http://orbilu.uni.lu The ORBi institutional repository system captures, stores, indexes, preserves, and distributes digital research material. Search this channel search http://orbilu.uni.lu/simple-search http://hdl.handle.net/10993/35998 Title: Venture Creation by Teams: How Joint Pre-Founding Circumstances Imprint on Effectual Decision-Making <br/> <br/>Author, co-author: Tryba, Anne <br/> <br/>Abstract: This study develops propositions regarding early decision-making preferences of entrepreneurial teams, impacting antecedents and contextual factors. Drawing on a multiple case study, it shows that teams tend to effectual decisions. Joint ambitions and perceived team diversity that emerge in shared pre-founding moments of transition shape the intensity of these preferences. http://hdl.handle.net/10993/35997 Title: Should Entrepreneurial Teams Plan or Experiment? The Interplay of Early Behavior, Diversity and Young Firm Growth <br/> <br/>Author, co-author: Tryba, Anne http://hdl.handle.net/10993/35996 Title: Should Entrepreneurial Teams Plan or Experiment? The Interplay of Early Behavior, Diversity and Young Firm Growth <br/> <br/>Author, co-author: Tryba, Anne http://hdl.handle.net/10993/35995 Title: Tapping the Potential of Diverse Founding Teams for Firm Growth: The Role of New Venture Activities <br/> <br/>Author, co-author: Tryba, Anne; Patzelt, Holger; Breugst, Nicola <br/> <br/>Abstract: Although education field diversity in founding teams can be an asset for new ventures, working in diverse teams might also be very challenging. Results from recent research indicate that the nature of diversity effects can only be revealed by exploring its contingencies. We build on upper echelons theory and argue that a new venture’s early activities are key contingencies influencing to what extent it can exploit the benefits of its founding team’s education field diversity. Using survey data from 103 young cofounded ventures in Luxembourg, this study shows that early planning helps new ventures to tap the potential of their educationally diverse teams and contribute to venture growth. In addition, simultaneous planning and experimentation in the early phase also moderate the relationship between education field diversity and venture growth, such that growth is highest when education field diversity, experimentation and planning are high. http://hdl.handle.net/10993/35994 Title: On bisymmetric and quasitrivial operations <br/> <br/>Author, co-author: Devillet, Jimmy <br/> <br/>Abstract: See attachment http://hdl.handle.net/10993/35993 Title: Enabling lock-free concurrent workers over temporal graphs composed of multiple time-series <br/> <br/>Author, co-author: Fouquet, Francois; Hartmann, Thomas; Mosser, Sébastien <br/> <br/>Abstract: Time series are commonly used to store temporal data, e.g., sensor measurements. However, when it comes to complex analytics and learning tasks, these measurements have to be combined with structural context data. Temporal graphs, connecting multiple time- series, have proven to be very suitable to organize such data and ultimately empower analytic algorithms. Computationally intensive tasks often need to be distributed and parallelized among different workers. For tasks that cannot be split into independent parts, several workers have to concurrently read and update these shared temporal graphs. This leads to inconsistency risks, especially in the case of frequent updates. Distributed locks can mitigate these risks but come with a very high-performance cost. In this paper, we present a lock-free approach allowing to concurrently modify temporal graphs. Our approach is based on a composition operator able to do online reconciliation of concurrent modifications of temporal graphs. We evaluate the efficiency and scalability of our approach compared to lock-based approaches. http://hdl.handle.net/10993/35992 Title: Subtyping attenuated psychotic symptoms: A cluster analytic approach <br/> <br/>Author, co-author: Laloyaux, Julien; Larøi, Frank; Nuyens, Filip; Billieux, Joël <br/> <br/>Abstract: Objective The aim of the present study is to examine the heterogeneity of attenuated psychotic symptoms (PS) and related personality factors using a cluster analytic approach. Method A large sample of participants from the general population was evaluated in terms of attenuated symptomatology (psychotic and affective) and two personality factors: encoding style and impulsivity traits. Results Cluster analysis emphasized the existence of five independent clusters: High Psychosis, High Positive, High Negative, High Impulsive-Low Psychosis, and Low Psychosis. Cluster comparisons demonstrated that the personality factors and PS are differentially involved in the clusters. Conclusions The present study demonstrated that reliable and relatively distinct clusters of individuals from the general population can be identified based on established PS and related personality factors. The fact that a variety of profiles was observed contributes to a better understanding of the nature of the heterogeneity characterizing PS and has clear theoretical and clinical implications. http://hdl.handle.net/10993/35991 Title: Characterizations of biselective operations <br/> <br/>Author, co-author: Devillet, Jimmy; Kiss, Gergely <br/> <br/>Abstract: Let