108 research outputs found

    Influence of Feeding Enzymatically Hydrolyzed Yeast Cell Wall on Growth Performance and Digestive Function of Feedlot Cattle during Periods of Elevated Ambient Temperature.

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    In experiment 1, eighty crossbred steers (239±15 kg) were used in a 229-d experiment to evaluate the effects of increasing levels of enzymatically hydrolyzed yeast (EHY) cell wall in diets on growth performance feedlot cattle during periods of elevated ambient temperature. Treatments consisted of steam-flaked corn-based diets supplemented to provide 0, 1, 2, or 3 g EHY/hd/d. There were no effects on growth performance during the initial 139-d period. However, from d 139 to harvest, when 24-h temperature humidity index averaged 80, EHY increased dry matter intake (DMI) (linear effect, p<0.01) and average daily gain (ADG) (linear effect, p = 0.01). There were no treatment effects (p>0.10) on carcass characteristics. In experiment 2, four Holstein steers (292±5 kg) with cannulas in the rumen and proximal duodenum were used in a 4×4 Latin Square design experiment to evaluate treatments effects on characteristics of ruminal and total tract digestion in steers. There were no treatment effects (p>0.10) on ruminal pH, total volatile fatty acid, molar proportions of acetate, butyrate, or estimated methane production. Supplemental EHY decreased ruminal molar proportion of acetate (p = 0.08), increased molar proportion of propionate (p = 0.09), and decreased acetate:propionate molar ratio (p = 0.07) and estimated ruminal methane production (p = 0.09). It is concluded that supplemental EHY may enhance DMI and ADG of feedlot steers during periods of high ambient temperature. Supplemental EHY may also enhance ruminal fiber digestion and decrease ruminal acetate:propionate molar ratios in feedlot steers fed steam-flaked corn-based finishing diets

    Life cycle assessment of households in Santiago, Chile: Environmental hotspots and policy analysis

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    Indexación ScopusThe aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophica-tion. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/2071-1050/13/5/252

    Interrater reliability of qualitative ultrasound assessment of gastric content in the third trimester of pregnancy

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    Q1Q11018-1023Background Pulmonary aspiration of gastric contents in pregnant women undergoing general anaesthesia is one of the most feared complications in obstetric anaesthesia. Bedside gastric ultrasonography is a feasible imaging tool to assess the gastric content. The purpose of this study was to investigate the reliability of qualitative bedside assessment of the gastric content performed by anaesthesiologists on third trimester pregnant women. Methods Pregnant women (≥32 weeks gestational age) were randomized to undergo ultrasound (US) assessments of their stomach in a fasting state (>8 h), or after ingestion of clear fluids only, or solid food. Three anaesthesiologists trained in gastric ultrasonography performed the assessments using a low-frequency curved-array US transducer (5–2 MHz). Primary outcome of the study was the consistency of raters in diagnosing the correct status of the gastric content, which was used to determine the interrater reliability among the three anaesthesiologists. Secondary outcomes were overall proportion of correct and incorrect diagnoses and the specific proportions of correct diagnosis across the three gastric content groups. Results We analysed 32 pregnant women. The interrater reliability displayed a kappa statistic of 0.74 (bias corrected 95% CI: 0.68–0.84). The overall proportion of correct diagnosis was 87.5% (84 of 96). The odds of correct diagnosis for ‘solid contents' were 16.7 times the odds for ‘empty', and 14.3 times for ‘clear fluid'. Conclusions Our results show the consistency of the qualitative US assessment of gastric contents of pregnant women in the third trimester by anaesthesiologists. A kappa of 0.74 suggests substantial agreement in terms of interrater reliability for this diagnostic measurement

    Modelo para la optimización del costo de operación de un campo de pozos en acuíferos

