Characterization of ovine PrP gene promoter activity in N2a neuroblastoma and ovine foetal brain cell lines   总被引：1，自引：0，他引：1  

G. T. O'Neill  K. Donnelly  E. Marshall  D. Cairns  W. Goldmann  N. Hunter 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2003,120(2):114-123

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Comparison of the rates of proliferation of adipocyte precursor cells derived from two lines of chicken which differ in their rates of adipose tissue development     

L. E. Donnelly  A. Cryer  S. C. Butterwith 《British poultry science》1993,34(1):187-193

1. Putative adipocyte precursor cells were isolated from the white adipose tissue of young broiler and layer chickens and cultured in vitro.

2. The cells from both sources were shown to have the characteristics of adipocyte precursor cells. On reaching confluence, lipoprotein lipase activity was induced and the cells from both strains accumulated large amounts of lipid in the presence of chicken serum.

3. Measurement of cell number over time in culture and calculation of cell doubling times showed that cells from broilers proliferated at a faster rate than those derived from layer‐strain chickens. This was the case whether primary or secondary cell cultures were used. Primary cultures of broiler cells had a doubling time of 22 h versus 39 h for layer cells.

4. The contribution of such a difference in proliferative rate to the differential rate of adipose tissue growth between broiler and layer strains observed in vivo is discussed.  相似文献   

Comparison of the specificty of human and bovine tuberculin PPD for testing cattle. 1--Republic of Ireland.     

I W Lesslie  C N Herbert  K J Burn  B N MacClancy  W J Donnelly 《The Veterinary record》1975,96(15):332-334

A tuberculin testing trial in cattle was carried out in the Republic of Ireland to compare the specificity for bovine tuberculosis of a human purified protein derivative (PPD) tuberculin (Weybridge) with that of a bovine PPD (Rotterdam), and to determine whether discrimination between specific and non-specific reactions to mammalian tuberculin is better with doses of tuberculins smaller than those traditonally used for testing cattle. Tests were carried out in 510 cattle, 395 of which were shown by post mortem examination to be tuberculous and 115 non-tuberculous. Three dilutions at five-fold intervals of both mammalian tuberculins were used together with two dose levels of avian tuberculin PPD (Weybridge), and all reactions were measured both by increase in skin fold thickness and by diameter of induration. In the environment of this trial, the bovine PPD was shown to be more specific for bovine tuberculosis than the human PPD, and particularly in differentiating from "skin tuberculosis". There was no indication of greater specificity at lower doses of tuberculin. Measurement of induration diameter proved a satisfactory alternative method of reading tuberculin reactions in cattle under field conditions.  相似文献   

Rates and quantities of carbon flux to ectomycorrhizal mycelium following 14C pulse labeling of Pinus sylvestris seedlings: effects of litter patches and interaction with a wood-decomposer fungus     

Leake JR  Donnelly DP  Saunders EM  Boddy L  Read DJ 《Tree physiology》2001,21(2-3):71-82

We used a novel digital autoradiographic technique that enabled, for the first time, simultaneous visualization and quantification of spatial and temporal changes in carbon allocation patterns in ectomycorrhizal mycelia. Mycorrhizal plants of Pinus sylvestris L. were grown in microcosms containing non-sterile peat. The time course and spatial distribution of carbon allocation by P. sylvestris to mycelia of its mycorrhizal partners, Paxillus involutus (Batsch) Fr. and Suillus bovinus (L.): Kuntze, were quantified following 14C pulse labeling of the plants. Litter patches were used to investigate the effects of nutrient resource quality on carbon allocation. The wood-decomposer fungus Phanerochaete velutina (D.C.: Pers.) Parmasto was introduced to evaluate competitive and territorial interactions between its mycelial cords and the mycelial system of S. bovinus. Growth of ectomycorrhizal mycelium was stimulated in the litter patches. Nearly 60% of the C transferred from host plant to external mycorrhizal mycelium (> 2 mm from root surfaces) was allocated to mycelium in the patches, which comprised only 12% of the soil area available for mycelial colonization. Mycelia in the litter patch most recently colonized by mycorrhizal mycelium received the largest investment of carbon, amounting to 27 to 50% of the total 14C in external mycorrhizal mycelium. The amount of C transfer to external mycelium of S. bovinus following pulse labeling was reduced from a maximum of 167 nmol in systems with no saprotroph to a maximum of 61 nmol in systems interacting with P. velutina. The 14C content of S. bovinus mycelium reached a maximum 24-36 h after labeling in control microcosms, but allocation did not reach a peak until 56 h after labeling, when S. bovinus interacted with mycelium of P. velutina. The mycelium of S. bovinus contained 9% of the total 14C in the plants (including mycorrhizae) at the end of the experiment, but this was reduced to 4% in the presence of P. velutina. The results demonstrate the dynamic manner in which mycorrhizal mycelia deploy C when foraging for nutrients. The inhibitory effect of the wood-decomposer fungus P. velutina on C allocation to external mycorrhizal mycelium has important implications for nutrient cycling in forest ecosystems.  相似文献   

