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See detailThe use of primary human fibroblasts for monitoring mitochondrial phenotypes in the field of Parkinson's disease.
Burbulla, Lena F.; Krüger, Rejko UL

in Journal of visualized experiments : JoVE (2012), (68),

Parkinson's disease (PD) is the second most common movement disorder and affects 1% of people over the age of 60 (1). Because ageing is the most important risk factor, cases of PD will increase during the ... [more ▼]

Parkinson's disease (PD) is the second most common movement disorder and affects 1% of people over the age of 60 (1). Because ageing is the most important risk factor, cases of PD will increase during the next decades (2). Next to pathological protein folding and impaired protein degradation pathways, alterations of mitochondrial function and morphology were pointed out as further hallmark of neurodegeneration in PD (3-11). After years of research in murine and human cancer cells as in vitro models to dissect molecular pathways of Parkinsonism, the use of human fibroblasts from patients and appropriate controls as ex vivo models has become a valuable research tool, if potential caveats are considered. Other than immortalized, rather artificial cell models, primary fibroblasts from patients carrying disease-associated mutations apparently reflect important pathological features of the human disease. Here we delineate the procedure of taking skin biopsies, culturing human fibroblasts and using detailed protocols for essential microscopic techniques to define mitochondrial phenotypes. These were used to investigate different features associated with PD that are relevant to mitochondrial function and dynamics. Ex vivo, mitochondria can be analyzed in terms of their function, morphology, colocalization with lysosomes (the organelles degrading dysfunctional mitochondria) and degradation via the lysosomal pathway. These phenotypes are highly relevant for the identification of early signs of PD and may precede clinical motor symptoms in human disease-gene carriers. Hence, the assays presented here can be utilized as valuable tools to identify pathological features of neurodegeneration and help to define new therapeutic strategies in PD. [less ▲]

Detailed reference viewed: 122 (2 UL)
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See detailUse of recycled concrete in construction in Luxembourg
Waldmann, Danièle UL; Thapa, Vishojit Bahadur UL

in Cahier Scientifique - Revue Technique Luxembourgeoise (2015)

Construction and demolition waste constitutes a major portion of total waste production in the world, and most of it is used in landfills. The re-use of concrete rubble collected from demolished ... [more ▼]

Construction and demolition waste constitutes a major portion of total waste production in the world, and most of it is used in landfills. The re-use of concrete rubble collected from demolished structures is an important issue. After crushing and screening, there is the possibility of appropriately treating and reusing such waste as aggregate in new concrete, especially in lower level applications. Different aspects of the topic beginning with a brief review of the European initiatives and definition in terms of C&D waste generated and recycled aggregates produced from C&D waste are given. Along with a brief overview of C&D waste, a summary of the situation in Luxembourg in use of recycled aggregate is discussed. This writing concludes by identifying some of the major barriers in more use of recycled aggregate concrete, including lack of awareness, lack of knowledge, barriers of specifications/codes for reusing these aggregates in new concrete. [less ▲]

Detailed reference viewed: 202 (41 UL)
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See detailThe use of simulation in the design of critical embedded systems
Navet, Nicolas UL

Scientific Conference (2016, June 09)

Les plate-formes virtuelles permettant de prédire par simulation numérique les performances deviennent peu à peu une réalité dans la conception des systèmes de contrôle les plus complexes et les plus ... [more ▼]

Les plate-formes virtuelles permettant de prédire par simulation numérique les performances deviennent peu à peu une réalité dans la conception des systèmes de contrôle les plus complexes et les plus contraints (automobile, aéronautique, contrôle de réseaux power-grid, etc). Dès les phases amont du cycle de conception, ces outils guident les concepteurs dans leurs choix de conception. Le premier objectif de cet exposé est de dresser un rapide panorama des modèles et techniques de simulation de l'embarqué critique: simulation du comportement fonctionnel (lois de contrôle), simulation "timing-accurate" des plate-formes d'exécution, de leur complémentarité et limites actuelles. Contrairement à des techniques mathématiques, la simulation ne fournit a priori aucune garantie sur la couverture de vérification et les situations pire-cas ("corner cases") ne sont pas nécessairement identifiées. Néanmoins la simulation est de plus en plus incontournable car les modèles analytiques ne sont généralement pas en mesure de capturer toute la complexité des systèmes réels. Le second objectif de cet exposé est d'identifier des bonnes pratiques méthodologiques pour l'utilisation de la simulation dans les systèmes critiques (ex: choix des temps de simulation et nombre d'expérimentations en fonction de caractéristiques structurelles des processus simulés, métriques de performances pour les événements rares, etc). [less ▲]

