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Background: Internet addiction can include psychological pathology. Several variables play a role in Internet addiction, which can be mentioned as depression, anxiety, stress, and self-esteem with Internet addiction. The question of research is whether there is a correlation between internet addiction and depression, anxiety, stress and self-esteem? Aims: The present study aimed to investigate psychopathologic correlates of internet addiction in Afghan Student studying in Iranian universities. Methods: The current research was a descriptive correlational study that was conducted in the academic year of 2022-2023.A total of 268 people (159 boys, 109 girls), from Afghan students studying in Iranian universities, who were selected by stratified random sampling, completed three scales; Internet addiction test, depression, anxiety, stress test and Rosenberg self-esteem test were used. The obtained data were analyzed using Pearson's correlation, regression analysis and t-test. Results: Results revealed a significant positive correlation between depression, anxiety, and stress with Internet addiction (P< 0.01).Furthermore, depression, stress, and anxiety were found to be significant predictors of Internet addiction (P< 0/0001). Anxiety which accounted for 13% of the variance was the best predictor, followed by depression (2%) and stress (3%).The Prevalence of internet addiction was significantly higher among male subjects. Finally, our results suggested that Self-Esteem is largely irrelevant to internet addiction (P> 0.05). Conclusion: Considering that Internet addiction can be predicted through the dimensions of depression and anxiety; therefore, the results of this research have important points in the field of education of students suffering from Internet addiction and therapeutic interventions to control their psychological dysfunction. [ABSTRACT FROM AUTHOR]

Introduction Rivers are known as the main sources of surface water in the world, which experience seasonal fluctuations in water level. These resources have severe damage to human societies and nature in flood conditions and have irreparable consequences in the drought seasons. Optimal utilization of these resources with maintaining the environmental conditions of the waterway and minimizing flood damage is considered one of the river engineering goals. Since the conventional methods of river management are imposed serious environmental threats on waterways and wetlands, consideration to these water resources requires attention to issues related to plant ecosystems, solving challenges of coastal bed erosion and predict the condition and management of the river in the future (Callow, 2012; Dawson and Haslam, 1983; Fan et al., 2013; Rose et al., 2010; Rowinski et al., 2018). One of the strategies that cause loss of flow energy in the river improves the hydrological system and river ecosystem is the presence of vegetation in the river banks and floodplains. Native vegetation in floodplains and coastal forests plays an important role in conserving waterway ecosystems, flood management, coastal protection in urban lands and agriculture adjacent to the river (Fathi-Moghadam, 1996). Vegetation will also control the width of the river and increase the stability of the shores by absorbing and settling suspended sediments in river banks. The plant species along rivers and waterways are composed of various vegetative components, mainly affected by the environmental conditions of their habitat, including the distance from the waterway bed, hydrological characteristics of the river, climatic and soil conditions. Obviously, the effect of each plant species in the ecosystem cycle varies and for each section of the river, a specific combination of plants will create optimal conditions. Methodology In this paper, effective parameters have been identified to investigate the effect of vegetation properties on drag force and the final functional relationship between dimensionless parameters for estimation of resistance to flow and drag coefficient in vegetated rivers will be: CD = f [yn/H, DI, ρV²yn4/EI] (1) Where CD is the drag coefficient, yn/H is the relative depth, DI is the vegetation density index and last parameter is the dimensionless number of the ratio of the flow velocity to the bending stiffness, which is used to investigate the effect of the vegetation flexibility. The experiments were conducted in an 8.30×0.80×0.55m flume with Plexiglas sidewalls and metal structure located in the Water and Environmental Engineering Faculty at Shahid Chamran University of Ahvaz, Ahvaz, Iran. The knife-edge part of the flume, which can move freely in a limited range, was used to measure the exerted force to the moveable part of the flume (which supports the vegetated model) by means of