X be a nonempty set and let i,j in {1,2,3,4}. We say that a binary operation F:X^2 -> X is (i,j)-selective if F(F(x_1,x_2),F(x_3,x_4)) = F(x_i,x_j), for all x_1,x_2,x_3,x_4 in X. In this paper we provide characterizations of the class of (i,j)-selective operations. We also investigate some subclasses by adding algebraic properties such as associativity or bisymmetry. http://hdl.handle.net/10993/35990 Title: The Failure of Binaural Stereo. Sound Engineers and the Introduction of Artificial Head Microphones <br/> <br/>Author, co-author: Krebs, Stefan <br/> <br/>Abstract: In 1973, binaural stereo was introduced to the German public during the International Broadcasting Fair in Berlin. Based on the development of artificial head microphones, binaural stereo provided facsimile sound recordings that enabled listeners, when listening with headphones, to experience the spatial acoustics of the original recording situation. During the fair, Berlin-based radio station Radio in the American Sector (RIAS) broadcast the first binaural radio play. Radio listeners and journalists praised it for its “super stereo” quality and highest fidelity, and expected that the future of radio would be three-dimensional. Despite this remarkable echo, German broadcasting stations were somewhat reluctant to adopt binaural stereo, and many sound engineers rejected to deploy artificial head microphones. They referred to certain technical shortcomings of binaural stereo in general, and available microphone models in particular. Based on contemporary publications, sources from broadcasting archives, and oral history interviews, this paper argues that recordists’ outright rejection of binaural stereo – its failure to be adopted in industry - was rather grounded in their listening and recording ideologies than in actual shortcomings of artificial head recording technology. http://hdl.handle.net/10993/35989 Title: Ernst Jünger beschreiben. Zur Mikrologie der 'historischen Phänomenologie' Hans Blumenbergs <br/> <br/>Author, co-author: Busch, Christopher http://hdl.handle.net/10993/35988 Title: merging urban form – Emerging pollution: Modelling endogenous health and environmental effects of traffic on residential choice <br/> <br/>Author, co-author: Schindler, Mirjam; Caruso, Geoffrey <br/> <br/>Abstract: Air pollution bears severe health and environmental impacts and is of increasing concern to urban planners but densification strategies have ambiguous impacts. We analyse how households’ aversion to generating and being exposed to traffic pollution at the residential place and during their commute influences emerging urban structures and how these structures in turn affect pollution exposure and the residential choice of households. Resulting spatial patterns are difficult to predict because of this feedback and the spatial form of urbanisation and road networks. We address this complexity with a micro-economic agent-based residential choice model dynamically coupled with a cellular automata model for pollution dispersion and its perception in neighbourhoods. Our simulation experiments on a theoretical grid suggest that the spatial scale of this perception is important. We also find that if both health and environmental concerns are to be addressed, a combination of reducing commuting distances and preserving local green spaces is necessary. In particular, locally dispersed urban development and intra-urban green spaces next to busy roads can mitigate pollution exposure. http://hdl.handle.net/10993/35987 Title: La mobilité transfrontalière des travailleurs est-elle une ressource pour la Grande Région <br/> <br/>Author, co-author: Pigeron-Piroth, Isabelle; Belkacem, Rachid <br/> <br/>Abstract: 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 ?; Die Großregion zählt zu den Grenzräumen mit dem höchsten Grenzgängeraufkommen. Kann die grenzüberschreitende Arbeitnehmermobilität angesichts der zahlreichen (wirtschaftlichen, demographischen, umweltbezogenen, etc.) Herausforderungen als Ressource für die Teilgebiete diskutiert werden? http://hdl.handle.net/10993/35986 Title: Identity Processes in Multicultural Antwerp: Report on an Ethnographic - Cross-Cultural Study <br/> <br/>Author, co-author: Stogianni, Maria; Van de Vijver, Fons http://hdl.handle.net/10993/35985 Title: STUDY OF THE INCORPORATION MECHANISMS OF ORGANIC CHEMICALS INTO HAIR <br/> <br/>Author, co-author: Chata, Caroline Georgette Samia <br/> <br/>Abstract: Hair presents several advantages for biomonitoring the exposure to pollutants. For instance, this matrix is representative of the mid to long term exposure depending on the length of the sample. However the question concerning the hair incorporation mechanism of chemicals remain partially unravelled. The subject of the present PhD was the “study of the incorporation mechanisms of organic chemicals into hair” (StICHa). Therefore we focused on the influence of biological and physicochemical parameters on the incorporation of pesticides into hair. The results presented in the project were obtained from three experiments whose two animal experiments conducted on rats. The first one allowed to link levels of exposure of pesticides to the corresponding concentrations in plasma and in hair. This also allowed to study the accumulation of pesticides in the rat body over