748 research outputs found

    Fusión de suturas craneales en el delfín franciscana, Pontoporia blainvillei (Gervais and D'Orbigny, 1844)

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    Se estudió la fusión de suturas craneales y su asimetría bilateral en el delfín franciscana, Pontoporia blainvillei. Nuestros resultados mostraron que el cierre de suturas presenta baja variabilidad asociada a la longitud corporal total, exceptuando la sutura premaxilar-maxilar, cuyo estado de fusión mostró cierta asociación con el tamaño. Las suturas no mostraron asimetría direccional en su patrón de cierre, en concordancia con los resultados encontrados para las especies de delfines estudiadas hasta ahora. Nuestros resultados apoyan la idea de que diferentes especies de delfines exhiben distintos patrones de cierre de suturas asociados con su historia evolutiva y sus demandas funcionales específicas, y que no hay un patrón común general.Cranial suture closure and its bilateral asymmetry in the franciscana dolphin, Pontoporia blainvillei, were studied. Our results showed that the closure of cranial sutures exhibit low variability associated to total body size, with the exception of the premaxilla-maxilla suture which showed some correlation with body size. The cranial sutures of franciscana dolphins showed closure with no directional asymmetry, in accordance with the results found in dolphin species studied to date. Our results support the idea that different species of dolphins exhibit distinct patterns of suture closure, associated with their specific evolutionary histories and functional demands, and that there is no general common pattern.Fil: del Castillo, Daniela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Flores, David Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo. San Miguel de Tucumán; ArgentinaFil: Cappozzo, Humberto Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Fundación de Historia Natural Félix de Azara; Argentin

    Stranded humpback whale (Megaptera novaeangliae) (Cetacea: Balaenopteridae) in Paraná River Delta, Buenos Aires Province, Argentina. Comments on the occurrence of marine mammals in the La Plata River Basin

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    The humpback whale (Megaptera novaeangliae) is distributed among most oceans and seas of the globe (except Mediterranean Sea). These whales migrate from feeding regions in the Antarctic waters to breeding areas in tropical and subtropical seas. Here we report the stranding of a female young humpback whale, which was founded dead in the vicinity of the Talavera Island, in the Paraná River Delta, Buenos Aires Province, Argentina. From the analysis of mitochondrial cytochrome c oxidase subunit I gene sequences, two novel haplotypes were found, totalizing four haplotypes described for the species. In the La Plata River Basin this species was found only twice at the end of the XIX century. Thus, the new finding constitutes an important addition to the list of cetaceans that occurs in Uruguay, Paraná and La Plata Rivers.Fil: Lucero, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Gariboldi, María Constanza. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Bauni, Valeria. Fundación de Historia Natural Félix de Azara; ArgentinaFil: Meluso, Juan Manuel. Fundación de Historia Natural Félix de Azara; ArgentinaFil: del Castillo, Daniela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Agnolin, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Bogan, Sergio. Fundación de Historia Natural Félix de Azara; Argentin

    Beak deviations in the skull of Franciscana dolphins Pontoporia blainvillei from Argentina

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    The Franciscana dolphin Pontoporia blainvillei is characterized by a long rostrum, a feature that is shared with the families formerly classified as river dolphins (Pontoporiidae, Platanistidae, Iniidae, Lipotidae). Although there are occasional reports on the existence of beak deformations, very little published information exists describing this process. The object of the present study was to describe and quantify the beak anomalies of Franciscana dolphins from the coastal waters of Argentina. Of 239 skulls analyzed 12% showed beak deviations (BD), affecting the premaxillary-maxillary and dentary bones to different extents. The occurrence of BD in the dentary bone represented 58%, whereas premaxillary-maxillary BDs were observed in 14% ofthe studied specimens, while the complete rostrum (dentary, premaxillary and maxillary) was affected in 28% of the skulls. Dorsoventral axis BD was more frequent than lateral BD (48 and 38%, respectively), and double BD was only observed in the dentary bone. Most of the BD observed in this study could be classified as mild/moderate, and we assume that it did not affect the feeding activities of individuals; however, 2 specimens (<1%) showed a severe and complex curvature that probably did affect them. The cause of these anomalies (natural or anthropogenic origins) is unknown but may be related to important parasite loads, heavy metal and organic contaminants and plastic ingestion that could affect the coastal dolphin in different ways. A more detailed and thorough study of these cranial anomalies is necessary.Fil: Denuncio, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Panebianco, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: del Castillo, Daniela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Rodriguez, Diego Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Capozzo, Luis H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Bastida, Ricardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

    Objectivity, Ecology and Environmental Problems

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    En este trabajo indagamos el modo en que la ecología se dirige a su objeto de estudio, la naturaleza. “Ilustramos” este modo de estudiar la naturaleza mediante una crítica a la objetividad desarrollada por Theodore Roszak. Destacando que la ecología opera, en el contexto de la problemática ambiental, fuese objetiva. En este marco, problematizamos: (i) cómo se construye un significado de la naturaleza desde la ecología, (ii) cómo se silencia la experiencia del ecólogo en la naturaleza, (iii) cómo se da el vínculo entre valores (espirituales, estéticos o recreativos) y conocimiento ecosistémico y finalmente (iv) abordamos el carácter del conocimiento ecosistémico y su posición hegemónica en el contexto de la problemática ambiental. En líneas generales, las conclusiones del presente trabajo se dirigen a relegar al conocimiento ecosistémico a un lugar más modesto dentro de la actual crisis ambiental.In this paper we inquire the way in which ecology approaches its object of study, nature. We "illustrate" this way of studying nature through a critique of objectivity developed by Theodore Roszak, emphasizing that ecology operates, in the context of environmental problems, it were objective. In this framework, we problematize: (i) how one meaning of nature is constructed in ecology, (ii) how the ecologist's experience in nature is silenced, (iii) how are values (spiritual, aesthetic or recreational) and ecosystemic knowledge linked together and finally (iv) we address the "nomad" condition of ecosystemic knowledge and its hegemonic position in the context of environmental issues. In general terms, the conclusions of this work are directed at relegating ecosystem knowledge to a more modest place within the current environmental crisis.Fil: Di Pasquo, Federico Martín. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Filosofía "Dr. Alejandro Korn"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Klier, Gabriela Ruth. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Bussan, Tomás Emilio. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: del Castillo, Daniela Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Theory of knowledge, ecology, and environmental problems

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    El objetivo de este trabajo es precisar el modo en que la ecología se inserta en las problemáticas ambientales. Para ello, indagaremos en su teoría de conocimiento y en cómo, a partir de esta se establece una relación asimétrica entre la ecología y otros actores presentes en estas temáticas. Siguiendo la noción de obediencia de Humberto Maturana, nuestras hipótesis son: (a) que la inserción de la ecología en las problemáticas ambientales exige una relación de obediencia, sobre otros actores; y (b) que la relación de obediencia se deriva directamente de su aparato epistemológico y ontológico asociado. Finalmente, destacamos, para el contexto de la problemática ambiental, algunas consecuencias negativas de la asimetría señalada y sugerimos recuperar cierta lectura constructivista al seno de la ecología.The aim of this study is to clarify how ecology is inserted in the environmental issues. To achieve this, we will analyze the implicit theory of knowledge, and how, based on this, an asymmetrical relationship between ecology and other actors involved in these issues is established. Following the notion of obedience of Humberto Maturana, our hypotheses are: (a) that the insertion of ecology in the environmental issues requires a relationship of obedience on other actors; and (b) that the ratio of obedience is directly derived from its ontological and associated epistemological apparatus. Finally, for the context of the environmental issues, we highlight some negative consequences of the asymmetry indicated, and we suggest recovering a certain constructivist approach within ecology.Fil: Di Pasquo, Federico Martín. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Filosofía "Dr. Alejandro Korn"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Busan, Tomás Emilio. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Ocampo Mallou, Carolina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Rodríguez, Esteban. Instituto Superior Perito Moreno; ArgentinaFil: Klier, Gabriela Ruth. Universidad Nacional de Río Negro. Sede Andina. Centro de Estudios en Ciencia, Tecnología, Cultura y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: del Castillo, Daniela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

    Depressive Symptoms during Pregnancy. Prevalence and Correlates with Affective Temperaments and Psychosocial Factors

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    Pregnancy is a unique experience in women's life, requiring a great ability of adaptation and self-reorganization; vulnerable women may be at increased risk of developing depressive symptoms. This study aimed to examine the incidence of depressive symptomatology during pregnancy and to evaluate the role of affective temperament traits and psychosocial risk factors in predicting them. We recruited 193 pregnant women, collected data regarding sociodemographic, family and personal clinical variables, social support and stressful life events and administered the Mood Disorder Questionnaire (MDQ), the Patient Health Questionnaire-9 (PHQ-9), and the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A). In our sample, prevalence of depressive symptomatology was 41.45% and prevalence of depression was 9.85% (6.75% mild and 3.10% moderate depression). We have chosen a cutoff &gt;4 on PHQ-9 to identify mild depressive symptoms which may predict subsequent depression. Statistically significant differences between the two groups were found in the following factors: gestational age, occupation, partner, medical conditions, psychiatric disorders, family psychiatric history, stressful life events, and TEMPS-A mean scores. In our sample mean scores on all affective temperaments but the hyperthymic, were significantly lower in the control group. Only depressive and hyperthymic temperaments were found to be, respectively, risk and protective factors for depressive symptomatology. The current study confirms the high prevalence and complex aetiology of depressive symptomatology during pregnancy and suggests that affective temperament assessment seems to be a useful adjunctive instrument to predict depressive symptomatology during pregnancy and postpartum

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file
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