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See detailDoes cargo matter? The impact of air cargo operations on departure on-time performance for combination carriers
Lange, Anne UL

in Transportation Research. Part A, Policy and Practice (in press)

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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 detailA Dual-Grid Multiscale Approach to CFD-DEM Couplings for Multiphase Flow
Pozzetti, Gabriele UL

Doctoral thesis (2018)

This thesis focuses on a novel dual-grid multiscale approach to CFD- DEM1 couplings, proposes its advantages in terms of numerical proper- ties and performance, and provides examples of engineering ... [more ▼]

This thesis focuses on a novel dual-grid multiscale approach to CFD- DEM1 couplings, proposes its advantages in terms of numerical proper- ties and performance, and provides examples of engineering applications that can benefit from it. In recent years, CFD-DEM couplings are be- coming a more and more adopted solution for the numerical simulation of particle-laden flows. In particular, couplings based on the volume av- eraging technique have become a standard for numerical simulations in chemical and process engineering. Furthermore, they are rapidly spread- ing to civil, geotechnical and mechanical applications due to their ability in dealing with arbitrarily complex mixtures of continuum and granular media. Despite the several advantages that these Eulerian-Lagrangian cou- plings provide, their rigorous application to complex scenarios is currently limited by two main factors. First, the computational traceability of the solutions can become problematic due to the lack of a general theory on the subject. In particular, grid-convergence studies for the solution of the continuous phases are often not feasible due to the averaging procedure that imposes limitations on the grid structure and refinement. Second, the parallel implementation of these numerical schemes holds important disadvantages in terms of memory consumption and inter-physics com- munication load. These disadvantages are significantly limiting the ex- tension of these approaches to large-scale scenarios. This thesis collects some of the most significant works published in the last years on a novel approach that allows solving the two above- mentioned problems, and, therefore, tackling more complex and expen- sive scenarios. I refer to this approach as dual-grid multiscale approach for CFD-DEM couplings. It consists in using two different computational grids, one for the coupling between continuum and discrete entities and one for the solution of the so-obtained continuum equations. The two grids, i.e. the two problems, are in this way resolved on two different scales. The first scale or “bulk” scale is chosen to optimize the averag- ing operation. At this length-scale, the discrete entities are considered as zero-dimensional, and interact with the fluid with local exchanges of momentum, mass, and energy. The second scale or “fluid-fine” scale is identified as the one at which a unique solution for the averaged equa- tions can be provided. In practice, this is chosen as the one at which the solution of the fluid equations becomes grid-independent. An inter-scale communication is adopted by interpolating fields from the fluid-fine scale to the bulk one and vice-versa. The theoretical description of the method is first provided with par- ticular reference to the DEM-VOF coupling. Even in its simplest version, the multiscale approach is shown to generate grid-convergent solutions and significantly higher accuracy than a standard CFD-DEM coupling. This shows how the new approach is able to overcome the first main limitation described above. Then, an optimized parallel implementation of the method is pro- posed to show how this multiscale approach can provide significant ben- efits also for what concerns the execution time. Technically, this is made possible by moving the communication cost of the coupling from the inter-physics communication that characterized the standard CFD-DEM couplings to an optimized inter-scale communication routine. This en- ables the method to overcome a major bottleneck of the parallel execution of CFD-DEM couplings and therefore the second main limitation of those schemes. Finally, the dual-grid multiscale method is applied to approach in- dustrially relevant problems that were till now out-of-reach for standard CFD-DEM couplings, proving how this technique can have direct real- case application and produce immediate benefits for practitioners willing to adopt it. [less ▲]

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See detailL'entretien préliminaire individuel. Une chance négligée pour la résolution constructive du conflit par la médiation.
Mischo-Fleury, Sylvie Monique UL

Doctoral thesis (2018)

Research on emotions and other psychic dimensions is now called upon to play an important role in preventing and resolving conflicts. Knowledge of psychological mechanisms, their normality and the ... [more ▼]

