Study of different strategies of control for geostationary satellites

The aim of the study is to determine the required maneuvers to control geostationary satellites within a delimited control window. It will be done defining different strategies of control for the calculation of impulsive maneuvers to obtain optimal values which will minimize the fuel consumption and will provide an automatic control for any situation. For each implemented strategy, an algorithm will be developed. These algorithms will be applied to some relevant longitudes in order to prove that they could be used for any longitude yielding good results. The geostationary control will only implement in-plane maneuvers (East/West). This means that only the longitude and the radial direction will be controlled, ignoring changes in inclination

Características personales y culturales de los emprendedores potenciales y su influencia en el autoempleo

[ES]El objetivo de este estudio es investigar las variables personales, culturales y contextuales que presentan los emprendedores potenciales y su influencia y mediación en la intención de emprender. En un primer momento definimos el término emprendedor haciendo referencia a diferentes clasificaciones señaladas por distintos autores, todas ellas realizadas en base a diferentes características, y determinando los distintos tipos de emprendedores que diferenciamos según nuestro criterio. Una vez clarificamos el concepto establecemos el marco teórico de referencia realizando un recorrido histórico del concepto de emprendedor, considerando la evolución del término y detallando las principales características según los diferentes enfoques que se resaltan dependiendo de la ciencia que lo estudie. Presenta una especial relevancia el estudio de las intenciones a la hora de iniciar cualquier proyecto, ya que constituye el punto de partida del emprendedor, desde esta perspectiva, realizamos una reflexión sobre diferentes enfoques y seleccionamos los modelos que más se adecuan a nuestro estudio. Seguidamente, en base a trabajos de diferentes autores, determinamos las características de la personalidad de los emprendedores que más les definen y que incluiremos en nuestro estudio una vez puntualizadas y detalladas. Con el fin de poder realizar un estudio conjunto que explique la intención emprendedora, teniendo en cuenta los rasgos de la personalidad y la influencia del contexto social en el emprendimiento, realizamos un recorrido por diferentes teorías en relación a los valores culturales, señalando y valorando las más interesantes para el estudio y profundizando en las diferentes dimensiones de cada una de ellas. Señalamos algunos aspectos contextuales y motivacionales, afectados por la diversidad regional. Para finalizar establecemos la relación entre las dos dimensiones: social y personal. Profundizamos en la inclusión y conceptualización de los rasgos característicos de los emprendedores y su relación con los valores y actitud hacía el emprendimiento y la percepción de los motivos, barreras y oportunidades que influyen en la intención de emprender. Una vez establecido el marco teórico de referencia y definidas las variables de estudio, realizamos el análisis de las mismas entre un grupo de estudiantes universitarios de diferentes Comunidades Autónomas y de diferentes contextos personales y familiares. Consideramos que la muestra de universitarios es la más adecuada para el estudio que nos proponemos siguiendo la idea defendida por diferentes autores. Los resultados muestran que los factores personales afectan a la decisión de emprender, de la misma manera que los factores sociales y culturales. Encontramos diferencias significativas en relación al sexo, estudios cursados, trabajo de los progenitores y Comunidad Autónoma de procedencia. Nuestro estudio también pone de manifiesto que la actitud, factibilidad y valoración social actúan como mediadoras en la relación factores predictores e intención de emprender. EL trabajo concluye con la discusión de las implicaciones prácticas y la identificación de posibles futuras líneas de trabajo que refuercen los resultados obtenidos

Modelling landscape management scenarios for equitable and sustainable futures in rural areas based on ecosystem services

Scenario analysis is a useful technique to inform landscape planning of social-ecological systems by modelling future trends in ecosystem service supply and distribution. This is especially critical in floodplain agroecosystems of rural areas, which are at risk of losing riparian forest corridors due to increasing land use conversion for agricultural production and other ecosystem services due to rural abandonment. However, few studies investigating the effects of land management combine social and ecological modelling in scenario analyses. We estimated the supply of 16 ecosystem services under five alternative scenarios along two gradients: agricultural intensification of the floodplain and active ecological restoration of the riparian forest. We used redundancy analyses to detect ecosystem service bundles and interviews to identify societal gains and losses associated with each management scenario. Our results show how land management influences both the supply and distribution of ecosystem services. Scenarios promoting active ecological restoration supplied more services and benefited a larger range of societal sectors than scenarios focused on provisioning services. We also found two consistent bundles across scenarios, one related to less intensive food supply and another one related to outdoor activities. Interestingly, additional services were included in these bundles in the different scenarios, reflecting land management effects. Landscape scale management promoting both the conservation of ecosystem functioning and the sustainable use of provisioning services could supply a more balanced set of ecosystem services and benefit a larger number of societal sectors, contributing to more equitable and sustainable futures in rural areas

Effects of Previous Land-Use on Plant Species Composition and Diversity in Mediterranean Forests

At some point in their history, most forests in the Mediterranean Basin have been subjected to intensive management or converted to agriculture land. Knowing how forest plant communities recovered after the abandonment of forest-management or agricultural practices (including livestock grazing) provides a basis for investigating how previous land management have affected plant species diversity and composition in forest ecosystems. Our study investigated the consequences of historical “land management” practices on present-day Mediterranean forests by comparing species assemblages and the diversity of (i) all plant species and (ii) each ecological group defined by species’ habitat preferences and successional status (i.e., early-, mid-, and late-successional species). We compared forest stands that differed both in land-use history and in successional stage. In addition, we evaluated the value of those stands for biodiversity conservation. The study revealed significant compositional differentiation among stands that was due to among-stand variations in the diversity (namely, species richness and evenness) of early-, intermediate-, and late-successional species. Historical land management has led to an increase in compositional divergences among forest stands and the loss of late-successional forest species

