4,962 research outputs found

    Lyne Toliaferro Barret, a Pioneer Texas Wildcatter

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    Investigation of Reactivity of Launch Vehicle Materials with Liquid Oxygen

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    Impact sensitivity and ignition mechanism of organic compounds in liquid oxygen correlated with chemical and physical propertie

    Scoping biological indicators of soil quality Phase II. Defra Final Contract Report SP0534

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    This report presents results from a field assessment of a limited suite of potential biological indicators of soil quality to investigate their suitability for national-scale soil monitoring

    Decolonising qualitative research with respectful, reciprocal, and responsible research practice: A narrative review of the application of Yarning method in qualitative Aboriginal and Torres Strait Islander health research

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    Background Indigenous academics have advocated for the use and validity of Indigenous methodologies and methods to centre Indigenous ways of knowing, being and doing in research. Yarning is the most reported Indigenous method used in Aboriginal and Torres Strait Islander qualitative health research. Despite this, there has been no critical analysis of how Yarning methods are applied to research conduct and particularly how they privilege Indigenous peoples. Objective To investigate how researchers are applying Yarning method to health research and examine the role of Aboriginal and Torres Strait Islander researchers in the Yarning process as reported in health publications. Design Narrative review of qualitative studies. Data sources Lowitja Institute LitSearch January 2008 to December 2021 to access all literature reporting on Aboriginal and Torres Strait Islander health research in the PubMed database. A subset of extracted data was used for this review to focus on qualitative publications that reported using Yarning methods. Methods Thematic analysis was conducted using hybrid of inductive and deductive coding. Initial analysis involved independent coding by two authors, with checking by a third member. Once codes were developed and agreed, the remaining publications were coded and checked by a third team member. Results Forty-six publications were included for review. Yarning was considered a culturally safe data collection process that privileges Indigenous knowledge systems. Details of the Yarning processes and team positioning were vague. Some publications offered a more comprehensive description of the research team, positioning and demonstrated reflexive practice. Training and experience in both qualitative and Indigenous methods were often not reported. Only 11 publications reported being Aboriginal and/or Torres Strait Islander led. Half the publications reported Aboriginal and Torres Strait Islander involvement in data collection, and 24 reported involvement in analysis. Details regarding the role and involvement of study reference or advisory groups were limited. Conclusion Aboriginal and Torres Strait Islander people should be at the forefront of Indigenous research. While Yarning method has been identified as a legitimate research method to decolonising research practice, it must be followed and reported accurately. Researcher reflexivity and positioning, and Aboriginal and Torres Strait Islander ownership, stewardship and custodianship of data collected were significantly under detailed in the publications included in our review. Journals and other establishments should review their processes to ensure necessary details are reported in publications and engage Indigenous Editors and peer reviewers to uphold respectful, reciprocal, responsible and ethical research practice

    The role of plasma membrane STIM1 and Ca2+entry in platelet aggregation. STIM1 binds to novel proteins in human platelets

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    Ca(2+) elevation is essential to platelet activation. STIM1 senses Ca(2+) in the endoplasmic reticulum and activates Orai channels allowing store-operated Ca(2+) entry (SOCE). STIM1 has also been reported to be present in the plasma membrane (PM) with its N-terminal region exposed to the outside medium but its role is not fully understood. We have examined the effects of the antibody GOK/STIM1, which recognises the N-terminal region of STIM1, on SOCE, agonist-stimulated Ca(2+) entry, surface exposure, in vitro thrombus formation and aggregation in human platelets. We also determined novel binding partners of STIM1 using proteomics. The dialysed GOK/STIM1 antibody failed to reduced thapsigargin- and agonist-mediated Ca(2+) entry in Fura2-labelled cells. Using flow cytometry we detect a portion of STIM1 to be surface-exposed. The dialysed GOK/STIM1 antibody reduced thrombus formation by whole blood on collagen-coated capillaries under flow and platelet aggregation induced by collagen. In immunoprecipitation experiments followed by proteomic analysis, STIM1 was found to extract a number of proteins including myosin, DOCK10, thrombospondin-1 and actin. These studies suggest that PM STIM1 may facilitate platelet activation by collagen through novel interactions at the plasma membrane while the essential Ca(2+)-sensing role of STIM1 is served by the protein in the ER

