226 research outputs found

    Solid-phase phosphorus speciation in Saharan Bodélé depression dusts and source sediments

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    Phosphorus (P) is one of the most important limiting nutrients for the growth of oceanic phytoplankton and terrestrial ecosystems, which in turn contributes to CO2 sequestration. The solid-phase speciation of P will influence its solubility and hence its availability to such ecosystems. This study reports on the results of X-ray diffraction, electron microprobe chemical analysis and X-ray mapping, chemical extractions and X-ray absorption near-edge spectroscopy analysis carried out to determine the solid-phase speciation of P in dusts and their source sediments from the Saharan BodĂ©lĂ© Depression, the world’s largest single source of dust. Chemical extraction data suggest that the BodĂ©lĂ© dusts contain 28 to 60% (mean 49%) P sorbed to, or co-precipitated with Fe (hydr)oxides, < 10% organic P, 21-50% (mean 32%) detrital apatite P, and 10-22% (mean 15%) authigenic-biogenic apatite P. This is confirmed by the other analyses, which also suggest that the authigenic-biogenic apatite P is likely fish bone and scale, and that this might form a larger proportion of the apatite pool (33 +/− 22%) than given by the extraction data. This is the first-ever report of fish material in aeolian dust, and it is significant because P derived from fish bone and scale is relatively soluble and is often used as a soil fertilizer. Therefore, the fish-P will likely be the most readily form of BodĂ©lĂ© P consumed during soil weathering and atmospheric processing, but given time and acid dissolution, the detrital apatite, Fe-P and organic-P will also be made available. The BodĂ©lĂ© dust input of P to global ecosystems will only have a limited life, however, because its major source materials, diatomite in the BodĂ©lĂ© Depression, undergo persistent deflation and have a finite thickness

    Star image, celebrity reality television and the fame cycle

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    In this article, I discuss the phenomenon of celebrity reality television and explore its function for those participating in it. Drawing on the success of their non-celebrity counterparts, programmes such as Celebrity Big Brother, I’m a Celebrity
 Get Me Out of Here and Dancing With the Stars have become popular globally and, although arguably no longer at their peak, continue to attract large audiences and significant amounts of publicity. In the article I discuss the role these shows can serve for celebrities at different levels of their careers. I argue that reality television appeals in different ways to celebrities at different points in the fame ‘cycle’: ‘ordinary’ people or ‘pre-celebrities’ seeking to become known through it; proto-celebrities who wish to expand their fame; celebrities engaged in the work of promotion for their other endeavours; celebrities who wish to remake their existing star image through using reality television as a rehabilitative strategy or an opportunity to develop new skills; and those whose careers are in a period of ‘post-celebrity’ who seek to renew their fame. I explore how a successful reality show cast is one that combines celebrities who are at a range of points in the fame cycle as the interactions between the cast members and their debates about fame and hierarchy prove a key attraction for audiences

    Tropospheric Carbon Monoxide Measurements from the Scanning High-Resolution Interferometer Sounder on 7 September 2000 in Southern Africa During SAFARI 2000

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    [1] Retrieved tropospheric carbon monoxide (CO) column densities are presented for more than 9000 spectra obtained by the University of Wisconsin-Madison (UWis) Scanning High-Resolution Interferometer Sounder (SHIS) during a flight on the NASA ER-2 on 7 September 2000 as part of the Southern African Regional Science Initiative (SAFARI 2000) dry season field campaign. Enhancements in tropospheric column CO were detected in the vicinity of a controlled biomass burn in the Timbavati Game Reserve in northeastern South Africa and over the edge of the river of smoke in south central Mozambique. Relatively clean air was observed over the far southern coast of Mozambique. Quantitative comparisons are presented with in situ measurements from five different instruments flying on two other aircraft: the University of Washington Convair-580 (CV) and the South African Aerocommander JRB in the vicinity of the Timbavati fire. Measured tropospheric CO columns (extrapolated from 337 to 100 mb) of 2.1 × 1018 cm−2 in background air and up to 1.5 × 1019 cm−2 in the smoke plume agree well with SHIS retrieved tropospheric CO columns of (2.3 ± 0.25) × 1018 cm−2 over background air near the fire and (1.5 ± 0.35) × 1019 cm−2 over the smoke plume. Qualitative comparisons are presented with three other in situ CO profiles obtained by the South African JRA aircraft over Mozambique and northern South Africa showing the influence of the river of smoke

    The Southern African Regional Science Initiative (SAFARI 2000): Overview of the Dry Season Field Campaign

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    The Southern African Regional Science Initiative (SAFARI 2000) is an international science project investigating the earth-atmosphere-human system in southern Africa. The programme was conducted over a two-year period from March 1999 to March 2001. The dry season field campaign (August-September 2000) was the most intensive activity and involved over 200 scientists from eighteen countries. The main objectives were to characterize and quantify biogenic, pyrogenic and anthropogenic aerosol and trace gas emissions and their transport and transformations in the atmosphere, and to validate NASA\u27s Earth Observing System\u27s satellite Terra within a scientific context. Five aircraft - two South African Weather Service Aerocommanders, the University of Washington\u27s CV-580, the U.K. Meteorological Office\u27s C-130, and NASA\u27s ER-2-with different altitude capabilities, participated in the campaign. Additional airborne sampling of southern African air masses, that had moved downwind of the subcontinent, was conducted by the CSIRO over Australia. Multiple observations were made in various geographical sectors under different synoptic conditions. Airborne missions were designed to optimize the value of synchronous over-flights of the Terra satellite platform, above regional ground validation and science targets. Numerous smaller-scale ground validation activities took place throughout the subcontinent during the campaign period