Plant β-diversity i in human-altered forest ecosystems: the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages

An understanding of spatial patterns of plant species diversity and the factors that drive those patterns is critical for the development of appropriate biodiversity management in forest ecosystems. We studied the spatial organization of plants species in human- modified and managed oak forests (primarily, Quercus faginea) in the Central Pre- Pyrenees, Spain. To test whether plant community assemblages varied non-randomly across the spatial scales, we used multiplicative diversity partitioning based on a nested hierarchical design of three increasingly coarser spatial scales (transect, stand, region). To quantify the importance of the structural, spatial, and topographical characteristics of stands in patterning plant species assemblages and identify the determinants of plant diversity patterns, we used canonical ordination. We observed a high contribution of ˟-diversity to total -diversity and found ˟-diversity to be higher and ˞-diversity to be lower than expected by random distributions of individuals at different spatial scales. Results, however, partly depended on the weighting of rare and abundant species. Variables expressing the historical management intensities of the stand such as mean stand age, the abundance of the dominant tree species (Q. faginea), age structure of the stand, and stand size were the main factors that explained the compositional variation in plant communities. The results indicate that (1) the structural, spatial, and topographical characteristics of the forest stands have the greatest effect on diversity patterns, (2) forests in landscapes that have different land use histories are environmentally heterogeneous and, therefore, can experience high levels of compositional differentiation, even at local scales (e.g., within the same stand). Maintaining habitat heterogeneity at multiple spatial scales should be considered in the development of management plans for enhancing plant diversity and related functions in human-altered forest

Use of water soluble extracts from ulva sp. by probiotics and fish bacterial pathogens

BACKGROUNDS The potential of seaweeds as dietary components is considered for a wide range of cultured fish species. In this context, Ulva is investigated as a good source of protein, minerals and vitamins. In addition, of probiotics are used to improve fish growth and modulate immune system and intestinal microbiota. To promote probiotics colonization and maintenance in the intestine, prebiotics are included in fish diets. Prebiotics are indigestible substrates used as energy sources for gastrointestinal microbiota, with a positive effect on the nutrition and health status of the host. In the present work, ability of selected probiotic and fish pathogen strains to use water soluble extracts from Ulva as nutrient source has been evaluated. MATERIALS AND METHODS Water-soluble extracts from Ulva sp. prepared by sonication of dehydrated samples were used to supplement minimum medium (M9). Probiotics and pathogens growth was evaluated based on the optical densities measured with a microplate reader. RESULTS AND CONCLUSIONS Probiotics were able to grow in minimum medium using water soluble extracts as nutrient source. On the other hand, P. damselae subsp. piscicida and V. harveyistrains were also able to grow with Ulvaextracts as nutrient source. However, incubation time to reach maximum growth was longer. Although Ulva extract may support growth of both probiotics and pathogen bacteria, faster growth of probiotics may help for the establishment of probiotic populations in the intestinal environment. In addition, beneficial effects on growth performance, gut microbiota, immunity and disease resistance of Ulva for Solea senegalensisare being studied. This work was funded by INIA, Ministerio de Economía y Competitividad and FEDER (RTA201400023 C0202).This work was funded by INIA, Ministerio de Economía y Competitividad and FEDER (RTA201400023 C0202).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Bias correction of global irradiance modelled with the Weather Research and Forecasting model over Paraguay

" In this contribution, we present a post-process analysis of the Weather Research and Forecasting (WRF) model which combines a Kalman Filter with Model Output Statistics for bias correction in order to improve the overall predicted values of GHI simulations over Paraguay. The hourly GHI is simulated at 4x4 km2 of spatial resolution. The annual evaluation of the hourly WRF model without post process shows relative mean bias error (rMBE) of 21% and relative root mean square error (rRMSE) of 81%. The results using several ground stations and combinations of post-process show an annual correction of systematic errors with rMBE of -0.7% and rRMSE of 70%."CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI

Bias correction of global irradiance modelled with the Weather Research and Forecasting model over Paraguay

In this contribution, we present a post-process analysis of Weather and Research Forecasting (WRF-ARW) model which combines a Kalman Filter with Model Output Statistics (MOS) for bias correction in order to improve the overall predicted values of GHI simulations over Paraguay.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI

Ovarian Fibrosarcoma: Clinicopathologic Considerations about the Intraoperative and Post-Surgical Procedures

Primary ovarian fibrosarcomas are very uncommon neoplasms. Since the diagnostic criteria were established in 1981, less than one hundred cases have been reported. This diagnosis can be difficult to establish and other similar appearing mesenchymal processes must be ruled out. In every case this diagnosis is under consideration. Multiple sections of the specimen and immunohistochemical stains will be necessary to support this diagnosis. The difficulty of recognition in frozen section in the majority of the situations implies that the diagnosis should be deferred to the definitive study of the permanent sections with immunohistochemical studies. There exists a histological resemblance between a primary ovarian fibrosarcoma and actively mitotic fibroma. In some cases, it can be impossible to separate exactly these two entities. We report a well-differentiated ovarian fibrosarcoma, with less than 1-2 mitosis ×10 HPF and low-grade cytological atypia, similar to active mitotic fibromas, developing liver metastasis one year later. Despite having distant metastasis, some cases with long survival rates have been reported in patients who received chemotherapy after surgery; so that the adjuvant chemotherapy should be considered, especially in young females