1834 research outputs found
Sort by
Human capital investments and skills outcomes specific to the different entrepreneurship phases
No full textEntrepreneurs require some elements of human capital investment (work experience, education, industry-specific and entrepreneurship-specific experience) and skills to perform entrepreneurial activities in different entrepreneurship phases. However, entrepreneurship literature is silent on which specific human capital investments and skills are needed in each of the entrepreneurship phases (nascent, new business and established phases). In addition, studies that applied human capital to understanding entrepreneurial behaviour focused on either opportunity recognition or exploitation without dealing with more than one phase of the entrepreneurship process. Accordingly, this study investigated the human capital investments and skills specific to the different entrepreneurship phases.
This study employed a sequential mixed-method research design using interviews and surveys. The interviews were conducted to: identify the sources of entrepreneurship skills; discover skills relevant in each entrepreneurship phase; and use the results of the qualitative phase to develop a survey instrument for measuring applied skills in a larger population of entrepreneurs. The data was collected in face-to-face interviews with a purposive sample of 15 entrepreneurs (five per entrepreneurship phase) and six national experts in entrepreneurship.
The quantitative study was aimed at confirming the skills sets derived from the qualitative phase, determining their significance across the different entrepreneurship phases, and testing the relationship between skills, sources of skills that are the human capital investments, and entrepreneurship phases. After validating the quantitative measuring instrument, a questionnaire survey covered 235 entrepreneurs who participated in the study. Through confirmatory factor analysis, the categories of skills developed were: start-up skills; core business skills (business management, financial management, human resource management and marketing skills); personal and leadership skills (social and interpersonal, leadership and personal skills); and technical skills. The hypotheses were tested using inferential statistics that included the Kruskal-Wallis test, Mann-Whitney U test, and hierarchical multiple regression.
The results showed that applying start-up, social and interpersonal, technical, and human resource management skills across the entrepreneurship phases produces an inverted U-shaped curvilinear relationship, thus they increase from the nascent to new-business phase and decline in the established phase. Marketing, personal and leadership skills have a negative curvilinear relationship with the entrepreneurship phases as they are applied maximally in the nascent phase but decrease in the new-business and established phases. Financial management and business management skills have a positive curvilinear relationship with the entrepreneurship phases as they increase from the nascent phase, through new business to the established phase. Overall, the relationship between skills and entrepreneurship phases was found to be an inverted U-shaped curvilinear, thus the application of skills positively increases from the nascent to new-business phase but declines from the new-business to established phases.
The study also revealed that, as entrepreneurs start businesses, in the nascent phase the use of human capital investments (especially formal education) as a source of skills declines, thus creating a need to acquire more entrepreneurship-specific investments. When the application of skills declines from the new-business to the established phase, entrepreneurs seek additional sources of skills to counter the depreciating skill sets. In addition to acquiring skills from human capital investments, entrepreneurs learn skills from actors in their social networks. So skills acquired from the human capital and social actors are applied unequally in the different entrepreneurship phases. Finally, the entrepreneurship phase and some identified contextual factors were found to have a moderating effect on the relationship between skills and human capital investments.
The results of the study assisted in developing a skills framework that will give a deeper understanding of human capital investments and skills needed in the entrepreneurship phases. This study makes a contribution to policy-makers, scholars and training institutions to categorize and sample entrepreneurs according to their skills requirements and entrepreneurship phases.National Research Foundatio
Performance of the Bio-Rad Geenius HIV1/2 supplemental assay in detecting “recent” HIV infection and calculating population incidence
No full textOBJECTIVE:HIV seroconversion biomarkers are being used in cross-sectional studies for HIV incidence estimation. Bio-Rad Geenius HIV-1/2 Supplemental Assay is an immunochromatographic single-use assay that measures antibodies (Ab) against multiple HIV-1/2 antigens. The objective of this study was to determine whether the Geenius assay could additionally be used for recency estimation.
DESIGN: This assay was developed for HIV-1/2 confirmation; however, quantitative data acquired give information on increasing concentration and diversity of antibody responses over time during seroconversion. A quantitative threshold of recent HIV infection was proposed to determine "recent" or "nonrecent" HIV infection; performance using this cutoff was evaluated.
METHODS: We tested 2500 highly characterized specimens from research subjects in the United States, Brazil, and Africa with well-defined durations of HIV infection. Regression and frequency estimation were used to estimate assay properties relevant to HIV incidence measurement: mean duration of recent infection (MDRI), false-recent rate, and assay reproducibility and robustness.
