Virus content of seed potato stocks produced in a unique seed potato production scheme

Western Australia has a unique seed potato production scheme which has remained virtually unchanged for more than 60 years, consisting of summer plantings of predominantly one cultivar in wind-exposed coastal swamplands. No rotation is used and the scheme relies on natural winter flooding and 'grazing' by sheep to eliminate unharvested tubers. Stocks are recycled every year with only limited inputs of pathogen-tested seed tubers in recent times. Virus spread in the crop is controlled by selecting large tubers for planting, roguing, aphicide application and growing season inspections. Potato viruses X and S were commonly detected in old seed stocks produced by this scheme attaining 100% infection in some. Both viruses were less frequently found in newly introduced seed stocks. By contrast, potato virus Y was never detected and potato leaf roll virus rarely found.     

A new method for induction of specific polyclonal antibodies using immunostained proteins on nitrocellulose membrane, and HIV 1 core antigen and Escherichia coli verotoxin as examples

Abstract Two polyclonal antibodies against verotoxin 1 and the core protein p24 of HIV 1 were raised in mice by a new immunization procedure. Both proteins were transferred to nitrocellulose, reacted with polyspecific antisera and the antigen-antibody complexes were then visualized by immunostaining. For preparation of antisera the stained protein bands were cut from the nitrocellulose sheets and implanted subcutaneously into the backs of BALB/c mice, without any adjuvant. A single booster was given 4 weeks later by implanting a second strip. All mice produced high titers of antibody directed against the antigen used for immunization. Thus, antibodies of high specificity can be elicited against protein bands in stained immunoblots.     

含有母性影响遗传基因的连锁定位系的构建

母性影响遗传基因由于其杂交后代的表型受母本基因型的影响, 而不能直接反映当代个体的基因型, 这给连锁定位测交亲本(三隐性或双隐性系统)的培育带来困难, 从而影响这类基因的定位研究。设计了一套杂交培育方案, 其核心是使母性影响遗传基因先纯合, 再使非母性影响遗传基因纯合。采用所设计的方案, 成功培育了家蚕第13连锁群的赤蚁(ch)、无鳞毛翅(nlw, 新突变)和褐色卵t (b-t, 母性影响遗传)的三隐性系统, 并培育了第19连锁群的狭胸(nb)和第二肾形卵(ki-2, 母性影响遗传, 待定位突变基因)的双隐性系统。     

Application of Partially Balanced Block Designs to Factorial Experiments

In this paper we present partially balanced block designs with F_p and C_p association schemes. These designs play a great role in the experimental theory since they can be applied to factorial experiments. A particular stress is put on the formulation of association schemes _p and C_p, presentation of exemplary constructions of these designs and their analysis of variance. The presented considerations are abundantly illustrated with examples.     

Modelling land-use sustainability using farmland birds as indicators

Biodiversity on farmland is declining due to agricultural intensification and occurs across many taxa such as plants, insects or birds. Here, we modelled population sizes of five farmland birds in central Germany as the German Sustainability Indicator for Species Diversity (SISD) is based on this taxon. We explored options for sustainable farmland management by generating land-use scenarios at the regional scale. For individual bird species, high SISD scores could be reached by changing environmental variables, such as landscape or crop diversity, percent cover of spring cereals or hedge density. However, contrasting species responses to these variables prevented from reaching high scores for all species simultaneously. We were able to improve the total SISD score from 0.77 at present to 0.94 by increasing landscape and crop diversity or to 0.87 by increasing hedge density and reducing spring cereals, respectively. An economic evaluation of the return losses associated with these changes revealed that annual costs of approx. 5.5 €/ha farmland would suffice for this latter increase by optimizing hedges and spring cereals towards high SISD. We conclude that balancing three levels of trade-offs, i.e. contrasting requirements of species, diverging responses in different landscapes, and alternative economic options, is difficult to achieve without systematic modelling. Yet, by accounting for differences in landscape structure and species distributions at a regional spatial scale and by focusing on clearly defined measures such as hedge density or the cover of spring cereals rather than composite indices like landscape or crop diversity it seems possible to develop realisable, affordable and sustainable management strategies.     

