11,489 research outputs found
Tonsillectomy among children with low baseline acute throat infection consultation rates in UK general practices: a cohort study.
OBJECTIVE: To investigate the effectiveness of tonsillectomy in reducing acute throat infection (ATI) consultation rates over 6 years' follow-up among children with low baseline ATI consultation rates.
DESIGN: Retrospective cohort study.
SETTING: UK general practices from the Clinical Practice Research Datalink.
PARTICIPANTS: Children aged 4-15 years with ≤3 ATI consultations during the 3 years prior to 2001 (baseline). 450 children who underwent tonsillectomy (tonsillectomy group) and 13 442 other children with an ATI consultation (comparison group) in 2001.
MAIN OUTCOME MEASURES: Mean differences in ATI consultation rates over the first 3 years' and subsequent 3 years' follow-up compared with 3 years prior to 2001 (baseline); odds of ≥3 ATI consultations at the same time points.
RESULTS: Among children in the tonsillectomy group, the 3-year mean ATI consultation rate decreased from 1.31 to 0.66 over the first 3 years' follow-up and further declined to 0.60 over the subsequent 3 years' follow-up period. Compared with children who had no operation, those who underwent tonsillectomy experienced a reduction in 3-year mean ATI consultations per child of 2.5 (95% CI 2.3 to 2.6, p<0.001) over the first 3 years' follow-up, but only 1.2 (95% CI 1.0 to 1.4, p<0.001) over the subsequent 3 years' follow-up compared with baseline, respectively. This equates to a mean reduction of 3.7 ATI consultations over a 6-year period and approximates to a mean annual reduction of 0.6 ATI consultations per child, per year, over 6 years' follow-up. Children who underwent tonsillectomy were also much less likely to experience ≥3 ATI consultations during the first 3 years' follow-up (adjusted OR=0.12, 95% CI 0.08 to 0.17) and the subsequent 3 years' follow-up (adjusted OR=0.24, 95% CI 0.14 to 0.41).
CONCLUSIONS: Among children with low baseline ATI rates, there was a statistically significant reduction in ATI consultation rates over 6 years' follow-up. However, the relatively modest clinical benefit needs to be weighed against the potential risks and complications associated with surgery
Eligibility for bariatric surgery among adults in England: analysis of a national cross-sectional survey.
This study aimed to determine the number eligible for bariatric surgery and their sociodemographic characteristics.We used Health Survey for England 2006 data, representative of the non-institutionalized English population.The number of people eligible for bariatric surgery in England based on national guidance is unknown. The UK National Institute for Health and Clinical Excellence criteria for eligibility are those with body mass index (BMI) 35-40 kg/m(2) with at least one comorbidity potentially improved by losing weight or a BMI > 40 kg/m(2).Of 13,742 adult respondents (≥18 years), we excluded participants with invalid BMI (n = 2103), comorbidities (n = 2187) or sociodemographic variables (n = 27) data, for a final study sample of 9425 participants.The comorbidities examined were hypertension, type 2 diabetes, stroke, coronary heart disease and osteoarthritis. Sociodemographic variables assessed included age, sex, employment status, highest educational qualification, social class and smoking status.5.4% (95% CI 5.0-5.9) of the non-institutionalized adult population in England could meet criteria for having bariatric surgery after accounting for survey weights. Those eligible were more likely than the general population to be women (60.1% vs. 39.9%, p<0.01), retired (22.4% vs. 12.8% p<0.01), and have no formal educational qualifications (35.7% vs. 21.3%, p<0.01).The number of adults potentially eligible for bariatric surgery in England (2,147,683 people based on these results and 2006 population estimates) far exceeds previous estimates of eligibility. In view of the sociodemographic characteristics of this group, careful resource allocation is required to ensure equitable access on the basis of need
Parameters of Integral Circulant Graphs and Periodic Quantum Dynamics
The intention of the paper is to move a step towards a classification of
network topologies that exhibit periodic quantum dynamics. We show that the
evolution of a quantum system, whose hamiltonian is identical to the adjacency
matrix of a circulant graph, is periodic if and only if all eigenvalues of the
graph are integers (that is, the graph is integral). Motivated by this
observation, we focus on relevant properties of integral circulant graphs.
