198 research outputs found

    Household Challenges, Family Dynamism and Online Learning under COVID-19 Pandemic in a South African University

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    Purpose: Reduce the spread of the virus amongst people, especially students and lecturers, thus online learning was introduced in 2020. To find out the effectiveness of online learning and family dynamics posed by this phenomenon. Design/methodology/approach: The researchers conducted a research at one of the University of Technology in South Africa, situated in the Province of Kwa-Zulu Natal, in Piet ermaritzburg. The main aim was to determine the challenges posed by online learning while students were at home, compounded by COVID-19 pandemic. Findings: The results of the analysis show ed the connection between family dynamics such as family settings, online learning and the impact of COVID-19 pandemic in this regard. It can then be concluded that there is a significant influence between family setting, such as bereavement, divorce, lack of internet connection and overcrowding at home, COVID-19 and the adjustment to online learning. Research limitations/implications: Lack of internet connection and overcrowding at home,COVID-19 and the adjustment to online learning. Paper type: Research paper

    Distributed Finite Element Analysis Using a Transputer Network

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    The principal objective of this research effort was to demonstrate the extraordinarily cost effective acceleration of finite element structural analysis problems using a transputer-based parallel processing network. This objective was accomplished in the form of a commercially viable parallel processing workstation. The workstation is a desktop size, low-maintenance computing unit capable of supercomputer performance yet costs two orders of magnitude less. To achieve the principal research objective, a transputer based structural analysis workstation termed XPFEM was implemented with linear static structural analysis capabilities resembling commercially available NASTRAN. Finite element model files, generated using the on-line preprocessing module or external preprocessing packages, are downloaded to a network of 32 transputers for accelerated solution. The system currently executes at about one third Cray X-MP24 speed but additional acceleration appears likely. For the NASA selected demonstration problem of a Space Shuttle main engine turbine blade model with about 1500 nodes and 4500 independent degrees of freedom, the Cray X-MP24 required 23.9 seconds to obtain a solution while the transputer network, operated from an IBM PC-AT compatible host computer, required 71.7 seconds. Consequently, the 80,000transputernetworkdemonstratedacost−performanceratioabout60timesbetterthanthe80,000 transputer network demonstrated a cost-performance ratio about 60 times better than the 15,000,000 Cray X-MP24 system

    Effects on the transcriptome upon deletion of a distal element cannot be predicted by the size of the H3K27Ac peak in human cells.

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    Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with increased risk for colorectal cancer (CRC). A molecular understanding of the functional consequences of this genetic variation is complicated because most GWAS SNPs are located in non-coding regions. We used epigenomic information to identify H3K27Ac peaks in HCT116 colon cancer cells that harbor SNPs associated with an increased risk for CRC. Employing CRISPR/Cas9 nucleases, we deleted a CRC risk-associated H3K27Ac peak from HCT116 cells and observed large-scale changes in gene expression, resulting in decreased expression of many nearby genes. As a comparison, we showed that deletion of a robust H3K27Ac peak not associated with CRC had minimal effects on the transcriptome. Interestingly, although there is no H3K27Ac peak in HEK293 cells in the E7 region, deletion of this region in HEK293 cells decreased expression of several of the same genes that were downregulated in HCT116 cells, including the MYC oncogene. Accordingly, deletion of E7 causes changes in cell culture assays in HCT116 and HEK293 cells. In summary, we show that effects on the transcriptome upon deletion of a distal regulatory element cannot be predicted by the size or presence of an H3K27Ac peak

    Trichostatin A Enhances Gap Junctional Intercellular Communication in Primary Cultures of Adult Rat Hepatocytes

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    The effects of histone deacetylase inhibitor Trichostatin A (TSA) on connexin (Cx) expression and gap junctional intercellular communication (GJIC) were investigated in primary cultures of adult rat hepatocytes. GJIC was monitored by using the scrape-loading/dye transfer method. Immunoblotting and immunocytochemistry were used to investigate Cx protein levels and localization. Cx gene expression was studied by means of quantitative reverse transcriptase-polymerase chain reaction. TSA increased Cx32 protein levels and affected negatively the Cx26 protein levels. The latter was preferentially located in the cytosol of cultured cells. TSA also promoted the appearance of Cx43 in the nuclear compartment of primary cultured hepatocytes. Overall, this resulted in enhanced GJIC activity. It is important to note that the time of onset of TSA treatment was crucial for the extent of its outcome and that the effects of TSA on Cx protein levels occurred independently of transcriptional changes. TSA differentially affects Cx proteins in primary rat hepatocyte cultures, suggesting distinct regulation and/or distinct roles of the different Cx species in the control of hepatic homeostasis. TSA enhances GJIC between primary cultured rat hepatocytes, an interesting finding supporting its use to further optimize liver-based in vitro models for pharmacotoxicological purpose

    Household Challenges, Family Dynamism and Online Learning under COVID-19 Pandemic in a South African University

    Get PDF
    Purpose: Reduce the spread of the virus amongst people, especially students and lecturers, thus online learning was introduced in 2020. To find out the effectiveness of online learning and family dynamics posed by this phenomenon. Design/methodology/approach: The researchers conducted a research at one of the University of Technology in South Africa, situated in the Province of Kwa-Zulu Natal, in Piet ermaritzburg. The main aim was to determine the challenges posed by online learning while students were at home, compounded by COVID-19 pandemic. Findings: The results of the analysis show ed the connection between family dynamics such as family settings, online learning and the impact of COVID-19 pandemic in this regard. It can then be concluded that there is a significant influence between family setting, such as bereavement, divorce, lack of internet connection and overcrowding at home, COVID-19 and the adjustment to online learning. Research limitations/implications: Lack of internet connection and overcrowding at home,COVID-19 and the adjustment to online learning. Paper type: Research paper

    Identification of DNA sequence variation in Campylobacter jejuni strains associated with the Guillain-Barre syndrome by high-throughput AFLP analysis.

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    BACKGROUND: Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious neuropathies such as the Guillain-Barre (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides (LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular. RESULTS: We compared 6 different isolates of the "genome strain" NCTC 11168 obtained from different laboratories. HtAFLP analysis generated approximately 3000 markers per stain, 19 of which were polymorphic. The DNA polymorphisms could not be confirmed by PCR-RFLP analysis, suggesting a baseline level of 0.6% AFLP artefacts. Comparison of NCTC 11168 with 4 GBS-associated strains revealed 23 potentially GBS-specific markers, 17 of which were identified by DNA sequencing. A collection of 27 GBS/MFS-associated and 17 enteritis control strains was analyzed with PCR-RFLP tests based on 11 of these markers. We identified 3 markers, located in the LOS biosynthesis genes cj1136, cj1138 and cj1139c
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