417 research outputs found

    Abundance and Seasonal Occurrence of Cetaceans in Outer Continental Shelf and Slope Waters of the North-Central and Northwestern Gulf of Mexico

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    Eight aerial line-transect surveys of outer continental shelf and continental slope waters (range 100-2,000 m deep) were conducted seasonally from summer 1992 through spring 1994 in the north-central and northwestern Gulf of Mexico to study the seasonal occurrence and spatial distribution of cetaceans and to estimate their abundances. The surveys sampled an 85,815 km2 study area, resulting in 49,960 km of effort and sightings of at least 18 cetacean species and 365 cetacean groups. Eight species identified in four seasons included bottlenose dolphin (Tursiops truncatus), pantropical spotted dolphin (Stenella attenuata), Risso\u27s dolphin (Grampus griseus), dwarf sperm whale (Kogia sima) and pygmy sperm whale (Kogia breviceps), sperm whale (Physeter macrocephalus), short-finned pilot whale (Globicephala macrorhynchus), rough-toothed dolphin (Steno bredanensis), and Atlantic spotted dolphin (Stenella frontalis). Clymene dolphin (Stenella clymene), striped dolphin (Stenella coeruleoalba), and beaked whales (Mesoplodon spp.) were sighted in three seasons. The number of species sighted seasonally ranged from 10 in fall to 15 in winter. The overall estimated abundance (number of animals) of five species, which accounted for 71% of the identified group sightings, were as follows: bottlenose dolphin, 2,890 (coefficient of variation [CV] = 0.20); pantropical spotted dolphin, 5,097 (CV = 0.24); Risso\u27s dolphin, 1,237 (CV = 0.28); dwarf-pygmy sperm whale, 176 (CV = 0.31 ); and sperm whale, 87 (CV = 0.27). Melon-headed whales (Peponocephala electra) were sighted less frequently but were abundant (2,561; CV = 0.74) because of large group sizes. Common species were widely distributed spatially but occurred in different water depth ranges. In general, species abundance estimates varied seasonally, but the precision of estimates was usually poor (CV \u3e 0.30) and provided little power to detect significant seasonal differences

    Estimates of cetacean abundance in the northern Gulf of Mexico from vessel surveys

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    The Southeast Fisheries Science Center (SEFSC) initiated annual, vessel-based visual sampling surveys of northern Gulf of Mexico marine mammals in 1990. The primary goal of these surveys was to meet Marine Mammal Protection Act requirements for estimating abundance and monitoring trends of marine mammal stocks in United States waters. The surveys were designed to collect: 1) marine mammal sighting data to estimate abundance and to determine distribution and diversity; and 2) environmental data to evaluate factors which may affect the distribution, abundance and diversity of marine mammals. The analyses for abundance estimation from the 1991-1994 surveys are presented in this report

    Indirect Recruitment of a CD40 Signaling Pathway in Dendritic Cells by B7-DC Cross-Linking Antibody Modulates T Cell Functions

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    The human IgM B7-DC XAb protects mice from tumors in both therapeutic and prophylactic settings. Its mechanism of action is mediated by its binding to B7-DC/PD-L2 molecules on the surface of dendritic cells (DCs) to induce a multimolecular cap and subsequent activation of signaling cascades that determine a unique combination of DC phenotypes. One such phenotype, the B7-DC XAb-induced antigen accumulation in mTLR-matured DCs, has been linked to signaling through TREM-2, but the signals required for other DC phenotypes critical for the therapeutic effects in animal models remain unclear. Here, FRET and co-immunoprecipitation studies show that CD40 is recruited to the multi-molecular complex by B7-DC XAb. Signals emanating from CD40 are important, as CD40−/− DCs treated with B7-DC XAb (DCXAb) activated DAP12, but failed to activate NFκB, and were not protected from cell death upon cytokine withdrawal or treatment with Vitamin D3. CD40−/− DCXAb also failed to secrete IL-6 and were unable to support the conversion of T regulatory cells into IL-17+ effector T cells in vitro. Importantly, the expression of CD40 was required for the overall ability of B7-DC XAb to induce anti-tumor CTL, to provide protection from a number of tumor types, and for DCXAb to be effective anti-tumor vaccines in vivo. These results indicate that B7-DC XAb modulation of DC phenotypes is through its ability to indirectly recruit common signaling molecules and elements of their endogenous signaling pathways through targeted binding to a cell-specific surface determinant

