Selección óptima bajo criterios múltiples de materiales refractarios y aislantes para cazuelas metalúrgicas

ResumenHasta el presente, el problema de la selección de materiales refractarios y aislantes no se ha tratado, en toda su complejidad, como una tarea de optimización bajo criterios múltiples, sino básicamente como un problema de carácter metalúrgico. En este artículo, se expone el modelado matemático de la tarea de selección óptima bajo criterios múltiples y se analiza su complejidad matemática, considerando las dimensiones de los materiales por capas y por zonas, y la interacción entre zonas. La complejidad de la tarea formulada requiere su descomposición en tareas más sencillas, por zonas de la cazuela. Se realiza la validación experimental de los resultados numéricos obtenidos, con lo cual se evidencia la eficiencia y la calidad que se obtienen con los procedimientos utilizados. Estos procedimientos se derivan de la aplicación del método de integración de variables. En particular, se utiliza el operador de búsqueda aleatoria del extremo de una función de un código variable aplicado al problema estudiado.SummaryUntil the present the problem of the refractory and isolating materials selection has not been treated, in all its complexity, as an optimization under multiple criteria task, but basically as a metallurgical problem. In the present article the mathematical modelling of the optimal under multiple criteria task, the analysis of it mathematical complexity, considering the dimensions of the materials by layers and by zones are exposed. The complexity of the formulated task conditions the necessity of its decomposition in simpler tasks by zones of the ladle. The experimental validation of the obtained numeric results, where the efficiency and resulting quality of the used procedures is evidenced. The procedures applied are a part of the Integration of Variables method. Particularly, the Random Search of the Extremes of a Function of a Variable Code operator is applied to the problem studied

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

Supervivencia de postlarvas de camarón blanco Litopenaeus vannamei a diferentes salinidades y temperaturas

RESUMEN Objetivo. Analizar el efecto combinado de salinidad (5, 15, 25, 35 y 45ups) y temperatura (15, 20, 25, 30 y 35oC) sobre la supervivencia y frecuencia de mudas en postlarvas (PL12) de Litopenaeus vannamei. Materiales y métodos. Los experimentos se realizaron por cuadriplicado por cada combinación de salinidad y temperatura. Las postlarvas se mantuvieron en acuarios de 3 L a una densidad de 100PL/l. La salinidad se incrementó disolviendo sal granulada libre de yodo, a partir de agua de mar, mientras que para alcanzar las salinidades menores se utilizó agua dulce filtrada. Las postlarvas aclimatadas a 35ups y 28°C (condición inicial) fueron sometidas abruptamente a las salinidades y temperaturas experimentales por 30 minutos. Después, se filtraron y se colocaron nuevamente en su condición inicial para su recuperación. Transcurridos 30 minutos, se contaron las postlarvas vivas y las mudas. Los datos fueron analizados por un ANOVA de dos vías. Resultados. Se determinó que la supervivencia y frecuencia de mudas fueron significativamente afectadas por la salinidad, temperatura y su interacción (p<0.05). Se obtuvo una supervivencia máxima y mínima de 99.8 y 94.4%. Los porcentajes de supervivencia y frecuencias de mudas disminuyeron a una baja salinidad en combinación a bajas y altas temperaturas, y aumentaron independientemente de la salinidad y temperatura, a excepción de 5ups con 15, 30 y 35°C. La mortalidad máxima de postlarvas fue de 5.6% (5ups y 30°C). Conclusiones. Se determinó que a temperaturas de 20 y 25°C en combinación a las salinidades utilizadas, fueron las mejores condiciones de supervivencia y de resistencia de las postlarvas ante dichas condiciones hidrológicas

Evidence of cross gene regulation of some virulence factors of Porphyromonas gingivalis by Streptococcus intermedius