Detailed reference viewed: 92 (7 UL)
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See detailThe use of strategies in motor learning: Validation of a new questionnaire
Bund, Andreas UL; Wiemeyer, Josef

in Beek, Peter; van de Langenberg, Rolf (Eds.) European Workshop on Movement Science - Book of Abstracts (2007, June)

Detailed reference viewed: 36 (0 UL)
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See detailThe use of strategies in motor learning: Validation of a new questionnaire.
Bund, Andreas UL; Wiemeyer, Josef

Poster (2007, June)

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See detailThe use of the discrete Sugeno integral in decision making: a survey
Dubois, Didier; Marichal, Jean-Luc UL; Prade, Henri et al

in International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems (2001), 9(5), 539-561

An overview of the use of the discrete Sugeno integral as either an aggregation tool or a preference functional is presented in the qualitative framework of two decision paradigms: multi-criteria decision ... [more ▼]

An overview of the use of the discrete Sugeno integral as either an aggregation tool or a preference functional is presented in the qualitative framework of two decision paradigms: multi-criteria decision-making and decision-making under uncertainty. The parallelism between the representation theorems in both settings is stressed, even if a basic requirement like the idempotency of the aggregation scheme should be explicitely stated in multi-criteria decision-making, while its counterpart is implicit in decision under uncertainty by equating the utility of a constant act with the utility of its consequence. Important particular cases of Sugeno integrals such as prioritized minimum and maximum operators, their ordered versions, and Boolean max-min functions are studied. [less ▲]

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See detailThe use of the discrete Sugeno integral in decision making: a survey
Dubois, Didier; Marichal, Jean-Luc UL; Prade, Henri et al

in Colorni, A.; Paruccini, M.; Roy, B. (Eds.) AMCDA - Aide Multi Critère à la Décision (Multiple Criteria Decision Aiding) (2001)

An overview of the use of the discrete Sugeno integral as either an aggregation tool or a utility function is presented in the qualitative framework of two decision paradigms: multi-criteria decision ... [more ▼]

An overview of the use of the discrete Sugeno integral as either an aggregation tool or a utility function is presented in the qualitative framework of two decision paradigms: multi-criteria decision-making and decision-making under uncertainty. The parallelism between the representation theorems in both settings is stressed, even if a basic requirement like idempotency should be explicitely stated in multi-criteria decision-making, while its counterpart is implicit in decision under uncertainty by equating the utility of a constant act with the utility of its consequence. Important particular cases of Sugeno integrals such as prioritized minimum and maximum operators, their ordered versions, and Boolean max-min functions are studied. [less ▲]

Detailed reference viewed: 37 (4 UL)
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See detailThe use of the discrete Sugeno integral in multi-criteria decision making
Marichal, Jean-Luc UL

Scientific Conference (2000, January)

We present a model allowing to aggregate decision criteria when the available information is of qualitative nature. The use of the Sugeno integral as an aggregation function is justified by an axiomatic ... [more ▼]

We present a model allowing to aggregate decision criteria when the available information is of qualitative nature. The use of the Sugeno integral as an aggregation function is justified by an axiomatic approach. [less ▲]

Detailed reference viewed: 35 (1 UL)
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See detailUse of the Heartrail II catheter as a distal stent delivery device; an extended case series.
Mamas, Mamas A.; Eichhofer, Jonas; Hendry, Cara et al

in EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology (2009), 5(2), 265-71

AIMS: The Terumo Heartrail catheter (Terumo Corp., Tokyo, Japan) allows extra deep catheter intubation of coronary vessels and has been shown to be useful in CTO lesions. The aim of this study is to ... [more ▼]

