Barrios cerrados

Fil: Murgida, Ana. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina.Parte de Testimonios, Tesista dirigida por Gérard Althab

Seasonal Summer Rainfall Prediction in Bermejo River Basin in Argentina

Bermejo River Basin is located in the Chaco Plains in northern Argentina. The river has an extension of 1450 km and the basin area covers 16048 km2, comprising the north of Salta and the entire Formosa and Chaco provinces. Its principal tributary is San Francisco River which brings mountain waters. Two different sections can be detected in Bermejo River: the upper and the middle-low Bermejo. Vegetation is wooded with more plains to the east and with the presence of isolated yungas. The worst areas are historically inhabited by indigenous communities with extensive farming practice. Historical data show that the region has been the scene of frequent hydro-meteorological disasters (floods and droughts) and the impacts of these events have had a strong impact on the welfare of the population, productive activities and infrastructure. There is ample evidence that climate change impacts are already being observed today and that policies that seek the best ways to meet them are essential for the development and welfare of the community. The Chaco region is one of the regions that, as a result of the change in land use, presents “hotspot "or critical areas in recent times (from 1980). They are the result of the implementation of deforestation as a technology for the advancement of agriculture and intensive farming. In this region the climate is subtropical with a mean annual rainfall cycle showing a minimum in winter, which is more pronounced in the west, with dry conditions prevailing from May to September. The Andes chain lies along the west of Argentina and prevents the access of humidity from the Pacific Ocean. Therefore, the flow is governed by the South Atlantic High and as a consequence, winds prevail from the north and the east. The great interannual rainfall variability generates the requirement to understand the large circulation patterns associated with different hydric situations. Some remote sources affect the mentioned interannual variability. Subtropical South America is known to be one of the regions of the world with an important El Niño-Southern Oscillation (ENSO) signal in the precipitation field. This signal varies along each of the ENSO phases, and it differs between sub-regions. Although ENSO is the most important remote forcing without a doubt, the variability originated by other regional or remote sources cannot be disregarded. The scientific basis of the seasonal climate predictability lies in the fact that slow variations in the earth’s boundary conditions (i.e. sea surface temperature or soil wetness) can influence global atmospheric circulation and thus precipitation. As the skill of seasonal numerical prediction models is still limited, it is essential the statistical study of the probable relationships between some local or remote forcing and rainfall. In this paper an example of seasonal rainfall prediction is presented for Bermejo River basin. As the maximum rainfall season was summer, from January until March (JFM), this period was used to study interannual rainfall variability and predictors in the previous December could be defined, for each one of two sub-basin (Lower-Middle Bermejo and Upper Bermejo). Athough it is a small area, some differences were detected all over the basin. Therefore, two mean rainfall series were constructed as the average of monthly precipitation of nineteen stations in the upper Bermejo river basin (UB) during the period 1982-2007 and fourteen stations in the lower and middle Bermejo River Basin (LB) during the period 1968-2007, in order to be representative as from the precipitation over each one of the basin regions. Different period were considered in each sub-basin because of the availability of data. Simultaneous and one month lagged correlations were calculated to find the existing relation between summer (JFM) rainfall in LB and UB and sea surface temperature, 1000 Hpa, 500 Hpa and 200 Hpa geopotential height SST and 850 Hpa zonal and meridional wind. The results allowed to define some predictors in previous December, which were used to develop a statistical forecast model using the forward stepwise regression method, which retained only the variables, correlated with a 95% significance level. Forward stepwise regression is a model-building technique that finds subsets of predictor variables that most adequately predict responses on a dependent variable by linear regression, given the specified criteria for adequacy of model fit. The basic procedures involve identifying an initial model, then predictors are added one-by-one with the remaining candidate predictor that reduces the size of the errors, and this process continues until the errors cannot be significantly reduced. Linear regression models were developed for both, UB and LB. The correlation between observed and forecast rainfall time series derived from cross-validation was 0,6 and the linear regression model explained the 49% of the variance of EFM LB rainfall. However, the summer rainfall in UB depended mainly of Pacific and Indian Ocean sea surface temperatures. The final model explained the 46% of the variance of JFM rainfall in UB and the correlation between observed and forecast series was 0,49. Results indicate that the two mayor factors that influence summer precipitation in Lower Bermejo were the South Antarctic Oscillation and the weaken Atlantic High. In Upper Bermejo it depends mainly on Pacific and Indian Ocean sea surface temperatures. The efficiency of the method was proved by calculating some statistics like the hit rate, the probability of detection and the false alarm ratio. Results in LB are better than in UB. The probability of above normal rainfall events is in general, better than the probability to detect below normal rainfall ones. The probability to give a false alarm in a below normal rainfall event is greater than in the above normal cases. Additionally, the probability functions resulting from estimated and observed JFM rainfall resulted similar at the 95% confidence level and reveal that the method underestimates the most extreme cases. These results are promising and encourage further work in order to examine new techniques to better estimate rainfall, especially the extremes, and to investigate other predictors which could affect precipitation in summer.Fil: González, Marcela Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Murgida, Ana Maria. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Interactions sur le terrain

