164 research outputs found
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Nutrient Enrichment and Marine Ecosystem Disturbance: A Deterministic and Stochastic Approach
Pollution of the marine areas that support much of the world's commercial fisheries is regarded as a pressing global environmental problem. One often-cited issue is nutrient enrichment, but this may be a mixed blessing: it contributes to primary productivity and increases the sustainable fish catch, while simultaneously causing occasional and damaging ecosystem events. Thus, enrichment's aggregate impact on the economic value of fisheries may be ambiguous. This research develops a method for analyzing such problems, using the example of the Black Sea anchovy fishery. Employing a bioeconomic model that incorporates nutrients directly into fish population dynamics, the problem is formulated in deterministic and stochastic terms and the results compared. The deterministic model assumes that nutrients only contribute positively to fish production for a given ecological state, and ignores stochastic events leading to shifts between states. Accordingly, marginal abatement of nutrients leads to annual welfare losses of US$ 45,000 to 713,00 per µ� (1989/90 prices), depending upon the ecosystem state. The stochastic formulation recognizes that planners may have some knowledge of potentially damaging shifts in ecological states, and wish to take this into account. When these shifts are related stochastically to the level of enrichment, nutrient abatement is shown to have an indeterminate welfare effect. However, an experimental empirical analysis indicates that a marginal change in nutrients can generate positive and sizeable aggregate benefits for the Black Sea anchovy fishery under certain conditions. The general applicability of such an approach for analyzing a range of marine environmental problems is noted
Common genetic variation in the glucokinase gene (GCK) is associated with type 2 diabetes and rates of carbohydrate oxidation and energy expenditure
International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol
Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature.
There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed
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