University of Johannesburg

About: University of Johannesburg is a education organization based out in Johannesburg, South Africa. It is known for research contribution in the topics: Population & Context (language use). The organization has 8070 authors who have published 22749 publications receiving 329408 citations. The organization is also known as: UJ.

Institutional context matters: the professional development of academics as teachers in South African higher education

Abstract: This study features the concept of ‘context’ and how various macro, meso and micro features of the social system play themselves out in any setting. Using South Africa as an example, it explores the features that may constrain or enable professional development, quality teaching and the work of teaching and learning centres at eight universities in varied socio-cultural settings. The article draws on the work of critical realists and their explication of the concepts of structure, culture and agency. The research design was participatory, where members of teaching and learning centres at the eight institutions defined the aims and key questions for the study. They collected the data on which this article is based, namely a series of descriptive and reflective reports. The findings clustered around six themes: history, geography and resources; leadership and administrative processes; beliefs about quality teaching and staff development; recognition and appraisal; and capacity, image and status of the TLC staff. These features play out in unique and unpredictable constellations in each different context, while at the same time, clusters of features adhere together. Whilst there is no one to one, predictive relationship between university type and outcome, there is a sense that socio-economic contextual features are salient and require greater attention than other features.

Apoptotic Efficacy of Multifaceted Biosynthesized Silver Nanoparticles on Human Adenocarcinoma Cells

Abstract: Metallic nanoparticles (NPs) especially silver (Ag) NPs have shown immense potential in medical applications due to their distinctive physio-chemical and biological properties This article reports the conjugation of Ag NPs with Rubus fairholmianus extract The modification of Ag NPs was confirmed using various physico-chemical characterization techniques The cytotoxic effect of Rubus-conjugated Ag NPs (RAgNPs) was studied by LDH assay and proliferation by ATP assay The apoptotic inducing ability of the NPs were investigated by Annexin V/PI staining, caspase 3/7 analysis, cytochrome c release, intracellular ROS analysis, Hoechst staining and mitochondrial membrane potential analysis using flow cytometry The expression of apoptotic proteins caspase 3, Bax and P53 were analyzed using ELISA and caspase 3, Bax using western blotting Cells treated with 10 µg/mL RAgNPs showed an increased number of cell death by microscopic analysis compared to untreated control cells The RAgNPs induced a statistically significant dose-dependent decrease in proliferation (p < 0001 for 5 and 10 µg/mL) and increased cytotoxicity in MCF-7 cells A 183 fold increase in cytotoxicity was observed in cells treated with 10 µg/mL (p < 005) compared to the untreated cells Nuclear damage and intracellular ROS production were observed upon treatment with all tested concentrations of RAgNPs and the highest concentrations (5 and 10 µg/mL) showed significant (p < 005, p < 001) expression of caspase 3, Bax and P53 proteins The data strongly suggest that RAgNPs induces cell death in MCF-7 cells through the mitochondrial-mediated intrinsic apoptosis pathway The present investigation supports the potential of RAgNPs in anticancer drug development

A 3.51 Ga bimodal volcanics‐BIF‐ultramafic succession from Singhbhum Craton: implications for Palaeoarchaean geodynamic processes from the oldest greenstone succession of the Indian subcontinent

Abstract: The Palaeoarchaean greenstone belt of the southern Iron Ore Group (SIOG) (3.51 Ga) in the Singhbhum Craton, eastern India, includes low-strained and low-greenstone grade bimodal volcanics, Banded Iron Formation (BIF) and chromiferous ultramafics as enclaves within tonalite–trondjhemite–granodiorite (TTG) granitoids, collectively referred to as the Singhbhum Granite (3.4 Ga to 3.1 Ga). The succession comprises, from base to top, a lower unit of massive and pillowed basalt conformably overlain by dacitic lava and pyroclastics which in turn is overlain by a major BIF unit. The ultramafics are juxtaposed with the volcanics-BIF succession along a thrust fault. The lithological association of pillow lava, subaqueous dacitic lava and pyroclastic rocks and BIF collectively, suggests that the entire succession was deposited in a deep-marine depositional setting. The ash-poor dacitic volcanic rock succession with evidences of a transition from suppressed-volatile deep-water lava flow and pyroclastics to more evolved mass-flow deposits with increasing trend of subaqueous flow transformation, records a transition from a deep-water low-height volcanic chain to a shallower subaqueous eruption in an aggradational volcanic chain. Geochemical proxies from the bimodal volcanics and ultramafics showing enrichment of La/Nb, Th/Nb, Th/La, Ba/La, Pb/Ce, depletion in Nb–Ta relative to neighbouring REE, together with tectonic discrimination criteria using Nb, Y, Zr, Ti compositions, suggest an extending oceanic arc–forearc geodynamic setting similar to many of the Phanerozoic supra-subduction zone ophiolites where ophiolite development in the extending upper plate in a relatively short time span is facilitated by slab rollback processes. The positive Eu-anomaly together with high Y/Ho values from the BIFs also suggests their deposition in close proximity to spreading centres that might have developed over a rifted arc. The bimodal volcanic rock-BIF-ultramafic succession of the SIOG with evidence of a convergent margin geodynamic setting is an important example for Palaeoarchaean plate tectonic processes operating on Earth. Copyright © 2011 John Wiley & Sons, Ltd.