2,233 research outputs found

    Pathology

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    The SABAP2 legacy: A review of the history and use of data generated by a long-running citizen science project

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    Significance:• The Second Southern African Bird Atlas Project (SABAP2) – initiated in 2007 – is one of the region’s longest-running citizen science programmes and collects spatial and temporal data on birds. • Data from the project are publicly available and used extensively by environmental impact assessment practitioners, conservationists, authors, protected area managers, scientists and the general public.• The project is the template for other established projects that now operate across the continent, collectively now falling under the ‘African Bird Atlas Project’ umbrella.• We show that since the initiation of SABAP2, there has been a three-fold increase in publications, with over 150 papers that can be attributed to SABAP2. • The contribution of citizen scientists to the published scientific domain has been enormous

    The Application of Image Recognition and Machine Learning to Capture Readings of Traditional Blood Pressure Devices: A Platform to Promote Population Health Management to Prevent Cardiovascular Diseases

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    Digital solutions for Blood Pressure Monitoring (or Telemonitoring) have sprouted in recent years, innovative solutions are often connected to the Internet of Things (IoT), with mobile health (mHealth) platform. However, clinical validity, technology cost and cross-platform data integration remain as the major barriers for the application of these solutions. In this paper, we present an IoT-based and AI-embedded Blood Pressure Telemonitoring (BPT) system, which facilitates home blood pressure monitoring for individuals. The highlights of this system are the machine learning techniques to enable automatic digits recognition, with F1 score of 98.5%; and the cloud-based portal developed for automated data synchronization and risk stratification. Positive feedbacks on trial implementation are received from three clinics. The overall system architecture, development of machine learning model in digit identification and cloud-based telemonitoring are addressed in this paper, alongside the followed implications

    Low-energy Spectra of the t-J-Type Models Studied by Variational Approach

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    We discuss recent progress of understanding the phenomena observed in high Tc cuprates by studying the d-wave resonating-valence-bond (d-RVB) based trial wave functions for the 2-dimensional t-J-type models. Treat exactly the strong correlation between electrons by numerical approach, we examine the evolution of ground states described by different variational wave functions and properties of the quasi-hole and -particle excitations of the d-RVB superconducting (SC) state. Properties related to the Fermi surface geometry deduced from quasi-hole energy dispersion of the SC state is shown to be consistent with the observation by photoemission spectroscopy. With the calculated spectral weights (SW's) for adding and removing an electron, we found not only the anti-correlation between conductance peak height and width between peaks seen in tunneling experiments, but also unique properties due to strong correlation which need to be verified by future experiments.Comment: 6 revtex pages with 5 (.eps) figures. To appear in a special volume of Journal of Magnetism and Magnetic Materials for the ICM 2006 proceeding

    Constraints on Three-Neutrino Mixing from Atmospheric and Reactor Data

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    Observations of atmospheric neutrinos are usually analyzed using the simplifying approximation that either νμντ\nu_\mu \leftrightarrow \nu_\tau or νeνμ\nu_e \leftrightarrow \nu_\mu two-flavor mixing is relevant. Here we instead consider the data using the simplifying approximation that only one neutrino mass scale is relevant. This approximation is the minimal three-flavor notation that includes the two relevant two-flavor approximations. The constraints in the parameter space orthogonal to the usual, two-flavor analyses are studied.Comment: 15 pages, preprint IUHET-26

    Kcne2 deletion causes early-onset nonalcoholic fatty liver disease via iron deficiency anemia

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    Nonalcoholic fatty liver disease (NAFLD) is an increasing health problem worldwide, with genetic, epigenetic, and environmental components. Here, we describe the first example of NAFLD caused by genetic disruption of a mammalian potassium channel subunit. Mice with germline deletion of the KCNE2 potassium channel {beta} subunit exhibited NAFLD as early as postnatal day 7. Using mouse genetics, histology, liver damage assays and transcriptomics we discovered that iron deficiency arising from KCNE2-dependent achlorhydria is a major factor in early-onset NAFLD in Kcne2(-/-) mice, while two other KCNE2-dependent defects did not initiate NAFLD. The findings uncover a novel genetic basis for NAFLD and an unexpected potential factor in human KCNE2-associated cardiovascular pathologies, including atherosclerosis

