber auch die Eltern und die Familie als Bedingungskontext und Bearbeitungsressource für Entwicklung in dieses Beobachtungsobjekt eingewoben werden. Dieses Beobachtungsobjekt ‚Entwicklung‘ ist, drittens, aber auch als hybrid zu bestimmen, weil es in den beiden Beobachtungsformaten Kindervorsorgen und Schuleingangsuntersuchungen, je spezifisch hervorgebracht wird, diese ‚einheimischen Entwicklungskonzepte‘ jedoch verschiedene Kontexte (Familie, Schule, Kita, etc.) miteinander vermitteln und in Form von weiteren Beobachtungsaufgaben auch in diese hinein reichen. Insofern ist das hybride Beobachtungsobjekt ‚Entwicklung‘ auch nicht einfach nur ein medizinisches Objekt, vielmehr ist es durch einen Verschnitt von medizinischen und pädagogischen Wissens‐ und Praxisformen aufgebaut. Mit Blick auf internationale Forschungsarbeiten, die herausarbeiten, dass die gesellschaftliche Konfigurierung der spätmodernen Familie maßgeblich über eine wissensbasierte Konzeption kompetenter Elternschaft aufgebaut ist, zeigen die hier eingereichten Studien auf, dass dieses erforderliche elterliche Wissen im praktischen Vollzug der Kindervorsorge‐und Schuleingangsuntersuchungen maßgeblich als Beobachtungswissen eingefordert und stimuliert wird. Und zwar sowohl mit Blick auf eine fortlaufende Entwicklungsbeobachtung der Kinder durch ihre Eltern, der Koordinierung von professionellen wie privaten Beobachtungspraxen zwischen Eltern und Professionellen, als auch über die Selbstbeobachtung der Eltern von sich selbst als Eltern. In den Kindervorsorge‐ und Schuleingangsuntersuchungen ‚materialisiert‘ sich die Entwicklung von Kindern somit als ein Beobachtungsprojekt, das nicht nur immer weitere Beobachtungen der kindlichen Entwicklung als notwendig erscheinen lässt, sondern in diese Konzeptualisierung von ‚Entwicklungskindheit‘ die Beobachtungskompetenz der Eltern als maßgebliches Kriterium für eine optimale Entwicklung einschreibt. Ihren ‚spätmodernen Charakter’ entfalten die Untersuchungen indem sie die Entwicklung der Kinder immanent als ‚riskant‘ entwerfen, womit der Projektcharakter der modernen Kindheitsidee sich gleichermaßen perpetuiert wie transformiert: als ein Projekt der Vervollkommnung, das sich darüber selbst plausibilisiert, dass es über seine ‚Kerntechnologie‘ der kontinuierlichen, präventiven Entwicklungsbeobachtung der Kinder, nicht nur deren Status als prekär definiert, sondern auch den ihrer Eltern. Neben diesen auf die Formierung von ‚Entwicklungskindheit‘ bezogenen empirischen Studien versammelt das Konvolut aber auch Studien, die sich zum einen mit methodologischen und methodischen Fragestellungen ethnographischen Forschens beschäftigen und zum anderen, das in dieser Dissertation entwickelte Modell der ‚verteilten Praktiken der Entwicklungsbeobachtung‘ auf einen weiteren zentralen Kontext der Dauerbeobachtung von Kindern beziehen, die fortlaufende Beobachtung kindlicher Entwicklungs‐ und Bildungsprozesse in Kindertageseinrichtungen. [less ▲]

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See detailEfficient Communication Protocols for ad hoc Networks
Ruiz Villalobos, Gracia Patricia UL

Doctoral thesis (2013)

Mobile ad hoc networks, also called MANETs, are self-organised networks spontaneously created between neighbouring devices that do not need any infrastructure. The possibility of deploying a communication ... [more ▼]

Mobile ad hoc networks, also called MANETs, are self-organised networks spontaneously created between neighbouring devices that do not need any infrastructure. The possibility of deploying a communication network at any moment and at any place opens a wide range of potential scenarios where the use of an ad hoc network is extremely important and useful. For example, we can imagine an area with no infrastructure, due to a natural disaster (flooding, earthquake, etc.), a war damage or simply a remote location. In such situations, the deployment of an ad hoc network for rescuing or evacuating people is key. %Allowing the communication between groups located in distant areas may be very helpful in critical situations in order to coordinate and reorganise them. However, ad hoc networks are not restricted to safety of disaster situations, they can also be used for gathering sensed data and send it to a remote server, exchanging safety road messages between vehicles or simply for infotainment, etc. Efficient communication protocols are very important for providing good services, but in ad hoc networks is very challenging. It is necessary to deal with packet loss, collisions, mobility, network partitions, fading, energy constraints, obstacles, etc. Due to the intrinsic broadcast nature of wireless medium, dissemination algorithms are one of the most appropriate protocols for communicating devices. Additionally, broadcasting is one of the main low level operation as many applications and even other protocols rely on its service. Therefore, in this thesis, we are proposing two different broadcasting algorithms for efficiently disseminate messages in the network. The first approach relays on an underlying tree topology, while the second is an energy aware algorithm that tries to reduce the energy consumption. In these unpredictable and changeable networks, protocols need to adapt to the current circumstances and this adaptability is usually obtained using thresholds. The values of these thresholds directly influence the behaviour of the algorithm. Finding them is a complex and critical task as protocols are usually very sensitive. We tackle this problem using approximation algorithms or metaheuristics, more specifically, we use a parallel iterative local search and two evolutionary algorithms. In order to ease this process, we have created a modular experimental framework for evaluating, validating and optimising any algorithm in MANETs. [less ▲]

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See detailErmüdungseigenschaften des Wabenkerns von sandwichpaneelen aus Aluminium
Wahl, Laurent UL

Doctoral thesis (2013)

In comparison to their weight, honeycomb composite structures have a high bending stiffness, which makes them very suited for every application where little weight is important, like airplanes, railway ... [more ▼]

In comparison to their weight, honeycomb composite structures have a high bending stiffness, which makes them very suited for every application where little weight is important, like airplanes, railway-cars and vehicles. These structures are subjected to cyclic loading. The sandwich panels consist of two thin and stiff aluminium face sheets, which are bonded to a thick and lightweight aluminium honeycomb core. The shear stresses in the core of these structures depend strongly on the angle of the load application, because the core is not homogeneous. The distribution and the level of the shear stresses are investigated using analytical calculations. The load direction which induces highest stresses in the honeycomb core is derived. This direction is not the W-direction, which is the most compliant one. In literature, there are few fatigue properties of the honeycomb core described. The fatigue properties of the core are investigated in this work using the finite element method and experiments. The experimental investigations consist of three-point bending tests, pulsating roller tests, Food-Cart Roller tests and several tests on real components. Depending on the load application, the honeycomb core fails either through core indentation or shear failure. Several fatigue tests were carried out at constant load amplitude and the failure mode is investigated. The sandwich structures were modeled with the ANSYS finite element software. The number of elements is reduced by replacing the honeycomb core with a homogeneous core with orthotropic properties. In order to get the stresses in the honeycomb core at the critical location, a submodel was created. In this work, some equations are derived in order to calculate the real shear stresses from the shear stresses of the homogeneous core. In addition, imperfections are included in the model. Furthermore, buckling analyses were used to examine core indentation failure. Based on these simulations, both failure modes described above can be explained. Core indentation occurs, when the honeycomb cells are buckling due to the load application. The buckling of the cells can be avoided by using a smoother load application. In this case, the core fails in the three-point bending test by shear failure. The fatigue life of the examined specimens is successfully approximated in this manuscript, with the lifetime analysis being based on the FKM-guideline. Every simulation is validated by experimental results. [less ▲]

