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111.
This paper describes in vitro and in vivo anthelmintic activities of Swertia chirata. In vitro studies revealed that at 25 mg/ml (P>/=0.05) the crude aqueous (CAE) and methanolic extracts (CME) of S. chirata whole plant showed an anthelmintic effect on live Haemonchus contortus. Moreover, in the in vivo study, the whole plant of S. chirata administered as crude powder (CP), CAE and CME at the dose of 3 g/kg to sheep naturally infected with mixed species of gastrointestinal nematodes, showed a significant reduction in egg per gram of faeces.  相似文献   
112.
Toxoplasma gondii is a parasite that has been extensively studied due to its medical and veterinary importance in terminating pregnancies. Consequently, a satisfactory vaccine is required to control its adverse effects on pregnant animals. The microneme protein, MIC3, is a major adhesion protein that binds to the surface of host cells and parasites, and is therefore a potential vaccine against T. gondii. The viability of MIC3 as a vaccine is investigated in this study. Sheep were injected twice, intramuscularly, with plasmids containing DNA encoding for the mature form of MIC3 protein formulated into liposomes. Control sheep were injected with an empty vector or received no injections. The injection of sheep with DNA plasmids encoding for MIC3 elicited an immune response after the first and second injections as indicated by antibody responses and the production of IFN-gamma. The immune response, as measured by the IgG2 and IgG1 serum levels, was boosted after the injection of the MIC3 DNA vaccine together with high anti-MIC3 antibodies. The results demonstrate that the intramuscular injection of sheep with a plasmid containing DNA coding for MIC3 protein induces a significant and effective immune response against T. gondii.  相似文献   
113.
Antioxidants play an important role in adapting plants to abiotic stress by detoxifying reactive oxygen species (ROS). Involvement of antioxidant enzymes in abiotic stress tolerance of highly stress‐tolerant quinoa was studied in a climatic chamber at 6 mOsm (milliosmolar) ionic (300 mm NaCl) and non‐ionic (600 mm mannitol) salts combined with increasing levels of potassium K1 and K2 (6, 12 mm ), respectively. Fifteen days of salt treatment (both ionic and non‐ionic) decreased plant growth (shoot and root fresh weight), stomatal conductance and chlorophyll content index. Furthermore, both forms of salt stress increased the activities of superoxide dismutase, catalase, ascorbate peroxidase and peroxidase up to 2.33‐, 3.98‐, 4.78‐ and 5.55‐folds, respectively, compared to no salt treatment, whereas membrane stability index decreased corresponding to increase in lipid peroxidation (malondialdehyde), with salt treatments compared to non‐stressed plants. However, no significant effect of potassium and salt treatments has been noticed on the maximal photochemical efficiency of PSII. The results suggested that enhanced antioxidant enzymes activity under salt stress could be one of the factors responsible for abiotic stress tolerance in quinoa.  相似文献   
114.
The information of soil compaction effects on growth and yield of crops for saline and waterlogged soils is scanty. A pot experiment was conducted on a sandy clay loam soil during 2001–2002 to study the interactive effects of soil compaction, salinity and waterlogging on grain yield and yield components of two wheat (Triticum aestivum) genotypes (Aqaab and MH-97). Compaction was achieved at 10% moisture level by dropping 5 kg weight, controlled by a tripod stand for 20 times from 0.6 m height on a wooden block placed inside the soil filled pots. Soil bulk density of non-compact and compact treatments was measured as 1.21 and 1.65 Mg m−3, respectively. The desired salinity level (15 dS m−1) was developed by mixing the required amount of NaCl in soil before filling the pots. Waterlogging was developed by flooding the pots for 21 days both at tillering and booting stages. Compaction aggravated the adverse effect of salinity on grain yield and different yield components of both the wheat genotypes. Average reduction in grain yield was 44% under non-compact saline conditions against 76% under compact saline conditions. Similarly, the reduction was about 20% more for 100 grain weight and shoot length, 30% more for number of spikelets per spike, 37% more for number of tillers per plant, and 32% more for straw weight in compact saline treatment than in non-compact saline treatment. Compaction alone caused a reduction of 36% in grain yield. The effect of waterlogging on grain yield and yield components was mostly not changed significantly due to compaction. Rather waterlogging mitigated the effect of compaction for most of the yield components except for number of spikes per plant. Therefore, as for normal soils, the cultivation of salt-affected soils should employ implements and techniques which minimize compaction of root zone soil. The effect of soil compaction can also be minimized by light irrigations with short intervals and by using a stress tolerant crop genotype.  相似文献   
115.
Abstract

Cotton (Gossypium hirsutum L.) is of prime importance because of its quality fiber and edible oil production. Boron (B) is among essential micronutrients for plant growth; it aids in the transfer of sugars and nutrients from leaves to fruit that are involved directly or indirectly in many plant functions. Cotton growth, yield and quality are strongly affected with boron application. A two-year study was conducted to evaluate the impact of foliar applied B (0, 2, 4, 6, 8 and 10?g of B L?1 of water) on the performance of cotton cultivars (FH-113, MNH-786 and CIM-496). The results indicated that growth, yield and quality traits of cotton were significantly influenced by different levels of foliar applied boron as well as cultivars of cotton. Among cotton cultivars, the yield and quality parameters were superior in cultivar “FH-113.” Foliar application of boron at 6?g L?1 of water improved leaf area index and leaf area duration and eventually improved the number of bolls per plant, boll retention percentage, average boll weight, lint yield, ginning out turn, fiber length and uniformity ratio of cotton. Foliar application of B at 6?g per liter of water, showed promising results by improving growth and quality parameters and is recommend to enhance the economical yield production of cotton cultivar “FH-113” with improved quality.  相似文献   
116.
