Theta-duality on Prym varieties and a Torelli Theorem

Let $\pi : \widetilde C \to C$ be an unramified double covering of irreducible smooth curves and let $P$ be the attached Prym variety. We prove the scheme-theoretic theta-dual equalities in the Prym variety $T(\widetilde C)=V^2$ and $T(V^2)=\widetilde C$, where $V^2$ is the Brill-Noether locus of $P$ associated to $\pi$ considered by Welters. As an application we prove a Torelli theorem analogous to the fact that the symmetric product $D^{(g)}$ of a curve $D$ of genus $g$ determines the curve.

On rigid analytic uniformizations of Jacobians of Shimura curves

The main goal of this article is to give an explicit rigid analytic uniformization of the maximal toric quotient of the Jacobian of a Shimura curve over Q at a prime dividing exactly the level. This result can be viewed as complementary to the classical theorem of Cerednik and Drinfeld which provides rigid analytic uniformizations at primes dividing the discriminant. As a corollary, we offer a proof of a conjecture formulated by M. Greenberg in hispaper on Stark-Heegner points and quaternionic Shimura curves, thus making Greenberg's construction of local points on elliptic curves over Q unconditional.

Equations of hyperelliptic Shimura curves

We describe an algorithm that computes explicit models of hyperelliptic Shimura curves attached to an indefinite quaternion algebra over Q and Atkin-Lehner quotients of them. It exploits Cerednik-Drinfeld���s nonarchimedean uniformisation of Shimura curves, a formula of Gross and Zagier for the endomorphism ring of Heegner points over Artinian rings and the connection between Ribet���s bimodules and the specialization of Heegner points, as introduced in [21]. As an application, we provide a list of equations of Shimura curves and quotients of them obtained by our algorithm that had been conjectured by Kurihara.

Scrfl restriction fragment length polymorphism at the D7S23 locus (probe pKM.19), closely linked to cystic fibrosis

Source/Description: pKM.19 is a 1.0 kb EcoRI genomic fragment in pUC13 (ref. 1,2). pPl was isolated independently but contains the same fragment as pKM.19 (ref. 3)...

Analysis of a Plant Complex Resistance Gene Locus Underlying Immune-Related Hybrid Incompatibility and Its Occurrence in Nature

Mechanisms underlying speciation in plants include detrimental (incompatible) genetic interactions between parental alleles that incur a fitness cost in hybrids. We reported on recessive hybrid incompatibility between an Arabidopsis thaliana strain from Poland, Landsberg erecta (Ler), and many Central Asian A. thaliana strains. The incompatible interaction is determined by a polymorphic cluster of Toll/interleukin-1 receptor-nucleotide binding-leucine rich repeat (TNL) RPP1 (Recognition of Peronospora parasitica1)-like genes in Ler and alleles of the receptor-like kinase Strubbelig Receptor Family 3 (SRF3) in Central Asian strains Kas-2 or Kond, causing temperature-dependent autoimmunity and loss of growth and reproductive fitness. Here, we genetically dissected the RPP1-like Ler locus to determine contributions of individual RPP1-like Ler (R1R8) genes to the incompatibility. In a neutral background, expression of most RPP1-like Ler genes, except R3, has no effect on growth or pathogen resistance. Incompatibility involves increased R3 expression and engineered R3 overexpression in a neutral background induces dwarfism and sterility. However, no individual RPP1-like Ler gene is sufficient for incompatibility between Ler and Kas-2 or Kond, suggesting that co-action of at least two RPP1-like members underlies this epistatic interaction. We find that the RPP1-like Ler haplotype is frequent and occurs with other Ler RPP1-like alleles in a local population in Gorz��w Wielkopolski (Poland). Only Gorz��w individuals carrying the RPP1-like Ler haplotype are incompatible with Kas-2 and Kond, whereas other RPP1-like alleles in the population are compatible. Therefore, the RPP1-like Ler haplotype has been maintained in genetically different individuals at a single site, allowing exploration of forces shaping the evolution of RPP1-like genes at local and regional population scales.