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See detailStabilität wechselrichtergeführter Inselnetze
Jostock, Markus UL

Doctoral thesis (2013)

The PhD thesis develops a control model for island grids, where voltage source inverters with droop control adapt frequency and voltage amplitude and no classic rotating generators are present. The ... [more ▼]

The PhD thesis develops a control model for island grids, where voltage source inverters with droop control adapt frequency and voltage amplitude and no classic rotating generators are present. The presented linear, time invariant model is based on a state space control model of inverters and linearised power flow equations for the grid lines, the grid topology is captured in a node incidence matrix. Such a compound model for inverter driven island grids has not yet been developed to the author’s knowledge. Most existing models have been formulated for very small grids or inverter constellations. The presented control model allows to investigate grids with a very high number of inverters and with arbitrary grid structures and facilitates the calculation of the compound state space model and the MIMO transfer function matrix. No explicit re-formulation of the differential equations is necessary for different grid topologies, as this information is captured in the node incidence matrix. The thesis further investigates the stability of inverter driven island grids, i.e. power grids decoupled from the interconnected European power grid and in which most of the primary sources are renewable energy sources, injected via voltage source inverters. As inverters do not have rotating masses and thus no rotational inertia, they can be actuated much faster than classical synchronous generators. The effect of this property on the overall system stability is investigated in this work. The grid frequency is considered as a distributed parameter, where during transient phases, each grid node has its own valid phase angle speed. During transient phases, the inverters adjust injection frequency according to their droop, due to a local active power change. Until all inverters have adapted their injection frequencies, in each grid node a separate phase speed is valid. This behaviour could be verified with laboratory experiments and is integrated into the formal model with a graph theory approach. The power flow through grid lines due to voltage changes is a physical effect and practically immediate, while the adaptation of voltage amplitude and frequency through the inverters is a slower action depending on the inverter control algorithm. The separate modelling of inverters with their droop control on the one hand and the passive grid structure with the load flows on the other hand is justified by singular perturbation. An inverter driven island grid in droop mode can become unstable. Different parameters of the model have an influence on the system stability. A stability analysis is performed on simple grid structures as line, ring and lattice structure based on pole-zero plots. The influence of single parameters on the pole positions is investigated. Three pole regions appear for the compound model, their position and form is depending on the model parameters. For the model of the inverter two time constants are assumed: the smaller time constant Tm models the physically minimal possible delay in a PT1 element, while the larger time constant TWR can be adjusted arbitrarily by programming in an inverter. Both time constants determine more or less the position and form of one pole region each. If both time constants approach each other, conjugate complex poles appear. For large values of TWR the system can become unstable as poles move into the right half pane. This thesis reaches the following conclusions: Small rated power values of the inverters lead to potential instability as small power perturbations may cause large frequency changes. Since this effect is related to the value of the time constants, a stabilising effect can be observed when the time constants of the inverters are minimised, which enables the inverters to react more quickly to the frequency changes. An increasing number of inverters in the grid increases the system order and thus the number of poles. Under unfavourable conditions these poles may be badly damped and may develop into dominant complex conjugate poles. Similar effects can be observed for short grid lines: in systems with short grid connections, the inverters have a stronger electric coupling, bringing forward dominant pole pairs. The control of voltage and frequency by droops has been developed for in- ductive high voltage grids. In low voltage grids with ohmic line characteristics the droops lead to cross coupling between the voltage and frequency controller, causing an additional voltage reaction due to an active power change and an additional frequency reaction due to a reactive power change. This effect can be counteracted by the rotation of the measured P and Q coordinates in the droop control. The rotation angle is strongly related to the impedance angle at the point of connection of the inverter. Using P/Q rotation reduces the number of dominant pole pairs and fosters the integration of higher numbers of inverters without reaching the stability limits of the grid. Based on the laboratory results, a method for detection of the optimal P/Q rotation angle has been filed for patent. [less ▲]

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See detailCrystallization in hard sphere systems
Radu, Marc UL

Doctoral thesis (2013)

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See detailSocially Augmented Content Distribution in Hybrid Networks
Klasen, Bernd UL

Doctoral thesis (2013)

Internet traffic is experiencing a great growth whose end cannot be foreseen. Whether it will always be possible to upgrade the infrastructure fast enough to keep up with the increasing demand is ... [more ▼]

Internet traffic is experiencing a great growth whose end cannot be foreseen. Whether it will always be possible to upgrade the infrastructure fast enough to keep up with the increasing demand is uncertain. On any account this undertaking will be expensive and the consequences that arise from the thereby growing complexity are hard to predict. For many files delivered via Internet a large degree of redundancy can be observed. Since such transfers use unicast transmission mode, the induced traffic increases linearly with the number of downloads. This is a challenge for the delivery network used and for the servers. This thesis argues that the peaks in Internet traffic can be truncated and the aggregated amount of bytes transferred be significantly reduced by shifting this redundant traffic to a broadcast network. Thereby the unicast and broadcast network are combined by means of a hybrid network that allows dynamic routing of data via either of them. Based on this infrastructure a socially augmented content distribution model relying on P2P technology is defined that manages the network selection and the delivery of data. It aims at delivering files to user caches prior to the demand and thus can level out the fluctuations in Internet and server load. Thereby it makes use of social networks by means of capitalizing information about social ties, similarities and mutual influence among individuals. It is shown that by this approach the Internet traffic can be significantly reduced while only requiring a comparatively small amount of broadcast network capacity. At the same time the user perceived quality of service is increased by means of a reduced delivery time. [less ▲]

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See detailAn Investigation of Number-Space Associations: Exploring Developmental and Cognitive Influences
Hoffmann, Danielle UL

Doctoral thesis (2013)

In order to comprehend higher order arithmetic it is of crucial importance to get a thorough understanding of basic number processes. One of the basic characteristics of numerical representations is its ... [more ▼]

