106 research outputs found

    Analysis of the groundwater resource decline in an intramountain aquifer system in Central Iran

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    The Shahrekord aquifer is located in an intramountain basin in Central Iran (90 km SW of Isfahan) and is the main resource of irrigation water for the intensively developed agriculture in the Shahrekord Plain. Early exploitation of the aquifer started back around 1950 but has intensified severely during the last decades. Irrigation water is provided by three means: spring water is tapped, water is pumped from around 650 wells and in historic times more than 100 karizes (or ghanats, deep underground channels that drain the water table and are accessed by shafts) were constructed and provide an additional source of water. However, groundwater levels have declined severely during the last decade, and although systematic piezometric monitoring already started in 1984, it stayed unclear whether the declining trend is related to increased water demand and exploitation or is due to climatic reasons, as around 2000 a severe drought lasted for three years. In this paper, exploitation and precipitation data are combined with the measured piezometric levels to analyse their relationship and help to understand the observed trend in declining groundwater storage. This aquifer is an example of a system that can easily deliver large amounts of groundwater because of a high transmissivity and considerable thickness, but has, for climatic reasons, a limited recharge. This imbalance makes the present level of exploitation unsustainable

    A lumped parameter balance model for modeling intramountain groundwater basins : application to the aquifer system of Shahrekord Plain, Iran

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    Intramountain basins are the preferred locations for agricultural and socio-economical development in mountain regions. They often consist of considerable subsurface sedimentary fillings which hold an aquifer system suitable for groundwater exploitation. In semi-arid climates with distinct dry and wet seasons, groundwater is the main source of irrigation water in the dry periods. The risk for overdrafting of these basins is realistic when management of exploitation is not based on the water balance of the basin. When the outlet of the basin is narrow, groundwater interaction with surrounding basins is limited and the water balance becomes very sensitive to changes in the balance components, such as increasing pumping rates. This paper presents a lumped parameter water balance model for intramountain basins which incorporates: (1) the water inflow components of diffuse recharge from rainfall, lateral inflow from the surrounding mountains (mountain front recharge) and irrigation return flow on the cultivated land, and (2) the water outflow components as water capture from wells, springs and underground galleries, water loss from evapotranspiration and river and groundwater outflow out of the basin. Although the model has been developed for a specific basin in a semi-arid climate, it can easily be used for other basins in comparable hydrogeological settings. The model has been applied to the Shahrekord basin in central Iran, where intense agricultural activity has required large amounts of groundwater for irrigation in the dry summer months. Consequently piezometric levels have declined nearly continuously during the last decades because of overdrafting. The model has been applied for the period 1990-2004 and some of the water balance components have been estimated by calibrating the model using an optimisation routine. Additionally, some predictive runs have been done with the calibrated model to investigate future development under three different exploitation scenarios

    Investigation and Sensitivity analysis of experimental methods for estimating evaporation from free surface of Choghakhor lake

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    Evaporation losses from free surface water in reservoir dams are one of the important processes in meteorology and hydrology. Each experimental methods estimates the evaporation based on the climatic conditions of each region. For this reason, calibration of the relationship between evaporation estimates in different regions are required (Vanzyl et al., 1989). experimental methods are common in engineering sciences. Most scholars, by modifying experimental methods and discovering new relationships, try to find a simple and high-level relationship to replace with the field methods. More than 50 experimental relationships have been proposed for estimating evapotranspiration by various researchers (Naorem and Devi, 2014). Despite the importance of evaporation in hydrology, less attention has been paid to it. However, with the correct estimation, it can be applied in water resource planning with fewer errors (Saadatkhah et al., 2002).In this research, the experimental methods of Mayer, Marciano, Shahthin, Henfer, Ivanov and USBR have been used to study the evaporation from the free surface of the Choghakhor lake, located in Chaharmahal and Bakhtiari province of Iran. The results have been compared with actual evaporation values from the free surface

