The intra-uterine device in Soweto and other townships

The complex of townships of Soweto (South-Western Townships), a few miles from Johannesburg, is inhabited solely by Blacks belonging to virtually all the tribes found in South Africa, though Zulus and Sothos predominate, The variation of adaptation to modern Western life ranges from close to tribal background, to completely Westernised and highly educated. About a quarter of a million people inhabit Soweto illegally. There are no slums, but Soweto is far from ideal. Nevertheless there is steady, rapid advancement, responsibilities are being accepted, attitudes are changing and the blessings of family spacing and limitation are generally understood. The family planning service is a great success. The performance of the intra-uterine device (IUD) is discussed against a background of well over 25000 insertions, A Lippes loop series and a Dalkon Shield evaluation are presented. Insertions into nulliparous young women, and post-Caesarean cases are discussed, and the importance of the IUD in a mass family planning programme emphasised.S. Afr. Med. J., 48, 1302 (1974)

Living in Living Cities

This paper presents an overview of current and potential applications of living technology to some urban problems. Living technology can be described as technology that exhibits the core features of living systems. These features can be useful to solve dynamic problems. In particular, urban problems concerning mobility, logistics, telecommunications, governance, safety, sustainability, and society and culture are presented, while solutions involving living technology are reviewed. A methodology for developing living technology is mentioned, while supraoptimal public transportation systems are used as a case study to illustrate the benefits of urban living technology. Finally, the usefulness of describing cities as living systems is discussed.Comment: 40 pages, 4 figures, overview pape

Sustainability, epistemology, ecocentric business and marketing strategy:ideology, reality and vision

This conceptual article examines the relationship between marketing and sustainability through the dual lenses of anthropocentric and ecocentric epistemology. Using the current anthropocentric epistemology and its associated dominant social paradigm, corporate ecological sustainability in commercial practice and business school research and teaching is difficult to achieve. However, adopting an ecocentric epistemology enables the development of an alternative business and marketing approach that places equal importance on nature, the planet, and ecological sustainability as the source of human and other species' well-being, as well as the source of all products and services. This article examines ecocentric, transformational business, and marketing strategies epistemologically, conceptually and practically and thereby proposes six ecocentric, transformational, strategic marketing universal premises as part of a vision of and solution to current global un-sustainability. Finally, this article outlines several opportunities for management practice and further research

The hydrodynamics of water-walking arthropods

We present the results of a combined experimental and theoretical investigation of the dynamics of water-walking insects and spiders. Using high-speed videography, we describe their numerous gaits, some analogous to those of their terrestrial counterparts, others specialized for life at the interface. The critical role of the rough surface of these water walkers in both floatation and propulsion is demonstrated. Their waxy, hairy surface ensures that their legs remain in a water-repellent state, that the bulk of their leg is not wetted, but rather contact with the water arises exclusively through individual hairs. Maintaining this water-repellent state requires that the speed of their driving legs does not exceed a critical wetting speed. Flow visualization reveals that the wakes of most water walkers are characterized by a series of coherent subsurface vortices shed by the driving stroke. A theoretical framework is developed in order to describe the propulsion in terms of the transfer of forces and momentum between the creature and its environment. The application of the conservation of momentum to biolocomotion at the interface confirms that the propulsion of water walkers may be rationalized in terms of the subsurface flows generated by their driving stroke. The two principal modes of propulsion available to small water walkers are elucidated. At driving leg speeds in excess of the capillary wave speed, macroscopic curvature forces are generated by deforming the meniscus, and the surface behaves effectively as a trampoline. For slower speeds, the driving legs need not substantially deform the surface but may instead simply brush it: the resulting contact or viscous forces acting on the leg hairs crossing the interface serve to propel the creature forward.National Science Foundation (U.S.) (Grant CTS-0624830) (Career Grant CTS-0130465)Mathematical Sciences Postdoctoral Research Fellowship