Non compact euclidean cone 3-manifolds with cone angles less than 2���

We study of noncompact Euclidean cone manifolds with cone angles less than c&2�� and singular locus a submanifold. More precisely, we describe its structure outside a compact set. As a corol lary we classify those with cone angles & 2��/3 and those with cone angles = 2��/3.

Organitzaci�� nuclear dels gens que codifiquen per a les prote��nes l��cties en c��lules epitelials mam��ries en diferents estadis de desenvolupament

Estudi realitzat a partir d���una estada al Institut National de la Recherche Agronomique (INRA), a Fran��a, entre 2006 i 2008. En el ultims anys, estudis realitzats en diferents tipus cel���lulars han pogut determinar l���import��ncia de l���organitzaci�� nuclear en el control i regulaci�� g��nica. S���han realizat diferents experiments per tal de determinar si la posici�� dels gens de les prote��nes l��cties en el nucli interf��sic de cel���lules epitelials mamaries ��s important per regular la seva expressi��. Els gens de les prote��nes de la llet s���expressen a la gl��ndula mamaria durant la lactaci�� en resposta a les hormones lactog��niques (majorit��riament prolactina i glucocorticoids). Mitjan��ant la t��cnica de FISH (fluorescent in situ hibridization) en 3D s���ha caracteritzat la localitzaci�� nuclear del gens WAP (whey acidic protein) i les case��nes en c��l���lules epitelials mamaries de ratol�� (HC11) cultivades en l���abs��ncia i presencia d���hormones lactog��niques. En abs��ncia d���hormones, els dos gens estan distribu��ts dins del nucli de forma no aleat��ria, el gen WAP es troba localitzat en l���interior del nucli, mentre que les case��nes es troben localitzades prop de la perif��ria nuclear. L���estimulaci�� hormonal indueix un canvi significatiu en la dist��ncia dels dos gens a la perif��ria nuclear. Aix�� mateix, la posici�� del locus de la case��na en relaci�� al seu territori cromos��mic (CT) 5 est�� correlacionada amb la inducci�� hormonal i per tant amb la seva activaci�� transcripcional, mentre que la posici�� del gen WAP amb relaci�� al seu CT11 sembla m��s determinada pel context cromos��mic del gen. Per ��ltim, no s���han trobat diferencies en la localitzaci�� dels gens en relaci�� a l'heterocromatina del centr��mer, descrit com a compartiment repressiu, entre les c��l���lules estimulades amb hormones i les que no. En els dos casos s���ha trobat un gran percentatge de gens que no estan associats als centr��mers.

Identificaci��n de variedades de vitis vinifera procedentes de diferentes regiones del mundo mediante t��cnica de biologia molecular de los microsat��llites

El objetivo de este estudio se centr�� en analizar una colecci��n privada de germoplasma de Vitis vinifera L., de 338 cultivares procedentes de 24 pa��ses, para caracterizarlas creando una base de datos, utilizando 11 marcadores microsat��lites o SSR (Simple Sequence Repeat). Como resultado se encontraron que algunas de las muestras analizadas presentaron un perfil id��ntico de SSR, indicando que se trata de una sinonimia (la misma variedad pero con diferente nombre). Se detectaron 293 perfiles ��nicos. Adicionalmente, 15 pares de variedades presentaron diferencias en un solo locus y otros 7 grupos difieren en 2 loci, lo cual indicar��a la alta proximidad gen��tica entre esas variedades, sin llegar a ser la misma. El germoplasma analizado cuenta con una compleja biodiversidad varietal que se debe preservar. El estudio se realiz�� programando para el primer a��o la revisi��n bibliogr��fica detallada, recolecci��n de las hojas y el inicio de la puesta a punto de la metodolog��a, en el segundo a��o se completa la puesta a punto de la metodolog��a, se trituran las hojas y se realiza la extraccin��n del ADN. El tercer a��o se emplea para amplificar los fragmentos de ADN por medio de la PCR (reacci��n en cadena de la polimerasa), obtener la longitud de los fragmentos con un secuenciador ABI PRISM 310, valorar resultados y realizar repeticiones. El ��ltimo a��o se analizan los resultados obtenidos, se realizan repeticiones pertinentes y se comienza la redacci��n de art��culos cient��ficos.

