Synoptic-scale variability and its relationship with total ozone and Antarctic vortex displacements

The main synoptic-scale circulation anomaly pattern over extratropical South America during the austral spring (September-November) is identified by means of rotated extended empirical orthogonal function techniques, applied to the meridional wind perturbation time series at 300 hPa. The dataset is based on 15 spring seasons (1979-93) of meteorological data from the National Centers for Environmental Prediction-Department of Energy Atmospheric Model Intercomparison Project version-2 daily averaged reanalyses, given in 17 vertical levels from 1000 to 10 hPa. The total-ozone daily measurements for the same period are from the Total Ozone Mapping Spectrometer instrument (version 7). The principal synoptic-scale anomaly pattern is associated with an anticyclone-cyclone pair evolving eastward along subpolar latitudes (and hence it is termed the subpolar mode), with a typical length scale of 5000 km and a phase velocity of 8 m s-1. The subpolar-mode waves, which display the main characteristics of midlatitude baroclinic waves, typically maximize near or above the tropopause and propagate upward into the lower stratosphere, showing large amplitudes even at 50 hPa and above. Subpolar-mode-related circulation anomalies are found to be responsible for large total-ozone daily fluctuations near southern South America and nearby regions. In the positive phase of the subpolar mode, total-ozone fluctuations, which are negative, adopt a sigmoid structure, with a zonal scale as large as the anticyclone-cyclone pair. Moreover, it is herein shown that the associated anticyclone produces a local ozone-column decrease to the north and east of its center, due to adiabatic uplift of air parcels in the upper troposphere and lower stratosphere. At the same time, the downstream cyclonic disturbance is responsible for large negative total-ozone anomalies to the west and south of its center. As the cyclone develops in the lower stratosphere, it promotes the northward incursion of the Antarctic vortex up to about 55°S, along with air masses of highly depleted ozone levels.Fil: Vigliarolo, Paula Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Vera, Carolina Susana. 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: Diaz, Susana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

Popular habitat and labor market: Unequal urban development in El Alto (Bolivia)

El Alto generalmente es descripto como un cinturón homogéneo de pobreza y de población de origen aymara. Sólo se encuentran afirmaciones incipientes, con escasa evidencia empírica sistematizada,sobre el desarrollo urbano desigual (y combinado) de la ciudad de El Alto. De aquí la pertinencia de esta investigación cuyo objetivo es analizar la inserción de los migrantes rurales en dos barrios de la ciudad de El Alto: en la zona periférica El Porvenir I y en el área céntrica 16 de Julio, en el período que comprende el inicio del neoliberalismo en el país (1985) hasta el año 2012.En primer lugar, se indaga sobre el acceso a la ciudad en relación a la calidad de la vivienda y la provisión de los servicios públicos domiciliarios.En segundo lugar, su inserción en el mercado laboral con el fin de abordar la problemática del desarrollo urbano desigual que se vislumbra en la periferia de El Alto. Una parte de la información fue obtenida mediante entrevistas semi-estructuradas a informantes clave y a los residentes de la ciudad; a través de la aplicación de una encuesta (muestreo estratégico no probabilístico) en los barrios bajo estudio, donde fueron seleccionados en total 100 hogares.El Alto is generally described as a homogeneous area of poverty with a population of Aymara origin. There is only preliminary information, with little systematized empirical evidence, about the unequal (and combined) urban development of the city. Hence the relevance of this research, which is intended to explore the incorporation of rural migrants into two neighborhoods of the city: “El Porvenir I”, located in the peripheral area of the city, and “16 de Julio”, located in the downtown area of El Alto. This research analyzes the period from the adoption of neoliberalism (1985) to 2012.In the first place, this research examines the access to the city in relation to the quality of dwellings and the provision of public domiciliary services. In second place, the incorporation into the labor market is analyzed in order to address the issues regarding the unequal urban development in the outskirts of El Alto. Part of the information was collected through semi-structured interviews with key actors and inhabitants of the city. Other information was collected through the implementation of a survey (non-probabilistic strategic sampling) that interviewed 100 households located in the case study neighborhoods.Fil: Diaz, Mariela Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentin

Mobility of bolivian families in villa 20 (Caba, Argentina): Problematizing the notion of plurilocality

