Estimating Learning Models with Experimental Data

We study the statistical properties of three estimation methods for a model of learning that is often tted to experimental data: quadratic deviation measures without unobserved heterogeneity, and maximum likelihood with and without unobserved heterogeneity. After discussing identi cation issues, we show that the estimators are consistent and provide their asymptotic distribution. Using Monte Carlo simulations, we show that ignoring unobserved heterogeneity can lead to seriously biased estimations in samples which have the typical length of actual experiments. Better small sample properties are obtained if unobserved heterogeneity is introduced. That is, rather than estimating the parameters for each individual, the individual parameters are considered random variables, and the distribution of those random variables is estimated

The effects of trade liberalization on R&D investments: the case of the Uruguayan manufacturing industry

In this paper we study the effects of increasing imports and foreign firm supply, as a consequence of trade liberalization policies, on the innovative activities of firms in a small developing economy. This is an interesting case as very little research exists on the R&D investments of firms in developing countries. The results show that foreign presence has a positive but not always significant effect, while import competition has a negative and significant effect on R&D investments. Firms that are able to export are also more innovative. The process of reallocation of resources from import substituting industries towards export-oriented industries, caused by the opening of the economy, seems to have reduced the incentives for R&D investments for firms in traditional industries, while increasing those for export-oriented firms. Taking into account the defensive and imitative nature of innovative activities of firms in developing countries, these results go in contrast with the evidence from developed countries, where foreign direct investments and imports seem to show positive effects on innovative activities.

Risk Dominance Selects the Leader: An Experimental Analysis

We perform an experimental analysis to test whether the risk dominance prediction is supported by the behavior of laboratory agents, in a 2X 2 coordination game whose equilibria are not Pareto ranked. This type of game arises very often in studies of industrial organization and international trade, and we extract the parameters for the experiment from a vertical product differentiation model with two asymmetric players choosing first qualities and then prices.We show that the higher the degree of asymmetry of the game, the higher the predictive power of the risk dominance criterion.Publicad

Estimating Human Capital Externalities:The Case of Spanish Regions

We estimate the strength of schooling externalities for Spanish regions over the 1981-2001 period. Our empirical work employs both main approaches available in the literature. Both methodologies yield significant externalities. Using a growth accounting exercise, we find that human capital externalities account for one half of the increase in real wages for the period between 1981 and 2001.externalities, human capital, constant composition.

La inviolabilidad del fuero parlamentario un estudio jurisprudencial y doctrinal sobre la responsabilidad penal por injuria, calumnia y otros delitos

Artículo de investigaciónArtículo de investigaciónLa presente investigación busca analizar la forma en que el fuero especial que conforma la inviolabilidad parlamentaria ha causado que los parlamentarios puedan en muchos casos sobrepasar los límites del mismo, causando sin saberlo que se vean envueltos en actos tendientes a la comisión de los delitos de injuria y calumnia. Por tanto en el presente escrito se busca analizar la verdadera naturaleza y extensión de dicha protección con el fin de delimitar la verdadera definición respecto de en qué punto puede o no estarse abusando de este derecho, desmitificando con esto ideas falsas que apunta a la existencia de ciertos “blindajes” que parecieran proteger desproporcionadamente las acciones de los parlamentarios.PregradoAbogad

A perturbation density functional theory for the competition between inter and intramolecular association

Using the framework of Wertheim's thermodynamic perturbation theory we develop the first density functional theory which accounts for intramolecular association in chain molecules. To test the theory new Monte Carlo simulations are performed at a fluid solid interface for a 4 segment chain which can both intra and intermolecularly associate. The theory and simulation results are found to be in excellent agreement. It is shown that the inclusion of intramolecular association can have profound effects on interfacial properties such as interfacial tension and the partition coefficient

Steady waves in flows over periodic bottoms

We study the formation of steady waves in two-dimensional fluids under a current with mean velocity $c$ flowing over a periodic bottom. Using a formulation based on the Dirichlet-Neumann operator, we establish the unique continuation of a steady solution from the trivial solution for a flat bottom, with the exception of a sequence of velocities $c_{k}$. The main contribution is the proof that at least two steady solutions for a near-flat bottom persist close to a non-degenerate $S^{1}$-orbit of non-constant steady waves for a flat bottom. As a consequence, we obtain the persistence of at least two steady waves close to a non-degenerate $S^{1}$-orbit of Stokes waves arising from the velocities $c_{k}$ for a flat bottom

