New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.

OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis

Projet de recherche "MORBLEU". Environnement des écosystèmes mytilicoles et crises de mortalité récentes, quelles interactions? Etude des facteurs pouvant favoriser les surmortalités de moules bleues (Mytilus edulis) dans les pertuis charentais et en Vendée (2014-2016)

Durant l’hiver 2014 jusqu’à mai 2014, des mortalités exceptionnelles (50-100%) ont affectées la moule bleue, Mytilus edulis dans les Pertuis Charentais (principalement secteur du Pertuis Breton) et en Vendée. A la demande du Ministère (DPMA) une expertise environnementale a été demandée à l’Ifremer. L’expertise a permis de montrer que les conditions hydrologiques de l’hiver 2014 ne permettent pas de mettre en évidence une cause environnementale à ces mortalités exceptionnelles. Les analyses en pathologie réalisées ont révélées dans les moules la présence de bactéries appartenant au groupe bactérien Vibrio splendidus, dont la virulence a été confirmée expérimentalement. Dans ce contexte, la DPMA a sollicité l’Ifremer pour conduire en 20105 une étude prospective et descriptive qui préciserait les conditions qui favorisent les surmortalités de moules en lien avec des Vibrio. L’étude, MORtalité moules BLEUes-MORBLEU-, proposée en réponse à la demande publique est constituée d’actions de recherche multidisciplinaires, multi-échelles, qui s’appuie sur cinq laboratoires de l’Ifremer et sur le réseau d'observation MYTILOBS. Cette étude a été reconduite pour l’année 2016. Les objectifs généraux du projet MORBLEU sont d’identifier des facteurs associés ou potentiellement corrélés avec les mortalités de moules observées dans les Pertuis Charentais : facteurs environnementaux (biotiques, abiotiques et hydrodynamiques) et facteurs intrinsèques aux animaux (traits d'histoire de vie, qualité cytogénétique et physiologie). Nous présentons rapidement la démarche, les objectifs de chaque action (hydrodynamique, contexte environnemental physico-chimique et biotique, génétique), et une vue partielle des résultats analysés pour l’année 2015 (dynamique des mortalités de moules dans les Pertuis, conditions hydrodynamiques et la connectivité des masses d’eau, paramètres physico-chimiques, contaminants, diversité planctonique, statut génétique et qualité cytogénétique,…)

Optimal Bitrate Allocation in the Scalable HEVC Extension for the Deployment of UHD Services

International audienceUltra high definition (UHD) is the latest trend in broadcasting area, which enables new services with 3840×2160 resolution and comes with enhanced color-gamut, frame-rate, dynamic range, and better audio system compared to the currently deployed HD services. The UHD format for broadcasting is already under standardization in the digital video broadcasting consortium which plans to introduce UHD services in three phases. The increase in data brought by these services requires more efficient compression and transmission systems. The recent scalable video coding standard scalable High Efficiency Video Coding (SHVC) is a promising candidate to handle these three phases while ensuring backward compatibility. Moreover, delivering such contents over networks needs an accurate control of the output bitrate from encoder engines to match rigid constraints on bandwidth and QoS. Several contributions have already been proposed to jointly encode scalable stream, but without considering the impact of bitrate ratio between layers on the compression performance. In this paper, the impact of the bitrate ratio between layers on the coding performance is first investigated for several UHD scalable schemes including spatial, color-gamut, and SDR-to-HDR scalability in SHVC. Based on this investigation, an adaptive rate control algorithm which dynamically allocates the bitrate between two layers is proposed to optimize the performance under quality and bitrate constraints. The algorithm has been implemented in the SHVC reference software (SHM9.0) and tested over 15 video sequences under two industrial usecases. The performance shows an average BD-BR improvement of 7.51% and 3.35% for these two use-cases

