A survey of anthelmintic resistance on ten goat farms in the Manawatu region in 1988     

Scherrer AM  Pomroy WE  Charleston WA 《New Zealand veterinary journal》1989,37(4):148-149

A survey of anthelmintic resistance on ten goat farms was carried out. The criterion for resistance was a faecal egg count reduction (FECR) of <90 percent based on arithmetic means of 11 to 19 goats per group. It was found that nine of the ten farms harboured nematodes resistant to oxfendazole when used at 5mg/kg although on two of these, the FECR's were 89.2 percent and 89.8 percent. Post treatment larval cultures indicated Haemonchus, Ostertagia and Trichostrongylus were the resistant genera involved. On none of the ten farms was resistance to oral ivermectin at 0.2mg/kg detected.  相似文献   

Retrospective Evaluation of Horses Diagnosed with Neuroborreliosis on Postmortem Examination: 16 Cases (2004–2015)          下载免费PDF全文

L.K. Johnstone  J.B. Engiles  H. Aceto  V. Buechner‐Maxwell  T. Divers  R. Gardner  R. Levine  N. Scherrer  D. Tewari  J. Tomlinson  A.L. Johnson 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2016,30(4):1305-1312

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Correlation between Chemical Structure and Biological Activity of Host-Selective Plant Pathogen Mycotoxins     

WEI Shuhua LIANG Jun YE Jianren ZHANG Xingyao** . School of Resources  Environment of Nanjing Forestry University  Nanjing  P.R. China . Institute of Forest Ecology  Environmental  Protection  Chinese Academy of Forestry  Beijing  P.R. China 《中国林业科技(英文版)》2007,6(1):62-68

Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.  相似文献   

The Advanced Locking Plate System (ALPS): A Retrospective Evaluation in 71 Small Animal Patients     

Tomás G. Guerrero PD Dr. med vet  Diplomate ECVS  Karin Kalchofner Dr. med vet  Diplomate ECVAA  Nicole Scherrer Dr. med vet  Patrick Kircher Dr. med vet PhD  Diplomate ECVD 《Veterinary surgery : VS》2014,43(2):127-135

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Stabilizing Lead-Salt Diode Lasers: Understanding and Controlling Chaotic Frequency Emission     

G Chin  LR Senesac  WE Blass  JJ Hillman 《Science (New York, N.Y.)》1996,274(5292):1498-1501

Lead-salt tunable diode lasers (TDLs) are the only devices currently available that can generate tunable monochromatic radiation at arbitrary wavelengths between 3 and 30 micrometers and are particularly useful for high-resolution spectroscopy over a wide range of spectral regimes. Detailed observations of TDLs show that the observed instrumental linewidth is actually a temporal average of many narrow (less than 0.5 megahertz) emission "modes." The time scale characteristic of these "modes," which appear to be of relatively constant intensity, is of the order of a microsecond. The laser's behavior is highly suggestive of a chaotic process, that is, seemingly random excursions of a dynamic variable (frequency) within a bounded range. This report shows experimentally that TDL emissions are indeed chaotic. Furthermore, in a simple and robust fashion, this chaotic behavior has been successfully controlled with the use of recent techniques that take advantage of chaos to produce a narrow band laser output.  相似文献   

Solar flare acceleration of solar wind: influence of active region magnetic field     

Lundstedt H  Wilcox JM  Scherrer PH 《Science (New York, N.Y.)》1981,212(4502):1501-1502

The direction of the photospheric magnetic field at the site of a solar flare is a good predictor of whether the flare will accelerate solar wind plasma. If the field has a southward component, high-speed solar wind plasma is usually observed near the earth about 4 days later. If the field has a northward component, such high-speed solar wind is almost never observed. Southward-field flares may then be expected to have much larger terrestrial effects than northward flares.  相似文献   

酸度对胡敏酸与镉和锌离子络合反应的影响     

刘保峰  王强  孟威  魏世强 《西南大学学报》2005,27(4)

用离子交换平衡法研究了不同pH下胡敏酸与锌、镉单独及复合存在下形成络合物的稳定性及配位数.结果表明:在Zn2+,Cd2+单独存在时,络合反应的稳定常数及配位数随着pH值的增大而增大;相同pH条件下,Zn2+和胡敏酸络合物的稳定常数及配位数大于Cd2+.在Zn2+,Cd2+复合存在时,pH的变化与胡敏酸络合金属离子的稳定常数及配位数没有明显依存关系;与单独存在时相比,在pH 3.5和pH7.0时,Zn2+,Cd2+和胡敏酸络合物的稳定常数和配位数都减小;而在pH 5.0时,Cd2+和胡敏酸络合物的稳定常数和配位数都增大,Zn2+和胡敏酸络合物的稳定常数和配位数都减小.  相似文献   

Computed tomographic assessment of vascular invasion and resectability of mediastinal masses in dogs and a cat     

WE Scherrer  AE Kyles  VF Samii  EM Hardie  PH Kass  CR Gregory 《New Zealand veterinary journal》2013,61(6):330-333

AIMS: To assess the sensitivity of non-angiographic contrast-enhanced computed tomography (CT) to determine the presence of vascular invasion of cranial mediastinal masses in dogs and a cat, and to evaluate the association between vascular invasion and peri-operative mortality.

