Editorial: Technical Advances in Cryo-Electron Microscopy

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Technology adoption and specialized labor

Empirical evidence identifies shortages of specialized labor as one of the main obstacles to technology adoption. In this paper, we explain this phenomenon by developing a model in which firms require specialized labor to produce with a new (more efficient) technology. We assume that the cost of specializing labor increases with the efficiency gains that can be attained through the new technology. This reveals two opposing effects on the endogenous share of specialized labor. On the one hand, there is a wage effect by which efficiency gains widen the wage gap between specialized and unspecialized workers, raising the share of specialized labor. On the other hand, there is a learning effect by which efficiency gains increase specialization costs, reducing the share of specialized labor. We show the learning effect will dominate when products are sufficiently differentiated

Oferta educativa de carreras de grado y posgrado en educación física en la República Argentina

En la actualidad la carrera de Educación Física presenta distintas alternativas en su formación. Las carreras de grado y posgrado son las dos variantes principales que ofrece el sistema educativo de Educación Superior. En el campo específico de la Educación Física, la formación de los profesores en la Argentina, data de comienzos del siglo XX, y desde su origen ha sido pensada para Instituciones de Formación Docente. Fue a partir de la Ley Nacional de Educación Superior (N°24.521) del año 1995, que se crean los mecanismos necesarios y se elaboran los procesos concretos para constituir la Formación del Profesorado dentro del sistema de Educación Superior Universitaria. El objetivo de este trabajo es elaborar un análisis preciso que permita determinar cuáles son las ofertas actuales en nuestro país de las distintas carreras de grado y posgrado en Educación Física

Pricing in two-sided markets and social Networks

This work analyzes the problem of optimal pricing policies in markets characterized by cross-group network externalities (two-sided markets) and in the presence of information held by companies about the social network of consumers. The thesis is divided in three chapters, each one readable as a distinct paper. The first chapter aims at providing a comprehensive overview of the state of the art in the literature of two-sided markets, i.e. markets characterized by the presence of platforms serving different groups of consumers linked with each other by network externalities. In particular, chapter 1 explains the main trade-offs and issues raised in the literature concerning different market structures (monopoly vs. oligopoly), exclusivity of the service (multi- vs. single-homing), price instruments (membership vs. transaction fees), type of externality (inter- vs. intra- group), interest of customers in quality and type of price discrimination (cross- vs. within-group). Chapter 2 is closely related to the first and aims at investigating about a very recent direction of the research in two-sided market. In particular, it provides an analysis of the practice of firms to offer different prices to consumers according to the past purchase behavior (BBPD) in the context of two-sided markets. In a two period model, two platforms compete for heterogeneous firms and end-users. Our contribution is that we allow platforms to discriminate prices on the users' side according to their past purchase behavior. The main findings are two. In the second period game with market shares taken as given, each platform may find it optimal either to offer discounts to rivals' users or to reward loyalty, depending on the number of users attracted in the past. Moreover, switching towards both platforms occurs if and only if the inherited market partition is symmetric enough. Making the first period game endogenous, BBPD affects both ex-ante and ex-post competition. Ex-post competition is strengthened compared to the regime in which a uniform price is charged in users' side. Ex-ante competition is relaxed (intensified) if users are the low (high) value group. The overall effect on inter-temporal profits of platforms is negative, confirming the previous results of BBPD literature. Chapter 3 changes completely topic compared to the first two. Specifically, it models the strategy of a monopolist that offers rewards to current clients in order to induce them to activate their social network and convince peers to buy from the company. In presence of heterogeneous search costs and reservation prices, this network-activation reward program may serve to expand the client base through a flow of information from informed to uninformed consumers. The offer of the monopolist affects individual incentives of aware people to share information, determining a minimal degree condition for investment. The optimal unitary reward balances the information spread effect (i.e. more receivers) and the crowding effect (i.e. less individual incentives) of an increase in the number of speakers. The monopolist always finds it profitable to use the bonus. Nevertheless, its introduction has ambiguous effects on the price and profits, depending on the process of spread of information and, in turn, on the network structure

