246 research outputs found

    A review of the “metallome” within neurons and glia, as revealed by elemental mapping of brain tissue

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    It is now well established that transition metals, such as Iron (Fe), Copper (Cu), and Zinc (Zn) are necessary for healthy brain function. Although Fe, Cu, and Zn are essential to the brain, imbalances in the amount, distribution, or chemical form (“metallome”) of these metals is linked to the pathology of numerous brain diseases or disorders. Despite the known importance of metal ions for both brain health and disease, the metallome that exists within specific types of brain cells is yet to be fully characterised. The aim of this mini-review is to present an overview of the current knowledge of the metallome found within specific brain cells (oligodendrocytes, astrocytes, microglia, and neurons), as revealed by direct elemental mapping techniques. It is hoped this review will foster continued research using direct elemental mapping techniques to fully characterise the brain cell metallome

    Workplace violence in Queensland, Australia: the results of a comparative study

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    [Abstract]: This paper presents the results on workplace violence from a larger study undertaken in 2004. Comparison is made with the results of a similar study undertaken in 2001. The study involved the random sampling of 3000 nurses from the Queensland Nurses’ Union’s membership in the public (acute hospital and community nursing), private (acute hospital and domiciliary nursing) and aged care sectors (both public and private aged care facilities). The self-reported results suggest an increase in workplace violence in all three sectors. Whilst there are differences in the sources of workplace violence across the sectors, the major causes of workplace violence are: clients/patients, visitors/relatives, other nurses, nursing management and medical practitioners. Associations were also found between workplace violence and gender, the designation of the nurse, hours of employment, the age of the nurse, morale and perceptions of workplace safety. Whilst the majority of nurses reported that policies were in place for the management of workplace violence, these policies were not always adequate

    Anthropometric and physiological factors affecting batted ball speed of adolescent baseball players

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    Fifty-seven junior baseball players performed eight swings off a tee to record ball exit speed, as well as tests of grip strength, standing broad jump, lateral-to-medial (LM) jumps, chin-ups and chest pass with a medicine ball. The height, weight and age of each participant was also recorded. All anthropometric and physiological tests were significantly positively correlated with ball speed (p \u3c 0.05). Collinearity between variables meant that only chest pass (RÂČ = 0.70, p = 0.000), body mass (ΔRÂČ = 0.03, Δp = 0.021) and LM jump (ΔRÂČ = 0.04, Δp = 0.005) made independent contributions to a stepwise linear regression. These findings corroborate the expectation that upper body power is a major determinant of batting speed, with leg power adding an additional, independent contribution to performance

    Recent advances in the application of mineral chemistry to exploration for porphyry copper–gold–molybdenum deposits: detecting the geochemical fingerprints and footprints of hypogene mineralization and alteration

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    In the past decade, significant research efforts have been devoted to mineral chemistrystudies to assist porphyry exploration. These activities can be divided into two majorfields of research: (1) porphyry indicator minerals (PIMs), which are used to identify thepresence of, or potential for, porphyry-style mineralization based on the chemistry ofmagmatic minerals such as zircon, plagioclase and apatite, or resistate hydrothermalminerals such as magnetite; and (2) porphyry vectoring and fertility tools (PVFTs),which use the chemical compositions of hydrothermal minerals such as epidote,chlorite and alunite to predict the likely direction and distance to mineralized centers,and the potential metal endowment of a mineral district. This new generation ofexploration tools has been enabled by advances in and increased access to laserablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), short wavelength infrared (SWIR), visible near-infrared (VNIR) and hyperspectral technologies.PIMs and PVFTs show considerable promise for exploration and are starting to beapplied to the diversity of environments that host porphyry and epithermal depositsglobally. Industry has consistently supported development of these tools, in the case ofPVFTs encouraged by several successful blind tests where deposit centers havesuccessfully been predicted from distal propylitic settings. Industry adoption is steadilyincreasing but is restrained by a lack of the necessary analytical equipment andexpertise in commercial laboratories, and also by the on-going reliance on well-established geochemical exploration techniques (e.g., sediment, soil and rock-chipsampling) that have aided the discovery of near-surface resources over many decades, are now proving less effective in the search for deeply buried mineral resources, and for those concealed under cover

