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See detailNonequilibrium thermodynamics of non-ideal chemical reaction networks
Avanzini, Francesco UL; Penocchio, Emanuele UL; Falasco, Gianmaria UL et al

in Journal of Chemical Physics (2021), 154

All current formulations of nonequilibrium thermodynamics of open chemical reaction networks rely on the assumption of non-interacting species. We develop a general theory that accounts for interactions ... [more ▼]

All current formulations of nonequilibrium thermodynamics of open chemical reaction networks rely on the assumption of non-interacting species. We develop a general theory that accounts for interactions between chemical species within a mean-field approach using activity coefficients. Thermodynamic consistency requires that rate equations do not obey standard mass-action kinetics but account for the interactions with concentration dependent kinetic constants. Many features of the ideal formulations are recovered. Crucially, the thermodynamic potential and the forces driving non-ideal chemical systems out of equilibrium are identified. Our theory is general and holds for any mean-field expression of the interactions leading to lower bounded free energies. [less ▲]

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See detailEfficient Federated Learning Algorithm for Resource Allocation in Wireless IoT Networks
Nguyen, van Dinh UL; Sharma, Shree Krishna UL; Vu, Thang Xuan UL et al

in IEEE Internet of Things Journal (2021), 8(5), 3394-3409

Federated learning (FL) allows multiple edge computing nodes to jointly build a shared learning model without having to transfer their raw data to a centralized server, thus reducing communication ... [more ▼]

Federated learning (FL) allows multiple edge computing nodes to jointly build a shared learning model without having to transfer their raw data to a centralized server, thus reducing communication overhead. However, FL still faces a number of challenges such as non-iid distributed data and heterogeneity of user equipments (UEs). Enabling a large number of UEs to join the training process in every round raises a potential issue of the heavy global communication burden. To address these issues, we generalize the current state-of-the-art Federated Averaging (FedAvg) by adding a weight-based proximal term to the local loss function. The proposed FL algorithm runs stochastic gradient descent in parallel on a sampled subset of the total UEs with replacement during each global round. We provide a convergence upper bound characterizing the trade-off between convergence rate and global rounds, showing that a small number of active UEs per round still guarantees convergence. Next, we employ the proposed FL algorithm in wireless Internet-of-Things (IoT) networks to minimize either total energy consumption or completion time of FL, where a simple yet efficient path-following algorithm is developed for its solutions. Finally, numerical results on unbalanced datasets are provided to demonstrate the performance improvement and robustness on the convergence rate of the proposed FL algorithm over FedAvg. They also reveal that the proposed algorithm requires much less training time and energy consumption than the FL algorithm with full user participation. These observations advocate the proposed FL algorithm for a paradigm shift in bandwidth- constrained learning wireless IoT networks. [less ▲]

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See detailUrban expansion re-visited
Hesse, Markus UL

in pnd - rethinking planning (2021), 2021(1), 42-54

This paper deals with urban expansion, that is, the growth of cities and inner-urban areas, both inside and outside of the dedicated planning perimeters. My aim is to give a brief overview of how this ... [more ▼]

This paper deals with urban expansion, that is, the growth of cities and inner-urban areas, both inside and outside of the dedicated planning perimeters. My aim is to give a brief overview of how this subject matter can be discussed from a contemporary perspective, with a certain focus on big projects that have evolved in recent decades and are on the rise again. Towards that end, I will situate the subject matter in historical contexts, provide some explanation as to the 1970s and more recent dynamics, and discuss how large-scale urban projects are being implemented. While big projects pursue different ambitions—such as economic, socio-demographic or ecological goals—they are set in place by a kind of managerial urbanism, often prioritise economic gains and thus challenge urban policy and planning. The paper concludes with a call to contextualise the variegated outcomes of new urban projects and to develop appropriate methods for monitoring and assessing urban life in these quarters. [less ▲]

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See detailNeutron study of magnetic correlations in rare-earth-free Mn-Bi magnets
Malyeyev, Artem UL; Titov, Ivan; Bender, Philipp et al

in Physical Review Materials (2021), 5

We report the results of an unpolarized small-angle neutron scattering (SANS) study on Mn-Bi-based rare-earth-free permanent magnets. The magnetic SANS cross section is dominated by long-wavelength ... [more ▼]

We report the results of an unpolarized small-angle neutron scattering (SANS) study on Mn-Bi-based rare-earth-free permanent magnets. The magnetic SANS cross section is dominated by long-wavelength transversal magnetization fluctuations and has been analyzed in terms of the Guinier-Porod model and the distance distribution function. This provides the radius of gyration which, in the remanent state, ranges between about $220-240 \, \mathrm{nm}$ for the three different alloy compositions investigated. Moreover, computation of the distance distribution function in conjunction with results for the so-called $s$-parameter obtained from the Guinier-Porod model indicate that the magnetic scattering of a Mn$_{45}$Bi$_{55}$ sample has its origin in slightly shape-anisotropic structures. [less ▲]

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See detailZur fairen Bewertung von Lernprodukten
Krämer, Charlotte UL

in Programme for Innovative Teaching and Training (PITT): #digitallife (2021)

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See detailExplorative analysis of potential MaaS customers: An agent-based scenario
Cisterna, Carolina UL; Giorgione, Giulio UL; Viti, Francesco UL

in Transportation Research Procedia (2021)

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See detailWho aspires to higher education? Axes of inequality, values of education and higher education aspirations in secondary schools in Luxembourg and the Swiss Canton of Bern
Hadjar, Andreas UL; Scharf, Jan; Hascher, Tina

in European Journal of Education (2021), 56(1), 9-26

This article reports a study that investigated secondary school students’ higher education aspirations (towards university studies, ISCED 6 and above) and how these differ between student groups as well ... [more ▼]

This article reports a study that investigated secondary school students’ higher education aspirations (towards university studies, ISCED 6 and above) and how these differ between student groups as well as how these are impacted by values of education. Panel data of more than 300 secondary school students in two countries, Luxembourg and Switzerland (the Swiss Canton of Bern) was analysed. Schools are structured differently in the education systems of Luxembourg and the Swiss Canton of Bern. The results of our analysis show that students in the Luxembourgish sample more often aspire to higher education than in the Swiss sample. Disparities in higher education aspirations were also more pronounced in the Luxembourgish sample, boys and students from families of low socio-economic status (SES) were less likely to aspire to higher education. While the effects of values of education are generally scarce, stimulation in terms of anticipated enjoyment and interest derived from participation in higher education seems to have a positive effect on higher education aspirations. [less ▲]

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See detailDigitales Lesen im Deutschunterricht
Baumann, Isabell Eva UL

in Programme for Innovative Teaching and Training (PITT) (2021)

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See detailRole of cation-mediated recombination in perovskite solar cells
Singh, Ajay UL; Kaiser, Waldemar; Gagliardi, Alessio

in Solar Energy Materials and Solar Cells (2021)

The origin of the hysteresis in the current–voltage (J–V) characteristics in perovskite solar cells (PSCs) is one of the most debated topics of recent years. Hysteretic effects are connected with the slow ... [more ▼]

The origin of the hysteresis in the current–voltage (J–V) characteristics in perovskite solar cells (PSCs) is one of the most debated topics of recent years. Hysteretic effects are connected with the slow redistribution of ionic defects during the voltage sweep. Existing literature focuses on the potential screening due to accumulated ions, solely, while neglecting the possibility of charge trapping and subsequent recombination via ions. We investigate the role of cation-mediated recombination of ions using time-dependent drift–diffusion simulations in MAPbI3 PSCs. Slow-moving cations are considered as traps for the electrons. Trapped electrons can subsequently recombine non-radiatively with holes. We analyze the role of the cation-mediated trapping and its parameters (capture coefficient, cation energy, ion mobility) as well as the scan rate on the device performance. For shallow cation energies, a decrease in open-circuit voltage and slight enhancement in hysteresis is observed. Deep cation energies lead to a substantial deterioration of device performance and large hysteresis enhancement. The presented study emphasizes the importance of considering the interaction of ions with charge carriers beyond the simple electrostatic models to improve our understanding of PSCs. [less ▲]

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See detailSmall urban green areas
Picard, Pierre M UL; Tran, Thi Thu Huyen UL

in Journal of Environmental Economics and Management (2021), 106

This paper studies the size and location of small urban green areas across city spaces. Small urban green areas offer amenities that affect residential choices, land consumption and land rent. This paper ... [more ▼]

This paper studies the size and location of small urban green areas across city spaces. Small urban green areas offer amenities that affect residential choices, land consumption and land rent. This paper discusses the land use and locations of those areas and the resulting residential space allocation. It is shown that the land share dedicated to small urban green areas results from the trade-off between land value and population density and is a single peaked function of the distance to the city center. This result is confirmed by the empirical study of urban structures in the 305 largest EU cities using GIS data. This spatial pattern is shown to be robust to many measures of urban land uses. [less ▲]

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See detailEmpowering large chemical knowledge bases for exposomics: PubChemLite meets MetFrag
Schymanski, Emma UL; Kondic, Todor UL; Neumann, Steffen et al

in Journal of Cheminformatics (2021), 13(1), 19

Abstract Compound (or chemical) databases are an invaluable resource for many scientific disciplines. Exposomics researchers need to find and identify relevant chemicals that cover the entirety of ... [more ▼]

Abstract Compound (or chemical) databases are an invaluable resource for many scientific disciplines. Exposomics researchers need to find and identify relevant chemicals that cover the entirety of potential (chemical and other) exposures over entire lifetimes. This daunting task, with over 100 million chemicals in the largest chemical databases, coupled with broadly acknowledged knowledge gaps in these resources, leaves researchers faced with too much—yet not enough—information at the same time to perform comprehensive exposomics research. Furthermore, the improvements in analytical technologies and computational mass spectrometry workflows coupled with the rapid growth in databases and increasing demand for high throughput “big data” services from the research community present significant challenges for both data hosts and workflow developers. This article explores how to reduce candidate search spaces in non-target small molecule identification workflows, while increasing content usability in the context of environmental and exposomics analyses, so as to profit from the increasing size and information content of large compound databases, while increasing efficiency at the same time. In this article, these methods are explored using PubChem, the NORMAN Network Suspect List Exchange and the in silico fragmentation approach MetFrag. A subset of the PubChem database relevant for exposomics, PubChemLite, is presented as a database resource that can be (and has been) integrated into current workflows for high resolution mass spectrometry. Benchmarking datasets from earlier publications are used to show how experimental knowledge and existing datasets can be used to detect and fill gaps in compound databases to progressively improve large resources such as PubChem, and topic-specific subsets such as PubChemLite. PubChemLite is a living collection, updating as annotation content in PubChem is updated, and exported to allow direct integration into existing workflows such as MetFrag. The source code and files necessary to recreate or adjust this are jointly hosted between the research parties (see data availability statement). This effort shows that enhancing the FAIRness (Findability, Accessibility, Interoperability and Reusability) of open resources can mutually enhance several resources for whole community benefit. The authors explicitly welcome additional community input on ideas for future developments. [less ▲]

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See detailLe droit à la sauce piquante n°22 - Mars 2021
Hiez, David UL; Laurent, Rémi

in Le droit à la sauce piquante (2021), 22

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See detailA Temporary Space Where Development and Planning Emergencies Meet? Notes on an International Building Exhibition (IBA) in the Cross- Border Territories of France and Luxembourg
Becker, Tom UL; Hesse, Markus UL

in Planning Theory and Practice (2021), 22(1), 148-154

An International Building Exhibition (IBA) is currently being planned for the cross-border area of southern Luxembourg and north-eastern France (Alzette-Belval). This planning approach, mainly known in ... [more ▼]

An International Building Exhibition (IBA) is currently being planned for the cross-border area of southern Luxembourg and north-eastern France (Alzette-Belval). This planning approach, mainly known in the German building and planning context, was developed as a temporary activity to foster planning innovation and experimentation, in order to bring both formal and informal processes and regulations forward. Some have also argued that an IBA can be considered a temporary case of planning emergency, a means for trying the unusual in settings where business as usual has failed to address important problems properly. Organising an IBA has recently become increasingly popular in other European countries, such as Austria, the Netherlands or Switzerland. The aim of this note is to address some general questions as to the particular role that this instrument can play, and what it may promise (and not) to spatial planning. We also discuss the specific framework conditions and problems the French-Luxembourgian border region is confronted with. Our comment should contribute to clarifying what the underlying problems are actually about and, more specifically, in what ways an IBA could help dealing with them. Particularly, we suggest decision-makers and practitioners to follow a practice of ‘reflection before selection’: to address the very specificities of both the region and of an IBA before turning to ‘project’-based routines. This would avoid rendering the IBA as an empty signifier or a mere branding tool, while practice remains challenged by vested interests, complex policy terrains and powerful political economies. [less ▲]

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See detailBewertungshilfe zur Unterrichtseinheit #gemeinsamlesen
Krämer, Charlotte UL

in Programme for Innovative Teaching and Training (PITT): #digitallife (2021)

