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991.
Ryegrass (Lolium perenne L.) in grassland is known to sustain with water and nitrogen (N). This study investigates biomass and N partitioning in plant organs (roots, main and the youngest tillers) under water-nitrogen interactions. Nitrogen was applied at the rates of 50 and 100 mg N kg?1 as N1 (low N) and N2 (high N) treatments, respectively, with uniform irrigation until 440 growing degree-days (GDD). Thereafter, the water supply was restricted to 50 mL on a weekly basis (W1) against 50 mL on a daily basis (W2) and concurrently, N enriched with 1 atom% 15N isotopes. Cumulative tillers’ biomass increased linearly from 1st to 8th order, but thereafter reached a plateau with further increases in number of negligible weights. Initially tiller mass and number per plan did not differ (P < 0.05) with water and/or N applications but changed at 788 GDD with clear differences at 911 GDD with the highest under N2W2 and lowest under N1W1. Nitrogen concentration sharply decreased from 530 to 700 GDD and then levelled off with age. The decline was more pronounced in tillers than roots. The high N treatment showed elevated N-concentration under both water treatments. Watering on a daily basis promoted vegetative growth. High water and N levels significantly (P < 0.05) influenced concentration of N absorbed during 15N labeling (NL) in all organs with relatively pronounced NL under N2. The additive positive effect of W2 and N2 was obvious on NL as compared to NT, which showed that plants discriminate N-uptake on mass basis. Nitrogen (mobile) was higher in young and 15N (heavier) was low in young tillers and vice versa. Accumulation of N absorbed during 15N labeling (15NA) was significant knowing that water is a strong determining factor of N concentration in ryegrass organs. 相似文献
992.
Masoud Selk Ghaffari Mohammad Ali Rezaei Amir Hessam Mirani Nargess Khorami 《Veterinary ophthalmology》2010,13(2):91-93
Objective To determine the effects of intravenous ketamine‐midazolam anesthesia on intraocular pressure (IOP) in ocular normotensive dogs. Animals Thirteen adult mixed‐breed dogs. Procedures Dogs were randomly assigned to treatment (n = 7) and control (n = 6) groups. Dogs in the treatment group received intravenous ketamine 15 mg/kg and midazolam 0.2 mg/kg and dogs in the control group received intravenous saline. The time of intravenous drug injection was recorded (T0). Measurements of IOP were then repeated 5 min (T5) and 20 min (T20) following the intravenous administration of ketamine‐midazolam combination and saline in both groups. Results Measurements showed normal IOP values in both groups. The mean ± SD baseline IOP values for treatment and control groups were 13.00 ± 1.47 and 10.33 ± 2.20, respectively. For baseline IOP values, there was no significant difference between treatment and control groups (P = 0.162). In the treatment group, the subsequent post‐treatment mean ± SD values were 15.64 ± 2.17 (5 min), and 14.92 ± 1.98 (20 min). There was no evidence of statistical difference between baseline values and post‐treatment values after treatment with ketamine‐midazolam (P5 = 0.139; P20 = 0.442). In control eyes, the mean ± SD values at 5 and 20 min were 10.41 ± 2.01 and 10.16 ± 1.69, respectively. There was no significant difference between baseline values and post‐treatment values in control group (P5 = 1.000; P20 = 1.000). Conclusion Ketamine‐midazolam combination has no clinically significant effect on IOP in the dog. 相似文献
993.
In the present study the antigenotoxic effect of apigenin was studied against a genotoxic dose of ethinylestradiol using the damage parameters of chromosomal aberrations (CAs), sister chromatid exchanges (SCEs) and cell cycle kinetics (CCK). Human peripheral blood lymphocytes were cultured and treated with 10 μM of ethinylestradiol along with doses of 5, 10, 15 and 20 μM of apigenin. A clear decrease in the genotoxic damage induced by ethinylestradiol was observed with increasing doses of apigenin, suggesting a protective role for apigenin during ethinylestradiol therapy. 相似文献
994.
在过去的几十年里,遥感与地理信息系统融合技术应用于土壤侵蚀评价的研究得到了显著的发展。本研究采用遥感资料、土壤和土地调查数据、数字地面模型和气象观测数据,利用地理信息系统技术来分别产生通用土壤流失方程(USLE)的各个参数,从而来评价水土流失量和空间分布状况。 相似文献
995.
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997.
Asgari Q Sarnevesht J Kalantari M Sadat SJ Motazedian MH Sarkari B 《Tropical animal health and production》2011,43(2):389-392
Toxoplasmosis is a widespread zoonotic disease that causes significant morbidity and mortality in human fetus and in immunocompromised
patients. Moreover, it becomes a major cause of abortion in sheep and goats. Since consumption of meat of infected lamb and
goat is considered as the main sources of human infection in Iran, this study was undertaken to determine the prevalence of
Toxoplasma infection in edible tissues of sheep and goats in Shiraz in 2008. Samples of brain, tongue, liver, and muscles of neck, intercostals,
and femoral were taken from 56 sheep and 22 goats and tested by PCR. The total prevalence of Toxoplasma infection among animals was found to be 33.3%. Five out of 22 goats (22.7%) and 21 out of 56 sheep (37.5%) were infected
by Toxoplasma. Differences between the prevalence rate of infection among females (nine out of 14 = 46%) and males animals (12 out of 45
= 29.5%) was significant (P = 0.013). Furthermore, a positive correlation was found between the age of animals and the rate of infection; animals greater
than 2 years old showed a higher rate of infection (47%) in comparison with those less than 2 years old (25%, P = 0.04). The highest infected tissue was tongue (21.8%) followed by brain (19.2%) and femoral and intercostal muscles (17.9%).
