104 research outputs found
Augmented reality in medical education: a systematic review
Introduction: The field of augmented reality (AR) is rapidly growing with many new potential applications in medical education. This systematic review investigated the current state of augmented reality applications (ARAs) and developed an analytical model to guide future research in assessing ARAs as teaching tools in medical education.
Methods: A literature search was conducted using PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar. This review followed PRISMA guidelines and included publications from January 1, 2000 to June 18, 2018. Inclusion criteria were experimental studies evaluating ARAs implemented in healthcare education published in English. Our review evaluated study quality and determined whether studies assessed ARA validity using criteria established by the GRADE Working Group and Gallagher et al., respectively. These findings were used to formulate an analytical model to assess the readiness of ARAs for implementation in medical education.
Results: We identified 100,807 articles in the initial literature search; 36 met inclusion criteria for final review and were categorized into three categories: Surgery (23), Anatomy (9), and Other (4). The overall quality of the studies was poor and no ARA was tested for all five stages of validity. Our analytical model evaluates the importance of research quality, application content, outcomes, and feasibility of an ARA to gauge its readiness for implementation.
Conclusion: While AR technology is growing at a rapid rate, the current quality and breadth of AR research in medical training is insufficient to recommend the adoption into educational curricula. We hope our analytical model will help standardize AR assessment methods and define the role of AR technology in medical education
Study protocol : the empirical investigation of methods to correct for measurement error in biobanks with dietary assessment
Peer reviewedPublisher PD
The dependence of the hard diffractive photoproduction of vector meson or photon and the range of pQCD validity
We consider two coupled problems.
We study the dependence on photon virtuality for the semihard
quasi--elastic photoproduction of neutral vector mesons on a quark, gluon or
real photon (at
GeV)). To this end we calculate the corresponding amplitudes (in an
analytical form) in the lowest nontrivial approximation of perturbative QCD. It
is shown that the amplitude for the production of light meson varies very
rapidly with the photon virtuality near .
We estimate the bound of the pQCD validity region for such processes. For the
real incident photon the obtained bound for the meson production is very
high. This bound decreases fast with the increase of , and we expect that
the virtual photoproduction at HERA gives opportunity to test the pQCD results.
The signature of this region is discussed. For the hard Compton effect the pQCD
should work good at not too high , and this effect seems measurable
at HERA.Comment: ReVTeX, 36 pages, 5 Postscript figures, uses epsf.st
Dangerous Skyrmions in Little Higgs Models
Skyrmions are present in many models of electroweak symmetry breaking where
the Higgs is a pseudo-Goldstone boson of some strongly interacting sector. They
are stable, composite objects whose mass lies in the range 10-100 TeV and can
be naturally abundant in the universe due to their small annihilation
cross-section. They represent therefore good dark matter candidates. We show
however in this work that the lightest skyrmion states are electrically charged
in most of the popular little Higgs models, and hence should have been directly
or indirectly observed in nature already. The charge of the skyrmion under the
electroweak gauge group is computed in a model-independent way and is related
to the presence of anomalies in the underlying theory via the
Wess-Zumino-Witten term.Comment: 31 pages, 4 figures; v2: minor changes, one reference added, version
to appear in JHEP; v3: erratum added, conclusions unchange
Coherent Photo- and Leptoproduction of Vector Mesons from Deuterium
We discuss the coherent photo- and leptoproduction of vector mesons from
deuterium at intermediate (virtual) photon energies, 3 GeV < nu < 30 GeV. These
processes provide several options to explore the space-time evolution of small
size quark-gluon configurations. Furthermore, we study the dependence of the
production cross section on the energy and momentum transfer t due to
variations of the finite longitudinal interaction length. Kinematic regions are
determined where the production cross section is most sensitive to the final
state interaction of the initially produced hadronic wave packet. For
unpolarized deuteron targets this double scattering contribution can be
investigated mainly at large values of the momentum transfer t. For polarized
targets kinematic windows sensitive to double scattering are available also at
moderate t. We suggest several methods for an investigation of color coherence
effects at intermediate energies.Comment: 34 pages, Late
Cut Diagrams for High Energy Scatterings
A new approach is introduced to study QCD amplitudes at high energy and
comparatively small momentum transfer. Novel cut diagrams, representing
resummation of Feynman diagrams, are used to simplify calculation and to avoid
delicate cancellations encountered in the usual approach. Explicit calculation
to the 6th order is carried out to demonstrate the advantage of cut diagrams
over Feynman diagrams.Comment: uu-encoded file containing a latex manuscript with 14 postscript
figure
The spin dependence of high energy proton scattering
Motivated by the need for an absolute polarimeter to determine the beam
polarization for the forthcoming RHIC spin program, we study the spin
dependence of the proton-proton elastic scattering amplitudes at high energy
and small momentum transfer.We examine experimental evidence for the existence
of an asymptotic part of the helicity-flip amplitude phi_5 which is not
negligible relative to the largely imaginary average non-flip amplitude phi_+.