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See detailInstitutional Investors and Infrastructure Investing
Kräussl, Roman UL; Andonov, Aleksandar; M. Rauh., Joshua

in Review of Financial Studies (2021), 34(8)(3880-3934),

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See detailUn vidimus mal interprété de Pierre de Vianden, prévôt de Saint-Martin de Liège, et de Conon, seigneur de Reuland (ca. 1264-ca. 1275
Salemme, Timothy UL

in Hemecht: Zeitschrift für Luxemburger Geschichte (2021), 72(1), 76-85

The work of editing medieval documents is full of pitfalls. Among the greatest difficulties is undoubtedly that of providing a critical edition of the copy of a document contained in a cartulary. What is ... [more ▼]

The work of editing medieval documents is full of pitfalls. Among the greatest difficulties is undoubtedly that of providing a critical edition of the copy of a document contained in a cartulary. What is the level of reliability of this copy with respect to its archetype? What is the role of the editor of the cartulary as mediator between the archetype and the copy? What should be done in the presence of an abbreviated copy of a lost archetype? In this paper, we offer a case study illustrating these issues, by focussing on a vidimus issued by Pierre de Vianden and Conon de Reuland at the end of the 1260s-early 1270s reporting an agreement between Count Philippe I of Vianden and Henri V of Luxembourg. Improperly dated and misinterpreted by researchers in the course of the 20th century, this document is the object of a new analysis which places it in a totally different historical perspective. [less ▲]

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See detailBewertungshilfe zur Unterrichtseinheit #ichhassedich
Krämer, Charlotte UL

in Programme for Innovative Teaching and Training (PITT): #digitallife (2021)

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See detailBewegte Balladen: Balladen durch Erklärvideos erschließen. Unterrichtsmaterialien für den Deutschunterricht
Baumann, Isabell Eva UL

in Programme for Innovative Teaching and Training (PITT) (2021)

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See detailBewertungshilfe zur Unterrichtseinheit #bewegteballaden
Krämer, Charlotte UL

in Programme for Innovative Teaching and Training (PITT): #digitallife (2021)

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See detailBewertungshilfe zur Unterrichtseinheit #keinfilter
Krämer, Charlotte UL; Kang, Liana; Bissen, Manuel

in Programme for Innovative Teaching and Training (PITT): #digitallife (2021)

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See detailRecent Developments and Overview of the Country and Practitioner’s Reports
Cole, Mark David UL

in European Data Protection Law Review (2021), 7(1), 91-93

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See detailVaria
Schafer, Valerie UL; Henriot, Carine

in Flux: Cahiers Scientifiques Internationaux Réseaux et Territoires (2021), 123

Numéro Varia de Flux coordonné par C. Henriot et V. Schafer

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See detailKernel Selection in Nonparametric Regression
Halconruy, Hélène UL; Marie, Nicolas

in Mathematical Methods of Statistics (2021)

In the regression model Y=b(X)+ε, where X has a density f, this paper deals with an oracle inequality for an estimator of bf, involving a kernel in the sense of Lerasle et al. (2016), selected via the PCO ... [more ▼]

In the regression model Y=b(X)+ε, where X has a density f, this paper deals with an oracle inequality for an estimator of bf, involving a kernel in the sense of Lerasle et al. (2016), selected via the PCO method. In addition to the bandwidth selection for kernel-based estimators already studied in Lacour, Massart and Rivoirard (2017) and Comte and Marie (2020), the dimension selection for anisotropic projection estimators of f and bf is covered. [less ▲]

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See detailAn annotation database for chemicals of emerging concern in exposome research
Meijer, Jeroen; Lamoree, Marja; Hamers, Timo et al

in Environment International (2021), 152

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See detailZur fairen Bewertung von Lernprodukten
Krämer, Charlotte

in Programme for Innovative Teaching and Testing (PITT): #digitallife (2021)

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See detailIntact pain modulation through manipulation of controllability and expectations in aging
González-Roldán, Ana María; Terrasa, Juan Lorenzo; Prats-Sedano, Maria Angeles et al

in European Journal of Pain (2021)

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See detailIntentions, concepts and conceptions of research supervision: a consideration of three disciplines
Kreber, Carolin; Wealer, Cyril UL

in Teaching in Higher Education (2021)

This interview-based study with thirty doctoral supervisors in the UK focused on the diverse goals and intentions behind their supervisory activities, from which we derived a six-dimensional model of ... [more ▼]

This interview-based study with thirty doctoral supervisors in the UK focused on the diverse goals and intentions behind their supervisory activities, from which we derived a six-dimensional model of concepts of supervision. We explored how strongly each of these concepts featured in supervisors’ intentions and whether this varied by discipline. Most of the intentions underlying the activities supervisors employed pertained to the concepts ‘Enculturation’ and ‘Functional’; far fewer pertained to the concepts ‘Emancipation’, ‘Critical Thinking’, ‘Care’ and ‘Preparation for Work and Life’. When supervisors were asked to identify the intentions behind their supervision practice more generally, not in direct reference to their activities, the functional perspective was less prominent. Some differences were observed between as well as within disciplines. The study confirms and extends previous research on concepts of graduate supervision and illustrates how supervisors’ personal views, their ‘conceptions’, of supervision can be described in relation to the six concepts. [less ▲]

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See detailInterdependenzen von Zeitlichkeit, Rahmung und Transgressivität im vormodernen Erzählen. Eine Einleitung
Bendheim, Amelie UL; Hammer, Martin Sebastian

in Beiträge zur mediävistischen Erzählforschung (2021), (9), 1-12

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See detailZeitRahmenÜberschreitungen im vormodernen Erzählen. Themenheft der Beiträge zur mediävistischen Erzählforschung
Bendheim, Amelie UL; Hammer, Martin Sebastian

in Beiträge zur mediävistischen Erzählforschung (2021)

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See detailZeichenhafte Überlegenheit. Zur Transgressivität des Stierwunders in der 'Silvesterlegende' Konrads von Würzburg
Bendheim, Amelie UL

in Beiträge zur mediävistischen Erzählforschung (2021), 9

Der Aufsatz befragt das Stierwunder in der ›Silvesterlegende‹ Konrads von Würzburg auf seine Funktion im Glaubensdisput zwischen Christen und Juden. Das Wunder, dessen Kraft sich über sein ... [more ▼]

Der Aufsatz befragt das Stierwunder in der ›Silvesterlegende‹ Konrads von Würzburg auf seine Funktion im Glaubensdisput zwischen Christen und Juden. Das Wunder, dessen Kraft sich über sein zeitrahmenüberschreitendes Potenzial begrün-det, vermag nicht nur christliche Überlegenheit in der erzählten Welt auszustellen, sondern erweist sich auch als offen für eine lebensweltliche, politische Inanspruchnahme. Die Heiligenlegende, die so in nicht unproblematischer Weise zum epochen-geschichtlichen Glaubenskonflikt Stellung zu beziehen vermag, rückt damit in engere Beziehung zu ›klassischen‹ Kreuzzugsepen, als es die Gattung qua Definition vermuten ließe. [less ▲]

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See detailAccounting for Differences in Income Inequality across Countries: Tax-benefit Policy, Labour Market Structure, Returns and Demographics
Sologon, Denisa UL; van Kerm, Philippe UL; Li, Jinjing et al

in Journal of Economic Inequality (2021), 19

This paper presents a framework for studying international differences in the distribution of household income. Integrating micro-econometric and micro-simulation approaches in a decomposition analysis ... [more ▼]

This paper presents a framework for studying international differences in the distribution of household income. Integrating micro-econometric and micro-simulation approaches in a decomposition analysis, it quantifies the role of tax-benefit systems, employment and occupational structures, labour and financial market returns, and demographic composition in accounting for differences in income inequality across countries. Building upon EUROMOD (the European tax-benefit calculator) and its harmonised datasets, the model is portable and can be implemented for cross-country comparisons between any participating country. An application to the UK and Ireland—two countries that have much in common while displaying different levels of inequality—shows that differences in tax benefit rules between the two countries account for roughly half of the observed difference in disposable household income inequality. Demographic differences play negligible roles. The Irish tax-benefit system is more redistributive than UK\textquoterights due to a higher tax progressivity and higher average transfer rates. These are largely attributable to policy parameter differences, but also to differences in pre-tax, pre-transfer income distributions. [less ▲]

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See detail1918, 1945, 1989: Childhood in Times of Political Transformation: Part I
Kind-Kovács, Friederike; Venken, Machteld UL

in Journal of Modern European History (2021), 19(2),

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See detailUAV-Assisted Secure Communications in Terrestrial Cognitive Radio Networks: Joint Power Control and 3D Trajectory Optimization
Nguyen, X. Nguyen; Nguyen, van Dinh UL; Nguyen, Van Hieu et al

in IEEE Transactions on Vehicular Communications (2021), 70(4), 3298-3313

This paper considers secure communications for an underlay cognitive radio network (CRN) in the presence of an external eavesdropper (Eve). The secrecy performance of CRNs is usually limited by the ... [more ▼]

This paper considers secure communications for an underlay cognitive radio network (CRN) in the presence of an external eavesdropper (Eve). The secrecy performance of CRNs is usually limited by the primary receiver’s interference power constraint. To overcome this issue, we propose to use an unmanned aerial vehicle (UAV) as a friendly jammer to interfere Eve in decoding the confidential message from the secondary transmitter (ST). Our goal is to jointly optimize the transmit power and UAV’s trajectory in the three-dimensional (3D) space to maximize the average achievable secrecy rate of the secondary system. The formulated optimization problem is nonconvex due to the nonconvexity of the objective and nonconvexity of constraints, which is very challenging to solve. To obtain a suboptimal but efficient solution to the problem, we first transform the original problem into a more tractable form and develop an iterative algorithm for its solution by leveraging the inner approximation framework. We further extend the proposed algorithm to the case of imperfect location information of Eve, where the average worst-case secrecy rate is considered as the objective function. Extensive numerical results are provided to demonstrate the merits of the proposed algorithms over existing approaches. [less ▲]

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See detailJoint Symbol Level Precoding and Combining for MIMO-OFDM Transceiver Architectures Based on One-Bit DACs and ADCs
Domouchtsidis, Stavros UL; Tsinos, Christos UL; Chatzinotas, Symeon UL et al

in IEEE Transactions on Wireless Communications (2021), 20(7), 4601-4613

Herein, a precoding scheme is developed for orthogonal frequency division multiplexing (OFDM) transmission in multiple-input multiple-output (MIMO) systems that use one-bit digital-to-analog converters ... [more ▼]

Herein, a precoding scheme is developed for orthogonal frequency division multiplexing (OFDM) transmission in multiple-input multiple-output (MIMO) systems that use one-bit digital-to-analog converters (DACs) and analog-to-digital converters (ADCs) at the transmitter and receiver, respectively, as a means to reduce the power consumption. Two different one-bit architectures are presented. In the first, a single user MIMO system is considered where the DACs and ADCs of the transmitter and the receiver are assumed to be one-bit and in the second, a network of analog phase shifters is added at the receiver as an additional analog-only processing step with the view to mitigate some of the effects of coarse quantization. The precoding design problem is formulated and then split into two NP-hard optimization problems, which are solved by an algorithmic solution based on the Cyclic Coordinate Descent (CCD) framework. The design of the analog post-coding matrix for the second architecture is decoupled from the precoding design and is solved by an algorithm based on the alternating direction method of multipliers (ADMM). Numerical results show that the proposed precoding scheme successfully mitigates the effects of coarse quantization and the proposed systems achieve a performance close to that of systems equipped with full resolution DACs/ADCs. [less ▲]

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See detailSwarm-based counter UAV defense system
Brust, Matthias R. UL; Danoy, Grégoire UL; Stolfi Rosso, Daniel UL et al

in Discover Internet of Things (2021), 1(1),

Unmanned Aerial Vehicles (UAVs) have quickly become one of the promising Internet-of-Things (IoT) devices for smart cities. Thanks to their mobility, agility, and onboard sensors'customizability, UAVs ... [more ▼]

Unmanned Aerial Vehicles (UAVs) have quickly become one of the promising Internet-of-Things (IoT) devices for smart cities. Thanks to their mobility, agility, and onboard sensors'customizability, UAVs have already demonstrated immense potential for numerous commercial applications. The UAVs expansion will come at the price of a dense, high-speed and dynamic traffic prone to UAVs going rogue or deployed with malicious intent. Counter UAV systems (C-UAS) are thus required to ensure their operations are safe. Existing C-UAS, which for the majority come from the military domain, lack scalability or induce collateral damages. This paper proposes a C-UAS able to intercept and escort intruders. It relies on an autonomous defense UAV swarm, capable of self-organizing their defense formation and to intercept the malicious UAV. This fully localized and GPS-free approach follows a modular design regarding the defense phases and it uses a newly developed balanced clustering to realize the intercept- and capture-formation. The resulting networked defense UAV swarm is resilient to communication losses. Finally, a prototype UAV simulator has been implemented. Through extensive simulations, we demonstrate the feasibility and performance of our approach. [less ▲]

