74 research outputs found

    Influence of incubation temperature on morphology and locomotion performance of Leatherback (<i>Dermochelys coriacea</i>) hatchlings

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    The journey of Leatherback (Dermochelys coriacea (Vandelli, 1761)) hatchlings from nest to the sea is a vulnerable life-history stage. Studies have shown that nest incubation temperatures influence hatchling morphology and locomotor performance, which may affect hatchling fitness. We obtained incubation temperature profiles from 16 Leatherback nests in Tobago, West Indies, during the 2008 nesting season (March-June). There was significant variation among mean nest incubation temperatures, which had a significant influence on hatchling morphology. Using principal components analysis, we determined the morphological traits that explained the most variation among hatchlings, which allowed investigation of the relationship between hatchling morphology and terrestrial locomotion speed. Hatchlings with a narrower carapace width and longer flipper reach (produced at lower incubation temperatures) had significantly faster terrestrial speed and total run time than those with opposite characteristics (produced at higher incubation temperatures). Our results demonstrate that lower incubation temperatures produce hatchlings with traits that are significantly advantageous to terrestrial locomotion. These findings suggest that nest incubation temperature is important in determining hatchling fitness, as nest incubation temperature significantly influences hatchling morphology and locomotor capabilities. This study supplements related findings in Green Turtles (Chelonia mydas (L., 1758)), but also illustrates some unique features in Leatherbacks

    Amphibia: Anura: Hylidae Scarthyla vigilans (Solano 1971): Range Extension and New Country Record for Trinidad, W.I. With Notes on Tadpoles, Habitat, Behaviour and Biogeographical Significance.

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    We report a range extension and new country record for Scarthyla vigilans in Trinidad, West Indies. The species was previously known only from populations on mainland South America. We include notes on behavior, habitat and tadpole development, and discuss the biogeographical significance of the species’ presence in Trinidad, particularly with respect to consequences for understanding colonization events on this Caribbean island

    Filgotinib Demonstrates Efficacy in Rheumatoid Arthritis Independent of Smoking Status: Post Hoc Analysis of Phase 3 Trials and Claims-Based Analysis

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    Objectives: To assess cigarette smoking’s effects on efficacy of the preferential Janus kinase (JAK) 1 inhibitor filgotinib and drug persistence in patients with rheumatoid arthritis (RA). Methods: Efficacy in non-smokers, former smokers, and current smokers from phase 3 filgotinib trials was analyzed, including patients with inadequate response (IR) to methotrexate (MTX) or biologic disease-modifying antirheumatic drugs (bDMARDs) or who were MTX-naïve. Proportions achieving Disease Activity Score in 28 joints with C-reactive protein (DAS28[CRP]) ≤ 3.2 were compared using logistic regression. Retrospective claims-based switching data were reviewed. Results: Week 12 (W12) DAS28(CRP) ≤ 3.2 was achieved by 50, 61, and 62% of MTX-IR non-smokers, former smokers, and current smokers taking filgotinib 200 mg (FIL200) + MTX vs. 23, 16, and 32% taking placebo + MTX (p < 0.001, < 0.001, and 0.001) and 50, 34, and 33% taking adalimumab + MTX (p = 0.97, 0.013, and 0.006 vs. FIL200 + MTX). W12 DAS28(CRP) ≤ 3.2 was achieved by 46, 48, and 32% of bDMARD-IR non-smokers, former smokers, and current smokers taking FIL200 + conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) vs. 16, 23, and 5% taking placebo + csDMARD (p < 0.001, 0.077, and 0.051); 57, 58, and 59% of respective MTX-naïve smoking groups achieved W12 DAS28(CRP) ≤ 3.2 with FIL200 + MTX vs. 28, 37, and 18% with MTX (p < 0.001, 0.026, and < 0.001). Claims data showed former/current smokers were likelier than non-smokers to switch from adalimumab to other biologics or JAK inhibitors. Conclusions: Greater proportions of MTX-IR current/former smokers responded to FIL200 + MTX vs. adalimumab + MTX. In non-smoking MTX-IR, bDMARD-IR, and MTX-naïve patients with RA, FIL200 + MTX demonstrated increased response vs. controls. Current/former smokers were likelier to discontinue adalimumab vs. non-smokers in real-world clinical settings. Trial Registration: NCT02889796, NCT02873936, NCT02886728

