251 research outputs found

    Challenging loop-mediated isothermal amplification (LAMP) technique for molecular detection of Toxoplasma gondii

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    Objective: To compare analytical sensitivity and specificity of a newly described DNA amplification technique, LAMP and nested PCR assay targeting the RE and B1 genes for the detection of Toxoplasma gondii (T. gondii) DNA. Methods: The analytical sensitivity of LAMP and nested-PCR was obtained against10-fold serial dilutions of T. gondii DNA ranging from 1 ng to 0.01 fg. DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays. Results: After testing LAMP and nested-PCR in duplicate, the detection limit of RE-LAMP, B1-LAMP, RE-nested PCR and B1-nested PCR assays was one fg, 100 fg, 1 pg and 10 pg of T. gondii DNA respectively. All the LAMP assays and nested PCRs were 100 specific. The RE-LAMP assay revealed the most sensitivity for the detection of T. gondii DNA. Conclusions: The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection of T. gondii. Furthermore, these findings indicate that primers based on the RE are more suitable than those based on the B1 gene. However, the B1-LAMP assay has potential as a diagnostic tool for detection of T. gondii. © 2015 Hainan Medical College

    FUSION OF NON-THERMAL AND THERMAL SATELLITE IMAGES BY BOOSTED SVM CLASSIFIERS FOR CLOUD DETECTION

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    The goal of ensemble learning methods like Bagging and Boosting is to improve the classification results of some weak classifiers gradually. Usually, Boosting algorithms show better results than Bagging. In this article, we have examined the possibility of fusion of non-thermal and thermal bands of Landsat 8 satellite images for cloud detection by using the boosting method. We used SVM as a base learner and the performance of two kinds of Boosting methods including AdaBoost.M1 and σ Boost was compared on remote sensing images of Landsat 8 satellite. We first extracted the co-occurrence matrix features of non-thermal and thermal bands separately and then used PCA method for feature selection. In the next step AdaBoost.M1 and σ Boost algorithms were applied on non-thermal and thermal bands and finally, the classifiers were fused using majority voting. Also, we showed that by changing the regularization parameter (C) the result of σ Boost algorithm can significantly change and achieve overall accuracy and cloud producer accuracy of 74%, and 0.53 kappa coefficient that shows better results in comparison to AdaBoost.M1

    Pilot-scale studies of combined clarification, filtration, and ultraviolet radiation systems for disinfection of secondary municipal wastewater effluent

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    Disinfection of municipal wastewater effluent was evaluated using three alternatives, including: (1) low-pressure (LP)+medium-pressure (MP) UV lamps; (2) clarifier+LP+MP; and (3) pressurized sand filter+ LP+MP. Total coliform (TC), fecal coliform (FC), fecal Streptococcus (FS), TSS, several physicochemical parameters, absorbtivity and UV transmittance (UVT; ) were tested. The UVT for secondary, clarified and filtered effluents were 3.5, 34 and 50, respectively. A 15 photo-reactivation in secondary effluent disinfected by LP lamp was observed, while it was limited to 0.03 by the MP lamp after filtration. Filtration to a surface overflow rate (SOR) of 1050 L/m2h, followed by MP irradiation at a dose of 230 mW s/cm2 was an effective alternative to reduce the TC, FC, and FS in the disinfected secondary effluent. Filtration+MP lamp met the standards of 1000 TC and 400 FC/100 mL for effluent discharge to receiving waters. This process can also inactivate FS, effecting a 6-log reduction. Among the evaluated alternatives, none of the other treatment systems performed as well as the pressurized sand filter+MP lamp, making this the best combination for post-treatment and disinfection of secondary effluent from a well-run wastewater treatment plant. © 2010 Elsevier B.V. All rights reserved

    Evaluating the scale, growth, and origins of right-wing echo chambers on YouTube

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    Although it is understudied relative to other social media platforms, YouTube is arguably the largest and most engaging online media consumption platform in the world. Recently, YouTube's outsize influence has sparked concerns that its recommendation algorithm systematically directs users to radical right-wing content. Here we investigate these concerns with large scale longitudinal data of individuals' browsing behavior spanning January 2016 through December 2019. Consistent with previous work, we find that political news content accounts for a relatively small fraction (11%) of consumption on YouTube, and is dominated by mainstream and largely centrist sources. However, we also find evidence for a small but growing "echo chamber" of far-right content consumption. Users in this community show higher engagement and greater "stickiness" than users who consume any other category of content. Moreover, YouTube accounts for an increasing fraction of these users' overall online news consumption. Finally, while the size, intensity, and growth of this echo chamber present real concerns, we find no evidence that they are caused by YouTube recommendations. Rather, consumption of radical content on YouTube appears to reflect broader patterns of news consumption across the web. Our results emphasize the importance of measuring consumption directly rather than inferring it from recommendations.Comment: 29 pages, 21 figures, 15 table

    Risk factors and control strategies for silicotuberculosis as an occupational disease

