120 research outputs found

    The question of intrinsic origin of the metal-insulator transition in i-AlPdRe quasicrystal

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    The icosahedral (i-) AlPdRe is the most resistive quasicrystalline alloy discovered so far. Resistivities (ρ\rho) of 1Ωcm1\Omega cm at 4K and correlated resistance ratios (RRR=ρ4K/ρ300KRRR = \rho_{4K}/\rho_{300K}) of more than 200 are observed in polycrystalline samples. These values are two orders of magnitude larger than for the isomorphous i-AlPdMn phase. We discuss here the controversial microscopic origin of the i-AlPdRe alloy electrical specificity. It has been proposed that the high resistivity values are due to extrinsic parameters, such as secondary phases or oxygen contamination. From comprehensive measurements and data from the literature including electronic transport correlated with micro structural and micro chemical analysis, we show that on the contrary there is mounting evidence in support of an origin intrinsic to the i-phase. Similarly to the other quasicrystalline alloys, the electrical resistivity of the i-AlPdRe samples depends critically on minute changes in the structural quality and chemical composition. The low resistivity in i-AlPdRe single-grains compared to polycrystaline samples can be explained by difference in chemical composition, heterogeneity and thermal treatment.Comment: 19 pages, 17 figure

    Inscrire l’égalitĂ© des sexes dans la Constitution Ă©tats-unienne : Equal Rights Amendment, promesses et dĂ©boires d’une campagne interminĂ©e

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    De nombreux mĂ©dias Ă©tats-uniens l’ont soulignĂ© au dĂ©but de l’annĂ©e 2020 : ne serait-ce pas un symbole fort et une victoire extraordinaire de voir l’amendement pour l’égalitĂ© des droits, Equal Rights Amendment (ERA), ajoutĂ© Ă  la Constitution Ă©tats-unienne l’annĂ©e oĂč le centenaire du 19e amendement Ă©tait cĂ©lĂ©bré ? Ce qui a suscitĂ© cet engouement fut la ratification de l’amendement par l’État de Virginie le 15 janvier, amenant le nombre d’États ayant votĂ© l’ERA Ă  38, ce qui correspond aux trois..

    Diffuser le combat suffragiste

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    The Story of the Woman’s Party d’Inez Irwin, ouvrage retraçant le combat des militantes du National Woman’s Party (NWP, parti national de la femme) en faveur du dix-neuviĂšme amendement qui accorda le droit de vote aux femmes blanches amĂ©ricaines en 1920, parut au dĂ©but de l’annĂ©e 1921, soit quelques mois seulement aprĂšs la ratification de l’amendement en aoĂ»t. Sa publication fut planifiĂ©e afin qu’elle pĂ»t coĂŻncider avec les cĂ©rĂ©monies organisĂ©es Ă  Washington en l’honneur du 101e anniversaire ..

    Introduction

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    Les contributions rĂ©unies dans ce volume sont issues de deux programmes de recherche menĂ©s en 2017 et 2018 Ă  l’UniversitĂ© Paris-Est Marne-la-VallĂ©e : « VisibilitĂ©, invisibilitĂ© des Savoirs des Femmes » et « Visiautrices, visibilitĂ© des femmes de lettres dans l’enseignement secondaire et supĂ©rieur ». Ces programmes ont Ă©tĂ© menĂ©s en partenariat avec le CNRS, l’UniversitĂ© de Californie du Sud Ă  Los Angeles, les associations AWARE et le deuxiĂšme texte, les Ă©ditions des Femmes-Antoinette Fouque. I..

    Symptomatic and Asymptomatic Neurological Complications of Infective Endocarditis: Impact on Surgical Management and Prognosis

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    International audienceObjectives:Symptomatic neurological complications (NC) are a major cause of mortality in infective endocarditis (IE) but the impact of asymptomatic complications is unknown. We aimed to assess the impact of asymptomatic NC (AsNC) on the management and prognosis of IE.Methods: From the database of cases collected for a population-based study on IE, we selected 283 patients with definite left-sided IE who had undergone at least one neuroimaging procedure (cerebral CT scan and/or MRI) performed as part of initial evaluation.Results Among those 283 patients, 100 had symptomatic neurological complications (SNC) prior to the investigation, 35 had an asymptomatic neurological complications (AsNC), and 148 had a normal cerebral imaging (NoNC). The rate of valve surgery was 43% in the 100 patients with SNC, 77% in the 35 with AsNC, and 54% in the 148 with NoNC (p<0.001). In-hospital mortality was 42% in patients with SNC, 8.6% in patients with AsNC, and 16.9% in patients with NoNC (p<0.001). Among the 135 patients with NC, 95 had an indication for valve surgery (71%), which was performed in 70 of them (mortality 20%) and not performed in 25 (mortality 68%). In a multivariate adjusted analysis of the 135 patients with NC, age, renal failure, septic shock, and IE caused by S. aureus were independently associated with in-hospital and 1-year mortality. In addition SNC was an independent predictor of 1-year mortality.Conclusions The presence of NC was associated with a poorer prognosis when symptomatic. Patients with AsNC had the highest rate of valve surgery and the lowest mortality rate, which suggests a protective role of surgery guided by systematic neuroimaging results

