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.

Watermelon as a potential fruit snack

Abstract: With the rapid increase in cardiovascular diseases, health-conscious consumers are increasingly showing more interest in foods that provide health benefits beyond the provision of essential nutrien...

Some properties of the Kermack-McKendrick epidemic model with fractional derivative and nonlinear incidence

Abstract: Kermack-McKendrick epidemic model is considered as the basis from which many other compartmental models were developed. But the development of fractional calculus applied to mathematical epidemiology is still ongoing and relatively recent. We provide, in this article, some interesting and useful properties of the Kermack-McKendrick epidemic model with nonlinear incidence and fractional derivative order in the sense of Caputo. In the process, we used the generalized mean value theorem (Odibat and Shawagfeh in Appl. Math. Comput. 186:286-293, 2007) extended to fractional calculus to conclude some of the properties. A model of the Kermack-McKendrick with zero immunity is also investigated, where we study the existence of equilibrium points in terms of the nonlinear incidence function. We also establish the condition for the disease free equilibrium to be asymptotically stable and provide the expression of the basic reproduction number. Finally, numerical simulations of the monotonic behavior of the infection are provided for different values of the fractional derivative order α ( ). Comparing to the model with first-order derivative, there is a similar evolution for close values of α. The results obtained may help to analyze more complex fractional epidemic models.

Educators\' perceptions of school climate and health in selected primary schools

Abstract: The aims in this research were to determine the perceptions of school climate held by educators of primary schools in the southern Cape. Six primary schools with a staff complement of 178 educators participated in the investigation. Two instruments were used: the Organisational Climate Description Questionnaire Rutgers Elementary (OCDQ-RE) and Dimensions of Organisational Health Inventory of Elementary Schools (OHI-E). The results indicated that primary school educators in the southern Cape perceived their relations with their principals as closed, while educator-educator relations were perceived as more open. An engaged school climate was taken as the typical prototype for the relevant primary schools. Average health profiles were drawn for the overall organisational health of primary schools. A significant relationship was found between primary schools' perceptions of organisational climate and organisational health. A significant difference was found between perceptions held by educators from different primary schools regarding the various dimensions of organisational climate and health. These findings have significant implications for the implementation of change in schools, educators' job satisfaction, motivation, productivity, well-being, and learner achievement. Keywords : educators' perceptions; health profiles; job satisfaction; organisational climate; organisational health; productivity; school climate; school health South African Journal of Education Vol. 29 (1) 2009: pp. 33-52