313 research outputs found

    Detecting independence of random vectors: generalized distance covariance and Gaussian covariance

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    Distance covariance is a quantity to measure the dependence of two random vectors. We show that the original concept introduced and developed by Sz\'{e}kely, Rizzo and Bakirov can be embedded into a more general framework based on symmetric L\'{e}vy measures and the corresponding real-valued continuous negative definite functions. The L\'{e}vy measures replace the weight functions used in the original definition of distance covariance. All essential properties of distance covariance are preserved in this new framework. From a practical point of view this allows less restrictive moment conditions on the underlying random variables and one can use other distance functions than Euclidean distance, e.g. Minkowski distance. Most importantly, it serves as the basic building block for distance multivariance, a quantity to measure and estimate dependence of multiple random vectors, which is introduced in a follow-up paper [Distance Multivariance: New dependence measures for random vectors (submitted). Revised version of arXiv: 1711.07775v1] to the present article.Comment: Published at https://doi.org/10.15559/18-VMSTA116 in the Modern Stochastics: Theory and Applications (https://www.i-journals.org/vtxpp/VMSTA) by VTeX (http://www.vtex.lt/

    Structure and Innervation of the Equine Supraspinous and Interspinous Ligaments

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    Pain related to the osseous thoracolumbar spine is common in the equine athlete, with minimal information available regarding soft tissue pathology. The aims of this study were to describe the anatomy of the equine SSL and ISL (supraspinous and interspinous ligaments) in detail and to assess the innervation of the ligaments and their myofascial attachments including the thoracolumbar fascia. Ten equine thoracolumbar spines (T15‐L1) were dissected to define structure and anatomy of the SSL , ISL and adjacent myofascial attachments. Morphological evaluation included histology, electron microscopy and immunohistochemistry (S100 and Substance P) of the SSL , ISL , adjacent fascial attachments, connective tissue and musculature. The anatomical study demonstrated that the SSL and ISL tissues merge with the adjacent myofascia. The ISL has a crossing fibre arrangement consisting of four ligamentous layers with adipose tissue axially. A high proportion of single nerve fibres were detected in the SSL (mean = 2.08 fibres/mm2) and ISL (mean = 0.75 fibres/mm2), with the larger nerves located between the ligamentous and muscular tissue. The oblique crossing arrangement of the fibres of the ISL likely functions to resist distractive and rotational forces, therefore stabilizing the equine thoracolumbar spine. The dense sensory innervation within the SSL and ISL could explain the severe pain experienced by some horses with impinging dorsal spinous processes. Documentation of the nervous supply of the soft tissues associated with the dorsal spinous processes is a key step towards improving our understanding of equine back pain

    Presencia del cooperativismo en Argentina

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    En el presente trabajo se realiza la reseña histórica del movimiento cooperativo en la República Argentina, haciendo una síntesis de las primeras manifestaciones y una breve referencia hasta nuestros días. Se cita el marco jurídico vigente para las cooperativas en este país, la presencia y distribución geográfica de las mismas. Con respecto a la educación y la investigación se mencionan distintas acciones implementadas tanto desde el ámbito universitario, como desde otras instituciones cooperativas y no cooperativas. Finalmente, y no obstante los aspectos comentados que ponen de manifiesto la relevancia del cooperativismo en Argentina, se exponen algunas normativas existentes que impiden a estas organizaciones no lucrativas, solidarias y humanistas, prestar determinados servicios, convirtiéndose en un verdadero obstáculo para su genuino desarrollo.No presente trabalho efetuou-se um levantamento histórico do movimento cooperativo na República Argentina sintetizando-se as primeiras manifestações e uma breve referência até os dias atuais. Cita-se o enquadramento jurídico vigente para as cooperativas no país, bem como a presença e a distribuição geográfica das mesmas. No tocante à educação e à pesquisa, são mencionadas as diferentes ações implementadas tanto no âmbito universitário como em outras instituições sejam elas cooperativas ou não. Finalmente, apesar dos aspectos mencionados que evidenciam a relevância do cooperativismo na Argentina, são apresentadas algumas regulamentções existentes que impedem essas instituições solidárias, humanistas e sem fins lucrativos de prestarem determinados serviços. Essas diretrizes constituem-se em obstáculos efetivos para o verdadeiro desenvolvimento das organizações.Facultad de Ciencias Económica

    Presencia del cooperativismo en Argentina

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    En el presente trabajo se realiza la reseña histórica del movimiento cooperativo en la República Argentina, haciendo una síntesis de las primeras manifestaciones y una breve referencia hasta nuestros días. Se cita el marco jurídico vigente para las cooperativas en este país, la presencia y distribución geográfica de las mismas. Con respecto a la educación y la investigación se mencionan distintas acciones implementadas tanto desde el ámbito universitario, como desde otras instituciones cooperativas y no cooperativas. Finalmente, y no obstante los aspectos comentados que ponen de manifiesto la relevancia del cooperativismo en Argentina, se exponen algunas normativas existentes que impiden a estas organizaciones no lucrativas, solidarias y humanistas, prestar determinados servicios, convirtiéndose en un verdadero obstáculo para su genuino desarrollo.No presente trabalho efetuou-se um levantamento histórico do movimento cooperativo na República Argentina sintetizando-se as primeiras manifestações e uma breve referência até os dias atuais. Cita-se o enquadramento jurídico vigente para as cooperativas no país, bem como a presença e a distribuição geográfica das mesmas. No tocante à educação e à pesquisa, são mencionadas as diferentes ações implementadas tanto no âmbito universitário como em outras instituições sejam elas cooperativas ou não. Finalmente, apesar dos aspectos mencionados que evidenciam a relevância do cooperativismo na Argentina, são apresentadas algumas regulamentções existentes que impedem essas instituições solidárias, humanistas e sem fins lucrativos de prestarem determinados serviços. Essas diretrizes constituem-se em obstáculos efetivos para o verdadeiro desenvolvimento das organizações.Facultad de Ciencias Económica

