1,462 research outputs found

    Accurate likelihood inference on the area under the ROC curve for small sample.

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    The accuracy of a diagnostic test with continuous-scale results is of high importance in clinical medicine. Receiver operating characteristics (ROC)curves, and in particular the area under the curve (AUC), are widely used to examine the effectiveness of diagnostic markers. Classical likelihood-based inference about the AUC has been widely studied under various parametric assumptions, but it is well-known that it can be inaccurate when the sample size is small, in particular in the presence of unknown parameters. The aim of this paper is to propose and discuss modern higher-order likelihood based procedures to obtain accurate point estimators and confidence intervals for the AUC. The accuracy of the proposed methodology is illustrated by simulation studies. Moreover, two real data examples are used to illustrate the application of the proposed methods

    Novel fluorescence membrane fusion assays reveal GTP-dependent fusogenic properties of outer mitochondrial membrane-derived proteins

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    We have shown that fusion of small unilamellar vesicles (SUV) with outer mitochondrial membranes occurs at physiological pH [Cortese et al., 1991, J. Cell Biol., Vol. 113, 1331-1340]. The proteins driving this process could be involved in mitochondrial membrane fusion, which is presently poorly understood. In this study, we release from rat liver mitochondria a soluble protein fraction (SF) that increases fusion at neutral pH measured by membrane fusion assays (MFAs). Since this fusogenic activity was specifically enhanced by GTP, we separate SF by GTP affinity chromatography into: i) a flow-through subfraction (G1) containing numerous proteins with low GTP affinity; and ii) a subfraction (G2) which may contain GTP-binding proteins. A novel array of MFAs is developed to study the fusogenic properties of these fractions, measuring the merging of membranes (membrane-mixing) or the mixing of intravesicular aqueous contents (content-mixing). The MFAs use: a) SUV/large unilamellar vesicles, lacking mitochondrial membranes; b) SUV/mitochondria, reconstituting membrane-mitochondrial interactions; and c) mitochondria/mitochondria, mimicking mitochondrial fusion. The results indicate that: i) G1 contains GTP-independent, in vitro fusogenic proteins that are not sufficient to induce mitochondrial fusion; and ii) G2 contains GTP-dependent proteins that stimulate mitochondrial fusion at neutral pH. The MFAs described here could be used to monitor the isolation of active proteins from these subfractions and to define the mechanism of intermitochondrial membrane fusion

    Trabajadores privados no registrados y trabajadores públicos precarios : dos caras de la "inclusión" en la explotación laboral : Mendoza 2003 - 2013

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    La presente ponencia se enmarca dentro de un proyecto de investigación que pretende trazar un panorama preciso de las condiciones del trabajo en la provincia de Mendoza. El supuesto más amplio es que la persistencia de las características de precariedad y no registración del trabajo constituye un rasgo estructural (no coyuntural) de la dinámica de acumulación. Se busca describir y caracterizar las modalidades del trabajo precario; explorar la composición que reviste el trabajo no registrado en el sector privado y estimar la dimensión y composición de la precariedad laboral en el sector público. No obstante, su abordaje se presenta como un complejo camino de acercamientos debido a la dificultad en el acceso a la información requerida.Fil: Bertolotti, María Florencia.Fil: Cortese, Carmelo.Fil: Raía, Laura

    Les services écosystémiques des marais collatéraux dans les bassins urbains de plaine : propositions pour leur gestion et leur conservation

