1,461 research outputs found

    Checklist of the shore and epipelagic fishes of Tonga

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    A checklist is given below of 1162 species of shore and epipelagic fishes belonging to 111 families that occur in the islands of Tonga, South Pacifie Ocean; 40 of these are epipelagic species. As might be expected, the fish fauna of Tonga is most similar to those of Samoa and Fiji; at least 658 species of the fishes found in Tonga are also known from Fiji and the islands of Samoa. Twelve species of shore fishes are presently known only from Tonga. Specimens of Tongan fishes are housed mainly in the fish collections of the National Museum ofNatural History, Washington D.C.; Bernice P. Bishop Museum, Honolulu; Museum National d'Histoire Naturelle, Paris; and the Australian Museum, Sydney. Native Tongan names offishes, when known, are presented afterspecies names

    Discord in the family Sparidae (Teleostei): divergent phylogeographical patterns across the Atlantic-Mediterranean divide

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    The Strait of Gibraltar has been proposed to be the divide between two marine biogeographical regions, the Mediterranean Sea and the Northeast Atlantic. Intraspecific studies have shown, for several of the examined species, a reduction of gene flow between the two basins. The present study examines genetic variation at nuclear and mitochondrial loci in five marine teleost species belonging to the family Sparidae. Four samples for each species were analysed spanning the Northeast Atlantic and the Mediterranean. For all individuals 17 allozyme loci were scored and a combined single strand conformation polymorphism-sequencing approach was used to survey approximately 190 bp of the mitochondrial DNA (mtDNA) D-loop region. All five species share similar biological features. For three species, namely Lithognathus mormyrus, Spondyliosoma cantharus, and Dentex dentex, large mtDNA divergence was observed between Atlantic and Mediterranean samples. Little or no mtDNA differentiation was found in the other two species, Pagrus pagrus and Pagellus bogaraveo. Allozyme data revealed strong differentiation when comparing Atlantic and Mediterranean samples of L. mormyrus and D. dentex, moderate for P. pagrus, and no differentiation for P. bogaraveo and S. cantharus. These results provide evidence for a sharp phylogeographical break (sensu Avise) between the Atlantic and the Mediterranean for two (or possibly three) sparid species of the five investigated. At the same time, the obtained results for the other two species raise the question on which ecological/historical factors might have caused the observed discrepancy in the geographical distribution of genetic variation among otherwise biologically similar species.info:eu-repo/semantics/publishedVersio

    Vector meson production and nucleon resonance analysis in a coupled-channel approach for energies m_N < sqrt(s) < 2 GeV I: pion-induced results and hadronic parameters

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    We present a nucleon resonance analysis by simultaneously considering all pion- and photon-induced experimental data on the final states gamma N, pi N, 2 pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), and D_{13}(1950). The omega N production mechanism is dominated by large P_{11}(1710) and P_{13}(1900) contributions. In this first part, we present the results of the pion-induced reactions and the extracted resonance and background properties with emphasis on the difference between global and purely hadronic fits.Comment: 54 pages, 26 figures, discussion extended, typos corrected, references updated, to appear in Phys. Rev.

    A genome-wide association study suggests that a locus within the ataxin 2 binding protein 1 gene is associated with hand osteoarthritis: The Treat-OA consortium

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    To identify the susceptibility gene in hand osteoarthritis (OA) the authors used a two-stage approach genomewide association study using two discovery samples (the TwinsUK cohort and the Rotterdam discovery subset; a total of 1804 subjects) and four replication samples (the Chingford Study, the Chuvasha Skeletal Aging Study, the Rotterdam replication subset and the Genetics, Arthrosis, and Progression (GARP) Study; a total of 3266 people). Five single-nucleotide polymorphisms (SNPs) had a likelihood of association with hand OA in the discovery stage and one of them (rs716508), was successfully confirmed in the replication stage (meta-analysis p = 1.81×10-5). The C allele conferred a reduced risk of 33% to 41% using a case-control definition. The SNP is located in intron 1 of the A2BP1 gene. This study also found that the same allele of the SNP significantly reduced bone density at both the hip and spine (p<0.01), suggesting the potential mechanism of the gene in hand OA might be via effects on subchondral bone. The authors' findings provide a potential new insight into genetic mechanisms in the development of hand OA
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