9,474 research outputs found
CHOICE SET CONSIDERATIONS IN MODELS OF RECREATION DEMAND: HISTORY AND CURRENT STATE OF THE ART
Demand and Price Analysis,
The Economic Value of Marine Recreational Fishing: Analysis of the MRFSS 1998 Pacific Add-on
Marine Recreational Fishing Statistics Survey (MRFSS) economic add-on data has been collected since 1994. The data are comprised of two geographically identical datasets for the Southeast region (1997, 2000), five identical datasets for the Northeast region (1994, 1996, 1997, 1999, 2000), and one dataset for the Pacific region (1998). Measures of the economic value of fishing sites and harvest have been derived from demand models estimated with data from the Northeast and the Southeast regions. In this paper we present a demand model estimated for the Pacific region (i.e., west coast). For consistency, the model is based on the 1994 and 1997 studies. Measures of the economic value of fishing sites and harvest are developed. We demonstrate how the model can be used for fisheries management decisions.
Phenalene-phosphazene complexes: effect of exocyclic charge densities on the cyclotriphosphazene ring system
The synthesis and properties of a new series of 1,9-diamino-substituted phenalene complexes of the cyclotriphosphazene ring system is described. One of the compounds is shown to be amphoteric, and this behavior allows an examination of the response of the phosphazene linkage to variations in exocyclic charge density at the spiro center in a plane perpendicular to the cyclotriphosphazene ring system. ^(31)P NMR spectroscopy indicates that substituent lone pairs with this orientation are not effective in long-range delocalization within the phosphazene linkage (in accord with our theoretical model of spiro delocalization). An X-ray crystal structure of one compound (7) identifies the presence of clathrated molecules of chloroform together with doubly hydrogen-bonded pairs of the phenalene-phosphazene complexes in the lattice. Crystal data for 7 (C_(13)H_8Cl_4N_5P_3•CHCl_3): monoclinic space group P2_1/c, a = 12.401 (4) Å, b = 28.404 (6) Å, c = 12.962 (3) Å, β = 91.76 (2)°, V = 4564 (2) Å^3, Z = 8, R = 0.050 for 4525 reflections
Explaining the Allocation of Bilateral and Multilateral Environmental Aid to Developing Countries
In this paper we examine how international development assistance for environmental purposes is allocated to developing countries. In particular, we investigate whether there are patterned differences between environmental aid for international public goods projects versus environmental projects having more localized impacts. We empirically investigate these questions using project project level development assistance data.International Development,
Angler Heterogeneity and the Species-Specific Demand for Marine Recreational Fishing
In this study we assess the viability of single-species recreation demand models given commonly available data sets. Using the 2000 MRFSS southeast intercept data combined with the economic add-on, we determine that the MRFSS data will support only a few species-specific recreation demand models. Considering species of management interest in the southeast, we focus on dolphin, king mackerel, red snapper and red drum. We examine single-species recreational fishing behavior using random utility models of demand. We explore mixed logit (i.e., random parameter) logit and finite mixture (i.e., latent class logit) models for dealing with angler heterogeneity. We compare these to the commonly used conditional and nested logit models in terms of the value of catching (and keeping) one additional fish. Mixed logit models illustrate that the value of catch can be highly heterogeneous and, in some cases, can include both positive and negative values. The finite mixture model generates value estimates that were some times strikingly different than conditional, nested and mixed logit models. Preference heterogeneity is significant within the MRFSS data. We find evidence that single-species models outperform multiple species models and recreational values differ. Key Words: marine recreational fishing, single-species demand, preference heterogeneity models
Retrodirective transponder feasibility experiment
Test program on feasibility of digital phase measuring subsystem of pulse-coherent retrodirective transponde
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A Dose Relationship Between Brain Functional Connectivity and Cumulative Head Impact Exposure in Collegiate Water Polo Players.
A growing body of evidence suggests that chronic, sport-related head impact exposure can impair brain functional integration and brain structure and function. Evidence of a robust inverse relationship between the frequency and magnitude of repeated head impacts and disturbed brain network function is needed to strengthen an argument for causality. In pursuing such a relationship, we used cap-worn inertial sensors to measure the frequency and magnitude of head impacts sustained by eighteen intercollegiate water polo athletes monitored over a single season of play. Participants were evaluated before and after the season using computerized cognitive tests of inhibitory control and resting electroencephalography. Greater head impact exposure was associated with increased phase synchrony [r (16) > 0.626, p < 0.03 corrected], global efficiency [r (16) > 0.601, p < 0.04 corrected], and mean clustering coefficient [r (16) > 0.625, p < 0.03 corrected] in the functional networks formed by slow-wave (delta, theta) oscillations. Head impact exposure was not associated with changes in performance on the inhibitory control tasks. However, those with the greatest impact exposure showed an association between changes in resting-state connectivity and a dissociation between performance on the tasks after the season [r (16) = 0.481, p = 0.043] that could also be attributed to increased slow-wave synchrony [F (4, 135) = 113.546, p < 0.001]. Collectively, our results suggest that athletes sustaining the greatest head impact exposure exhibited changes in whole-brain functional connectivity that were associated with altered information processing and inhibitory control
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