Main Variables Affecting a Chemical-Enzymatic Method to Obtain Protein and Amino Acids from Resistant Microalgae

he development of microalgae uses requires further investigation in cell disruption alternatives to reduce the costs associated to this processing stage. This study aimed to evaluate the main variables affecting an extraction method to obtain protein and amino acids from microalgae. The method was based on a sequential alkaline-enzymatic process, with separate extractions and noncontrolled pH, and was applied to fresh biomass of a resistant species. The processed microalgae were composed of a consortium with Nannochloropsis sp. as predominant species. After the optimization of the pH of the alkaline reaction, the effect of the time of the alkaline reaction (30-120min), the time (30-120min) and temperature (40-60 degrees C) of the enzymatic reaction, and the biomass concentration (50-150mgml(-1)), on the extraction yields of protein and free amino nitrogen (FAN) and on the final concentration of protein in the extract, was studied using a response surface methodology. Even though all the variables and some interactions among them had a significant effect, the biomass concentration was the most important factor affecting the overall process. The results showed relevant information about the different options in order to maximize not only the response variables individually but also different combinations of them. Assays with optimized values reached maximum yields of 80.3% and 1.07% of protein (% of total protein) and FAN (% of total biomass), respectively, and a protein concentration in the extract of 15.2mgml(-1). The study provided the essential information of an alternative approach to obtain protein and amino acids from fresh biomass of resistant microalgae with a high yield, also opening perspectives for further research in particular aspects

Design and performance evaluation of the "iTIVA" algorithm for manual infusion of intravenous anesthetics based on effect-site target

Introduction: Remifentanil and propofol infusion using TCI pumps has proven to be beneficial for the practice of anesthesia but the availability of these systems is limited. Objective: Designing a pharmacokinetic model-based algorithm for calculating manual infusion regimens to achieve plasma and effect-site concentrations that may be used in volume infusion pumps, and to compare the difference between the desired and the forecasted concentrations via pharmacokinetic simulation. Methods: Using the Minto & Schnider models for remifentanil and propofol respectively, the algorithm was implemented on an iTIVA application (interactive TIVA) for iOS and Android operating systems. The performance of the algorithm was evaluated estimating the infusion regimens for achieving different effect-site concentrations for induction and maintenance in 34 theoretical patients for 240. minutes. Results: The infusion regimens obtained for remifentanil and propofol resulted in less than 5% average systemic deviation versus the target effect-site concentrations during induction and maintenance. Only one induction infusion was required for remifentanil and propofol. Just one infusion rate was required for remifentanil during maintenance, and between 2 to 5 infusion rate changes for propofol to maintain a stable concentration. The iTIVA-based algorithm estimates concentrations similar to the TivaTrainer® software. Conclusions: The performance of the algorithm to achieve effect-site concentrations during induction and maintenance for remifentanil and propofol was excellent, with a low systemic deviation versus the desired target concentrations

Genealogical data of Boer and Nubian goats in Mexico

The pedigree file of the Boer and Nubian goat breeds in Mexico was constructed using the national database provided by the Asociación Mexicana de Criadores de Ganado Caprino de Registro. Field technicians routinely updated the goat national database by recording information from flocks participating in the performance-recording system. Information on animal identification number, parents, birth date, sex, breed, and farm of origin were used to undertake pedigree analyses using the ENDOG program (version 4.8). This paper presents a pedigree data file, tables and figures of characteristics of pedigree data, pedigree analyses, pedigree integrity, effective population size and genetic conservation index. The data can be used to estimate other population parameters, to monitor the genetic diversity of the Boer and Nubian goat breeds in Mexico, and also to design balanced breeding programs, maintaining genetic variation at reasonable levels and maximizing genetic progress in these populations.202

Determinación de niveles de fitoestrógenos en tréboles rojos (T. pratense var. Triel y Levezou) y trébol blanco (T. repens var. Ladino) asociado a gramíneas forrajeras durante el establecimiento.

