1,562 research outputs found
Quality of life in children and adolescents with Osteogenesis Imperfecta: a qualitative interview based study
BACKGROUND: Osteogenesis Imperfecta (OI) is a disease with varying severity affecting physical, social and emotional well-being of the child and their family. There is no existing evidence on how the OI population regard their quality of life (QoL). The main aim of this study was to determine how OI impacts on the quality of life and well-being of children and their family. It is the first stage of a larger project to develop a disease specific quality of life measure for children with OI. METHODS: Purposive sampling was used to cover the diversity of the OI population. Twenty-five qualitative interviews were undertaken with children (n = 10), parents (n = 10) and health professionals (n = 5). Interviews were digitally recorded and transcribed verbatim. Significant themes were identified, extracted and organised, undergoing framework analysis. RESULTS: Six main themes were identified; being safe and careful, reduced function, pain, fear, isolation, independence. There was a large amount of agreement between the three groups of interviewees, although discrepancies did occur between parents and children, with regard to the themes independence and fear. CONCLUSIONS: This data presents the first step in developing items for a disease specific QoL measure for children with OI. Several of the themes uncovered showed similarity to other QoL measures, but the addition of being safe and careful, particularly in relation to fractures, demonstrated the need for a disease specific measure for children with OI
Physical and psychological morbidity of patients waiting for hip and knee replacement surgery
No Evidence Supporting Flare Driven High-Frequency Global Oscillations
The underlying physics that generates the excitations in the global
low-frequency, < 5.3 mHz, solar acoustic power spectrum is a well known process
that is attributed to solar convection; However, a definitive explanation as to
what causes excitations in the high-frequency regime, > 5.3 mHz, has yet to be
found. Karoff and Kjeldsen (Astrophys. J. 678, 73-76, 2008) concluded that
there is a correlation between solar flares and the global high-frequency solar
acoustic waves. We have used the Global Oscillations Network Group (GONG)
helioseismic data in an attempt to verify Karoff and Kjeldsen (2008) results as
well as compare the post-flare acoustic power spectrum to the pre-flare
acoustic power spectrum for 31 solar flares. Among the 31 flares analyzed, we
observe that a decrease in acoustic power after the solar flare is just as
likely as an increase. Furthermore, while we do observe variations in acoustic
power that are most likely associated with the usual p-modes associated with
solar convection, these variations do not show any significant temporal
association with flares. We find no evidence that consistently supports flare
driven high-frequency waves.Comment: 20 pages, 9 figures, Accepted for publication in Solar Physic
Recent experimental results in sub- and near-barrier heavy ion fusion reactions
Recent advances obtained in the field of near and sub-barrier heavy-ion
fusion reactions are reviewed. Emphasis is given to the results obtained in the
last decade, and focus will be mainly on the experimental work performed
concerning the influence of transfer channels on fusion cross sections and the
hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier
fusion taught us that cross sections may strongly depend on the low-energy
collective modes of the colliding nuclei, and, possibly, on couplings to
transfer channels. The coupled-channels (CC) model has been quite successful in
the interpretation of the experimental evidences. Fusion barrier distributions
often yield the fingerprint of the relevant coupled channels. Recent results
obtained by using radioactive beams are reported. At deep sub-barrier energies,
the slope of the excitation function in a semi-logarithmic plot keeps
increasing in many cases and standard CC calculations over-predict the cross
sections. This was named a hindrance phenomenon, and its physical origin is
still a matter of debate. Recent theoretical developments suggest that this
effect, at least partially, may be a consequence of the Pauli exclusion
principle. The hindrance may have far-reaching consequences in astrophysics
where fusion of light systems determines stellar evolution during the carbon
and oxygen burning stages, and yields important information for exotic
reactions that take place in the inner crust of accreting neutron stars.Comment: 40 pages, 63 figures, review paper accepted for EPJ
Attitudes and practices in the laboratory monitoring of conventional synthetic disease modifying anti-rheumatic drugs by rheumatologists and rheumatology trainees
Published online: 17 October 2022Objectives: There is scant research about laboratory monitoring in people taking conventional synthetic diseasemodifying anti-rheumatic drugs (csDMARDs) for rheumatic disease. Our objective was to conduct a scoping study to assess the range of current attitudes and the variation in practice of laboratory monitoring of csDMARDs by rheumatologists and trainees. Methods: Australian and overseas rheumatologists or trainees were invited through newsletter, Twitter and personal e-mail, to complete an anonymous online survey between 1 February and 22 March 2021. Questions focused on laboratory tests requested by csDMARD prescribed, frequency/pattern of monitoring, influence of additional factors and combination therapy, actions in response to abnormal tests, and attitudes to monitoring frequencies. Results were presented descriptively and analysed using linear and logistic regression. Results: There were 221 valid responses. Most respondents were from Australia (n = 53, 35%) followed by the US (n = 39, 26%), with a slight preponderance of women (n = 84, 