a dynamic load cell installed between the movable and fixed parts of the flume. the artificial vegetation models used in this study were similar to the natural sample of trees. Galvanized and polyethylene sheets have been used to make rigid and flexible artificial specimens with the same geometric shape and form to allow more accurate comparisons. Results and Discussion In this section, with the aim of practical use of the results, the independent variables are defined as dimensionless numbers based on the drag coefficient. Investigating the effect of the vegetation density index, the results showed that in both rigid and flexible models, increase of the vegetation density index leads to a decrease in the drag coefficient. By increasing the vegetation density index in the flexible model at yn/H = 1, the drag coefficient decreased by 19.8%, which is the highest rate of decrease in the drag coefficient. Also, the lowest rate for reduction of the drag coefficient with increase of the vegetation density index occurred in the rigid model and at yn/H = 0.6, which is equivalent to 10.3%. In fact, in the case of the maximum decrease in the drag coefficient, for an 80% increase in the vegetation density index, the drag force increased by 43.8%, and in the case of the minimum decrease in the drag coefficient, the drag force increased by 66.5%. By comparing the effect of flexibility of vegetation in rigid and flexible models, the results showed that in both cases, the drag coefficient decreases with increasing in velocity. In the flexible models, the slope of the drag coefficient curve has a decreasing trend faster than the rigid case. For the effect of the relative depth of the flow, the results showed that the drag coefficient in both models decreases with the increase in the relative depth, so that in the rigid and flexible models, with the increase in the relative depth from 0.6 to 0.8 and from 0.8 to 1, the drag coefficient decreases by 12.81% and 10.43%, respectively. Correlating the results, following relationships were obtained for the estimation of the drag coefficient for the rigid and flexible models, respectively: CD = 3.26 [yn/H]0.13 - 2.65(DI)-0.12 + 0.28[ρV²yn4/EI]-0.29 R² = 0.87 (2) CD = [yn/H]1.2 + (DI)0.16 - 0.32[ρV²yn4/EI]0.21 R² = 0.89 (3) Conclusions In the present study, the drag force absorption rate and the resistance coefficient were investigated and equations were correlated to estimate the drag coefficient. All experiments were performed in steady, uniform and turbulent flow. Rigid and flexible models were tested by different hydraulic parameters according to the flow conditions. A new index is produced to account for the effect of vegetation density on the drag coefficient. Investigating the effect of the vegetation density index showed that the increase in this index has a significant effect on reducing the drag coefficient, so that at the maximum increase of the density index, a decrease of 19.8% in the drag coefficient was measured. The results showed an increase in drag force absorption as a result of increase in vegetation density index and relative depth. In general, the increase in vegetation density index ranges 0.4 < DI ≤ 0.8, 0.8 < DI ≤ 1.1, 1.1 < DI ≤ 2.2 and 2.2 < DI ≤ 3.8 in comparison to the range of 0.2 ≤ DI ≤ 0.4; the drag force absorbed increases by 1.63, 2.46, 4.12 and 6.33 times, respectively. Also, increase of the relative depth from 0.6 to 0.8 and 1, the drag force increased by 49.7% and 46.9%, respectively. The index introduced in this study can be a reference index for monitoring the types of vegetation in floodplains and aquatic plants. The results of this study can be used in the numerical modeling for estimation water level during flood events and river engineering management. [ABSTRACT FROM AUTHOR]

Introduction and Objective: The use of agricultural by-products instead of grain seeds in livestock diets has been an important issue for scientific study. One of these products is potato waste that, if properly processed by methods such as ensiling, can replace cereal seeds such as barley in the diet, due to the proper nutritional value of this product, improving animal growth performance, reducing feed costsand prevent food from being wasting. Therefore, the purpose of this study was to investigate the effect of replacing different levels of potato waste silage with barley on growth performance, digestibility, and rumen and blood parameters of fattening lambs. Material and Methods: In this study, 30 Zell and Afshar mixed male lambs with a mean weight of 26±2 kg and mean age of 5.5±0.4 months were used in a completely randomized design (CRD) with 5 treatments and 6 replications for 90 days. The experimental treatments included the control treatment (without potato waste silage) and the treatments containing 25, 50, 75 and 100 