19 research outputs found
A simulation study of semiparametric estimation in copula models based on minimum Alpha-Divergence
The purpose of this paper is to introduce two semiparametric methods for the
estimation of copula parameter. These methods are based on minimum
Alpha-Divergence between a non-parametric estimation of copula density using
local likelihood probit transformation method and a true copula density
function. A Monte Carlo study is performed to measure the performance of these
methods based on Hellinger distance and Neyman divergence as special cases of
Alpha-Divergence. Simulation results are compared to the Maximum
Pseudo-Likelihood (MPL) estimation as a conventional estimation method in
well-known bivariate copula models. These results show that the proposed method
based on Minimum Pseudo Hellinger Distance estimation has a good performance in
small sample size and weak dependency situations. The parameter estimation
methods are applied to a real data set in Hydrology.Comment: 14 page
An Online Calculating Model for Leachate Production in Mazandaranâs Waste Landfills; (Case Study: Babol Municipal Waste Landfill)
Leachate production and management is a challenging environmental issue in municipal landfills and depots in Iran. Leachate contains toxic materials, heavy metals, and organic and microbial pollutants on a significant scale. Its uncontrolled entrance into the surface, groundwater, and soils can also substantially inverse impacts on human health and natural habitats. In Mazandaran province, during the last decades, depots and landfilling of municipal and industrial waste have led to environmental degradation in its eco-sensitive natural zones and brought a series of health, social, and security challenges to the region. Due to the region's high precipitation rate and landfills with no cover, these places practically convert into an extensive resource for leachate production. To diminish the environmental impacts, a lot of work has been done in recent years to develop a sort of leakage gathering system and treatment plants in these landfills, based primarily on an overall estimation. In this study, a calculating computer model has been developed for leakage production based on regional climate conditions and the characteristics of municipal waste. This model is different from the HELP model, which is commonly used for sanitary landfills and is specifically developed for the waste depots of the Mazandaran province. In this model, hydrological methods, which are based on the water balance in the landfill sites, were used for the calculation. The developed model was uploaded as an online service for public use. By referring to the internet address provided, the developed model in the landfill part and the leachate section, the amount of produced leachate for the landfill site of Mazandaran province can be calculated. Also, the leachate volume of the Babol Anjilsi landfill has been calculated as a case study. As a result of this study, the lowest and highest amount of the production leachate for hot and dry months of the year (June and July) and for wet and rainy months (October) was about 63.39 and 260.07 cubic meters per day, respectively
Arbutin attenuates nephrotoxicity induced by gentamicin
Objective: In this study, the impact of arbutin was examined in a gentamicin (GM)-induced nephrotoxicity model.
Materials and Methods: Forty adult male Wistar rats were randomly assigned to five groups including control group; GM group, and three groups of GM+arbutin (25, 50 and 75 mg/kg). One day after the last injection of GM, creatinine, urea, carbonyl, thiobarbituric acid-reacting substance (TBARs), ferric reducing antioxidant power (FRAP) and 8-hydroxyguanosine levels were assessed in serum samples. Left and right kidneys were used for biochemical assays and histological evaluation, respectively.
Results: Our data showed that the FRAP level (p<0.05), urea (p<0.001), creatinine (p<0.001), and 8-hydroxyguanosine (p<0.001) levels of serum samples, were increased in GM-treated rats compared to the controls. The serum levels of TBARS (p<0.001) and carbonyl increased in serum and renal tissue (p<0.001) of GM-treated animals. Conversely, arbutin attenuated serum creatinine, urea and 8-hydroxyguanosine, and TBARS (p<0.001). Administration of arbutin significantly decreased carbonyl levels in serum and renal tissue samples (p<0.001). Furthermore, the levels of FRAP increased in the serum (p<0.01) and renal tissue samples (p<0.001) of arbutin-treated animals. Histological staining showed that arbutin significantly inhibits kidney damages.