Changes in renal WT-1 expression preceding hypertension development

Background: Hypertension is a public health problem with mostly unknown causes, and where strong hereditary genetic alterations have not been fully elucidated. However, the use of experimental models has provided valuable information. Recent evidences suggest that alterations in key nephrogenic factors, such as Wilms' tumor 1 transcription factor (WT-1), could contribute to the development of hypertension. The aim of this paper is to evaluate the expression of WT-1 and related genes in the nephrogenic process in connection with the development of hypertension as well as the corresponding anatomical and functional correlation. Methods: Male spontaneously hypertensive and control rats were evaluated weekly from birth until week 8 of life. Their blood pressure was taken weekly using the tail-cuff blood pressure system. Weekly, 5 rats per group were sacrificed with a lethal injection of pentobarbital, and their kidneys were removed, decapsulated and weighed. The serum was collected for measuring biochemical parameters. The results were assessed using one-way analysis of variance for comparisons between groups. Results: The relationship between renal weight/total body weights was established, without significantly different values. These data were compared with apoptosis, fibrosis, number and size of the glomeruli. The elevation of systolic blood pressure was significant since week 6. Biochemical values differed slightly. Histology showed a slight increase in deposits of collagen fibers since week 4. Additionally, in kidney cortices, the expression of WT-1, heat shock protein 70 (Hsp70) and vitamin D receptors (VDR) decreased since week 4. Finally, we demonstrated ultrastructural damage to mitochondria since week 4. Conclusions: Our results would suggest an unprecedented link, possibly a regulatory mechanism, between WT-1 on nephrogenic alteration processes and their relationship with hypertension. Moreover, and previous to the increase in blood pressure, we demonstrated low expressions of WT-1, VDR and Hsp70 in kidneys from neonatal SHRs. If so, this may suggest that deregulation in the expression of WT-1 and its impact on nephrogenesis induction could be crucial in understanding the development and maintenance of hypertension.Fil: Mazzei, Luciana Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: García, Isabel Mercedes. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Calvo, Juan Pablo. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Casarotto, Mariana. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Fornes, Miguel Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Abud, María Angélica. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Cuello Carrión, Fernando Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Ferder, León. Universidad de Puerto Rico; Puerto RicoFil: Manucha, Walter Ariel Fernando. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

Antagonistic and synergistic responses to solar ultraviolet radiation and increased temperature of phytoplankton from cenotes (sink holes) of the Yucatán Peninsula, México

Cenotes (sink holes) are karstic formations characteristic of the Yucatán Peninsula and are the main source of fresh water in the region. Because of their tropical location, they receive high levels of solar radiation and are exposed to high temperatures. However, the effect of these global-change-related variables on phytoplankton in cenotes is unknown. We carried out experiments with phytoplankton communities collected from 2 cenotes differing in their penetration of solar radiation (Leona Vicario [LV]: turbid, Las Mojarras [LM]: clear) to assess the combined effect of solar ultraviolet radiation (UVR; 280–400 nm) and increased temperature on their photosystem (PS) II photochemistry. We exposed samples in microcosms to solar radiation (with and without UVR) and 2 temperatures (ambient = 25°C and increased by 3°C) and analyzed photochemical performance over daily cycles. A significant antagonistic interaction between UVR and temperature in LV caused a combined inhibition of the effective photochemical quantum yield (ΦPSII) that was smaller (63%) than the sum of the 2 individual effects of UVR and temperature (116%). In contrast, a significant synergistic interaction between UVR and temperature in LM caused the combined inhibition of ΦPSII (172%) to be higher than the sum of the individual effects of the 2 variables (134%). Differences in the size distribution and taxonomic composition of the phytoplankton communities, with smaller cells in LV than in LM, seem to account for much of the variability in responses to UVR and increased temperature between the 2 communities. Our results suggest that phytoplankton communities from clear cenotes will be more affected by the combined effects of solar UVR and increased temperature that those from turbid cenotes.Fil: Villafañe, Virginia Estela. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guendulain García, Sergio D.. Universidad Nacional Autónoma de México; MéxicoFil: Valadez, Francisco. Universidad Juárez Autónoma de Tabasco; México. Centro de Investigación Científica de Yucatán; MéxicoFil: Rosiles González, Gabriela. Centro de Investigación Científica de Yucatán; MéxicoFil: Helbling, Eduardo Walter. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Banaszak, Anastazia T.. Universidad Nacional Autónoma de México; Méxic