503 resultados para Noirfontaine, Pauline de


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Ocean acidification is predicted to impact the structure and function of all marine ecosystems in this century. As focus turns towards possible impacts on interactions among marine organisms, its effects on the biology and transmission potential of marine parasites must be evaluated. In the present study, we investigate two marine trematode species (Philophthalmus sp. and Parorchis sp., both in the family Philophthalmidae) infecting two marine gastropods. These trematodes are unusual in that their asexually multiplying stages within snails display a division of labour, with two distinct castes, a large-bodied morph producing infective stages and a smaller morph playing a defensive role against other competing parasites. Using a potentiometric ocean acidification simulation system, we test the impacts of acidified seawater (7.8 and 7.6 pH) on the production of free-living infective stages (cercariae), the size and survival of encysted resting stages (metacercariae), and the within-host division of labour measured as the ratio between numbers of the two morphs. In general, low pH conditions caused an increase in cercarial production and a reduction in metacercarial survival. The ratio of the two castes within snail hosts tended to shift towards more of the smaller defensive morphs under low pH. However, the observed effects of reduced pH were species specific and not always unimodal. These results suggest that ocean acidification can affect the biology of marine parasites and may also impact transmission success and parasite abundance of some trematodes, with possible consequences for marine communities and ecosystems.

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This dataset contains the results of granulometric and bulk geochemical analyses of Van Veen surface samples obtained by the Alfred Wegener Institute (AWI) in the course of the 2012 and 2013 summer field seasons. The sampling was performed along transects in depths generally <13 m, to a distance of about <5 km off Herschel Island. In 2012, 75 samples in Pauline Cove and in the vicinity of Simpson Point were obtained. Sample collection was expanded in 2013, on transects established the previous year, with additional locations in Tetris Bay and Workboat Passage. Samples consisted of approximately 100 g of the top 3-6 cm of sediment, and were frozen in the field and freeze dried at the AWI before undergoing analytical procedures. Sample locations were recorded with the onboard global positioning system (GPS) unit. Grain size distributions in our study were obtained using laser diffractometry at the AWI (Beckman Coulter LS200) on the <1 mm fraction of samples oxidized with 30% H2O2 until effervescence ceased to remove organics. Some samples were also sieved using a sieve stack with 1 phi intervals. GRADISTAT (Blott and Pye, 2001) was used to calculate graphical grain size statistics (Folk and Ward, 1957). Grain diameters were logarithmically transformed to phi values, calculated as phi=-log2d, where d is the grain diameter in millimeters (Blott and Pye, 2001; Krumbein, 1934). Freeze dried samples were ground and ground using an Elemetar Vario EL III carbon-nitrogen-sulphur analyzer at the AWI to measure total carbon (TC) and total nitrogen (TN). Tungsten oxide was added to the samples as a catalyst to the pyrolysis. Following this analysis, total organic carbon (TOC) was determined using an Elementar VarioMax. Stable carbon isotope ratios of 13C/12C of 118 samples were determined on a DELTAplusXL mass spectrometer (ThermoFisher Scientific, Bremen) at the German Research Centre for Geosciences (GFZ) in Potsdam, Germany . An additional analysis on 69 samples was carried out at the University of Hamburg with an isotope ratio mass spectrometer (Delta V, Thermo Scientific, Germany) coupled to an elemental analyzer (Flash 2000, Thermo Scientific, Germany). Prior to analysis, soil samples were treated with phosphoric acid (43%) to release inorganic carbon. Values are expressed relative to Vienna Peedee belemnite (VPDB) using external standards (USGS40, -26.4 per mil VPDB and IVA soil 33802153, -27.5 per mil VPDB).

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Ocean acidification is predicted to have severe consequences for calcifying marine organisms especially molluscs. Recent studies, however, have found that molluscs in marine environments with naturally elevated or fluctuating CO2 or with an active, high metabolic rate lifestyle may have a capacity to acclimate and be resilient to exposures of elevated environmental pCO2. The aim of this study was to determine the effects of near future concentrations of elevated pCO2 on the larval and adult stages of the mobile doughboy scallop, Mimachlamys asperrima from a subtidal and stable physio-chemical environment. It was found that fertilisation and the shell length of early larval stages of M. asperrima decreased as pCO2 increased, however, there were less pronounced effects of elevated pCO2 on the shell length of later larval stages, with high pCO2 enhancing growth in some instances. Byssal attachment and condition index of adult M. asperrima decreased with elevated pCO2, while in contrast there was no effect on standard metabolic rate or pHe. The responses of larval and adult M. asperrima to elevated pCO2 measured in this study were more moderate than responses previously reported for intertidal oysters and mussels. Even this more moderate set of responses are still likely to reduce the abundance of M. asperrima and potentially other scallop species in the world's oceans at predicted future pCO2 levels.

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Ocean acidification is anticipated to decrease calcification and increase dissolution of shelled molluscs. Molluscs with thinner and weaker shells may be more susceptible to predation, but not all studies have measured negative responses of molluscs to elevated pCO2. Recent studies measuring the response of molluscs have found greater variability at the population level than first expected. Here we investigate the impact of acidification on the predatory whelk Morula marginalba and genetically distinct subpopulations of the Pacific oyster Crassostrea gigas. Whelks and eight family lines of C. gigas were separately exposed to ambient (385 ppm) and elevated (1000 ppm) pCO2 for 6 weeks. Following this period, individuals of M. marginalba were transferred into tanks with oysters at ambient and elevated pCO2 for 17 days. The increase in shell height of the oysters was on average 63% less at elevated compared to ambient pCO2. There were differences in shell compression strength, thickness, and mass among family lines of C. gigas, with sometimes an interaction between pCO2 and family line. Against expectations, this study found increased shell strength in the prey and reduced shell strength in the predator at elevated compared to ambient pCO2. After 10 days, the whelks consumed significantly more oysters regardless of whether C. gigas had been exposed to ambient or elevated CO2, but this was not dependent on the family line and the effect was not significant after 17 days. Our study found an increase in predation after exposure of the predator to predicted near-future levels of estuarine pCO2.

