112 research outputs found
Assessing the Potential Impacts to Riparian Ecosystems Resulting from Hemlock Mortality in Great Smoky Mountains National Park
Hemlock Woolly Adelgid (Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should, therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality
Bioprospecting the African Renaissance: The new value of muthi in South Africa
This article gives an overview of anthropological research on bioprospecting in general and of available literature related to bioprospecting particularly in South Africa. It points out how new insights on value regimes concerning plant-based medicines may be gained through further research and is meant to contribute to a critical discussion about the ethics of Access and Benefit Sharing (ABS). In South Africa, traditional healers, plant gatherers, petty traders, researchers and private investors are assembled around the issues of standardization and commercialization of knowledge about plants. This coincides with a nation-building project which promotes the revitalization of local knowledge within the so called African Renaissance. A social science analysis of the transformation of so called Traditional Medicine (TM) may shed light onto this renaissance by tracing social arenas in which different regimes of value are brought into conflict. When medicinal plants turn into assets in a national and global economy, they seem to be manipulated and transformed in relation to their capacity to promote health, their market value, and their potential to construct new ethics of development. In this context, the translation of socially and culturally situated local knowledge about muthi into global pharmaceuticals creates new forms of agency as well as new power differentials between the different actors involved
EVOTECH® endoscope cleaner and reprocessor (ECR) simulated-use and clinical-use evaluation of cleaning efficacy
<p>Abstract</p> <p>Background</p> <p>The objective of this study was to perform simulated-use testing as well as a clinical study to assess the efficacy of the EVOTECH<sup>® </sup>Endoscope Cleaner and Reprocessor (ECR) cleaning for flexible colonoscopes, duodenoscopes, gastroscopes and bronchoscopes. The main aim was to determine if the cleaning achieved using the ECR was at least equivalent to that achieved using optimal manual cleaning.</p> <p>Methods</p> <p>Simulated-use testing consisted of inoculating all scope channels and two surface sites with Artificial Test Soil (ATS) containing 10<sup>8 </sup>cfu/mL of <it>Enterococcus faecalis, Pseudomonas aeruginosa </it>and <it>Candida albicans</it>. Duodenoscopes, colonoscopes, and bronchoscopes (all Olympus endoscopes) were included in the simulated use testing. Each endoscope type was tested in triplicate and all channels and two surface sites were sampled for each scope. The clinical study evaluated patient-used duodenoscopes, bronchoscopes, colonoscopes, and gastroscopes (scopes used for emergency procedures were excluded) that had only a bedside flush prior to being processed in the ECR (i.e. no manual cleaning). There were 10 to 15 endoscopes evaluated post-cleaning and to ensure the entire ECR cycle was effective, 5 endoscopes were evaluated post-cleaning and post-high level disinfection. All channels and two external surface locations were sampled to evaluate the residual organic and microbial load. Effective cleaning of endoscope surfaces and channels was deemed to have been achieved if there was < 6.4 μg/cm<sup>2 </sup>of residual protein, < 1.8 μg/cm<sup>2 </sup>of residual hemoglobin and < 4 Log<sub>10 </sub>viable bacteria/cm<sup>2</sup>. Published data indicate that routine manual cleaning can achieve these endpoints so the ECR cleaning efficacy must meet or exceed these to establish that the ECR cleaning cycle could replace manual cleaning</p> <p>Results</p> <p>In the clinical study 75 patient-used scopes were evaluated post cleaning and 98.8% of surfaces and 99.7% of lumens met or surpassed the cleaning endpoints set for protein, hemoglobin and bioburden residuals. In the simulated-use study 100% of the Olympus colonoscopes, duodenoscopes and bronchoscopes evaluated met or surpassed the cleaning endpoints set for protein, and bioburden residuals (hemoglobin was not evaluated).</p> <p>Conclusions</p> <p>The ECR cleaning cycle provides an effective automated approach that ensures surfaces and channels of flexible endoscopes are adequately cleaned after having only a bedside flush but no manual cleaning. It is crucial to note that endoscopes used for emergency procedures or where reprocessing is delayed for more than one hour MUST still be manually cleaned prior to placing them in the ECR.</p
Energy and carbon audit of a rooftop wind turbine
Abstract: Microgeneration is being promoted as a means of lowering carbon dioxide (CO2) emissions by replacing electricity from the grid with production from small domestic genera-tors. One concern over this drive is that the use of smaller plant could lead to the loss of econ-omies of scale. Partly, this relates to cost but also in terms of energy consumed and CO2 emitted over the life cycle of the microgenerator. Here, an analysis is presented of a life-cycle audit of the energy use and CO2 emissions for the ‘SWIFT’, a 1.5 kW rooftop-mounted, grid-connected wind turbine. The analysis shows that per kilowatt-hour of electricity generated by the turbine, the energy intensity and CO2 emissions are comparable with larger wind turbines and significantly lower than fossil-fuelled generation. With energy and carbon intensities sensitive to assumed levels of production, assessments were carried out for an annual production range of 1000–4000 kWh, representing capacity factors of 8–31 per cent. For the manufacturer’s estimated production of 2000 to 3000 kWh and, giving credit for component recycling, the energy payback period was found to be between 17 and 25 months, whereas the CO2 payback was between 13 and 20 months. Across the full production range, the energy and carbon payback periods were 13–50 months and 10–39 months, respectively. A key outcome of the study is to inform the manufacturer of the opportunities for improving the energy and carbon intensities of the turbine. A simple example is presented showing the impact of replacing one of the larger aluminium components with alternative materials
Criteria for the use of omics-based predictors in clinical trials: Explanation and elaboration
High-throughput 'omics' technologies that generate molecular profiles for biospecimens have been extensively used in preclinical studies to reveal molecular subtypes and elucidate the biological mechanisms of disease, and in retrospective studies on clinical specimens to develop mathematical models to predict clinical endpoints. Nevertheless, the translation of these technologies into clinical tests that are useful for guiding management decisions for patients has been relatively slow. It can be difficult to determine when the body of evidence for an omics-based test is sufficiently comprehensive and reliable to support claims that it is ready for clinical use, or even that it is ready for definitive evaluation in a clinical trial in which it may be used to direct patient therapy. Reasons for this difficulty include the exploratory and retrospective nature of many of these studies, the complexity of these assays and their application to clinical specimens, and the many potential pitfalls inherent in the development of mathematical predictor models from the very high-dimensional data generated by these omics technologies. Here we present a checklist of criteria to consider when evaluating the body of evidence supporting the clinical use of a predictor to guide patient therapy. Included are issues pertaining to specimen and assay requirements, the soundness of the process for developing predictor models, expectations regarding clinical study design and conduct, and attention to regulatory, ethical, and legal issues. The proposed checklist should serve as a useful guide to investigators preparing proposals for studies involving the use of omics-based tests. The US National Cancer Institute plans to refer to these guidelines for review of proposals for studies involving omics tests, and it is hoped that other sponsors will adopt the checklist as well. © 2013 McShane et al.; licensee BioMed Central Ltd
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