399 research outputs found

    Dynamics of Impurity and Valence Bands in GaMnAs within the Dynamical Mean Field Approximation

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    We calculate the density-of-states and the spectral function of GaMnAs within the dynamical mean-field approximation. Our model includes the competing effects of the strong spin-orbit coupling on the J=3/2 GaAs hole bands and the exchange interaction between the magnetic ions and the itinerant holes. We study the quasi-particle and impurity bands in the paramagnetic and ferromagnetic phases for different values of impurity-hole coupling at the Mn doping of x=0.05. By analyzing the anisotropic angular distribution of the impurity band carriers at T=0, we conclude that the carrier polarization is optimal when the carriers move along the direction parallel to the average magnetization.Comment: 6 pages, 4 figure

    Attenuation of serum laminin concentrations upon treatment of chronic hepatitis

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    Objectives: The aim of this work was to determine the serum laminin level cutoff point for predicting liver fibrosis highlighting its diagnostic value and determining the effect of treatment on serum laminin concentrations. Methods: Serum laminin concentrations in chronic hepatitis patients (n=62) and controls (n=20) were compared by ELISA and stages of fibrosis were assessed according to the modified Knodell score system. Results: Mean serum laminin concentration in patients (91.9 ± 20.9 ng/ml) was greater than controls (46.2 ± 10.2 ng/ml; p <0.001). Serum concentrations of laminin in all stages of hepatic fibrosis were significantly higher than those of healthy controls (p <0.05). A cutoff point of 52ng laminin/ml of serum was obtained for the discrimination of various stages of liver fibrosis showing a good sensitivity (96.8%) and specificity (80%). After 6 months of treatment, a gradual decrease in serum laminin concentrations were observed, however the level was still higher than that of the healthy group (p<0.05). Conclusions: Our findings suggest that the serum laminin concentration is a useful noninvasive marker of liver fibrosis and shows a strong positive correlation with different stages of the disease

    Deriving optimal operational policies for off-stream man-made reservoir considering conjunctive use of surface- and groundwater at the Bar dam reservoir (Iran)

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    Study region: The off-stream artificial Bar lake, built in 2015 to store the flood flows of the Bar river for domestic and industrial needs and with the objective to intentionally recharge the aquifer, is situated in the Razavi Khorasan province (Iran). Study focus: We present a methodology, based on the combination of a MODFLOW groundwater flow model for estimating seepage rates, and an optimization model, for the management and operation of an artificial reservoir considering surface/groundwater interactions for satisfying 12 Mm3/year of water demand. We simulated the reliable amount of water that can be supplied from the reservoir, considering reservoir seepage, maximizing water supply yields subject to the water supply reliability requirements, and the additional intentional volume of groundwater recharge. New hydrological insights for the region: Our results demonstrate the reliability of conjunctive use of surface-and ground-water in water scarce areas by exploiting reservoir infrastructures with relevant leakage losses, also for creating additional aquifer storage. In such systems, man-induced changes of lake stages can significantly affect the volume of water that seeps through the lakebed. The aquifer, under managed aquifer recharge operations, may then provide the resource not satisfied by the reservoir release, fulfilling 100 % reliability of water supply. The conjunctive use of surface- and ground-water, by improving water security, may open new sustainability views for leaking reservoirs, even if they were not initially designed for increasing aquifer recharge, in many areas worldwide

    Gene action for some agronomic traits in maize (Zea mays L.)

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    Results indicated over-dominance gene effects for days from silking to physiological maturity, days from anthesis to physiological maturity, plant height, kernel depth, number of rows per ear and grain yield. The most appropriate strategy for the exploitation of these effects is to obtain hybrid cultivars and evaluate these characteristics in hybrid combinations. The gene effect for days from emergence to physiological maturity and number of kernels per row was complete dominance, suggesting that reciprocal recurrent selection would be effective. Ear leaf area and ear length were controlled by partial dominance, indicating that additive gene effects were more important than non-additive gene effects for controlling the inheritance of these traits. Therefore, improvement of these traits through selection of breeding materials is highly feasible. Broad-sense heritability ranged between 47.4% and 89.4% for days to physiological maturity and number of rows per ear; however, narrow-sense heritability varied between 7.3% and 50.6% for days from anthesis to physiological maturity and ear leaf area, respectively. Non-additive gene effects were predominant for controlling the majority of traits

    Role of Protective Relaying in the Smart Grid

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    This paper discusses the role of protective relaying in a Smart Grid. It outlines the definition, attributes, and benefits of a Smart Grid. The role that protective relays can play in implementing Smart Grid functionality and the impact that a Smart Grid design may have on modern protective relays is discussed. Specific examples of Smart Grid applications that may be implemented using modern protective relays and other intelligent electronic devices are provided

    Burden of ischemic heart diseases in Iran, 1990-2010: Findings from the global burden of disease study 2010

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    Background: Cardiovascular diseases are viewed worldwide as one of the main causes of death.This study aims to report the burden of ischemic heart diseases (IHDs) in Iran by using data of the global burden of disease (GBD) study, 1990-2010. Materials and Methods: The GBD study 2010 was a systematic effort to provide comprehensive data to calculate disability-adjusted life years (DALYs) for diseases and injuries in the world. Years of life lost (YLLs) due to premature mortality were computed on the basis of cause-of-death estimates, using Cause of Death Ensemble model (CODEm). Years lived with disability (YLDs) were assessed by the multiplication of prevalence, the disability weight for a sequel, and the duration of symptoms. A systematic review of published and unpublished data was performed to evaluate the distribution of diseases, and consequently prevalence estimates were calculated with a Bayesian meta-regression method (DisMod-MR). Data from population-based surveys were used for producing disability weights. Uncertainty from all inputs into the calculations of DALYs was disseminated by Monte Carlo simulation techniques. Results: The age-standardized IHDs DALY specified rate decreased 31.25 over 20 years from 1990 to 2010 from 4720 (95% uncertainty interval (UI): 4,341-5,099) to 3,245 (95% UI: 2,810-3,529) person-years per 100,000. The decrease were 38.14% among women and 26.87% among men. The age-standardized IHDs death specefied rate decreased by 21.17% from 222) 95% UI: 207-243 (to 175 (95% UI:152-190) person-years per 100,000 in both the sexes. The age-standardized YLL and YLD rates decreased 32.05% and 4.28%, respectively, in the above period. Conclusion: Despite decreasing age-standardized IHD of mortality, YLL, YLD, and DALY rates from 1990 to 2010, population growth and aging increased the global burden of IHD. YLL has decreased more than IHD deaths and YLD since 1990 but IHD mortality remains the greatest contributor to disease burden. © 2015 Journal of Research in Medical Sciences
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