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    The city of La Plata, Argentina, is situated in a low alluvial zone, with streams having insufficient drainage into the Río de la Plata estuary. In April 2013, a prodigious storm front caused unprecedented flooding in the city and environs that resulted in extensive loss of life and property, especially in the Del Gato stream basin. Through an analysis of water quality and the conditions of the habitat on the basis of the macroinvertebrates present as bioindicators of environmental quality, this work aims to contribute to a reevaluation of the role of the marshes adjacent to the stream as flood-alleviation elements, and then propose alternatives for flooding management in the basin. Consequently, quantitative seasonal samples of vegetation, sediments, and benthic organic matter were taken and limnologic parameters measured in three sectors of the basin having different land uses: rural, periurban, and urban-industrial. The macroinvertebrate assemblages, as analyzed through the application of ecological indices, exhibited a marked decline in richness and in the Pampean Biotic Index towards the low-lying basin. Principalcomponents analysis associated Site 1 with the dissolved-oxygen concentration, Site 2 with high nitrate values, and Site 3 with oxygen demands. Redundancy analysis indicated a positive relationship between Baetidae and Aeolosomatidae with the dissolved-oxygen concentration and between Enchytraeidae and Stratiomyidae with the conductivity. These marshes are fundamental in maintaining good environmental conditions and attenuating the effects of the flooding that is predicted to become increasingly catastrophic in this region as the climate changes.La ville de La Plata, en Argentine, est située dans une zone alluvionnaire, avec des cours d’eau ayant un écoulement insuffisant dans l’estuaire du Río de la Plata. En avril 2013, un front de tempête exceptionnel a causé des inondations sans précédent dans la ville et dans les environs, qui a entraîné des pertes en vie humaine et en propriétés, en particulier dans le bassin de Del Gato. Grâce à une analyse de la qualité de l’eau et des conditions de l’habitat sur la base des macroinvertébrés présents en tant que bioindicateurs de la qualité de l’environnement, ce travail vise à contribuer à une réévaluation du rôle des marais adjacents à la rivière en tant qu’éléments d’atténuation des inondations et propose ensuite des solutions alternatives pour la gestion des inondations dans le bassin. Simultanément des échantillons saisonniers quantitatifs de végétation, de sédiments et de matières organiques benthiques ont été pris et des paramètres limnologiques mesurés dans trois secteurs du bassin ayant des utilisations de terres différentes : rurales, périurbaines et urbaines-industrielles. Les différences de macroinvertébrés, analysées par l’application d’indices écologiques, ont montré un déclin marqué de la richesse et de l’indice biotique Pampean vers l’aval. L’analyse en composantes principales associe le site 1 avec la concentration en oxygène dissous, le site 2 avec des valeurs élevées de nitrate et le site 3 avec des demandes en oxygène. L’analyse de redondance a indiqué une relation positive des Baetidae et Aeolosomatidae avec la concentration en oxygène dissous et des Enchytraeidae et Stratiomyidae avec la conductivité. Ces marais sont fondamentaux pour maintenir de bonnes conditions environnementales et atténuer les effets des inondations qui devraient devenir de plus en plus catastrophiques dans cette région à mesure que le climat change.Facultad de Ciencias Naturales y Muse

    Angiostrongylus vasorum: Epidemiological, clinical and histopathological insights

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    Background: Canine angiostrongylosis is a nematode infection in domestic dogs and wild carnivores. The present report focuses on epidemiological, clinical and histopathological findings in a case of fatal disseminated angiostrongylosis in a dog living in southern Italy and provides data on the extent of the spread of Angiostrongylus vasorum in the same area.Case presentation: A 4-year-old female English Setter from the Campania region of southern Italy was referred with a 2-week history of cough and severe respiratory distress that did not respond to antimicrobial therapy. Based on clinical, radiological, echographical and cytological findings (including the presence of larvae), a suspect diagnosis of lungworm infection was performed. After few days the dog died due to progressive clinical aggravation. Complete postmortem examination was conducted within 24 hours from death and samples from lungs, heart, liver, kidney, spleen, stomach and small intestine were fixed in 10% buffered formalin. Grossly, several hemorrhagic foci were observed mostly in the lungs, liver, kidney. Microscopically, the lungs contained numerous, multifocal to coalescing granulomas composed of epitheliod macrophages, multinucleated giant cells and some neutrophils, frequently associated with parasite eggs and larvae. The lungs contained many firm nodules, many adult nematodes approximately 1.5 to 2 cm in length were observed in cut sections and identified as A. vasorum. A subsequent parasitological survey performed with FLOTAC on stray dogs living in the same area showed the presence of A. vasorum larvae in 17 of 1639 stray dogs examined (1.04%).Conclusion: This survey provides new data on distribution of A. vasorum and underlines that canine angiostrongylosis should be considered as differential diagnosis in dogs

    Antimicrobial Resistant Staphylococcus Species Colonization in Dogs, Their Owners, and Veterinary Staff of the Veterinary Teaching Hospital of Naples, Italy

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    This study aimed to identify Staphylococcus species isolated from nasal swabs of both healthy and diseased dogs, and those of human origin, obtained from nasal swabs of both owners and veterinary staff. Firstly, pet owners were requested to complete a questionnaire relating to the care and relationship with their pets, whose results mainly showed a statistically significant higher frequency of hand washing in diseased dogs’ owners than in healthy dogs’ owners. Canine nasal swabs were obtained from 43 diseased dogs and 28 healthy dogs, while human nasal swabs were collected from the respective dogs’ owners (71 samples) and veterinary staff (34 samples). The isolation and identification of Staphylococcus spp. were followed by disk diffusion method to define the antimicrobial resistance profiles against 18 different molecules. Staphylococcus pseudintermedius was the most frequent isolated strain in both diseased (33.3%) and healthy (46.1%) dogs. Staphylococcus epidermidis was the most frequent isolated bacterium in diseased dogs’ owners (66.6%), while in nasal samples of healthy dogs’ owners, the same frequency of isolation (38.4%) was observed for both Staphylococcus epidermidis and Staphylococcus aureus. All the isolated strains showed good susceptibility levels to the tested antimicrobials; however, the carriage of oxacillin-resistant strains was significantly higher in diseased dogs than in healthy ones (71% and 7.7%, respectively). Only in three cases the presence of the same bacterial species with similar antimicrobial resistance profiles in dogs and their owners was detected, suggesting the potential bacterial transmission. In conclusion, this study suggests potential transmission risk of staphylococci from dogs to humans or vice versa, and highlights that the clinical relevance of Staphylococcus pseudintermedius transmission from dog to human should not be underestimated, as well as the role of Staphylococcus aureus from human to dog transmission

