北极狐发情期阴道分泌物电阻值变化规律的观察

为正确判断北极狐适宜的人工输精时间提供依据 ,测定了 36只北极狐发情期阴道分泌物电阻值(Ω)。结果表明 ,在接近发情旺期时 ,Ω值急聚上升。有 80 .6 %的狐在Ω值由最高峰急聚下降的第 1,2d内放对 ,很快达成交配 ;有 5 .6 %的狐在Ω值达到最高峰时可达成交配 ;有 13.9%的狐在整个配种过程中Ω值始终处于平衡波动状态 ,不出现高峰 ,需以外阴鉴定为主 ,判断发情放对     

不同有机肥料对暖季型草坪冬季质量的影响

在暖季型草种马尼拉草和假俭草上铺施不同厚度的东北泥炭土、花生麸、蘑菇肥、木渣肥、木糠肥、河沙、硫酸钾复合肥及空白对照进行对比研究。在试验设计范围内，花生麸对草坪冬季质量效果最佳，作用时间也最持久；泥炭土在短期内使用效果好，但随时间延长肥力明显降低；蘑菇肥从肥力与作用时间来看均比较适中；木糠肥明显优于木渣肥，但二者肥力较低；河沙仅在较短的时间内起作用；硫酸钾复合肥作为化合肥与有机肥相比较，作用时间短，安全性较差。     

农杆菌介导木本植物遗传转化的研究进展

农杆菌介导法是目前应用较广泛的转基因技术。该研究对农杆菌介导木本植物遗传转化的发展状况、转化方法进行了综述,重点分析了在木本植物中,外植体类型、农杆菌浸染时间、共培养条件和筛选转化等主要因素对农杆菌转化效率的影响,以期为提高木本植物的转化效率和转基因技术提供参考依据。     

Canine and feline emphysematous gastritis may be differentiated from gastric emphysema based on clinical and imaging characteristics: Five cases

Gastric pneumatosis is an imaging finding defined as the presence of gas foci in the gastric wall. In humans, this imaging feature can result from one of two separate clinical entities: life‐threatening emphysematous gastritis or clinically benign gastric emphysema. This retrospective case series study describes the clinical and imaging features in five animals diagnosed with spontaneous gastric pneumatosis without gastric dilatation‐volvulus. Three canine and two feline cases of spontaneous gastric pneumatosis were identified on radiographic and ultrasonographic examinations. In addition to gastric pneumatosis, one dog and two cats presented concomitant systemic signs such as lethargy, hematemesis, anemia, or leukocytosis. Two dogs remained asymptomatic or presented mild gastrointestinal signs. Portal gas was described in two dogs and one cat, and pneumoperitoneum in one dog. These features were not considered clinically significant. The dog and two cats with systemic signs were euthanized due to clinical deterioration and diagnosed with emphysematous gastritis. The gastric pneumatosis of both dogs without systemic signs resolved while on medical management without antibiotic therapy. These latter cases were interpreted as consistent with gastric emphysema. Findings from the current study indicated that gastric pneumatosis can occur without gastric dilatation‐volvulus in cats and dogs and that a combination of clinical and imaging characteristics may help to differentiate between potentially life‐threatening emphysematous gastritis and relatively benign gastric emphysema. More studies are needed to determine the etiology and risk factors associated with these conditions.     

New thiadiazine derivatives with activity against Trypanosoma cruzi amastigotes.

The cytotoxicity of 18 new 1,2,6-thiadiazin-3,5-dione 1,1-dioxides was evaluated. This group of products was previously assayed against epimastigotes of Trypanosoma cruzi and some of them showed a high antiprotozoal activity. Thereafter 13 compounds with a high anti-epimastigote activity and low cytotoxicity were selected to be assayed against amastigotes. Some of the products showed the same or even lower cytotoxicity than nifurtimox and benznidazole, but most of them were very toxic for macrophages at 100 microg/ml. Only one of the compounds had an anti-amastigote activity similar to that of reference drugs at 10 microg/ml, but unfortunately this disappeared at lower concentrations.     

Characterization and genetic analysis of field isolates ofBotryotinia fuckeliana (Botrytis cinerea) resistant to dichlofluanid

Field isolates ofBotryotinia fuckeliana were collected from naturally infected plants. Their responses to the multisite fungicide dichlofluanid in mycelium growth test fell into three phenotypic classes, characterized by the following EC₅₀ (and MIC) values ing ml^–1: sensitivity, 1–3 (6–10); low resistance, 3–10 (> 100); high resistance, 10–30 (> 100). The corresponding values obtained for these classes in a spore germination test were respectively: 0.05 (0.2), 0.05–0.1 (0.5), 0.5–1 (0.9–1.5). Resistant isolates were crossed with two sensitive and two resistant strains of appropriate mating type to determine the genetic basis of resistance. Distribution of resistance phenotypes in ascospore progeny indicated that a gene, namedDic1, was probably responsible for the low or high resistance of 14 mutants selectively collected from experimental plots of greenhouse-grown gerbera sprayed several times with dichlofluanid or tolyfluanid. A second gene, namedDic2, was probably responsible for the low resistance displayed by two isolates (from grapevine and from carnation) maintained in the laboratory collection. As a result of the investigation, the use of dichlofluanid in integrated management programmes against grey mould is discussed.     

吉林中部地区紫花苜蓿地除草剂筛选试验

紫花苜蓿(Medicago sativa)苗期生长缓慢,导致杂草生长迅速,严重影响苜蓿草产品的产量和质量。为此,本研究选择市场上6种安全、低毒且适于豆科植物使用的除草剂进行筛选试验。结果表明,播后苗前土壤中施用剂量为2.0L·hm~(-2)的90%乙草胺除草效果最好,相对株防效达到93.81%,虽然紫花苜蓿幼苗生长缓慢,但不影响其产量形成。茎叶喷施时建议根据紫花苜蓿地杂草种类,选择不同的除草剂,对水稗(Echinochloa phyllopogon)进行杂草防除时,施用3.0L·hm~(-2)的40%灭草松,相对株防效达到97.09%,没有药害。施用1.0L·hm~(-2)的15%精吡氟禾草灵可有效防除小蓟(Cirsium setosum)和萝藦(Metaplexis japonica),相对株防效分别达到93.63%和100%。而针对藜(Chenopodium album)、马齿苋(Portulaca oleracea)和苘麻(Abutilon theophrasti),建议不严重时不要施用除草剂,而采取人工除草方式。     

基于遥感和USLE模型的2000-2010年甘肃省土壤侵蚀变化评价

本研究将通用土壤流失方程(USLE)和遥感、地理信息技术相结合,定量评价甘肃省2000-2010年土壤侵蚀状况.研究结果表明,甘肃省主要侵蚀强度为轻度和中度侵蚀,2000、2005和2010年甘肃省土壤侵蚀面积分别为24 872.9、27 503.6和28 000.8 km2.主要侵蚀地区分布在甘肃省南部地区;林地的土壤侵蚀面积最大,草地次之,这两类土地利用类型为主要侵蚀地带.陇南山地、甘南高原和陇中黄土高原为土壤侵蚀的主要地貌类型.2000-2010年土壤侵蚀变化分析表明,造成土壤侵蚀的原因除了降水量分布不均、土地利用类型和地貌类型的变化外,人类对生态环境的不合理利用也是另一重要原因.