Investigating usage of social media platforms in South Africa

This study investigated the differences in usage of different social media platforms within the South African context, broken down by user characteristics, specifically gender and age, in addition to investigating the correlation between usage of differing social media platforms. This was carried out to determine which social media needs do the different population groups aim to fulfill when using different social media platforms. Based on the results, the study confirmed the existence of preferences between types of social media platforms and groups of social media platforms in South Africa, based on frequency of use by age group and gender. Social media can thus be seen as a useful tool for collaboration and sharing knowledge to users in a South African context but must be tailored for specific audience needs

Die Bibliothek als Erfolgsfaktor:

Im Jahr 2012 konnte die Universitätsbibliothek ihr 50. Jubiläum feiern. Aus diesem Anlass hat die Bibliothek eine Festschrift herausgegeben. Es findet keine Rückschau auf die Vergangenheit statt. Hingegen wird in drei Themenbereichen "Die Universitätsbibliothek - professionelle Partnerin für Lehre , Studium und Forschung", "Innovationen für die campusweiten Dienstleistungen der Universitätsbibliothek" und "Ein scharfes Profil für die Ruhr-Universität Bochum - der Beitrag der Universitätsbibliothek" auf die Rolle und Funktion der Universitätsbibliothek Bochum bis hin zu aktuellen Veränderungen bei Arbeitsabläufen in der Universitätsbibliothek im Jahr 2012 eingegangen

Detection of mitochondrial defects by laser fluorimetry

Abstract The mitochondrial function in skeletal muscle biopsies of three patients with chronic progressive external ophthalmoplegia, having deletions of the mitochondrial DNA, was studied by laser-excited fluorescence measurements of NAD(P)H and flavoproteins in saponin-skinned fibers. We detected substantially elevated steady state redox states of the mitochondrial NADsystem in the muscle fibers of these patients. Moreover, the respiratory chain-linked autofluorescence changes in the muscle fibers of these patients were larger in comparison to controls indicating substantial alterations of the mitochondrial content. These results are in line with the presence of elevated numbers of partially respiratory chain inhibited mitochondria in the skeletal muscle of chronic progressive external ophthalmoplegia patients. (Mol Cell Biochem 174: [97][98][99][100] 1997

Contributions of woody and herbaceous vegetation to tropical savanna ecosystem productivity: a quasi-global estimate

To estimate the relative contributions of woody and herbaceous vegetation to savanna productivity, we measured the13C/12C isotopic ratios of leaves from trees, shrubs, grasses and the surface soil carbon pool for 22 savannas in Australia, Brazil and Ghana covering the full savanna spectrum ranging from almost pure grassland to closed woodlands on all three continents. All trees and shrubs sampled were of the C3 pathway and all grasses of the C4 pathway with the exception of Echinolaena inflexa (Poir.) Chase, a common C3 grass of the Brazilian cerrado. By comparing the carbon isotopic compositions of the plant and carbon pools, a simple model relating soil δ13C to the relative abundances of trees + shrubs (woody plants) and grasses was developed. The model suggests that the relative proportions of a savanna ecosystem's total foliar projected cover attributable to grasses versus woody plants is a simple and reliable index of the relative contributions of grasses and woody plants to savanna net productivity. Model calibrations against woody tree canopy cover made it possible to estimate the proportion of savanna productivity in the major regions of the world attributable to trees + shrubs and grasses from ground-based observational maps of savanna woodiness. Overall, it was estimated that 59% of the net primary productivity (Np) of tropical savannas is attributable to C4 grasses, but that this proportion varies significantly within and between regions. The C4 grasses make their greatest relative contribution to savanna Np in the Neotropics, whereas in African regions, a greater proportion of savanna Np is attributable to woody plants. The relative contribution of C4 grasses in Australian savannas is intermediate between those in the Neotropics and Africa. These differences can be broadly ascribed to large scale differences in soil fertility and rainfall