VERSATILE VIDEO CODING AND SUPER-RESOLUTION FOR EFFICIENT DELIVERY OF 8K VIDEO WITH 4K BACKWARD-COMPATIBILITY

International audienceIn this paper, we propose, through an objective study, to compare and evaluate the performance of different coding approaches allowing the delivery of an 8K video signal with 4K backward-compatibility on broadcast networks. Presented approaches include simulcast of 8K and 4K single-layer signals encoded using High-Efficiency Video Coding (HEVC) and Versatile Video Coding (VVC) standards, spatial scalability using SHVC with 4K base layer (BL) and 8K enhancement-layer (EL), and super-resolution applied on 4K VVC signal after decoding to reach 8K resolution. For up-scaling, we selected the deep-learning-based super-resolution method called Super-Resolution with Feedback Network (SRFBN) and the Lanczos interpolation filter. We show that the deep-learning-based approach achieves visual quality gain over simulcast, especially on bit-rates lower than 30Mb/s with average gain of 0.77dB, 0.015, and 7.97 for PSNR, SSIM, and VMAF, respectively and out-performs the Lanczos filter in average by 29% of BD-rate savings

Backward Compatible Layered Video Coding for 360° Video Broadcast

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New Insight for the Genetic Evaluation of Resistance to Ostreid Herpesvirus Infection, a Worldwide Disease, in Crassostrea gigas

The Pacific oyster, Crassostrea gigas, is the most important commercial oyster species cultivated in the world. Meanwhile, the ostreid herpesvirus 1 (OsHV-1) is one of the major pathogens affecting the Pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. To assess the genetic basis of resistance to OsHV-1 infection in spat C. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib families using three field methods and a controlled challenge by OsHV-1 in the laboratory. In the field, three methods were tested: (A) one family per bag; (B) one family per small soft mesh bag and all families inside one bag; (C) same as the previous methods but the oysters were individually labelled and then mixed. The mean mortality ranged from 80 to 82% and was related to OsHV-1 based on viral DNA detection. The narrow-sense heritability for mortality, and thus OsHV-1 resistance, ranged from 0.49 to 0.60. The high positive genetic correlations across the field methods suggested no genotype by environment interaction. Ideally, selective breeding could use method B, which is less time- and space-consuming. The narrow sense heritability for mortality under OsHV-1 challenge was 0.61, and genetic correlation between the field and the laboratory was ranged from 0.68 to 0.75, suggesting a weak genotype by environment interaction. Thus, most of families showing the highest survival performed well in field and laboratory conditions, and a similar trend was also observed for families with the lowest survival. In conclusion, this is the first study demonstrating a large additive genetic variation for resistance to OsHV-1 infection in C. gigas, regardless of the methods used, which should help in selective breeding to improve resistance to viral infection in C. gigas

CAESR: Conditional Autoencoder and Super-Resolution for Learned Spatial Scalability

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Scalable Video Coding for Backward-Compatible 360° Video Delivery Over Broadcast Networks

International audienceRecently, the coding and transmission of immersive 360 • video has been intensely studied. The technologies provided by standards developing organizations mainly address requirements coming from over-the-top services. The terrestrial broadcast remains in many countries the mainstream medium to deliver high quality contents to a wide audience. To enable seamless introduction of immersive 360 • video services over terrestrial broadcast, the deployed technologies shall fulfill requirements such as backward compatibility to legacy receivers and high bandwidth efficiency. While bandwidth efficiency is addressed by existing techniques, none of them enables legacy video services decoding. In this paper, a novel scalable coding scheme is proposed to enable immersive 360 • video services introduction over broadcast networks. The experiments show that the proposed scalable coding scheme provides substantial coding gains of 14.99% compared to simulcast coding and introduces a limited coding overhead of 5.15% compared to 360 • single-layer coding. A real-time decoding implementation is proposed, highlighting the relevance of the proposed design. Eventually, an end-to-end demonstrator illustrates how the proposed solution could be integrated in a real terrestrial broadcast environment