    Precarización laboral en Mendoza en el marco del nuevo modelo productivo

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    Fil: Bauzá, Javier. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y SocialesFil: Carabaca, Carla. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y SocialesFil: Cortese, Carmelo. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y SocialesFil: Jiménez, Miguel. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y SocialesFil: Perelli, Paula. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y SocialesFil: Raía, Laura. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y SocialesFil: Rojo, Ricardo. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y Sociale

    The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) III. The Ultraviolet Source Catalogs

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    In this paper we introduce the deepest and most extensive ultraviolet extragalactic source catalogs of the Virgo Cluster area to date. Archival and targeted GALEX imaging is compiled and combined to provide the deepest possible coverage over ~120 deg^2 in the NUV (lambda_eff=2316 angstroms) and ~40 deg^2 in the FUV (lambda_eff=1539 angstroms) between 180 deg <= R.A. <= 195 deg and 0 deg <= Decl. <= 20 deg. We measure the integrated photometry of 1770 extended UV sources of all galaxy types and use GALEX pipeline photometry for 1,230,855 point-like sources in the foreground, within, and behind the cluster. Extended source magnitudes are reliable to m_UV ~22, showing ~0.01 sigma difference from their asymptotic magnitudes. Point-like source magnitudes have a 1 sigma standard deviation within ~0.2 mag down to m_uv ~23. The point-like source catalog is cross-matched with large optical databases and surveys including the SDSS DR9 (> 1 million Virgo Cluster sources), the Next Generation Virgo Cluster Survey (NGVS; >13 million Virgo Cluster sources), and the NED (~30,000 sources in the Virgo Cluster). We find 69% of the entire UV point-like source catalog has a unique optical counterpart, 11% of which are stars and 129 are Virgo cluster members neither in the VCC nor part of the bright CGCG galaxy catalog (i.e., m_pg < 14.5). These data are collected in four catalogs containing the UV extended sources, the UV point-like sources, and two catalogs each containing the most relevant optical parameters of UV-optically matched point-like sources for further studies from SDSS and NGVS. The GUViCS catalogs provide a unique set of data for future works on UV and multiwavelength studies in the cluster and background environments.Comment: 35 pages, 24 figures, 15 tables, Accepted for publication in A&

    Neonatal inhibition of DNA methylation disrupts testosterone-dependent masculinization of neurochemical phenotype

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    Many neural sex differences are differences in the number of neurons of a particular phenotype. For example, male rodents have more calbindin-expressing neurons in the medial preoptic area (mPOA) and bed nucleus of the stria terminalis (BNST), and females have more neurons expressing estrogen receptor alpha (ERα) and kisspeptin in the ventromedial nucleus of the hypothalamus (VMH) and the anteroventral periventricular nucleus (AVPV), respectively. These sex differences depend on neonatal exposure to testosterone, but the underlying molecular mechanisms are unknown. DNA methylation is important for cell phenotype differentiation throughout the developing organism. We hypothesized that testosterone causes sex differences in neurochemical phenotype via changes in DNA methylation, and tested this by inhibiting DNA methylation neonatally in male and female mice, and in females given a masculinizing dose of testosterone. Neonatal testosterone treatment masculinized calbindin, ERα and kisspeptin cell number of females at weaning. Inhibiting DNA methylation with zebularine increased calbindin cell number only in control females, thus eliminating sex differences in calbindin in the mPOA and BNST. Zebularine also reduced the sex difference in ERα cell number in the VMH, in this case by increasing ERα neuron number in males and testosterone-treated females. In contrast, the neonatal inhibition of DNA methylation had no effect on kisspeptin cell number. We conclude that testosterone normally increases the number of calbindin cells and reduces ERα cells in males through orchestrated changes in DNA methylation, contributing to, or causing, the sex differences in both cell types.Fil: Cisternas, Carla Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Cortese, Maria Laura. Georgia State University; Estados UnidosFil: Golynker, Ilona. Georgia State University; Estados UnidosFil: Castillo-Ruiz, Alexandra. Georgia State University; Estados UnidosFil: Forger, Nancy G.. Georgia State University; Estados Unido
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