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101.
102.
ABSTRACT

Addition of more resistant organic materials, such as biochars, to soils not only enhances soil C sequestration but also can also benefit soil fertility. The aim of this study was to investigate the effect of two organic materials (sheep manure and vermicompost) and their biochars produced at two pyrolysis temperatures (300 and 500°C) applied at 5% (w/w) on the chemical fractions of Zn and Cu and some chemical characteristics of an unpolluted, light textured calcareous soil. Addition of the raw organic materials and their-derived biochars significantly enhanced plant available K, P, and Zn but significantly decreased plant available Cu in the soil. Sheep manure biochar produced at 300°C was most effective at increasing plant available P (13-fold) and K (1.9 fold) likely due to formation of more soluble forms of P and K compared to raw material or biochar produced at higher temperature (500°C). Whereas, raw vermicompost and sheep manure were most effective at enhancing plant available Zn, by increasing water soluble and exchangeable Zn fraction likely due to organic complexation. All amendments, especially biochars produced at 300°C reduced water soluble and exchangeable Cu mainly attributed to increased soil P availability. The results of this study showed that in the short-term, addition of the low-temperature biochars was best for enhancing soil P and K availability, but concomitantly reduced Cu availability the most, whereas, addition of the raw organic materials was better for enhancing Zn availability compared to the biochars.  相似文献   
103.

In order to study the effects of seed nitrogen content and biofertilizer priming on germination indices of wheat seeds under salinity stress, a factorial experiment based on a completely randomized design with four replications was conducted in 2009. Experimental factors consisted of: (1) the application of different nitrogen fertilizer rates (0, 55, 110 and 165 kg ha?1 N) on parent plants; (2) priming of achieved seeds by biofertilizers (Nitragin, Biophosphorus and distilled water); and (3) different levels of salinity produced by NaCl (0, ?0.4, ?0.8 and ?1.2 MPa). Germination percentage, germination rate, mean germination time, germination index, radicle and plumule length, radicle and plumule dry weight and radicle number per seedling were measured. Nitrogen application increased seed nitrogen content in parent plants. All germination indices decreased with increasing in salinity levels. Biofertilizer priming, especially Nitragin, had a positive effect on germination percentage, radicle number and radicle and plumule length in most salinity levels. The highest values for germination factors were related to achieved seeds from parent plants that were treated with 110 kg ha?1 N. Overall, application of middle levels of N fertilizer (55 and 110 kg ha?1 N) on parent plants combined with seed priming with Nitragin biofertilizer improved the germination indices of wheat under salinity stress.  相似文献   
104.
Biochar has been shown to be an effective organic soil amendment for the in-situ immobilization of lead (Pb).Little research has been done on the effects of biochar and zeolite interactions on Pb immobilization in contaminated calcareous soils.Therefore,the aim of this study was to investigate the effects of different levels of zeolite (2% and 4%,weight:weight) and biochars (3%,weight:weight) prepared from green compost (GB),poultry manure (PB),and municipal waste (MB) on the content of Pb in sp...  相似文献   
105.
Summary