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See detailEnergy Efficiency Maximization in RIS-Aided Cell-Free Network with Limited Backhaul
Le, Nhat Le; Nguyen, van Dinh UL; Dobre, Octavia A. et al

in IEEE Communications Letters (2021), 25(6), 1974-1978

Integrating the reconfigurable intelligent surface in a cell-free (RIS-CF) network is an effective solution to improve the capacity and coverage of future wireless systems with low cost and power ... [more ▼]

Integrating the reconfigurable intelligent surface in a cell-free (RIS-CF) network is an effective solution to improve the capacity and coverage of future wireless systems with low cost and power consumption. The reflecting coefficients of RISs can be programmed to enhance signals received at users. This letter addresses a joint design of transmit beamformers at access points and reflecting coefficients at RISs to maximize the energy efficiency (EE) of RIS-CF networks, taking into account the limited backhaul capacity constraints. Due to a very computationally challenging nonconvex problem, we develop a simple yet efficient alternating descent algorithm for its solution. Numerical results verify that the EE of RIS-CF networks is greatly improved, showing the benefit of using RISs. [less ▲]

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See detailStatistical and Machine Learning Techniques in Human Microbiome Studies: Contemporary Challenges and Solutions
Moreno-Indias, Isabel; Lahti, Leo; Nedyalkova, Miroslava et al

in Frontiers in Microbiology (2021), 12

The human microbiome has emerged as a central research topic in human biology and biomedicine. Current microbiome studies generate high-throughput omics data across different body sites, populations, and ... [more ▼]

The human microbiome has emerged as a central research topic in human biology and biomedicine. Current microbiome studies generate high-throughput omics data across different body sites, populations, and life stages. Many of the challenges in microbiome research are similar to other high-throughput studies, the quantitative analyses need to address the heterogeneity of data, specific statistical properties, and the remarkable variation in microbiome composition across individuals and body sites. This has led to a broad spectrum of statistical and machine learning challenges that range from study design, data processing, and standardization to analysis, modeling, cross-study comparison, prediction, data science ecosystems, and reproducible reporting. Nevertheless, although many statistics and machine learning approaches and tools have been developed, new techniques are needed to deal with emerging applications and the vast heterogeneity of microbiome data. We review and discuss emerging applications of statistical and machine learning techniques in human microbiome studies and introduce the COST Action CA18131 “ML4Microbiome” that brings together microbiome researchers and machine learning experts to address current challenges such as standardization of analysis pipelines for reproducibility of data analysis results, benchmarking, improvement, or development of existing and new tools and ontologies. [less ▲]

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See detailL-plastin Ser5 phosphorylation is modulated by the PI3K/SGK pathway and promotes breast cancer cell invasiveness
Machado, Raquel A.C.; Stojevski, Dunja; de Landtsheer, Sébastien UL et al

in Cell Communication and Signaling (2021), 19(22), 1-22

Background: Metastasis is the predominant cause for cancer morbidity and mortality accounting for approxima‑ tively 90% of cancer deaths. The actin‑bundling protein L‑plastin has been proposed as a ... [more ▼]

Background: Metastasis is the predominant cause for cancer morbidity and mortality accounting for approxima‑ tively 90% of cancer deaths. The actin‑bundling protein L‑plastin has been proposed as a metastatic marker and phos‑ phorylation on its residue Ser5 is known to increase its actin‑bundling activity. We recently showed that activation of the ERK/MAPK signalling pathway leads to L‑plastin Ser5 phosphorylation and that the downstream kinases RSK1 and RSK2 are able to directly phosphorylate Ser5. Here we investigate the involvement of the PI3K pathway in L‑plastin Ser5 phosphorylation and the functional effect of this phosphorylation event in breast cancer cells. Methods: To unravel the signal transduction network upstream of L‑plastin Ser5 phosphorylation, we performed computational modelling based on immunoblot analysis data, followed by experimental validation through inhi‑ bition/overexpression studies and in vitro kinase assays. To assess the functional impact of L‑plastin expression/ Ser5 phosphorylation in breast cancer cells, we either silenced L‑plastin in cell lines initially expressing endogenous L‑plastin or neoexpressed L‑plastin wild type and phosphovariants in cell lines devoid of endogenous L‑plastin. The established cell lines were used for cell biology experiments and confocal microscopy analysis. Results: Our modelling approach revealed that, in addition to the ERK/MAPK pathway and depending on the cellular context, the PI3K pathway contributes to L‑plastin Ser5 phosphorylation through its downstream kinase SGK3. The results of the transwell invasion/migration assays showed that shRNA‑mediated knockdown of L‑plastin in BT‑20 or HCC38 cells significantly reduced cell invasion, whereas stable expression of the phosphomimetic L‑plastin Ser5Glu variant led to increased migration and invasion of BT‑549 and MDA‑MB‑231 cells. Finally, confocal image analysis combined with zymography experiments and gelatin degradation assays provided evidence that L‑plastin Ser5 phosphorylation promotes L‑plastin recruitment to invadopodia, MMP‑9 activity and concomitant extracellular matrix degradation. Conclusion: Altogether, our results demonstrate that L‑plastin Ser5 phosphorylation increases breast cancer cell invasiveness. Being a downstream molecule of both ERK/MAPK and PI3K/SGK pathways, L‑plastin is proposed here as a potential target for therapeutic approaches that are aimed at blocking dysregulated signalling outcome of both pathways and, thus, at impairing cancer cell invasion and metastasis formation. [less ▲]

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See detailThermofield dynamics: Quantum chaos versus decoherence
Xu, Zhenyu; Chenu, Aurélia UL; Prosen, Tomaž et al

in Physical Review. B, Condensed Matter and Materials Physics (2021)

Quantum chaos imposes universal spectral signatures that govern the thermofield dynamics of a many-body system in isolation. The fidelity between the initial and time-evolving thermofield double states ... [more ▼]

Quantum chaos imposes universal spectral signatures that govern the thermofield dynamics of a many-body system in isolation. The fidelity between the initial and time-evolving thermofield double states exhibits as a function of time a decay, dip, ramp, and plateau. Sources of decoherence give rise to a nonunitary evolution and result in information loss. Energy dephasing gradually suppresses quantum noise fluctuations and the dip associated with spectral correlations. Decoherence further delays the appearance of the dip and shortens the span of the linear ramp associated with chaotic behavior. The interplay between signatures of quantum chaos and information loss is determined by the competition among the decoherence, dip, and plateau characteristic times, as demonstrated in the stochastic Sachdev-Ye-Kitaev model. [less ▲]

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See detailPathoFact: a pipeline for the prediction of virulence factors and antimicrobial resistance genes in metagenomic data
de Nies, Laura UL; Lopes, Sara; Busi, Susheel Bhanu UL et al

in Microbiome (2021)

Background Pathogenic microorganisms cause disease by invading, colonizing, and damaging their host. Virulence factors including bacterial toxins contribute to pathogenicity. Additionally, antimicrobial ... [more ▼]

Background Pathogenic microorganisms cause disease by invading, colonizing, and damaging their host. Virulence factors including bacterial toxins contribute to pathogenicity. Additionally, antimicrobial resistance genes allow pathogens to evade otherwise curative treatments. To understand causal relationships between microbiome compositions, functioning, and disease, it is essential to identify virulence factors and antimicrobial resistance genes in situ. At present, there is a clear lack of computational approaches to simultaneously identify these factors in metagenomic datasets. Results Here, we present PathoFact, a tool for the contextualized prediction of virulence factors, bacterial toxins, and antimicrobial resistance genes with high accuracy (0.921, 0.832 and 0.979, respectively) and specificity (0.957, 0.989 and 0.994). We evaluate the performance of PathoFact on simulated metagenomic datasets and perform a comparison to two other general workflows for the analysis of metagenomic data. PathoFact outperforms all existing workflows in predicting virulence factors and toxin genes. It performs comparably to one pipeline regarding the prediction of antimicrobial resistance while outperforming the others. We further demonstrate the performance of PathoFact on three publicly available case-control metagenomic datasets representing an actual infection as well as chronic diseases in which either pathogenic potential or bacterial toxins are hypothesized to play a role. In each case, we identify virulence factors and AMR genes which differentiated between the case and control groups, thereby revealing novel gene associations with the studied diseases. Conclusion PathoFact is an easy-to-use, modular, and reproducible pipeline for the identification of virulence factors, bacterial toxins, and antimicrobial resistance genes in metagenomic data. Additionally, our tool combines the prediction of these pathogenicity factors with the identification of mobile genetic elements. This provides further depth to the analysis by considering the genomic context of the pertinent genes. Furthermore, PathoFact’s modules for virulence factors, toxins, and antimicrobial resistance genes can be applied independently, thereby making it a flexible and versatile tool. PathoFact, its models, and databases are freely available at https://pathofact.lcsb.uni.lu. [less ▲]

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See detailDesign Optimization for Low-Complexity FPGA Implementation of Symbol-Level Multiuser Precoding
Haqiqatnejad, Alireza UL; Krivochiza, Jevgenij UL; Merlano Duncan, Juan Carlos UL et al

in IEEE Access (2021), 9

This paper proposes and validates a low-complexity FPGA design for symbol-level precoding (SLP) in multiuser multiple-input single-output (MISO) downlink communication systems. In the optimal case, the ... [more ▼]

This paper proposes and validates a low-complexity FPGA design for symbol-level precoding (SLP) in multiuser multiple-input single-output (MISO) downlink communication systems. In the optimal case, the symbol-level precoded transmit signal is obtained as the solution to an optimization problem tailored for a given set of users’ data symbols. This symbol-by-symbol design, however, imposes excessive computational complexity on the system. To alleviate this issue, we aim to reduce the per-symbol complexity of the SLP scheme by developing an approximate yet computationally-efficient closed-form solution. The proposed solution allows us to achieve a high symbol throughput in real-time implementations. To develop the FPGA design, we express the proposed solution in an algorithmic way and translate it to hardware description language (HDL). We then optimize the processing to accelerate the performance and generate the corresponding intellectual property (IP) core. We provide the synthesis report for the generated IP core, including performance and resource utilization estimates and interface descriptions. To validate our design, we simulate an uncoded transmission over a downlink multiuser channel using the LabVIEW software, where the SLP IP core is implemented as a clock-driven logic (CDL) unit. Our simulation results show that a throughput of 100 Mega symbols per second per user can be achieved via the proposed SLP design. We further use the MATLAB software to produce numerical results for the conventional zero-forcing (ZF) and the optimal SLP techniques as benchmarks for comparison. Thereby, it is shown that the proposed FPGA implementation of SLP offers an improvement of up to 50 percent in power efficiency compared to the ZF precoding. Remarkably, it enjoys the same per-symbol complexity order as that of the ZF technique. We also evaluate the loss of the real-time SLP design, introduced by the algebraic approximations and arithmetic inaccuracies, with respect to the optimal scheme. [less ▲]

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See detailWhy flipping the classroom is not enough: Digital curriculum making after the pandemic
Backes, Susanne UL; Baumann, Isabell Eva UL; Harion, Dominic UL et al

in PROSPECTS Comparative Journal of Curriculum, Learning, and Assessment (2021)

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See detailGenome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into its genetic architecture
Chia, Ruth; Sabir, Marya S.; Bandres-Ciga, Sara et al

in Nature Genetics (2021)

The genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic ... [more ▼]

The genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic architecture of this understudied form of dementia, and to generate a resource for the scientific community. Genome-wide association analysis identified five independent risk loci, whereas genome-wide gene-aggregation tests implicated mutations in the gene GBA. Genetic risk scores demonstrate that LBD shares risk profiles and pathways with Alzheimer’s disease and Parkinson’s disease, providing a deeper molecular understanding of the complex genetic architecture of this age-related neurodegenerative condition. [less ▲]

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See detailBenefits, Motivations, and Challenges of International Collaborative Research: A Sociology of Science Case Study
Dusdal, Jennifer UL; Powell, Justin J W UL

in Science and Public Policy (2021), 48(2), 235-245

Contemporary science is marked by expanding, diverse forms of teamwork. Collaboration across organizational and cultural boundaries extends the possibilities of discovery. International collaborative ... [more ▼]

Contemporary science is marked by expanding, diverse forms of teamwork. Collaboration across organizational and cultural boundaries extends the possibilities of discovery. International collaborative research projects can provide findings beyond what one team could achieve alone. Motivated to grow their scientific network and maintain existing relationships, researchers increasingly collaborate, despite often unrecognized costs, since such projects are challenging to manage and carry out. Rarely studied in-depth and longitudinally, researcher perspectives are crucial to better understand the dynamics of durable collaboration networks. Thus, this retrospective, longitudinal case study of a sociology of science project applies the novel method of autoethnography to examine teamwork benefits, motivations, and challenges. Key challenges found include spatial distance and differences of culture, language, and career stage. This study, spanning North America, Europe, the Middle East, and East Asia, focused on collaborators’ characteristics and evolving perceptions of team dynamics over a decade. [less ▲]