RESULTS: Using the manufacturer's proposed cutoff index of 1.5 to identify "recent" infection, the assay has an estimated false-recent rate of 4.1% (95% CI: 2.2 to 7.0) and MDRI of 179 days (155 to 201) in specimens from treatment-naive subjects, presenting performance challenges similar to other incidence assays. Lower index cutoffs associated with lower MDRI gave a lower rate of false-recent results.
CONCLUSIONS: These data suggest that with additional interpretive analysis of the band intensities using an algorithm and cutoff, the Geenius HIV-1/2 Supplemental Assay can be used to identify recent HIV infection in addition to confirming the presence of HIV-1 and HIV-2 antibodies.National Research Foundation (South Africa
Social-ecological resilience and biosphere-based sustainability science
No full textHumanity has emerged as a major force in the operation of the biosphere. The focus is shifting from the environment as externality to the biosphere as precondition for social justice, economic development, and sustainability. In this article, we exemplify the intertwined nature of social-ecological systems and emphasize that they operate within, and as embedded parts of the biosphere and as such coevolve with and depend on it. We regard social-ecological systems as complex adaptive systems and use a social-ecological resilience approach as a lens to address and understand their dynamics. We raise the challenge of stewardship of development in concert with the biosphere for people in diverse contexts and places as critical for long-term sustainability and dignity in human relations. Biosphere stewardship is essential, in the globalized world of interactions with the Earth system, to sustain and enhance our life-supporting environment for human well-being and future human development on Earth, hence, the need to reconnect development to the biosphere foundation and the need for a biosphere-based sustainability science.National Research Foundation (South Africa
Wavelength-modulated spectroscopy of the sub-bandgap response of solar cell devices
No full textA wavelength-modulation setup for measuring the differential photo-response of a GaSb/GaAs quantum ring solar cell structure is reported. The pseudo-monochromatic wavelength is modulated at the output of a conventional monochromator by means of a vibrating slit mechanism. The vibrating slit was able to modulate the excitation wavelength up to 33 nm. The intensity of the light beam was kept constant through a unique flux correction module, designed and built in-house. The setup enabled measurements in the near-infrared range (from 1000 to 1300 nm), which is specifically used to probe the sub-band gap differential photo-response of GaAs solar cellsNational Research Foundation (South Africa
Rapid synthesis of blue emitting ZnO nanoparticles for fluorescent applications
No full textZnO nanoparticles (NPs), with size ∼16–20 nm were produced using simple, cost effective and rapid synthesis method. In this method zinc salt (typically zinc acetate dehydrate) is directly annealed in air at a temperature from to for 2 h to form ZnO (NPs). This synthesis method, only requires zinc precursor to produce NPs that can emit visible emission without external doping. X-ray diffraction (XRD) patterns confirm the prepared ZnO NPs is polycrystalline structure with wurtzite phase. The observed variation in scanning electron microscopy (SEM) images showed spherical shape of the ZnO NPs. It was found that the NPs exhibited the estimated direct bandgap (Eg) of 3.28 eV, 3.29 eV, 3.33 eV and 3.39 eV for a decomposition temperature of 500, 400, 300 and. Energy dispersive X-ray (EDX) analysis showed that carbon is the only impurity at lower temperature which was most likely originated from the acetate group. The photoluminescence (PL) spectra of ZnO NPs showed the appearance of a blue emission, attributed to Zn interstitials, whose intensity reduces with increase in decomposition temperature and the underlying mechanism are discussed. For the samples prepared at and 300 °C a temperature dependent PL was studied and found out that there are about three transition lines at ∼3.01 eV, ∼3.21 eV and ∼3.33 eV, which are ascribed to zinc vacancy (Vzn), donor–acceptor pairs(DAP) and excitons bound to structural defects respectively. It is hoped that ZnO NPs produced using this method would be ideal for blue light emitting fluorescent application as it is catalyst free growth, uses simple equipment, less hazardous and easy to control particle size and morphologies by scalable temperature.National Research Foundation (South Africa
Minimum wages and youth: the case of South Africa
No full textThis article applies the econometric methods of the new minimum wage literature to assess the impact of minimum wages on employment, wages and non-wage benefits for youth in South Africa. We find a statistically significant but small decline in youth employment in Agriculture. In addition, a small but significant increase in youth employed in Retail and the Taxi sector is observed. For the other sectors, we find no effect. There is a positive wage effect for young people in four of the six minimum wage sectors in our preferred estimation. At the intensive margin, hours of work were adjusted downward in three of the six minimum wage sectors and increased in the post-law period for one sector. It is only in one sector, Retail, where the law appears to have increased the probability of having a written employment contract. In addition, we measure minimum wage violation and find significant levels of non-compliance with the law for a large cohort of young people in South Africa.National Research Foundation (South Africa
