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排序方式: 共有236条查询结果,搜索用时 31 毫秒
61.
A feeding trial was conducted to evaluate the effect of replacing fish meal protein with fermented soybean meal (FSM) on the growth performance, feed utilization, amino acid profile, body composition, morphological parameters, activity of antioxidant and digestive enzymes of black sea bream (Acanthopagrus schlegeli) juvenile. Five isonitrogenic and isolipidic diets were prepared with levels of 0 (control), 80, 160, 240 and 320 g kg?1 FSM. Triplicate groups (40 fish per tank) of juvenile black sea bream with initial weight of 1.17 ± 0.04 g were hand‐fed to visual satiation at three meals per day for 8 weeks. The fish fed diets containing different levels of FSM had no significant differences regarding survival and specific growth rate compared with control group. Feed and protein efficiency ratios of fish fed diet containing 320 g kg?1 FSM were significantly lower than those of control group. Daily feed intake and daily protein intake of fish fed diet containing 240–320 g kg?1 were significantly higher than those of control group. Hepatosomatic index and condition factor of fish were not affected by different dietary FSM level. Fish fed diets containing 240–320 g kg?1 FSM had significantly higher visceral somatic index than control group. Whole body proximate and amino acid compositions of fish were not affected by dietary FSM level. The activity of digestive enzymes in the intestine was not affected by dietary FSM level. The activity of glutathione peroxidase in liver was significantly higher for fish fed the diet containing 160 g kg?1 FSM compared with control group. This study showed that up to 40% fish meal in the diets of juvenile black sea bream could be replaced by fermented soybean meal with supplementation of methionine, lysine and taurine. 相似文献
62.
We used a goal programming technique to determine the optimal harvest volume for the Iranian Caspian forest. We collected data including volume, growth, wood price at forest roadside, and variable harvesting costs. The allometric method was used to quantify seques- trated carbon. Regression analysis was used to derive growth models. Expected mean price was estimated using wood price and variable harvesting costs. Questionnaire was used to determine the constraints and the equation coefficients of the goal programming model. The optimal volume was determined using the goal programming method according to multipurpose forest management. LINGO software was used for analysis. Results indicated that the optimum volumes of species were 250.25 m3.ha-1 for beech, 59 m3.ha-1 for hornbeam, 73 m3.ha-1 for oak, 41 m3.ha-1 for alder, and 32 m3.ha-1 for other species. The total optimum volume is 455.25 m3.ha-1. 相似文献
63.
Forest fires are an important environmental concern worldwide, affecting the soil, forests and human lives. During the process of burning, soil nutrients are depleted and the soil is subsequently more vulnerable to erosion. Nowadays it is necessary to identify the factors influencing the occurrence of fire and fire hazard areas, in order to minimize the frequency of fire and avert damage. Logistic regression was used to study the forest fire risk and identify the most influential factors in the occurrence of forest fires. Climatic variables (temperature and annual precipitation), human factors (distance from streams and farmland) and physiography (land slope and elevation) were considered and their correlation with the occurrence of fires investigated. Results of model validation and sensitivity of various areas to fire were examined with the ROC coefficient and Hosmer–Lemeshow test. The estimated coefficients for the independent variables indicated that the probability of occurrence of fire is negatively related to land slope, site elevation and distance from farmlands, but is positively related to amount of annual precipitation. 相似文献
64.
Tropical Animal Health and Production - Separation of autosomal and sex-linked direct additive genetic effects has significant role in sheep breeding programs. Hence, this study was conducted to... 相似文献
65.
Reza Mohammadi Kouresh Nader Mahmoodi Reza Haghparast Stefania Grando Maryam Rahmanian Salvatore Ceccarelli 《Journal of Crop Science and Biotechnology》2011,14(4):281-288
This study was carried out to identify superior barley genotypes for the rainfed areas of western Iran using a participatory
varietal selection (PVS) approach. Three field experiments were conducted in two randomly selected farmers’ fields and in
one rainfed research station in the 2006–07 cropping season with 69 genotypes (including one local and one improved check).
Several univariate and multivariate methods were used to analyze qualitative (farmers’ scores) and quantitative (grain yield)
data. Individual farmers’ scores in each village were positively correlated, indicating that the farmers tended to discriminate
genotypes in similar fashion, although the genotypes actually selected by farmers were different in the two villages. In recent
years, a greater number of farmers in western Iran preferred the improved variety (Sararood-1) over the local barley (Mahali),
while in this project the farmers preferred the new genotypes over the two checks. This was also verified by the quantitative
data showing that the checks were outyielded by the new genotypes. Farmers were efficient in identifying the best genotypes
for their specific environment, as shown by biplot analysis, indicating their competence in selection. The genotypes selected
by the breeder and farmers were almost similar but some differences existed. In conclusion, PVS is a powerful way to involve
farmers for selecting and testing new cultivars that are adapted to their needs, systems and environments. 相似文献
66.
Mohamadi Yalsuyi Ahmad Forouhar Vajargah Mohammad Hajimoradloo Abdolmajid Mohammadi Galangash Mohsen Prokić Marko D. Faggio Caterina 《Veterinary research communications》2022,46(2):389-396
Veterinary Research Communications - Industrial chemical solutions are widely used as a method to disinfection of aquaculture water and environments. The aim of the present study was to evaluate... 相似文献
67.
