Homopteran chemical signatures reduce aggression of tending ants

Summary. Because generalist ants are aggressive towards foreign insects, the recognition of homopterans by tending ants is critical in ant/homopteran trophobiosis. Herein we report experimental evidence indicating that Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae) learn to associate the production of honeydew with the chemical characteristics of homopteran cuticle, suppressing ant aggression and allowing the ants to tend homopterans. Although chemically-mediated associative learning is well understood in honeybee foraging, to our knowledge, it has not been reported before in ant/homopteran trophobiosis.     

The ability of conditioned Microplitis croceipes (Hymenoptera: Braconidae) to distinguish between odors of aflatoxigenic and non-aflatoxigenic fungal strains

Summary. The parasitic wasp Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) learns to associate odors with food resources and subsequently exhibits a characteristic food-seeking behavior when encountering the learned odor. Wasps so conditioned, learned and subsequently demonstrated an ability to distinguish among aflatoxigenic and non-aflatoxigenic Aspergillus flavus and A. parasiticus strains. The effects of fungal species, strain, age (5, 10-12, 20, and 30 d) and growth media (potato dextrose agar, peanut agar and corn agar) on the learning and recognition responses of the conditioned wasps were examined. The level of differentiation between fungal strains by conditioned wasps was lowest when working with 5-d-old fungal cultures but increased with age and generally peaked with 20-d-old fungi. Wasps responded generally stronger to the fungal strain conditioned to independent of growth media. This ability of parasitic wasps to learn and distinguish fungal odors can open new avenues in insect learning.     

浅谈CNC板材加工设备在钣金加工中的应用

介绍了数控冲床、数控折弯机、数控激光切割机、数控剪板机等CNC板材加工设备的特点,以及这些先进的设备在钣金加工业中的应用和我国钣金生产的加工技术的发展趋向.     

The shadow of the past: environmental issues and institutional learning in EU enlargement processes

This paper compares the role of environmental issues in negotiating Spanish membership of the European Union (EU) with the ongoing enlargement talks with Central and Eastern European countries. The paper first argues that the EU has recognized a need to change the way in which it has traditionally managed environmental issues in enlargement processes. Second, the paper provides evidence of learning processes at the Community level that could have effected a change in Community approaches to enlargement in the environmental field. However, the paper shows that the fundamental principles and procedures applied in preparing for eastern enlargement match those used in previous enlargement rounds, resembling a largely technical exercise with exclusive focus on the applicants' ability to align with the acquis communautaire and the length of transition periods. The lack of sufficient adaptation or reform suggests that path dependence and institutional inertia have constrained the scope for innovations at the level of policy strategy and institutions, for which the shadow of the past has reinforced established patterns of institutional behaviour and practices. Copyright © 2002 John Wiley & Sons, Ltd.     

高性能水刺玻纤复合滤料性能的研究

通过实验对比水刺类与针刺类玻纤复合滤料的机械性能、过滤性能，阐述了针刺玻纤复合滤料存在的缺陷及水刺玻纤复合滤料的技术优势。     

煤层瓦斯压力测定中的钻孔注浆新技术研究

为简化复杂地质条件下测定煤层瓦斯压力的工序并提高高压注浆的成功率和可靠性,以达到准确、快速测量瓦斯压力的效果,基于胶囊注水封孔器的原理和特性及高压注浆的现场情况,提出了一种新型的注浆方法。通过钻孔注浆模型的建立和数值分析、模拟,发现新式注浆工艺可满足10 MPa的注浆压力,能有效封堵钻孔中的裂隙。现场对比实验证明新式注浆方法较传统注浆方法减少了工序,提高了安全性和可操作性,节省时间约35 h。新型注浆方法在复杂地质条件下可提高测压工作整体的效率。     

Research Training for Releasable Animals

Abstract:  Restrictions on training potentially releasable animals such as those undergoing rehabilitation care or wild-caught captives have limited our understanding of sensory processes, cognition, and physiology important for conservation of species. It is common practice among several U.S. federal agencies to limit training of animals available for release. The behavioral argument justifying this practice is that training habituates subjects to people and conditions them to associate people with rewards such as food; habituation to and positive associations with people will lead animals into dangerous situations after their release. If under special circumstances research training is permitted, all trained behaviors must be extinguished before release because behaviors will transfer to the natural setting. Research on animal learning and memory indicates that these may not be accurate scenarios. A review of the literature on habituation, classical and instrumental conditioning, and compound conditioning suggests that learning within a research setting does not add to learning that already occurs in procedures associated with basic feeding and care. In fact, animals probably learn less about people in a training setting. Furthermore, context-specific effects on memory limit behavior transfer from captive to natural settings. Extinction is strongly susceptible to context effects, which suggests that extinction does not effectively transfer to the postrelease setting. Counterintuitively, extinction of responses to experimental stimuli under some circumstances may enhance undesirable learning about humans. Under those circumstances in which isolation from human contact is difficult or undesirable, behavioral research can present an ideal format for minimizing learning about humans and provide biological information important for conservation.     

A role-playing game as a tool to facilitate social learning and collective action towards Climate Smart Agriculture: Lessons learned from Apuí, Brazil

Addressing the global challenges of climate change (CC), food security and poverty alleviation requires enhancing the adaptive capacity and mitigation potential of land use systems. To this end, Climate Smart Agriculture (CSA) aims to identify land use practices that sustainably increase productivity, enhance climate change (CC) adaptation and contribute to CC mitigation. A transition towards CSA requires technical, but also socio-institutional changes, for improved smallholder agricultural systems. Such changes may be triggered by stakeholder participation processes that stimulate social learning and collective action. This article evaluates whether a role-playing game (RPG) is an effective participatory tool to encourage social learning and collective action among local stakeholders towards adoption of CSA strategies. We designed and implemented an RPG with three groups of farmers in Apuí (Southern Amazonas), evaluating the game’s impact on social learning by interviewing each farmer before and after the RPG. Our findings show that the RPG induced not only technical learning, but also socio-institutional learning and engagement for collective action, though outcomes varied between different RPG sessions and among farmer participants.     

Designing monitoring arrangements for collaborative learning about adaptation pathways

Adaptation pathways approaches support long-term planning under uncertainty. The use of adaptation pathways implies a systematic monitoring effort to inform future adaptation decisions. Such monitoring should feed into a long-term collaborative learning process between multiple actors at various levels. This raises questions about who should monitor what, when and for whom. We formulate an approach that helps to address these questions, developed around the conceptual core offered by adaptive policy pathways methods and their notion of signposts and triggers. This is embedded in a wider approach that revisits the critical assumptions in underlying basic policies, looks forward to future adaptation decisions, and incorporates reciprocity in the organization of monitoring and evaluation. The usefulness and practical feasibility of the approach is studied for a case of the Delta Programme in the Netherlands, which incorporated adaptation pathways in its planning approach called adaptive delta management. The case results suggest that our approach adds value to existing monitoring practices. They further show that different types of signposts exist. Technical signposts, in particular, need to be distinguished from political ones, and require different learning processes with different types of actors.     

地理邻近性与区域创新关系探讨

与“地理学已死”的认识相反．由于知识的特性和创新的背量依赖，在区域创新的研究中地理邻近得到重视。地理邻近在区域创新经济学中的位置与传统空间经济学中的位置一样．只是创新的促进因素．而不是决定性因素。空间经济学和创新经济学在目的上是一样的．但由于各自不同的经济决定变量导致了对地理邻近性的认识是不一样的。尝试从知识流动和集体学习视角，对一直被视为“黑箱”的地理邻近性的作用机理进行探讨。研究表明。地理邻近是“距离产生美”，太多或太少的地理邻近对集体学习和区域创新都是不利的。同时地理邻近性既不是区域创新的充分条件，也不是必要条件，它和其它类型的邻近相互促进．相互替代。ICIS的发展使传统空间经济学中地理邻近的重要性降低，ICIS更进一步发展同样会使区域创新经济学中的地理邻近性重要性降低，也许未来的虚拟经济的世界里真的不太需要物理世界的地理邻近。