potato waste silage replacement of barley seeds (based on dry matter). Results: The results of performance traits showed that there was a significant difference in fattening weight, daily weight gain, dry matter intake and feed conversion ratio between experimental treatments (p<0.05). The highest and lowest final weight, daily weight gain and dry matter intake were observed in the treatment containing 50% of potato waste silage and the control treatment, respectively. The results of the apparent digestibility of nutrients of experimental diets showed that there was a significant difference in the apparent digestibility of raw protein and neutral detergent fiber (NDF) between experimental treatments (p<0.05). The highest and lowest apparent digestibility of crude protein (CP) was observed in the treatment containing 50% of potato waste silage and the control treatment, respectively. The results of some blood serum parameters showed that there was a significant difference in the concentration of glucose, triglyceride, Low density Lipoprotein (LDL) and blood urea nitrogen (BUN) between the experimental treatments (p<0.05). The results of rumen fermentation parameters showed that there was a significant difference in the population of lactic acid bacteria, coliforms, protozoa, rumen liquid ammonia nitrogen, total volatile fatty acids (VFAs), acetic acid, propionic acid, butyric acid, valeric acid and isovaleric acid between experimental treatments (p<0.05). The highest population of lactic acid bacteria 100%, the lowest coli form population, the highest population of protozoa and the highest concentration of VFAs were observed in the treatment containing 100%, 70%, 100% and 50% of potato waste silage, respectively. Conclusion: The overall results of the present study showed that growth performance, the appearance of crude protein digestion, the total concentration of rumen fluid fatty acids and the population of bacteria and protozoa improved by consuming 50 % of potato waste silage. [ABSTRACT FROM AUTHOR]

Introduction Soil, as habitat substrate, helps to regulate important ecosystem processes, including nutrient absorption, organic matter decomposition. Water availability and the well-being of humanity are directly linked to soil functions. On the other hand, vegetation with different species and ages have significant effects on the status of the surface soil layer through the creation of diverse environmental conditions and the production of different organic substances. However, few studies have been conducted in relation to the effect of the age of afforestation and the type of vegetation on the soil status. Considering that a practical, complete and effective assessment of soil condition should be the result of simultaneous measurement of physical, chemical and biological indicators, hereupon, the present study aimed to investigate the effect of 20-year old poplar stand, 20-year old maple stand, 10-year old poplar stand, 10-year old maple stand and rangeland cover, in plot 3 of Delak-Khil series of wood and paper forests in Mazandaran province, on the organic layer properties and physical, chemical and biological (including microbial activities, enzyme activity, earthworm population and biomass, the number of soil nematodes and root biomass) properties of the surface soil layer. Materials and Methods For this purpose, some parts of the study area were selected which are continuous with each other and have minimum height difference from the sea level, minimum change in percentage and direction of slope. Then, in order to take samples from the organic and surface layer of the soil, three one-hectare plots with distances of at least 600 meters were selected in each study habitats. From each of the one-hectare plots, 5 leaf litter samples and 5 soil samples (30 cm X 30 cm by 10 cm depth) were taken to the laboratory for analysis. In total, 15 litter samples and 15 soil samples were collected from each of the habitats under study. One part of the soil samples was passed through a 2 mm sieve after air-drying to perform physical and chemical tests, and the second part of the samples was kept at 4 °C for biological tests. One-way analysis of variance tests was used to compare the characteristics of organic layer and soil between the studied habitats. In the following, Duncan's test (P>0.05) was used to compare the average parameters that had significant differences among different habitats. Results and Discussion The results of this research showed that afforested stands with different ages and pasture cover had a significant effect on the characteristics of the organic and surface soil layers. The results indicated the improvement of most of the characteristics of the organic and surface soil layer in the afforested stands, especially the 20-year old afforestation compared