The defect passivation effect of hydrogen on the optical properties of solution-grown ZnO nanorods
No full textIn this study the effect of annealing environment on both low temperature and room temperature photoluminescence (PL) characteristics of ZnO nanorods, grown in solution, is presented. Particular attention is given to the effect of hydrogen defect passivation and its PL related line. It is shown that, irrespective of annealing ambient, an optimum annealing temperature of 300 °C suppresses the defect related emission and significantly improves the UV emission. By considering the stability of hydrogen impurities, the observed results in the PL spectra are analyzed. There is an observed asymmetric broadening on the low energy side of the bound exciton luminescence in the low temperature annealed samples which is explained by a high concentration of ionized impurities related to hydrogen. This has been attributed primarily to the conversion of hydrogen molecule to substitutional hydrogen on the oxygen site (HO) as a result of annealing.National Research Foundation (South Africa
Surface characterisation of ZnO nanorods grown by chemical bath deposition
No full textThe surface composition of as-grown and annealed ZnO nanorods (ZNs) grown by a two-step chemical bath deposition method is investigated by the following surface-sensitive techniques: Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS), X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). The presence of H on the surface and throughout the entire thickness of ZNs is confirmed by TOF-SIMS. Based on TOF-SIMS results, the O2 XPS peak mostly observable at ~531.5 is assigned to O bound to H. Furthermore, it is found that the near surface region of as-grown ZNs is Zn-rich, and annealing at high temperature (~850 °C) removes H-related defects from the surface of ZNs and affect the balance of zinc and oxygen concentrations.National Research Foundation (South Africa
Habitat use and home range of black-backed jackals (Canis mesomelas) on farmlands in the Midlands of KwaZulu-Natal, South Africa
No full textBlack-backed jackals (Canis mesomelas) are an abundant mesopredator on farmlands (croplands and rangelands) across South Africa. Given their adaptability in a changing anthropogenic landscape, knowledge of spatial movements can provide important ecological information on the species. We captured, collared and monitored five black-backed jackals in the Midlands of KwaZulu-Natal to determine their home range and habitat use in farmlands. The 95% fixed kernel (95% FK) home range sizes were large, showing a marked seasonal variation in movement. One adult male dispersed 150 km over two seasons (winter and spring) and thereafter settled into a home range that it maintained. Transient home ranges of males and juveniles were larger than resident home ranges. The mean resident home ranges (95% FK) across seasons for adult males, adult female and juvenile males were 11.4 ± 4.3 km2, 5.6 ± 0.36 km2 and 2.15 ± 0.45 km2, respectively. The mean transient home ranges (95% FK) of all the seasons for adult and juvenile males were 1 181.93 ± 575.81 km2 and 104.27 ± 35.64 km2, respectively. Adult jackal preferred croplands in spring, summer and autumn but avoided croplands in winter. Variable habitat use and large home ranges in our study confirmed the species’ ability to adapt to agricultural areas.National Research Foundation (South Africa
Hadedas in the hood: Hadeda Ibis activity in suburban neighbourhoods of Pietermaritzburg, KwaZulu-Natal, South Africa
No full textUrban environments are a combination of green and grey spaces and although many species are unable to live in these transformed areas there are some that can use urban features to benefit their persistence here. The Hadeda Ibis (Bostrychia hagedash) is one such species and this study investigated the urban activities of these birds. Five suburbs of Pietermaritzburg in KwaZulu-Natal, South Africa were surveyed for Hadeda Ibis engaged in flying, foraging, perching and calling behaviours. Each suburb differed in the degree of urbanisation and we expected that their morning activity would differ accordingly. A difference in Hadeda Ibis calling, foraging and flying activity between summer and winter was also expected because of seasonal rainfall patterns. Although Hadeda Ibis were more common in suburbia than the city centre in Pietermaritzburg, they occurred throughout. More were observed calling in summer than in winter probably because of changes in distribution during the breeding season with more family groups of two or three individuals. There was no significant difference in Hadeda Ibis flock size when comparing foraging during summer with winter despite greater summer rainfall. Also there was no significant difference in flock size with flying activity for both seasons nor suburb although it was expected that Hadeda Ibis would need to travel further during winter and from suburbs with more grey space to access ideal foraging areas. Hadeda Ibis need moist soil to forage effectively and in an urban environment short grassed, well watered lawns provided an ideal foraging habitat regardless of season. Hadeda Ibis used urban structures like house roofs, poles, pylons, and fences for perching but continued to roost in trees so while they are able to use urban features, they still rely on a certain degree of green space for urban persistence.National Research Foundation (South Africa