AIMS: The Terumo Heartrail catheter (Terumo Corp., Tokyo, Japan) allows extra deep catheter intubation of coronary vessels and has been shown to be useful in CTO lesions. The aim of this study is to assess the safety and efficacy of using the Heartrail II catheter as a distal stent delivery system in PCI following failure of conventional techniques. METHODS AND RESULTS: We prospectively identified cases performed over a 15-month period in which a Heartrail catheter was used to facilitate stent delivery following failure of conventional techniques. Stent delivery using the Heartrail catheter was performed in 35 cases and was successful in 31 cases. Success rates of 100% in grafts, 95% in RCA, 80% in LAD and 60% in circumflex cases were recorded respectively. Successful stent delivery was associated with intubation depth, with 29/29 succeeding when the intubation depth was > 2 cm and failure in 4/5 cases when the intubation depth <or= 2 cm. There were no complications related to deep intubation of the catheter. CONCLUSIONS: Use of the Heartrail catheter is safe and highly effective for aiding stent delivery across proximal obstructions in both left and right coronary systems. The small number of unsuccessful cases were related to inability of the catheter to traverse stenotic proximal obstructions within 2 cm of the RCA and LCA origins. [less ▲]

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See detailThe use of the minus sign in solving arithmetical equations
Vlassis, Joëlle UL

Poster (2013)

Detailed reference viewed: 58 (5 UL)
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See detailUse of the sheathless guide catheter during routine transradial percutaneous coronary intervention: a feasibility study.
Mamas, Mamas; D'Souza, Savio; Hendry, Cara et al

in Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions (2010), 75(4), 596-602

OBJECTIVE: The aim of this study is to investigate the feasibility of using a 6.5 Fr sheathless guide catheter as a default system in transradial (TRA) percutaneous coronary intervention (PCI). BACKGROUND ... [more ▼]

OBJECTIVE: The aim of this study is to investigate the feasibility of using a 6.5 Fr sheathless guide catheter as a default system in transradial (TRA) percutaneous coronary intervention (PCI). BACKGROUND: TRA PCI has been shown to reduce mortality rates through a reduction in access site related bleeding complications compared with procedures performed though a femoral approach. Complications associated with the TRA route increase with the size of sheath used. These complications may be reduced by the use of a sheathless guide catheter system (Asahi Intecc, Japan) that is 1-2 Fr sizes smaller in diameter than the corresponding introducer sheath. METHODS: We performed PCI in 100 consecutive cases using 6.5 Fr sheathless guides to determine the procedural success, rates of symptomatic radial spasm and radial occlusion. RESULTS: Procedural success using the 6.5 Fr sheathless guide catheter system was 100% with no cases requiring conversion to a conventional guide and catheter system. There were no procedural complications recorded associated with the use of the catheter. Adjunctive devices used in this cohort included IVUS, stent delivery catheters, distal protection devices, and simple thrombectomy catheters. The rate of radial spasm was 5% and the rate of radial occlusion at 2 months was 2%. CONCLUSION: Use of the 6.5 Fr sheathless guide catheter system, which has an outer diameter <5 Fr sheath, as the default system in routine PCI is feasible with a high rate of procedural success via the radial artery. [less ▲]

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See detailUse of the Sideguard (Cappella) stent in bifurcation lesions: a real-world experience.
Mamas, Mamas A.; Farooq, Vasim; Latib, Azeem et al

in EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology (2012), 7(10), 1170-80

AIMS: The Sideguard(R) stent (Cappella Medical Devices Ltd, Galway, Ireland), is a novel nitinol self-expanding dedicated bifurcation stent that flares proximally at the ostium of the side branch (SB ... [more ▼]

