40 research outputs found

    Security challenges in mobile assisted language learning in the millennium for education

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    Distance learning technologies enrich learning opportunities due to many advantages like ubiquity and flexibility. Although the usefulness of such technologies in teaching and learning is clear, their testing part is remained to be discussed due to the security issue. Administrators and teachers need to use more authentic and secure distant testing software in which the scores are guaranteed and the testees keep away from cheating. Static and online authentication systems like “username” and “password” and face detection have empowered educational parties to have more reliable testing outcomes. Mobile devices as the necessity of the new millennium need to use authentication software in their testing. Mobile devices with their multimedia course materials provide learners with many optimistic learning opportunities through collaboration, cooperation, interaction and testing. The unique chances of ubiquity, individualization, informality, and spontaneity make the mobile learning of particular importance not only for digital natives but also for teachers, administrators, developers, instructors, and policy makers. Yielding an economical learning opportunity along with providing authentic contexts for collaborative learning is beneficial for the economy of the country in general an d for the meaningful and deep learning of the learners. This paper will discuss how authentication techniques have applied to electronic devices like mobile phones

    The Effect of Agency Costs on the Speed of Stock Price Adjustment: Evidence of Tehran Stock Exchange

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    The investigation of the effects of agency costs on the firms’ performance and investors’ decision is very important. The purpose of this study is to evaluate the effect of agency costs on the speediness of stock price adjustment. To measure the agency costs, three variables of the ratios of operating costs to sales, asset turnover, and the interaction between growth opportunities and free cash flows were used and to measure the speed of stock price adjustment, Hou and Moskowitz method was applied. The population of this research consists of firms listed in Tehran Stock Exchange. The study used data from the years 2008 to 2014 for 130 companies. To analyze the data and test the hypothesis, correlation and regression method is used. The results indicate that the ratio of operating costs to sales significantly affect the speed of stock price adjustment. However, no significant effect of the asset turnover and the interaction between growth opportunities and free cash flows on the speediness of stock price adjustment was seen

    Influence of Different Land Uses on Some Soil Microbial Indices (Case Study: Lasjerd, Semnan Province, Iran)

