Dental indicators of adaptation in the Sahara Desert during the Late Holocene.

The present paper examines dental diseases and linear enamel hypoplasia among the Garamantes, a Late Holocene Saharan population, and aims to draw conclusions about nutrition and adaptation to a hyper-arid environment. Archaeological evidence suggests that the Garamantian diet included animal protein and local, Mediterranean and Near Eastern plants. Moreoever, although the Garamantes had developed urban centres, the size of these was not large enough to allow for particularly unhygienic conditions to appear. The above archaeological findings were partly corroborated by the current bioarchaeological study. At an intra-population level, the Garamantes showed limited sex differences in dental disease prevalence, while all dental conditions increased in frequency with age, as expected. At an inter-population level, the frequency of all dental conditions was comparable to that found among other North African groups, with the exception of ante-mortem tooth loss. The low frequency of most dental conditions is an indication that the Garamantian diet was overall balanced, while the high frequency of ante-mortem tooth loss may be related to factors such as oral hygiene, food preparation or eating mode, which cannot be controlled for osteologically. Finally, the low frequency of enamel hypoplasia suggests either that the Sahara did not inflict particular stresses on the population, or, more likely, that the Garamantes had developed effective mechanisms for coping with their natural environment.

Effect of selective serotonin re-uptake inhibitors (SSRIs) on functional outcome in patients with acute ischemic stroke treated with tPA.

BACKGROUND: Selective serotonin re-uptake inhibitors (SSRIs) may have therapeutic potential in the treatment of ischemic stroke by effects on neuronal cell survival and the plasticity of brain processes. In the present study, we investigated whether prior treatment with a SSRI is associated with more favorable functional outcome in a cohort of patients with acute ischemic stroke treated with tissue plasminogen activator (tPA). METHODS: In a prospective observational cohort study of 476 acute ischemic stroke patients treated with tPA we investigated the relationship between prior SSRI treatment and functional outcome at 3 months. Ischemic stroke subtypes were defined according to the Oxfordshire Community Stroke Project Classification. Favorable outcome was defined as a modified Rankin Scale score

Secular trends in growth among urban Brazilian children of European descent.

PRIMARY OBJECTIVE: The purpose of this paper is to describe and discuss a significant secular trend in stature and weight in an urban Brazilian population. METHODOLOGY: Anthropometric measurements of 7878 children and adolescents from São Paulo, Brazil, obtained in 1997/98 were compared with data from a previous study carried out in 1978. Both samples include children of middle-class urban families of European ancestry. MAIN OUTCOMES AND RESULTS: Comparisons between the two samples reveal strong positive secular trends in both height and weight. Furthermore, the 1997/98 sample shows no growth deficits in relation to the WHO/NCHS international reference. CONCLUSIONS: The positive trend can be explained as the result of economic development and improvement of social indicators, while the absence of growth deficits, contrary to what is reported in other studies carried out in developing countries, follows from the common genetic background of the Brazilian sample surveyed here and the US sample which is the basis of the NCHS/WHO reference.

Towards a theory of modern human origins: geography, demography, and diversity in recent human evolution.

The origins of modern humans have been the central debate in palaeoanthropology during the last decade. We examine the problem in the context of the history of anthropology, the accumulating evidence for a recent African origin, and evolutionary mechanisms. Using a historical perspective, we show that the current controversy is a continuation of older conflicts and as such relates to questions of both origins and diversity. However, a better fossil sample, improved dates, and genetic data have introduced new perspectives, and we argue that evolutionary geography, which uses spatial distributions of populations as the basis for integrating contingent, adaptive, and demographic aspects of microevolutionary change, provides an appropriate theoretical framework. Evolutionary geography is used to explore two events: the evolution of the Neanderthal lineage and the relationship between an ancestral bottleneck with the evolution of anatomically modern humans and their diversity. We argue that the Neanderthal and modern lineages share a common ancestor in an African population between 350,000 and 250,000 years ago rather than in the earlier Middle Pleistocene; this ancestral population, which developed mode 3 technology (Levallois/Middle Stone Age), dispersed across Africa and western Eurasia in a warmer period prior to independent evolution towards Neanderthals and modern humans in stage 6. Both lineages would thus share a common large-brained ancestry, a technology, and a history of dispersal. They differ in the conditions under which they subsequently evolved and their ultimate evolutionary fate. Both lineages illustrate the repeated interactions of the glacial cycles, the role of cold-arid periods in producing fragmentation of populations, bottlenecks, and isolation, and the role of warmer periods in producing trans-African dispersals.