Degradation of selected polycyclic aromatic hydrocarbons in coastal sediments: Importance of microbes and polychaete worms     

Wayne S. Gardner  Richard F. Lee  Kenneth R. Tenore  Larry W. Smith 《Water, air, and soil pollution》1979,11(3):339-347

Rates of degradation of polycyclic aromatic hydrocarbons (PAH) were examined after addition of crude oil enriched with anthracene, fluoranthene, benz(a)anthracene, and benzo(a)pyrene to coastal sediments in a laboratory (20°) flowing seawater system. Three types of sediment (fine sand, medium sand, and marsh sediment) with and without the benthic polychaete worm, Capitella capitata, were used. After extraction from the sediment, PAH concentrations were measured by liquid chromatography with fluorescent detection. Microbial degradation was studied by incubating sediments with radioactive PAH and measuring subsequent production of ¹⁴C0₂. Concentrations of the four PAH decreased significantly with time in fine and medium sized sands. PAH levels also decreased in marsh sediment but trends were not significant (P < 0.05). C. capitata stimulated PAH degradation. Microbial degradation was more rapid in upper surfaces than in lower layers of the sediments.  相似文献   

Kinetic and stoichiometric assessment of the antioxidant activity of flavonoids by electron spin resonance spectroscopy     

McPhail DB  Hartley RC  Gardner PT  Duthie GG 《Journal of agricultural and food chemistry》2003,51(6):1684-1690

There is current interest in the use of naturally occurring flavonoids as antioxidants for the preservation of foods and the prevention of diseases such as atherosclerosis and cancers. To establish the molecular characteristics required for maximum antioxidant activity, electron spin resonance (ESR) spectroscopy has been used to determine the stoichiometry and kinetics of the hydrogen-donating ability of 15 flavonoids and d-alpha-tocopherol to galvinoxyl, a resonance-stabilized, sterically protected aryloxyl radical. The second-order reaction rates, which will be governed by O-H bond dissociation energies, were myricetin > morin > quercetin > fisetin approximately catechin > kaempferol approximately luteolin > rutin > d-alpha-tocopherol > taxifolin > tamarixetin > myricetin 3',4',5'-trimethyl ether > datiscetin > galangin > hesperitin approximately apigenin. Reactivity is highly dependant on the configuration of OH groups on the flavonoid B and C rings, there being little contribution from the A ring to antioxidant effectiveness. Highest reaction rates and stoichiometries were observed with flavonols capable of being oxidized to orthoquinones or extended paraquinones. However, rates and stoichiometries did not always correlate and the data suggest that kinetic factors may be of greater importance within a biological context.  相似文献   

Preparation of tetrahydroagathic acid: a serum metabolite of isocupressic acid, a cattle abortifacient in ponderosa pine     

Garrossian M  Gardner DR  Panter KE  James LF 《Journal of agricultural and food chemistry》2002,50(8):2235-2240

Isocupressic acid (1) was used to synthetically prepare a mixture of (8S,13R,S)-labda-15,19-dioic acid (tetrahydroagathic acid) (5) via a two-step oxidation procedure followed by hydrogenation of the double bonds at C13 and C8. Reduction of the C8,17 double bond was stereospecific producing only the 8S isomer and confirmed by the nOe interaction between the resulting C17 and C20 methyl groups. The 13R and 13S isomers of 5 were separated and analyzed by HPLC/MS, and (13S)-tetrahydroagathic acid was isolated and identified by comparison to a standard prepared by hydrogenation of naturally occurring (13S)-dihydroagathic acid (4). (13R,S)-dihydroagathic acid was prepared by selective sodium metal-catalyzed hydrogenation of the C13,14 allylic double bond of agathic acid (3). The prepared compounds were then used as standards to confirm the presence of 4 and 5 and their respective 13R and 13S isomers in bovine serum samples. Tetrahydroagathic acid was shown to be the only metabolite detected in serum samples taken from a suspected cattle abortion case submitted for diagnosis; and, thus, 5 could be a valuable diagnostic marker for pine needle-induced abortions.  相似文献   

Disease of geese caused by a new herpesvirus   总被引：3，自引：0，他引：3  

PJ KETTERER  BJ RODWELL  HA WESTBURY†  PT HOOPER†  AR MACKENZIE‡  JG DINGLE§  HC PRIOR 《Australian veterinary journal》1990,67(12):446-448

A goose flock farmed outdoors in south-eastern Queensland suffered an outbreak of peracute disease with high death rate (97%). Small button ulcers and large plaques overlying lymphocyte aggregates were present on the mucosa of the small intestine of affected birds. Small white foci of necrosis and focal haemorrhages were seen in the livers. Numerous intranuclear inclusion bodies were observed microscopically in hepatocytes and a herpesvirus which grew rapidly in chicken kidney cells was isolated from tissues. Duck virus enteritis (DVE) was suspected but DVE antiserums failed to neutralise the virus. Further serological studies with a limited range of known avian herpesviruses have failed to identify the virus. Experimental transmission resulted in high mortality in geese (100%), lower mortality in ducklings and nil mortality in chickens. Surveillance studies showed no evidence of infection in domestic and wild birds beyond the original farm and the infection appears not to have been established in the area. Wild ducks, which were frequent visitors to the farm dam, were considered the most likely source of the infection.  相似文献   