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    IntroductionWidespread lands in arid, semi-arid, or dry sub-humid areas of the world have been influenced by the consequences of the land degradation resulting from natural factors and human activities like agriculture, changes in the land use. A large part of Iran is located in arid and semi-arid regions. The degradation of soil can be greatly impacted by agricultural activities, incorrect management, and improper land management. The most suitable solution to reduce the negative effects of land use change on the desert is to choose the best type of land management with the least degradation. The fragile nature of these ecosystems and the large area of arid and semi-arid areas of the country require proper and accurate management. Soil is an important and valuable terrestrial source of OC storage, which plays a significant role in the global C cycle by storing about 1500 billion tons of C. The total C in microbial biomass is 1.4% of the total SOC. demonstrating the significant contribution of this sector to the global C cycle. Land use change can be one of the most important factors of land degradation that affects the quality and quantity of soil organic C, and soil characteristics. The present study was done to investigate the role of different land uses including rangeland as control, abandoned land, Triticum aestivum L. cultivation, Hordeum vulgare L. cultivated lands and Medicago sativa L. cultivation, on some soil microbial indices such as basal soil respiration, substrate induced respiration, microbial biomass carbon, microbial biomass nitrogen, microbial quotient, metabolic coefficient and carbon access index, in Lasjerd , Semnan province in two depths  of 0 to 10 cm and 10 to 30 cm. Material and MethodsThe initial step was to select various treatments that included rangeland as control treatment, abandoned land, Triticum aestivum cultivation, Hordeum vulgare cultivated lands and Medicago sativa cultivation. In the second step, soil sampling was performed at two depths of 0-10 and 10-30 cm in five replications. In this regard, one soil profile in the center and four other profiles were dug in the form of a cross, considering the marginal effect. The samples needed for soil biological tests were carried and stored in the refrigerator containing dry ice and biological tests were performed later. The considered factors were measured by valid scientific guidelines and methods. Data related to soil microbial properties were analyzed by a factorial test in the form of a completely random design with five repetitions. All statistical computing was done using SPSS 19 software and the mean comparison tests were performed by Duncan test. Results and DiscussionThe results of the present study indicated that there is significant impact of the treatments on the properties studied at the two depths, at the first soil layer equals to the depth of 0 to 10 cm, basal soil respiration, substrate induced respiration, microbial biomass carbon, microbial biomass nitrogen, microbial quotient, and metabolic coefficient have been affected by different land uses, as the highest level of basal soil respiration in the abandoned land equals to 0.424 mgCO2g-1dm24h-1 and the lowest in Triticum aestivum cultivation 0.006 mgCO2g-1dm24h-1, as well as the second depth- 10 to 30 cm- basal soil respiration, microbial quotient, metabolic coefficient are affected by different types of land uses. The highest amount of metabolic coefficient was observed in abandoned lands as 0.068 mgCO2-Cg-1MBCday-1 and the lowest was found in Medicago sativa cultivation lands equals to 0.013 mgCO2-Cg-1MBCday-1. Soil microbial indices are sensitive to land use changes. The first top 10 cm of the soil studied, has been most affected by these indices.Due to the failure of soil pedons, the change in land use from rangeland to agricultural lands increases the speed of litter decomposition and decreases the storage of soil nutrients, the microbial population, composition and activity of the soil as an indicator of soil quality, health and fertility. But techniques of no-tillage or minimal-tillage, as well as the principles of sustainable agriculture (such as returning the residues to the soil, proper use of chemical fertilizers, using biological fertilizers, and biological control of pests) cause the destructive process of the biological indices to be adjusted and get balanced in a shorter time period with environment. Considering the changes in the biological indicators of the soil, which have caused the destruction of the cultivated lands in the studied area, it is suggested to rehabilitate the bare lands with native rangeland species of the region, such as Artemisia sieberi Besser, Zygophyllum eurypterum Boiss. & Buhse, and Astragalus tribuloides Delile. Range management plans are the only way to allocate rangelands in the region, and a detailed survey of rangelands in the region is necessary. To prevent land use change, it is important to address the multi-purpose uses of rangelands and the determination of economic units to support the lives of beneficiary households

    The Impacts of Financial Structure on Financial Performance of Banks listed in Tehran Stock Exchange: An Empirical Application

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    Financial structure is a combination of debt and equity and regards as one of the most important issues in banking industry. The purpose of financial structure decision is to create an appropriate combination of financing resources to minimize the cost of capital and thus maximize the company's market value. This study investigates the impacts of banks financial structure on their Returns (ROA and ROE). In addition, it investigates the moderating roles of corporate governance, financial constraints, capital intensity and size. This research is an applied descriptive correlational research. To test the hypotheses, unbalanced panel data is used. The financial data extracted from “Rah Avarde Novin" software and the database of "Tadbir Pardaz" company. The statistical population includes all banks listed on Tehran Stock Exchange during the years 2009 to 2016. The results indicate a positive significant impacts of financial structure and the banks’ ROA and ROE. Moreover, the results show that capital intensity and the size significantly moderate the relation between financial structure with ROA and ROE

    Antibiotic resistance in patients suffering from nosocomial infections in Besat Hospital

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    This study was performed to determine the trend of antibiotic resistance of the causative organisms among the patients suffering from nosocomial infections in Besat Hospital since 2013 to 2015.In this observational study that was performed as a retrospective cohort, 935 consecutive patients with nosocomial infection were enrolled in Besat Hospital since 2013 to 2015. The trend of antibiotic resistance of the causative organisms among them was determined and contributing factors were assessed. The finding of this study revealed that type of microorganisms had significant variation (p = 0.024): while the gram-negative bacilli have shown an increased level of resistance, the gram positive cocci had less resistance. The antibiotic resistance was increased for ampicillin/sulbactam, piperacillin/tazoactam, ceftriaxone, ceftazidime, cefepime, meropenem, gentamicin, amikacin, ciprofloxacine, levofloxacine, nitrofurantoin, and ampicilline. However, it was decreased for colistin. It may be concluded that antibiotic resistance has an increasing trend and that strategic measures of prevention are needed to reduce nosocomial infections

    Effect of ESS on Olfactory Threshold of Patients with CRS without Nasal Polyps.