In order to comprehend higher order arithmetic it is of crucial importance to get a thorough understanding of basic number processes. One of the basic characteristics of numerical representations is its association to space. Empirical evidence for the number-space association is the SNARC effect (Spatial Numerical Associations of Response Codes, Dehaene et al., 1993): in binary classification judgments participants are faster responding to small/large digits on the left/right response side respectively. However, only 65-75% of participants display this signature effect of number-space associations (Wood et al., 2006a; 2006b). Although some influencing factors on the SNARC effect such as response speed and writing habits (Gevers et al., 2006; Shaki et al., 2009) have been identified, research on this issue remains scarce. Another question mark in the number-space research is the ontogenetic emergence and evolution of the numerical-spatial relationship. The present work gives a brief overview of what is known about the number-space association and adds empirical data to existing scientific knowledge. Specifically we found that number-space associations in the form of a SNARC effect emerge early in life (from age 5.5) and that its relationship to basic number knowledge at that age depends on the task at hand. Moreover, in adults, arithmetic proficiency, as well as interference inhibition capacities are related to the strength of the SNARC effect. A very strong relationship exists between the strength of the SNARC effect and chronological age, as the SNARC effect becomes stronger with increasing age. [less ▲]

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See detailDisplacement and Resettlement: The Livelihoods of Resettlers and Hosts Displacement and Resettlement: The Livelihoods of Resettlers and Hosts
Wayessa, Gutu Olana UL

Doctoral thesis (2013)

The study focuses on population displacement and the livelihood implications of state-planned resettlement schemes that have been implemented in Western Oromia, Ethiopia. It addresses the livelihoods of ... [more ▼]

The study focuses on population displacement and the livelihood implications of state-planned resettlement schemes that have been implemented in Western Oromia, Ethiopia. It addresses the livelihoods of both the resettlers and the hosts. Although such resettlements have been implemented in the country since the 1960s, this study addresses those carried out since 2003. The broad objective of the study was to explore the dynamics of displacement and resettlement, and their impacts on the livelihoods of resettler and host populations. The specific objectives were: (1) to assess the policies and practices of the resettlement program carried out during the tenure of the current government; (2) to analyze the livelihood outcomes of the resettlements for resettlers and hosts in terms of changes in access to livelihood resources and social services; and (3) to examine resettlers’ and hosts’ perceptions of and attitudes towards the resettlement program. The theory of impoverishment risks and livelihood reconstruction (IRLR), the sustainable livelihood framework (SLF), and political ecology constitute the pillars of the theoretical framework. Primary data were collected in 2009 through a survey of 630 households in eight resettlement sites, and 68 thematic (group and individual) interviews in 13 resettlement sites. Several interviews were also held with government officials. Households were selected for the survey through stratified random sampling, whereas informants were selected for the interviews purposively. The primary data were complemented with relevant secondary data. The study is interdisciplinary, and combines both qualitative and quantitative methods through a concurrent mixed-methods design. Qualitative methods were used to address how and why questions through thematic analysis of the interviews and policy documents, thereby illuminating the substantive significance of the issues at stake. Quantitative methods were employed to quantify changes and establish the statistical significance of variables of interest. The quantitative methods used include descriptive statistics, such as percentages, means and cross-tabulations, and inferential statistics, such as logistic regression, mean comparisons using non-parametric tests, factor analysis, Chi-square tests, and loglinear analysis. The complementary relation between the two methods has proved useful in understanding and explaining the processes and the outcomes of the resettlement scheme. The research illuminates the causes, the processes, and the outcomes of the current resettlement program in particular, and critically analyzes the assumptions underlying the resettlement policies of the current and the previous regimes in general. Multiple causes and assumptions underlay the resettlement scheme, most notably land and rainfall shortages in resettlers’ areas of origin, and the government’s claim of land abundance. This last assumption has been persistently made by regime after regime, despite empirical counter-evidence, as also shown in this study. By revealing that the scheme resulted in the displacement of the host population to make way for resettlement, that the resettlers were given less land than promised, and that the relocation led to serious conflicts and disputes over land between resettlers and hosts, the study challenges the state’s supposition and rhetoric of “ample land.” The evidence also illuminates the relocation’s glaring lack of inclusiveness of both resettlers and hosts, despite the benign principles of “voluntarism” and “consultation.” The outcomes were multiple, leaving some better-off, others worse-off, and still others with no noticeable livelihood deterioration or improvement. In cases where old problems were alleviated, new ones emerged in a context of little plan and capacity to meet contingencies. This calls into question government propagation of generalized “success” in the resettlement scheme. Although little is known about the sustainability of the improved outcomes for some resettlers in some resettlement sites, the evidence from this study also counteracts the depiction of the scheme as a general “failure.” The findings suggest that the relative importance of the risks experienced by the resettlers and the hosts varied between the two population groups, and among different resettlement sites. The resettlement sites were widely differentiated in terms of biophysical factors, notably soil fertility and the availability of grazing land. This has serious implications for the resettlers and the hosts as their livelihoods are almost entirely based on agricultural activities. Moreover, historical issues, wider socio-political structures, physical infrastructure, and resettler-host relations are crucial for the understanding of how people’s access to livelihood resources and social services is shaped. However, resettler-host relations should be seen in a broader context of state-society relations, as the state is a key actor in planning and implementing the resettlement programs. An important policy lesson from this study is that when one focuses on certain livelihood aspects, one also needs to be aware that other potential livelihood components not evident today may become vital in the future. This awareness should motivate adaptive planning and management to meet contingencies in a way that reflects the multifaceted nature of livelihoods. [less ▲]

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See detailStrukturen, Engagement und Motivation bei LAN-Gaming, Techno und Parkour. Eine qualitative Studie in jugendkulturellen Szene-Eliten in Luxemburg
Zeimet, Jean-Claude UL

Doctoral thesis (2013)

Politics and research in Luxembourg pay little attention to the local youth(sub)cultures despite their manifold activities and high visibility. In youth research und youth studies youth(sub)cultures were ... [more ▼]

