3,986 research outputs found
A Review of Regional Economic Models for Fisheries Management in the U.S.
In 1986, Andrews and Rossi reviewed input-output (IO)studies of U.S. fisheries. Since then, many more fisheries studies have appeared using IO and other types of regional economic models, such as Fishery Economic Assessment Models, Social Accounting Matrices, and Computable General Equilibrium models. However, to our knowledge no updated summary of these studies or models has appeared since 1986. This paper attempts to fill this gap by briefly reviewing the types of regional economic models that have been applied to fisheries, reviewing studies using these models that have been conducted for U.S. fisheries, and identifying data and modeling issues associated with regional economic analysis of fisheries in the U.S. The authors conclude that although economic impact analysis of fisheries policy is required under federal law, development of more representative regional economic models for this purpose is not likely to be forthcoming without increased information obtained through some type of comprehensive data collection program.Review, regional economic models, fisheries, IO, FEAM, SAM, CGE, IMPLAN, data., Community/Rural/Urban Development, Resource /Energy Economics and Policy, R1, R13, R15,
TRANDESNF: A computer program for transonic airfoil design and analysis in nonuniform flow
The use of a transonic airfoil code for analysis, inverse design, and direct optimization of an airfoil immersed in propfan slipstream is described. A summary of the theoretical method, program capabilities, input format, output variables, and program execution are described. Input data of sample test cases and the corresponding output are given
Describing Function Analysis of the Field-effect Transistor Oscillator
Recently, due to advances in fabrication techniques, it has become possible to manufacture field-effect transistors having electrical properties which make them very attractive for circuit applications. In the bipolar transistor both positive and negative free carriers take part in the functioning of the device; hence the name bipolar. On the other hand, in unipolar devices, the current is carried only by the free majority carriers in the conducting channel and no essential role is played by the small number of minority carriers; hence the name unipolar. The purpose of this paper is to study the applicability of the describing-function method to field-effect transistors employed in RC phase-shift oscillators. The major concerns in oscillator design are frequency precision and stability and amplitude of oscillation. Also, a design method is presented for the phase-shift oscillator with prescribed frequency and amplitude by using describing functions. Because oscillating condition varies with the operating points of the field-effect transistor, some discussion is included concerning reduction of this effect
Transonic analysis and design of axisymmetric bodies in nonuniform flow
An inviscid nonuniform axisymmetric transonic code was developed for applications in analysis and design. Propfan slipstream effect on pressure distribution for a body with and without sting was investigated. Results show that nonuniformity causes pressure coefficient to be more negative and shock strength to be stronger and more rearward. Sting attached to a body reduced the pressure peak and moves the rear shock forward. Extent and Mach profile shapes of the nonuniformity region appeared to have little effect on the pressure distribution. Increasing nonuniformity magnitude made pressure coefficient more negative and moved the shock rearward. Design study was conducted with the CONMIN optimizer for an ellipsoid and a body with the NACA-0012 counter. For the ellipsoid, the general trend showed that to reduce the pressure drag, the front portion of the body should be thinner and the contour of the rear portion should be flatter than the ellipsoid. For the design of a body with a sharp trailing edge in transonic flow with an initial shape given by the NACA-0012 contour, the pressure drag was reduced by decreasing the nose radius and increasing the thickness in the aft portion. Drag reduction percentages are given
Subcellular organization of UBE3A in human cerebral cortex.
BackgroundLoss of UBE3A causes Angelman syndrome, whereas excess UBE3A activity appears to increase the risk for autism. Despite this powerful association with neurodevelopmental disorders, there is still much to be learned about UBE3A, including its cellular and subcellular organization in the human brain. The issue is important, since UBE3A's localization is integral to its function.MethodsWe used light and electron microscopic immunohistochemistry to study the cellular and subcellular distribution of UBE3A in the adult human cerebral cortex. Experiments were performed on multiple tissue sources, but our results focused on optimally preserved material, using surgically resected human temporal cortex of high ultrastructural quality from nine individuals.ResultsWe demonstrate that UBE3A is expressed in both glutamatergic and GABAergic neurons, and to a lesser extent in glial cells. We find that UBE3A in neurons has a non-uniform subcellular distribution. In somata, UBE3A preferentially concentrates in euchromatin-rich domains within the nucleus. Electron microscopy reveals that labeling concentrates in the head and neck of dendritic spines and is excluded from the PSD. Strongest labeling within the neuropil was found in axon terminals.ConclusionsBy highlighting the subcellular compartments in which UBE3A is likely to function in the human neocortex, our data provide insight into the diverse functional capacities of this E3 ligase. These anatomical data may help to elucidate the role of UBE3A in Angelman syndrome and autism spectrum disorder
Optimism–Pessimism and Stress Appraisal: Testing a Cognitive Interactive Model of Psychological Adjustment in Adults
An interactive model of optimism–pessimism and stress was examined in predicting psychological symptoms and life satisfaction in a group of younger ( n = 340; M = 20.4 years) and a group of older adults ( n = 316; M = 46.6 years). For each group, results of conducting a series of regression analyses indicated that optimism–pessimism and stress appraisal accounted for a significant amount of the variance in each of the adjustment measures. Moreover, a significant optimism–pessimism × Stress Appraisal interaction was found in predicting each of the outcomes for both younger and older adults, even after controlling for the main effects of optimism–pessimism and stress appraisal. However, no significant interaction was found in predicting life satisfaction in older adults. For both younger and older adults, post hoc analyses of the significant interactions indicated a consistent pattern in which pessimism exacerbated the association between appraised stress and poor psychological adjustment. Potential implications of the present findings for future research are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44341/1/10608_2004_Article_450570.pd
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