3,037 research outputs found

    The Effects of Stochastic Water Availability on Water Allocations in Utah

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    A methodology to estimate stochastic surface water flows was developed and applied to a case study area using chance constrained programming model. The results were analyzed as to the effects on different areas of production in Utah

    A Chance-Constrained Programming Model of Water Allocations in Utah

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    A chance-constrained separable programming model of water allocations between agriculture and energy production was developed in order to examine the effect of the variability of water supplies in Utah. Using an incomplete gamma function, based on method of moments estimation of parameters, the water flows at 85, 90, and 95 percent probabilities of occurence were generated. These flows were then used as constraints in the allocation model. Results indicate that water quality could be a more significant constraint on irrigated agriculture than water quantity in the face of large scale energy development, and the variability of water availability alone is likely not to be a significant factor in economic growth in Utah

    Situación actual del personal técnico-deportivo en las empresas del sector en la Comunidad Valenciana

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    Actualmente, el tema de los recursos humanos está produciendo un fuerte impacto en España y sólo hay que acercarse a la bibliografía empresarial para comprobar que el estudio del sector de la actividad física y el deporte representa un campo de interés científico y social que requiere ser investigado. Mediante una metodología cuantitativa de corte descriptivo y mediante el empleo de la entrevista estandarizada como instrumento de recogida de información se reproducen aquellas características más relevantes observadas en la Comunidad Valenciana. Los resultados explican que las personas que trabajan en funciones físico-deportivas en empresas del sector son mayoritariamente hombres jóvenes que desarrollan una amplia variedad de las mismas, con situaciones laborales en las que no existe contratación y manifestando una elevada temporalidad. Asimismo, el estudio revela que más de la mitad de las personas desempeñan su trabajo con una duración laboral que no supera los cuatro años, existiendo personas sin titulación oficial de actividad física y deporte, y siendo el aspecto más importante para encontrar trabajo los contactos personales

    Characterization Of Chemically Induced Ovarian Carcinomas In An Ethanol-preferring Rat Model: Influence Of Long-term Melatonin Treatment.

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    Ovarian cancer is the fourth most common cause of cancer deaths among women, and chronic alcoholism may exert co-carcinogenic effects. Because melatonin (mel) has oncostatic properties, we aimed to investigate and characterize the chemical induction of ovarian tumors in a model of ethanol-preferring rats and to verify the influence of mel treatment on the overall features of these tumors. After rats were selected to receive ethanol (EtOH), they were surgically injected with 100 µg of 7,12-dimethyl-benz[a]anthracene (DMBA) plus sesame oil directly under the left ovarian bursa. At 260 days old, half of the animals received i.p. injections of 200 µg mel/100 g b.w. for 60 days. Four experimental groups were established: Group C, rats bearing ovarian carcinomas (OC); Group C+EtOH, rats voluntarily consuming 10% (v/v) EtOH and bearing OC; Group C+M, rats bearing OC and receiving mel; and Group C+EtOH+M, rats with OC consuming EtOH and receiving mel. Estrous cycle and nutritional parameters were evaluated, and anatomopathological analyses of the ovarian tumors were conducted. The incidence of ovarian tumors was higher in EtOH drinking animals 120 days post-DMBA administration, and mel efficiently reduced the prevalence of some aggressive tumors. Although mel promoted high EtOH consumption, it was effective in synchronizing the estrous cycle and reducing ovarian tumor mass by 20%. While rats in the C group displayed cysts containing serous fluid, C+EtOH rats showed solid tumor masses. After mel treatment, the ovaries of these rats presented as soft and mobile tissues. EtOH consumption increased the incidence of serous papillary carcinomas and sarcomas but not clear cell carcinomas. In contrast, mel reduced the incidence of sarcomas, endometrioid carcinomas and cystic teratomas. Combination of DMBA with EtOH intake potentiated the incidence of OC with malignant histologic subtypes. We concluded that mel reduces ovarian masses and the incidence of adenocarcinomas in ethanol-deprived rats.8e8167

    Actualizaciones Institucionales

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    Serendipitous discovery of RR Lyrae stars in the Leo V ultra-faint galaxy