Les « quartiers privés » ou « clôturés » se développent un peu partout en Amérique latine depuis les années quatre‑vingt‑dix. En Argentine, ils sont devenus un phénomène en constante croissance, si bien qu’ils constituent désormais un sujet d’étude important en anthropologie. Les urbanisations clôturées sont des espaces résidentiels encerclés, avec un système de surveillance centralisé. Ils se trouvent physiquement séparés de la trame urbaine consolidée soit par la distance géographique, soit..

Ковид-19 и аутохтони народи: Aнализа из перспективе социјалне антропологије

: In this article we describe and analyze several impacts that coronavirus has produced over some aboriginal population from America and Argentina, taking into consideration, their responses, understanings and developed strategies, related to state policies. Likewise, we develop an analytical description of possibilities that the ethnographic method, belonging to the anthropological sciences, offers, for a multidimensional approach. This method also makes it possible to advise, evaluate and monitor certain public policies. When it comes to the information obtained, it was acquired using several secondary sources of data and interviews posted on the Internet.У овом раду описујемо и анализирамо неколико утицаја које је вирус корона имао на неке староседеоце из Америке и Аргентине, узимајући у обзир њихове одговоре, схватања и стратегије у вези са државном политиком. Исто тако, развијамо аналитички опис могућности које етнографски метод, који припада антрополошким наукама, нуди за вишедимензионални приступ. Овај метод такође омогућава саветовање, процену и праћење одређених јавних политика. С обзиром на добијене информације, до њих се дошло коришћењем неколико секундарних извора података и интервјуа који су објављени на интернету.Fil: Barandela, Ana Clara. Universidad de Buenos Aires; ArgentinaFil: Morey, Eugenia Maria Teresa. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Ciencias Antropológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Murgida, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15; ArgentinaFil: Radovich, Juan Carlos. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The alkaline transition of cytochrome c revisited: Effects of electrostatic interactions and tyrosine nitration on the reaction dynamics

Here we investigated the effect of electrostatic interactions and of protein tyrosine nitration of mammalian cytochrome c on the dynamics of the so-called alkaline transition, a pH- and redox-triggered conformational change that implies replacement of the axial ligand Met80 by a Lys residue. Using a combination of electrochemical, time-resolved SERR spectroelectrochemical experiments and molecular dynamics simulations we showed that in all cases the reaction can be described in terms of a two steps minimal reaction mechanism consisting of deprotonation of a triggering group followed by ligand exchange. The pK a alk values of the transition are strongly modulated by these perturbations, with a drastic downshift upon nitration and an important upshift upon establishing electrostatic interactions with a negatively charged model surface. The value of pK a alk is determined by the interplay between the acidity of a triggering group and the kinetic constants for the forward and backward ligand exchange processes. Nitration of Tyr74 results in a change of the triggering group from Lys73 in WT Cyt to Tyr74 in the nitrated protein, which dominates the pK a alk downshift towards physiological values. Electrostatic interactions, on the other hand, result in strong acceleration of the backward ligand exchange reaction, which dominates the pK a alk upshift. The different physicochemical conditions found here to influence pK a alk are expected to vary depending on cellular conditions and subcellular localization of the protein, thus determining the existence of alternative conformations of Cyt in vivo.Fil: Oviedo Rouco, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Castro, Maria Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Álvarez Paggi, Damián Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Spedalieri, Ana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Tortora, Verónica. Universidad de la República; UruguayFil: Tomasina, Florencia. Universidad de la República; UruguayFil: Radi, Rafael. Universidad de la República; UruguayFil: Murgida, Daniel Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Ковид-19 и аутохтони народи: Aнализа из перспективе социјалне антропологије

