Witchcraft, Violence, and Democracy in South Africa

Witchcraft, Violence, and Democracy in South Africa . Adam Ashforth. Chicago: University of Chicago Press, 2005. 396 pp.     

Disease progress of non-specialised fungal pathogens in intraspecific mixed stands of cereal cultivars. I. Models

Two mathematical models are presented which describe progress of disease, caused by an unspecialised pathogen, in pure and mixed stands of cereal cultivars. One is a simple, discrete model utilising the parameters infection frequency (lesions/spore) and sporulation rate (spores/lesion/event) on each cultivar. The model predicts that, in most circumstances, the amount of disease in mixtures will be equal to or less than the arithmetic mean of the component pure stands. An increase in disease is only predicted in situations where the ranking of cultivars with respect to infection frequency and sporulation rate is opposed. In the other model differential equations are proposed. Solutions of these equations indicate that disease amelioration can usually be expected in such mixtures, confirming the conclusions of the discrete model and that disease levels will deviate around the geometric, rather than arithmetic, mean of the pure stands. However the advantages of this model lie in wider generality and conceptual, rather than practical, utility.     

A One Year Audit of Fine Needle Aspiration Cytology For the Pre-Operative Diagnosis of Breast Disease

In 1988, 985 patients presenting with breast disease, most with a palpable abnormality, were investigated by the triple approach (clinical examination, imaging and fine needle aspiration cytology [FNAC]). Using FNAC, 28% of patients were diagnosed as having carcinoma, 45% benign disease, 4% had suspicious cytology and 3% equivocal cytology. The remaining 20% had inadequate aspirates. Two false positive diagnoses of carcinoma were made (a false positive rate of 0.7%); one was a case of high grade non-Hodgkin's lymphoma and the other a papillary lesion with epithelial atypia. The false negative rate was 6.4%. Of these 49 patients, six had carcinoma-in-situ and 19 had low grade tumours. The absolute and complete sensitivities for the diagnosis of carcinoma in this series were 84.7% and 91.9% respectively and the absolute and complete specificities 99.7% and 98.3%, respectively. These figures compare favourably with those from other centres and confirm the efficacy of FNAC as part of the triple approach to the diagnosis of breast disease. The use of FNAC has resulted in a reduction in the number of Trucut and frozen section biopsies performed. Eighty three per cent of the patients with benign disease diagnosed by the triple approach have avoided excision biopsy, none of whom have subsequently been found to have carcinoma. Eighty patients with advanced breast carcinoma were spared operative intervention.     

Aspects of the biology of Hyolitha (Mollusca)

Hyolitha constitute an extinct group of class rank assigned to Molhsca. Two orders, Ortho-thecida and Hyolithida, are well established and most knowledge of morphologic detail is derived from the latter. Both orders had an operculum not hinged to the conch. Hyolithida also had paired, curved, whiskerlike appendages, requiring complex musculature to move them and the operculum. The Hyolithida were probably deposit feeders living in shallow water, and accordingly were tentaculate. A reconstruction of the soft parts of this sedentary organism is given — a shallow mantle cavity on the dorsal side, anterior tentacles, a long intestine, and a reduced ventral foot. Except for the more complex musculature associated with an elaborate operculum, Orthothecida are judged to have had a similar anatomy.