121 research outputs found

    Cenozoic Tectonic and Paleogeographic Evolution of the Horse Prairie Half-graben, Southwest Montana

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    The Horse Prairie basin (HPB) of southwestern Montana is a complex, east dipping half-graben that contains three angular unconformity-bounded sequences of Tertiary lacustrine, paludal, and fluvial sediments overlying middle Eocene volcanic rocks. The basin is near the eastern edge of the Cordilleran thrust belt, and represents the western half of a larger Paleogene rift basin. Geologic mapping within the Everson Creek and Bannock Pass 7.5 minute quadrangles indicates that five temporally and geometrically distinct episodes of extension characterize the late Mesozoic (?) to Cenozoic tectonic evolution of the upper HPB. The first episode of extension occurred prior to emplacement of middle Eocene volcanic rocks on an enigmatic, low-angle, southeast-dipping fault. Pre-volcanic extension (?) may reflect gravitational collapse of the Sevier thrust belt beginning in the lateMesozoic. The second episode of extension occurred in middle Eocene time on northwestdipping syn-volcanic normal faults. Syn-volcanic faults can be attributed to extension of the Challis volcanic arc, and typically accommodate less than I km of dip-slip separation. The third generation of normal faulting occurred on the low-angle, south-southwest- and west-dipping Lemhi Pass and Maiden Peak fault systems, respectively. Slip may have initiated during the waning phases of Challis volcanism, but these late to post-volcanic normal faults probably reflect continued gravitational collapse of the Sevier thrust belt, because they generally parallel contractional structures in the region. Late to post-volcanic normal faults accommodate the bulk of extensional strain in the study area, and are responsible for the deposition and preservation of the majority of basin-fill deposits in the HPB. Two episodes of middle Miocene and younger extension also occur within the study area; however, structural and basin analysis indicates the HPB experienced only minor extension in the last 17 m.y. Spatial and temporal relationships between magmatism and extension suggest that large magnitude extension in the HPB (episodes I and 3) was not associated with magmatism, and that extension in this portion of the Basin and Range province initiated due to gravitational instabilities imparted on the crust during the Sevier orogeny

    Development of an international survey attitude scale: measurement equivalence, reliability, and predictive validity

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    Declining response rates worldwide have stimulated interest in understanding what may be influencing this decline and how it varies across countries and survey populations. In this paper, we describe the development and validation of a short 9-item survey attitude scale that measures three important constructs, thought by many scholars to be related to decisions to participate in surveys, that is, survey enjoyment, survey value, and survey burden. The survey attitude scale is based on a literature review of earlier work by multiple authors. Our overarching goal with this study is to develop and validate a concise and effective measure of how individuals feel about responding to surveys that can be implemented in surveys and panels to understand the willingness to participate in surveys and improve survey effectiveness. The research questions relate to factor structure, measurement equivalence, reliability, and predictive validity of the survey attitude scale. The data came from three probability-based panels: the German GESIS and PPSM panels and the Dutch LISS panel. The survey attitude scale proved to have a replicable three-dimensional factor structure (survey enjoyment, survey value, and survey burden). Partial scalar measurement equivalence was established across three panels that employed two languages (German and Dutch) and three measurement modes (web, telephone, and paper mail). For all three dimensions of the survey attitude scale, the reliability of the corresponding subscales (enjoyment, value, and burden) was satisfactory. Furthermore, the scales correlated with survey response in the expected directions, indicating predictive validity

    Effect of different photoperiods on the growth, infectivity and colonisation of Trinidadian fungal strains and spore types of paecilomyces fumosoroseus on the greenhouse whitefly, trialeurodes vaporariorum, using a glass slide bioassay

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    Growth, infectivity and colonization rates for blastospores and conidia of Trinidadian strains T, T10, and T11 of Paecilomyces fumosoroseus (Wize) Brown & Smith were assessed for activity against late fourth-instar nymphs of Trialeurodes vaporariorum (Westwood) (Homoptera:Aleyrodidae) under two different photoperiods (24 and 16 hour photophase). A glass-slide bioassay and a fungal development index, modified for both blastospores and conidia, were used to compare the development rates of the fungal strains on the insect hosts. Fewer adult whiteflies emerged from nymphs treated with blastospores and reared under a 16:8 hour light:dark photoperiod than a 24:0 hour photoperiod. Eclosion times of whitefly adults that emerged from nymphs treated with the different strains of conidia were similar over the 8 day experimental period at both light regimes. The percent eclosion of adult whiteflies seems to be directly correlated with the speed of infection of the blastospore or conidial treatment and the photoperiod regime. The longer photophase had a significant positive effect on development index for blastospores; however, a lesser effect was observed for the conidia at either light regime. Blastospore strain T11 offered the most potential of the three Trinidadian strains against T. vaporariorum fourth-instar nymphs, especially under constant light. The glass-slide bioassay was successfully used to compare both blastospores and conidia of P. fumosoroseus. It can be used to determine the pathogenicity and the efficacy of various fungal preparations against aleyrodid pests

    2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

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    The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011
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