    Molecular dynamic simulation on the thermal conductivity of nanofluids in aggregated and non-aggregated states

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    Nanofluids are engineered by suspending nanoparticles in convectional heat transfer fluids to enhance thermal conductivity. This study is aimed at identifying the role of nanoparticle aggregation in enhancing the thermal conductivity of nanofluids. Molecular dynamic simulation with the Green Kubo method was employed to compute thermal conductivity of nanofluids in aggregated and non-aggregated states. Results show that the thermal conductivity enhancement of nanofluids in an aggregated state is higher than in a non-aggregated state, by up to 35. The greater enhancement in aggregated nanofluids is attributed to both higher collision among nanoparticles and increases in the potential energy of nanoparticles

    Superconductivity in CoO2_2 Layers and the Resonating Valence Bond Mean Field Theory of the Triangular Lattice t-J model

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    Motivated by the recent discovery of superconductivity in two dimensional CoO2_2 layers, we present some possibly useful results of the RVB mean field theory applied to the triangular lattice. Away from half filling, the order parameter is found to be complex, and yields a fully gapped quasiparticle spectrum. The sign of the hopping plays a crucial role in the analysis, and we find that superconductivity is as fragile for one sign as it is robust for the other. Nax_xCoO2y_2\cdot yH2_2O is argued to belong to the robust case, by comparing the LDA Fermi surface with an effective tight binding model. The high frequency Hall constant in this system is potentially interesting, since it is pointed out to increase linearly with temperature without saturation for T >> Tdegeneracy_{degeneracy}.Comment: Published in Physical Review B, total 1 tex + 9 eps files. Erratum added as separate tex file on November 7, 2003, a numerical factor corrected in the erratum on Dec 3, 200

    Dispersion of a single hole in the t-J model

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    The dispersion of a single hole in the t-J model obtained by the exact result of 32 sites and the results obtained by self-consistent Born approximation and the Green function Monte Carlo method can be simply derived by a mean-field theory with d-RVB and antiferromagnetic order parameters. In addition, it offers a simple explanation for the difference observed between those results. The presence of the extended van Hove region at (pi,0) is a consequence of the d-RVB pairing independenct of the antiferromagnetic order. Results including t' and t" are also presented and explained consistently in a similar way.Comment: LaTex file, 5 pages with 5 embedded eps figure

    Deletion of the Androgen Receptor in Adipose Tissue in Male Mice Elevates Retinol Binding Protein 4 and Reveals Independent Effects on Visceral Fat Mass and on Glucose Homeostasis

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    Testosterone deficiency is epidemic in obese ageing males with type 2 diabetes, but the direction of causality remains unclear. Testosterone-deficient males and global androgen receptor (AR) knockout mice are insulin resistant with increased fat, but it is unclear whether AR signaling in adipose tissue mediates body fat redistribution and alters glucose homoeostasis. To investigate this, mice with selective knockdown of AR in adipocytes (fARKO) were generated. Male fARKO mice on normal diet had reduced perigonadal fat but were hyperinsulinemic and by age 12 months, were insulin deficient in the absence of obesity. On high-fat diet, fARKO mice had impaired compensatory insulin secretion and hyperglycemia, with increased susceptibility to visceral obesity. Adipokine screening in fARKO mice revealed a selective increase in plasma and intra-adipose retinol binding protein 4 (RBP4) that preceded obesity. AR activation in murine 3T3 adipocytes downregulated RBP4 mRNA. We conclude that AR signaling in adipocytes not only protects against high-fat diet–induced visceral obesity but also regulates insulin action and glucose homeostasis, independently of adiposity. Androgen deficiency in adipocytes in mice resembles human type 2 diabetes, with early insulin resistance and evolving insulin deficiency
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