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See detailThermotropic Liquid Crystal-Assisted Chemical and Biological Sensors
Popov, Nicolai; Honaker, Lawrence William UL; Popova, Maia et al

in Materials (2017), 11(20),

In this review article, we analyze recent progress in the application of liquid crystal-assisted advanced functional materials for sensing biological and chemical analytes. Multiple research groups ... [more ▼]

In this review article, we analyze recent progress in the application of liquid crystal-assisted advanced functional materials for sensing biological and chemical analytes. Multiple research groups demonstrate substantial interest in liquid crystal (LC) sensing platforms, generating an increasing number of scientific articles. We review trends in implementing LC sensing techniques and identify common problems related to the stability and reliability of the sensing materials as well as to experimental set-ups. Finally, we suggest possible means of bridging scientific findings to viable and attractive LC sensor platforms. [less ▲]

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See detailPreparing Future Teachers for Strategic Uses of Educational Technology: A Project-Based Approach
Reuter, Bob UL; Busana, Gilbert UL

Scientific Conference (2017, December 01)

Given (1) the need for teachers who are willing and able to design, implement and reflect meaningful and successful educational technology practices in schools and (2) the current rarity of strategic uses ... [more ▼]

Given (1) the need for teachers who are willing and able to design, implement and reflect meaningful and successful educational technology practices in schools and (2) the current rarity of strategic uses of ICT in education in Luxembourgish schools, the self-declared lack of competencies and the low confidence of teachers when it comes to teaching with ICT (Reuter, Busana & Linckels, 2016), we have designed, implemented and tested a project-based approach to the development of practice- oriented TPACK in pre-service teachers. Future teacher students are instructed to define an educational problem they want to solve, to explore existing pedagogical and technological solutions and to design an original solution that involves the strategic use of ICT (theoretically grounded and practically meaningful). They then have to implement the designed learning & teaching scenario in a classroom, to document the teaching & learning processes, to analyse, evaluate and to critically reflect them. Finally, they are required to write a structured report about their project and to present it to their peers and to interested teachers from schools. Overall, we observe that while most students become able to design and implement relatively meaningful educational technology practices, they still tend to feel that they are not ready to teach with technology in a more general sense, because their work was focused on one or two tools and does not give them access to a broader range of meaningful ICT-enriched teaching scenarios for their later professional career. [less ▲]

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See detailFast Discretized Gaussian Sampling and Post-quantum TLS Ciphersuite
Xinwei, Gao; Li, Lin; Jintai, Ding et al

in The 13th International Conference on Information Security Practice and Experience - ISPEC 2017 (2017, December 01)

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See detailEvaluating the Impact of Juice Filming Charging Attack in Practical Environments
Meng, Weizhi; Lee, Wanghao; Liu, Zhe UL et al

in The 20th Annual International Conference on Information Security and Cryptology - ICISC2017 (2017, December 01)

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See detailFacing the Safety-Security Gap in RTES: the Challenge of Timeliness
Volp, Marcus UL; Kozhaya, David UL; Verissimo, Paulo UL

Scientific Conference (2017, December)

Safety-critical real-time systems, including real-time cyber-physical and industrial control systems, need not be solely correct but also timely. Untimely (stale) results may have severe consequences that ... [more ▼]

Safety-critical real-time systems, including real-time cyber-physical and industrial control systems, need not be solely correct but also timely. Untimely (stale) results may have severe consequences that could render the control system’s behaviour hazardous to the physical world. To ensure predictability and timeliness, developers follow a rigorous process, which essentially ensures real-time properties a priori, in all but the most unlikely combinations of circumstances. However, we have seen the complexity of both real-time applications, and the environments they run on, increase. If this is matched with the also increasing sophistication of attacks mounted to RTES systems, the case for ensuring both safety and security through aprioristic predictability loses traction, and presents an opportunity, which we take in this paper, for discussing current practices of critical realtime system design. To this end, with a slant on low-level task scheduling, we first investigate the challenges and opportunities for anticipating successful attacks on real-time systems. Then, we propose ways for adapting traditional fault- and intrusiontolerant mechanisms to tolerate such hazards. We found that tasks which typically execute as analyzed under accidental faults, may exhibit fundamentally different behavior when compromised by malicious attacks, even with interference enforcement in place. [less ▲]

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See detailSymbol-level Precoding for the Non-linear Multiuser MISO Downlink Channel
Spano, Danilo UL; Alodeh, Maha; Chatzinotas, Symeon UL et al

in IEEE Transactions on Signal Processing (2017)

This paper investigates the problem of the interference among multiple simultaneous transmissions in the downlink channel of a multi-antenna wireless system. A symbol-level precoding scheme is considered ... [more ▼]

