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See detailMajor changes of cell function and toxicant sensitivity in cultured cells undergoing mild, quasi-natural genetic drift
Gutbier, Simon; May, Patrick UL; Berthelot, Sylvie et al

in Archives of Toxicology (2018)

Genomic drift affects the functional properties of cell lines, and the reproducibility of data from in vitro studies. While chromosomal aberrations and mutations in single pivotal genes are well explored ... [more ▼]

Genomic drift affects the functional properties of cell lines, and the reproducibility of data from in vitro studies. While chromosomal aberrations and mutations in single pivotal genes are well explored, little is known about effects of minor, possibly pleiotropic, genome changes. We addressed this question for the human dopaminergic neuronal precursor cell line LUHMES by comparing two subpopulations (SP) maintained either at the American-Type-Culture-Collection (ATCC) or by the original provider (UKN). Drastic differences in susceptibility towards the specific dopaminergic toxicant 1-methyl-4-phenylpyridinium (MPP+) were observed. Whole-genome sequencing was performed to identify underlying genetic differences. While both SP had normal chromosome structures, they displayed about 70 differences on the level of amino acid changing events. Some of these differences were confirmed biochemically, but none offered a direct explanation for the altered toxicant sensitivity pattern. As second approach, markers known to be relevant for the intended use of the cells were specifically tested. The “ATCC” cells rapidly down-regulated the dopamine-transporter and tyrosine-hydroxylase after differentiation, while “UKN” cells maintained functional levels. As the respective genes were not altered themselves, we conclude that polygenic complex upstream changes can have drastic effects on biochemical features and toxicological responses of relatively similar SP of cells. [less ▲]

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See detailBildungswerte und Schulentfremdung: Institutions- und Kompositionseffekte in den Bildungskontexten Luxemburgs und der Schweiz
Scharf, Jan UL

Doctoral thesis (2018)

Values and attitudes towards schooling – as the core concepts of this research – are increasingly recognized as important factors affecting educational achievement and attainment. Values of Education (VoE ... [more ▼]

Values and attitudes towards schooling – as the core concepts of this research – are increasingly recognized as important factors affecting educational achievement and attainment. Values of Education (VoE) are conceptualised along the five instrumental goals outlined in the social production function theory by Lindenberg (1991; Ormel et al., 1999). School alienation (SAL) is defined as negative attitudes towards academic domains of schooling, namely teachers and learning (Hascher & Hadjar, 2018: 179). Based on the assumption that SAL depicts a process intensified over the course of secondary education (Finn, 1989), this dissertation finds evidence for developmental trends between grade seven and grade eight comparatively across country settings and to show how educational contexts and the perceived VoE affect SAL. This sociological study provides an in-depth comparison of the stratified school systems of Luxembourg and of the Canton of Berne (Switzerland) based upon newly-collected panel data of the international research project School Alienation in Switzerland and Luxembourg (SASAL) (N = 465/508). Following the distinction of primary and secondary effects of social origin by Boudon (1974), these core concepts are discussed in the frames of Bourdieu’s (1982 [1979], 1992) habitus theory, emphasizing the transmission of cultural capital in families, and of rational choice approaches (e.g. Esser, 1999). Moreover, theoretical approaches on disparities structured by gender (e.g. Breen et al., 2010) and migration background (Kristen & Dollmann, 2010) as well as further axes of educational inequalities are considered to explain found differences in students’ educational values and attitudes towards schooling. The validation of the measurement instrument of VoE by means of factor analysis indicates four dimensions of VoE among school students in these contexts: stimulation as an intrinsic value, comfort and status related to standards of living and future career goals, behavioural confirmation in terms of expectations of significant others, and the social goal affection. Structural equation models demonstrate that the lower value of stimulation through education among boys mediates their higher level of SAL across country contexts. Yet, a higher value of comfort/status among students increases the development of negative attitudes. Whereas immigrant students’ higher behavioural confirmation in the Canton of Bern backs the immigrant optimism thesis (Kao & Tienda, 1995), immigrant students in Luxembourg reveal a general lower VoE and are more alienated from teachers. Contextual effects estimated in multilevel models explain the higher prevalence of alienation from learning in Luxembourgish classrooms. Within the stratified and segregated secondary schooling, students in the academic track are more alienated compared to students in technical secondary education. This result contradicts the differentiation–polarization theory (Van Houtte, 2006) in the context of Luxembourg. On the other hand, in Berne, alienation from learning does not differ between school tracks, but is overall lower in the less segregated, more permeable schools. Classroom composition effects, however, show no clear pattern. In line with prior research, alienation from learning is lower in Luxembourgish classrooms with a higher percentage of immigrant students. With regard to the consequences of SAL, the results show a negative impact of alienation from learning on school achievement in both country settings. Deriving implications, the findings provide some arguments in favour of comprehensive school models. [less ▲]

