195 research outputs found
MARKOV CHAIN MODEL FOR PROBABILITY OF DRY, WET DAYS AND STATISTICAL ANALISIS OF DAILY RAINFALL IN SOME CLIMATIC ZONE OF IRAN
Water scarcity is a major problem in arid and semi-arid areas. The scarcity of water is further stressed by the growing demand due to increase in population growth in developing countries. Climate change and its outcomes on precipitation and water resources is the other problem in these areas. Several models are widely used for modeling daily precipitation occurrence. In this study, Markov Chain Model has been extensively used to study spell distribution. For this purpose, a day period was considered as the optimum length of time. Given the assumption that the Markov chain model is the right model for daily precipitation occurrence, the choice of Markov model order was examined on a daily basis for 4 synoptic weather stations with different climates in Iran (Gorgan, Khorram Abad, Zahedan, Tabriz)during 1978-2009. Based on probability rules, events possibility of sequential dry and wet days, these data were analyzed by stochastic process and Markov Chain method. Then probability matrix was calculated by maximum likelihood method. The possibility continuing2-5days of dry and wet days were calculated. The results showed that the probability maximum of consecutive dry period and climatic probability of dry days has occurred in Zahedan. The probability of consecutive dry period has fluctuated from 73.3 to 100 percent. Climatic probability of occurrence of dry days would change in the range of 70.96 to 100 percent with the average probability of about 90.45 percent
Novel 5-oxo-hexahydroquinoline derivatives: design, synthesis, in vitro P-glycoprotein-mediated multidrug resistance reversal profile and molecular dynamics simulation study
Overexpression of the efflux pump P-glycoprotein (P-gp) is one of the important mechanisms of multidrug resistance (MDR) in many tumor cells. In this study, 26 novel 5-oxo-hexahydroquinoline derivatives containing different nitrophenyl moieties at C-4 and various carboxamide substituents at C-3 were designed, synthesized and evaluated for their ability to inhibit P-gp by measuring the amount of rhodamine 123 (Rh123) accumulation in uterine sarcoma cells that overexpress P-gp (MES-SA/Dx5) using flow cytometry. The effect of compounds with highest MDR reversal activities was further evaluated by measuring the alterations of MES-SA/Dx5 cells' sensitivity to doxorubicin (DXR) using MTT assay. The results of both biological assays indicated that compounds bearing 2-nitrophenyl at C-4 position and compounds with 4-chlorophenyl carboxamide at C-3 demonstrated the highest activities in resistant cells, while they were devoid of any effect in parental nonresistant MES-SA cells. One of the active derivatives, 5c, significantly increased intracellular Rh123 at 100 mu M, and it also significantly reduced the IC50 of DXR by 70.1% and 88.7% at 10 and 25 mu M, respectively, in MES-SA/Dx5 cells. The toxicity of synthesized compounds against HEK293 as a noncancer cell line was also investigated. All tested derivatives except for 2c compound showed no cytotoxicity. A molecular dynamics simulation study was also performed to investigate the possible binding site of 5c in complex with human P-gp, which showed that this compound formed 11 average H-bonds with Ser909, Thr911, Arg547, Arg543 and Ser474 residues of P-gp. A good agreement was found between the results of the computational and experimental studies. The findings of this study show that some 5-oxo-hexahydroquinoline derivatives could serve as promising candidates for the discovery of new agents for P-gp-mediated MDR reversal
Challenges toward Sustainability? Experiences and Approaches to Literary Tourism from Iran
Interdisciplinary narrative studies are of great importance in several disciplines, especially in the humanities and social sciences. Cultural tourism and its sub-disciplines, including the complex issue of ‘literary tourism’, is an interdisciplinary field of investigation, positioned in between geography and urban–rural studies. In Iran, this form of tourism has been neglected so far—with no distinction between urban and rural areas—despite a particularly rich literary heritage. The present study recognizes the challenge of literary tourism in Iran, delineating some possible actions to develop it as a future engine of economic growth, especially in rural districts. As a contribution to a refined comprehension of literary tourism development paths, a content analysis was run collecting views and textual data on literary tourism in Iran. The empirical results of this study indicate that the mentioned challenges can be classified into several main dimensions and a broader set of sub-themes. The possible actions responding to such challenges can be classified into more dimensions and a vast number of sub-themes. Actions reducing territorial disparities and fueling entrepreneurship in local communities are appropriate to stimulate the emergence (and, possibly, consolidation) of literary tourism districts in Iran, giving an original contribution to sustainable development especially—but not exclusively—in rural settlements