This paper investigates the problem of the interference among multiple simultaneous transmissions in the downlink channel of a multi-antenna wireless system. A symbol-level precoding scheme is considered, in order to exploit the multi-user interference and transform it into useful power at the receiver side, through a joint utilization of the data information and the channel state information. In this context, this paper presents novel strategies which exploit the potential of symbol-level precoding to control the per-antenna instantaneous transmit power. In particular, the power peaks amongst the transmitting antennas and the instantaneous power imbalances across the different transmitted streams are minimized. These objectives are particularly relevant with respect to the non-linear amplitude and phase distortions induced by the per-antenna amplifiers, which are important sources of performance degradation in practical systems. More specifically, this work proposes two different symbol-level precoding approaches. A first approach performs a weighted per-antenna power minimization, under Quality-of-Service constraints and under a lower bound constraint on the per-antenna transmit power. A second strategy performs a minimization of the spatial peak-to-average power ratio, evaluated amongst the transmitting antennas. Numerical results are presented in a comparative fashion to show the effectiveness of the proposed techniques, which outperform the state of the art symbol-level precoding schemes in terms of spatial peak-to-average power ratio, spatial dynamic range, and symbol-error-rate over non-linear channels. [less ▲]

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See detailIsolation of nucleic acids from low biomass samples: detection and removal of sRNA contaminants
Heintz-Buschart, Anna; Yusuf, Dilmurat; Kaysen, Anne UL et al

E-print/Working paper (2017)

Sequencing-based analyses of low-biomass samples are known to be prone to misinterpretation due to the potential presence of contaminating molecules derived from laboratory reagents and environments. Due ... [more ▼]

Sequencing-based analyses of low-biomass samples are known to be prone to misinterpretation due to the potential presence of contaminating molecules derived from laboratory reagents and environments. Due to its inherent instability, contamination with RNA is usually considered to be unlikely. Here we report the presence of small RNA (sRNA) contaminants in widely used microRNA extraction kits and means for their depletion. Sequencing of sRNAs extracted from human plasma samples was performed and significant levels of non-human (exogenous) sequences were detected. The source of the most abundant of these sequences could be traced to the microRNA extraction columns by qPCR-based analysis of laboratory reagents. The presence of artefactual sequences originating from the confirmed contaminants were furthermore replicated in a range of published datasets. To avoid artefacts in future experiments, several protocols for the removal of the contaminants were elaborated, minimal amounts of starting material for artefact-free analyses were defined, and the reduction of contaminant levels for identification of bona fide sequences using 'ultra-clean' extraction kits was confirmed. In conclusion, this is the first report of the presence of RNA molecules as contaminants in laboratory reagents. The described protocols should be applied in the future to avoid confounding sRNA studies. [less ▲]

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See detail100 Jaar Prandtl-Wig: De draagkrachtfactoren
Van Baars, Stefan UL

in Geotechniek (2017), December

In 1920 publiseerde Prandtl een artikel over het bezwijken van een materiaal onder een strookbelasting. De bezweken grondmoot is hierbij verdeeld in drie zones, die tezamen de zogenoemde Prandtl-wig ... [more ▼]

In 1920 publiseerde Prandtl een artikel over het bezwijken van een materiaal onder een strookbelasting. De bezweken grondmoot is hierbij verdeeld in drie zones, die tezamen de zogenoemde Prandtl-wig vormen. Prandtl heeft nooit aan de funderingstechnische toepassing gedacht, maar geotechnici vertalen deze oplossing nu als een analytische oplossing voor de draagkracht van de grond onder een strookfundering. Deze oplossing is uitgebreid door Reissner met een bovenbelasting naast de funderingsstrook en door Keverling Buisman en Terzaghi voor het grondgewicht. Terzaghi schreef dit als eerste met drie gescheiden draagkrachtfactoren en Meyerhof als eerste met “inclinatie-” en “shape” factoren, voor de drie afzonderlijke draagkrachtcomponenten; cohesie, bovenbelasting en het grondgewicht. Deze schrijfwijze werd later door Brinch Hansen overgenomen. In dit artikel zijn een groot aantal numerieke berekeningen gemaakt om het bezwijkmechanisme van de Prandtl-wig en de bijbehorende draagkrachtfactoren te controleren. Het blijkt dat het Prandtl-wig bezwijkmechanisme juist is, maar niet in alle gevallen. Ook blijkt dat de analytische oplossingen voor de draagkrachtfactoren die tegenwoordig worden gebruikt, alleen juist zijn voor grond met een onrealistisch hoge dilatantiehoek. [less ▲]

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See detailModular classes of Q-manifolds: a review and some applications
Bruce, Andrew UL

in Archivum Mathematicum (2017)

