Corporate entrepreneurship: the role of middle-level management on corporate entrepreneurship within the telecommunications industry in South Africa

A research report submitted to the Faculty of Commerce, Law and Management, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Management in Entrepreneurship and New Venture Creation March 2015Guth and Ginsberg (1990) stressed that Corporate Entrepreneurship (CE) encompasses two major phenomena: new venture creation within existing organisations and the transformation of on-going organisations through strategic renewal. Zahra (1991, p. 262) observed that Corporate Entrepreneurship may be formal or informal activities aimed at creating new business in established companies through product and process innovations and market developments. The research study was quantitative and data was collected through an online questionnaire, which used closed-ended questionnaires. The questionnaires entail assessing the degree of CE within the telecommunications industry in South Africa. The analysis involved 172 samples of responses to the online questionnaire. The research indicated that that there is a correlation between the dependent variable (entrepreneurial orientation) and the independent variables (innovation, performance, risk taking, and pro-activeness). The findings of the research contribute to the South African telecommunications industry in terms of innovation, regulation, external collaboration and entrepreneurial orientation literature and studies.MT201

Structural integrity monitoring using vibration measurements

The detection of damage in structures through the use of vibrational methods offers particular advantages, which makes it an attractive method to use in specific applications. In this work the advantages and some of the possible applications of vibrational damage detection methods will be discussed. A study of the field of damage detection using vibration techniques is undertaken. Available methods are categorised in general groups according to the underlying principles. The principle, on which each group functions, as well as the advantages and disadvantages of each, concerning the practical application thereof, is explained. The goal of this work, which entails developing a damage detection method using large amounts of raw data directly and combining some of the most favourable properties of the different groups to detect damage, are set. The new method is developed and compared both numerically as well as experimentally to two methods, chosen from the literature because of similar methodology and their reputation for effective damage detection. The methods will be tested numerically with respect to accuracy, sensitivity and multiple damage detection ability. Finally experimental data is gathered and used to verify the methods damage detection ability. The new method provides a different approach to damage detection, by combining an available vibration detection method with the maximum available amount of data in order to increase the damage detection ability.Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2006.Mechanical and Aeronautical Engineeringunrestricte

