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301.
The little fire ant, Wasmannia auropunctata, constitutes one clonal supercolony throughout Israel, providing an opportunity to examine the effects of genotype versus environment on nestmate recognition. Intraspecific encounters among field-collected or among laboratory-maintained colonies were nonaggressive, but encounters between freshly collected and laboratory-maintained colonies were highly aggressive. Analyses of cuticular hydrocarbons revealed that freshly field-collected colonies had distinguishable profiles. Moreover, freshly collected colonies had profiles disparate from those of the same colonies after 4 months in the laboratory. These results indicate a strong interplay between genetic-based and environmentally based effects on the recognition cues. We propose that in the field the ants’ diet breadth is broad and consequently the incorporation of diet-borne substances is insufficient to mask the genetically determined cues. In the laboratory, however, the restricted diet promoted the incorporation of alien hydrocarbons at high levels, thus altering the genetically based cues to the point of alienation. These results shed a new light on the mechanisms by which environmental cues may affect label and/or template formation in ants. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
302.
矿柱是地下矿山支撑顶板围岩、维持采场稳定的关键结构要素。为迅速准确地判别矿柱稳定性,选取矿柱宽度、矿柱高度、矿柱宽高比、矿岩单轴抗压强度和矿柱承受载荷作为影响指标,利用高斯过程机器学习算法建立矿柱状态与其主要影响因素之间的非线性映射关系,进而提出一种基于高斯过程二元分类(GPC)的矿柱状态识别模型。结合工程实例,以40组样本数据进行训练,以10组样本数据对该模型进行检验,并与ANN和SVM进行对比。结果表明,矿柱状态识别的高斯过程模型是科学可行的,该模型具有参数自适应化获取、分类精度高、计算复杂度低等优点,还可对矿柱状态判别结果的不确定性或可信度进行定量化评价。  相似文献   
303.
本文设计了人工神经网络识别带不同噪声信号的英文字母。结果表明:噪声信号的平均水平低于0.2时,神经网络模型能够完全正确识别26个字母;噪声水平在0.2时,神经网络模型开始出现错误,随着噪声水平的增加,神经网络模型的识别率逐渐下降。  相似文献   
304.
介绍了传统评分法和模糊模式识别模型的基本计算步骤,并对比了二者的优缺点。在此基础上,将评分法计算过程简单与模糊模式识别模型计算结果精确的优点相结合,对大连市区地下水质量进行了系统的评价,得出具有实际意义的地下水质量评价结果。  相似文献   
305.
本文通过对数字时间序列分析中最大熵谱法的研究,给出了分辨率比传统谱方法高得多的功率谱,针对扬沸过程燃烧噪声的谱特性,建立了扬沸前兆噪声的工程识别模型。本文第二部分讨论了该模型的建立方法,并在实验中得到验证。  相似文献   
306.
大气环境质量评价的属性识别法   总被引:17,自引:0,他引:17  
阐述了评价大气环境质量的属性识别法,介绍了属性识别理论模型和属性权重的确定方法,并根据GB 3095—1996((大气环境质量标准》,分别采用模糊数学综合评价法和属性识别法对武汉市大气环境监测结果进行了实例评价,结果表明,用属性识别法评价的结果比用模糊数学综合评价法评价的结果更能反映真实情况。  相似文献   
307.
属性识别理论模型在环境质量评价中的应用   总被引:7,自引:0,他引:7  
把近来提出的属性识别理论模型引用到环境质量评价中,经实例分析,与模糊数学模型及综合指数法作了比较,表明属性识别理论模型评价环境质量是合理可行的。  相似文献   
308.
The capabilities of third world countries in dealing withenvironmental problems are often limited by available resources and the tremendous costs of environmental monitoring.This paper attempts to introduce a newmethodology that can be used to derive information aboutenvironmental quality in its spatial and temporal dimensions.This methodology, based on an inquiry-feedback network of 8,000families and iteration with controlled-feedback of expertcommunity, has been first tested in Shanghai, China andprocedurally can be divided into two steps: Base-year evaluationand forecasting. Fuzzy pattern recognition is introduced for thesubjective assessment of the citizens' feelings theirperceived environment and a four-round Delphi-Cross Impactanalysis is conducted for forecasting the environmental changesup to 2000. Results show that the base-year environmentalsituations were poor. In the foreseeable future, the conditionsfor housing, social services, public health, greenspace anddrinking water will be substantially improved. Due to the rapidgrowth of manufacturing, the city will continue its deteriorating trend of air and water quality into the next century according to the forecast.  相似文献   
309.
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   
310.
Cave animals are widely recognised as model organisms to study regressive evolutionary processes like the reduction of eyes. In this paper, we report on the regressive evolution of species discrimination in the cave molly, Poecilia mexicana, which, unlike other cave fishes, still has functional eyes. This allowed us to examine the response to both visual and non-visual cues involved in species discrimination. When surface-dwelling females were given a chance to associate with either a conspecific or a swordtail (Xiphophorus hellerii) female, they strongly preferred the conspecific female both when multiple cues and when solely visual cues were available to the female. No association preference was observed when only non-visual cues were provided. In contrast, cave-dwelling females showed no preference under all testing conditions, suggesting that species recognition mechanisms have been reduced. We discuss the role of species discrimination in relation to habitat differences.  相似文献   
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