Hardy-Weinberg Equilibrium and the Ternary Plot

The Hardy-Weinberg law, formulated about 100 years ago, states that under certainassumptions, the three genotypes AA, AB and BB at a bi-allelic locus are expected to occur inthe proportions p2, 2pq, and q2 respectively, where p is the allele frequency of A, and q = 1-p.There are many statistical tests being used to check whether empirical marker data obeys theHardy-Weinberg principle. Among these are the classical xi-square test (with or withoutcontinuity correction), the likelihood ratio test, Fisher's Exact test, and exact tests in combinationwith Monte Carlo and Markov Chain algorithms. Tests for Hardy-Weinberg equilibrium (HWE)are numerical in nature, requiring the computation of a test statistic and a p-value.There is however, ample space for the use of graphics in HWE tests, in particular for the ternaryplot. Nowadays, many genetical studies are using genetical markers known as SingleNucleotide Polymorphisms (SNPs). SNP data comes in the form of counts, but from the countsone typically computes genotype frequencies and allele frequencies. These frequencies satisfythe unit-sum constraint, and their analysis therefore falls within the realm of compositional dataanalysis (Aitchison, 1986). SNPs are usually bi-allelic, which implies that the genotypefrequencies can be adequately represented in a ternary plot. Compositions that are in exactHWE describe a parabola in the ternary plot. Compositions for which HWE cannot be rejected ina statistical test are typically ���close" to the parabola, whereas compositions that differsignificantly from HWE are ���far". By rewriting the statistics used to test for HWE in terms ofheterozygote frequencies, acceptance regions for HWE can be obtained that can be depicted inthe ternary plot. This way, compositions can be tested for HWE purely on the basis of theirposition in the ternary plot (Graffelman & Morales, 2008). This leads to nice graphicalrepresentations where large numbers of SNPs can be tested for HWE in a single graph. Severalexamples of graphical tests for HWE (implemented in R software), will be shown, using SNPdata from different human populations

Prominent use of distal 5��� transcription start sites and discovery of a large number of additional exons in ENCODE regions

This report presents systematic empirical annotation of transcript products from 399 annotated protein-coding loci across the 1% of the human genome targeted by the Encyclopedia of DNA elements (ENCODE) pilot project using a combination of 5' rapid amplification of cDNA ends (RACE) and high-density resolution tiling arrays. We identified previously unannotated and often tissue- or cell-line-specific transcribed fragments (RACEfrags), both 5' distal to the annotated 5' terminus and internal to the annotated gene bounds for the vast majority (81.5%) of the tested genes. Half of the distal RACEfrags span large segments of genomic sequences away from the main portion of the coding transcript and often overlap with the upstream-annotated gene(s). Notably, at least 20% of the resultant novel transcripts have changes in their open reading frames (ORFs), most of them fusing ORFs of adjacent transcripts. A significant fraction of distal RACEfrags show expression levels comparable to those of known exons of the same locus, suggesting that they are not part of very minority splice forms. These results have significant implications concerning (1) our current understanding of the architecture of protein-coding genes; (2) our views on locations of regulatory regions in the genome; and (3) the interpretation of sequence polymorphisms mapping to regions hitherto considered to be "noncoding," ultimately relating to the identification of disease-related sequence alterations.

L'Exercici de la doc��ncia de la psicologia i el Burnout

En l���actualitat el burnout o s��ndrome de cremar-se per la feina ��s considerat un risc emergent als pa��sos occidentals essent el col��lectiu docent un dels m��s afectats. L���espai europeu d���educaci�� superior proposa un nou rol pel professor que haur�� de ser compaginat amb la gesti��, la recerca i la transfer��ncia de coneixement. En la present recerca s���analitza el nivell de burnout en una mostra formada per 42 docents (mitjana d���edat: 37,21 anys; D.T.: 8,98; 70,8% dones) del departament de Psicologia de la Universitat de Girona. El burnout s���ha avaluat amb el Maslach Burnout Inventory (MBI) aix�� com amb un q��estionari d���elaboraci�� pr��pia que recull variables sociodemogr��fiques, caracter��stiques del tipus de treball i de l�����s del temps lliure, el locus de control i el burnout percebut. Els resultats obtinguts indiquen valors mitjans en les puntuacions de les dimensions Cansament Emocional i Despersonalitzaci��, i valors elevats en Realitzaci�� Personal. El 20,5% dels docents es percep cremat per la feina

