589 research outputs found

    A human environmentalist approach to diffusion in ICT policies: A case study of the FOSS policy of the South African Government

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    Purpose – Through an evaluation of the information technology (IT) adoption and diffusion models and the free and/or open source policy of the South African Government, the underlying assumption is that the developmental divide between those with and those without access to technology is purely technical. This paper aims to illustrate that if Free and/or Open Source Software is to be used as a building block to bridge the “digital divide” a more social and environmental perspective, which embraces the philosophy behind the software, needs to complement the technical perspective. The human environmental model is presented as a useful alternative which, if embraced, can inform more holistic information and communication technology (ICT) policies. Design/methodology/approach – Through a review of diffusion of innovations models an alternative diffusion framework is described and applied to an interpretive open source case study in South Africa. Findings – Contemporary diffusion and innovation models are narrowly focused on IT as a purely technological linear phenomenon. This perspective also underlies many ICT policies. A more socio-technical adoption model can assist in providing amore holistic approach to ICTpolicy development. Originality/value – The application of a new innovation model, the human environmental model, to ICT policy provides a holistic framework in which the complexity of the innovation process can be reflected in policy. Such an approach to ICT policy formulation will assist with broadening the perspective of policy makers from IT as a technical solution to IT as part of a socio-technical solution and recognise the duality of the innovation process

    Aligning national policy imperatives with internal information systems innovations: a case study of an open source enterprise content management system in the South African public sector

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    This paper addresses the question: Can changes in internal organisational practices be effectively aligned with contentious national policy imperatives? One of the authors followed the implementation process of an Open Source Enterprise Management System in the South African Public Sector. During this process change management was observed in relation to challenges and opportunities in the alignment of the internal organisational changes to the imperatives of the national Free and Open Source Software policy. Based on this reflection it is proposed that the alignment of the organisational environment, change management strategies and \u22technologies in practice\u22 is required to address many of the \u22common\u22 change management challenges. However, this approach does not assist in addressing the major challenge of attaining harmonious internal organisational changes which attempt to implement contentious national policy

    Editorial: Selected Papers from IFIP Working Group 9.4, Social Implications of Computers in Developing Countries, Assessing the Contribution of ICT to Development Goals

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    The guest editors of this issue are the organizers of the 10th International Conference of the International Federation for Information Processing (IFIP) 9.4 working group on Social Implications of Computers in Developing Countries. This special issue of Information Technologies \u26 International Development presents selected papers from the conference

    Increased colonic propionate reduces anticipatory reward responses in the human striatum to high-energy foods

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    Background: Short-chain fatty acids (SCFAs), metabolites produced through the microbial fermentation of nondigestible dietary components, have key roles in energy homeostasis. Animal research suggests that colon-derived SCFAs modulate feeding behavior via central mechanisms. In humans, increased colonic production of the SCFA propionate acutely reduces energy intake. However, evidence of an effect of colonic propionate on the human brain or reward-based eating behavior is currently unavailable. Objectives: We investigated the effect of increased colonic propionate production on brain anticipatory reward responses during food picture evaluation. We hypothesized that elevated colonic propionate would reduce both reward responses and ad libitum energy intake via stimulation of anorexigenic gut hormone secretion. Design: In a randomized crossover design, 20 healthy nonobese men completed a functional magnetic resonance imaging (fMRI) food picture evaluation task after consumption of control inulin or inulin-propionate ester, a unique dietary compound that selectively augments colonic propionate production. The blood oxygen level–dependent (BOLD) signal was measured in a priori brain regions involved in reward processing, including the caudate, nucleus accumbens, amygdala, anterior insula, and orbitofrontal cortex (n = 18 had analyzable fMRI data). Results: Increasing colonic propionate production reduced BOLD signal during food picture evaluation in the caudate and nucleus accumbens. In the caudate, the reduction in BOLD signal was driven specifically by a lowering of the response to high-energy food. These central effects were partnered with a decrease in subjective appeal of high-energy food pictures and reduced energy intake during an ad libitum meal. These observations were not related to changes in blood peptide YY (PYY), glucagon-like peptide 1 (GLP-1), glucose, or insulin concentrations. Conclusion: Our results suggest that colonic propionate production may play an important role in attenuating reward-based eating behavior via striatal pathways, independent of changes in plasma PYY and GLP-1. This trial was registered at clinicaltrials.gov as NCT00750438

    An enhanced CRISPR repressor for targeted mammalian gene regulation.

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    The RNA-guided endonuclease Cas9 can be converted into a programmable transcriptional repressor, but inefficiencies in target-gene silencing have limited its utility. Here we describe an improved Cas9 repressor based on the C-terminal fusion of a rationally designed bipartite repressor domain, KRAB-MeCP2, to nuclease-dead Cas9. We demonstrate the system's superiority in silencing coding and noncoding genes, simultaneously repressing a series of target genes, improving the results of single and dual guide RNA library screens, and enabling new architectures of synthetic genetic circuits

    Computer simulation of glioma growth and morphology

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    Despite major advances in the study of glioma, the quantitative links between intra-tumor molecular/cellular properties, clinically observable properties such as morphology, and critical tumor behaviors such as growth and invasiveness remain unclear, hampering more effective coupling of tumor physical characteristics with implications for prognosis and therapy. Although molecular biology, histopathology, and radiological imaging are employed in this endeavor, studies are severely challenged by the multitude of different physical scales involved in tumor growth, i.e., from molecular nanoscale to cell microscale and finally to tissue centimeter scale. Consequently, it is often difficult to determine the underlying dynamics across dimensions. New techniques are needed to tackle these issues. Here, we address this multi-scalar problem by employing a novel predictive three-dimensional mathematical and computational model based on first-principle equations (conservation laws of physics) that describe mathematically the diffusion of cell substrates and other processes determining tumor mass growth and invasion. The model uses conserved variables to represent known determinants of glioma behavior, e.g., cell density and oxygen concentration, as well as biological functional relationships and parameters linking phenomena at different scales whose specific forms and values are hypothesized and calculated based on in vitro and in vivo experiments and from histopathology of tissue specimens from human gliomas. This model enables correlation of glioma morphology to tumor growth by quantifying interdependence of tumor mass on the microenvironment (e.g., hypoxia, tissue disruption) and on the cellular phenotypes (e.g., mitosis and apoptosis rates, cell adhesion strength). Once functional relationships between variables and associated parameter values have been informed, e.g., from histopathology or intra-operative analysis, this model can be used for disease diagnosis/prognosis, hypothesis testing, and to guide surgery and therapy. In particular, this tool identifies and quantifies the effects of vascularization and other cell-scale glioma morphological characteristics as predictors of tumor-scale growth and invasion

    TB STIGMA – MEASUREMENT GUIDANCE

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    TB is the most deadly infectious disease in the world, and stigma continues to play a significant role in worsening the epidemic. Stigma and discrimination not only stop people from seeking care but also make it more difficult for those on treatment to continue, both of which make the disease more difficult to treat in the long-term and mean those infected are more likely to transmit the disease to those around them. TB Stigma – Measurement Guidance is a manual to help generate enough information about stigma issues to design and monitor and evaluate efforts to reduce TB stigma. It can help in planning TB stigma baseline measurements and monitoring trends to capture the outcomes of TB stigma reduction efforts. This manual is designed for health workers, professional or management staff, people who advocate for those with TB, and all who need to understand and respond to TB stigma

    Gene expression by marrow stromal cells in a porous collagen-glycosaminoglycan scaffold is affected by pore size and mechanical stimulation.

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    Marrow stromal cell (MSC) populations, which are a potential source of undifferentiated mesenchymal cells, and culture scaffolds that mimic natural extracellular matrix are attractive options for orthopaedic tissue engineering. A type I collagen-glycosaminoglycan (CG) scaffold that has previously been used clinically for skin regeneration was recently shown to support expression of bone-associated proteins and mineralisation by MSCs cultured in the presence of osteogenic supplements. Here we follow RNA markers of osteogenic differentiation in this scaffold. We demonstrate that transcripts of the late stage markers bone sialoprotein and osteocalcin are present at higher levels in scaffold constructs than in two-dimensional culture, and that considerable gene induction can occur in this scaffold even in the absence of soluble osteogenic supplements. We also find that bone-related gene expression is affected by pore size, mechanical constraint, and uniaxial cyclic strain of the CG scaffold. The data presented here further establish the CG scaffold as a potentially valuable substrate for orthopaedic tissue engineering and for research on the mechanical interactions between cells and their environment, and suggest that a more freely-contracting scaffold with larger pore size may provide an environment more conducive to osteogenesis than constrained scaffolds with smaller pore sizes
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