to the rangeland cover. The organic matter produced in 20-year old afforestation, especially with poplar species, had a higher quality (high nitrogen and carbon content and low carbon-to-nitrogen ratio) compared to organic matter produced in 10-year old afforestation and pasture cover. Most of the physicochemical characteristics of the soil under 20-year old afforestation were in a better condition than the other studied habitats. Also, according to the results of this research, the highest values of biological characteristics such as microbial activity, enzyme activity, and the population of earthworms and nematodes were observed in the subsoil of 20-year old afforestation especially with poplar species. Based on the results obtained from the principal component analysis, the higher values of nitrogen, phosphorus, calcium, magnesium and potassium content of the organic layer led to the improvement of soil fertility characteristics, microbial activities, enzyme activity, earthworm population, the number of soil nematodes and root biomass, respectively, under poplar and maple plantation for 20 years, meanwhile, 10-year old plantation, especially with maple species, and rangeland with the production of organic materials with high carbon content and carbon to nitrogen ratio, resulted in the reduction of organic matter decomposition (greater thickness of organic layer), and consequently the reduction of the mentioned properties of the surface soil layer. Conclusion According to the findings of this research, it can be concluded that plantation with poplar species, especially after 20 years, had a higher ability to improve the soil condition compared to maple, which can be considered by managers in future afforestation. Also, with the passage of time, the presence of tree covers (poplar and maple) had a higher priority than rangeland cover in improving the fertility status and suitable edaphological conditions of the soil. [ABSTRACT FROM AUTHOR]

Forest destruction can lead to soil degradation, which in turn puts terrestrial ecosystems at risk. To prevent such destruction and preserve the health of ecosystems, it is crucial to monitor and evaluate changes in soil properties over time using scientific data. This study examined the chemical and biological characteristics of soil in two sites with Brant's oak (Quercus brantii Lindl.) - Chari and Mavarz - located in the Zagros Forests of Chaharmahal and Bakhtiari province, Iran. Soil samples were collected from a depth of 0-10 cm, and measurements were taken in 2019 and 2021. The results showed significant differences between the two sites. In the Chari site, values of organic carbon, organic matter, substrate-induced respiration, and nitrification potential increased significantly from the first year to the second year. This improvement can be attributed to factors such as greater species diversity, higher canopy percentage, and relative protection of the Chari site. On the other hand, only electrical conductivity and dry weight of soil showed significant changes in the Mavarz site in the second year compared to the first year, possibly due to livestock grazing and reduced rainfall. Overall, the trend of changes in the Chari site has been positive, suggesting an improvement in some soil characteristics. This highlights the importance of managing and protecting habitats in the Zagros Forests to promote the health of oak trees that are facing the threat of oak decline. By preserving the biological and chemical characteristics of the soil, we can prevent forest destruction and protect the delicate balance of terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

A landscape consists of two dimensions, natural and man-made, and is one of the most important components of a visual representation of the human-environmental relationship. Natural has undergone many changes. The purpose of this study is to evaluate the aesthetic quality of natural landscapes in the years 1363, 1381, 1398. The nature of research is developmental-applied and descriptive-analytical. Data were collected through library studies, questionnaires, and field surveys. The quality of landscapes was evaluated with the DEMATEL-ANP model. Considering three criteria (uniqueness, naturalness and diversity) and not sub-criteria, in the layers: (tourist places, mines and industries, Arasbaran forest area), for the first criterion, (land cover, Activity centers, ground surface temperature) were prepared for the second criterion and (land cover diversity, land structural diversity, elevation and elevation) for the third criterion. The relationships between influence and governance of the sub-criteria were determined by Demetel method and then analyzed by ANP method in Super Decision software. Finally, using ArcMap software, the beauty quality map of landscapes Was drawn. The results obtained from the final weight of the effective factors by ANP_DEMATEL method show that the highest coefficient belongs to the natural factor of land cover with a weight of 0.385736 and the uniqueness of the land cover with a weight of 0.169653, which indicates a clear display of the cover. The green landscapes of this region are considered by experts as an example of society. And the obtained maps, entitled the quality of the beauty of the landscapes, show the trend of quality reduction from the west to the east of the city. This decrease in quality can be felt in the lands located near the Sungun copper mine and the two populous cities of Varzeqan and Kharvana. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effects of Lactobacillus acidophilus and Candida utilis probiotics on mucus immunity, growth indices and liver enzymes of common carp (Cyprinus carpio). This study was in the form of a completely randomized design with 4 treatments and 3 repetitions including: 1-basic diet, 2- basic diet + bacteria (1.23 g), 3- basic diet + yeast (0.67 g) and 4- basic ration + bacteria (0.625 g) and yeast (0.333 g) per kg of diet in 60 days. A number of 300 fish with an average weight of 12 ± 0.33 g were randomly distributed in 12 tanks (300 L) with a density of 25 fish in each tank. Based on the results, no significant difference was observed in terms of growth indices between the treatments except for the protein efficiency ratio (p>0.05). However, significant differences were found between the treatments (p<0.05) in terms of mucus immune parameters, lysozyme activity, total immunoglobulin and total protein. It was also true for AST and ALP which exhibited significant differences between the treatments (p<0.05). Based on the general results of this study, using Lactobacillus acidophilus and Candida utilis as probiotics displayed the highest enhancement on the fish immune system. [ABSTRACT FROM AUTHOR]

Introduction: Degradation of forest habitats and alteration of soil vegetation are efficient factors affecting the variability of ecological indices of organic and mineral layers of soils. In Iran, degradation of forest habitats and changes in habitat type, especially over the last century, affected soil quality, plant biomass production and environmental sustainability. Hence, in this study, the effect of different forest and rangeland vegetation types on the ecological parameters of soil organic and mineral layer has been investigated. Materials and Methods: To study and evaluate the effects of forest degradation and site change on soil organic and mineral ecological indices, four types of vegetation were selected in Gorgpas areas, southwest of Chalus city, Mazandaran Province. The land cover is as follows in the study area: (1) Less-degraded forest dominated by Carpinus betulus L.- Parrotia persica C. A. May (2) Fourty year's old plantation of Pinea abies (L.) Karst - Pinus nigra Arnold (3) Deforested areas including Carpinus betulus L. - Parrotia persica C. A. May (4) Exclosure rangeland dominated by Coronilla varia L. Physiographically similar land covers, were selected during a field research in the studied areas. Eight litter and soil samples (0-15 cm in depth and 30 cm × 30 cm in depth) were collected from each area in summer. In order to reduce the boundary effects, sampling was performed in the center of each land cover. The collected samples of organic layer (litter) and soil mineral transferred to the laboratory for analysis. The collected data was stored as a database in Excel. Then, to analyze and compare the data, the normality distribution of observations was evaluated by Kolmogorov-Smirnov test and variance homogeneity by Levene test. Analysis of variance used to investigate the significant/non-significant differences of different soil organic and inorganic layer characteristics in relation to the studied areas. Duncan test used for multiple mean comparisons. All statistical analyzes were performed by SPSS software version 23. Principal component analysis (PCA) was employed to study the relationship between soil organic matter and soil mineral quality in the studied land cover. Results and Discussion: According to the results, in the soil organic layer the highest carbon/nitrogen ratio (%) assigned to the rangeland, while the nitrogen (%) content was highest in the natural forest. The highest amount of carbon and organic layer thickness were also observed in rangeland and degraded forest cover, respectively. In the mineral soil layer, the highest value of sand (%), moisture (%), carbon (%) and carbon to nitrogen ratios (%) belonged to the rangeland cover, while the highest amount of clay v (%), pH (1:2.5 H2O), electrical conductivity (ds m-1), nitrogen (%), phosphorus (%), potassium (mg kg-1), calcium (mg kg-1) and magnesium (mg kg-1) were