Search results for "LOCUS"

On the Oort conjecture for Shimura varieties of unitary and orthogonal types

2014

In this paper we study the Oort conjecture on Shimura subvarieties contained generically in the Torelli locus in the Siegel modular variety $\mathcal{A}_g$. Using the poly-stability of Higgs bundles on curves and the slope inequality of Xiao on fibred surfaces, we show that a Shimura curve $C$ is not contained generically in the Torelli locus if its canonical Higgs bundles contains a unitary Higgs subbundle of rank at least $(4g+2)/5$. From this we prove that a Shimura subvariety of $\mathbf{SU}(n,1)$-type is not contained generically in the Torelli locus when a numerical inequality holds, which involves the genus $g$, the dimension $n+1$, the degree $2d$ of CM field of the Hermitian space,…

La singularité de O’Grady

2006

Let M 2 v M_{2v} be the moduli space of semistable sheaves with Mukai vector 2 v 2v on an abelian or K 3 K3 surface where v v is primitive such that ⟨ v , v ⟩ = 2 \langle v,v \rangle =2 . We show that the blow-up of the reduced singular locus of M 2 v M_{2v} provides a symplectic resolution of singularities. This provides a direct description of O’Grady’s resolutions of M K 3 ( 2 , 0 , 4 ) M_{K3}(2,0,4) and M A b ( 2 , 0 , 2 ) M_{Ab}(2,0,2) . Résumé. Soit M 2 v M_{2v} l’espace de modules des faisceaux semi-stables de vecteur de Mukai 2 v 2v sur une surface K 3 K3 ou abélienne où v v est primitif tel que ⟨ v , v ⟩ = 2 \langle v,v \rangle =2 . Nous montrons que l’éclatement de M 2 v M_{2v} le…

The Oort conjecture on Shimura curves in the Torelli locus of curves

2014

Oort has conjectured that there do not exist Shimura curves contained generically in the Torelli locus of genus-$g$ curves when $g$ is large enough. In this paper we prove the Oort conjecture for Shimura curves of Mumford type and Shimura curves parameterizing principally polarized $g$-dimensional abelian varieties isogenous to $g$-fold self-products of elliptic curves for $g>11$. We also prove that there do not exist Shimura curves contained generically in the Torelli locus of hyperelliptic curves of genus $g>7$. As a consequence, we obtain a finiteness result regarding smooth genus-$g$ curves with completely decomposable Jacobians, which is related to a question of Ekedahl and Serre.

Projecting 4-folds from G(1, 5) to G(1, 4)

2002

We study 4-dimensional subvarieties of the Grassmannian G(1,5) with singular locus of dimension at most 1 that can be isomorphically projected to G(1,4).

2-Aminoethylphosphonic acid is the main phosphorus compound in locust hemolymph

1991

Genome-wide significant association of ANKRD55 rs6859219 and multiple sclerosis risk.

2013

Multiple sclerosis (MS) is a genetically complex disease that shares a substantial proportion of risk loci with other autoimmune diseases.1 Along these lines, ANKRD55 , originally implicated in rheumatoid arthritis, was recently reported as a potential novel MS risk gene (rs6859219, p=1.9×10−7).2 Here, we comprehensively validated this effect in independent datasets comprising 8846 newly genotyped subjects from Germany and France as well as 5003 subjects from two genome-wide association studies (GWAS). Upon meta-analysis of all available data (19 686 subjects), ANKRD55 rs6859219 now shows compelling evidence for association with MS at genome-wide significance (OR=1.19, p=3.1×10−11). Our stu…

Current Technologies for Pseudomonas spp. And Ralstonia solanacearum Detection and Molecular Typing

2008

Standard protocols for detection of phytopathogenic Pseudomonas spp. and Ralstonia solanacearum in plant material, soil, water or other sources, often still rely on the isolation of bacterial colonies on appropriate media, and/or on the use of serological techniques. However, over the last several years, molecular techniques, mainly based on PCR methods after extraction of nucleic acids from samples, have improved enough to allow a more rapid, reliable detection of these bacteria. When maximum accuracy is required the use of multiple techniques in an integrated approach is advised. Other promising technologies like flow cytometry, electronic nose or microarrays are emerging due to the need …

Pre-invasion history and demography shape the genetic variation in the insecticide resistance-related acetylcholinesterase 2 gene in the invasive Col…

2012

Abstract Background Invasive pest species offers a unique opportunity to study the effects of genetic architecture, demography and selection on patterns of genetic variability. Invasive Colorado potato beetle (Leptinotarsa decemlineata) populations have experienced a rapid range expansion and intense selection by insecticides. By comparing native and invasive beetle populations, we studied the origins of organophosphate (OP) resistance-associated mutations in the acetylcholinesterase 2 (AChE2) gene, and the role of selection and demography on its genetic variability. Results Analysis of three Mexican, two US and five European populations yielded a total of 49 haplotypes. Contrary to the exp…

Genome-wide association study identifies multiple risk loci for chronic lymphocytic leukemia

2013

Genome-wide association studies (GWAS) have previously identified 13 loci associated with risk of chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL). To identify additional CLL susceptibility loci, we conducted the largest meta-analysis for CLL thus far, including four GWAS with a total of 3,100 individuals with CLL (cases) and 7,667 controls. In the meta-analysis, we identified ten independent associated SNPs in nine new loci at 10q23.31 (ACTA2 or FAS (ACTA2/FAS), P = 1.22 × 10-14), 18q21.33 (BCL2, P = 7.76 × 10-11), 11p15.5 (C11orf21, P = 2.15 × 10 -10), 4q25 (LEF1, P = 4.24 × 10-10), 2q33.1 (CASP10 or CASP8 (CASP10/CASP8), P = 2.50 × 10-9), 9p21.3 (CDKN2B-AS1, P = 1.27 × 10…

Vigna mungo, V. radiata and V. unguiculata plants sampled in different agronomical-ecological-climatic regions of India are nodulated by Bradyrhizobi…

2009

International audience; Vigna mungo, Vigna radiata and Vigna unguiculata are important legume crops cultivated in India, but little is known about the genetic resources in native rhizobia that nodulate these species. To identify these bacteria, a core collection of 76 slow-growing isolates was built from root nodules of V. mungo, V. radiata and V. unguiculata plants grown at different sites within three agro-ecological-climatic regions of India. The genetic diversity of the bacterial collection was assessed by restriction fragment length polymorphism (RFLP) analysis of PCR-amplified DNA fragments of the 16S–23S rDNA intergenic spacer (IGS) region, and the symbiotic genes nifH and nodC. One …