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71.
ABSTRACT

The effects of deficit irrigation and fertilizer use under drip irrigation (DI), on vegetative growth of mature cherry trees were studied in two field experiments. Treatments for the assessment of deficit irrigation consisted of two drip line arrays: double drip lines (T1) and loop (T2) as main treatments. Three irrigation levels: irrigation at 100% of crop evapotranspiration (ETc or I1), 75% ETc or I2, and 50% ETc or I3, constituted the sub-treatments. To assess soil fertility practices, the main treatments consisted of T1 and single drip line (T3) arrays; sub-treatments were two fertilizer regimes: basic fertilizer recommendation plus 0.5 m3 sheep manure per tree (F1) and basic fertilizer recommendation plus 1300 g potassium sulfate, 350 g of zinc (Zn), 140 g of iron (Fe), and 600 g ammonium phosphate (F2). Total irrigation amount, which was applied routinely in control treatment (7466.7 m3ha? 1), was less than the crop water requirement (8764.5 m3 ha? 1). A significant correlation between both the length of young branches and canopy volume with annual applied irrigation water was observed. Mean canopy volume under T1 was 26.0 m3 tree? 1, which was significantly less than 28.6 m3 tree? 1 under T2. Water use efficiency (kg m? 3) was increased by water stress, but there was no significant yield reduction from I1 to I2. Concentration of Fe, phosphorus (P), potassium (K), and magnesium (Mg) in leaf samples increased with the use of double drip lines array compared to use of single drip line array and it was higher under F2 fertilizer level. The concentration of calcium (Ca) in leaf samples was higher than critical level in all treatments. We conclude that I2 irrigation level and F2 fertilizer management was the most efficient practice for cherry trees in the study area.  相似文献   
72.
In order to investigate the effect of nitrogen (N) and sulfur (S) fertilizers on yield and seed quality of three canola cultivars, a factorial based on randomized complete block experiment was conducted during 2005–2006 in Iran. Treatments included four nitrogen rates (0, 75, 150, and 225 kg N ha?1 source of urea), four sulfur rates (0, 100, 200, and 300 kg S ha?1), and three cultivars (‘Pf’, ‘Option-500’, and ‘Hyola-401’). Results indicated cultivar had a significant effect on all studied traits. ‘Option-500’ and ‘Hyola-401’ cultivars had the highest seed yield, protein content, and N:S ratio in seed. The levels of 150 and 220 kg N ha?1 resulted in the maximum protein content. Increasing N levels resulted in N content and decreased the oil content. The interaction effect between S and N levels showed the highest N content in seed was obtained with 300 kg S ha?1 and 225 kg N ha?1.  相似文献   
73.
Barchan dunes are among the most common accumulative phenomena made by wind erosion, which are usually formed in regions where the prevailing wind direction is almost constant throughout the year and there is not enough sand to completely cover the land surface. Barchans are among the most common windy landscapes in Pashoueyeh Erg in the west of Lut Desert, Iran. This study aims to elaborate on morphological properties of barchans in this region using mathematical and statistical models. The results of these methods are very important in investigating barchan shapes and identifying their behavior. Barchan shapes were mathematically modeled by simulating them in the coordinate system through nonlinear parabolic equations, so that two separate equations were calculated for barchan windward and slip-face parabolas. The type and intensity of relationships between barchan morphology and mathematical parameters were determined by the statistical modeling. The results indicated that the existing relationships followed the power correlation with the maximum coefficient of determination and minimum error of estimate. Combining the above two methods is a powerful basis for stimulating barchans in virtual and laboratory environments. The most important result of this study is to convert the mathematical and statistical models of barchan morphology to each other. Focal length is one of the most important parameters of barchan parabolas, suggesting different states of barchans in comparison with each other. As the barchan's focal length decreases, its opening becomes narrower, and the divergence of the barchan's horns reduces. Barchans with longer focal length have greater width, dimensions, and volume. In general, identifying and estimating the morphometric and planar parameters of barchans is effective in how they move, how much they move, and how they behave in the environment. These cases play an important role in the management of desert areas.  相似文献   
74.