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    peer reviewed[en] OBJECTIVES: Chronic rhinosinusitis (CRS) is characterized by a long-time inflammatory disease of nasal and sinus mucosa. Olfactory dysfunction is common among CRS patients with a prevalence ranging from 48% to 83%. We aimed to assess the effect of ESS on olfactory function of patients with chronic rhinosinusitis without nasal polyps. METHOD: This randomized clinical trial was conducted on 30 patients with chronic rhinosinusitis without nasal polyps. Patients were randomly allocated to two intervention and control groups; patients in intervention group underwent endoscopic sinus surgery by a single surgeon and control group continued standard treatment with nasal irrigation of normal saline (4 times daily) and nasal corticosteroids (one puff in each nostril daily). Olfactory threshold was evaluated using smell threshold test (STT) before, one month and three months after intervention. RESULTS: Eventually 33 patients with a mean age of 42.70 ± 15.50 years in intervention and 43.12 ± 11.50 years in control group underwent analysis (p value=0.930). Mean olfactory threshold was 2.79 ± 0.73 in intervention and 2.67 ± 1.05 in control group prior to intervention (p value=0.345). Mean change of olfactory threshold was 0.30 ± 0.79 in intervention and 0.38±1.09 in control group one month after intervention (p value=0.214). Mean change of olfactory threshold was 0.13 ± 0.94 in ESS and 0.33 ± 0.60 in control group three months after intervention (p value=0.196). CONCLUSION: Our study revealed that changes in olfactory threshold were not significantly different between two ESS and standard medical therapy groups one and three months after intervention

    The comprehensive study of possibility ecological control Mnemiopsis leidyi in Caspian Sea activity: The study and recognization parasitic fauna and Bacterial flore in ctenophore (Mnemiopsis leidyi and Bereo ovata)

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    Bacterial flora and parasitic fauna of M. leidyi an exotic invader jelly fish to Caspian Sea ecosystem and B. ovata to Black sea an alternative biological control agent was studied. During summer 1382 to spring 1383, using routine Bacteriological work. 72 sample of sea water Caspian Sea obtained from depth 20 and 50 meters, 36 sample of M. leidyi from depth 20 meters, 10 sample of B. ovata and 3 sample of sea water (Black sea) were collected and according to Bacteriological was studied. 216 sample of M. leidyi from depth 10 to 50 meters of Caspian Sea and 47 sample of B. ovata from Black and Marmarreh Sea (Turkey) were collected and was studied. In this study no parasite from was identified in M. leidyi (Caspian sea) but 64 percentage and 73 percentage of B. ovata (Marmarreh and Black sea respectively) contaminated to Trichodina ctenophore at varians concentration B. ovata of Black sea (130 min 1050 max) and B. ovata Marmarre sea (420 min 2100 max). While B. ovata kept at high salinity of 21 ppt was more contaminated with this pretrichial protozoan (Trichodina) than in low salinity (12/5 ppt). in comparision of bacterial flore in two cetenophore (M. leidyi and B. ovata) was observed that some of bacteria such as micrococcus sp, Aeromonas sp. Bacillus coagulans in both ctenophore and some other bacteria such as Agromobacterium and chromobacterium only observed in B. ovata but other researcher have reported fram Caspin sea and some of bacteria to specific Shewanella , Vibrio harveiy and bacillus linens was observed in B. ovata . Of course specific bacteria cannot transfer to Caspian Sea (different of salinity black sea (2/1%) to Caspian Sea (1/25 %)). Therefore if B. ovata to introduce to south Caspian Sea for biological control population M. leidyi. it is necessary at first some of viral pathogen in aquatic animal (fish) such as VNN, IPN,IHN,VHS,SVC was studied and then with confidence 95% non-infestation B. ovata to viruses and pass from bath anti parasite and anti-bacterial must be introduce to south Caspian sea

    National, sub-national, and risk-attributed burden of thyroid cancer in Iran from 1990 to 2019

