959 research outputs found

    Effect of Threonine and the Bioactive Component of Saccharomyces Cerevisiae on the Productive Performance of the Broiler Cobb 500

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    This study was conducted in Chimborazo province, Riobamba Canton to evaluate the effect of threonine and the bioactive component of Saccharomyces cerevisiae on the productive performance of the broiler Cobb 500. A total of 270 one-day-old broiler chicken of both sexes were included, which corresponded to an experimental unit size of 15 birds. Two growth promoters were used for the treatments -- T1: Threonine (aminoacid) 200 g/Tn; and T2: bioactive oligosaccharides, obtained from the cell wall of selected strains of S. Cerevisiae (probiotic) 750 g/Tn. These were compared to a control group. The data were analyzed through Analysis of Variance (ADEVA). The separation of means was performed using the Tukey statistic at a level of significance of p < 0.05 and p < 0.01. The data were processed using the Infostat software version 2010. The results showed that the best productive yields were with treatment 2; the values for this treatment were: weight at 28 days: 1369.42 g; weight gain at 28 days: 48.90 g; food conversion at 28 days: 1.39 points; carcass weight: 2527.05 g; and yield to the carcass: 83.85%. Through the economic analysis, it was determined that the highest cost-benefit index was 1.30 USD with the application of T2. So according to the results, a better use of the nutrients that are present in the feed is achieved when bioactive components of S. cerevisiae are supplied in the diet of broiler chickens. Keywords: Threonine, Saccharomyces cerevisiae, productive performance, broiler, Cobb 500. RESUMEN Se realizó un experimento en la provincia de Chimborazo, Cantón Riobamba, para evaluar los efectos de treonina y componentes bioactivos de Saccharomyces cerevisiae sobre el comportamiento productivo en aves Cobb 500. Se utilizaron 270 pollitos mixtos Cobb 500 de un día de edad de ambos sexos, con un tamaño de unidad experimental de 15 aves. Para los tratamientos se manejaron dos promotores de crecimiento, T1: Treonina (aminoácido) 200 g/Tn y T2: Oligosacáridos bioactivos, obtenidos a partir de la pared celular de cepas seleccionadas de S. Cerevisiae750 g/Tn; frente a un testigo (T0). Los datos obtenidos fueron sometidos a Análisis de Varianza (ADEVA); la separación de medias se realizó mediante el estadístico Tukey a un nivel de significancia (p < 0,05) y (p < 0,01); los datos se procesaron mediante el software Infostat versión 2010. Los resultados muestran los mejores rendimientos productivos con el Tratamiento 2, para los parámetros: peso a los 28 días 1369,42 g; ganancia de peso a los 28 días 48,90 g; y conversión alimenticia a los 28 días con 1,39 puntos; así como peso a la canal 2527,05 g; y rendimiento a la canal 83,85%. Mediante el análisis económico se determinó que el mayor índice beneficio costo fue de 1,30 USD con la aplicación del T2. Lo que brinda un indicativo que mediante el suministro de componentes bioactivos de S. cerevisiae en la dieta de pollos broiler, se logra un mejor aprovechamiento de los nutrientes que se encuentran presentes en el alimento, lo que se refleja en los parámetros productivos. Palabras clave: treonina, Saccharomyces cerevisiae, comportamiento productivo, broilers, Cobb 500

    Variabilidad espacial de las propiedades físicas de un suelo Fluventic Ustropepts en la cuenca baja del río Las Ceibas - Huila

