75 research outputs found
Le collĂšge et lâacadĂ©mie de Saumur, un mĂȘme Ă©tablissement ?
Entre les lettres patentes de mars 1593 par lesquelles Henri IV accorde Ă Philippe Duplessis-Mornay lâautorisation de « faire construire, Ă©riger et bĂątir un collĂšge » Ă Saumur et, en 1613, la tenue dâun registre « des affaires de lâacadĂ©mie », vingt annĂ©es sâĂ©coulent au cours desquelles le gouverneur de Saumur se bat pour lâouverture dâun collĂšge de plein exercice et, Ă partir de 1606, dâune acadĂ©mie pour la formation thĂ©ologique des pasteurs. Câest donc un Ă©tablissement composĂ© de deux corps distincts, celui du collĂšge et de ses rĂ©gents avec un principal Ă sa tĂȘte, celui de lâacadĂ©mie et de ses professeurs dirigĂ©s par un recteur, qui fonctionne du dĂ©but du XVIIe siĂšcle jusquâĂ lâarrĂȘt du conseil du 8 janvier 1685 « portant extinction et suppression du collĂšge et AcadĂ©mie » .
Ă Saumur, on peut distinguer quatre principales institutions rĂ©formĂ©es qui interviennent dans le domaine Ă©ducatif : le collĂšge de plein exercice, lâacadĂ©mie en tant que telle donnant une formation thĂ©ologique, le consistoire, mais aussi jusquâau dĂ©but des annĂ©es 1620 le gouverneur qui est omniprĂ©sent dans le fonctionnement de lâinstitution scolaire. Mais synodes nationaux et synodes provinciaux jouent Ă©galement un rĂŽle dans le systĂšme scolaire .
MalgrĂ© cette distinction collĂšge dâune part, acadĂ©mie dâautre part, les deux corps sont Ă©troitement liĂ©s, autant sur un plan institutionnel que dans la vie quotidienne. Ce sont ces relations Ă©troites que nous proposons dâĂ©tudier en sâappuyant principalement sur trois sources essentielles : les registres de lâacadĂ©mie qui couvrent les annĂ©es 1613-1673, puis les annĂ©es 1683-1684 , le livre des recettes de lâacadĂ©mie pour les annĂ©es 1631-1685 , les actes des synodes provinciaux dâAnjou-Touraine-Maine qui ont Ă©tĂ© retrouvĂ©s, soit de 1594 pour les plus anciens Ă 1683, annĂ©e du dernier synode tenu par la province . Quelle valeur peut-on attribuer Ă cette distinction collĂšge-acadĂ©mie ? Peut-on considĂ©rer que lâinstitution traite diffĂ©remment les deux corps ? Au sein des deux corps, cette distinction est-elle ressentie et faite ? Ces diffĂ©rentes questions peuvent ĂȘtre abordĂ©es Ă partir du cadre institutionnel existant, puis de la volontĂ© de mettre en avant ces deux corps, et enfin de voir quels sont les autres Ă©lĂ©ments dâopposition entre collĂšge et acadĂ©mie.
Probing the interface magnetism in the FeMn/NiFe exchange bias system using magnetic second harmonic generation
Second harmonic generation magneto-optic Kerr effect (SHMOKE) experiments,
sensitive to buried interfaces, were performed on a polycrystalline NiFe/FeMn
bilayer in which areas with different exchange bias fields were prepared using
5 KeV He ion irradiation. Both reversible and irreversible uncompensated spins
are found in the antiferromagnetic layer close to the interface with the
ferromagnetic layer. The SHMOKE hysteresis loop shows the same exchange bias
field as obtained from standard magnetometry. We demonstrate that the exchange
bias effect is controlled by pinned uncompensated spins in the
antiferromagnetic layer.Comment: submitted to Phys. Rev. Let
Numerical evidence toward a 2-adic equivariant ''Main Conjecture''
International audienceWe test a conjectural non abelian refinement of the classical 2-adic Main Conjecture of Iwasawa theory. In the first part, we show how, in the special case that we study, the validity of this refinement is equivalent to a congruence condition on the coefficients of some power series. Then, in the second part, we explain how to compute the first coefficients of this power series and thus numerically check the conjecture in that setting
On the non-abelian Brumer-Stark conjecture and the equivariant Iwasawa main conjecture
We show that for an odd prime p, the p-primary parts of refinements of the
(imprimitive) non-abelian Brumer and Brumer-Stark conjectures are implied by
the equivariant Iwasawa main conjecture (EIMC) for totally real fields.
