Using agroecology to stimulate the greening of agriculture in China: a reflection on 15 years of teaching and curriculum development

Even though worldwide research and teaching in Agroecology blossomed in the 1980s, until recently, the development of Agroecology in China has been constrained by technical, cultural and economic considerations. The delay in the assimilation of Agroecology, as a science, a practice and a movement, has resulted in the discipline of Agroecology in China lacking the holistic, interdisciplinary approaches needed to respond to current global and regional agricultural challenges. There is a need to redefine Agroecology both as a critical discipline and as a pedagogical approach. By using an ecology-oriented systematic approach to integrate education and research, a reframed Agroecology is proposed; this is based on a re-imagined, holistic consideration of the hierarchy of agroecosystems. The practical experience of a 15-year international team-taught Agroecology education programme among participants from Canada and China has helped refine disciplinary classifications, both from horizontal and vertical hierarchies. There are evolving impacts of this experiment in Sino-Canadian cooperation in Agroecological research and education; they include a new generation of highly trained agroecologists prepared to act across inter-related disciplines; the alignment of Chinese universities to international agricultural curricula and a better- informed policy-making process towards greening agriculture in China

Palladium carbene complexes for selective alkene di- and oligomerization

A series of palladium complexes were synthesized that comprise three sterically different C,N-bidentate coordinating NHC-pyridine ligands (NHC = N-heterocyclic carbene). In one set, the pyridine and the carbene are linked by a flexible CH2 group (a), in the other two sets, the two ligand units are directly linked and feature a shielding mesityl substituent on the carbene and either an unsubstituted pyridine (b) or a xylyl-substituted pyridine unit (c). Investigation of the reactivity of cationic complexes [Pd(C^N)Me(NCMe)]+, 6, analogues to Brookhart’s α-diimine system, towards alkenes showed a strong correlation between the catalytic activity and selectivity and the ligand setting. While 6a was inactive in ethylene conversion, 6b afforded low-molecular weight olefins (oligomerization), and 6c produced exclusively butene (dimerization). With styrene as substrate, exclusive dimerization occurred with all three complexes. Steric and electronic factors were identified that govern the disparate activity and selectivity, and that allow for efficient tailoring of the catalytic performance.Other funderSwiss National Science FoundationMIUR (Italy)University College DublinNB embargo date January 12, 2013 -- JG; au, ti, sp, ke, li -TS 08.05.1