829 research outputs found

    Intervalo entre partos en el vacuno de carne extensivo de raza retinta

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    La eficacia reproductiva en el vacuno depende, entre otros parámetros, del intervalo entre partos. Esta variable está considerada una de las más importantes para la rentabilidad de la explotación en el caso del vacuno de carne en régimen extensivo. En este trabajo se estudia la influencia de distintos factores sobre el intervalo entre partos en la raza retinta mediante el análisis de 7356 partos de 1803 vacas pertenecientes al Núcleo de Control de Rendimientos de la Asociación de Ganaderos de esta raza. Nuestros resultados muestran que este parámetro se ve afectado principalmente por la ganadería, la campaña ganadera, época, sus interacciones y el tipo de parto, no existiendo relación significativa entre este período y el peso al destete de los terneros El valor medio obtenido para todo el intervalo analizado ha sido de 16,144 ± 0,086 meses y la heredabilidad estimada para este carácter fue de 0,1104 ± 0,08

    Estudio de la respuesta de plantas de pepino (Cucumis Sativbus L. CV). Hyclos) a diferentes relaciones NO3/NH4+

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    En este trabajo se estudia la respuesta de plantas de pepino a diversas relaciones N03-/NH4+ (100/0, 80/20, 60/40, 30/70), al objeto de comprobar el grado de tolerancia de esta especie vegetal a concentraciones crecientes de NH4 + en el medio de cultivo. Las plantas cultivadas con la relación 60/40 presentaron un peso superior a las testigo (100/0). Por el contrario, las sometidas a las relaciones 80/20 y 30/70 ofrecieron una reducción en el crecimiento. A medida que aumenta el aporte de NH4+ disminuye la concentración de Ca, Mg, Mn y B en hoja, de Ca y Mg en raíz y aumenta la concentración de P, K Y Zn en hoja y de Fe, B y Zn en raíz. Finalmente a las plantas de pepino cv. Hyclos no les beneficia el NH4+ cuando la mayor parte del N está como N03- (80/20); les resulta eficaz el catión cuando se suministra en concentraciones casi equivalentes a las de N03-, a la vez que niveles muy altos de NH4+ (70%) causan efectos perjudiciales.STUDY OF CUCUMBER PLANT RESPONSE TO N03- /NH4 + RATIOS Cucumber plants were hydroponically grown in a greenhouse with four N03- /NH/ ratios (100/0, 80/20, 60/40 and 30/70), in order to study their tolerance to NH/ supply. Plants grown in 60/40 N03- /NH/ solution displayed higher weight than N03- treated plants. By contrast, plants grown with N03- /NH/ ratios of 80/20 and 30/70 showed lower growth than plants fed with N03- as the sole source of N. As the proportion of NH/ in the nutrient solution was increased Ca, Mg, Mn and B in the leaf and Ca and Mg in the root decreased, whereas P, K, and Zn concentrations in the leaf and Fe, B and Zn levels in the root increased. Finally, NH/ supplied in low and high concentrations was harmful to cucumber plants cv. Hyclos development, whereas it is really efficient when N03• and NH/ are supplied in about equivalent amounts (60/40)

    Estudio de la respuesta de plantas de pepino (Cucumis Sativbus L. CV). Hyclos) a diferentes relaciones NO3/NH4+

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    Cucumber plants were hydroponically grown in a greenhouse with four N03-/NH4+ ratios (100/0, 80/20, 60/40 and 30/70), in order to study their tolerance to NH/ supply. Plants grown in 60/40 N03- /NH/ solution displayed higher weight than N03- treated plants. By contrast, plants grown with N03-/NH4+ ratios of 80/20 and 30/70 showed lower growth than plants fed with N03- as the sole source of N. As the proportion of NH4+ in the nutrient solution was increased Ca, Mg, Mn and B in the leaf and Ca and Mg in the root decreased, whereas P, K, and Zn concentrations in the leaf and Fe, B and Zn levels in the root increased. Finally, NH/ supplied in low and high concentrations was harmful to cucumber plants cv. Hyclos development, whereas it is really efficient when N03- and NH4+ are supplied in about equivalent amounts (60/40).En este trabajo se estudia la respuesta de plantas de pepino a diversas relaciones N03-/NH4+ (100/0, 80/20, 60/40, 30/70), al objeto de comprobar el grado de tolerancia de esta especie vegetal a concentraciones crecientes de NH4 + en el medio de cultivo. Las plantas cultivadas con la relación 60/40 presentaron un peso superior a las testigo (100/0). Por el contrario, las sometidas a las relaciones 80/20 y 30/70 ofrecieron una reducción en el crecimiento. A medida que aumenta el aporte de NH4+ disminuye la concentración de Ca, Mg, Mn y B en hoja, de Ca y Mg en raíz y aumenta la concentración de P, K Y Zn en hoja y de Fe, B y Zn en raíz. Finalmente a las plantas de pepino cv. Hyclos no les beneficia el NH4+ cuando la mayor parte del N está como N03- (80/20); les resulta eficaz el catión cuando se suministra en concentraciones casi equivalentes a las de N03-, a la vez que niveles muy altos de NH4+ (70%) causan efectos perjudiciales

