27 research outputs found

    Genetic Sharing with Cardiovascular Disease Risk Factors and Diabetes Reveals Novel Bone Mineral Density Loci.

    Get PDF
    Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False Discovery Rate (FDR) method to identify single nucleotide polymorphisms (SNPs) associated with BMD by leveraging cardiovascular disease (CVD) associated disorders and metabolic traits. By conditioning on SNPs associated with the CVD-related phenotypes, type 1 diabetes, type 2 diabetes, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein, triglycerides and waist hip ratio, we identified 65 novel independent BMD loci (26 with femoral neck BMD and 47 with lumbar spine BMD) at conditional FDR < 0.01. Many of the loci were confirmed in genetic expression studies. Genes validated at the mRNA levels were characteristic for the osteoblast/osteocyte lineage, Wnt signaling pathway and bone metabolism. The results provide new insight into genetic mechanisms of variability in BMD, and a better understanding of the genetic underpinnings of clinical comorbidity

    Sensitivity Analysis of a Fire Spread Model in a Chaparral Landscape

    No full text
    ABSTRACT Due to a unique combination of environmental conditions, the chaparral shrublands of southern California are prone to large, intense wildland fires. There is ongoing work in the fire research community to establish whether fuel accumulation or weather conditions are the determining factor in the prevalence of large chaparral fires. This study introduces a framework for contributing a modeling perspective to understanding these alternative hypotheses. As models formalize our understanding of the physical process of fire spread, the sensitivity of the models to the meteorological and fuel inputs should be indicators of their relative importance. A global sensitivity analysis (GSA) was conducted on HFire, a spatially explicit raster model developed for modeling fire spread in chaparral fuels, based on the Rothermel spread equations. The GSA provided a quantitative measure of the importance of each of the model inputs on the predicted fire size. The results indicate that, under extreme weather conditions, wind speed was over three times more influential on predicted fire sizes than any other single model input. This finding supports the idea that fires burning under Santa Ana conditions are primarily driven by high wind speeds. Future research will involve extending the GSA methodology to quantify the relative importance of these inputs in terms of the long-term fire regime in chaparral ecosystems.JRC.G.9-Econometrics and applied statistic

    Pathophysiology and treatment of osteoporosis: challenges for clinical practice in older people

    No full text
    Osteoporosis, a common chronic metabolic bone disease is associated with considerable morbidity and mortality. As the prevalence of osteoporosis increases with age, a paralleled elevation in the rate of incident fragility fractures will be observed. This narrative review explores the origins of bone and considers physiological mechanisms involved in bone homeostasis relevant to management and treatment. Secondary causes of osteoporosis, as well as osteosarcopenia are discussed followed by an overview of the commonly used pharmacological treatments for osteoporosis in older people

    Specifying the saturation temperature for the HyspIRI 4-μm channel

    No full text
    The investigation of high-temperature natural phenomena, such as wildland fires and active lava flows, is a primary science objective for the proposed Hyperspectral Infrared Imager (HyspIRI) mission. Current planning for HyspIRI includes a mid-infrared (MIR) channel centered at 4 μm that will allow measurement of radiance emitted from high-temperature targets. In this paper we present the results of a study to specify the saturation temperature for the MIR channel. This study was based on reviews of the literature, together with case studies of airborne and satellite-based data acquired over high-temperature targets. The spatial resolution of MIR radiance measurements is an important consideration in the remote sensing of high-temperature phenomena, due to the presence of materials at different temperatures within the area covered by an image pixel. The HyspIRI MIR channel will provide a spatial resolution of 60. m, which is ~ 40 times finer (in terms of area) than the finest spatial resolution provided by heritage instruments (370m). This fine spatial resolution will increase the probability that high-temperature targets fill an image pixel and, therefore, the HyspIRI MIR channel will require a saturation temperature 2 to 4 times higher than the saturation limits of heritage instruments. Based on our study, we recommend a saturation temperature of 1200 K (927°C). This recommendation accounts for the high temperatures expected for natural phenomena, expected performance of the MIR channel, and overlap in sensitivity between the MIR and thermal infrared (7.5-12μm) HyspIRI channels.</p
    corecore