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See detailThe Cab Rank Rule: English Barristers in Foreign Courts
Happold, Matthew UL

in New Law Journal (2021)

When the cab rank rule is no longer a defense: considerations when accepting instructions overseas. Barristers have hit the headlines recently for taking instructions on controversial cases in foreign ... [more ▼]

When the cab rank rule is no longer a defense: considerations when accepting instructions overseas. Barristers have hit the headlines recently for taking instructions on controversial cases in foreign jurisdictions, to which the cab rank rule obliging a barrister to accept any work does not apply. When accepting such cases, barristers should bear in mind whether those foreign proceedings are at odds with their core duties under the Bar Standard Board’s Code of Conduct, particularly in politically sensitive cases. [less ▲]

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See detailNRAS is unique among RAS proteins in requiring ICMT for trafficking to the plasma membrane
Ahearn, Ian M.; Court, Helen R.; Siddiqui, Farid et al

in Life Science Alliance (2021)

Isoprenylcysteine carboxyl methyltransferase (ICMT) is the third of three enzymes that sequentially modify the C-terminus of CaaX proteins, including RAS. Although all four RAS proteins are substrates for ... [more ▼]

Isoprenylcysteine carboxyl methyltransferase (ICMT) is the third of three enzymes that sequentially modify the C-terminus of CaaX proteins, including RAS. Although all four RAS proteins are substrates for ICMT, each traffics to membranes differently by virtue of their hypervariable regions that are differentially palmitoylated. We found that among RAS proteins, NRAS was unique in requiring ICMT for delivery to the PM, a consequence of having only a single palmitoylation site as its secondary affinity module. Although not absolutely required for palmitoylation, acylation was diminished in the absence of ICMT. Photoactivation and FRAP of GFP-NRAS revealed increase flux at the Golgi, independent of palmitoylation, in the absence of ICMT. Association of NRAS with the prenyl-protein chaperone PDE6δ also required ICMT and promoted anterograde trafficking from the Golgi. We conclude that carboxyl methylation of NRAS is required for efficient palmitoylation, PDE6δ binding, and homeostatic flux through the Golgi, processes that direct delivery to the plasma membrane. [less ▲]

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See detailEnergy-Efficient Hybrid Symbol-Level Precoding for Large-Scale mmWave Multiuser MIMO Systems
Haqiqatnejad, Alireza UL; Kayhan, Farbod UL; Ottersten, Björn UL

in IEEE Transactions on Communications (2021), 69(5), 3119-3134

We address the symbol-level precoding design problem for the downlink of a multiuser millimeter wave (mmWave) multiple-input multiple-output (MIMO) wireless system where the transmitter is equipped with a ... [more ▼]

We address the symbol-level precoding design problem for the downlink of a multiuser millimeter wave (mmWave) multiple-input multiple-output (MIMO) wireless system where the transmitter is equipped with a large-scale antenna array. The high cost and power consumption associated with the massive use of radio frequency (RF) chains prohibit fully-digital implementation of the precoder, and therefore, we consider a hybrid analog-digital architecture where a small-sized baseband precoder is followed by two successive networks of analog on-off switches and variable phase shifters according to a fully-connected structure. We jointly optimize the digital baseband precoder and the states of the switching network on a symbol-level basis, i.e., by exploiting both the channel state information (CSI) and the instantaneous data symbols, whereas the phase-shifting network is designed only based on the CSI due to practical considerations. Our approach to this joint optimization is to minimize the Euclidean distance between the optimal fully-digital and the hybrid symbol-level precoders. Remarkably, the use of a switching network allows for power-savings in the analog precoder by switching some of the phase shifters off according to the instantaneously optimized states of the switches. Our numerical results indicate that, on average, up to 50 percent of the phase shifters can be switched off. We provide an analysis of energy efficiency by adopting appropriate power dissipation models for the analog precoder, where it is shown that the energy efficiency of precoding can substantially be improved thanks to the phase shifter selection approach, compared to the fully-digital and the state-of-the-art hybrid symbol-level schemes. [less ▲]

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See detailCompte rendu de Jakob Müller, Die importierte Nation
Brüll, Christoph UL

in H-Soz-Kult: Kommunikation und Fachinformation für die Geschichtswissenschaften (2021)

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See detailMathematical modeling of thermal behavior of single iron ore pellet during heat hardening oxidation
Amani, Hafez; Alamdari, E.K; Ale Ebrahim, H. et al

in Journal of Thermal Analysis and Calorimetry (2021)

In this study, a one-dimensional generic model capable of being integrated with reactor scale models is proposed for a single pellet through solving the transient diferential conservation equations ... [more ▼]

In this study, a one-dimensional generic model capable of being integrated with reactor scale models is proposed for a single pellet through solving the transient diferential conservation equations. Predicted results comparison with the experimental data showed close agreement. In addition, the model was used to investigate the relevance of physical characteristics of pellet, reacting gas composition, difusion factors, and prevailing regime. It was found that the pure magnetite pellet could achieve a temperature rise of about 245 K at oxygen concentration of 40 vol.%, whereas the maximum temperature diference inside the pellet was approximately 24 K. Moreover, increasing pellet size, the maximum attainable temperature reached a peak and then leveled out. Furthermore, by decreasing the pore diameter, the pellet size with peak temperature shifted to the smaller pellet sizes. Analyzing the numerical results also showed that for the small pellet sizes, shortening the difusion path leads to the spreading of the reaction interface. The modeling methodology herein can be applied to any particulate processes and is not limited to the aforementioned case. [less ▲]

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See detailBackscatter-Assisted Data Offloading inOFDMA-based Wireless Powered Mobile EdgeComputing for IoT Networks
Nguyen, Xuan Phu; Tran Dinh, Hieu UL; Onireti, ‪Oluwakayode et al

in IEEE Internet of Things Journal (2021)

Mobile edge computing (MEC) has emerged as a prominent technology to overcome sudden demands on computation-intensive applications of the Internet of Things (IoT) with finite processing capabilities ... [more ▼]

Mobile edge computing (MEC) has emerged as a prominent technology to overcome sudden demands on computation-intensive applications of the Internet of Things (IoT) with finite processing capabilities. Nevertheless, the limited energy resources also seriously hinders IoT devices from offloading tasks that consume high power in active RF communications. Despite the development of energy harvesting (EH) techniques, the harvested energy from surrounding environments could be inadequate for power-hungry tasks. Fortunately, Backscatter communications (Backcom) is an intriguing technology to narrow the gap between the power needed for communication and harvested power. Motivated by these considerations, this paper investigates a backscatter-assisted data offloading in OFDMA-based wireless-powered (WP) MEC for IoT systems. Specifically, we aim at maximizing the sum computation rate by jointly optimizing the transmit power at the gateway (GW), backscatter coefficient, time-splitting (TS) ratio, and binary decision-making matrices. This problem is challenging to solve due to its non-convexity. To find solutions, we first simplify the problem by determining the optimal values of transmit power of the GW and backscatter coefficient. Then, the original problem is decomposed into two sub-problems, namely, TS ratio optimization with given offloading decision matrices and offloading decision optimization with given TS ratio. Especially, a closedform expression for the TS ratio is obtained which greatly enhances the CPU execution time. Based on the solutions of the two sub-problems, an efficient algorithm, termed the fast-efficient algorithm (FEA), is proposed by leveraging the block coordinate descent method. Then, it is compared with exhaustive search (ES), bisection-based algorithm (BA), edge computing (EC), and local computing (LC) used as reference methods. As a result, the FEA is the best solution which results in a near-globally-optimal solution at a much lower complexity as compared to benchmark schemes. For instance, the CPU execution time of FEA is about 0.029 second in a 50-user network, which is tailored for ultralow latency applications of IoT networks. [less ▲]

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See detailPredictive QM/MM Modeling of Modulations in Protein–Protein Binding by Lysine Methylation
Sanim Rahman; Vered Wineman-Fisher; Yasmine Al-Hamdani et al

in Journal of Molecular Biology (2021)

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See detailPromotion of cancer cell stemness by Ras
Chippalkatti, Rohan UL; Abankwa, Daniel UL

in Biochemical Society Transactions (2021)

Cancer stem cells (CSC) may be the most relevant and elusive cancer cell population, as they have the exquisite ability to seed new tumors. It is plausible, that highly mutated cancer genes, such as KRAS ... [more ▼]

Cancer stem cells (CSC) may be the most relevant and elusive cancer cell population, as they have the exquisite ability to seed new tumors. It is plausible, that highly mutated cancer genes, such as KRAS, are functionally associated with processes contributing to the emergence of stemness traits. In this review, we will summarize the evidence for a stemness driving activity of oncogenic Ras. This activity appears to differ by Ras isoform, with the highly mutated KRAS having a particularly profound impact. Next to established stemness pathways such as Wnt and Hedgehog (Hh), the precise, cell cycle dependent orchestration of the MAPK-pathway appears to relay Ras activation in this context. We will examine how non-canonical activities of K-Ras4B (hereafter K-Ras) could be enabled by its trafficking chaperones calmodulin and PDE6D/PDEδ. Both dynamically localize to the cellular machinery that is intimately linked to cell fate decisions, such as the primary cilium and the centrosome. Thus, it can be speculated that oncogenic K-Ras disrupts fundamental polarized signaling and asymmetric apportioning processes that are necessary during cell differentiation. [less ▲]

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See detailCollective motion in large deviations of active particles
Keta, Yann-Edwin; Fodor, Etienne UL; van Wijland, Frédéric et al

in Physical Review. E. (2021)

We analyze collective motion that occurs during rare (large deviation) events in systems of active particles, both numerically and analytically. We discuss the associated dynamical phase transition to ... [more ▼]

We analyze collective motion that occurs during rare (large deviation) events in systems of active particles, both numerically and analytically. We discuss the associated dynamical phase transition to collective motion, which occurs when the active work is biased towards larger values, and is associated with alignment of particles’ orientations. A finite biasing field is needed to induce spontaneous symmetry breaking, even in large systems. Particle alignment is computed exactly for a system of two particles. For many-particle systems, we analyze the symmetry breaking by an optimal-control representation of the biased dynamics, and we propose a fluctuating hydrodynamic theory that captures the emergence of polar order in the biased state. [less ▲]

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See detailLatent Dirichlet Allocation Models for World Trade Analysis
Kozlowski, Diego UL; Semeshenko, Viktoriya; Molinari, Andrea

in PLoS ONE (2021), 16(2), 0245393

The international trade is one of the classic areas of study in economics. Nowadays, given the availability of data, the tools used for the analysis can be complemented and enriched with new methodologies ... [more ▼]

The international trade is one of the classic areas of study in economics. Nowadays, given the availability of data, the tools used for the analysis can be complemented and enriched with new methodologies and techniques that go beyond the traditional approach. The present paper shows the application of the Latent Dirichlet Allocation Models, a well known technique from the area of Natural Language Processing, to search for latent dimensions in the product space of international trade, and their distribution across countries over time. We apply this technique to a dataset of countries' exports of goods from 1962 to 2016. The findings show the possibility to generate higher level classifications of goods based on the empirical evidence, and also allow to study the distribution of those classifications within countries. The latter show interesting insights about countries' trade specialisation. [less ▲]

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See detailPathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
Dewan, Ramita; Chia, Ruth; Ding, Jinhui et al

in Neuron (2021), 109(3), 448-460

We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients ... [more ▼]

We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington's disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered. [less ▲]

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See detailWärmemarktstudie für das Großherzogtum Luxemburg - Eine Analyse des Wärmemarktes im Kontext nationaler Rahmenbedingungen und energiepolitischer Zielsetzungen
Bechtel, Steffen UL; Scholzen, Frank UL

in Bauphysik (2021), 42(6),

In 2020 hat Luxemburg seinen Klimaplan für den Zeitraum 2021 bis 2030 beschlossen, welcher ehrgeizige Ziele für den Wärmesektor enthält. Die Datenlage im Wärmesektor, vor allem bei der ... [more ▼]

In 2020 hat Luxemburg seinen Klimaplan für den Zeitraum 2021 bis 2030 beschlossen, welcher ehrgeizige Ziele für den Wärmesektor enthält. Die Datenlage im Wärmesektor, vor allem bei der Schlüsseltechnologie Wärmepumpe, ist jedoch unzureichend, zum Nachteil aller beteiligten Akteure. Die Universität Luxemburg hat deshalb eine Wärmemarktstudie erstellt, die Verkaufszahlen nationaler Hersteller und Händler im Zeitraum von 2014 bis 2018 auswertet und auf diese Weise wesentliche Trends im Hinblick auf die Klimaziele aufzeigt. Die Auswertung zeigt signifikante Unterschiede zur bisherigen Datenlage bei Wärmepumpen, die sich aufgrund der Nichtinanspruchnahme der staatlichen Förderung ergeben. Insgesamt werden deutlich mehr Anlagen installiert als bisher angenommen Der Absatz fossiler Heizkessel ist konstant, wobei eine Verschiebung des Energieträgers von Öl zu Erdgas zu verzeichnen ist. Der allgemeine Trend bewegt sich in Richtung der gesteckten Ziele. Dennoch besteht signifikanter Handlungsbedarf, da zum Erreichen der nationalen Klimaziele u. a. ein jährliches Wachstum des Luxemburger Wärmepumpenmarktes von 16 % bis 2030 angenommen wurde. [less ▲]

