Adaptive changes of human islets to an obesogenic environment in the mouse

Routing protocols in wireless sensor networks (WSN) face two main challenges: first, the challenging environments in which WSNs are deployed negatively affect the quality of the routing process. Therefore, routing protocols for WSNs should recognize and react to node failures and packet losses. Second, sensor nodes are battery-powered, which makes power a scarce resource. Routing protocols should optimize power consumption to prolong the lifetime of the WSN. In this paper, we present a new adaptive routing protocol for WSNs, we call it M^2RC. M^2RC has two phases: mesh establishment phase and data forwarding phase. In the first phase, M^2RC establishes the routing state to enable multipath data forwarding. In the second phase, M^2RC forwards data packets from the source to the sink. Targeting hop-by-hop reliability, an M^2RC forwarding node waits for an acknowledgement (ACK) that its packets were correctly received at the next neighbor. Based on this feedback, an M^2RC node applies multiplicative-increase/additive-decrease (MIAD) to control the number of neighbors targeted by its packet broadcast. We simulated M^2RC in the ns-2 simulator and compared it to GRAB, Max-power, and Min-power routing schemes. Our simulations show that M^2RC achieves the highest throughput with at least 10-30% less consumed power per delivered report in scenarios where a certain number of nodes unexpectedly fail.National Science Foundation (ITR ANI-0205294, EIA-0202067, ANI-0095988, ANI-9986397

A Match in Time Saves Nine: Deterministic Online Matching With Delays

We consider the problem of online Min-cost Perfect Matching with Delays (MPMD) introduced by Emek et al. (STOC 2016). In this problem, an even number of requests appear in a metric space at different times and the goal of an online algorithm is to match them in pairs. In contrast to traditional online matching problems, in MPMD all requests appear online and an algorithm can match any pair of requests, but such decision may be delayed (e.g., to find a better match). The cost is the sum of matching distances and the introduced delays. We present the first deterministic online algorithm for this problem. Its competitive ratio is $O(m^{\log_2 5.5})$ $= O(m^{2.46})$, where $2 m$ is the number of requests. This is polynomial in the number of metric space points if all requests are given at different points. In particular, the bound does not depend on other parameters of the metric, such as its aspect ratio. Unlike previous (randomized) solutions for the MPMD problem, our algorithm does not need to know the metric space in advance

Deep Learning: A Philosophical Introduction

Deep learning is currently the most prominent and widely successful method in artificial intelligence. Despite having played an active role in earlier artificial intelligence and neural network research, philosophers have been largely silent on this technology so far. This is remarkable, given that deep learning neural networks have blown past predicted upper limits on artificial intelligence performance—recognizing complex objects in natural photographs, and defeating world champions in strategy games as complex as Go and chess—yet there remains no universally-accepted explanation as to why they work so well. This article provides an introduction to these networks, as well as an opinionated guidebook on the philosophical significance of their structure and achievements. It argues that deep learning neural networks differ importantly in their structure and mathematical properties from the shallower neural networks that were the subject of so much philosophical reflection in the 1980s and 1990s. The article then explores several different explanations for their success, and ends by proposing ten areas of research that would benefit from future engagement by philosophers of mind, epistemology, science, perception, law, and ethics

ETUDE DES EFFETS DE L'ALIMENTATION SUR LA PRODUCTION D'OVOCYTES ET D'EMBRYONS PAR OPU-FIV CHEZ LA GENISSE LAITIERE SUPEROVULEE

La technique d'Ovum Pick Up - Fécondation In vitro (OPU?FIV) apparue vers la fin des années 1980 représente une avancée dans le domaine des biotechnologies de la reproduction chez les bovins. La collecte des ovocytes par voie transvaginale peut ainsi être réalisée avant la puberté, chez la vache cyclée et pendant le début de la gestation. La fécondation et la culture in vitro des embryons jusqu'à J7 permet d'obtenir des blastocystes pouvant être transférés à l'état frais ou cryoconservés. Cette technique permet aussi d'explorer les effets des modifications de l'environnement sur la qualité des gamètes. Notre étude bibliographique montre que l'alimentation des donneuses joue un rôle certain dans les résultats obtenus. Chez la génisse, il semble que le niveau d'apport énergétique n'influence pas le nombre d'ovocytes collectés. Une restriction alimentaire modérée à court terme avant la collecte serait par contre favorable à la production de blastocystes. Dans les élevages, les génisses laitières sont souvent suralimentées ce qui diminue leur production d'embryons. Notre travail expérimental est une première étape pour tenter de montrer l'intérêt d'une diminution des apports alimentaires avant superovulation. Mené sur 16 génisses laitières superovulées initialement suralimentées (GMQ = 1000 g/j pendant 6 semaines), il a permis de confirmer qu'une restriction alimentaire modérée à court terme (GMQ = 600 g/j pendant 6 semaines) avant collecte d'ovocytes était favorable à la production de blastocytes (GMQ = 600g/j : 4,4 1,2 par femelle et par séance vs GMQ = 1000 g/j : 1,6 1,2 ; p<0,05). Il reste à confirmer dans les élevages et sur un plus grand nombre d'animaux l'effet de cette restriction modérée sur la production d'embryons in vitro.MAISONS-ALFORT-Ecole Vétérin (940462302) / SudocSudocFranceF

The transition from strong to weak coupling and the onset of lasing in semiconductor microcavities

Angular-dependent emission spectra are investigated in a strongly coupled InGaAs-GaAs-AlAs-based semiconductor microcavity as a function of excitation intensity and of detuning between the uncoupled exciton and photon modes. Under conditions of nonresonant excitation, it is shown that the onset of stimulated emission always occurs in the weak coupling regime. Angular-dependent studies show that the transition to weak coupling occurs when the linewidth of high k excitons becomes of the order of the normal mode splitting of the exciton-polariton coupled modes. We conclude that, under nonresonant excitation, "polariton lasing," where stimulated polariton scattering followed by photon emission occurs in the strong coupling regime, is only likely to be achieved in systems with larger exciton binding energy than in GaAs-based structures or possibly also in GaAs microcavities containing excess concentrations of free electrons. The experimental results below threshold are found to be in good agreement with numerical solution of Boltzmann kinetic equations for the photoexcited polariton distribution