3,273 research outputs found

    Elective Recital: Mason St. Pierre, trumpet

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    The role of risk perception and affect in predicting support for conservation policy under rapid ecosystem change

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    Conservation conflicts are damaging for humans and wildlife, with differences in people's objectives fuelling challenges of managing complex, dynamic systems. We investigate the relative importance of economic, psychological (affect, trust and risk perception) and ecological factors in determining farmers' management preferences, using Greenland barnacle geese (Branta leucopsis) on Islay, Scotland, as a case study. Barnacle geese reduce agricultural productivity on Islay, negatively impacting household economies. Since 1992, farmers have received partial compensation but a new culling scheme has escalated conflict between conservation and agricultural interests. Using a questionnaire, we collected data from 75% of the farmers receiving goose payments. We found that affect was a strong driver of both risk perception and management preferences. However, we revealed complexity in these relationships, with trust and economic factors also influencing decision‐making. Psychological and economic factors surrounding wildlife management must be understood if we are to achieve conservation objectives in human dominated landscapes

    Aqueous phase methylation as a potential source of methylmercury in wet deposition

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    Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V for personal use, not for redistribution. The definitive version was published in Atmospheric Environment 41 (2007): 1663-1668, doi:10.1016/j.atmosenv.2006.10.032.The source of monomethylmercury (MMHg) in wet deposition is unknown. Volatilization of gaseous MMHg, evasion and demethylation of dimethylmercury, and methylation of Hg0 have been either proposed or tested unsuccessfully as potential sources. Here, we show that MMHg in precipitation, sampled across a wide geographical range in North America, is related positively to an operationally defined and measured reactive Hg species (HgR), but connected weakly to total Hg. The mean molar ratio of MMHg:HgR measured in continental precipitation (0.025 ± 0.006) is comparable to the MMHg:Hg(II) ratio estimated from first-order rate constants for acetate-mediated Hg methylation and MMHg photolysis (0.025 ± 0.002). This suggests MMHg may be formed in the atmosphere through a reaction between labile Hg(II) complexes and an unknown methylating agent(s), potentially acetate or similar molecules. Availability of Hg(II) appears to limit the reaction, and accordingly, increased atmospheric loadings of Hg could lead to enhanced MMHg in precipitation.This study was supported by a grant from the National Science Foundation-Office of Polar Programs (0425562) and the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding from the Doherty Foundation

    The C-terminal fragment of the internal 110-kilodalton passenger domain of the Hap protein of nontypeable Haemophilus influenzae is a potential vaccine candidate

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    Nontypeable Haemophilus influenzae is a major causative agent of bacterial otitis media in children. H. influenzae Hap autotransporter protein is an adhesin composed of an outer membrane Hapβ region and a moiety of an extracellular internal 110-kDa passenger domain called Hap(S). The Hap(S) moiety promotes adherence to human epithelial cells and extracellular matrix proteins, and it also mediates bacterial aggregation and microcolony formation. A recent work (D. L. Fink, A. Z. Buscher, B. A. Green, P. Fernsten, and J. W. St. Geme, Cell. Microbiol. 5:175-186, 2003) demonstrated that Hap(S) adhesive activity resides within the C-terminal 311 amino acids (the cell binding domain) of the protein. In this study, we immunized mice subcutaneously with recombinant proteins corresponding to the C-terminal region of Hap(S) from H. influenzae strains N187, P860295, and TN106 and examined the resulting immune response. Antisera against the recombinant proteins from all three strains not only recognized native Hap(S) purified from strain P860295 but also inhibited H. influenzae Hap-mediated adherence to Chang epithelial cells. Furthermore, when mice immunized intranasally with recombinant protein plus mutant cholera toxin CT-E29H were challenged with strain TN106, they were protected against nasopharyngeal colonization. These observations demonstrate that the C-terminal region of Hap(S) is capable of eliciting cross-reacting antibodies that reduce nasopharyngeal colonization, suggesting utility as a vaccine antigen for the prevention of nontypeable H. influenzae diseases

    Development And Field Application Of A Single Rotor Design Dry Gas Seal.

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    LecturePg. 107-116Improving centrifugal compressor seal performance and reliability can be accomplished through development of new technology and/or by improvement of existing technology. An improved dry gas lubricating seal of single rotor design has been designed for high pressure gas compressors. A more durable seal of simpler design has been created through implementation of ductile materials and reduction of components. Currently, the tandem dry gas seal configuration is the accepted standard for high pressure natural gas pipeline compressor applications. These applications still suffer problems with process and lube oil contamination, brittle fracture of carbide materials, and explosive decompression of 0-rings. Real costs associated with these problems are considerable. Development and potential benefits of the single rotor design seal, along with field application, in a high pressure natural gas centrifugal compressor is discussed

    The Onfp Class in the Magellanic Clouds

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    The Onfp class of rotationally broadened, hot spectra was defined some time ago in the Galaxy, where its membership to date numbers only eight. The principal defining characteristic is a broad, centrally reversed He II λ\lambda4686 emission profile; other emission and absorption lines are also rotationally broadened. Recent surveys in the Magellanic Clouds (MCs) have brought the class membership there, including some related spectra, to 28. We present a survey of the spectral morphology and rotational velocities, as a first step toward elucidating the nature of this class. Evolved, rapidly rotating hot stars are not expected theoretically, because the stellar winds should brake the rotation. Luminosity classification of these spectra is not possible, because the principal criterion (He II λ\lambda4686) is peculiar; however, the MCs provide reliable absolute magnitudes, which show that they span the entire range from dwarfs to supergiants. The Onfp line-broadening distribution is distinct and shifted toward larger values from those of normal O dwarfs and supergiants with >99.99% confidence. All cases with multiple observations show line-profile variations, which even remove some objects from the class temporarily. Some of them are spectroscopic binaries; it is possible that the peculiar profiles may have multiple causes among different objects. The origin and future of these stars are intriguing; for instance, they could be stellar mergers and/or gamma-ray-burst progenitors.Comment: 27 pages, 8 figures, 2 tables; AJ accepte

    DNA strand scission induced by a non-thermal atmospheric pressure plasma jet

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    The DNA molecule is observed to be very susceptible to short term exposures to an atmospheric pressure plasma jet. The DNA damage induced by plasma-generated species, i.e. excited atoms, charged particles, electrons and UV light is determined
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