: In this article we describe and analyze several impacts that coronavirus has produced over some aboriginal population from America and Argentina, taking into consideration, their responses, understanings and developed strategies, related to state policies. Likewise, we develop an analytical description of possibilities that the ethnographic method, belonging to the anthropological sciences, offers, for a multidimensional approach. This method also makes it possible to advise, evaluate and monitor certain public policies. When it comes to the information obtained, it was acquired using several secondary sources of data and interviews posted on the Internet.У овом раду описујемо и анализирамо неколико утицаја које је вирус корона имао на неке староседеоце из Америке и Аргентине, узимајући у обзир њихове одговоре, схватања и стратегије у вези са државном политиком. Исто тако, развијамо аналитички опис могућности које етнографски метод, који припада антрополошким наукама, нуди за вишедимензионални приступ. Овај метод такође омогућава саветовање, процену и праћење одређених јавних политика. С обзиром на добијене информације, до њих се дошло коришћењем неколико секундарних извора података и интервјуа који су објављени на интернету.Fil: Barandela, Ana Clara. Universidad de Buenos Aires; ArgentinaFil: Morey, Eugenia Maria Teresa. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Ciencias Antropológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Murgida, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15; ArgentinaFil: Radovich, Juan Carlos. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Charge localization in Co-doped ceria with oxygen vacancies

In this paper we report density functional theory (DFT) calculations on bulk cerium oxide (ceria) doped with magnetic impurities of cobalt atoms in the presence of oxygen vacancies. Using the framework of the DFT+U approach to take into account the effects of electronic correlations in the Ce 4f states, we evaluate the relative stability of different configurations of vacancies. We show that, within the approximations considered, the vacancies tend to locate close to the Co impurities. In addition, we address the issue of the charge localization that takes place due to de-oxygenation processes, finding that the excess electrons reside at Ce atoms which are next-nearest neighbors of the vacancy sites.Fil: Murgida, Gustavo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Vildosola, Veronica Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Ferrari, Valeria Paola. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Llois, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentin

VULNERABILIDAD CULTURAL Y ESCENARIOS DE RIESGO POR INUNDACIONES

En las localidades de Dique Luján y Rincón de Milberg (Partido de Tigre/ Provincia de Buenos Aires) se han expandido una significativa cantidad de urbanizaciones cerradas polderizadas para mitigar el riesgo por inundaciones propio de esa zona. Éstas últimas operarían como un elemento simbólico en la articulación de la construcción identitaria y de la percepción del riesgo para dos sectores socioeconómico y culturalmente diferentes. Nos referimos a dos grupos que poseen estratégias propias para mitigar el riesgo por inundaciones. Por un lado, los nuevos habitantes de lãs urbanizaciones cerradas, confían en la tecnología, en los profesionales, y en las millonarias inversiones económicas realizadas por los empresarios. Por el otro, quienes poseen cierta antigüedad en la zona, depositan la confianza en los sistemas constructivos propios del lugar como los palafitos, en saberes transmitidos de generación en generación, y su inclusión en redes solidarias locales. En suma, en este trabajo se analizan, los aspectos culturales de la vulnerabilidad social frente a las inundaciones, y su articulación con la cuestión identitaria a partir de los cambios ocurridos para ambos grupos.A significant number of gated communities have spread in the localities of Dique Luján and Rincón de Milberg (Partido de Tigre/ Buenos Aires Province) in the last decades. These gated communities have been polderized in order to mitigate the flood risk typical of this area. They might serve as a symbolic element in the articulation of identity construction and risk perception for two sectors economically and culturally differentiated. We refer to two groups that have their own strategies to mitigate risk. On the one hand, the new inhabitants of the gated communities trust in technology,in the professionals and in the millionaire economic investments of some companies. On the other,those who have lived in the area for many years trust in local building systems –such as houses on piles-, in knowledge transmitted from generation to generation and in local solidarity networks.Summarizing, this paper analyzes the cultural aspects of social vulnerability to floods and its articulation with the identity issue based on the changes experienced by both groups.En las localidades de Dique Luján y Rincón de Milberg (Partido de Tigre/ Provincia de Buenos Aires) se han expandido una significativa cantidad de urbanizaciones cerradas polderizadas para mitigar el riesgo por inundaciones propio de esa zona. Éstas últimas operarían como un elemento simbólico en la articulación de la construcción identitaria y de la percepción del riesgo para dos sectores socioeconómico y culturalmente diferentes. Nos referimos a dos grupos que poseen estratégias propias para mitigar el riesgo por inundaciones. Por un lado, los nuevos habitantes de lãs urbanizaciones cerradas, confían en la tecnología, en los profesionales, y en las millonarias inversiones económicas realizadas por los empresarios. Por el otro, quienes poseen cierta antigüedad en la zona, depositan la confianza en los sistemas constructivos propios del lugar como los palafitos, en saberes transmitidos de generación en generación, y su inclusión en redes solidarias locales. En suma, en este trabajo se analizan, los aspectos culturales de la vulnerabilidad social frente a las inundaciones, y su articulación con la cuestión identitaria a partir de los cambios ocurridos para ambos grupos