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Esta tese é um estudo do conceito de transformação místico-apocalíptica na perspectiva da experiência religiosa e que tem como objeto o caso paulino. As pesquisas sobre Paulo Apóstolo geralmente acompanham a abordagem tradicional que o vê como pensador e teólogo. Mas, em sintonia com algumas obras do passado e especialmente as mais recentes sobre Paulo em relação à apocalíptica e misticismo judaicos, esta tese desenvolve uma análise na perspectiva da experiência religiosa. Considerando a tradição de ascensão visionária como quadro de plausibilidade, é apresentada uma análise dos relatos de ascensão da literatura judaica antiga, com destaque para Moisés, aqui comparado com a recepção paulina do Moisés transformado em 2º Coríntios. O resultado da pesquisa foi que a literatura judaica antiga testemunha um padrão de transformação proléptica em ascensão celestial que fazia parte das crenças e práticas religiosas. A linguagem usada por Paulo em 2º Coríntios, notoriamente no capítulo 3, demonstra que ele estava envolvido em tais crenças e práticas, ainda que com conotações próprias. O Moisés transformado de face gloriosa de Êxodo 34, que foi recebido pelas tradições judaicas como um viajante celestial, o que era corrente nos tempos paulinos, é o foco de Paulo em 2º Coríntios 3. Para Paulo, sua condição é superior à de Moisés porque ele tem acesso livre e permane nte à gloria de Deus, acesso esse estendido a seus correligionários e que resulta em processo de transformação proléptica. Também porque seu evangelho é uma revelação cristológica divina última superior ao que foi revelado a Moisés no Sinai. Este acesso livre e permanente que inclui esta transformação antecipada se dá em termos de cultos extáticos de natureza visionária.(AU)

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Esta tese é um estudo do conceito de transformação místico-apocalíptica na perspectiva da experiência religiosa e que tem como objeto o caso paulino. As pesquisas sobre Paulo Apóstolo geralmente acompanham a abordagem tradicional que o vê como pensador e teólogo. Mas, em sintonia com algumas obras do passado e especialmente as mais recentes sobre Paulo em relação à apocalíptica e misticismo judaicos, esta tese desenvolve uma análise na perspectiva da experiência religiosa. Considerando a tradição de ascensão visionária como quadro de plausibilidade, é apresentada uma análise dos relatos de ascensão da literatura judaica antiga, com destaque para Moisés, aqui comparado com a recepção paulina do Moisés transformado em 2º Coríntios. O resultado da pesquisa foi que a literatura judaica antiga testemunha um padrão de transformação proléptica em ascensão celestial que fazia parte das crenças e práticas religiosas. A linguagem usada por Paulo em 2º Coríntios, notoriamente no capítulo 3, demonstra que ele estava envolvido em tais crenças e práticas, ainda que com conotações próprias. O Moisés transformado de face gloriosa de Êxodo 34, que foi recebido pelas tradições judaicas como um viajante celestial, o que era corrente nos tempos paulinos, é o foco de Paulo em 2º Coríntios 3. Para Paulo, sua condição é superior à de Moisés porque ele tem acesso livre e permane nte à gloria de Deus, acesso esse estendido a seus correligionários e que resulta em processo de transformação proléptica. Também porque seu evangelho é uma revelação cristológica divina última superior ao que foi revelado a Moisés no Sinai. Este acesso livre e permanente que inclui esta transformação antecipada se dá em termos de cultos extáticos de natureza visionária.(AU)

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Acknowledgements James J. Waggitt was funded by a NERC Case studentship supported by OpenHydro Ltd and Marine Scotland Science (NE/J500148/1). Vessel-based transects were funded by a NERC (NE/J004340/1) and a Scottish National Heritage (SNH) grant. FVCOM modelling was funded by a NERC grant (NE/J004316/1). Marine Scotland Science provided time on the FRV Alba-na-Mara as part as the Marine Collaboration Research Forum (MarCRF). The bathymetry data used in hydrodynamic models (HI 1122 Sanday Sound to Westray Firth) was collected by the Maritime & Coastguard Agency (MCA) as part of the UK Civil Hydrography Programme. We wish to thank Christina Bristow, Matthew Finn and Jennifer Norris at the European Marine Energy Centre (EMEC); Marianna Chimienti, Ciaran Cronin, Tim Sykes and Stuart Thomas for performing vessel-based transects; Marine Scotland Science staff Eric Armstrong, Ian Davies, Mike Robertson, Robert Watret and Michael Stewart for their assistance; Shaun Fraser, Pauline Goulet, Alex Robbins, Helen Wade and Jared Wilson for invaluable discussions; Thomas Cornulier, Alex Douglas, James Grecian and Samantha Patrick for their help with statistical analysis; and Gavin Siriwardena, Leigh Torres, Mark Whittingham and Russell Wynn for their constructive comments on earlier versions of this manuscript.