Politics and research in Luxembourg pay little attention to the local youth(sub)cultures despite their manifold activities and high visibility. In youth research und youth studies youth(sub)cultures were mainly perceived in connection with leisure activities and delinquent behaviour but have never been a topic of their own. The present dissertation expands the existing data and supplements youth research in Luxembourg by adding a further and important element. It allows a first empirical view on Luxembourgish youth(sub)cultures and their scenes. The study is based on a field research project following a qualitative heuristic design (Kleining, 1982) and focussing on three youth(sub)cultures: LAN-gaming, Techno and Parkour. All collected data was subject to a computer aided data analysis on commonalities for the different research topics. Two research questions emerging from the field study were of main interest. The primarily focus is on the structure of the youth(sub)cultures, the way they are conceived and constituted. Knowledge of the structure is regarded as an essential and important starting point to understand youth(sub)cultures. The structure's analysis is led by the 'scene concept' by Hitzler and Niederbacher (2010b). It could be demonstrated, that the explored youth(sub)cultures can be considered as scenes in terms of the 'scene concept'. However, the analysis shows some further characteristics, e.g. requirements to join the scene, and the scene's way to deal with preconceptions. Scenes in Luxembourg seem to show tendencies to break with their informal structure and apparently approach more traditional and formal ways of association. Youth(sub)cultures seem to face some elementary changes and developments in the future. Identifying the framework of the three scenes allowed elaborating an appropriate and meaningful thematic depth. Already at an early stage of the field research it became apparent that few scene members invest considerable time and energy to create and establish the scene. By doing so they are practically also in charge of the scene's structure. According to the 'scene concept' these people could be described as organisational elite – the scene's motor. Using methods of the free field research concept (Girtler, 2001) the study asked for the motives lying behind this commitment by asking: What lies behind the fun? So the second research topic targeted first these members' commitment and could identify decision levels with assigned roles and fields of activity, e.g. the administrator, the organiser or the expert. The organisational elite's commitment shows two different stages of motives; motives to start and motives to continue the work. The Maynooth-model was developed to illustrate the findings of this research. It shows the interaction and the circuit of the members' motives and influencing framework factors. There is a rather enclosed and complex interaction system, which provides room and questions for further research within the field. There’s a lot more than fun to make a scene happen and work [less ▲]

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See detailRegulation of microRNA Expression by STAT1 Transcription Factors - Relevance for Melanoma Development
Schmitt, Martina UL

Doctoral thesis (2013)

The type-II-cytokine IFN-γ (interferon gamma) is not only a pivotal player in innate immune responses but also assumes functions in controlling tumor cell growth by orchestrating cellular responses ... [more ▼]

The type-II-cytokine IFN-γ (interferon gamma) is not only a pivotal player in innate immune responses but also assumes functions in controlling tumor cell growth by orchestrating cellular responses against neoplastic cells. It predominantly triggers cellular responses through the Janus Kinase (Jak)/ Signal Transducer and Activator of Transcription 1 (STAT1) pathway leading to STAT1 binding to the promoter region of target genes. As key regulators of mRNA and protein expression levels, microRNAs (small non-coding RNAs) take part in fine-tuning complex biological processes such as cell proliferation, neoplastic transformation, apoptosis, immune surveillance and differentiation. MiR-29, one of the most interesting miRNA families in humans to date, consists of three mature members miR-29a, miR-29b and miR-29c, which are encoded in two genetic clusters. In this PhD thesis, the miR-29 primary cluster pri-29a~b-1 was shown to be IFN-γ-induced and STAT1-dependently up-regulated in melanoma cell lines. Furthermore, expression levels of mature miR-29a and miR-29b were elevated in cell lines and in primary melanoma patient samples while the pri-29b-2~c cluster was almost undetectable in cell lines. Moreover, tumor-suppressing properties of miR-29 family members have been detected: inhibition of melanoma cell proliferation could be induced by miR-29a, which down-regulated CDK6 (cyclin-dependent kinase 6), an important player in cell cycle G1/S transition. Also, knockdown of CDK6 resulted in reduced proliferation of melanoma cells, suggesting that miR-29-mediated growth inhibitory effects may be brought about by CDK6-downregulation. These findings identify the pri-29a~b-1 cluster as a novel IFN-γ-regulated gene. Furthermore, a potential novel signaling pathway was identified: IFN-γ  Jaks  P-STAT1  miR-29  CDK6, which opens up new connections between miRNAs, interferon signaling and malignant melanoma, possibly clearing the way to novel concepts for new treatment options in the future. [less ▲]

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See detailLa dynamique de la complexité en matière de relations extérieures des Etats membres de l'Union européenne
Lickova, Magdalena UL

Doctoral thesis (2013)

In its capacity of a member of the European Union, the State agrees to submit to a set of rules framing its autonomy in the field of external relations. While this set of rules can be assessed in terms of ... [more ▼]

In its capacity of a member of the European Union, the State agrees to submit to a set of rules framing its autonomy in the field of external relations. While this set of rules can be assessed in terms of categories of legal effects acting unilaterally upon the EU Member State, the present study attempts to go further by examining what we believe to be a dynamic chain of complexity, composed of actions, reactions, and retroactions of the actors involved. During our research, we indeed found that the manner in which the Union affects the EU Member States’ external relations is far from being a one-way process, but rather constitutes permanent and circular dynamics of interaction between what we shall call an integrated Member State and the Union, between the Union and what we shall call a global Member State, and between the respective Member State’s global and integrated faces. The integrated Member State may step aside to let the Union act in its stead, or act in conjunction with the Union, but ʽtaking the back seatʼ in this manner does not engage its global face, its alter ego, which will return to take center stage (if it did not simply stay there to begin with) to complete (or to compete with) the actions of the Union, or even to solicit the Unionʼs support with respect to the relations it established vis-à-vis third parties. As we proceed, we find that the Member State, who initially appeared to be a mere passive object of our research, is in fact an active agent, contributing, whether through retroaction or through the competing exercise of its sovereign competencies, to the face of the Unionʼs external relations. Accordingly, no research into the external relations of the EU can be complete without taking into account the impact of EU law on the integrated Member States, and the impact felt in turn by the EU as the result of the Member Statesʼ global actions. In the same way, such research should consider the impact of international law on the global Member States and the impact felt in turn by international law as a result of the actions of the integrated face of these same Member States [less ▲]

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See detailSuprarégionalisation transfrontalière? Grande Région Saar-Lor-Lux
Evrard, Estelle UL

Doctoral thesis (2013)

European Union integration policy has challenged traditional border functions resulting in regionalisation processes and policy makers facing diverse functional interdependencies across multiple scales ... [more ▼]

European Union integration policy has challenged traditional border functions resulting in regionalisation processes and policy makers facing diverse functional interdependencies across multiple scales and territories. Local and regional authorities participate in a European multi-level governance system. Within regions, cross-border cooperation institutionalises distinct forms of governance. This thesis investigates the regionalisation process launched across borders at a subnational level using the case study of the Greater Region Saar-Lor-Lux. Conceptually, this study defines regionalization as construction of a region. This analysis of cross-border cooperation in the Greater Region explains “cross-border supraregionalisation” through three processes. First, the discursive construction of a cross-border strategy illustrates the complexity of joint positioning. The metropolitan impetus advocated in the Greater Region reveals the ambivalent objectives of the partners and the dominance of the metropolitan discourse at the national and European level. Second, beyond the institutional cooperation space (“Vertragraum”), the space of the mandate (“Mandatsraum”) serves as a medium to territorialise the joint strategy. It results from the ideal projection of the strategy in space and thus, evokes a bordering process. This “soft space” is constantly negotiated between the partners and illustrates patterns of cross-border spatial empowerment. Third, the study analyses the extent to which cross-border partners delegate responsibilities and legitimacy to joint cross-border institutions, especially through the innovative legal instrument European Grouping for Territorial Cooperation. [less ▲]

