فهرست مطالب s saadat

Geobotany, as a useful tool in the exploration of minerals, has found a lot of use in environmental studies and the cleaning of contaminated environments. Chalpo is located 45 km north of Kashmer city (Khorasan Razavi). Due to the occurrence of antimony-gold deposit and geological and geochemical characteristics along with the specific vegetation of the region, the geobotanical study of the plants of the area was carried out to identify mineral indicator plants, introduce endemic plants and the geochemical effect of the region on important metallophytes. Sampling was done in precise and specific steps from the plant organs and the soil where the roots of the plants are located. The amount of elements in the soil, root and shoot samples of the plant was compared.Based on the results of chemical analyses, the arsenic content of all plant species is higher than the normal level in plants. Ih has measured above 2000 ppm arsenic in Asperula glomerata subsp. turcomanica. Most plants concentrated one or more elements higher than normal, which is very important both from the point of view of the exploration of metal minerals and from the environmental studies. Despite the proximity location of the collected samples, the plants showed very different absorption rates in each element. The endemic plant Astragalus hekmat-safaviae with a very high accumulation coefficient of arsenic (9), antimony (25) and molybdenum (51) can be introduced as an absorbent or superabsorbent for these metals and as an accumulator for copper and zinc elements. The Asperula glomerata subsp. turcomanica, one of the typical plants of the region, shows an accumulation coefficient of about 2 for zinc and molybdenum. The Jurinea sp. which was observed in this study for the first time, shows the accumulation coefficient and the transfer coefficient factor higher than one for zinc and molybdenum.

The present study evaluated the effect of aquifer exploitation on the quality of groundwater resources in Neyshabour Plain (Khorasan Razavi). In this research, the qualitative and quantitative changes in water in observation wells were investigated over a period of 10 years. In order to better understand the changes in water quality, a chemograph diagram and Shuler and Wilcox diagrams were used. According to these diagrams, the quality of underground water in Neyshabour plain varies from good to completely unpleasant for drinking purposes, and about 27% of the samples are in C4-S4 and C4-S3 categories, which are very salty and is not suitable for agriculture. According to the chemograph schematic diagram, the average electrical conductivity had an increasing trend through the years 1389 to 1399 from 3600 micromos/cm to 3800 micromos/cm. The highest values of EC are in the western part of Kal-Shor. Significant amounts of silty-clay sediments with evaporative salts, placement in the catchment basin and small morphological slope have reduced the water quality. The results show that with the excessive use of groundwater in the last ten years, the water level has decreased 1.29 meter on average annually. Based on the results of this study, which indicates the decrease in the groundwater level and water quality in the study area, it can be mentioned that with the current trend, there will be numerous environmental effects, such as the reduction of irrigation or the drying up of springs, qanats, and wells, change of land use, cultivation pattern and land subsidence in the region in the future.

Academic burnout is one of the major challenges during the academic year that is affected by various factors. Therefore, the aim of this study was to investigate the relationship between COVID- 19 anxiety and academic burnout with the moderating role of academic commitment in medical students.

This is an analytical cross- sectional study. the research population consisted of stager and intern medical students at Guilan University of Medical Sciences in the academic year 2020- 2021. 230 people (115 stagers and 115 interns) were selected as the sample by stratified random sampling. Data were collected using Corona Disease Anxiety Scale, Maslach Burnout Inventory- Student Survey, and the Academic Commitment Scale. Data were analyzed using descriptive and analytical statistics (Pearson correlation and adjustment regression) through SPSS.

Out of 230 distributed questionnaires, 190 could be analyzed (participation rate=82.60%). Pearson correlation coefficient shows that academic burnout is positively related with COVID- 19 anxiety (r= 0.332,P=0.001) and has a negative and significant relationship with academic commitment (r=-0.304, P=0.001). There is also a negative relationship between COVID- 19 anxiety and academic commitment (r=-0.265, P= 0.0001). Also, the results of adjustment regression analysis showed that the predictor variables (ß) COVID- 19 anxiety (0.26), academic commitment (-0.29) and adjustment role (0.21) in total, predict 0.20 of the variance of the variable of academic burnout.

With an increase in academic commitment in students, the effect of COVID- 19 anxiety on academic burnout decreases. It is recommended that medical education planners pay attention to training programs in this area.

