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Food, water, and worker protection regulations have driven availability, and loss, of pesticides for use in pest management programs. In response, public-supported research and extension projects have targeted investigation and demonstration of reduced-risk integrated pest management (IPM) techniques. But these new techniques often result in higher financial burden to the grower, which is counter to the IPM principle that economic competitiveness is critical to have IPM adopted. As authorized by the 2002 Farm Bill and administered by the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS), conservation programs exist for delivering public-supported financial incentives to growers to increase environmental stewardship on lands in production. NRCS conservation programs are described, and the case for providing financial incentives to growers for implementing IPM is presented. We also explored the opportunity and challenge to use one key program, the Environmental Quality Incentives Program (EQIP), to aid grower adoption of IPM. The EQIP fund distribution to growers from 1997 to 2002 during the last Farm Bill cycle totaled approximately 1.05 billion dollars with a portion of funds supporting an NRCS-designed pest management practice. The average percentage of allocation of EQIP funds to this pest management practice among states was 0.77 +/- 0.009% (mean +/- SD). Using Michigan as an example, vegetable and fruit grower recognition of the program's use to implement IPM was modest (25% of growers surveyed), and their recognition of its use in aiding implementation of IPM was improved after educational efforts (74%). Proposals designed to enhance program usefulness in implementing IPM were delivered through the NRCS advisory process in Michigan. Modifications for using the NRCS pest management practice to address resource concerns were adopted, incentive rates for pest management were adjusted, and an expanded incentive structure for IPM technique adoption was tabled for future consideration. The case is strong for using public-supported financial incentives offered by the EQIP to aid grower adoption of IPM as a means to address resource concerns, but current use of the EQIP for this purpose is modest to meager. With appropriate program adjustments and increased grower awareness, USDA NRCS conservation programs, and the EQIP in particular, may provide an important opportunity for growers to increase their use of IPM as a resource conservation and farm management tool.  相似文献   
64.
我国奶牛乳房炎致病性金黄色葡萄球菌血清型分布   总被引:1,自引:0,他引:1  
本试验采用玻片凝集法对从临床型乳房炎病乳中分离获得的56株金黄色葡萄球菌进行血清型分型。结果表明336型占67.9%(38/56),5型占7.1%(4/56),8型占3.6%(2/56)。  相似文献   
65.
Evaluating the impact of plant domestication on the population structure of the associated pathogens provides an opportunity to increase our understanding of how and why diseases emerge. Here, we investigated the evolution of the population structure of the apple scab fungus Venturia inaequalis in response to the domestication of its host. Inferences were drawn from multilocus microsatellite data obtained from samples collected on (i) the Central Asian Malus sieversii, the main progenitor of apple, (ii) the European crabapple, Malus sylvestris, a secondary progenitor of apple, and (iii) the cultivated apple, Malus×domestica, in orchards from Europe and Central Asia. Using clustering methods, we identified three distinct populations: (i) a large European population on domesticated and wild apples, (ii) a large Central Asian population on domesticated and wild apples in urban and agricultural areas, and (iii) a more geographically restricted population in M. sieversii forests growing in the eastern mountains of Kazakhstan. Unique allele richness and divergence time estimates supported a host‐tracking co‐evolutionary scenario in which this latter population represents a relict of the ancestral populations from which current populations found in human‐managed habitats were derived. Our analyses indicated that the domestication of apple induced a significant change in the genetic differentiation of populations of V. inaequalis in its centre of origin, but had little impact on its population dynamics and mating system. We discuss how the structure of the apple‐based agrosystem may have restricted changes in the population structure of the fungus in response to the domestication of its host.  相似文献   
66.
微小RNA(miRNAs)是一大类小的非编码RNA,它通过与靶mRNA 3′非翻译区部分互补配对来调节特定基因的表达。近来研究表明,miRNA可作为癌基因或抑癌基因在肺癌发生发展过程中起重要作用。比较癌组织和非癌组织中miRNA表达谱的差异可筛选出部分miRNA分子作为肺癌诊断和预后判断的潜在生物标记。调节具有致癌或抑癌功能的miRNA表达可能成为肺癌治疗新方法,而结合传统放化疗及其敏感性miRNA标志也为肺癌治疗研究提供了新的策略。该文对miRNA在肺癌发生与发展、基因诊断和治疗中的作用做一综述。  相似文献   
67.
A new species of Phylloscopus warbler, which we name Phylloscopus calciatilis Limestone Leaf Warbler, is described from central and northern Vietnam and central and northern Laos; it probably also breeds in southernmost China. In morphology, the new species is very similar to Sulphur-breasted Warbler Phylloscopus ricketti , but it is smaller with a proportionately larger bill and rounder wing. Its song and calls are diagnostic. Based on mitochondrial and nuclear DNA, the new species is most closely related to P. ricketti and Yellow-vented Warbler Phylloscopus cantator , and it is inferred to be sister to the latter. The mitochondrial divergences between these three species are at the low end of the variation found in other species of Phylloscopus and Seicercus warblers, but greater than in other taxa generally treated as subspecies. Possible introgressive hybridization between the new species and P. ricketti is discussed, but more data are needed to establish whether it does occur and, if it does, to what extent. The new species appears to have a restricted breeding range in limestone karst environments, where it is locally common and therefore not under any immediate threat. In view of the recognition of the new species, all previous records of P. ricketti sensu lato need to be re-evaluated.  相似文献   
68.
不同细菌对家蝇幼虫抗菌蛋白/肽的诱导效应   总被引:4,自引:0,他引:4  
利用抑菌圈测量法和毛细管电泳研究、比较不同细菌对家蝇Musca domesticaL.幼虫抗菌蛋白/肽的诱导效应。结果表明,家蝇幼虫受细菌诱导后抗菌活性比对照都有不同程度的增加,同时不同细菌诱导表达样品对于相应的诱导菌均表现很高的抗菌活性。毛细管电泳图谱表明鼠伤寒沙门氏菌Salmonella typhimurium50013诱导后抗菌蛋白/肽表达强度增加了50倍,其它细菌诱导后抗菌蛋白/肽表达强度增加了1~40倍。与G+细菌相比,G-细菌具有更强的诱导效应。结论:家蝇幼虫对不同的细菌刺激有特异性反应,即不同细菌诱导抗菌蛋白/肽的强度、种类和数量都不一致。  相似文献   
69.
Following publication of On the Origin of Species, biologists concentrated on and resolved the mechanisms of adaptation and speciation, but largely ignored extinction. Thus, extinction remained essentially a discipline of palaeontology. Adequate language is not available to describe extinction phenomena because they must be discussed in the passive voice, wherein populations simply ‘go extinct’ without reference to process, specifics, effects, or causality. Extinction is also described typically in terms of its dynamics (including rate or risk), and although correlative variables enhance our ability to predict extinction, they do not necessarily enable an understanding of process. Yet background extinction, like evolution, is a process requiring a functional explanation, without which it is impossible to formulate mechanisms. We define the mechanism of background extinction as a typically long‐term, multi‐generational loss of reproductive fitness. This simple concept has received little credence because of a perception that excess generation of progeny ensures population sustainability, and perhaps the misconception that the loss of reproductive fitness somehow constitutes selection against reproduction itself. During environmental shifts, reproductive fitness is compromised when biotic or abiotic extremes consistently exceed existing norms of reaction. Subsequent selection will now favour individual survival over reproductive fitness, initiating long‐term negative selection pressure and population decline. Background extinction consists typically of two intergrading phases: habitat attenuation and habitat dissolution. These processes generate the relict populations that characterize many species undergoing background extinction. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 255–268.  相似文献   
70.
本文以雄性罗斯肉鸡为材料,探讨饲粮添加不同蛋氨酸源:蛋氨酸(DLM)、蛋氨酸羟基类似物(HMTBA)和蛋氨酸羟基类似物钙盐(HMTB-Ca)对肉鸡骨骼性能和基因表达的影响。结果表明,HMTBA和HMTB-Ca能提高肉鸡终体重、日增重、血液GSH/GSSG比值、抗氧化酶(CAT)水平、总抗氧化能力(T-AOC)、骨骼长度、重量、骨骼指数(p<0.05)。不同蛋氨酸源对肉仔鸡采食量、料重比和灰分含量影响不显著(p>0.05),HMTBA组骨生长分化因子-5(GDF-5)表达量显著上升(p<0.05)。HMTB-Ca显著提高骨骼强度、钙磷含量,下调金属基质蛋白酶-2(MMP-2)、金属基质蛋白酶-9(MMP-9)的表达水平(p<0.05)。由此可知,采食蛋氨酸羟基类似物及其钙盐饲粮,可提高肉鸡体增重,改善血液氧化还原状态,改善骨骼生长发育,其中HMTB-Ca对骨骼作用更显著。  相似文献   
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