Paris West University Nanterre La Défense

About: Paris West University Nanterre La Défense is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Finite element method. The organization has 895 authors who have published 1430 publications receiving 21712 citations.

Enforcement vs Deterrence in Merger Control: Can Remedies Lead to Lower Welfare?

Abstract: This paper deals with the enforcement of merger policy, and aims to identify situations where the introduction of remedies can lead to a lower welfare. For this we study how merger remedies affect the deterrence accomplished by controlling mergers, and determine the optimal frequency of investigations launched by the agency. We find that when conditional approvals are possible, it may be harder to deter the most welfare-detrimental mergers, and the agency might have to investigate mergers more often. The resulting welfare from merger control can indeed be lower than without remedies.

Three-Dimensional Microwave Holography Based on Broadband Huygens' Metasurface

Abstract: Benefiting from prominent performance in various scientific fields, metasurface research has been flourishing over the past decade. Huygens' metasurface, as an emerging subcategory of metasurface, can theoretically achieve full control of electric field distribution within the subwavelength scale. Driven by its outstanding manipulation capacity, the three-dimensional holography utilizing broadband Huygens' metasurface is demonstrated in the microwave regime in this paper. For the broadband working properties, two types of equivalent circuit are integrated into the design of Huygens' meta-atom. Besides, for high image quality, the modified weighted Gerchberg-Saxton (GSW) algorithm is implemented for specific interfacial phase distribution. The proof-of-concept experiments show notable microwave holographic images, with an 86.2% transmittance efficiency, a 62.7% imaging efficiency, and an 88.1 signal-to-noise ratio at 12 GHz. The proposed holography extends the route to broadband microwave applications in security, data storage, and antenna systems.

Curvature and transport inequalities for Markov chains in discrete spaces

Abstract: We study various transport-information inequalities under three different notions of Ricci curvature in the discrete setting: the curvature-dimension condition of Bakry and Emery (In Seminaire de Probabilites, XIX, 1983/84 (1985) 177–206 Springer), the exponential curvature-dimension condition of Bauer et al. (Li-Yau Inequality on Graphs (2013)) and the coarse Ricci curvature of Ollivier (J. Funct. Anal. 256 (2009) 810–864). We prove that under a curvature-dimension condition or coarse Ricci curvature condition, an $L_{1}$ transport-information inequality holds; while under an exponential curvature-dimension condition, some weak-transport information inequalities hold. As an application, we establish a Bonnet–Myers theorem under the curvature-dimension condition $\operatorname{CD}(\kappa,\infty)$ of Bakry and Emery (In Seminaire de Probabilites, XIX, 1983/84 (1985) 177–206 Springer).

Recent Discoveries of New Hantaviruses Widen Their Range and Question Their Origins

Abstract: Hantaviruses belong to the Bunyaviridae family. While usually hosted by wild mammals, they are potentially pathogenic for humans, and several serologically distinct groups associated with different syndromes have been identified. Yet, investigations have mostly been conducted where human infections by hantaviruses constitute a real and well-identified public health problem, i.e., the holarctic and neotropical areas. Some hantaviruses have also been described from a Suncus murinus in India and a Bandicota indica in Thailand. In addition, recent investigations in Cambodia revealed new Hantavirus types. More recently, two new Hantavirus species were described: Sangassou from a Hylomyscus simus, and Tanganya from a Crocidura theresae, both from Africa (Guinea), thus strongly questioning the current views about geographic range, evolution, and epidemiology of hantaviruses. In such a framework, we have conducted a survey of Hantavirus diversity in Southeast Asia which allows us to isolate the Thailand virus and address questions about the taxonomy of their rodent hosts. Here we present a molecular analysis of representatives of all currently known Hantavirus species, thus allowing the comparison between the newly described ones with a large range sample of rodent hantaviruses. Our results clearly point to the presence of a particular lineage of hantaviruses in Southeast Asia. It also strongly suggests that new viruses, additional mammalian hosts and different related syndromes in humans are likely to be discovered in the near future, particularly in Southeast Asia and in Africa, where Muridae rodents are highly diversified. Furthermore, additional work is also urgently needed to investigate the hantaviruses associated with Crociduridae and Soricidae.