The southern African marine realm is located at the transition zone between the Atlantic and Indo-Pacific biomes. Its biodiversity is particularly rich and comprises faunal and floral elements from the two major oceanic regions, as well as a large number of endemics. Within this realm, strikingly different biota occur in close geographic proximity to each other, and many of the species with distributions spanning two or more of the region's marine biogeographic provinces are divided into evolutionary units that can often only be distinguished on the basis of genetic data. In this review, we describe the state of marine phylogeography in southern Africa, that is, the study of evolutionary relationships at the species level, or amongst closely related species, in relation to the region's marine environment. We focus particularly on coastal phylogeography, where much progress has recently been made in identifying phylogeographic breaks and explaining how they originated and are maintained. We also highlight numerous shortcomings that should be addressed in the near future. These include: the limited data available for commercially important organisms, particularly offshore species; the paucity of oceanographic data for nearshore areas; a dearth of studies based on multilocus data; and the fact that studying the role of diversifying selection in speciation has been limited to physiological approaches to the exclusion of genetics. It is becoming apparent that the southern African marine realm is one of the world's most interesting environments in which to study the evolutionary processes that shape not only regional, but also global patterns of marine biodiversity.

OBJECTIVE: To determine the metabolic status of the brain in post traumatic brain injury(TBI) depression using proton magnetic resonance spectroscopy (MRS). DESIGN: Case-control study including 5 TBI depressed subjects and 5 age matched non-TBI non-depressed controls. METHODS: Metabolic status was assessed using proton MRS. Ratios of N-acetylaspartate (NAA), choline (Cho) and total creatine (Cr) were calculated in frontal cortex, basal ganglia and thalamus. RESULTS: NAA/Cho or NAA/Cr ratios were significantly reduced in the TBI depressed group compared to controls in frontal cortex, basal ganglia and thalamus. CONCLUSION: Reduced levels of NAA in frontal regions, basal ganglia and thalamus in TBI depression suggest neuronal damage or dysfunction which may be a associated with the primary brain injury or with depressed mood.

Os autores deste ensaio entendem que é preciso testar de forma mais completa as afirmações empíricas das recentes teorias da mudança científica. Tendo em vista facilitar tal empreendimento, apresentam-se em linguagem não-técnica as afirmações empíricas de Kuhn, Feyerabend, Lakatos e Laudan, que estão organizadas por autor e por assunto. Ao final, inclui-se uma bibliografia de estudos de caso.

The authors call for a more thorough testing of the empirical claims of recent theories of scientific change. To facilitate this the empirical claims of Kuhn, Feyerabend, Lakatos and Laudan are listed in nontechnical language, both by author and by topic. A bibliography of case studies is included.