GeSn/Ge heterostructure short-wave infrared photodetectors on silicon

status: publishe

Results of an international phosphorus digestibility ring test with broiler chickens

The objective of this ring test was to investigate the prececal phosphorus (P) digestibility of soybean meal (SBM) in broiler chickens using the trial protocol proposed by the World's Poultry Science Association. It was hypothesized that prececal P digestibility of SBM determined in the collaborating stations is similar. Three diets with different inclusion levels of SBM were mixed in a feed mill specialized in experimental diets and transported to 17 collaborating stations. Broiler chicks were raised on commercial starter diets according to station-specific management routine. Then they were fed the experimental diets for a minimum of 5 d before content of the posterior half of the ileum was collected. A minimum of 6 experimental replicates per diet was used in each station. All diets and digesta samples were analyzed in the same laboratory. Diet, station, and their interaction significantly affected (P < 0.05) the prececal digestibility values of P and calcium of the diets. The prececal P digestibility of SBM was determined by linear regression and varied among stations from 19 to 51%, with significant differences among stations. In a subset of 4 stations, the prececal disappearance of myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate)-P; InsP6-P) also was studied. The prececal InsP6-P disappearance correlated well with the prececal P digestibility. We hypothesized that factors influencing InsP6 hydrolysis were main contributors to the variation in prececal P digestibility among stations. These factors were probably related to the feeding and housing conditions (floor pens or cages) of the birds in the pre-experimental phase. Therefore, we suggest that the World's Poultry Science Association protocol for the determination of digestible P be should extended to the standardization of the pre-experimental period. We also suggest that comparisons of P digestibility measurements among studies are made only with great caution until the protocol is more refined

La decisione di significare. Il libro 'Gamma' della 'Metafisica', testo critico, commentario

Traduzione dal greco all'italiano di S. Maso. Saggio introduttivo di B.Cassin. Edizione del testo greco di B. Cassin e M. Narc

Sb-based laser sources grown by molecular beam epitaxy on silicon substrates

International audienc

Sistemas de lagunaje como tecnología alternativa para el tratamiento de aguas residuales: vigencia de esta técnica en Costa Rica

Los sistemas de lagunaje son una tecnología ampliamente utilizada a nivel mundial para para el tratamiento de las aguas residuales, especialmente en pequeñas poblaciones y zonas rurales. Actualmente el reto en su funcionamiento consiste en maximizar la eficiencia para recibir cargas altas y potenciar el aprovechamiento biotecnológico de las algas que proliferan en este tipo de sistemas. En el presente estudio se presenta el análisis de un sistema de lagunas para el tratamiento de aguas residuales, ubicado en Costa Rica, que recibe aguas residuales domésticas. El sistema se estudió en cuanto a la remoción individual de contaminantes en cada una de las lagunas que lo componen y se identificaron los principales tipos de algas presentes en las aguas residuales dentro de la misma. Se observó una remoción alta especialmente de materia orgánica y la presencia de algas con un papel relevante a nivel de su aprovechamiento biotecnológico.Wastewater treatment ponds are a sanitation technology used worldwide especially in small towns and rural areas. The current challenge in its operation is to maximize efficiency, to receive high loads and enhance the biotechnological use of the algae that proliferate in this type of system. This study presents the analysis of a domestic wastewater treatment pond, located in Costa Rica. The system was studied in terms of the individual removal of contaminants in each of the ponds and the main types of algae present in wastewater. It was observed a high removal especially of organic matter and the presence of algae with a relevant biotechnological use.Universidad Nacional, Costa RicaEscuela de Ciencias BiológicasEscuela de Químic