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    An updated exploration of the burden of thyroid cancer across a country is always required for making correct decisions. The objective of this study is to present the thyroid cancer burden and attributed burden to the high Body Mass Index (BMI) in Iran at national and sub-national levels from 1990 to 2019. The data was obtained from the GBD 2019 study estimates. To explain the pattern of changes in incidence from 1990 to 2019, decomposition analysis was conducted. Besides, the attribution of high BMI in the thyroid cancer DALYs and deaths were obtained. The age-standardized incidence rate of thyroid cancer was 1.57 (95% UI: 1.33–1.86) in 1990 and increased 131% (53–191) until 2019. The age-standardized prevalence rate of thyroid cancer was 30.19 (18.75–34.55) in 2019 which increased 164% (77–246) from 11.44 (9.38–13.85) in 1990. In 2019, the death rate, and Disability-adjusted life years of thyroid cancer was 0.49 (0.36–0.53), and 13.16 (8.93–14.62), respectively. These numbers also increased since 1990. The DALYs and deaths attributable to high BMI was 1.91 (0.95–3.11) and 0.07 (0.04–0.11), respectively. The thyroid cancer burden and high BMI attributed burden has increased from 1990 to 2019 in Iran. This study and similar studies’ results can be used for accurate resource allocation for efficient management and all potential risks’ modification for thyroid cancer with a cost-conscious view

    Health in times of uncertainty in the eastern Mediterranean region, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013

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    Background: The eastern Mediterranean region is comprised of 22 countries: Afghanistan, Bahrain, Djibouti, Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Morocco, Oman, Pakistan, Palestine, Qatar, Saudi Arabia, Somalia, Sudan, Syria, Tunisia, the United Arab Emirates, and Yemen. Since our Global Burden of Disease Study 2010 (GBD 2010), the region has faced unrest as a result of revolutions, wars, and the so-called Arab uprisings. The objective of this study was to present the burden of diseases, injuries, and risk factors in the eastern Mediterranean region as of 2013. Methods: GBD 2013 includes an annual assessment covering 188 countries from 1990 to 2013. The study covers 306 diseases and injuries, 1233 sequelae, and 79 risk factors. Our GBD 2013 analyses included the addition of new data through updated systematic reviews and through the contribution of unpublished data sources from collaborators, an updated version of modelling software, and several improvements in our methods. In this systematic analysis, we use data from GBD 2013 to analyse the burden of disease and injuries in the eastern Mediterranean region specifically. Findings: The leading cause of death in the region in 2013 was ischaemic heart disease (90·3 deaths per 100 000 people), which increased by 17·2% since 1990. However, diarrhoeal diseases were the leading cause of death in Somalia (186·7 deaths per 100 000 people) in 2013, which decreased by 26·9% since 1990. The leading cause of disability-adjusted life-years (DALYs) was ischaemic heart disease for males and lower respiratory infection for females. High blood pressure was the leading risk factor for DALYs in 2013, with an increase of 83·3% since 1990. Risk factors for DALYs varied by country. In low-income countries, childhood wasting was the leading cause of DALYs in Afghanistan, Somalia, and Yemen, whereas unsafe sex was the leading cause in Djibouti. Non-communicable risk factors were the leading cause of DALYs in high-income and middle-income countries in the region. DALY risk factors varied by age, with child and maternal malnutrition affecting the younger age groups (aged 28 days to 4 years), whereas high bodyweight and systolic blood pressure affected older people (aged 60–80 years). The proportion of DALYs attributed to high body-mass index increased from 3·7% to 7·5% between 1990 and 2013. Burden of mental health problems and drug use increased. Most increases in DALYs, especially from non-communicable diseases, were due to population growth. The crises in Egypt, Yemen, Libya, and Syria have resulted in a reduction in life expectancy; life expectancy in Syria would have been 5 years higher than that recorded for females and 6 years higher for males had the crisis not occurred. Interpretation: Our study shows that the eastern Mediterranean region is going through a crucial health phase. The Arab uprisings and the wars that followed, coupled with ageing and population growth, will have a major impact on the region's health and resources. The region has historically seen improvements in life expectancy and other health indicators, even under stress. However, the current situation will cause deteriorating health conditions for many countries and for many years and will have an impact on the region and the rest of the world. Based on our findings, we call for increased investment in health in the region in addition to reducing the conflicts