    Systematics of the Neotropical Genus Leptodactylus Fitzinger, 1826 (Anura: Leptodactylidae): Phylogeny, the Relevance of Non-molecular Evidence, and Species Accounts

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    A phylogeny of the species-rich clade of the Neotropical frog genus Leptodactylus sensu stricto is presented on the basis of a total evidence analysis of molecular (mitochondrial and nuclear markers) and non-molecular (adult and larval morphological and behavioral characters) sampled from > 80% of the 75 currently recognized species. Our results support the monophyly of Leptodactylus sensu stricto, with Hydrolaetare placed as its sister group. The reciprocal monophyly of Hydrolaetare and Leptodactylus sensu stricto does not require that we consider Hydrolaetare as either a subgenus or synonym of Leptodactylus sensu lato. We recognize Leptodactylus sensu stricto, Hydrolaetare, Adenomera, and Lithodytes as valid monophyletic genera. Our results generally support the traditionally recognized Leptodactylus species groups, with exceptions involving only a few species that are easily accommodated without proposing new groups or significantly altering contents. The four groups form a pectinate tree, with the Leptodactylus fuscus group diverging first, followed by the L. pentadactylus group, which is sister to the L. latrans and L. melanonotus groups. To evaluate the impact of non-molecular evidence on our results, we compared our total evidence results with results obtained from analyses using only molecular data. Although non-molecular evidence comprised only 3.5% of the total evidence matrix, it had a strong impact on our total evidence results. Only one species group was monophyletic in the molecular-only analysis, and support differed in 86% of the 54 Leptodactylus clades that are shared by the results of the two analyses. Even though no non-molecular evidence was included for Hydrolaetare, exclusion of that data partition resulted in that genus being nested within Leptodactylus, demonstrating that the inclusion of a small amount of non-molecular evidence for a subset of species can alter not only the placement of those species, but also species that were not scored for those data. The evolution of several natural history and reproductive traits is considered in the light of our phylogenic framework. Invasion of rocky outcrops, larval oophagy, and use of underground reproductive chambers are restricted to species of the Leptodactylus fuscus and L. pentadactylus groups. In contrast, larval schooling, larval attendance, and more complex parental care are restricted to the L. latrans and L. melanonotus groups. Construction of foam nests is plesiomorphic in Leptodactylus but their placement varies extensively (e.g., underground chambers, surface of waterbodies, natural or excavated basins). Information on species synonymy, etymology, adult and larval morphology, advertisement call, and geographic distribution is summarized in species accounts for the 30 species of the Leptodactylus fuscus group, 17 species of the L. pentadactylus group, eight species of the L. latrans group, and 17 species of the L. melanonotus group, as well as the three species that are currently unassigned to any species group.Se presenta una filogenia del género Leptodactylus, un ciado neotropical rico en especies, basada en análises combinados de datos moleculares (marcadores nuclear y mitocondriales) y no moleculares (caracteres de la morfología de adultos y larvas así como de comportamiento) se muestrearon > 80% de las 75 especies reconocidas. Los resultados apoyan la monofília de Leptodactylus sensu stricto, con Hydrolaetare como su grupo hermano. La monofília recíproca de Hydrolaetare y Leptodactylus no requiere considerar a Hydrolaetare como un subgénero o sinónimo de Leptodactylus sensu lato. Se reconocen Leptodactylus sensu stricto, Hydrolaetare, Adenomera y Lithodytes como géneros monofiléticos válidos. Los resultados en general resuelven los grupos tradicionalmente reconocidos de Leptodactylus, con excepciones de algunas especies que son reasignadas sin la necesidad de proponer nuevos grupos o alterar significativamente el contenido de los grupos tradicionales. Los cuatro grupos de especies forman una topología pectinada donde el grupo de L. fuscus tiene una posición basal, seguido por el grupo de L. pentadactylus que es el grupo hermano al clado formado por los grupo de L. latrans y L. melanonotus. Se estimó el impacto de los datos no moleculares en los resultados, comparándose los resultados de evidencia total con los de los análises de datos moleculares solamente. Los datos no moleculares representan un 3.5% de la matriz de evidencia total, pero estos datos tuvieron un impacto significativo en los resultados del análisis de evidencia total. En el análisis estrictamente molecular solamente un grupo de especies resultó monofilético, y el apoyo difirió en 86% de los 54 ciados de Leptodactylus compartidos entre los dos análises. A pesar que datos no moleculares no fueron incluidos para Hydrolaetare, la exclusión de evidencia no molecular resultó en el género estar dentro de Leptodactylus, demostrando que la inclusión de evidencia no molecular pequeña para un subgrupo de especies altera no solamente la posición topológica de esas especies, sino tambien de las especies para las cuales dichos datos no fueron codificados. La evolución de patrones de historia natural y reprodución se evalúan en el contexto filogenético. La invasión de afloramientos rocosos y la construción de cámaras de reprodución subterraneas está limitada a los grupos de Leptodactylus fuscus y L. pentadactylus, mientras que la oofagia larval está restringida al grupo de L. pentadactylus. Por otro lado, los cárdumenes larvales, la proteción del cárdumen, y otros comportamientos parentales complejos carecterizan al clado formado por los grupos de especies de L. latrans y L. melanonotus. Los resúmenes de especies incluyen información de sinonimias, etimología, morfología de adultos y larvas, cantos, y distribución geográfica para las 30 especies del grupo de Leptodactylus fuscus, 17 especies del grupo L. pentadactylus, ocho especies del grupo de L. latrans, 17 especies del grupo de L. melanonotus, así como para las tres especies que actualmente no se encuentran asociadas a ninguno de los grupos de especies.Taran Grant was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico Proc. 307001/2011-3 and Fundação de Amparo à Pesquisa do Estado de São Paulo Proc. 2012/10000-5

