11,211 research outputs found
Zero-mode contribution to the light-front Hamiltonian of Yukawa type models
Light-front Hamiltonian for Yukawa type models is determined without the
framework of canonical light-front formalism. Special attention is given to the
contribution of zero modes.Comment: 14 pages, Latex, revised version with minor changes, Submitted to
J.Phys.
Angular EPR paradox
The violation of local uncertainty relations is a valuable tool for detecting
entanglement, especially in multi-dimensional systems. The orbital angular
momentum of light provides such a multi-dimensional system. We study quantum
correlations for the conjugate variables of orbital angular momentum and
angular position. We determine an experimentally testable criterion for the
demonstration of an angular version of the EPR paradox. For the interpretation
of future experimental results from our proposed setup, we include a model for
the indeterminacies inherent to the angular position measurement. For this
measurement angular apertures are used to determine the probability density of
the angle. We show that for a class of aperture functions a demonstration of an
angular EPR paradox, according to our criterion, is to be expected.Comment: 21 pages, 9 figures, to be published in J. Mod. Opt. special issue on
quantum imagin
Pathways Thinking as a Mediator between Positive Emotions and General Life Satisfaction in Middle School Students
Informed by the broaden-and-build theory of positive emotions, we tested a model of the origins of life satisfaction with a sample of 567 middle school students from the Southeastern United States. The pathways thinking domain of hope was proposed to mediate the relation between positive emotions and general life satisfaction at a single time point, as well as over one year. At Time 1, pathways thinking was a significant mediator of positive emotions and life satisfaction. In the longitudinal model, pathways thinking did not significantly mediate this relation between positive emotions and later life satisfaction. These findings have implications for understanding the role of positive emotions in early adolescents
A conserved U-rich RNA region implicated in regulation of translation in Plasmodium female gametocytes.
Translational repression (TR) plays an important role
in post-transcriptional regulation of gene expression
and embryonic development in metazoans. TR
also regulates the expression of a subset of the
cytoplasmic mRNA population during development
of fertilized female gametes of the unicellular
malaria parasite, Plasmodium spp. which results
in the formation of a polar and motile form, the
ookinete. We report the conserved and sex-specific
regulatory role of either the 3’- or 5’-UTR of a subset
of translationally repressed mRNA species as
shown by almost complete inhibition of expression
of a GFP reporter protein in the female gametocyte.
A U-rich, TR-associated element, identified previously
in the 3’-UTR of TR-associated transcripts,
played an essential role in mediating TR and a
similar region could be found in the 5’-UTR shown in
this study to be active in TR. The silencing effect of
this 5’-UTR was shown to be independent of its
position relative to its ORF, as transposition to a
location 3’ of the ORF did not affect TR. These
results demonstrate for the first time in a unicellular
organism that the 5’ or the 3’-UTR of TR-associated
transcripts play an important and conserved role in
mediating TR in female gametocytes
A twin-mirrored galvanometer laser light sheet generator
A galvanometer mirror-based laser light sheet system has been developed for use in the Basic Aerodynamics Research Tunnel at NASA Langley. This system generates and positions single or multiple light sheets over aeronautical research models being tested in the low speed tunnel. This report describes a twin mirrored galvanometer laser light sheet generator and shows typical light sheet arrangements in use. With this system, illumination of smoke entrained in the flow over a delta wing model reveals the vortical flow produced by the separation of the flow at the leading edge of the model. The light sheet system has proven to be very adaptable and easy to use in sizing and positioning light sheets in wind tunnel applications
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