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Orang-utans (Pongo pygmaeus) at the Singapore Zoological Gardens were presented with two thick-shelled edible seeds, Mezzettia parviflora (Annonaceae) and Macadamia ternifolia (Proteaceae) in order to estimate their maximum bite forces. The orang-utans could break the Macadamia seeds in one bite, while those of Mezzettia required repeated attempts. Examination of shell fragments showed that many had scratches and some had clear, but small (ca. 1-2 mm diameter), impressions on them. Building upon this information, semi-imitative tests were performed on the seeds in a universal testing machine by loading them in compression with either flat plates or metal casts of orang-utan cheek teeth. The maximum forces required to break the seeds were similar with both the flat plates and the metal teeth; the average for the Macadamia seeds being about 2,000 N (which forms a minimum estimate for the maximum bite forces in orang-utans) and for the Mezzettia seeds, 6,000 N. The work done with the metal teeth was much greater than with the plates. A mechanical analysis showed that this extra work went into producing permanent impressions ('bite marks') in the shell with the tooth cusps. These impressions were larger than those found on the shells of seeds bitten by the orang-utans. Nevertheless, it is shown theoretically that the size of these indentations can give an estimate of the bite forces used. The maximum force developed in the machine tests with the metal teeth was correlated with the force calculated from analysis of the bite marks. The method is suitable for use in field studies where the marks left on remnants of hard foods eaten by primates may be used to estimate, very roughly, the forces used to produce them.

In the early 1970s, excavation at the King site, a contact period Mississippian village in northwest Georgia, yielded the skeletal remains of a robust male (King 65) possessing marked hypertrophy of the acetabulo-cristal buttress. The buttress is morphologically similar to that of Plio-Pleistocene Homo but it is accompanied by an anatomically modern degree of thickening of the gluteal table of the ilium. Although the degree of cortical thickness of the gluteal table of the ilium is apparently species-specific, hypertrophy of the acetabulo-cristal buttress is developmental and may be expressed in all species of Homo.

We describe here performance enhancements provided by an anti-reflective coating (ARC), developed for deep UV applications. The reduction in substrate reflections provided by the ARC layer results in significant increases in resolution capability and process latitude compared to single layer deep UV resist. Increased linewidth control and patterning capability for highly reflective, grainy, and topographical substrates is demonstrated.

Abstract: A small minority of Africa''s wild plant foods are C4. These are primarily the seeds of some of the C4 grasses, the rootstocks and stem/leaf bases of some of the C4 sedges (especially papyrus), and the leaves of some of the C4 herbaceous dicots (forbs). These wild food plants are commonly found in disturbed ground and wetlands (particularly the grasses and sedges). Multiple lines of evidence indicate that C4 grasses were present in Africa by at least the late Miocene. It is a reasonable hypothesis that the prehistory of the C4 sedges parallels that of the C4 grasses, but the C4 forbs may not have become common until the late Pleistocene. CAM plants may have a more ancient history, but offer few opportunities for an additional C4-like dietary signal. The environmental reconstructions available for the early South African hominid sites do not indicate the presence of large wetlands, and therefore probably the absence of a strong potential for a C4 plant food diet. However, carbon isotope analyses of tooth enamel from three species of early South African hominids have shown that there was a significant but not dominant contribution of C4 biomass in their diets. Since it appears unlikely that this C4 component could have come predominantly from C4 plant foods, a broad range of potential animal contributors is briefly considered, namely invertebrates, reptiles, birds, and small mammals. It is concluded that the similar average C4 dietary intake seen in the three South African hominid species could have been acquired by differing contributions from the various sources, without the need to assume scavenging or hunting of medium to large grazing ungulates. Effectively similar dominantly dryland paleo-environments may also be part of the explanation. Theoretically, elsewhere in southern and eastern Africa, large wetlands would have offered early hominids greater opportunities for a C4 plant diet. [Copyright &y& Elsevier]

A small minority of Africa's wild plant foods are C4. These are primarily the seeds of some of the C4 grasses, the rootstocks and stem/leaf bases of some of the C4 sedges (especially papyrus), and the leaves of some of the C4 herbaceous dicots (forbs). These wild food plants are commonly found in disturbed ground and wetlands (particularly the grasses and sedges). Multiple lines of evidence indicate that C4 grasses were present in Africa by at least the late Miocene. It is a reasonable hypothesis that the prehistory of the C4 sedges parallels that of the C4 grasses, but the C4 forbs may not have become common until the late Pleistocene. CAM plants may have a more ancient history, but offer few opportunities for an additional C4-like dietary signal. The environmental reconstructions available for the early South African hominid sites do not indicate the presence of large wetlands, and therefore probably the absence of a strong potential for a C4 plant food diet. However, carbon isotope analyses of tooth enamel from three species of early South African hominids have shown that there was a significant but not dominant contribution of C4 biomass in their diets. Since it appears unlikely that this C4 component could have come predominantly from C4 plant foods, a broad range of potential animal contributors is briefly considered, namely invertebrates, reptiles, birds, and small mammals. It is concluded that the similar average C4 dietary intake seen in the three South African hominid species could have been acquired by differing contributions from the various sources, without the need to assume scavenging or hunting of medium to large grazing ungulates. Effectively similar dominantly dryland paleo-environments may also be part of the explanation. Theoretically, elsewhere in southern and eastern Africa, large wetlands would have offered early hominids greater opportunities for a C4 plant diet.