Browsing by Author "Vaughan, Christopher L"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Open Access
    A commentary on the intellectual health of the nation
    (2007) Vaughan, Christopher L; Reddy, B Dayanand; Noakes, Timothy D; Moran, V C
    The record of high-quality research at South African universities is not as impressive as we may have thought, according to some international rankings. Whatever we might think of these assessments, we have to take them seriously. We suggest ways in which our universities and other institutions of higher learning might raise the level of their game.
  • Thumbnail Image
    Item
    Open Access
    Alternatives to the publication subsidy for research funding
    (2008) Vaughan, Christopher L
    Government policy on research funding has a direct impact on the behaviour of academics, so we need to ask what sort of behaviour should be encouraged in South Africa. Instead of an emphasis on the number of publications, our focus should rather be on a subsidy system that inspires our institutions to aim for a level of scholarship that is able to withstand the scrutiny of an international audience. Perhaps now is the time to grasp the nettle and to consider using the National Research Foundation's rating system instead of the publication count.
  • Thumbnail Image
    Item
    Open Access
    Digital X-rays come of age
    (2006) Vaughan, Christopher L
    In early November 1895 Willem Röntgen performed an experiment in which invisible cathode rays, generated by electrostatic discharges from within an evacuated glass tube, caused a cardboard screen painted with barium platinocyanide to fluoresce. Although the new rays would also come to bear his name, Röntgen called them X-rays, apparently using the mathematical designation for something unknown.1 While investigating the ability of various materials to stop the Xrays, he stepped into the line of the rays to introduce a piece of lead and was startled to see an image of his own skeleton shimmering on the fluorescent screen. His groundbreaking article2 was published less than 2 months later on 28 December 1895.
  • Thumbnail Image
    Item
    Open Access
    Re-interpreting the evidence for bipedality in Homo floresiensis
    (2007) Blaszczyk, Maria B; Vaughan, Christopher L
    The unveiling in October 2004 of the remains of a pygmy-sized hominin recovered from a cave on the island of Flores, Indonesia, sparked an intense series of debates within the palaeoanthropology community. The discoverers diagnosed it to be a new species of Homo, which they called Homo floresiensis, and they interpreted the postcranial morphology as being 'consistent with human-like obligate bipedalism'. We have examined the morphology with the aim of determining whether biomechanical evidence supports the claim that this hominin - known as LB1 - was indeed habitually bipedal. LB1's innominate bone differs from that of modern humans through the marked lateral flaring of the ilium, while her femur has a small head and a relatively long neck. Although these features are also found in australopithecines and are commonly regarded as 'primitive' traits, we concluded that none would have prevented her from exhibiting an efficient, bipedal gait. Having established that LB1 walked on two legs, we employed the principle of dynamic similarity to speculate how she might have walked. Assuming the gait of LB1 was dynamically similar to that of modern Homo sapiens, we used known dimensionless parameters, together with her leg length (0.55 m), to estimate her fundamental gait parameters : step length = 0.45 m, step frequency = 2.48 steps / second and speed = 1.11 m/s. Our review has provided insights regarding the way in which LB1 and her fellow diminutive hominins walked about the island of Flores over 18 000 years ago.