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See detailQM7-X, a comprehensive dataset of quantum-mechanical properties spanning the chemical space of small organic molecules
Hoja, Johannes UL; Medrano Sandonas, Leonardo UL; Ernst, Brian G. et al

in Scientific Data (2021), 8(43),

We introduce QM7-X, a comprehensive dataset of 42 physicochemical properties for ≈4.2 million equilibrium and non-equilibrium structures of small organic molecules with up to seven non-hydrogen (C, N, O ... [more ▼]

We introduce QM7-X, a comprehensive dataset of 42 physicochemical properties for ≈4.2 million equilibrium and non-equilibrium structures of small organic molecules with up to seven non-hydrogen (C, N, O, S, Cl) atoms. To span this fundamentally important region of chemical compound space (CCS), QM7-X includes an exhaustive sampling of (meta-)stable equilibrium structures—comprised of constitutional/structural isomers and stereoisomers, e.g., enantiomers and diastereomers (including cis-/trans- and conformational isomers)—as well as 100 non-equilibrium structural variations thereof to reach a total of ≈4.2 million molecular structures. Computed at the tightly converged quantum-mechanical PBE0+MBD level of theory, QM7-X contains global (molecular) and local (atom-in-a-molecule) properties ranging from ground state quantities (such as atomization energies and dipole moments) to response quantities (such as polarizability tensors and dispersion coefficients). By providing a systematic, extensive, and tightly-converged dataset of quantum-mechanically computed physicochemical properties, we expect that QM7-X will play a critical role in the development of next-generation machine-learning based models for exploring greater swaths of CCS and performing in silico design of molecules with targeted properties. [less ▲]

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See detailBistability in oxidative stress response determines the migration behavior of phytoplankton in turbulence
Carrara, Francesco; Sengupta, Anupam UL; Behrendt, Lars et al

in Proceedings of the National Academy of Sciences of the United States of America (2021), 118(5), 2005944118

Turbulence is an important determinant of phytoplankton physiology, often leading to cell stress and damage. Turbulence affects phytoplankton migration both by transporting cells and by triggering ... [more ▼]

Turbulence is an important determinant of phytoplankton physiology, often leading to cell stress and damage. Turbulence affects phytoplankton migration both by transporting cells and by triggering switches in migratory behavior, whereby vertically migrating cells can actively invert their direction of migration upon exposure to turbulent cues. However, a mechanistic link between single-cell physiology and vertical migration of phytoplankton in turbulence is currently missing. Here, by combining physiological and behavioral experiments with a mathematical model of stress accumulation and dissipation, we show that the mechanism responsible for the switch in the direction of migration in the marine raphidophyte Heterosigma akashiwo is the integration of reactive oxygen species (ROS) signaling generated by turbulent cues. Within timescales as short as tens of seconds, the emergent downward-migrating subpopulation exhibited a twofold increase in ROS, an indicator of stress, 15% lower photosynthetic efficiency, and 35% lower growth rate over multiple generations compared to the upward-migrating subpopulation. The origin of the behavioral split as a result of a bistable oxidative stress response is corroborated by the observation that exposure of cells to exogenous stressors (H2O2, UV-A radiation, or high irradiance), in lieu of turbulence, caused comparable ROS accumulation and an equivalent split into the two subpopulations. By providing a mechanistic link between the single-cell mechanics of swimming and physiology on the one side and the emergent population-scale migratory response and impact on fitness on the other, the ROS-mediated early warning response we discovered contributes to our understanding of phytoplankton community composition in future ocean conditions. [less ▲]

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See detailMapping the Metabolic Networks of Tumor Cells and Cancer-Associated Fibroblasts
Karta, Jessica UL; Bossicard, Ysaline UL; Kotzamanis, Konstantinos UL et al

in Cells (2021)

Metabolism is considered to be the core of all cellular activity. Thus, extensive studies of metabolic processes are ongoing in various fields of biology, including cancer research. Cancer cells are known ... [more ▼]

Metabolism is considered to be the core of all cellular activity. Thus, extensive studies of metabolic processes are ongoing in various fields of biology, including cancer research. Cancer cells are known to adapt their metabolism to sustain high proliferation rates and survive in unfavorable environments with low oxygen and nutrient concentrations. Hence, targeting cancer cell metabolism is a promising therapeutic strategy in cancer research. However, cancers consist not only of genetically altered tumor cells but are interwoven with endothelial cells, immune cells and fibroblasts, which together with the extracellular matrix (ECM) constitute the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs), which are linked to poor prognosis in different cancer types, are one important component of the TME. CAFs play a significant role in reprogramming the metabolic landscape of tumor cells, but how, and in what manner, this interaction takes place remains rather unclear. This review aims to highlight the metabolic landscape of tumor cells and CAFs, including their recently identified subtypes, in different tumor types. In addition, we discuss various in vitro and in vivo metabolic techniques as well as different in silico computational tools that can be used to identify and characterize CAF–tumor cell interactions. Finally, we provide our view on how mapping the complex metabolic networks of stromal-tumor metabolism will help in finding novel metabolic targets for cancer treatment. [less ▲]

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See detailInternal and international parental migration and the living conditions of children in Ghana
Cebotari, Victor UL; Dito, Bilisuma

in Children and Youth Services Review (2021), 121(February), 105821

Relatively little is known about the effects of parental migration on the living conditions of children who stay behind. Using survey data collected in 2010 from Ghanaian school children (11–18 years; N ... [more ▼]

Relatively little is known about the effects of parental migration on the living conditions of children who stay behind. Using survey data collected in 2010 from Ghanaian school children (11–18 years; N = 2100), this study investigates variations in children’s durable goods and private utilities when parents migrate internally or internationally compared to a control group of children who live with their parents. The study also investigates whether the effects are contingent upon the marital situation of the parents. The findings show that parental migration is not associated with poorer living conditions for Ghanaian children. Rather, specific factors, such as parental divorce, internal migration and the gender of the child, influence whether children experience a decline in their living conditions when parents migrate. [less ▲]

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See detailRaumplanung und Weiterbildung in Luxemburg
Becker, Tom UL; Hesse, Markus UL

in RaumPlanung (2021), 2021(210), 60-65

Das Großherzogtum Luxemburg ist eines der kleinsten Mitgliedsländer der Europäischen Union und hat in der jüngeren Vergangenheit ein massives Wachstum von Wirtschaft und Bevölkerung erfahren. COVID-19 und ... [more ▼]

Das Großherzogtum Luxemburg ist eines der kleinsten Mitgliedsländer der Europäischen Union und hat in der jüngeren Vergangenheit ein massives Wachstum von Wirtschaft und Bevölkerung erfahren. COVID-19 und die Gegenmaßnahmen der Politik haben die hohe Außenorientierung des Landes jedoch empfindlich getroffen. Am Beispiel der Raumplanungs-Weiterbildung ‚Formation Continue Aménagement du Territoire (FCAT)‘ zeigt dieser Beitrag, wie raumplanerische Lehre und Forschung auf diese neuen Herausforderungen reagieren, sowohl inhaltlich wie auch didaktisch. [less ▲]

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See detailDie Beteiligung privater Rundfunkveranstalter an einer staatlich veranlassten Finanzierung - Eine Untersuchung möglicher Unterstützungsmaßnahmen auf ihre Vereinbarkeit mit dem deutschen Rundfunkverfassungs- und EU-Beihilfenrecht
Cole, Mark David UL

in UFITA - Archiv für Medienrecht und Medienwissenschaft (2021), 84(2),

Die Corona-Pandemie hat wie in einem Brennglas zweierlei für den Mediensektor gezeigt: einerseits die Wichtigkeit der Medien für die Information der Bürger (was an deutlich gestiegenen Nutzungszahlen von ... [more ▼]

Die Corona-Pandemie hat wie in einem Brennglas zweierlei für den Mediensektor gezeigt: einerseits die Wichtigkeit der Medien für die Information der Bürger (was an deutlich gestiegenen Nutzungszahlen von Qualitätsmedien ablesbar ist) und andererseits, bedingt durch die erheblichen wirtschaftlichen Folgen etwa wegen ausbleibender Werbeeinnahmen, die Schwierigkeiten für bestimmte Inhalteanbieter eine nachhaltige finanzielle Stabilität aufzuweisen. Als Konsequenz wurden verschiedene Instrumentarien auf mitgliedstaatlicher und EU-Ebene eingeführt, um die negativen Folgen abzumildern. Solche Formen von Unterstützungsleistungen werden im Beitrag daraufhin untersucht, ob sie grundsätzlich mit rundfunkverfassungsrechtlichen Bedingungen in Deutschland sowie dem einschlägigen EU-Beihilfenrecht vereinbar sind. Der Beitrag basiert auf einem Gutachten, in dem die Autoren lange vor der Pandemie umfassend untersucht haben und zu einem bejahenden Ergebnis kommen, ob private Rundfunkveranstalter an einer staatlich veranlassten Finanzierung teilhaben könnten und wie bei der Einführung eines solchen Instrumentariums, das rundfunkverfassungsrechtlich möglich, aber de lege lata nach aktuellem Medienstaatsvertrag als Regelmaßnahme nicht durchführbar wäre, die Rahmenbedingungen auszugestalten wären. Neben der ausführlichen Anwendung der relevanten Urteile des Bundesverfassungsgerichts auf eine solche Konstellation, enthält der Beitrag aus akutellem Anlass auch eine kurze Darstellung der ersten medienbezogenen Beihilfeentscheidung der Kommission für ein Förderprogramm, das von Dänemark ausdrücklich zur Abwendung von Nachteilen eingeführt wurde, die der dortige Mediensektor als Resultat staatlicher Vorsorgemaßnahme erlitten hat. [less ▲]

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See detailA Typical Case Report: Internet Gaming Disorder Psychotherapy Treatment in Private Practice
Niedermoser, Daryl Wayne; Hadjar, Andreas UL; Ankli, Vivian et al

in International Journal of Environmental Research and Public Health (2021), 18(4),

Background: Online or internet gaming disorder (IGD) is currently not recognized as a mental disorder in the actual Diagnostic and Statistical Manual of Mental Disorders (DSM-5), although it is an ... [more ▼]

Background: Online or internet gaming disorder (IGD) is currently not recognized as a mental disorder in the actual Diagnostic and Statistical Manual of Mental Disorders (DSM-5), although it is an emerging disease. Non-substance-related addictions often have similarities with substance addictions. It is therefore important to have a good understanding of the client but also to have a good endurance. Due to the rise of e-sports, there is an anticipated and therefore possible trend to have many more patients with a non-substance addiction. There are many parallels, for instance tolerance, withdrawal and social problems, resulting from an increasing investment of time spent on the internet. Case presentation: To reduce possible inhibition in treating a patient with IGD, we present a case of a 19-year-old adolescent man who exhibited IGD and showed social problems associated with his addiction. Conclusions: This paper shows the importance and the effects of treating a non-substance addiction with cognitive behavioral therapy (CBT). After having successfully coped with an addiction, several shifts in addiction were often reported. In this case, no shifts were reported. The absence of such shifts makes our case a distinct and unique case. This is not a multimorbidity case, and that is the reason why we think this is an excellent example to show what we achieved, how we achieved it, and what we could establish. Of course, additional research and manuals are urgently needed. [less ▲]

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See detailTowards Optimal Energy Efficiency in Cell-Free Massive MIMO Systems
Papazafeiropoulos, Anastasios; Ngo, Hien Quoc; Kourtessis, Pandelis et al

in IEEE Transactions on Green Communications and Networking (2021), 5(2), 816-831

Motivated by the ever-growing demand for green wireless communications and the advantages of cell-free (CF) massive multiple-input multiple-output (mMIMO) systems, we focus on the design of their downlink ... [more ▼]

