Genotypes and antibiotic resistance of canine Campylobacter jejuni isolates

Campylobacter jejuni is the most important cause of bacterial gastroenteritis in humans. It is a commensal in many wild and domestic animals, including dogs. Whereas genotypes of human and chicken C. jejuni isolates have been described in some detail, only little information on canine C. jejuni genotypes is available. To gain more information on genotypes of canine C. jejuni and their zoonotic potential, isolates from routine diagnostics of diarrheic dogs as well as isolates of a prevalence study in non-diarrheic dogs were analyzed. Prevalence of thermophilic Campylobacter among non-diarrheic dogs was 6.3% for C. jejuni, 5.9% for Campylobacter upsaliensis and 0.7% for Campylobacter coli. The C. jejuni isolates were genotyped by multi locus sequence typing (MLST) and flaB typing. Resistance to macrolides and quinolones was genetically determined in parallel. Within the 134 genotyped C. jejuni isolates 57 different sequence types (ST) were found. Five STs were previously unrecognized. The most common STs were ST-48 (11.2%), ST-45 (10.5%) and ST-21 (6.0%). Whereas no macrolide resistance was found, 28 isolates (20.9%) were resistant to quinolones. ST-45 was significantly more prevalent in diarrheic than in non-diarrheic dogs. Within the common time frame of isolation 94% of the canine isolates had a ST that was also found in human clinical isolates. In conclusion, prevalence of C. jejuni in Swiss dogs is low but there is a large genetic overlap between dog and human isolates. Given the close contact between human and dogs, the latter should not be ignored as a potential source of human campylobacteriosis.     

柴油机多层涡流回油结构的开发与研究

采用多层涡流回油原理,开发了一种新型回油装置。此装置结构尺寸虽小,且结构并不太复杂,但其采用的多层涡流回油原理,在柴油机行业属于首创,具有发明创造价值。     

人工马尾松复层混交林林分结构规律的研究

From the analysis and simulated study on the stand structures of present the multi-stories mixed uneven-agedPinus massoniana planted forests in Fujian, the correlationships between stand diameter distribution structure, stand stockdistribution structure, tree height and DBH were obtained. Several proposals for the rational management and structure ad-justment of the present forests were put forward.     

杉木适宜多用途伴生树种的选择

应用层次分析方法对21种潜在的多用途杉木伴生树种从经济、生态及可行性3方面出发,采用22个因素评价,进行选择.结果表明在前7名的适宜多用途什生树种有马尾松、丝栗栲、毛竹、木荷、苦槠、上杭锥、三年桐,为筛选多用途伴生树种提供新途径.     

汽车半主动悬架的多目标遗传优化

汽车采用磁流变液减振器，可根据不同的道路行驶条件，通过改变磁场强度来改变减振器的阻尼特性。提出了一种多目标汽车半主动悬架的遗传优化技术，以行驶安全性、乘坐舒适性、结构空间需要作为优化设计目标或约束，选择悬架系统阻尼作为优化参数，以一个受路面谱激励的1／4汽车模型为例，采用一种高效十进制遗传算法对半主动悬架的减振效果进行验证，结果表明该遗传算法对汽车半主动悬架的参数优化具有较好的效果。     

多履带机械结构参数,驱动方式对转向性能的影响

在建立多履带机械稳态转向数学模型的基础上，分析了履带宽长比、各条履带中心间的距离等结构参数对转向性能的影响；提出了转向性能的衡量指标和一种改善转向性能的转向方式。最后通过模型试验对理论分析的结果进行了验证     

连栋温室简易内保温幕保温节能研究

对连栋温室内简易内保温幕保温节能研究结果表明,使用简易内保温幕初冬时节可使供暖设施启动时间推延14d左右,早7:0 0平均气温提高2 .6 5℃,比双层充气膜温室约节煤6 2 5 0 .5 g/m2 ,节能率达38.2 4 % ;启动供暖设施后可使温室内早7:0 0平均气温提高2 .16℃,比阳光板温室约节煤70 g/m2 ·d ,节能率为11.84 %。简易保温幕降低了试验开间内光照度,但其透光率仍高于双层充气膜温室和阳光板温室     

不同立地管理措施对2代杉木1年生幼林生长影响的研究

关于现有人工林的地力衰退问题，在世界林学界范围内已得到基本一致的认同，但也有持不同意见者，有的将２代人工林的多种表现称之为“第２代效应”，包括品种改良和施肥等措施可能产生的积极影响以及常规措施导致的负面影响在内，造成认识不同的原因在于试验的方法和数据...     

浅析青海省小尾寒羊的发展现状与方向

通过对青海省引进、纯繁、推广小尾寒羊的情况调查，适应性观察，以及杂交试验分析表明，从山东梁山、郓城等地引进的小尾寒羊在舍饲，羊舍饲条件下，能够适应青海省海拔较低的农区环境，较好的保持了原产地小尾寒羊的品种特性，产羔率220％，羔羊成活率85．67％。生长发育快，体格高大。小尾寒羊不是一个肉用品种，它的品种特性在于生长发育快、早熟、常年发情和多胎性，利用这一优势的有效途径是经济杂交。以小尾寒羊或其杂种一、二代羊为母本，选用良种肉用公羊进行杂交，建立高效、集约化的肉羊生产体系，生产优质羊肉是青海省小尾寒羊养殖的发展方向。     

Application of Communication between PC and Multi SCM in Vehicle Transmission Test Bed

In existing equipment vehicle transmission test bed can be controlled only by 8031 SCM and data can not be transmitted from SCM to PC. In order to take most advantage of available equipment, data transfer between PC and Multi SCM is put forward. By this way, torque of eddycurrent dynamometer can be controlled by PC programs and satisfy the needs of torque convert experiment. Making use of Dynamic Link Library 8250 registers can be read and written directly. Programs can set the ninth bit easily without Microsoft Communication Control. Data are transmitted between PC and Multi SCM though RS232 COM successfully by using Visual Basic programs. Cost and time are sharply reduced.