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See detailEssays on Dutch Disease and International Finance
Vermeulen, Wessel UL

Doctoral thesis (2013)

Detailed reference viewed: 74 (9 UL)
See detailWas bleibt… Literarische Zeugenschaft im Kontext des Holocaust
Wehming, Marie-Christine UL

Doctoral thesis (2013)

Detailed reference viewed: 113 (6 UL)
See detailSystems Engineering, Systems Thinking, and Learning: a Case Study in Space Industry
Moser, Hubert UL

Doctoral thesis (2013)

Systems thinking is a prerequisite of systems engineering, which is performed in multi-disciplinary teams, i.e. software engineers, mechanical engineers, electronic engineers, and others, work together to ... [more ▼]

Systems thinking is a prerequisite of systems engineering, which is performed in multi-disciplinary teams, i.e. software engineers, mechanical engineers, electronic engineers, and others, work together to develop, build, and test technical systems such as space systems. The more team members consider a systems perspective the less rework is expected and the less effort of systems engineers is required. How systems thinking evolves in practice is not sufficiently understood. Therefore, work activity of multi-disciplinary teams has been studied in an empirical study. Data from multiple sources and of different temporal resolution has been collected over four years in four studies in space systems engineering. These studies are a concept exploration project in a summer school, two concept exploration projects in a concurrent design facility, and five projects in several lifecycle stages in a small space systems company. An analytical framework has been developed based on an activity-theoretical analysis and a theme-and-key-event analysis. Contradicting multiple roles, differences in parameter definition and impact, differences in work approaches and ways of interacting, contradicting work standards, trust and doubts in extra-disciplinary decisions, awareness of diversity and orientation towards extra-disciplinary interactors, and velocity and availability of information are identified contradictions with learning potential. These contradictions provoke initiators of multi-disciplinary interaction. These are proactive provision of extra-disciplinary advice and three types of questions: critical questioning across disciplinary boundaries, asking for extra-disciplinary advice, and questioning the current work approach. The contradictions prompt the selection of themes that comprise several key events. These themes and key events are analysed on three levels (macro, meso, and micro) with a focus on systems thinking content and discourse features. Systems thinking evolves in interaction within a broad temporal range, from minutes to years. It evolves vertically, i.e. within a discipline, and horizontally, i.e. across disciplines. The evolution of systems thinking is influenced by the multi-disciplinary quality of interaction. This quality is defined by the diversity or multi-disciplinarity of the interaction, the awareness of the diversity, the orientation towards extra-disciplinary interactors, the differences in interactional responsiveness, and the cohesion of interaction. Improving the multi-disciplinary quality of interaction to foster the evolution of systems thinking is the major goal of the developed WAVES (Work Activity for a Versatile Evolution of Systems engineering and thinking) strategy. The WAVES strategy comprises two paths. The first path focuses on the introduction of employees into professional life, (space) industry, a company, a team, and a task. The second path focuses on the continuous improvement of the work activity. The implementation and evaluation of WAVES in a small space system company is the basic contribution to industry. The implementation within systems engineering departments of large space organisations has been prepared. The developed analytical framework contributes a new approach to analyse work activity in practice. Finally, the answers to the first part of the main research question contribute to a better understanding of systems engineering, systems thinking, and its learning in practice. [less ▲]

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See detailApplications of Combinatorial Optimization for Online Shopping
Musial, Jedrzej UL

Doctoral thesis (2013)

Detailed reference viewed: 61 (2 UL)
See detailResearch on DNA sequence assembly using graph approach
Gawron, Piotr UL

Doctoral thesis (2013)

Detailed reference viewed: 123 (18 UL)
See detailDie Flexion der Nominalphrase im Luxemburgischen
Breckler, Christine UL

Doctoral thesis (2013)

Detailed reference viewed: 158 (16 UL)
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See detailMicroarchitectural Side-Channel Attacks
Gallais, Jean-Francois UL

Doctoral thesis (2013)

Cryptanalysis is the science which evaluates the security of a cryptosystem and detects its weaknesses and flaws. Initially confined to the black-box model, where only the input and output data were ... [more ▼]

Cryptanalysis is the science which evaluates the security of a cryptosystem and detects its weaknesses and flaws. Initially confined to the black-box model, where only the input and output data were considered, cryptanalysis is now broadened to the security evaluation of the physical implementation of a cryptosystem. The implementation attacks which compose physical cryptanalysis are divided into fault attacks, exploiting the effect of disruption of the normal functioning of the device, and side-channel attacks, exploiting the dependency between the instructions and data (including key bits) processed by a device and its physical characteristics (e.g. execution time, power consumption, electromagnetic (EM) radiations). In the scope of this thesis, we particularly focus on the latter attacks. “Every computation leaks information” and lowering the physical leakages of an implementation is indeed a complex task both from cryptographic and engineering viewpoints, especially when performance and cost enter the equation. The development of adequate countermeasures necessitates a thorough knowledge of the various vulnerabilities that the microcontroller induces. Although generic side-channel attacks such as Differential Power Analysis (DPA) can generally retrieve the key with weak assumptions on a cryptographic implementation, we show in this thesis that the focus on specific components and properties from the architecture of the target device may allow an adversary to yield better success in a key recovery and sometimes to thwart DPA countermeasures. First, we elaborate on attacks which deduce the cache activity of a device from single side-channel traces and algebraically exploit this information to recover the key. We propose different attacks against embedded software implementations of the Advanced Encryption Standard (AES) in the chosen- and known-plaintext scenarios and make them tolerant to environments where high noise or a partially preloaded cache would normally introduce errors in the key recovery. Second, we discuss the failure of standard DPA against the modular addition and propose a practical and generic approach to circumvent it. Third, we show that microarchitectural leakages and fault inductions can be exploited in a constructive way when induced by hardware Trojans implemented on general-purpose microprocessors. Such Trojans can either provide an adversary with a backdoor access to the trojanized device executing an arbitrary cryptographic software or serve to protect the Intellectual Property (IP) of the chip designer through digital watermarking. The last part concerns divide and conquer side-channel attacks such as DPA. Testing different combinations of key chunk candidates turns out to be very complex when the individual chunk recoveries are bounded in measurement complexity or performed in noisy environments. We address the so-called key enumeration problem with an efficient sorting method. [less ▲]

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See detailOn Intersection Codes and Iterative Decoding
Franck, Christian UL

Doctoral thesis (2013)

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See detailDevelopment and Application of an Asymptotic Level Transport Pollution Model for Luxembourg Energy Air Quality Project
Aleluia Da Silva Reis, Lara UL

Doctoral thesis (2013)

The connections between air pollution and the increase of respiratory diseases, are well known. In Europe, many efforts have been carried out towards the mitigation of the pollutants’ emissions over the ... [more ▼]

