Archean foreland basin tectonics in the Witwatersrand, South Africa

The Witwatersrand Basin of South Africa is the best-known of Archean sedimentary basins and contains some of the largest gold reserves in the world. Sediments in the basin include a lower flysch-type sequence and an upper molassic facies, both of which contain abundant silicic volcanic detritus. The strata are thicker and more proximal on the northwestern side of the basin which is, at least locally, bound by thrust faults. These features indicate that the Witwatersrand strata may have been deposited in a foreland basin and a regional geologic synthesis suggests that this basin developed initially on the cratonward side of an Andean-type arc. Remarkably similar Phanerozoic basins may be found in the southern Andes above zones of shallow subduction. It is suggested that the continental collision between the Kaapvaal and Zimbabwe Cratons at about 2.7 Ga caused further subsidence and deposition in the Witwatersrand Basin. Regional uplift during this later phase of development placed the basin on the cratonward edge of a collision-related plateau, now represented by the Limpopo Province. Similarities are seen between this phase of Witwatersrand Basin evolution and that of active basins north of the Tibetan Plateau. The geologic evidence does not agree with earlier suggestions that the Witwatersrand strata were deposited in a rift or half-graben

Late Archean greenstone tectonics: Evidence for thermal and thrust-loading lithospheric subsidence from stratigraphic sections in the Slave Province, Canada

How late Archean tectonics could be seen to have operated in the Slave Province is illustrated. Lithospheric thinning and stretching, with the formation of rifted margins (to continental or island arc fragments), and lithospheric flexural loading of the kind familiar in arcs and mountain belts could be discerned

Quantum chaos in a Bose-Hubbard dimer with modulated tunnelling

In the large-$N$, classical limit, the Bose-Hubbard dimer undergoes a transition to chaos when its tunnelling rate is modulated in time. We use exact and approximate numerical simulations to determine the features of the dynamically evolving state that are correlated with the presence of chaos in the classical limit. We propose the statistical distance between initially similar number distributions as a reliable measure to distinguish regular from chaotic behaviour in the quantum dynamics. Besides being experimentally accessible, number distributions can be efficiently reconstructed numerically from binned phase-space trajectories in a truncated Wigner approximation. Although the evolving Wigner function becomes very irregular in the chaotic regions, the truncated Wigner method is nevertheless able to capture accurately the beyond mean-field dynamics.Comment: 10 pages, 10 figure

Banda Aceh-The Value of Earth Observation Data in Disaster Recovery and Reconstruction: A Case Study

On 26 December 2004, Banda Aceh in Indonesia was at the center of one of the worst natural disasters to affect mankind. Large amounts of international aid poured in to assist in the relief and reconstruction efforts. Amongst this effort, were investments in basic earth observation data from in-situ, airborne and space observations. While the use of this data is assumed to be crucial, few efforts have gone into quantifying the benefits of its acquisition. The objectives of this study were to interview a cross-section of agencies operating in Banda Aceh and across the province of Nanggroe Aceh Darussalam on the use, sources and quality of earth observation data in the relief/reconstruction effort; and to analyze and quantify the value that earth observation data brings to the relief/reconstruction effort based on the survey results and specific examples. Key findings from the interviews point to an overall improvement in the spatial data situation since the tsunami. Problems identified included insufficient training, lack of timely data and sometimes poor spatial resolution. Specific examples of the cost-benefits of earth observation data were typically on the order of millions of dollars and involved large time savings. IIASA is one of 12 partners in the European Union sponsored project "Global Earth Observation/Benefit Estimation: Now, Next and Emerging" (GEO-BENE). Additional GEO-BENE partner countries include Germany, Switzerland, Slovakia, Netherlands, Finland, South Africa and Japan. Within GEO-BENE we are developing methodologies and analytical tools to assess societal benefits of GEO in nine societal benefit areas- one of which is disasters. The tsunami affected province of Nanggroe Aceh Darussalam, and specifically Banda Aceh, has been selected as a case study. Other case studies representing different societal benefit areas include: biodiversity in South Africa, health and climate in Finland, fire in Europe, etc. For more information please refer to: www.geo-bene.eu

GEO Information For Disaster Recovery -- Case Study: The Use of Orthophotos in Aceh, Indonesia

This study, carried out between July-September 2008, looks specifically at the use of a high resolution aerial photograph (orthophoto) data set acquired in June 2005 over post tsunami Aceh, Indonesia. The study clearly demonstrates the benefit of the use of EO data for disaster recovery showing that the orthophoto data set, costing 1.4 million Euro, critically supported projects (primary users of the data set), worth over 16 times its actual cost (28 million Euro) and provided support to projects worth over 600 times its actual cost (880 million Euro). The study concludes that a simple robust methodology to quantify the benefit of EO data in disaster recovery may be implemented by monitoring the total costs of projects that are critically supported by the EO data set. To implement that monitoring mechanism, a robust and straightforward method must be in place with the EO data distributor that records simple criteria for each of the data users and related projects. The report provides a number of lessons that have been learnt from the spatial data initiatives between Official Development Agencies and the Government of Indonesia in response to the Tsunami. The report recommends that in order to ensure that the spatial data is used to its greatest benefit, prior to the initiation of any campaign, the donor funding the project must ensure that there is a defined and clearly proven, transparent, and accountable mechanism to ensure that the data is effectively delivered to the humanitarian aid community in a timely and efficient manner

Psychopatholgy, fundamental assumptions and CD-4 T lymphocyte counts in HIV-positive patients

Objective:  Key words: Fundamental Assumptions; HIV; PsychopathologyWe investigated whether psychopathology in HIV-positive patients was associated with more negative fundamental assumptions than in healthy controls. In addition, we explored whether psychopathology and negative fundamental assumptions in HIV-positive patients were associated with lower CD4 T-lymphocyte counts. Method: Self-rating questionnaires to assess depressive symptoms, posttraumatic stress symptoms, alcohol abuse, general psychopathology and fundamental assumptions, were completed by 123 HIV-positive patients and 84 uninfected clinic attendees at three primary health care clinics in the Western Cape, South Africa. CD4 T-lymphocyte counts were obtained from chart records. Results: HIV-positive patients reported more depressive and posttraumatic symptoms than uninfected individuals. However when controlling for socio-economic status, the number of traumatic events experienced and other potential confounds, no differences remained. Fundamental assumptions (FA) were mainly positive in both HIV-positive patients and controls and no correlations were found between fundamental assumptions, psychiatric symptoms and CD4 levels. However, in infected patients FA and psychopathology were negatively associated with all participants scoring in the positive range of the FA scale. Conclusion: The positive scores on the FA scale indicate that positive assumptions are related to less psychopathology. Longitudinal studies investigating the association between the valence of fundamental assumptions and HIV morbidity are needed

Collaboration in electronic resource provision in university libraries: SHEDL, a Scottish case study

This case study examines the growth of collaboration among Scottish higher education institutions. Following a summary of the work of the Scottish Confederation of University and Research Libraries (SCURL), more detailed information is provided on collaboration in the fields of acquisition, licensing, selection, and purchasing. Some of the UK background is outlined, relating to NESLi2 in particular, in order to illuminate the options within Scotland. The origins of negotiations on electronic resource provision within Scotland are described, drawing on developments in other countries including Ireland and Scandinavia. After initial setbacks, the implementation of the Scottish Higher Education Digital Library (SHEDL) from 2007 to 2009 is detailed. Current benefits arising from SHEDL are explained, and some possible future developments are discussed