179 research outputs found

    Extending the Ehresmann-Schein-Nambooripad Theorem

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    We extend the `join-premorphisms' part of the Ehresmann-Schein-Nambooripad Theorem to the case of two-sided restriction semigroups and inductive categories, following on from a result of Lawson (1991) for the `morphisms' part. However, it is so-called `meet-premorphisms' which have proved useful in recent years in the study of partial actions. We therefore obtain an Ehresmann-Schein-Nambooripad-type theorem for meet-premorphisms in the case of two-sided restriction semigroups and inductive categories. As a corollary, we obtain such a theorem in the inverse case.Comment: 23 pages; final section on Szendrei expansions removed; further reordering of materia

    Geology and genesis of the cerro la mina porphyry-high sulfidation Au (Cu-Mo) prospect, Mexico

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    The Cerro la Mina Au (Cu-Mo) porphyry-high sulfidation prospect is located in Chiapas State, southeastern Mexico, outside of the major metallogenic provinces of Mexico. The prospect is hosted by Pleistocene alkaline volcanic rocks of the Chiapanecan volcanic arc that formed in a complex triple-junction tectonic setting. Cerro la Mina's stratigraphy comprises pyroclastic flows that were intruded by monzodiorites and diorites at 1.04 ± 0.04 Ma (U-Pb, zircon), and that were overlain by debris flows and synvolcanic trachyandesite domes. The volcanic stratigraphy of Cerro la Mina is dominated by pyroclastic flows and rare basalts that are cut by the Cerro la Mina breccia pipe, a matrix-rich granular, vertically oriented, downward-Tapering, polymict lithic rock unit that is host to all of the significant alteration and mineralization. A NW-Trending sinistral wrench fault, which was active throughout the history of Cerro la Mina, is responsible for dismembering the prospect after mineralization. The magmatic hydrothermal system was composed of early porphyry-style potassic veins (quartz + K-feldspar ± biotite) and stage 1 pyrite that are preserved in clasts within the breccia pipe, suggesting that brecciation disrupted an embryonic porphyry system. Late potassic alteration occurred after the formation of the breccia pipe, as its matrix is strongly K-feldspar altered. Hydrothermal fluids then produced phyllic alteration composed of quartz, muscovite, illite, illite-smectite, and chlorite that is associated with stage 2 pyrite ± chalcopyrite ± molybdenite ± quartz veins. An unusual zoned pattern of advanced argillic-Argillic alteration overprinted potassic and phyllic alteration. This zoning included a low-Temperature (<110°C) halloysite + kaolinite that extends from 800 to 250 m below present-day surface and is deeper than higher temperature (>120°C) quartz + dickite ± kaolinite ± pyrophyllite ± alunite that occurs from 250 m to the present-day surface. The advanced argillic-Argillic altered rocks host the most significant Au-Cu mineralization, which is associated with stage 3 marcasite, sphalerite, galena, and barite, and stage 4 arsenian pyrite ± enargite ± covellite. The magmatic hydrothermal system at Cerro la Mina began sometime between monzodiorite emplacement (1.04 ± 0.04 Ma; zircon U-Pb) and the precipitation of porphyry stage 2 molybdenite at 780 ± 10 ka (Re-Os). 40Ar/39Ar dating of biotite (689 ± 13 ka) records the age at which the hydrothermal system cooled below the biotite closure temperature of 300°C and provides a maximum estimate for the onset of advanced argillicargillic alteration. Sulfur isotope results of sulfides (-2.5 to +4.9‰; mean +0.7‰; n = 20) and a sulfate (barite; +10.5‰; n = 1) suggest a magmatic source of sulfur for all four stages of mineralization. The lack of residual quartz, rare alunite, and anomalous halloysite-kaolinite alteration may be explained by the high acid-buffering capacity of alkaline volcanic host rocks, high CO2 contents of the alkaline magma, and/or potentially by a highly reduced magmatic hydrothermal fluid. At the regional metallogenic scale, the Cerro la Mina prospect along with the nearby Santa Fé mine and Campamento deposit represent parts of a porphyry copper system-specifically, a porphyry/high-sulfidation, proximal skarn and intermediate sulfidation deposit, respectively. The characteristics of Cerro la Mina (i.e., anomalous halloysite-kaolinite alteration) broaden the window for additional discoveries to be made in the porphyry-epithermal environment

    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

    Porphyry indicator minerals and their mineral chemistry as vectoring and fertility tools

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    Information contained in this publication or product may be reproduced, in part or in whole, and by any means, for personal or public non-commercial purposes, without charge or further permission, unless otherwise specified. You can freely download the publication in its entirety by visiting the publisher's website

    COVID-19 trajectories among 57 million adults in England:a cohort study using electronic health records

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    Background: Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework. Methods: In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status. Findings: Among 57 032 174 individuals included in the cohort, 13 990 423 COVID-19 events were identified in 7 244 925 individuals, equating to an infection rate of 12·7% during the study period. Of 7 244 925 individuals, 460 737 (6·4%) were admitted to hospital and 158 020 (2·2%) died. Of 460 737 individuals who were admitted to hospital, 48 847 (10·6%) were admitted to the intensive care unit (ICU), 69 090 (15·0%) received non-invasive ventilation, and 25 928 (5·6%) received invasive ventilation. Among 384 135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23 485 [30·4%] of 77 202 patients) than wave 2 (44 220 [23·1%] of 191 528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15 486 (9·8%) of 158 020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10 884 (6·9%) of 158 020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1. Interpretation: Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources. Funding: British Heart Foundation Data Science Centre, led by Health Data Research UK.</p

