548 research outputs found
Applying the Betts-Miller-Janjic scheme of convection in prediction of the Indian monsoon
The performance of the Betts-Miller-Janjic scheme of convection has been investigated for prediction of the Indian monsoons. For this purpose a limited area numerical weather prediction model with two schemes of convection, one with the Betts-Miller scheme and other with the Betts-Miller-Janjic scheme, is run for five cases of monsoon depression that made landfall over the Indian coast. The results from the two schemes are compared. Detailed analyses of mean sea level pressure, wind, and rainfall have shown that the Betts-Miller-Janjic scheme has considerably improved the rainfall prediction over the Indian landmass and improvement is also seen in the mean sea level pressure fields and cyclonic circulation associated with the depression at the 850-hPa level. The forecast results are further verified by computing the root-mean-square errors, and the difference in the skill scores between the two model runs are tested for their statistical significance. It is found that the Betts-Miller-Janjic scheme has a statistically significant effect on the model skill beyond 24 h, with maximum impact on mean sea level pressure and geopotential height. The performance of the Betts-Miller-Janjic scheme of convection has been investigated for prediction of the Indian monsoons. For this purpose a limited area numerical weather prediction model with two schemes of convection, one with the Betts-Miller scheme and other with the Betts-Miller-Janjic scheme, is run for five cases of monsoon depression that made landfall over the Indian coast. The results from the two schemes are compared. Detailed analyses of mean sea level pressure, wind, and rainfall have shown that the Betts-Miller-Janjic scheme has considerably improved the rainfall prediction over the indian landmass and improvement is also seen in the mean sea level pressure fields and cyclonic circulation associated with the depression at the 850-hPa level. The forecast results are further verified by computing the root-mean-square errors, and the difference in the skill scores between the two model runs are tested for their statistical significance. It is found that the Betts-Miller-Janjic scheme has a statistically significant effect on the model skill beyond 24 h, with maximum impact on mean sea level pressure and geopotential height
Thermodynamic adjustment parameters in the Betts-Miller scheme of convection
The sensitivity of the prediction of a monsoon depression to the adjustment parameters in a Betts-Miller scheme of deep convection is examined and an optimum parameter set is identified for the monsoon depression. For this purpose, a number of experiments have been carried out with a limited area model by assigning different values to the adjustment parameters, namely, the saturation pressure departure, the stability weight, and the adjustment time period. When one parameter is varied, the other two are kept constant. Results indicate that the depression track is sensitive to all three adjustment parameters. The upper-tropospheric temperature is sensitive to the stability weight and the rainfall rates are sensitive to the saturation pressure departure values. The rainfall shows minor sensitivity to the stability weight and the adjustment time period. A set of adjustment parameters that produced the best forecasts is taken as the optimum parameter set for the monsoon depression
Link between break/active phases of summer monsoon over India and China
An attempt has been made to examine the relationship between break/active phases of the Indian summer monsoon and rainfall activity over China. Twelve cases of active and fifteen cases of break phases during the Indian summer monsoon have been examined. Rainfall data over China from 'Asian Precipitation -Highly-Resolved Observational Data Integration Towards Evaluation of the Water Resources' have been used for this study. The amount and areal coverage of rainfall over China were examined during break/active phases of the Indian summer monsoon. It was found that during initiation of break phase in the Indian summer monsoon, rainfall amount and its areal coverage increased over China. The onset of its decrease marked the beginning of the end of the break phase. Exactly opposite trend was observed during the active monsoon phases. This study provides some clue about the end of the break or active phase, although it does not give any signal of initiation of break or active phase in monsoon
Socioeconomic profile of diabetic patients with and without foot problems
Introduction: To identify the differences in a socioeconomic profile between two cohorts of diabetic patients – one with diabetic foot problems and another without diabetic foot problems. Materials and methods: The cohort with diabetic foot problems (including cellulitis, abscess, osteomyelitis, septic arthritis, gangrene, ulcers, or Charcot joint disease) consisted of 122 diabetic patients, while the other cohort without foot problems consisted of 112 diabetic patients. Both were seen at the National University Hospital from January to April 2007. A detailed protocol was designed and the factors studied included patient profile, average monthly household income, education, compliance to diabetic medication, attendance at clinics for diabetic treatment, exercise, smoking, alcohol consumption, gender, and glycosylated haemoglobin (HbA1C) level. These were studied for significant differences using univariate and stepwise multivariate logistic regression analysis. Results: With multivariate analysis, Malay ethnicity (p<0.001), education of up to secondary school only (p=0.021), low average monthly household income of less than SGD $2,000 (p=0.030), lack of exercise (at least once a week, p=0.04), and elevated HbA1C level (>7.0%; p=0.015) were found to be significantly higher in the cohort with diabetic foot problems than the cohort without. Conclusions: There are significant differences in the socioeconomic factors between diabetic patients with diabetic foot problems and those without
