220 research outputs found

    Estrategias en el manejo reproductivo de la cerda para la mejora de la fertilidad = Reproductive management strategies for improving sow fertility

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    237 p.El presente trabajo de Tesis Doctoral aborda cuatro ensayos experimentales cuyo principal objetivo ha sido la mejora del rendimiento reproductivo de la cerda mediante la identificación de las nulíparas con el mayor potencial fértil y la implantación de nuevas técnicas de manejo de la reproducción que mejoren la fertilidad en partos subsiguientes

    Spatiotemporal Analysis of Urban Thermal Effects Caused by HeatWaves through Remote Sensing

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    In recent years there has been an increase in the number of extreme weather events that lead to higher mortality, such as heat waves. This study carries out a new investigation that integrates the environmental quality parameters-the Surface Urban Heat Island (SUHI) and the Terrestrial Surface Temperature (LST)-during these periods of high temperatures and compares them with normal periods. The study of the relationship between these variables will allow improving the quality of life through new mitigation measures that will minimize the effects of climate change in urban areas. This study analyzes eight cities in the south of Spain (Andalusia) to assess environmental quality through gases SO2, NO2, CO, O-3 and aerosols, obtained through Sentinel-5P satellite images, and the LST and SUHI obtained through Sentinel-3 images. Next, the results of periods of heat waves are compared with periods of normal environmental conditions during the summers of the years 2020 and 2021. The objective is to determine the possible impact of heat waves on environmental quality, as well as on the LST and SUHI of the investigated cities, which are located in an area identified as highly vulnerable to the effects of global warming. During the period of the heat wave and compared to the periods without a heat wave, a variety of environmental pollutants was found: SO2 (+165%), NO2 (+24%), CO (+8%), O-3 (-4%) and aerosols (+193%). Both the LST and the SUHI suffered an average increase of 2.8 K. The results of this document can help to establish pollutant reduction mechanisms in periods prior to heat waves. This could minimize major effects on the population and provide sustainable development

    Beyond liberal discourse: Teachers’ conceptions of democracy and education in England and Spain

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    This study explores the conceptions developed by primary and secondary education teachers in Spain and England about democracy in education. To this end, we conducted a phenomenographic study involving 39 teachers. The results identify four major conceptions of democracy in education: (a) democracy as freedom, (b) democracy understood as participation and collaboration, (c) democracy as a principle for achieving social justice in schools and in the education system and (d) democracy as a principle to learn to live together and social norms. The discussion highlights that the way teachers articulate their conceptions is dominated by a liberal discourse of democracy in education. However, their ideas also show other nuances and traces of more open perspectives. This work stresses the importance of continuing to investigate teachers’ conceptions and how alternatives to the dominant trend can be glimpsed through them

    Does hotel management matter to overcoming the COVID-19 crisis? The Spanish case

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    This paper analyses the influence that the initial actions and strategies pursued by hotel managers have on the recovery of occupancy after a crisis such as the COVID-19 pandemic. To do this, a specific survey is carried out on managers of Spanish hotels. The main findings show that labour actions, especially plans for temporary employment regulations, innovation and differentiation strategies, reorientation to closer markets and obtaining information from official sources as a guarantee of their certainty, are the measures that have a greater impact on the possibilities of recovering hotel activity. In addition, government measures that contribute to the improvement of the financial situation of firms can also play a relevant role in hotel recoveryThis research was supported by the Spanish Ministry of Science and Innovation (Research Project ECO2017-82445-R). We appreciate the comments of three anonymous reviewers who have significantly improved the articl

    Larva 2021: metamorfosis de una escritura plural. Homenaje a Julián Ríos

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    Presentación del dossierPresentación del dossie

    Larva 2021: metamorfosis de una escritura plural. Homenaje a Julián Ríos

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    Presentación del dossierPresentación del dossie

    Optimization of Multimedia Embedded Applications using Parallel Genetic Algorithms

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    Energy-efficient design of multimedia embedded systems demands optimizations in both hardware and software. Software optimization has no received much attention, although modern multimedia applications exhibit high resource utilization. In order to efficiently run this kind of applications in embedded systems, the dynamic memory subsystem needs to be optimized. A key role in this optimization is played by the Dynamic Data Types (DDTs) that reside in every reallife application. It would be desirable to organize this set of DDTs to achieve the best performance in the target embedded system. This problem is NP-complete, and cannot be fully explored. In these cases the use of parallel processing can be very usefull because it allows not only to explore more solutions spending the same time, but also to implement new algorithms. In this work, we propose a method that uses parallel processing and evolutionary computation to explore DDTs in the design of embedded applications. We propose a parallel Multi-Objective Evolutionary Algorithm (MOEA) which combines NSGA-II and SPEA2. We use Discrete Event Systems Specification (DEVS) to implement this parallel evolutionary algorithm over Service Oriented Architecture (SOA). Parallelism improves the solutions found by the corresponding sequential algorithms, and it allows system designers to reach better solutions than previous approximation

