Administración crónica del resveratrol como una molécula antienvejecimiento en hipocampo de ratas Wistar

"En el envejecimiento un organismo sufre una serie de modificaciones morfológicas, fisiológicas y bioquímicas. El envejecimiento cerebral se considera la principal causa de deterioro cognitivo y un factor de riesgo para desarrollar algún trastorno neurodegenerativo. Se han propuesto diversas teorías relacionadas con el envejecimiento, una de las más estudiadas es la relacionada al estrés oxidante. En este sentido la acumulación de radicales libres promueve la progresión de procesos oxidativos como la lipoperoxidación y el consecuente daño a las macromoléculas. Para contrarrestar este daño, el sistema antioxidante endógeno mantiene el estado homeostático en el organismo, sin embargo, con la edad la eficacia de este sistema disminuye y se requiere de apoyo externo mediante terapias preventivas como los antioxidantes exógenos. El resveratrol un importante antioxidante que ha demostrado funciones antienvejecimiento, por ello en este trabajo nos planteamos el objetivo de evaluar el efecto de la administración crónica con resveratrol sobre el daño celular asociado al envejecimiento en hipocampo de ratas Wistar"

Análisis de los factores restrictivos o limitantes para la conformación de los Clústeres en las MYPES des Sector Pesquero Artesanal en el Puerto de Chimbote en el año 2009

El objetivo principal de la presente investigación fue determinar los factores restrictivos o limitantes del Sector Pesquero Artesanal para la conformación de Clústeres de la Ciudad de Chimbóte, cuya problemática principal se enmarcó en aspectos principales tales como: La depredación de los productos hidrobiológicos, la contaminación del medio ambiente, la excesiva flota pesquera y como no, la informalidad y el desinterés por conformar redes de interrelación en este sector como los clústeres y la ya conocida diferencia entre el Sector Artesanal e industrial, tanto en su capacidad de bodega para la pesca, los volúmenes y diversidad de productos hidrobiológicos, como el precio de venta, entre otras, así mismo las embarcaciones extranjeras que entran a competir en el mercado. Considerando los antecedentes y toda la problemática respecto de las variables en estudio, esto nos conllevo a suponer que existen factores restrictivos o limitantes para la conformación de Clústeres Pesqueros Artesanales. Con la finalidad de lograr el objetivo mencionado inicialmente y dar solución a la problemática se diseñó instrumentos de investigación -Cuestionarios. Ver anexo- los cuales fueron validados en base a métodos científicos permitiéndonos así medir los factores restrictivos o limitantes de las MYPES del Sector Pesquero Artesanal, así como de la predisposición para la conformación en Clústeres, obteniéndose entre los principales resultados lo siguiente: Los factores limitantes o restrictivos que presentan las Mypes del sector pesquero artesanal, son en su gran mayoría el desconocimiento de los beneficios o ventajas de la asocian de tipo clúster, así mismo la falta de información para tener acceso a los organismos de apoyo y el carácter individual de los dueños. Estos resultados se sometieron a la prueba Chi Cuadrado, la cual nos permitió demostrar científicamente la relación existente entre las variables de estudio (Factores restrictivos y predisposición para la conformación del Sector Pesquero Artesanal en Clústeres), contribuyendo de esta manera a que el sector considere la problemática principal y tome las decisiones pertinentes considerando como una alternativa de solución la conformación en Clústeres

Big data en educación: tipologías de los estudiantes a partir del estudio de las interacciones dentro del triángulo pedagógico

Fac. de Comercio y TurismoFALSEsubmitte

SHREC’20 Track:Retrieval of digital surfaces with similar geometric reliefs

International audienceThis paper presents the methods that have participated in the SHREC'20 contest on retrieval of surface patches with similar geometric reliefs and 1 the analysis of their performance over the benchmark created for this challenge. The goal of the context is to verify the possibility of retrieving 3D models only based on the reliefs that are present on their surface and to compare methods that are suitable for this task. This problem is related to many real world applications, such as the classification of cultural heritage goods or the analysis of different materials. To address this challenge, it is necessary to characterize the local "geometric pattern" information, possibly forgetting model size and bending. Seven groups participated in this contest and twenty runs were submitted for evaluation. The performances of the methods reveal that good results are achieved with a number of techniques that use different approaches

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E$^{-2}$ shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E$^{-2}$ be able to explain the observations