    COVID-19 trajectories among 57 million adults in England:a cohort study using electronic health records

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    Background: Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework. Methods: In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status. Findings: Among 57 032 174 individuals included in the cohort, 13 990 423 COVID-19 events were identified in 7 244 925 individuals, equating to an infection rate of 12·7% during the study period. Of 7 244 925 individuals, 460 737 (6·4%) were admitted to hospital and 158 020 (2·2%) died. Of 460 737 individuals who were admitted to hospital, 48 847 (10·6%) were admitted to the intensive care unit (ICU), 69 090 (15·0%) received non-invasive ventilation, and 25 928 (5·6%) received invasive ventilation. Among 384 135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23 485 [30·4%] of 77 202 patients) than wave 2 (44 220 [23·1%] of 191 528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15 486 (9·8%) of 158 020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10 884 (6·9%) of 158 020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1. Interpretation: Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources. Funding: British Heart Foundation Data Science Centre, led by Health Data Research UK.</p

    COVID-19 trajectories among 57 million adults in England: a cohort study using electronic health records

    Get PDF
    BACKGROUND: Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework. METHODS: In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status. FINDINGS: Among 57 032 174 individuals included in the cohort, 13 990 423 COVID-19 events were identified in 7 244 925 individuals, equating to an infection rate of 12·7% during the study period. Of 7 244 925 individuals, 460 737 (6·4%) were admitted to hospital and 158 020 (2·2%) died. Of 460 737 individuals who were admitted to hospital, 48 847 (10·6%) were admitted to the intensive care unit (ICU), 69 090 (15·0%) received non-invasive ventilation, and 25 928 (5·6%) received invasive ventilation. Among 384 135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23 485 [30·4%] of 77 202 patients) than wave 2 (44 220 [23·1%] of 191 528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15 486 (9·8%) of 158 020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10 884 (6·9%) of 158 020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1. INTERPRETATION: Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources. FUNDING: British Heart Foundation Data Science Centre, led by Health Data Research UK

    Integrated Multi-Parameter Exploration Footprints of the Canadian Malartic Disseminated Au, McArthur River-Millennium Unconformity U, and Highland Valley Porphyry Cu Deposits: Preliminary Results from the NSERC-CMIC Mineral Exploration Footprints Research Network

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    Mineral exploration in Canada is increasingly focused on concealed and deeply buried targets, requiring more effective tools to detect large-scale ore-forming systems and to vector from their most distal margins to their high grade cores. A new generation of ore system models is required to achieve this. The Mineral Exploration Footprints Research Network is a consortium of 70 faculty, research associates, and students from 20 Canadian universities working with 30 mining, mineral exploration, and mining service providers to develop new approaches to ore system modelling based on more effective integration and visualization of multi-parameter geological-structural-mineralogical-lithogeochemical-petrophysical-geophysical exploration data. The Network is developing the next generation ore system models and exploration strategies at three sites based on integrated data visualization using self-consistent 3D Common Earth Models and geostatistical/machine learning technologies. Thus far over 60 footprint components and vectors have been identified at the Canadian Malartic stockwork-disseminated Au deposit, 20–30 at the McArthur-Millennium unconformity U deposits, and over 20 in the Highland Valley porphyry Cu system. For the first time, these are being assembled into comprehensive models that will serve as landmark case studies for data integration and analysis in the today’s challenging exploration environment

    Ethical Awareness, Ethical Judgment and Whistleblowing: A Moderated Mediation Analysis

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    This study aims to examine the ethical decision-making (EDM) model proposed by Schwartz (J Bus Ethics, doi:10.1007/s10551-015-2886-8,2016), where we consider the factors of non-rationality and aspects that affect ethical judgments of auditors to make the decision to blow the whistle. In this paper, we argue that the intention of whistleblowing depends on ethical awareness (EAW) and ethical judgment (EJW) as well as there is a mediation–moderation due to emotion (EMT) and perceived moral intensity (PMI) of auditors. Data were collected using an online surveywith 162 external auditors who worked on audit firms in Indonesia as well as 173 internal auditors working in the manufacturing and financial services. The result of multigroup analysis shows that emotion (EMT) can mediate the relationship between EAW and EJW. The nature of this relationship is more complex and then tested by adding moderating variables using consistent partial least squares approach. We found that EMT and PMI can improve the relationship between ethical judgments and whistleblowing intentions. These findings indicate that internal auditors are more likely to blow the whistle than external auditors; and reporting wrongdoing internally and anonymously are the preferred way of professional accountants to blow the whistle in Indonesia

    The benefits of strength training on musculoskeletal system health: practical applications for interdisciplinary care

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    Global health organizations have provided recommendations regarding exercise for the general population. Strength training has been included in several position statements due to its multi-systemic benefits. In this narrative review, we examine the available literature, first explaining how specific mechanical loading is converted into positive cellular responses. Secondly, benefits related to specific musculoskeletal tissues are discussed, with practical applications and training programmes clearly outlined for both common musculoskeletal disorders and primary prevention strategies
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