312 research outputs found

    Transforming a Research Concept into Commercial Practice: Addressing the ‘Hurdles’ of Single-Species eDNA-based Detection

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    The use of environmental DNA (eDNA) for measuring and monitoring biodiversity has been identified as a novel molecular based method to complement more commonly utilised traditional ecological sampling techniques. It is a time and cost-efficient technique, which is rapidly advancing due to the capabilities of low eDNA detection levels. As the efficiency of the technique has increased, commercial organisations and end-users have gained a greater interest in its application. Despite this, the technique is currently only commercially available from a select few service providers. In the UK, the main target species for commercial scale eDNA-based detection is the great crested newt (Triturus cristatus). Interest has now been sparked for the development of eDNA assays to detect various other species, both for use as a regulated informative tool and a conservation aid. However, many recent studies have highlighted various limitations associated with the use of eDNA-based detection and this appears to be hampering commercialisation of this tool. eDNA-based detection methods remain relatively underdeveloped and un-validated for use as reliable and accurate widespread monitoring programs and other such applications. Here, the so called ‘hurdles’ associated with the development and validation of eDNA-based methods and its use as a fully available commercial service are reviewed and addressed, in order to develop and validate a commercially applicable eDNA assay for the endangered white-clawed crayfish, Austropotamobius pallipes, as a target organism. When designing novel species-specific assays, detailed validation steps need to be undertaken, ensuring they perform under various conditions, habitats, and which sampling methods should be utilised. Currently, more traditional methods used to asses populations of white-clawed crayfish (such as trapping and hand searching) are becoming increasingly more difficult to undertake as the species become rarer and populations more fragmented. Such techniques are therefore expensive (with regard to time spent surveying) and often result in low probability of detection. A new species-specific qPCR assay to detect white-clawed crayfish was developed and tested under various conditions both ex-situ (laboratory and mesocosms) and in-situ (ponds and rivers) to explore the optimum sampling strategy giving the most reliable results. Experiments were also conducted on a wider scale to determine the impact of DNA degradation and seasonal influence on eDNA persistence. Interestingly, this thesis illustrates that sample collection choice is not simple, and the ‘best’ methodology was shown to vary between habitat type. This indicates that great care should be taken when designing any such assays and implementing them in the field. Furthermore, this study highlights that a ‘standard operating procedure’ for eDNA-based detection in the commercial sector may not be possible and this will have to be explored on an assay by assay basis. Alongside case studies from real-world application of the technique, recommendations are made on how this novel eDNA assay can be used for the commercial practice of white-clawed crayfish assessment.SureScreen Scientific

    The Teacher-Training Program in Music at Chautauqua Institution, 1905–1930

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68865/2/10.2307_3344393.pd

    Low NOx heavy fuel combustor concept program addendum: Low/mid heating value gaseous fuel evaluation

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    The combustion performance of a rich/quench/lean (RQL) combustor was evaluated when operated on low and mid heating value gaseous fuels. Two synthesized fuels were prepared having lower heating values of 10.2 MJ/cu m. (274 Btu/scf) and 6.6 MJ/cu m (176 Btu/scf). These fuels were configured to be representative of actual fuels, being composed primarily of nitrogen, hydrogen, carbon monoxide, and carbon dioxide. A liquid fuel air assist fuel nozzle was modified to inject both of the gaseous fuels. The RQL combustor liner was not changed from the configuration used when the liquid fuels were tested. Both gaseous fuels were tested over a range of power levels from 50 percent load to maximum rated power of the DDN Model 570-K industrial gas turbine engine. Exhaust emissions were recorded for four power level at several rich zone equivalence ratios to determine NOx sensitivity to the rich zone operating point. For the mid Btu heating value gas, ammonia was added to the fuel to simulate a fuel bound nitrogen type gaseous fuel. Results at the testing showed that for the low heating value fuel NOx emissions were all below 20 ppmc and smoke was below a 10 smoke number. For the mid heating value fuel, NOx emissions were in the 50 to 70 ppmc range with the smoke below a 10 smoke number