Factors underlying life quality in urban contexts: Evidence from an industrial city (arak, iran)
Cities play a vital role in local development providing a high education level, specialized jobs and advanced services. When assessing living conditions and wellbeing in cities, economic indicators alone are generally unable to evaluate the inherent complexity of the 'quality of life' issue in urban environments. With rapid urbanization, shortage of infrastructures and services emerged in metropolitan regions of developing countries, leading to disadvantaged settlements, urban poverty, lower citizens' satisfaction, and an overall decline in life quality. Based on these premises, the present study illustrates a subjective investigation of life quality in an emerging economy such as Iran, focusing on Arak, the fourth largest industrial pole of the country. Based on a literature review on quality of life in industrial cities of emerging economies, subjective indicators of citizens' satisfaction on living quality in Arak were identified and quantified using empirical results from a field survey. Results of our study show that the overall satisfaction for living quality in Arak is rather low, reaching the lowest rank in the issues of environmental sanitation and public transportation. Lack of investments in urban infrastructure justifies the low citizens' perception of life quality in Arak city. The paper concludes outlining the urgent need of homogeneous and comparable macro-and micro-data on multiple aspects of quality of life at both city-level and metropolitan-level in emerging economies
Effects of probiotic (Pediococcus acidilactici) on growth and survival of kutum (Rutilus kutum) fingerlings
In the present study effects of different levels of probiotic Pediococcus acidilactici, on growth performance and survival rate of Rutilus kutum fingerlings were investigated. Kutum fingerlings with a mean weight of 1±0.235 g were reared for 8 weeks in 500-l fiberglass tanks (15 fish per tank) with 4 diet treatments (3 replicates for each). Treatments included 1×10^9, 2:1×10^9, 3×10^9 CFU kg^-1 dry food and a control without probiotic. At the end of the study, specific growth rate (SGR) and survival rate (SR) were significantly higher in treatments supplemented with probiotic compared to the control (p<0.05), while the fish fed with probiotics showed lowest food conversion ratio (FCR) (p<0.05). The results indicated that the use of 3× 109 CFU kg^-1 dry food probiotics improved growth parameters and survival rate in R. kutum fingerlings
Effective low-cost pediatric vision screening by naive nonophthalmic examiners using the 'Arclight' device
Purpose: To explore whether a low-cost ophthalmoscope (Arclight) can be used by naive nonophthalmic examiners to effectively screen for pediatric eye disease. Methods: Fifty-four children (108 eyes) were examined by five medical students using an Arclight. Gold standard examination was performed by an ophthalmologist using a slit lamp and indirect ophthalmoscope. Examinations performed included ophthalmoscopy of the optic disc, estimation of the cup-to-disc ratio (CDR), corneal light reflex test (CRT), Bruckner’s reflex test (BRT), and evaluation of refractive error. We determined the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the nonophthalmologist’s Arclight exam compared to the gold standard findings of comprehensive evaluation by pediatric ophthalmologists. Results: Using the Arclight, the optic nerve exam was successfully completed in 65% of patients. CDRs above and below 0.5 could be determined with 66.7% sensitivity and 84.4% specificity. Arclight CRT measurements were significant (P < .00001) predictors of strabismus, with 80% sensitivity, 95.1%, specificity, 80% PPV, and 95.1% NPV. BRT was not a significant predictor of amblyopia, with a 34.6% sensitivity, 85.7% specificity, 69.2% PPV, and 58.5% NPV. Refractive error was estimated with a success rate of 81% for emmetropia, 38% for myopia, and 21% for hyperopia. The Arclight ease-of-use was rated on average as 4.4 (SD = 0.9) on a scale of 1 to 5, with 1 being the hardest and 5 being the easiest. Conclusions: Our study shows the Arclight as an affordable and effective alternative to the traditional ophthalmoscope for assessing eye disease in children. This device can improve eye health services in under-resourced regions.Peer reviewe
Positive effect of low dose vitamin D supplementation on growth of fetal bones: A randomized prospective study