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See detailEvaluating Vulnerability Prediction Models
Jimenez, Matthieu UL

Doctoral thesis (2018)

Today almost every device depends on a piece of software. As a result, our life increasingly depends on some software form such as smartphone apps, laundry machines, web applications, computers ... [more ▼]

Today almost every device depends on a piece of software. As a result, our life increasingly depends on some software form such as smartphone apps, laundry machines, web applications, computers, transportation and many others, all of which rely on software. Inevitably, this dependence raises the issue of software vulnerabilities and their possible impact on our lifestyle. Over the years, researchers and industrialists suggested several approaches to detect such issues and vulnerabilities. A particular popular branch of such approaches, usually called Vulnerability Prediction Modelling (VPM) techniques, leverage prediction modelling techniques that flag suspicious (likely vulnerable) code components. These techniques rely on source code features as indicators of vulnerabilities to build the prediction models. However, the emerging question is how effective such methods are and how they can be used in practice. The present dissertation studies vulnerability prediction models and evaluates them on real and reliable playground. To this end, it suggests a toolset that automatically collects real vulnerable code instances, from major open source systems, suitable for applying VPM. These code instances are then used to analyze, replicate, compare and develop new VPMs. Specifically, the dissertation has 3 main axes: The first regards the analysis of vulnerabilities. Indeed, to build VPMs accurately, numerous data are required. However, by their nature, vulnerabilities are scarce and the information about them is spread over different sources (NVD, Git, Bug Trackers). Thus, the suggested toolset (develops an automatic way to build a large dataset) enables the reliable and relevant analysis of VPMs. The second axis focuses on the empirical comparison and analysis of existing Vulnerability Prediction Models. It thus develops and replicates existing VPMs. To this end, the thesis introduces a framework that builds, analyse and compares existing prediction models (using the already proposed sets of features) using the dataset developed on the first axis. The third axis explores the use of cross-entropy (metric used by natural language processing) as a potential feature for developing new VPMs. Cross-entropy, usually referred to as the naturalness of code, is a recent approach that measures the repetitiveness of code (relying on statistical models). Using cross-entropy, the thesis investigates different ways of building and using VPMs. Overall, this thesis provides a fully-fledge study on Vulnerability Prediction Models aiming at assessing and improving their performance. [less ▲]

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See detailDas Palux-Projekt in Luxemburg: Forschungsdesign und erste Ergebnisse einer Pilotstudie
Eckelt, Melanie UL; Hutmacher, Djenna UL; Steffgen, Georges UL et al

in Bartsch, Fabienne; Mombeck, Mona; Müller, Merle (Eds.) et al Tägliche Herausforderungen meistern - Sportlehrkräfte im Fokus (2018, October)

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See detailQualitative Interviewstudie zum Französischunterricht in Luxemburg
Morys, Nancy UL

in Lenz, Thomas (Ed.) Bildungsbericht 2018. Bildungsverläufe und Bildungserfolge (2018)

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See detailThe Veneto Banks Resolution: It Shall Be Called ‘Liquidation’
Asimakopoulos, Ioannis UL

in European Company Law (2018), (5),

The establishment of Banking Union and the Single Resolution Mechanism has been arguably a success for the Eurozone. However, the enforcement of the new rules seems to meet significant challenges related ... [more ▼]