    Inoculation with rumen fluid in early life as a strategy to optimize the weaning process in intensive dairy goat systems

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    Ruminants are born with an undeveloped physical, metabolic, and microbial rumen. Rumen development is limited under artificial rearing systems when newborn animals are separated from the dam, fed on milk replacer, and weaned at an early age. This study aims to evaluate the effects of early-life inoculation of young ruminants with rumen fluid from adult animals. Eighty newborn goat kids were randomly allocated to 1 of 4 experimental treatments and inoculated daily from d 1 to wk 11 with autoclaved rumen fluid (AUT), fresh rumen fluid obtained from adult goats fed either a forage diet (RFF) or concentrate-rich diet (RFC), or absence of inoculation (CTL). Goat kids were artificially reared with ad libitum access to milk replacer, starter concentrate, and forage hay. Blood was sampled weekly and rumen microbial fermentation was monitored at 5 (preweaning), 7 (weaning), and 9 wk of age (postweaning). Results indicated that inoculation with fresh rumen fluid accelerated the rumen microbial and fermentative development before weaning. As a result, RFC and RFF animals had higher solid feed intake (+73%), rumen concentrations of ammonia-N (+26%), total volatile fatty acids (+46%), butyrate (+50%), and plasma β-hydroxybutyrate (+48%), and lower milk intake (−6%) than CTL and AUT animals at wk 5. Inoculation with fresh inoculum also promoted early rumen colonization by a complex and abundant protozoal community, whereas CTL animals remained protozoa free. Although all kids experienced moderate growth retardation during 1 wk after weaning, inoculation with fresh rumen fluid favored the weaning process, leading to 2.2 times higher weight gain than CTL and AUT animals during wk 8. Some of these advantages were retained during the postweaning period and RFF and RFC animals showed higher forage intake (up to +44%) than CTL and AUT animals with no detrimental effects on feed digestibility or stress levels. The superior microbial load of RFC compared with RFF inoculum tended to provide further improvements in terms of forage intake, plasma β-hydroxybutyrate, and rumen protozoa, whereas AUT inoculation provided minor (if any) advantages with respect to CTL animals. Although no differences were noted on animal growth, this study suggests that early life inoculation of goat kids with rumen microbiota can represent an effective strategy to accelerate the rumen development, facilitating a smooth transition from milk to solid feed and to the potential implementation of early weaning strategies.This study was funded by the Spanish government through the project AGL2017-86938-R and the Training Program for Academics grant, Madrid, Spain (FPU16/01981)

    Extracellular Vesicles, the Road toward the Improvement of ART Outcomes

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    Nowadays, farm animal industries use assisted reproductive technologies (ART) as a tool to manage herds’ reproductive outcomes, for a fast dissemination of genetic improvement as well as to bypass subfertility issues. ART comprise at least one of the following procedures: collection and handling of oocytes, sperm, and embryos in in vitro conditions. Therefore, in these conditions, the interaction with the oviductal environment of gametes and early embryos during fertilization and the first stages of embryo development is lost. As a result, embryos obtained in in vitro fertilization (IVF) have less quality in comparison with those obtained in vivo, and have lower chances to implant and develop into viable offspring. In addition, media currently used for IVF are very similar to those empirically developed more than five decades ago. Recently, the importance of extracellular vesicles (EVs) in the fertility process has flourished. EVs are recognized as effective intercellular vehicles for communication as they deliver their cargo of proteins, lipids, and genetic material. Thus, during their transit through the female reproductive tract both gametes, oocyte and spermatozoa (that previously encountered EVs produced by male reproductive tract) interact with EVs produced by the female reproductive tract, passing them important information that contributes to a successful fertilization and embryo development. This fact highlights that the reproductive tract EVs cargo has an important role in reproductive events, which is missing in current ART media. This review aims to recapitulate recent advances in EVs functions on the fertilization process, highlighting the latest proposals with an applied approach to enhance ART outcome through EV utilization as an additive to the media of current ART procedures
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