1,055 research outputs found

    Estratigrafía y análisis de facies de la Formación Vaca Muerta en el área de El Trapial

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    La importancia de los análisis estratigráficos, de facies y sedimentológicos para evaluar el potencial de un reservorio no convencional para identificar las zonas más favorables para la prospección y explotación de hidrocarburos.Fil: González Tomassini, Federico. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; ArgentinaFil: Kietzmann, Diego Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos ; ArgentinaFil: Fantin, Manuel A.. Chevron; ArgentinaFil: Crousse, Luisa C.. Chevron; ArgentinaFil: Reijenstein, Hernán M.. Chevron Latin America Business; Estados Unido

    Geotecnologias e aprendizagem espacial em ambiente educacional: o mapeamento de nascentes utilizando técnicas de geoprocessamento por meio de softwares livres.

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    The headwaters of streams are extremely important to maintain the water sources and contribute to the permanent preservation areas (PPA) and hence with the ecosystems of any region. Thus this aspect were investigated by mapping using GIS techniques by free software. The data were validated by field research conducted by students of the 1st year of high school ? Escola Estadual de Ensino Médio Pedro Migliorini, located in the municipality of Monte Belo do Sul, Brazil. The objective of the study was to allow students to assess quantitatively and qualitatively the headwaters of the city, analyzing water usage, as well as the situation of the same as the environmental laws. Students were divided into work areas, conducted interviews with landowners in order to research on the consumption and use of water and what methods are used for the preservation of the spring on the property. To assess if the sources informed the owners comply with current legislation, GIS tools were employed and was generated a buffer of 50 meters (area corresponding to PPA) around the source. At the end of the study were located 427 points with the following observations: 1) 95 are used for human consumption, 2) 107 for animal consumption, 3) 145 have some protection; 4) 23 are in accordance with current legislation . 37 springs were not informed about the use

    Dark Matter Direct Detection with Non-Maxwellian Velocity Structure

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    The velocity distribution function of dark matter particles is expected to show significant departures from a Maxwell-Boltzmann distribution. This can have profound effects on the predicted dark matter - nucleon scattering rates in direct detection experiments, especially for dark matter models in which the scattering is sensitive to the high velocity tail of the distribution, such as inelastic dark matter (iDM) or light (few GeV) dark matter (LDM), and for experiments that require high energy recoil events, such as many directionally sensitive experiments. Here we determine the velocity distribution functions from two of the highest resolution numerical simulations of Galactic dark matter structure (Via Lactea II and GHALO), and study the effects for these scenarios. For directional detection, we find that the observed departures from Maxwell-Boltzmann increase the contrast of the signal and change the typical direction of incoming DM particles. For iDM, the expected signals at direct detection experiments are changed dramatically: the annual modulation can be enhanced by more than a factor two, and the relative rates of DAMA compared to CDMS can change by an order of magnitude, while those compared to CRESST can change by a factor of two. The spectrum of the signal can also change dramatically, with many features arising due to substructure. For LDM the spectral effects are smaller, but changes do arise that improve the compatibility with existing experiments. We find that the phase of the modulation can depend upon energy, which would help discriminate against background should it be found.Comment: 34 pages, 16 figures, submitted to JCAP. Tables of g(v_min), the integral of f(v)/v from v_min to infinity, derived from our simulations, are available for download at http://astro.berkeley.edu/~mqk/dmdd

    Neuropilin-1 mediates vascular permeability independently of vascular endothelial growth factor receptor-2 activation

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    Neuropilin-1 (NRP1) regulates developmental and pathological angiogenesis, arteriogenesis, and vascular permeability, acting as a coreceptor for semaphorin 3A (Sema3A) and the 165–amino acid isoform of vascular endothelial growth factor A (VEGF-A165). NRP1 is also the receptor for the CendR peptides, a class of cell- and tissue-penetrating peptides with a specific R-x-x-R carboxyl-terminal motif. Because the cytoplasmic domain of NRP1 lacks catalytic activity, NRP1 is mainly thought to act through the recruitment and binding to other receptors. We report here that the NRP1 intracellular domain mediates vascular permeability. Stimulation with VEGF-A165, a ligand-blocking antibody, and a CendR peptide led to NRP1 accumulation at cell-cell contacts in endothelial cell monolayers, increased cellular permeability in vitro and vascular leakage in vivo. Biochemical analyses, VEGF receptor-2 (VEGFR-2) silencing, and the use of a specific VEGFR blocker established that the effects induced by the CendR peptide and the antibody were independent of VEGFR-2. Moreover, leakage assays in mice expressing a mutant NRP1 lacking the cytoplasmic domain revealed that this domain was required for NRP1-induced vascular permeability in vivo. Hence, these data define a vascular permeability pathway mediated by NRP1 but independent of VEGFR-2 activation