Borcherds products and arithmetic intersection theory on Hilbert modular surfaces

We prove an arithmetic version of a theorem of Hirzebruch and Zagier saying that Hirzebruch-Zagier divisors on a Hilbert modular surface are the coefficients of an elliptic modular form of weight 2. Moreover, we determine the arithmetic selfintersection number of the line bundle of modular forms equipped with its Petersson metric on a regular model of a Hilbert modular surface, and we study Faltings heights of arithmetic Hirzebruch-Zagier divisors.

Bounds on multisecant lines

The purpose of this paper is two fold. First, we give an upper bound on the orderof a multisecant line to an integral arithmetically Cohen-Macaulay subscheme in Pn of codimension two in terms of the Hilbert function. Secondly, we givean explicit description of the singular locus of the blow up of an arbitrary local ring at a complete intersection ideal. This description is used to refine standardlinking theorem. These results are tied together by the construction of sharp examples for the bound, which uses the linking theorems.

Evolutionary dynamics of molecular markers during local adaptation: a case study in Drosophila subobscura

Background: Natural selection and genetic drift are major forces responsible for temporal genetic changes in populations. Furthermore, these evolutionary forces may interact with each other. Here we study the impact of an ongoing adaptive process at the molecular genetic level by analyzing the temporal genetic changes throughout 40 generations of adaptation to a common laboratory environment. Specifically, genetic variability, population differentiation and demographic structure were compared in two replicated groups of Drosophila subobscura populations recently sampled from different wild sources. Results: We found evidence for a decline in genetic variability through time, along with an increase in genetic differentiation between all populations studied. The observed decline in genetic variability was higher during the first 14 generations of laboratory adaptation. The two groups of replicated populations showed overall similarity in variability patterns. Our results also revealed changing demographic structure of the populations during laboratory evolution, with lower effective population sizes in the early phase of the adaptive process. One of the ten microsatellites analyzed showed a clearly distinct temporal pattern of allele frequency change, suggesting the occurrence of positive selection affecting the region around that particular locus. Conclusion: Genetic drift was responsible for most of the divergence and loss of variability between and within replicates, with most changes occurring during the first generations of laboratory adaptation. We also found evidence suggesting a selective sweep, despite the low number of molecular markers analyzed. Overall, there was a similarity of evolutionary dynamics at the molecular level in our laboratory populations, despite distinct genetic backgrounds and some differences in phenotypic evolution.

ORMDL proteins are a conserved new family of endoplasmic reticulum membrane proteins

Background: Annotations of completely sequenced genomes reveal that nearly half of the genes identified are of unknown function, and that some belong to uncharacterized gene families. To help resolve such issues, information can be obtained from the comparative analysis of homologous genes in model organisms. Results: While characterizing genes from the retinitis pigmentosa locus RP26 at 2q31-q33, we have identified a new gene, ORMDL1, that belongs to a novel gene family comprising three genes in humans (ORMDL1, ORMDL2 and ORMDL3), and homologs in yeast, microsporidia, plants, Drosophila, urochordates and vertebrates. The human genes are expressed ubiquitously in adult and fetal tissues. The Drosophila ORMDL homolog is also expressed throughout embryonic and larval stages, particularly in ectodermally derived tissues. The ORMDL genes encode transmembrane proteins anchored in the endoplasmic reticulum (ER). Double knockout of the two Saccharomyces cerevisiae homologs leads to decreased growth rate and greater sensitivity to tunicamycin and dithiothreitol. Yeast mutants can be rescued by human ORMDL homologs. Conclusions: From protein sequence comparisons we have defined a novel gene family, not previously recognized because of the absence of a characterized functional signature. The sequence conservation of this family from yeast to vertebrates, the maintenance of duplicate copies in different lineages, the ubiquitous pattern of expression in human and Drosophila, the partial functional redundancy of the yeast homologs and phenotypic rescue by the human homologs, strongly support functional conservation. Subcellular localization and the response of yeast mutants to specific agents point to the involvement of ORMDL in protein folding in the ER.