164 research outputs found

    Investigation on 2007 abnormal wave occured at the West coast of Korea

    Get PDF
    Swell-type unexpected waves occurred along western coast of Korean at March, 2007 and it caused several deaths and heavy economic loss. Available field measurement data are collected to investigate this event, numerical model is setup to reproduce this unknown waves. We found several 1-min interval tidal elevation and sea level pressure (SLP) data along the western coast of Korea and analyzed it using wavelet technique. The wavelet power spectrum for sea water level anomalies is computed using the Morlet mother function. The high wave energy is occurred between 8 and 16 minutes during 0???2 KST 31 March 2007, and the sudden pressure jump of 3???5 hPa occurred simultaneously with high wave energy event. The numerical experiments of the abnormal wave were performed using 2-dimensional shallow water wave model (COMCOT), and air pressure forcing is made from the variation of SLP field and pressure jump from weather charts. We assume the air pressure jump of around 5 hPa is moving from Shandong of China to west coast of Korea. The sea water level by the travel of SLP field was changed all over west coast of Korea with low frequency and SLP field was not considered an original forcing of the abnormal wave. The sea level under the forcing of air pressure jump was obviously amplified by the Proudman resonant effect and it can reproduce the 2007 abnormal wave qualitatively

    Research on sea level rise due to global warming in the Nortwestern Pacific using a non-Boussinesq numerical model

    Get PDF
    To study the seawater volume change due to the warming of the oceans, this work adapts the Modular\ud Ocean Model Version 4 (MOM4) oceanic general circulation model, which does not consider the Boussinesq\ud approximation, to regional model. Simulation data of Climate Model 2.1 (CM2.1), the Hadley Center Coupled Climate\ud Model 3 (HADCM3), and the Model for Interdisciplinary Research on Climate 3.2 (MIROC3.2), provided by the\ud Intergovernmental Panel on Climate Change (IPCC), were used as initial and boundary values, and the Special Report\ud on Emissions Scenarios (SRES) A1B and B1 were selected as the global warming scenarios. The Northwestern Pacific\ud region, which includes Korea, was selected as the study area, and the Yellow Sea, which has a complex coastline, was\ud expressed in detail by increasing the resolution. The average values of the results for the three experiments include a\ud temperature/sea level increase of approximately 3 ??C/35 cm from 2000 to 2100 in SRES A1B, and approximately 2 ??C\ud /27 cm in SRES B1. The East Sea experienced a larger change owing to the steric effect and showed a larger influence\ud resulting from density changes as the temperature of the Tsushima Warm Current, which passes through the Korea\ud Strait, increased. The result of the study that directly considered the steric effect predicted a higher sea level rise than\ud that of indirect computation because the indirectly computed dynamic height was eliminated; sea level rise in a shallow\ud area cannot be computed, and the unchanged volume serves as undersea pressure. Moreover, the Kuroshio Current,\ud which is a major current in the Northwestern Pacific, showed a decrease in transport as global warming progressed.\ud Despite the differences between models, a decrease of 4???5 SV in transport was observed for 2100; however, there was\ud no notable change in the transport of the Tsushima Warm Current

    Axial tubule junctions control rapid calcium signaling in atria.

    Get PDF
    The canonical atrial myocyte (AM) is characterized by sparse transverse tubule (TT) invaginations and slow intracellular Ca2+ propagation but exhibits rapid contractile activation that is susceptible to loss of function during hypertrophic remodeling. Here, we have identified a membrane structure and Ca2+-signaling complex that may enhance the speed of atrial contraction independently of phospholamban regulation. This axial couplon was observed in human and mouse atria and is composed of voluminous axial tubules (ATs) with extensive junctions to the sarcoplasmic reticulum (SR) that include ryanodine receptor 2 (RyR2) clusters. In mouse AM, AT structures triggered Ca2+ release from the SR approximately 2 times faster at the AM center than at the surface. Rapid Ca2+ release correlated with colocalization of highly phosphorylated RyR2 clusters at AT-SR junctions and earlier, more rapid shortening of central sarcomeres. In contrast, mice expressing phosphorylation-incompetent RyR2 displayed depressed AM sarcomere shortening and reduced in vivo atrial contractile function. Moreover, left atrial hypertrophy led to AT proliferation, with a marked increase in the highly phosphorylated RyR2-pS2808 cluster fraction, thereby maintaining cytosolic Ca2+ signaling despite decreases in RyR2 cluster density and RyR2 protein expression. AT couplon "super-hubs" thus underlie faster excitation-contraction coupling in health as well as hypertrophic compensatory adaptation and represent a structural and metabolic mechanism that may contribute to contractile dysfunction and arrhythmias

    Austenite in Transformation-Induced Plasticity Steel Subjected to Multiple Isothermal Heat Treatments