    Predicting students' performance using machine learning algorithms and educational data mining (a case study of Shahed University)

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    The purpose of this research is to investigate the effective factors in predicting the academic performance of undergraduate students in the classification of four classes. To achieve this goal, the study follows the CRISP data mining method. The data set was extracted from the NAD educational system for the bachelor's degree in Shahed University for the entry of the years 2011 to 2021. 1468 records were used in data mining. First, the effective features on students' academic performance were extracted. Modeling was done using Rapidminer9.9 tool. To improve classification performance and satisfactory prediction accuracy, we use a combination of principal component analysis combined with machine learning algorithms and feature selection techniques and optimization algorithms. The performance of the prediction models is verified using 10-fold cross-validation. The results showed that the decision tree algorithm is the best algorithm in predicting students' performance with an accuracy of 84.71%. This algorithm correctly predicted the graduation of 77.88% of excellent students, 85.26% of good students, 84.69% of medium students, and 85.96% of weak students based on the final GPA

    Assessment of Toxoplasma Seropositivity in Children Suffering from Attention Deficit Hyperactivity Disorder

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    peer reviewedBackground: Toxoplasmosis, a protozoan infection caused by Toxoplasma gondii, is suggested to be a risk factor for many psychological disorders such as schizophrenia and depression. Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders among children. Previous studies have assessed the correlation between ADHD and infectious diseases like toxoplasmosis. So we aimed to investigate the possible correlation between Toxoplasma seropositivity and ADHD in children. Materials and Methods: In this cross-sectional study children with signs of ADHD were regarded as patients and underwent clinical assessments. Diagnosis of these patients was based on DSM-IV-TR system which was performed by a pediatric psychiatrist. Forty-eight Children without signs of ADHD or other psychic disorders were considered as control, and 48 patients were considered as case group. Parents were asked to answer a questionnaire including demographic, pregnancy and habitual questions. Blood samples were taken from all individuals and assessed for anti-Toxoplasma IgM and IgG antibodies. Results: Ninety-six male and female patients with a mean age of 8.12 years underwent analysis. Seropositivity rate for anti-T.gondii IgG antibody was 4.2% in the case and 2.1% in control individuals (P=0.92). Anti-T.gondii IgM antibodies were not found in control individuals while it was found in 2.1% of case individuals (P=0.74). There was no statistically significant association between seroprevalence of IgM (P=0.74) and IgG (P=0.92) antibodies and ADHD in study individuals. Conclusion: Our findings showed that the toxoplasmosis seropositivity has no significant difference between children with and without ADHD. Further studies are needed with a larger amount of individuals. [GMJ. 2016;5(4):188-93

    The global, regional, and national burden of stomach cancer in 195 countries, 1990-2017 : a systematic analysis for the Global Burden of Disease study 2017

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    Background: Stomach cancer is a major health problem in many countries. Understanding the current burden of stomach cancer and the differential trends across various locations is essential for formulating effective preventive strategies. We report on the incidence, mortality, and disability-adjusted life-years (DALYs) due to stomach cancer in 195 countries and territories from 21 regions between 1990 and 2017. Methods: Estimates from GBD 2017 were used to analyse the incidence, mortality, and DALYs due to stomach cancer at the global, regional, and national levels. The rates were standardised to the GBD world population and reported per 100 000 population as age-standardised incidence rates, age-standardised death rates, and age-standardised DALY rates. All estimates were generated with 95% uncertainty intervals (UIs). Findings: In 2017, more than 1·22 million (95% UI 1·19–1·25) incident cases of stomach cancer occurred worldwide, and nearly 865 000 people (848 000–885 000) died of stomach cancer, contributing to 19·1 million (18·7–19·6) DALYs. The highest age-standardised incidence rates in 2017 were seen in the high-income Asia Pacific (29·5, 28·2–31·0 per 100 000 population) and east Asia (28·6, 27·3–30·0 per 100 000 population) regions, with nearly half of the global incident cases occurring in China. Compared with 1990, in 2017 more than 356 000 more incident cases of stomach cancer were estimated, leading to nearly 96 000 more deaths. Despite the increase in absolute numbers, the worldwide age-standardised rates of stomach cancer (incidence, deaths, and DALYs) have declined since 1990. The drop in the disease burden was associated with improved Socio-demographic Index. Globally, 38·2% (21·1–57·8) of the age-standardised DALYs were attributable to high-sodium diet in both sexes combined, and 24·5% (20·0–28·9) of the age-standardised DALYs were attributable to smoking in males. Interpretation: Our findings provide insight into the changing burden of stomach cancer, which is useful in planning local strategies and monitoring their progress. To this end, specific local strategies should be tailored to each country's risk factor profile. Beyond the current decline in age-standardised incidence and death rates, a decrease in the absolute number of cases and deaths will be possible if the burden in east Asia, where currently almost half of the incident cases and deaths occur, is further reduced. Funding: Bill & Melinda Gates Foundation