A Q-manifold is a supermanifold equipped with an odd vector field that squares to zero. The notion of the modular class of a Q-manifold – which is viewed as the obstruction to the existence of a Q ... [more ▼]

A Q-manifold is a supermanifold equipped with an odd vector field that squares to zero. The notion of the modular class of a Q-manifold – which is viewed as the obstruction to the existence of a Q-invariant Berezin volume – is not well know. We review the basic ideas and then apply this technology to various examples, including $L_{\infty}$-algebroids and higher Poisson manifolds. [less ▲]

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See detailMultiagent Deontic Logic and its Challenges from a Normative Systems Perspective
Pigozzi, Gabriella; van der Torre, Leon UL

in The IfCoLog Journal of Logics and their Applications (2017)

This article gives an overview of several challenges studied in deontic logic, with an emphasis on challenges involving agents. We start with traditional modal deontic logic using preferences to address ... [more ▼]

This article gives an overview of several challenges studied in deontic logic, with an emphasis on challenges involving agents. We start with traditional modal deontic logic using preferences to address the challenge of contrary-toduty reasoning, and STIT theory addressing the challenges of non-deterministic actions, moral luck and procrastination. Then we turn to alternative normbased deontic logics detaching obligations from norms to address the challenge of Jørgensen’s dilemma, including the question how to derive obligations from a normative system when agents cannot assume that other agents comply with their norms. We discuss also some traditional challenges from the viewpoint of normative systems: when a set of norms may be termed ‘coherent’, how to deal with normative conflicts, how to combine normative systems and traditional deontic logic, how various kinds of permission can be accommodated, how meaning postulates and counts-as conditionals can be taken into account,how sets of norms may be revised and merged, and how normative systems can be combined with game theory. The normative systems perspective means that norms, not ideality or preference, should take the central position in deontic semantics, and that a semantics that represents norms explicitly provides a helpful tool for analysing, clarifying and solving the problems of deontic logic. We focus on the challenges rather than trying to give full coverage of related work, for which we refer to the handbook of deontic logic and normative systems. [less ▲]

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See detailLaw and the software development life cycle
Bartolini, Cesare UL; Lenzini, Gabriele UL

Scientific Conference (2017, November 25)

The increasing demand of reliable software services and the dependability that our daily personal and professional life have on them is bringing significant changes in the domain of software service ... [more ▼]

The increasing demand of reliable software services and the dependability that our daily personal and professional life have on them is bringing significant changes in the domain of software service engineering. One of the most revolutionary is the introduction of regulations, repeating what in the past has concerned the product market. Regulations need to find a balance between the interests of several roles and reduce the inevitable tensions that would otherwise arise among them, as well as to defend the right of the weakest parties (normally the end users). There are multiple interests to balance: the interests of end users, the protection of intellectual property, a fair competition against other enterprises, just to name a few. While some of these requirements concern the structure and organization of the enterprise, some of them are fit to penetrate into the software development life cycle. This would serve multiple purposes: allow the enterprise to design services which already take the legal requirements into account; visually represent the requirements and their interaction with the functionality of the system; develop the software components using tools and methodologies that are able to deal with those requirements; define metrics to measure the degree to which such requirements are met; measure the impact of the requirements on the functionality of the service and on other parameters of the service (such as performance or storage occupation); verify and monitor whether the legal requirements are met; and, last but not least, to have an argument to be used in case of a complaint in a court or at a competent authority. Before being considered in the software service life cycle, legal requirements must undergo a preprocessing phase in which they are translated into some form which is compatible with the tools and methodologies proper of the software engineering, for instance being modelled into a formalism that makes them processable by a machine. There is a significant amount of interdisciplinary topics that need to be combined together to reach an integration between regulation and software life cycle. In particular, at least from three complementary perspectives are needed. One perspective requires the analysis of the provisions of the law, the extraction of the legal requirements classified according to the stakeholders affected, and the translation of those requirements into some formal model that can be processed using appropriate software tools. A second perspective requires a study of the legal requirements from the point of view of requirements engineering techniques, also defining metrics to measure them. The third concerns the models used in the various stages of software engineering (design, modeling, development, validation and testing), which need to be extended to accommodate the legal requirements in their formal representation. Only by putting together these perspectives a comprehensive approach to deal with legal requirements in software engineering is possible. [less ▲]

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See detailLoss of Myosin Vb in colorectal cancer is a strong prognostic factor for disease recurrence
Letellier, Elisabeth UL; Schmitz, Martine UL; Ginolhac, Aurélien UL et al

in British Journal of Cancer (2017), 117(11), 1689-1701

Background: Selecting the most beneficial treatment regimens for colorectal cancer (CRC) patients remains challenging due to a lack of prognostic markers. Members of the Myosin family, proteins recognized ... [more ▼]

