The differentiation of pleural effusions

CITATION: Martiz, F. J. 1982. The differentiation of pleural effusions. South African Medical Journal, 62:553-556.The original publication is available at http://www.samj.org.zaThe causes and pathophysiology of pleural effusions are briefly discussed. A method for staining pleural effusions is described and the importance of side-room microscopy in the evaluation of pleural fluids is emphasized. The value of various investigations in the differentiation of pleural effusions is reviewed.Publisher’s versio

SOME THOUGHTS ON THE CLASSICAL ALLUSIONS IN THE WORK OF MBZIMUNYA

I ftrst met Prof. P J Conradie in 1960 when I was a ftrst year Latin student at the University of Stellenbosch, and he was a young lecturer teaching the course on Catullus. In my Honours year he taught me Tacitus, and when I later did Greek it was he who introduced me to the dramatists. In 1970 I was privileged to become a colleague and the next year attended the party organised in his honour by Prof. van Rensburg, to mark Dr. Conradie's appointment as Professor. For the last three years he has been External Examiner at the University of Zimbabwe where I now teach, so in the course of 35 years I have been associated with Prof. Conradie in various capacities. I welcome the opportunity to join his many students and colleagues in paying tribute to him, for his scholarship and for the great influence he has had on the teaching of Classics in Southern Africa

THE COURTAULD COLLECTION AS A TEACIDNG TOOL

Although western civilization has its roots in Classical antiquity, much of the Greek and Roman world is strange to us. This is particularly true in Southern Africa where we do not have the Romance languages, nor the physical remains - roads, bridges, aqueducts, villas, often still in the process of being excavated - surrounding us and therefore do not experience the same continuity of history as our European or British colleagues. It is also difficult to visualize the material culture. Photos help, but do not convey a sense of scale, or texture. Real understanding often depends on a hands-on experience, or at least a look at the original

The politics of development in Southern Africa: Givens in the quest for a paradigm

Looking back, it is apparent that the late fifties of this century were vintage years in a time of faith in modernization - developing "them" (in the Third World) to look like "us" (in the First World) - as the basic paradigm for development. The success of the Marshall Plan in the re­ development of Europe inspired the conclusion by the West that what was needed to "develop" Africa, Asia and Latin America was foreign aid, technical expertise and revamped administrative systems in Third World countries, which had to see to the diffusion of technical know-how as well as to the assimilation of this external input by these countries

A statistical exploration of interval-deficient wind speed data for application to wind power assessments

Gathering quality wind speed data can be time-consuming and expensive. The present study established whether interval-deficient wind speed data could be rendered useful for wind power assessments. The effect of interval deficiency on the quality of the wind speed data was investigated by studying the behaviour of the Weibull scale and shape factors as the interval size between wind speed measurements increased. Five wind speed data sets obtained from the Southern African Universities Radiometric Network (Sauran) were analysed, based on a proposed procedure to find the true Weibull parameters from an interval-deficient wind speed data set. It was found that the relative errors in the Weibull parameters were, on average, less than 1%, compared with the Weibull parameters computed from a wind speed data set that complies with the IEC 61400-12-1:2005(E) standard. This finding may contribute to time and cost reduction in wind power assessments. It may also promote the application of statistical methods in the renewable energy sector

Stratification and domination in graphs.

Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.In a recent manuscript (Stratification and domination in graphs. Discrete Math. 272 (2003), 171-185) a new mathematical framework for studying domination is presented. It is shown that the domination number and many domination related parameters can be interpreted as restricted 2-stratifications or 2-colorings. This framework places the domination number in a new perspective and suggests many other parameters of a graph which are related in some way to the domination number. In this thesis, we continue this study of domination and stratification in graphs. Let F be a 2-stratified graph with one fixed blue vertex v specified. We say that F is rooted at the blue vertex v. An F-coloring of a graph G is a red-blue coloring of the vertices of G such that every blue vertex v of G belongs to a copy of F (not necessarily induced in G) rooted at v. The F-domination number yF(GQ of G is the minimum number of red vertices of G in an F-coloring of G. Chapter 1 is an introduction to the chapters that follow. In Chapter 2, we investigate the X-domination number of prisms when X is a 2-stratified 4-cycle rooted at a blue vertex where a prism is the cartesian product Cn x K2, n > 3, of a cycle Cn and a K2. In Chapter 3 we investigate the F-domination number when (i) F is a 2-stratified path P3 on three vertices rooted at a blue vertex which is an end-vertex of the F3 and is adjacent to a blue vertex and with the remaining vertex colored red. In particular, we show that for a tree of diameter at least three this parameter is at most two-thirds its order and we characterize the trees attaining this bound. (ii) We also investigate the F-domination number when F is a 2-stratified K3 rooted at a blue vertex and with exactly one red vertex. We show that if G is a connected graph of order n in which every edge is in a triangle, then for n sufficiently large this parameter is at most (n — /n)/2 and this bound is sharp. In Chapter 4, we further investigate the F-domination number when F is a 2- stratified path P3 on three vertices rooted at a blue vertex which is an end-vertex of the P3 and is adjacent to a blue vertex with the remaining vertex colored red. We show that for a connected graph of order n with minimum degree at least two this parameter is bounded above by (n —1)/2 with the exception of five graphs (one each of orders four, five and six and two of order eight). For n > 9, we characterize those graphs that achieve the upper bound of (n — l)/2. In Chapter 5, we define an f-coloring of a graph to be a red-blue coloring of the vertices such that every blue vertex is adjacent to a blue vertex and to a red vertex, with the red vertex itself adjacent to some other red vertex. The f-domination number yz{G) of a graph G is the minimum number of red vertices of G in an f-coloring of G. Let G be a connected graph of order n > 4 with minimum degree at least 2. We prove that (i) if G has maximum degree A where A 4 with maximum degree A where A 5 with maximum degree A where

Pharmacological challenge with a serotonin 1D agonist in alcohol dependence

BACKGROUND: Both animal and clinical studies have implicated serotonergic dysfunction in the pathogenesis of alcohol abuse and dependence. However the exact mechanisms involved remain unknown. Theoretically, low serotonin promotes alcohol seeking behavior. Sumatriptan is a serotonin1D agonist. It is postulated that sumatriptan's agonism at this terminal autoreceptor increases negative feedback, creating a net effect of decreased serotonergic neurotransmission. Administration of sumatriptan should therefore produce a craving for alcohol and the desire to drink. METHODS: Fifteen patients with alcohol dependence who had undergone detoxification were recruited. Sumatriptan (100 mg) and placebo was administered in cross-over fashion on 2 separate days 72 hours apart. Both patients and raters were blind to all treatments. Patients were assessed on the following scales at -30, 0, 30, 90, 150 and 210 minutes: A 6-item scale designed to rate the patient's intention to drink; The Sensation Scale; a 13-item affect analog scale designed to rate the pattern and extent of emotional changes; and an 8-item scale designed to rate the patient's craving for alcohol RESULTS: No significant differences were found between the placebo and sumatriptan groups and no significant cross over effects were found. CONCLUSION: The general lack of efficacy of sumatriptan in producing alcohol-like symptoms or a desire to drink alcohol may suggest that the 5HT1D receptor plays little role in the pathophysiology of alcoholism

A radiological study of the rheumatoid hand in black South Africans

Objective: To determine wrist and hand involvement in black South African patients with rheumatoid arthritis. Methods: Larsen scoring of the wrist and hand was done in 75 patients. The mean finger score was 9.67 (range 0-100) on the left hand and 10.3 (range 0-100) on the right. Scores for the wrists were 2.5 (range 0-5) for the left and 2.7 (range 0-5) for the right. Conclusion: Finger and thumb involvement were considerably less in the South African black population than in other series consisting mainly of white patients.South African Medical Journal Vol. 95(10) 2005: 795-79

Scale-dependent orientation in movement paths: a case study of an African viper

Decisions relating to the orientation of movement by animals and how this translates into movement patterns can occur at multiple spatial scales simultaneously, but this interaction is poorly understood for many groups of animals. Using the tracks left by moving snakes in their sandy habitat, we studied the movement paths of the African snake Bitis schneideri (Namaqua dwarf adder) for evidence of broad-scale directional persistence and short-range avoidance of exposure. Although snakes clearly displayed directional persistence, they preferentially moved to nearby shrubs, thereby minimizing exposure to solar and thermal radiation and/or predation. Thus, snakes made decisions relating to orientation at a minimum of two scales, the interaction of which resulted in snakes moving ≈17% (mean straightness index = 0.85) further than the simple broad-scale straight-line distance. We assert that the actual path chosen by moving snakes represents a trade-off of various costs and risks that include risk of predation, exposure to the elements, time and energy expenditure. Our study highlights the need for cognizance of the possibility of the scale dependence of orientation and movement in studies of snake movement, and adds to a growing literature demonstrating previously unrecognized behavioural complexity in snakes