The connections between air pollution and the increase of respiratory diseases, are well known. In Europe, many efforts have been carried out towards the mitigation of the pollutants’ emissions over the last decades. The European Union supports the implementation of structural planning measures to control air pollution. The assessment and evaluation of these air quality policies must be carried out with the help of dedicated integrated assessment models. The use of integrated assessment models, which combine models from different fields, raises the need for developing specific modelling concepts in order to provide results to support policy decisions within a practical time frame. This work presents the methodology and the development of a dedicated air quality model for an integrated assessment model. This approach has been designed for the Luxembourg Energy and Air Quality, LEAQ, integrated assessment model. It combines an air quality model, AUSTAL2000-AYLTP, with a techno-economic model, ETEM, which computes ozone precursors emissions related to energy consumption. The models are coupled via an optimization engine, which minimizes the total energy cost for a given ozone level. AUSTAL2000, a Lagrangian transport model, has been adapted to receive a photochemical module, the AsYmptotic Level Transport Pollution, AYLTP. This module consists of a Look-Up Table of quasi-linear reaction rates. A balance has been found that gives an acceptable level of accuracy, given the reduction of computational time. The results of the air quality model have been compared with measurements, and with the regional model LOTOS-EUROS and are considered satisfactory for this type of approach. Regarding the LEAQ framework, two study cases have been simulated, one including only the national emissions from Luxembourg country, and a second one for the Luxembourg region, including the neighbouring countries emissions. [less ▲]

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See detailEducational assessment: Two sides of the same coin
Fischbach, Antoine UL

Doctoral thesis (2013)

Detailed reference viewed: 260 (55 UL)
See detailLa poésie graphique : Christian Dotremont, Roland Giguère, Henri Michaux et Jérôme Peignot
Pelard, Emmanuelle UL

Doctoral thesis (2013)

The purpose of this thesis is to define a type of modern visual poetry (20th – 21st), that we called graphic poetry. The graphic poetry focuses on a plastic and visual experimentation of the graphic sign ... [more ▼]

The purpose of this thesis is to define a type of modern visual poetry (20th – 21st), that we called graphic poetry. The graphic poetry focuses on a plastic and visual experimentation of the graphic sign, demonstrates an important conscience of the visual potential of the written form and tries to produce poetry in the materiality of the writing shapes. This artistic practice of poetry follows and also renews the poetic and plastic avant-gardes of the 20th century, more particularly surrealism. The graphic poetry refers to a practice of poem which is specifically graphic and includes a painting of the sign as a typographic work of the letter in order to produce the poem. The main characteristic of graphic poets is their double vocation : they are writers and visual artists. They experiment writing in its linguistic dimension and its graphic dimension, because they believe that the action of drawing a line or making of a linotype setting — namely the painting or the drawing of the word, of the graphic sign, the typography and the publishing — is already literature. In other words, graphic poets think that the creation and the materialization of the poem proceed of the same gesture. Christian Dotremont’s logograms, Roland Giguère’s artists’ books (Editions Erta) and prints-poems, Henri Michaux’s anthologies of invented painted signs and Jérôme Peignot’s typoems are some forms of graphic poetry. Our study focuses on francophone works, which come from Belgian, French and Quebec fields, published between 1950 and 2004. Three characteristics mainly define the graphic poetry : the ambiguity and the nomadism of the sign in relation to the semiotic systems (graphic, iconic and plastic), graphics rhythm and lyricism, as modalities of the expression of the subject in the graphic material, and a questioning of the distinction between autographic arts and allographic arts, requiring new ways of perception and reading of the poem and the book, that we called visual-reading and touch-reading. [less ▲]

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See detailNuevas estrategias farmacológicas en el tratamiento de la psoriasis
Andres Ejarque, Rosa Maria UL

Doctoral thesis (2013)

La psoriasis es una enfermedad inflamatoria crónica caracterizada por la inflamación de la piel, que viene acompañada por hiperproliferación de los queratinocitos, infiltración leucocitaria dérmica y una ... [more ▼]

La psoriasis es una enfermedad inflamatoria crónica caracterizada por la inflamación de la piel, que viene acompañada por hiperproliferación de los queratinocitos, infiltración leucocitaria dérmica y una angiogénesis incrementada. Los mecanismos patológicos que dirigen esta patología incluyen tanto respuestas de la inmunidad innata como de la adaptativa. En la presente tesis doctoral se ha ahondado en el estudio de la respuesta fisiopatológica de los queratinocitos a los cambios que se producen en el entorno de una placa psoriásica, con el objetivo de aportar evidencia de relevancia para el desarrollo de nuevos tratamientos farmacológicos. De este modo, se ha puesto de manifiesto que los mediadores proinflamatorios presentes en el contexto psoriásico son capaces de alterar la expresión de los receptores de adenosina, nucleósido implicado en el efecto antiinflamatorio del metotrexato, produciéndose una disminución de los receptores A2B y un aumento de los A2A. Así mismo, se ha demostrado que en piel psoriásica lesional existe una sobreactivación de los transductores de señales y activadores de la transcripción (STAT) 1 y 3, pese a que se produce una disminución mayoritaria de la expresión de las Janus cinasas (Jak). Además, se ha caracterizado el papel de diversos mediadores proinflamatorios en la modulación de estas vías de señalización. Recientemente se ha puesto de manifiesto la importancia de STAT3, así como del factor de transcripción nuclear κB (NF-κB) en la patogénesis de la psoriasis. Por ello, y con el fin de obtener nuevos fármacos útiles para el tratamiento de la enfermedad, en la presente tesis hemos evaluado el potencial efecto antipsoriásico de diversos derivados de origen natural en base a su capacidad para inhibir la activación de estos dos factores de transcripción. Para ello, iniciamos nuestro estudio mediante un screening previo en la línea de macrófagos murinos RAW 264.7 de una serie de moléculas obtenidas en su mayoría de esponjas marinas, así como del condroitín sulfato (CS), proteoglicano de amplio uso en la terapéutica de la osteoartritis. La siguiente fase de nuestro proceso de cribado se realizó en cultivos primarios de queratinocitos humanos, en los que se evaluó la capacidad para inhibir la liberación de las citocinas factor de necrosis tumoral α (TNFα) e interleucina (IL)8. Estos estudios preliminares nos llevaron a la selección del derivado semisintético 4-Benzo[b]tiofen-2-il-3-bromo-5-hidroxi-5H-furan-2-ona (BTH) y del CS para su estudio en profundidad. En la última fase de nuestro estudio, el pretratamiento de queratinocitos primarios humanos con el CS inhibió la activación del NF-κB y, en consecuencia, la liberación de citocinas proinflamatorias. Además, disminuyó la translocación al núcleo de STAT3 así como su actividad transcripcional, demostrando su potencial interés como nuevo fármaco antipsoriásico. Por otro lado, el derivado semisintético BTH también disminuyó la liberación de citocinas y quimiocinas proinflamatorias gracias a su efecto inhibidor de la activación del NF-κB. Además, disminuyó la activación de STAT3 a través del bloqueo de la fosforilación en el residuo de tirosina 705 (Tyr705). Estos resultados fueron confirmados in vivo mediante dos modelos de psoriasis en ratón: la hiperplasia epidérmica inducida por 12-O-tetradecanoilforbol-13-acetato (TPA) y la inflamación psoriásica inducida por imiquimod. En ambos modelos, la administración tópica del BTH previno el desarrollo de lesiones psoriásicas a través de la supresión de la fosforilación del NF-κB y el STAT3, confirmando el potencial de esta molécula como nuevo fármaco antipsoriásico. Globalmente, la presente tesis arroja nueva luz sobre el papel de la adenosina y las vías de señalización del NF-κB y el STAT3 en la patogénesis de la psoriasis y pone de manifiesto la eficacia de moléculas sencillas de origen natural en la paliación de su curso, sugiriendo el potencial interés de estas estrategias farmacológicas en el desarrollo de nuevos abordajes terapéuticos para el tratamiento de esta enfermedad. [less ▲]