AIMS: The Sideguard(R) stent (Cappella Medical Devices Ltd, Galway, Ireland), is a novel nitinol self-expanding dedicated bifurcation stent that flares proximally at the ostium of the side branch (SB) into a trumpet shape thereby achieving full ostial coverage. The aim of this study is to report the utility and limitations of this stent in patients undergoing treatment to bifurcation coronary lesions in a real-world setting. METHODS AND RESULTS: We prospectively identified 20 successive patients admitted over a 6-month period in whom there was significant SB disease and who were suitable for a bifurcation procedure. The Sideguard(R) stent was successfully used in all 20 cases including several that would have been technically difficult using conventional bifurcation techniques. We highlight use of this system using five illustrative cases that illustrate its utility and limitations in the treatment of bifurcation lesions. CONCLUSIONS: The Sideguard(R) stent can be used to treat complex bifurcation lesions in a straight forward manner and is not subject to the limitations associated with conventional bifurcation PCI techniques including jailing of the SB ostium and inability to fully cover/scaffold the ostium of the SB. [less ▲]

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See detailUSE OF TIME- AND FREQUENCY-DOMAIN APPROACHES FOR DAMAGE DETECTION IN CIVIL ENGINEERING STRUCTURES
Nguyen, Viet Ha UL; Mahowald, Jean UL; Golinval, Jean-Claude et al

in Maia, NNM; Matos Neves, M.; Chedas Sampaio, R.P. (Eds.) International Conference on Structural Engineering Dynamics (ICEDyn 2013) - Sesimbra 17-19 June 2013 (2013, June)

The aim of this paper is to apply both time- and frequency-domain-based approaches on real-life civil engineering structures and to assess their capability for damage detection. The first structure is the ... [more ▼]

The aim of this paper is to apply both time- and frequency-domain-based approaches on real-life civil engineering structures and to assess their capability for damage detection. The first structure is the Champangshiehl Bridge located in Luxembourg. Several damage levels were intentionally created by cutting a growing number of prestressed tendons and vibration data were acquired by the University of Luxembourg for each damaged state. The second example consists in reinforced and prestressed concrete panels. Successive damages were introduced in the panels by loading heavy weights and by cutting steel wires. The illustrations show different consequences in damage identification by the considered techniques. [less ▲]

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See detailUse Of Time- And Frequency-Domain Approaches For Damage Detection In Civil Engineering Structures
Nguyen, Viet Ha UL; Mahowald, Jean UL; Maas, Stefan UL et al

in Shock and Vibration (2014), 2014

The aim of this paper is to apply both time- and frequency-domain-based approaches on real-life civil engineering structures and to assess their capability for damage detection. The methodology is based ... [more ▼]

The aim of this paper is to apply both time- and frequency-domain-based approaches on real-life civil engineering structures and to assess their capability for damage detection. The methodology is based on Principal Component Analysis. The first structure is the Champangshiehl Bridge located in Luxembourg. Several damage levels were intentionally created by cutting a growing number of prestressed tendons and vibration data were acquired by the University of Luxembourg for each damaged state. The second example consists in reinforced and prestressed concrete panels. Successive damages were introduced in the panels by loading heavy weights and by cutting steel wires. The illustrations show different consequences in damage identification by the considered techniques [less ▲]

Detailed reference viewed: 129 (13 UL)
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See detailThe use of value-added models for the identification of schools that perform “against the odds”
Levy, Jessica UL; Brunner, Martin; Keller, Ulrich UL et al

Poster (2019, July)

Value-added (VA) modeling aims to quantify the effect of pedagogical actions on students’ achievement, independent of students’ backgrounds. VA modeling is primarily used for accountability and high ... [more ▼]

Value-added (VA) modeling aims to quantify the effect of pedagogical actions on students’ achievement, independent of students’ backgrounds. VA modeling is primarily used for accountability and high-stakes decisions. To date, there seems to be no consensus concerning the calculation of VA models. Our study aims to systematically analyze and compare different school VA models by using longitudinal large-scale data emerging from the Luxembourg School Monitoring Programme. Regarding the model covariates, first findings indicate the importance of language (i.e., language(s) spoken at home and prior language achievement) in VA models with either language or math achievement as a dependent variable, with the highest amount of explained variance in VA models for language. Concerning the congruence of different VA approaches, we found high correlations between school VA scores from the different models, but also high ranges between VA scores for single schools. We conclude that VA models should be used with caution and with awareness of the differences that may arise from methodological choices. Finally, we discuss the idea that VA models could be used for the identification of schools that perform “against the odds”, especially for those schools that have positive VA scores over several years. [less ▲]

Detailed reference viewed: 62 (4 UL)
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See detailUse of vitamin D supplements during infancy in an international feeding trial
Lehtonen, E.; Ormisson, A.; Nucci, A. et al

in Public Health Nutrition (2014), 17(4), 810-822

To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial. Longitudinal study.