117.
Our understanding of nitrogen transformation in paddy fields or wetlands is limited due to the complex interactions between soil, water, and biomass. Therefore, we studied transformation patterns resulting from the oxic level in the soil, and studied saturated (anoxic) and unsaturated (oxic) flow conditions. We present a model designed to predict concentrations of nitrate and ammonium at several soil depths resulting from the processes of nitrification, denitrification, and ammonification. Model equations were obtained that describe NO3-N and NH4-N concentrations in terms of position, rate constant, and average flow velocity. Although many parameters were included in the model equations, some were determined from the literature and others were derived from experiments. A sensitivity analysis of the rate coefficients for NO3-N and NH4-N revealed that they are extremely sensitive to denitrification and ammonification respectively. Experimental results show that there were large differences in the transformations of NO3-N and NH4-N, the water pressure distributions, and the oxygen reduction potentials (ORP) between saturated and unsaturated pore water flow conditions. The performance of the model for sequential transformations during the transport of NO3-N is well documented under both saturated and unsaturated flow conditions.  相似文献   
118.
In a cross-sectional study, the associations of age, serological status against Campylobacter fetus (CF), Haemophilus somnus (HS) and Leptospira hardjo (LH) with the seroprevalence of bovine viral diarrhea virus (BVDV) in dairy cattle were evaluated. Six hundred and thirty cattle from a herd in Tulare county of California were included in the study. Blood samples from the cattle were collected in December 1986. Enzyme-linked immunosorbant assay (ELISA) was used to determine the positive or negative status of cows against CF, HS, LH and BVDV antigens. Loglinear analysis was used to describe the relationships of four categorical variables with the seroprevalence of BVDV. The final loglinear model was interpreted as a logit model and obtained by conditioning on explanatory variables in the model found to relate significantly with BVDV seropositivity. The hierarchical logit model included two two-way interactions (BVDV × HS and BVDV × LH) and a three-way interaction (BVDV × CF × age). HS-seronegative cattle had 4.7 times greater odds of being BVDV-seropositive compared with HS-seropositive cattle. In contrast, LH-seropositive cattle had 2.7 times increased odds of BVDV seropositivity compared with LH-seronegative cattle. The presence of the three-way interaction term in the model involving age, CF and BVDV seroprevalence implies that among heifers, CF-seronegative and CF-seropositive animals had about the same odds of BVDV seropositivity (e.g. adjusted odds ratios = 20.5 vs. 24.5), whereas, among cows, CF-seronegative animals had at least twice the odds of being BVDV-seropositive than those of CF-seropositive animals (e.g. adjusted odds ratios = 23.0 vs. 11.0).  相似文献   
119.
Rainwater harvesting in small dams has good potential to provide supplementary agricultural irrigation during critical crop growth stages. Field experiments were conducted to evaluate cropping patterns: fallow–wheat (FW), mash–wheat (MaW), sorghum–wheat (SW), maize (grain)–wheat (MW), maize (grain)–gram (MG) and mung–canola (MuC); under two conditions: irrigated (Command area of Pira Fatehial small dam) and rainfed (Un‐command area) on sandy loam soil during three years (2009 to 2011). Treatments were arranged in a randomized complete block design, three factor factorial (cropping patterns, irrigated/non‐irrigated conditions and years) using four replications. The highest grain yield of wheat (5.6 Mg ha−1) was obtained from the MaW cropping pattern as compared to those from MW, FW and SW cropping patterns. Summer crops (sorghum fodder, maize grain and mash) performed excellent under irrigated conditions. Water use efficiency of wheat (14.3 kg ha−1mm−1) following mash under both the conditions exhibited higher values than when compared with those from SW, FW and MW cropping patterns. However, nutrient use efficiency in SW cropping pattern surpassed the others. Performance of all crops remained better under the irrigated condition during both all seasons and years, as rainfall deficiency was compensated by supplementary irrigations. Hence, this study concluded that farmers having water resources for supplemental irrigation should adopt the MW cropping pattern, based on grain yield, efficient utilization of available supplemental water and better utilization of nutrients. Similarly, based on improved nutrient utilization and monitory outputs, the MaW sequence should be followed in rain‐fed areas for better resource management. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
120.
The soluble fraction (105 000g) from goose, pig and sheep liver-homogenates was found to contain an enzyme which metabolised a mixture of atrazine and simazine in in-vitro incubations by a combination of hydrolysis and partial N-dealkylation. Complete dealkylation was not observed as shown by the removal of only one alkyl group, but not both, from the compounds containing chlorine or hydroxyl-groups attached to the triazine ring.  相似文献   
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