Reduced CeO2 (111) ordered phases as bulk terminations: Introducing the structure of Ce3O5

Reduced ceria (CeO2−x ) has a rich phase diagram comprising a variety of bulk phases with stoichiometries ranging from CeO2 to Ce2O3 as the reduction conditions are increased. Some observed reduced ceria (111) surface reconstructions are terminations of stable bulk phases, such as √7 × √7, whereas others are not associated with any known stable phases, namely, √7 × 3, 3 × 3, and √3 × √3. In this paper, we analyze different periodic reconstructions of reduced ceria (111) surfaces within a theoretical framework. We describe the surfaces of stable bulk phases and elucidate the structure of the observed periodicities not corresponding to terminations of known stable bulk phases. Extending the 3 × 3 and √3 × √3 terminations into a bulk structure, we find a new quasistable Ce3O5 bulk phase, which explains both periodicities. On the contrary, the √7 × 3 surface structure cannot be extended into a bulk but stabilizes as a very thin overlayer. We also analyze other reported bulk structures with stoichiometry close to the Ce3O5 one, namely, the C-type Ce2O3+δ bulk phase, which cannot describe the observed terminations. Our goal is to provide a unified picture to describe the road map of CeO2−δ (111) surface reconstructions and, when possible, their relationship to reduced ceria bulk phases.Fil: Murgida, Gustavo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Ferrari, Valeria Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Llois, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Ganduglia Pirovano, Maria Veronica. Consejo Superior de Investigaciones Científicas; Españ

Modelos de trabajo en la interdisciplina : un análisis relacional de colaboración para el planeamiento hídrico en la Patagonia Norte (Argentina)

Este artículo analiza la estructura de las relaciones de un proyecto de investigación orientado al planeamiento y manejo ambiental, coordinado por una institución académica local y con financiamiento internacional. La metodología se compone de dos ejes: análisis antropológico y análisis de redes sociales; y se aplica el concepto de "espacio de frontera" para caracterizar las comunidades involucradas en las redes (científicos, tomadores de decisiones públicas y privadas, y técnicos en terreno). Este análisis nos impulsó a proponer nuevas herramientas para mejorar el seguimiento de las colaboraciones interdisciplinarias y comprender la dinámica del proceso de investigación desde su diseño, desarrollo e implementación. Los resultados sugieren que estas herramientas visualizan en tiempo real los éxitos y fracasos de la interfaz ciencia-política-sociedad a partir de las características estructurales de la red de relaciones en distintos momentos del proyecto: la organización de las relaciones sociales, la comunicación entre los actores involucrados y los grados de colaboración entre componentes.This article analyses the structure of relationships and networking in a research project aimed at environmental planning and management, which was coordinated by a local academic institution and funded by an international agency. Our methodology combines: anthropological analysis, social network analysis and the "boundary work" concept applied to the communities involved (scientists, decision makers and technical assistants). This analysis led us to new conceptual tools to improve the assessment of interdisciplinary collaborations and to understand the project dynamics throughout its design, development and implementation in a wide range of contexts. Results shows in real time the successes and failures of the science-policy-society interface through the analysis of structural features of relational networks at different times of the project: the organization of social relationships, communication between social actors, and degrees of collaboration among project components and participants