Effects of helminth infection on the pre-weaning production of ewes and lambs: evaluation of pre- and post-lambing drenching and provision of safe lambing pasture     

P J Waller  J R Donnelly  R J Dobson  A D Donald  A Axelsen  F H Morley 《Australian veterinary journal》1987,64(11):339-343

The pre-weaning production of ewes and lambs in spring on pastures grazed during the previous autumn and early winter by either weaner sheep, adult sheep, or cattle was investigated together with estimating the benefits of pre- and post-lambing drenches to ewes. These treatments were compared with one in which parasitism was uncontrolled in ewes lambing on pastures grazed previously by untreated weaner sheep, and another where parasitism was suppressed by 2-weekly drenching of the weaner sheep and also of the ewes and their lambs. Prior grazing by cattle effectively eliminated infection of pastures with intestinal Trichostrongylus and Nematodirus spp, but less so for Ostertagia spp. Worthwhile reductions in contamination were also achieved by grazing by adult sheep compared with grazing by undrenched weaners. Despite differences in the parasitological status of the pastures, there were no indications that pre-weaning growth rates of lambs were affected. However, wool growth in ewes was reduced by 10 to 20% by parasite infection. Wool growth of ewes on pastures grazed by cattle during the pre-experimental period exceeded that on any other treatment, and was significantly greater than that of ewes on pastures grazed by undrenched weaners. There was no production benefit in giving a pre-lambing drench to ewes on plots contaminated by weaners, or in giving the additional post-lambing drench to ewes grazing on plots contaminated by weaners, adult sheep or cattle.  相似文献   

Photosynthetic capacity of red spruce during winter     

Schaberg PG  Shane JB  Cali PF  Donnelly JR  Strimbeck GR 《Tree physiology》1998,18(4):271-276

We measured the photosynthetic capacity (P(max)) of plantation-grown red spruce (Picea rubens Sarg.) during two winter seasons (1993-94 and 1994-95) and monitored field photosynthesis of these trees during one winter (1993-94). We also measured P(max) for mature montane trees from January through May 1995. Changes in P(max) and field photosynthesis closely paralleled seasonal changes in outdoor air temperature. However, during thaw periods, field photosynthesis was closely correlated with multiple-day temperature regimes, whereas P(max) was closely correlated with single-day fluctuations in temperature. There was a strong association between short-term changes in ambient temperature and P(max) during the extended thaw of January 1995. Significant increases in P(max) occurred within two days of the start of this thaw. Repeated measurements of cut shoots kept indoors indicated that temperature-induced increases in P(max) can occur within 3 h. Although significant correlations between P(max) and stomatal conductance (g(s)) or intracellular CO(2) concentration (C(i)) raised the possibility that increases in P(max) resulted from increases in stomatal aperture, fluctuations in g(s) or C(i) explained little of the overall variation in P(max). Following both natural and simulated thaws, P(max) increased considerably but plateaued at only 37% of the mean photosynthetic rate reported for red spruce during the growing season. Thus, even though shoots were provided with near-optimal environmental conditions, and despite thaw-induced changes in physiology, significant limitations to winter photosynthesis remained.  相似文献   

