Stochastic volatility models and the Taylor effect

It has been often empirically observed that the sample autocorrelations of absolute financial returns are larger than those of squared returns. This property, know as Taylor effect, is analysed in this paper in the Stochastic Volatility (SV) model framework. We show that the stationary autoregressive SV model is able to generate this property for realistic parameter specifications. On the other hand, the Taylor effect is shown not to be a sampling phenomena due to estimation biases of the sample autocorrelations. Therefore, financial models that aims to explain the behaviour of financial returns should take account of this property

Trade and Private R&D in Mexico

Using the National Survey on Employment, Wages, Technology and Training (Enestyc), this paper tries to find the relationship between increasing trade and the proportion of total income Mexican manufacturing firms invest on R&D. Based on two cross-sectional and a panel estimation procedures, the results confirm the idea that increasing the exposure to foreign markets affect the innovative efforts of Mexican firms. We also find that the firms engaging in some kind of R&D do not conform a random sample. More specifically, our results show that, in 1992, the probability of finding a firm engaging resources in some kind of R&D increased with size, a market diversification measure, and a measure of industrial market power at a 2-digit level, while the intensity of the R&D effort depended, on market power and an industry concentration measure. For the 1999 estimation our results show that the probability of R&D investment at a firm level increased with size, a market diversification measure, and exposure to foreign competition, while the magnitude of the R&D effort of a firm was determined by the decrease in average import tariffs at the industry level and by the exporting efforts of the firm. We find strong complementarities between public and private innovation efforts in both years, but find that younger firms are doing stronger R&D efforts in 1999. The 1992- 99 balanced panel results show that exporting firms invest more in R&D while import competing firms invest less, once size, market power and other control variables are taken into account. Our estimation indicates that exporting give firms a great incentive to innovate, and that not only large, but also small firms contribute to the R&D efforts of a nation.R&D, trade liberalization, foreign direct investment, exposure to foreing markets

Prácticas, representaciones y experiencias: propuestas teórico-metodológicas en investigaciones socio-antropológicas sobre el cuerpo

Las diversas corrientes teóricas de la antropología del cuerpo conllevan propuestas metodológicas. Desde el llamado pionero de Marcel Mauss para investigar las técnicas corporales, se han desplegado diferentes temáticas de interés, enfoques teóricos y perspectivas metodológicas para el abordaje del cuerpo en contextos socio-culturales específicos. Se considerarán aquí distintos grupos de perspectivas teórico-metodológicas sobre el cuerpo, que se distinguen por centrar sus enfoques en distintas dimensiones: las representaciones, los discursos, las prácticas y las experiencias. Luego de plantear las implicancias metodológicas de las perspectivas revisadas, se intentarán buscar modos de integración entre ellas.The several theoretical approaches of anthropology of the body involve methodological proposals. From Marcel Mauss pioneering call to investigate body techniques, various topics of interest have been deployed, as well as theoretical and methodological approaches for addressing the body in specific sociocultural contexts. Considered here are different groups of theoretical and methodological proposals about the body, which are distinguished by their focus on distinct dimensions: representations, discourses, practices and experiences. After setting forth the methodological implications of the revised perspectives, will try to find ways of integration between them.Fil: Mora, Ana Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Humanidades y Ciencias Sociales. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales; Argentin

Development of new bioactive systems for regenerative medicine using 3D printing and microfluidic technologies

Regenerative medicine is an interdisciplinary field that combines different principles of engineering and life sciences to potentially promote the regeneration and healing of injured tissues. The use of biomaterials to replace damaged tissues or to contribute to their healing is an important component of current regenerative medicine strategies. Biomaterials are defined as any material intended to interface with biological systems to treat or replace any tissue, organ, or function in the body. They can be classified in metals, ceramics, polymers, and composites depending on chemical composition.Presidente: Belen Levenfeld Laredo - Secretaria: M. Dolores Gurruchaga Torrecilla - Vocal: Francisco M. Goycoole

La subordinación jurídica como elemento delimitante frente a las nuevas formas contractuales

Trabajo final de graduación de 55 páginas en formato pdfLas transformaciones económicas, tecnológicas y productivas –también hay que decirlo, el reposicionamiento de los paradigmas ideológicos –someten al Derecho del Trabajo a duras pruebas. No es sólo la función tutelar misma, en especial sus técnicas y niveles, lo que se ha puesto en cuestión. Sucede también que categorías básicas del área, diseñadas para denotar conceptualmente los fenómenos que prevalecían cuando se les construyera, sufren hoy los embates de aquellos cambios y levantan nuevos interrogantes: ¿ conservan esos conceptos su aptitud para enmarcar el substrato fáctico y contractual que se proponen expresar?. Si así no fuera, ¿implica ese desajuste sólo una cuestión de recalificación y reclasificación teórica de las categorías tradicionales o importa, por el contrario, una redefinición sustantiva del objeto y contenidos del propio ordenamiento laboral. Por su virtual condición –si así se le puede llamar- de “llave maestra” que habilita la aplicación efectiva de las normas del Derecho de Trabajo a las relaciones concretas que le contienen, el instituto de la dependencia o subordinación laboral es uno de los que a mi juicio, se le debe dar el más cuidadoso seguimiento. Con el presente trabajo, se pretende averiguar qué correspondencia guarda con los modos dominantes en los que hoy y en los inmediatos tiempos 7 por venir se contrata y se despliega el trabajo humano, si todos ellos tienen cabida en aquel molde tradicional y, en consecuencia, si encuentran respuesta a sus específicas necesidades de regulación y amparo; si en todo caso, la categorización universalizadora del concepto tradicional de la dependencia, deja espacio suficiente para la diversificación regulatoria que demanda la creciente heterogeneidad productiva.Universidad Estatal a Distancia de Costa Ric

Las tics en la enseñanza universitaria : blogs digitales

This study is an innovative educational experience to analyse to what extent the use of blogs contributes to the acquisition of specific skills of a subject in Early Childhood Education Degree, and assess the level of learning that students considered achieved. A quantitative methodological approach based on the analysis of a closed questionnaire and on assessment rubric was used. The results allowed to verify that the use of blogs in the university is very useful to promote the active role of the student through a critical, reflective and collaborative learning, which allows you to get a high level of professional skills acquisition. Keywords: Blogs, collaborative learning, higher education, educational innovation, web technologies 2.0

Modeling an Aquifer: Numerical Solution to the Groundwater Flow Equation

We present a model of groundwater dynamics under stationary flow and governed by Darcy's Law of water motion through porous media, we apply it to study a 2D aquifer with water table of constant slope comprised of an homogeneous and isotropic media, the more realistic case of an homogeneous anisotropic soil is also considered. Taking into account some geophysical parameters we develop a computational routine, in the Finite Difference Method, that solves the resulting elliptic partial equation, both in a homogeneous isotropic and homogeneous anisotropic media. After calibration of the numerical model, this routine is used to begin a study of the Ayamonte-Huelva aquifer in Spain, a modest analysis of the system is given, we compute the average discharge vector as well as its root mean square as a first predictive approximation of the flux in this system, providing us a signal of the location of best exploitation; long term goal is to develop a complete computational tool for the analysis of groundwater dynamics.Comment: 13 pages and 12 figure