地西他滨联合小剂量HAG方案对急性髓系白血病患者细胞免疫功能及血清COX-2、bFGF的影响

目的:探讨地西他滨联合小剂量高三尖杉酯碱⁺阿糖胞苷⁺重组人粒细胞集落刺激因子(HAG)方案对急性髓系白血病(AML)患者细胞免疫功能及血清环氧合酶-2(COX-2)、碱性成纤维细胞生长因子(bFGF)的影响。方法:选取2016年4月~2019年4月期间山西白求恩医院收治的AML患者93例,根据随机数字表法分为对照组(n=46,HAG方案)和研究组(n=47,地西他滨联合小剂量HAG方案),比较两组患者临床疗效、细胞免疫功能、血清COX-2、bFGF水平的变化情况,记录两组治疗期间不良反应情况。结果:研究组治疗后的临床总有效率为80.85%(38/47),高于对照组的56.52%(26/46)(P<0.05)。两组治疗后CD3⁺、CD4⁺/CD8⁺、CD4⁺水平均下降,但研究组高于对照组(P<0.05);两组患者CD8⁺水平均升高,且研究组高于对照组(P<0.05)。两组治疗后血清COX-2、bFGF水平均下降,且研究组低于对照组(P<0.05)。两组不良反应发生率比较无差异(P>0.05)。结论:地西他滨联合小剂量HAG方案治疗可减轻AML患者机体免疫抑制,改善血清COX-2、bFGF水平,且用药安全性较好。     

以多功能为目标的森林模拟优化系统(FSOS)的算法与应用前景

森林模拟优化模型(forest simulation and optimization system,FSOS)已在加拿大不列颠哥伦比亚省和中国长白山区得到广泛应用.FSOS模型基于多种资源协调平衡管理观点,采用金属模拟退火优化算法安排森林经营作业方案,在实现森林经营多目标长期可持续协调发展的基础上达到森林资源的理想状态.FSOS模型中的多功能(或多目标)包括水的储存和净化、二氧化碳的截获、野生动物生境保护、生物多样性维持、可视景观质量与木材生产等,其目标的参照系“森林理想状态”由专家、环境组织和政府政策根据生态系统的多功能进行综合界定.本文详细介绍了FSOS基本参数和理想状态的界定,及金属模拟退火优化算法在森林生态系统规划中的应用,为实现森林生态系统多种资源的规划管理以及政府定量分析和管理森林生态系统的多种资源并有效监督森林作业和多种资源变化、实现森林资源可持续利用提供帮助.     

Sheep breeding schemes utilising artificial insemination; large-scale simulation with a complex breeding goal

Alternative Norwegian sheep breeding schemes were evaluated by stochastic simulation of a breeding population with about 120 000 ewes, considering the gain for an aggregate genotype including nine traits and also the rate of inbreeding. The schemes were: a scheme where both young unproven rams (test rams) and proven rams (elite rams) are used in artificial insemination (AI scheme), a scheme with test rams in natural mating in ram circles and elite rams (from one and a half years of age) in AI across all flocks in the country (NMAI2 scheme), a scheme where, in addition to testing rams, the youngest elite rams (one and a half years of age) are also used in natural mating in ram circles, while older elite rams are used in AI (NMAI1 scheme), and a scheme, acting as a control, where both test and elite rams are used in natural mating (NM scheme). Within the NMAI- and AI-schemes, experimentation was performed for percent ewes inseminated to elite rams v. test rams (EM%), numbers of ewes inseminated per elite ram (EAIn), and numbers of ewes mated per test ram by natural service (TNMn) or by AI (TAIn), respectively. With a restriction on the rate of inbreeding (⩽0.8% per generation), the AI scheme gave similar gain to the NMAI2 scheme (and about 40% more than did the NM scheme). Less gain was generated by the NMAI1 scheme, but it was still considerably more than for the NM scheme (about 25%). In the AI scheme, relatively few ewes (200/300) should be inseminated to each test/elite ram, and a low EM% should be chosen (10%). In the NMAI schemes, TNMn should be relatively high (40 to 50), combined with average and somewhat larger than average EAIn (NMAI2: 700 ewes, NMAI1: 900 ewes), and EM% medium (30%).     