The establishment of Banking Union and the Single Resolution Mechanism has been arguably a success for the Eurozone. However, the enforcement of the new rules seems to meet significant challenges related to legacy problems that could make bank resolution economically and politically unfavourable for Member States. Italy and the two Veneto banks that were liquidated under national laws in June 2017 constitute such a case. However, this paper argues that this ‘orderly liquidation’ was, in essence, a hidden resolution, which raises logical legality concerns as to the actions ultimately taken by the European and national resolution authorities. The fact that public interest for resolution was not found by the Single Resolution Board, but was instead established by the Commission to provide liquidation aid on the grounds of 107(3)(b) TFEU, combined with the reasoning of the Commission’s decision do not seem to conform with the bank resolution and state aid rules currently in place. [less ▲]

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See detailChanges in Childhood and Adolescence: Current Challenges for Physical Education
Scheuer, Claude; Bund, Andreas UL; Holzweg, Martin

Book published by Logos (2018)

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See detailForword by the Editors
Scheuer, Claude; Bund, Andreas UL; Holzweg, Martin

in Scheuer, Claude; Bund, Andreas; Holzweg, Martin (Eds.) Changes in Childhood and Adolescence: Challenges for Physical Education (2018)

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See detailFür ein ‘anderes’ Verständnis von Grenze: Erfordernisse und Entwicklungen in den Border Studies. Einführungsvortrag
Wille, Christian UL

Presentation (2018, October)

Die Tagungsreihe zum Phänomen der Deplatzierung (2017-2019) fokussiert auf aktuelle Entwicklungen im Schnittfeld von Flucht, Grenze und Integration. Im Jahr 2018 stehen der Begriff der Grenze und seine ... [more ▼]

Die Tagungsreihe zum Phänomen der Deplatzierung (2017-2019) fokussiert auf aktuelle Entwicklungen im Schnittfeld von Flucht, Grenze und Integration. Im Jahr 2018 stehen der Begriff der Grenze und seine Bezüge zu Migrationsphänomenen im Zentrum. Dafür leitend ist das Verhältnis von Grenze und Flucht und vor diesem Hintergrund die Frage, wie Grenzen im Spiegel von aktuellen Entwicklungen gedacht werden können und müssen. Damit ist es Ziel der Tagung, das Konzept der Grenze sowie Migrationsphänomene in Verbindung zu bringen und ein zeitgemäßes Verständnis von ‚Grenze‘ zu entwickeln. Dafür leitend ist die Auffassung, dass Migration konstitutiv ist für Grenzen, die wiederum als Praktiken der Regulierung – und damit als Prozesse – gedacht werden und mit Phänomenen der Flucht in Beziehung stehen. Das bedeutet, ein ‚anderes’ Verständnis von Grenze muss es leisten, diese jenseits territorialer Markierungen zu denken und als Regulierungspraxis an unterschiedlichen Orten sichtbar zu machen. Dies führt zu der Frage, wo und wie sich Grenzen ‚ereignen‘ und zu der Einsicht, dass Grenze nicht resultieren aus dem vereinfacht gedachten Zusammenspiel von staatlicher Regulierungspraxis einerseits und migrancy andererseits. Vielmehr geht es darum, solche performativen Prozesse in ihrer Vielschichtigkeit in den analytischen Blick zu bekommen und kritisch zu untersuchen. Der Einführungsvortrag greift diese Erfordernisse auf und versucht theoretisch-konzeptuelle Antworten in den Border Studies zu finden. Dieses aufstrebende Arbeitsfeld der Sozial- und Kulturwissenschaften ist spätestens seit der Jahrtausendwende von einem Zuwachs der beteiligten Disziplinen, einer Gleichzeitigkeit der praktizierten Paradigmen und von einer fortschreitenden Binnendifferenzierung gekennzeichnet. Daran knüpft der Vortrag an und macht rezente Entwicklungen der kulturwissenschaftlichen Border Studies (Cultural Border Studies) für das Thema der Tagung produktiv. [less ▲]

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See detailLa mobilité transfrontalière des travailleurs est-elle une ressource pour la Grande Région?
Pigeron-Piroth, Isabelle UL; Belkacem, Rachid

Report (2018)

La Grande Région est l’un des espaces transfrontaliers les plus concernés par les flux de travail frontalier. Face aux nombreux défis (économiques, démographiques, environnementaux, etc.) auxquels elle se ... [more ▼]

