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141.
Abstract 1. Patch time allocation has been mostly studied in female parasitoids exploiting patches of hosts. Different parameters such as oviposition, host encounters, patch quality, etc. have been repeatedly shown to modify the time females invest on hosts. 2. Male parasitoids are expected to maximise their lifetime fitness by maximising the number of females inseminated during their life. Because they can be sperm and/or time limited, they should optimise their time allocation on emergence patches. 3. Patch time allocation thus appears to be an important question for both male and female parasitoids. 4. In this study, we determined the parameters used by males of the egg parasitoid Trichogramma turkestanica to decide when to leave the emergence patch. Among the different patch‐leaving parameters tested, only contacts with parasitised hosts and presence of virgin females significantly influenced the patch‐leaving tendency. 5. Our results suggest that males express behaviours that could enable them to optimise their patch exploitation time, as females do, but using different strategies.  相似文献   
142.
目的:探讨目标教学法在护理教学查房中的临床应用价值,以培养护生的临床思维能力,并且提高实践工作能力。方法:选取我院2014年5月~2014年9月在急诊科实习的护生120人为研究对象,在实习之初,按照随机的原则将其分为观察组与对照组,每组60人。在查房中,观察组实施目标教学法,对照组实施常规护理教学法。实习结束后,调查两组护生对查房时教学与课堂效果的满意程度,记录两组护生病历书写的质量以及在实习结束后,通过考核,统计两组护生的在理论成绩、基础护理成绩、专科护理成绩以及护理综合技能方面的成绩,然后对所得到的数据进行统计,以探讨目标教学法在护理教学查房中的临床应用价值。结果:从查房时教学的满意程度及对课堂效果的满意程度来看,观察组都高于对照组,差异具有统计学意义(P0.05);观察组病历书写优良的人数为48,优良率为80%,高于对照组,差异具有统计学意义(P0.05);观察组护生的理论成绩、基础护理成绩、专科护理成绩及护理综合技能的成绩均高于对照组,差异具有统计学意义(P0.05)。结论:目标教学法是一种科学、合理并且适合时代发展要求的新型教学法,应用于护理教学查房中,能提高护生的主动性,激发护生的学习兴趣,充分发掘其潜能,做到理论与实际的结合,从而提高学习者的自身能力,值得临床推广应用。  相似文献   
143.
目的:探讨不同类型心力衰竭患者心电图QRS 波时限与血浆N末端B型利钠肽原(NT-proBNP)水平之间的关系及其临床 意义。方法:选择我院2012 年7 月至2014 年6 月接收的慢性心力衰竭患者300 例,作为研究组,将患者分为收缩性心力衰竭组 (S组)和舒张性心力衰竭组(D组);另外,选取我院非CHF 患者132 例,作为对照组。测定所有受试者的心电图QRS 波时限,及 血浆中NT-proBNP 水平,分析血浆NT-proBNP 水平与QRS 波时限及NYHA心功能分级关系。结果:与对照组相比,研究组QRS 波时限均延长,血浆NT-proBNP水平显著升高(P<0.05),其中S 组比D 组明显延长,且S 组血浆NT-proBNP水平高于D 组 (P<0.05)。三组NYHA 分级对比发现,差异均具有统计学意义(P<0.05);S 组患者血浆NT-proBNP水平与QRS 波时限及NYHA 心功能分级之间呈正相关;D 组患者血浆NT-proBNP水平与QRS 波时限及NYHA心功能分级之间无明显的相关性。结论:临床 上可以将NT-proBNP水平和QRS 波时限结合起来诊断慢性心力衰竭患者的类型,以便于之后的治疗。  相似文献   
144.
Population growth and the subsequent increased demand for food, along with the rise in cost of feed, have led insect feed to be considered as an alternative to conventional animal feed. Insect feed is a sustainable and nutritious option; however, it does carry the risk of lower microbiological safety than conventional feed. Although there is some hesitancy from farmers in adapting insect feed due to fear of market rejection of insect‐fed animals, surveys seem to show positive attitudes of people towards insect feed when they informed of the benefits. Traditional methods of harvesting insects is not a sustainable method of production, and therefore further research will be needed to access appropriate methods of mass‐producing insects without putting a strain on the natural ecosystem. This review discusses the benefits and risks of using insect feed, its acceptance, type of animals that can be fed by insects, and future directions of insect feed.  相似文献   
145.
An extension of the selection differential in the Robertson–Price equation for the mean phenotype in an age‐structured population is provided. Temporal changes in the mean phenotype caused by transient fluctuations in the age‐distribution and variation in mean phenotype among age classes, which can mistakenly be interpreted as selection, will disappear if reproductive value weighting is applied. Changes in any weighted mean phenotype in an age‐structured population may be decomposed into between‐ and within‐age class components. Using reproductive value weighting the between‐age class component becomes pure noise, generated by previous genetic drift or fluctuating selection. This component, which we call transient quasi‐selection, can therefore be omitted when estimating age‐specific selection on fecundity or viability within age classes. The final response can be computed at the time of selection, but can not be observed until lifetime reproduction is realized unless the heritability is one. The generality of these results is illustrated further by our derivation of the selection differential for the continuous time age‐structured model with general age‐dependent weights. A simple simulation example as well as estimation of selection components in a house sparrow population illustrates the applicability of the theory to analyze selection on the mean phenotype in fluctuating age‐structured populations.  相似文献   
146.
Incorporation of proteins in biomimetic giant unilamellar vesicles (GUVs) is one of the hallmarks towards cell models in which we strive to obtain a better mechanistic understanding of the manifold cellular processes. The reconstruction of transmembrane proteins, like receptors or channels, into GUVs is a special challenge. This procedure is essential to make these proteins accessible to further functional investigation. Here we describe a strategy combining two approaches: cell-free eukaryotic protein expression for protein integration and GUV formation to prepare biomimetic cell models. The cell-free protein expression system in this study is based on insect lysates, which provide endoplasmic reticulum derived vesicles named microsomes. It enables signal-induced translocation and posttranslational modification of de novo synthesized membrane proteins. Combining these microsomes with synthetic lipids within the electroswelling process allowed for the rapid generation of giant proteo-liposomes of up to 50 μm in diameter. We incorporated various fluorescent protein-labeled membrane proteins into GUVs (the prenylated membrane anchor CAAX, the heparin-binding epithelial growth factor like factor Hb-EGF, the endothelin receptor ETB, the chemokine receptor CXCR4) and thus presented insect microsomes as functional modules for proteo-GUV formation. Single-molecule fluorescence microscopy was applied to detect and further characterize the proteins in the GUV membrane. To extend the options in the tailoring cell models toolbox, we synthesized two different membrane proteins sequentially in the same microsome. Additionally, we introduced biotinylated lipids to specifically immobilize proteo-GUVs on streptavidin-coated surfaces. We envision this achievement as an important first step toward systematic protein studies on technical surfaces.  相似文献   
147.
尖孢镰刀菌生产蒽醌色素的液体发酵条件研究   总被引:2,自引:0,他引:2  
优化了尖孢镰刀菌液体发酵生产蒽醌类红色素的发酵条件。通过单因素实验和正交优化实验,确定最佳产色素发酵培养基为:可溶性淀粉30%,(NH4)2SO4 3%,MgSO4 0.3%,KH2PO4 4%,pH 6.0。产色素最适培养条件为:初始pH6.0,装液量20%,接种量10%,吐温-80添加量1%,温度28℃,摇床转速200r/min,发酵周期120h。此条件下,色素效价即可达到8.184U/ml,比优化前提高了1.8倍。国内首次对尖孢镰刀菌所产蒽醌色素进行研究,为其进一步应用奠定基础。  相似文献   
148.
149.
For Swedish Warmblood sport horses, breeding values (BVs) are predicted using a multiple-trait animal model with results from competitions and young horse performance tests. Data go back to the beginning of the 1970s, and earlier studies have indicated that some of the recorded traits have changed through the years. The objective of this study was to investigate the effects of including all performance data or excluding the older ones compared to a bivariate model (BM) considering performance traits in early and late periods as separate traits. The bivariate approach was assumed to give the most correct BVs for the actual breeding population. Competition results in dressage and show jumping for almost 40 000 horses until 2006 were available. For riding horse quality test (RHQT), data of 14 000 horses judged between 1973 and 2007 were used. Genetic correlations of 0.69 to 1.00 were estimated between traits recorded at different time periods (RHQT data) or different birth year groups (competition data). A cross-validation study and comparison of BVs using different sets of data showed that most accurate and similar results were obtained when BVs were predicted from either the BM or the univariate model including all data from the beginning of the recording. We recommend using all data and applying the univariate model to minimise the computational efforts for genetic evaluations and for provision of reliable BVs for as many horses as possible.  相似文献   
150.
The aim of this study was to assess genome size variation and multivariate morphometric analyses to ascertain cytotype distribution patterns and the morphological differentiation within the Ranunculus parnassifolius group in the Pyrenees and the Alps. Although divergences in nuclear DNA content among different species within a genus are widely acknowledged, intraspecific variation is still a somewhat controversial issue. Holoploid and monoploid genome sizes (C‐ and Cx‐values) were determined using propidium iodide flow cytometry in 125 plants of R. parnassifolius s.l. distributed across four European countries. Three different DNA ploidy levels were revealed in the study area: diploid (2n ~ 2x, 57.14%), triploid (2n ~ 3x, 1.19%), and tetraploid (2n ~ 4x, 41.67%). The mean population 2C‐values ranged from 8.15 pg in diploids to 14.80 pg in tetraploids, representing a ratio of 1 : 1.8. Marked intraspecific/interpopulation differences in nuclear DNA content were found. Diploid populations prevail in the Pyrenees, although tetraploid cytotypes were reported throughout the distribution area. In general, mixed‐cytotype populations were not found. The Spearman correlation coefficient did not reveal significant correlations between genome size and altitude, longitude, or latitude. Morphometric analyses and cluster analyses based on genome size variation revealed the presence of three major groups, which exhibited a particular biogeographical pattern. A new cytotype, DNA triploid, was found for the first time. Tetraploid populations showed constant nuclear DNA levels, whereas diploid populations from the Pyrenees, in which introgressive hybridization is suggested as a presumable trigger for genome size variation, did not. Scenarios for the evolution of geographical parthenogenesis in R. parnassifolius s.l. are discussed. Finally, the different levels of effectiveness between plant and animal reference standards are analysed. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 251–271.  相似文献   
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