1,714 research outputs found
Mesoscopic constitutive relations for dilute polymer solutions
A novel approach to the dynamics of dilute solutions of polymer molecules
under flow conditions is proposed by applying the rules of mesoscopic
nonequilibrium thermodynamics (MNET). The probability density describing the
state of the system is taken to be a function of the position and velocity of
the molecules, and on a local vector parameter accounting for its deformation.
This function obeys a generalized Fokker-Planck equation, obtained by
calculating the entropy production of the system, and identifying the
corresponding probability currents in terms of generalized forces. In simple
form, this coarse-grained description allows one to derive hydrodynamic
equations where molecular deformation and diffusion effects are coupled. A
class of non-linear constitutive relations for the pressure tensor are
obtained. Particular models are considered and compared with experiments.Comment: To be published in Physica A (16 pages, 2 figures
Problemática de la peste porcina africana en Europa. Alternativas futuras
African swine fever (ASF) is one of the most important infectious diseases of swine. It is a complex disease caused by African swine fever virus (ASFV), the only member of the Asfarviridae family, without available vaccine or effective treatment. The latest introduction of ASFV in Europe was in 2007 through Georgia and rapidly spreading to Eastern European countries. The first cases of ASF in the European Union (EU) were reported in 2014, producing 2346 outbreaks so far. It currently represents a huge threat to the EU pig production since the EU is the second largest pig producer and the largest exporter in the world.La peste porcina africana (PPA) es una de las enfermedades infecciosas más importantes en la especie porcina. Se trata de una enfermedad compleja producida por el virus de la peste porcina africana (VPPA) para la que no se dispone de vacuna ni tratamiento efectivo. La última introducción del VPPA en Europa tuvo lugar en 2007 a través de Georgia, expandiéndose rápidamente por los países de Europa del Este. En 2014 se dieron los primeros casos de PPA en la Unión Europea (UE), produciéndose 2.346 brotes hasta el momento. Teniendo en cuenta que la UE es el segundo productor de carne de porcino y la principal exportadora del planeta, en la actualidad, la PPA representa una amenaza para la producción porcina europea
Performance of malolactic fermentation by inoculation of selected Lactobacillus plantarum and Oenococcus oeni strains isolated from Rioja red wines
Malolactic fermentations (MLF) of wines inoculated with selected lactic acid bacteria strains of the species Oenococcus oeni and Lactobacillus plantarum were studied and compared with spontaneous MLF. Bacterial populations were monitored along the whole process of MLF and bacteria identifications were carried out at species and strain level. Macrorestriction analysis with SfiI endonuclease and subsequent PFGE was carried out in order to identify O. oeni individual strains. L. plantarum active lyophila did not survive competing with the indigenous microbiota in a wine with 15.3 % (vol/vol) alcohol, whereas the selected O. oeni strains carried out wine MLF. The highest production of histamine took place during MLF in those wines that underwent spontaneous MLF with a mixed population of indigenous strains. The lowest levels of histamine were obtained with the selected commercial O. oeni strain that succeeded 100 % over the indigenous microbiota. Results indicate that development of MLF leaded by selected O. oeni active lyophila provides negligible histamine levels in red wines of quality that can be submitted to subsequent ageing in wood.
Aprovechamiento de la política pública en el fomento de la empresa familiar
The policy of promoting businesses is looks for exploiting the potential of the country, the objective of this study was: To determine the use of public policies in the growth of the family business.The descriptive research was applied to two hundred and twelve family businesses and the results found were: Family businesses are run by family members, especially the founder, with a capacity to improve the quality of life of their workers, which coincides with the National Plan for Good Living. Public policies have not been considered of long term and for this specialized educational strategies in family have been created and in recruitment of technical staff in areas of organizational development.La política de promoción de las empresas nace desde la constitución y planes de desarrollo; en Ecuador, se busca el aprovechamiento de la potencialidad del país, buscando investigar el nivel de aprovechamiento de las políticas públicas en el crecimiento de la empresa familiar. Se considera 212 empresas familiares de la Provincia de Tungurahua a las cuales se aplica un cuestionario que arroja resultados medidos por test de Kruskal Wallis.Se encuentra que las empresas familiares participan activamente en programas de fomento auspiciados por el Estado como capacitación, financiamiento, asesoramiento en procesos y gestión administrativa. Por su parte, las empresas crean estrategias de educación especializada de la familia propietaria y contratación de personal especializado en áreas de desarrollo de la organización.
Modeling Biomass Production in Seasonal Wetlands Using MODIS NDVI Land Surface Phenology
Plant primary production is a key driver of several ecosystem functions in seasonal marshes, such as water purification and secondary production by wildlife and domestic animals. Knowledge of the spatio-temporal dynamics of biomass production is therefore essential for the management of resources—particularly in seasonal wetlands with variable flooding regimes. We propose a method to estimate standing aboveground plant biomass using NDVI Land Surface Phenology (LSP) derived from MODIS, which we calibrate and validate in the Doñana National Park’s marsh vegetation. Out of the different estimators tested, the Land Surface Phenology maximum NDVI (LSP-Maximum-NDVI) correlated best with ground-truth data of biomass production at five locations from 2001–2015 used to calibrate the models (R2 = 0.65). Estimators based on a single MODIS NDVI image performed worse (R2 ≤ 0.41). The LSP-Maximum-NDVI estimator was robust to environmental variation in precipitation and hydroperiod, and to spatial variation in the productivity and composition of the plant community. The determination of plant biomass using remote-sensing techniques, adequately supported by ground-truth data, may represent a key tool for the long-term monitoring and management of seasonal marsh ecosystems.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).David Aragonés, Isabel Afán, Ricardo Díaz-Delgado and Diego García Díaz (EBD-LAST)
provided support for remote-sensing and LSP analyses. Alfredo Chico, José Luis del Valle and Rocío Fernández
Zamudio (ESPN, ICTS-RBD) provided logistic support and taxonomic expertise during the field work (validation
dataset). Ernesto García and Cristina Pérez assisted with biomass harvesting and processing (calibration dataset).
Gerrit Heil provided support in the project design. This study received funding from Ministerio de Medio
Ambiente-Parque Nacional de Doñana, Consejeria de Medio Ambiente, Junta de Andalucia (1999–2000): RNM118
Junta de Andalucia (2003); the European Union’s Horizon 2020 Research and Innovation Program under grant
agreement No. 641762 to ECOPOTENTIAL project; and the Spanish Ministry of Economy, Plan Estatal de I+D+i
2013–2016, under grant agreement CGL2016-81086-R to GRAZE project
Tres notas sobre el lenguaje cinematográfico de Pasolini en el Decamerón
En estas breves notas se analizarán los elementos propios del lenguaje cinematográfico como son el montaje, el sonido, la estructura narrativa y el uso que de ellos hace Pasolini para lograr una visión popular de la obra de Boccaccio
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