6,965 research outputs found
Habitat Correlates of Jaguar Kill-Sites of Cattle in Northeastern Sonora, Mexico
Predation on cattle by the endangered jaguar (Panthera onca) can be a serious ecological and economic conflict. We investigated habitat characteristics of kill sites of cattle in Sonora, Mexico, from 1999 to 2004 to see whether habitat management or cattle distribution could be used as effective nonlethal methods to limit predation. Kill-sites were positively associated with oak, semitropical thornscrub, and xeric thornscrub vegetation types, whereas they were negatively associated with upland mesquite. Sites of cattle kills were also positively associated with proximity to permanent water sources and roads. A model including these relationships fi t kill locations well (AUC = 0.933) and correctly classified 93% of all kill-site locations. Because kill-sites were associated with specific habitat attributes, management practices that alter cattle distribution, such as placement of permanent water sources in uplands, herding, and fencing riparian areas characterized by frequent depredations, can be used to minimize co-occurrence of jaguars and cattle and, thus, potentially limit predation without illegal killing of jaguars. These practices could also lead to more uniform use of pastures and, consequently, higher stocking rates, resulting in increased profitability to landowners. Managing habitat attributes that predispose cattle to predation may provide a viable alternative for maintaining both livestock enterprises and a large endangered carnivore in areas of conflict
Beyond conventional factorization: Non-Hermitian Hamiltonians with radial oscillator spectrum
The eigenvalue problem of the spherically symmetric oscillator Hamiltonian is
revisited in the context of canonical raising and lowering operators. The
Hamiltonian is then factorized in terms of two not mutually adjoint factorizing
operators which, in turn, give rise to a non-Hermitian radial Hamiltonian. The
set of eigenvalues of this new Hamiltonian is exactly the same as the energy
spectrum of the radial oscillator and the new square-integrable eigenfunctions
are complex Darboux-deformations of the associated Laguerre polynomials.Comment: 13 pages, 7 figure
Wronskian formula for confluent second-order supersymmetric quantum mechanics
The confluent second-order supersymmetric quantum mechanics, for which the
factorization energies tend to a single value, is studied. We show that the
Wronskian formula remains valid if generalized eigenfunctions are taken as seed
solutions. The confluent algorithm is used to generate SUSY partners of the
Coulomb potential.Comment: 7 pages, 1 figure, to be published in Physics Letters
Exactly Solvable Hydrogen-like Potentials and Factorization Method
A set of factorization energies is introduced, giving rise to a
generalization of the Schr\"{o}dinger (or Infeld and Hull) factorization for
the radial hydrogen-like Hamiltonian. An algebraic intertwining technique
involving such factorization energies leads to derive -parametric families
of potentials in general almost-isospectral to the hydrogen-like radial
Hamiltonians. The construction of SUSY partner Hamiltonians with ground state
energies greater than the corresponding ground state energy of the initial
Hamiltonian is also explicitly performed.Comment: LaTex file, 21 pages, 2 PostScript figures and some references added.
To be published in J. Phys. A: Math. Gen. (1998
Quantum mechanical spectral engineering by scaling intertwining
Using the concept of spectral engineering we explore the possibilities of
building potentials with prescribed spectra offered by a modified intertwining
technique involving operators which are the product of a standard first-order
intertwiner and a unitary scaling. In the same context we study the iterations
of such transformations finding that the scaling intertwining provides a
different and richer mechanism in designing quantum spectra with respect to
that given by the standard intertwiningComment: 8 twocolumn pages, 5 figure
Upper and lower nearly (i, j)-continuous multifunctions
In this paper the authors introduce and study upper and lower nearly
(I,J)-continuous multifunctions. Some characterizations and several properties concerning upper (lower) nearly (I,J)-continuous multifunctions are obtained. The results
improves many results in Literature
MamÃferos encontrados em dois castanhais localizados ao sudoeste do Estado do Acre, Brasil.
bitstream/CPAF-AC-2010/22928/1/publicacao113.pd
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