    Influence of Ceramic Recycled Aggregates on the Properties of Prestressed Precast Concrete Elements

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    This work presents the results of an experimental study performed on the mechanical behavior of concrete manufactured with ceramic recycled aggregates (CRA), from precast ventilation ducts, that once made have been rejected by defective. The ultimate objective is to use these wastes to manufacture prestressed concrete joists used in building floors. The coarse fraction and the fine fraction have been considered. The work has been carried out in three phases: characterization of the material, characterization of concrete with CRA and manufacturing and testing of prestressed joists. With the results obtained it is determined the influence of the ceramic recycled aggregate on the properties analyzed. There are not enough studies about prestressed elements that include the replacement of the aggregate in the fine fraction. In view of the results obtained could both of fine and coarse fraction can be used in these applications

    Design and implementation of synchronization and AGC for OFDM-based WLAN receivers

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    An efficient implementation of several tasks at the receiver becomes crucial in OFDM-based high-speed WLAN systems, such as automatic gain control, time and frequency synchronization and offset tracking. This paper deals with fixed point constraints and accuracy requirements for implementation of those algorithms. Also, a complete set of thresholds for the practical implementation of time and frequency synchronization sub-blocks is obtained. Moreover, a technique to mitigate the remaining frequency offset after coarse acquisition is proposed, yielding a good trade-off between performance and complexity. Finally, we propose the implementation of a simple and effective automatic gain control procedure.This work has been partially funded by Spanish government with project TIC 2002-03498 (ORISE), Telefonica I+D by the contract nº 25756, and the Chamber of Madrid Community and European Social Fund by a grant to the first author

    Rabbit seminal plasma proteome: The importance of the genetic origin

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    [EN] The present study was conducted to characterise rabbit seminal plasma proteins (SP proteins) focusing on the influence of the genetic origin and seasonality. In addition, ß-NGF protein quantity in SP was determined. Semen samples were recovered from January to December 2014 using 6 males belonging to genotype A and six from genotype R. For each genotype, one pooled sample at the beginning, middle and end of each season was selected to develop the experiment. A total of 24 pools (3 for each season and genetic line) were analysed. SP proteins of the two experimental groups were recovered and subjected to in-solution digestion nano LC¿MS/MS and bioinformatics analysis. The resulting library included 402 identified proteins validated with ¿95% Confidence (unused Score¿1.3). These data are available via ProteomeXchange with identifier PXD006308. Only 6 proteins were specifically implicated in reproductive processes according to Gene Ontology annotation. Twenty-three proteins were differentially expressed between genotypes, 11 over-expressed in genotype A and 12 in genotype R. Regarding the effect of season on rabbit SP proteome, results showed that there is no clear pattern of protein variation throughout the year. Similar ß-NGF relative quantity was observed between seasons and genotypes. In conclusion, this study generates the largest library of SP proteins reported to date in rabbits and provides evidence that genotype is related to a specific abundance of SP proteins.This research was supported in part by the RTA2013-00058-00-00 from INIA, the European Social Fund and the European FEDER Funds. L. Casares-Crespo is supported by a scholarship from Instituto Valenciano de Investigaciones Agrarias (IVIA) and the European Social Fund. P. Fernandez-Serrano is supported by Spanish funds from IVIA and Ministerio de Empleo y Seguridad Social (Youth Guarantee Program). The authors are grateful to M. Luz Valero for her excellent technical assistance.Casares-Crespo, L.; Fernández-Serrano, P.; Vicente Antón, JS.; Marco-Jiménez, F.; Viudes De Castro, MP. (2018). Rabbit seminal plasma proteome: The importance of the genetic origin. Animal Reproduction Science. 189:30-42. https://doi.org/10.1016/j.anireprosci.2017.12.004S304218

    Disruptores endocrinos. El caso particular de los xenobióticos estrogénicos. II Estrógenos sintéticos

