Analisis pluviometrico de la Region del Maule en el siglo XX

Resumen (Spanish, English)75 p.El reducido número de estudios referentes al clima y especialmente a la pluviometría efectuados en la Región del Maule, fue el principal motivo en la realización de este trabajo, el cual consideró un análisis pluviométrico realizado a través de datos de agua caída en los últimos cien años (1900-2000), provenientes de once estaciones meteorológicas, distribuidas a lo largo de la Región. Con los datos recopilados se procedió a hacer diferentes análisis para conocer la tendencia y la estacionalidad de las precipitaciones. La tendencia fue calculada considerando todas las series de datos para cada estación meteorológica y para la estacionalidad se creó un índice estacional decadal. Y a su vez determinar si hay alguna relación entre las precipitaciones con el fenómeno de El Niño Oscilación del Sur (ENOS) o con algunos de sus componentes: Temperatura Superficial del Mar (TSM) e Índice de Oscilación del Sur (IOS). La tendencia de precipitaciones mostró un leve descenso en el tiempo que comprende el estudio, y a su vez la estacionalidad de las lluvias presentó cambios en el comportamiento de éstas, con lo cual se puede decir que estamos en presencia de un cambio climático desde el punto de vista pluviométrico. Para hacer un estudio más acabado, en cuanto al recurso agua, también se calculó la tendencia de los milímetros de nieve caída de dos Rutas de Nieve y del Volumen de agua del embalse natural Laguna del Maule. Dando como resultado en ambas situaciones, que esta también a disminuido, colocándonos en alerta para así hacer un mejor uso y aprovechamiento de ella. Además se ratificó que existe una relación inversa entre el IOS y la TSM y que el fenómeno de El Niño se relaciona con la fase negativa del IOS. Así, cuando se está en presencia de dicho evento, éste índice comienza a disminuir acrecentando la generación de lluvias invernales

Bostonia: 1998-1999, no. 1, 3-4

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Lupus risk variants in the PXK locus alter B-cell receptor internalization

Genome wide association studies have identified variants in PXK that confer risk for humoral autoimmune diseases, including systemic lupus erythematosus (SLE or lupus), rheumatoid arthritis and more recently systemic sclerosis. While PXK is involved in trafficking of epidermal growth factor Receptor (EGFR) in COS-7 cells, mechanisms linking PXK to lupus pathophysiology have remained undefined. In an effort to uncover the mechanism at this locus that increases lupus-risk, we undertook a fine-mapping analysis in a large multi-ancestral study of lupus patients and controls. We define a large (257kb) common haplotype marking a single causal variant that confers lupus risk detected only in European ancestral populations and spans the promoter through the 3' UTR of PXK. The strongest association was found at rs6445972 with P < 4.62 × 10-10, OR 0.81 (0.75 - 0.86). Using stepwise logistic regression analysis, we demonstrate that one signal drives the genetic association in the region. Bayesian analysis confirms our results, identifying a 95% credible set consisting of 172 variants spanning 202 kb. Functionally, we found that PXK operates on the B-cell antigen receptor (BCR); we confirmed that PXK influenced the rate of BCR internalization. Furthermore, we demonstrate that individuals carrying the risk haplotype exhibited a decreased rate of BCR internalization, a process known to impact B cell survival and cell fate. Taken together, these data define a new candidate mechanism for the genetic association of variants around PXK with lupus risk and highlight the regulation of intracellular trafficking as a genetically regulated pathway mediating human autoimmunity

Transcription factor induction of vascular blood stem cell niches in vivo

The hematopoietic niche is a supportive microenvironment composed of distinct cell types, including specialized vascular endothelial cells that directly interact with hematopoietic stem and progenitor cells (HSPCs). The molecular factors that specify niche endothelial cells and orchestrate HSPC homeostasis remain largely unknown. Using multi-dimensional gene expression and chromatin accessibility analyses in zebrafish, we define a conserved gene expression signature and cis-regulatory landscape that are unique to sinusoidal endothelial cells in the HSPC niche. Using enhancer mutagenesis and transcription factor overexpression, we elucidate a transcriptional code that involves members of the Ets, Sox, and nuclear hormone receptor families and is sufficient to induce ectopic niche endothelial cells that associate with mesenchymal stromal cells and support the recruitment, maintenance, and division of HSPCs in vivo. These studies set forth an approach for generating synthetic HSPC niches, in vitro or in vivo, and for effective therapies to modulate the endogenous niche