Motivated by the ever-growing demand for green wireless communications and the advantages of cell-free (CF) massive multiple-input multiple-output (mMIMO) systems, we focus on the design of their downlink (DL) for optimal energy efficiency (EE). To address this fundamental topic, we assume that each access point (AP) is deployed with multiple antennas and serves multiple users on the same time-frequency resource while the APs are Poisson point process (PPP) distributed, which approaches realistically their opportunistic spatial randomness. Relied on tools from stochastic geometry, we derive a lower bound on the DL average achievable spectral efficiency (SE). Next, we consider a realistic power consumption model for CF mMIMO systems. These steps enable the formulation of a tractable optimization problem concerning the DL EE, which results in the analytical determination of the optimal pilot reuse factor, the AP density, and the number of AP antennas and users that maximize the EE. Hence, we provide useful design guidelines for CF mMIMO systems relating to fundamental system variables towards optimal EE. Among the results, we observe that an optimal pilot reuse factor and AP density exist, while larger values result in an increase of the interference, and subsequently, lower EE. Overall, it is shown that the CF mMIMO technology is a promising candidate for next-generation networks achieving simultaneously high SE and EE. [less ▲]

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See detailWhat´s in a diagnosis: The Effect of Externalizing and Internalizing Students´ Behaviour on Pre-service Teachers' Classroom Management and Interaction Strategies
Glock, Sabine UL; Pit-Ten Cate, Ineke UL

in British Journal of Educational Psychology (2021), 91(4), 1185-1201

Background. All over the word, classrooms are getting more and more diverse and teachers are required to effectively manage these classes even when students have special education needs (SEN). Aims. The ... [more ▼]

Background. All over the word, classrooms are getting more and more diverse and teachers are required to effectively manage these classes even when students have special education needs (SEN). Aims. The study aimed to investigate classroom management strategies and interpersonal teacher behaviour in relation to students internalizing and externalizing behaviour, whereby we varied the diagnosis of special educational needs. Sample. Two hundred and fifty-four German pre-service teachers (143 female) with a mean age of 26.04 years participated in the study. Method. Using an experimental between-subjects design, a fictitious student was described as exhibiting either internalizing or externalizing behaviour. Additionally, we varied whether the student was diagnosed as having SEN or not. The participants were asked to indicate which strategies they would apply and how they would interact with students. Results. Results showed that teacher interaction in response to both students with internalizing and externalizing behaviour approached ideal interpersonal teacher behaviour (i.e. high level of cooperativeness with certain level of dominance), whereas pre-service teachers applied all classroom management strategies to minimize effects of student behaviour on learning time. Although pre-service teachers adapted their responses based on type of behaviour, they only made allowances for internalizing behaviour while their response to externalizing behaviour did not vary much as a function of a SEN diagnosis. Conclusions. Together, these findings highlight the importance of providing preservice teachers with the pedagogical knowledge concerning effective classroom management and flexible use of strategies in response to diverse student needs in inclusive classrooms. [less ▲]

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See detailTowards Optimal Energy Efficiency in Cell-Free Massive MIMO Systems
Papazafeiropoulos, A.; Ngo, H.Q.; Kourtessis, Pandelis et al

in IEEE Transactions on Green Communications and Networking (2021), 5(2), 816-831

Motivated by the ever-growing demand for green wireless communications and the advantages of cell-free (CF) massive multiple-input multiple-output (mMIMO) systems, we focus on the design of their downlink ... [more ▼]

Motivated by the ever-growing demand for green wireless communications and the advantages of cell-free (CF) massive multiple-input multiple-output (mMIMO) systems, we focus on the design of their downlink (DL) for optimal energy efficiency (EE). To address this fundamental topic, we assume that each access point (AP) is deployed with multiple antennas and serves multiple users on the same time-frequency resource while the APs are Poisson point process (PPP) distributed, which approaches realistically their opportunistic spatial randomness. Relied on tools from stochastic geometry, we derive a lower bound on the DL average achievable spectral efficiency (SE). Next, we consider a realistic power consumption model for CF mMIMO systems. These steps enable the formulation of a tractable optimization problem concerning the DL EE, which results in the analytical determination of the optimal pilot reuse factor, the AP density, and the number of AP antennas and users that maximize the EE. Hence, we provide useful design guidelines for CF mMIMO systems relating to fundamental system variables towards optimal EE. Among the results, we observe that an optimal pilot reuse factor and AP density exist, while larger values result in an increase of the interference, and subsequently, lower EE. Overall, it is shown that the CF mMIMO technology is a promising candidate for next-generation networks achieving simultaneously high SE and EE. [less ▲]

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See detailAgency and the school-to-work transition of care leavers: A retrospective study of Luxembourgish young people
Göbel, Sabrina; Hadjar, Andreas UL; Karl, Ute et al

in Children and Youth Services Review (2021), early online

This article presents empirical results from a study (2015–2018) on young people leaving care in Luxembourg. A special focus deals with the processes of transitioning from care to work. Education appears ... [more ▼]

This article presents empirical results from a study (2015–2018) on young people leaving care in Luxembourg. A special focus deals with the processes of transitioning from care to work. Education appears to be crucial for a successful transition, as it determines life chances, such as labour market chances, but so far inequality studies have neither researched transitions from care nor have the theoretical concepts developed in inequality research been used to understand the situation of care leavers. They might help to explain the different mechanisms behind the disadvantages of students in foster and residential care and their educational attainment. This paper thus attempts to theorise leaving care from an inequality perspective and the interdependencies with concepts of relational agency, taking into account the heterogeneity among care leavers, their trajectories and achievements (see also Göbel, Hadjar, Karl, Peters, & Jäger, 2020). The main objective of our analysis is to investigate how agency is achieved in the transition from school to work among care leavers, taking into consideration institutional pathways (continuities and discontinuities) in the care and the educational system. [less ▲]

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See detailLe dilemme de sécurité : caractériser la vision stratégique d’un État au XXIe siècle ?
Fouillet, Thibault UL

in Revue Défense Nationale (2021), n°837

The concept of a security dilemma has seen numerous changes and would appear to have regained some pertinence in the characterisation of the strategic vision of a state as it establishes its defence ... [more ▼]

The concept of a security dilemma has seen numerous changes and would appear to have regained some pertinence in the characterisation of the strategic vision of a state as it establishes its defence policy. This approach can help us to understand the attitude of small countries that face greater powers. [less ▲]

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See detailAdaptive Content Seeding for Information-Centric Networking under High Topology Dynamics: Where You Seed Matters
Turcanu, Ion UL; Engel, Thomas UL; Sommer, Christoph

in IEEE Vehicular Technology Magazine (2021), 16(2),

High-fidelity content distribution and other emerging applications of 5G and beyond-5G mobile broadband networking can put massive load on the core and Radio Access Network (RAN). To address this, direct ... [more ▼]

High-fidelity content distribution and other emerging applications of 5G and beyond-5G mobile broadband networking can put massive load on the core and Radio Access Network (RAN). To address this, direct Device to Device (D2D) communication has recently become a first-class citizen of these networks. While Information-Centric Vehicular Networking (ICVN) based on fog computing can indeed exploit such D2D links to alleviate the load on the RAN by proactively seeding content in the network, it has been shown that such seeding can cause even more load if performed where not needed. In addition, trying to determine where to seed content often causes additional load, negating the benefit of seeding. In this work, we therefore propose to adaptively seed fog nodes based on a purely virtual clustering approach. Here, vehicles are unaware of clustering decisions, thus no longer requiring an explicit exchange of control messages. We show that the benefit of such an adaptive approach goes beyond simply being able to flexibly trade off performance metrics versus each other: instead, it can consistently lower the load on the RAN link. We also show that this property even holds if node location information is only available as coarsely-grained as macro-scale grid cells. [less ▲]

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See detailCut-and-Mouse and Ghost Control: Exploiting Antivirus Software with Synthesized Inputs
Genç, Ziya Alper UL; Lenzini, Gabriele UL; Sgandurra, Daniele

in Digital Threats: Research and Practice (2021), 2(1),

To protect their digital assets from malware attacks, most users and companies rely on antivirus (AV) software. AVs' protection is a full-time task against malware: This is similar to a game where malware ... [more ▼]

To protect their digital assets from malware attacks, most users and companies rely on antivirus (AV) software. AVs' protection is a full-time task against malware: This is similar to a game where malware, e.g., through obfuscation and polymorphism, denial of service attacks, and malformed packets and parameters, tries to circumvent AV defences or make them crash. However, AVs react by complementing signature-based detection with anomaly or behavioral analysis, and by using OS protection, standard code, and binary protection techniques. Further, malware counter-acts, for instance, by using adversarial inputs to avoid detection, and so on. In this cat-and-mouse game, a winning strategy is trying to anticipate the move of the adversary by looking into one's own weaknesses, seeing how the adversary can penetrate them, and building up appropriate defences or attacks. In this article, we play the role of malware developers and anticipate two novel moves for the malware side to demonstrate the weakness in the AVs and to improve the defences in AVs' side. The first one consists in simulating mouse events to control AVs, namely, to send them mouse "clicks" to deactivate their protection. We prove that many AVs can be disabled in this way, and we call this class of attacks Ghost Control. The second one consists in controlling whitelisted applications, such as Notepad, by sending them keyboard events (such as "copy-and-paste") to perform malicious operations on behalf of the malware. We prove that the anti-ransomware protection feature of AVs can be bypassed if we use Notepad as a "puppet" to rewrite the content of protected files as a ransomware would do. Playing with the words, and recalling the cat-and-mouse game, we call this class of attacks Cut-and-Mouse. We tested these two attacks on 29 AVs, and the results show that 14 AVs are vulnerable to Ghost Control attack while all 29 AV programs tested are found vulnerable to Cut-and-Mouse. Furthermore, we also show some weaknesses in additional protection mechanisms of AVs, such as sandboxing and CAPTCHA verification. We have engaged with the affected AV companies, and we reported the disclosure communication with them and their responses. [less ▲]

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See detailA covalent calmodulin inhibitor as a tool to study cellular mechanisms of K-Ras-driven stemness
Okutachi, Sunday Ojochegbe UL; Manoharan, Ganesh Babu UL; Kiriazis, Alexandros et al

in Frontiers in Cell and Developmental Biology (2021)

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See detailChildhood in Times of Political Transformation in the 20th Century: An Introduction
Kind-Kovács, Friederike; Venken, Machteld UL

in Journal of Modern European History (2021), 19(2), 111

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See detailMood-induced changes in the cortical processing of food images in bulimia nervosa
Lutz, Annika UL; Dierolf, Angelika; van Dyck, Zoé UL et al

in Addictive Behaviors (2021), 113

Background Negative mood often triggers binge eating in bulimia nervosa (BN). We investigated motivational salience as a possible underlying mechanism using event-related potentials (ERPs) as indicators ... [more ▼]

Background Negative mood often triggers binge eating in bulimia nervosa (BN). We investigated motivational salience as a possible underlying mechanism using event-related potentials (ERPs) as indicators of motivated attention allocation (P300) and sustained processing (LPP). Methods We collected ERPs (P300: 350–400 ms; LPP: 600–1000 ms) from 21 women with full-syndrome or partially remitted BN and 21 healthy women (HC), matched for age and body mass index. Idiosyncratic negative and neutral situations were used to induce corresponding mood states (counterbalanced), before participants viewed images of high- and low-calorie foods and neutral objects, and provided ratings for pleasantness and desire to eat. Results P300 was larger for foods than objects; LPP was largest for high-calorie foods, followed by low-calorie foods, then objects. The BN group showed an increased desire to eat high-calorie foods under negative mood and stronger mood induction effects on ERPs than the HC group, with generally reduced P300 and a small increase in LPP for high-calorie foods. Effects were limited to circumscribed electrode positions. Exploratory analyses showed clearer effects when comparing high vs. low emotional eaters. Conclusion We argue that negative mood decreased the availability of cognitive resources (decreased P300) in BN, thereby facilitating disinhibition and food cravings (increased desire-to-eat ratings). Increased sustained processing might be linked to emotional eating tendencies rather than BN pathology per se, and reflect approach motivation, conflict, or regulatory processes. Negative mood appears to induce complex changes in food image processing, whose understanding may contribute to the development of tailored interventions in the future. [less ▲]

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See detailMobility-Driven and Energy-Efficient Deployment of Edge Data Centers in Urban Environments
Vitello, Piergiorgio UL; Capponi, Andrea UL; Fiandrino, Claudio UL et al

in IEEE Transactions on Sustainable Computing (2021)

Multi-access Edge Computing (MEC) brings storage and computational capabilities at the edge of the network into so-called Edge Data Centers (EDCs) to better support low-latency applications. In this paper ... [more ▼]

Multi-access Edge Computing (MEC) brings storage and computational capabilities at the edge of the network into so-called Edge Data Centers (EDCs) to better support low-latency applications. In this paper, we tackle the problem of EDC deployment in urban environments. Previous research on mobile phone data has exposed a strong correlation between the demand for mobile communications and the urban tissue. For example, joint analysis of mobile data and vehicle traffic can be extrapolated to estimate demand for transportation and human activities, thereby inferring the land use of the area where such activities take place. Our work takes into account the mobility of citizens and their spatial patterns to estimate the optimal placement of MEC EDCs in urban environments, in order to minimize outages while guaranteeing energy-efficiency. This is achieved by modeling both the energy consumption attributed to network components (e.g., base stations) and computing components (e.g., servers). We propose and compare three heuristics and show that mobility-aware deployments achieve superior performance. The results are obtained with a custom-designed simulator able to operate over large-scale realistic urban environments. [less ▲]

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See detailPartnership and cognitive aging in Europe: Mediating factors and social stratification
Bertogg, Ariane; Leist, Anja UL

in Journals of Gerontology. Series B, Psychological Sciences and Social Sciences (2021)

Objectives. Living in a partnership has been shown to benefit later life health in general and decrease the risk of cognitive impairment. Few studies have, however, examined whether different types of ... [more ▼]

Objectives. Living in a partnership has been shown to benefit later life health in general and decrease the risk of cognitive impairment. Few studies have, however, examined whether different types of partnership transitions also differ with respect to their impact on cognitive trajectories, and whether financial resources, health behaviors, cognitive stimulation and social integration can explain these differences. Methods. Data came from six waves of the Survey of Health, Ageing and Retirement in Europe, which is a representative panel for the population aged 50 years or older, and was collected between 2004 and 2017 in 20 European countries. Our sample includes 213,023 valid person-year observations from 81,814 persons. Mean age at baseline is 63.86 years, and individuals were observed on average 2.6 times. Cognitive functioning was assessed with measures of immediate and delayed recall on a memory test, and verbal fluency. Fixed-effects regression models were employed to exploit individual-level variation in partnership and simultaneous cognitive changes. Results. Partnership status was stable in most respondents (around 90%). Compared to remaining partnered and after controlling for socio-demographic factors, transition to divorce was associated with a steeper decline in immediate and delayed recall. Exploring possible mechanisms, both financial resources and social integration explained these differences. Additional analyses suggested that effects were mostly driven by individuals with lower education. Discussion. Partnership transitions remain infrequent events in later life, but our findings indicate that they can induce less favorable cognitive trajectories compared to partnered individuals, particularly for those with lower cognitive reserve. [less ▲]

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See detailLost in transition – Learning analytics on the transfer from knowledge acquisition to knowledge application in complex problem solving
Nicolay, Björn Fabrice UL; Krieger, Florian UL; Stadler, Matthias et al

in Computers in Human Behavior (2021), 115

Since Complex Problem Solving (CPS) skills represent a key competence for educational success, they are of great relevance for learning analytics. More specifically, CPS serves as a pertinent showcase for ... [more ▼]

Since Complex Problem Solving (CPS) skills represent a key competence for educational success, they are of great relevance for learning analytics. More specifically, CPS serves as a pertinent showcase for addressing a crucial existing gap contemporary education is facing, the gap between students' ability to acquire and subsequently apply knowledge in uncertain situations, which are increasingly important in the 21st century. While the CPS process incorporates both the acquisition and application of knowledge, many earlier studies have focused on identifying the factors relevant for success in knowledge acquisition. Given the dearth of existing research on factors influencing a successful transition between both CPS phases, we investigated the rates of successful and unsuccessful knowledge transition over the course of nine CPS items in a sample of N = 1151 students in 9th grade. Results showed that many participants were unable to transition their knowledge from the acquisition to the application phase, which was presumably due to an inefficient mental model transfer. Furthermore, the likelihood of students being ‘lost in transition’ was higher in more complex items. Implications are discussed in light of learning analytics, and particularly with regard to the factors to be taken into account by future CPS training programs. [less ▲]

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See detailSecondary school principals and liminality in Polish Upper Silesia (1919-1939)
Venken, Machteld UL

in Journal of Modern European History (2021), 19(2), 206-221

Establishing and implementing rules that would teach young people to become active citizens became a crucial technique for turning those spots on the map of Europe whose sovereignty had shifted after ... [more ▼]

Establishing and implementing rules that would teach young people to become active citizens became a crucial technique for turning those spots on the map of Europe whose sovereignty had shifted after World War I into lived social spaces. This article analyses how principals of borderland secondary schools negotiated transformation in Polish Upper Silesia with the help of Arnold Van Gennep’s notion that a shift in social statuses possessed a spatiality and temporality of its own. The article asks whether and how school principals were called on to offer elite training that would make Polish Upper Silesia more cohesive with the rest of Poland in terms of the social origins of pupils and the content of the history curriculum. In addition, it examines the extent to which borderland school principals accepted, refuted, or helped to shape that responsibility. The social origins of pupils are detected through a quantitative analysis of recruitment figures and the profiles of pupils’ parents. This analysis is combined with an exploration of how school principals provided a meaningful explanation of the recent past (World War I and the Silesian Uprisings). The article demonstrates that while school principals were historical actors with some room to make their own decisions when a liminal space was created, changed, and abolished, it was ultimately a priest operating in their shadows who possessed more possibilities to become a master of ceremonies leading elite education through its rites of passage. [less ▲]

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See detailNein to ‘Transfer Union’: the German brake on the construction of a European Union fiscal capacity
Howarth, David UL; Schild, Joachim

in Journal of European Integration (2021), 43(2), 207-224

This paper argues that, on the development of European Union (EU)/Eurozone fiscal capacity German governments have consistently engaged in foot-dragging. Few German state elites have ever supported ... [more ▼]

This paper argues that, on the development of European Union (EU)/Eurozone fiscal capacity German governments have consistently engaged in foot-dragging. Few German state elites have ever supported European fiscal capacity building beyond the EC budget. Following the outbreak of the Eurozone sovereign debt crisis, German governments agreed to the creation of financial support mechanisms only with reluctance. We see a case of continuity in German policy preferences driven by consistent ordoliberal and, specifically, moral hazard concerns. The important longterm change that we can observe relates to the growing importance for successive governments of avoiding audience costs driven by sceptical public opinion and the rise of a challenger party in German politics. German government support for a massive EU fiscal response to the economic crisis triggered by the COVID-19 pandemic demonstrates an exceptional policy position in favour of temporary financial mechanisms involving no fiscal transfers among member state governments. [less ▲]

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See detailGestaltungsspielraum der EU-Mitgliedstaaten bei Einschränkungen der Dienstleistungsfreiheit - Beispiel der Beschränkung regionaler Werbung im Fernsehen durch den Medien-staatsvertrag mit dem Ziel der Förderung der Medienvielfalt
Cole, Mark David UL

in AfP - Zeitschrift für das gesamte Medienrecht (2021), 51(1),

Deutsches Rundfunkrecht sieht ein Verbot regionaler Werbung im bundesweit verbreiteten Fernsehen vor. Der einschlägige (frühere) § 7 Abs. 11 RStV ist im Hinblick auf seine Vereinbarkeit mit EU-Recht ... [more ▼]

Deutsches Rundfunkrecht sieht ein Verbot regionaler Werbung im bundesweit verbreiteten Fernsehen vor. Der einschlägige (frühere) § 7 Abs. 11 RStV ist im Hinblick auf seine Vereinbarkeit mit EU-Recht Gegenstand eines Verfahrens vor dem Gerichtshof der Europäischen Union (EuGH). Das Verfahren berührt auch die grundsätzlichere Frage des Handlungsspielraums der EU-Mitgliedstaaten insbesondere im Bereich der Sicherung des Medienpluralismus und der Nachprüfung durch den EuGH. Die Unionrechtskonformität der nationalen Vielfaltssicherungsvorschrift, die sich auch im Medienstaatsvertrag weiterhin findet, wird wie in diesem Beitrag auch durch den Generalanwalt in seinen Schlussanträgen bestätigt. [less ▲]

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See detailCity-states in relational urbanization: the case of Luxembourg and Singapore
Wong, Catherine; Hesse, Markus UL; Sigler, Thomas UL

in Urban Geography (2021), 43(4), 501-522

Post-industrial global urbanisation has seen the rise of territorial economic development strategies predicated on reconfiguring the urban landscape to conform to novel forms of economic production, often ... [more ▼]

Post-industrial global urbanisation has seen the rise of territorial economic development strategies predicated on reconfiguring the urban landscape to conform to novel forms of economic production, often under the guise of ‘global city’ development. This paper reorients the conversation on global city development by highlighting the intermediary roles that particular cities play in brokering flows of global knowledge, goods, and capital through novel spatial-economic configurations. We identify a sub-set of city-states characterized by territorial economic development strategies that are exemplary of ‘relational’ processes. Luxembourg and Singapore serve as illustrative cases in which urban territorial development is guided almost entirely by an exogenous orientation benefitting from an intermediary positionality. They focus on intermediary services supported by technologically intensive infrastructures and niche economic strategies enables a relational competitive advantage. Although all cities are in some way ‘relational’ in their politico-economic orientation, these extraordinary cases highlight a number of novel concurrent socio-spatial processes. We conclude that a combination of forward-looking and unconventional ‘relational’ territorial development strategies including digital infrastructures and entrepreneurial legislation support the emergence of novel industrial configurations whose key advantages are conferred by their positionality in relation to regional and global flows. [less ▲]

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See detailAddressing COVID through PCD: policy coherence for vulnerability in development and its relationship to the coronavirus pandemic
Moldes-Anaya, Sergio; Koff, Harlan UL; da Porto, Angelica UL et al

in Equality, Diversity and Inclusion (2021)

This analysis frames vulnerability as a socially constructed condition and through implementation of a PCD approach, it indicates how policy strategies contribute to or mitigate vulnerabilities. In doing ... [more ▼]

This analysis frames vulnerability as a socially constructed condition and through implementation of a PCD approach, it indicates how policy strategies contribute to or mitigate vulnerabilities. In doing so, it intends to contribute conceptually to the literature on vulnerability by showing how policy incoherences contribute to the construction of this condition. Empirically, the originality of this article is its statistical analysis of regional variance of coronavirus risk and the qualitative analysis of policy strategies in representative cases and how they have affected vulnerabilities and coronavirus impacts. The research shows that significant regional variance exists in terms of coronavirus risk, based on statistical analysis of the INFORM COVID-19 Risk Report prepared by the European Commission. The PCD analysis highlights important relationships between public policy strategies and the construction of both underlying vulnerabilities and coronavirus impacts. [less ▲]

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See detailMachine Learning-Enabled Joint Antenna Selection and Precoding Design: From Offline Complexity to Online Performance
Vu, Thang Xuan UL; Chatzinotas, Symeon UL; Nguyen, van Dinh UL et al

in IEEE Transactions on Wireless Communications (2021), 20(6), 3710-3722

We investigate the performance of multi-user multiple-antenna downlink systems in which a base station (BS) serves multiple users via a shared wireless medium. In order to fully exploit the spatial ... [more ▼]

We investigate the performance of multi-user multiple-antenna downlink systems in which a base station (BS) serves multiple users via a shared wireless medium. In order to fully exploit the spatial diversity while minimizing the passive energy consumed by radio frequency (RF) components, the BS is equipped with M RF chains and N antennas, where M < N. Upon receiving pilot sequences to obtain the channel state information (CSI), the BS determines the best subset of M antennas for serving the users. We propose a joint antenna selection and precoding design (JASPD) algorithm to maximize the system sum rate subject to a transmit power constraint and quality of service (QoS) requirements. The JASPD overcomes the non-convexity of the formulated problem via a doubly iterative algorithm, in which an inner loop successively optimizes the precoding vectors, followed by an outer loop that tries all valid antenna subsets. Although approaching the (near) global optimality, the JASPD suffers from a combinatorial complexity, which may limit its application in real-time network operations. To overcome this limitation, we propose a learning-based antenna selection and precoding design algorithm (L-ASPA), which employs a deep neural network (DNN) to establish underlaying relations between the key system parameters and the selected antennas. The proposed L-ASPD is robust against the number of users and their locations, BS's transmit power, as well as the small-scale channel fading. With a well-trained learning model, it is shown that the L-ASPD significantly outperforms baseline schemes based on the block diagonalization and a learning-assisted solution for broadcasting systems and achieves higher effective sum rate than that of the JASPA under limited processing time. In addition, we observed that the proposed L-ASPD can reduce the computation complexity by 95% while retaining more than 95% of the optimal performance. [less ▲]

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See detailZero-Rating ist nicht „netzneutral”
Cole, Mark David UL

in Neue Juristische Wochenschrift (2021), 74(4), 208-210

Nach der erheblichen politischen Diskussion vor Verabschiedung der sogenannten Netzneutralitäts-Verordnung der EU (NN-VO)1 und der seither leiser gewordenen Beschäftigung mit diesem ... [more ▼]

Nach der erheblichen politischen Diskussion vor Verabschiedung der sogenannten Netzneutralitäts-Verordnung der EU (NN-VO)1 und der seither leiser gewordenen Beschäftigung mit diesem telekommunikationsrechtlichen Regelungswerk hat der EuGH mit dem ersten Urteil zur NN-VO diese wieder ins Rampenlicht geholt. [less ▲]

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See detailEstimating worldwide effects of non‐pharmaceutical interventions on COVID‐19 incidence and population mobility patterns using a multiple‐event study
Askitas, Nikolaos; Tatsiramos, Konstantinos UL; Verheyden, Bertrand

in Scientific Reports (2021), 11(1972 (2021)), 1-13

Various non‐pharmaceutical interventions were adopted by countries worldwide in the fight against the COVID‐19 pandemic with adverse socioeconomic side effects, which raises the question about their ... [more ▼]