56%), ≥ 11 years in rheumatology practice (n = 83, 56%) and in mostly public practice (n = 79, 53%). Respondents had a wide variation in the frequency and scheduling of tests. In general, respondents reported increasing monitoring frequency if patients had numerous comorbidities or if both methotrexate and leflunomide were being taken concurrently. There was a wide variety of responses to abnormal monitoring results and 27 (40%) considered that in general, monitoring tests are performed too frequently. Conclusions: The results demonstrated a wide variation in the frequency of testing, factors that should influence this, and what responses to abnormal test results are appropriate, indicates a likely lack of evidence and the need to define the risks, benefits and costs of different csDMARD monitoring regimens.James J. Tsakas, David F. L. Liew, Cameron L. Adams, Catherine L. Hill, Susanna Proudman, Samuel Whittle, Rachelle Buchbinder, and Philip C. Robinso
Superradiation from Crystals of High-Spin Molecular Nanomagnets
Phenomenological theory of superradiation from crystals of high-spin
molecules is suggested. We show that radiation friction can cause a
superradiation pulse and investigate the role of magnetic anisotropy, external
magnetic field and dipole-dipole interactions. Depending on the contribution of
all these factors at low temperature, several regimes of magnetization of
crystal sample are described. Very fast switch of magnetization's direction for
some sets of parameters is predicted.Comment: 10 pages, 3 figure
Oscillations above the barrier in the fusion of 28Si + 28Si
Fusion cross sections of 28Si + 28Si have been measured in a range above the
barrier with a very small energy step (DeltaElab = 0.5 MeV). Regular
oscillations have been observed, best evidenced in the first derivative of the
energy-weighted excitation function. For the first time, quite different
behaviors (the appearance of oscillations and the trend of sub-barrier cross
sections) have been reproduced within the same theoretical frame, i.e., the
coupled-channel model using the shallow M3Y+repulsion potential. The
calculations suggest that channel couplings play an important role in the
appearance of the oscillations, and that the simple relation between a peak in
the derivative of the energy-weighted cross section and the height of a
centrifugal barrier is lost, and so is the interpretation of the second
derivative of the excitation function as a barrier distribution for this
system, at energies above the Coulomb barrier.Comment: submitted to Physics Letters
Interpreting Helioseismic Structure Inversion Results of Solar Active Regions
Helioseismic techniques such as ring-diagram analysis have often been used to
determine the subsurface structural differences between solar active and quiet
regions. Results obtained by inverting the frequency differences between the
regions are usually interpreted as the sound-speed differences between them.
These in turn are used as a measure of temperature and magnetic-field strength
differences between the two regions. In this paper we first show that the
"sound-speed" difference obtained from inversions is actually a combination of
sound-speed difference and a magnetic component. Hence, the inversion result is
not directly related to the thermal structure. Next, using solar models that
include magnetic fields, we develop a formulation to use the inversion results
to infer the differences in the magnetic and thermal structures between active
and quiet regions. We then apply our technique to existing structure inversion
results for different pairs of active and quiet regions. We find that the
effect of magnetic fields is strongest in a shallow region above 0.985R_sun and
that the strengths of magnetic-field effects at the surface and in the deeper
(r < 0.98R_sun) layers are inversely related, i.e., the stronger the surface
magnetic field the smaller the magnetic effects in the deeper layers, and vice
versa. We also find that the magnetic effects in the deeper layers are the
strongest in the quiet regions, consistent with the fact that these are
basically regions with weakest magnetic fields at the surface. Because the
quiet regions were selected to precede or follow their companion active
regions, the results could have implications about the evolution of magnetic
fields under active regions.Comment: Accepted for publication in Solar Physic
Mayer and virial series at low temperature
We analyze the Mayer pressure-activity and virial pressure-density series for
a classical system of particles in continuous configuration space at low
temperature. Particles interact via a finite range potential with an attractive
tail. We propose physical interpretations of the Mayer and virial series'
radius of convergence, valid independently of the question of phase transition:
the Mayer radius corresponds to a fast increase from very small to finite
density, and the virial radius corresponds to a cross-over from monatomic to
polyatomic gas. Our results have consequences for the search of a low density,
low temperature solid-gas phase transition, consistent with the Lee-Yang
theorem for lattice gases and with the continuum Widom-Rowlinson model.Comment: 36 pages, 1 figur
Multipartite entangled coherent states
We propose a scheme for generating multipartite entangled coherent states via
entanglement swapping, with an example of a physical realization in ion traps.
Bipartite entanglement of these multipartite states is quantified by the
concurrence. We also use the --tangle to compute multipartite entanglement
for certain systems. Finally we establish that these results for entanglement
can be applied to more general multipartite entangled nonorthogonal states.Comment: 7 pages, two figures. We added more detail discussions on the
generation of multipartite entangled coherent states and multipartite
entangelemen
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