How honeybees perceive communication dances,studied by means of a mechanical model

Summary A mechanical model of a dancing honeybee was used to investigate the role of various components of the wagging dance in the transfer of information to follower bees. The model simulates the dance, carries a scent, and has an acoustic near-field similar to that of live dancers. The movements of the model are controlled by a computer, and selected components of the dance can be manipulated independently of others. The number of bees approaching scented baits at various distances and directions from the hive was observed, both during simulated normal dances and dances in which different components provided potentially conflicting information about the location of the food. The results indicate that the wagging run is the master component of the dance. The figure-of-eight dance path does not seem to convey information. Both sound and wagging must be present in the dance, but no specific roles were found for these components. Both sound and wagging convey information about distance and direction, and they appear to be largely redundant. Offprint requests to: A. Michelsen     

生物学模型与海洋学模型的耦合

海洋生态系统的动力问题,如可观测的化学-生物量的时空变化是由于生物和物理过程决定的.预报海洋系统的未来发展需要有一个理论框架.如模型,而这个模型是根据对相关的各个不同过程的研究和了解而发展的.从理论上描述海洋系统的自然方法似乎是把化学生物模型与环境模型结合在一起.但是,环境模型相对比较先进,而化学-生物过程的定量理论描述比较落后.本文讨论了一些关于发展相容理论的方法和问题,指出了海洋生物学模型和海洋学模型耦合的潜在盖处.     

Methods for determining the biomass content of waste.

As CO2 emission trading in Europe has been established it is of essential importance to distinguish between biogenic and fossil emissions. Emissions resulting from bio-fuels and biogenous fractions are categorized as climate-neutral. Determination of plants using only fossil or bio-fuels is simple but categorization becomes more difficult for plants using a mix of fossil and bio-fuel such as solid recovered fuels. In the meantime, different methods for solving this problem have been developed. Using different approaches and technologies, all of these methods have the same goal: determining the biomass content (biogenic fraction), for example, in solid recovered fuels or in the off-gas of a mono- or co-incineration plant in order to calculate the biogenic carbon dioxide emissions. In the following article, the most common methods for determining the biogenic fraction of fuels, namely the Selective Dissolution Method, the Balance Method and the 14C-Method will be explained in detail.