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101.
Aznar I McGrath G Murphy D Corner LA Gormley E Frankena K More SJ Martin W O'Keeffe J De Jong MC 《Veterinary microbiology》2011,151(1-2):104-111
The principal wildlife reservoir of Mycobacterium bovis in Ireland is the European badger. Studies in the Republic of Ireland (RoI) have shown that badgers culled in association with cattle herd tuberculosis breakdowns (focal culling) have a higher prevalence of infection than the badger population at large. This observation is one rationale for the medium term national strategy of focal badger culling. A vaccination strategy for the control of bovine tuberculosis (bTB) in badgers is a preferred long-term option. The Bacillus Calmette-Guérin (BCG) vaccine has been shown to decrease disease severity in captive badgers under controlled conditions. As the vaccine has been tested in a controlled environment with precise information on infection pressure, it cannot be assumed a priori that the effects of vaccination are similar in the wild, where other environmental and/or ecological factors prevail. For this reason we have designed a vaccine field trial to assess the impact of vaccination on the incidence of TB infection in a wild badger population. The selected study area for the vaccine trial (approximately 755 square kilometers) is divided into three zones each of which has similar characteristics in terms of size, number of main badger setts, cattle herds, cattle and land classification type. Three vaccination levels (100%, 50% and 0%) will be allocated to the three zones in a way that a gradient of vaccination coverage North to South is achieved. The middle zone (zone B) will be vaccinated at a 50% coverage but zone A and C will be randomly allocated with 100% or 0% vaccination coverage. Vaccination within zone B will be done randomly at individual badger level. The objective of this paper is to describe the design of a field tuberculosis vaccination trial for badgers, the epidemiological methods that were used to design the trial and the subsequent data analysis. The analysis will enable us to quantify the magnitude of the observed vaccination effect on M. bovis transmission in badgers under field conditions and to improve our knowledge of the biological effects of vaccination on susceptibility and infectiousness. 相似文献
102.
Herregods G Van Camp J Morel N Ghesquière B Gevaert K Vercruysse L Dierckx S Quanten E Smagghe G 《Journal of agricultural and food chemistry》2011,59(2):552-558
In this project we report on the angiotensin I-converting enzyme (ACE)-inhibitory activity of a bovine gelatin hydrolysate (Bh2) that was submitted to further hydrolysis by different enzymes. The thermolysin hydrolysate (Bh2t) showed the highest in vitro ACE inhibitory activity, and interestingly a marked in vivo blood pressure-lowering effect was demonstrated in spontaneously hypertensive rats (SHR). In contrast, Bh2 showed no effect in SHR, confirming the need for the extra thermolysin hydrolysis. Hence, an angiotensin I-evoked contractile response in isolated rat aortic rings was inhibited by Bh2t, but not by Bh2, suggesting ACE inhibition as the underlying antihypertensive mechanism for Bh2t. Using mass spectrometry, seven small peptides, AG, AGP, VGP, PY, QY, DY and IY or LY or HO-PY were identified in Bh2t. As these peptides showed ACE inhibitory activity and were more prominent in Bh2t than in Bh2, the current data provide evidence that these contribute to the antihypertensive effect of Bh2t. 相似文献
103.
Talaat El Sebaï Marion Devers-Lamrani Bernard Lagacherie Nadine Rouard Guy Soulas Fabrice Martin-Laurent 《Biology and Fertility of Soils》2011,47(4):427-435
The impact of soil moisture content and temperature on isoproturon (3-(4-isopropylphenyl)-1,1-dimethyl-urea [IPU]) mineralization
activity was assessed on an agricultural soil regularly exposed to this herbicide. Mineralization of 14C-IPU was monitored on soil microcosms incubated at different temperatures (10°C, 20°C, 28°C) and soil moisture contents (9%,
12%, 15, 18%, 21%, 24%). An increase in temperature and/or soil moisture significantly enhanced the maximum rate and percentage
of IPU mineralization while it decreased the lag time before mineralization. The maximum rate and percentage of IPU mineralization
respectively ranged from 0.18% day−1 and 9% for the lowest temperature and soil moisture content pair (10°C–9%) to 1.51% day−1 and 27.1% for the highest pair (28°C–24%). Statistics revealed a cross interaction of temperature and soil moisture content
on the maximum rate of IPU mineralization. The optimum conditions for IPU mineralization, estimated from the double Gaussian
model, were 25.8°C and 24% soil moisture content. The influence of fluctuations in soil moisture content on IPU-mineralization
was investigated by subjecting the soil microcosms to drought stress. When IPU was added at the end of the drought stress,
it had no statistical effect on IPU mineralization. However, when it was added before the drought stress, two mineralization
phases were observed: (1) one corresponding to the drought stress for which mineralization was low and (2) another one observed
after restoration of soil moisture content characterized by higher mineralization rate. It can be concluded that climatic
fluctuations affect the activity of IPU mineralizing microbial community, and may lead to an increase in IPU persistence. 相似文献
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Green peach aphid populations were monitored by using water trap pans and by taking leaf samples in 38 southwestern Idaho potato fields from 1972 to 1975. Numbers of winged aphids in trap pans were correlated with populations of aphids developing in adjacent fields but were not predictive of future population trends. Trap pan data are, however, useful in alerting growers to the possibility of damaging field populations which exist in a field at the time of sampling. 相似文献
108.
Guy Carvajal William Thilly 《Plant foods for human nutrition (Dordrecht, Netherlands)》1988,38(2):105-114
Cultured AHH1 human lymphoblast cells were exposed to an extract ofMintostachys mollis, which is used as a medicinal plant and preservative in Peru, to detect its mutagenic activity. A three-day exposure to concentrations of 1, 10, 30 and 50 µg/ml resulted in induced mutant fraction of 1.02, 1.79, 2.21 and 3.80 mutations per million cells per day, expressed as 6-Thioguanine resistance. A concentration of 10µg/ml induced 11.9 times the spontaneous mutant fraction of AHH1 cells. The doubling dose determined to be 838 ng/ml. A concentration of 30 µg/ml of this compound resembled the induced rate of 1 µM benzo () pryene. 相似文献
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