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See detailEuropean Economic Integration through 'fiscality': A legal perspective
Pantazatou, Aikaterini UL

Doctoral thesis (2013)

The present thesis aims to explore the role and the evolution of tax and fiscal integration (and by implication, a central component of economic integration) from a legal perspective. “Integration through ... [more ▼]

The present thesis aims to explore the role and the evolution of tax and fiscal integration (and by implication, a central component of economic integration) from a legal perspective. “Integration through fiscality”, as perceived in this dissertation, comprises two components: direct taxation and fiscal policies (the public finance management of the Member States). The present thesis sets out by pointing to the paradox that, despite their central role in the attainment of an “economic union” without frontiers, “fiscal matters” remain without any solid constitutional framework. After demonstrating the lack of a “constitutional fiscal framework”, the thesis proceeds with a historical account, through the turning points of European Economic integration (Pre- Maastricht, Post-Maastricht and financial crisis). This narrative aims to show the inter institutional struggles among the different actors (the legislator, the Member States, the executive and the judiciary) in their bid to fill this lacuna in the European (Economic) Constitution, through distinct or sometimes parallel ways. To this end, the thesis primarily gives the institutional and constitutional background of ‘fiscality’, while it continues by analysing the different possibilities of integration through ‘fiscality’: a) positive integration through the legislator via hard or soft law means, b) spontaneous integration triggered by regulatory competition and the Member States, c) ‘coordinated’ integration prompted by the Member States, d) negative integration prompted by the CJEU, e) crisis-induced integration outside or within the EU law framework, f) integration by ‘force’, g) integration by exception. The thesis maintains that, notwithstanding the efforts of the CJEU that has risen as the key player pushing for integration in the area of the tax policy, it has been the recent financial crisis which has spurred the other actors towards more integration in the area of fiscal policies with the anticipated domino effects in the direct taxation field. The final part of the thesis attempts, by means of a normative claim, to sketch the salient features of a ‘fiscal Constitution’ for the EU, as part of the ‘new economic governance construction’, that will be both (politically) feasible and compliant with certain standards of legitimacy and the rule of law desiderata. [less ▲]

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See detailPrivacy in RFID and mobile objects
Trujillo Rasua, Rolando UL

Doctoral thesis (2013)

Detailed reference viewed: 41 (2 UL)
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See detailRelevance marking in lectures: a corpus-based study
Deroey, Katrien UL

Doctoral thesis (2013)

This dissertation by publication contains five articles and six introductory chapters. Deroey & Taverniers (2011) is a general study of the genre and provides an overview of lecture functions based on an ... [more ▼]

This dissertation by publication contains five articles and six introductory chapters. Deroey & Taverniers (2011) is a general study of the genre and provides an overview of lecture functions based on an examination of a lecture subcorpus and a literature study. Deroey (2012) investigates one information highlighting construction, basic wh-clefts, to establish what are the functions of the highlighted discourse and what this reveals about the genre and its disciplinary variation. Deroey & Taverniers (2012a) presents a comprehensive overview of lexicogrammatical markers of important discourse and classifies these into different patterns, while Deroey (submitted) proposes a classification in terms of their interactive and textual orientation. Finally, Deroey & Taverniers (2012b) explores the ways in which lecturers mark less important discourse lexicogrammatically. The six introductory chapters sketch the background to these studies by discussing (1) the lecture genre; (2) relevance marking as a metadiscursive feature; (3) internationalisation and English-medium instruction in higher education; (4) non-native speakers‖ difficulties with English lecture delivery and comprehension; (5) the research rationale; and (6) the lecture corpus. [less ▲]

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See detailModalities for Access Control: Logics, Proof-Theory and Applications
Genovese, Valerio UL

Doctoral thesis (2012)

Detailed reference viewed: 98 (3 UL)
See detailINACS: An Incremental and Adaptive System to manage Conversational Streams
Poray, Jayanta UL

Doctoral thesis (2012)

Detailed reference viewed: 199 (94 UL)
See detailTrust Dynamics: Beliefs, Preferences, Learning and Performance
Cortesi, Maurizio UL

Doctoral thesis (2012)

Detailed reference viewed: 59 (5 UL)
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See detailSimulation and computer-assisted analysis of actin cytoskeleton dynamics in living cells using fluorescence microscopy methods
Halavatyi, Aliaksandr UL

Doctoral thesis (2012)

Controlled in time and space by a variety of actin-binding proteins, assembly and disassembly of the actin cytoskeleton is involved in many biological and biophysical phenomena. In order to understand the ... [more ▼]

Controlled in time and space by a variety of actin-binding proteins, assembly and disassembly of the actin cytoskeleton is involved in many biological and biophysical phenomena. In order to understand the dynamics of such a complex intracellular system quantitative time-lapse imaging approaches are required. This thesis presents the results of the interdisciplinary project aimed at the quantitative evaluation of the effects of actin-binding proteins on actin turnover under physiological conditions. It combines fluorescence microscopy experiments, development of mathematical models and data processing tools to understand how regulatory proteins control actin dynamics. Confocal-microscopy-based Fluorescence Recovery After Photobleaching (FRAP) technique is a major experimental tool to measure the exchange of actin and actin-binding proteins between polymerised and monomeric pools. The developed models and computational algorithms allow to predict actin dynamics depending on regulatory proteins and to connect the experimental data to parameters characterising polymerisation dynamics, length and structures of actin filaments and activities of tested regulatory proteins. To test the models and to evaluate the activities of actin binding proteins without cellular constrains I combined quantitative FRAP analysis with a biomimetic assay which allows to reproduce major features of actin motility. This combination of techniques was utilised to measure the influence of previously characterised actin-binding proteins working together on actin dynamics in a concentration-dependent manner. In particular we investigated how capping and severing of actin filaments influences actin exchange in a bulk meshwork generated from spatially restricted nucleation. The experimental and analysis methods I developed were also used to investigate the dynamics of the actin cytoskeleton at focal adhesions of living cells. Taking as an example the focal adhesion protein zyxin and its binding partner Tes we addressed how the interactions of these proteins with actin regulate cytoskeleton dynamics. Taken together, the developed approaches and collected data help to better understand how regulatory proteins control actin dynamics in living cells. [less ▲]

