A new genus of neobatrachian frog from southern Patagonian forests, Argentina and Chile

In 1975 Lynch named a new species of frog based on two specimens from Puerto Eden, Wellington Island, southern Chile, tentatively allocated to the genus Telmatobius. Telmatobius grandisonae Lynch was later included by the same author in his genus Atelognathus. Based on a reappraisal of the type material and the description of the internal and external morphology, karyotype, tadpole morphology and molecular evidence from recently discovered specimens collected at Lago del Desierto, southern Argentina, we describe the monotypic genus Chaltenobatrachus, with Telmatobius grandisonae (Lynch) serving as the type species. Chaltenobatrachus differs from Atelognathus mainly in having a uniform bright green dorsal coloration, with brown to reddish warts; orange iris with gold spots; fingers with interdigital membrane; frontoparietals well developed, small nasals; well ossified sphenethmoid; anteriorly expanded homosternum; skin of tadpole transparent; oral disc with protruding anterior and lateral papillae; diploid number 2n = 32 chromosomes. The genetic distances between Chaltenobatrachus and Atelognathus meet or exceed most other intergeneric comparisons.Fil: Basso, Nestor Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Úbeda, Carmen A.. 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: Bunge, Maria M.. 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: Martinazzo Giménez, Liza Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Melanophryniscus aff. montevidensis

Distribución restringida a las Sierras y la región costera del sur de la provincia de Buenos Aires. El estatus taxonómico de estas poblaciones no ha sido esclarecido aún, pero estudios en curso indican que podrían ser poblaciones de M. montevidensis, distribuida también en Uruguay y extremo sureste de Rio Grande do Sul en Brasil (Baldo, datos no publ.)...Fil: Cairo, Samanta Lis. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Zalba, Sergio Martín. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; ArgentinaFil: Úbeda, Carmen A.. Universidad Nacional del Comahue. Centro Reg.universidad Bariloche. Departamento de Zoología. Cátedra de Vertebrados; Argentin

Relationship between morphotypes of Atelognathus patagonicus (Anura, Neobatrachia) and environmental conditions: evidence and possible explanation

The frog Atelognathus patagonicus (Gallardo, 1962) is endemic to an endorheic pond system in basaltic basins, in Laguna Blanca National Park and its surroundings, in northwest Argentinean Patagonia. The species has two morphotypes, aquatic and littoral, which were studied in Laguna Batea, a semi permanent pond. Aquatic and terrestrial samples were taken over a period of 31 months, including periods of drought and periods of normal precipitation. Evidence was found of the reversible character of the two morphotypes. The changes in the phenotype were consistent with the water level and limnological conditions in the pond. We believe that the change and subsequent reversal of the somatic features in these frogs are an opportunistic alternative showing remarkable plasticity of the species, which can thus inhabit both permanent and temporary ponds. Therefore, the two morphotypes, aquatic and littoral, cannot be considered as "fixed forms" within a given population, as other authors have speculated, and do not correspond to ontogenetic states

Scanning electron microscopy of the oral apparatus and buccopharyngeal cavity of Atelognathus salai larvae (Anura, Neobatrachia)

The aim of this study is to describe the horny structures of the buccal apparatus and buccopharyngeal cavity of A. salai by means ofscanning electron microscopy (SEM), and to compare them to those of the other known species of Atelognathus and related genera

Reproductive pattern in the southernmost populations of South American redbelly toads

Anurans can be classified as explosive or prolonged breeders. In species with short breeding periods, intensive competition for females is expected. We analyse the temporal breeding pattern of Melanophryniscus aff. montevidensis, a bufonid inhabiting grasslands of Argentina, whose breeding is concentrated in events of short duration. Males are active during more than one breeding event per season, whereas most females take part in a single event per season. Active males outnumbered females by up to 14 times at one event, operational sex ratio (OSR) ranged from 0.07 to 0.75 and intensity of sexual selection (I s) from 0.69 to 24. We found a negative association between I s and OSR, but no correlation between number of active males per event and OSR or I s. The OSR is the key that regulates the intensity of sexual selection, nevertheless, and in spite of being explosive breeders, females would potentially have chances to select their mate.Fil: Cairo, Samanta Lis. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; ArgentinaFil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; ArgentinaFil: Úbeda, Carmen A.. Universidad Nacional del Comahue. Centro Reg.universidad Bariloche. Departamento de Zoologia. Catedra de Vertebrados; Argentin

Biosensors in Rehabilitation and Assistance Robotics

Robotic developments in the field of rehabilitation and assistance have seen a significant increase in the last few years [...

Stable cycling in quasi-linkage equilibrium:fluctuating dynamics under gene conversion and selection

Genetic systems with multiple loci can have complex dynamics. For example, mean fitness need not always increase and stable cycling is possible. Here, we study the dynamics of a genetic system inspired by the molecular biology of recognition-dependent double strand breaks and repair as it happens in recombination hotspots. The model shows slow-fast dynamics in which the system converges to the quasi-linkage equilibrium (QLE) manifold. On this manifold, sustained cycling is possible as the dynamics approach a heteroclinic cycle, in which allele frequencies alternate between near extinction and near fixation. We find a closed-form approximation for the QLE manifold and use it to simplify the model. For the simplified model, we can analytically calculate the stability of the heteroclinic cycle. In the discrete-time model the cycle is always stable; in a continuous-time approximation, the cycle is always unstable. This demonstrates that complex dynamics are possible under quasi-linkage equilibrium.Comment: 35 pages, 6 figure

Integración de un ratón inercial y una interfaz ocular para el control del cursor del ordenador.

En este artículo se presenta la integración de un ratón inercial y una interfaz ocular para el control del cursor del ordenador. El ratón inercial se utiliza para controlar la posición del puntero, mientrasque la interfaz ocular permite hacer click en pantalla a través del parpadeo. Para evaluar la interfaz combinada se ha empleado un software de evaluación específico (Fitts Study) que ha permitido obtener parámetros de evaluación de la realización de diversas pruebas de alcance y selección de objetivos. Los resultados se han comparado con el uso del ratón inercial mediante selección por tiempo de permanencia.IBERADA (Red Iberoamericana para el estudio y desarrollo de aplicaciones TIC basadas en interfaces adaptadas a personas con discapacidad, 512TR0466), financiada por CYTED (Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo). Gracias también a la Obra Social de Caja Cantabria, entidad financiadora del proyecto IVANPACE.Peer reviewe