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Université de Fribourg

Band gap formation and Anderson localization in disordered photonic materials with structural correlations

Froufe-Pérez, Luis S. ; Engel, Michael ; Sáenz, Juan José ; Scheffold, Frank

In: Proceedings of the National Academy of Sciences, 2017, vol. 114, no. 36, p. 9570–9574

Disordered dielectric materials with structural correlations show unconventional optical behavior: They can be transparent to long-wavelength radiation, while at the same time have isotropic band gaps in another frequency range. This phenomenon raises fundamental questions concerning photon transport through disordered media. While optical transparency in these materials is robust against...

Université de Fribourg

Information filtering based on corrected redundancy-eliminating mass diffusion

Zhu, Xuzhen ; Yang, Yujie ; Chen, Guilin ; Medo, Matúš ; Tian, Hui ; Cai, Shi-Min

In: PLOS ONE, 2017, vol. 12, no. 7, p. e0181402

Methods used in information filtering and recommendation often rely on quantifying the similarity between objects or users. The used similarity metrics often suffer from similarity redundancies arising from correlations between objects’ attributes. Based on an unweighted undirected object-user bipartite network, we propose a Corrected Redundancy-Eliminating similarity index (CRE) which is...

Université de Fribourg

Quantifying and suppressing ranking bias in a large citation network

Vaccario, Giacomo ; Medo, Matúš ; Wider, Nicolas ; Mariani, Manuel Sebastian

In: Journal of Informetrics, 2017, vol. 11, no. 3, p. 766–782

It is widely recognized that citation counts for papers from different fields cannot be directly compared because different scientific fields adopt different citation practices. Citation counts are also strongly biased by paper age since older papers had more time to attract citations. Various procedures aim at suppressing these biases and give rise to new normalized indicators, such as the...

Université de Fribourg

Losses and depolarization of ultracold neutrons on neutron guide and storage materials

Bondar, V. ; Chesnevskaya, S. ; Daum, M. ; Franke, B. ; Geltenbort, P. ; Göltl, L. ; Gutsmiedl, E. ; Karch, J. ; Kasprzak, Malgorzata ; Kessler, G. ; Kirch, K. ; Koch, Hans-Christian ; Kraft, Andreas ; Lauer, Thorsten ; Lauss, B. ; Pierre, E. ; Pignol, G. ; Reggiani, D. ; Schmidt-Wellenburg, P. ; Sobolev, Yuri ; Zechlau, T. ; Zsigmond, G.

In: Physical Review C, 2017, vol. 96, no. 3, p. 035205

At Institut Laue-Langevin (ILL) and Paul Scherrer Institute (PSI), we have measured the losses and depolarization probabilities of ultracold neutrons on various materials: (i) nickel-molybdenum alloys with weight percentages of 82/18, 85/15, 88/12, 91/9, and 94/6 and natural nickel Ni100, (ii) nickel-vanadium NiV93/7, (iii) copper, and (iv) deuterated polystyrene (dPS). For the different...

Université de Fribourg

Brownian systems with spatially inhomogeneous activity

Sharma, Abhinav ; Brader, Joseph M.

In: Physical Review E, 2017, vol. 96, no. 3, p. 032604

We generalize the Green-Kubo approach, previously applied to bulk systems of spherically symmetric active particles [J. Chem. Phys. 145, 161101 (2016)], to include spatially inhomogeneous activity. The method is applied to predict the spatial dependence of the average orientation per particle and the density. The average orientation is given by an integral over the self part of the Van Hove...

Université de Neuchâtel

Quantification of Degradation of Chlorinated Hydrocarbons in Saturated Low Permeability Sediments Using Compound-Specific Isotope Analysis

Wanner, Philipp ; Parker, Beth L ; Chapman, Steven W ; Aravena, Ramon ; Hunkeler, Daniel

In: Environmental Science & Technology, 2016, vol. 50, no. 11, p. 5622-5630

This field and modeling study aims to reveal if degradation of chlorinated hydrocarbons in low permeability sediments can be quantified using compound-specific isotope analysis (CSIA). For that purpose, the well-characterized Borden research site was selected, where an aquifer−aquitard system was artificially contaminated by a three component chlorinated solvent mixture (tetrachloroethene (PCE)...

Université de Fribourg

Effects of age on the soccer-specific cognitive-motor performance of elite young soccer players: Comparison between objective measurements and coaches’ evaluation

Hicheur, Halim ; Chauvin, Alan ; Chassot, Steve ; Chenevière, Xavier ; Taube, Wolfgang

In: PLOS ONE, 2017, vol. 12, no. 9, p. e0185460

The cognitive-motor performance (CMP), defined here as the capacity to rapidly use sensory information and transfer it into efficient motor output, represents a major contributor to performance in almost all sports, including soccer. Here, we used a high-technology system (COGNIFOOT) which combines a visual environment simulator fully synchronized with a motion capture system. This system...

Université de Fribourg

Spatiotemporal brain dynamics supporting the immediate automatization of inhibitory control by implementation intentions

De Pretto, Michael ; Rochat, Lucien ; Spierer, Lucas

In: Scientific Reports, 2017, vol. 7, no. 1, p. 10821

While cognitive interventions aiming at reinforcing intentional executive control of unwanted response showed only modest effects on impulse control disorders, the establishment of fast automatic, stimulus-driven inhibition of responses to specific events with implementation intention self-regulation strategies has proven to be an effective remediation approach. However, the neurocognitive...

Università della Svizzera italiana

Essays in asset pricing

Orlowski, Piotr ; Trojani, Fabio (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2017 ; 2017ECO002.

My dissertation consists of three chapters, each of which focuses on a different area of research in asset pricing. The first chapter's focal point is the measurement of the premium for jump risks in index option markets. The second chapter is devoted to non- parametric measurement of pricing kernel dispersion. The third chapter contributes to the literature on latent state variable recovery in...

Université de Fribourg

Targeting tumor-associated macrophages by anti-tumor Chinese materia medica

Pu, Wei-ling ; Sun, Li-kang ; Gao, Xiu-mei ; Rüegg, Curzio ; Cuendet, Muriel ; Hottiger, Micheal O. ; Zhou, Kun ; Miao, Lin ; Zhang, Yun-sha ; Gebauer, Margaret

In: Chinese Journal of Integrative Medicine, 2017, vol. 23, no. 10, p. 723–732

Tumor-associated macrophages (TAMs) play a key role in all stages of tumorigenesis and tumor progression. TAMs secrete different kinds of cytokines, chemokines, and enzymes to affect the progression, metastasis, and resistance to therapy depending on their state of reprogramming. Therapeutic benefit in targeting TAMs suggests that macrophages are attractive targets for cancer treatment....