Detailed reference viewed: 86 (0 UL)
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See detailUser Experience challenges for designing and evaluating Computer-Based Assessments for children
Lehnert, Florence Kristin UL

in IDC '19 Proceedings of the 18th ACM International Conference on Interaction Design and Children (2019, June 12)

Computer-Based Assessment (CBA), i.e., the use of computers instead of paper & pencil for testing purposes is now increasingly used, both in education and in the workforce. Along with this trend, several ... [more ▼]

Computer-Based Assessment (CBA), i.e., the use of computers instead of paper & pencil for testing purposes is now increasingly used, both in education and in the workforce. Along with this trend, several issues regarding the usage of computers in assessment can be raised. With respect to CBA, test validity and acceptance appear at stake during interacting with a complex assessment system. For instance, individual differences in computer literacy (i.e. ability to handle technology) might cause different outcomes that are not related to the problem-solving task. Prior investigation has shown that there is a scarcity of research on the User Experience (UX) in the context of CBA, also due to a focus on adult users. This doctoral thesis aims to adapt and develop new evaluation methods from the Human-Computer Interaction (HCI) field, applied in the context of CBA. The contributions will result in the development of best practices guidelines for both research and practitioners by adopting design and evaluation methods drawn from the field of Child-computer Interaction (CCI). [less ▲]

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See detailUser Experience Design for E-Voting: How mental models align with security mechanisms
Zollinger, Marie-Laure UL; Distler, Verena UL; Roenne, Peter UL et al

in Electronic Voting (2019, October)

This paper presents a mobile application for vote-casting and vote-verification based on the Selene e-voting protocol and explains how it was developed and implemented using the User Experience Design ... [more ▼]

This paper presents a mobile application for vote-casting and vote-verification based on the Selene e-voting protocol and explains how it was developed and implemented using the User Experience Design process. The resulting interface was tested with 38 participants, and user experience data was collected via questionnaires and semi-structured interviews on user experience and perceived security. Results concerning the impact of displaying security mechanisms on UX were presented in a complementary paper. Here we expand on this analysis by studying the mental models revealed during the interviews and compare them with theoretical security notions. Finally, we propose a list of improvements for designs of future voting protocols. [less ▲]

Detailed reference viewed: 127 (8 UL)
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See detailUser Experience: a concept without consensus? Exploring practitioners' perspectives through an international survey.
Lallemand, Carine UL; Gronier, Guillaume; Koenig, Vincent UL

in Computers in Human Behavior (2015), (43), 35-48

For more than a decade, User Experience (UX) has grown into a core concept of Human–Computer Inter- action (HCI). Practitioners and researchers from a wide range of disciplines are daily working with this ... [more ▼]

For more than a decade, User Experience (UX) has grown into a core concept of Human–Computer Inter- action (HCI). Practitioners and researchers from a wide range of disciplines are daily working with this concept. However, despite many attempts to understand, define and scope UX, one may still wonder whether a consensus has been reached on this concept. In a willingness to address the complexity of this research topic and bring the concept of UX to maturity, a replication of an international survey has been conducted. The main goal of the present study is to get a better understanding of practitioners’ view- points on the notion of UX and to analyze potential evolutions over time in the understanding and prac- tical use of the concept. As both practical and theoretical implications of UX are of the greatest importance for whoever designs interactive systems, the exploration of practitioners’ perspectives is a valuable step toward continual improvement of UX activities. The present survey has been conducted amongst 758 practitioners and researchers from 35 nationalities. It allows to better understand how this concept is understood and used throughout the world. Amongst interesting results, important differences were observed according to the geographical location and background of the respondents. [less ▲]

Detailed reference viewed: 276 (33 UL)