375 research outputs found
BSE: Risk, Uncertainty, and Policy Change
The authors discuss how, in our risk society, a range of potential risks and uncertainties are associated with new technologies and new diseases, such as BSE. These risks bring with them worries about human health, while the ability to assess and manage new health scares is an essential skill for government and related industries
Funding Antibiotic Innovation with Vouchers: Recommendations on How to Strengthen A Flawed Incentive Policy
A serious need to spur antibiotic innovation has arisen because of the lack of antibiotics to combat certain conditions and the overuse of other antibiotics leading to greater antibiotic resistance. In response to this need, proposals have been made to Congress to fund antibiotic research through a voucher program for new antibiotics, which would delay generic entry for any drug, even potential blockbuster lifesaving generics. We find this proposal to be inefficient, in part because of the mismatch between the private value of the voucher and the public value of the antibiotic innovation. However, vouchers have the political advantage in the United States of being able to raise sufficient amounts of money without annual appropriations from Congress. We propose that if antibiotic vouchers are to be considered, the design should include dollar and time caps to limit their volatility, sufficient advance notice to protect generic manufacturers, and market-based linkages between the value of the voucher and the value of the antibiotic innovation. We also explore a second option: The federal government could auction vouchers to the highest bidders and use the money to create an antibiotics innovation fund
Performance Accuracy of Real-Time GPS Asset Tracking Systems for Timber Haulage Trucks Travelling on Both Internal Forest Road and Public Road Networks
The GPSTRACK project has arisen as a result of a recommendation in the Forest Industry Transport Group (FITG) Code of Practice for Timber Haulage, which was to “Encourage closer co-operation between consignors and hauliers to plan routes in a manner which optimizes the economic returns within a legal framework.” The project involved the installation of Bluetree global positioning systems (GPS) asset tracking systems onto two timber haulage trucks: an articulated Iveco Stralis 530 6*2 tractor unit with tri-axle road friendly air suspension flatbed trailer with a design gross vehicle weight (dgvw) equal to 44 t and a Scania 124 (400) with a rigid (3 axle) + trailer (3 axle) + crane combination with an equivalent dgvw of 44 t. This paper discusses the background and use of real-time asset tracking devices in the context of timber haulage in Ireland. Real-time location information is a relatively new concept for Irish applications (less than 5 years), but there is an increasing deployment of the technology into the truck transport sector in Ireland. The goal of this study was to test the accuracy of the recorded GPS locations relative to the underlying travelled route network based on the criteria of: 1) a fixed GPS receiver location, 2) a truck travelling on public routes, and 3) comparing accuracy of public routes to the accuracy of the truck travelling in a more demanding environment such as the internal forest road network. The results analysis calculated the horizontal root mean square (HRMS) 63 percent GPS accuracy of both trucks tracklog on both the public road network and the internal forest road network over a period of 4 weeks which totalled approximately 15,000 GPS data points. The HRMS accuracy values ranged from 2.55 to 2.47 m for the public roads, while the forest road accuracy were approximately 27 m and 41 m for Iveco and Scania, respectively
Novel Approaches to Optimise Early Growth in Willow Crops
peer-reviewedWillow is a fast growing, high yielding biomass crop that can help reduce reliance on fossil fuels. However, long establishment times to get to profitability and sustainable yield may deter interest in planting the crop. A number of different approaches were investigated to optimise and accelerate early growth. These approaches were water immersion, plastic application, altering stem orientation at planting, altering coppicing timings and applying growth hormone. Glasshouse and field trials were used to test the different approaches. In this work, planting material was soaked for a varying number of days and plastic was applied or not applied in field trials. In the planting orientation approach, stems were planted diagonally or vertically with half of the planting material above the ground level or horizontally below ground level. Additionally, willow crops were coppiced at different times throughout their first growing season and a growth hormone trial was also incorporated in this work. Water soaking, plastic application, coppicing during the growing season or hormone application did not improve early growth or yield. However, early growth and yield were increased by manipulating the planting orientation of willow stems. Planting orientation treatments in which part of the stem was left above the ground increased early growth and yield significantly compared to the control without requiring extra inputs at planting. The beneficial effects of coppicing can be achieved by manipulating the planting procedure so that the first year’s growth is not disregarded
