Diseño de un sistema de indicadores para la gestión integrada del recurso hídrico en la cuenca del arroyo Ludueña, Santa Fe

El presente trabajo selecciona e integra un conjunto de indicadores que evalúan los recursos hídricos de la cuenca del arroyo Ludueña, Santa Fe, República Argentina. Se utilizó un abordaje multiescalar, sistémico y complejo a escala de cuenca mediante la combinación del método GEO orientado a la Gestión Integrada del Recurso Hídrico (GIRH) y del modelo FPEIR (Fuerzas motrices – Presión – Estado – Impacto - Respuesta). La Gestión Integrada del Recurso Hídrico (GIRH) considera la intervención humana como parte esencial del ciclo hidrológico a nivel de cuenca y lo considera un ciclo hidrosocial. Se detectaron veintiséis (26) puntos críticos que podrían permitir la implementación de políticas públicas orientadas a la sustentabilidad. Esta metodología puede adaptarse y replicarse en cuencas hídricas similares. Los conocimientos aquí volcados constituyen un aporte al diagnóstico ambiental y resulta útil para articularlo con los Organismos públicos que deben velar por la conservación de los recursos hídricos de la cuenca del arroyo Ludueña.The present work evaluates the water resources of the Ludueña’s stream-basin (Santa Fe, Argentina) through several indicators that were selected and integrated in a sustainable indicators’s system. It used a multiscalar, systematic, and a complex approach on basin-scale through the GEO method applied to Integrated Water Resources Management (IWRM) combined with the DPSIR model (Driving forces – Pressure – State – Impact – Responses). The Integrated Water Resources Management (IWRM) considers anthropic intervention as an essential part of the hydrological cycle in a basin-scale, this results in a water-social cycle. It detected twenty-six (26) critical points which could allow a development for criteria destined for a sustainable management’s territory political. This approach can be adapted and replied in similar basins. This essay contributes to environment diagnosis and the result also be useful for the articulation with the political administration who must guarantee the conservation of the Ludueña stream-basin’s water resources.Martín, Lía. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin

Diseño de un sistema de indicadores para la gestión integrada de los recursos hídricos (GIRH) en la Cuenca del Arroyo Ludueña, Santa Fe

El presente trabajo seleccionó e integró un conjunto de indicadores que evaluaron los recursos hídricos de la cuenca del arroyo Ludueña, Santa Fe, República Argentina. Se utilizó un abordaje multiescalar, sistémico y complejo a escala de cuenca mediante la combinación del método GEO orientado a la Gestión Integrada del Recurso Hídrico (GIRH) y del modelo FPEIR (Fuerzas motrices – Presión – Estado – Impacto - Respuesta). La Gestión Integrada del Recurso Hídrico (GIRH) considera la intervención humana como parte esencial del ciclo hidrológico a nivel de cuenca y lo considera un ciclo hidrosocial. Se detectaron veintiséis (26) puntos críticos que podrían permitir la implementación de políticas públicas orientadas a la sustentabilidad. Esta metodología puede adaptarse y replicarse en cuencas hídricas similares. Este trabajo constituye un aporte al diagnóstico ambiental integrado y resulta útil como insumo para los Organismos Públicos que deben velar por la conservación de los recursos hídricos de la cuenca del arroyo Ludueña

Linear polarization of a group of symbiotic systems

We report linear polarization measurements of a set of symbiotic stars, made at several epochs during the period 1994-1998. Evidence of intrinsic polarization is looked for from the wavelength dependence of the polarization degree and position angle in UBVRI bands. The results have also been analysed to search for temporal variability of polarization. Several objects have shown a polarization spectrum different from that produced by interstellar dust grains and/or polarimetric variations on time scales as short as several days or months, indicating the presence of polarization component of circumstellar origin.Facultad de Ciencias Astronómicas y Geofísica

Occurrence of scab disease of pecan caused by Cladosporium caryigenum in Argentina

Pecan (Carya illinoinensis) is a new crop in Argentina. The planted area is expanding quickly with around 4000 h in the Pampas region. In 2007 and 2008 typical scab symptoms on seedlings and mature trees were commonly observed in La Plata. A Cladosporium-like fungus was isolated on potato dextrose agar (PDA) from surface-sterilized pecan leaves collected from the Experimental Station of UNLP. Fungus' characteristics agree with a published description of Cladosporium caryigenum (Gottwald, 1982).Centro de Investigaciones en FitopatologíaFacultad de Ciencias Astronómicas y Geofísica

Linear polarization of a group of symbiotic systems

We report linear polarization measurements of a set of symbiotic stars, made at several epochs during the period 1994-1998. Evidence of intrinsic polarization is looked for from the wavelength dependence of the polarization degree and position angle in UBVRI bands. The results have also been analysed to search for temporal variability of polarization. Several objects have shown a polarization spectrum different from that produced by interstellar dust grains and/or polarimetric variations on time scales as short as several days or months, indicating the presence of polarization component of circumstellar origin.Facultad de Ciencias Astronómicas y Geofísica

Host species of the hemiparasitic shrub Phoradendron nervosum Oliv. in densely urban areas of Quito, Ecuador.

