EC scientist in UN poverty project

Award-winning Grahamstown professor Tebello Nyokong is reaching for the stars after she was appointed to a prestigious United Nations panel tasked with using science to reduce world poverty

Computational study of the hydrodefluorination of fluoroarenes at [Ru(NHC)(PR₃)<sub style="vertical-align: sub;">2</sub>(CO)(H)<sub style="vertical-align: sub;">2</sub>]: predicted scope and regioselectivities

Density functional theory calculations have been employed to investigate the scope and selectivity of the hydrodefluorination (HDF) of fluoroarenes, C6F6-nHn (n = 0-5), at catalysts of the type [Ru(NHC)(PR3)(2)(CO)(H)(2)]. Based on our previous study (Angew. Chem., Int. Ed., 2011, 50, 2783) two mechanisms featuring the nucleophilic attack of a hydride ligand at a fluoroarene substrate were considered: (i) a concerted process with Ru-H/C-F exchange occurring in one step; and (ii) a stepwise pathway in which the rate-determining transition state involves formation of HF and a Ru-sigma-fluoroaryl complex. The nature of the metal coordination environment and, in particular, the NHC ligand was found to play an important role in both promoting the HDF reaction and determining the regioselectivity of this process. Thus for the reaction of C6F5H, the full experimental system (NHC = IMes, R = Ph) promotes HDF through (i) more facile initial PR3/fluoroarene substitution and (ii) the ability of the NHC N-aryl substituents to stabilise the key C-F bond breaking transition state through F center dot center dot center dot HC interactions. This latter effect is maximised along the lower energy stepwise pathway when an ortho-H substituent is present and this accounts for the ortho-selectivity seen in the reaction of C6F5H to give 1,2,3,4-C6F4H2. Computed C-F bond dissociation energies (BDEs) for C6F6-nHn substrates show a general increase with larger n and are most sensitive to the number of ortho-F substituents present. However, HDF is always computed to remain significantly exothermic when a silane such as Me3SiH is included as terminal reductant. Computed barriers to HDF also generally increase with greater n, and for the concerted pathway a good correlation between C-F BDE and barrier height is seen. The two mechanisms were found to have complementary regioselectivities. For the concerted pathway the reaction is directed to sites with two ortho-F substituents, as these have the weakest C-F bonds. In contrast, reaction along the stepwise pathway is directed to sites with only one ortho-F substituent, due to difficulties in accommodating ortho-F substituents in the C-F bond cleavage transition state. Calculations predict that 1,2,3,5-C6F4H2 and 1,2,3,4-C6F4H2 are viable candidates for HDF at [Ru(IMes)(PPh3)(2)(CO)(H)(2)] and that this would proceed selectively to give 1,2,4-C6F3H3 and 1,2,3-C6F3H3, respectively.</p

Tourism can also play a vital role

Commissioned by the Eastern Cape Gambling and Betting Board (ECGBB), the Status of Traditional Horse Racing in the Eastern Cape report provides a fascinating glimpse into the long-lasting and often little known connection many Xhosa people have with horses. A cornerstone of rural Xhosa life, horses have been used for generations for work and transport - as well as racing

How a Networked Approach to Building Capacity in Knowledge Mobilization Supports Research Impact

Research impact is emerging as a common feature in national research systems. Knowledge mobilization (KMb) includes efforts undertaken to aid and accelerate research impact pathways by directing focus to processes that support impact. To date, researchers and universities have struggled to increase their capacity in KMb. This study explores the perceptions held by 16 leaders of Research Impact Canada, representing 14 networked universities, about the usefulness and use of networked learning to build institutional capacity in KMb. The analysis of data, which was collected using a mixed-methods survey design, highlights two overarching themes: 1) the contextual variability in how institutions engage in KMb work, and how practice-based subgroups can support the diverse KMb needs of different institutions; and 2) how capacity is developed through networked learning is distributed among individuals and groups within institutions, and how networked institutions need to be self-referential to the ways knowledge about KMb is sourced, validated, shared, interpreted, and employed

Studies in the concept of ideology: from the Hegelian dialectic to western Marxism

Ideology is interpreted broadly in this study as consciousness, where consciousness is the relation of knowledge to its object. This thesis investigates the connection between Hegel’s theory of consciousness and society and Marx’s political and social thought. It shows that many discoveries, previously considered to be those of Marx alone, like surplus-value and the transition from capitalism to communism, were first developed and employed by Hegel. The study also demonstrates that key concepts, which remain only implicit in Marx, such as social class, alienation, revolutionizing praotice, contradiction and dialectic are given full theoretical form only In the works of Hegel. It examines and shows the strong similarities between Hegel’s and Marx’s theory of religion, capitalism and the state, and stresses that their theory details not the conditions for the emancipation of a class, but rather the liberation and freedom of the social individual. The dissertation explores the writings of the young Marx and Feuerbach and shows that Western Marxism, to its theoretical detriment, owes much more to them than it does to Hegel and the mature Marx. The connection between the philosophies of Kant and Feuerbach and the ideology of contemporary bourgeois society is demonstrated, as is the organic, if antagonistic, unity between the alienated consciousness of Western Marxism and that of its bourgeois opponent. Contemporary Marxist theory is subjected to critical analysis within the framework of a comprehensive account of dialectic method and exposition. The thesis concludes that social thought and political action might be enriched and extended through a new synthesis of Marx with Hegel