Correlations between ultrasonography findings and hormonal profiles at oestrus in pure Spanish breed mares     

JC ILLERA  MJ ILLERA  G SIL VAN  M ILLERA 《Australian veterinary journal》1993,70(7):273-275

  相似文献   

Auxin relations in hot-water-treated sugarcane stems     

BRANDES EW  VAN OVERBEEK J 《Journal of agricultural research》1948,77(7-8):223-238

  相似文献   

Fever and acute phase response induced in dwarf goats by endotoxin and bovine and human recombinant tumour necrosis factor alpha     

A. S. J. P. A. M. VAN  MIEKT  C. T. M. VAN  DUIN Th. WENSING† 《Journal of veterinary pharmacology and therapeutics》1992,15(4):332-342

Tumour necrosis factor (TNF), a polypeptide produced by mononuclear phagocytes, has been implicated as an important mediator of inflammatory processes and of clinical manifestations in acute infectious diseases. To study further the potential role of TNF in infectious diseases, recombinant Escherichia coli (E. coli) derived human (r.HuTNF-alpha) and bovine TNF (r.BoTNF-alpha) were intravenously (i.v.) administered in dwarf goats. Rectal temperature, heart rate, rumen motility, plasma zinc and iron concentrations, and certain other blood biochemical and haematological values were studied and compared with the changes seen after E. coli endotoxin (LPS) was administered (dose: 0.1 microgram/kg i.v.). Following a single injection of 4 micrograms/kg of r.BoTNF-alpha, shivering and biphasic febrile response were observed, accompanied by tachycardia, inhibition of rumen contractions, drop in plasma zinc and iron concentrations, lymphopenia, and neutropenia followed by neutrophilia. The i.v. administration of a single injection of 4 micrograms/kg r.HuTNF-alpha induced shivering and biphasic febrile responses, accompanied by anorexia and a similar drop in plasma trace metal concentrations when compared with r.BoTNF-alpha-treated goats. The TNF-alpha-induced symptoms were essentially the same as those that occurred after LPS administration. However, the time of onset of these changes after the injection of TNF-alpha was significantly shorter than after LPS. Moreover, the r.BoTNF-alpha induced a longer lasting neutrophilic leucopenia, less neutrophilia, and a more persistent lymphopenia than after LPS injection. Neither r.BoTNF-alpha nor LPS caused severe haemo-concentration. Furthermore, no cross-tolerance between r.BoTNF-alpha and LPS could be demonstrated. We conclude that both r.BoTNF-alpha and r.HuTNF-alpha induce many of the physiologic, haematologic and metabolic changes that characterize the acute phase response to LPS. The overlapping biological activities of r.BoTNF-alpha, r.HuTNF-alpha and LPS in dwarf goats may indicate that both recombinant tumour necrosis factors have some homology with caprine TNF-alpha.  相似文献   

Response: the largest galaxy     

Simkin SM  VAN Gorkom J 《Science (New York, N.Y.)》1987,237(4817):823-824

  相似文献   

放牧管理对西藏高寒沼泽植物群落结构和土壤碳氮的影响     

曲广鹏  参木友  赵景学  田莉华 《草原与草坪》2016,(4):27-33

对西藏当雄县3种不同放牧管理模式(冬季放牧、冬春季放牧和全年放牧)下的高寒沼泽的植物群落结构和土壤碳氮进行了调查。调查发现,3种放牧管理模式下的高寒沼泽植物群落总盖度差异不显著,而优势物种藏嵩草的高度和盖度差异显著;放牧管理对沼泽群落结构和物种多样性影响较大,随着放牧强度的增加,物种丰富度增加;放牧利用显著降低了高寒沼泽湿地群落优势物种藏嵩草的高度和盖度,其优势度也显著降低,使得高寒沼泽逐渐退化。冬季放牧、冬春季放牧和全年放牧沼泽地上生物量和地下生物量依次降低。同时,随着放牧强度的增加,高寒沼泽表层土壤有机碳氮的含量也显著降低,且高寒沼泽表层土壤碳氮与地上和地下生物量显著正相关。通过对比分析,冬季放牧是当前西藏高寒沼泽较好的放牧管理模式。  相似文献   

Acute oral toxicity of zinc phosphide: an assessment for wild house mice (Mus musculus)     

Lyn A. HINDS  Steve HENRY  Nikki VAN DE WEYER  Freya ROBINSON  Wendy A. RUSCOE  Peter R. BROWN 《Integrative zoology》2023,18(1):63-75