The effect of vitamin D supplementation on growth of fetal bones during pregnancy is unclear. The aim of this study was to assess the effect of low dose vitamin D supplementation during pregnancy on bony anthropometric aspects of the fetus. In this prospective randomized trial, 140 patients were divided into two equally matched groups according to age, 25(OH)D level, exercise, and dietary intake. Then 1000 IU per day vitamin D supplement was given to the intervention group while the control group received placebo. Then crown-rump length (CRL) and femur length (FL) during the first trimester and humerus and femur lengths as well as their proximal metaphyseal diameter (PMD), midshaft diameter (MSD) and distal metaphyseal diameter (DMD) in the second and third trimester were measured using ultrasonography technique. Finally, no significant difference was observed for CRL (p = 0.93). Although FL was not statistically significant in the first trimester (p = 0.54), its measurement in the intervention group and the control group in the second (28.87 ± 2.14 vs. 26.89 ± 2.08; p ≤0.001) and the third (65.31 ± 2.17 vs. 62.85 ± 1.94; p ≤0.001) trimesters was significantly different. Femoral PMD, MSD, and DMD measurement increased more in the intervention group in comparison with the control group with P values <0.05. HL measurement in the intervention group and the control group in the second (28.62 ± 1.94 vs. 27.23 ± 2.08; p ≤0.001) and the third (61.29 ± 2.84 vs. 59.85 ± 1.79; p ≤0.001) trimesters revealed significant differences. Humeral PMD, MSD, and DMD measurement increased in the intervention group in comparison with the control group with P values <0.001 for all. It is suggested to prescribe low dose vitamin D (1000 IU per day) from early pregnancy with possible increment in length and diameter of femur and humerus bones of the fetus
Spatial planning, urban governance and the economic context: The case of 'Mehr' housing plan, Iran
With the increasing concentration of population and economic activities in metropolitan regions, dwelling shortages and housing quality have become critical issues in urban management. Town plans considering social, economic, political, and cultural features of local communities have been developed with the aim of supporting housing, especially in emerging economies. In Iran, the 'Mehr Housing' Plan has been considered as one of the most relevant strategies for social housing since the 2000s. However, the acceptance of 'Mehr Housing' plans at the community scale has been rather low, reflecting the fact that it is a top-down, non-participatory policy. The present study investigates the most important factors affecting social acceptance of 'Mehr Housing' plans by interviewing 45 experts through a structured questionnaire that evaluated multiple analyses' dimensions of housing and urban planning in Iran. Results showed that six dimensions (physical, institutional-managerial, economic, socio-cultural, legal, and locational) had contributed to social dissatisfaction with 'Mehr Housing' local initiatives. In particular, socio-cultural and legal dimensions were demonstrated to have a large impact on local communities' dissatisfaction
Classification of coastal-marine habitats in Gwatr Bay using ecological standard classification (CMECS)
This research was conducted during 2007-2008 with the main aim of classifying marine coastal habitats in Gwatr Bay located in Iran-Pakistan border, south east of Sistan-Blaluchetan Province. We used Coastal-Marine Ecological Standard Classification (CMECS) with three data layers covering water column, benthic cover classifier and geomorphology. Layers and habitats information were analyzed in a GIS environment and the indicator species were determined. WCC classification was done based on temperature, salinity and clarity classifiers for Ichthyoplankton communities. The result showed that two main seasonal habitats including spring habitat (spring, summer and winter) and fall habitat, affected by the monsoon season is present in the area. Also we considered particle size and total organic matter in sediment as classifiers for benthic habitats which indicated two different habitats based on distances from shore. Habitats were divided into unmixed macro-benthos community (polychaete) and mixed macro-benthos community including: Polychaete, Amphipoda and Gastropoda. The habitats were shown on digital GIS maps with their specific codes
COVID-19 under spotlight: A close look at the origin, transmission, diagnosis, and treatment of the 2019-nCoV disease
Months after the outbreak of a new flu-like disease in China, the entire world is now in a state of caution. The subsequent less-anticipated propagation of the novel coronavirus disease, formally known as COVID-19, not only made it to headlines by an overwhelmingly high transmission rate and fatality reports, but also raised an alarm for the medical community all around the globe. Since the causative agent, SARS-CoV-2, is a recently discovered species, there is no specific medicine for downright treatment of the infection. This has led to an unprecedented societal fear of the newly born disease, adding a psychological aspect to the physical manifestation of the virus. Herein, the COVID-19 structure, epidemiology, pathogenesis, etiology, diagnosis, and therapy have been reviewed. © 2020 Wiley Periodicals, Inc
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