Isolation of Mycoplasma synoviae from the brains of commercial meat turkeys with meningeal vasculitis     

R P Chin  C U Meteyer  R Yamamoto  H L Shivaprasad  P N Klein 《Avian diseases》1991,35(3):631-637

Mycoplasma synoviae (MS) was isolated from the brains of 22-week-old commercial meat turkeys displaying severe synovitis and infrequent central nervous system signs. Histological examination of the brains revealed mild-to-severe meningeal vasculitis. The vasculitis ranged from fibrinoid necrosis with little inflammation to a marked infiltration of lymphocytes and plasma cells disrupting the architecture of the vessel wall, accumulating as perivascular cuffs, and involving surrounding meninges. Occasional arteries were undergoing thrombosis. Similar lesions were occasionally seen in renal, synovial, and splenic vessels. MS isolates from the brain, trachea, and joint showed similar protein-banding patterns by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, the protein profile differed markedly from the standard MS reference strain, WVU 1853. This is the first known field case of MS isolation from the brains of turkeys.  相似文献   

Comparison of seroreactivity of rams with brucellosis in a complement fixation test, whole cell ELISA and by immunoblotting     

J C Chin  B Pang  M Carrigan 《Veterinary microbiology》1991,26(3):291-299

In rams with ovine brucellosis, a high degree of serological correlation exists between the complement fixation (CF) test which utilises antigen extracted from bacteria with hot saline, and the ELISA reactivity using methanol-fixed Brucella ovis as the assay reagent. Since the whole cell ELISA (CELISA) detects mainly antibodies against surface antigens of B. ovis, it was concluded that the similar findings of the two serological tests is due in part to the presence of membrane antigens in the CF test antigen following hot saline extraction of intact bacteria. Immunoblots with pooled sera representing different CF titres confirmed that the major immunoreactive antigens of B. ovis were located in four zones: alpha, beta, gamma 1 and 2 with corresponding apparent molecular masses of 55 and 60 kDa; 27 and 29 kDa; 18.5-20 kDa and 17-18 kDa, respectively. These zones of reactivity were consistently present in immunoblots when assayed against different B. ovis isolates even though Coomassie brilliant blue staining of SDS-PAGE gels revealed some differences in polypeptide banding patterns. However, these intensely-stained CBB bands located at 38 and 40 kDa which distinguished three of the seven B. ovis isolates were considerably less reactive in immunoblots compared to polypeptides that were located at positions equivalent to alpha, beta or gamma reactivities. Intensity of immunoblot reactivity against polypeptides located in the alpha, beta and gamma zones intensified with increasing CF titre. Sera with CF titres greater than 32 also tended to react against bands of higher apparent molecular masses located at 65, 70, 73, 78, 80 and 86 kDa.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Simulation of nitrate-N movement in southern Ontario,Canada with DRAINMOD-N   总被引：1，自引：0，他引：1  

Chun-Chieh Yang  Shiv O. Prasher  Shaoli Wang  Seung Hyun Kim  Chin S. Tan  Craig Drury  Ramanbhai M. Patel 《Agricultural Water Management》2007

DRAINMOD-N, a mathematical model to predict nitrate-N concentrations in surface runoff and drain outflows from subsurface-drained farmlands, has been tested against field data collected in southern Ontario. The data was collected in a corn field from 16 conventional drainage and subirrigation plots in Woodslee, Ontario, from 1992 to 1994. The model performance was evaluated by comparing the observed and simulated nitrate-N concentrations in surface runoff and drain outflows. A precise calculation of water-table depth is an essential prerequisite for a model to obtain a proper prediction of nitrate-N movement. For the simulation of water-table depth, the lowest root mean square error and the highest correlation coefficient of linear regression were 173 mm and 0.51 for the subirrigation plots; and 178 mm and 0.84 for the subsurface drainage plots. Therefore, the performance of DRAINMOD-N for soil hydrologic simulations was satisfactory and it could be used for assessing nitrogen fate and transport. For the simulation of nitrate-N losses in the subirrigation plots, the lowest root mean square error and the highest correlation coefficient of linear regression were 0.74 kg/ha and 0.98 for surface runoff; and 6.53 kg/ha and 0.91 for drain outflow. For the simulation in the subsurface drainage plots, the lowest root mean square error and the highest correlation coefficient of linear regression were 0.70 kg/ha and 0.96 for surface runoff; and 6.91 kg/ha and 0.92 for drain outflow. The results show that DRAINMOD-N can perform satisfactory simulation of soil hydrology and nitrate-N losses in surface runoff under various water-table management practices. The model can, therefore, be used to evaluate different water pollution scenarios and help in the development and testing of various pollution control strategies for fields in cold weather such as that in southern Canada.  相似文献   