Various non‐pharmaceutical interventions were adopted by countries worldwide in the fight against the COVID‐19 pandemic with adverse socioeconomic side effects, which raises the question about their differential effectiveness. We estimate the average dynamic effect of each intervention on the incidence of COVID‐19 and on people’s whereabouts by developing a statistical model that accounts for the contemporaneous adoption of multiple interventions. Using daily data from 175 countries, we show that, even after controlling for other concurrent lockdown policies, cancelling public events, imposing restrictions on private gatherings and closing schools and workplaces had significant effects on reducing COVID‐19 infections. Restrictions on internal movement and public transport had no effects because the aforementioned policies, imposed earlier on average, had already de facto reduced human mobility. International travel restrictions, although imposed early, had a short‐lived effect failing to prevent the epidemic from turning into a pandemic because they were less stringent. We interpret the impact of each intervention on containing the pandemic using a conceptual framework which relies on their effects on human mobility behaviors in a manner consistent with time‐use and epidemiological factors. [less ▲]

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See detailHybrid automatic repeat request‐based intelligent reflecting surface‐assisted communication system
Ai, Yun; Mohamed, M.; Kong, Long UL et al

in Electronics Letters (2021)

The intelligent reflecting surface (IRS) is an emerging technique to extend wireless coverage. In this letter, the performance of the hybrid automatic repeat request (hybrid ARQ) for an IRS‐assisted ... [more ▼]

The intelligent reflecting surface (IRS) is an emerging technique to extend wireless coverage. In this letter, the performance of the hybrid automatic repeat request (hybrid ARQ) for an IRS‐assisted system is analysed. More specifically, the outage performance of the IRS‐aided system using hybrid ARQ protocol with chase combining is studied. The asymptotic analysis also shows that the outage performance is better and improves linearly by increasing the number of reflectors of the IRS‐aided system. The results also verify the potential of combining the ARQ scheme in the link layer of the IRS‐aided system and demonstrate that a very small change of path loss condition can impact the performance largely. [less ▲]

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See detailCompletion Time Minimization in NOMA Systems:Learning for Combinatorial Optimization
Wang, Anyue UL; Lei, Lei UL; Lagunas, Eva UL et al

in IEEE Networking Letters (2021)

In this letter, we study a completion-time minimization problem by jointly optimizing time slots (TSs) and power allocation for time-critical non-orthogonal multiple access (NOMA) systems. The original ... [more ▼]

In this letter, we study a completion-time minimization problem by jointly optimizing time slots (TSs) and power allocation for time-critical non-orthogonal multiple access (NOMA) systems. The original problem is non-linear/non-convex with discrete variables, leading to high computational complexity in conventional iterative methods. Towards an efficient solution, we train deep neural networks to perform fast and high-accuracy predictions to tackle the difficult combinatorial parts, i.e., determining the minimum consumed TSs and user-TS allocation. Based on the learning-based predictions, we develop a low-complexity post-process procedure to provide feasible power allocation. The numerical results demonstrate promising improvements of the proposed scheme compared to other baseline schemes in terms of computational efficiency, approximating optimum, and feasibility guarantee. [less ▲]

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See detailRobust Multidimensional Pricing: Separation without Regret
Kocyigit, Cagil UL; Rujeerapaiboon, Napat; Kuhn, Daniel

in Mathematical Programming (2021)

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See detailDynamical strengthening of covalent and non-covalent molecular interactions by nuclear quantum effects at finite temperature
Huziel E. Sauceda; Vassilev Galindo, Valentin UL; Stefan Chmiela et al

in Nature Communications (2021)

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See detailOptical conductivity of triple point fermions
Habibi, Alireza UL; Farajollahpour, Tohid; Jafari, S A

in Journal of Physics: Condensed Matter (2021), 33

As a low-energy effective theory on non-symmorphic lattices, we consider a generic triple point fermion Hamiltonian, which is parameterized by an angular parameter λ. We find strong λ dependence in both ... [more ▼]

As a low-energy effective theory on non-symmorphic lattices, we consider a generic triple point fermion Hamiltonian, which is parameterized by an angular parameter λ. We find strong λ dependence in both Drude and interband optical absorption of these systems. The deviation of the T2 coefficient of the Drude weight from Dirac/Weyl fermions can be used as a quick way to optically distinguish the triple point degeneracies from the Dirac/Weyl degeneracies. At the particular λ = π/6 point, we find that the 'helicity' reversal optical transition matrix element is identically zero. Nevertheless, deviating from this point, the helicity reversal emerges as an absorption channel. [less ▲]

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See detailRewealthization in twenty-first century Western countries: the defining trend of the socioeconomic squeeze of the middle class
Chauvel, Louis UL; Bar Haim, Eyal; Hartung, Anne et al

in Journal of Chinese Sociology (2021), 8

The wealth-to-income ratio (WIR) in many Western countries, particularly in Europe and North America, increased by a factor of two in the last three decades. This represents a defining empirical trend: a ... [more ▼]

The wealth-to-income ratio (WIR) in many Western countries, particularly in Europe and North America, increased by a factor of two in the last three decades. This represents a defining empirical trend: a rewealthization (from the French repatrimonialisation)—or the comeback of (inherited) wealth primacy since the mid-1990s. For the sociology of social stratification, “occupational classes” based on jobs worked must now be understood within a context of wealth-based domination. This paper first illustrates important empirical features of an era of rising WIR. We then outline the theory of rewealthization as a major factor of class transformations in relation to regimes stabilized in the post-WWII industrial area. Compared to the period where wealth became secondary to education and earnings for middle-class lifestyles, rewealthization steepens society's vertical structure; the "olive-shaped" Western society is replaced by a new one where wealth "abundance" at the top masks social reproduction and frustrations below. [less ▲]

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See detailCoulomb interactions between dipolar quantum fluctuations in van der Waals bound molecules and materials
Stoehr, Martin UL; Sadhukhan, Mainak; Al-Hamdani, Yasmine S. et al

in Nature Communications (2021), 12(1), 137

Mutual Coulomb interactions between electrons lead to a plethora of interesting physical and chemical effects, especially if those interactions involve many fluctuating electrons over large spatial scales ... [more ▼]

Mutual Coulomb interactions between electrons lead to a plethora of interesting physical and chemical effects, especially if those interactions involve many fluctuating electrons over large spatial scales. Here, we identify and study in detail the Coulomb interaction between dipolar quantum fluctuations in the context of van der Waals complexes and materials. Up to now, the interaction arising from the modification of the electron density due to quantum van der Waals interactions was considered to be vanishingly small. We demonstrate that in supramolecular systems and for molecules embedded in nanostructures, such contributions can amount to up to 6 kJ/mol and can even lead to qualitative changes in the long-range van der Waals interaction. Taking into account these broad implications, we advocate for the systematic assessment of so-called Dipole-Correlated Coulomb Singles in large molecular systems and discuss their relevance for explaining several recent puzzling experimental observations of collective behavior in nanostructured materials. [less ▲]

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See detailInvestigating Major Recurring Campylobacter jejuni Lineages in Luxembourg Using Four Core or Whole Genome Sequencing Typing Schemes
Nennig, Morgane UL; LLARENA, Ann-Katrin; HEROLD, Malte et al

in Frontiers in Cellular and Infection Microbiology (2021), 10

Campylobacter jejuni is the leading cause of bacterial gastroenteritis, which has motivated the monitoring of genetic profiles circulating in Luxembourg since 13 years. From our integrated surveillance ... [more ▼]

Campylobacter jejuni is the leading cause of bacterial gastroenteritis, which has motivated the monitoring of genetic profiles circulating in Luxembourg since 13 years. From our integrated surveillance using a genotyping strategy based on an extended MLST scheme including gyrA and porA markers, an unexpected endemic pattern was discovered in the temporal distribution of genotypes. We aimed to test the hypothesis of stable lineages occurrence by implementing whole genome sequencing (WGS) associated with comprehensive and internationally validated schemes. This pilot study assessed four WGS-based typing schemes to classify a panel of 108 strains previously identified as recurrent or sporadic profiles using this in-house typing system. The strain collection included four common lineages in human infection (N = 67) initially identified from recurrent combination of ST-gyrA-porA alleles also detected in non-human samples: veterinary (N = 19), food (N = 20), and environmental (N = 2) sources. An additional set of 19 strains belonging to sporadic profiles completed the tested panel. All the strains were processed by WGS by using Illumina technologies and by applying stringent criteria for filtering sequencing data; we ensure robustness in our genomic comparison. Four typing schemes were applied to classify the strains: (i) the cgMLST SeqSphere+ scheme of 637 loci, (ii) the cgMLST Oxford scheme of 1,343 loci, (iii) the cgMLST INNUENDO scheme of 678 loci, and (iv) the wgMLST INNUENDO scheme of 2,795 loci. A high concordance between the typing schemes was determined by comparing the calculated adjusted Wallace coefficients. After quality control and analyses with these four typing schemes, 60 strains were confirmed as members of the four recurrent lineages regardless of the method used (N = 32, 12, 7, and 9, respectively). Our results indicate that, regardless of the typing scheme used, epidemic or endemic signals were detected as reflected by lineage B (ST2254-gyrA9-porA1) in 2014 or lineage A (ST19-gyrA8-porA7), respectively. These findings support the clonal expansion of stable genomes in Campylobacter population exhibiting a multi-host profile and accounting for the majority of clinical strains isolated over a decade. Such recurring genotypes suggest persistence in reservoirs, sources or environment, emphasising the need to investigate their survival strategy in greater depth. [less ▲]

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See detailCo-evaporation of CH3NH3PbI3: How Growth Conditions Impact Phase Purity, Photostriction, and Intrinsic Stability
Gallet, Thibaut UL; Goncalinho Poeira, Ricardo Jorge UL; Martin Lanzoni, Evandro UL et al

in ACS Applied Materials and Interfaces (2021), 13(2), 26422653

Hybrid organic–inorganic perovskites are highly promising candidates for the upcoming generation of single- and multijunction solar cells. Despite their extraordinarily good semiconducting properties ... [more ▼]

Hybrid organic–inorganic perovskites are highly promising candidates for the upcoming generation of single- and multijunction solar cells. Despite their extraordinarily good semiconducting properties, there is a need to increase the intrinsic material stability against heat, moisture, and light exposure. Understanding how variations in synthesis affect the bulk and surface stability is therefore of paramount importance to achieve a rapid commercialization on large scales. In this work, we show for the case of methylammonium lead iodide that a thorough control of the methylammonium iodide (MAI) partial pressure during co-evaporation is essential to limit photostriction and reach phase purity, which dictate the absorber stability. Kelvin probe force microscopy measurements in ultrahigh vacuum corroborate that off-stoichiometric absorbers prepared with an excess of MAI partial pressure exhibit traces of low-dimensional (two-dimensional, 2D) perovskites and stacking faults that have adverse effects on the intrinsic material stability. Under optimized growth conditions, time-resolved photoluminescence and work functions mapping corroborate that the perovskite films are less prone to heat and light degradation. [less ▲]

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See detailEVALUATION OF THE JOINT BASED ON DIFFERENT SURFACE CONDITIONS FOR ALUMINUM-POLYAMIDE LASER WELDING
Amne Elahi, Mahdi UL; Koch, Marcus; Plapper, Peter UL

in Journal of Laser Applications (2021)

Laser welding is one of the most promising joining techniques to realize hybrid joints between metals and polymers in order to achieve weight reduction and functionalization of the parts. The surface ... [more ▼]

Laser welding is one of the most promising joining techniques to realize hybrid joints between metals and polymers in order to achieve weight reduction and functionalization of the parts. The surface treatment of the metal has a decisive effect on the joint quality and thus on the mechanical properties. In the present study, different mechanical and laser-based surface treatments have been investigated to develop diverse surface conditions on aluminum. Abrasive blasting and laser ablation were used to increase the surface roughness, while abrasive polishing and laser polishing were applied to minimize the surface roughness. In contrast to abrasive surface treatments, laser-based ones were implemented to create artificial oxide layers on the aluminum surface. The surface structures of pretreated samples have been studied with scanning electron microscopy and roughness test. The laser welding of pretreated aluminum with polyamide was achieved with the heat conduction joining technique. To enlarge the welding area and control the heat input, spatial and temporal modulations of the laser beam were implemented. Finally, a single lap tensile-shear test, microscopic analysis of fractured surfaces, and welding cross sections were employed to evaluate the joints. Results show that the presence of an artificial aluminum oxide layer and low roughness are essential to achieve a superior joint between aluminum and polyamide (improvement of approximately 58% in the shear load of the joint compared to as-received welded samples). The cross section of the superior joint which is the laser-polished aluminum welded to polyamide is studied with transmission electron microscopy. [less ▲]

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