Background: Acrylamide (ACR) is a well-known industrial toxic chemical that produces neurotoxicity, which is characterized by progressive central and peripheral neuronal degeneration. Chrysin is a natural, biologically active flavonoid compound, which is commonly found in many plants. The antioxidant and neuroprotective properties of chrysin have been demonstrated. Methods: In this study, the possible effect of chrysin on ACR-induced toxicity was evaluated in both in vitro and in vivo experiments. PC12 cells were used as a suitable in vitro model. Cells were exposed to chrysin (0.5-5 µM) for 12 and 24 h, and then ACR in IC50 concentration was added to the cells. Finally, cell viability was determined using (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. For in vivo assay, Wistar rats were treated with ACR (50 mg/kg i.p. for 11 days) alone or in combination with chrysin (12.5, 25, and 50 mg/kg). At the end of treatment, behavioral index was evaluated. Results: ACR decreased cell viability and pre-treatment with chrysin (0.5-5 µM) significantly decreased ACR-induced cytotoxicity in the time- and dose-dependent manner. In Wistar rats, exposure to ACR significantly induced severe gait abnormalities, but treatment with chrysin (50 mg/kg) reduced ACR-induced neurotoxicity in animals. Conclusion: In the current study, chrysin exhibited neuroprotective effect on PC12 cells as an in vitro model and also on Wistar rats. Iran. Key Words: Acrylamide, Chrysin, Neurotoxicity, Antioxidant  相似文献   
75.
Varicocele is classified as grade I-III regarding its severity. This study was aimed to determine the correlation between height and weight with varicocele grade in 18-30 years age group. We enrolled 400 persons aged 18-30 years referred to the specialist's clinics of Tabriz Medical Sciences University or Medical Commission Since Sep. 2004 to Mar. 2005. First we divided the volunteers in two groups including Varicocele Group and Non-varicocele Group, then varicocele patients were classified to three grades considering the severity of the disease: severe (Grade III), moderate (Grade II) and mild (Grade I). Finally, the correlation between height, weight and Body Mass Index (BMI) was evaluated. There was a significant relation between height and grades of left-side varicocele; in other words the severity of disease was increased with height (p = 0.004). Also, height increased the prevalence ofvaricocele (p = 0.011). On the other hand, low weight and BMI increased the prevalence of varicocele (p = 0.000, p = 0.004) but did not affect the severity of disease (p = 0.364, p = 0.172). In conclusion, the height of patients directly affected the prevalence and severity of left-side varicocele which probably is related to length of left internal spermatic veins in these patients and increased hydrostatic pressure in taller patients. Also, the weight and BMI is effective on the prevalence of varicocele. It seems that slim and tall persons will benefit from evaluation while puberty.  相似文献   
76.
Background: One of the most widely used anticancer agents is microbial L-ASNase. Herein, we assessed the biochemical and biological properties of an isolated L-ASNase from a Gram-negative bacteria strain, Escherichia coli MF-107. Methods:Using garden asparagus, we obtained several bacterial isolates. These strains were further screened for L-ASNase activity. A promising bacterial isolate was selected for L-ASNase production and subsequent purification. The molecular weight of purified L-ASNase was determined. The MTT assay was applied to assess the cytotoxic effect of the purified enzyme. Also, for caspase activity determination and the apoptotic effect of purified enzyme on in cells, we conducted a real-time PCR method. Results:The molecular weight of the enzyme was approximately 37 kDa. In the pH range of 7.5 to 8, the enzyme had considerable stability. At 35 °C, the purified L-ASNase optimum activity was recorded. The cytotoxic effect of the enzyme on treated cells was dose-dependent with an IC50 value of 5.7 IU/ml. The Bax gene expression considerably raised by 5.75-fold (p < 0.001) upon L-ASNase treatment. On the other hand, the anti-apoptotic Bcl-2 gene expression showed a 2.63-fold increase compared to the control (p < 0.05). It was detected that the mRNA levels of caspase-3 and p53 were considerably upregulated (5.93 and 1.85-fold, respectively). We did not find any alternation in the caspase-8 activity of the treated cells compared to untreated cells. Conclusion:In this research, the proliferation of the breast cancer cells remarkably inhibited via the cytotoxic effect of isolated L-ASNase from microbial sources.Key Words: Apoptosis, Breast cancer, Escherichia coli, MCF7 cell line  相似文献   
77.
