1,721,196 research outputs found
Epidemiological research methods. Part I. Why epidemiology?
Full text linkCITATION: Yach, D. & Botha, J. L. 1986. Epidemiological research methods. Part I. Why epidemiology? South African Medical Journal, 70:267-270.The original publication is available at http://www.samj.org.zaIn the first article in a series on epidemiological research
methods, we describe the origins and uses of epidemiology and
introduce the different types of epidemiological study design.Publisher’s versio
Epidemiological research methods. Part III. Randomised controlled trials (for interventions)
Full text linkCITATION: Botha, J. L. & Yach, D. 1987. Epidemiological research methods. Part III. Randomised controlled trials (for interventions). South African Medical Journal, 71:657-660.The original publication is available at http://www.samj.org.zaOnce the magnitude and distribution of a health problem
and its possible determinants have been established, anempts
to prevent, treat, or control the problem by intervening on one
or more of the determinants should be made.Publisher’s versio
The oldest cynodont: new clues on the origin and early diversification of the Cynodontia
No full textBotha, J., Abdala, F., Smith, R. (2007): The oldest cynodont: new clues on the origin and early diversification of the Cynodontia. Zoological Journal of the Linnean Society 149 (3): 477-492, DOI: 10.1111/j.1096-3642.2007.00268.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2007.00268.
Epidemiological research methods. Part VI. Planning a research project
Full text linkCITATION: Botha, J. L. & Yach, D. 1987. Epidemiological research methods. Part VI. Planning a research project. South African Medical Journal, 72:563-566.The original publication is available at http://www.samj.org.zaThe need for writing a good
protocol is still paramount and applies not only to randomised
controlled trials (RCTs), but to all research projects. Writing a
good protocol reflects good planning, and in this paper we
address some vital aspects of planning a study and writing a
protocol. The information given here should be augmented by
referring to earlier articles in this series, as well as guidelines
published elsewhere.Publisher’s versio
Epidemiological research methods. Part IV. Case-control studies
Full text linkThe original publication is available at http://www.samj.org.zaCITATION: Yach, D. & Botha, J. L. 1987. Epidemiological research methods. Part IV. Case-control studies. South African Medical Journal, 71:763-766.Randomised controlled trials (RCTs), although regarded as
the best method for assessing the efficacy of an intervention, have several shoncomings and may be impossible to conduct,
for example in the case of harmful risk factors or aetiological
factors such as smoking4 or schistosomes. Analytical studies such as case-eontrol studies or non-RCT follow-up studies provide alternative approaches for assessing drug or vaccine efficacy, health service8 interventions, as well as the role of risk factors for disease.South African Medical JournalPublishers' Versio
Figure 2. A in The oldest cynodont: new clues on the origin and early diversification of the Cynodontia
No full textFigure 2. A, chronostratigraphic, lithostratigraphic and biostratigraphic chart of the Permian section of the Beaufort Group; B, sedimentological section of the locality showing the occurrence of Charassognathus gracilis gen. et sp. nov., SAM-PK-K10369 (arrow). Abbreviations: AZ, Assemblage Zone; BIO., biostratigraphy; CHRONO., chronostratigraphy; Chsn, Changhsingian; Ciste., Cistecephalus; FM., Formation; LITHO., lithostratigraphy; MEM., Member; Steenkamp., Steenkampsberg; Tapino., Tapinocephalus; Tropid., Tropidostoma.Published as part of Botha, J., Abdala, F. & Smith, R., 2007, The oldest cynodont: new clues on the origin and early diversification of the Cynodontia, pp. 477-492 in Zoological Journal of the Linnean Society 149 (3) on page 480, DOI: 10.1111/j.1096-3642.2007.00268.x, http://zenodo.org/record/542912
Figure 1. A in The oldest cynodont: new clues on the origin and early diversification of the Cynodontia
No full textFigure 1. A, map of South Africa showing the extent of the Hoedemaker Member in the Beaufort Group; B, detailed map showing fossiliferous localities of the Tropidostoma Assemblage Zone, including the locality where Charassognathus gracilis gen. et sp. nov., SAM-PK-K10369, was found (star, locality 16; for additional information on material found in these localities see Table 1).Published as part of Botha, J., Abdala, F. & Smith, R., 2007, The oldest cynodont: new clues on the origin and early diversification of the Cynodontia, pp. 477-492 in Zoological Journal of the Linnean Society 149 (3) on page 479, DOI: 10.1111/j.1096-3642.2007.00268.x, http://zenodo.org/record/542912
Subjective pulsatile tinnitus cured by carotid endarterectomy
Full text linkCITATION: Louwrens, H.D., Botha, J. & Van Der Merwe, D.M. 1989. Subjective pulsatile tinnitus cured by carotid endarterectomy. A case report. S Afr Med J, 75:496-497.The original publication is available at http://www.samj.org.zaA 70-year-old woman with unilateral pulsatile tinnitus was relieved of the complaint after carotid endarterectomy. Internal carotid artery stenosis presenting with pulsatile tinnitus is rare. Endarterectomy can relieve symptoms if the correct diagnosis is made.Publisher’s versio
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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