We discuss theoretical estimates of r_5, essentially the ratio of phi_5 to
phi_+, based upon extrapolation of low and medium energy Regge phenomenological
results to high energies, models based on a hybrid of perturbative QCD and
non-relativistic quark models, and models based on eikonalization techniques.
We also apply the model-independent methods of analyticity and unitarity.The
preponderence of evidence at available energy indicates that r_5 is small,
probably less than 10%. The best available experimental limit comes from
Fermilab E704:those data indicate that |r_5|<15%. These bounds are important
because rigorous methods allow much larger values. In contradiction to a
widely-held prejudice that r_5 decreases with energy, general principles allow
it to grow as fast as ln(s) asymptotically, and some models show an even faster
growth in the RHIC range. One needs a more precise measurement of r_5 or to
bound it to be smaller than 5% in order to use the classical Coulomb-nuclear
interference technique for RHIC polarimetry. As part of this study, we
demonstrate the surprising result that proton-proton elastic scattering is
self-analysing, in the sense that all the helicity amplitudes can, in
principle, be determined experimentally at small momentum transfer without a
knowledge of the magnitude of the beam and target polarization
Hard diffractive electroproduction of vector mesons in QCD
Hard diffractive electroproduction of longitudinally polarized vector mesons
is calculated within the leading
approximation of QCD using the leading order parton densities within the
nucleon. Novel QCD features of the production of excited states and of the
restoration of flavor symmetry are analyzed. At the onset of the asymptotic
regime, our analysis finds an important role of quark Fermi motion within the
diffractively produced vector mesons, and we suggest to use this effect to
measure the high momentum tail of the wave function of the vector mesons. We
deduce a kinematical boundary for the region of applicability of the
decomposition of the hard amplitudes over powers of and/or a limit on the
increase of the cross sections of hard processes at small , and briefly
analyze its consequences. We also estimate the nuclear attenuation of the
diffractive electroproduction of vector mesons and compare with estimates of
the shadowing of the longitudinal structure function.Comment: 64 pages, REVTeX, 16 figures optionally included using epsfig.sty,
Revisions in regards to Charmonium photo- and electroproduction, final
version to appear in Phys. Rev.
A High Statistics Search for Ultra-High Energy Gamma-Ray Emission from Cygnus X-3 and Hercules X-1
We have carried out a high statistics (2 Billion events) search for
ultra-high energy gamma-ray emission from the X-ray binary sources Cygnus X-3
and Hercules X-1. Using data taken with the CASA-MIA detector over a five year
period (1990-1995), we find no evidence for steady emission from either source
at energies above 115 TeV. The derived upper limits on such emission are more
than two orders of magnitude lower than earlier claimed detections. We also
find no evidence for neutral particle or gamma-ray emission from either source
on time scales of one day and 0.5 hr. For Cygnus X-3, there is no evidence for
emission correlated with the 4.8 hr X-ray periodicity or with the occurrence of
large radio flares. Unless one postulates that these sources were very active
earlier and are now dormant, the limits presented here put into question the
earlier results, and highlight the difficulties that possible future
experiments will have in detecting gamma-ray signals at ultra-high energies.Comment: 26 LaTeX pages, 16 PostScript figures, uses psfig.sty to be published
in Physical Review
- âŠ