World Watch     

Gardner Murray 《Australian veterinary journal》2003,81(7):393-393

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Toxigenic type D Pasteurella multocida in New South Wales pig herds—prevalence and factors associated with infection     

I A Gardner  G J Eamens  M J Turner  C L Hornitzky 《Australian veterinary journal》1989,66(10):318-321

Between March and July 1987, a study was undertaken to determine the prevalence of and factors associated with toxigenic type D Pasteurella multocida infection in New South Wales pig herds. Toxigenic type D P. multocida was isolated from the nasal cavities of pigs in one (2%) of 50 randomly selected herds. Toxigenic isolates were also recovered from 2 (8%) of a separate group of 25 herds that had purchased pigs from a known infected piggery in South Australia (herd SA). Snout abnormalities were present in 9.4%, 3.2% and 1.8% of grower pigs in the 3 affected herds. Isolation of toxigenic P. multocida was significantly associated (p less than 0.0001) with the occurrence of clinically affected pigs in the herd. Purchase of at least 5 pigs from herd SA was associated with an elevated risk (p less than 0.05) of isolation of toxigenic P. multocida.  相似文献   

Response of the Rieger begonia to ozone and sulphur dioxide     

J.O. Gardner  D.P. Ormrod 《Scientia Horticulturae》1976,5(2):171-181

Ozone (O₃) and sulphur dioxide (SO₂) are at present the two most pervasive air pollutants in the urban and suburban areas in which most Rieger begonias are grown. These air pollutants have been shown to impair crop productivity and quality in many other species. Controlled environment experiments were therefore conducted to elucidate the responses of ‘Schwabenland Red’ to separate or bombined O₃ and SO₂ at different growth stages.Plants at the early vegetative or prefloral stages had much more leaf damage after combined O₃ + SO₂ than after separate gases at 15 p.p.h.m. O₃ or 60 p.p.h.m. SO₂ for 5 days in a synergistic type of response. Exposure for an additional day at twice these concentrations greatly increased leaf damage. Growth reductions were not found after 2 weeks but delaying measurements until 8 weeks after treatment revealed some growth reductions.Experiments were conducted with flowering plants using O₃ of 0, 10, 20 or 30 p.p.h.m. in all combinations with SO₂ at 0, 60, 120 or 180 p.p.h.m. Fully developed leaves were damaged, and undamaged leaves were smaller and lighter on plants exposed to 20 p.p.h.m. or more O₃, 120 p.p.h.m. or more SO₂, or any combination of O₃ and SO₂ at or above 10 and 60 p.p.h.m., respectively.  相似文献   

The effect of the molluscicide Frescon on smooth and cross-striated muscles of Lymnaea stagnalis and Helix aspersa     

B.L. Brezden  D.R. Gardner 《Pesticide biochemistry and physiology》1983,20(3):259-268

The molluscicide Frescon (N-(triphenylmethyl)morpholine) induces prolonged, irreversible contractions (contractures) in the isolated heart ventricle, penis retractor, and foot muscles of the aquatic snail Lymnaea stagnalis. It also causes contracture of the penis retractor muscle, but not the heart ventricle, of the terrestrial snail Helix aspersa. Since Frescon-induced contracture is not accompanied by a depolarization of the sarcolemma of Lymnaea heart ventricle muscle cells, it is suggested that the action of this molluscicide is associated with a membrane potential-independent activation of the contractile machinery. The rapid response of Lymnaea musculature to Frescon suggests that the direct contracture-inducing action of this molluscicide could explain its toxicity to the whole animal.  相似文献   

Enzootic pneumonia: comparison of cough and lung lesions as predictors of weight gain in swine.   总被引：4，自引：0，他引：4       下载免费PDF全文

C R Morris  I A Gardner  S K Hietala    T E Carpenter 《Canadian journal of veterinary research》1995,59(3):197-204

A prospective cohort study was undertaken in a commercial swine herd to determine the relationship between weight gain and the occurrence of enzootic pneumonia (EP). Estimates of the association between EP and weight gain were obtained from multiple linear regression models, using coughing episodes or slaughter checks as indicators of EP status. Models were estimated for pigs in 2 different age groups: roasters (n = 1084, sold at 32 to 50 kg) and market hogs (n = 1162, sold at 100 to 110 kg). The relationship between presence of lung lesions at slaughter and previous coughing episodes was also investigated. Throughout the study period, clinical evaluations were performed weekly, and coughing episodes recorded for each pig. Lungs were inspected at slaughter, and scores were expressed as the percentage of the lung with gross pneumonic lesions. Coughing and lung scores were significantly correlated, after adjusting for other covariates (R = 0.32 and 0.59, respectively, for market hogs and roasters). However, the agreement beyond chance between coughing history and lung lesions at slaughter was poor among both roasters and market hogs (kappa = 0.17 and 0.07, respectively). Although very specific, weekly assessment of coughing was not a sensitive indicator of lung lesions at slaughter. In multiple regression, lung score was a highly significant predictor of lower final weight in pigs of both age groups (P < 0.001 in the selected regression models).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Response in mice to erythropoiesis regulatory factors     

J P Lewis  C S Wright  R R Moores  W A Neal  E T Welch  L L Smith  E Gardner  W G Lewis 《American journal of veterinary research》1973,34(10):1367-1368

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