This study demonstrated a high level of Toxoplasma infection in slaughtered animals in Shiraz and these should be considered as the main sources of infection for human population
in the region. 相似文献
998.
Shirzad MR Seifi S Gheisari HR Hachesoo BA Habibi H Bujmehrani H 《Tropical animal health and production》2011,43(8):1601-1604
Coccidiosis is a disease of almost universal importance in Poultry production. The subclinical form of coccidiosis has most
significant economic impact due to impaired growth rate and feed conversion. Some factors such as: age, size of flock, season,
etc., may effect on severity of this disease. In this study, the relationships between some major risk factors and prevalence
of subclinical coccidiosis were investigated. This study was done in 120 broiler farms in five different cities of Mazandaran
province, north of Iran. Five chicks (3–8 weeks of ages) were taken randomly from every 120 farms and post-mortem and parasitological
examinations were performed. Five Eimeria spp. were recognized: Eimeria tenella, Eimeria maxima, Eimeria acervulina, Eimeria brunetti, and Eimeria necatrix. The prevalence rate of subclinical coccidiosis among them is 75% (90 farms out of 120). E. acervulina was the most prevalent species (65.5%) followed by E. maxima (17.7%), E. tenella (15.5%), E. brunetti (10%), and E. necatrix (5.5%). According to what the results approve, the occurrence of subclinical coccidiosis is significantly related to the
age and size of flock, whereas the other factors such as the season of year, industrial strains, chicken’s keeping system,
and anticoccidial drugs do not affect this phenomenon remarkably. 相似文献
999.
Freeman L Rahmani EY Burgess RC Al-Haddad M Selzer DJ Sherman S Constable P 《Veterinary surgery : VS》2011,40(2):140-150
Objective: Study the learning curve for canine Natural Orifice Transluminal Endoscopic Surgery (NOTES) ovariectomy by evaluating operative times and complications. Study Design: Preclinical research study. Animals: Adult female dogs (n=20). Methods: NOTES ovariectomy procedures were performed as follows: Feasibility Group 1 (n=5), Feasibility Group 2 (n=5), and Early Clinical Group 3 (n=10). Six steps of the procedure were identified, timed separately, and the overall time was recorded from introduction to removal of the endoscope. Complications were recorded. Repeated measures analysis of variance using ranked data compared the effect of group (3 levels) on the time for each step. Nonlinear regression using an exponential model with nonzero asymptote was used to model the operative time–procedure number relationship. Results: Overall median operative time was significantly longer for Group 1 (195 minutes; range, 160–265 minutes) than Group 2 (108 minutes; range, 81–148 minutes; P=.048) and Group 3 (77 minutes; range, 41–136 minutes; P=.0008). The estimated asymptotic operative time was 71 minutes (95% confidence interval, 41–100 minutes); this time was reached after 10 procedures. Gastric cleansing and removing the left ovary took significantly longer in Group 1 than in Group 2 or 3. Operative complications included incomplete ovarian excision, dropping an ovary during retrieval, and conversion to an open procedure. No intraoperative complications occurred in Group 3. Conclusion: NOTES procedures result in longer operative times in the early part of the learning curve and require considerable experience before reaching proficiency. 相似文献
1000.
Mohammad Mofizur Rahman Jahangir Dries Roobroeck Oswald Van Cleemput Pascal Boeckx 《Biology and Fertility of Soils》2011,47(7):753-766
Nitrous oxide (N2O) emissions, soil microbial community structure, bulk density, total pore volume, total C and N, aggregate mean weight diameter
and stability index were determined in arable soils under three different types of tillage: reduced tillage (RT), no tillage
(NT) and conventional tillage (CT). Thirty intact soil cores, each in a 25 × 25-m2 grid, were collected to a depth of 10 cm at the seedling stage of winter wheat in February 2008 from Maulde (50°3′ N, 3°43′ W),
Belgium. Two additional soil samples adjacent to each soil core were taken to measure the spatial variance in biotic and physicochemical
conditions. The microbial community structure was evaluated by means of phospholipid fatty acids analysis. Soil cores were
amended with 15 kg NO3−-N ha−1, 15 kg NH4+-N ha−1 and 30 kg ha−1 urea-N ha−1 and then brought to 65% water-filled pore space and incubated for 21 days at 15°C, with regular monitoring of N2O emissions. The N2O fluxes showed a log-normal distribution with mean coefficients of variance (CV) of 122%, 78% and 90% in RT, NT and CT, respectively,
indicating a high spatial variation. However, this variability of N2O emissions did not show plot scale spatial dependence. The N2O emissions from RT were higher (p < 0.01) than from CT and NT. Multivariate analysis of soil properties showed that PC1 of principal component analysis had
highest loadings for aggregate mean weight diameter, total C and fungi/bacteria ratio. Stepwise multiple regression based
on soil properties explained 72% (p < 0.01) of the variance of N2O emissions. Spatial distributions of soil properties controlling N2O emissions were different in three different tillages with CV ranked as RT > CT > NT. 相似文献