Migraciones en el chaco semiárido de salta: su relación con la ganadería, la explotación forestal y el uso de la fauna silvestre en el departamento rivadavia

Considerando que la Colonia Rivadavia se fundó en 1862, con el objetivo principal de aprovechar los pastizales del Chaco Semiárido para exportar ganado al Norte de Chile, analizamos desde una perspectiva histórica y demográfica, la relación existente entre las migraciones humanas y las principales actividades económicas del Departamento Rivadavia. Usando el método residual, se calcularon los saldos migratorios entre los censos nacionales de población y vivienda de 1914, 1947, 1960, 1970, 1980, 1991 y la población proyectada a 1998, resultando todos negativos. La expulsión constante de población, obedece al retroceso de la actividad ganadera por sobrepastoreo, lo que condujo a la degradación del ecosistema y la caída del ingreso, induciendo a los pobladores locales a presionar mas sobre el bosque y la fauna silvestre. La pobreza, consecuencia directa de un problema ambiental, obligó a emigrar de Rivadavia. Esta conclusión se sustenta en la evolución de distintos indicadores socio-económicos que se comparan para distintos períodos de los últimos treinta años: necesidades básicas insatisfechas, desnutrición infantil y el fracaso de distintos proyectos de desarrollo dirigidos principalmente a aborígenes en el período 1969 199

QUBIC: the Q and U bolometric interferometer for cosmology

International audienc

Thermal architecture for the QUBIC cryogenic receiver

International audienceQUBIC, the QU Bolometric Interferometer for Cosmology, is a novel forthcoming instrument to measure the B-mode polarization anisotropy of the Cosmic Microwave Background. The detection of the B-mode signal will be extremely challenging; QUBIC has been designed to address this with a novel approach, namely bolometric interferometry. The receiver cryostat is exceptionally large and cools complex optical and detector stages to 40 K, 4 K, 1 K and 350 mK using two pulse tube coolers, a novel 4He sorption cooler and a double-stage 3He/4He sorption cooler. We discuss the thermal and mechanical design of the cryostat, modelling and thermal analysis, and laboratory cryogenic testing

Optical modelling and analysis of the Q and U bolometric interferometer for cosmology

International audienceRemnant radiation from the early universe, known as the Cosmic Microwave Background (CMB), has been redshifted and cooled, and today has a blackbody spectrum peaking at millimetre wavelengths. The QUBIC (Q&U Bolometric Interferometer for Cosmology) instrument is designed to map the very faint polaristion structure in the CMB. QUBIC is based on the novel concept of bolometric interferometry in conjunction with synthetic imaging. It will have a large array of input feedhorns, which creates a large number of interferometric baselines. The beam from each feedhorn is passed through an optical combiner, with an off-axis compensated Gregorian design, to allow the generation of the synthetic image. The optical-combiner will operate in two frequency bands (150 and 220 GHz with 25% and 18.2 % bandwidth respectively) while cryogenically cooled TES bolometers provide the sensitivity required at the image plane. The QUBIC Technical Demonstrator (TD), a proof of technology instrument that contains 64 input feed-horns, is currently being built and will be installed in the Alto Chorrillos region of Argentina. The plan is then for the full QUBIC instrument (400 feed-horns) to be deployed in Argentina and obtain cosmologically significant results. In this paper we will examine the output of the manufactered feed-horns in comparison to the nominal design. We will show the results of optical modelling that has been performed in anticipation of alignment and calibration of the TD in Paris, in particular testing the validity of real laboratory environments. We show the output of large calibrator sources (50 ° full width haf max Gaussian beams) and the importance of accurate mirror definitions when modelling large beams. Finally we describe the tolerance on errors of the position and orientation of mirrors in the optical combiner

The relationship between people and lizards in Patagonia

Abstract: Understanding how human beings perceive and interact with the local herpetofauna is fundamental for its conservation. In this chapter, we propose looking forward to the local ecological knowledge (LEK) of the Patagonian lizards, especially the "matuasto". The preliminary analysis of ethnohistorical sources points out the relevant role of "matuastos" in the cosmologies of the original people from Patagonia, often considered as immortal, selfish and harmful beings. Field reports agree on the warning not to disturb these territorial lizards, otherwise they would react aggressively with bites. The recorded stories account for frequent biting events on sheep. The local perception on "matuastos" as harmful beings would provoke an attitude of caution and rejection towards them. This work provides a first overview on the relationship of lizards and the people from Patagonia while constituting an initial step for future research.Fil: Aigo, Juana del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Ladio, Ana Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Boretto, Jorgelina Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Cabezas Cartes, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Ibarguengoytía, Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin