163 research outputs found

    The role of temperature and oxygen availability on the distribution of Corbicula largillierti

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    The invasiveness of Corbicula largillierti has been underestimated, but this bivalve is currently receiving more attention. The first study of the distribution of this species along one of the major basins of central Argentina showed that it was completely absent in the major central reservoir, but was present along its tributary and effluent rivers. Ten years later, this discontinuous distribution has not changed, despite the bivalve's high dispersion capacity. The main environmental differences between the reservoir and the rivers are that the former has finer sediment grain size, higher temperatures, and lower oxygen concentration during summer months. This study aimed to evaluate whether one of these factors could be limiting the distribution of C. largillierti. We assessed the metabolic response and burial behavior (under different grain sizes) of C. largillierti over 8 weeks at 30°C against a control condition at 20°C. We also analyzed the oxygen consumption (vO2) as a function of environmental oxygen concentration (pO2) at 25°C, estimating its metabolic regulation capacity (R). This showed the existence of an environmental oxygen concentration threshold (Pt) that could be an indicative of physiological limiting concentrations that compromise species survival and settlement. After 8 weeks at 30°C, the metabolic rate of individuals of C. largillierti increased and their burial behavior was slightly compromised but mostly for coarser sediments. Concerning environmental oxygen availability, C. largillierti is an oxyconformer with a low R (39.9%), a clear pattern of negative regulation, and a low Pt (48.4% air saturation). The lack of any regulation capacity of C. largillierti under environmental oxygen limitations and the extremely low pO2 at the bottom of the reservoir during summer months may explain its failure to colonize and survive there.Fil: Rodriguez, Florencia Anahi. Universidad Nacional de Córdoba; ArgentinaFil: Reyna, Paola Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Maggioni, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Gimenez, Diego R.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Torre, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

    Deep-sea ascidians (Chordata, Tunicata) from the SW Atlantic: Species richness with descriptions of two new species

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    The understudied deep-sea benthic communities from the Southwestern Atlantic continental slope (200 m–3000 m depth) were sampled on August 2012 in an area located around 38°S that included the Mar del Plata submarine canyon. In these samplings we found a total of 16 ascidian species from six different families, of which two corresponded to new species. These were: Aplidium meridianum (Sluiter, 1906); Aplidium variabile (Herdman, 1886); Aplidium marplatensis Maggioni & Tatián (sp. nov. present work); Aplidium solitarium Maggioni & Tatián (sp. nov. present work); Synoicum georgianum Sluiter, 1932; Synoicum molle (Herdman, 1886); Synoicum sp.; Polysyncraton trivolutum (Millar, 1960); Sycozoa umbellata (Michaelsen, 1898); Ascidia meridionalis Herdman, 1880; Cnemidocarpa drygalskii (Hartmeyer, 1911); Styela squamosa Herdman, 1881; Pyura pilosa Monniot C. & Monniot F., 1974; Molgula pyriformis Herdman, 1881; Molgula setigera Ärnbäck-Christie-Linde, 1938 and Asajirus indicus (Oka, 1913). Based on morphological evidence, we propose the new synonymy: Molgula setigera Ärnbäck-Christie-Linde, 1938 = Molgula marioni Millar, 1960 = Molgula robini Monniot C. & Monniot F., 1983. We also propose to maintain Molgula pyriformis and Molgula malvinensis as separate species. We report: the extension of the distribution range of Aplidium meridianum, Synoicum georgianum, Polysyncraton trivolutum, Sycozoa umbellata, Cnemidocarpa drygalskii, Pyura pilosa and Molgula setigera, being the first time they are collected off La Plata River; the deepest registers for Synoicum georgianum, Poylsyncraton trivolutum, Sycozoa umbellata, Ascidia meridionalis, Pyura pilosa, Molgula pyriformis and Molgula setigera; and the shallowest register for Synoicum molle.Fil: Maggioni, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Taverna, Anabela Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Reyna, Paola Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Alurralde, Roque Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Rimondino, Clara Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Tatian, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

    Ascidian distribution provides new insights to help define the biogeographic provinces in the South American Region

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    The validity and size of the biogeographic Magellan Province of marine organisms have been the focus of discussion of many authors. The distribution of fish and other organisms has revealed a lack of homogeneity in the area, which has also been interpreted as comprising four different Provinces: Southern Chile (SCH), Tierra del Fuego (TDF), Southern Argentina (SAR), and the Malvinas/Falkland Islands (MAI). For the first time, we assess the ascidian fauna of this region to determine if the distribution of benthic sessile filter feeders corresponds to these biogeographic provinces. Ascidian species richness and percentages of endemism for these four areas were estimated using data from the literature and new sampling. Biogeographic affinities among SCH, TDF, SAR, and MAI were also calculated. The species Pyura pilosa, Molgula malvinensis, and Molgula manhattensis, the latter frequently considered as invasive, were found for the first time on the TDF shelf. The highest ascidian species richness was found in TDF (70 species), while the percentages of endemism greater than 10% (the minimum to qualify an area as a province) were found in TDF (15.7%) and SCH (11.1%). SAR and MAI showed the lowest percentages of endemism and the strongest affinity. Based on percentages of endemism, faunal affinities, and differences among the four provinces, we propose a separation of the South American Region into three Provinces: SCH, TDF, and SAR/MAI. Continued sampling of ascidians is considered to be particularly important, given the potential spread of invasive species throughout this region.Fil: Taverna, Anabela Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Lagger, Cristian Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Maggioni, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Reyna, Paola Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Tatian, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

    GLUCOCORTICOID USE IN STEVENS-JOHNSON SYNDROME AND TOXIC EPIDERMAL NECROLYSIS CASES IN HOSPITAL NOSSA SENHORA DA CONCEIÇÃO - MARCH 2007 TO AUGUST 2014

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    Introdução: A síndrome de Stevens-Johnson e a necrólise epidérmica tóxica (NET) são reações cutâneas severas, associadas a lesões mucosas e comprometimento sistêmico. Os glicocorticoides foram empregues por muitos anos no tratamento da síndrome de Stevens-Johnson/necrólise epidérmica tóxica, mas não há evidências que sustentem esta conduta.Objetivo: Avaliação da mortalidade em casos de síndrome de Stevens-Johnson/necrólise epidérmica tóxica em um grupo de pacientes que fez uso de glicocorticoides sistêmico e em outro grupo não fez uso.Objetivo secundário: Descrição da população estudada; avaliação de infecção secundária e complicações extra-cutâneas nos dois grupos de pacientes.Material e Métodos: Coorte retrospectiva de pacientes avaliados por meio de consultorias solicitadas ao Serviço de Dermatologia do Hospital Nossa Senhora da Conceição, bem como pelo diagnóstico na internação ou óbito, durante o período de Março de 2007 a Agosto de 2014.Resultados: Mortalidade foi de 63.2% no grupo que usou corticoide e 9,1% no grupo que não usou corticoide, com p valor de 0,005 (IC 95% 1.79-163.8). Análise multivariada ajustada pelo SCORTEN demonstrou apenas uma tendência, com odds ratio para mortalidade no grupo de pacientes que usou glicocorticoides sendo de 7.38 (IC 95% 0.87-161.43) e p valor de 0.06.Conclusão: Este estudo sugere uma tendência de malefício relacionado ao uso de glicocorticoides para o tratamento dessas doenças, principalmente no que diz respeito à mortalidade.Introduction: Stevens-Johnson syndrome and toxic epidermal necrolysis are severe skin reactions associated with mucosal lesions and systemic involvement. Glucocorticoids were used for many years in the treatment of Stevens-Johnson syndrome / Toxic Epidermal Necrolysis, but there is no evidence to support this approach.Objective: Assessment of mortality in Stevens-Johnson syndrome/Toxic Epidermal Necrolysis cases in a group of patients that used systemic glucocorticoids and another group who did not.Secondary objective: Description of the study population; review of secondary infection and extra-cutaneous complications in both groups of patients.Material and Methods: Retrospective cohort of patients selected by consulting requested to the Dermatology Service of the Hospital Nossa Senhora da Conceição, as well as the diagnosis at admission or death, during the period March 2007 to August 2014.Results: Mortality rate was 63.2% in the group that used corticosteroids and 9.1% in the group that did not use steroids, with p value 0.005 (95% CI 1.79-163.8). Multivariate analysis adjusted for SCORTEN showed only a trend for harm, with an odds ratio for mortality in patients who used glucocorticoids being of 7:38 (95% CI 0.87-161.43) and p value 0.06.Conclusion: This study suggests a trend for harm associated with glucocorticoids use for treatment of these diseases, especially in regard to mortality
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