    L’animal : une source d’inspiration dans les arts

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    L’animal a toujours reprĂ©sentĂ© pour l’homme une source d’inspiration fĂ©conde dans le domaine artistique ; tous les arts font appel Ă  lui, dans des statuts et relations Ă  l’homme qui ont largement variĂ© selon les Ă©poques et les disciplines. De nombreux exemples en tĂ©moignent, qu’il s’agisse des arts visuels, des formes littĂ©raires, de la musique ou de la danse. L’examen de ces Ɠuvres constitue une matiĂšre riche pour l’étude de la relation entre l’animal et l’homme dans son Ă©volution au fil du temps

    Femmes à l’Ɠuvre dans la construction des savoirs

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    Le volume de contributions rĂ©unies ici est issu de deux programmes de recherche pluridisciplinaires menĂ©s en 2017 et 2018 Ă  l’UniversitĂ© Paris-Est Marne-la-VallĂ©e, devenue UniversitĂ© Gustave Eiffel en 2020 : « VisibilitĂ©, invisibilitĂ© des Savoirs des Femmes » et « Visiautrices, visibilitĂ© des femmes de lettres dans l’enseignement secondaire et supĂ©rieur ». Ces recherches visent Ă  mieux connaĂźtre le rĂŽle jouĂ© par des femmes dans la construction des savoirs en s’intĂ©ressant Ă  leurs Ɠuvres. Elles mettent au jour les principes qui fondent la construction des savoirs, les Ă©pistĂ©mologies dans leur contexte social et historique. Les contributions montrent les diffĂ©rentes stratĂ©gies de femmes qui, du xvie au xxe siĂšcle, ont crĂ©Ă© les espaces de leur action, de leur pensĂ©e et de la conservation de sa mĂ©moire, un lieu d’interaction entre le privĂ© et le public, le sujet et le monde. L’étude des Ɠuvres et de leur rĂ©ception permet d’observer les choix stratĂ©giques faits par les crĂ©atrices pour donner forme Ă  leur pensĂ©e, Ă  leur connaissance, en s’insĂ©rant dans le jeu de force instituĂ© par les rapports de pouvoir. Elle rĂ©vĂšle les mĂ©canismes paradoxaux qui les rĂ©gissent en donnant une place centrale aux mĂ©canismes de visibilitĂ© et d’invisibilitĂ© qui les affectent. Chaque Ă©tude s’attache Ă  montrer la complexitĂ© de la position de ces femmes qui ont fait Ɠuvre, et notamment Ɠuvre Ă©crite, en participant Ă  la construction des savoirs de leur temps dans des domaines aussi divers que la mĂ©decine, la botanique, la philosophie, la pensĂ©e religieuse, l’anthropologie, l’ethnologie, la politique, l’histoire, la littĂ©rature et les arts

    A rare truncating BRCA2 variant and genetic susceptibility to upper aerodigestive tract cancer

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    © The Author 2015. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact [email protected] Funding This work was supported the National Institutes of Health (R01CA092039 05/05S1) and the National Institute of Dental and Craniofacial Research (1R03DE020116). Notes The authors thank all of the participants who took part in this research and the funders and technical staff who made this study possible. We acknowledge and thank Simone Benhamou (INSERM, France) for sample contributions. We also acknowledge and thank The Cancer Genome Atlas initiative, whose data contributed heavily to this study.Peer reviewedPublisher PD

    Platelets Alter Gene Expression Profile in Human Brain Endothelial Cells in an In Vitro Model of Cerebral Malaria

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    Platelet adhesion to the brain microvasculature has been associated with cerebral malaria (CM) in humans, suggesting that platelets play a role in the pathogenesis of this syndrome. In vitro co-cultures have shown that platelets can act as a bridge between Plasmodium falciparum-infected red blood cells (pRBC) and human brain microvascular endothelial cells (HBEC) and potentiate HBEC apoptosis. Using cDNA microarray technology, we analyzed transcriptional changes of HBEC in response to platelets in the presence or the absence of tumor necrosis factor (TNF) and pRBC, which have been reported to alter gene expression in endothelial cells. Using a rigorous statistical approach with multiple test corrections, we showed a significant effect of platelets on gene expression in HBEC. We also detected a strong effect of TNF, whereas there was no transcriptional change induced specifically by pRBC. Nevertheless, a global ANOVA and a two-way ANOVA suggested that pRBC acted in interaction with platelets and TNF to alter gene expression in HBEC. The expression of selected genes was validated by RT-qPCR. The analysis of gene functional annotation indicated that platelets induce the expression of genes involved in inflammation and apoptosis, such as genes involved in chemokine-, TREM1-, cytokine-, IL10-, TGFÎČ-, death-receptor-, and apoptosis-signaling. Overall, our results support the hypothesis that platelets play a pathogenic role in CM
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