Root biomass distribution of triploid Populus tomentosa under wide- and narrow-row spacing planting schemes and its responses to soil nutrients

三倍体毛白杨(triploid Populus tomentosa)是我国华北地区主要纸浆林品种, 在该地区多采用宽窄行模式栽植。为基于根系结构特征制定该模式下毛白杨人工林高效水肥管理策略和明确影响其根系空间分布的主要因子, 在5年生林分中于8株样树周围挖取2106个土柱, 研究该栽植模式下毛白杨根系生物量的空间分布特征, 并分析了细根垂直分布对土壤有机质、速效磷和碱解氮等的响应。结果表明, 一维垂向上, 宽行内细根根重密度(FRBD)在0-30 cm土层中随深度增加而递减, 但在30 cm以下土层呈均匀分布(p = 0.079); 窄行内FRBD呈“双峰”分布, 即在0-20 cm (22%)和70-110 cm (31%)土层均有较多细根分布; 10-150 cm各土层中, 窄行FRBD较宽行高17%-148%。宽、窄行内, 随深度增加, 粗根根重密度(CRBD)均呈先增后减变化, 而细根粗根比(F/C)无显著变化(p > 0.05), 窄行平均F/C较宽行高60%。一维径向上, 宽、窄行内FRBD均呈近均匀分布, 而CRBD和F/C均随距离增加分别显著递减和增大。二维尺度上, FRBD在窄行内分布相对均匀, 但在宽行内主要集中在表土层且随距离增加细根浅层化程度增强; CRBD在树干两侧呈“不对称”分布; 垂向0-20 cm、径向160-300 cm范围是宽行内平均FRBD和F/C较高区域, 分别为宽行相应指标总平均的2.8和1.1倍。FRBD在0-30 cm土层中随土壤有机质、速效磷和碱解氮含量的增加而逐渐增大, 但在30 cm以下土层中无明显变化趋势。研究结果表明, 宽、窄行间毛白杨根系分布的差异性主要体现在细根一维垂直分布和细根、粗根二维分布上。土壤有机质、速效磷和碱解氮是0-30 cm土层中毛白杨细根垂直分布的重要影响因子, 但对下层土壤中根系分布无影响。对宽窄行栽植的毛白杨林分灌溉时, 灌溉水应供给到窄行区域; 施肥时, 缓释肥和速效肥应分别浅施在宽行中央附近和窄行内。     

Hydrological improvement of a former floodplain in an urban area: Potential and limits

The Lobau near Vienna used to be a dynamic floodplain which was cut off from the Danube River in the course of regulation measures in the 19th century. In order to compensate for deficits in the water budget, a water enhancement scheme for the upstream part of the floodplain, the Obere Lobau, was initiated in 2001. The aims of this scheme were to increase water levels in the floodplain and to discharge nutrients from the area's highly eutrophic water bodies by imposing a controlled surface water exchange through the main side arm. Our study evaluates the effects of this artificial water supply on the hydrological and trophic state of the backwaters.The effects of the water enhancement scheme were partly overlaid by the impoundment of the Danube after the construction of a power plant. Both the artificial water enhancement and the Danube impoundment improved the hydrological and trophic condition of the backwaters through an increased surface or sub-surface water supply. In addition, the water enhancement scheme provided a surface water exchange through the chain of backwaters, creating uniformity among the connected water bodies and leading to a significant decrease in temporal variability. However, spatial and temporal restrictions in the scheme ensured that the individual backwaters could maintain their specific biogeochemical character. Our long-term observations of mitigation effects in degraded urban wetlands demonstrate the need for a steady and well controlled water supply in order to achieve successful long-term maintenance of such systems.