太谷地区番茄病毒病研究初探

本试验就太谷地区番茄病毒病的消长情况作了重点的描述；同时对症状和病原进行了初步探讨。症状以的卷叶和条斑并重，病原以烟草花叶病毒（ＴＭＶ）为主     

加工现场微机控制系统抗干扰的研究

针对制造业加工现场的环境特点，分析了微机控制系统的干扰来源和途径，介绍了实用的抗干扰措施。实践证明：这些软硬件抗干扰措施的综合运用，使自动化加工中微机控制系统的稳定性得到了较大的提高。     

河流水质污染中的反问题（Ⅱ）

继续讨论了一类半线性抛物偏微分方程的反问题，在一定条件下，得到了问题的解的存在性，唯一性，并给出了近似解法。     

Growth and production of a Cortaderia ptlosa (Gramineae) community in the Falkland Islands

Above ground production of a typical Cortaderia pilosa dominant sward in the Falkland Islands was estimated over one growing season by summing significant positive increments in DM production of various sward components and by sequential cutting to ground level. The standing crop was characterized by a high proportion of standing dead matter at all times of the year. Net herbage production was estimated as 2200 kg ha^-1 and 1440 kg ha^-1 by the 'difference' and "sequential culling" techniques, respectively. The pattern of leaf growth was determined on another site by regular linear measurements of a population of physiologically similar C. pilosa leaves. There was very little early season growth and most of the DM was produced in a short period in the middle part of the growing season. The poor early season growth was attributed to adverse climatic conditions. A significant increase in green matter digestibility in October and November was masked by the low digestibility and high contribution to the overall DM by the standing dead component of the herbage.
The implications of these findings are briefly discussed in relation to the increased utilization of C. pilosa by improved pasture management, including burning and possibly reseeding areas with improved species. Tissue turnover studies combined with more knowledge of sheep nutrition cycles would enable grazing systems to be developed on a sounder basis than previously.     

中国姜瘟病的研究进展

姜瘟病是中国生姜生产上发生较为普遍的病害,是由青枯劳尔氏菌(Ralstoniasolanacearum)引起的。此病原菌寄主范围广,可侵染44个科300多种植物。菌体短杆状,在TZC选择性培养基上培养出现白边较宽和白边较窄的两种菌落。菌系划分为5个生理小种和5个生化型,中国的姜瘟菌主要属生理小种1号,生物型属II、III、IV。此病害是一种较难防治的土传病害,在高温、高湿、雨水多、氮肥过量的情况下发生较为严重。中国植病工作者对此病害作了大量的研究工作,对中国姜瘟病的病原菌、发病规律、及防治等研究进展作一综述。     

Long-term variation in brown trout, Salmo trutta L., stocking success in a large lake: interplay between availability of suitable prey and size at release

Abstract –  Factors affecting long-term variation in brown trout, Salmo trutta L., stocking success were examined in a large lake, Lake Oulujärvi, in central Finland. Brown trout were stocked in spring (late May to early June) in 1974–1991 and in summer (late June to early July) in 1992–2001. The biomass of the vendace, Coregonus albula (L.), population (prey) at release time had the largest positive effect on stocking success within both periods: biomass of adult vendace in spring and both 0+ and adult vendace in summer. Increasing the size of stocked fish had a positive effect if the vendace available at release were only adults. The increasing trend of predator-catch-per-unit-effort (CPUE) [combined CPUE of northern pike Esox lucius L., burbot Lota lota (L.), and pike-perch Stizostedion lucioperca (L.)] through the study period and its negative effect on trout stocking success suggested an increasing effect of predation within the entire time series.     

Periodontal disease. Therapy and prevention

Success in veterinary dentistry lies in good home care and regular, thorough dental prophylaxis. The removal of supragingival and subgingival calculus must be accomplished before periodontal disease can be controlled. When gingival sulcus depths exceed 4 or 5 mm, the gingivae must be excised or reflected to allow proper treatment of the pocket area. Antibiotic therapy should be instituted in the extensively involved veterinary dental patient.     

Fate of Escherichia coli and Escherichia coli O157 in soils and drainage water following cattle slurry application at 3 sites in southern Scotland

Abstract. Slurry from farm animals may contaminate water supplies, rivers and bathing waters with faecal coliforms, such as Escherichia coli . Where animals harbour the O157 strain the hazard to human health is particularly high, but both the hazard level, and the low incidence and sporadic nature of the excretion of E. coli O157 make it difficult to study this strain under field conditions. The survival of total E. coli and of E. coli O157 were compared in the laboratory for two soils under controlled temperature and moisture. E. coli O157 die-off rate was the same as or quicker than for total E. coli . This result meant that field experiments studying the fate of total E. coli should give a satisfactory evaluation of the risk of water contamination by the O157 strain. In four field experiments at three sites, slurry containing total E. coli numbers of 2.2 × 10⁴ to 5.7 × 10⁵ colony forming units per mL (c.f.u. mL^–1) was applied to drained field plots. Field die-off was faster than expected from laboratory experiments, especially in one experiment where two weeks dry weather followed application. In all but this experiment, the first drain flow events after slurry application led to very high E. coli concentrations in the drains (10³ to 10⁴ c.f.u. mL^–1). E. coli O157 was present in the slurry used for two of the experiments (33 c.f.u. per 100 mL in each case). However the proportion of E.coli O157 was very low (about 1 in 10⁵) and it was not detected in the drainage water. After the first week E. coli drainage water numbers decreased rapidly but they were 1–10 c.f.u. mL^–1 for much of the sampling period after slurry application (1–3 months).