24,697 research outputs found

    Challenges for South African anthropology in the 3rd Millennium

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    Towards the end of one’s career, there’s a powerful inclination to look backwards instead of forwards. You become more interested in histories, biographies and obituaries; you reflect on your own life and career. It’s not inevitable, and it can be resisted. Marshall McLuhan was well into his 50s – an obscure Canadian Eng Lit academic – when he had his vision of the nature and future of the media and anticipated a ‘global village’ that the Internet has turned into a reality since his death in 1980 (McLuhan and Powers 1989) – but more on that in due course. Cui Bono? At first I gave into the tendency to look back. Initially, for this lecture, I thought to analyse my own career in South Africa in terms of who benefited most from it: South African anthropology and my students … or me. I would call the lecture ‘Cui Bono?’ But then I realised, with Latin tags on the way out, younger colleagues and students in the audience might think I was referring to a traditional Australian greeting (Coo-ee) and an Irish philanthropist pop singer (Bono). The title would be totally mystifying to many until I explained that it meant ‘to whom the good’ – in other words, who benefits? But there were other objections to this project besides the title. Even the most postmodern of reflexive anthropologists would balk at making such a self-assessment – it was not for me to judge. Anyway, I already knew the answer: My career in South Africa has not been impeded by political harassments, imprisonment or conscription. I did make some small negligible contributions to the ‘struggle’ through writing or drawing, and I did some community service, on campus or off in the same way. At a critical stage I assisted with the process that eventually produced a national staff association, now called NTESU. The only price I have paid for these distractions from serious publishing at a critical stage of my career was deservedly slow promotion. I continue to contribute to the community mainly through membership of the older of Grahamstown’s two very active Rotary clubs. It’s all I have time for, but nothing to boast about. In sum, I’ve enjoyed what my long-term colleague and Grahamstown’s Citizen of the Year (another Rotary initiative) Michael Whisson likes to call ‘sheltered employment’ – his typically ironic way of reminding us of how privileged we academics are, doing what we enjoy, in pleasant surroundings, among intelligent colleagues and the cream of our youth, with plenty of flexi-time and opportunities for subsidized travel. And now I have benefited again by being promoted to full professor without sufficiently earning my keep through subsidies on academic outputs. Whatever I might have given back through teaching and administration the net is in my favour, and I am grateful beyond words

    Research Notes : United States : A possible interaction between cyt-Y3 and y20-k2

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    Interactions of organelle genomes are a well-documented fact. Interac-tion can take the form of metabolite and energy exchange, co-production of enzyme subunits, and co-production of membrane structural and organizational components (Wallace, 1982). Nucleo-cytoplasmic interaction also has been documented for various traits affecting vegetative and harvest indices (Rob-ertson and Frey, 1984), cytoplasmic male sterility (Levings, 1983), and other agronomic characters (Harvey et al., 1972; Kihara, 1982)

    Research Notes : United States : Summary of locus-to-locus linkage data in soybean

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    Summary of locus-to-locus linkage data in soybea

    A knowledge-based approach to configuration layout, justification, and documentation

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    The design, development, and implementation is described of a prototype expert system which could aid designers and system engineers in the placement of racks aboard modules on Space Station Freedom. This type of problem is relevant to any program with multiple constraints and requirements demanding solutions which minimize usage of limited resources. This process is generally performed by a single, highly experienced engineer who integrates all the diverse mission requirements and limitations, and develops an overall technical solution which meets program and system requirements with minimal cost, weight, volume, power, etc. This system architect performs an intellectual integration process in which the underlying design rationale is often not fully documented. This is a situation which lends itself to an expert system solution for enhanced consistency, thoroughness, documentation, and change assessment capabilities

    GRBs and the thermalization process of electron-positron plasmas

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    We discuss the temporal evolution of the pair plasma created in Gamma-Ray Burst sources. A particular attention is paid to the relaxation of the plasma into thermal equilibrium. We also discuss the connection between the dynamics of expansion and the spatial geometry of the plasma. The role of the baryonic loading parameter is emphasized.Comment: 4 pages, 3 figures, in the Proceedings of the "Gamma Ray Bursts 2007" meeting, November 5-9, 2007, Santa Fe, New Mexico, US

    A Knowledge-Based Approach to Configuration Layout, Justification, and Documentation

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    The design, development, and implementation of a prototype expert system which could aid designers and system engineers in the placement of racks aboard modules on the Space Station Freedom are described. This type of problem is relevant to any program with multiple constraints and requirements demanding solutions which minimize usage of limited resources. This process is generally performed by a single, highly experienced engineer who integrates all the diverse mission requirements and limitations, and develops an overall technical solution which meets program and system requirements with minimal cost, weight, volume, power, etc. This system architect performs an intellectual integration process in which the underlying design rationale is often not fully documented. This is a situation which lends itself to an expert system solution for enhanced consistency, thoroughness, documentation, and change assessment capabilities

