Showing 15 results for Khosravi
Heshmatollah Khosravinia, Mohammad Ali Edriss, Javad Pourreza, Saeid Ansari,
Volume 3, Issue 1 (spring 1999)
Abstract
To estimate heritability, and genetic and phenotypic relationships and also to study the effect of sex and rearing environment on body weight, weight gain, feed consumption and feed conversion coefficient, the data from 1200 pedigreed male and female chickens from three genetic groups including 90 sires were used. The included genetic groups were crosses of native chickens and an exotic breed (group A), native chickens which were selected for two generations on the basis of 8th week body weight (group B) and a control group of native chickens (group C). All the chicks were reared up to four weeks of age on the ground in separated pens according to their sire groups. In order to calculate feed conversion coefficient, 498 chicks were placed in individual cages during four to ten weeks of age. The results showed that the cross group (A) compared to the other two groups had a higher body weight at 2, 3, 6, 8 and 10 weeks of age. Weight gain, feed conversion coefficient and consumption at periods of 4-6, 6-8, 8-10 and 4-10 weeks were also higher in the cross group. Genetic groups B and C, in spite of better performance of group B for most of the traits, did not have any significant differences for the compared traits. Estimated heritabilities on the basis of sire variance component showed that these traits were medium to highly heritable. Estimated heritabilities for feed consumption at different ages ranged from 0.15 to 0.44 which at any age was lower than that estimated for feed conversion coefficient. Genetic and phenotypic correlations between growth traits were positive and, in most of the cases, high. Correlations between nutritional traits at different ages were variable.
M.a. Edriss, H. Khosravinia, J. Pourreza,
Volume 4, Issue 1 (spring 2000)
Abstract
Data of 1200 male and female chicks from 90 sires were used to estimate the heritabilities as well as genetic and phenotypic correlations of body measurements and carcass characteristics in three genetic groups, namely, crosses of native chickens with an exotic breed (group A), native chickens which were selected for two generations on the basis of 8th week body weight (group B) and a native control group (group C).
The effects of genetic group, sex and system (litter vs. cage) on body measurements (shank and breast traits) and carcass characteristics were studied. Data of body measurements were collected at 6th week of age, and carcass traits were recorded at slaughter time at 10th week of age (except breast angle which was recorded at 8th week).
All carcass traits and body measurements except shank were significantly affected by genetic groups (P<0.05). Sex and system of rearing did not have any significant effect on body measurements and carcass traits. Estimated heritabilities for body measurements and carcass traits showed a wide range. Breast and shank measurements had the lowest and those related to abdominal fat had the highest heritabilities. Phenotypic correlations for all of the body measurements were lower than genetic correlations among these traits. Genetic correlations between body measurements and carcass characteristics were mostly significant
A. Jafari Malekabadi, M. Afyuni, S. F. Mousavi, A. Khosravi,
Volume 8, Issue 3 (fall 2004)
Abstract
In recent decades, the use of nitrogen fertilizers has increased irrespective of their effects on soil properties, agricultural products and, particularly, on environmental pollution. Nitrate easily leaches from soils into groundwater. The objective of this study was to determine temporal and spatial nitrate concentrations in groundwater in agricultural, industrial and urban regions in some parts of Isfahan Province. Water samples were collected monthly from 75 agricultural, industrial, and urban wells of Isfahan, Najaf-abad, Shahreza, Natanz and Kashan during January-May 2001. The results indicated that NO3-N concentrations in most of the regions studied were higher than the standard level (10 mg/l) and nitrate pollution must be reckoned among the most serious problems of sustainable agriculture and exploitation of groundwater resources. Average NO3-N concentration in different wells ranged from 1.03 to 50.78 mg/l (4.64 to 228.5 mg/l as nitrate). The average NO3-N concentration in groundwater of Najaf-abad, Shahreza, Isfahan and Natanz-Kashan was 17.56, 14.6, 16.04, and 8.24 mg/l and 95.5, 100, 84 and 33.3 % of total wells in these regions had nitrate concentrations above the standard level, respectively. Maximum NO3-N concentration was detected in the agricultural region south of Najaf-abad (64.6 mg/l). Nitrate pollution in most of the sampling areas was mainly linked to agricultural activities. The average NO3-N concentration in groundwater of all agricultural, industrial, and urban regions, except for urban regions of Natanz and Kashan, were above the standard level. Generally, nitrate concentration level in groundwater increased with time and was maximum in March and April.
J. Pourreza, M.a. Edriss, H. Khosravinia, A. Aghaee,
Volume 8, Issue 3 (fall 2004)
Abstract
In a completely randomized design, the effects of six different additive compounds including limestone, hydrochloric acid, zeolite, aluminum sulfate, pad ammoniac, and fatty acids on nitrogen, pH, temperature, moisture, water soluble phosphorus, and microbial count of litter of broiler chicken were investigated. Each compound was added at a level of one kg/m2 of litter. Six–hundred-and-sixteen (616) day- old broiler chickens (both sexes) were divided into 28 groups, 22 chicks per group. Four replications were allocated to each treatment from 1 to 56 days. All groups were fed with the same diet. Litter moisture was not affected by the treatment. Experimental treatments significantly (p<0.05) influenced the litter pH on day 21. The lowest pH was obtained with aluminum sulfate and the highest pH was obtained with limestone. At the end of the experimental period, all treatments had nearly the same pH levels. Litter temperature was not affected by the treatments . Experimental treatments had a significant (p<0.05) effect on litter nitrogen and bacterial count. Correlation between litter pH and nitrogen was significant and negative (r = -0.95, p<0.05). Effect of treatments on soluble P was significant and the lowest soluble P belonged to aluminum sulfate and pad ammoniac. Correlation between soluble P and pH was positive (r = 0.48, p<0.05). The results showed that some chemical compounds can be used to reduce litter pH, nitrogen, and soluble P and their effectiveness diminishes as chicks grow older.
E. Khosravi, Sh. Dokhani, G. H. Kabir,
Volume 9, Issue 3 (fall 2005)
Abstract
The meat productions are the most popular among different food products. On of the serious problems of this kind of products may be the change of the physical and chemical properties. The Restriction of the use of synthetic antioxidants have prompted the extensive research on the effect of the natural antioxidant and replacement of synthetic antioxidant with the natural ones. In this study, the effect of α-tochopherol (vitamin E) and propyl gallate on German sausage was evaluated. Four different German sausages were formulated and prepared in 30 Kg batches as follows: control without antioxidant, sausages plus α- tochopherol (200 or 500 ppm) and sausages plus propyl gallate (200 ppm). Twelve Kg of the samples were filled into cellulosic casings and the other 18 Kg in polyamidic casings. All samples were cooked. One third of the packed samples were stored at (4˚C ± 1) for 10 days and the rest were stored at (– 18 ˚C ± 1) for 6 months. The extent of autoxidation for samples were determind by peroxid and TBA values. During the storage period, autoxidation rates of control samples were more than other treatments. Propyl gallate was more effective in reduction of autoxidation than α- tochopherol treatments. Addition of 500 ppm vitamin E was more effective than 200 ppm. Significant differences were observed among treatments (P< 0.05). The study of the shear strength of the stored susages at the (4 ºC ±1) for the 10 days indicated that the most shear strength is seen in the cellulosic casing samples. The same results obtained for the stored samples at the (-18 ºC ±1) for the 6 months.
M. Amanzadeh, A. Moumeni, M. Okhovat, M.j. Javan. Nikkhah, V. Khosravi,
Volume 11, Issue 42 (winter 2008)
Abstract
Blast, caused by Magnaprthe grisea, is often an important fungal disease in the production of rice in temperate and tropical areas including Iran. To determine reaction of rice cultivars against blast disease, 40 rice genotypes from Iran and other sources from Asia were selected. Four blast isolates from different races were used to test all rice genotypes in different greenhouse tests. In blast nursery, experiments were conducted in a Randomized Complete Block Design (RCBD) with three replications. In different experiments inoculated plant materials were evaluated for Infected Neck Number(INN), Neck Lesion Size(NLS), Infection Type(IT), Diseased Leaf Area(DLA), Area Under the Disease Progress Curve(AUDPC), Lesion Number(LN), and Sporulating Region Diameter(SRD). Most of the Iranian traditional cultivars together with CO-39 and C104-PKT showed susceptible reaction for AUDPC, IT, INN and NLS. Performance of improved cultivars from Iran, IRRI and NILs (except C104-PKT) was resistant. Some cultivars including Fujiminori, Onda , Hassan saraii were moderatly susceptible to leaf blast in blast nursery. All components of resistance in both growing stages in greenhouse and nursery tests were significantly correlated. In some cases such as cultivar Haraz different reaction was observed in seedling and flowering stages, indicating that genetics of resistance in two stages could be different.
M. Khosravi, R. Ebadi, H. Seyedoleslami, B. Hatami, Kh. Talebi Jahromi,
Volume 12, Issue 45 (fall 2008)
Abstract
In this study diflubenzuron as a chitin synthesis inhibitor with a dosage of 25 mg A.I/L, and Pyriproxyfen as a juvenile hormone analogue with a dosage of 0.4 mgA.I/L were incorporated in the wax diets of young and last instar larvae of greater wax moth and reared at different temperatures (25, 30, 35°C). Results showed that these compounds in comparison with control increased larval mortality. Diflubenzuron and pyriproxyfen caused 33.9% and 24.1% mortality respectively. The young larvae showed higher mortality with the mean of 57.8% in diflubenzuron and 31.5% in pyriproxyfen. In evaluation of pupation and emergence of adults, no significant differences were observed between diflubenzuron and control. Pyriproxyfen induced reduction in pupation about 48.4% and adult emergence about 44.8% and caused some abnormalities of pupae. Last larval instar was more sensitive to JHA in this respect. Maximum pupation disruption occurred at 25ºC and 30ºC in comparison with 35ºC which reduced abnormal pupae up to 19.7%. IGRs were effective in last larval instar at 35 ºC and increased abnormality of adult up to 49.4%. Reproductive potential (egg viability, hatchability) of adults reduced in F1 generation and was 70-90 percent. IGRs have unfavorable effects on biological aspects of larvae therefore, it is possible to use IGRs alone or in conjunction with other pesticides (Fumigants) in integrated control of these pests.
Gh. Vahabzadeh, A. Safari, M.h. Farhoudi, H.r. Abdollahi, H. Fathizad, Gh.r. Khosravi,
Volume 18, Issue 70 (winter 2015)
Abstract
In this research, sediment production and delivery amount by Darabkola forest roads was estimated using the SEDMODL model. To evaluate the model results, the sedimentation rate in the above roads was directly measured using rainfall simulator. Also, the paired t-test, BIAS, RE and RMSE were used to assess the results. The analysis showed that the rate of sediment production from study roads' surface using the SEDMODL model and direct measurement under the rainfall simulation were 420.97 and 341.19 tons per year, respectively, and rate of sediment delivered to the stream with sediment delivery ratios of 42% and 51%, respectively, was about 177.58 and 174.02 tons per year. Also, results of the statistical methods of BIAS, RE and RMSE for the aforesaid model were 0.04, 17.59 and 0.71, respectively, and at 95% confidence level, no significant difference was obtained between the observed and estimated data. Therefore, the aforesaid model has the appropriate accuracy and efficiency to estimate the sedimentation rate of the Darabkola forest roads. It was also found that from among the input parameters of model, longitudinal slope of road, precipitation and sediment delivery factors were the most influential factors in the sediment production and transport, respectively.
M. Mombeni, A. Karamshahi, Graee, F. Azadnia, H. Khosravi,
Volume 19, Issue 72 (summer 2015)
Abstract
Desertification is currently a big problem in many countries, especially in developing countries, and includes natural processes and improper human activities. The present study was conducted to evaluate the potential of desertification with an emphasis on water, climate and soil criteria using IMDPA Model in Abbas plain, Ilam province with an area about 18028.8 hectare. Geometric averages for indices including water table fluctuations, EC of water, SAR, irrigation system, annual precipitation, aridity index, drought continuity index, soil texture, soil thickness and Ec of soil were obtained using ArcGIS 9.3 and the status map of each criterion was prepared. The results of climate indicated that 100% of the area is in severe class. The desertification intensity map based on soil criteria demonstrated that over 4843 hectare (28.86 percent of total area) and 13185 hectare (73.13 percent of total area) are in low and moderate classes, respectively. Also, the obtained results from geometric average of water criteria indices showed that 10861.4 hectare (60.2 percent of total area) and 7166.6 hectare (39.75 percent of total area) are in low and moderate classes, respectively. The results also indicated that climate with the value of 2.81 is the most influential criterion in the severity of desertification in the study area. Accordingly, it can be said that the quantitative value of desertification intensity of total area is in moderate class.
D. Khosraviani, A. R. Davoudian Dehkordi, J. Givi, M. Sheibi,
Volume 19, Issue 74 (Winter 2016)
Abstract
The concentrations of rare-earth elements (REEs) were determined with the aim of investigating the behavior of these elements in granitic rock, granitic soils and soils between rock and lichen in Shir-kuh of Yazd province. Rare earth element patterns of the P-rich granite were determined by the mixture of Eu-enriched feldspars, middle REEs to heavy REEs-enriched apatite and Light REEs-enriched monazite. Granite-normalized REEs patterns for soils and soil lichen-granite interface represented the same signatures and similar to parent rocks. The REEs levels of the soils lichen-granite interface were similar to the concentrations of the elements in the natural compositions (Upper Continental Crust and Post-Archean Australian Shale). PAAS-normalized Rare earth element patterns for three soils’ lichen-granite interface were identical to each other and PAAS and close to the reference axis (PAAS). The same signatures of REEs in granitic rock, granitic soils and soils lichen-granite interface in arid and semi-arid mountainous areas indicate that the elements are immobile and therefore, they can be used as a suitable tracer in soil provenance studies.
A. Khosravi-Dehkordi, M. Afyuni, A. Soffianian,
Volume 20, Issue 77 (Fall 2016)
Abstract
Pollutants are considered the disturbing factors of environment, and among them the heavy metals are more important considering their non-degradability and physiological effects on organisms in low concentrations. The goal of this research was to investigate the effect of industrial landuse on Cd and Pb concentrations in surface soils of the southwest Isfahan. According to satellite images and topographic maps (1:50000) of the study area, soil samples (depth: 0–20 cm) were collected using random sampling. A total of 38 surface soil samples were obtained from industrial areas (lowest distance = 1480 m) in the area of 73481 ha. Total concentrations of Cd and Pb in the digested solution were measured by Atomic Absorption Spectrophotometry (AAS). Using Arc GIS, the spatial distribution patterns and Cd and Pb variography of samples were analysed and finally the best models of spatial distribution of heavy metals were achieved. The primary results showed that the mean concentrations of Cd, and Pb of surface soil samples in industrial areas were 1.8 to 31.5 mg Kg-1 higher than the world’s mean values, respectively. Although the mean concentrations of Cd and Pb were respectively 8 to 700 mg Kg-1 lower than the standard of Iranian Department of Environment for industrial landuse.
S. Pishyar, H. Khosravi, A. Tavili, A. Malekian,
Volume 21, Issue 4 (Winter 2018)
Abstract
In this study, to study the status of water resources degradation in Kashan region, Isfahan Province, eight indices including: drop in groundwater, water salinity, irrigation efficiency, Well-to-Qanat development ratio, the pumping time, shortage of water supplies for animals and humans and the water negative balance were selected according to previous studies conducted on desertification in Iran and the world. Existing evaluation models were determined. Desertification map of the study area was provided according to MEDALUS model and selected indices. The selected indices were weighted using a multi-criteria decision method and each index having weight more than 0.5 were selected as the most effective indices of desertification. Again, the desertification status map of the study area was prepared by the most effective indices. Finally, the two desertification maps were compared. The results showed that the drop in groundwater, water salinity, the pumping time and water negative balance have the most effect on water resources degradation among selected indices. The results of comparing two groundwater degradation maps showed that based on map provided with eight indices, 87.78 and 8.30 percent of the total area are classified in critical conditions c and b, respectively. While the map provided by the most effective indicators shows that 99.15% of the total area is classified in the critical condition "c" and just 0.849% is classified in the critical condition "b". It can be concluded that to assess desertification status, it is better to first determine the indicators by weighting and prioritizing methods. This will identify the indicators that have not had a significant effect on the desertification phenomenon in the area and prevent their impact on desertification classes and reduction of scores.
