106 research outputs found

    Phytoplankton of Aras dam reservoir (Iran): an attempt to assess water quality

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    The Aras reservoir, located in the north-west of Iran, plays an important role in fisheries, drinking and agricultural water supplies and recreational activities in the region. This study was performed to characterize the seasonal fluctuations of phytoplankton communities and their relationship with environmental factors in the Aras reservoir from August 2013 to May 2014. Sampling was carried out seasonally from 5 sampling locations. In each location three samples were taken for phytoplankton identification and enumeration, chemical analysis and chlorophyll a determination. In total, 72 species belonging to 5 divisions were determined. Cyanobacteria contained the highest density (74%) during the study period with Pseudanabaena limnetica as the most abundant species. This group retained its dominance the whole year round which indicated the poor quality and high nutrient load of the Aras reservoir, mainly due to human activities. On average, Trophic State Index (TSI) showed that water in the reservoir was eu-hypereutrophic. The results indicated that phytoplankton density negatively correlated with Secchi disc depth (R^2 = -0.479), total alkalinity (R^2 = -0.564), total hardness (R^2 = -0.727) and HCO_3 concentration (R^2 = -0.589). On the other hand, there was a positive correlation between the phytoplankton density and TP (R^2 = 0.734). A comparison between the present and a previous study indicated that the cyanobacterial bloom pattern in the Aras reservoir has shifted from warm season toward an all year round cycle which in addition to basin pollution due to anthropogenic activities, can be related to global warming and climate change

    A Study on anisotropy of cosmic ray distribution with a small array of water-cherenkov detectors

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    The study of the anisotropy of the arrival directions is an essential tool to investigate the origin and propagation of cosmic rays primaries. A simple way of recording many cosmic rays is to record coincidences between a number of detectors. We have monitored multi-TeV cosmic rays by a small array of water cherenkov detectors in Tehran(35 43 N, 51 20 E, 1200m a.s.l). More than 1.1*10^6 extensive air shower events were recorded. In addition to the Compton- Getting effect due to the motion of the earth in the Galaxy, an anisotropy has been observed which is due to a unidirectional anisotropy of cosmic ray flow along the Galactic arms.Comment: 16 pages 9 figs and one tabl

    Geographical and socioeconomic inequalities in female breast cancer incidence and mortality in Iran: A Bayesian spatial analysis of registry data

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    Background In Iran, trends in breast cancer incidence and mortality have generally been monitored at national level. The purpose of this study is to examine province-level disparities in age-standardised breast cancer incidence versus mortality from 2000 to 2010 and their association with socioeconomic status. Methods In this study, data from Iran’s national cancer and death registry systems, and covariates from census and household expenditure surveys were used. We estimated the age-standardised incidence and mortality rates in women aged more than 30 years for all 31 provinces in the consecutive time intervals 2000–2003, 2004–2007 and 2008–2010 using a Bayesian spatial model. Results Mean age-standardised breast cancer incidence across provinces increased over time from 15.0 per 100,000 people (95% credible interval 12.0,18.3) in 2000–2003 to 39.6 (34.5,45.1) in 2008–2010. The mean breast cancer mortality rate declined from 10.9 (8.3,13.8) to 9.9 (7.5,12.5) deaths per 100,000 people in the same period. When grouped by wealth index quintiles, provinces in the highest quintile had higher levels of incidence and mortality. In the wealthiest quintile, reductions in mortality over time were larger than those observed among provinces in the poorest quintile. Relative breast cancer mortality decreased by 16.7% in the highest quintile compared to 10.8% in the lowest quintile. Conclusions Breast cancer incidence has increased over time, with lower incidence in the poorest provinces likely driven by underdiagnoses or late-stage diagnosis. Although the reported mortality rate is still higher in wealthier provinces, the larger decline over time in these provinces indicates a possible future reversal, with the most deprived provinces having higher mortality rates. Ongoing analysis of incidence and mortality at sub-national level is crucial in addressing inequalities in healthcare systems and public health both in Iran and elsewhere