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    Se estudió la variabilidad espacial de algunas propiedades físicas del suelo asociadas a cultivos de caña, pasto y moringa en un “Fluventic Ustropepts” de la Cuenca baja del Rio Las Ceibas. Se hizo muestreo con grilla de 50 m x 50 m en 26 puntos para los análisis físicos, 8 pruebas de infiltración en muestreo aleatorio simple y 3 muestras integradas para análisis químicos en un área de 6.5 ha. El estudio consta de 5 etapas: 1) recolección de muestras y análisis de las propiedades físicas y químicas del suelo, 2) análisis estadístico y descriptivo de las variables usando los software Statgraphic Centurión XVIII y Excel 2010, 3) análisis geoestadístico basado en la interpolación por el método Kriging con software GS+10, 4) análisis multivariado de las componentes principales generando un gráfico bidimensional (biplot) con InfoStat y 5) elaboración de mapas de variabilidad espacial de las propiedades físicas del suelo por medio de software Surfer 10 para la implementación del plan de cultivos y los mapas de uso del suelo, por medio de los software ArcGis 10. La infiltración del suelo resultó extremadamente heterogénea con un coeficiente de variación del 74,5% y dependencia moderada con rango de alcance de 610,9 m. Se delimitaron tres sectores para los cultivos mencionados, basados en los análisis del suelo según el uso potencial del suelo

    Variaciones en el número y función de los linfocitos asesinos naturales durante infecciones recurrentes o graves

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    Introduction: The information about defects affecting natural killer cell (NK) development and activity in patients with an abnormal increase of recurrent infections is scarce.Objective: To perform a systematic analysis of NK abnormalities in patients with recurrent infections.Materials and methods: Our study enrolled twenty patients with severe or recurrent viral infections. Natural killer cell subsets, surface receptors expression and cytotoxicity were analyzed. Results were compared with those from age- and sex-matched healthy controls.Results: Transient alterations were observed in the percentages and absolute numbers of NK cells in patients with infection active episodes. We also described five patients with stable disturbances in the distribution of NK cell subpopulations. These defects are mainly due to a decrease in the CD56dimCD16bright cells in peripheral blood. In addition, NK cell function abnormalities were observed in some patients, however, those were always transient and mainly associated to active disease.Conclusions: These findings demonstrate transient alterations in the percentages and absolute numbers of NK cells in patients with recurrent or severe infection. Also, stable disturbances in CD56dimCD16bright NK cells are observed in these patients. Nevertheless, these parameters must be thoroughly studied to determine the mechanisms that entail these immune abnormalities and investigate how they alter the immune response.Introducción. Existen pocos datos sobre los defectos que afectan el desarrollo y función de los linfocitos asesinos naturales (natural killers, NK) en pacientes con un incremento anormal en la recurrencia de infecciones.Objetivo. Realizar una evaluación sistemática de las diferentes subpoblaciones y la función de estas células en pacientes con infecciones recurrentes.Materiales y métodos. Se incluyeron 20 pacientes con infecciones graves o recurrentes y se analizaron las subpoblaciones y la respuesta citotóxica de los linfocitos NK en sangre periférica. Los resultados de los pacientes se compararon con controles sanos pareados por edad y sexo.Resultados. Los pacientes con episodios infecciosos activos presentaron anormalidades transitorias en el porcentaje o el número absoluto de linfocitos NK. Se caracterizaron, además, cinco pacientes con alteraciones persistentes en la distribución de las subpoblaciones de linfocitos NK. Estas alteraciones se debieron principalmente a la disminución de células CD56dimCD16bright. Se evidenciaron, también, defectos en la función de los linfocitos NK en algunos de nuestros pacientes; sin embargo, estas alteraciones fueron transitorias y se asociaron principalmente a la fase activa de la enfermedad.Conclusiones. Nuestros resultados evidencian defectos transitorios en el número y función de los linfocitos NK en pacientes con infecciones recurrentes o graves, además de alteraciones persistentes en los LNK CD56dimCD16bright en algunos individuos. Es necesario profundizar en los mecanismos que conllevan al desarrollo de estos defectos inmunes y estudiar cómo estas alteraciones influyen en la respuesta inmune

    Plaque-Associated Oligomeric Amyloid-Beta Drives Early Synaptotoxicity in APP/PS1 Mice Hippocampus: Ultrastructural Pathology Analysis