Questioning Ecosystem Assessment and Restoration Practices in a Major Urban Estuary: Perpetuating Myths of Degradation in Spite of Facts
The Jamaica Bay ecosystem is a dichotomy. It encompasses more than 12,000 acres of coastal estuarine marshes and an ecological diversity rivaling any coastal environment in the world. It is considerably altered, and is affected by a variety of ecological insults directly related to the fact that more than 14 million people live in its vicinity. Environmental protection institutions responded to the challenge of protecting the bay, surrounding wetlands and recreational benefits by addressing the increasing load of contaminants into the ecosystem. Billions of dollars have been spent during the past five decades on restoration attempts, including upgrading wastewater treatment plantsand the closure of three major sanitary landfills. Even with the curtailment of untreated wastewater release and ending periodic dredging and filling programs, all activities that are necessary processes in maintaining an urban harbor, the Jamaica Bay ecosystem has reached a point where many believe it to be unrecoverable, requiring massive infusions of restoration dollars. This categorization has been perpetuated based on questionable data (the “myths”) that, when investigated in rigorous scientific detail, prove to be unsubstantiated. In this paper, the origin of these myths and the scientific investigation that dispel them are discussed
V559A and N822I double KIT mutant melanoma with predictable response to imatinib?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88125/1/j.1755-148X.2010.00822.x.pd
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The Influence of Scale in a Structured Decision Making Framework for Chinook Salmon Management
The goal of my dissertation was to explore how scale influences stream restoration prioritization strategies for an anadromous species and identify influential uncertainties that exist at different scales. My objectives were to (1) produce a comprehensive review of the Chinook salmon management challenges in California’s Central Valley and identify the those related to scale of the management, (2) apply a structured decision making (SDM) to a large scale, spatially implicit stream restoration decision problem and derive an optimal stream restoration strategy, (3) apply a SDM to a small scale, spatially explicit stream restoration decision problem and use dynamic programming to derive an optimal stream restoration strategy, and (4) develop an approach to derive optimal policies for multi-scale stream restoration decision problem with multiple decision makers working in a hierarchy.
Issues of scale can create distinct problems in natural resource management. I used salmon management in the Central Valley of California an example where scale mismatches that have hindered conservation goals. Salmon stocks in California’s Central Valley have been declining steadily over the last century, which has resulted the congressional establishment of the Central Valley Plan Improvement Act (CVPIA) in 1992 to address the declines. Despite the oversight of the CVPIA, fisheries management in the basin has remained largely uncoordinated and unstructured with management actions often occurring simultaneously and at potentially conflicting scales. Having such large differences in spatial scales meant that any reduction of system uncertainties wasn’t necessarily transferable to other populations of anadromous fish within the Central Valley. The hierarchical structure of the CVPIA and the entities that implement CVPIA related actions provide an opportunity to evaluate how scale may influence restoration decision making.
I developed a large scale, spatially implicit decision model to evaluate the effects of potential habitat restoration projects on populations of fall-run Chinook salmon in California’s Central Valley. The extent of the model was the entire Central Valley and the grain was an individual watershed, 25 in total. Large scale natural resource management problems require special considerations relative to smaller scale problems due in part to the fact that uncertainties tend to increase as spatial scale increases. The model was primarily parameterized with expert judgement due to a lack of available empirical data at the watershed scale. This model and the decision alternatives were formatted as a Markov decision model (MDP) that I solved using dynamic programming and policy iteration. The results of the policy optimization suggest that focusing multiple restoration efforts on a small set of watersheds is the most effective habitat restoration strategy.
