5,005 research outputs found
Traditional Economic Models of Fishing Vessels: A Review with Discussion
Environmental Economics and Policy, Resource /Energy Economics and Policy,
PUBLIC LAND POLICY AND THE VALUE OF GRAZING PERMITS
This article provides an empirical test of the traditional theory of permit value and investigates the impact of recent changes in public land policies on the value of grazing permits. Results suggest that the cost advantage for grazing on public lands has been capitalized into substantial permit values, but other economic and hedonic factors influencing land prices also have contributed to the value of grazing permits. Public land grazing permits have fallen in value relative to deeded land as grazing fees have increased and as assurance has waned that public land policies will continue to be favorable to ranchers.Land Economics/Use,
Closed-shell interaction in silver and gold chlorides
Hartree-Fock and coupled-cluster calculations have been performed for cubic
AgCl and for AuCl having a cubic or the observed structure with space group
I4_1/amd. Cohesive energies and lattice constants are in excellent agreement
with experiment for AgCl; for AuCl we find good agreement, and the experimental
structure is correctly predicted to be lower in energy than the cubic one.
Electron-correlation effects on lattice constants are very large, of up to 0.8
\AA for cubic AuCl. We especially discuss the strength of the closed-shell
interactions, and for the first time a quantitative analysis of the so-called
"aurophilic" Au(I)-Au(I) interaction is presented in solids.Comment: accepted by J. Chem. Phy
Density functional study of the adsorption of K on the Ag(111) surface
Full-potential gradient corrected density functional calculations of the
adsorption of potassium on the Ag(111) surface have been performed. The
considered structures are Ag(111) (root 3 x root 3) R30degree-K and Ag(111) (2
x 2)-K. For the lower coverage, fcc, hcp and bridge site; and for the higher
coverage all considered sites are practically degenerate.
Substrate rumpling is most important for the top adsorption site. The bond
length is found to be nearly identical for the two coverages, in agreement with
recent experiments. Results from Mulliken populations, bond lengths, core level
shifts and work functions consistently indicate a small charge transfer from
the potassium atom to the substrate, which is slightly larger for the lower
coverage.Comment: to appear in Phys Rev
Phase changes in 38 atom Lennard-Jones clusters. II: A parallel tempering study of equilibrium and dynamic properties in the molecular dynamics and microcanonical
We study the 38-atom Lennard-Jones cluster with parallel tempering Monte
Carlo methods in the microcanonical and molecular dynamics ensembles. A new
Monte Carlo algorithm is presented that samples rigorously the molecular
dynamics ensemble for a system at constant total energy, linear and angular
momenta. By combining the parallel tempering technique with molecular dynamics
methods, we develop a hybrid method to overcome quasi-ergodicity and to extract
both equilibrium and dynamical properties from Monte Carlo and molecular
dynamics simulations. Several thermodynamic, structural and dynamical
properties are investigated for LJ, including the caloric curve, the
diffusion constant and the largest Lyapunov exponent. The importance of
insuring ergodicity in molecular dynamics simulations is illustrated by
comparing the results of ergodic simulations with earlier molecular dynamics
simulations.Comment: Journal of Chemical Physics, accepte
Proteomics of Cytochrome c Oxidase-Negative versus -Positive Muscle Fiber Sections in Mitochondrial Myopathy
The mosaic distribution of cytochrome c oxidase(+) (COX+) and COX - muscle fibers in mitochondrial disorders allows the sampling of fibers with compensated and decompensated mitochondrial function from the same individual. We apply laser capture microdissection to excise individual COX+ and COX- fibers from the biopsies of mitochondrial myopathy patients. Using mass spectrometry-based proteomics, we quantify >4,000 proteins per patient. While COX+ fibers show a higher expression of respiratory chain components, COX- fibers display protean adaptive responses, including upregulation of mitochondrial ribosomes, translation proteins, and chaperones. Upregulated proteins include C1QBP, required for mitoribosome formation and protein synthesis, and STOML2, which organizes cardiolipin-enriched microdomains and the assembly of respiratory supercomplexes. Factoring in fast/slow fiber type, COX (-) slow fibers show a compensatory upregulation of beta-oxidation, the AAA(+) protease AFG3L1, and the OPA1-dependent cristae remodeling program. These findings reveal compensatory mechanisms in muscle fibers struggling with energy shortage and metabolic stress
Waveguiding in planar photonic crystals
Photonic crystal planar circuits designed and fabricated in silicon on silicon dioxide are demonstrated. Our structures are based on two-dimensional confinement by photonic crystals in the plane of propagation, and total internal reflection to achieve confinement in the third dimension. These circuits are shown to guide light at 1550 nm around sharp corners where the radius of curvature is similar to the wavelength of light
Ground-state properties of rutile: electron-correlation effects
Electron-correlation effects on cohesive energy, lattice constant and bulk
compressibility of rutile are calculated using an ab-initio scheme. A
competition between the two groups of partially covalent Ti-O bonds is the
reason that the correlation energy does not change linearly with deviations
from the equilibrium geometry, but is dominated by quadratic terms instead. As
a consequence, the Hartree-Fock lattice constants are close to the experimental
ones, while the compressibility is strongly renormalized by electronic
correlations.Comment: 1 figure to appear in Phys. Rev.
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