11,407 research outputs found
Legal Implications of Clinical Investigation
There is an increasing concern among the members of the medical profession with legal rights, obligations and limitations affecting clinical investigation. This is understandable in light of the virtual explosion of clinical investigation within medical science. Clinical investigation is the systematic collection, evaluation and reporting, by or under the supervision of physicians, of data about other human beings for the purpose of advancing scientific medical knowledge. Thus it includes neither investigation relating to animals (even though such investigation may also advance scientific medical knowledge), nor investigation of human beings for purposes unrelated to medical science, nor the trial of unproven procedures in the treatment of patients unless this is also a part of a systematic program of clinical investigation. Nevertheless, clinical investigation need not occur within the physician-patient relationship, which arises when a person seeks and a physician undertakes to furnish medical diagnosis or treatment. For example, a person who volunteers as a subject of clinical investigation does not have a physician-patient relationship with a physician who does not undertake to furnish him any medical benefit
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Prioritization and pruning in multicriterion mathematical programming.
Legal Implications of Clinical Investigation
There is an increasing concern among the members of the medical profession with legal rights, obligations and limitations affecting clinical investigation. This is understandable in light of the virtual explosion of clinical investigation within medical science. Clinical investigation is the systematic collection, evaluation and reporting, by or under the supervision of physicians, of data about other human beings for the purpose of advancing scientific medical knowledge. Thus it includes neither investigation relating to animals (even though such investigation may also advance scientific medical knowledge), nor investigation of human beings for purposes unrelated to medical science, nor the trial of unproven procedures in the treatment of patients unless this is also a part of a systematic program of clinical investigation. Nevertheless, clinical investigation need not occur within the physician-patient relationship, which arises when a person seeks and a physician undertakes to furnish medical diagnosis or treatment. For example, a person who volunteers as a subject of clinical investigation does not have a physician-patient relationship with a physician who does not undertake to furnish him any medical benefit
Fermions on one or fewer Kinks
We find the full spectrum of fermion bound states on a Z_2 kink. In addition
to the zero mode, there are int[2 m_f/m_s] bound states, where m_f is the
fermion and m_s the scalar mass. We also study fermion modes on the background
of a well-separated kink-antikink pair. Using a variational argument, we prove
that there is at least one bound state in this background, and that the energy
of this bound state goes to zero with increasing kink-antikink separation, 2L,
and faster than e^{-a2L} where a = min(m_s, 2 m_f). By numerical evaluation, we
find some of the low lying bound states explicitly.Comment: 7 pages, 4 figure
Simple one-dimensional quantum-mechanical model for a particle attached to a surface
We present a simple one-dimensional quantum-mechanical model for a particle
attached to a surface. We solve the Schr\"odinger equation in terms of Weber
functions and discuss the behavior of the eigenvalues and eigenfunctions. We
derive the virial theorem and other exact relationships as well as the
asymptotic behaviour of the eigenvalues. We calculate the zero-point energy for
model parameters corresponding to H adsorbed on Pd(100) and also outline the
application of the Rayleigh-Ritz variational method
Quantized Non-Abelian Monopoles on S^3
A possible electric-magnetic duality suggests that the confinement of
non-Abelian electric charges manifests itself as a perturbative quantum effect
for the dual magnetic charges. Motivated by this possibility, we study vacuum
fluctuations around a non-Abelian monopole-antimonopole pair treated as point
objects with charges g=\pm n/2 (n=1,2,...), and placed on the antipodes of a
three sphere of radius R. We explicitly find all the fluctuation modes by
linearizing and solving the Yang-Mills equations about this background field on
a three sphere. We recover, generalize and extend earlier results, including
those on the stability analysis of non-Abelian magnetic monopoles. We find that
for g \ge 1 monopoles there is an unstable mode that tends to squeeze magnetic
flux in the angular directions. We sum the vacuum energy contributions of the
fluctuation modes for the g=1/2 case and find oscillatory dependence on the
cutoff scale. Subject to certain assumptions, we find that the contribution of
the fluctuation modes to the quantum zero point energy behaves as -R^{-2/3} and
hence decays more slowly than the classical -R^{-1} Coulomb potential for large
R. However, this correction to the zero point energy does not agree with the
linear growth expected if the monopoles are confined.Comment: 18 pages, 5 figures. Minor changes, reference list update
Aharonov-Bohm Radiation of Fermions
We analyze Aharonov-Bohm radiation of charged fermions from oscillating
solenoids and cosmic strings. We find that the angular pattern of the radiation
has features that differ significantly from that for bosons. For example,
fermionic radiation in the lowest harmonic is approximately isotropically
distributed around an oscillating solenoid, whereas for bosons the radiation is
dipolar. We also investigate the spin polarization of the emitted
fermion-antifermion pair. Fermionic radiation from kinks and cusps on cosmic
strings is shown to depend linearly on the ultraviolet cut-off, suggesting
strong emission at an energy scale comparable to the string energy scale.Comment: 14 pages, 6 figures. Version 2: Expanded discussion on boundary
conditions obeyed by Dirac equation mode functions (in Section V B).
Acknowledgements and references added. Version 3: Minor changes made in
response to referee's comment
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