Specifically, we bound the number of vertices of integral circulant graphs in
terms of their degree, characterize bipartiteness and give exact bounds for
their diameter. Additionally, we prove that circulant graphs with odd order do
not allow perfect state transfer.Comment: 12 page
A novel HoxB cluster protein expressed in the hindbrain and pharyngeal arches
We describe a novel zebrafish line that fluorescently tags a previously unknown protein, CT74a, allowing us to follow its endogenous expression in real time and at subcellular resolution in live embryos. Our results showed that CT74a-Citrine fusion protein is expressed in the developing pharyngeal arches, hindbrain, and fin buds in a pattern highly reminiscent of transcription factors belonging to anterior Hox gene families, including expression in a subset of neuronal nuclei. Consistent with this, splinkerette-PCR revealed that CT74a-Citrine's genomic integration is within the HoxB region, and 3′ RACE demonstrated that its downstream coding sequence has no recognizable homology. Thus, CT74a is a previously unknown protein located within the HoxB cluster adjacent to Hoxb4a and is expressed in a Hoxb4a-like pattern
The glass transition and crystallization kinetic studies on BaNaB9O15 glasses
Transparent glasses of BaNaB9O15 (BNBO) were fabricated via the conventional
melt-quenching technique. The amorphous and the glassy nature of the
as-quenched samples were respectively, confirmed by X-ray powder diffraction
(XRD) and differential scanning calorimetry (DSC). The glass transition and
crystallization parameters were evaluated under non-isothermal conditions using
DSC. The correlation between the heating rate dependent glass transition and
the crystallization temperatures was discussed and deduced the Kauzmann
temperature for BNBO glass-plates and powdered samples. The values of the
Kauzmann temperature for the plates and powdered samples were 776 K and 768 K,
respectively. Approximation-free method was used to evaluate the
crystallization kinetic parameters for the BNBO glass samples. The effect of
the sample thickness on the crystallization kinetics of BNBO glasses was also
investigated.Comment: 23 pages, 12 figure
Scattering of a solitary pulse on a local defect or breather
A model is introduced to describe guided propagation of a linear or nonlinear
pulse which encounters a localized nonlinear defect, that may be either static
or breather-like one (the model with the static defect applies to an optical
pulse in a long fiber link with an inserted additional section of a nonlinear
fiber). In the case when the host waveguide is linear, the pulse has a Gaussian
shape. In that case, an immediate result of its interaction with the nonlinear
defect can be found in an exact analytical form, amounting to transformation of
the incoming Gaussian into an infinite array of overlapping Gaussian pulses.
Further evolution of the array in the linear host medium is found numerically
by means of the Fourier transform. An important ingredient of the linear medium
is the third-order dispersion, that eventually splits the array into individual
pulses. If the host medium is nonlinear, the input pulse is taken as a
fundamental soliton. The soliton is found to be much more resistant to the
action of the nonlinear defect than the Gaussian pulse in the linear host
medium. In this case, the third-order-dispersion splits the soliton proper and
wavepackets generated by the action of the defect.Comment: a revtex text file and 13 pdf files with figures. Physica Scripta, in
pres
Towards efficient calibration for webcam eye-tracking in online experiments
Calibration is performed in eye-tracking studies to map raw model outputs to gaze-points on the screen and improve accuracy of gaze predictions. Calibration parameters, such as user-screen distance, camera intrinsic properties, and position of the screen with respect to the camera can be easily calculated in controlled offline setups, however, their estimation is non-trivial in unrestricted, online, experimental settings. Here, we propose the application of deep learning models for eye-tracking in online experiments, providing suitable strategies to estimate calibration parameters and perform personal gaze calibration. Focusing on fixation accuracy, we compare results with respect to calibration frequency, the time point of calibration during data collection (beginning, middle, end), and calibration procedure (fixation-point or smooth pursuit-based). Calibration using fixation and smooth pursuit tasks, pooled over three collection time-points, resulted in the best fixation accuracy. By combining device calibration, gaze calibration, and the best-performing deep-learning model, we achieve an accuracy of 2.580−a considerable improvement over reported accuracies in previous online eye-tracking studies
Scaled free energies, power-law potentials, strain pseudospins and quasi-universality for first-order structural transitions
We consider ferroelastic first-order phase transitions with
order-parameter strains entering Landau free energies as invariant polynomials,
that have structural-variant Landau minima. The total free energy
includes (seemingly innocuous) harmonic terms, in the {\it
non}-order-parameter strains. Four 3D transitions are considered,
tetragonal/orthorhombic, cubic/tetragonal, cubic/trigonal and
cubic/orthorhombic unit-cell distortions, with respectively, and 2; and and 6. Five 2D transitions are also considered, as
simpler examples. Following Barsch and Krumhansl, we scale the free energy to
absorb most material-dependent elastic coefficients into an overall prefactor,
by scaling in an overall elastic energy density; a dimensionless temperature
variable; and the spontaneous-strain magnitude at transition .
To leading order in the scaled Landau minima become
material-independent, in a kind of 'quasi-universality'. The scaled minima in
-dimensional order-parameter space, fall at the centre and at the
corners, of a transition-specific polyhedron inscribed in a sphere, whose
radius is unity at transition. The `polyhedra' for the four 3D transitions are
respectively, a line, a triangle, a tetrahedron, and a hexagon. We minimize the
terms harmonic in the non-order-parameter strains, by substituting
solutions of the 'no dislocation' St Venant compatibility constraints, and
explicitly obtain powerlaw anisotropic, order-parameter interactions, for all
transitions. In a reduced discrete-variable description, the competing minima
of the Landau free energies induce unit-magnitude pseudospin vectors, with values, pointing to the polyhedra corners and the (zero-value) center.Comment: submitted to PR
Reaction-diffusion systems and nonlinear waves
The authors investigate the solution of a nonlinear reaction-diffusion
equation connected with nonlinear waves. The equation discussed is more general
than the one discussed recently by Manne, Hurd, and Kenkre (2000). The results
are presented in a compact and elegant form in terms of Mittag-Leffler
functions and generalized Mittag-Leffler functions, which are suitable for
numerical computation. The importance of the derived results lies in the fact
that numerous results on fractional reaction, fractional diffusion, anomalous
diffusion problems, and fractional telegraph equations scattered in the
literature can be derived, as special cases, of the results investigated in
this article.Comment: LaTeX, 16 pages, corrected typo
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