164 research outputs found

    A Comparison of Experiential and Classroom Learning Models in Teaching Health Problems of the Poor

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    The general problem was to assess differences, if any, in selected areas of knowledge, attitudes and behavior among students exposed to a classroom model with students exposed to an experiential (community live-in} model in learning about health problems of the poor. Specific problems included: the selection of instruments, the development of methods and materials for teaching the classroom and experiential groups, and the measurement of students\u27 knowledge, attitudes, and behavior related to the poor and their health problems

    Habitat use by Red Deer and Fallow Deer in Doñana National Park

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    Habitat use by roe and red deer in Southern Spain

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    Modelling of bismuth segregation in InAsBi/InAs superlattices: Determination of the exchange energies

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    InAsBi dilute alloys are potential new candidates for the improvement of infrared optoelectronic devices such as photodetectors or lasers. In this work, InAsBi/InAs superlattices (SLs)with Bi contents ranging between 1 and 3% were grown by molecular beam epitaxy with different Bi fluxes and growth temperatures to analyze Bi segregation by cross sectional transmission electron microscopy techniques. Bi segregation profiles have been described layer-by-layer using a three-layer fluid exchange mechanism, extracting the values of the As/Bi exchange energies (E 1 , 1.26 ± 0.01 eV and E 2 , 1.36 ± 0.02 eV). A relationship to calculate the activation energies for exchange from the binding energies in III–V alloys is proposed, which would allow predicting them for other hitherto unknown compounds

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Relación longitud-peso y condición del Barbo de Sclater (Barbus barbus sclateri G.), en el río Guadiato, Córdoba, España.Estudio biométrico y biológico de la tortuga mora (Testudo graeca) en la Reserva Biológica de Doñana, HuelvaEtograma del lagarto de Tenerife, Gallotia galloti galloti (Sauria-LacertidaeOrganización temporal en las comunidadesde avesAlimentación y relaciones tróficas entre los paseriformes en paso otoñal por una localidad de Andalucía centralVariación anual de régimen alimenticio y densidad de población de dos estrigiformes:sus causaslas Adeidas en la cuenca del Duero.Niveles de contaminantes organoclorados y metales pesados en huevos de aves de las Marismas del Guadalquivir, 1975Alimentación primaveral de la garcilla bueyera.la reproducción de un ave parásita: el tordomirlo (Molothrus bonariensis) en los llanos de Apure (Venezuela)Estructuras de sexos y edades en una poblaciónde conejos (Oryctolagus cunicuLus l.) de Andalucía OccidentaParámetros de gregarismo del gamo (Dama dama) en el Coto de Doñana.Primeros datos sobre la distribución de Cobitis calderoni Bacescu, 1961 (pisces, cobitidae) en la Península IbéricaSobre la existencia de Telestes soufia Risso, 1826 y Leuciscus leuciscus L. 1758 en España.La distrtibución de Hemidactylus turciscus en la provincia de Córdoba.Predación de Vipera latastei sobre Mustela nivalis.Sobre las poblaciones de Podarcis en el macizo del GuadarramaDatos sobre la reproducción de Lacerta vivipara en la cordillera CantábricaCasos de melanismo en Natrix natrix y Malpolon monspessulanusMedidas máximas para Coluber hippocrepis LUna nueva población de Lacerta sicula rafinesque para el norte de España.Captura de la barnacla carinegra, Branta bernicla en la costa mediterránea Europea.Datos sobre la dieta frugívora del mirlo (Turdus merula) en dos localidades del sur de EspañaLa ocupación de nidos de Hirundo daurica.La invasión de Hirunda daurica Temm. en la Península IbéricaHíbridos de anátidas en las marismas del GuadalquiviDatos sobre la reproducción de Alouatta seniculus en los Llanos de VenezuelaPeer reviewe

    Modeling Ecosystems Using P Systems: The Bearded Vulture, a Case Study

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    The Bearded Vulture (Gypaetus barbatus) is an endangered species in Europe that feeds almost exclusively on bone remains of wild and domestic ungulates. In this paper, we present a model of an ecosystem related to the Bearded Vulture in the Pyrenees (NE Spain), by using P systems. The evolution of six species is studied: the Bearded Vulture and five subfamilies of domestic and wild ungulates upon which the vulture feeds. P systems provide a high level computational modeling framework which integrates the structural and dynamic aspects of ecosystems in a comprehensive and relevant way. P systems explicitly represent the discrete character of the components of an ecosystem by using rewriting rules on multisets of objects which represent individuals of the population and bones. The inherent stochasticity and uncertainty in ecosystems is captured by using probabilistic strategies. In order to experimentally validate the P system designed, we have constructed a simulator that allows us to analyze the evolution of the ecosystem under different initial conditions.Ministerio de Educación y Ciencia TIN2006-13425Junta de Andalucía TIC-58

