Brachiaria decumbens y fotosensibilización.

Evaluaciones de campo y laboratorio fueron realizadas en bovinos consumiendo Brachiaria decumbens bajo condiciones naturales y experimentales. En condiciones naturales se observaron signos de fotosensibilización, hemoglobinuria e ictericia, compatibles con daño hepático y disfunción renal. Experimentalmente se obtuvieron cambios detectables con laboratorio clínico, que indicaron marcada disfunción hepática y en menor grado renal. La histología bajo las dos condiciones de observación, mostró cambios de diversa intensidad de parénquima hepático y renal, e indicios de depresión en la hematopoyesis. Por los hallazgos descritos, Brachiaria decumbens fue hepatotóxico, con efectos clínicos y anatomopatológicos comparables a toxicidad, producida por la Brachiaria sp. (Tanner grass), Brachiaria brizantha y Tribulus terrestrisMaestría en CienciasMaestrí

Diagnóstico y alternativas de control al problema de la mortalidad bovina en un área del departamento del Vichada.

Se presenta un estudio que trata de identificar las posibles causas de la presencia de un síndrome que afecta generalmente a vacas paridas de ganado de carne, que se caracteriza en términos generales por: aislamiento del animal al apartarse de la manada, ataxia del tren anterior y, o del tren posterior, decúbito sin pérdida de apetito y posteriormente muerte, proceso que puede durar entre 7 y 25 días. El estudio se realizó en la altillanura del Vichada, entre noviembre de 1994 y octubre de 1995, período en el cual se recolectó información de 10 fincas, con muestreo de suelos de sabanas con bovinos en pastoreo, forrajes de sabana como oferta nutritiva y en 6 predios se tomaron muestras de sangre a terneros, novillas y vacas en época de verano e invierno. En las muestras de suelo se determinó análisis físico químico completo, en el forraje se analizó: proteina cruda, fibra detergente neutro, degradabilidad ruminal a las 48 horas, minerales en materia seca. En los sueros de bovinos se determinaron: colesterol, Ca, P, Fe, Mg, proteinas, albúmina y globulinas. Se determinaron diferencias significativas en análisis de suelo por época del año y por localidad. En los análisis foliares, diferencias significativas según época del año. En sueros bovinos, diferencias significativas para hemoglobina, hematocrito, globulinas, entre terneros, novillas y vacas, siendo el último grupo el más crítico. Se sugiere la producción de sal mineralizada que supla deficiencias minerales, suministro contínuo de ésta, mejoramiento en disponibilidad de proteina y energía para mejorar eficiencia productiv

The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V

The eighteenth data release (DR18) of the Sloan Digital Sky Survey (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs or “Mappers”: the Milky Way Mapper (MWM), the Black Hole Mapper (BHM), and the Local Volume Mapper. This data release contains extensive targeting information for the two multiobject spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration and scientifically focused components. DR18 also includes ∼25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field. © 2023. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Diminishing benefits of urban living for children and adolescents’ growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified. © 2023, The Author(s)