    The complex TIE between macrophages and angiogenesis

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    Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway

    KIT is required for fetal liver hematopoiesis

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    In the mouse embryo, endothelial cell (EC) progenitors almost concomitantly give rise to the first blood vessels in the yolk sac and the large vessels of the embryo proper. Although the first blood cells form in the yolk sac before blood vessels have assembled, consecutive waves of hematopoietic progenitors subsequently bud from hemogenic endothelium located within the wall of yolk sac and large intraembryonic vessels in a process termed endothelial-to-hematopoietic transition (endoHT). The receptor tyrosine kinase KIT is required for late embryonic erythropoiesis, but KIT is also expressed in hematopoietic progenitors that arise via endoHT from yolk sac hemogenic endothelium to generate early, transient hematopoietic waves. However, it remains unclear whether KIT has essential roles in early hematopoiesis. Here, we have combined single-cell expression studies with the analysis of knockout mice to show that KIT is dispensable for yolk sac endoHT but required for transient definitive hematopoiesis in the fetal liver

    The non-convex shape of (234) Barbara, the first Barbarian

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    Asteroid (234) Barbara is the prototype of a category of asteroids that has been shown to be extremely rich in refractory inclusions, the oldest material ever found in the Solar system. It exhibits several peculiar features, most notably its polarimetric behaviour. In recent years other objects sharing the same property (collectively known as ‘Barbarians') have been discovered. Interferometric observations in the mid-infrared with the ESO VLTI (Very Large Telescope Interferometer) suggested that (234) Barbara might have a bi-lobated shape or even a large companion satellite. We use a large set of 57 optical light curves acquired between 1979 and 2014, together with the timings of two stellar occultations in 2009, to determine the rotation period, spin-vector coordinates, and 3-D shape of (234) Barbara, using two different shape reconstruction algorithms. By using the light curves combined to the results obtained from stellar occultations, we are able to show that the shape of (234) Barbara exhibits large concave areas. Possible links of the shape to the polarimetric properties and the object evolution are discussed. We also show that VLTI data can be modelled without the presence of a satellit

    Clinical manifestations in patients with PI*MMMalton genotypes. A matter still unsolved in alpha-1 antitrypsin deficiency

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    We report the genetic variants associated with alpha-1 antitrypsin deficiency (AATD) in 117 patients admitted to our outpatient clinic and characterized by a serum concentration of AAT lower than 113 mg/dL. We focused on the M-like heterozygous variant of the SERPINA1 gene called PI*MMMalton, and describe three patients with this variant. While the role of homozygous AATD in liver and pulmonary disease is well established, the association between heterozygous AATD and chronic liver and pulmonary disease is still under investigation. The PI*MMMalton genotype was found in 5.8% of patients with a pathological genotype of AATD and in 14.3% of the subjects when considering only those with intermediate AATD. There were no liver or renal abnormalities in patients with the PI*MMMalton genotype. The PI*MMMalton patients included here showed a normal liver function, and none had renal function abnormalities or abdominal aortic aneurysm. Only a prevalence of lung disease was detected

    Pobreza en el norte grande. Determinación de niveles con un indicador integrado de privación de medios de vida

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    Para el estudio de la pobreza en el Norte Grande argentino, se elaboró el Índice de Privación de Medios de Vida, buscando diseñar un indicador que permitiera combinar determinadas características de la pobreza coyuntural y de la pobreza estructural, a través de la utilización de datos censales. Se buscaba, además, que el mismo fuera funcional para su aplicación a nivel de radios censales, con el objeto de afinar la percepción del fenómeno de distribución espacial de la pobreza en las nueve provincias más carenciadas de Argentina. El Índice de Privación de Medios de Vida (IPMV), deviene de la elaboración de un Índice de Capacidad de Subsistencia (ICS) que es ajustado, en lo que se refiere a su versatilidad para medir la dimensión estructural de la pobreza, por la Condición Habitacional (CH). El IPMV intenta aproximar los dos grandes métodos utilizados en la evaluación de la pobreza –LP y NBI—que responden a estructurasconceptuales diferentes basadas en sus respectivas relaciones con el ingreso y el consumo privado el primero, y con el consumo público y la inversión privada y pública, el segundo. El objetivo de la presente propuesta es la discusión operacional del funcionamiento del IPMV y de su grado de capacidad para la medir y discriminar los distintos niveles de pobreza
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