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Zvi Mendel Lev Zegelman Alfred Hassner Fabienne Assael Miriam Harel Shlomo Tam Ezra Dunkelblum 《Journal of chemical ecology》1995,21(3):331-341
The active component of the sex pheromone ofMatsucoccus josephi is (2E,6E,8E)-5,7-dimethyl-2,6,8-decatrien-4-one; the chemical is also a powerful kairomone of adult males and females of the bugElatophilus hebraicus the principal predator ofM. josephi. The presence of theZ isomer (2E,6Z,8E)-5,7-dimethyl-2,6,8-decatrien-4-one does not interfere with the attractancy of the activeE component forM. josephi males or the bug. Our results show a clear dose-response between trap catch ofM. josephi males andE. hebraicus. Conversely, increasing amounts of theZ isomer in the mixture did not affect the attraction of the scale insect males or the bug. The catch ofM. josephi males did not differ significantly among traps of different color, and was significantly higher with traps attached to the tree trunk than those suspended between trees. Comparison of the catch ofM. josephi among the three forests and between pine species suggests that the level of infestation ofPinus halepepsis andPinus brutia ssp.brutia is similar, despite the fact that the latter pine is resistant to the scale insect. Both sexes ofE. hebraicus were trapped in much lower numbers at the more infested sites. This may be related to interference with the activity ofE. hebraicus due to deterioration and drying of parts of the tree crowns and heavy colonization by generalist predators in injured trees. 相似文献
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Masi Iacopo Trần Anh Tuấn Hassner Tal Sahin Gozde Medioni Gérard 《International Journal of Computer Vision》2019,127(6-7):642-667
International Journal of Computer Vision - We identify two issues as key to developing effective face recognition systems: maximizing the appearance variations of training images and minimizing... 相似文献
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Chang Feng-Ju Tran Anh Tuan Hassner Tal Masi Iacopo Nevatia Ram Medioni Gérard 《International Journal of Computer Vision》2019,127(6-7):930-956
International Journal of Computer Vision - We present a novel method for modeling 3D face shape, viewpoint, and expression from a single, unconstrained photo. Our method uses three deep... 相似文献
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The same scene can be depicted by multiple visual media. For example, the same event can be captured by a comic image or a movie frame; the same object can be represented by a photograph or by a 3D computer graphics model. In order to extract the visual analogies that are at the heart of cross-media analysis, spatial matching is required. This matching is commonly achieved by extracting key points and scoring multiple, randomly generated mapping hypotheses. The more consensus a hypothesis can draw, the higher its score. In this paper, we go beyond the conventional set-size measure for the quality of a match and present a more general hypothesis score that attempts to reflect how likely is each hypothesized transformation to be the correct one for the matching task at hand. This is achieved by considering additional, contextual cues for the relevance of a hypothesized transformation. This context changes from one matching task to another and reflects different properties of the match, beyond the size of a consensus set. We demonstrate that by learning how to correctly score each hypothesis based on these features we are able to deal much more robustly with the challenges required to allow cross-media analysis, leading to correct matches where conventional methods fail. 相似文献
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A stereoselective total synthesis of (±)-ptilocaulin 1 , an antimicrobial anticancer agent as well as of its 7-epimer 23 is described. The strategy involves an aldol condensation of the dilithio dianion of the Z-aldoxime ( 13 ) with a ketone 6 to produce 11 and the stereospecific intramolecular cycloaddition of the nitrile oxide 5 , generated in situ from 11. The resulting isoxazoline 4 was converted to hydroxy ketone 3 which serves as a starting point for introduction of the fourth stereocenter at C-7. Lithium in ethylamine reduction of 3 produces stereospecifically the 7β-methyl compound which leads to ptilocaulin 1 , while catalytic hydrogenation of 3 introduces the 7α-methyl substituent and finally 7-epiptilocaulin 23. H- and C NMR analysis permits differentiation between isomers of intermediates. When, in the last step of the synthesis of 1 or 23 from 19 or 22 and guanidine, a higher temperature (>130 °C) was applied, an interesting disproportionation to aminopyrimidine 25 or 28 and cyclic guanidine 24 or 27 was observed. 相似文献
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Segmenting a moving foreground (fg) from its background (bg) is a fundamental step in many Machine Vision and Computer Graphics applications. Nevertheless, hardly any attempts have been made to tackle this problem in dynamic 3D scanned scenes. Scanned dynamic scenes are typically challenging due to noise and large missing parts. Here, we present a novel approach for motion segmentation in dynamic point‐cloud scenes designed to cater to the unique properties of such data. Our key idea is to augment fg/bg classification with an active learning framework by refining the segmentation process in an adaptive manner. Our method initially classifies the scene points as either fg or bg in an un‐supervised manner. This, by training discriminative RBF‐SVM classifiers on automatically labeled, high‐certainty fg/bg points. Next, we adaptively detect unreliable classification regions (i.e. where fg/bg separation is uncertain), locally add more training examples to better capture the motion in these areas, and re‐train the classifiers to fine‐tune the segmentation. This not only improves segmentation accuracy, but also allows our method to perform in a coarse‐to‐fine manner, thereby efficiently process high‐density point‐clouds. Additionally, we present a unique interactive paradigm for enhancing this learning process, by using a manual editing tool. The user explicitly edits the RBF‐SVM decision borders in unreliable regions in order to refine and correct the classification. We provide extensive qualitative and quantitative experiments on both real (scanned) and synthetic dynamic scenes. 相似文献
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Organisational changes are recognised as a specific project type that can benefit from the application of project management skills, tools and techniques. Associated with this trend is evidence of rivalry in the marketplace between Project Managers and Change Managers concerning who should be managing business change. And these are not the only contenders. Corporate executives and senior managers, although they may engage the assistance of both Project Managers and Change Managers, generally see themselves as taking the leading roles in managing major organisational changes and transformations. As such endeavours are most likely to take the form of programs, comprising multiple projects across the organization, Program Managers are seen by some as being most likely to be responsible for managing organisational change initiatives. This paper reports on research undertaken to explore the differences in approach and practice of Project, Program and Change Managers as a basis for determining the competencies required to effectively manage change initiatives. 相似文献
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Studies on UV/Vis Absorption Spectra of Azo Dyes. XVIII. Substituent Effects on the Absorption Maxima of the n → π* and π → π* Bands of 4-N,N-Diethylaminoazobenzenes The spectra of 27 substituted 4-N.N-diethylaminoazobenzenes are determined. The band systems can be separated by deconvolution into two Gaussian curves. The results so obtained show that the effects of substituents on n → π* and π → π* transitions are similar and that electron withdrawing substituents in the phenylazo residue cause a bathochromic shift of both the n → π* and the π → π* bands. 相似文献