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251.
We examined recognition of individual neighbors in hooded warblers (Wilsonia citrina) and Kentucky warblers (Oporornis formosus) by comparing responses to playbacks of neighbors' songs from appropriate and inappropriate boundaries of the subjects' territories. Kentucky warblers, which sing one song type each, responded more strongly to the songs of neighbors broadcast from incorrect than from correct boundaries. Hooded warblers use their repertoires of three to nine song types in two distinct modes of singing: repeat mode involves repeated presentation of one song type; mixed mode involves presentation of two or more song types in irregular sequence. Playbacks of neighbors' mixed-mode songs from appropriate and inappropriate boundaries indicated capabilities of individual recognition similar to those reported previously for repeat-mode songs (Godard 1991) and to those of Kentucky warblers. Repertoires of moderate size, therefore, have no pronounced influence on eventual recognition of individual neighbors in hooded warblers. 相似文献
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253.
目前激光荧光遥感是探测海面溢油最有效的工具。作者将神经网络(ANN)的自组织特征映射SOM模型引入激光遥感的荧光光谱鉴别领域。本文主要进行的是理论建模和分析工作,而且用计算机软件方法实现了神经网络的模式识别和分类功能,对推广能力进行了实验分析。经过改进神经网络已具有比较理想的推广能力,并认为SOM应作为溢油识别的较理想方法。 相似文献
254.
Conte Yves Le Sreng Leam Sacher Nelly Trouiller Jérôme Dusticier Georges Poitout Serge Henri 《Chemoecology》1994,5(1):6-12
Summary Honey bee workers are able to nurse or to destroy and thus to recognize the capped queen cells containing a pupa. Fatty acid esters, especially methyl oleate, methyl palmitate and ethyl oleate were found in significant amounts on the queen pupal cuticle. Methyl oleate, the major component, along with smaller amounts of methyl linoleate and methyl linolenate, were involved in the recognition of queen cells by workers. In natural conditions of the colony, queen cells containing a paraffin pupal lure with methyl oleate were accepted 5.9 days by workers, releasing about 1.8 queen pupa equivalents during that period, when control cells (without ester) were kept only 2.1 days. Although these esters are non specific to honey bees, they are of great importance in social regulation of the honey bee colony. 相似文献
255.
Jasminca Behrmann-Godel Gabriele Gerlach Reiner Eckmann 《Behavioral ecology and sociobiology》2006,59(4):461-468
Prior studies have shown that perch (Perca fluviatilis L.) of Lake Constance belong to two genetically different but sympatric populations and that local aggregations of juveniles
and adults contain closely related kin. In this study, we analysed the genetic structure of pelagic perch larvae to investigate
if kin-structured shoals already exist during early ontogenetic development or might be the result of homing to natal sites.
Analysis of the gene frequencies at five microsatellite loci revealed that three out of five pelagic aggregations of larvae
showed significant accumulation of kin. To investigate possible mechanisms of shoal formation, we tested if perch use olfactory
cues to recognize their kin. Choice tests in a fluviarium showed preference for odours of unfamiliar kin vs unfamiliar non-kin.
Additionally, we showed that perch could differentiate between the odours of the two sympatric populations and significantly
preferred unfamiliar and unrelated conspecifics of their own over the foreign population. Our results present a behavioural
mechanism that can lead to the observed formation of kin-structured shoals in perch. We further discuss if the ability to
discriminate between their own and a foreign population can result in assortative mating within populations and thus form
the basis of “socially mediated speciation” in perch. 相似文献
256.
Pollimyrus adspersus discriminates the individually variable waveforms of Electric Organ Discharges (EODs) of conspecifics of only 150–250 s duration. We examined: (1) the discrimination threshold for artificially generated EODs of similar waveform, (2) the mechanism of signal analysis (spectral vs temporal) present, by determining the discrimination between different waveforms of identical amplitude spectra, and (3) the threshold field intensity and reach of discrimination. The triphasic P. adspersus EOD waveform was artificially generated by superimposing two Gaussians, one wide, the second narrow, inverted, and of threefold amplitude. The natural variability among individual EOD waveforms was simulated by phase-shifting one Gaussian relative to the other. The symmetrical waveform where the peaks of the two Gaussians coincided was used as a reference (phase shift=0, rewarded stimulus S+). Results were: (1) in food-rewarded conditioning experiments, trained fish (N=7) detected a phase-shift in artificial EOD stimuli as low as 2 s (N=2 fish), 6 s (N=1) and 10 s (N=1). (2) All fish tested (N=3) discriminated between artificial EODs of identical amplitude spectra but different waveforms (hence, different phase spectra), demonstrating a temporal mechanism of signal analysis. (3) The maximum reach of waveform discrimination was 130 cm at 4.9 Vp-p/cm and 100 S/cm water conductivity (test signal generated at natural amplitude), that is, similar to the reach of EOD detection. Therefore, among the three kinds of electroreceptor organ present in mormyrids, we consider Knollenorgane the relevant sensory organs for EOD waveform discrimination.Communicated by J. Krause 相似文献
257.
258.
概述了我国纺织化学品风险管理在法规、标准指南、风险评估方面与国外的差距。并就纺织印染加工用化学品风险评估中的3个环节,即行业调研、化学品安全数据库构建和危害识别,提出并探讨了8个问题。行业调研环节,重点探讨了纺织化学品生产使用企业的调研问题,纺织化学品的信息透明度问题和混合组分问题;化学品安全数据库构建环节,探讨了纺织化学品安全信息的完整度和定量结构活性关系计算的缺陷;危害识别环节,探讨了纺织化学品中持久性、生物蓄积性和有毒(PBT)化学品,致癌、致畸和生殖毒性化学品(CMR)以及内分泌干扰物质(EDC)的识别。 相似文献
259.
为提取灾害性新闻中的基本要素,迅速掌握灾害事件信息和发展趋势,将目标分类和命名实体识别(named entity recognition,NER)相结合,提出改进的灾害新闻3要素提取方法。构建滑动窗检测器搭载不同的分类模型,实现对新闻文本的灾害主题识别与时空位置要素范围判定,结合命名实体识别完成对时空位置要素的精准提取,并以灾害事故信息文本为例进行测试。研究结果表明:通过在火灾、地震和滑坡新闻中进行数据集中测试,发现本文方法相较于LSTM,BILSTM,BILSTM-CRF提取效果更优;本文方法可对大量灾害性新闻的灾害3要素进行识别提取,对灾害信息进行时空规律分析,研究结果可在灾害应急响应中发挥重要作用。 相似文献
260.
Albrecht M 《Die Naturwissenschaften》2007,94(12):951-966
This review gives an introduction into supramolecular chemistry describing in the first part general principles, focusing on terms like noncovalent interaction, molecular recognition, self-assembly, and supramolecular function. In the second part those will be illustrated by simple examples from our laboratories. Supramolecular chemistry is the science that bridges the gap between the world of molecules and nanotechnology. In supramolecular chemistry noncovalent interactions occur between molecular building blocks, which by molecular recognition and self-assembly form (functional) supramolecular entities. It is also termed the "chemistry of the noncovalent bond." Molecular recognition is based on geometrical complementarity based on the "key-and-lock" principle with nonshape-dependent effects, e.g., solvatization, being also highly influential. Self-assembly leads to the formation of well-defined aggregates. Hereby the overall structure of the target ensemble is controlled by the symmetry features of the certain building blocks. Finally, the aggregates can possess special properties or supramolecular functions, which are only found in the ensemble but not in the participating molecules. This review gives an introduction on supramolecular chemistry and illustrates the fundamental principles by recent examples from our group. 相似文献