SPECIALIZATION AND RESEARCH IN THE MEDICAL SCIENCES     

Gay FP 《Science (New York, N.Y.)》1917,45(1150):25-33

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Root diseases, weeds, and nematodes with poultry litter and conservation tillage in a sweet corn–snap bean double crop     

Donald R. Sumner  Melvin R. Hall  J. Danny Gay  Greg MacDonald  Stanley I. Savage  R. Keith Bramwell 《Crop Protection》2002,21(10):963-972

The effect of continuous applications of poultry litter on root diseases, nematodes, and weeds with different tillage practices in vegetable production in Georgia was investigated. Litter treatments (noncomposted and composted broiler or breeder litter) applied 3–5 weeks before planting were compared with no litter. In sweet corn and snap bean there were differences among years, and tillage and litter treatments had a variable effect on yield, post-emergence damping-off and plant stand. Crown and brace root rot in corn induced by Rhizoctonia solani AG 2-2 increased after 3 years conservation tillage, but there were no differences among litter treatments. Population densities of R. solani AG-4 were increased by conservation tillage before planting snap bean the first year but not in later years, while litter treatments had no effect. After 3 years, populations of Pythium spp., Fusarium solani, and Fusarium spp. did not differ among treatments, but noncomposted broiler litter increased populations of saprophytic fungi in soil compared with no litter. Population densities of stylet-bearing nematodes were low and usually not different among treatments. After 3 years of sweet corn populations of Meloidogyne incognita increased with conventional tillage compared with conservation tillage, populations of Paratrichodorus christiei were reduced by litter treatments and populations of Helicotylenchus dihystera were reduced by noncomposted broiler litter compared with no litter. Weed infestation increased in both tillage systems with time, but in snap bean there was a greater infestation in conservation tillage than in conventional tillage. Litter treatments had little effect on weed infestation.  相似文献   

An isotopically labeled internal standard liquid chromatography-tandem mass spectrometry method for determination of ephedrine alkaloids and synephrine in dietary supplements     

Gay ML  Niemann RA  Musser SM 《Journal of agricultural and food chemistry》2006,54(2):285-291

We report a simplified analytical procedure for determination of ephedrine alkaloids and synephrine in dietary supplements. Cleanup by simple filtration, when combined with tandem mass spectrometry (MS/MS) detection, provided results comparable to our published method with solid phase extraction (SPE) cleanup and single-stage MS detection with in-source fragmentation. We also compared three mass spectrometric experimental configurations: electrospray (ESI) and atmospheric pressure chemical ionization (APCI) with MS/MS and APCI-MS with fragmentation provided by increasing cone voltage. Because these methods used one isotopically labeled internal standard to determine several different analytes, quantitation errors may arise from susceptibility to ionization suppression caused by the matrix. We therefore compared the results obtained by ESI and APCI ionization.  相似文献   

Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders          下载免费PDF全文

NLAF Sarmento  EFF Martins  DC Costa  WS Silva  CC Mattioli  MR Luz  RK Luz 《Reproduction in domestic animals》2017,52(1):144-152

The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross‐frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen.  相似文献   

Partitioning the Mortality Risk Associated with Inadequate Passive Transfer of Colostral Immunoglobulins in Dairy Calves     

Jeff W. Tyler  Dale D. Hancock  James G. Thorne  Clive C. Gay  John M. Gay 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1999,13(4):335-337

This study developed a method to partition the risk of mortality in dairy calves in the 1st 16 weeks of life. Observed population mortality and the relative risk of mortality in each serum protein concentration stratum were used to determine the population baseline mortality rate and the mortality rate due to inadequate passive transfer of colostral immunoglobulin. A total of 3,479 calves were studied, 8.2% of which died before 16 weeks of age. The population baseline mortality rate was 5.0% and the mortality rate due to inadequate passive transfer was 3.2%. Thirty-nine percent of the observed mortality was attributed to inadequate passive transfer. This partitioning of risk between passive transfer-related and unrelated sources should prove useful in conducting investigations of calf mortality problems in dairy herds.  相似文献   

Microarray-assisted Marker Development for Molecular Breeding     

The advantage of being able to investigate the abundance  composition of millions of sequences in parallel has established microarrays as an attractive technology for genome wide transcription  sequence variation profiling 《分子植物育种》2007,5(2):232-233

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