Leaching of 2,4-D and dicamba from home lawns     

A. J. Gold  T. G. Morton  W. M. Sullivan  J. McClory 《Water, air, and soil pollution》1988,37(1-2):121-129

Leaching of the broadleaf herbicides 2,4-D and dicamba from home lawns was monitored with ceramic extraction plates placed at a 0.2 m depth beneath undisturbed sod. The site was located on a Merrimac sandy loam. Four treatments, consisting of two rates of herbicide applications coupled with two irrigation regimes. were evaluated on 12 plots. The low herbicide rate consisted of 1.1 and 0.1 kg ha^?1 yr^?1 of 2,4-D and dicamba, respectively. The high rate used was 3.3 and 0.33 kg ha^?1 yr^?1 of 2,4-D and dicamba applied in three equal applications. Irrigation treatments were (1) minimal irrigation to avoid drought stress and percolation from the root zone and (2) overwatering at 37.5 mm week^?1. Geometric mean concentra tions of 2,4-D ranged from 0.55 to 0.87 μg L^?1 compared to 0.26 to 0.55 μg L^?1 for dicamba. The low application-minimum irrigation treatment generated significantly higher concentrations than the other treatments for both herbicides. The low concentrations observed for both herbicides suggest that excellent degradation conditions exist in the root zone of turfgrass during the summer months when application occurs.  相似文献   

Cerebellar cortical atrophy in a baboon   总被引：1，自引：0，他引：1  

D A Sadoff  W E Giddens  W R Morton 《Veterinary pathology》1986,23(3):335-336

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The in vitro degradation of [¹⁴C]malathion by enzymatic extracts from resistant and susceptible strains of Drosophila melanogaster     

B.C. Holwerda  R.A. Morton 《Pesticide biochemistry and physiology》1983,20(2):151-160

Enzyme preparations from Drosophila melanogaster flies degraded [¹⁴C]malathion to α- and β-malathion monoacids and, hence, were considered to contain malathion carboxylesterase (ME) activity. Although ME- activity was stable during preincubation in the absence of malathion, it decreased dramatically during the course of the reaction, and could not be completely recovered by Sephadex G-25 chromatography. Furthermore, the protein fraction after chromatography still contained ¹⁴C, suggesting that the enzyme had become inhibited by a bound, ¹⁴C-labeled derivative. Extracts from a resistant (malathion-selected), an intermediate control, and the susceptible Canton S strains of D. melanogaster differed in the lability of ME activity during the reaction. This difference was partly attributed to the production of small amounts of malaoxon (2–8%) by the extracts from the more resistant strains. No consistent strain differences were found when the rate of malathion degradation was measured during the first minute of reaction, either with or without a microsomal oxidase inhibitor (metyrapone) present. These results, together with the cross-resistance of the malathion-selected strain to other insecticides and the lack of a synergistic effect of two carboxylesterase inhibitors (triphenyl phosphate and S,S,S-tributylphosphorotrithioate) suggested that malathion carboxylesterase does not contribute significantly to the observed differences in malathion resistance between strains.  相似文献   

Effects of some clinically significant mycotoxins on the incorporation of DNA, RNA and protein precursors in cultured mammalian cells     

F H Jeffery  J G Morton  J K Miller 《Research in veterinary science》1984,37(1):30-38

The effects of zearalenone (F-2), ochratoxin A and T-2 toxins on the synthesis of DNA, RNA and proteins in mouse L cells were studied. F-2 toxin inhibited protein synthesis to a lesser extent than DNA and RNA synthesis, whereas ochratoxin A inhibited the synthesis of each equally. Exposure to the toxins for 24 hours relatively reduced the synthetic ability of the cells. T-2 toxin inhibited protein and DNA synthesis in parallel but RNA synthesis to a lesser extent. Enhanced incorporation of tritiated thymidine was found when L cells were exposed to 0.4 to 0.016 ng of T-2 toxin ml-1 for 24 hours.  相似文献   

Hemodynamics in the guinea pig after anesthetization with ketamine/xylazine   总被引：2，自引：0，他引：2  

M V Hart  J R Rowles  A R Hohimer  M J Morton  J D Hosenpud 《American journal of veterinary research》1984,45(11):2328-2330

The resting hemodynamics were determined in 8 guinea pigs after they were anesthetized with ketamine/xylazine. Measurements were made of blood pressure, heart rate, cardiac output, arterial blood gases, and pH. These measurements were obtained initially at 4 to 5 hours after an injection (IM) of ketamine HCl (25 mg) and xylazine (0.15 mg) was given to anesthetize the animals for catheterization (period 1), again 5 days after the operation (period 2), and finally 4 to 5 hours after a 2nd injection of ketamine/xylazine (period 3). There were no differences in heart rates, respiratory rates, or cardiac outputs among the 3 study periods. However, arterial blood pressure was slightly, but significantly, lowered after, and presumably due to, instrumentation (62 +/- 4 mm of Hg, P less than 0.05) when compared with the 5-day postoperative period (67 +/- 7 mm of Hg) or after the readministration of anesthetics (66 +/- 7 mm of Hg). The partial pressure of carbon dioxide in the arterial blood was slightly lower (4 mm of Hg, P less than 0.05) in both acutely postanesthetic periods (period 1 and period 3) than in the same animals at postoperative day 5 (period 2). This study has demonstrated that resting hemodynamics measured shortly after this anesthesia with ketamine/xylazine are not largely different from those in chronically instrumented animals.  相似文献   