METHODS: A retrospective study was conducted on 25 dogs and one cat. CT scans were completed with slices ranging from 2 to 10 mm. CT images were evaluated by a board-certifi ed radiologist blinded to previous diagnoses and surgical fi ndings. Each CT study was evaluated for vascular invasion, defi ned as disruption of the vessel wall and extension of the mass into the vessel lumen. Data retrieved from the surgery reports included surgical approach, whether vascular invasion was present, the surgeon's decision on operability, and post-operative complications.

RESULTS: Computed tomographic evaluation revealed 25/26 masses had no evidence of vascular invasion. During surgical exploration, 10/26 masses were found to invade major regional vasculature; the cranial vena cava (CVC) was the vessel most commonly invaded (7/10 animals), and 4/7 (57%) patients with invasion of the CVC were euthanised or died in the perioperative period, from surgical or disease-related problems, which was signifi cantly higher than patients without vascular invasion (p=0.045).

CONCLUSIONS: Non-angiographic contrast-enhanced CT was signifi cantly less sensitive for detecting vascular invasion of cranial mediastinal masses when compared with surgical evaluation. If the CVC was invaded by a tumour there was a signifi cant risk of death peri-operatively when compared with non-invasive cases.

CLINICAL RELEVANCE: Due to the signifi cantly higher mortality risk associated with invasion of the CVC, a more sensitive method than CT should be investigated to determine vascular invasion of mediastinal masses pre-operatively.  相似文献   

Multiple resistance in Trichostrongylus and Teladorsagia (Ostertagia) in goats to oxfendazole,levamisole and moxidectin,and ineffi cacy of trichlorphon     

DM West  WE Pomroy  DM Leathwick 《New Zealand veterinary journal》2013,61(5):298-299

Extract

We wish to report the identification, from a flock of commercially-traded goats, of nematode worms that we have been unable to kill using the anthelmintic groups currently registered for use in sheep in New Zealand.  相似文献   

Prevalence of anthelmintic resistance on sheep farms in New Zealand     

TS Waghorn  DM Leathwick  AP Rhodes  KE Lawrence  R Jackson  WE Pomroy 《New Zealand veterinary journal》2013,61(6):271-277

AIM: To establish the prevalence of anthelmintic resistance in parasitic nematodes on sheep farms in New Zealand.

METHODS: A cross-sectional prevalence study was conducted, using a standardised faecal nematode egg count (FEC) reduction (FECR) test (FECRT) for ivermectin, at a full (0.2 mg/kg) and half (0.1 mg/kg) dose rate, and albendazole, levamisole and albendazole-levamisole in combination, on 60 lambs (n=10 per group) on farms selected from throughout New Zealand. Farms that conformed with selection criteria were chosen at random (n=80) or with a history of suspected resistance to macrocy- clic lactone (ML) anthelmintics (n=32). Resistance to an an- thelmintic was inferred when there was <95% reduction in FEC 7-10 days after treatment. Larval cultures were performed for all control groups and for treated groups for which resistance was evident.

RESULTS: Of the farms randomly selected, 36% showed ≥95% FECR for all anthelmintics tested; resistance to ivermectin at 0.1 and 0.2 mg/kg liveweight was evident on 36% and 25% of these farms, respectively. Resistance to both ivermectin (0.2 mg/kg) and levamisole was evident on 8/80 (10%) farms, to ivermectin and albendazole on 10/80 (13%) farms, and to iver- mectin, levamisole and albendazole on 6/80 (8%) farms. The prevalence of resistance to a half dose of ivermectin tended to be more prevalent on farms with a history of suspected ML resistance (p=0.06). Resistance to albendazole was seen across all the main parasite genera, and to levamisole in Nematodirus, Ostertagia (= Teladorsagia) and Trichostrongylus species. Resistance to ivermectin was dominated by Ostertagia spp, although Cooperia, Nematodirus and Trichostrongylus species were also implicated.

CONCLUSION: Anthelmintic resistance in parasitic nema-todes of sheep is common in New Zealand. Not only was resistance to albendazole and levamisole common, but resistance to the ML, ivermectin, was at a higher prevalence than expected. Sheep farmers and advisors in New Zealand need to re-evaluate the way they manage parasites, and more research is urgently needed if the steady decline in anthelmintic susceptibility is to be halted.  相似文献