observed in the forest cover. The highest number and biomass of earthworms (n m-2), nematode population (In 100-gram soil), nitrogen mineralization (mg kg-1l), ammonium (mg kg-1), nitrate (mg kg-1), basal respiration (mg CO2 g-1 day-1), substrate induced respiration (mg CO2 g-1 day-1), microbial nitrogen biomass (mg kg-1) and metabolic coefficient (μg CO2-C mg-1 MBC day-1) observed in forest cover. There was no significant difference between the studied vegetations for bulk density (g cm-3) characteristics, silt (%), microbial biomass of carbon (mg kg-1) and microbial coefficient (μg CO2-C mg-1 MBC day-1). Higher nitrate density in natural forest and under cultivated soils are due to the presence of litter species with low carbon/nitrogen ratio, high pH and calcium. Conversion of natural broadleaf covers to needle leaf plantation and rangeland reduces the biochemical processes of ammonium. Nitrogen mineralization rates are strongly influenced by area management and forest canopy cover, so that under the broadleaf stands, this rate was more than the needle leaf stands. This probably was due to the greater nitrogen of litter, the lower carbon to nitrogen ratio and the faster rate of decomposition of organic matter in broadleaves. Most of the time the increase in pH increases the rate of mineralization of nitrogen. Conclusion: The present study indicated that forest habitat had the highest number and biomass of earthworms, soil nematode population, ammonium, nitrate, metabolic coefficient, basal and substrate induced respiration, carbon availability index, microbial biomass and nitrogen mineralization, while, there was no significant difference between the studied forests and rangelands in carbon microbial biomass and microbial coefficient. In general, the results of this study showed that the physicochemical and biological characteristics of soil organic matter in the forest habitats were better than other studied vegetations and the forest degradation and land-use changes reduced soil fertility and microbial indices. [ABSTRACT FROM AUTHOR]

The prediction of local scouring as a dynamic and nonlinear phenomenon using methods of acceptable predictive capability has always been of interest to researchers. The shape of the bridge pier is one of the important factors in the formation and magnitude of the scour hole. In this paper, the scour depth of three bridge piers with cylindrical, sharp nose and rectangular shapes was predicted in two scenarios using the support vector machine algorithm with 395 field data obtained from the US Geological Survey and Froehlich (1988), based on different combinations of dimensionless parameters as the water attack angle (α), Froud number (Fr), the ration of pier length to width (l/b), and the ratio of mean sediment size to pier width (D50/b). The results of the study, while confirming the acceptable performance of the SVM algorithm for all piers in both scenarios, showed that in the first and second scenarios, the most optimal performance was related to the rectangular pier shape with correlation coefficient of 0.8702 and 0.8838, with and maximum Ds (DDR) values of 0.854 and 1.229 respectively, during the testing phase. The positive effect of increasing the number of data on the performance of the SVM algorithm was also confirmed by further probing the evaluation indicators. The results of the comparison pointed out the overestimation of the predicted scour depth values of absolute error between 11% to 35%. [ABSTRACT FROM AUTHOR]

To study the effect of deficit irrigation and zeolite application on water use efficiency, oil yield and phenology of hemp, a split plot experiment was conducted in a randomized complete block design with three replications in Shahrekord University. Treatments included irrigation at four levels (supplying 40, 60, 80 and 100% water requirement of crop) as the main plot and application of zeolite at three levels (no application, application of 5 and 10 tons of zeolite per hectare) as sub plot. The results showed that the length of the reproductive period was affected by irrigation and zeolite treatments and their interactions. By decreasing irrigation water supply, the length of the growth period decreased, although the reproductive stages were more sensitive than the vegetative stages. With increasing defficit irrigation intensity, oil yield, as a function of grain yield and oil content, decreased significantly. But, zeolite application prevented the oil yields to be reduced to some extent. Zeolite improved the water consumption per unit of yield on low and medium levels of drought stress with 19.9% and 17.5% than control treatment. Application of 10 tons of zeolite per hectare, at 60 and 80 percent supplying of the crop water requirement, modified the adverse effects of drought stress to hemp. [ABSTRACT FROM AUTHOR]