传统制造业集群协同演进机制探析——天津自行车集群纵向案例研究

产业集群对区域乃至国家经济发展具有重要的作用,然而产业集群发展过程中的影响因素及其相互作用机制至今仍未得到系统的阐述.从协同演进理论视角,结合组织生态学、制度理论、战略管理理论和社会网络理论等,对天津自行车产业集群的发展历程展开多层次、时间序列的分析,以深入挖掘产业集群发展过程中各种要素的相互作用、协同演进机制,提出产业集群的发展是企业战略、产业环境以及制度环境协同演进的过程,同时集群发展过程中创业者的社会资本发挥重要作用.这种将多维理论视角相结合起来进行分析的方法,有利于更好地理解产业集群的演进机制.     

Benzodiazepine administration prevents the use of error-correction mechanisms during fear extinction

Three experiments examined the effect of systemic administration of the benzodiazepine midazolam on extinction and re-extinction of conditioned fear. Experiment 1 demonstrated that midazolam administration prior to extinction of a conditioned stimulus (CS) impaired that extinction when rats were subsequently tested drug free; however, extinction was spared if rats were extinguished, reconditioned, and re-extinguished under midazolam. Experiment 2 provided a replication of this effect within-subjects; rats were conditioned to two CSs (A and B), extinguished to one (A-), reconditioned to both, and then extinguished/re-extinguished to both stimuli in compound (AB-), under either vehicle or midazolam. On the drug-free test, rats given midazolam froze more to the CS that had been extinguished (B) than the one that been re-extinguished (A). The final experiment examined whether extinction under midazolam was regulated by prediction error. Rats were trained with three CSs (A, B, C) and extinguished to two (A-, C-). These stimuli then underwent additional extinction under midazolam or vehicle, with one CS now presented in compound with the non-extinguished CS (AB-, C-). Rats were then tested for fear of A relative to C. Rats given vehicle showed a deepening of extinction to A relative to C, as is predicted from error-correction models; however, rats given midazolam failed to show any such discrepancy in responding. The results are interpreted to indicate that the drug reduced prediction error during extinction by reducing fear, and rats were able to re-extinguish fear via a retrieval mechanism that is independent of prediction error.     

Participation in transition review meetings: a case study of young people with learning disabilities leaving a special school

Transition into adulthood has been identified as a critical period in the lives of young people with learning disabilities, with national guidance and legislation emphasising the role of participation and inclusion as central to the transition process. In this article, Steven Carnaby, a clinical psychologist working with adults with learning disabilities in London and a lecturer in learning disability at the Tizard Centre, University of Kent; Patricia Lewis, head of the sixth form and SENCo; Di Martin, senior teacher and former SENCo; John Naylor, deputy head of the sixth form and head of arts; David Stewart OBE, headteacher, all from the Shepherd School, Nottingham, report the outcomes of a small-scale case study exploring these issues. The project ran for four years and, in Phase 1, evaluated the ways in which students with learning disabilities were involved in their transition review meetings as they entered their final year at school. This first phase found that many students were excluded from meaningful discussion in their planning meetings, highlighting students with more severe disabilities as being more vulnerable to exclusion. After a series of recommendations were made for improving practice in terms of inclusion and participation, Phase 2 of the study assessed ways in which practice in these areas had improved. The school had developed more individualised ways of working using person-centred techniques to enhance meaning for students. At the close of this article, the authors summarise these improvements and propose further strategies for enhancing the participation process.