time and to investigate the influence of the pesticide physicochemical properties on their incorporation into hair. The second one provided pharmacokinetic (PK) parameters of pesticides in blood after a single exposure and highlighted the concept of background exposure corresponding to the detectable chemicals concentration in the animals before exposure due to environmental contamination. An in vitro test was also conducted to investigate bonds between pesticides and blood components and their influence on hair incorporation. http://hdl.handle.net/10993/35984 Title: Development of mass spectrometry-based assays to measure the ERCC1/XPF proteins as potential biomarkers in lung cancer <br/> <br/>Author, co-author: Antonelli, Daniela <br/> <br/>Abstract: In the last two decades, the integration of personalized medicine approaches in the management of oncology patients has led to important progress. Indeed, the use of predictive biomarkers in clinical practice to improve treatment strategies has represented an important achievement for both patient clinical outcomes and quality of medical care. In the context of lung cancer, several studies have highlighted a potential role of the excision repair cross-complementation group 1 (ERCC1) protein as a predictive biomarker of platinum-based chemotherapy efficacy in the treatment of non-small cell lung cancer (NSCLC) patients. ERCC1 protein and its binding partner, the DNA repair endonuclease XPF, are key players in the nucleotide excision repair (NER) pathway where they repair DNA lesions caused by platinum-based drugs. However, the presence of four ERCC1 isoforms, of which only one, ERCC1-202, is functional in the NER pathway, complicates the clinical scenario. Indeed, the lack of an antibody that specifically recognizes ERCC1-202 hampers the development of a valid clinical assay to assist clinicians in therapeutic decision making. Moreover, the essential nature of the ERCC1/XPF interaction to repair DNA lesions, suggested the pivotal role of the ERCC1/XPF complex in the prediction of therapy response. Because of the need to discriminate among the four ERCC1 isoforms, to selectively quantify ERCC1-202 in an antibody-independent fashion, and because of the required contribution of the XPF protein in the DNA lesion processing, the present project aimed to develop robust mass spectrometry (MS)-based assays for the ERCC1 and XPF isoforms to provide accurate quantification of the ERCC1-202/XPF proteins as binding partners. Combining ERCC1 or XPF immunoenrichment from biological samples with targeted mass spectrometry, the selected ERCC1 and XPF proteotypic peptides (PTPs) were measured by parallel reaction monitoring (PRM) using a quadrupole-obitrap mass spectrometer. The quantification of the ERCC1-202/XPF proteins was performed using stable isotope labeled (SIL) peptides. The associated results showed that the simultaneous detection of three ERCC1 PTPs, named isoform discriminating peptides, represents a signature of ERCC1-202 and that the inclusion of control peptides allows to avoide ERCC1 isoform misclassification. The immuno-affinity studies and the evaluation of XPF stability highlighted that ERCC1-202 interacts and stabilizes XPF. Finally, a correlation between ERCC1-202/XPF protein levels was observed. In the light of the poor analytic specificity of the current immunohistochemistry (IHC) assay for the ERCC1 protein, the use of targeted MS-based assays to detect and quantify both ERCC1-202 and XPF proteins represents a more selective approach. These findings strongly suggest to assess the role of the ERCC1-202/XPF proteins as predictive biomarkers in clinical samples with the final goal to guide the clinicians’ therapeutic decisions. http://hdl.handle.net/10993/35983 Title: Identification of DNA damage response genes as targets for personalized treatment of Glioblastoma through RNA interference screens <br/> <br/>Author, co-author: Erasimus, Hélène Claudine Pascale <br/> <br/>Abstract: Despite surgical resection and genotoxic treatment with ionizing radiation and the DNA alkylating agent temozolomide (TMZ), glioblastoma (GBM) remains one of the most lethal cancers, due in part to the action of DNA repair factors that drive resistance and lead to tumor relapse. Important features of these mechanisms include the inherent redundancy and complexity of the many DNA repair pathways activated as part of the DNA damage response (DDR). One important DDR factor is encoded by the O-6-methylguanine-DNA methyltransferase (MGMT) gene whose epigenetic silencing is a strong predictive marker for favorable outcome in GBM patients treated with TMZ. However, even patients displaying MGMT promoter methylation succumb to tumor relapse, indicating that other DNA repair mechanisms promote resistance to the treatment. The main aim of this work was to identify essential DDR factors that support GBM cell survival under TMZ treatment in order to provide novel targets and thus, novel insights into drug combinations that could overcome GBM chemoresistance. The strategy to achieve this goal was to use well-characterized GBM cell lines in focused loss of function shRNA screens performed under different conditions. Indeed, screens were designed to uncover DDR genes that are essential for GBM cells i) under normal