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Extract Myophosphorylase deficiency (glycogen storage disease Type V) has been diagnosed in Charolais calves in New Zealand. It is manifested as exercise intolerance and recumbency, usually at several weeks of age, due to an inability to mobilise glucose, as glucose phosphate, from glycogen. Affected calves may rise and walk after a rest to again become affected on further exercise. There is rhabdomyolysis and after repeated or severe attacks the calf may remain recumbent and need to be euthanised. The mutant phosphorylase gene has been described. We have established a PCR-RFLP test based on a published method, and have confirmed the diagnosis in affected calves and heterozygous status of sires, dams and other related individuals belonging to an extended family. In addition, several other non-related heterozygotes have been identified in that and another herd. There appears to have been importations of the gene from both England and America. 相似文献
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Images of an active region on the far side of the sun were derived by applying seismic holography to recent helioseismic observations from space. Active regions are the centers of energetic phenomena such as solar flares and coronal mass ejections, whose resulting electromagnetic and particle radiation interfere with telecommunications and power transmissions on Earth and can pose significant hazards to astronauts and spacecraft. Synoptic seismic imaging of far-side solar activity will now allow anticipation of the appearance of large active regions more than a week ahead of their arrival on the east solar limb. 相似文献
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Derek Herbert Kevin A. Walker Lindsey J. Price David J. Cole Kenneth E. Pallett Stuart M. Ridley John L. Harwood 《Pest management science》1997,50(1):67-71
Acetyl-CoA carboxylase catalyses the first committed step in fatty acid (and acyl lipid) formation. The enzyme has been shown to exert a high degree of flux control for lipid biosynthesis in leaves and, therefore, it is not surprising that chemicals which can inhibit it effectively are successful herbicides. These chemicals belong mainly to the cyclohexanedione and aryloxyphenoxypropionate classes and are graminicides. The reason for the selectivity of these herbicides towards grasses lies in the nature of the target site, acetyl-CoA carboxylase. Recent advances in our knowledge of acetyl-CoA carboxylases from sensitive and resistant plants has revealed some important facts. Dicotyledons, which are resistant, have a multi-enzyme complex type of carboxylase in their chloroplasts while grasses have a multifunctional protein. Both divisions of plants have two isoforms of the enzyme, the second being in the cytosol. Detailed study of multifunctional forms of acetyl-CoA carboxylases, which have different sensitivities to herbicides, suggests that herbicide resistance is correlated with cooperativity of herbicide binding to the native dimeric form of the carboxylase. © 1997 SCI. 相似文献
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Evaluation of risk factors for the spread of low pathogenicity H7N2 avian influenza virus among commercial poultry farms 总被引:5,自引:0,他引:5
McQuiston JH Garber LP Porter-Spalding BA Hahn JW Pierson FW Wainwright SH Senne DA Brignole TJ Akey BL Holt TJ 《Journal of the American Veterinary Medical Association》2005,226(5):767-772
OBJECTIVE: To identify risk factors associated with the spread of low pathogenicity H7N2 avian influenza (AI) virus among commercial poultry farms in western Virginia during an outbreak in 2002. DESIGN: Case-control study. PROCEDURE: Questionnaires were used to collect information about farm characteristics, biosecurity measures, and husbandry practices on 151 infected premises (128 turkey and 23 chicken farms) and 199 noninfected premises (167 turkey and 32 chicken farms). RESULTS: The most significant risk factor for AI infection was disposal of dead birds by rendering (odds ratio [OR], 73). In addition, age > or = 10 weeks (OR for birds aged 10 to 19 weeks, 4.9; OR for birds aged > or = 20 weeks, 4.3) was a significant risk factor regardless of poultry species involved. Other significant risk factors included use of nonfamily caretakers and the presence of mammalian wildlife on the farm. Factors that were not significantly associated with infection included use of various routine biosecurity measures, food and litter sources, types of domestic animals on the premises, and presence of wild birds on the premises. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that an important factor contributing to rapid early spread of AI virus infection among commercial poultry farms during this outbreak was disposal of dead birds via rendering off-farm. Because of the highly infectious nature of AI virus and the devastating economic impact of outbreaks, poultry farmers should consider carcass disposal techniques that do not require off-farm movement, such as burial, composting, or incineration. 相似文献
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Sanjaya Gyawali Michael L. Derie Emily W. Gatch Dipak Sharma-Poudyal Lindsey J. du Toit 《Plant pathology》2021,70(4):778-792
Although the maritime Pacific Northwest (PNW) is the only region of the United States suitable climatically for spinach seed production, the acidic soils are highly conducive to spinach Fusarium wilt caused by Fusarium oxysporum f. sp. spinaciae. A soil bioassay developed to quantify the risk of spinach Fusarium wilt in fields has been offered to seed growers annually since 2010. Soil sampled from growers' fields each winter was planted with highly susceptible, moderately susceptible, and partially resistant spinach inbred lines, and the plants rated weekly to calculate a Fusarium wilt severity index (FWSI) and the area under the disease progress curve (AUDPC). Results for 147 soils tested from 2010 to 2013 have been published. This study examined results for an additional 248 soils tested from 2014 to 2019 with the bioassay modified to include an option of agricultural limestone amendment to the soils tested. FWSI and AUDPC were affected significantly (p < .001) by the main effects of soil and spinach inbred line, and the interaction of these factors. Correlation analyses showed a range in degree of association of FWSI and AUDPC with spinach seed crop rotation duration and soil properties, depending on the spinach inbred line (r = −.255 to –.267, n = 172 soils with characteristics suitable for correlation analyses). Stepwise regression models for 172 soils with relevant parameters for regression analyses identified spinach seed crop rotation interval, rate of agricultural limestone amendment, soil pH, and soil Fe, Mn, and Zn concentrations as most strongly associated with FWSI and AUDPC. However, the models accounted for ≤33.4% (R2) of the variability in Fusarium wilt risk. The soil bioassay remains a primary tool for spinach seed growers to select fields with low risk of Fusarium wilt. 相似文献
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High mortality of southern bluefin tuna (SBT) Thunnus maccoyii larvae in captivity is a major problem hindering culture of this species. The relationships between body density of SBT larvae, swimbladder inflation and survival were investigated in this study. Swimbladder inflation and changes in volume have a direct effect on body density in larval SBT. Swimbladder inflation was first observed at 3 days post hatch, and larvae with successful swimbladder inflation were able to maintain their body density within a narrow range (?ρ = 0.0006 g cm?3). Although swimbladder volume increased with larval growth, it could not compensate for the increase in body density and did not prevent nocturnal sinking. The increase in body density was greater for larvae that did not inflate their swimbladder. Low percentages of swimbladder inflation (27.5 ± 3.5 %) coupled with negative body buoyancy of SBT might contribute to mortality as larvae sank in the dark phase and made contact with the tank bottom. Management strategies that maintain larvae within the water column and enhance swimbladder inflation are required to improve survival of SBT larvae reared in hatcheries. 相似文献
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