    Global, regional, and national incidence and mortality for HIV, tuberculosis, and malaria during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013

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    BACKGROUND: The Millennium Declaration in 2000 brought special global attention to HIV, tuberculosis, and malaria through the formulation of Millennium Development Goal (MDG) 6. The Global Burden of Disease 2013 study provides a consistent and comprehensive approach to disease estimation for between 1990 and 2013, and an opportunity to assess whether accelerated progress has occured since the Millennium Declaration. METHODS: To estimate incidence and mortality for HIV, we used the UNAIDS Spectrum model appropriately modified based on a systematic review of available studies of mortality with and without antiretroviral therapy (ART). For concentrated epidemics, we calibrated Spectrum models to fit vital registration data corrected for misclassification of HIV deaths. In generalised epidemics, we minimised a loss function to select epidemic curves most consistent with prevalence data and demographic data for all-cause mortality. We analysed counterfactual scenarios for HIV to assess years of life saved through prevention of mother-to-child transmission (PMTCT) and ART. For tuberculosis, we analysed vital registration and verbal autopsy data to estimate mortality using cause of death ensemble modelling. We analysed data for corrected case-notifications, expert opinions on the case-detection rate, prevalence surveys, and estimated cause-specific mortality using Bayesian meta-regression to generate consistent trends in all parameters. We analysed malaria mortality and incidence using an updated cause of death database, a systematic analysis of verbal autopsy validation studies for malaria, and recent studies (2010-13) of incidence, drug resistance, and coverage of insecticide-treated bednets. FINDINGS: Globally in 2013, there were 1·8 million new HIV infections (95% uncertainty interval 1·7 million to 2·1 million), 29·2 million prevalent HIV cases (28·1 to 31·7), and 1·3 million HIV deaths (1·3 to 1·5). At the peak of the epidemic in 2005, HIV caused 1·7 million deaths (1·6 million to 1·9 million). Concentrated epidemics in Latin America and eastern Europe are substantially smaller than previously estimated. Through interventions including PMTCT and ART, 19·1 million life-years (16·6 million to 21·5 million) have been saved, 70·3% (65·4 to 76·1) in developing countries. From 2000 to 2011, the ratio of development assistance for health for HIV to years of life saved through intervention was US$4498 in developing countries. Including in HIV-positive individuals, all-form tuberculosis incidence was 7·5 million (7·4 million to 7·7 million), prevalence was 11·9 million (11·6 million to 12·2 million), and number of deaths was 1·4 million (1·3 million to 1·5 million) in 2013. In the same year and in only individuals who were HIV-negative, all-form tuberculosis incidence was 7·1 million (6·9 million to 7·3 million), prevalence was 11·2 million (10·8 million to 11·6 million), and number of deaths was 1·3 million (1·2 million to 1·4 million). Annualised rates of change (ARC) for incidence, prevalence, and death became negative after 2000. Tuberculosis in HIV-negative individuals disproportionately occurs in men and boys (versus women and girls); 64·0% of cases (63·6 to 64·3) and 64·7% of deaths (60·8 to 70·3). Globally, malaria cases and deaths grew rapidly from 1990 reaching a peak of 232 million cases (143 million to 387 million) in 2003 and 1·2 million deaths (1·1 million to 1·4 million) in 2004. Since 2004, child deaths from malaria in sub-Saharan Africa have decreased by 31·5% (15·7 to 44·1). Outside of Africa, malaria mortality has been steadily decreasing since 1990. INTERPRETATION: Our estimates of the number of people living with HIV are 18·7% smaller than UNAIDS's estimates in 2012. The number of people living with malaria is larger than estimated by WHO. The number of people living with HIV, tuberculosis, or malaria have all decreased since 2000. At the global level, upward trends for malaria and HIV deaths have been reversed and declines in tuberculosis deaths have accelerated. 101 countries (74 of which are developing) still have increasing HIV incidence. Substantial progress since the Millennium Declaration is an encouraging sign of the effect of global action. FUNDING: Bill & Melinda Gates Foundation
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