Conclusion: Our data suggest that arbutin attenuates GM-induced nephrotoxicity through its free radicals-scavenging activity
Oxidationâreduction potential and sperm DNA fragmentation, and their associations with sperm morphological anomalies amongst fertile and infertile men
Objective: To assess seminal oxidationâreduction potential (ORP) and sperm DNA fragmentation (SDF) in male infertility and their relationships with sperm morphology in fertile and infertile men. Patients and methods: Prospective case-control study comparing the findings of infertile men (n = 1168) to those of men with confirmed fertility (n = 100) regarding demographics and semen characteristics (conventional and advanced semen tests). Spearman rank correlation assessed the correlation between ORP, SDF, and different morphological indices. Means of ORP and SDF were assessed in variable levels of normal sperm morphology amongst all participants. Results: Infertile patients had a significantly lower mean sperm count (32.7 vs 58.7 Ă 10 6 sperm/mL), total motility (50.1% vs 60.4%), and normal morphology (5.7% vs 9.9%). Conversely, infertile patients had significantly higher mean head defects (54% vs 48%), and higher ORP and SDF values than fertile controls. ORP and SDF showed significant positive correlations and significant negative correlations with sperm head defects and normal morphology in infertile patients, respectively. ORP and SDF were significantly inversely associated with the level of normal sperm morphology. Using receiver operating characteristic curve analysis, ORP and SDF threshold values of 1.73 mV/10 6 sperm/mL and 25.5%, respectively, were associated with 76% and 56% sensitivity and 72% and 72.2% specificity, respectively, in differentiating <4% from â„4% normal morphology. Conclusion: A direct inverse relationship exists between seminal ORP and SDF with various levels of normal sperm morphology. Using ORP and SDF measures in conjunction with standard semen morphology analysis could validate the result of the fertility status of patients. © 2017 Arab Association of UrologyScopu
Rehabilitation of the Parkinson's tremor by using robust adaptive sliding mode controller: a simulation study
One of the efficient methods in controlling the Parkinson's tremor is Deep Brain Stimulation (DBS) therapy. The stimulation of Basal Ganglia (BG) by DBS brings no feedback though the existence of feedback reduces the additional stimulatory signal delivered to the brain. So this study offers a new adaptive architecture of a closed-loop control system in which two areas of BG are stimulated simultaneously to decrease the following three indicators: hand tremor, the level of a delivered stimulation signal in the disease condition, and the level of a delivered stimulation signal in health condition to the disease condition. One area (STN: subthalamic nucleus) is stimulated with an adaptive sliding mode controller and the other area (GPi: Globus Pallidus internal) with partial state feedback controller. The simulation results of stimulating two areas of BG showed satisfactory performance
Renal vein thrombosis due to metastatic germ cell tumor, report of a case with a very rare clinical scenario
Abstract Background Renal metastasis is a rare manifestation of germ cell tumors. Extension of malignant lesions into the renal vein can complicate the scenario. Case This report presents a 35âyearâold man with primary stage IS NSGCT. Fourteen months after radical orchiectomy he presented with metastasis in the lung, kidney, and paraâaortic lymph nodes. He received multiple lines of salvage treatments including chemotherapy and surgery. Intraoperative exploration during radical nephrectomy and retroperitoneal lymphadenectomy revealed intraârenal vein involvement with a prominent teratomatous component. Conclusion Defining the exact extent of malignant lesions, especially endovascular lesions, is very important to clarify how advanced the malignant lesions are. The surgeons must be aware of the risk factors that predict vascular involvement, and therefore, providing intraoperative access to vascular surgery procedures when needed
Haematological and biochemical alterations caused by epidural and intramuscular administration of xylazine hydrochloride in dromedary camels (Camelus dromedarius)
This study was conducted in 16 healthy immature dromedary camels weighing 120-150 kg to evaluate and compare the effects of epidural and intramuscular injections of xylazine administered at 0.1 mg/kg and 0.2 mg/kg. Haematological parameters included haemoglobin, packed cell volume, total erythrocyte count and total leukocyte count. Biochemical parameters included alkaline phosphates, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, creatinine and glucose. Parameters were measured at different intervals before (baseline) and after the administration of drugs. Our study showed that the effect of xylazine on haematological and biochemical parameters is dose-dependant and is also related to the route of administration. The low dose of xylazine administered using both intramuscular and epidural methods showed minimal effects, whereas high doses of the drug, especially when injected intramuscularly, caused greater changes in haematological and biochemical parameters