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| 1 | 基于类别空间的基因选择显示文摘基因选择通常是在基因空间中进行的.由于基因空间的维数(基因数目)比该空间中的样本数要多得多,这种做法存在严重的维数发难(curse of dimensionality)问题,其结果是在基因空间中所建立数据模型难于获得满意的精度,基于所建立模型的基因选择结果可信度低.如何对具有极少样本的极高维空间进行特征选择(基因选择)是一个极具挑战性的课题.将基因空间变换为它的对偶空间,称为类别空间,从而空间的维数仅为基因空间中样本的类别数,空间中的样本数则为基因空间的维数.显然,在类别空间中不存在任何维数发难现象;提出了在类别空间中基于将不同的类尽可能分开的原则、并借助主分量分析的基于类别空间基因选择方法.对真实基因数据的基因选择实验,并通过Fisher指标、加权Fisher指标以及leave-one-out cross validation等可分性指标,与其他两种基因选择方法进行了深入的比较,结果表明该方法是十分有效的. | 张军英 Y.J.Wang J.Khan R.Clarke | 2003 | 中国科学(E辑)2003,33,12: | 9 |
| 2 | 对用于涡轮机械上的优化涂层的HVOF工艺条件的评论显示文摘在磨损和腐蚀非常严重的情况下,由超音速火焰喷涂(HVOF)工艺产生的涂层成功地延长了涡轮机械零件的使用寿命。在喷涂过程中,粉末粒子达到极高的冲击速度,从而形成具有高耐磨抗腐蚀能力的坚固耐用的涂层。本文介绍有关HVOF工艺、涂层以及HVOF在涡轮机械上的典型应用。 | R.Clarke G.barbezat S.Keller A.R.Niall 朱有利 | 1996 | 表面工程1996,,3: | 6 |
| 3 | Cystatin C and risk of vascular and nonvascular mortality: a prospective cohort study of older men显示文摘 | J. R.Emberson R.Haynes T.Dasgupta M.Mafham M. J.Landray C.Baigent R.Clarke | 2010 | Journal of Internal Medicine2010,,2: | 1 |
| 4 | Bremsstrahlung emission from high power laser interactions with constrained targets for industrial radiography显示文摘Laser-solid interactions are highly suited as a potential source of high energy X-rays for nondestructive imaging.A bright,energetic X-ray pulse can be driven from a small source,making it ideal for high resolution X-ray radiography.By limiting the lateral dimensions of the target we are able to confine the region over which X-rays are produced,enabling imaging with enhanced resolution and contrast.Using constrained targets we demonstrate experimentally a(20±3)μm X-ray source,improving the image quality compared to unconstrained foil targets.Modelling demonstrates that a larger sheath field envelope around the perimeter of the constrained targets increases the proportion of electron current that recirculates through the target,driving a brighter source of X-rays. | C.D.Armstrong C.M.Brenner C.Jones D.R.Rusby Z.E.Davidson Y.Zhang J.Wragg S.Richards C.Spindloe P.Oliveira M.Notley R.Clarke S.R.Mirfayzi S.Kar Y.Li T.Scott P.McKenna D.Neely | 2019 | High Power Laser Science and Engineering2019,7,2: | 0 |
| 5 | Development of internal COI primers to improve and extend barcoding of fruit flies (Diptera: Tephritidae: Dacini)显示文摘Accurate species-level identifications underpin many aspects of basic and applied biology;however,identifications can be hampered by a lack of discriminating morphological characters,taxonomic expertise or time.Molecular approaches,such as DNA'barcoding'of the cytochrome c oxidase(COI)gene,are argued to overcome these issues.However,nuclear encoding of mitochondrial genes(numts)and poor amplification success of suboptimally preserved specimens can lead to erroneous identifications.One insect group for which these molecular and morphological problems are significant are the dacine fruit flies(Diptera:Tephritidae:Dacini).We addressed these issues associated with COI barcoding in the dacines by first assessing several'universal'COI primers against public mitochondrial genome and numt sequences for dacine taxa.We then modified a set of four primers that more closely matched true dacine COI sequence and amplified two overlapping portions of the COI barcode region.Our new primers were tested alongside universal primers on a selection of dacine species,including both fresh preserved and decades-old dry specimens.Additionally,Bactrocera tiyoni mitochondrial and nuclear genomes were compared to identify putative numts.Four numt clades were identified,three of which were amplified using existing universal primers.In contrast,our new primers preferentially amplified the'true'mitochondrial COI barcode in all dacine species tested.The new primers also successfully amplified partial barcodes from dry specimens for which full length barcodes were unobtainable.Thus we recommend these new primers be incorporated into the suites of primers used by diagnosticians and quarantine labs for the accurate identification of dacine species. | Matt N.Krosch Francesca Strutt Mark J.Blacket Jana Batovska Melissa Starkie Anthony R.Clarke Stephen L.Cameron Mark K.Schutze | 2020 | Insect Science2020,27,1: | 0 |