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    Ramos-Arzola, L. C., Cabrera-Estupiñán, E., Molina-Pérez, D., Hernández-Valdés, A. O., & Marón-Domínguez, D. E. (mayo-junio, 2017). Modelo para la optimización del costo de operación de un campo de pozos en acuíferos. Tecnología y Ciencias del Agua, 8(3), 39-53. El componente de mayor costo en la producción de agua subterránea en un sistema de suministro (una vez que los pozos están construidos) es el bombeo de agua desde los pozos. En la presente contribución se propone un nuevo módulo en MADA (modelo de administración de acuíferos), que se basa en la inclusión de un modelo de simulaciónoptimización para la minimización del costo de operación en acuíferos. La propuesta utiliza un modelo de simulación bidimensional del flujo del agua subterránea (AQÜIMPE) basado en el método de los elementos finitos. Se emplea el enfoque matriz respuesta para vincular AQÜIMPE con un problema de programación cuadrática, que se resuelve empleando la función quadprog del asistente matemático MATLAB. Se aplica el modelo en la administración de la explotación del acuífero Cuenca Sur y se obtiene una política de explotación que permite un 15% de ahorro del costo de bombeo en relación con el costo de la explotación real del año 2007. Además, el patrón de explotación obtenido satisface un conjunto de restricciones de demanda, de niveles en el acuífero y de capacidad instalada en cada pozo de explotación

    PP2A is activated by cytochrome c upon formation of a diffuse encounter complex with SET/TAF-Iß

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    Intrinsic protein flexibility is of overwhelming relevance for intermolecular recognition and adaptability of highly dynamic ensemble of complexes, and the phenomenon is essential for the understanding of numerous biological processes. These conformational ensembles—encounter complexes—lack a unique organization, which prevents the determination of well-defined high resolution structures. This is the case for complexes involving the oncoprotein SET/template-activating factor-Iß (SET/TAF-Iß), a histone chaperone whose functions and interactions are significantly affected by its intrinsic structural plasticity. Besides its role in chromatin remodeling, SET/TAF-Iß is an inhibitor of protein phosphatase 2A (PP2A), which is a key phosphatase counteracting transcription and signaling events controlling the activity of DNA damage response (DDR) mediators. During DDR, SET/TAF-Iß is sequestered by cytochrome c (Cc) upon migration of the hemeprotein from mitochondria to the cell nucleus. Here, we report that the nuclear SET/TAF-Iß:Cc polyconformational ensemble is able to activate PP2A. In particular, the N-end folded, globular region of SET/TAF-Iß (a.k.a. SET/TAF-Iß ¿C)—which exhibits an unexpected, intrinsically highly dynamic behavior—is sufficient to be recognized by Cc in a diffuse encounter manner. Cc-mediated blocking of PP2A inhibition is deciphered using an integrated structural and computational approach, combining small-angle X-ray scattering, electron paramagnetic resonance, nuclear magnetic resonance, calorimetry and molecular dynamics simulations

    Evaluation of Mannan oligosaccharides (MOS) in balanced diets for tropical gar juveniles (Atractosteus tropicus)