Elaboración de un Instrumento para la determinación de las necesidades vocacionales de los egresados de la carrera de Educación Física de la Facultad de Educación de la UMaza

Este proyecto consiste en la elaboración de un instrumento para poder obtener información sobre las necesidades vocacionales de los egresados de la carrera de Educación Física de la UMaza y de esta forma generar carreras de posgrado en la Facultad de Educación, teniendo en cuenta que la misma posee una escasa cantidad de ofertas de carreras de posgrado y más aún en el área de Educación Física. Algo relevante a destacar es que en la región hay pocas instituciones que ofrezcan este tipo de formación. Es por ello que se plantea elaborar un instrumento que facilite la obtención de información necesaria para establecer las necesidades vocacionales para la generación de proyectos de posgrado (Diplomaturas, Especializaciones, Maestrías, Doctorados, et.) en la Facultad de Educación. Para todo ello será de suma importancia los aportes de las áreas de: Egresados, Asesoría Educativa y Posgrados de la universidad Juan Agustín Maza. Esta propuesta está basada en un tipo de estudio descriptivo bajo un diseño propio de una investigación proyectiva, cuyos beneficiarios directos serán egresados de la UMaza y profesionales de la Educación Física, e indirectos docentes, directivos y autoridades de la universidad

Correlación entre alteraciones posturales de columna y niveles de dolor en varones entre 20 y 40 años que asisten al gimnasio “URBANO” durante los meses de agosto a noviembre de 2008

Se realizó un estudio de investigación correlacional con el objetivo de determinar si existe relación entre las alteraciones posturales de columna y la manifestación de dolor, en varones entre 20 y 40 años que asisten al gimnasio “Urbano” durante los meses de Agosto a Noviembre de 2008. Se evaluó una muestra no aleatoria de n=45 varones y los resultados obtenidos a partir del Análisis Multivariado de la Varianza (ANOVA) y la prueba exacta de Fisher’, demostraron que los niveles de dolor no difieren significativamente entre las personas que padecen distintas alteraciones de columna, pero que si existe correlación entre poseer alteraciones posturales de columna y padecer algún nivel de dolor. Se llegó a la conclusión de que el 33% de la población padece dolor y presenta alteración postural de columna; el (15%) manifiesta alguna alteración postural de columna sin presentar dolor y el 13%, no posee alteración postural de columna pero si presenta manifestación de dolor. Es por ello que el profesional de la educación física debería realizar una evaluación general de la postura a cada persona que comienza una actividad física (cualquiera que ésta sea) para poder planificar adecuadamente las sesiones de entrenamiento adaptada a cada situación individual, de acuerdo a los resultados obtenidos

Response of Contrasting Cocksfoot Varieties to Summer Moisture Availability in a Mediterranean Environment

The responsiveness to water availability in summer and the effect of summer drought were assessed in a Mediterranean environment on both temperate and Mediterranean cocksfoot (Dactylis glomerata L.) materials. Three consecutive evaluation phases were contemplated: i) under rainfed conditions from autumn to spring; ii) under contrasting moisture conditions in the following summer; and iii) under rainfed conditions in the subsequent autumn-spring season to assess the effect of the previous summer treatments. The ability to become summer dormant under conducive conditions, such as in Mediterranean germplasm, proved a plant pre-requisite for survival under drought. All the “summer-active”, temperate varieties did not survive drought stress. Mediterranean materials showed a facultative dormancy behaviour in that they responded to moisture availability in summer. There was evidence that selection for such responsiveness was effective, as shown by a variety selected from Mediterranean germplasm also considering this criterion. Forcing summer growth by preventing dormancy had little detrimental effect on subsequent autumn recovery of Mediterranean improved varieties but more evidence is required on this aspect