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171.
Rebecca L. Smith Michael W. Sanderson Rodney Jones Yapo N’Guessan David Renter Robert Larson Brad J. White 《Preventive veterinary medicine》2014
A stochastic model was designed to calculate the cost-effectiveness of biosecurity strategies for bovine viral diarrhea virus (BVDV) in cow-calf herds. Possible sources of BVDV introduction considered were imported animals, including the calves of pregnant imports, and fenceline contact with infected herds, including stocker cattle raised in adjacent pastures. Spread of BVDV through the herd was modeled with a stochastic SIR model. Financial consequences of BVDV, including lost income, treatment costs, and the cost of biosecurity strategies, were calculated for 10 years, based on the risks of a herd with a user-defined import profile. Results indicate that importing pregnant animals and stockers increased the financial risk of BVDV. Strategic testing in combination with vaccination most decreased the risk of high-cost outbreaks in most herds. The choice of a biosecurity strategy was specific to the risks of a particular herd. 相似文献
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Simpson JA Anglin JD Balogh A Burrows JR Cowley SW Ferrando P Heber B Hynds RJ Kunow H Marsden RG McKibben RB Müller-Mellin R Page DE Raviart A Sanderson TR Staines K Wenzel KP Wilson MD Zhang M 《Science (New York, N.Y.)》1992,257(5076):1543-1550
The Ulysses spacecraft made the first exploration of the region of Jupiter's magnetosphere at high Jovigraphic latitudes ( approximately 37 degrees south) on the dusk side and reached higher magnetic latitudes ( approximately 49 degrees north) on the day side than any previous mission to Jupiter. The cosmic and solar particle investigations (COSPIN) instrumentation achieved a remarkably well integrated set of observations of energetic charged particles in the energy ranges of approximately 1 to 170 megaelectron volts for electrons and 0.3 to 20 megaelectron volts for protons and heavier nuclei. The new findings include (i) an apparent polar cap region in the northern hemisphere in which energetic charged particles following Jovian magnetic field lines may have direct access to the interplanetary medium, (ii) high-energy electron bursts (rise times = 1 minute and energies extending to > approximately 17 megaelectron volts) on the dusk side that are apparently associated with field-aligned currents and radio burst emissions, (iii) persistence of the global 10-hour relativistic electron "clock" phenomenon throughout Jupiter's magnetosphere, (iv) on the basis of charged-particle measurements, apparent dragging of magnetic field lines at large radii in the dusk sector toward the tail, and (v) consistent outflow of megaelectron volt electrons and large-scale departures from corotation for nucleons. 相似文献
175.
Seedpiece protectants containing thiabendazole (TBZ) were deleterious to stand establishment and yield and were associated with the formation of secondary tubers from seedpieces on Monona potatoes in four of five years (1980–1984) in Wisconsin. Seed tubers treated with a pre- and/or poststorage mist application of TBZ prior to a post-cutting treatment with a dust formulation containing 0.5% TBZ were most severely affected. The negative effects of pre- and post-cutting TBZ treatment on yield were additive. Observations in grower fields during 1981 indicated that cultivars differed in their sensitivity to this fungicide. Ontario, LaChipper, and Monona were most severely affected while problems were not observed on the Superior and Russet Burbank cultivars. 相似文献
176.
The effects of offering ensiled red clover (Trifolium pratense), lucerne (Medicago sativa), pea (Pisum sativum), kale (Brassica oleracea) and hybrid ryegrass (Lolium hybridicum) on the productivity and nutrient‐use efficiency of lambs were investigated. Forages were cut, wilted for 24 h and ensiled as round bales. A hundred Suffolk‐cross lambs, aged 8 months, were offered grass silage during a 5‐week standardization period and then group‐housed for 14 d and offered ad libitum access to a treatment silage. For the measurement period, lambs were split into four replicate groups of five lambs per treatment. Dry matter intake and live weight were recorded every 7 d over 56 d. The chemical composition of the silages differed for all the variables measured. Lambs offered pea silage had a very low liveweight gain and this treatment was discontinued after 21 d. Lambs offered the other forages had a higher liveweight gain than lambs offered ryegrass silage (P < 0·001). Food conversion and nitrogen‐use efficiency were higher in lambs offered the red clover, lucerne and kale silages compared with those offered ensiled ryegrass (P < 0·001). These findings demonstrate the potential for using ensiled alternative forages rather than ryegrass to increase the productivity and nutrient use efficiency of livestock systems. 相似文献
177.