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    In recent years, it has been demonstrated that endocrine systems of living beings can be altered by many chemical substances of anthropogenic origin, designated as endocrine disrupters. There are growing concerns about the number of these endocrine disrupters. It has not been possible to define a single chemical structure that allows the classification of a chemical compound as a mimic of female sex hormones, so that chemical structures similar to natural estrogens, based on cyclopentanoperhydrophenanthrene, share their hormonal effect with stilbenes, bisphenols, alkylphenols, dioxins, furans and parabenes. The recognition of estrogenic activity in different biological models has been used to update the list of xenoestrogens and reveal sources of human exposure that were previously unknown. New previously unsuspected chemical compounds have been added to the list, as well as their precursors, metabolites and degradation products, whose effects are only now beginning to be recognised.En los últimos años se ha puesto en evidencia que muchas sustancias químicas de origen antropogénico son capaces de alterar el sistema endocrino de los seres vivos y se ha acuñado el nombre de disruptores endocrinos para definirlas. El número de disruptores endocrinos es una preocupación creciente si se añade a la inclusión de nuevos compuestos químicos, hasta ahora insospechados, la información generada sobre sus precursores, metabolitos y productos de degradación que tan solo ahora empiezan a conocerse. No se ha podido definir una estructura química única que permita clasificar a un compuesto químico como mimetizador de las hormonas sexuales femeninas, de tal manera que estructuras químicas similares a los estrógenos naturales, basados en el ciclopentanoperhidrofenantreno, comparten con los estilbenos, bisfenoles, bifenilos, alquilfenoles, dioxinas, furanos y parabenes su efecto hormonal estrogénico. El reconocimiento de la actividad estrogénica en diferentes modelos biológicos se ha utilizado para actualizar el censo de xenoestrógenos y poner de manifiesto fuentes de exposición humana hasta el momento insospechadas

    Influencia de la información sobre la sostenibilidad del riego en la elección, percepción y disposición a pagar del consumidor de vino (póster)

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    Este trabajo evalúa el efecto de añadir información sobre la sostenibilidad del riego en la respuesta del consumidor de vino. Se evaluaron dos formas diferentes de incluir la información en la etiqueta trasera de la botella, mediante un texto y mediante un logo diseñado específicamente con ese fin. El 52% de los 167 consumidores que participaron en el estudio eligió el vino con el logo. El vino con el texto fue elegido por un 38% de los consumidores mientras que únicamente un 10% eligió el control. El principal motivo para elegir los vinos con información sobre la sostenibilidad del riego fue que ambos se percibieron como más respetuosos con el medio ambiente. De hecho, en una escala de sostenibilidad de 9 puntos, estos vinos recibieron puntuaciones cercanas a 7 frente a valores inferiores a 5 del control. Además, el logo hizo que la etiqueta resultase más atractiva al consumidor, mientras que, en el caso del texto, el ahorro de agua fue la segunda causa que más influyó en la elección. Un 70% de los consumidores estuvo dispuesto a pagar entre un 15 y 30% más por el vino regado de forma sostenible respecto al vino control

    Effects of herbaceous covers and mineral fertilizers on the nutrient stocks and fluxes in a Mediterranean olive grove

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    Altres ajuts: acord transformatiu CRUE-CSICThe preservation of nutrient capital, soil fertility, and carbon (C) sequestration capacity in Mediterranean olive groves requires evaluation of agricultural practices beyond short-term productivity. We aim to contribute with a mechanistic understanding on the effects that the preservation of herbaceous cover and the use of chemical fertilizers have on the performance of olive trees and on the biogeochemical cycles of the agroecosystem. We compared nutrient fluxes and aboveground leafy stocks in an olive grove that had been organically managed for more than 60 years, in a treatment in which the annual spontaneous herbaceous cover was maintained (H), and after two years of shift to conventional management treatments in which the growth of herbaceous vegetation was avoided by the use of herbicides (NH), and where exclusion of the herbaceous cover is also combined with the supply of mineral fertilizers (NHF). Maintenance of herbaceous vegetation in H contributed to the retention of a high aboveground capital of C and nutrients, particularly nitrogen, (N), phosphorus (P) and potassium (K) that were about 2.9, 3.9 and 7.4 times greater than in NH, respectively. The permanence of herbaceous cover stimulated olive tree leaf litter decomposition rates by about 86 % and increased nutrient release. However, the H treatment led to a 37 % decrease in olive yield and lowered olive foliar N and P content as negative short-term effects. The addition of fertilizers (N, P, K, and Mg) in mineral and solid form in NHF resulted inefficient to improve olive tree nutritional status and olive production, and decelerated olive tree litter decomposition rates by 21 % and nutrient release. The nutrient retention in organic forms in the fast-growing species of herbaceous covers and the progressive nutrient release as litter decomposes may contribute to regulate and better adapt nutrient availability to the nutrient requirements of olive trees
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