Factors influencing red expression in autumn foliage of sugar maple trees   总被引：1，自引：0，他引：1  

Schaberg PG  Van Den Berg AK  Murakami PF  Shane JB  Donnelly JR 《Tree physiology》2003,23(5):325-333

We evaluated factors influencing the development of autumn red coloration in leaves of sugar maple (Acer saccharum Marsh.) by measuring mineral nutrient and carbohydrate concentrations, water content, and phenology of color development of leaves from 16 mature open-grown trees on 12 dates from June through October 1999. Mean foliar nutrient and carbohydrate concentrations and water content were generally within the range published for healthy sugar maple trees. However, foliar nitrogen (N) concentrations were near deficiency values for some trees. The timing and extent of red leaf coloration was consistently correlated with both foliar N concentrations and starch or sugar concentrations, which also varied with N status. Leaves of trees with low foliar N concentrations turned red earlier and more completely than those of trees with high foliar N concentrations. Low-N trees also had higher foliar starch concentrations than high-N trees. During the autumn development of red leaf coloration, foliar starch, glucose and fructose concentrations were positively correlated with red leaf color expression. At peak red expression, the concentrations of glucose, fructose, sucrose and stachyose were all positively correlated with red color expressed as a percent of total leaf area.  相似文献   

Extending the Encounter–Norm–Crowding Generalization to Angler Evaluations of Other Social and Resource Indicators     

Mark D. Needham  Jerry J. Vaske  Doug Whittaker  Maureen P. Donnelly 《Human Dimensions of Wildlife》2014,19(3):288-299

Recreationists who encounter more people than their normative tolerance for seeing others usually feel more crowded than those encountering fewer than their norm. This research note extends this observation–norm–evaluation relationship (e.g., encounter–norm–crowding) to other evaluations and indicators. Data were from a survey of anglers on the Gulkana National Wild River in Alaska (n = 288). Respondents who encountered more people than their norm felt more crowded than those encountering fewer than their norm. When impacts from other social indicators (e.g., camping within sight or sound of other groups, fishing area competition) exceeded user norms, crowding was higher and satisfaction with overall trip quality was lower than for those experiencing less than their norms. When impacts from resource indicators (e.g., litter, impacted campsites) exceeded norms, satisfaction with both environmental quality and trip quality were lower than for those experiencing less than their norms. The encounter–norm– crowding generalization, therefore, extended to other indicators and evaluations.  相似文献   

Mutagenic activity of soils amended with two refinery wastes     

K. W. Brown  K. C. Donnelly  J. C. Thomas  P. Davol  B. R. Scott 《Water, air, and soil pollution》1986,29(1):1-13

The mutagenic potential of the acid, base, and neutral fractions of petroleum sludge amended soil was determined using the Salmonella/microsome assay and Aspergillus methionine assay. Organic compounds were extracted from two different soils amended with either storm-water runoff impoundment or combined API-separator/slop-oil emulsion solids waste. Application of either waste to soil reduced the mutagenic activity of organic compounds extracted from equal weights of soil. However, biodegradation increased both the total and the direct-acting mutagenicity of all fractions residual in the waste-amended soil. The maximum level of mutagenic activity per milligram residual C was detected in the sample collected 360 days after waste application for the acid and base fractions from the storm-water runoff impoundment amended soils and the acid, base, and neutral fractions of the combined API separator/slop-oil emulsion waste amended soils. A comparison of the results based on equivalent weights of soil indicates that the mutagenic potential of both wastes was reduced by soil incorporation. The results from the Salmonella assay indicate that while the bulk of the solvent extractable organics in both wastes was rendered non-mutagenic, the mutagenic potential of the organic compounds in the acid fraction from the storm-water runoff impoundment sludge amended soil was increased. The results from the Aspergillus assay of both wastes indicate that the mutagenic potential of all three fractions was eventually reduced to a level that would be considered non-mutagenic. Thus, while degradation may have increased the mutagenic potential of specific organic compounds that were residual in the soil, the overall effect of degradation was to reduce the weighted activity of the waste amended soil.  相似文献   

Low temperature physics     

Donnelly RJ 《Science (New York, N.Y.)》1976,194(4261):176

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