Institution
University of South Africa
Education•Pretoria, 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.
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TL;DR: It is demonstrated that exotic plant species play an important part as medicinal remedies employed by Bapedi healers to treat different human diseases in the Limpopo Province and there is a need to formulate an appropriate policy to retain some of the useful medicinal exotics within the environment before their medicinal value vanishes as they are eradicated through management strategies adopted by the South African government.
72 citations
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TL;DR: The study provided evidence that A. ferox, E. elephantina and L. leonurus extracts possess anthelminthic activity, thus justifying their use in the treatment of GI helminthosis, and need to assess the safety of these plants in vivo and also to undertake in vivo efficacy studies.
Abstract: Aloe ferox (Mill), Leonotis leonurus (L) R. BR; and Elephantorrhiza elephantina (Burch.) Skeels are plants frequently used by resource-limited farmers in the Eastern Cape Province to control gastrointestinal parasites in goats. A study was conducted to validate their anthelminthic activities in-vitro on the egg and larvae of the nematode parasite Haemonchus contortus. The crude aqueous extracts of leaves of A. ferox and L. leonurus; and roots of E. elephantina were used. Eggs and larvae of the parasite were incubated at 25°C in aqueous extracts at concentrations of 0.625–20 mg/ml for 48 h and 7 days for the egg hatch and larval development assays respectively. Albendazole and water were the positive and negative controls respectively. Inhibition of egg hatching and larval development increased significantly (P 96% and this was comparable to albendazole at the same concentration. E. elephantina and L. leonurus also totally inhibited larval development at concentrations of 1.25 mg/ml. The study provided evidence that A. ferox, E. elephantina and L. leonurus extracts possess anthelminthic activity, thus justifying their use in the treatment of GI helminthosis. There is however need to assess the safety of these plants in vivo and also to undertake in vivo efficacy studies.
72 citations
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Cornell University1, University of Texas at Austin2, Syracuse University3, University of Illinois at Urbana–Champaign4, J.P. Morgan & Co.5, University of North Carolina at Chapel Hill6, University of South Africa7, Pennsylvania State University8, United States Department of the Army9, Northwestern University10, University of Pittsburgh11, Washington University in St. Louis12
TL;DR: In this article, the first successful demonstration of a black hole moving freely through a three-dimensional computational grid via a Cauchy evolution was reported, with a hole moving near 6M at 0.1c during a total evolution of duration near 60M.
Abstract: Binary black-hole interactions provide potentially the strongest source of gravitational radiation for detectors currently under development. We present some results from the Binary Black Hole Grand Challenge Alliance three-dimensional Cauchy evolution module. These constitute essential steps towards modeling such interactions and predicting gravitational radiation waveforms. We report on single black-hole evolutions and the first successful demonstration of a black hole moving freely through a three-dimensional computational grid via a Cauchy evolution: a hole moving near 6M at 0.1c during a total evolution of duration near 60M. [S0031-9007(98)05652-X]
72 citations
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TL;DR: A simple adaptive algorithm for the efficient time-frequency representation of noisy signals using the Wigner distribution is developed and can be generalized for application on multicomponent signals with any distribution from the Cohen (1989, 1990, 1992) class.
Abstract: Time-frequency representations using the Wigner distribution (WD) may be significantly obscured by the noise in the observations. The analysis performed for the WD of discrete-time noisy signals shows that this time-frequency representation can be optimized by the appropriate choice of the window length. However, the practical value of this analysis is not significant because the optimization requires knowledge of the bias, which depends on the unknown derivatives of the WD. A simple adaptive algorithm for the efficient time-frequency representation of noisy signals is developed in this paper. The algorithm uses only the noisy estimate of the WD and the analytical formula for the variance of this estimate. The quality of this adaptive algorithm is close to the one that could be achieved by the algorithm with the optimal window length, provided that the WD derivatives were known in advance. The proposed algorithm is based on the idea that has been developed in our previous work for the instantaneous frequency (IF) estimation. Here, a direct addressing to the WD itself, rather than to the instantaneous frequency, resulted in a time and frequency varying window length and showed that the assumption of small noise and bias is no longer necessary. A simplified version of the algorithm, using only two different window lengths, is presented. It is shown that the procedure developed for the adaptive window length selection can be generalized for application on multicomponent signals with any distribution from the Cohen (1989, 1990, 1992) class. Simulations show that the developed algorithms are efficient, even for a very low value of the signal-to-noise ratio.
72 citations
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TL;DR: In this article, the authors argue that specific patterns of codeswitching indicate how language is both an index of identity and a tool of communication in South Africa, and that speakers exhibit strong loyalty to their own first languages.
Abstract: ‘Mixed Language,’ a characteristic pattern of language use among African township residents in South Africa, may well include words or full constituents from several languages. However, from both a structural and a social perspective, such speech has a systematic nature. In reference to grammatical structure, within any CP (projection of COMP) showing codeswitching, only one language (the Matrix Language) provides the grammatical frame in the data studied. Also, while speakers from different educational levels engage in codeswitching with similar frequencies, the types of codeswitched constitutents they prefer are different. In reference to the social use of language, we argue that specific patterns of codeswitching indicate how language is both an index of identity and a tool of communication in South Africa. In the codeswitching patterns they use, speakers exhibit strong loyalty to their own first languages. Yet, because they recognize that codeswitching facilitates communication with members of other ethnic groups, they use a number of codeswitching strategies as a means of accommodating to their addressees and simultaneously as a means of projecting multiple identities for themselves.
72 citations
Authors
Showing all 8743 results
Name | H-index | Papers | Citations |
---|---|---|---|
Alvaro Avezum | 93 | 279 | 48888 |
Jordan J. Louviere | 93 | 356 | 38739 |
Jürgen Eckert | 92 | 1368 | 42119 |
Simon Henry Connell | 83 | 506 | 25147 |
Elina Hyppönen | 81 | 258 | 33011 |
David Wilkinson | 80 | 631 | 27578 |
Béla Bollobás | 78 | 566 | 34767 |
Richard A. Matzner | 72 | 317 | 16389 |
Tim Olds | 71 | 412 | 21758 |
Nicolin Govender | 71 | 412 | 18740 |
Paul A. Webley | 70 | 374 | 18633 |
Dusan Losic | 70 | 398 | 16550 |
Alexander Shapiro | 70 | 252 | 26450 |
Kerin O'Dea | 69 | 359 | 16435 |
Shrikant I. Bangdiwala | 68 | 359 | 21650 |