Catalytic activity of nickel sulfide catalysts supported on Al-pillared montmorillonite for thiophene hydrodesulfurization.

Al-pillared clays, prepared by exchange with partly hydrolyzed aluminium nitrate solutions, dried in air or freeze-dried, and calcined, were used as supports for nickel sulfide catalysts. The catalysts were tested on their hydrodesulfurization (HDS) activity for thiophene. The catalysts show a high thiophene HDS activity. It appears that details in the preparation and calcination of the pillared clays have a strong influence on the catalytic activity

Catalytic activity of nickel sulfide catalysts supported on Al-pillared montmorillonite for thiophene hydrodesulfurization.

Al-pillared clays, prepared by exchange with partly hydrolyzed aluminium nitrate solutions, dried in air or freeze-dried, and calcined, were used as supports for nickel sulfide catalysts. The catalysts were tested on their hydrodesulfurization (HDS) activity for thiophene. The catalysts show a high thiophene HDS activity. It appears that details in the preparation and calcination of the pillared clays have a strong influence on the catalytic activity

Modelling tyre-road contact stresses in pavement design and analysis

Paper presented at the 32nd Annual Southern African Transport Conference 8-11 July 2013 "Transport and Sustainable Infrastructure", CSIR International Convention Centre, Pretoria, South Africa.Growing traffic volumes, increasing construction and maintenance costs continually drive for more innovative approaches and methodologies towards sustainable road infrastructure. At the current price levels of around R6000 per metric tonne, bitumen, as a “raw” product, is by far the most costly element in flexible pavements, for example compared to Crushed stone, which is at approximately R170 per metric tonne. Since the asphalt layer or relatively thin bituminous seal acts as the stress barrier between rolling tyres and the road structure it needs to be durable so as to withstand current traffic loading and hence contact stresses, given the environmental forces also acting on it. For road infrastructure to perform as expected, it is important to optimize road pavement design, especially close to the surface of the pavement requiring accurate modelling of tyre-road contact stresses. The aim of this paper is to demonstrate modern ways to idealise tyre-road interaction based on Stress-In-Motion (SIM) results, in particular the way in which numerical analyses are used (and developed) to address non-uniformly distributed tyre contact stresses on the surface of the pavements. A tyre model is demonstrated whereby the SIM measured contact stress distribution is idealised with a multitude of circular and rectangular shapes, mimicking the non-uniform characteristics of the contact stresses inside the tyre contact patch. An example, in terms of pavement layer life and strain energy of distortion, is given highlighting the effects of different tyre-road models on a typical flexible road structure, compared to the traditional circular shape model of a single uniformly distributed contact stress (1D).This paper was transferred from the original CD ROM created for this conference. The material was published using Adobe Acrobat 10.1.0 Technology. The original CD ROM was produced by Document Transformation Technologies Postal Address: PO Box 560 Irene 0062 South Africa. Tel.: +27 12 667 2074 Fax: +27 12 667 2766 E-mail: nigel@doctech URL: http://www.doctech.co.zamv201

Earliest hominin cancer: 1.7-million-year- old osteosarcoma from Swartkrans Cave, South Africa

The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirmed cases of Middle or Later Pleistocene dates reported. It has generally been assumed that premodern incidence of neoplastic disease of any kind is rare and limited to benign conditions, but new fossil evidence suggests otherwise. We here present the earliest identifiable case of malignant neoplastic disease from an early human ancestor dated to 1.8–1.6 million years old. The diagnosis has been made possible only by advances in 3D imaging methods as diagnostic aids. We present a case report based on re-analysis of a hominin metatarsal specimen (SK 7923) from the cave site of Swartkrans in the Cradle of Humankind, South Africa. The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient specimens. Such tumours are not related to lifestyle and often occur in younger individuals. As such, malignancy has a considerable antiquity in the fossil record, as evidenced by this specimen.NCS201

Taenia solium Cysticercosis, Irian Jaya, Indonesia

Centers for Disease Control and Prevention, Toni, Wandra ; Akira, Ito ; Hiroshi, Yamasaki ; Thomas, Suroso ; Sri S. Margono, Emerging Infectious Diseases, 9(7), 2003, 884-885. publishe

Depth-specific fluctuations of gene expression and protein abundance modulate the photophysiology in the seagrass <i>Posidonia oceanica</i>

Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA expression levels. The results show that the diel oscillations of P. oceanica photophysiological and respiratory responses were related to transcripts and proteins expression of the genes involved in those processes and that there was a response asynchrony between shallow and deep plants probably caused by the strong differences in the light environment. The photochemical pathway of energy use was more effective in shallow plants due to higher light availability, but these plants needed more investment in photoprotection and photorepair, requiring higher translation and protein synthesis than deep plants. The genetic differentiation between deep and shallow stands suggests the existence of locally adapted genotypes to contrasting light environments. The depth-specific diel rhythms of photosynthetic and respiratory processes, from molecular to physiological levels, must be considered in the management and conservation of these key coastal ecosystems