Choosing new ways to chew

No abstract availabl

Variability in shape of the dental arcade of Homo sapiens in Late Pleistocene and modern samples from southern Africa

Mandibles are among the most common skeletal elements of Late Pleistocene specimens of Homo sapiens from southern African sites (notably Klasies River Mouth and Border Cave). For this reason mandibles have been selected for study to compare with samples drawn from modem populations (including South African negroes, Khoisanoid "Bushmen" and caucasoids). An analysis of shape of the dental arcade, based on the spatial distribution of molars, premolars and canines, indicates that several of the Late Pleistocene samples (including KRM 41815) are outside the range of variation found in modem African and caucasoid populations, and in this respect, cannot be described as "anatomically modem", sensu strictu. There appears to be a trend in the process of modernisation, from very flared dental arcades (notably in the case of the Kabwe skull, representing "archaic" H. sapiens), through moderately flared arcades (as found in Late Pleistocene "nearly modem" samples) towards a less flared condition which is found in modern Africans and caucasoids.Foundation for Research Developmen

Workshop on research p riorities for migrant pests of agriculture in Southern Africa, Plant Protection Research Institute, Pretoria, South Africa, 24–26 March 1999

The Workshop was held at the Agricultural Research Council – Plant Protection Research Institute, Pretoria, from 24 to 26 March 1999 and was attended by 66 delegates from Botswana, Malawi, Namibia, South Africa, Sudan, Swaziland, Tanzania, United Kingdom, Zimbabwe, the International Red Locust Control Organisation for Central and Southern Africa (IRLCO-CSA) and the Food and Agriculture Organization of the United Nations (FAO) (see pages xiii–xvi for list of delegates). The first day focused on presenting a synopsis of current research on the three main migrant pests in southern Africa – armyworm, locusts and quelea – and described the national, regional (IRLCO-CSA, Southern African Development Community, SADC) and international (FAO) infrastructures for dealing with them. On the second and third days, after consideration of the issues to be addressed to ensure uptake of research findings by resource-poor farmers, the Workshop divided into three groups according to pest species. Each group adopted a generalised Logical Framework approach to identifying research priorities, constraints, risks and linkages. Four Logical Frameworks, covering armyworm, locust, quelea and cross-cutting research priorities were developed and an informal ad hoc steering committee (names annotated in list, pages xiii–xvi) undertook to bring together the Workshop’s findings in a Summary Report and to make recommendations on further actions

V2:Performance of the solid deuterium ultra-cold neutron source at the pulsed reactor TRIGA Mainz

The performance of the solid deuterium ultra-cold neutron source at the pulsed reactor TRIGA Mainz with a maximum peak energy of 10 MJ is described. The solid deuterium converter with a volume of V=160 cm3 (8 mol), which is exposed to a thermal neutron fluence of 4.5x10^13 n/cm2, delivers up to 550 000 UCN per pulse outside of the biological shield at the experimental area. UCN densities of ~ 10/cm3 are obtained in stainless steel bottles of V ~ 10 L resulting in a storage efficiency of ~20%. The measured UCN yields compare well with the predictions from a Monte Carlo simulation developed to model the source and to optimize its performance for the upcoming upgrade of the TRIGA Mainz into a user facility for UCN physics.Comment: 23 pages, 8 figure

Coronary artery bypass grafting: Part 1—the evolution over the first 50 years

Surgical treatment for angina pectoris was first proposed in 1899. Decades of experimental surgery for coronary artery disease finally led to the introduction of coronary artery bypass grafting (CABG) in 1964. Now that we are approaching 50 years of CABG experience, it is appropriate to summarize the advancement of CABG into a procedure that is safe and efficient. This review provides a historical recapitulation of experimental surgery, the evolution of the surgical techniques and the utilization of CABG. Furthermore, data on contemporary clinical outcomes are discusse

A connection between stress and development in the multicelular prokaryote Streptomyces coelicolor

Morphological changes leading to aerial mycelium formation and sporulation in the mycelial bacterium Streptomyces coelicolor rely on establishing distinct patterns of gene expression in separate regions of the colony. sH was identified previously as one of three paralogous sigma factors associated with stress responses in S. coelicolor. Here, we show that sigH and the upstream gene prsH (encoding a putative antisigma factor of sH) form an operon transcribed from two developmentally regulated promoters, sigHp1 and sigHp2. While sigHp1 activity is confined to the early phase of growth, transcription of sigHp2 is dramatically induced at the time of aerial hyphae formation. Localization of sigHp2 activity using a transcriptional fusion to the green fluorescent protein reporter gene (sigHp2–egfp) showed that sigHp2 transcription is spatially restricted to sporulating aerial hyphae in wild-type S. coelicolor. However, analysis of mutants unable to form aerial hyphae (bld mutants) showed that sigHp2 transcription and sH protein levels are dramatically upregulated in a bldD mutant, and that the sigHp2–egfp fusion was expressed ectopically in the substrate mycelium in the bldD background. Finally, a protein possessing sigHp2 promoter-binding activity was purified to homogeneity from crude mycelial extracts of S. coelicolor and shown to be BldD. The BldD binding site in the sigHp2 promoter was defined by DNase I footprinting. These data show that expression of sH is subject to temporal and spatial regulation during colony development, that this tissue-specific regulation is mediated directly by the developmental transcription factor BldD and suggest that stress and developmental programmes may be intimately connected in Streptomyces morphogenesis