Ultralight reactive metal foams produced as structural shapes in space: System design

This autonomous experiment for foaming metals in space involved: (1) payload support structure; (2) furnace and foaming apparatus; (3) electronic controls; (4) battery power; and (5) metallurgy. Emphasis was laid on a modular design which was easily modifiable and which offered maximum durability, safety, and failure tolerance

The role of 'African Chemists' in the health care system of the Eastern Cape province of South Africa

Self-medication is documented as an integral part of health care therapy in developing countries such as Ethiopia, Cameroon, Uganda and Mexico. In South Africa the types of illnesses and health problems that are referred to both traditional healers and biomedical practices have been well documented. However, very little literature exists on self-diagnosis, self-medication or sources of the medicines used for self-medication. This bias in the literature has come about largely because anthropological studies have focused on the later stages of the illness referral system when treatment is sought from a specialist for symptoms which have not responded to forms of self-medication. As a result of this, health care studies have documented the more exceptional exotic healing rituals and culturally bound syndromes of a particular society or community, and not discussed the more ordinary practices of self-medication of everyday illness. Self-medication is however an important initial response to illness and many illnesses are successfully managed at this stage. Amayeza stores (singular-iyeza store) — or ‘African chemists’ — are an important source of medicines for self-diagnosed illnesses. The current discussion focuses on the types of medicines and treatments that are obtained from amayeza stores without professional consultation in the Eastern Cape province of South Africa

Electron scattering and transport in liquid argon

The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann's equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-section with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies.Comment: 32 pages, 16 figures; minor corrections, added 1 figur

The trade in medicinal plants in the Eastern Cape Province, South Africa

A study of the trade in medicinal plants in the Eastern Cape Province of South Africa undertook to document the species traded, to determine the quantities harvested annually, and to assess the economic value of the trade. All the participants involved at the different levels of the trade were included in the survey, that is, informal street hawkers, owners of amayeza esiXhosa stores, traditional healers, and consumers of traditional medicines. In total, 282 questionnaires were administered in six urban centres. It was found that poorly educated black middle-aged women of low economic standing dominate the trade. A minimum of 166 medicinal plant species were traded at the study sites alone, providing 525 tonnes of plant material valued at approximately R27 million annually. Plants were harvested from a diverse range of vegetation types including Valley Thicket, Afromontane Forest, Coastal Forest and Moist Upland Grassland, the most frequently sold species differing significantly from those documented in similar studies in other regions. The Forest Biome was the vegetation type found to be most threatened by over-harvesting. Of the species documented, 93% were being harvested unsustainably and 34 species have been prioritised for conservation management

Traditional veterinary medicine in the Alice district of the Eastern Cape Province, South Africa

Resource-poor farmers in rural and peri-urban areas have limited access to veterinary care in terms of support services (from state and private veterinarian and animal health technicians), information about the prevention and treatment of livestock diseases, and preventative and therapeutic veterinary medicines. This results in reduced productivity and in livestock disease and deaths, which is a great burden on these farmers, who can least afford the loss of their animals. There is a need to encourage disadvantaged farmers to use available resources and methods, at minimal cost, and to improve their productivity. One of these resources is ethnoveterinary medicine. A list of 53 plants used as veterinary medicines by stock farmers in the Alice district in the Eastern Cape is presented together with their preparation and methods of administration

Time-Reversal-Invariant Hofstadter-Hubbard Model with Ultracold Fermions

We consider the time-reversal-invariant Hofstadter-Hubbard model which can be realized in cold atom experiments. In these experiments, an additional staggered potential and an artificial Rashba--type spin-orbit coupling are available. Without interactions, the system exhibits various phases such as topological and normal insulator, metal as well as semi--metal phases with two or even more Dirac cones. Using a combination of real-space dynamical mean-field theory and analytical techniques, we discuss the effect of on-site interactions and determine the corresponding phase diagram. In particular, we investigate the semi--metal to antiferromagnetic insulator transition and the stability of different topological insulator phases in the presence of strong interactions. We compute spectral functions which allow us to study the edge states of the strongly correlated topological phases.Comment: 4+ pages, 4 figures; includes Supplemental Material (5 pages). Published versio

Evolution in Segregating Genotype Mixtures of Subterranean Clover

A complex segregating mixture of subterranean clover (Trifolium subterraneum L.), was sown in 1978 at Nabawa and Mt Barker, two contrasting sites in Western Australia. Seed harvested from both sites from 1980-1994 was grown out at Shenton Park in 1995, along with seed of the original mixture. Populations diverged markedly for mean days to first flowering (DFF) within three seasons. No further trends in mean DFF occurred in plants derived from the next 14 years, although standard deviation declined significantly in plants from Mt Barker. Between season differences in mean DFF were correlated with estimated growing season length at Nabawa and with May- October rainfall at Mt Barker

Further evidence of response by leukaemia patients in remission to antigen(s) related to acute myelogenous leukaemia.

Fifteen patients with acute myelogenous leukaemia were studied to determine if their remission blood leucocytes could be stimulated into taking up [3H] thymidine after in vitro culture with their own cryo-preserved irradiated AML leukaemia cells. In 6/15 patients it was possible to show autologous recognition and equal recognition of their stored leukaemia cells, even when they had previously been maintained in in vitro proliferative cultures in liquid suspension and undergoing myeloid maturation for one week. After in vitro proliferative culture, 4 populations of leukaemia cells produced material in the supernatant media between 3 and 7 days capable of inducing [3H] thymidine uptake in autologous (2 pts, 5 supernatants) and allogeneic (2 pts, 2 supernatants) AML remission lymphocytes, but not in normal donor lymphocytes. The relevance of these observations to tumour-associated AML antigen is discussed

Adaptive significance of within-site variation in morphological and reproductive traits of naturalized wild radish (Raphanus raphanistrum) populations in South-Western Australia

Genotypic variation between and within populations of the outbreeding wild radish (Raphanus raphanistrum L.), was studied using seeds collected from 55 sites across the West Australian wheat belt along 2 transects in December 1999 and February 2000. The seeds were grown at the University of Western Australia field station at Shenton Park, Perth, WA over the 2000 growing season, and 14 morphological and phenological characters were scored. A high degree of variation was present in all traits, and within site variation was greater than between sites. The greatest variation was recorded in the reproductive traits such as time to flowering, seed weight, and pod weight. Variation between sites was associated with geo-clusters based primarily on rainfall and temperature. Populations from sites with a high annual rainfall and low average temperature had longer and wider pods, larger seeds and pods with more segments, compared to populations from sites with a low annual rainfall and a high average temperature. These plants also tended to flower later than those from hotter, drier sites. The results show that wild radish in the wheat-belt of Western Australia has formed genotypically distinct populations in the 150 years since it was introduced, that are adapted to the climate at the site of collection