共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Francesco Ciliberti Job de HaanGerard de Groot Pierpaolo Pontrandolfo 《Journal of Cleaner Production》2011,19(8):885-894
The benefits of corporate social responsibility (CSR) affect the entire supply chains a firm participates in. However, not every firm is in a position to force the implementation of CSR in its supply chains as some, especially small and medium-sized enterprises (SMEs), lack the necessary power. Chain directors can implement it acting as a principal, whereas the other chain members can act as agents.In the principal-agent framework, two main problems occur due to information asymmetry: adverse selection and moral hazard. This paper examines how a code of conduct (i.e. Social Accountability 8000) can help address the principal-agent problem, for SMEs, between chain directors and partners. The research method involves four case studies on CSR practices as implemented by Italian and Dutch SMEs within their supply chains. 相似文献
3.
4.
A chemical structure for humic substances 总被引:1,自引:0,他引:1
Dedicated to Prof. Dr. H. D. Beckey on the occasion of his 70th birthday. 相似文献
5.
6.
Giovanni Benelli Cesare Stefanini Giulia Giunti Serena Geri Russell H. Messing Angelo Canale 《Die Naturwissenschaften》2014,101(9):753-757
Animals rely on associative learning for a wide range of purposes, including danger avoidance. This has been demonstrated for several insects, including cockroaches, mosquitoes, drosophilid flies, paper wasps, stingless bees, bumblebees and honeybees, but less is known for parasitic wasps. We tested the ability of Psyttalia concolor (Hymenoptera: Braconidae) females to associate different dosages of two innately attractive host-induced plant volatiles (HIPVs), ethyl octanoate and decanal, with danger (electric shocks). We conducted an associative treatment involving odours and shocks and two non-associative controls involving shocks but not odours and odours but not shocks. In shock-only and odour-only trained wasps, females preferred on HIPV-treated than on blank discs. In associative-trained wasps, however, P. concolor’s innate positive chemotaxis for HIPVs was nullified (lowest HIPV dosage tested) or reversed (highest HIPV dosage tested). This is the first report of associative learning of olfactory cues for danger avoidance in parasitic wasps, showing that the effects of learning can override innate positive chemotaxes. 相似文献
7.
8.
9.
Dr. R. Harold Holbrook Jr Ann M. Krovoza Susan Schelley James E. Ferguson II 《黑龙江环境通报》1987,7(9):653-655
Anencephaly in twin B was accompanied by elevated amniotic fluid alpha-fetoprotein (AFP) and a positive acetylcholinesterase (AChE) band on gel electrophoresis in both twin sacs, although twin A was normal. AChE results did not help distinguish the false positive AFP in this set of twins, implying that AChE may diffuse transamniotically as has been previously postulated for AFP. In light of the low concordance rate for neural tube defects in twins, patient counselling in this situation must include the information that AFP and AChE may be falsely elevated in normal twin when the other twin has a neural tube defect. 相似文献
10.
11.
12.
13.
14.
15.
16.
A. K. Powell 《Die Naturwissenschaften》1962,49(8):186-187
17.
18.
19.