Background: Selecting the most beneficial treatment regimens for colorectal cancer (CRC) patients remains challenging due to a lack of prognostic markers. Members of the Myosin family, proteins recognized to play a major role in trafficking and polarization of cells, have recently been reported to be closely associated with several types of cancer and might thus serve as potential prognostic markers in the context of CRC. Methods: We used a previously established meta-analysis of publicly available gene expression data to analyse the expression of different members of the Myosin V family, namely MYO5A, 5B, and 5C, in CRC. Using laser-microdissected material as well as tissue microarrays from paired human CRC samples, we validated both RNA and protein expression of MYO5B and its known adapter proteins (RAB8A and RAB25) in an independent patient cohort. Finally, we assessed the prognostic value of both MYO5B and its adapter-coupled combinatorial gene expression signatures. Results: The meta-analysis as well as an independent patient cohort study revealed a methylation-independent loss of MYO5B expression in CRC that matched disease progression. Although MYO5B mutations were identified in a small number of patients, these cannot be solely responsible for the common down-regulation observed in CRC patients. Significantly, CRC patients with low MYO5B expression displayed shorter overall, disease- and metastasis-free survival, a trend that was further reinforced when RAB8A expression was also taken into account. Conclusions: Our data identifies MYO5B as a powerful prognostic biomarker in CRC, especially in early stages (stages I and II), which might help stratifying patients with stage II for adjuvant chemotherapy. [less ▲]

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See detailElucidating the fine details of cholesteric liquid crystal shell reflection patterns
Geng, Yong; Noh, Junghyun UL; Drevensek-Olenik, Irena et al

in Liquid Crystals (2017), 44(12-13),

Clusters of planar-aligned short-pitch cholesteric liquid crystal spheres generate dynamic colourful patterns due to multiple selective reflections from the radially oriented cholesteric helices in ... [more ▼]

Clusters of planar-aligned short-pitch cholesteric liquid crystal spheres generate dynamic colourful patterns due to multiple selective reflections from the radially oriented cholesteric helices in neighbour shells at varying distances. These photonic communication patterns were widely investigated for the cases of both droplets and shells, demonstrating not only intriguing optical phenomena but also potential for applications as new optical elements for photonics, sensing or security pattern generation. However, the optics of these clusters is truly complex and until now only the strongest and most fundamental reflections have been analysed and explained. In this report, we elucidate the origin of a number of more subtle reflections and we explain the extension in space of various spots as well as their internal colour variations. [less ▲]

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See detailAlternative Paths Towards Sustainable Localized Food Sovereignty. Convergence between Prosumers and Ethical Entrepreneurs over Time
Reckinger, Rachel UL

Scientific Conference (2017, November 14)

Recently, a number of resourceful community-driven initiatives for local food production and retail have arisen in Luxembourg, in a context of particularly low organic agricultural rates paradoxically ... [more ▼]

Recently, a number of resourceful community-driven initiatives for local food production and retail have arisen in Luxembourg, in a context of particularly low organic agricultural rates paradoxically paired with high consumer demands for organic produce, leading to a specific market of largely imported organic goods. As an encompassing reaction to this situation, a niche of social innovators are combining agro-ecological land use and food production with locavoracity and circular economy. Based on qualitative in-depth interviews and participant observation, we would like to expand on four micro-case studies of circular-economy-type fruit and vegetable production as well as unpackaged and/or socially responsible food retail in today’s Luxembourg. One has been established since the 1980s with over 150 employees, partly in social insertion measures, producing and importing organic fruits and vegetables, delivered via a classical box scheme system. Additionally, over the last three years three significantly smaller initiatives with higher citizen and/or community involvement have emerged. They are characterized by a cooperative governance structure, a claimed community-supported agricultural outlook, a more dynamic presence on social media and regular hands-on workshops and activities. These more recent initiatives are also more radical in their agro-ecological and/or permaculture practices, focusing on local production without relying on imports, as a politicized step further than mere (possibly industrialized) organic production, which is an altogether renewed enacting of circular economy precepts. Yet their position on the market is for the moment more fragile and marginal. Particularly, the retailers among them have to build creative consensus – according to specific priorities and stances – between their standards and the adjustment to consumers who, albeit sensitized, are in search for a certain variety and convenience. By focusing on heterodox experiences of more or less established alternative actors in diverse yet complementary food production and retail niches, we will explore topics such as emotional collective commitment and consensus-building, ethical entrepreneurship in relation to possibly reframed standards over time, governmentality, political enabling or disabling structures and regulations, as well as commodification and upscaling issues. Therefore, this paper touches on political processes and strategies, urban agro-ecological practices as well as post-capitalist economics. [less ▲]

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