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    Silicotuberculosis is critical in community settings among workers and employees exposed to silica dust. Older age of entry (>30 years), male sex, infection with human immunodeficiency virus (HIV), exposure duration, smoking, chronic obstructive pulmonary disease, migration, the severity of the silicosis and the intensity of the exposure are potential risk factors. Lack of timely diagnosis and treatment for tuberculosis (TB) may also raise the rate of infection; previous treatment of TB is possibly associated with the development of silicotuberculosis in more than half of patients, increasing with age (>40 years). Identification of risk factors benefits not only the academic research community, but also the workers or employees and policy making. Some strategies can be implemented, such as controlling or reducing exposure to silica dust, ensuring continuity of treatment of TB or extended anti-TB treatment, management of the situation by occupational health professionals, prevention of oscillating migration, providing workers with compensation, training and education in occupational health, improving the quality of life of miners and workers, intensive medical surveillance and TB screening in routine health check ups, and policy making for higher immunity to inhibit inhalation of dust by workers or employees

    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

    Mycobacterium avium paratuberculosis and Mycobacterium avium complex and related subspecies as causative agents of zoonotic and occupational diseases

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    Mycobacterium avium complex (MAC) and Mycobacterium avium paratuberculosis (MAP) cause zoonotic infections transmitted by birds and livestock herds. These pathogens have remained as serious economic and health threats in most areas of the world. As zoonotic diseases, the risk of development of occupational disease and even death outcome necessitate implementation of control strategies to prevent its spread. Zoonotic MAP infections include Crohn's disease, inflammatory bowel disease, ulcerative colitis, sarcoidosis, diabetes mellitus, and immune-related diseases (such as Hashimoto's thyroiditis). Paratuberculosis has classified as type B epidemic zoonotic disease according to world health organization which is transmitted to human through consumption of dairy and meat products. In addition, MAC causes pulmonary manifestations and lymphadenitis in normal hosts and human immunodeficiency virus (HIV) progression (by serotypes 1, 4, and 8). Furthermore, other subspecies have caused respiratory abscesses, neck lymph nodes, and disseminated osteomyelitis in children and ulcers. However, the data over the occupational relatedness of these subspecies is rare. These agents can cause occupational infections in susceptible herd breeders. Several molecular methods have been recognized as proper strategies for tracking the infection. In this study, some zoonotic aspects, worldwide prevalence and control strategies regarding infections due to MAP and MAC and related subspecies has been reviewe

    Socioeconomic inequality in oral health behavior in Iranian children and adolescents by the Oaxaca-Blinder decomposition method: The CASPIAN- IV study

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    Background: The present study set to describe the socioeconomic inequality associated with oral hygiene behavior among Iranian pediatric population. Methods: A representative sample of 13486 school students aged 6-18 years was selected through multistage random cluster sampling method from urban and rural areas of 30 provinces in Iran. Principle Component Analyses (PCA) correlated variables summarized as socioeconomic status (SES). Association of independent variables with tooth brushing was assessed through logistic regression analysis. Decomposition of the gap in tooth brushing between the first and fifth SES quintiles was assessed using the counterfactual decomposition technique. To assess the relation between tooth brushing and each socioeconomic category, Concentration Index (C) and the slope index of inequality (SII) were used, representing the linear regression coefficient. Results: The participation rate was 90.6 (50.7 boys and 75.6 urban inhabitants). The mean age of participants was 12.47 ± 3.36 years. The frequency of tooth brushing increased across SES quintiles, prevalence of tooth brushing between the first and fifth quintile, under 20 difference, increased from 58.22 (95 CI: 56.24,60.20) to 78.61 (95 CI: 77.00,80.24). Only 3 of the difference is explained by the factors considered in the study, and 17 remained unknown. Residence area, family size, and smoking status made a significant contribution to the gap between the first and last SE groups. Residence area -2.01 (95 % CI: -3.46, -0.55) was along the maximum levels of gaps between SE categories. Conclusions: The findings revealed a socio-economic inequality in oral health behavior in Iranian children and adolescents. Also, factors influencing oral health are addressed to develop and implement complementary public health actions. © 2016 The Author(s)

    National and sub-national burden of chronic diseases attributable to lifestyle risk factors in Iran 1990-2013; study protocol

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    Background: Non-communicable diseases, as the major public health problem, are caused by different risk factors. The main leading lifestyle risk factors for most diseases burden in Iran are unhealthy diet, physical inactivity, and smoking. The aim of this study is to provide data collection and methodology processes for estimating the trends of exposures to the selected lifestyle risk factors and their attributed burden at national and sub-national levels. Methods: Systematic review will be performed through PubMed/MEDLINE, Scopus and ISI/Web of Science as well as Iranian databases such as IranMedex, Irandoc and Scientific Information Database (SID). In addition, hand searching of unpublished data sources will be used to identify relevant population-based studies. The searched studies will be included only if it is reasonably population-based and representative, and exposure data has been reported or could be plausibly obtained from the study. For risk factors with no surveys identified, other sources of potential data will be considered. The target population is healthy Iranian adult population living within Iran from 1990 to 2013. Other data sources include national censuses, national registration systems, and national and sub-national surveys. Spatio-temporal Bayesian hierarchical model and Bayesian multilevel autoregressive model will be used to overcome the problem of data gaps in provinces, and in some age or sex groups or in urban/rural areas. The problem of misaligned areal units will be also addressed in these models. Conclusion: National and sub-national assessment of major lifestyle risk factors such as unhealthy diet, physical inactivity, and smoking is necessary for priority setting and policy making in different regions of Iran
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