Selection for Replicases in Protocells
PMCID: PMC3649988This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Screen or not to screen for peripheral arterial disease: Guidance from a decision model
__Abstract__
Background: Asymptomatic Peripheral Arterial Disease (PAD) is associated with greater risk of acute cardiovascular events. This study aims to determine the cost-effectiveness of one time only PAD screening using Ankle Brachial Index (ABI) test and subsequent anti platelet preventive treatment (low dose aspirin or clopidogrel) in individuals at high risk for acute cardiovascular events compared to no screening and no treatment using decision analytic modelling. Methods. A probabilistic Markov model was developed to evaluate the life time cost-effectiveness of the strategy of selective PAD screening and consequent preventive treatment compared to no screening and no preventive treatment. The analysis was conducted from the Dutch societal perspective and to address decision uncertainty, probabilistic sensitivity analysis was performed. Results were based on average values of 1000 Monte Carlo simulations and using discount rates of 1.5% and 4% for effects and costs respectively. One way sensitivity analyses were performed to identify the two most influential model parameters affecting model outputs. Then, a two way sensitivity analysis was conducted for combinations of values tested for these two most influential parameters. Results: For the PAD screening strategy, life years and quality adjusted life years gained were 21.79 and 15.66 respectively at a lifetime cost of 26,548 Euros. Compared to no screening and treatment (20.69 life years, 15.58 Quality Adjusted Life Ye
Oxidative stress causes ERK phosphorylation and cell death in cultured retinal pigment epithelium: Prevention of cell death by AG126 and 15-deoxy-delta 12, 14-PGJ(2)
BACKGROUND: The retina, which is exposed to both sunlight and very high levels of oxygen, is exceptionally rich in polyunsaturated fatty acids, which makes it a favorable environment for the generation of reactive oxygen species. The cytotoxic effects of hydrogen peroxide (H(2)O(2)) induced oxidative stress on retinal pigment epithelium were characterized in this study. METHODS: The MTT cell viability assay, Texas-Red phalloidin staining, immunohistochemistry and Western blot analysis were used to assess the effects of oxidative stress on primary human retinal pigment epithelial cell cultures and the ARPE-19 cell line. RESULTS: The treatment of retinal pigment epithelial cells with H(2)O(2 )caused a dose-dependent decrease of cellular viability, which was preceded by a significant cytoskeletal rearrangement, activation of the Extracellular signal-Regulated Kinase, lipid peroxidation and nuclear condensation. This cell death was prevented partially by the prostaglandin derivative, 15d-PGJ(2 )and by the protein kinase inhibitor, AG126. CONCLUSION: 15d-PGJ(2 )and AG126 may be useful pharmacological tools in the future capable of preventing oxidative stress induced RPE cell death in human ocular diseases
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Recent trends in breast cancer incidence in US white women by county-level urban/rural and poverty status
<p>Abstract</p> <p>Background</p> <p>Unprecedented declines in invasive breast cancer rates occurred in the United States between 2001 and 2004, particularly for estrogen receptor-positive tumors among non-Hispanic white women over 50 years. To understand the broader public health import of these reductions among previously unstudied populations, we utilized the largest available US cancer registry resource to describe age-adjusted invasive and <it>in situ </it>breast cancer incidence trends for non-Hispanic white women aged 50 to 74 years overall and by county-level rural/urban and poverty status.</p> <p>Methods</p> <p>We obtained invasive and <it>in situ </it>breast cancer incidence data for the years 1997 to 2004 from 29 population-based cancer registries participating in the North American Association of Central Cancer Registries resource. Annual age-adjusted rates were examined overall and by rural/urban and poverty of patients' counties of residence at diagnosis. Joinpoint regression was used to assess trends by annual quarter of diagnosis.</p> <p>Results</p> <p>Between 2001 and 2004, overall invasive breast cancer incidence fell 13.2%, with greater reductions among women living in urban (-13.8%) versus rural (-7.5%) and low- (-13.0%) or middle- (-13.8%) versus high- (-9.6%) poverty counties. Most incidence rates peaked around 1999 then declined after second quarter 2002, although in rural counties, rates decreased monotonically after 1999. Similar but more attenuated patterns were seen for <it>in situ </it>cancers.</p> <p>Conclusion</p> <p>Breast cancer rates fell more substantially in urban and low-poverty, affluent counties than in rural or high-poverty counties. These patterns likely reflect a major influence of reductions in hormone therapy use after July 2002 but cannot exclude possible effects due to screening patterns, particularly among rural populations where hormone therapy use was probably less prevalent.</p
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