猪源乳酸菌对湖鸭免疫功能的影响     

赵红梅  苏加义  赵健 《长江大学学报》2006,(2)

应用免疫SPA菌体花环法和间接ELISA法测定了雏鸭饲喂异源乳酸菌后其外周血液中T淋巴细胞、B淋巴细胞数量和IgGI、gMI、gA 3种免疫球蛋白的含量。结果表明:雏鸭应用异源乳酸菌后,外周血液中T淋巴细胞、B淋巴细胞数量和IgGI、gMI、gA 3种免疫球蛋白的含量均较未饲喂异源乳酸菌的对照组雏鸭不同程度地增加,且于饲喂后9~13 d达到高峰,说明应用异源乳酸菌能使雏鸭免疫功能增强。  相似文献   

果蔬中5种农药的同时检测与残留量分析   总被引：4，自引：0，他引：4  

徐爱平  王富华  赖穗春  李乃坚  王晓容 《华中农业大学学报》2003,22(6):561-563

建立了蔬菜和水果中甲基毒死蜱、毒死蜱、联苯菊酯、甲氰菊酯和氯氰菊酯残留量的分析方法。将样品中的甲基毒死蜱、毒死蜱、联苯菊酯、甲氰菊酯和氯氰菊酯经盐析提取和固相萃取(SPE)小柱净化，用毛细管色谱柱分离，气相色谱仪带微电子捕获检测器(u-ECD)测定。该分析方法中5种农药的检出限为0．002～0．005mg／kg，添加回收率为84．0％～104．0％，在0．002～3．00mg／kg范围内检测线性关系良好，其线性相关系数为0．995。该分析方法灵敏、准确，操作简便，适合蔬菜和水果中甲基毒死蜱、毒死蜱、联苯菊酯、甲氰菊酯和氯氰菊酯残留量的分析。  相似文献   

桃树体内苦杏仁甙含量年变化研究   总被引：1，自引：0，他引：1  

赵宇瑛  程丽琴  尚冰 《长江大学学报》2006,(11)

对桃(Prunus persica)树体内苦杏仁甙含量年变化的研究结果表明,叶片中苦杏仁甙含量为单峰曲线变化;一年生枝条韧皮部的苦杏仁甙含量在休眠期较高,而木质部的苦杏仁甙含量在休眠期较低;在旺盛生长期,韧皮部的苦杏仁甙含量较低,而木质部的苦杏仁甙含量较高;果肉及种仁的苦杏仁甙含量变化趋势相似,都呈上升趋势,5月中旬前果肉中苦杏仁甙含量高于种仁的苦杏仁甙含量,5月中旬之后相反,种仁的苦杏仁甙含量大于果肉中苦杏仁甙含量。  相似文献   

Effect of urea on volatile generation from Maillard reaction of cysteine and ribose     

Chen Y  Xing J  Chin CK  Ho CT 《Journal of agricultural and food chemistry》2000,48(8):3512-3516

