GENERAL EQUILIBRIUM ECOSYSTEM MODELING WITH ALTERNATIVE PREFERENCE SPECIFICATIONS

This paper reconciles two sets of literature with regard to the interactive ecological and economic impacts of invasive grass species and cattle stocking. We model cattle as optimal foragers, satiation foragers, and proportional foragers in order to understand the impact that each assumption imposes on predicted economic and ecological outcomes. Through this model sensitivity (as opposed to parameter sensitivity) analysis, we are able to identify three main drivers of plant invasions: exogenous forces such as climate change or nitrogen deposition, poor land management decisions, and a misalignment of incentives between cattle and ranchers even when ranchers behave optimally.     

QUININE SULFATE AS A FLUORESCENCE QUANTUM YIELD STANDARD

Abstract— Samples of quinine sulfate or bisulfate from a number of vendors have been examined. The light absorptivity and fluorescence excitation spectra of quinine bisulfate prepared from six sources of hydrated quinine sulfate had satisfactory agreement with each other. The solid samples of quinine sulfate or bisulfate showed good agreement (2.2 per cent relative difference) in their fluorescence quantum yields but the one commercial solution of quinine sulfate was 20 per cent low. The relative fluorescence quantum yield of quinine sulfate was evaluated with excitation from 240 through 400 nm and was found to have no unexplainable deviations from a constant value. It is suggested that some of the conflicting results in the literature may be due to the common practice of using a different spectral bandwidth for absorbance measurements than that used for excitation.     

Some exact results for nonlinear diffusion with absorption

Simple exact solutions and first integrals are obtained fornonlinear diffusion incorporating absorption. These are obtainedby the standard techniques of separation of variables and theuse of invariant one-parameter group transforma-tions to reducethe governing partial differential equation to various ordinarydifferential equations. For two of the equations so obtained,first integrals are deduced which subsequently give rise toa number of explicit simple solutions. As with all special solutionsof nonlinear partial differential equations, the associatedinitial and boundary conditions are imposed by the particularfunctional form of the solution and irrespective of their physicalapplicability, simple exact solutions are always important,because one of the key features of nonlinearity is the rangeand variety of response which is often bizarre and unexpected,but which is frequently embodied in the simplest of exact solutions.Many of the solutions obtained here are illustrated graphicallywith particular reference to the phenomena of ‘extinction’and ‘blow-up’ and in general demonstrate a widevariety of differing physical response embodied in the disposableconstants, which is characteristic of nonlinear theories.     

FISHERY SHARE SYSTEMS,ITQ MARKETS,AND THE DISTRIBUTION OF RENTS

Although, in most commercial fisheries, fishing crews are remunerated under a share system, the implications of share systems for individual transferable quotas markets have received relatively little attention. In this paper, we model the impact of extending crew shares of vessel operating costs to include payments for quota. Allocative efficiency is maintained as long as any share system is adopted consistently across the entire fleet. Making crews bear a share of quota costs, however, simply inflates the quota price: at market equilibrium the vessel owner's profit share is unaffected. Crews lose out if the vessel is leasing quota in, but gain if the vessel owner is a net seller of quota. We also consider the outcome if only net purchasers of quota involve crews in the cost of quota. Here, all vessel owners benefit, while all crews see a reduction in their earnings. These results are illustrated with a simple numerical example.     

Computation and analysis of molecular Hartree—Fock momentum intracules

An efficient general algorithm for the computation of molecular momentum intracule densities from Hartree-Fock wavefunctions using Gaussian basis functions is described. The momentum intracules for a number of systems are examined, and comparison with their position space counterparts discussed.