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Pressure at infinity and strong positive recurrence in negative curvature

In the context of geodesic flows of noncompact negatively curved manifolds, we propose three different definitions of entropy and pressure at infinity, through growth of periodic orbits, critical exponents of Poincar\'e series, and entropy (pressure) of invariant measures. We show that these notions coincide. Thanks to these entropy and pressure at infinity, we investigate thoroughly the notion of strong positive recurrence in this geometric context. A potential is said strongly positively recurrent when its pressure at infinity is strictly smaller than the full topological pressure. We show in particular that if a potential is strongly positively recurrent, then it admits a finite Gibbs measure. We also provide easy criteria allowing to build such strong positively recurrent potentials and many examples

Blastocistosis y otras infecciones por protozoos intetinales en comunidades humanas ribereñas de la cuenca del rio Valdivia, Chile

Between March and October 1987, the prevalence of infection by Blastocystis hominis and other intestinal protozoan, their relationship with the age and sex of the hosts, and the percentage of in fected persons in family groups were determined in riverside communities of Valdivia River Basin, Chile. One or more intestinal protozoan species were determined in 72.5% of the examined persons. The prevalence was greater for B. hominis (61.8%). The prevalences of B. hominis, Endolimax nana and Entamoeba coli were greater in relation to the age of the host. The sex of the host and prevalence of infections by B. hominis and other species of intestinal protozoans did not show association. Prevalence of B. hominis was greater in persons from houses with no sanitary faeces disposal. Over 60% of the members of family groups showed infection by B. hominis in 53.1% of the groups compared to 2.4%-21.8% of infections by other protozoan species. Faecal samples of 45 pigs revealed 22.2% of infection by Blastocystis.Entre marzo y octubre de 1987 se examinaron muestras coprológicas de 970 personas (20, 9% de la población) pertenecientes a 209 grupos familiares de las comunidades ribereñas de la cuenca del rio Valdivia, Chile; con el propósito de determinar las prevalencias de infección por Blastocystis hominis y otros protozoos intestinales para establecer relaciones con la edad y sexo de los hospedadores, saneamiento ambiental y porcentaje de individuos infectados por grupo familiar. Un 72, 5% de las personas presentó una o más especies de protozoos intestinales. La mayor prevalencia se registró para B. hominis (61, 8%), que se incrementó con la edad del hospedador al igual que en las infecciones por Endolimax nana y Entamoeba coli. No se demostró asociación entre el sexo del hospedador y la prevalencia de infección por B. hominis y otras especies de protozoos. La prevalencia de B. hominis fue mayor en individuos que habitaban viviendas cuya disposition de excrementos era no sanitaria. Más del 60% de los integrantes de los grupos familiares presentaron infección por B. hominis en el 53, 1% de las familias encuestadas en contraposición al 2,4%-21,8% observado en infecciones por otros protozoos. El examen de 45 muestras de excrementos de cerdos, reveló infección por Blastocystis en el 22,2% de estos animales

Selectivity in subunit composition of Ena/VASP tetramers

The members of the actin regulatory family of Ena/VASP proteins form stable tetramers. The vertebrate members of the Ena/VASP family, VASP, Mena and EVL, have many overlapping properties and expression patterns, but functional and regulatory differences between paralogues have been observed. The formation of mixed oligomers may serve a regulatory role to refine Ena/VASP activity. While it has been assumed that family members can form mixed oligomers, this possibility has not been investigated systematically. Using cells expressing controlled combinations of VASP, Mena and EVL, we evaluated the composition of Ena/VASP oligomers and found that VASP forms oligomers without apparent bias with itself, Mena or EVL. However, Mena and EVL showed only weak hetero-oligomerization, suggesting specificity in the association of Ena/VASP family members. Co-expression of VASP increased the ability of Mena and EVL to form mixed oligomers. Additionally, we found that the tetramerization domain (TD) at the C-termini of Ena/VASP proteins conferred the observed selectivity. Finally, we demonstrate that replacement of the TD with a synthetic tetramerizing coiled coil sequence supports homo-oligomerization and normal VASP subcellular localization.Massachusetts Institute of Technology. Ludwig Center for Molecular OncologyNational Institutes of Health (U.S.) (Grants U54- CA112967 and 1-DP5-OD019815)National Cancer Institute (U.S.) (David H. Koch Institute for Integrative Cancer Research at MIT. Grant P30-CA14051)National Institutes of Health (U.S.) ( Pre-Doctoral Training Grant T32GM007287