    Revista de Vertebrados de la Estación Biológica de Doñaña

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    Comportamiento reproductor del camaleón común (Chamaeleo chamaeleon L.) en el sur de EspañaDistribución de los reptiles en la provincia de Granada (SE. Península Ibérica)Datos sobre la reproducción y el crecimientode Psammodromus hispanicus Fitzinger, 1826 en un medio adehesado de la España CentralVariación en la colocación y orientación del nido del Alzacola (Cercotrichas galactotes) en dos especies de árbolesOrganización de la comunidad de aves reproductora en las landas montanas del País Vasco AtlánticoEcología de una población ibérica de lobos (Canis Lupus)Etude biométrique des Crosidures (Soricidae, Insectivora) de la región de Massa (Souss, Maroe).Variación geográfica del género Eliomys en la Península IbéricaTendencias gregarias del Ciervo (Cervus elaphus) en Doñana.Data on the autumn diet of the red deer (Cervus elaphus L. 1758) in the Montes de Toledo (Central Spain)Nota sobre la coexistencia de Hyla arborea (L. 1758E Hyla meridionalis (Boettger 1874) rn rl Valle del TiétarCalendario reproductivo y tamaño de las puesta en el galápago leproso, Mauremys leprosa (Shweigger, 1812), en Doñana, HuelvaPelícola (Felicola) inaqualis Piager, 1880 (MALLOPHAGA:TRICHODECTIDAE) parásito deE Herpestes ichneumon L (CARNIVORA: HERPESTIDAE)Abundancia y amplitud de los desplazamientos de Apodemus sylvaticus en cuatro biotopos de Doñana que difieren en cobertura vegetalPeer reviewe

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Descripción de una nueva subespecie de lagarto ágil (Lacerta agilis garzoni) de los PirineosDiet of the Montagu's Harrier (Circus pygargus) in southwestern Spain SpainObservaciones ornitológicas en la Guayana francesaDaily feeding rhythm of ducks on the marismas of the Guadalquivir and their responses to birds of preyA note on the emetic technique for obtaining food samples from passerine birds.Distribución de contaminantes organoclorados en tejidos de garza imperial (Ardea purpurea) y pato cuchara (Anas clypeata) de la Reserva Biológica de Doñana.Etograma cuantificado del gamo (Dama dama) en libertad.Peer reviewe

    Mother's occupation and sex ratio at birth

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    <p>Abstract</p> <p>Background</p> <p>Many women are working outside of the home, occupying a multitude of jobs with varying degrees of responsibilities and levels of psychological stress. We investigated whether different job types in women are associated with child sex at birth, with the hypothesis that women in job types, which are categorized as "high psychological stress" jobs, would be more likely to give birth to a daughter than a son, as females are less vulnerable to unfavourable conditions during conception, pregnancy and after parturition, and are less costly to carry to term.</p> <p>Methods</p> <p>We investigated the effects of mother's age, maternal and paternal job type (and associated psychological stress levels) and paternal income on sex ratio at birth. Our analyses were based on 16,384 incidences of birth from a six-year (2000 to 2005 inclusive) childbirth dataset from Addenbrooke's Hospital in Cambridge, UK. We obtained a restricted data set from Addenbrooke's hospital with: maternal age, maternal and paternal occupations, and whether or not the child was first-born.</p> <p>Results</p> <p>Women in job types that were categorized as "high stress" were more likely to give birth to daughters, whereas women in job types that were categorized as "low stress" had equal sex ratios or a slight male bias in offspring. We also investigated whether maternal age, and her partner's income could be associated with reversed offspring sex ratio. We found no association between mother's age, her partner's job stress category or partner income on child sex. However, there was an important interaction between job stress category and partner income in some of the analyses. Partner income appears to attenuate the association between maternal job stress and sex ratios at moderate-income levels, and reverse it at high-income levels.</p> <p>Conclusions</p> <p>To our knowledge this is the first report on the association between women's job type stress categories and offspring sex ratio in humans, and the potential mitigating effect of their partners' income.</p

    Synthesis of diamondlike carbon films with superlow friction and wear properties

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    In this study, the authors introduce a new diamondlike carbon (DLC) film providing a friction coefficient of 0.001 and wear rates of 10{sup {minus}9} to 10{sup {minus}10} mm{sup 3}/N.m in inert-gas environments (e.g., dry nitrogen and argon). The film was grown on steel and sapphire substrates in a plasma enhanced chemical vapor deposition system that uses using a hydrogen-rich plasma. Employing a combination of surface and structure analytical techniques, they explored the structural chemistry of the resultant DLC films and correlated these findings with the friction and wear mechanisms of the films. The results of tribological tests under a 10-N load (creating initial peak Hertz pressures of 1 and 2.2 GPa on steel and sapphire test pairs, respectively) and at 0.2 to 0.5 m/s sliding velocities indicated that a close correlation exists between the friction and wear coefficients of DLC films and the source gas chemistry. Specifically, films grown in source gases with higher hydrogen-to-carbon ratios had the lowest fiction coefficients and the highest wear resistance. The lowest friction coefficient (0.001) was achieved with a film on sapphire substrates produced in a gas discharge plasma consisting of 25% methane and 75% hydrogen
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