Urea occurs naturally in many food products, and its presence affects food quality. However, little is known about its impact on flavor generation in food production. In this study, the urea contents in beef, pork, and chicken were determined. The effects of urea and pH on thermal flavor generation were investigated using the model system of cysteine with ribose, which was heated to the roasting temperature of 180 degrees C for 2 h at pH 5 and pH 8.5. The results revealed relatively large amounts of urea in these meats and demonstrated that pH affects aroma generation. Volatiles identified from the reaction system of ribose and cysteine showed that sulfur-containing compounds such as thiophenes, thiazoles, and thiophenethiols were the most abundant compounds. The addition of urea into the reaction mixture caused the disappearance or reduction in content of some sulfur-containing compounds but resulted in the generation of several important nitrogen-containing volatiles, like pyrazine, methylpyrazine, 2,5- (and 2,6-)dimethylpyrazine and other alkylpyrazines, which are known to elicit roasty, nutty flavor notes. A plausible explanation for this phenomenon is that ammonia can be released from urea upon heating and the formed ammonia competes with hydrogen sulfide to react with Maillard reaction precursors to produce nitrogen-containing compounds such as alkylpyrazines.  相似文献   

Complete genome sequences and properties of Spartina mottle virus isolates from hybrid Bermuda grass (Cynodon dactylon × Cynodon transvaalensis)     

John E. Thomas  Myriam Raymond  Nga T. Tran  Kathleen S. Crew  Ai Chin Teo  Andrew D. W. Geering 《Plant pathology》2021,70(5):1062-1071

Full genome sequences are presented for two isolates of Spartina mottle virus (SpMoV) from two accessions of the hybrid turf grass Cynodon dactylon × C. transvaalensis (Bermuda grass, green couch), originally from the USA but detected during post-entry quarantine in Australia. Both isolates had a genome of 9,346 nucleotides, encoding a single polyprotein of 3,029 amino acids and predicted to be cleaved into 10 mature proteins. Phylogenetic analysis strongly supported placement in a new genus within the family Potyviridae. The isolates possess 715–780 × 11–12 nm flexuous virions and produce cylindrical (pinwheel) inclusions in infected cells. They were mechanically transmitted to several species in the Poaceae including Zea mays (maize, sweet corn), Chloris gayana (Rhodes grass), and Echinochloa colona (awnless barnyard grass).  相似文献   

基于温室内气象数据的适用于冬季日光温室番茄蒸腾量各子模型对比研究     

王淼  罗新兰  尹佳琪  苏慧  常姝婷 《干旱地区农业研究》2021,39(1):182-190

北方寒区日光温室冬季生产基本无通风,为了探寻温室内不同边界层空气动力学阻力(r_a)与气孔平均阻力(r_c)表达式计算植株蒸腾量的差别及适用于此环境下的最优子模型模拟式,以Penman-Monteith(P-M)方程为基础,比较分析了4组适用于北方寒区冬季日光温室(基本无通风条件)的r_a、r_c子模型模拟的温室内番茄植株蒸腾量。结果表明:子模型的变化具有波动性,采用不同子模型模拟的蒸腾量值差异较大,北方寒区冬季日光温室植株蒸腾作用主要集中于白天,此时不同子模型模拟的r_a、r_c平均变化量分别为5.73%、37.10%;本试验环境下,温室仅在中午前后通风,其余时间处于密闭状态,此时,室内风速垂直流通且并不均匀,选用包含空气温度、植株叶片温度及植株生理指标(叶片特征长度、单株植株叶面积指数LAI)等参数模拟单株植株边界层空气动力学阻力值,选用的r_a模拟式在晴天、阴天平均变化范围分别为185～489、249～357 s·m~(-1),模型检验结果为:Pearson=0.826,MRE=21.69%,MAE=0.02,RMSE=18.59,EF=0.81;应用反演式模拟单株植株气孔平均阻力的准确率较高,选用的r_c反演式在晴天、阴天平均变化范围分别为253～1 356、235～1 260 s·m~(-1),模型检验结果为:Pearson=0.955,MRE=7.16%,MAE=0.01,RMSE=8.56,EF=0.95。  相似文献   

Consumption of a durable termite bait matrix by subterranean termites (Isoptera: Rhinotermitidae) and resulting insecticidal activity     

Ronda L Hamm  Joseph J DeMark  Eva Chin‐Heady  Mike P Tolley 《Pest management science》2013,69(4):507-511

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