Research on emotions and other psychic dimensions is now called upon to play an important role in preventing and resolving conflicts. Knowledge of psychological mechanisms, their normality and the possibilities of intervening on their distortions in the conflict may contribute to offer answers to the mediator addressing these issues and enhanced skills to handle the face-to-face of a confrontational encounter. We have many years of experience in the treatment of psychopathologies, the regulation of mental dysfunctional mechanisms and their impact on social behaviors and cognitive processes triggered by emotions. During mediation session, if the actors of the litigation come to the negotiating table, it is precisely to address the crucial and highly emotional issues. Our practical experience of mediation, our partnerships with various mediation associations, the exchange with many field mediators, the research that we conducted, led us to think about practical solutions to the need for mediation based on psychology. We drew up a comprehensive review of the scientific literature and chose to set our questioning within the framework of action-research and mediation engineering and using the creative and participative methodology of design thinking. With a team of 7 mediators-users we have decoded, decrypted, the basic data of the psychic dimensions inherent to the conflict (perception, thought, emotion, will and values, behavior and communication). In our professional practice, we have built and experimented a structured matrix of analysis and intervention on the psychic dimensions in the conflict, the metamodel PRECAUCUS, to be used especially in pre-mediation, a restructured and fully integrated phase of the mediation process. An inductive qualitative analysis - in empirical research - enabled us to analyze the date collected during collaborative meetings as well as the benefits of using the first test of the metamodel. The results show the relevance of the solutions proposed both by the know-how and the "savoir-être" gained by the mediator and by the co-construction of the mediator/disputant work, as well as by the fact that psychology is, from now on, the most important fundamental discipline the when it comes to optimizing mediation process and contributing to the future of mediation. [less ▲]

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See detailFaut-il lire, et que faut-il lire, pour mieux savoir lire? La compréhension de textes parmi les adolescents: tentative d'explication des différences interindividuelles
Reichert, Monique UL; Krämer, Charlotte UL; Rivas, Salvador UL et al

Scientific Conference (2018, January 11)

En matière d’éducation en général, et plus précisément dans le contexte de l’acquisition de compétences et de connaissances scolaires, on ne cesse de souligner que dans beaucoup de pays il existe des ... [more ▼]

En matière d’éducation en général, et plus précisément dans le contexte de l’acquisition de compétences et de connaissances scolaires, on ne cesse de souligner que dans beaucoup de pays il existe des écarts importants entre des élèves en fonction de leur arrière-fond socio-économique, de leur langue maternelle, ou de leur statut de migration. Souvent, cependant, il importe de clarifier quelles pourraient être des caractéristiques qui interagissent avec les variables pré-mentionnées. Cela aiderait à saisir le pourquoi des ces différences et à élucider quelles mesures de soutien pourraient être adoptées. En supposant que la fréquence de lecture puisse avoir un impact important sur le niveau de lecture, nous nous intéressons, dans la présente étude, aux différences en matière de lecture et ce en fonction des différentes caractéristiques socio-culturelles et des habitudes de lecture des élèves. À cet effet, nous aurons recours aux données issues des Épreuves Standardisées de l’année 2016/2017. Tous les élèves du grade 9 de l’enseignement secondaire du Luxembourg y ont participé à des tests de lecture de textes en français et en allemand. En outre, ces mêmes élèves ont été questionnés sur leur arrière-fond socio-culturel, ainsi que sur leurs habitudes de lecture. Plus précisément, il leur était demandé d’indiquer à quelle fréquence ils lisaient différents types de textes en dehors de l’école. Les résultats montrent que les textes en format numérique sont ceux qui sont le plus attrayants pour les adolescents. Cette préférence générale pour des textes numériques se retrouve parmi tous les groupes socio-culturels sans exception. Des analyses de régression mettent en évidence que ce sont surtout le fait et la fréquence de lire des textes narratifs qui ont un impact sur les compétences de lecture, et ce même si on prend en compte les variables d’arrière-fond socio-culturel des élèves. La discussion des résultats mettra d’un côté l’accent sur l’importance de la lecture ainsi que sur les possibilités de stimuler la motivation de lecture auprès des jeunes, mais aussi sur la popularité croissante de textes en format numérique et les conséquences correspondantes. [less ▲]

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See detailPurchase Order Financing: Credit, Commitment, and Supply Chain Consequences
Reindorp, Matthew; Tanrisever, Fehmi; Lange, Anne UL

in Operations Research (2018), 66(5), 1287-1303

We study a supply chain where a retailer buys from a supplier who faces financial constraints. Informational problems about the supplier’s demand prospects and production capabilities restrict her access ... [more ▼]

