The Systematic Status and Biology of Telmatobius montanus Lataste (Amphibia, Leptodactylidae)

The poorly known Telmatobius montanus was rediscovered in the high Andean mountains between Mendoza and Talca on the Argentinian- Chilean frontier. Morphological characters of the adults and tadpoles are described. There is convergence in male secondary sex characters toward the leptodactylid frogs of the genus Eupsophus (nodosus group).Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

The Systematic Status and Biology of Telmatobius montanus Lataste (Amphibia, Leptodactylidae)

The poorly known Telmatobius montanus was rediscovered in the high Andean mountains between Mendoza and Talca on the Argentinian- Chilean frontier. Morphological characters of the adults and tadpoles are described. There is convergence in male secondary sex characters toward the leptodactylid frogs of the genus Eupsophus (nodosus group).Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

La presencia de monticulos tipo Mima en la Argentina en relación con roedores del género Ctenomys

The discovery of Mima mounds pocking the Pampean region in the south-east of San Luis, south of Córdoba and north of La Pampa, as well as in some Monte regions in Mendoza, confirms the hypothesis that fossorial rodents are the origin of this type of phenomenon and that such mounds are present in different regions of the world coinciding with the presence of families of fossorial rodents showing similar morphology and behavior. This similarity with geomyds of the United States and other families from West and South Africa, becomes evident in Argentine Ctenomydae, which activity is responsible for the formation of this type of relief, Which has nowadays disappeared in most of the central part of the country due to agricultural practices. The discovery of Mima mounds in Argentina unquestionably confirms the discussed origin of this type of topographic accident, which has been subject to the most varied interpretations.The discovery of Mima mounds pocking the Pampean region in the south-east of San Luis, south of Córdoba and north of La Pampa, as well as in some Monte regions in Mendoza, confirms the hypothesis that fossorial rodents are the origin of this type of phenomenon and that such mounds are present in different regions of the world coinciding with the presence of families of fossorial rodents showing similar morphology and behavior. This similarity with geomyds of the United States and other families from West and South Africa, becomes evident in Argentine Ctenomydae, which activity is responsible for the formation of this type of relief, Which has nowadays disappeared in most of the central part of the country due to agricultural practices. The discovery of Mima mounds in Argentina unquestionably confirms the discussed origin of this type of topographic accident, which has been subject to the most varied interpretations

Regulación de la temperatura en Chaetophractus villosus

Chaetophractus villosus body temperature was observed by means of teletermometers placed at different body depths while kept in captivity in chambers of constant temperature. At a periferical level high variations were recorded. Below 4-5 cm depth temperature variations were alternated until a termical gradient is reached. Nictimeral rithms are showed in nocturnal activity, being, ore evident in reponse to the environmental temperature.Coments about feeding behavior, ecology and fisiology are included. General considerations about filogeny of termo regulation are also given

Comparison of approaches to deal with matrix effects in LC-MS/MS based determinations of mycotoxins in food and feed

This study deals with one of the major concerns in mycotoxin determinations: the matrix effect related to LC-MS/ MS systems with electrospray ionization sources. To this end, in a first approach, the matrix effect has been evaluated in two ways: monitoring the signal of a compound (added to the mobile phase) during the entire chromatographicrun, and by classical post-extraction addition. The study was focused on nine selected mycotoxins: aflatoxin B1, fumonisins B1, B2 and B3, ochratoxin A, deoxynivalenol, T-2 and HT-2 toxins and zearalenone in various sample extracts giving moderate to strong matrix effects (maize, compound feed, straw, spices). Although the permanent monitoring of a compound provided a qualitative way of evaluating the matrix effects at each retention time, we concluded that it was not adequate as a quantitative approach to correct for the matrix effect. Matrix effects measured by post-extraction addition showed that the strongest ion suppression occurred for the spices (up to -89%). Five different calibration approaches to compensate for matrix effects were compared: multi-level external calibration using isotopically labelled internal standards, multi-level and single level standard addition, and two ways of singlepoint internal calibration: one point isotopic internal calibration and isotope pattern deconvolution. In general, recoveries and precision meeting the European Union requirements could be achieved with all approaches, with the exception of the single level standard addition at levels too close to the concentration in the sample. When an isotopically labelled internal standard is not available, single-level standard addition is the most efficient option.The Dutch Ministry of Economic Affairs is acknowledged for financially supporting this work. The authors acknowledge the financial support from Generalitat Valenciana (Research group of excellence Prometeo 2009/054 and Collaborative Research on Environment and Food Safety ISIC/2012/016). N. Fabregat-Cabello also acknowledges the Generalitat Valenciana for her Ph.D. research grant under the Program VALi+D