Se evaluó in vitro la actividad biológica de los estrógenos presentes en 4 variedades de tréboles, con el fin de establecer las diferencias y sus fluctuaciones con la edad de las plantas cuando se cultivan solas o asociadas a las gramíneas Pennisetum clandestinum, Lolium hybridum y L. perenne x L. mutiflorum o manawa. La cuantificación se hizo mediante la técnica de competencia radio-receptor de los extractos acuosos del trébol contra 17-B estradiol. Hubo diferencias significativas en la actividad estrogénica de los tréboles entre variedades y debidas a la edad, siendo la de menor actividad el trébol blanco y las de mayor los tréboles triel y levezou. No es evidente el efecto de la asociación a gramíneas. La naturaleza de la relación entre actividad estrogénica y la edad de los tréboles triel y levezou, se expresa en ecuaciones de regresión. Los tréboles blanco y rojo no siguieron una relación lineal o cuadrática. Para establecer praderas mixtas de manawa con leguminosas se recomienda usar tréboles triel o levezou que entre 30 y 45 días manifiestan una actividad estrogénica promedio de 83.65 y 82.27 mg de 17-B estradiol/g de materia seca, respectivamente. Comportamiento similar se observa con tetralite. El kikuyo debería asociarse a tréboles blanco y rojo, que entre 75 y 90 días manifiestan una estrogeneidad promedio equivalente a 83.95 y 78.18 mg de 17-B estradiol/g de materia seca, respectivamentePastos y forrajesMaestría en CienciasMaestrí

The impact of man on the morphodynamics of the Huelva coast (SW Spain)

The Huelva coast is composed by large sandy beaches and spits, only interrupted by the presence of the estuarine mouths of the Guadiana, Piedras, Tinto-Odiel and Guadalquivir which are in an advanced state of sediment infilling. The morphology and processes of the Huelva coast are mainly linked to tidal regime, wave action, coastal-drift currents, fluvial dynamics, climatic change and anthropogenic activity. In the last five decades anthropogenic activity has modified the natural dynamics by the construction of jetties, docks, harbour and coastal developments. The main consequences have been the interruption of the sedimentary bypassing caused by an active west-to-east littoral drift, the modification of the tidal regime, the wave refraction-diffraction scheme and the intensification of the littoral erosive processes. All these effects will increase with the slow sea-level rise, close to 0.6 cm per year, which will induce a higher efficacy of the erosional events. A future retreat of about 10-15 m of the coastline is estimated.La costa de Huelva esta constituida por extensas playas y flechas litorales, interrumpidas por la presencia de grandes estuarios (Guadiana, Piedras, Tinto-Odiel y Guadalquivir) en un estado avanzado de colmatación. La morfología y los procesos de la costa se deben principalmente a una serie de factores: régimen mareal, olas, corrientes de deriva, dinámica fluvial, cambio climático y la actividad antrópica. En las últimas cinco décadas la actividad antrópica ha modificado la dinámica natural debido a la construcción de espigones, escolleras, puertos y urbanizaciones. Las principales consecuencias de esta actividad han sido la interrupción del trasvase de sedimentos del Este hacia el Oeste por la corriente de deriva litoral, la alteración del régimen mareal, la modificación de los procesos de refracción-difracción de olas y la intensificación de los procesos erosivos. Todos estos efectos se verán incrementados con el paulatino ascenso del nivel del mar en el Golfo de Cádiz, del orden de 0,6 cm anuales, repercutiendo en una mayor eficacia de los eventos erosivos. Se estima una pérdida del orden de 10-15 m en el perfil de las playas

Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits

[EN] We evaluated the impact of concurrent pregnancy and lactation on: nest-building (i.e., digging, straw-carrying, hair-pulling), food intake, milk output, body weight, and the concentration of estradiol and progesterone in blood. Digging was lower in pregnant-lactating (PL) rabbits, compared with pregnant-only (PO) does, on 21-23 d (52±64 vs. 104±86 g, respectively; mean±SD; P<0.05). Straw-carrying was also reduced in PL does on 24-26 d (9±27 vs. 79±94 g; P<0.005), 27-29 (27±56 vs. 99±77 g; P<0.005), and in the total amount of material introduced into the nest box (132±167 vs. 286±217 g; P<0.02). Hair-pulling was expressed by practically all animals. Food intake declined in PO does on the three days preceding parturition (P<0.01) and increased markedly during lactation; this increase was much larger in PL than in lactating-only (LO) rabbits (P<0.01). Milk output was similar between PL and LO does during the first 21 d of lactation but a marked decline in this parameter occurred in PL does from then until 30 d. The differences in nest-building between PL and PO rabbits may be related to the concentrations of estradiol and progesterone on specific days of pregnancy. PL does showed significantly higher estradiol levels than PO animals on pregnancy 1 d (33±13 vs. 23±4 pg/mL; P<0.02) and 21 (34±19 vs. 24±6 pg/mL; P<0.05) and also higher levels of progesterone on pregnancy 1 d (4±5 vs. 1±2 ng/mL; P<0.05). However, PL rabbits had lower levels of progesterone on 7 d (6±3 vs. 9±2 ng/mL; P<0.02) and 14 d (8±3 vs. 11±3 ng/mL; P<0.005) than PO does. Our results indicate that the unique endocrine milieu of PL rabbits has a direct bearing on specific behavioral and physiological phenomena that impact productivity on the farm.González-Mariscal, G.; Gallegos, J.; Sierra-Ramírez, A.; Garza Flores, J. (2009). Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits. World Rabbit Science. 17(3):145-152. doi:10.4995/wrs.2009.65414515217

Optimal electricity price calculation model for retailers in a deregulated market

The electricity retailing, a new business in deregulated electric power systems, needs the development of efficient tools to optimize its operation. This paper defines a technical-economic model of an electric energy service provider in the environment of the deregulated electricity market in Spain. This model results in an optimization problem, for calculating the optimal electric power and energy selling prices that maximize the economic profits obtained by the provider. This problem is applied to different cases, where the impact on the profits of several factors, such as the price strategy, the discount on tariffs and the elasticity of customer demand functions, is studied. © 2005 Published by Elsevier Ltd

Sub-Gaussian short time asymptotics for measure metric Dirichlet spaces

This paper presents estimates for the distribution of the exit time from balls and short time asymptotics for measure metric Dirichlet spaces. The estimates cover the classical Gaussian case, the sub-diffusive case which can be observed on particular fractals and further less regular cases as well. The proof is based on a new chaining argument and it is free of volume growth assumptions

DESARROLLO DE UN AMBIENTE SEMIAUTOMATIZADO PARA LA ENSEÑANZA Y APRENDIZAJE DE CONCEPTOS DE PRODUCCIÓN APLICADOS A LA INDUSTRIA DE CONFECCIONES

This article presents the result of a research project whose objective was the design, development and implementation of a semi-automated environment for teaching and learning production processes in confection, formed with the use of a conveyor belt with discrete movements controlled by PLC, buttons at each station and software SCADA supervision. The environment allows Sena apprentices to be taught clothing, with a greater appropriation of concepts and useful manufacturing techniques slender, in a practical, playful and didactic way. The environment serves as a laboratory and is a reference as a production model for the clothing industry in Medellin. This model breaks paradigms of the use of automation in a sector in which productivity and quality depend largely on the ability of the operator, and in which the product reference changes are continuous due to in fashion.En este artículo se presenta el resultado de un proyecto de investigación cuyoobjetivo fue el diseño, desarrollo e implementación de un ambiente semiautomatizadode enseñanza y aprendizaje de procesos de producción enconfección, conformado con el uso de una banda transportadora con movimientosdiscretos controlados por PLC, botones en cada estación y softwarede supervisión SCADA. El ambiente permite enseñar a los aprendices del Sena de confecciones,con una mayor apropiación de conceptos y técnicas útiles de manufacturaesbelta, de una manera práctica, lúdica y didáctica. El ambiente sirve de laboratorio yes referente como un modelo de producción para la industria de las confecciones enMedellín. Con este modelo se rompen paradigmas del uso de la automatización en unsector en el que, la productividad y calidad, dependen en gran medida de la habilidaddel operario, y en el cual los cambios de referencia de producto son continuos debidoa la moda