    The behaviour of political parties and MPs in the parliaments of the Weimar Republic

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    Copyright @ 2012 The Authors. This is the author's accepted manuscript. The final published article is available from the link below.Analysing the roll-call votes of the MPs of the Weimar Republic we find: (1) that party competition in the Weimar parliaments can be structured along two dimensions: an economic left–right and a pro-/anti-democratic. Remarkably, this is stable throughout the entire lifespan of the Republic and not just in the later years and despite the varying content of votes across the lifespan of the Republic, and (2) that nearly all parties were troubled by intra-party divisions, though, in particular, the national socialists and communists became homogeneous in the final years of the Republic.Zukunftskolleg, University of Konstan

    Bartonella species detection in captive, stranded and free-ranging cetaceans

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    We present prevalence of Bartonella spp. for multiple cohorts of wild and captive cetaceans. One hundred and six cetaceans including 86 bottlenose dolphins (71 free-ranging, 14 captive in a facility with a dolphin experiencing debility of unknown origin, 1 stranded), 11 striped dolphins, 4 harbor porpoises, 3 Risso's dolphins, 1 dwarf sperm whale and 1 pygmy sperm whale (all stranded) were sampled. Whole blood (n = 95 live animals) and tissues (n = 15 freshly dead animals) were screened by PCR (n = 106 animals), PCR of enrichment cultures (n = 50 animals), and subcultures (n = 50 animals). Bartonella spp. were detected from 17 cetaceans, including 12 by direct extraction PCR of blood or tissues, 6 by PCR of enrichment cultures, and 4 by subculture isolation. Bartonella spp. were more commonly detected from the captive (6/14, 43%) than from free-ranging (2/71, 2.8%) bottlenose dolphins, and were commonly detected from the stranded animals (9/21, 43%; 3/11 striped dolphins, 3/4 harbor porpoises, 2/3 Risso's dolphins, 1/1 pygmy sperm whale, 0/1 dwarf sperm whale, 0/1 bottlenose dolphin). Sequencing identified a Bartonella spp. most similar to B. henselae San Antonio 2 in eight cases (4 bottlenose dolphins, 2 striped dolphins, 2 harbor porpoises), B. henselae Houston 1 in three cases (2 Risso's dolphins, 1 harbor porpoise), and untyped in six cases (4 bottlenose dolphins, 1 striped dolphin, 1 pygmy sperm whale). Although disease causation has not been established, Bartonella species were detected more commonly from cetaceans that were overtly debilitated or were cohabiting in captivity with a debilitated animal than from free-ranging animals. The detection of Bartonella spp. from cetaceans may be of pathophysiological concern

    Electron ionization mass spectral fragmentation study of sulfation derivatives of polychlorinated biphenyls

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    <p>Abstract</p> <p>Background</p> <p>Polychlorinated biphenyls are persistent organic pollutants that can be metabolized via hydroxylated PCBs to PCB sulfate metabolites. The sensitive and selective analysis of PCB sulfate monoesters by gas chromatography-mass spectrometry (GC-MS) requires their derivatization, for example, as PCB 2,2,2-trichloroethyl (TCE) sulfate monoesters. To aid in the identification of unknown PCB sulfate metabolites isolated from biological samples, the electron impact MS fragmentation pathways of selected PCB TCE sulfate diesters were analyzed and compared to the fragmentation pathways of the corresponding methoxylated PCBs.</p> <p>Results</p> <p>The most abundant and characteristic fragment ions of PCB TCE sulfate diesters were formed by releasing CHCCl<sub>3</sub>, SO<sub>3</sub>, HCl<sub>2 </sub>and/or CCl<sub>3 </sub>from the TCE sulfate moiety and Cl<sub>2</sub>, HCl, ethyne and chloroethyne from an intermediate phenylcyclopentadienyl cation. The fragmentation pattern depended on the degree of chlorination and the position of the TCE sulfate moiety (i.e., <it>ortho </it>vs. <it>meta/para </it>to the second phenyl ring), but were independent of the chlorine substitution pattern. These fragmentation pathways are similar to the fragmentation pathways of structurally related methoxylated PCBs.</p> <p>Conclusion</p> <p>Knowledge of the fragmentation patterns of PCB TCE sulfate diesters will greatly aid in determining the position of sulfate moiety (<it>ortho </it>vs. <it>meta/para</it>) of unknown PCB sulfate metabolites isolated from environmental or laboratory samples.</p
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