    The reference value of trabecular bone score (TBS) in the Iranian population

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    Trabecular bone score (TBS), as a tool for measurement of bone microarchitecture, represents fracture risk independently of bone density. The aim of this study was to estimate the reference values of TBS in both genders among the Iranian population to evaluate osteoporotic fractures in the future. Methods: The study was performed on healthy Iranian subjects who live in urban areas of Bushehr city, the capital of Bushehr province in southwestern Iran. The participants in this study were selected through a multistage, age and sex stratified, cluster random sampling. The TBS of L1-L4 was assessed by spine DXA images using TBS iNsight software (Discovery WI, Hologic Inc, USA). Age-related models of TBS were constructed using piecewise linear regression analysis. Results: In total, 691 participants aged ≥ 18 years (381 men and 310 women) were selected for the study. The mean and standard deviation (SD) of TBS value for men was 1.420 ± 0.094 and the age at the peak TBS was 30.0 years. Among women, the corresponding value for the mean of TBS was 1.428 ± 0.070 and the age at the peak TBS was 24.5 years. Two SDs below the mean of TBS were 1.326 in men and 1.357 in women. Therefore, the following normal range for TBS values has been proposed: Among men, TBS ≥ 1.326 is considered to be normal; TBS between 1.231 and 1.326 is considered to be partially degraded microarchitecture; and TBS ≤ 1.231defined degraded microarchitecture. Among women, TBS categories are defined as normal ≥ 1.357, partially degraded between 1.287 and 1.357 and degraded ≤ 1.287. Conclusions: This was the first study to propose evaluation of the normal range for TBS values in both genders in the Middle- East and Iran. According to our results: TBS ≤ 1.231 in men and TBS ≤ 1.287 in women is considered to be degraded microarchitecture among the Iranian population

    Socioeconomic inequality in childhood obesity and its determinants: a Blinder�Oaxaca decomposition Desigualdade socioeconômica na obesidade infantil e seus determinantes: decomposição de Oaxaca-Blinder

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    Objective: Childhood obesity has become a priority health concern worldwide. Socioeconomic status is one of its main determinants. This study aimed to assess the socioeconomic inequality of obesity in children and adolescents at national and provincial levels in Iran. Methods: This multicenter cross-sectional study was conducted in 2011�2012, as part of a national school-based surveillance program performed in 40,000 students, aged 6�18-years, from urban and rural areas of 30 provinces of Iran. Using principle component analysis, the socioeconomic status of participants was categorized to quintiles. Socioeconomic status inequality in excess weight was estimated by calculating the prevalence of excess weight (i.e., overweight, generalized obesity, and abdominal obesity) across the socioeconomic status quintiles, the concentration index, and slope index of inequality. The determinants of this inequality were determined by the Oaxaca Blinder decomposition. Results: Overall, 36,529 students completed the study (response rate: 91.32); 50.79 of whom were boys and 74.23 were urban inhabitants. The mean (standard deviation) age was 12.14 (3.36) years. The prevalence of overweight, generalized obesity, and abdominal obesity was 11.51, 8.35, and 17.87, respectively. The SII for overweight, obesity and abdominal obesity was �0.1, �0.1 and �0.15, respectively. Concentration index for overweight, generalized obesity, and abdominal obesity was positive, which indicate inequality in favor of low socioeconomic status groups. Area of residence, family history of obesity, and age were the most contributing factors to the inequality of obesity prevalence observed between the highest and lowest socioeconomic status groups. Conclusion: This study provides considerable information on the high prevalence of excess weight in families with higher socioeconomic status at national and provincial levels. These findings can be used for international comparisons and for healthcare policies, improving their programming by considering differences at provincial levels. © 2017 Sociedade Brasileira de Pediatri

    Socioeconomic inequality in childhood obesity and its determinants: a Blinder�Oaxaca decomposition Desigualdade socioeconômica na obesidade infantil e seus determinantes: decomposição de Oaxaca-Blinder

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    Objective: Childhood obesity has become a priority health concern worldwide. Socioeconomic status is one of its main determinants. This study aimed to assess the socioeconomic inequality of obesity in children and adolescents at national and provincial levels in Iran. Methods: This multicenter cross-sectional study was conducted in 2011�2012, as part of a national school-based surveillance program performed in 40,000 students, aged 6�18-years, from urban and rural areas of 30 provinces of Iran. Using principle component analysis, the socioeconomic status of participants was categorized to quintiles. Socioeconomic status inequality in excess weight was estimated by calculating the prevalence of excess weight (i.e., overweight, generalized obesity, and abdominal obesity) across the socioeconomic status quintiles, the concentration index, and slope index of inequality. The determinants of this inequality were determined by the Oaxaca Blinder decomposition. Results: Overall, 36,529 students completed the study (response rate: 91.32); 50.79 of whom were boys and 74.23 were urban inhabitants. The mean (standard deviation) age was 12.14 (3.36) years. The prevalence of overweight, generalized obesity, and abdominal obesity was 11.51, 8.35, and 17.87, respectively. The SII for overweight, obesity and abdominal obesity was �0.1, �0.1 and �0.15, respectively. Concentration index for overweight, generalized obesity, and abdominal obesity was positive, which indicate inequality in favor of low socioeconomic status groups. Area of residence, family history of obesity, and age were the most contributing factors to the inequality of obesity prevalence observed between the highest and lowest socioeconomic status groups. Conclusion: This study provides considerable information on the high prevalence of excess weight in families with higher socioeconomic status at national and provincial levels. These findings can be used for international comparisons and for healthcare policies, improving their programming by considering differences at provincial levels. © 2017 Sociedade Brasileira de Pediatri