    Porphyry Indicator Minerals (PIMS) and Porphyry Vectoring and Fertility Tools (PVFTS) – Indicators of Mineralization Styles and Recorders of Hypogene Geochemical Dispersion Halos

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    In the past decade, significant research efforts have been devoted to mineral chemistry studies to assist porphyry exploration. These activities can be divided into two major fields of research: (1) porphyry indicator minerals (PIMS), which aims to identify the presence of, or potential for, porphyry-style mineralization based on the chemistry of magmatic minerals such as plagioclase, zircon and apatite, or resistate hydrothermal minerals such as magnetite; and (2) porphyry vectoring and fertility tools (PVFTS), which use the chemical compositions of hydrothermal minerals such as epidote, chlorite and alunite to predict the likely direction and distance to mineralized centres, and the potential metal endowment of a mineral district. This new generation of exploration tools has been enabled by advances in laser ablation-inductively coupled plasma mass spectrometry, short wave length infrared data acquisition and data processing, and the increased availability of microanalytical techniques such as cathodoluminescence. PVFTS and PIMS show considerable promise for porphyry exploration, and are starting to be applied to the diversity of environments that host porphyry and epithermal deposits around the circum-Pacific region. Industry has consistently supported development of these tools, in the case of PVFTS encouraged by several successful “blind tests” where deposit centres have successfully been predicted from distal propylitic settings. Industry adoption is steadily increasing but is restrained by a lack of the necessary analytical equipment and expertise in commercial laboratories.Item freely available with no apparent Creative Commons License or copyright statement. The attached file is the published pdf

    The Historical Context of the Gender Gap in Mathematics

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    This chapter is based on the talk that I gave in August 2018 at the ICM in Rio de Janeiro at the panel on "The Gender Gap in Mathematical and Natural Sciences from a Historical Perspective". It provides some examples of the challenges and prejudices faced by women mathematicians during last two hundred and fifty years. I make no claim for completeness but hope that the examples will help to shed light on some of the problems many women mathematicians still face today

    Using mineral chemistry to aid exploration: a case study from the resolution porphyry Cu-Mo deposit, Arizona

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    The giant, high-grade Resolution porphyry Cu-Mo deposit in the Superior district of Arizona is hosted in Proterozoic and Paleozoic basement and in an overlying Cretaceous volcaniclastic breccia and sandstone package. Resolution has a central domain of potassic alteration that extends more than 1 km outboard of the ore zone, overlapping with a propylitic halo characterized by epidote, chlorite, and pyrite that is particularly well developed in the Laramide volcaniclastic rocks and Proterozoic dolerite sills. The potassic and propylitic assemblages were overprinted in the upper parts of the deposit by intense phyllic and advanced argillic alteration. The district was disrupted by Tertiary Basin and Range extension, and the fault block containing Resolution and its Cretaceous host succession was buried under thick mid-Miocene dacitic volcanic cover, obscuring the geologic, geophysical, and geochemical footprint of the deposit. To test the potential of propylitic mineral chemistry analyses to aid in the detection of concealed porphyry deposits, a blind test was conducted using a suite of epidote-chlorite ± pyrite-altered Laramide volcaniclastic rocks and Proterozoic dolerites collected from the propylitic halo, with samples taken from two domains located to the north and south and above the Resolution ore zone. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data of epidote provided indications of deposit fertility and proximity. Competition for chalcophile elements (As, Sb, Pb) between coexisting pyrite and epidote grains led to a subdued As-Sb fertility response in epidote, consistent with epidote collected between 0.7 and 1.5 km from the center of a large porphyry deposit. Temperature-sensitive trace elements in chlorite provided coherent spatial zonation patterns, implying a heat source centered at depth between the two sample clusters, and application of chlorite proximitor calculations based on LA-ICP-MS analyses provided a precisely defined drill target in this location in three dimensions. Drilling of this target would have resulted in the discovery of Resolution, confirming that epidote and chlorite mineral chemistry can potentially add value to porphyry exploration under cover
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