La Grande Région est l’un des espaces transfrontaliers les plus concernés par les flux de travail frontalier. Face aux nombreux défis (économiques, démographiques, environnementaux, etc.) auxquels elle se trouve confrontée, peut-on considérer la mobilité transfrontalière comme une ressource pour les territoires frontaliers ? Telle était la question de départ posée aux différents spécialistes présents lors du Forum Grande Région du 7 juin 2018. Cette table ronde a réuni près de 70 participants issus du monde politique, économique, universitaire, mais également des citoyens intéressés par ces questions. Elle a donné lieu à de nombreux échanges et débats, révélant d’intéressantes pistes de recherche futures. [less ▲]

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See detailWhy Energy Matters? Profiling Energy Consumption of Mobile Crowdsensing Data Collection Frameworks
Tomasoni, Mattia; Capponi, Andrea UL; Fiandrino, Claudio UL et al

in Pervasive and Mobile Computing (2018)

Mobile Crowdsensing (MCS) has emerged in the last years and has become one of the most prominent paradigms for urban sensing. The citizens actively participate in the sensing process by contributing data ... [more ▼]

Mobile Crowdsensing (MCS) has emerged in the last years and has become one of the most prominent paradigms for urban sensing. The citizens actively participate in the sensing process by contributing data with their mobile devices. To produce data, citizens sustain costs, i.e., the energy consumed for sensing and reporting operations. Hence, devising energy efficient data collection frameworks (DCF) is essential to foster participation. In this work, we investigate from an energy-perspective the performance of different DCFs. Our methodology is as follows: (i) we developed an Android application that implements the DCFs, (ii) we profiled the energy and network performance with a power monitor and Wireshark, (iii) we included the obtained traces into CrowdSenSim simulator for large-scale evaluations in city-wide scenarios such as Luxembourg, Turin and Washington DC. The amount of collected data, energy consumption and fairness are the performance indexes evaluated. The results unveil that DCFs with continuous data reporting are more energy-efficient and fair than DCFs with probabilistic reporting. The latter exhibit high variability of energy consumption, i.e., to produce the same amount of data, the associated energy cost of different users can vary significantly. [less ▲]

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See detailMesophilic and Thermophilic Anaerobic Digestion of Model Kitchen Waste with Variation of Fat Content
Sobon-Muehlenbrock, Elena UL; Greger, Manfred UL; Schlienz, Markus UL

in Mesophilic and Thermophilic Anaerobic Digestion of Model Kitchen Waste with Variation of Fat Content (2018, October)

Synthetic kitchen waste, produced on basis of a real kitchen waste, and two of its variations are studied. Previous study showed that the fermentation of kitchen waste was similar to the degradation of ... [more ▼]

Synthetic kitchen waste, produced on basis of a real kitchen waste, and two of its variations are studied. Previous study showed that the fermentation of kitchen waste was similar to the degradation of synthetic kitchen waste, further called model kitchen waste (MKW) with the same amounts of carbohydrates, fats and proteins. In this study the anaerobic degradation of this MKW (named MKW1; 23 % rapeseed oil) was investigated under mesophilic and thermophilic conditions at 2 different loadings. Additional experiments were performed with lower (MKW2; 14.7 %) and higher (MKW3; 27.2 %) rapeseed oil content at the expense of starch. An organic loading of 5 gVS/l leads to a fast and undisturbed degradation under mesophilic conditions. The volatile fatty acids (mainly acetic acid) appeared only during the first 3 days. Finally the amount of biogas been produced is weakly correlated with the oil content. Under thermophilic conditions the biogas production was retarded and the concentrations of the volatile fatty acids were generally higher whereas acetic acid was present for a period of 10 days. The final biogas amount was higher than compared to mesophilc conditions. At a higher loading of 25 gVS/l a strong retardation of biogas production was observed which correlates with very high concentrations of volatile fatty acids over the whole runtime period of 50 days. [less ▲]

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See detailHITECS: A UML Profile and Analysis Framework for Hardware-in-the-Loop Testing of Cyber Physical Systems
Shin, Seung Yeob UL; Chaouch, Karim UL; Nejati, Shiva UL et al

in Proceedings of ACM/IEEE 21st International Conference on Model Driven Engineering Languages and Systems (MODELS’18) (2018, October)