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See detailWandel und Differenzierung von Kindheit als Re-Institutionalisierung. Eine Analyse der Reformpolitik zur Kleinkindbetreuung in Luxemburg
Haag, Christian UL

Doctoral thesis (2012)

The thesis focuses on the Luxembourgian social policy and law with regard to early childhood education and care for the last 25 years. Young children are not yet obligated to attend school. The care and ... [more ▼]

The thesis focuses on the Luxembourgian social policy and law with regard to early childhood education and care for the last 25 years. Young children are not yet obligated to attend school. The care and education of these children takes place in day care centres and in the household of child minders as well as in the private sphere of the parents’ home. Policy shapes the care of young children between parents’ home and day care through law and social rights. Along with that, policy implicitly uses ideas of early childhood and mental constructions of how young children grow up. The re-institutionalisation of early childhood is the central approach to analyse these ideas and constructions. In light of the social, cultural and political developments in Europe, especially concerning transformations of family forms and labour markets as well as welfare state change and restructuring, the mental constructions and ideas of early childhood fundamentally change. They become increasingly embedded in rationales in which the care of young children is oriented towards the labour market and the child care market. The qualitative document analysis examines this nexus with reference to the Luxembourgian social policy and law in three continuous phases. The 1990s are dominated by traditional ideas of ‘the young child in domestic care’ in an intimate relationship with the non-working mother. Around the turn of the century, this idea is overlaid by the idea of ‘the young child of working parents’ who is looked after outside the private sphere. Here, the main political rationales are based, not on the situation of young children, but on the occupational and private circumstances of parents and how to support them by means of child care. In the late 2000s, an entirely new idea of early childhood emerges in social policy and law on young children’s care. For the first time, the law strengthens the independent societal status of children and confers the right of care and education to ‘the legally individualised young child’. Paradoxically, these very different constructions of young children and corresponding ideas of early childhood nowadays pertain simultaneously. Therefore, the diversity and multi-layered nature of ideas shapes the contemporary everyday life of young children in Luxembourg. [less ▲]

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See detailL'application du droit européen de la concurrence aux entreprises des Etats tiers
Islentyeva, Ekaterina UL

Doctoral thesis (2012)

The aim of my thesis named “The Application of the European Competition Law to the third countries’ enterprises” was to study the specificity of the application of the EU competition law to the non-EU ... [more ▼]

The aim of my thesis named “The Application of the European Competition Law to the third countries’ enterprises” was to study the specificity of the application of the EU competition law to the non-EU enterprises. In the thesis all the conditions of the application of the EU law to the non-EU enterprise are examined in order to explain how exactly it is happening and what are the consequences, as well as the difficulties in the case of such application (the principle non bis in idem has been examined as well as the possibility of a conflict between the competition law and the intellectual property law and the international private law). However, not only the direct application of the EU competition law is possible. The EU Commission cooperates very actively with the third countries’ antitrust authorities by providing the assistance to the countries developing their Competition policies. Such cooperation between EU and China and between EU and Russia has been analyzed as well as national competition laws of these countries. The final result of the work is the proposal of an International agreement on competition law within the WTO, which contains a new mechanism of cooperation between the states and a formula for calculating and imposing the fines on the enterprises that violate the competition law. [less ▲]

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See detailConceptual Approaches for Securing Networks and Systems
Becker, Sheila UL

Doctoral thesis (2012)

Peer-to-peer real-time communication and media streaming applications optimize their performance by using application-level topology estimation services such as virtual coordinate systems. Virtual ... [more ▼]

Peer-to-peer real-time communication and media streaming applications optimize their performance by using application-level topology estimation services such as virtual coordinate systems. Virtual coordinate systems allow nodes in a peer-to-peer network to accurately predict latency between arbitrary nodes without the need of performing extensive measurements. However, systems that leverage virtual coordinates as supporting building blocks, are prone to attacks conducted by compromised nodes that aim at disrupting, eavesdropping, or mangling with the underlying communications. Recent research proposed techniques to mitigate basic attacks (inflation, deflation, oscillation) considering a single attack strategy model where attackers perform only one type of attack. In this work, we define and use a game theory framework in order to identify the best attack and defense strategies assuming that the attacker is aware of the defense mechanisms. Our approach leverages concepts derived from the Nash equilibrium to model more powerful adversaries. We apply the game theory framework to demonstrate the impact and efficiency of these attack and defense strategies using a well-known virtual coordinate system and real-life Internet data sets. Thereafter, we explore supervised machine learning techniques to mitigate more subtle yet highly effective attacks (frog-boiling, network-partition) that are able to bypass existing defenses. We evaluate our techniques on the Vivaldi system against a more complex attack strategy model, where attackers perform sequences of all known attacks against virtual coordinate systems, using both simulations and Internet deployments. [less ▲]

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See detailFinanzierung des Bildungswesens um 1800 in der Helvetischen Republik. Darstellung verschiedener Akteure sowie deren Einflussfaktoren und Wirkungen auf die wirtschaftliche Grundlage der Schule anhand ausgewählter Gemeinden und Städte in der Helvetischen Republik
Brühwiler, Ingrid UL

Doctoral thesis (2012)

In 1798/99 the Helvetic minister of education Stapfer interrogated all schools of the whole Helvetic Republic with a standardized questionnaire to get around 2400 answers. In my PhD thesis I focus on the ... [more ▼]

In 1798/99 the Helvetic minister of education Stapfer interrogated all schools of the whole Helvetic Republic with a standardized questionnaire to get around 2400 answers. In my PhD thesis I focus on the financial issues of the schools with the Stapfer-inquiry as the main-source; in addition I use different sources of different regional archives. My central question is how the elementary school system was financed at the end of the early modern period (around 1800). This main question leads to five sub-questions. As already in small regional areas different currencies occurred, one has to be selected as key currency. In my thesis it’s the Schaffhauser Batzen. Furthermore the teachers were paid in different wages of kind. All the miscellaneous fragments were standardized. Main results of my thesis are: the financing of schools were affected by the rural or urban areas the school or the teacher belonged to, the political background of the region, organizational structures of the school (like the election mode), economical issues (like the amount of the capital belonging to the school) and social structures. In some regions some factors were more dominant than in others. Additionally: the combination of different factors is varying and influences interact. The following factors were taken into account as well: the age of the teacher, the years of service and the range of subjects he taught. This second set of factors shaped the teachers income as well, but much less as the main parameters. Furthermore it can be demonstrated that the denominational affiliation had no influence to the salaries of the teachers if the main influences are taken into account. [less ▲]

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