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    During the analysis of RR Lyrae stars discovered in the High cadence Transient Survey (HiTS) taken with the Dark Energy Camera at the 4-m telescope at Cerro Tololo Inter-American Observatory, we found a group of three very distant, fundamental mode pulsator RR Lyrae (type ab). The location of these stars agrees with them belonging to the Leo V ultra-faint satellite galaxy, for which no variable stars have been reported to date. The heliocentric distance derived for Leo V based on these stars is 173 +/- 5 kpc. The pulsational properties (amplitudes and periods) of these stars locate them within the locus of the Oosterhoff II group, similar to most other ultra-faint galaxies with known RR Lyrae stars. This serendipitous discovery shows that distant RR Lyrae stars may be used to search for unknown faint stellar systems in the outskirts of the Milky Way.Comment: Accepted in ApJ Letter

    Ali Mustafá Cave: a new archaeological site with an early occupation in the Eastern Tandilia Mountain Range (Argentina)

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    Se exponen los resultados preliminares de los trabajos arqueológicos realizados en la Cueva Ali Mustafá, sitio que se suma a otros reparos rocosos usados por grupos de cazadores-recolectores bajo la modalidad de ocupaciones de corta duración ocurridas durante la transición Pleistoceno-Holoceno. La información que incorpora este nuevo sitio temprano apoya una propuesta anterior sobre el valor arqueológico que tuvieron los reparos rocosos que poseen ocupaciones efímeras, en algunos casos presentan ocupaciones redundantes y se localizan en relación estratégica con el paisaje serrano. Este sitio fue seleccionado para su uso como paradero durante las travesías por los valles serranos y por su localización de alta visualización del valle de San Pedro.Here we present the preliminary results of the archaeological research in Ali Mustafá Cave. This site is one of several rockshelters used by hunter-gatherer groups for shortterm occupations during the Pleistocene-Holocene transition. The data from this new early site supports previous research regarding the archaeological value of rock shelters with ephemeral occupations. In some cases, these shelters show evidence of recurrent occupations, and were located in a strategic position in relation with the surrounding mountain landscape. Due to its location with high visual dominance over the San Pedro Valley, this site was used as a stopover during movement through the intermontane valleys.Fil: Mazzanti, Diana Leonis. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Departamento de Historia. Laboratorio de Arqueología Regional Bonaerense; ArgentinaFil: Bonnat, Gustavo Federico. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Departamento de Historia. Laboratorio de Arqueología Regional Bonaerense; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Donadei Corada, Juanpablo. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Departamento de Historia. Laboratorio de Arqueología Regional Bonaerense; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Martinez, Gustavo A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; Argentin

    Constrained simulations of the local universe: I. Mass and motion in the Local Volume

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    It has been recently claimed that there is no correlation between the distribution of galaxies and their peculiar velocities within the Local Volume (LV), namely a sphere of R=7/h Mpc around the Local Group (LG). It has been then stated that this implies that either locally dark matter is not distributed in the same way as luminous matter, or peculiar velocities are not due to fluctuations in mass. To test that statement a set of constrained N-body cosmological simulations, designed to reproduce the main observed large scale structure, have been analyzed. The simulations were performed within the flat-Lambda, open and flat matter only CDM cosmogonies. Two unconstrained simulations of the flat-Lambda and open CDM models were performed for comparison. LG-like objects have been selected so as to mimic the real LG environment. The local gravitational field due to all halos found within each LV is compared with the exact gravitational field induced by all matter in the simulation. We conclude that there is no correlation between the exact and the local gravitational field obtained by pairwise newtonian forces between halos. Moreover, the local gravitational field is uncorrelated with the peculiar velocities of halos. The exact gravitational field has a linear correlation with peculiar velocities but the proportionality constant relating the velocity with gravitational field falls below the prediction of the linear theory. Upon considering all matter inside the LVs, the exact and local gravitational accelerations show a much better correlation, but with a considerable scatter independent on the cosmological models. The main conclusion is that the lack of correlation between the local gravitation and the peculiar velocity fields around LG-like objects is naturally expected in the CDM cosmologies.Comment: 10 pages, 19 figures. Accepted for publication in MNRA
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