    Economic inequality in prevalence of underweight and short stature in children and adolescents: The weight disorders survey of the caspian-IV study

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    Objective: The aim of this study was to determine the determinants of socio-economic inequality in the prevalence of short stature and underweight in Iranian children and adolescents. Subjects and methods: This cross-sectional nationwide study was conducted on 36,486 participants, aged 6-18 years. This school-based surveillance (CASPIAN-IV) program and its complementary part on weight disorders evaluation was conducted in urban and rural areas of 30 provinces in Iran. In addition to physical examination, a validated questionnaire was completed from students and their parents. Socio-economic status (SES) was determined using principal component analysis, and was classified in quintile scale. Inequality in the prevalence of underweight and short stature was assessed using concentration (C) index and slop index of inequality (SII) by the Oaxaca-Blinder decomposition method. Results: The prevalence (95 CI) of underweight and short stature at national level was 10.89 (10.55, 11.23) and 4.15 (3.94, 4.38), respectively; it had a downtrend from the lowest to highest SES quintile. Furthermore, the value of C for underweight and short stature was negative, i.e. inequality was in favor of high SES groups. Moreover, the prevalence gap of underweight and short stature in the first and fifth quintiles of SES was 6.58 and 5.80, respectively. The highest proportion of this gap was explained by living area. In the multiple logistic model, odds of underweight and short stature were significantly lower in individuals with higher SES. Compared to boys, odds of underweight were decreased in girls, whereas odds of short stature were increased in them. Odds of underweight and short stature were increased in participants from rural areas than in urban areas. With increasing age, the odds of underweight and short stature decreased significantly. Conclusions: The results of this study showed that inequality in the prevalence of short stature and underweight was in favor of high SES groups. Moreover, living area was one of the most important determinants that explained this inequality. Therefore, this issue needs to be considered in health promotion policies. © 2020, Sociedade Brasileira de Endocrinologia e Metabologia. All rights reserved

    Liver cancer mortality at national and provincial levels in Iran between 1990 and 2015: A meta regression analysis

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    Background: Liver cancer is a highly lethal cancer with 5 year survival rate of about 18. This cancer is a leading cause of death in many countries. As there is not a comprehensive population base study on liver cancer mortality rates by cause in national and provincial level in Iran. We aimed to estimate the liver cancer mortality rate, its patterns, and temporal trends during 26 years by sex, age, geographical distribution, and cause. Methods: We used the Iranian death registration system (DRS), in addition to demographic and statistical methods, to address the incompleteness and misclassification and uncertainty of death registration system to estimate annual liver cancer mortality rate. Direct age standardized approach was applied using Iran national population 2015 as a standard population to facilitate the comparison between the provinces. Results: Liver cancer age standardized mortality rate in Iran increased by more than four times from 1.18 (95 uncertainty interval; 0.86 to 1.61) deaths per 100,000 person in 1990 to 5.66 (95 uncertainty interval; 4.20 to 7.63) deaths per 100,000 person in 2015. Male to female age adjusted mortality ratio changed from 0.87 to 1.82 during the 26 years of the study. With increasing age, liver cancer mortality rate increased in both sex and all provinces. At provincial level, the province with highest mortality rate have 2.96 times greater rate compare to the lowest. Generally, about 71 of mortality at national level is due to hepatitis B and C infection. Conclusions: In order to reduce liver cancer mortality rate, it is recommended to control main risk factors including chronic hepatitis infections. Because of the growing rate of mortality from liver cancer, augmenting life expectancy, and increasing number of the elderly in Iran, policy makers are more expected to adopt measures including hepatitis B vaccination or hepatitis C treatment. © 2018, Hepatitis Monthly

    Investigating the TeV Morphology of MGRO J1908+06 with VERITAS

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    We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy (VHE) gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14 sigma) and measure a photon index of 2.20 +/- 0.10_stat +/- 0.20_sys. The TeV emission is extended, covering the region near PSR J1907+0602 and also extending towards SNR G40.5--0.5. When fitted with a 2-dimensional Gaussian, the intrinsic extension has a standard deviation of sigma_src = 0.44 +/- 0.02 degrees. In contrast to other TeV PWNe of similar age in which the TeV spectrum softens with distance from the pulsar, the TeV spectrum measured near the pulsar location is consistent with that measured at a position near the rim of G40.5--0.5, 0.33 degrees away.Comment: To appear in ApJ, 8 page
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