Hardware-in-the-loop (HiL) testing is an important step in the development of cyber physical systems (CPS). CPS HiL test cases manipulate hardware components, are time-consuming and their behaviors are ... [more ▼]

Hardware-in-the-loop (HiL) testing is an important step in the development of cyber physical systems (CPS). CPS HiL test cases manipulate hardware components, are time-consuming and their behaviors are impacted by the uncertainties in the CPS environment. To mitigate the risks associated with HiL testing, engineers have to ensure that (1) HiL test cases are well-behaved, i.e., they implement valid test scenarios and do not accidentally damage hardware, and (2) HiL test cases can execute within the time budget allotted to HiL testing. This paper proposes an approach to help engineers systematically specify and analyze CPS HiL test cases. Leveraging the UML profile mechanism, we develop an executable domain-specific language, HITECS, for HiL test case specification. HITECS builds on the UML Testing Profile (UTP) and the UML action language (Alf). Using HITECS, we provide analysis methods to check whether HiL test cases are well-behaved, and to estimate the execution times of these test cases before the actual HiL testing stage. We apply HITECS to an industrial case study from the satellite domain. Our results show that: (1) HITECS is feasible to use in practice; (2) HITECS helps engineers define more complete and effective well-behavedness assertions for HiL test cases, compared to when these assertions are defined without systematic guidance; (3) HITECS verifies in practical time that HiL test cases are well-behaved; and (4) HITECS accurately estimates HiL test case execution times. [less ▲]

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See detailSuccessive convex approximation algorithms for sparse signal estimation with nonconvex regularizations
Yang, Yang UL; Pesavento, Marius; Chatzinotas, Symeon UL et al

in IEEE Journal of Selected Topics in Signal Processing (2018)

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See detailL'université, entre connaissance et intérêt.
Vomacka, Eloïse UL

Article for general public (2018)

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See detailSmall States in the European Union : Luxembourg
Danescu, Elena UL

in Hartly, Cathy (Ed.) WESTERN EUROPE 2019 (2018)

Detailed reference viewed: 59 (13 UL)
See detailDas Forschungsprojekt MuLiPEC (Developing multilingual pedagogies in early childhood)
Kirsch, Claudine UL; Mortini, Simone UL

in University of Luxembourg (Ed.) Bildungsbericht.Bildungsverläufe und Bildungserfolge (2018)

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See detailAuf dem Weg zur mehrsprachigen Bildung in der frühen Kindheit
Kirsch, Claudine UL

in Universität Luxembourg (Ed.) Bildungsbericht.Bildungsverläufe und Bildungserfolge (2018)

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See detailEnabling Model Testing of Cyber-Physical Systems
Gonzalez Perez, Carlos Alberto UL; Varmazyar, Mojtaba UL; Nejati, Shiva UL et al

in Proceedings of ACM/IEEE 21st International Conference on Model Driven Engineering Languages and Systems (MODELS’18) (2018, October)

Applying traditional testing techniques to Cyber-Physical Systems (CPS) is challenging due to the deep intertwining of software and hardware, and the complex, continuous interactions between the system ... [more ▼]

Applying traditional testing techniques to Cyber-Physical Systems (CPS) is challenging due to the deep intertwining of software and hardware, and the complex, continuous interactions between the system and its environment. To alleviate these challenges we propose to conduct testing at early stages and over executable models of the system and its environment. Model testing of CPSs is however not without difficulties. The complexity and heterogeneity of CPSs renders necessary the combination of different modeling formalisms to build faithful models of their different components. The execution of CPS models thus requires an execution framework supporting the co-simulation of different types of models, including models of the software (e.g., SysML), hardware (e.g., SysML or Simulink), and physical environment (e.g., Simulink). Furthermore, to enable testing in realistic conditions, the co-simulation process must be (1) fast, so that thousands of simulations can be conducted in practical time, (2) controllable, to precisely emulate the expected runtime behavior of the system and, (3) observable, by producing simulation data enabling the detection of failures. To tackle these challenges, we propose a SysML-based modeling methodology for model testing of CPSs, and an efficient SysML-Simulink co-simulation framework. Our approach was validated on a case study from the satellite domain. [less ▲]

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