Background: Cryptosporidium parvum is an important coccidian parasite infecting many mammals, including human. This parasite can manifest as chronic severe diarrhea in immunocompromised individuals, especially those with AIDS. The present study reports the recombinant production of rP2 and rP23 antigens of C. parvum as antigens for detecting human cryptosporidiosis using indirect ELISA tests. Methods:The coding sequences of rP2 and rP23 proteins were codon-optimized, commercially synthesized and sub-cloned in the pET28a expression vector. The expressed proteins were purified by Ni-NTA column chromatography and confirmed by Western blotting. The efficacy of rP2/rP23 proteins for serodiagnosis was evaluated by positive (n = 20) and negative (n = 20) human sera, confirmed by the Ziehl-Neelsen staining as the gold standard test. Results:In ELISA test, the sera from C. parvum-infected patients reacted strongly to rP2/rP23. The sensitivity and specificity related to the diagnostic potential of rP2/rP23 in the ELISA assay were 100%. Conclusion:Our results showed that combination of rP23 and rP2 antigens in ELISA significantly increases the performance of C. parvum serodiagnosis in human cryptosporidiosis. Key Words: Cryptosporidiosis, Enzyme-Linked Immunosorbent Assay, Western blotting  相似文献   
78.
The objective of this study was to evaluate the effect of dystocia on the reproductive performance and functional longevity in Iranian Holsteins. Data consisted of 1 467 064 lactation records of 581 421 Holstein cows from 3083 herds which were collected by the Animal Breeding Center of Iran from April 1987 to February 2014. Reproduction traits in this study included interval from first to second calving, days open and days from first calving to first service. The generalized linear model was used for the statistical analysis of reproductive traits. Survival analysis was performed using the Weibull proportional hazards models to analyse the impact of dystocia on functional longevity. The incidence of dystocia had an adverse effect on the reproductive performance of dairy cows. Therefore, reproductive traits deteriorated along with increase in dystocia score (p < 0.05). The culling risk was increased along with increase in the score of dystocia (p < 0.0001). The greatest culling risk was observed in primiparous cows, small herds and low‐yielding cows (p < 0.0001). Also, the lowest culling risk was found for cows calving at the youngest age (<27 months), and cows with age at first calving >33 months had the greatest risk (p < 0.0001). The results of current study indicated that dystocia had important negative effects on the reproductive performance and functional longevity in dairy cows, and it should be avoided as much as possible to provide a good perspective in the scope of economic and animal welfare issues in dairy herds.  相似文献   
79.
Paddy and Water Environment - The aim of this study was to evaluate the impacts of land leveling on some of soil properties. Land leveling as an effective strategy for paddy land management is one...  相似文献   
80.
Pomegranate fruits were treated with putrescine (Put) or spermidine (Spd) at 1 mM either by pressure infiltration or by immersion and then were stored at 2 degrees C for 60 days. Samples were taken biweekly and were further stored 3 days at 20 degrees C for shelf life study. The treatments were effective on maintaining the concentration of ascorbic acid, total phenolic compounds, and total anthocyanins in arils at higher levels than in control samples. In addition, the two ways of polyamine application increased the levels of total antioxidant activity (TAA) during storage, especially when polyamines were applied by pressure infiltration. Moreover, Spd showed the best results on increasing TAA through maintenance of total phenolic compounds.  相似文献   
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