Experiments conducted at Charlottetown, Prince Edward Island (P.E.I.) during 1979–1982 on potato (Solanum tuberosum L. cv. ‘Kennebec’) demonstrated that excessive levels of applied nitrogen made leaf and stem desiccation with diquat (6,7-dihydrodipyrido [1,2- :2′ ,1′-C] pyrazinediium ion) more difficult. A split application of diquat (0.42 kg ai/ha 5 days apart) improved leaf and stem desiccation by as much as 21 and 27% respectively compared to a single application at 0.84 kg ai/ha. Diquat treatments had no effect on vascular discoloration. The high levels of applied nitrogen increased the yield of tubers greater than 60 mm in diameter but reduced the yield of seed size tubers in the 40 to 60 mm size range. 相似文献
178.
Verticillium albo-atrum, cultured on potato dextrose agar plates or on sterilized wheat kernels, was used to incite disease in field studies. Immediately prior to planting, seed potatoes were dipped in a spore/mycelium suspension that was prepared from agar plate cultures. A second inoculation treatment involved placing infested wheat kernels under the potato seed at planting time. Both inoculation methods resulted in verticillium wilt development. However, the inoculum suspension dip method resulted in slightly greater incidences of verticillium wilt than did the infested wheat method. Inoculation by means of a suspension dip immediately after cutting the seed resulted in more wilted plants than when seed was inoculated 24 hours or 7 days after cutting. The spore/mycelium suspension dip method is now routinely used for field studies on disease susceptibility or resistance in potato cultivars. 相似文献
179.
Singh M Arseneault M Sanderson T Murthy V Ramassamy C 《Journal of agricultural and food chemistry》2008,56(13):4855-4873
Polyphenols are the most abundant antioxidants in diet. Indeed, fruits, vegetables, beverages (tea, wine, juices), plants, and some herbs are loaded with powerful antioxidant polyphenols. Despite their wide distribution, research on human health benefits truly began in the mid-1990s (Scalbert, A.; Johnson, I. T.; Saltmarsh, M. Am. J. Clin. Nutr. 2005, 81, S15S-217S). Phenolic compounds have been receiving increasing interest from consumers and manufacturers because numerous epidemiological studies have suggested associations between consumption of polyphenol-rich foods or beverages and the prevention of certain chronic diseases such as cancers and cardiovascular diseases (Manach, C.; Mazur, A.; Scalbert, A. Curr. Opin. Lipidol. 2005, 16, 77-84; Duthie, S. J. Mol. Nutr. Food Res. 2007, 51, 665-674). Furthermore, in the past 10 years, research on the neuroprotective effects of dietary polyphenols has developed considerably. These compounds are able to protect neuronal cells in various in vivo and in vitro models through different intracellular targets (Ramassamy, C. Eur. J. Pharmacol. 2006, 545, 51-64). However, it is not at all clear whether these compounds reach the brain in sufficient concentrations and in a biologically active form to exert beneficial effects. On the other hand, it has become clear that the mechanisms of action of these polyphenols go beyond their antioxidant activity and the attenuation of oxidative stress. Therefore, there is a need for more research on their intracellular and molecular targets as special pathways underlying distinct polyphenol-induced neuroprotection. The focus of this review is aimed at presenting the role of some polyphenols from fruits, vegetables, and beverages in neuroprotection and particularly in Alzheimer's disease and the research challenges in this area. 相似文献