    Adventures with amphibians

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    The Music Information Retrieval Evaluation eXchange: Some Observations and Insights

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    Asymmetric larval competition between two species of neotropical foam-nesting frogs: Leptodactylus fuscus and Engystomops pustulosus

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    Larval competition was investigated in foam-nesting frogs with contrasting breeding strategies. Leptodactylus fuscus nests in burrows with moderate numbers of large eggs, mainly on dry nights; Engystomops pustulosus makes floating nests with large numbers of small eggs, mainly on wet nights. Both use the same temporary pools in open habitat over an extended breeding season. Larval growth to metamorphosis was assessed in a semi-natural experiment and in the laboratory. Tanks contained either single species or equal numbers of both species. Inter-specific competition was asymmetric; L. fuscus survived as well as or better in competition with E. pustulosus than in intra-specific competition. Leptodactylus fuscus attained larger sizes with E. pustulosus present. In interspecific competition E. pustulosus showed worse survival and grew slower and to a smaller size. Outdoors, both species tolerated water temperatures that often rose to 42&#176;C and reached metamorphosis in very short times: 14 days after oviposition in L. fuscus and 17 days in E. pustulosus

    External gill motility and striated muscle presence in the embryos of anuran amphibians

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    Anuran external gills were assessed for motility and striated muscle content in 16 species from seven families. Motility of three kinds was observed. Pulsatory movements related to heart beat rhythm were common. In embryos developing to a late stage before hatching, movements of the whole embryo were frequent, with gills rearranging as a consequence. The only clearly active movement, presumably muscle driven, was ‘gill flicking’, a posterior movement of the entire gill into the body either on one side only, or both together, followed by a return to the normal spread-out position. Some species may actively spread their gills when hanging from the water surface film, but we did not observe this. In some species, active gill movement developed over time, but we were not able to follow all species over such a developmental sequence. The relationship between active motility and muscle content was good in most cases. Observations on late stage embryos of the aromobatid Mannophryne trinitatis are presented for the first time. In one species, we noted spread external gills being used to adhere hatchlings to a surface
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