    Removing the Cloak of Invisibility: The Vietnam Women\u27s Memorial

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    Doris Troth Lippman is Professor of Nursing at Fairfield University. This talk was presented at Sacred Heart University on March 28, 1995, sponsored by the Women\u27s Studies Program in celebration of Women\u27s History Month

    Analytical fuel property effects--small combustors

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    The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions

    Letter from Emily Troth to James B. Finley

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    Emily tells Finley that religion is at a low ebb in Bainbridge. Quarterly Meeting has just begun. The people in Bainbridge are much in need of a revival. Abstract Number - 982https://digitalcommons.owu.edu/finley-letters/1966/thumbnail.jp

    The Industrial Dynamics of Order Rationing, Shortage Gaming, and Retail Promotions Demand Shock: A Discrete Event Simulation Experiment

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    This research investigates the impact of order rationing strategies, shortage gaming responses, and retail promotions demand shock on the long-term system performance of the inventory ordering and fulfillment process between competing retailers and a shared upstream manufacturer. The research addresses a need to understand the horizontal dynamics of competition for supply inventory among interconnected entities within business systems. It also expands understanding of the interactions between various manufacturer order rationing strategies and retailer shortage gaming responses, in the context of supply capacity constraints arising from a retail promotions demand shock. A discrete event simulation based on a US major appliance supply chain was developed. Results from the simulation experiment indicate a strong impact from order rationing strategies and shortage gaming responses on long-term outcomes such as demand variance, order fill rates, opportunity loss, and inventory carrying cost. In contrast, a single retail promotions demand shock has limited long-term impact on system performance. Overall, the findings suggest that both vertical and horizontal entities within business systems are significantly impacted by each entity’s actions within the inventory ordering and fulfillment feedback loop. Also, interactions between manufacturer order rationing strategies, retailer shortage gaming responses, and retail promotions demand shock are complex, particularly when considered over time. There are both positive and negative impacts relative to each entity within the inventory ordering and fulfillment feedback loop

    Upland aspen/birch and black spruce stands and their litter and soil properties in interior Alaska

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    Low NOx Heavy Fuel Combustor Concept Program

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    The development of the technology required to operate an industrial gas turbine combustion system on minimally processed, heavy petroleum or residual fuels having high levels of fuel-bound nitrogen (FBN) while producing acceptable levels of exhaust emissions is discussed. Three combustor concepts were designed and fabricated. Three fuels were supplied for the combustor test demonstrations: a typical middle distillate fuel, a heavy residual fuel, and a synthetic coal-derived fuel. The primary concept was an air staged, variable-geometry combustor designed to produce low emissions from fuels having high levels of FBN. This combustor used a long residence time, fuel-rich primary combustion zone followed by a quick-quench air mixer to rapidly dilute the fuel rich products for the fuel-lean final burnout of the fuel. This combustor, called the rich quench lean (RQL) combustor, was extensively tested using each fuel over the entire power range of the model 570 K engine. Also, a series of parameteric tests was conducted to determine the combustor's sensitivity to rich-zone equivalence ratio, lean-zone equivalence ratio, rich-zone residence time, and overall system pressure drop. Minimum nitrogen oxide emissions were measured at 50 to 55 ppmv at maximum continuous power for all three fuels. Smoke was less than a 10 SAE smoke number

    The Use of Role-Playing To Help Students Understand Information Systems Case Studies

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    A role-playing approach that introduced real world cases of information systems issues in business was compared to the traditional approach of discussing case studies for 32 first year university information systems students. Results showed students considered the role-play approach to be superior to the traditional case study discussions, although observers of role-play were not as enthusiastic as participants. Students considered the role-play approach helped them understand how information systems can be used in business. They also considered that role-play enhanced their learning and they felt very comfortable with the role-playing approach. The authors suggest that role-playing is useful for first year students provided that all members of the tutorial class participate and sufficient preparation done by teaching staff before the tutorial. Students suggested that they would feel more comfortable if each character in the role-play consisted of two or three students. This would reduce the stress associated with one person having to field all questions with the additional benefit of having all students involved
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