Most stream restoration efforts occur on a small spatial scales, often on reaches less than 1 km. I developed a fine scale, spatially explicit structured decision model to derive a state-specific stream restoration strategy for a population of Chinook salmon from a stream in lower American River. The decision problem was represented as Markov decision problem and I used dynamic programming to derive a state-specific, optimal policy for individual reaches within the study stream. The optimal policies depended on four pieces of observable information in a given reach: the amount of spawning habitat, the amount of juvenile rearing habitat, the average number of redds counted over a 5 year period, and the temperature suitability of the reach. Implementing the optimal policy during a 100 year simulation resulted in significant increases in natural production compared to a scenario where no actions were taken over the same time horizon.
Decision problems in natural resource management often involve several, interconnected decision makers, usually working at different temporal and spatial scales. Multitime-scale Markov decision processes (MMDPs) provide a framework to derive optimal decisions from hierarchically structured sequential decision making processes. The work in this study bridges the gap between large and small-scale decision models in natural resource management by applying a MMDP to a Chinook salmon management problem in CVPIA streams with two tiers of decision makers. The fundamental objective of each tier of decision makers was to maximize the production of natural origin Chinook salmon. The decision problem was structured with an upper tier decision maker (large scale) allocating funds to lower tier decision makers (fine scale) who actually implement on the ground restoration projects. The upper tier optimal policy identified optimal resource allocation strategies that favored providing funds to watersheds with high juvenile survival despite high costs
Effect of Harvest Timing and Soil Moisture Content on Compaction, Growth and Harvest Yield in a Miscanthus Cropping System
peer-reviewedHarvesting Miscanthus × giganteus (J.M. Greef & Deuter ex Hodkinson & Renvoize) after shoot emergence is known to reduce yields in subsequent seasons. This research was conducted in Miscanthus to assess the effects on crop response and soil compaction of annually repeated traffic, applied both before new growth in the rhizomes (early harvest) and after shoot emergence (late harvest), at two different soil moisture contents. While an annual early harvest, yields more than a late harvest, because damage to new shoots is avoided, soil compaction may be increased following repeated harvests. Five treatments were tested: (a) An untrafficked control, (b) early-traffic on soil with typical soil moisture content (SMC) (early-normal), (c) early-traffic on soil with elevated SMC (early-elevated), (d) late-traffic on soil with typical SMC (late-normal) and (e) late-traffic on soil with elevated SMC (late-wet). The experiment was conducted on a Gleysol in Co. Dublin, Ireland during 2010 and 2011. Crop response effects were assessed by measuring stem numbers, stem height, trafficked zone biomass yield (November) and overall stem yield (January). Compaction effects were assessed by measuring penetration resistance, bulk density and water infiltration rate. Trafficked zone biomass yield in the early-dry and early-wet treatments was, respectively, 18% and 23% lower than in the control, but was, respectively, 39% and 31% higher than in the late-dry treatment. Overall, stem yield was significantly lower in the late-normal and late-wet treatments (10.4 and 10.1 tdm ha−1 respectively) when compared with the control (12.4 tdm ha−1), but no significant difference was recorded in overall stem yield between both early-traffic treatments and the control. Penetration resistance values were significantly higher in all trafficked treatments when compared with the control at depths of 0.15 m (≥54–61%) and 0.30 m (≥27–57%) and were significantly higher in 2011 when compared with 2010 at depths of 0.15 and 0.30 m. Baler system traffic in Miscanthus significantly reduced yields and significantly increased compaction annually. Miscanthus harvested early, on a dry soil, yielded 1.1 tdm ha−1 more than when harvested late on a dry soil. The yield advantage increased to 1.3 tdm ha−1 when early harvesting on a soil with 40–43% moisture content was compared with late harvesting on a wetter soil (51–52% moisture content). In this study, the magnitude of yield losses from compaction or other causes in early harvests was substantially lower than the yield losses, which resulted from shoot damage in late harvests. It is likely in similar climates that the results of this study would also apply to other perennial crops growing in similar soil type
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