    Global, regional and national burden of bladder cancer and its attributable risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease study 2019

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    Introduction The current study determined the level and trends associated with the incidence, death and disability rates for bladder cancer and its attributable risk factors in 204 countries and territories, from 1990 to 2019, by age, sex and sociodemographic index (SDI; a composite measure of sociodemographic factors). Methods Various data sources from different countries, including vital registration and cancer registries were used to generate estimates. Mortality data and incidence data transformed to mortality estimates using the mortality to incidence ratio (MIR) were used in a cause of death ensemble model to estimate mortality. Mortality estimates were divided by the MIR to produce incidence estimates. Prevalence was calculated using incidence and MIR-based survival estimates. Age-specific mortality and standardised life expectancy were used to estimate years of life lost (YLLs). Prevalence was multiplied by disability weights to estimate years lived with disability (YLDs), while disability-adjusted life years (DALYs) are the sum of the YLLs and YLDs. All estimates were presented as counts and age-standardised rates per 100 000 population. Results Globally, there were 524 000 bladder cancer incident cases (95% uncertainty interval 476 000 to 569 000) and 229 000 bladder cancer deaths (211 000 to 243 000) in 2019. Age-standardised death rate decreased by 15.7% (8.6 to 21.0), during the period 1990–2019. Bladder cancer accounted for 4.39 million (4.09 to 4.70) DALYs in 2019, and the age-standardised DALY rate decreased significantly by 18.6% (11.2 to 24.3) during the period 1990–2019. In 2019, Monaco had the highest age-standardised incidence rate (31.9 cases (23.3 to 56.9) per 100 000), while Lebanon had the highest age-standardised death rate (10.4 (8.1 to 13.7)). Cabo Verde had the highest increase in age-standardised incidence (284.2% (214.1 to 362.8)) and death rates (190.3% (139.3 to 251.1)) between 1990 and 2019. In 2019, the global age-standardised incidence and death rates were higher among males than females, across all age groups and peaked in the 95+ age group. Globally, 36.8% (28.5 to 44.0) of bladder cancer DALYs were attributable to smoking, more so in males than females (43.7% (34.0 to 51.8) vs 15.2% (10.9 to 19.4)). In addition, 9.1% (1.9 to 19.6) of the DALYs were attributable to elevated fasting plasma glucose (FPG) (males 9.3% (1.6 to 20.9); females 8.4% (1.6 to 19.1)). Conclusions There was considerable variation in the burden of bladder cancer between countries during the period 1990–2019. Although there was a clear global decrease in the age-standardised death, and DALY rates, some countries experienced an increase in these rates. National policy makers should learn from these differences, and allocate resources for preventative measures, based on their country-specific estimates. In addition, smoking and elevated FPG play an important role in the burden of bladder cancer and need to be addressed with prevention programmes.publishedVersio

    Burden of cancer in the Eastern Mediterranean Region, 2005-2015: findings from the Global Burden of Disease 2015 Study

