2,913 research outputs found

    Caracterización de las heladas en la región pampeana y su variabilidad en los últimos 10 años

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    p.247-257Conocer las fechas medias de primera y última helada, así como la duración del período con heladas y sus corrimientos a través del tiempo, es de fundamental importancia al momento de tomar decisiones respecto de los calendarios agrícolas de una región. El objetivo de este trabajo es estudiar las características del régimen de heladas para el periodo 1964-1993 denominado normal es una vasta zona de la Región Pampeana y las anomalías producidas en la última década. Se observó una disminución del período con heladas en casi toda la región, y únicamente en el sur de la provincia de Buenos Aires un aumento. En general, la fecha de primera helada tuvo mayor corrimiento que la fecha de última, generando un corrimiento del período con heladas hacia la primavera

    Mild and short-term caloric restriction prevents obesity-induced cardiomyopathy in young zucker rats without changing in metabolites and fatty acids cardiac profile

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    Caloric restriction (CR) ameliorates cardiac dysfunction associated with obesity. However, most of the studies have been performed under severe CR (30-65% caloric intake decrease) for several months or even years in aged animals. Here, we investigated whether mild (20% food intake reduction) and short-term (2-weeks) CR prevented the obese cardiomyopathy phenotype and improved the metabolic profile of young (14 weeks of age) genetically obese Zucker fa/fa rats. Heart weight (HW) and HW/tibia length ratio was significantly lower in fa/fa rats after 2 weeks of CR than in counterparts fed ad libitum. Invasive pressure measurements showed that systolic blood pressure, maximal rate of positive left ventricle (LV) pressure, LV systolic pressure and LV end-diastolic pressure were all significantly higher in obese fa/fa rats than in lean counterparts, which were prevented by CR. Magnetic resonance imaging revealed that the increase in LV end-systolic volume, stroke volume and LV wall thickness observed in fa/fa rats was significantly lower in animals on CR diet. Histological analysis also revealed that CR blocked the significant increase in cardiomyocyte diameter in obese fa/fa rats. High resolution magic angle spinning magnetic resonance spectroscopy analysis of the LV revealed a global decrease in metabolites such as taurine, creatine and phosphocreatine, glutamate, glutamine and glutathione, in obese fa/fa rats, whereas lactate concentration was increased. By contrast, fatty acid concentrations in LV tissue were significantly elevated in obese fa/fa rats. CR failed to restore the LV metabolomic profile of obese fa/fa rats. In conclusion, mild and short-term CR prevented an obesity-induced cardiomyopathy phenotype in young obese fa/fa rats independently of the cardiac metabolic profile.This study was supported by grants from Spanish Ministry of Science and Innovation (BFU2011-25303), Spanish Institute of Health Carlos III (CP15/00129), UCM groups (GR-921641), SESCAMET, Fundación Mutua Madrileña, Fundación Eugenio Rodríguez Pascual and Fondos FEDER.Peer Reviewe

    Design and validation of the INCUE questionnaire: assessment of primary healthcare nurses’ basic training needs in palliative care

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    Many instruments have been created to measure knowledge and attitudes in palliative care. However, not only is it important to acquire knowledge, but also that this knowledge should reach patients and their relatives through application in clinical practice. This study aimed to develop and psychometrically test the INCUE questionnaire (Investigación Cuidados Enfermeros/Investigation into Nurses’ Care Understanding of End-of-Life) to assess the basic training needs of primary or home healthcare nurses in palliative care. A questionnaire was developed based on the classical theory of tests and factor analysis models. Initially, 18 experts developed 67 items in two blocks and determined content validity by two rounds of expert panels. Exploratory factor analysis and reliability testing were conducted with a non-probabilistic sample of 370 nurses. Some items were observed to have very low homogeneity indices or presented convergence problems and were eliminated. Questionnaire reliability was 0.700 in the theoretical block (KR20 Index) and 0.941 in the practical block (Cronbach’s alpha). The model converges and shows an adequate fit, specifically CFI = 0.977, TLI = 0.977 and RMSEA = 0.05. The correlation between the two factors in the model is ρ = 0.63. The questionnaire objectively evaluates primary or home healthcare nurses’ knowledge of palliative care and its practical application, thereby facilitating more efficient training plans

    Reconstrucción de defectos óseos segmentarios postraumáticos mediante técnica de inducción de membrana