Phoradendron nervosum is a hemiparasitic shrub with a wide distribution area. Despite this, the ecology of natural history of this species is not well studied. Host species of P. nervosum are reported from Mexico and Costa Rica mainly with recent reports from Ecuador. Inside the urban areas of the metropolitan area of the city of Quito, P. nervosum infects 21 species of plants, where introduced and cultivated species are more prone to infection. This study raises the reported host species of P. nervosum from Ecuador to 26 species. More sampling is needed in other areas in the wide distribution of P. nervosum to test if introduced and cultivated species are mor prone to infection and to raise the list of the host species of this common species

Occurrence of scab disease of pecan caused by Cladosporium caryigenum in Argentina

Pecan (Carya illinoinensis) is a new crop in Argentina. The planted area is expanding quickly with around 4000 h in the Pampas region. In 2007 and 2008 typical scab symptoms on seedlings and mature trees were commonly observed in La Plata. A Cladosporium-like fungus was isolated on potato dextrose agar (PDA) from surface-sterilized pecan leaves collected from the Experimental Station of UNLP. Fungus' characteristics agree with a published description of Cladosporium caryigenum (Gottwald, 1982).Centro de Investigaciones en FitopatologíaFacultad de Ciencias Astronómicas y Geofísica

Spectroscopic orbits and variations of RS Ophiuchi

The aims of our study are to improve the orbital elements of the giant, and to derive the spectroscopic orbit for the white dwarf companion. Spectral variations related to the 2006 outburst are also studied. Methods. We performed an analysis of about seventy optical and near infrared spectra of RS Oph that were acquired between 1998 and June 2008. The spectroscopic orbits have been obtained by measuring the radial velocities of the cool component absorption lines and the broad Hα emission wings, which seem to be associated with the hot component. A set of cF-type absorption lines were also analyzed for a possible connection with the hot component motion. Results. A new period of 453.6 days, and a mass ratio, q = Mg/Mh = 0.59 ± 0.05, were determined. Assuming a massive white dwarf as the hot component (Mh = 1.2 − 1.4M⊙) the red giant mass is Mg = 0.68 − 0.80M⊙ and the orbit inclination, i = 49◦ − 52◦. The cF-type lines are not associated with either binary component, and are most likely formed in the material streaming towards the hot component. We also confirm the presence of the Li I doublet in RS Oph and its radial velocities fit very well the M-giant radial velocity curve. Regardless of the mechanism involved to produce lithium, its origin is most likely from within the cool giant rather than material captured by the giant at the time of the nova explosion. The quiescent spectra reveal a correlation of the HI and He I emission line fluxes with the monochromatic magnitudes at 4800 Å indicating that the hot component activity is responsible for those flux variations. We also discuss the spectral characteristics around 54–55 and 240 days after the 2006 outburst. In April 2006 most of the emission lines present a broad pedestal with a strong and narrow component at about -20 kms−1 and two other extended emission components at -200 and +150 kms−1. These components could originate in a bipolar gas outflow supporting the model of a bipolar shock-heated shell expanding through the cool component wind perpendicularly to the binary orbital plane. Our observations also indicate that the cF absorption system was disrupted during the outburst, and restored about 240 days after the outburst, which is consistent with the resumption of accretion.Facultad de Ciencias Astronómicas y Geofísica

Construyendo Pedagogías Emancipatórias: La Escuela Campesina de Agroecología - Mendoza, Argentina

Neste artigo analisamos a experiência da Escola Camponesa de Agroecologia, na província de Mendoza, Argentina, com foco na construção de seu projeto político pedagógico. O principal objetivo da escola é a formação de educadores especializados em agroecologia, e contribuir para a construção de um novo paradigma no campo argentino, com base na garantia da soberania alimentar. Há o reconhecimento de que os processos de mudança e transformação da realidade dependem, diretamente, das ações relacionadas com a educação. Assim, os princípios políticos-pedagógicos, o desempenho escolar, a estrutura curricular e de avaliação consistentes são analisados ​​como uma pedagogia crítica e emancipatória

Spectroscopic orbits and variations of RS Ophiuchi

The aims of our study are to improve the orbital elements of the giant, and to derive the spectroscopic orbit for the white dwarf companion. Spectral variations related to the 2006 outburst are also studied. Methods. We performed an analysis of about seventy optical and near infrared spectra of RS Oph that were acquired between 1998 and June 2008. The spectroscopic orbits have been obtained by measuring the radial velocities of the cool component absorption lines and the broad Hα emission wings, which seem to be associated with the hot component. A set of cF-type absorption lines were also analyzed for a possible connection with the hot component motion. Results. A new period of 453.6 days, and a mass ratio, q = Mg/Mh = 0.59 ± 0.05, were determined. Assuming a massive white dwarf as the hot component (Mh = 1.2 − 1.4M⊙) the red giant mass is Mg = 0.68 − 0.80M⊙ and the orbit inclination, i = 49◦ − 52◦. The cF-type lines are not associated with either binary component, and are most likely formed in the material streaming towards the hot component. We also confirm the presence of the Li I doublet in RS Oph and its radial velocities fit very well the M-giant radial velocity curve. Regardless of the mechanism involved to produce lithium, its origin is most likely from within the cool giant rather than material captured by the giant at the time of the nova explosion. The quiescent spectra reveal a correlation of the HI and He I emission line fluxes with the monochromatic magnitudes at 4800 Å indicating that the hot component activity is responsible for those flux variations. We also discuss the spectral characteristics around 54–55 and 240 days after the 2006 outburst. In April 2006 most of the emission lines present a broad pedestal with a strong and narrow component at about -20 kms−1 and two other extended emission components at -200 and +150 kms−1. These components could originate in a bipolar gas outflow supporting the model of a bipolar shock-heated shell expanding through the cool component wind perpendicularly to the binary orbital plane. Our observations also indicate that the cF absorption system was disrupted during the outburst, and restored about 240 days after the outburst, which is consistent with the resumption of accretion.Facultad de Ciencias Astronómicas y Geofísica