Jehangir H. Bhadha Timothy A. Lang Samira H. Daroub 《Journal of Soils and Sediments》2014,14(5):991-1003
Purpose
The Everglades Agricultural Area (EAA), USA, comprises nearly 280,000 ha of organic soil farmlands that are drained by a network of farm canals. During the wet summer season, the water-table in the farmlands is maintained by moving water from farm canals via low-fit, high-volume drainage pumps. The drainage pumping creates a hydraulic pressure gradient, which has the potential to deliver particulate and dissolved substrates from surrounding farmlands into farm canals. This study investigated the role that seasonal drainage plays on the fate and transport of farm canal water including nutrients and metals, plants, and sediments.Materials and methods
Intact sediment cores were collected from eight farm canals during the months of November and June, sectioned into two depth intervals (0–2.5 and 2.5–5 cm), and tested for organic matter (OM), phosphorus (P), iron (Fe), and aluminum (Al). In addition, water from the canal (core-water) was also collected and tested for total P, total dissolved P, soluble reactive P, particulate P, dissolved organic carbon, and calcium (Ca). Oxalate extractable Fe, Al, and P were used to estimate sediment P storage capacity. In order to evaluate the seasonal variability in aquatic vegetation coverage in the farm canals, spatial assessment of coverage was conducted every 2 months over a 2-year period.Results and discussion
Significant increases in Fe and Al concentrations were observed in the sediment in November compared with June, possibly derived from surrounding soils. The source of OM to the sediments was directly associated with aquatic plants, following a seasonal trend. Total P and Ca were significantly higher in the water during June compared with November. The seasonal trends in sediment and core-water concentrations can be explained by groundwater inputs, surface runoff, and plant coverage within farm canals. High concentrations of Fe and Al in the sediments did not reflect a high P storage capacity, due to the presence of high OM content and seasonal fluctuations in redox potential.Conclusions
The discharge of groundwater from surrounding farmlands is seasonal and has the potential to deliver nutrients, OM, and metals into adjacent farm canals. During summer, primary productivity is at its peak, and this has a direct effect on the percent aquatic plant coverage, nutrient cycling, and P storage capacity within the farm canals. Within the EAA farm canals, the presence of Ca-carbonate may have a greater influence on P storage capacity of the sediments than Fe and Al. 相似文献68.
An investigation on the dimensional properties of plain knitted fabric produced from cotton yarn and subjected to different
relaxation treatments is presented in this paper. The main aim of this research is to characterize the internal energy of
fabric by using yarn-pullout test method in ultrasonic relaxation state and compare it with other common mechanical relaxation
treatments. A comprehensive experimental analysis showed that, by using ultrasonic waves, the area geometry constant value
(k
s) achieved was higher than the conventional relaxation methods. Then, we introduced residual-energy forming and loss-energy
uniforming. The former appeared due to fabric shrinkage and the later one appeared due to release of fabric loops from extra
forces which imposed during knitting process. The results also indicated that ultrasonic waves energy causes more uniformity
on loop and consequently, the fabric reaches to a less internal energy than washing treatment. 相似文献
69.
Simin Riahi Mohammad Taghi Mohammadi Vahid Sobhani Shima Ababzadeh 《Iranian Biomedical Journal》2016,20(1):26-32
Background:
Overexpression of lectin-like low density lipoprotein (LOX-1) receptor plays an important role in hyperglycemia-induced vascular complications such as atherosclerosis. Based on the beneficial effects of exercise on preventing cardiovascular complications of diabetes, we aimed to examine the protective effects of aerobic exercise on expression of LOX-1 receptor and production of free radicals in the heart of diabetic rats.Methods:
Four groups of rats were used: (n = 5 per group): sedentary normal, trained normal, sedentary diabetes and trained diabetes. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg). The exercise protocol was consisted of swimming 30 min/day, 5 days/week for eight weeks. Plasma glucose was evaluated at initiation, weeks 4 and 8 of experiment. At the end of experiment, rats were sacrificed and the heart was removed for determination of nitrate, malondialdehyde, and LOX-1 gene expression.Results:
In normal non-diabetic rats, the blood glucose level was <150 mg/dl; however, the induction of diabetes resulted in levels more than >400 mg/dl. Gene expression of LOX-1 was increased in the heart of diabetic rats. Exercise reduced the gene expression of this protein in diabetic states without reducing the blood glucose. Finally, swimming exercise decreased the malondialdehyde and nitrate levels in heart tissue both in control and diabetic rats.Conclusion:
Swimming exercise reduces heart expression of the LOX-1 receptor in accompany with reduction of free radicals production. Since these parameters are important in generation of diabetic complications, swimming exercise is a good candidate for reducing these complications. Key Words: Hyperglycemia, Diabetic complications, LOX-1 receptor, Exercise, Free radicals 相似文献70.
Maryam?Mohammadi Loghman?KarimiEmail author Mohammad?Mirjalili 《Fibers and Polymers》2016,17(9):1371-1377
In this study, synthesis of zinc oxide nanoparticles was carried out along with the hydrolysis of polyester fabric using sodium hydroxide to increase the surface activity and enhance the nanoparticles adsorption. The polyester fabrics were treated with zinc acetate and sodium hydroxide at different bath conditions, ultrasound and stirrer, resulting in formation of ZnO nanospheres and ZnO nanorods. The presence of zinc oxide with different shapes on the surface of the polyester fabrics was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Also, the X-ray diffraction patterns established the composition of wurtzite structure of zinc oxide. The self-cleaning property of treated polyester fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that the photocatalytic and antibacterial activities of the ultrasound treated polyester fabrics were superior compared to the stirrer treated samples. 相似文献