Nanoscale electrical analyses of axial-junction GaAsP nanowires for solar cell applications

Axial p-n and p-i-n junctions in GaAs0.7P0.3 nanowires are demonstrated and analyzed using electron beam induced current microscopy. Organized self-catalyzed nanowire arrays are grown by molecular beam epitaxy on nanopatterned Si substrates. The nanowires are doped using Be and Si impurities to obtain p- and n-type conductivity, respectively. A method to determine the doping type by analyzing the induced current in the vicinity of a Schottky contact is proposed. It is demonstrated that for the applied growth conditions using Ga as a catalyst, Si doping induces an n-type conductivity contrary to the GaAs self-catalyzed nanowire case, where Si was reported to yield a p-type doping. Active axial nanowire p-n junctions having a homogeneous composition along the axis are synthesized and the carrier concentration and minority carrier diffusion lengths are measured. To the best of our knowledge, this is the first report of axial p-n junctions in self-catalyzed GaAsP nanowires

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

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Adaptive Rate Control Algorithm for SHVC: Application to HD/UHD

International audienceScalable video coding consists in compressing the video sequence into a layered bitstream where each layer refers to different spatial, temporal or quality representation of the video. Scalability enables compression gain compared to the simulcast encoding of layers thanks to inter-layer predictions. The scalable HEVC extension (SHVC) is the latest scalable technology promising up to 30\% bitrate gains under the common test conditions, defined by JCT-VC. These conditions do not consider UHD and use fixed quantization step, which is not relevant in operational environment. In this paper, we propose an innovative adaptive rate control algorithm for SHVC. We consider HD as a base layer and UHD as an enhancement layer, with a constant global bitrate and a dynamic bitrate ratio adjustment between layers. The proposed algorithm is evaluated on a UHD data set where enables on average a BD-BR gain of 4.25% compared to a fixed-ratio encoding

Purification and characterization of an inducible p-coumaric acid decarboxylase from Lactobacillus plantarum

Lactobacillus plantarum cells displayed substrate-inducible decarboxylase activities on p-coumaric and ferulic acids of 0.6 and 0.01 mu mol min(-1) mg(-1), respectively. Activity in uninduced cells or corresponding cell extracts was undetectable (< 10(-4) mu mol min(-1) mg(-1)). Specificity of induction indicates that at least two phenolic acid decarboxylases are produced in this bacterium. SDS-PAGE of partially purified protein extract from p-coumaric acid-induced cells showed one band of 23.5 kDa that was absent in the extract from uninduced cells, The native molecular mass of 93 kDa indicates that the enzyme is a homotetramer. The 1276-fold purified enzyme had a K-m of 1.4 mM, a V-m of about 766 mu mol min(-1) mg(-1), and a K-cat of 10(3) s(-1) for p-coumaric and caffeic acids, but did not display any detectable activity on ferulic acid. Maximum activity was at 30 degrees C, at pH 5.5-6, Cofactors or metal ions were not required for activity

Optimal Bitrate Allocation for High Dynamic Range and Wide Color Gamut Services Deployment using SHVC

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Evolution tectonique de la partie Sud Est de la Ceinture de Roche Verte de Barberton (Afrique du Sud, Eswatini). Place de l'évènement minéralisateur magmato-hydrothermal et implications sur le style tectonique archéen.

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Toward Optimal Bitrate Allocation in the Scalable HEVC Extension: Application to UHDTV

International audienceScalable video encoders compress a single video sequence to produce a bitstream composed of several layers, corresponding to different temporal, spatial and quality representations of the input video sequence. This technique improves the coding efficiency compared to simulcast encoding of each representation by exploiting additional correlations through inter-layer predictions. The latest scalable video coding standard SHVC --the extension of the recent HEVC standard-- announces up to 30% bandwidth reduction. However, this gain is valid under the common test conditions, established by the JCT-VC expert group, which are not necessarily relevant in broadcasting environment and do not include video sequences in UHD resolution. In this paper, we expose the results of an extended study about the optimum gains that scalability can bring in concrete broadcast use-cases. Indeed, we consider SHVC with HDTV/UHDTV as spatial enhancement layers. Then, we search the optimum balance of layers' dedicated bitrates in sense of coding efficiency and objective quality for different UHDTV video sequences and use-cases

Babel en éducation

Études réunies par Monique Travers et Bernard Viselthier.Ce volume présente un ensemble de travaux de Jean Janitza (1940-2002) susceptibles d'alimenter la réflexion sur l'enseignement et la didactique des langues vivantes la formation des maîtres et sur l'utilisation des nouvelles technologies. Ils ne manqueront pas d'éclairer ceux qui cherchent le moyen de relier la réflexion théorique à la pratique pédagogique.This volume presents a collection of Jean Janitza’s (1940 – 2002) works, contributing to the reflection on modern languages’ teaching and didactics, on the formation of teachers and on the use of new technologies. They will enlighten those searching for ways to connect theoretical reflections to pedagogical practices. Table of contents: The good usage of contrastivity – Language, lexicon, culture and communication – Didactics, between theory and practice – Teachers’ formation – New technologies in teaching/learning – Positions and propositions – Jean Janitza’s Biography and bibliography