Ghana airborne geophysics project in the Volta and Keta Basin : BGS final report

This report describes the work undertaken by BGS between November 2006 and March 2009 in collaboration with Fugro Airborne Surveys Pty Ltd on an airborne geophysical survey and ground reconnaissance mapping of the Volta River and Keta Basins, Ghana. The project was supported by the EU as part of the Mining Sector Support Programme, Project Number 8ACP GH 027/13. The initial contract duration was three years, but this was extended by five months to account for acquisition of gravity data by another project. Some parts of Ghana have been airborne surveyed as part of the Mining Sector Development and Environmental Project, co-funded by the World Bank and the Nordic Development Fund, but no work was carried out on the Volta River and Keta basins, which together form a major portion of the Ghanaian territory. The approximate areas covered by the surveys are estimated at 98,000 km² for the satellite imagery and the airborne geophysics, except for the Time Domain Electromagnetic (TDEM) survey which was limited to 60,000 km². The main beneficiary of this project is the Geological Survey Department, GSD. The work enhanced its geological infrastructure and its personnel received hands-on training on modern geological mapping technology. Indirect beneficiaries were the mining and exploration companies that can follow up the reconnaissance work with detailed exploration work. The project was conducted in five phases, and this document reports on the BGS input to Phase 1, 4 and 5, with no inputs required in Phases 2 and 3: • Phase1: geological outline through Radar and optical satellite imageries. • Phase 2: airborne geophysical survey over the two basins for magnetics and Gamma Ray spectrometry (Fugro survey). • Phase 3: airborne electromagnetic and magnetic geophysical survey of specific areas, following the completion and interpretation of phase 2, using fixed wing time domain technology (Fugro survey). • Phase 4: interpretation of the combined geology and geophysics. • Phase 5: production of factual and interpretation maps. The full list of BGS products is outlined in Table 1 below, while Jordan et al. (2006) describe the products delivered on schedule in Phase 1

Diffraction Analysis of 2-D Pupil Mapping for High-Contrast Imaging

Pupil-mapping is a technique whereby a uniformly-illuminated input pupil, such as from starlight, can be mapped into a non-uniformly illuminated exit pupil, such that the image formed from this pupil will have suppressed sidelobes, many orders of magnitude weaker than classical Airy ring intensities. Pupil mapping is therefore a candidate technique for coronagraphic imaging of extrasolar planets around nearby stars. Unlike most other high-contrast imaging techniques, pupil mapping is lossless and preserves the full angular resolution of the collecting telescope. So, it could possibly give the highest signal-to-noise ratio of any proposed single-telescope system for detecting extrasolar planets. Prior analyses based on pupil-to-pupil ray-tracing indicate that a planet fainter than 10^{-10} times its parent star, and as close as about 2 lambda/D, should be detectable. In this paper, we describe the results of careful diffraction analysis of pupil mapping systems. These results reveal a serious unresolved issue. Namely, high-contrast pupil mappings distribute light from very near the edge of the first pupil to a broad area of the second pupil and this dramatically amplifies diffraction-based edge effects resulting in a limiting attainable contrast of about 10^{-5}. We hope that by identifying this problem others will provide a solution.Comment: 23 pages, 13 figures, also posted to http://www.orfe.princeton.edu/~rvdb/tex/piaaFresnel/ms.pd

A Multi-Scalar Socio-Policy Analysis of Resource Reallocation and Water Security in Twenty-First Century Utah, USA

As drought and a warming climate continue to impact the western United States, balancing the water needs of cities, agriculture, and natural systems is becoming increasingly more complex. One approach commonly promoted to address water supply issues is the transfer of water between users via markets. However, markets for water face multiple obstacles that can often be costly for participants due to constraints inherent in western U.S. water law. Coinciding with issues of cost, water markets must overcome disinterest among water rights holders in releasing their water rights for uses even if temporarily. Moreover, water transfers bring to light the potential impacts to security in access to water for other needs when water is moved between locations and uses. This research examined key challenges to the establishment and use of market-based transfer arrangements known as water banks. Existing water banks in other states were first analyzed to assess how they have added flexibility to existing water law in order to address specific or broad impacts of water scarcity. Northern Utah’s Bear River Basin then served as a case setting to examine the complexities of establishing water banks through the perspectives of individual water users and others involved in water management. Data were collected through interviews, focus groups, observations of legislative workgroups, and analysis of existing literature. This research found that the benefits of transfers through water banks are potentially dependent on the scale of interest that the transaction is assessed at and how the consumption of water is managed. Moreover, this work found that the prevailing behaviors and attitudes regarding water transfers are in part rooted in how existing water laws and organizations have controlled allocation and use of the resource. Understanding these social factors is critical to the policy designs of market-based approaches to sharing water that rely on participation of water rights holders to contribute towards rebalancing water supplies and meeting policy objectives at all scales of interest

Opportunities in the United States for Training in Biotechnology for Parasitic Disease Investigations

In the United States there are academic, governmental and industrial training opportunities in biotechnology that are applicable to the study of parasitic disease. Academic opportunities are the most plentiful. At least 130 universities in the Unites States have training programs in which current biotechnologies are being used to investigate parasites of economic or public health importance. Further, there are at least 70 centers of biotechnology in the United States. In these centers, many of which are located on university campuses, new biological techniques are being applied to both basic and applied research projects. The Unites States government administers more than 20 research programs that utilize current biotechnology to conduct parasitic disease research programs. These programs are conducted in or supported with resources of the following agencies: the Departments of Agriculture, Health and Human Services, Defense, and Interior, the Agency for International Development, the National Science Foun­dation, the National Academy of Sciences, and the Environmental Protection Agency. Commercial firms using biotechnological methods for production of biologicals and other reagents, provide an opportunity for on-the-job training and experience in the application of these new technologies to parasites diseases of major economic or public health importance

Current Technological Approaches to the Study of Trematodes

Advances in biology sciences over the past decade have provided additional technology for dealing with trematode parasitoses. Although trematode diseases of man and animals in Indonesia are essentially the same as they were ten years ago, scientific methods available to deal with them have improved significantly. One can now exploit the innate ability of cells to replicate and produce biological products upon demand, manipulate the genetic make up of an organism, biologically or synthetically manufacture peptides and rationally develop drugs that target idiosyncrasies of parasites at the cellular and molecular levels. Further, one can now manage and analyze massive amounts of biological data using desk top computers. These new biological techniques and the computing ability to interpret the data generated provide parasitologists in Indonesia and elsewhere with the ability to document the economic and public health impact of trematode parasitoses and to develop new strategies and reagents for diagnosing, treating, preventing and controlling the diseases they cause. In addition, biotechnology offers university scientists and their students with additional opportunities to investigate basic and esoteric aspects of host-parasite interrelationship that are such an intriguing aspect of biology