Magnetic Moment of the Fragmentation Aligned 61Fe(9/2)+ Isomer

We report on the g factor measurement of the isomer in $^{61}Fe$ ($E^{*}=861 keV$). The isomer was produced and spin-aligned via a projectile-fragmentation reaction at intermediate energy, the Time Dependent Perturbed Angular Distribution (TDPAD) method being used for the measurement of the g factor. For the first time, due to significant improvements of the experimental technique, an appreciable residual alignment of the isomer has been observed, allowing a precise determination of its g factor: $g=-0.229(2)$. Comparison of the experimental g factor with shell-model and mean field calculations confirms the $9/2^+$ spin and parity assignments and suggests the onset of deformation due to the intrusion of Nilsson orbitals emerging from the $\nu g_{9/2}$.Comment: 4 figures. Submitted to Phys. Rev. Let

Apuntes batracológicos de un itinerario de observaciones biológicas en las Llanuras Pampeanas y en el Litoral

Los autores han recorrido en el período desde el 30 de noviembre al 10 de diciembre de 1963 las provincias de Córdoba, Santa Fe, Chaco y Corrientes con el objeto de realizar observaciones biológicas sobre elementos de su fauna herpetológica. Ha sido así posible durante varias noches seguidas estudiar en esta época del año la actividad de los anfibios anuros en distintas comunidades biocenóticas, tratándose de un período en que las funciones reproductivas son más intensas, en el cual la mayoría de las especies concurren a los ambientes acuáticos a los efectos de su copulación y desove. Habiéndose reunido un notable conjunto de notas ecológicas y de datos útiles para una más completa definición de la distribución geográfica de varias de las formas encontradas, se ha considerado oportuno reunirlos en estos apuntes como una contribución al mejor conocimiento del mundo viviente del litoral argentino. El itinerario seguido fue el siguiente: desde Mendoza, por San Luis a Río Cuarto, de allí cruzando las llanuras pampeanas que se extienden desde esta ciudad hasta Villa María y San Francisco, se alcanzó Santa Fe y luego de atravesar la zona norte de dicha ciudad, modificada fuertemente por los cultivos, fue seguida la Ruta 11 hasta Reconquista y Resistencia (Chaco). Los límites meridionales chaqueños son actualmente inciertos debido a la acción del hombre que ha en gran parte alterado la fisonomía originaria, pero desde San Justo (Santa Fe) hacia Reconquista se empieza a reconocer netamente la formación que ha sido denominada Chaco santafecino y donde predominan las asociaciones de palmares y que- brachales. En los meses más lluviosos del año se forman extensos bañados y lagunas los que favorecen extraordinariamente el desarrollo y la multiplicación de una abundante fauna anfibia. Después de Reconquista, hacia el norte, el monte se hace más denso, en parte más árido, y adquiere los caracteres típicos del bosque chaqueño. El itinerario seguido en el viaje de vuelta a Mendoza, fue desde Resistencia a Corrientes y de allí a Goya siguiendo la Ruta 12, la que atraviesa amplias extensiones de los "campos" correntinos, pudiéndose subrayar sobre todo en la región litoral, densas comunidades de Erhingium. También en esta zona, en razón de las lluvias primaverales, se hallan extensos bañados y pantanos temporarios, en particular en los bordes de la ruta Cruzando el Paraná entre Goya y Reconquista, el itinerario de vuelta repitió, luego, el camino de ida. Se exponen ahora las observaciones realizadas, ordenadamente, de acuerdo con el itinerario indicado.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Batracios recolectados por la expedición biológica Erspamer, en Corrientes y Selva Oriental de Misiones

Se estudian los materiales batracológicos recolectados en Febrero de 1961 en las provincias de Corrientes y Misiones, elevando a 36 formas de anuros la fauna de la primera, y a 40 formas la de la segunda. Se señalan por primera vez en la Argentina Crossodactylus dispar, Hyla semi guttata, Hyla albopunctata, Phyllomedusa iheringi, Pseudopaludicola ameghini, Physalaemus riograndensis, dando de este último una completa redescripción. Se exponen algunas consideraciones biogeográficas generales sobre esta parte de la herpetofauna correntino-misionera.Amphibians collections by the Instituto de Biología of Mendoza during 1961 Herpetological Expedition to the Misiones Subtropical rain forest were studied and discussed. Six forms new for the argentine herpetofauna were reported, with a redescription of Physalaemus riograndensis Milstead. Biogeographical interest of the present indings was pointed out.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Batracios recolectados por la expedición biológica Erspamer, en Corrientes y Selva Oriental de Misiones

Se estudian los materiales batracológicos recolectados en Febrero de 1961 en las provincias de Corrientes y Misiones, elevando a 36 formas de anuros la fauna de la primera, y a 40 formas la de la segunda. Se señalan por primera vez en la Argentina Crossodactylus dispar, Hyla semi guttata, Hyla albopunctata, Phyllomedusa iheringi, Pseudopaludicola ameghini, Physalaemus riograndensis, dando de este último una completa redescripción. Se exponen algunas consideraciones biogeográficas generales sobre esta parte de la herpetofauna correntino-misionera.Amphibians collections by the Instituto de Biología of Mendoza during 1961 Herpetological Expedition to the Misiones Subtropical rain forest were studied and discussed. Six forms new for the argentine herpetofauna were reported, with a redescription of Physalaemus riograndensis Milstead. Biogeographical interest of the present indings was pointed out.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse