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41.
A. Jafari P. A. Finke J. Vande Wauw S. Ayoubi H. Khademi 《European Journal of Soil Science》2012,63(2):284-298
The main objectives of this study were to compare binary logistic regression as an indirect approach and multinomial logistic regression as a direct approach to produce soil class maps in the Zarand region of southeast Iran. With indirect prediction, the occurrence of relevant diagnostic horizons was first mapped, and subsequently, various maps were combined for a pixel‐wise classification by combining the presence or absence of diagnostic horizons. In direct prediction, the dependent variable was the great group itself, so the probability distribution of the great soil groups was directly predicted. Among the predictors, the geomorphology map was identified as an important tool for digital soil mapping approaches as it helped to increase the accuracy. The results of prediction showed larger mean probability values for each great soil group in the areas actually covered by the great soil groups compared with other areas, indicating the reliability of the prediction. In most predictions, the global purity was slightly better than the actual purity for the models; however, both models provided poor predictions for Haplocambids and Calcigypsids. The results showed that soils with better prediction were those much influenced by topographical and geomorphological characteristics and soils with very poor accuracy of prediction were only slightly influenced by topographical and geomorphological characteristics. An advantage of the indirect method is that it gives insight into the causes of errors in prediction at the scale of diagnostic horizons, which helps in the selection of better covariates. 相似文献
42.
Monitoring is essential for appropriate rangeland management. The present study aimed to examine the potential of moderate resolution imaging spectroradiometer (MODIS) satellite imagery in rangeland condition assessment and monitoring within and across vegetation types in the arid and semi-arid rangelands of central Iran. The normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) were calculated from MODIS Aqua/Terra Level 1B data (related to 2003–2013). The obtained values were compared with vegetation cover measurements and rangeland condition classes at 110 sampling sites using linear regression, one-way analysis of variance (ANOVA), independent-samples t-tests, and Tukey’s pairwise comparisons. The results showed that two indices made stronger predictions of vegetation cover within a vegetation type (R2?>?0.87, P?R2?>?0.51, P?P?≤?0.001) in predicting rangeland condition classes (poor, fair, and good), but their performance varied between vegetation types. The NDVI classified about 73, 19, and 7.5% of the rangelands in poor, fair, and good condition classes, respectively. The good performance of MODIS NDVI index at different landscapes indicates that this index has high potential in detecting vegetation cover and discriminating different condition classes, therefore, it can be used to aid field- based techniques in rangeland condition assessment and monitoring. 相似文献
43.
Hossein Sabahi Morteza Rabiei Yaser Jafari Kamal Sadat Asilan 《Communications in Soil Science and Plant Analysis》2017,48(3):285-293
It has been shown that pomegranate fruit powder (PFP) has the potential to decrease urea-nitrogen (N) mineralization and improve grain yield of maize, but the mechanisms of this effect are not fully understood. Therefore, the objective of this study was to investigate these mechanisms. For this purpose, an incubation and a pot experiment were conducted, in which four levels of PFP coating equivalent to 0%, 30%, 70%, and 100% (w/w) of urea were studied. PFP had very little effect on nitrification (1.4–2.9%). Mineral N and nitrite (NO2?)–N decreased (23% and 38%, respectively) with increasing PFP application, probably due to N-immobilization or urea hydrolysis inhibition. Biomass and grain yield of maize increased with increasing phosphorus (P)/N ratio of leaf and stem, and decreasing P/N ratio of grain, indicating soil-P-mobilization and soil-N-immobilization during vegetative growth and the inverse, during grain filling by PFP. According to these results, PFP can be introduced as an urea-N immobilizer and soil-P mobilizer. 相似文献
44.
A. Aiman-Zakaria M. Ali-Rajion S. Jafari M. Faseleh-Jahromi P. Shokriyazdan 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2017,67(1-2):76-84
Oil palm leaf is rich source of secondary metabolites. An in vitro study was conducted to identify the effects of oil palm leaf extract (OPLE) on rumen characteristics of goats by adding 0% (CON), 2.5% (T1), 5% (T2), and 10% (T3)/250?mg DM in 30?mL of buffered rumen fluid for 24?h. Methane gas production (mL/g DM) decreased (P?P?P?P?P?相似文献
45.
Saeed Khazaie Mahvash Jafari Javad Heydari Alireza Asgari Kavoos Tahmasebi Maryam Salehi Mohammad Saleh Abedini 《Journal of animal physiology and animal nutrition》2019,103(5):1619-1628
Diazinon (DZN) as an organophosphate pesticide may cause oxidative stress in different tissues. Antioxidants increase tissue protection from oxidative stress. The aim of the present study was to investigate prophylactic and therapeutic effects of vitamin C against oxidative stress caused by DZN in various tissues of male Wistar rats. Thirty rats were divided into five groups: control group received corn oil as DZN solvent, DZN group received 100 mg/kg of DZN, C group received 200 mg/kg of vitamin C, C‐DZN and DZN‐C groups received vitamin C before and after DZN injection. Plasma and various tissues were prepared and evaluated for measurement of the biochemical parameters and oxidative stress biomarkers. Results showed that acute administration of DZN significantly increased superoxide dismutase and glutathione‐S‐transferase activities and malondialdehyde level in all tissues, catalase (CAT) activity in liver, kidney and heart and some plasma biochemical indices, while it decreased cholinesterase and lactate dehydrogenase activities and glutathione content in all tissues. CAT activity in erythrocytes, brain and spleen was decreased in DZN‐exposed rats compared with the control group. Administration of vitamins C in both prophylactic and therapeutic groups ameliorated in these parameters, although all these tests in tissues did not return to the normal level. These data suggest that oxidative stress is an essential mechanism involved in DZN‐induced adversity effect, as evidenced by the altered activity of antioxidant enzymes, depleted GSH content and the enhanced membrane lipid peroxidation. Both the prophylactic and therapeutic treatments of rats to vitamin C have beneficial effects against oxidative stress and cholinergic hyperactivity induced by DZN in tissues especially in the brain tissue through free radical scavenging. 相似文献
46.
Morteza Saberi Alireza Shahriari Farajollah Tarnian Mohammad Jafari Hanie Safari 《Frontiers of Agriculture in China》2011,5(3):310-321
Seed priming technique has been known to improve germination and seedling emergence under different environment stresses. The objective of this study was to evaluate the effectiveness of seed priming in improving the seed germination and seedling vigor of Agropyron elongatum and Bromus inermis in response to five concentrations of the allelopathic extract of Thymus kotschyanus (0, 5%, 25%, 50% and 75%) under laboratory conditions. Pretreatments included gibberellic acid (250, 500 and 1000 ppm), potassium nitrate (0.1%, 0.2% and 0.3%) and salicylic acid (100, 200 and 300 mg/L). This experiment was carried out as a factorial experiment based on a completely randomized design with four replications. The results showed that seed germination, germination speed and seedling vigor were significantly decreased (P < 0.01) by increasing extract concentrations of Thymus kotschyanus allelopathic compounds in unprimed seed (control) compared with primed seeds. Seed priming enhanced germination percentage, germination speed and initial growth. Overall, the results of this study showed that the response of both species to pretreatment of seeds was positive. Therefore, pretreatments of seeds with the aforementioned chemical stimulators before planting can significantly reduce the negative effect of allelopathic compounds in Thymus kotschyanus during the germination stage and contribute to plant establishment by increasing germination speed and growth of embryos. 相似文献
47.
Gossypium species (+49) represent a vast resource of genetic diversity for improvement of cultivated cotton.To determine intra- and inter-specific genetic diversity and relationships,we employed 30 RAPD random detainer primers on twenty eight cotton accessions from 2 diploid cultivated species (G.arboreum,G.herbaceum) and 2 tetraploid cultivated species (G.hirsuturn,G.barbadense). 相似文献
48.
This study aimed to evaluate the antilisterial and antioxidative effects of chitosan nanocomposites and rosemary extract coating on the fillet of Huso huso inoculated with Listeria monocytogenes during refrigerated storage (4°C). Fish fillets were subjected as control (without coating), 0.5% rosemary extract (RE), 1% chitosan (CS), and combination of chitosan and rosemary extract as chitosan nanocomposite (CS/RE). Then, samples were inoculated with L. monocytogenes. Subsequently, the chemical parameters (total volatile basic nitrogen (TVB-N), peroxide value (PV), pH, and thiobarbituric acid (TBA)) and antilisterial effects of coatings were monitored during 16 days of storage at 4°C. According to the results, CS/RE demonstrated a significant (p < 0.05) ability to inhibit the growth of L. monocytogenes from 4.14 log cfu/g to 2.23 log cfu/g at the end of the storage period, followed by CT and RET treatments, respectively, compared to the control. Even though samples coated with CS/RE had the lowest pH and TVB-N values (p < 0.05), this coating was not able to pause the protein denaturation after 8 days of storage (p > 0.05) compared to the other treatments. On the other hand, CS/RE coating retarded lipid oxidation by decreasing PV and TBA production in the samples compared to the control up to the end of refrigerated storage (p < 0.05). 相似文献
49.
Feeding live cultures of Enterococcus faecium and Saccharomyces cerevisiae induces an inflammatory response in feedlot steers 总被引：1，自引：0，他引：1
Emmanuel DG Jafari A Beauchemin KA Leedle JA Ametaj BN 《Journal of animal science》2007,85(1):233-239
Two experiments were conducted to investigate the effects of oral supplementation of the lactic-acid-producing bacterium Enterococcus faecium EF212 alone or in combination with Saccharomyces cerevisiae (yeast) on mediators of the acute phase response in feedlot steers. Eight fistulated steers were used to study the effects of E. faecium alone or with yeast in a crossover design with 2 Latin squares, 4 steers within each square, and 2 periods. The length of each period was 3 wk, with a 10-d adaptation and an 11-d measurement period. The experimental diet contained 87% steam-rolled barley, 8% whole-crop barley silage, and 5% supplement (DM basis). In Exp. 1, treatments were control vs. the lactic-acid-producing bacterium E. faecium (6 x 10(10) cfu/d). In Exp. 2, treatments were control vs. E. faecium (6 x 10(10) cfu/d) and S. cerevisiae (6 x 10(10) cfu/d). The bacteria and yeast supplements were blended with calcium carbonate to supply 6 x 10(10) cfu/d when top-dressed into the diet once daily at the time of feeding (10 g/d). Steers fed the control diet received only carrier (10 g/d). Blood samples were collected from the jugular vein on d 17 and 21 of each period, and serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), haptoglobin, and alpha1-acid glycoprotein (alpha1-AGP) were measured. Supplementation of feed with E. faecium had no effect on concentrations of SAA, LBP, haptoglobin, or alpha1-AGP in plasma compared with those of controls. However, feeding E. faecium and yeast increased (P = 0.02) plasma concentrations of SAA, LBP, and haptoglobin but had no effect on plasma alpha1-AGP. In conclusion, oral supplementation of E. faecium alone had no effect on the mediators of the acute phase response that were measured, whereas feeding of E. faecium and yeast induced an inflammatory response in feedlot steers fed high-grain diets. Further research is warranted to determine the mechanism(s) by which E. faecium and yeast stimulated production of acute phase proteins in feedlot steers. 相似文献
50.
The use of fenugreek seed meal in fish diets: growth performance,haematological and biochemical parameters,survival and stress resistance of common carp (Cyprinus carpio L.) 
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下载免费PDF全文 Zahra Roohi Mohammad Reza Imanpoor Valiolah Jafari Vahid Taghizadeh 《Aquaculture Research》2017,48(3):1209-1215
The present study was conducted to investigate the effects of fenugreek seed meal (FKSM) on growth performance, blood haematological and biochemical factors, survival and stress resistance of the common carp (2.46 ± 0.06 g) fingerlings. Four practical diets containing 0 (control), 0.5%, 1% and 1.5% FKSM were used to feed fish. Fish were fed on the tested diets at a rate of 3% of body weight for 8 weeks. Results indicated that fish fed the control diet had a significantly lower weight gain, specific growth rate and condition factor compared to the other treatments (P < 0.05). Feed conversion ratio decreased significantly in fish fed diets containing FKSM. There were no significant differences in glucose levels, red blood cell count, haematocrit and haemoglobin between treatment groups and the control group (P > 0.05). Significantly lower white blood cells count was observed in fish treatment with FKSM when compared with the control group (P < 0.05). The cholesterol level in group fed supplemented diet by 1% fenugreek significantly lower than other groups (P < 0.05). Total protein levels were significantly higher in all treatments compared to the control (P < 0.05). No mortality was recorded during the feeding trial. In salinity stress experiment, highest survival rate belong to fish fed supplemented diet by 1% fenugreek. These results indicate that FKSM can be considered as a beneficial dietary supplement for improving the growth performance and blood indices of common carp fingerling. 相似文献