Irregular plagues of house mice, Mus musculus, incur major economic impacts on agricultural production in Australia. The efficacy of zinc phosphide (ZnP), the only registered broadacre control agent for mice, is reported as increasingly variable. Have mice become less sensitive over time or are they taking a sub-lethal dose and developing aversion? In this laboratory study, the sensitivity of mice (wild caught; outbred laboratory strain) was assessed using oral gavage of a range of ZnP concentrations. The estimated LD₅₀ values (72–79 mg ZnP/kg body weight) were similar for each mouse group but are significantly higher than previously reported. The willingness of mice to consume ZnP-coated grains was determined. ZnP-coated grains (50 g ZnP/kg grain) presented in the absence of alternative food were consumed and 94% of wild mice died. Mice provided with alternative food and ZnP-coated wheat grains (either 25 or 50 g ZnP/kg grain) consumed toxic and non-toxic grains, and mortality was lower (33–55%). If a sublethal amount of ZnP-coated grain was consumed, aversion occurred, mostly when alternative food was present. The sensitivity of wild house mice to ZnP in Australia is significantly lower than previously assumed. Under laboratory conditions, ZnP-coated grains coated with a new higher dose (50 g ZnP/kg grain) were readily consumed. Consumption of toxic grain occurred when alternative food was available but was decreased. Our unambiguous findings for house mice indicate a re-assessment of the ZnP loading for baits used for control of many rodents around the world may be warranted.  相似文献   

南非克鲁格斯多普禁猎区珠鸡的社群组织     

J.H.VAN NIEKERK 《中国鸟类》2010,1(1):22-29

1982年3月至1984年2月,在南非豪登省的克鲁格斯多普禁猎区(Krugersdorp Game Reserve),通过翼标观察对珠鸡(Numida meleagris)的社群组织进行了研究.珠鸡必须以社群的方式才能在野外存活,而集群(7-10只珠鸡)并非随机组成.地位最高的雄鸟(雄鸟A)是群体日常活动的核心,例如决定觅食方向等.地位较高的雄鸟(雄鸟A和B)密切协作以驱赶闯入者.在繁殖期,繁殖雌鸟与高地位雄鸟的结合更为紧密.尽管雄鸟中存在明显的等级差异,但群内争斗频率很低,这些争斗只是在维系群体稳定时才发生.雌性成鸟始终位于优势雄鸟和亚成体之间,以免受天敌伤害.但优势雄鸟与其配偶暂时离开群体进行繁殖时,次优势雄鸟(雄鸟B)成为集群中心,其余个体聚集在其周围以保持集群的稳定.大多数成鸟都协助抚育优势雄鸟的雏鸟.珠鸡的集群具有监视天敌的作用,以保障其在地表植被有限的环境中觅食并在冬季最大限度地获得食物.  相似文献   

Weed seedbank responses to 12 years of applications of composts,animal slurries or mineral fertilisers     

B DE CAUWER  K VAN DEN BERGE  M COUGNON  R BULCKE  D REHEUL 《Weed Research》2010,50(5):425-435

  相似文献   

In vitro evaluation of the antagonistic properties of Trichoderma spp. against Pyrenochaeta lycopersici and Phomopsis sclerotioides1     

A. VANACHTER  E. VAN WAMBEKE  C. VAN ASSCHE 《EPPO Bulletin》1988,18(1):1-7

In vitro evaluation of the antagonistic properties of Trichoderma spp. against Pyrenochaeta lycopersici and Phomopsis sclerotioides was carried out, using two different methods: the cellophane-agar plate method and the duaí culture method. With these methods, the direct interaction between pathogen and antagonist was demonstrated, showing very remarkable differences between the different isolates. Growth inhibition ranging from 20 to 100% was found. Proliferation in non-sterilized soil was investigated for the isolates showing the most interesting antagonistic properties. A Belgian isolate of Trichoderma hamatum was found to be able to proliferate very well in soil and to maintain a high population density during the whole experimental period.  相似文献   

Rhizoctonia leaf spot of tobacco in South Africa   总被引：1，自引：0，他引：1  

J. C. MEYER  R. J. VAN  WYK A. J. L. PHILLIPS 《Plant pathology》1990,39(1):206-207

Leaf spot of tobacco caused by Rhizoctonia solani isreported forthe first time from South Africa. All the leaf spot isolates anastomosed with the AG-3 tester strain.  相似文献