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

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

ADSORPTION ESSAYS OF PALLADIUM IN MODIFIED SILICA GEL WITH THIOURONIUM GROUPS: EXPERIMENTAL AND THEORICAL STUDIES

Indexación: Web of Science; ScieloThe silylant 3-cloropropyltriethoxysilyl was anchored over silica gel in anhydrous conditions in order to react with thiourea to obtain modified silica gel with thiouronium. The aim to obtain an inorganic support that is able to hijack metals from the VIII group such as palladium. The product was characterized by Sbet and FTIR infrared spectroscopy. For the determination of the structure in the modified silica gel NMR spectra of silicon and carbon were preformed in solid state. The coordination form of the modified silica gel to the metal was studied computationally in the context of the DFT theory, using the ADF code. This was a collaborative work with "Fundación Chile" for the recuperation of precious metals from the mining industry.http://ref.scielo.org/gk7rm

Creatividad y profesores

La literatura especializada e investigaciones en el área demuestran la necesidad urgente de buscar estrategias innovadoras en el plano de las prácticas docentes. En el plano universitario, especialistas nacionales expresan su preocupación respecto a las prácticas de la docencia universitaria, en Latinoamérica y en nuestro país, percibiéndola dentro de un modelo anacrónico y de "transmisión analógica" renuente a la diferenciación y flexibilización. La investigación del comportamiento creativo del profesor, ha sido descuidada, posiblemente por la falta de instrumentos adecuados, la situación es diferente a la hora de medir la creatividad de las personas

Functional characterization of a melon alcohol acyl-transferase gene family involved in the biosynthesis of ester volatiles. Identification of the crucial role of a threonine residue for enzyme activity

Volatile esters, a major class of compounds contributing to the aroma of many fruit, are synthesized by alcohol acyl-transferases (AAT). We demonstrate here that, in Charentais melon (Cucumis melo var. cantalupensis), AAT are encoded by a gene family of at least four members with amino acid identity ranging from 84% (Cm-AAT1/Cm-AAT2) and 58% (Cm-AAT1/Cm-AAT3) to only 22% (Cm-AAT1/Cm-AAT4). All encoded proteins, except Cm-AAT2, were enzymatically active upon expression in yeast and show differential substrate preferences. Cm-AAT1 protein produces a wide range of short and long-chain acyl esters but has strong preference for the formation of E-2-hexenyl acetate and hexyl hexanoate. Cm-AAT3 also accepts a wide range of substrates but with very strong preference for producing benzyl acetate. Cm-AAT4 is almost exclusively devoted to the formation of acetates, with strong preference for cinnamoyl acetate. Site directed mutagenesis demonstrated that the failure of Cm-AAT2 to produce volatile esters is related to the presence of a 268-alanine residue instead of threonine as in all active AAT proteins. Mutating 268-A into 268-T of Cm-AAT2 restored enzyme activity, while mutating 268-T into 268-A abolished activity of Cm-AAT1. Activities of all three proteins measured with the prefered substrates sharply increase during fruit ripening. The expression of all Cm-AAT genes is up-regulated during ripening and inhibited in antisense ACC oxidase melons and in fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. The data presented in this work suggest that the multiplicity of AAT genes accounts for the great diversity of esters formed in melon

Identification of circulating miRNA profiles that distinguish malignant pleural mesothelioma from lung adenocarcinoma

Accurate diagnosis of malignant pleura mesothelioma (MPM) is challenging. Differential diagnosis of MPM versus lung adenocarcinoma (AD) is particularly difficult, yet clinically important since the two neoplasias call for different treatment approaches. Circulating miRNA-profiling to identify miRNAs that can be used to distinguish MPM from AD has not been reported. We conducted a wide screening study of miRNA profiles in serum pools of MPM patients (N = 11), AD patients (N = 36), and healthy subjects (N = 45) to identify non-invasive biomarkers for differential diagnosis of MPM and AD, using deep sequencing. Sequencing detected up to 300 known miRNAs and up to 25 novel miRNAs species in the serum samples. Among known miRNAs, 7 were upregulated in MPM and 12 were upregulated in AD compared to healthy controls. Of these, eight were distinctive for AD and three were unique for MPM. Direct comparison of the miRNA profiles for MPM and AD revealed differences in miRNA levels that could be useful for differential diagnosis. No differentially expressed novel miRNAs were found. Further bioinformatics analysis indicated that three upregulated miRNAs in MPM are associated with the p38 pathway. There are unique alterations in serum miRNAs in MPM and AD compared to healthy controls, as well as differences between MPM and AD profiles. Differing miRNA levels between MPM and AD may be useful for differential diagnosis. A potential association to p38 pathway of three upregulated miRNAs in MPM was revealed

MASTREE+ : time-series of plant reproductive effort from six continents

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics