Why do honey bees dance?

The honey bee dance language, used to recruit nestmates to food sources, is regarded by many as one of the most intriguing communication systems in animals. What were the ecological circumstances that favoured its evolution? We examined this question by creating experimental phenotypes in which the location information of the dances was obscured. Surprisingly, in two temperate habitats, these colonies performed only insignificantly worse than colonies which were able to communicate normally. However, foraging efficiency was substantially impaired in an Asian tropical forest following this manipulation. This indicates that dance language communication about food source locations may be important in some habitats, but not in others. Combining published data and our own, we assessed the clustering of bee forage sites in a variety of habitats by evaluating the bees’ dances. We found that the indicated sites are more clustered in tropical than in temperate habitats. This supports the hypothesis that in the context of foraging, the dance language is an adaptation to the particular habitats in which the honey bees evolved. We discuss our findings in relation to spatial aggregation patterns of floral food in temperate and tropical habitats.     

Variation in zonal recovery in four Talitrus saltator populations from different coastlines: a comparison of orientation in the field and in an experimental arena

Under stressful conditions (e.g. finding themselves on dry or moisture-saturated substrates) littoral talitrids (Crustacea, Amphipoda) demonstrate zonal orientation, in which they must promptly reach the optimal zone of the beach, the wet fringe near the shoreline. A relationship might therefore exist between the use of orientation and the frequency of such stressful conditions in the natural environment. Moreover, the efficiency of orientation toward the sea could be related to the possibility of using strategies other than zonal orientation in order to avoid stress. This study analysed the actual use and efficiency of orientation under natural conditions of four Talitrus saltator (Montagu, 1808) populations from Mediterranean and northern European Atlantic coasts with different ecological features. Orientation tests were carried out on the beach with all natural cues available. Then the same individuals underwent control experiments to study their sun orientation far from the sea in an experimental arena. The following results emerge from the comparison of the circular distributions: (1) marked differences among populations in the precision of zonal recovery under natural conditions; (2) a common solar orientation capacity in the control tests far from the sea; (3) different orientation choices of the same individuals according to the test conditions, natural or controlled. The habitat diversity of the four populations (amount, distribution and kind of detritus and wrack on the beach, degree of coastal erosion, orientation of the shoreline, human use of the beach) provides an ecological interpretation for the differences in orientation observed among populations. Received: 13 October 1997 / Accepted after revision: 26 April 1998     

省级清洁生产中心职能定位思考

在对省级清洁生产中心的职能渐变过程进行总结的基础上,将其当前主要职能定位为:开展评估验收工作、审核咨询机构及其从业人员的管理、相关政策法规的在研究与制定、清洁生产相关宣传培训4项工作内容。省级清洁生产中心职能定位的明确,不仅有益于的其自身建设,从而更好地为清洁生产管理服务;同时,也有助于进一步提升了省级清洁生产管理工作的全面性和规范性。     

处理电镀废水新型设备的研制

活动式小型自动化离子交换再生一体化设备系国家“八五”科技攻关课题研制的新型电镀废水处理设备。其结构为拼装式,交换柱可依工况(交换或再生)由三维驱动器控制,自动完成与固定管道系统离合,从而实现水的连续处理。