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61.
Tomato serves as a model to introduce agronomically important genes into dicotyledonous crop plants and to develop edible vaccines and produce cost-effective therapeutics. This study has developed an efficient protocol of shoot organogenesis for Lycopersicon esculentum Mill. through using of different types of explants and growth regulators. Generally, all explants responded significantly to presence of BAP. Best shoot regeneration for leaf (100%) was achieved on MS supplemented with BAP (2 mg/L) + IAA (0.1 mg/L), whereas it was recorded on MS supplemented with BAP (2 mg/L) and BAP (2 mg/L) + IAA (0.5 mg/L) for cotyledons (95%). In addition, hypocotyls (77%) showed the best shoot response on MS supplemented BAP (3 mg/L). Highest number of shoots per explant was 13.33, 12.25, 7.94 respectively for hypocotyls, leaves, cotyledons. The best medium for highest length of shoot was in the presence of BAP (3 and 2 mg/L) + IAA (0.1 mg/L) respectively for hypocotyl (45 mm) and leaf (40.50 mm) explants. This parameter was achieved for cotyledons (13.32 and 12.5 mm) on MS medium supplemented with BAP (3 and 2) mg/L + IAA (0.1 mg/L), respectively. The increasing of BAP concentration up to 3 (mg/L) causes shoot length to continue developing, but it fell down in the presence of BAP (4 mg/L) due to the toxic effect of growth regulators accumulation. Root formation took place within 10–14 days after culturing on the rooting media. Best root induction (100%) was observed on MS medium supplemented with IAA (0.1 and 0.2 mg/L). All rooted shoots acclimated in phytotron and then cultivated in the greenhouse.  相似文献   
62.
预防疾病决不只是进行疫苗接种,而是一项复杂得多的工作。鸡群未得到充分保护时,疫苗常常成为被责怪的对象,但事实上免疫失败常常是由其它因素造成的。  相似文献   
63.
Due to the heavy costs of wind erosion control measures, the correct selection of technical methods is indispensable for a sustainable land management in arid and semiarid regions. Thus, the main goal of this research was to investigate the feasibility of using the clay minerals (i.e., bentonite), polyvinyl acetate and palm biochar for reducing the wind erosion in deserts surrounding the cities. The treatments were sprayed uniformly onto the containers (5 × 35 × 105 cm, 0.37 m2) with sand (collected from sand dunes surrounding Isfahan city, central Iran) in 3 replicates. The experiments were conducted in a wind tunnel with sequential repetitions after 1, 10, and 20 weeks. Among the studied treatments, the bentonite planters demonstrated to be the most effective soil erosion control measure by reducing soil loss and improving sand ablation. On the contrary, the palm biochar had less influence on the soil erosion control and only a slight effect on the threshold speed. For the future, further studies are required to select the best and most relevant soil erosion control measures under field conditions considering all the environmental aspects in arid regions of Iran.  相似文献   
64.
The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe3O4 cores is reported here for the first time. The formation of this magnetic spongin–Fe3O4 composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe3O4 composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe3O4 and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe3O4 nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications.  相似文献   
65.
The main aim of the present work was to evaluate the effect of dietary butylated-hydroxytoulene (BHT as an antioxidant) and dietary lipid level on flesh lipid quality of Beluga sturgeon during frozen storage. An initial 135-day feeding trial evaluated practical-type diets containing 0 or 250 mg BHT kg?1 with two lipid levels (12 and 24% diet on dry matter basis) in a factorial arrangement. Fillet samples were analyzed fresh or after storage at ?18 ± 1°C for 12 months. Dietary antioxidant supplementation had no significant effect on fat content and fatty acid composition in the studied fish muscle, but increasing the lipid concentration in the feed increased muscle lipid concentration. Lipid oxidation in fish muscle is related to increasing lipid concentration in the feed. In addition, oxidation was reduced for fish fed BHT. Results showed that dietary BHT supplementation can slow down the level of lipid oxidation in Beluga sturgeon muscles during frozen storage, but it had a direct relationship with dietary lipid level.  相似文献   
66.