We study a supply chain where a retailer buys from a supplier who faces financial constraints. Informational problems about the supplier’s demand prospects and production capabilities restrict her access to capital. By committing to a minimum purchase quantity, the retailer can mitigate these informational problems and expand the supplier’s feasible production set. We assume a newsvendor model of operations and analyze the strategic interaction of the two parties as a sequential game. Key parameters in our model are the supplier’s ex ante credit limit, her informational transparency—which conditions the amount of additional capital released by the commitment—and the demand characteristics of the final market. We show that in equilibrium the supplier can benefit from a lower ex ante credit limit or lower informational transparency. The retailer always benefits from an increase in these parameters. We also indicate limits to the commitment approach: under certain conditions, the retailer may prefer to relax the supplier’s financial constraint by adjusting the wholesale price, or a combination of wholesale price and commitment. Our study provides a novel perspective on capital market frictions in supply chains. The e-companion is available at https://doi.org/10.1287/opre.2018.1727. [less ▲]

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See detailDéjà vu Davidoff - The German Federal Court of Justice (FCJ) has asked the Court of Justice of the European Union (CJEU) for guidance on the role and responsibilities of fulfilment service providers in trademark protection
Ullrich, Carsten UL

in Journal of Intellectual Property Law and Practice (2018)

The German Federal Court of Justice (FCJ) has asked the Court of Justice of the European Union (CJEU) for guidance on the role and responsibilities of fulfilment service providers in trademark protection.

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See detailNetwork concentration indices for less-than-truckload transportation
Lange, Anne UL; Delfmann, Werner

in TRANSPORTATION (2017), 44(6), 1475-1497

An efficient and service-oriented transportation network is a necessary resource for successful less-than-truckload operations. The design and evaluation of transportation networks are mainly driven by ... [more ▼]

An efficient and service-oriented transportation network is a necessary resource for successful less-than-truckload operations. The design and evaluation of transportation networks are mainly driven by quantitative particularly cost-oriented measures, such as transport and transshipment costs. This type of measurement, however, simply cannot represent the manifold performance of a transportation network. In particular, incorporating network concentration into network design decisions overcomes the shortcomings of purely cost-oriented decisions because spatial network concentration is at the root of many aspects of network performance (e.g., congestion and network vulnerability). This paper suggests modifications to the network concentration index and the hubbing concentration index from the passenger airline context for less-than-truckload road transportation. The modified indices enable information to be conveyed by network concentration into less-than-truckload network design decisions and provide a suitable perspective to include service-oriented aspects into network design. [less ▲]

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See detailRobust Scheduling: An Empirical Study of Its Impact on Air Traffic Delays
Lonzius, Marc Christopher; Lange, Anne UL

in TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW (2017), 100

We develop an econometric model to analyze the real-life impact of two robust scheduling approaches, namely limiting hub connectivity and implementing swap opportunities, based on a broad dataset of the U ... [more ▼]

We develop an econometric model to analyze the real-life impact of two robust scheduling approaches, namely limiting hub connectivity and implementing swap opportunities, based on a broad dataset of the U.S. domestic market. Our analysis is from a novel aircraft routing perspective. We confirm a delay-driving effect of direct hub connectivity and a delay-reducing effect of swap opportunities. Indirect hub connectivity provides airlines with another approach to limit delays. We furthermore contrast that the business model of Southwest Airlines cannot leverage the delay-reducing effects resulting from swap opportunities. (C) 2017 Elsevier Ltd. All rights reserved. [less ▲]

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See detailThe impact of hubbing concentration on flight delays within airline networks: An empirical analysis of the US domestic market
Baumgarten, Patrick; Malina, Robert; Lange, Anne UL

in TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW (2014), 66

This paper explores the relationship between hubbing activities and flight delays in the United States from an airline-specific network perspective. Airline hubbing is measured with the Hubbing ... [more ▼]

This paper explores the relationship between hubbing activities and flight delays in the United States from an airline-specific network perspective. Airline hubbing is measured with the Hubbing Concentration Index. We estimate the impact of hubbing behavior on delays, using three measures of delay, two based on delay against schedule, and the third based on buffer-corrected excess travel times. A significant (and positive) influence of hubbing concentration can only be found for the latter delay indicator. We conclude that airlines use buffer times to mitigate passenger-perceived delays against schedule that would, without buffers, arise from more complex network operations. (C) 2014 Elsevier Ltd. All rights reserved. [less ▲]

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