4,063 research outputs found
Unidirectional Nonlinear PT-symmetric Optical Structures
We show that non-linear optical structures involving a balanced gain-loss
profile, can act as unidirectional optical valves. This is made possible by
exploiting the interplay between the fundamental symmetries of parity (P) and
time (T), with optical nonlinear effects. This novel unidirectional dynamics is
specifically demonstrated for the case of an integrable PT-symmetric nonlinear
system.Comment: 6 pages,5 figure
Recommended from our members
Effects of a Mindfulness-Based Intervention on Distress, Weight Gain, and Glucose Control for Pregnant Low-Income Women: A Quasi-Experimental Trial Using the ORBIT Model.
BackgroundStress can lead to excessive weight gain. Mindfulness-based stress reduction that incorporates mindful eating shows promise for reducing stress, overeating, and improving glucose control. No interventions have tested mindfulness training with a focus on healthy eating and weight gain during pregnancy, a period of common excessive weight gain. Here, we test the effectiveness of such an intervention, the Mindful Moms Training (MMT), on perceived stress, eating behaviors, and gestational weight gain in a high-risk sample of low income women with overweight/obesity.MethodWe conducted a quasi-experimental study assigning 115 pregnant women to MMT for 8 weeks and comparing them to 105 sociodemographically and weight equivalent pregnant women receiving treatment as usual. Our main outcomes included weight gain (primary outcome), perceived stress, and depression.ResultsWomen in MMT showed significant reductions in perceived stress (β = - 0.16) and depressive symptoms (β = - 0.21) compared to the treatment as usual (TAU) control group. Consistent with national norms, the majority of women (68%) gained excessive weight according to Institute of Medicine weight-gain categories, regardless of group. Slightly more women in the MMT group gained below the recommendation. Among secondary outcomes, women in MMT reported increased physical activity (β = 0.26) and had lower glucose post-oral glucose tolerance test (β = - 0.23), being 66% less likely to have impaired glucose tolerance, compared to the TAU group.ConclusionA short-term intervention led to significant improvements in stress, and showed promise for preventing glucose intolerance. However, the majority of women gained excessive weight. A longer more intensive intervention may be needed for this high-risk population. Clinical Trials.gov #NCT01307683
Weak Value in Wave Function of Detector
A simple formula to read out the weak value from the wave function of the
measuring device after the postselection with the initial Gaussian profile is
proposed. We apply this formula for the weak value to the classical experiment
of the realization of the weak measurement by the optical polarization and
obtain the weak value for any pre- and post-selections. This formula
automatically includes the interference effect which is necessary to yields the
weak value as an outcome of the weak measurement.Comment: 3 pages, no figures, Published in Journal of the Physical Society of
Japa
Implications of Pseudospin Symmetry on Relativistic Magnetic Properties and Gamow - Teller Transitions in Nuclei
Recently it has been shown that pseudospin symmetry has its origins in a
relativistic symmetry of the Dirac Hamiltonian. Using this symmetry we relate
single - nucleon relativistic magnetic moments of states in a pseudospin
doublet to the relativistic magnetic dipole transitions between the states in
the doublet, and we relate single - nucleon relativistic Gamow - Teller
transitions within states in the doublet. We apply these relationships to the
Gamow - Teller transitions from to its mirror nucleus .Comment: 17 pages, 2 figures, to be published in PRC. Slightly revised text
with one reference adde
Violation of pseudospin symmetry in nucleon-nucleus scattering: exact relations
An exact determination of the size of the pseudospin symmetry violating part
of the nucleon-nucleus scattering amplitude from scattering observables is
presented. The approximation recently used by Ginocchio turns out to
underestimate the violation of pseudospin symmetry. Nevertheless the conclusion
of a modestly broken pseudospin symmetry in proton-208Pb scattering at
EL=800MeV remains valid.Comment: 8 pages, 2 figure
Relativistic Symmetry Suppresses Quark Spin-Orbit Splitting
Experimental data indicate small spin-orbit splittings in hadrons. For
heavy-light mesons we identify a relativistic symmetry that suppresses these
splittings. We suggest an experimental test in electron-positron annihilation.
Furthermore, we argue that the dynamics necessary for this symmetry are
possible in QCD.Comment: 16 pages, LaTeX. Two postscript figures. Final version to be
published in Physical Review Letter
Off Mass Shell Effects in Hadron Electric Dipole Moments
We note that off the quark mass shell the operators
and , both of which reduce to
in the non-relativistic limit, are no longer
identical. In this paper we explore the effects of this difference in the
contribution of these quark electric moments to hadronic electric moments.Comment: 21 pages, 1 figure, Revtex, uses psfi
Two-photon diffraction and quantum lithography
We report a proof-of-principle experimental demonstration of quantum
lithography. Utilizing the entangled nature of a two-photon state, the
experimental results have bettered the classical diffraction limit by a factor
of two. This is a quantum mechanical two-photon phenomenon but not a violation
of the uncertainty principle.Comment: 5 pages, 5 figures Submitted to Physical Review Letter
- …
