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151.
George Rigos Alexandros Samartzis Morgane Henry Eleni Fountoulaki Efthimia Cotou John Sweetman Simon Davies Ioannis Nengas 《Aquaculture International》2010,18(6):1093-1104
The comparative effects of iron-supplemented levels on growth, tissue distribution, haematology and immunology of gilthead
sea bream, Sparus aurata (2 g) were investigated, using four organic (50, 100, 200, 300 mg ORG/kg diet) and one inorganic iron source (200 INOR mg/kg diet).
Fish were treated for 12 weeks with the experimental diets and maintained at a water temperature of 19–22°C. Growth (final
weight and specific growth rate), tissue distribution (spleen, liver and muscle), haematological parameters (red blood cells,
haematocrit, haemoglobin and mean corpuscular haemoglobin concentration) and non-specific immune indexes (respiratory burst
activity and antibacterial activity of serum) were analysed. No significant differences were found in growth and iron tissue
distribution among the tested groups. Red blood cell counting was statistically higher in fish given 50 ORG, 100 ORG, 200
ORG and 200 INOR feeds. However, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration were not significantly
affected by increasing dietary iron. Fish receiving the 100 ORG diet had the best performance with respect to the respiratory
burst activity and significantly higher values for antibacterial activity of serum were obtained in fish fed with the 300
ORG diet. The present findings provided no clear evidence of the optimum iron concentration. However, there was adequate indication
that iron supplementation enhanced the performance of gilthead sea bream, mainly from a haematological and immunological point
of view. 相似文献
152.
Jeff R. Powell Rachel G. Campbell Kari E. Dunfield Robert H. Gulden Miranda M. Hart David J. Levy-Booth John N. Klironomos K. Peter Pauls Clarence J. Swanton Jack T. Trevors Pedro M. Antunes 《Applied soil ecology》2009,41(1):128-136
Most soybeans grown in North America are genetically modified (GM) to tolerate applications of the broad-spectrum herbicide glyphosate; as a result, glyphosate is now extensively used in soybean cropping systems. Soybean roots form both arbuscular mycorrhizal (AM) and rhizobial symbioses. In addition to individually improving host plant fitness, these symbioses also interact to influence the functioning of each symbiosis, thereby establishing a tripartite symbiosis. The objectives of this study were to (1) estimate the effects of glyphosate on the establishment and functioning of AM and rhizobial symbioses with GM soybean, and (2) to estimate the interdependence of the symbioses in determining the response of each symbiosis to glyphosate. These objectives were addressed in two experiments; the first investigated the importance of the timing of glyphosate application in determining the responses of the symbionts and the second varied the rate of glyphosate application. Glyphosate applied at recommended field rates had no effect on Glomus intraradices or Bradyrhizobium japonicum colonization of soybean roots, or on soybean foliar tissue [P]. N2-fixation was greater for glyphosate-treated soybean plants than for untreated-plants in both experiments, but only when glyphosate was applied at the first trifoliate soybean growth stage. These data deviate from previous studies estimating the effect of glyphosate on the rhizobial symbiosis, some of which observed negative effects on rhizobial colonization and/or N2-fixation. We did observe evidence of the response of one symbiont (stimulation of N2-fixation following glyphosate) being dependent on co-inoculation with the other; however, this interactive response appeared to be contextually dependent as it was not consistent between experiments. Future research needs to consider the role of environmental factors and other biota when evaluating rhizobial responses to herbicide applications. 相似文献
153.
David C. Griffiths John A. Pickett Lesley E. Smart Christine M. Woodcock 《Pest management science》1989,27(3):269-276
The probing and feeding behaviour of aphids can result in uptake of viruses from infected plants and subsequent transmission to healthy plants. It is possible to interfere with virus acquisition and transmission by influencing aphid host-selection and feeding behaviour with antifeedant chemicals. Published work is reviewed and new work is presented in this paper. The two most successful classes of antifeedants against aphids are (a) compounds derived from the aphid alarm pheromone and (b) plant-derived antifeedants such as the sesquiterpene (-)-polygodial. Results with these and other compounds are discussed in terms of antifeedant activity against Myzus persicae, their effects on resistant aphids and the evidence for dec?ease in virus spread by aphids in laboratory and field. 相似文献
154.
The eukaryotic cell membrane is thought to consist of a mobile bilayer of phospholipid, sometimes intercalated with sterols, in which peripheral and transmembrane proteins are embedded. This provides a model whereby the mode of action of many fungicidal and herbicidal compounds can be rationalised and understood. Some compounds, such as the polyene antibiotics, steroidal saponins and certain phytoalexins, induce membrane malfunction by direct insertion, often complexing with vital components. Others, such as paraquat and the nitrodiphenyl ether herbicides, cause membrane damage by inducing lipid peroxidations. Furthermore, there are many compounds, including the sterol-biosynthesis-inhibiting fungicides and the aryloxyphenoxypropionate and cyclohexanedione herbicides, which interfere with the biosynthesis of membrane components. Because membrane structure is fundamentally similar in eukaryotes, it is important to discover the reasons for any differential toxicity displayed by these compounds and, if necessary, to find ways of optimising desirable patterns of selectivity. 相似文献
155.