The comparative effects of Freund's and Aloe vera gel as adjuvants on the expression of IL‐1β and TNF‐α genes were studied in vaccinated common carp (Cyprinus carpio) with Aeromonas hydrophila bacterin. Fishes were intraperitoneally immunized with A. hydrophila bacterin in combination with Aloe vera gel or Freund's and also without any adjuvant. At day 28 after immunization, all groups were challenged by lethal dose of A. hydrophila (107 cells/fish). Changes in the expression of IL‐1β and TNF‐α genes were evaluated in anterior kidney before challenge and 12, 24, 72 and 7 days postchallenge using quantitative real‐time PCR. Higher expression levels of both genes were observed in all vaccinated groups compared with non‐immunized group. Fishes which received Aloe vera gel showed higher expression of IL‐1β and TNF‐α in relation to animals which vaccinated with or without Freund's adjuvant. We concluded that Aloe vera gel in compared with Freund's adjuvant had a more stimulatory effect on the expression of immune‐related genes in vaccinated common carp and it can use as a novel adjuvant in aquaculture.  相似文献   
67.
The success of plantation, establishment, and growth of trees and shrubs is an important concern in afforestation efforts. There have been extensive efforts to use Haloxylon ammodendron in many desert areas throughout the world in desert combating projects, but these efforts have not always been successful, despite high costs. In this study, we propose a new application of fuzzy decision-making method for selecting suitable sites for the growth of this species. We determine, based on available autecological studies, the most effective factors in desert habitats, and a fuzzy membership function is designed for each of the factors. A suitability index is constructed by unifying the fuzzified factors. This model is then applied to an actual plantation area to evaluate the suitability of different parts of this trial area. Finally, the predicted results are compared to the actual rate of success, based on the canopy cover percentage. The coefficient of determination for the observed canopy cover percentage plotted against the predicted suitability values is higher than 98%, which demonstrates that the presented fuzzy decision-making approach is potentially a powerful tool in site selection for this and, probably, other species.  相似文献   
68.
Reproductive performance of Holstein dairy cows in Iran   总被引:2,自引:2,他引:0  
The objectives of the present study were to describe the current reproductive parameters of Holstein dairy cows in Iran and to determine factors which have a significant effect on reproductive performance with emphasis on high-producing dairy cows. Five large Holstein dairy herds from the major milk production areas of Iran were selected for this study. Reproduction data including parity of dam, calving date, days to first service, days open, number of services, dry period, and occurrence of diseases for cows that calved from 2004 to 2007 were collected from the herds' databases. To determine the effects of year and season of calving, disease status, level of milk production, and parity of dam on reproductive parameters, the proc-mixed procedure in SAS software was used. Overall, data about 8,204 lactation were collected for the study. Results showed that mean (±SD) days open, calving interval, and days to first service for study herds were 134 (±89), 403 (±86), and 67 (±38) days, respectively. Conception rates at the first service and the overall service-conception rate were 41.6% and 41%, respectively. The level of milk production and diseases had significant negative effects on days open and service per conception (P < 0.05); statistical analysis showed that for every 100-kg increase in milk yield, days open will increase by about 0.3 days. However, no significant effect of level of productivity was observed on days to first service. The results of this study indicate that high milk production is a risk factor for decreasing fertility in Iran, like many other parts of the world.  相似文献   
69.
Lipoblastoma is a rare benign tumour of adipose tissue that usually occurs in young children. Although around 100 cases of lipoblastoma have been reported in humans, no report has been previously described in animals. This case report describes the clinical and histopathological findings of a congenital lipoblastoma located at the tail base of a 2-day-old male calf. Grossly, the mass was pink with a partly ulcerated and haemorrhagic surface. The calf showed no neurological deficits. Radiographs of the vertebral column revealed no abnormalities, and surgical excision was performed. Histopathology of the mass was consistent with lipoblastoma. The calf was followed up for 13 months and found to be healthy with no signs of recurrence. To the best of the authors' knowledge, this is the first case of lipoblastoma in the veterinary literature. Lipoblastoma should thus be considered in the differential diagnosis list for congenital adipose tissue tumours in animals.  相似文献   
70.
The Arasbaran Protected Area is an important but little studied nature reserve in NW Iran. In the past habitat heterogeneity and biodiversity have been threatened by over-exploitation; in the future depopulation may lead to partial abandonment. The soil seed bank was examined to see whether there are sufficient species represented as persistent seeds to reconstitute the vegetation in the event of habitat deterioration. There were differences between seed banks from different soils and vegetation types but essentially all soil seed banks contained few species and low densities of seed. Moreover, the species in the seed bank were unrepresentative of the vegetation. During future periods of changing land use it will be important to maintain the existing vegetation. There are however indications of successful recent conservation management. Annuals are abundant in the woodland seed bank but absent from the vegetation. The forest is recovering from the disturbance of collecting fire-wood.  相似文献   
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