    Presencia del cooperativismo en Argentina

    Get PDF
    En el presente trabajo se realiza la reseña histórica del movimiento cooperativo en la República Argentina, haciendo una síntesis de las primeras manifestaciones y una breve referencia hasta nuestros días. Se cita el marco jurídico vigente para las cooperativas en este país, la presencia y distribución geográfica de las mismas. Con respecto a la educación y la investigación se mencionan distintas acciones implementadas tanto desde el ámbito universitario, como desde otras instituciones cooperativas y no cooperativas. Finalmente, y no obstante los aspectos comentados que ponen de manifiesto la relevancia del cooperativismo en Argentina, se exponen algunas normativas existentes que impiden a estas organizaciones no lucrativas, solidarias y humanistas, prestar determinados servicios, convirtiéndose en un verdadero obstáculo para su genuino desarrollo.No presente trabalho efetuou-se um levantamento histórico do movimento cooperativo na República Argentina sintetizando-se as primeiras manifestações e uma breve referência até os dias atuais. Cita-se o enquadramento jurídico vigente para as cooperativas no país, bem como a presença e a distribuição geográfica das mesmas. No tocante à educação e à pesquisa, são mencionadas as diferentes ações implementadas tanto no âmbito universitário como em outras instituições sejam elas cooperativas ou não. Finalmente, apesar dos aspectos mencionados que evidenciam a relevância do cooperativismo na Argentina, são apresentadas algumas regulamentções existentes que impedem essas instituições solidárias, humanistas e sem fins lucrativos de prestarem determinados serviços. Essas diretrizes constituem-se em obstáculos efetivos para o verdadeiro desenvolvimento das organizações.Facultad de Ciencias Económica

    Holomorphic transforms with application to affine processes

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    In a rather general setting of It\^o-L\'evy processes we study a class of transforms (Fourier for example) of the state variable of a process which are holomorphic in some disc around time zero in the complex plane. We show that such transforms are related to a system of analytic vectors for the generator of the process, and we state conditions which allow for holomorphic extension of these transforms into a strip which contains the positive real axis. Based on these extensions we develop a functional series expansion of these transforms in terms of the constituents of the generator. As application, we show that for multidimensional affine It\^o-L\'evy processes with state dependent jump part the Fourier transform is holomorphic in a time strip under some stationarity conditions, and give log-affine series representations for the transform.Comment: 30 page

    Observational Study Design in Veterinary Pathology, Part 1: Study Design

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    Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature. Investigators should recognize the importance of creativity, insight, and innovation in devising studies that solve problems and fill important gaps in knowledge. Studies should focus on specific and testable hypotheses, questions, or objectives. The methodology is developed to support these goals. We consider the merits and limitations of different types of analytic and descriptive studies, as well as of prospective vs retrospective enrollment. Investigators should define clear inclusion and exclusion criteria and select adequate numbers of study subjects, including careful selection of the most appropriate controls. Studies of causality must consider the temporal relationships between variables and the advantages of measuring incident cases rather than prevalent cases. Investigators must consider unique aspects of studies based on archived laboratory case material and take particular care to consider and mitigate the potential for selection bias and information bias. We close by discussing approaches to adding value and impact to observational studies. Part 2 of the series focuses on methodology and validation of methods

    Polarization of AGN in UV Spectral Range

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    We present the review of some new problems in cosmology and physics of stars in connection with future launching of WSO. We discuss three problems. UV observations of distant z > 6 quasars allow to obtain information on the soft < 1 KeV X-ray radiation of the accretion disk around a supermassive black hole because of its cosmological redshift. Really the region of X-ray radiation is insufficiently investigated because of high galactic absorption. In a result one will get important information on the reionization zone of the Universe. Astronomers from ESO revealed the effect of alignment of electric vectors of polarized QSOs. One of the probable mechanism of such alignment is the conversion of QSO radiation into low mass pseudoscalar particles (axions) in the extragalactic magnetic field. These boson like particles have been predicted by new SUSY particle physics theory. Since the probability of such conversion is increasing namely in UV spectral range one can expect the strong correlation between UV spectral energy distribution of QSO radiation and polarimetric data in the optical range. In the stellar physics one of the interesting problems is the origin of the X-ray sources with super Eddington luminosities. The results of UV observations of these X-ray sources will allow to find the origin of these sources as accreting intermediate mass black holes.Comment: 6 pages, 3 figure
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