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    Objetivos: Describir y evaluar los resultados del tratamiento quirúrgico de defectos óseos postraumáticos (DOPT) segmentarios mediante técnica de inducción de membrana. Material y métodos: Estudio descriptivo longitudinal de 20 casos de DOPT segmentarios tratados en el Hospital Nacional Cayetano Heredia de Lima, desde enero de 2009 a junio de 2014, mediante reconstrucción en dos etapas con técnica de inducción de membrana. En la primera etapa se indujo la formación de membrana con un espaciador de cemento óseo impregnado con antibiótico. En la segunda etapa se reemplazó el espaciador por injerto óseo. Se evaluó el tiempo de consolidación, grado de acortamiento de la extremidad y resultado funcional. Se registraron las complicaciones. Resultados: Se incluyeron 20 pacientes (15 varones y 5 mujeres), con edad promedio de 29 años (rango: 13-54). Once casos fueron DOPT en tibia, 7 casos en fémur, uno en radio y uno en cúbito. El 90% de los DOPT fueron en longitud mayor o igual a 50 mm, con un promedio de 73 mm; 60% de los casos tenían cultivos positivos al inicio del tratamiento. Presentaron consolidación el 90% de los casos con un único aporte de injerto óseo, el tiempo promedio para la consolidación fue 8 meses. Uno requirió un segundo aporte de injerto y un caso presentó persistencia de infección sin consolidación. Conclusiones: La técnica de inducción de membrana es un método eficaz para el tratamiento de DOPT segmentarios

    The ALHAMBRA survey: evolution of galaxy spectral segregation

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    We study the clustering of galaxies as a function of spectral type and redshift in the range 0.35<z<1.10.35 < z < 1.1 using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The data cover 2.381 deg2^2 in 7 fields, after applying a detailed angular selection mask, with accurate photometric redshifts [σz<0.014(1+z)\sigma_z < 0.014(1+z)] down to IAB<24I_{AB} < 24. From this catalog we draw five fixed number density, redshift-limited bins. We estimate the clustering evolution for two different spectral populations selected using the ALHAMBRA-based photometric templates: quiescent and star-forming galaxies. For each sample, we measure the real-space clustering using the projected correlation function. Our calculations are performed over the range [0.03,10.0]h1[0.03,10.0] h^{-1} Mpc, allowing us to find a steeper trend for rp0.2h1r_p \lesssim 0.2 h^{-1} Mpc, which is especially clear for star-forming galaxies. Our analysis also shows a clear early differentiation in the clustering properties of both populations: star-forming galaxies show weaker clustering with evolution in the correlation length over the analysed redshift range, while quiescent galaxies show stronger clustering already at high redshifts, and no appreciable evolution. We also perform the bias calculation where similar segregation is found, but now it is among the quiescent galaxies where a growing evolution with redshift is clearer. These findings clearly corroborate the well known colour-density relation, confirming that quiescent galaxies are mainly located in dark matter halos that are more massive than those typically populated by star-forming galaxies.Comment: 14 pages, 9 figures, accepted by Ap

    The ALHAMBRA survey : BB-band luminosity function of quiescent and star-forming galaxies at 0.2z<10.2 \leq z < 1 by PDF analysis

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    Our goal is to study the evolution of the BB-band luminosity function (LF) since z=1z=1 using ALHAMBRA data. We used the photometric redshift and the II-band selection magnitude probability distribution functions (PDFs) of those ALHAMBRA galaxies with I24I\leq24 mag to compute the posterior LF. We statistically studied quiescent and star-forming galaxies using the template information encoded in the PDFs. The LF covariance matrix in redshift-magnitude-galaxy type space was computed, including the cosmic variance. That was estimated from the intrinsic dispersion of the LF measurements in the 48 ALHAMBRA sub-fields. The uncertainty due to the photometric redshift prior is also included in our analysis. We modelled the LF with a redshift-dependent Schechter function affected by the same selection effects than the data. The measured ALHAMBRA LF at 0.2z<10.2\leq z<1 and the evolving Schechter parameters both for quiescent and star-forming galaxies agree with previous results in the literature. The estimated redshift evolution of MBQzM_B^* \propto Qz is QSF=1.03±0.08Q_{\rm SF}=-1.03\pm0.08 and QQ=0.80±0.08Q_{\rm Q}=-0.80\pm0.08, and of logϕPz\log \phi^* \propto Pz is PSF=0.01±0.03P_{\rm SF}=-0.01\pm0.03 and PQ=0.41±0.05P_{\rm Q}=-0.41\pm0.05. The measured faint-end slopes are αSF=1.29±0.02\alpha_{\rm SF}=-1.29\pm0.02 and αQ=0.53±0.04\alpha_{\rm Q}=-0.53\pm0.04. We find a significant population of faint quiescent galaxies, modelled by a second Schechter function with slope β=1.31±0.11\beta=-1.31\pm0.11. We find a factor 2.55±0.142.55\pm0.14 decrease in the luminosity density jBj_B of star-forming galaxies, and a factor 1.25±0.161.25\pm0.16 increase in the jBj_B of quiescent ones since z=1z=1, confirming the continuous build-up of the quiescent population with cosmic time. The contribution of the faint quiescent population to jBj_B increases from 3% at z=1z=1 to 6% at z=0z=0. The developed methodology will be applied to future multi-filter surveys such as J-PAS.Comment: Accepted for publication in Astronomy and Astrophysics. 25 pages, 20 figures, 7 table

    The ALHAMBRA survey : Estimation of the clustering signal encoded in the cosmic variance