Use of DNA fingerprint analysis in identification of the sire     

D B Morton  R E Yaxley  I Patel  A J Jeffreys  S J Howes  P G Debenham 《The Veterinary record》1987,121(25-26):592-594

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Application of a scaling model to establish and validate an interval level pain scale for assessment of acute pain in dogs     

Morton CM  Reid J  Scott EM  Holton LL  Nolan AM 《American journal of veterinary research》2005,66(12):2154-2166

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Sudden death in racing Thoroughbreds in Victoria, Australia     

Boden LA  Charles JA  Slocombe RF  Sandy JR  Finnin PJ  Morton JM  Clarke AF 《Equine veterinary journal》2005,37(3):269-271

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Reproduction in female cattle in a communal farming area of Zimbabwe     

N. Honhold  F. W. G. Hill  D. C. Knottenbelt  B. D. Perry  D. Morton 《Tropical animal health and production》1992,24(3):183-191

Summary Cattle in a communal farming area of Zimbabwe were identified and examined in the late dry and mid wet season of 1985/86. Ovarian activity rates were 17·9% and 38·6% in the dry and wet season respectively. Pregnancy rates were 16·1% and 24·6% respectively. A major limitation to reproduction was the percentage of anoestrous females. There was no evidence of a seasonal calving pattern. Median body condition score was 2·0 in the dry season and 1·5 in the wet season. Adult females of body condition score 2·5 and above had ovarian activity rates of 41·9% and pregnancy rates of 41·9 per cent. Those with a body condition score below 2·5 had rates of 26·8% and 16·4% respectively. Serum progesterone levels in pregnant animals were positively related to body condition score, with some animals having progesterone levels similar to non-pregnant animals. Metabolic profiles suggested that the major limiting nutrient in both seasons was nitrogen, although other micronutrients might also be involved in low reproductive rates.

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Resumen Se identificó un grupo de ganado en un área comunal pastoril en Zimbabwe, el que se estudió al final de la estación seca y en la mitad de la estación lluviosa. El estudio se llevó a cabo de 1985 a 1986. La tasas de actividad ovárica fueron de 17·9% y 38·6% y las de pre?ez de 16·1% y 24·6%, en la estación seca y lluviosa, respectivamente. La mayor limitación para la reproducción, fue el porcentaje alto de hembras en anestro. No hubo un patrón claro de partos estacionales. La condición corporal media fue de 2·0 en la estación seca y de 1·5 en la estación lluviosa. Las hembras adultas que tenian una condición corporal de 2·5 ó mayor, tuvieron tasas de actividad ovárica de 41·9% y tasas de pre?ez de 41·9 por vaca. Aquellas con una condición corporal por debajo de 2·5, tuvieron tasas de actividad ovárica de 26·8% y tasas de pre?ez de 16·4%, respectivamente. Los niveles de progesterona en animales pre?ados, estuvieron positivamente relacionados con el puntaje obtenido en el análisis de la condición corporal, aunque algunos animales tuvieron niveles de progesterona bajos, como de animales no pre?ados. Los perfiles matabólicos revelaron, que el nutriente más deficitario fue el nitrógeno, aunque otros nutrientes tambien fueron deficitarios.

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Résumé Dans une zone agricole de type communautaire, le bétail a été identifié et examiné à la fin de la saison humide et jusqu’au milieu de la saison sèche en 1985/1986. Les taux d’activité ovarienne étaient respectivement de 17,9 et 38,6 p. 100 au cours de la saison sèche et de la saison humide. Les taux de gestation étaient de 16,1 et 24,6 p. 100 respectivement. Un obstacle essentiel à la reproduction s’est révélé être le nombre de femmelles en anoestrus. Aucune preuve n’a pu être apportée d’un mode de mise bas lié à la saison. L’indice de condition corporelle moyenne mesuré à l’aide d’une échelle de points était de 2,0 en saison sèche et de 1,5 en saison humide. Les femelles adultes dont la condition corporelle était de 2,5 et au dessus, avaient des taux d’activité ovarienne de 41,9 p. 100 et des taux de gestation par co?t identiques. Celles dont l’indice était inférieur à 2,5 avaient des taux de 26,8 et de 16,4 p. 100 respectivement. Les taux de progestérone sérique chez les animaux en gestation étaient positivement liés à l’indice de condition corporelle, avec quelques sujets dont le taux de progestérone était identique à celui d’animaux non-gestants. Les profils métaboliques font penser que le facteur alimentaire limitant majeur pour les deux saisons était l’azote, quoique d’autres micronutriments aient pu être également en cause dans les taux de reproduction bas.

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SUMO1 haploinsufficiency leads to cleft lip and palate     

Alkuraya FS  Saadi I  Lund JJ  Turbe-Doan A  Morton CC  Maas RL 《Science (New York, N.Y.)》2006,313(5794):1751

The posttranslational modification sumoylation can have multiple effects on its substrate proteins. We studied a patient with isolated cleft lip and palate and a balanced chromosomal translocation that disrupts the SUMO1 (small ubiquitin-related modifier) gene, resulting in haploinsufficiency. In mouse, we found that Sumo1 is expressed in the developing lip and palate and that a Sumo1 hypomorphic allele manifests an incompletely penetrant orofacial clefting phenotype. Products of several genes implicated in clefting are sumoylated, and the Sumo1 hypomorphic allele interacts genetically with a loss-of-function allele for one of these loci. Thus, sumoylation defines a network of genes important for palatogenesis.  相似文献