    Dual-source computed tomography in patients with acute chest pain: feasibility and image quality

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    The aim of this study was to determine the feasibility and image quality of dual-source computed tomography angiography (DSCTA) in patients with acute chest pain for the assessment of the lung, thoracic aorta, and for pulmonary and coronary arteries. Sixty consecutive patients (32 female, 28 male, mean age 58.1±16.3 years) with acute chest pain underwent contrast-enhanced electrocardiography-gated DSCTA without prior beta-blocker administration. Vessel attenuation of different thoracic vascular territories was measured, and image quality was semi-quantitatively analyzed by two independent readers. Image quality of the thoracic aorta was diagnostic in all 60 patients, image quality of pulmonary arteries was diagnostic in 59, and image quality of coronary arteries was diagnostic in 58 patients. Pairwise intraindividual comparisons of attenuation values were small and ranged between 1±6 HU comparing right and left coronary artery and 56±9 HU comparing the pulmonary trunk and left ventricle. Mean attenuation was 291±65 HU in the ascending aorta, 334±93 HU in the pulmonary trunk, and 285±66 HU and 268±67 HU in the right and left coronary artery, respectively. DSCTA is feasible and provides diagnostic image quality of the thoracic aorta, pulmonary and coronary arteries in patients with acute chest pain

    Scenario-Based Design Theorizing:The Case of a Digital Idea Screening Cockpit

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    As ever more companies encourage employees to innovate, a surplus of ideas has become reality in many organizations – often exceeding the available resources to execute them. Building on insights from a literature review and a 3-year collaboration with a banking software provider, the paper suggests a Digital Idea Screening Cockpit (DISC) to address this challenge. Following a design science research approach, it suggests a prescriptive design theory that provides practitioner-oriented guidance for implementing a DISC. The study shows that, in order to facilitate the assessment, selection, and tracking of ideas for different stakeholders, such a system needs to play a dual role: It needs to structure decision criteria and at the same be flexible to allow for creative expression. Moreover, the paper makes a case for scenario-based design theorizing by developing design knowledge via scenarios

    Assessing the use of an essential health package in a sector wide approach in Malawi

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    <p>Abstract</p> <p>Background</p> <p>The sector wide approach (SWAp) used in many developing countries is difficult to assess. One way is to consider the essential health package (EHP) which is commonly the vehicle for a SWAp's policies and plans. It is not possible to measure the impact of an EHP by measuring health outcomes in countries such as Malawi. But it is possible to assess the choice of interventions and their delivery in terms of coverage. This paper describes an attempt to assess the Malawi SWAp through its EHP using these available measures of technical efficiency.</p> <p>Methods</p> <p>A burden of disease model was used to identify the priority diseases and their estimated incidence. Data from the health management information system (HMIS) were used to measure the coverage of these interventions. A review of the cost-effectiveness of the chosen and potential interventions was undertaken to assess the appropriateness of each intervention used in the EHP. Expenditure data were used to assess the level of funding of the EHP.</p> <p>Results</p> <p>33 of the 55 EHP interventions were found to be potentially cost-effective (<150/DALY),12werenotsocost−effective(>150/DALY), 12 were not so cost-effective (>150/DALY) and cost-effective estimates were not available for ten. 15 potential interventions, which were cost-effective and tackling one of the top 20 ranked diseases, were identified.</p> <p>Provision had increased in nearly all EHP services over the period of the SWAp. The rates of out patient attendances and inpatient days per 1000 population had both increased from 929 attendances in 2002/3 to 1135 in 2007/08 and from 124 inpatient days in 2002/03 to 179 in 2007/08.</p> <p>However, by 2007/08 the mean gap between what was required and what was provided was 0.68 of the estimated need. Two services involving the treatment of malaria were overprovided, but the majority were underprovided, with some such as maternity care providing less than half of what was required.</p> <p>The EHP was under-funded throughout the period covering on average 57% of necessary costs. By 2007/08 the funding paid by SWAp partners including the government of Malawi to fund the EHP was at US$13.5 per capita per annum, which was almost half of the revised EHP estimated required expenditure per capita per annum.</p> <p>Discussion</p> <p>The SWAp had invested in some very cost-effective health interventions. In terms of numbers of patients treated, the EHP had delivered two thirds of the services required. This was despite serious under-funding of the EHP, an increase in the population and shortage of staff.</p> <p>Conclusions</p> <p>The identification of interventions of proven effectiveness and good value for money and earmarked funding through a SWAp process can produce measurable improvement in health service delivery at extremely low cost.</p
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