    Resonant hyper-Raman scattering in spherical quantum dots

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    A theoretical model of resonant hyper-Raman scattering by an ensemble of spherical semiconductor quantum dots has been developed. The electronic intermediate states are described as Wannier-Mott excitons in the framework of the envelope function approximation. The optical polar vibrational modes of the nanocrystallites (vibrons) and their interaction with the electronic system are analized with the help of a continuum model satisfying both the mechanical and electrostatic matching conditions at the interface. An explicit expression for the hyper-Raman scattering efficiency is derived, which is valid for incident two-photon energy close to the exciton resonances. The dipole selection rules for optical transitions and Fr\"ohlich-like exciton-lattice interaction are derived: It is shown that only exciton states with total angular momentum L=0,1L=0,1 and vibrational modes with angular momentum lp=1l_p=1 contribute to the hyper-Raman scattering process. The associated exciton energies, wavefunctions, and vibron frequencies have been obtained for spherical CdSe zincblende-type nanocrystals, and the corresponding hyper-Raman scattering spectrum and resonance profile are calculated. Their dependence on the dot radius and the influence of the size distribution on them are also discussed.Comment: 12 pages REVTeX (two columns), 2 tables, 8 figure

    Aridification of Central Asia and uplift of the Altai and Hangay mountains, Mongolia: stable isotope evidence

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    Central Asia has become increasingly arid during the Cenozoic, though the mechanisms behind this aridification remain unresolved. Much attention has focused on the influence and uplift history of the Tibetan Plateau. However, the role of ranges linked to India-Asia convergence but well north of the Plateau—including the Altai, Sayan, and Hangay—in creating the arid climate of Central Asia is poorly understood. Today, these ranges create a prominent rain shadow, effectively separating the boreal forest to the north from the deserts of Central Asia. To explore the role of these mountains in modifying climate since the late Eocene, we measured carbon and oxygen stable isotopes in paleosol carbonates from three basins along a 650 km long transect at the northern edge of the Gobi Desert in Mongolia and in the lee of the Altai and Hangay mountains. We combine these data with modern air-parcel back-trajectory modeling to understand regional moisture transport pathways at each basin. In all basins, δ¹³C increases, with the largest increase in western Mongolia. The first δ¹³C increase occurs in central and southwestern Mongolia in the Oligocene. δ¹³C again increases from the upper Miocene to the Quaternary in western and southwestern Mongolia. We use a 1-D soil diffusion model to demonstrate that these δ¹³C increases are linked to declines in soil respiration driven by dramatic increases in aridity. Using modern-day empirical relations between mean annual precipitation and soil respiration, we estimate that precipitation has likely more than halved over the Neogene. Given the importance of the Hangay and Altai in steering moisture in Mongolia, we attribute these changes to differential surface uplift of the Hangay and Altai. Surface uplift in the Hangay began by the early Oligocene, blocking Siberian moisture and aridifying the northern Gobi. In contrast, surface uplift of the Altai began in the late Miocene, blocking moisture from reaching western Mongolia. Thus, the northern Gobi became increasingly arid east to west since the late Eocene, likely driven by orographic development in the Hangay during the Oligocene and the Altai in the late Miocene through Pliocene

    Benthic enrichment in the Georgia Bight related to Gulf Stream intrusions and estuarine outwelling

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    The distribution patterns of benthic biomass (microbiota, meiofauna, and macrofauna) over the expansive continental shelf of the Georgia Bight suggest nutrient inputs from intrusions of deep Gulf Stream waters at the shelf break…
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