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991.
水稻新品种“吉农大8号”选育及栽培技术 总被引:7,自引:7,他引:0
水稻新品种“吉农大8号”是通过品种间有性复合杂交,经系谱法育成。该品种主要优点是高产,抗病,适应性广等。3年区试结果,平均产量7896.0kg/hm^2,比对照增产5.7%,2年生产试验结果,平均产量78979.5kg/hm^2,比对照增产7.6%^,为吉林省中熟品种。 相似文献
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Yi-Ping Li Christina S. Vegge Lone Brøndsted Mogens Madsen Hanne Ingmer Dang Duong Bang 《Veterinary microbiology》2011
Campylobacter jejuni (C. jejuni) is the most common cause of human acute bacterial gastroenteritis. Poultry is a major reservoir of C. jejuni and considered an important source of human infections, thus, it is important to understand the host response to C. jejuni from chicken origin. In this study, we demonstrated firstly that a chicken isolate SC11 colonized chicks faster than clinical isolate NCTC11168. Using the SC11, we further studied the host responds to C. jejuni in terms of inflammatory response and involvement of cellular signaling pathways. Infection of C. jejuni SC11 was able to activate phosphatidylinositol 3-kinase (PI3K)/Akt pathway and induce pro-inflammatory interleukin-8 (IL-8) as well as anti-inflammatory cytokine IL-10 in human intestinal epithelial cell line Colo 205. The signalling pathways PI3K/Akt and mitogen-activated protein (MAP) kinases ERK and p38 were involved in C. jejuni-induced IL-8 and IL-10 expression. Inhibition of PI3K resulted in augmentation of C. jejuni-induced IL-8 production, concomitant with down-regulation of IL-10 mRNA, indicating an anti-inflammatory response was activated and associated with the activation of P13K/Akt. Similar effect was observed for cytolethal distending toxin (CDT) deficient mutants. Moreover, we demonstrated that heat-killed bacteria were able to induce IL-8 and IL-10 expression to a lower level than live bacteria. We therefore conclude that C. jejuni activate a PI3K/Akt-dependent anti-inflammatory pathway in human intestinal epithelial cells which may benefit the intracellular survival of C. jejuni during infection. 相似文献
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2008年从湖北省分离到1株H3N8亚型马流感病毒A/equine/Hubei/6/08。以2002年美国KENTUKY株为模板设计HA基因测序引物,进行RT-PCR,然后测定该分离株的HA基因核苷酸序列。经NCBI上Blast同源性比较发现,与A/equine/Newmarket/5/2003(H3N8)同源性较高为98.7%。HA蛋白遗传进化分析表明该毒株隶属于H3N8亚型马流感病毒中的美洲系福罗里达亚系。该株与OIE现在推荐的疫苗候选株A/equine/Kentuck-y/5/2002(H3N8)HA1蛋白氨基酸序列比对发现有3处氨基酸替换位点;与OIE以往推荐的疫苗候选株A/e-quine/Kentucky/1/1994(H3N8)比对发现有11处氨基酸替换位点。研究结果表明该分离株可作为中国研制马流感疫苗的候选株。 相似文献
996.
为解决智能化采收中红花识别性能易受田间复杂环境、设备计算资源等限制的问题,该研究提出一种基于改进YOLOv8n的轻量化红花识别方法,以便将模型部署在移动端上进行目标检测。该研究应用Vanillanet轻量化网络结构代替YOLOv8n的骨干特征提取网络,降低了模型的复杂程度;将大型可分离核注意力模块(large separable kernel attention, LSKA)引入特征融合网络,以降低存储量和计算资源消耗;将YOLOv8n的损失函数从中心点与边界框的重叠联合(center intersection of union, CIoU)替换为动态非单调的聚焦机制(wise intersection of union, WIoU)提升检测器的总体性能;并选用随机梯度下降算法(stochastic gradient descent, SGD)进行模型训练,以提高模型鲁棒性。试验结果表明,改进后的轻量化模型每秒传输帧数(frames per second, FPS)为123.46帧/s,与原YOLOv8n模型相比提高了7.41%,而模型大小为3.00MB,仅为原来的50.17%,并且精确度(precision, P)和平均精度值(mean average precision, mAP)达到了93.10%和96.40%,与YOLOv5s与YOLOv7-tiny检测模型相比,FPS分别提高了25.93%和19.76%,模型大小为原模型的21.90%和25.86%,研究结果为后续红花的智能化采收装备研发提供技术支持。 相似文献
997.