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    Alzheimer’s disease (AD) is a devastating neurodegenerative disorder characterized by initial memory impairments that progress to dementia. In this sense, synaptic dysfunction and loss have been established as the pathological features that best correlate with the typical early cognitive decline in this disease. At the histopathological level, post mortem AD brains typically exhibit intraneuronal neurofibrillary tangles (NFTs) along with the accumulation of amyloid-beta (Abeta) peptides in the form of extracellular deposits. Specifically, the oligomeric soluble forms of Abeta are considered the most synaptotoxic species. In addition, neuritic plaques are Abeta deposits surrounded by activated microglia and astroglia cells together with abnormal swellings of neuronal processes named dystrophic neurites. These periplaque aberrant neurites are mostly presynaptic elements and represent the first pathological indicator of synaptic dysfunction. In terms of losing synaptic proteins, the hippocampus is one of the brain regions most affected in AD patients. In this work, we report an early decline in spatial memory, along with hippocampal synaptic changes, in an amyloidogenic APP/PS1 transgenic model. Quantitative electron microscopy revealed a spatial synaptotoxic pattern around neuritic plaques with significant loss of periplaque synaptic terminals, showing rising synapse loss close to the border, especially in larger plaques. Moreover, dystrophic presynapses were filled with autophagic vesicles in detriment of the presynaptic vesicular density, probably interfering with synaptic function at very early synaptopathological disease stages. Electron immunogold labeling showed that the periphery of amyloid plaques, and the associated dystrophic neurites, was enriched in Abeta oligomers supporting an extracellular location of the synaptotoxins. Finally, the incubation of primary neurons with soluble fractions derived from 6-month-old APP/PS1 hippocampus induced significant loss of synaptic proteins, but not neuronal death. Indeed, this preclinical transgenic model could serve to investigate therapies targeted at initial stages of synaptic dysfunction relevant to the prodromal and early AD.This study was supported by the Instituto de Salud Carlos III (ISCiii) of Spain, co-financed by the FEDER funds from European Union, through grants PI18/01557 (to AG) and PI18/01556 (to JV); by the Junta de Andalucia Consejería de Economía y Conocimiento through grants UMA18-FEDERJA-211 (to AG), P18-RT-2233 (to AG), and US-1262734 (to JV) co-financed by Programa Operativo FEDER 2014–2020; by the Spanish Minister of Science and Innovation grant PID2019-108911RA-100 (to DB-V), Beatriz Galindo program BAGAL18/00052 (to DB-V) grant PID2019-107090RA-I00 (to IM-G), and Ramon y Cajal Program RYC-2017-21879 (to IM-G); and by the Malaga University grants B1-2019_07 (to ES-M) and B1-2019_06 (to IM-G). MM-O held a predoctoral contract from Malaga University and ES-M a postdoctoral contract (DOC_00251) from Junta de Andalucia

    LEMUR: Large European Module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission

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    Understanding the solar outer atmosphere requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1" and 0.3"), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 17 and 127 nm. The LEMUR slit covers 280" on the Sun with 0.14" per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km/s or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission.Comment: 35 pages, 14 figures. To appear on Experimental Astronom

    Animal and Cellular Models of Alzheimer’s Disease: Progress, Promise, and Future Approaches

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    Alzheimer’s disease (AD) is an incurable neurodegenerative disease affecting over 45 million people worldwide. Transgenic mouse models have made remarkable contributions toward clarifying the pathophysiological mechanisms behind the clinical manifestations of AD. However, the limited ability of these in vivo models to accurately replicate the biology of the human disease have precluded the translation of promising preclinical therapies to the clinic. In this review, we highlight several major pathogenic mechanisms of AD that were discovered using transgenic mouse models. Moreover, we discuss the shortcomings of current animal models and the need to develop reliable models for the sporadic form of the disease, which accounts for the majority of AD cases, as well as human cellular models to improve success in translating results into human treatments.Peer reviewe
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