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    The relative cosmic variance (σv\sigma_v) is a fundamental source of uncertainty in pencil-beam surveys and, as a particular case of count-in-cell statistics, can be used to estimate the bias between galaxies and their underlying dark-matter distribution. Our goal is to test the significance of the clustering information encoded in the σv\sigma_v measured in the ALHAMBRA survey. We measure the cosmic variance of several galaxy populations selected with BB-band luminosity at 0.35z<1.050.35 \leq z < 1.05 as the intrinsic dispersion in the number density distribution derived from the 48 ALHAMBRA subfields. We compare the observational σv\sigma_v with the cosmic variance of the dark matter expected from the theory, σv,dm\sigma_{v,{\rm dm}}. This provides an estimation of the galaxy bias bb. The galaxy bias from the cosmic variance is in excellent agreement with the bias estimated by two-point correlation function analysis in ALHAMBRA. This holds for different redshift bins, for red and blue subsamples, and for several BB-band luminosity selections. We find that bb increases with the BB-band luminosity and the redshift, as expected from previous work. Moreover, red galaxies have a larger bias than blue galaxies, with a relative bias of brel=1.4±0.2b_{\rm rel} = 1.4 \pm 0.2. Our results demonstrate that the cosmic variance measured in ALHAMBRA is due to the clustering of galaxies and can be used to characterise the σv\sigma_v affecting pencil-beam surveys. In addition, it can also be used to estimate the galaxy bias bb from a method independent of correlation functions.Comment: Astronomy and Astrophysics, in press. 9 pages, 4 figures, 3 table

    In silico and In vitro analysis of MAP3773c protein from Mycobacterium avium subsp. Paratuberculosis

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    Paratuberculosis is a disease caused by Mycobacterium avium subsp. paratuberculosis (MAP). It is of great interest to better understand the proteins involved in the pathogenicity of this organism in order to be able to identify potential therapeutic targets and design new vaccines. The protein of interest–MAP3773c–was investigated, and molecular modeling in silico, docking, cloning, expression, purification, and partial characterization of the recombinant protein were achieved. In the in silico study, it was shown that MAP3773c of MAP has 34% sequence similarity with Mycobacterium tuberculosis (MTB) FurB, which is a zinc uptake regulator (Zur) protein. The docking data showed that MAP3773c exhibits two metal-binding sites. The presence of structural Zn2+ in the purified protein was confirmed by SDS-PAGE PAR staining. The purification showed one band that corresponded to a monomer, which was confirmed by liquid chromatography–mass spectrometry (LC-MS). The presence of a monomer was verified by analyzing the native protein structure through BN-SDS-PAGE (Native Blue (BN) Two-Dimensional Electrophoresis) and BN–Western blotting. The MAP3773c protein contains structural zinc. In conclusion, our results show that MAP3773c displays the features of a Fur-type protein with two metal-binding sites, one of them coordinating structural Zn2+

    Ipsilesional Hippocampal GABA Is Elevated and Correlates With Cognitive Impairment and Maladaptive Neurogenesis After Cortical Stroke in Mice.

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    BACKGROUND Cognitive dysfunction is a frequent stroke sequela, but its pathogenesis and treatment remain unresolved. Involvement of aberrant hippocampal neurogenesis and maladaptive circuitry remodeling has been proposed, but their mechanisms are unknown. Our aim was to evaluate potential underlying molecular/cellular events implicated. METHODS Stroke was induced by permanent occlusion of the middle cerebral artery occlusion in 2-month-old C57BL/6 male mice. Hippocampal metabolites/neurotransmitters were analyzed longitudinally by in vivo magnetic resonance spectroscopy. Cognitive function was evaluated with the contextual fear conditioning test. Microglia, astrocytes, neuroblasts, interneurons, γ-aminobutyric acid (GABA), and c-fos were analyzed by immunofluorescence. RESULTS Approximately 50% of mice exhibited progressive post-middle cerebral artery occlusion cognitive impairment. Notably, immature hippocampal neurons in the impaired group displayed more severe aberrant phenotypes than those from the nonimpaired group. Using magnetic resonance spectroscopy, significant bilateral changes in hippocampal metabolites, such as myo-inositol or N-acetylaspartic acid, were found that correlated, respectively, with numbers of glia and immature neuroblasts in the ischemic group. Importantly, some metabolites were specifically altered in the ipsilateral hippocampus suggesting its involvement in aberrant hippocampal neurogenesis and remodeling processes. Specifically, middle cerebral artery occlusion animals with higher hippocampal GABA levels displayed worse cognitive outcome. Implication of GABA in this setting was supported by the amelioration of ischemia-induced memory deficits and aberrant hippocampal neurogenesis after blocking pharmacologically GABAergic neurotransmission, an intervention which was ineffective when neurogenesis was inhibited. These data suggest that GABA exerts its detrimental effect, at least partly, by affecting morphology and integration of newborn neurons into the hippocampal circuits. CONCLUSIONS Hippocampal GABAergic neurotransmission could be considered a novel diagnostic and therapeutic target for poststroke cognitive impairment.S
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