    Get PDF
    The thermodynamic limit to the progress of the bainite reaction in steels containing a cementite inhibitor often leaves large quantities of thermally or mechanically unstable austenite. Such austenite is not effective in delaying the onset of plastic instabilities during the course of deformation. In such circumstances, it is useful to conduct isothermal transformation at a high temperature where the rate of reaction is relatively rapid, followed by a lower temperature step that permits more bainite to be generated. This in turn increases the stability of the refined austenite, which then transforms gently over a large range of strain during a tensile test. A significant corollary is that the two-step heat treatments are unnecessary in low-carbon steels, where the bainite reaction is able to proceed to a greater extent before reaching the thermodynamic limit. Furthermore, the two-step process can be counterproductive in low carbon steel, because the austenite content is reduced to a level below which it does not enhance the mechanical properties. Other circumstances in which multiple heat treatments are necessary are also discussed.The authors are grateful to POSCO for support through Steel Innovation Programme, and to the World Class University Programme of the National Research Foundation of Korea, Ministry of Education, Science and Technology, project number R32-2008-000-10147.This is the accepted manuscript version. The final published version is available from Springer at http://link.springer.com/article/10.1007%2Fs11661-014-2405-z

    Multiethnic meta-analysis identifies ancestry-specific and cross-ancestry loci for pulmonary function

    Get PDF
    Nearly 100 loci have been identified for pulmonary function, almost exclusively in studies of European ancestry populations. We extend previous research by meta-analyzing genome-wide association studies of 1000 Genomes imputed variants in relation to pulmonary function in a multiethnic population of 90,715 individuals of European (N = 60,552), African (N = 8429), Asian (N = 9959), and Hispanic/Latino (N = 11,775) ethnicities. We identify over 50 additional loci at genome-wide significance in ancestry-specific or multiethnic meta-analyses. Using recent fine-mapping methods incorporating functional annotation, gene expression, and differences in linkage disequilibrium between ethnicities, we further shed light on potential causal variants and genes at known and newly identified loci. Several of the novel genes encode proteins with predicted or established drug targets, including KCNK2 and CDK12. Our study highlights the utility of multiethnic and integrative genomics approaches to extend existing knowledge of the genetics of l

    A review of symptomatic leg length inequality following total hip arthroplasty

    Get PDF
    Leg length inequality (LLI) following total hip replacement is a complication which features increasingly in the recent literature. The definition of LLI is complicated by lack of consensus regarding radiological measurement, clinical measurement and the incomplete relationship between LLI and associated symptoms. This paper reviews 79 reports relating to LLI post hip replacement, detailing definitions and classification and highlighting patient populations prone to symptomatic LLI. While there is no universal definition of LLI, there is a broad consensus that less than 10 mm of difference on AP view plain radiographs is clinically acceptable. There are few techniques described that consistently produce a postoperative LLI of less than this magnitude. Where postoperative LLI exists, lengthening appears to cause more problems than shortening. In cases of mild LLI, non-surgical management produces adequate outcomes in the majority of cases, with functional LLI cases doing better than those with true LLI. Operative correction is effective in half of cases, even where nerve palsy is present, and remains an important option of last resort. Poor outcomes in patients with LLI may be minimised if individuals at risk are identified and counselled appropriately

    Measurement of the muon flux from 400 GeV/c protons interacting in a thick molybdenum/tungsten target

    Get PDF
    The SHiP experiment is proposed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. About 1011 muons per spill will be produced in the dump. To design the experiment such that the muon-induced background is minimized, a precise knowledge of the muon spectrum is required. To validate the muon flux generated by our Pythia and GEANT4 based Monte Carlo simulation (FairShip), we have measured the muon flux emanating from a SHiP-like target at the SPS. This target, consisting of 13 interaction lengths of slabs of molybdenum and tungsten, followed by a 2.4 m iron hadron absorber was placed in the H4 400 GeV/c proton beam line. To identify muons and to measure the momentum spectrum, a spectrometer instrumented with drift tubes and a muon tagger were used. During a 3-week period a dataset for analysis corresponding to (3.27±0.07) × 1011 protons on target was recorded. This amounts to approximatively 1% of a SHiP spill

    Track reconstruction and matching between emulsion and silicon pixel detectors for the SHiP-charm experiment

    Get PDF
    In July 2018 an optimization run for the proposed charm cross section measurement for SHiP was performed at the CERN SPS. A heavy, moving target instrumented with nuclear emulsion films followed by a silicon pixel tracker was installed in front of the Goliath magnet at the H4 proton beam-line. Behind the magnet, scintillating-fibre, drift-tube and RPC detectors were placed. The purpose of this run was to validate the measurement's feasibility, to develop the required analysis tools and fine-tune the detector layout. In this paper, we present the track reconstruction in the pixel tracker and the track matching with the moving emulsion detector. The pixel detector performed as expected and it is shown that, after proper alignment, a vertex matching rate of 87% is achieved

    Repositioning of the global epicentre of non-optimal cholesterol

    Get PDF
    High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.</p
    corecore