5,866 research outputs found
Stepping On Fall Prevention Project
Background: Falls are a major problem in the United States among the older adult population and provide opportunity for community outreach via student-led physical therapy projects. Objective: The purpose of this project was to investigate the relationship between fall related outcome measures and questionnaires with the completion of the Stepping On Fall Prevention program along with evaluating the benefits of Physical Therapy student development with participation in service learning projects. Methods: The research quantified the fall risk of 13 participants with assessment of: gait speed (Timed Up and Go), lower extremity strength (30-Second Chair Stand), balance (4-Stage Balance Test), and psychological factors (Stay Independent Questionnaire, Falls Efficacy Scale-International, and Geriatric Depression Scale). Results: Of the functional measures, significant improvements were observed in the Timed up and Go (TUG) (∆1.72s ± 1.66, p=0.003), the 30-second chair stand (∆4.54 ± 4.27, p= 0.002), Stage 4 of the 4-Stage Balance Test (∆3.37s ± 3.26, p= 0.003), and the Stay Independent questionnaire (∆1.77 ± 2.52, p=0.026). Conclusion: Stepping On demonstrated improvements in gait speed, strength, and balance. These improvements allow older adults to improve their overall safety in both their own homes and the community. More research is needed to evaluate the psychological benefits of completing Stepping On. Furthermore, service learning project opportunities should become more of a standard practice across physical therapy programs
Photodissociation of Conformer-Selected Ubiquitin Ions Reveals Site-Specific Cis/Trans Isomerization of Proline Peptide Bonds
Ultraviolet photodissociation (UVPD) of gas-phase proteins has attracted increased attention in recent years. This growing interest is largely based on the fact that, in contrast to slow heating techniques such as collision induced dissociation (CID), the cleavage propensity after absorption of UV light is distributed over the entire protein sequence, which can lead to a very high sequence coverage as required in typical top-down proteomics applications. However, in the gas phase, proteins can adopt a multitude of distinct and sometimes coexisting conformations, and it is not clear how this three-dimensional structure affects the UVPD fragmentation behavior. Using ion mobility–UVPD–mass spectrometry in conjunction with molecular dynamics simulations, we provide the first experimental evidence that UVPD is sensitive to the higher order structure of gas-phase proteins. Distinct UVPD spectra were obtained for different extended conformations of 11+ ubiquitin ions. Assignment of the fragments showed that the majority of differences arise from cis/trans isomerization of one particular proline peptide bond. Seen from a broader perspective, these data highlight the potential of UVPD to be used for the structural analysis of proteins in the gas phas
Termination of Electron Acceleration in Thundercloud by Intra/Inter-cloud Discharge
An on-ground observation program for high energy atmospheric phenomena in
winter thunderstorms along Japan Sea has been performed via measurements of
gamma-ray radiation, atmospheric electric field and low-frequency radio band.
On February 11, 2017, the radiation detectors recorded gamma-ray emission
lasting for 75 sec. The gamma-ray spectrum extended up to 20 MeV and was
reproduced by a cutoff power-law model with a photon index of
, being consistent with a Bremsstrahlung radiation from a
thundercloud (as known as a gamma-ray glow and a thunderstorm ground
enhancement). Then the gamma-ray glow was abruptly terminated with a nearby
lightning discharge. The low-frequency radio monitors, installed 50 km
away from the gamma-ray observation site recorded leader development of an
intra/inter-cloud discharge spreading over 60 km area with a 300 ms
duration. The timing of the gamma-ray termination coincided with the moment
when the leader development of the intra/inter-cloud discharge passed 0.7 km
horizontally away from the radiation monitors. The intra/inter-cloud discharge
started 15 km away from the gamma-ray observation site. Therefore, the
glow was terminated by the leader development, while it did not trigger the
lightning discharge in the present case.Comment: 12 pages, 4 figures, accepted for publication in Geophysical Research
Letter
Casimir Energy for Spherical boundaries
Calculations of the Casimir energy for spherical geometries which are based
on integrations of the stress tensor are critically examined. It is shown that
despite their apparent agreement with numerical results obtained from mode
summation methods, they contain a number of serious errors. Specifically, these
include (1) an improper application of the stress tensor to spherical
boundaries, (2) the neglect of pole terms in contour integrations, and (3) the
imposition of inappropriate boundary conditions upon the relevant propagators.