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    Antecedentes: Los prebióticos son polisacáridos no digestibles por el huésped, pero, por otro lado, son los encargados de estimular la actividad de microorganismos benéficos en el sistema digestivo, lo que puede maximizar la ganancia en peso, la conversión alimenticia y la activación de la respuesta inmune. Los oligosacáridos de manano (MOS) han sido evaluados en varias especies de peces de importancia comercial. Objetivos: Determinar el efecto de diferentes niveles de MOS integrados en dietas balanceadas para juveniles de Atractosteus tropicus sobre el crecimiento, parámetros productivos, supervivencia, índices somáticos y actividad de enzimas digestivas. Métodos: Se evaluaron por triplicado seis dietas experimentales con inclusión de MOS (0.0, 0.2, 0.4, 0.6 y 0.8%) y una dieta control de trucha (DC) durante 62 días. Se distribuyeron 180 juveniles (5.11 ± 0.08 g) en un sistema de recirculación con 18 tanques de 70 L con flujo de 10 L min-1. Resultados: La supervivencia en todos los tratamientos fue superior al 96%. La dieta 0.2% de MOS presentó los valores más altos en peso ganado (WG), tasa específica de crecimiento (SGR) y tasa de eficiencia proteínica (PER), y el menor valor en tasa de conversión alimenticia (FCR). El índice hepatosomático (HSI) fue mayor para el tratamiento 0.4%, mientras que el índice viscerosomático fue mayor para los tratamientos 0.4% y 0.6%. Todas las actividades enzimáticas determinadas mostraron diferencias entre tratamientos (proteasa ácida, proteasa alcalina, tripsina, quimotripsina, leucina aminopeptidasa, carboxipeptidasas, lipasas, α-amilasa, fosfatasas ácidas y fosfatasas alcalinas). Conclusiones: La suplementación de 0.2% de MOS en dietas para juveniles de A. tropicus genera beneficios en el crecimiento y el rendimiento productivo. La inclusión de MOS en dietas para juveniles de A. tropicus modifica los índices somáticos y la actividad de enzimas digestivas en juveniles.Background: Prebiotics are polysaccharides that cannot be digested by the host; however, they generate benefits by stimulating the activity of beneficial microorganisms in the digestive system, which can maximize weight gain, feed conversion, and stimulate the immune response. Mannan oligosaccharides (MOS) have been evaluated in several fish species of commercial importance. Goals: Determine inclusion effects of different MOS levels in balanced diets for juveniles of Atractosteus tropicus on the growth, productive parameters, survival, somatic indexes, and activity of digestive enzymes. Methods: Six experimental diets including MOS (0.0, 0.2, 0.4, 0.6, and 0.8%) and a trout control diet (DC) were designed, manufactured, and evaluated in triplicate during 62 days. A hundred and eighty juveniles (5.11 ± 0.08 g) were distributed in a recirculation system with 18 tanks of 70 L with a flow of 10 L min-1. Results: The 0.2% MOS diet produced the highest values in weight gained (WG), specific growth rate (SGR), and protein efficiency rate (PER) and the lowest value in feed conversion rate (FCR). Survival in all treatments was greater than 96%. The hepatosomatic index was higher for the 0.4% treatment, while the viscerosomatic index was higher for the 0.4% and 0.6% treatments. All the enzymatic activities (acid protease, alkaline protease, trypsin, chymotrypsin, leucine aminopeptidase, carboxypeptidases, lipases, α-amylase, acid phosphatases, and alkaline phosphatases) showed significant differences by the inclusion of MOS in the diet. Conclusions: Supplementation of 0.2% MOS in diets for juveniles of A. tropicus, generates benefits in growth and productive performance. The inclusion of MOS in diets for juveniles of A. tropicus modifies somatic indices and the activity of digestive enzymes of juveniles.info:eu-repo/semantics/publishedVersio

    Increased dynamics in the 40-57 Ω-loop of the G41S variant of human cytochrome c promote its pro-apoptotic conformation

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    Thrombocytopenia 4 is an inherited autosomal dominant thrombocytopenia, which occurs due to mutations in the human gene for cytochrome c that results in enhanced mitochondrial apoptotic activity. The Gly41Ser mutation was the first to be reported. Here we report stopped-flow kinetic studies of azide binding to human ferricytochrome c and its Gly41Ser variant, together with backbone amide H/D exchange and 15N-relaxation dynamics using NMR spectroscopy, to show that alternative conformations are kinetically and thermodynamically more readily accessible for the Gly41Ser variant than for the wild-type protein. Our work reveals a direct conformational link between the 40-57 Ω-loop in which residue 41 resides and the dynamical properties of the axial ligand to the heme iron, Met80, such that the replacement of glycine by serine promotes the dissociation of the Met80 ligand, thereby increasing the population of a peroxidase active state, which is a key non-native conformational state in apoptosis
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