University of South Africa

About: University of South Africa is a education organization based out in Pretoria, South Africa. It is known for research contribution in the topics: Context (language use) & Population. The organization has 8478 authors who have published 19960 publications receiving 237688 citations. The organization is also known as: Unisa.

H2O emission in high-z ultra-luminous infrared galaxies

Abstract: Using the IRAM Plateau de Bure interferometer (PdBI), we report the detection of water vapor in six new lensed ultra-luminous starburst galaxies at high redshift, discovered in the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). The sources are detected either in the 2$_{02}$-1$_{11}$ or 2$_{11}$-2$_{02}$ H$_{2}$O emission lines with integrated line fluxes ranging from 1.8 to 14 Jy km s$^{-1}$. The corresponding apparent luminosities are {$μ$}L$_{H2}$O ~{} 3-12 { imes} 10$^{8}$ L$_{⊙}$, where {$μ$} is the lensing magnification factor (3 {lt} {$μ$} {lt} 12). These results confirm that H$_{2}$O lines are among the strongest molecular lines in high-z ultra-luminous starburst galaxies, with intensities almost comparable to those of the high-J CO lines, and similar profiles and line widths (~{}200-900 km s$^{-1}$). With the current sensitivity of the PdBI, the water lines can therefore easily be detected in high-z lensed galaxies (with F(500 {$μ$}m) {gt} 100 mJy) discovered in the Herschel surveys. Correcting the luminosities for amplification, using existing lensing models, L$_{H2}$O is found to have a strong dependence on the infrared luminosity, varying as ~{}L$_{IR}$$^{1.2}$. This relation, which needs to be confirmed with better statistics, may indicate a role of radiative (infrared) excitation of the H$_{2}$O lines, and implies that high-z galaxies with L$_{IR}$ {gsim} 10$^{13}$ L$_{⊙}$ tend to be very strong emitters in water vapor, that have no equivalent in the local universe. Herschel (Pilbratt et al. 2010) is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

“What is the Point of Knowing?”: Psychosocial Barriers to HIV/AIDS Voluntary Counselling and Testing Programmes in South Africa:

Abstract: Voluntary Counselling and Testing (VCT) programmes are regarded as an important strategy in the management of the HIV/AIDS pandemic worldwide. Such programmes, however, often have limited success due to various problems such as the existence of attitudes and beliefs that act as psychosocial barriers. This article, which presents a study of attitudes towards VCT in South Africa, attempts to ascertain the reasons for people's continued resistance to VCT programmes. A semi-structured questionnaire was used to survey the views of 1422 people. The results indicate that while the research participants, in principle, were not opposed to VCT, they professed a deep mistrust of health-care professionals, and feared discrimination and rejection by the latter, their sexual partners, and their communities. Participants did not know how to disclose their HIV-positive status, and were concerned about testing that did not include treatment and/or follow-up support, as well as their ability to deal with the ensuing psycho...

Biosorbents for the removal of synthetic organics and emerging pollutants: Opportunities and challenges for developing countries

Abstract: Contamination of aquatic systems by synthetic organic contaminants and emerging pollutants poses significant public and environmental health risks in developing countries. These contaminants mainly originate from textile, agrochemical, and pharmaceutical industries. The removal of such contaminants is problematic in developing countries because advanced water treatment methods are still lacking in developing countries due to their high costs. The application of biosorption for removal of organic contaminants in developing countries is attractive for three reasons; (1) large quantities of biomaterials for use as biosorbents are readily available; (2) lack of advanced water and wastewater treatment systems for removal of organic contaminants; and (3) the technology is relatively cheap compared to advanced methods (e.g. membrane filtration) often used in developed countries. Overall, this has the potential to remove organic contaminants from aqueous systems while simultaneously reducing the public health and environmental impacts associated with the disposal of such biowastes. However, large-scale application of biosorption faces potential challenges including lack of funding, poor mechanical properties of biosorbants, complex adsorption mechanisms involved, and poor regeneration capacity. In addition, spent biosorbents present an environmental risk and their disposal is problematic due to the potential of contaminating surface and ground water. Possible disposal methods for spent biosorbent include use as a filler in road surfacing, as a soil amendment, and in phytoremediation cells where the organics are absorbed and broken down by plants. Overall, biosorption is a potentially viable alternative, but further research on its ability to remove pollutants from multi-component systems, its regeneration capacity, and plant design parameters is required before the benefits of the technology are realised in developing countries.

Tourism Governance and Attainment of the Sustainable Development Goals in Africa

Abstract: Inclusiveness that improves tourism governance is significant for development if benefits from tourism are distributed equitably. Declaration of 2017 as the International Year of Sustainable Touris...