| 6 | The “sequential cues hypothesis”: a conceptual model to explain host location and ranking by polyphagous herbivores显示文摘Successfully locating a host plant is crucial for an insect herbivore to feed and/or oviposit.However,locating a host within a complex environment that may contain an array of different plant species is a difficult task.This is particularly the case for polyphagous herbivores,which must locate a host within environments that may simultaneously contain multiple suitable and unsuitable hosts.Here we review the mechanisms of host selection used by polyphagous herbivores,as well as exploring how prior experience may modify a generalist's response to host cues.We show that recent research demonstrates that polyphagous herbivores have the capacity to detect both common cues from multiple host species,as well as specific cues from individual host species.This creates a paradox in that generalists invariably rank hosts when given a choice,a finding at odds with the“neural limitations”hypothesis that says generalist insect herbivores should not have the neural capacity to identify cues specific to every possible host.To explain this paradox we propose a model,akin to parasitoid host location,that postulates that generalist herbivores use different cues sequentially in host location.We propose that initially common host cues,associated with all potential hosts,are used to place the herbivore within the host habitat and that,in the absence of any other host cues,these cues are sufficient in themselves to lead to host location.As such they are true “generalist”cues.However,once within the host habitat,we propose that the presence of a smaller group of cues may lead to further host searching and the location of preferred hosts:these are“specialist”cues.This model explains the current conflict in the literature where generalists can respond to both common and specific host-plant cues,while also exhibiting specialist and generalist host use behavior under different conditions. | Rehan Silva Anthony R.Clarke | 2020 | Insect Science2020,27,6: | 0 |
| 7 | From laboratory to the field: consistent effects of experience on host location by the fruit fly parasitoid Diachasmimorpha kraussii (Hymenoptera: Braconidae)显示文摘Associative learning is well documented in Hymenopteran parasitoids, where it is thought to be an adaptive mechanism for increasing successful host location in complex environments. Based on this learning capacity, it has been suggested that providing prerelease training to parasitoids reared for inundative release may lead to a subsequent increase in their efficacy as biological control agents. Using the fruit fly parasitoid Diachasmimorpha krausii we tested this hypothesis in a series of associative learning experiments which involved the parasitoid, two host fruits (tomatoes and nectarine), and one host fly (Bactrocera ttyoni). In sequential Y-tube olfactometer studies, large field-cage studies, and then open field studies, naive wasps showed a consistent preference for nectarines over tomatoes. The preference for nectarines was retained, but not significantly increased, for wasps which had prior training exposure to nectarines. However, and again consistently at all three spatial scales, prior experience on tomatoes led to significantly increased attraction to this fruit by tomato-trained wasps, including those liberated freely in the environment. These results, showing consistency of learning at multiple spatial scales, gives confidence to the many laboratory-based learning studies which are extrapolated to the field without testing. The experiment also provides direct experimental support for the proposed practice of enhancing the quality of inundatively released parasitoids through associative learning. | Ayad Masry John P.Cunningham Anthony R.Clarke | 2019 | Insect Science2019,26,5: | 0 |