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    Fitzmaurice C, Alsharif U, El Bcheraoui C, et al. Burden of cancer in the Eastern Mediterranean Region, 2005-2015: findings from the Global Burden of Disease 2015 Study. INTERNATIONAL JOURNAL OF PUBLIC HEALTH. 2018;63(Suppl. 1):151-164.To estimate incidence, mortality, and disability-adjusted life years (DALYs) caused by cancer in the Eastern Mediterranean Region (EMR) between 2005 and 2015. Vital registration system and cancer registry data from the EMR region were analyzed for 29 cancer groups in 22 EMR countries using the Global Burden of Disease Study 2015 methodology. In 2015, cancer was responsible for 9.4% of all deaths and 5.1% of all DALYs. It accounted for 722,646 new cases, 379,093 deaths, and 11.7 million DALYs. Between 2005 and 2015, incident cases increased by 46%, deaths by 33%, and DALYs by 31%. The increase in cancer incidence was largely driven by population growth and population aging. Breast cancer, lung cancer, and leukemia were the most common cancers, while lung, breast, and stomach cancers caused most cancer deaths. Cancer is responsible for a substantial disease burden in the EMR, which is increasing. There is an urgent need to expand cancer prevention, screening, and awareness programs in EMR countries as well as to improve diagnosis, treatment, and palliative care services

    Trends in HIV/AIDS morbidity and mortality in Eastern 3 Mediterranean countries, 1990–2015: findings from the Global 4 Burden of Disease 2015 study

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    Objectives We used the results of the Global Burden of Disease 2015 study to estimate trends of HIV/AIDS burden in Eastern Mediterranean Region (EMR) countries between 1990 and 2015. Methods Tailored estimation methods were used to produce final estimates of mortality. Years of life lost (YLLs) were calculated by multiplying the mortality rate by population by age-specific life expectancy. Years lived with disability (YLDs) were computed as the prevalence of a sequela multiplied by its disability weight. Results In 2015, the rate of HIV/AIDS deaths in the EMR was 1.8 (1.4–2.5) per 100,000 population, a 43% increase from 1990 (0.3; 0.2–0.8). Consequently, the rate of YLLs due to HIV/AIDS increased from 15.3 (7.6–36.2) per 100,000 in 1990 to 81.9 (65.3–114.4) in 2015. The rate of YLDs increased from 1.3 (0.6–3.1) in 1990 to 4.4 (2.7–6.6) in 2015. Conclusions HIV/AIDS morbidity and mortality increased in the EMR since 1990. To reverse this trend and achieve epidemic control, EMR countries should strengthen HIV surveillance,and scale up HIV antiretroviral therapy and comprehensive prevention services

    Burden of cardiovascular diseases in the Eastern Mediterranean Region, 1990-2015 : findings from the Global Burden of Disease 2015 study

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    To report the burden of cardiovascular diseases (CVD) in the Eastern Mediterranean Region (EMR) during 1990-2015. We used the 2015 Global Burden of Disease study for estimates of mortality and disability-adjusted life years (DALYs) of different CVD in 22 countries of EMR. A total of 1.4 million CVD deaths (95% UI: 1.3-1.5) occurred in 2015 in the EMR, with the highest number of deaths in Pakistan (465,116) and the lowest number of deaths in Qatar (723). The age-standardized DALY rate per 100,000 decreased from 10,080 in 1990 to 8606 in 2015 (14.6% decrease). Afghanistan had the highest age-standardized DALY rate of CVD in both 1990 and 2015. Kuwait and Qatar had the lowest age-standardized DALY rates of CVD in 1990 and 2015, respectively. High blood pressure, high total cholesterol, and high body mass index were the leading risk factors for CVD. The age-standardized DALY rates in the EMR are considerably higher than the global average. These findings call for a comprehensive approach to prevent and control the burden of CVD in the region.Peer reviewe
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