Characterisation of new full-length HIV-1 subtype D viruses from South Africa

Thesis (MSc (Medical Virology )--University of Stellenbosch, 2004.150 leaves printed on single pages, preliminary pages i-vii and numberd pages 1-143. Includes bibliography and figures digitized at 300 dpi grayscale and 300 dpi 24-bit Color to pdf format (OCR), using a Hp Scanjet 8250 Scanner and digitized at 600 dpi grayscale to pdf format (OCR), using a Bizhub 250 Konica Minolta Scanner.ENGLISH ABSTRACT: The first episode of HIV-1 in South Africa was documented in 1982. Homosexual transmission of the virus was the predominate mode of transmission in an epidemic of mainly HIV-1 subtype Band D infections. To date, no full-length sequences of Subtype D strains from South Africa has been reported. Here we describe the characterization and some of the unique features of the Tygerberg HIV-1 subtype D strains. A near full-length 9 kb fragment was obtained through a one step PCR using high molecular weight DNA. Cloning was done successfully with the pCR-XLTapa cloning kit. Large quantities of plasmid DNA was grown and sequenced on both strands of the DNA. ORF determination and subtyping was followed by standard phylogenetic methods to construct evolutionary phylogenetic trees. Subtyping and similarity plots revealed that the sequences from Tygerberg are pure subtype D. All the Tygerberg strains had intact genes with no premature stop codons. At the tip of the V3 loop, the Tygerberg strains have the GOGO motif. R214 has a more variable vpu gene than the rest of the Tygerberg strains, but is still subtype D in this region. No premature stop codons have been observed in the tat gene and the glycosilation of the strains are less than the subtype D consensus. We are the first to report full-length sequences of HIV-1 subtype D strains from South Africa. The sequences represent non-mosaic genomes of subtype D. Our results confirm that the subtype D sequences from the beginning of the HIV-1 epidemic differ from the Subtype D sequences from recent isolates.AFRIKAANSE OPSOMMING: Die eerste episode van HIV-1 infeksie in Suid Afrika is in 1982 gedokumenteer. Die epidemie het hoofsaaklik uit subtipe B en D bestaan en was deur homoseksuele kontak oorgedra. Geen vollengte subtipe D DNS volgordes van Suid-Afrika is tans beskryf nie. Hier beskryf ons die karakterisering van vollengte subtipe D stamme asook sommige van die unieke eienskappe van die virusse. Die vollengte 9 kb genoom volgorde was verkry deur 'n eenstap PKR reaksie met hoë molekulêre gewig DNS uit te voer. Die 9 kb fragment was suksesvol gekloneer met behulp van die peR-Xl-TOPO klonerings toetsstel. Groot hoeveelhede plasmied DNS was opgegroei en die nukleotied volgorde bepaal op beide stringe van die genoom. Die stamme was gesubtipeer en filogenetiese analise was uitgevoer met standaard metodes. Die volledige DNS volgordes was bepaal en subtipering het daarop gedui dat die stamme van Tygerberg suiwer subtipe D is. Geen premature stop kodons is in die nukleotied volgordes van die Tygerberg stamme gevind nie. By die draai van die varieerbare deel (V3) het al die Tygerberg stamme die GQGQ motief gehad. R214 het 'n meer varieerbare vpu geen, maar behoort steeds tot die subtipe D groep in die gedeelte. Daar was geen premature stop kodons in die tat geen gevind nie en die glikosilasie van die stamme is minder as die van die konsensus subtipe D stam. Ons is die eerste groep om vollengte subtipe D stamme van Suid-Afrika te karakteriseer. Die DNS volgordes verteenwoordig suiwer subtipe D genome. Ons resultate bevestig die van ander dat die nukleotied volgordes van die ouer subtipe D stamme verskil van die nuwer stamme

A combination of an antimitotic and a bromodomain 4 inhibitor synergistically inhibits the metastatic MDA-MB-231 breast cancer cell line

CITATION: Mqoco, T., et al. 2019. A combination of an antimitotic and a bromodomain 4 inhibitor synergistically inhibits the metastatic MDA-MB-231 breast cancer cell line. BioMed Research International, 2019(1850462):1-13. doi:10.1155/2019/1850462The original publication is available at https://www.hindawi.com/journals/bmri/Current chemotherapeutic agents have many side effects and are toxic to normal cells, providing impetus to identify agents that can effectively eliminate tumorigenic cells without damaging healthy cells. The aim of this study was to examine whether combining a novel BRD4 inhibitor, ITH-47, with the antimitotic estradiol analogue, ESE-15-ol, would have a synergistic effect on inhibiting the growth of two different breast cancer cell lines in vitro. Our docking and molecular dynamics studies showed that compared to JQ1, ITH-47 showed a similar binding mode with hydrogen bonds forming between the ligand nitrogens of the pyrazole, ASN99, and water of the BRD4 protein. Data from cell growth studies revealed that the GI50 of ITH-47 and ESE-15-ol after 48 hours of exposure was determined to be 15 μM and 70 nM, respectively, in metastatic MDA-MB-231 breast cancer cells. In tumorigenic MCF-7 breast cancer cells, the GI50 of ITH-47 and ESE-15-ol was 75 μM and 60 nM, respectively, after 48 hours of exposure. Furthermore, the combination of 7.5 μM and 14 nM of ITH-47 and ESE-15-ol, respectively, resulted in 50% growth inhibition of MDA-MB-231 cells resulting in a synergistic combination index (CI) of 0.7. Flow cytometry studies revealed that, compared to the control, combination-treated MDA-MB-231 cells had significantly more cells present in the sub-G1 phase and the combination treatment induced apoptosis in the MDA-MB-231 cells. Compared to vehicle-treated cells, the combination-treated cells showed decreased levels of the BRD4, as well as c-Myc protein after 48 hours of exposure. In combination, the selective BRD4 inhibitor, ITH-47, and ESE-15-ol synergistically inhibited the growth of MDA-MB-231 breast cancer cells, but not of the MCF-7 cell line. This study provides evidence that resistance to BRD4 inhibitors may be overcome by combining inhibitors with other compounds, which may have treatment potential for hormone-independent breast cancers.NRF Thuthuka grantCancer Association of South AfricaMedical Research CouncilSchool of Medicine Research CommitteeStruwig Germeshuysen Trusthttps://www.hindawi.com/journals/bmri/2019/1850462/Publisher’s versio

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

The Role of Earth Observation, with a Focus on SAR Interferometry, for Sinkhole Hazard Assessment

Sinkholes are global phenomena with significant consequences on the natural- and built environment. Significant efforts have been devoted to the assessment of sinkhole hazards to predict the spatial and temporal occurrence of future sinkholes as well as to detect small-scale deformation prior to collapse. Sinkhole hazard maps are created by considering the distribution of past sinkholes in conjunction with their geomorphic features, controlling conditions and triggering mechanisms. Quantitative risk assessment then involves the statistical analysis of sinkhole events in relation to these conditions with the aim of identifying high risk areas. Remote sensing techniques contribute to the field of sinkhole hazard assessment by providing tools for the population of sinkhole inventories and lend themselves to the monitoring of precursory deformation prior to sinkhole development. In this paper, we outline the background to sinkhole formation and sinkhole hazard assessment. We provide a review of earth observation techniques, both for the compilation of sinkhole inventories as well as the monitoring of precursors to sinkhole development. We discuss the advantages and limitations of these approaches and conclude by highlighting the potential role of radar interferometry in the early detection of sinkhole-induced instability resulting in a potential decrease in the risk to human lives and infrastructure by enabling proactive remediation

A simple normalized difference approach to burnt area mapping using multi-polarisation C-band SAR

CITATION: Engelbrecht, J., et al. 2017. A simple normalized difference approach to burnt area mapping using multi-polarisation C-band SAR. Remote Sens, 9(8):764, doi:10.3390/rs9080764.The original publication is available at http://www.mdpi.com/2072-4292/9/8/764In fire-prone ecosystems, periodic fires are vital for ecosystem functioning. Fire managers seek to promote the optimal fire regime by managing fire season and frequency requiring detailed information on the extent and date of previous burns. This paper investigates a Normalised Difference α-Angle (NDαI) approach to burn-scar mapping using C-band data. Polarimetric decompositions are used to derive α-angles from pre-burn and post-burn scenes and NDαI is calculated to identify decreases in vegetation between the scenes. The technique was tested in an area affected by a wildfire in January 2016 in the Western Cape, South Africa. The quad-pol H-A-α decomposition was applied to RADARSAT-2 data and the dual-pol H-α decomposition was applied to Sentinel-1A data. The NDαI results were compared to a burn scar extracted from Sentinel-2A data. High overall accuracies of 97.4% (Kappa = 0.72) and 94.8% (Kappa = 0.57) were obtained for RADARSAT-2 and Sentinel-1A, respectively. However, large omission errors were found and correlated strongly with areas of high local incidence angle for both datasets. The combined use of data from different orbits will likely reduce these errors. Furthermore, commission errors were observed, most notably on Sentinel-1A results. These errors may be due to the inability of the dual-pol H-α decomposition to effectively distinguish between scattering mechanisms. Despite these errors, the results revealed that burnt areas could be extracted and were in good agreement with the results from Sentinel-2A. Therefore, the approach can be considered in areas where persistent cloud cover or smoke prevents the extraction of burnt area information using conventional multispectral approacheshttp://www.mdpi.com/2072-4292/9/8/764Publisher's versio