Afsoo area is located in northeastern Iran. Limestone and shale are the main host mineralization and monzonite and pyroclastic rocks are exposed in this area. Barite and galena mineralization occurred mainly as veins and veinlets within the limestone or shale and limestone boundaries. Galena with bented triangular cleavage and barite with compressive and polysynthetic twinning are observed. The highest amounts of barium oxide present is about of 57.4%, strontium oxide 4.8%, lead oxide 3.3%, copper oxide 1.2% and zinc oxide 0.1% in ore containing barite and galena. Concentrations of Rare Earth Elements in barite, galena and exposed rocks in this area are different and indicate at least part of the ore-bearing fluid have originated from deeper sources. The Amount of all rare earth elements in the barite samples from the study area is very low and about 1 to 1.8 g/t that can be a sign of crystallization from a fluid that has originated far away. The low Al2O3 and the high Sr content in the deposit are also indicative of the origin from low temperature hydrothermal-type ore-bearing fluid. Comparison of the distribution pattern of these elements with the patterns presented globally indicates that most of the samples fall within the range of barites from low temperature hydrothermal fluids.

Phosphorus (P) is a key element in many biological processes of plants and animals. We aimed to investigate the effect of different salinity levels and Ca:Mg ratios of irrigation water arid lands on soil available P, soluble P, and P absorbed by the pistachio plant. For this purpose, a greenhouse experiment was conducted by sowing the seeds of pistachio in a factorial randomized block design with four soil salinity levels (S1 (6 dS.m-1irrigation water salinity, leaching fraction (LF) = 50), S2, S3, and S4 (9 dS.m-1 irrigation water salinity, LF = 50, 30 and 20, respectively)) and three Ca:Mg ratios (M1, M2, and M3 equal to 1, 0.5, and 0.25, respectively). After harvesting the plants, the amount of soil available P (Po), water-soluble P (Pw), and total P (Pt) at soil depths of 0-5, 5-25, 25-50, and 50-75 cm, and P concentration in the leaves of Pistachio seedlings were measured.The results showed that the salinity of soil saturated extract had no significant effect on Po, Pw, and Pt. The reduction in Ca:Mg ratio increased Po and Pw in soil surface but it did not affect Pt. Increasing salinity from S1 to S2 augmented plant P uptake but at higher salinity levels, P uptake was reduced. The decrease in Ca:Mg ratio had no significant effect on plant P contents.

Numerous studies indicated that consanguineous marriages are associated with the increased risk for several diseases. The prevalence of consanguinity has a geographical distribution, it is high among Asian and African populations, including Islamic countries and very rare in European populations. Given the hazards effects of such marriages on health of offspring, efforts should be made to identify the reasons of its tendency in each population and its cultural roots can be identified in order to reduce it in the population. In the present study the frequency of consanguinity in folktales collected form Bandar Khamir and Bastak (Hormozgan province) was investigated. In 70 folktales from Bandar Khamir, 35 marriages were recorded. From these, 26, 1, and 8 were marriages between unrelated persons, first-degree relatives and first cousins, respectively. In 13 folktales collected form Bastak, 10 marriages (9 with unrelated and 1 with first cousins) were recorded. It may conclude that consanguineous marriage is a deeply rooted cultural trait and it is associated with positive attitude to this type of marriages.

Modeling plant response to salinity and nitrogen deficiency is very important for estimating optimum yield in arid and semi-arid regions. For this purpose, the models of Leibig-Sprengel (LS) and Mitscherlich-Baule (MB) originally proposed to explain plant response to nutrients only were modified to evaluate plant yield response to combined nitrogen and salinity stress conditions. Afterwards, in order to model canola (Brassica napus L.) response to combined salinity and nitrogen stress, an experiment was designed with different nitrogen and salinity levels. The water salinity treatments consisted of non-saline water, 3, 6, 9 and 12 dS m-1. The nitrogen treatments were 0, 75, 150 and 300 mg kg soil-1 added as ammonium nitrate. The results indicated that both modified models can satisfactorily predict canola yield. However, the modified MB model (R2=0.94) provided better estimation than the modified LS model (R2=0.87). The calculated statistics including Maximum Error, Root Mean Square Error, Modeling Efficiency, Coefficient of Determination and Coefficient of Residual Mass for the modified models indicated that the estimated relative grain yield for soil nitrogen, salinity and each rate of soil nitrogen in salinity levels by modified MB model compared with those by modified LS model is closer to the measured relative yield. Therefore, the use of modified MB model for estimating canola relative grain yield in salinity and nitrogen stresses is recommended. Using modified LS model showed that the salinity threshold value changes with the applied nitrogen. In this case, by application of each 75 mgN kg-1 soil, the salinity threshold value decreased 4 dS m-1 in saline conditions. Application of nitrogen decreased chloride concentration in grains under saline conditions. Nitrogen uptake also augmented with increasing canola transpiration, because nitrogen was carried over from soil to the uptake sites mainly by mass flow.