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141.
Despite a recent emphasis on ‘evidence based policy’ accompanied by an abundance of ‘green’ policy instruments, experience from the European Union and OECD countries shows that decisions which truly aim to balance environmental considerations with social and economic ones remain thin on the ground. Moreover, many policies seem to fall short of, or directly contradict what the available ‘evidence’ suggests is required. This is a synthesis paper bringing together literature from the fields of political science, geography, sociology and science and technology studies to outline some of the obscurities relating to the use of scientific evidence in environmental decision-making. In this paper, we suggest that an exploration of three key inter-related issues is necessary to develop a richer understanding of why evidence and policy interact as they do. These are the nature of evidence itself; the normative, moral or ethical ‘politics’ of policy-making; and the operation of power in the policy process. Our primary goal is to bring various literatures together to better conceptualise the evidence–policy relationship. In so doing, we outline specific challenges for knowledge producers who set research priorities, and design and direct research projects. We also highlight significant implications for policy decision-making processes.  相似文献   
142.
Workers from social insect colonies use different defence strategies to combat invaders. Nevertheless, some parasitic species are able to bypass colony defences. In particular, some beetle nest invaders cannot be killed or removed by workers of social bees, thus creating the need for alternative social defence strategies to ensure colony survival. Here we show, using diagnostic radioentomology, that stingless bee workers (Trigona carbonaria) immediately mummify invading adult small hive beetles (Aethina tumida) alive by coating them with a mixture of resin, wax and mud, thereby preventing severe damage to the colony. In sharp contrast to the responses of honeybee and bumblebee colonies, the rapid live mummification strategy of T. carbonaria effectively prevents beetle advancements and removes their ability to reproduce. The convergent evolution of mummification in stingless bees and encapsulation in honeybees is another striking example of co-evolution between insect societies and their parasites.  相似文献   
143.
Efficient cooperation in eusocial insect colonies requires effective communication, and there is abundant evidence of non-volatile chemicals playing a role in regulating reproduction within colonies. In contrast, there have been fewer studies investigating the role of volatile chemicals. This study investigated the potential role of volatile chemicals in regulating queen reproduction either by directly inhibiting queen reproduction or by honestly signalling queen fecundity to workers. We tested this using multiple queen colonies of the ant (Leptothorax acervorum) from a functionally monogynous population where one queen monopolizes all reproduction. Nine colonies, each with an established laying queen, were split to produce two colony fragments—one containing the reproducing queen (group 1) and one containing only previously non-reproducing queens (group 2). Each group was separated by a fine wire mesh preventing physical contact, but allowing volatile chemical contact. In each group 2 fragment, we found that a single formerly non-reproductive queen commenced reproduction and that the rate of egg laying and maximum number of eggs recorded did not significantly differ between groups 1 and 2, results that do not support volatile chemicals as playing a role in regulating queen reproduction. Instead, our findings suggest that physical contact is necessary to maintain functional monogyny.  相似文献   
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