INTEGRATED SEISMIC-REFLECTION AND MICROGRAVITY IMAGING ACROSS THE SOUTHERN BOUNDARY OF THE CHARLESTON UPLIFT, NEW MADRID SEISMIC ZONE, USA

The Charleston Uplift (CU), a 30-km-long by 7-km-wide, N46°E-oriented subsurface geologic anomaly in the northern Mississippi embayment near Charleston, Missouri, exhibits up to 36 m of vertical relief across the Paleogene/Quaternary unconformity. Subsurface structural relief, along with the CU’s coincident boundary alignment with contemporary microseismicity and the New Madrid North Fault (NMNF), suggest a structural origin. Subsequent seismic soundings indicate vertical structural relief is present in Cretaceous and Paleozoic horizons, supporting the fault-controlled origin. The southern boundary (CU-s) had not been investigated, nor had any direct fault images been acquired. Integrated microgravity and seismic-reflection methods across the inferred CU-s establish the first image of this fault. Forward modeling indicated that the vertical variation of strata across the CU-s would induce a microgravity anomaly of 1.6 mGal. The observed microgravity anomaly survey across the southern boundary is 1.616 ± .004 mGal, and is consistent with the tectonic interpretation. A subsequently acquired seismic-reflection profile corroborates this interpretation. The imaged fault shows approximately 60, 35, and 35 meters of vertical down-to-the-south throw across the tops of Paleozoic, Cretaceous, and Tertiary horizons, respectively. This confirms the CU is not an erosional feature, but a structurally controlled extension of the NMNF

A review of the benefits and limitations of waste nutrient treatment in aquaculture pond facilities

Abstract Managing waste nutrients from intensive freshwater and marine pond aquaculture is a global challenge. Nutrient-enriched water released from farms can have detrimental effects on aquatic ecosystem health. There are a range of treatment options for discharge water from fish and crustacean ponds, and this review examines the benefits and limitations of these options. Much of the nutrient waste is derived from the addition of formulated feed. In recent years, reduction in waste from feeds and feeding has been largely incremental. In terms of treatment, there are low-cost approaches, such as settlement ponds, but they are inefficient at reducing nutrients. Biological systems, using aquatic plants, microalgae and filter feeders to reduce nutrient release from farms have variable levels of effectiveness. Establishing wetlands requires considerable additional land area, and success to date has been highly variable. Overall, this review found no simple cost-effective solution for managing nutrient enriched water from ponds. This is due, in many cases, to challenges with treating the large volumes of discharge water with relatively low nutrient concentrations. This means that more technologically advanced and reliable treatment options, for example, bioreactors, are prohibitively expensive. However, some systems, such as use of recirculation systems typically increase nutrient concentrations, and hence the efficiency and effectiveness of more expensive treatment methods. Biofloc systems can also provide a mechanism for in-situ nutrient treatment as well as a supplementary food source for animals. Overall, there is scope to improve treatment of waste nutrients, but significant modifications to many production systems are needed to achieve this

Speech-Language Pathology Graduate Student Clinicians’ Self-Perceived Competency in Dysphagia Management

Speech-language pathologists (SLPs) are the preferred healthcare providers for managing the direct clinical care of patients with dysphagia. By assessing self-perceived competency during academic training, SLP graduate student clinicians may increase their understanding of their skills in dysphagia management. We modified the Dysphagia Competency Verification Tool (DCVT) to use a 5-point ordinal scale to explore how SLP graduate student clinicians’ self-perception of competency in dysphagia management changes over time and to determine the impact of clinical practicum experiences. Seventy-two SLP graduate student clinicians rated their self-perceived competency for four DCVT domains. We used Generalized Estimating Equations (GEE) models to analyze the statistical significance of self-perception of competency ratings for each of the DCVT domains across semesters while accounting for clinical practicum experiences. Overall, the SLP graduate student clinicians indicated an increase in DCVT scores from the beginning of their graduate training program to the time of graduation, but did not perceive themselves as Adequate on most items of the DCVT until their last semester. These results suggest that both SLP graduate student clinicians and SLP graduate training programs would benefit from using a standardized metric to assess self-perceived competence in dysphagia management. DCVT self-perceived competency ratings could inform SLP graduate student clinicians about areas of dysphagia management practice and skills that need further development, allowing them to target these specific areas and gain actual competence

Ocean urea fertilization for carbon credits poses high ecological risks

The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. (C) 2008 Elsevier Ltd. All rights reserved

Technology integration project: Environmental Restoration Technologies Department Sandia National Laboratories

Sandia National Laboratories Environmental Restoration Technologies Department is developing environmental restoration technologies through funding form the US Department of Energy`s (DOE`s) Office of Science and Technology. Initially, this technology development has been through the Mixed Waste Landfill Integrated Demonstration (MWLID). It is currently being developed through the Contaminant Plume containment and Remediation Focus Area, the Landfill Stabilization Focus Area, and the Characterization, Monitoring, and Sensor Cross-Cutting Program. This Technology Integration Project (TIP) was responsible for transferring MWLID-developed technologies for routine use by environmental restoration groups throughout the DOE complex and commercializing these technologies to the private sector. The MWLID`s technology transfer/commercialization successes were achieved by involving private industry in development, demonstration, and technology transfer/commercialization activities; gathering and disseminating information about MWLID activities and technologies; and promoting stakeholder and regulatory involvement. From FY91 through FY95, 30 Technical Task Plans (TTPs) were funded. From these TTPs, the MWLID can claim 15 technology transfer/commercialization successes. Another seven technology transfer/commercialization successes are expected. With the changeover to the focus areas, the TIP continued the technology transfer/commercialization efforts begun under the MWLID

Mobility and survival of Salmonella Typhimurium and human adenovirus from spiked sewage sludge applied to soil columns

Aims: This study investigated the survival and transport of sewage sludge-borne pathogenic organisms in soils. Methods and Results: Undisturbed soil cores were treated with Salmonella enterica ssp. enterica serovar Typhimurium-lux (STM-lux) and human adenovirus (HAdV)-spiked sewage sludge. Following an artificial rainfall event, these pathogens were analysed in the leachate and soil sampled from different depths (0-5 cm, 5-10 cm and 10-20 cm) after 24 h, 1 and 2 months. Significantly more STM-lux and HAdV leached through the soil cores when sewage sludge was present. Significantly more STM-lux were found at all soil depths, at all time periods in the sewage sludge treatments, compared to the controls. The rate of decline of STM-lux in the controls was more rapid than in the sewage sludge treatments. Survival and transport of HAdV were minimal. Conclusions: The presence of sewage sludge can significantly influence the transport and survival of bacterial pathogens in soils, probably because of the presence of organic matter. Environmental contamination by virus is unlikely because of strong soil adsorption. Significance and Impact of the Study: This study suggests that groundwater contamination from vertical movement of pathogens is a potential risk and that it highlights the importance of the treatment requirements for biosolids prior to their application to land

Task analysis for error identification: Theory, method and validation

This paper presents the underlying theory of Task Analysis for Error Identification. The aim is to illustrate the development of a method that has been proposed for the evaluation of prototypical designs from the perspective of predicting human error. The paper presents the method applied to representative examples. The methodology is considered in terms of the various validation studies that have been conducted, and is discussed in the light of a specific case study