conditions, ii) under TMZ treatment, iii) and under TMZ treatment in MGMT negative contexts. Pooled shRNAs targeting more than 500 DDR genes were introduced into GBM cells reflecting two clinically-relevant GBM contexts: a MGMT-positive context using MGMT-expressing cells and a negative one, using cell lines in which MGMT was depleted hrough pharmacological inhibition or RNA interference. Potential DDR targets that could sensitize GBM cells to TMZ have been identified and some of them validated. Surprisingly, some of these targets are not only involved in pathways that are commonly known to drive TMZ resistance (i.e. Double strand break repair, Direct repair), but also in repair pathways such as transcription-coupled nucleotide excision repair (TC-NER) or the early steps of the Fanconi Anemia pathway (FA). While components of the early FA pathway might be attractive targets especially in MGMT-negative contexts, it may be interesting to target factors involved in the early steps of the TC-NER to sensitize MGMTpositive cells to TMZ. So in addition to its predictive and prognostic value, MGMT might be a relevant stratification marker to treat patients in a personalized way. Supporting this hypothesis, the screen analyses revealed that the curative inhibition of some genes in combination with TMZ treatment might turn to be deleterious depending on MGMT expression level. One of the promising target will be further investigated in vitro as well as in vivo to elucidate the molecular mechanisms by which this gene operates to confer cellular resistance to TMZ. This study opens up new horizons for combinatorial therapies and hopefully, will be used to improve therapeutical approaches, particularly for MGMT-positive GBM patients, who currently do not benefit at all from chemotherapy. http://hdl.handle.net/10993/35982 Title: Exploring Multilingual Pedagogies: Forced Migrants’ Learning Experiences in Luxembourg <br/> <br/>Author, co-author: Kalocsanyiova, Erika <br/> <br/>Abstract: While most societies are structured around diverse flows of people and complex linguistic repertoires, (language) education schemes are still dominated by monolingual instructional practices. This paper aims to contribute to current discussions on the affordances of multilingual pedagogies in contexts of forced migration. It draws on a range of linguistic ethnographic data (Copland & Creese, 2015) that was collected over the period of 2016-2017 in diverse settings of language learning and socialization. Our research sites in Luxembourg included language courses in French, English and German, mathematics courses, application and web development training, and diverse leisure activities. Having followed the learning trajectory of five asylum applicants, we explored how they built on their old and newly-acquired language resources. Our findings confirm that in order to make their voices heard, the learners often drew upon elements from multiple languages, including those local languages they had no extensive competence in. This multilingual orientation enabled them to see the local languages as new functional resources in their growing repertoires (Kalocsányiová, 2017). This is of special relevance in contexts of forced migration, where learners need to become users of the languages they are learning from the first day onward. http://hdl.handle.net/10993/35981 Title: Energy-Efficient Data Acquisition in Mobile Crowdsensing Systems <br/> <br/>Author, co-author: Capponi, Andrea <br/> <br/>Abstract: Mobile Crowdsensing (MCS) is one of the most promising paradigms for monitoring phenomena in urban environments. The success of a MCS campaign relies on large participation of citizens, who may be reluctant in joining a campaign due to sensing and reporting costs they sustain. Hence, it is fundamental to propose efficient data collection frameworks (DCFs). In the first stages of our work, we proposed an energyefficient DCF that aims to minimize energy consumption while maximizing the utility of contributed data. Then, we developed an Android application and proposed a methodology to compare several DCFs, performing energy- and network-related measures with Power Monitor and Wireshark. Currently, we are investigating collaborative data delivery as a more efficient solution than the individual one. The key idea is to form groups of users and elect a responsible for aggregated data delivery. To this end, it is crucial to analyze device to device (D2D) communications and propose efficient policies for group formation and owner election. To evaluate the performance in realistic urban environments we exploit CrowdSenSim, which runs large-scale simulations in citywide scenarios. http://hdl.handle.net/10993/35980 Title: Développement d’un test de compétences numériques précoces destiné à mesurer les effets d’une intervention mise en place auprès d’élèves de 4 à 6 ans <br/> <br/>Author, co-author: de Chambrier, Anne-Françoise; Vlassis, Joëlle; Fagnant, Annick; Giauque, Nadine; Auquière, Amélie; Luxembourger, Christophe; Dierendonck, Christophe; Tinnes, Mélanie http://hdl.handle.net/10993/35979 Title: Developing a tool for assessing elementary algebraic knowledge for teaching : a twofold perspective for understanding teachers' decision-making <br/> <br/>Author, co-author: Demonty, Isabelle; Vlassis, Joëlle