Beth A. Snyder Breno Leite John Hipskind Larry G. Butler Ralph L. Nicholson 《Physiological and Molecular Plant Pathology》1991,39(6)
Microspectrophotometry was performed on intact, pigmented vesicle-like inclusions within living sorghum cells that were accumulating phytoalexins as a response to attempted fungal infection. The results indicate that the deoxyanthocyanidin phytoalexins are present in inclusions. Moreover, the phytoalexin concentration within a single inclusion, based on luteolinidin, was calculated to be 0·15 m. The amounts of luteolinidin and apigeninidin in cells involved in the phytoalexin response at individual infection sites were also determined. The data showed that luteolinidin accumulated to levels of 0·48–1·20 ng/cell whereas apigeninidin accumulated to levels of 0·24–0·91 ng/cell. The results of both analyses confirmed that at the infection site the deoxyanthocyanidins accumulate to levels in substantial excess of those required for inhibition of the fungus Colletotrichum graminicola. 相似文献
156.
Geoffrey G. Briggs George R. Cayley Glenn W. Dawson David C. Griffiths Ewen D. M. Macaulay John A. Pickett Mary M. Pile Lester J. Wadhams Christine M. Woodcock 《Pest management science》1986,17(4):441-448
Two analogues of the aphid alarm pheromone (E)-β-farnesene, a trifluorofarnesene and a difluoro-1-norfarnesene, were found to be highly active and were more readily detectable than the parent compound. For (Z)-hexadec-11-enal, a component of some lepidopteran sex attractant pheromones, replacement of the carbonyl oxygen with a difluoromethyl group to give a difluoroheptadecadiene resulted in loss of activity. A trifluoroacetoxyhexadecanolide was a more volatile analogue of the mosquito oviposition pheromone (?)-(5R,6S)-6-acetoxy-5-hexadecanolide and was highly active. 相似文献
157.
John P 《Science (New York, N.Y.)》2001,292(5523):1847-1848
158.
Hrubec TC Smith SA Robertson JL 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2001,30(1):8-15
Hybrid striped bass (Morone chrysops X Morone saxatilis ) are an important aquaculture species yet there are few diagnostic tools available to assess their health. Hematology and clinical chemistry analyses are not used extensively in fish medicine due to the lack of reference intervals for various fish species, and because factors such as age can affect blood values. There is little published information regarding age-related changes in blood values of juvenile fish. It is important to evaluate juvenile fish, as this is the time they are raised in aquaculture settings. Determining age-related changes in the blood values of fishes would further develop clinical pathology as a diagnostic tool, enhancing both fish medicine and the aquaculture industry. The results of standard hematology and clinical chemistry analysis were evaluated in juvenile hybrid striped bass at 4, 6, 9, 15, and 19 months of age. Values for PCV and RBC indices were significantly lower, and plasma protein concentration was significantly higher in younger fish. Total WBC and lymphocyte counts were significantly higher in fish at 6 and 9 months of age, while neutrophil and monocyte counts were higher at 6, 9, and 15 months. Eosinophil counts were significantly higher in 9-month-old fish. The majority of hematologic values fell within previously established reference intervals, indicating that only slight modification to the intervals is necessary for evaluating hematologic results of hybrid striped bass at different ages. The following analytes deviated sufficiently from adult reference intervals to warrant separate reference values: plasma protein concentration at 4 months, WBC and lymphocyte counts at 15 and 19 months, and thrombocyte-like-cells at 9 months of age. Values for most biochemical analytes were significantly different among age groups except for creatinine and potassium concentrations. Comparisons with reference intervals were not made for biochemical analytes, because established reference intervals were not available. Age-related changes in hematologic and biochemical values of striped bass were similar to those reported for rainbow trout and mammals. 相似文献
159.
160.
Binding of ciprofloxacin labelled with technetium Tc 99m versus 99mTc-pertechnetate to a live and killed equine isolate of Escherichia coli 下载免费PDF全文
Kate Alexander Wm. Tod Drost John S. Mattoon Joseph J. Kowalski Julie A. Funk Amanda C. Crabtree 《Canadian journal of veterinary research》2005,69(4):272-277
This paper describes a simple methodology for evaluating the bacterial binding of ciprofloxacin labelled with technetium Tc 99m. Using this methodology, the binding of 99mTc-ciprofloxacin by live Escherichia coli was compared with the binding of 99mTc-ciprofloxacin by killed E. coli and the binding of 99mTc-pertechnetate (99mTcO4-) by live E. coli. The antimicrobial effect of 99mTc-ciprofloxacin on E. coli was evaluated. Four groups were defined: live E. coli with 99mTc-ciprofloxacin, live E. coli with 99mTcO4 , killed E. coli with 99mTc-ciprofloxacin, and killed E. coli with 99mTcO4-. After 0, 2, and 4 h of incubation of 1 x 10(8) colony-forming units of E. coli suspended in 5 mL of sterile distilled water with 1.85 MBq of 99mTc-ciprofloxacin or 99mTcO4, 1 mL from each sample was centrifuged. The radioactivity of the bacterial pellet and that of the supernatant were measured separately, and the percentage of sample radioactivity attributable to bacterial binding was calculated. Of the 99mTc-ciprofloxacin, 3.6% to 5.9% was bound to live or killed E. coli; only 0.1% to 0.2% of the 99mTcO4- was bound to live E. coli (P < 0.0001). No significant difference in 99mTc-ciprofloxacin binding was found between live and killed E. coli (P = 0.887). An antimicrobial effect on E. coli was seen with 99mTc-ciprofloxacin: colony counts were reduced after 4 h. The small amount of 99mTc-ciprofloxacin binding and the lack of difference in binding between live and killed E. coli may limit the utility of this methodology in evaluating the presence of E. coli infection. 相似文献