Periodontal disease has been associated with poor dental care, which promotes the accumulation of bacteria and the development of diseases of the mouth. Porphyromonas gingivalis are anaerobic Gramnegative bacteria found in the subgingival plaque. They are largely responsible for chronic periodontal disease. Streptococcus intermedius is a Gram positive coccus found in the supragingival plaque. The objective of the present work was to evaluate the expression of several virulence genes of P. gingivalis in a mixed culture with S. intermedius using qPCR and heterologous microarrays. P. gingivalis ATCC 33277 and W83 and S. intermedius ATCC 27335 strains were cultured and total RNA was extracted using the High Pure RNA isolation kit. Oligodeoxynucleotides were designed to make multiple comparisons with organisms. Microarray was performed to identify gene expression. To quantify gene expression, cDNA samples from three different P. gingivalis:S. intermedius ratios were diluted 10-1, 10-2 and 10-3. The microarray experiment indicated that in P. gingivalis, 29 genes were upregulated. The putative function of upregulated genes was the biosynthesis of different metabolic pathways. Heterologous microarrays are a new approach that are useful for investigating gene expression.Keywords: Porphyromonas gingivalis, Streptococcus intermedius, periodontal disease, virulence genes, cross gene regulation.African Journal of Biotechnology Vol. 12(28), pp. 4498-450

High-performance reconstruction of microscopic force fields from Brownian trajectories

The accurate measurement of microscopic force fields is crucial in many branches of science and technology, from biophotonics and mechanobiology to microscopy and optomechanics. These forces are often probed by analysing their influence on the motion of Brownian particles. Here we introduce a powerful algorithm for microscopic force reconstruction via maximum-likelihood-estimator analysis (FORMA) to retrieve the force field acting on a Brownian particle from the analysis of its displacements. FORMA estimates accurately the conservative and non-conservative components of the force field with important advantages over established techniques, being parameter-free, requiring ten-fold less data and executing orders-of-magnitude faster. We demonstrate FORMA performance using optical tweezers, showing how, outperforming other available techniques, it can identify and characterise stable and unstable equilibrium points in generic force fields. Thanks to its high performance, FORMA can accelerate the development of microscopic and nanoscopic force transducers for physics, biology and engineering

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

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

Sheep reproductive management

Objetive: Describe some reproductive management programs that have made it possible to increase the productive efficiency of sheep. Desing/methodology/approach: Description of the main hormones and their application in sheep reproductive management protocols. The topics are addressed from academic references and use in sheep reproductive protocols in the Reproduction Laboratory for Sheep and Goat of the Colegio de Postgraduados, Mexico. Results: The use of hormones, socio-sexual strategies, reproductive protocols and techniques are tools that improve the reproductive efficiency of sheep during the reproductive and seasonal anestrus season. Study limitations/implications: The basic techniques of reproductive management and protocols in sheep are mostly available, however they still have a wide margin for improvement, which requires multiple efforts that involve all participating sectors, such as the primary sector, institutions public and private. Findings/conclusions: Reproductive management is a pillar of great importance in animal production, which is why it is essential to implement it to improve the reproductive and productive efficiency of the herd.Objective: To describe some reproductive management programs that allow increasing the productive efficiency of ewes. Design/methodology/approach: Description of the main hormones and their application in sheep reproductive management protocols. The subjects are reviewed based on academic references as well as on their use in sheep reproductive protocols at the Sheep and Goat Reproduction Laboratory of the Colegio de Postgraduados, Mexico. Results: Hormones, socio-sexual strategies, reproductive protocols and techniques are tools that improve the reproductive efficiency of ewes during the reproductive season and seasonal anestrus. Study limitations/implications: The basic techniques of reproductive management and protocols in sheep are mostly available, however, they still have room for improvement, therefore, multiple efforts involving all participants, such as the primary sector, public and private institutions, are required. Findings/conclusions: Reproductive management is an important pillar for animal production; thus its implementation is fundamental to improve the reproductive and productive efficiency of a her

Glecaprevir-Pibrentasvir for 8 or 12 Weeks in HCV Genotype 1 or 3 Infection

The trials (NCT02604017, NCT02640157) were funded by AbbVie Inc