Crucially, this result does not depend on the vanishing of the relevant Iwasawa
mu-invariant. In combination with the authors' previous work on the EIMC, this
leads to unconditional proofs of the non-abelian Brumer and Brumer-Stark
conjectures in many new cases.Comment: 33 pages; to appear in Mathematische Zeitschrift; v3 many minor
updates including new title; v2 some cohomological arguments simplified; v1
is a revised version of the second half of arXiv:1408.4934v
On the Milnor formula in arbitrary characteristic
The Milnor formula relates the Milnor number , the
double point number and the number of branches of a plane curve
singularity. It holds over the fields of characteristic zero. Melle and Wall
based on a result by Deligne proved the inequality in
arbitrary characteristic and showed that the equality
characterizes the singularities with no wild vanishing cycles. In this note we
give an account of results on the Milnor formula in characteristic . It
holds if the plane singularity is Newton non-degenerate (Boubakri et al. Rev.
Mat. Complut. (2010) 25) or if is greater than the intersection number of
the singularity with its generic polar (Nguyen H.D., Annales de l'Institut
Fourier, Tome 66 (5) (2016)). Then we improve our result on the Milnor number
of irreducible singularities (Bull. London Math. Soc. 48 (2016)). Our
considerations are based on the properties of polars of plane singularities in
characteristic .Comment: 18 page
The combinatorics of plane curve singularities. How Newton polygons blossom into lotuses
This survey may be seen as an introduction to the use of toric and tropical
geometry in the analysis of plane curve singularities, which are germs
of complex analytic curves contained in a smooth complex analytic surface .
The embedded topological type of such a pair is usually defined to be
that of the oriented link obtained by intersecting with a sufficiently
small oriented Euclidean sphere centered at the point , defined once a
system of local coordinates was chosen on the germ . If one
works more generally over an arbitrary algebraically closed field of
characteristic zero, one speaks instead of the combinatorial type of .
One may define it by looking either at the Newton-Puiseux series associated to
relative to a generic local coordinate system , or at the set of
infinitely near points which have to be blown up in order to get the minimal
embedded resolution of the germ or, thirdly, at the preimage of this
germ by the resolution. Each point of view leads to a different encoding of the
combinatorial type by a decorated tree: an Eggers-Wall tree, an Enriques
diagram, or a weighted dual graph. The three trees contain the same
information, which in the complex setting is equivalent to the knowledge of the
embedded topological type. There are known algorithms for transforming one tree
into another. In this paper we explain how a special type of two-dimensional
simplicial complex called a lotus allows to think geometrically about the
relations between the three types of trees. Namely, all of them embed in a
natural lotus, their numerical decorations appearing as invariants of it. This
lotus is constructed from the finite set of Newton polygons created during any
process of resolution of by successive toric modifications.Comment: 104 pages, 58 figures. Compared to the previous version, section 2 is
new. The historical information, contained before in subsection 6.2, is
distributed now throughout the paper in the subsections called "Historical
comments''. More details are also added at various places of the paper. To
appear in the Handbook of Geometry and Topology of Singularities I, Springer,
202
An entire exon 3 germ-line rearrangement in the BRCA2 gene: pathogenic relevance of exon 3 deletion in breast cancer predisposition
<p>Abstract</p> <p>Background</p> <p>Germ-line mutations in the <it>BRCA1 </it>and <it>BRCA2 </it>genes are major contributors to hereditary breast/ovarian cancer. Large rearrangements are less frequent in the <it>BRCA2 </it>gene than in <it>BRCA1</it>. We report, here, the first total deletion of exon 3 in the <it>BRCA2 </it>gene that was detected during screening of 2058 index cases from breast/ovarian cancer families for <it>BRCA2 </it>large rearrangements. Deletion of exon 3, which is in phase, does not alter the reading frame. Low levels of alternative transcripts lacking exon 3 (Î3 delta3 transcript) have been reported in normal tissues, which raises the question whether deletion of exon 3 is pathogenic.</p> <p>Methods</p> <p>Large <it>BRCA2 </it>rearrangements were analysed by QMPSF (Quantitative Multiplex PCR of Short Fluorescent Fragments) or MLPA (Multiplex Ligation-Dependent Probe Amplification). The exon 3 deletion was characterized with a "zoom-in" dedicated CGH array to the <it>BRCA2 </it>gene and sequencing. To determine the effect of exon 3 deletion and assess its pathogenic effect, three methods of transcript quantification were used: fragment analysis of FAM-labelled PCR products, specific allelic expression using an intron 2 polymorphism and competitive quantitative RT-PCR.</p> <p>Results</p> <p>Large rearrangements of <it>BRCA2 </it>were detected in six index cases out of 2058 tested (3% of all deleterious <it>BRCA2 </it>mutations). This study reports the first large rearrangement of the <it>BRCA2 </it>gene that includes all of exon 3 and leads to an <it>in frame </it>deletion of exon 3 at the transcriptional level. Thirty five variants in exon 3 and junction regions of <it>BRCA2 </it>are also reported, that contribute to the interpretation of the pathogenicity of the deletion. The quantitative approaches showed that there are three classes of delta3 <it>BRCA2 </it>transcripts (low, moderate and exclusive). Exclusive expression of the delta3 transcript by the mutant allele and segregation data provide evidence for a causal effect of the exon 3 deletion.</p> <p>Conclusion</p> <p>This paper highlights that large rearrangements and total deletion of exon 3 in the <it>BRCA2 </it>gene could contribute to hereditary breast and/or ovarian cancer. In addition, our findings suggest that, to interpret the pathogenic effect of any variants of exon 3, both accurate transcript quantification and co-segregation analysis are required.</p
Alcohol Consumption, Cigarette Smoking, and Risk of Breast Cancer for BRCA1 and BRCA2 Mutation Carriers: Results from The BRCA1 and BRCA2 Cohort Consortium.
BACKGROUND: Tobacco smoking and alcohol consumption have been intensively studied in the general population to assess their effects on the risk of breast cancer, but very few studies have examined these effects in BRCA1 and BRCA2 mutation carriers. Given the high breast cancer risk for mutation carriers and the importance of BRCA1 and BRCA2 in DNA repair, better evidence on the associations of these lifestyle factors with breast cancer risk is essential. METHODS: Using a large international pooled cohort of BRCA1 and BRCA2 mutation carriers, we conducted retrospective (5,707 BRCA1 mutation carriers and 3,525 BRCA2 mutation carriers) and prospective (2,276 BRCA1 mutation carriers and 1,610 BRCA2 mutation carriers) analyses of alcohol and tobacco consumption using Cox proportional hazards models. RESULTS: For both BRCA1 and BRCA2 mutation carriers, none of the smoking-related variables was associated with breast cancer risk, except smoking for more than 5 years before a first full-term pregnancy (FFTP) when compared with parous women who never smoked. For BRCA1 mutation carriers, the HR from retrospective analysis (HRR) was 1.19 [95% confidence interval (CI), 1.02-1.39] and the HR from prospective analysis (HRP) was 1.36 (95% CI, 0.99-1.87). For BRCA2 mutation carriers, smoking for more than 5 years before an FFTP showed an association of a similar magnitude, but the confidence limits were wider (HRR = 1.25; 95% CI, 1.01-1.55 and HRP = 1.30; 95% CI, 0.83-2.01). For both carrier groups, alcohol consumption was not associated with breast cancer risk. CONCLUSIONS: The finding that smoking during the prereproductive years increases breast cancer risk for mutation carriers warrants further investigation. IMPACT: This is the largest prospective study of BRCA mutation carriers to assess these important risk factors
Polygenic risk scores and breast and epithelial ovarian cancer risks for carriers of BRCA1 and BRCA2 pathogenic variants
Purpose We assessed the associations between population-based polygenic risk scores (PRS) for breast (BC) or epithelial ovarian cancer (EOC) with cancer risks forBRCA1andBRCA2pathogenic variant carriers. Methods Retrospective cohort data on 18,935BRCA1and 12,339BRCA2female pathogenic variant carriers of European ancestry were available. Three versions of a 313 single-nucleotide polymorphism (SNP) BC PRS were evaluated based on whether they predict overall, estrogen receptor (ER)-negative, or ER-positive BC, and two PRS for overall or high-grade serous EOC. Associations were validated in a prospective cohort. Results The ER-negative PRS showed the strongest association with BC risk forBRCA1carriers (hazard ratio [HR] per standard deviation = 1.29 [95% CI 1.25-1.33],P = 3x10(-72)). ForBRCA2, the strongest association was with overall BC PRS (HR = 1.31 [95% CI 1.27-1.36],P = 7x10(-50)). HR estimates decreased significantly with age and there was evidence for differences in associations by predicted variant effects on protein expression. The HR estimates were smaller than general population estimates. The high-grade serous PRS yielded the strongest associations with EOC risk forBRCA1(HR = 1.32 [95% CI 1.25-1.40],P = 3x10(-22)) andBRCA2(HR = 1.44 [95% CI 1.30-1.60],P = 4x10(-12)) carriers. The associations in the prospective cohort were similar. Conclusion Population-based PRS are strongly associated with BC and EOC risks forBRCA1/2carriers and predict substantial absolute risk differences for women at PRS distribution extremes.Peer reviewe
Geolocation with respect to persona privacy for the Allergy Diary app - a MASK study
Background: Collecting data on the localization of users is a key issue for the MASK (Mobile Airways Sentinel network: the Allergy Diary) App. Data anonymization is a method of sanitization for privacy. The European Commission's Article 29 Working Party stated that geolocation information is personal data. To assess geolocation using the MASK method and to compare two anonymization methods in the MASK database to find an optimal privacy method. Methods: Geolocation was studied for all people who used the Allergy Diary App from December 2015 to November 2017 and who reported medical outcomes. Two different anonymization methods have been evaluated: Noise addition (randomization) and k-anonymity (generalization). Results: Ninety-three thousand one hundred and sixteen days of VAS were collected from 8535 users and 54,500 (58. 5%) were geolocalized, corresponding to 5428 users. Noise addition was found to be less accurate than k-anonymity using MASK data to protect the users' life privacy. Discussion: k-anonymity is an acceptable method for the anonymization of MASK data and results can be used for other databases.Peer reviewe
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