2,102 research outputs found

    Modelos poblacionales de dos sexos aplicados a especies poligínicas

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    En este trabajo revisamos un modelo poblacional de dos sexos enfocándolo en la relación entre demografía y estructura social para una especie poligínica. El modelo fue aplicado a la población de elefantes marinos del sur de Península Valdés, una población que muestra tendencias contrastantes en dos subunidades con distinta estructura social. Este enfoque provee un marco general que permite incluir variables sociales en la dinámica de poblaciones como una extensión del modelo lineal estándar y aporta una herramienta al análisis de la dinámica identificando las influencias relativas de cada sexo.We review a two-sex population model and focus on the link between demography and social structure in a polygynous species. The model was applied to the southern elephant seal population of Península Valdés, one that shows contrasting trends in two demographic subunits with distinct social structure. This approach provides a general framework to include social variables into population dynamics. This perspective extends the scope of standard lineal models and adds a tool that identifies the relative effect of changes in number of one sex on the population.Fil: Ferrari, Mariano Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Lewis, Mirtha Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Campagna, Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Wildlife Conservation Society; Estados Unido

    Theoretical definitions and research areas proposed from constructivism, in latin american publications of psychology and education in database Redalyc

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    El objetivo del presente trabajo fue brindar una síntesis actualizada de los lineamientos teóricos y áreas de investigación abordada desde el constructivismo, en revistas latinoamericanas de psicología y educación publicadas durante los últimos diez años aproximadamente. Con tal fin, se exploró la base de datos REDALYC, por ser considerada uno de los principales repositorios latinoamericanos de acceso abierto, con disponibilidad de artículos completos vinculados al área de psicología y educación. En primer lugar, se analizaron los supuestos epistemológicos del constructivismo. En segundo lugar, ya en relación directa con la psicología y la educación, se repasaron los aspectos centrales y las diferenciaciones teóricas internas de dicha perspectiva. Finalmente, se identificaron algunas tendencias temáticas abordadas desde constructivismo en psicología y educación, presentes en la base de datos explorada. Las mismas se agruparon en torno a tres áreas: estrategias de enseñanza-aprendizaje, didáctica de las ciencias, incorporación de las TICs a los procesos de enseñanza-aprendizaje.This paper aimed to provide an updated summary of theoretical tendences and research areas proposed from constructivism, in Latin American journals of psychology and education published during last ten years. For that, we explored the database REDALYC, which is considered as one of main Latin American open-access repository, with full text articles linked to psychology and education. First, we analyzed the epistemological assumptions of constructivism. Then, directly related to psychology and education, we reviewed central aspects and internal theoretical distinctions of this perspective. Finally, we identified some research topics studied from constructivism in psychology and education, in explored database. These were grouped into three areas: teaching and learning strategies, science teaching, and incorporation of TICs into teaching and learning process.Fil: Castellaro, Mariano Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación. Universidad Nacional de Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educacion; Argentin

    On booms and busts in Latin American economies

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    This thesis deals with one obsession: the role of external factors in generating boombust cycles in Latin American countries. In the first chapter, I employ a Markov switching model to statistically validate the claim that the region is currently experiencing a combination of unprecedented favourable external conditions: high commodity prices and low global real interest rates. Based on this evidence, I introduce a model of a resource-rich small open economy with financial frictions in which external conditions switch stochastically between two regimes: “windfall” and “shortfall”. The model is calibrated to Argentina to study how changes in external conditions give rise to boom-bust cycles. I contribute to the current debate on the desirability of controls on capital inflows by studying, from a positive perspective, the effects of introducing a regime contingent tax rate on debt holdings. I conclude that the welfare effect, albeit always very small, is determined by the strength of the domestic financial frictions. The third chapter attempts to empirically evaluate the model by performing an event study. I assess the ability of the model to reproduce the behaviour of the economy during a five-year window period centered around the Great Recession of 2008/09. To capture the external environment following Lehman Brothers’ collapse, I introduce a regime switch in global financial conditions: normal and panic periods. I conclude that the model captures remarkably well the dynamic in this period and that its main weakness is the inability to reproduce the large swings observed in asset prices. The second chapter presents and studies a novel mechanism through which low-frequency fluctuations in foreign interest rates can generate different boom-bust patterns in an internationally borrowing constrained small open economy: intertemporal spillovers via collateral markets. When interest rates are low, the presence of a binding international borrowing constraint creates an intertemporal wedge that spills over into the intertemporal equation for capital due to its dual role as physical capital and financial collateral. As a result, in economies where the main source of collateral is reproducible capital, the spillover effect resembles an investment subsidy and fluctuations are smooth since there are no valuation effects. In contrast, when non-reproducible capital is posted as collateral, the disturbance resembles a financial service dividend and the interest rate fluctuations cause ample swings in macro aggregates due to their strong impact on asset valuations. It is my belief that in these chapters, I have contributed to our understanding of medium-run macroeconomic fluctuations in “semi-peripheral” countries

    Communication: Inferring the equation of state of a metastable hard-sphere fluid from the equation of state of a hard-sphere mixture at high densities

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    A possible approximate route to obtain the equation of state of the monodisperse hard-sphere system in the metastable fluid region from the knowledge of the equation of state of a hard-sphere mixture at high densities is discussed. The proposal is illustrated by using recent Monte Carlo simulation data for the pressure of a binary mixture. It is further shown to exhibit high internal consistency.Comment: 4 pages, 2 figures; v2: Simulation data for one-component hard spheres included in Fig.
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