A calculation which is based on the stress tensor and which avoids such
problems is shown to be possible. It is, however, equivalent to the mode
summation method and does not therefore constitute an independent calculation
of the Casimir energy.Comment: Revtex, 7 pages, Appendix added providing details of failure of
stress tensor metho
Anisotropic static solutions in modelling highly compact bodies
Einstein field equations for anisotropic spheres are solved and exact
interior solutions obtained. This paper extends earlier treatments to include
anisotropic models which accommodate a wider variety of physically viable
energy densities. Two classes of solutions are possible. The first class
contains the limiting case for the energy density which
arises in many astrophysical applications. In the second class the singularity
at the center of the star is not present in the energy density. The models
presented in this paper allow for increasing and decreasing profiles in the
behavior of the energy density.Comment: 9 pages, to appear in Pramana - J. Phy
Casimir Energy of a Spherical Shell
The Casimir energy for a conducting spherical shell of radius is computed
using a direct mode summation approach. An essential ingredient is the
implementation of a recently proposed method based on Cauchy's theorem for an
evaluation of the eigenfrequencies of the system. It is shown, however, that
this earlier calculation uses an improper set of modes to describe the waves
exterior to the sphere. Upon making the necessary corrections and taking care
to ensure that no mathematically ill-defined expressions occur, the technique
is shown to leave numerical results unaltered while avoiding a longstanding
criticism raised against earlier calculations of the Casimir energy.Comment: LaTeX, 14 pages, 1 figur
Breaking rotational symmetry in two-flavor color superconductors
The color superconductivity under flavor asymmetric conditions relevant to
the compact star phenomenology is studied within the Nambu-Jona-Lasinio model.
We focus on the effect of the deformation of the Fermi surfaces on the pairing
properties and the energy budget of the superconducting state. We find that at
finite flavor asymmetries the color superconducting BCS state is unstable
towards spontaneous quadrupole deformation of the Fermi surfaces of the and
quarks into ellipsoidal form. The ground state of the phase with deformed
Fermi surfaces corresponds to a superposition of prolate and oblate deformed
Fermi ellipsoids of and quarks.Comment: 6 pages, 4 figures. Parameter changes, references added, conclusions
unchange
A new algorithm for anisotropic solutions
We establish a new algorithm that generates a new solution to the Einstein
field equations, with an anisotropic matter distribution, from a seed isotropic
solution. The new solution is expressed in terms of integrals of an isotropic
gravitational potential; and the integration can be completed exactly for
particular isotropic seed metrics. A good feature of our approach is that the
anisotropic solutions necessarily have an isotropic limit. We find two examples
of anisotropic solutions which generalise the isothermal sphere and the
Schwarzschild interior sphere. Both examples are expressed in closed form
involving elementary functions only.Comment: 16 pages, to appear in Pramana - J. Phy
Prognostic factors for chronic headache: A systematic review
OBJECTIVE: To identify predictors of prognosis and trial outcomes in prospective studies of people with chronic headache. METHODS: This was a systematic review of published literature in peer-reviewed journals. We included (1) randomized controlled trials (RCTs) of interventions for chronic headache that reported subgroup analyses and (2) prospective cohort studies, published in English, since 1980. Participants included adults with chronic headache (including chronic headache, chronic migraine, and chronic tension-type headache with or without medication overuse headache). We searched key databases using free text and MeSH terms. Two reviewers independently extracted data and assessed the methodologic quality of studies and overall quality of evidence identified using appropriate published checklists. RESULTS: We identified 16,556 titles, removed 663 duplicates, and reviewed 199 articles, of which 27 were included in the review-17 prospective cohorts and 10 RCTs with subgroup analyses reported. There was moderate-quality evidence indicating that depression, anxiety, poor sleep and stress, medication overuse, and poor self-efficacy for managing headaches are potential prognostic factors for poor prognosis and unfavorable outcomes from preventive treatment in chronic headache. There was inconclusive evidence about treatment expectations, age, age at onset, body mass index, employment, and several headache features. CONCLUSIONS: This review identified several potential predictors of poor prognosis and worse outcome postinterventions in people with chronic headache. The majority of these are modifiable. The findings also highlight the need for more longitudinal high-quality research of prognostic factors in chronic headache
The D/H Ratio in Interstellar Gas Towards G191-B2B
We reinvestigate the question of spatial variation of the local D/H
abundance, using both archival GHRS spectra, and new echelle spectra of
G191-B2B obtained with the Space Telescope Imaging Spectrograph (STIS) aboard
HST. Our analysis uses stratified line-blanketed non-LTE model atmosphere
calculations to determine the shape of the intrinsic WD Lyman-alpha profile and
estimate the WD photospheric contamination of the interstellar lines. Although
three velocity components were reported previously towards G191-B2B, we detect
only two velocity components. The first component is at V(hel) ~ 8.6 km/s and
the second at V(hel) ~ 19.3 km/s, which we identify with the Local Interstellar
Cloud (LIC). From the STIS data we derive D/H = 1.60(+0.39,-0.27)X10^-5 for the
LIC component, and D/H > 1.26X10^-5 for the 8.6 km/s component (uncertainties
denote 2-sigma or 95% confidence limits). The STIS data provide no evidence for
local or component-to-component variation in the D/H ratio. Despite using two
velocity components for the profile fitting and using a more physically
realistic WD Lyman-alpha profile for G191-B2B, our re-analysis of the GHRS data
indicates a component-to-component variation as well as a variation of the D/H
ratio in the LISM, neither of which are supported by the newer STIS data. We
believe the most probable cause for this difference is the characterization of
the background due to scattered light in the GHRS and STIS spectrographs. The
two-dimensional MAMA detectors of STIS measure both the spatial and wavelength
dependences of scattered light, allowing more accurate scattered light
corrections than was possible with GHRS.Comment: Accepted for publication in Astrophysical Journal Letters. 10 pages +
3 figures. (Abstract is abridged.
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