104 research outputs found

    Extended Czjzek model applied to NMR parameter distributions in sodium metaphosphate glass

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    The Extended Czjzek Model (ECM) is applied to the distribution of NMR parameters of a simple glass model (sodium metaphosphate, NaPO3\mathrm{NaPO_3}) obtained by Molecular Dynamics (MD) simulations. Accurate NMR tensors, Electric Field Gradient (EFG) and Chemical Shift Anisotropy (CSA), are calculated from Density Functional Theory (DFT) within the well-established PAW/GIPAW framework. Theoretical results are compared to experimental high-resolution solid-state NMR data and are used to validate the considered structural model. The distributions of the calculated coupling constant CQVzzC_Q\propto |V_{zz}| and of the asymmetry parameter ηQ\eta_Q that characterize the quadrupolar interaction are discussed in terms of structural considerations with the help of a simple point charge model. Finally, the ECM analysis is shown to be relevant for studying the distribution of CSA tensor parameters and gives new insight into the structural characterization of disordered systems by solid-state NMR.Comment: 17 pages, 12 figures to be published in J. Phys.: Condens. Matte

    Regulation by protein kinase-C of putative P-type Ca channels expressed in Xenopus oocytes from cerebellar mRNA

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    AbstractXenopus oocytes injected with rat cerebellar mRNA expressed functional voltage-dependent Ca channels detected as an inward Ba current (IBa). The pharmacological resistance to dihydropyridines and ω-conotoxin together with the blockade obtained with Agelenopsis aperta venom suggest that these channels could be somehow assimilated to P-type Ca channels. The precise nature of the transplanted Ca channels was assessed by hybrid-arrest experiments using a specific oligonucleotide antisense-derivated from the recently cloned α1-subunit of P channels (BI-1 clone). In addition, we demonstrate that exogenous Ca channel activity was enhanced by two different PKC activators (a phorbol ester and a structural analog to diacylglycerol). The general electrophysiological and pharmacological properties of the stimulated Ca channels remain unchanged. This potentiation induced by PKC activators is antagonized by a PKC inhibitor (staurosporine) and by a monoclonal antibody directed against PKC. It is concluded that P-type Ca channels are potentially regulated by PKC phosphorylation and the functional relevance of this intracellular pathway is discussed

    The Gut Microbiota Regulates Intestinal CD4 T Cells Expressing RORγt and Controls Metabolic Disease

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    SummaryA high-fat diet (HFD) induces metabolic disease and low-grade metabolic inflammation in response to changes in the intestinal microbiota through as-yet-unknown mechanisms. Here, we show that a HFD-derived ileum microbiota is responsible for a decrease in Th17 cells of the lamina propria in axenic colonized mice. The HFD also changed the expression profiles of intestinal antigen-presenting cells and their ability to generate Th17 cells in vitro. Consistent with these data, the metabolic phenotype was mimicked in RORγt-deficient mice, which lack IL17 and IL22 function, and in the adoptive transfer experiment of T cells from RORγt-deficient mice into Rag1-deficient mice. We conclude that the microbiota of the ileum regulates Th17 cell homeostasis in the small intestine and determines the outcome of metabolic disease

    New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.

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    Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes

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

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    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

    A genome-wide association search for type 2 diabetes genes in African Americans.

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    African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have examined T2DM using genome-wide association approaches in this ethnicity. The aim of this study was to identify genes associated with T2DM in the African American population. We performed a Genome Wide Association Study (GWAS) using the Affymetrix 6.0 array in 965 African-American cases with T2DM and end-stage renal disease (T2DM-ESRD) and 1029 population-based controls. The most significant SNPs (n = 550 independent loci) were genotyped in a replication cohort and 122 SNPs (n = 98 independent loci) were further tested through genotyping three additional validation cohorts followed by meta-analysis in all five cohorts totaling 3,132 cases and 3,317 controls. Twelve SNPs had evidence of association in the GWAS (P<0.0071), were directionally consistent in the Replication cohort and were associated with T2DM in subjects without nephropathy (P<0.05). Meta-analysis in all cases and controls revealed a single SNP reaching genome-wide significance (P<2.5×10(-8)). SNP rs7560163 (P = 7.0×10(-9), OR (95% CI) = 0.75 (0.67-0.84)) is located intergenically between RND3 and RBM43. Four additional loci (rs7542900, rs4659485, rs2722769 and rs7107217) were associated with T2DM (P<0.05) and reached more nominal levels of significance (P<2.5×10(-5)) in the overall analysis and may represent novel loci that contribute to T2DM. We have identified novel T2DM-susceptibility variants in the African-American population. Notably, T2DM risk was associated with the major allele and implies an interesting genetic architecture in this population. These results suggest that multiple loci underlie T2DM susceptibility in the African-American population and that these loci are distinct from those identified in other ethnic populations

    Une expérience indigéniste en Guyane Française.

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    Charpentier G., Charpentier S. Une expérience indigéniste en Guyane Française.. In: Journal de la Société des Américanistes. Tome 42, 1953. pp. 418-421

    Salins (Jura). La Saline

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    Charpentier Gérard. Salins (Jura). La Saline. In: Archéologie médiévale, tome 18, 1988. p. 396

    Salins-les-Bains (Jura). La Saline

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    Charpentier Gérard. Salins-les-Bains (Jura). La Saline. In: Archéologie médiévale, tome 16, 1986. p. 254

    Remplois et restitution : le cas des sanctuaires de Yanouh (Liban)

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    L’approvisionnement en pierre des différents chantiers de construction a fait l’objet de présentations spécifiques dans le cadre de séminaires organisés à la MOM, sur le thème « Chantier et matériaux de construction ». Les études de cas présentées à cette occasion se sont focalisées en grande partie sur l’exploitation des gisements et la gestion des carrières, à partir de cartes topographiques et géologiques enrichies de données historiques et géomorphologiques. D’autres aspects concernant le..
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