Las villas de la ciudad autónoma de Buenos Aires (CABA), conformadas hacia la década de 1930 en el contexto de implantación del modelo de sustitución de importaciones, constituyen el prototipo clásico de hábitat informal y precario en Argentina. La Villa 20 se encuentra en la zona sur y cuenta con una población migrante proveniente de los países limítrofes. Según el Censo del Instituto de la Vivienda de la CABA (2016), los principales sostenes del hogar nacidos en Bolivia superan a los nativos y a los oriundos de otros países fronterizos (Paraguay y Perú). El objetivo de este trabajo es analizar los lazos con sus lugares de origen y sus vinculaciones con la dimensión socioeconómica y sociodemográfica de los hogares de migrantes bolivianos en el marco de la política local de reurbanización actual (2015-2019). De este modo, se propone analizar de manera incipiente la posibilidad de prácticas plurilocales desde una perspectiva transnacional que problematiza la definición demográfica y clásica de la migración. Para llevar a cabo este trabajo, que forma parte de un proyecto de investigación mayor, se utilizó una estrategia metodológica fundamentalmente cuantitativa, incorporando datos de fuentes primarias y secundarias. Se aplicó una encuesta con un muestreo estratégico (no probabilístico) a 60 hogares de migrantes bolivianos, donde la selección de los casos es de índole teórica. Este documento constituye una primera aproximación y se considera el primer eslabón para el desarrollo de un posterior abordaje cualitativo.The slums in the Autonomous City of Buenos Aires (CABA, in Spanish), set up in the 1930’s within the context of the import substitution model’s implementation, follow the classic prototype of informal precarious living in Argentina. Villa 20, or Slum 20, is in the south of the city and has a migrant population from neighboring countries. According to the CABA Housing Institute Census (2016), the main heads of household born in Bolivia outnumber locals or those from other neighboring countries (Paraguay and Peru). The goal is this work is to analyze the links with their places of origin and with the socioeconomic and sociodemographic aspect of Bolivian migrant homes in the context of the current local re-urbanization policy (2015-2019). In this way, the proposal is to make an initial analysis of the possibility of plurilocal practices from a transnational perspective, questioning the classic and demographic definition of migration. An essentially quantitative methodological strategy, which forms part of a larger research project, was used to carry out this work, incorporating both primary and secondary data sources. A survey was applied with a strategic (non-probabilistic) sampling to 60 homes of Bolivian migrants, where the case selection is theoretical in nature. This work constitutes a first approach and is considered as the first step for the development of a later qualitative approach.Fil: Diaz, Mariela Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentina. Universidad de Buenos Aires. Facultad de Arquitectura, Diseño y Urbanismo; Argentin

A grid of Synthetic Spectra for Hot DA White Dwarfs and Its Application in Stellar Population Synthesis

In this work we present a grid of LTE and non-LTE synthetic spectra of hot DA white dwarfs (WDs). In addition to its usefulness for the determination of fundamental stellar parameters of isolated WDs and in binaries, this grid will be of interest for the construction of theoretical libraries for stellar studies from integrated light. The spectral grid covers both a wide temperature and gravity range, with 17,000 K <= T_eff <= 100,000 K and 7.0 <= log(g) <= 9.5. The stellar models are built for pure hydrogen and the spectra cover a wavelength range from 900 A to 2.5 microns. Additionally, we derive synthetic HST/ACS, HST/WFC3, Bessel UBVRI and SDSS magnitudes. The grid was also used to model integrated spectral energy distributions of simple stellar populations and our modeling suggests that DAs might be detectable in ultraviolet bands for populations older than ~8 Gyr.Comment: to be published in The Astrophysical Journal Supplement Serie

Effect of Fragarin on the Cytoplasmic Membrane of the Phytopathogen Clavibacter michiganensis

Fragarin, an antibiotic that was isolated and purified from a soluble fraction of strawberry leaves, may be a new type of preformed antimicrobial compound (phytoanticipin). Here, we report that the growth and oxygen consumption of the phytopathogenic bacterium Clavibacter michiganensis were rapidly inhibited after the addition of fragarin to cultures. Also, dissipation of the membrane potential and an increase of cell membrane permeability were observed in the presence of fragarin. The ability of fragarin to dissipate the membrane potential was confirmed with the use of small unilamellar liposomes made with lipids extracted from C. michiganensis. Our results suggest that fragarin is able to act at the membrane level, and that this action is correlated with a decrease in cell viability.Fil: Filippone, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Diaz Ricci, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Castagnaro, Atilio Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Farias, Ricardo Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin