Spin-harmonic structures and nilmanifolds

We introduce spin-harmonic structures, a class of geometric structures on Riemannian manifolds of low dimension which are defined by a harmonic unitary spinor. Such structures are related to SU(2) (dim=4,5), SU(3) (dim=6) and G_2 (dim=7) structures; in dimension 8, a spin-harmonic structure is equivalent to a balanced Spin(7) structure. As an application, we obtain examples of compact 8-manifolds endowed with non-integrable Spin(7) structures of balanced type.Comment: 34 pages, no figure

Gas hydrate in sediments on the Southern Chile continental slope

The convergent plate margin of Chile has vast mineral resources associated with active or fossil hydrothermal systems. One of the natural resources that came into the focus of the Chilean government and institutions is gas hydrate in the offshore area of the Pacific Ocean margin, which is a solid ice-like form of water that contains gas molecules highly‐concentrated in methane. To identify the presence of hydrates, in this thesis it was used the bottom-simulating reflector BSR, which has the half amplitude and opposite polarity relative to the seafloor. Moreover, fluids play a key role in the nucleation and rupture propagation of earthquakes in convergent margins, since are a major agent of advective heat transfer from depth to the Earth’s surface. If we provide enough information for the regional heat flow, we will improve our knowledge of the tectono-thermal signature of the convergent margins. For this purpose, it is crucial to know the BSR-depth, which serves to calculate the steady-state heat flow q (mW m–2) by using a simple formula, and therefore, the heat flow can be envisaged in a regional overview. This thesis aims to investigate the tectonic processes of the Chilean forearc through the calculation of the regional BSR-derived heat flow, identification of fluid escape sites, description of the distribution of gas hydrates and estimation of the gas hydrate and free gas reservoirs

Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores)

Two sectors, Itata and Valdivia, which are located in the Chilean margin were analysed by using seismic data with the main purpose to characterize the gas hydrate concentration. Strong lateral velocity variations are recognised, showing a maximum value in Valdivia offshore (2380 ms−1 above the BSR) and a minimum value in the Itata offshore (1380 m·s−1 below the BSR). In both of the sectors, the maximum hydrate concentration reaches 17% of total volume, while the maximum free gas concentration is located Valdivia offshore (0.6% of total volume) in correspondence of an uplift sector. In the Itata offshore, the geothermal gradient that is estimated is variable and ranges from 32 °C·km−1 to 87 °C·km−1, while in Valdivia offshore it is uniform and about 35 °C·km−1. When considering both sites, the highest hydrate concentration is located in the accretionary prism (Valdivia offshore) and highest free gas concentration is distributed upwards, which may be considered as a natural pathway for lateral fluid migration. The results that are presented here contribute to the global knowledge of the relationship between hydrate/free gas presence and tectonic features, such as faults and folds, and furnishes a piece of the regional hydrate potentiality Chile offshore

Interferon Gamma Inducible Protein 10 (IP-10) and Regulatory T Cells in Leishmaniasis

Leishmania are intracellular parasites that reside inside macrophages and induce weak innate immune responses. We hypothesize that transgenic parasites that express immune response genes could modify the nature of the host response to the parasite. We previously generated transgenic parasites that produce interferon gamma inducible protein 10 (IP-10). C57BL/6 mice are resistant to wild type L. major infection but when infected with IP-10 transgenic parasites they develop large lesions in the footpad that do not resolve. Recently it was discovered that nTregs express CXCR3, the receptor for IP-10. We hypothesized that IP-10 transgenic parasites could actively recruit nTregs and thereby enhance parasite persistence. We found higher numbers of CD4+CD25+Foxp3+ cells in the draining lymph nodes of IP-10 parasites infected mice compared to wild type infected mice. This work suggests that IP-10 secreting parasites might recruit a population of regulatory T cells that modulates the immune response to the parasite allowing parasite persistence

Calculo del costo total de calidad en una empresa regional certificada con la norma ISO 9002 sobre Aseguramiento de la Calidad

149 p.En la presente investigación se calcularon los Costos Totales de Calidad para cada una de las Unidades de Negocio de una empresa regional certificada con la Norma de ISO 9002 sobre Aseguramiento de la Calidad. Para el logro de los objetivos propuestos, se utilizo como metodología de trabajo el Sistema de Costos Basado en las actividades o ABC. Este trabajo constituye una respuesta a la necesidad de conocer el Costo Total de Calidad en una empresa certificada con la Norma ISO 9000. El calculo de dichos costos es una herramienta Mil para medir el desempeño llevado a cabo después de la implementación de un Sistema de Aseguramiento de la Calidad. La metodología utilizada para la determinación del Costo Total de Calidad permite costear cada una de las Actividades relacionadas con la calidad y clasificarlas entre los Costos de Calidad y No Calidad correspondientes a su naturaleza y entre cada una de las unidades de negocio. De este modo, es posible obtener el Costo Total de Calidad incurrido en la empresa. Además, se exponen por medio de la metodología, los requerimientos de tiempo y de recursos que implica cada actividad relacionada con la calidad, antecedentes muy Miles para la planificación de la misma en la empresa. El análisis de las cifras a las que ascienden los Costos Totales de Calidad permite conocer en que actividades la empresa consume una mayor cantidad de recursos, lo cual hace posible administrar y controlar de una mejor forma los recursos utilizados

The bright galaxy population of five medium redshift clusters. II. Quantitative Galaxy Morphology

Aims: Following the study already presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 $\leq$ z $\leq$ 0.25, imaged in the central 0.5-2 Mpc in very good seeing conditions, we have studied the quantitative morphology of their bright galaxy population Methods: We have analyzed the surface brightness profiles of the galaxy population in those clusters. Previously, we have performed simulations in order to check the reliability of the fits. We have also derived a quantitative morphological classification. Results: The structural parameters derived from these analysis have been analyzed. We have obtained that the structural parameters of E/S0 galaxies are similar to those showed by galaxies in low redshift clusters. However, the disc scales are different. In particular, the scales of the discs of galaxies at medium redshift clusters are statistically different than those located in similar galaxies in the Coma cluster. But, the scales of the discs of galaxies in medium redshift clusters are similar to nearby field galaxies. Conclusions: The results suggest that the evolution of the disc component of galaxies in clusters is faster than in field ones. Mechanisms like galaxy harassment showing timescales of $\sim 1$Gyr could be the responsible of this disc scale evolution. This indicates that spiral galaxies in clusters have suffered a strong evolution in the last 2.5 Gyr or that Coma is in some way anomalous.Comment: 13 pages, 10 figures, Accepted for publication in A&

Follistatin-like 3 mediates paracrine fibroblast activation by cardiomyocytes

Follistatins are extracellular inhibitors of the TGF-β family ligands including activin A, myostatin and bone morphogenetic proteins. Follistatin-like 3 (FSTL3) is a potent inhibitor of activin signalling and antagonises the cardioprotective role of activin A in the heart. FSTL3 expression is elevated in patients with heart failure and is upregulated in cardiomyocytes by hypertrophic stimuli, but its role in cardiac remodelling is largely unknown. Here, we show that the production of FSTL3 by cardiomyocytes contributes to the paracrine activation of cardiac fibroblasts, inducing changes in cell adhesion, promoting proliferation and increasing collagen production. We found that FSTL3 is necessary for this response and for the induction of cardiac fibrosis. However, full activation requires additional factors, and we identify connective tissue growth factor as a FSTL3 binding partner in this process. Together, our data unveil a novel mechanism of paracrine communication between cardiomyocytes and fibroblasts that may provide potential as a therapeutic target in heart remodelling.British Heart Foundation [PG/08/084/25827]; Heart Research UK; National Institute for Health Research Cardiovascular Biomedical Research Unit at the Royal Brompton; Harefield NHS Foundation Trust; Imperial College; European Union [ERG-239158, ITN-289600]; Spanish Ministry of Science and Innovation [BFU2009-10016, CP08/00144]; Regional Government of Madrid [S2010/BMD-2321 'Fibroteam']S

Detecting the dark matter annihilation at the ground EAS detectors

In this paper we study the possibility of detecting gamma rays from dark matter annihilation in the subhalos of the Milky Way by the ground based EAS detectors within the frame of the minimal supersymmetric standard model. Based on the Monte Carlo simulation we also study the properties of two specific EAS detectors, the ARGO and HAWC, and the sensitivities of these detectors on the detection of dark matter annihilation. We find the ground EAS detectors have the possibility to observe such signals. Conversely if no signal observed we give the constraints on the supersymmetric parameter space, which however depends on the subhalos properties.Comment: 23 pages, 9 figures, accepted by NP