Disruption of cut flower water relations due to the growth and proliferation of microorganisms in the vase solution is one of the most important factors causing reduced vase-life and deterioration in cut flowers. These experiments were conducted to study the effects of some biocides in controlling microbial proliferation in vase solutions and on water relations in cut Narcissus tazetta L. cv. ‘Shahla-e-Shiraz’, a native bulbous cut flower of Iran. The stems of ‘Shahla-e-Shiraz’ Narcissus cut flowers were exposed to 17 treatments: aluminium sulphate (at 100, 200 or 300 mg l–1), citric acid (at 150, 300 or 450 mg l–1), 8-hydroxyquinoline citrate (at 200, 300 or 400 mg l–1), sodium hypochlorite (at 400, 600 or 800 mg l–1), calcium hypochlorite (at 400, 600 or 800 mg l–1), sterilised distilled water, or tap water (control). Generally, the least effective compounds in controlling microbial proliferation were low concentrations of aluminium sulphate or citric acid. 8-Hydroxyquinoline citrate treatments were most effective, and the vase solution did not contain any microbes until day-6. Vase solution contaminants were yeasts, Bacillus ssp., Staphylococcus ssp., Actinomycetes and Aspergillus ssp. Yeasts and bacilli were the most common microorganisms. Severe symptoms of phytotoxicity such as bud abortion and yellowing in aluminium sulphate-treated flowers, stem proximal-end browning and shrinking in 8-hydroxyquinoline citrate-treated flowers, and bleaching of soaked parts in sodium hypochlorite treatments, were seen. Most solution was taken up in 150 mg l–1 citric acid, while the reduction in fresh weight was least in 200 mg l–1 8-hydroxyquinoline citrate. The correlation between microbial counts and growth rate with solution uptake was slightly negative, but their correlation with fresh weight loss was slightly positive.  相似文献   
106.
The purpose of this study was to determine the effects of different concentrations of coenzyme Q10 (CoQ10) and α-tocopherol (T) along with their interaction effects on the quality of preserved stallion semen at 5°C for a period of 48 hours. Semen was collected and diluted with skim milk–based extender that was supplemented with different antioxidants: no antioxidant (negative control [NC]), 0.9% (vol/vol) dimethyl sulfoxide (positive control [PC]), α-tocopherol (5 [T5] or 10 [T10] mM), CoQ10 (1 [C1] or 2 [C2] μM), 1 μM CoQ10 + 5 mM α-tocopherol (C1T5), 1 μM CoQ10 + 10 mM α-tocopherol (C1T10), 2 μM CoQ10 + 5 mM α-tocopherol (C2T5), and 2 μM CoQ10 + 10 mM α-tocopherol (C2T10), then kept at 5°C. The results showed that C1 extender resulted in higher total motility (62.44 ± 3.82) and plasma membrane integrity (65.16 ± 3.63%) compared with NC after 48 hours of storage (P < .05). Different concentrations of α-tocopherol had no significant effects on sperm quality, with the exception of plasma membrane integrity, compared with NC and PC extenders (P > .05). Also, C1T5 extender improved total and progressive motility, plasma membrane integrity and functionality, and decreased lipid peroxidation compared with NC and C2T10 extenders over 48 hours of storage at 5°C (P < .05). The C1T5 extender was similar to C1 and T5 extenders in all semen parameters evaluated during storage time. In conclusion, between previously mentioned extenders, C1T5 could improve stallion sperm quality during 48 hours of storage. In the present study, none of extenders had effect on sperm quality until 24-hour storage.  相似文献   
107.
Silymarin, an extract from “milk thistle” (Silybum marianum) plant is traditionally used as herbal medicine. The present study was conducted to investigate the clinical effects and possible side effects of silymarin on biochemical blood parameters of rainbow trout (Oncorhynchus mykiss). Fishes were treated with 0 (control), 100, 400, and 800 mg of silymarin per kg of food during 4 weeks. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine kinase (CK), glucose, total protein, creatinine, triglyceride, cholesterol, urea, uric acid and liver cellular total antioxidant, and protein content were measured after 7, 14, and 28 days of silymarin treatment. The results showed that oral administration of silymarin in fish significantly reduced plasma glucose and cholesterol levels and relatively increased plasma total protein and globulin concentrations (P < 0.05). Increasing plasma albumin levels indicate the important role of albumin in drug transportation in circulatory system of fish. Silymarin also stabilized cellular membrane structure and regulated the levels of AST, ALT, ALP, CK, and LDH activity. In conclusion, on the basis of these results, oral administration of silymarin up to 400 mg per 1 kg of food has no side effect on blood biochemical and clinical parameters of fishes. However, oral administration of 800 mg/kg- of silymarin caused cytotoxicity and modifications in blood biochemical parameters of fish.  相似文献   
108.
Nanofibrous mats of poly (?-caprolactone)/nanoclay nanocomposites were fabricated using electrospinning method. Effects of nanoclay content of the nanocomposite on final nanofiber structures were investigated and characterized by scanning electron microscope (SEM) and differential scanning calorimetry (DSC) analysis. The results showed that the presence of the nanoclay promoted the creation of fibrous structure in comparison with solely poly (?-caprolactone). Furthermore, increase in nanoclay content led to the formation of more uniform nanofiber structures and caused a decrease in the mean nanofiber diameter. DSC results showed that the addition of nanoclay reduced the crystallinity of the nanocomposite in compared with pristine PCL. Studies of the mechanical properties, wettability and degradability showed that the presence of nanoclay improved tensile modulus, tensile strength, wettability and biodegradability of the nanocomposites. To evaluate the effect of nanoclay on the cell adhesion and bioactivity of the poly (?-caprolactone)/nanoclay nanocomposites, fibroblasts cells were seeded on the mats. The results showed that the prepared nanocomposite could be a potential candidate for tissue engineering.  相似文献   
109.
OBJECTIVE: To compare antimicrobial susceptibility patterns of Escherichia coli isolates cultured from fecal samples from cows and calves on dairy farms that used organic (ie, no or severely limited antimicrobial use) versus conventional production methods. DESIGN: Cross-sectional study. SAMPLE POPULATION: Fecal samples from 10 cows and 10 calves on each of 30 organic dairy farms and 30 neighboring conventional dairy farms in Wisconsin. PROCEDURE: E. coli isolates obtained from the fecal samples were tested for susceptibility to 17 antimicrobials by means of a microbroth dilution test. Prevalence of antimicrobial resistance was compared between organic and conventional dairy farms. RESULTS: E. coli was isolated from 1,121 (94%) fecal samples. Farm type (organic vs conventional) and animal age (cow vs calf) were significantly associated with odds that E. coli isolates would be resistant to various antimicrobials. After controlling for age, logistic regression analyses indicated that isolates from conventional dairy farms had significantly higher rates of resistance to ampicillin, streptomycin, kanamycin, gentamicin, chloramphenicol, tetracycline, and sulfamethoxazole than did isolates from organic dairy farms. However, no significant differences were detected for the 10 other antimicrobials that were tested. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that compared with isolates from conventional dairy farms, E. coli isolates from organic dairy herds have significantly lower prevalences of resistance to 7 antimicrobials; however, prevalence of resistance was not significantly different for 10 other antimicrobials. Resistance was more common for isolates from calves than for isolates from adult dairy cows.  相似文献   
110.
The mode of inheritance of spotting in both breeds (ES and DRS) is compatible with incompletely dominant resp. intermediate segregation, though a broad variability of spotted areas exists, indicating the influence of minor genes or other ontogenetic factors. Additional findings support the conclusion, that there is a very distinct predisposition of homozygous KK animals to develop megacolon with growing age. This also has consequences for the relative organ weight of the heart and of the adrenals in this genotype. Sporadically encountered accessory adrenal cortical tissue however did not exhibit genotypic preferences.  相似文献   
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