    Sediment Management for Southern California Mountians, Coastal Plains and Shoreline. Part D: Special Inland Studies

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    In southern California the natural environmental system involves the continual relocation of sedimentary materials. Particles are eroded from inland areas where there is sufficient relief and, precipitation. Then, with reductions in hydraulic gradient along the stream course and at the shoreline, the velocity of surface runoff is reduced and there is deposition. Generally, coarse sand, gravel and larger particles are deposited near the base of the eroding surfaces (mountains and hills) and the finer sediments are deposited on floodplains, in bays or lagoons, and at the shoreline as delta deposits. Very fine silt and clay particles, which make up a significant part of the eroded material, are carried offshore where they eventually deposit in deeper areas. Sand deposited at the shoreline is gradually moved along the coast by waves and currents, and provides nourishment for local beaches. However, eventually much of this littoral material is also lost to offshore areas. Human developments in the coastal region have substantially altered the natural sedimentary processes, through changes in land use, the harvesting of natural resources (logging, grazing, and sand and gravel mining); the construction and operation of water conservation facilities and flood control structures; and coastal developments. In almost all cases these developments have grown out of recognized needs and have well served their primary purpose. At the time possible deleterious effects on the local or regional sediment balance were generally unforeseen or were felt to be of secondary importance. In 1975 a large-scale study of inland and coastal sedimentation processes in southern California was initiated by the Environmental Quality Laboratory at the California Institute of Technology and the Center for Coastal Studies at Scripps Institution of Oceanography. This volume is one of a series of reports from this study. Using existing data bases, this series attempts to define quantitatively inland and coastal sedimentation processes and identify the effects man has had on these processes. To resolve some issues related to long-term sediment management, additional research and data will be needed. In the series there are four Caltech reports that provide supporting studies for the summary report (EQL Report No. 17). These reports include: EQL Report 17-A Regional Geological History EQL Report 17-B Inland Sediment Movements by Natural Processes EQL Report 17-C Coastal Sediment Delivery by Major Rivers in Southern California EQL Report 17-D -- Special Inland Studies Additional supporting reports on coastal studies (shoreline sedimentation processes, control structures, dredging, etc.) are being published by the Center for Coastal Studies at Scripps Institution of Oceanography, La Jolla, California

    Differences in Carbon Sequestration and Water Use Between a Semi-Arid Native Grassland and Encroaching \u3ci\u3eVachellia karroo\u3c/i\u3e Woodland

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    Tree and shrub encroachment and proliferation in global grasslands and savannas is widely considered to imply a trade-off between ecosystem C and H2O regulating functions, based on the premise that increased C sequestration associated with higher woody biomass ostensibly drive declines in water production through concomitant increases in evapotranspiration (ET), but evidence for this across climatic and environmental gradients is equivocal. To evaluate these claims, we ran a paired eddy covariance experiment in a native semi-arid C4 grassland and adjacent encroaching Vachellia karroo woodland on the eastern seaboard of South Africa and compared ecosystem C and H2O budgets over nearly a full year. Near complete failure of spring/early summer rains resulted in reduced ecosystem physiological activity and C uptake in the early growing season in 2019, but systems recovered following above average rainfall over mid-summer/early autumn in 2020, with both the grassland and woodland achieving net negative C balances. The woodland was more productive than the grassland over the majority of the year, but these marginal C gains were offset by consistently higher respiration effluxes, resulting in the grassland sequestering significantly more C (197. 6 g C m-1) than the woodland (114.5 g C m-1). Differences in water use between the two systems were insignificant, and is likely explained by shallow soils and the absence of subsurface water at the site, which largely negated the competitive advantage in terms of access to water conferred by deeper rooting systems of V. karroo. Ecosystem water use efficiencies (WUEE) were essentially identical across the year, but the grassland was more efficient at the peak of the growing season. Our data suggest that encroachment by V. karroo in semi-arid grasslands may result in significant declines in C sequestration despite higher rates of productivity, but is unlikely to lead to substantial increases in water use where trees do not have access to water in deeper soil horizons on the other. These results support growing arguments to preserve semi-arid grassland ecosystems even when C sequestration is the primary objective of land management interventions

    In-flight absolute radiometric calibration of the thematic mapper

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    The TM multispectral scanner system was calibrated in an absolute manner before launch. To determine the temporal changes of the absolute radiometric calibration of the entire system, spectroradiometric measurements of the ground and the atmosphere were made simultaneously with TM collections over White Sands, New Mexico. By entering the measured values in an atmospheric radiative transfer program, the radiance levels of the in four of the spectral bands of the TM were determined. Tables show values for the reflectance of snow at White Sands measured by a modular 8 channel radiometer, and values for exoatmospheric irradiance within the TM passbands, calculated for the Earth-Sun distance using a solar radiometer
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