S. P. Mousavi, M. A. Asghar Mokhtari, Y. Khosravi, A. Rafiee, R. Hoseinzade,
Volume 22, Issue 2 (Summer 2018)
Abstract
In this study, the distribution of heavy metals pollution including arsenic, antimony, nickel, copper, cadmium, cobalt, bismuth, lead and zinc in the stream sediments of Zarshuran- Aghdarreh area was investigated by using statistical techniques and the geometric integration of each sample basin. For this purpose, the degree of pollution in 154 stream sediment samples was analyzed and the distribution maps for enrichment factors were prepared by using a combination technique, pixel estimation, and statistical and geostatistical methods. The results of calculating the enrichment factors indicated that the higher enrichment was related to arsenic, antimony, bismuth, cadmium and lead. Furthermore, the concentration of zinc, copper, lead, arsenic, antimony, cadmium and bismuth in the stream sediment samples was higher than the global average. Application of the principal component analysis on the data led to the recognition of 9 main components for the dataset; the first 5 were components with eigen values greater than 1 and a cumulative percentage more than 85%. Arsenic, antimony, cadmium, lead and zinc in the first component, cobalt in the second component, bismuth in the third component, copper in the fourth component and nickel in the fifth component had the highest values.
M. Sayadi, H. Khosravi, S. Zareh, Kh. Ahmadali, S. Bagheri,
Volume 25, Issue 3 (Fall 2021)
Abstract
Desertification is a phenomenon that has more destructive effects in arid, semi-arid, and semi-humid regions than in other regions. This paper tries to provide a map of the future of desertification in Tehran Province, for futurism in the face of land degradation and desertification. The IMDPA model was used to evaluate land degradation and desertification. To use this model and evaluate desertification, three criteria of groundwater including groundwater depletion, electrical conductivity, and sodium adsorption ratio indices, climate criterion including precipitation, aridity, and drought indices, and land use criteria were selected as key criteria effected on desertification according to regional conditions. Land use index map with IGBP standard and zoning map of other indicators were prepared by IDW method for 2011 and 2016. The maps of land use index and other indices were predicted using the CA-Markov model in TerrSet software, and using the RBF method in artificial neural network toolbox, respectively. Scoring based on the IMDPA model, the maps of indices and criteria maps were prepared for 2011, 2016, and 2021. Finally, the desertification intensity map was calculated by geometric averaging for all three criteria for all three time periods. The results showed that 59.78% and 40.22% of the area of Tehran Province were in the low and medium classes, respectively. However, in 2016, the area of the medium class has increased to a 44.8%, and it is predicted that this increase will continue until 2021 so that 47.65% of the area of Tehran Province will be in the medium class. In addition, in this year, about 1% of the area of Tehran Province will be allocated to the high class in the western regions, which did not exist in the previous two periods. In general, due to human activities, the intensity of desertification in the western and southern parts of the province is higher than in the eastern and northern regions.
H. Nazaripour, M. Hamidianpour, M. Khosravi, M. Vazirimehr,
Volume 26, Issue 4 (Winiter 2023)
Abstract
In this study, the decade variability of frequency and severity of drought in Iran has been investigated. The one-month scale data from the standardized precipitation-evapotranspiration index (SPEI 01) in the period 1956 - 2015 have been used. Based on the common numerical thresholds, the characteristics of the frequency and severity of drought for each pixel have been calculated and they are the basis for the analysis of the drought situation. Then, the frequency of drought severity classes was calculated and its trend was investigated using the non-parametric Mann-Kendall test. The findings indicated the spatio-temporal variability of drought frequency and intensity patterns in Iran. The frequency of mild droughts has decreased from south to north and from east to west; while the frequency of more severe droughts has increased from north to south and from west to east. The frequency of mild droughts in the southeast, northwest, and northeast has increased by 5 to 40 percent. While the frequency of more severe droughts in most parts of Iran has increased between 10 and 20 percent. Variability in the frequency of more severe droughts is more pronounced in the Central Plateau catchment area as well as in the Persian Gulf-Oman Sea. The trend of drought intensity is decreasing (drought intensification) at the same time as the prevailing rainfall regime in Iran. A significant increase in drought intensity (wet season intensification) is observed only in southeastern Iran at the same time as the monsoon regime. However, extra-arid and arid regions of southeastern Iran are affected by the frequency and severity of drought and have a high degree of vulnerability.