Pure bacterial cultures were isolated from diseased snakeheads, Channa maculata (Lacepède), suffering high mortality in a farm in Zhongshan, southern China. Three isolates, namely ZS20100725, ZS20100725-1 and ZS20100725-2, were identified as Aeromonas schubertii. All the isolates showed high 16S rRNA sequence similarities with A. schubertii. The isolates exhibited strong virulence to snakeheads in experimental challenges with LD(50) ranging between 1.4 × 10(4) and 6.4 × 10(6) CFU g(-1). Two of the isolates were positive for haemolysin, elastase, lipase and lecithinase by phenotypic determination, which was further confirmed by PCR amplification of the haemolysin and elastase genes. In sterile liquid medium, the best growth conditions of strain ZS20100725 were 30 °C, pH 7 and 0.5% salinity (w/v). Antibiotic susceptibility tests showed that strain ZS20100725 was susceptible to cefoxitin, cefoperazone and chloramphenicol. Furthermore, histopathology of diseased snakeheads infected with A. schubertii showed necrosis and congestion in liver, kidney and spleen and also damage to the cardiac muscle, intestine and gills. 相似文献
998.
通过对紧凑型玉米弘犬8号进行6种不同宽窄行和5种密度的组合试验.探讨紧凑型玉米的最佳宽窄行行距和密度.结果表明:在不同的宽窄行行距下弘大8号的最佳种植密度不同,最佳种植密度分布79 500~91 500株/hm2之间;同一密度不同的宽窄行处理,弘大8号的产量不同,宽行80 cm窄行40 cm的产量最高.在种植密度较大的条件下,实行宽窄行种植可增产.弘大8号的最佳宽窄行行距和密度组合是:宽行80 cm窄行40 cm,密度79 500株/hm2,产量为9 950 kg/hm2. 相似文献
999.
Bacterial canker of tomato caused by Clavibacter michiganensis subsp. michiganensis produces considerable economic losses in many countries because effective control measures are lacking. The extent to which bactericides control this disease effectively is low and has not yet been well documented for Southern European conditions. In this study the bactericidal effect of several products on this pathogen was assessed in vitro and in vivo in tomato plants under greenhouse conditions. Seven antibacterial substances (bronopol, copper sulphate, kasugamycin, oxolinic acid, oxytetracycline, streptomycin and 8-hydroxy-quinoline), three commercial formulates (Antibak RZ, an oligoelements mixture containing copper plus zinc; Orthopol, a potassium soap; and Param, a resistance inductor) and combinations thereof were tested. In vitro assessment showed that minimal inhibitory concentration (MIC) of antibacterial substances was between 4–8 μg ml−1, except for copper sulphate with a MIC value of 150 μg ml−1 and kasugamycin, which was not active at 500 μg ml−1. MIC values of commercial formulates ranged between 5 and 40 μl ml−1. Furthermore, combinations of 8-hydroxy-quinoline+copper sulphate, 8-hydroxy-quinoline+Antibak RZ, streptomycin+Antibak RZ and streptomycin+Orthopol showed a synergistic effect at sub-inhibitory concentrations. Treatments containing copper sulphate greatly reduced disease symptoms on plants sprayed with the bacteria, whereas streptomycin was less effective. In two independent trials, the percentage of leaves showing symptoms was significantly lower (2.4% and 11.9%) after treatment with copper sulphate combined with 8-hydroxy-quinoline at half-dose, than in inoculated controls (75.1% and 59.6%). These results were better than copper sulphate alone. However, plants inoculated by pricking rapidly developed systemic infection, which no product managed to control significantly, although several treatments did reduce symptoms. We conclude that copper sulphate combined with 8-hydroxy-quinoline may be useful in controlling external symptoms of this disease in greenhouses, and is environmentally friendly, reducing the amount of copper applied to crops. 相似文献
1000.