1,541 research outputs found

    Two meta-analyses of noncontact healing studies

    Get PDF
    Reviews of empirical work on the efficacy of noncontact healing have found that interceding on behalf of patients through prayer or by adopting various practices that incorporate an intention to heal can have some positive effect upon their wellbeing. However, reviewers have also raised concerns about study quality and the diversity of healing approaches adopted, which makes the findings difficult to interpret. Some of these concerns can be addressed by adopting a standardised approach based on the double-blind randomised controlled clinical trial, and a recent review restricted to such studies has reported a combined effect size of .40 (p < .001). However, the studies in this review involve human participants for whom there can be no guarantee that control patients are not beneficiaries of healing intentions from friends, family or their own religious groups. We proposed to address this by reviewing healing studies that involved biological systems other than ‘whole’ humans (i.e. to include animal and plant work but also work involving human biological matter such as blood samples or cell cultures), which are less susceptible to placebo and expectancy effects and also allow for more circumscribed outcome measures. Secondly, doubts have been cast concerning the legitimacy of some of the work included in previous reviews so we planned to conduct an updated review that excluded that work. For phase 1, 49 non-whole human studies from 34 papers were eligible for review. The combined effect size weighted by sample size yielded a highly significant r of .258. However the effect sizes in the database were heterogeneous, and outcomes correlated with blind ratings of study quality. When restricted to studies that met minimum quality thresholds, the remaining 22 studies gave a reduced but still significant weighted r of .115. For phase 2, 57 whole human studies across 56 papers were eligible for review. When combined, these studies yielded a small effect size of r = .203 that was also significant. This database was also heterogeneous, and outcomes were correlated with methodological quality ratings. However, when restricted to studies that met threshold quality levels the weighted effect size for the 27 surviving studies increased to r = .224. Taken together these results suggest that subjects in the active condition exhibit a significant improvement in wellbeing relative to control subjects under circumstances that do not seem to be susceptible to placebo and expectancy effects. Findings with the whole human database gave a smaller mean effect size but this was still significant and suggests that the effect is not dependent upon the previous inclusion of suspect studies and is robust enough to accommodate some high profile failures to replicate. Both databases show problems with heterogeneity and with study quality and recommendations are made for necessary standards for future replication attempts

    Response of a spaceborne gravitational wave antenna to solar oscillations

    Full text link
    We investigate the possibility of observing very small amplitude low frequency solar oscillations with the proposed laser interferometer space antenna (LISA). For frequencies ν\nu below 3×104Hz3\times 10^{-4} {\rm Hz} the dominant contribution is from the near zone time dependent gravitational quadrupole moments associated with the normal modes of oscillation. For frequencies ν\nu above 3×104Hz 3\times 10^{-4} {\rm Hz} the dominant contribution is from gravitational radiation generated by the quadrupole oscillations which is larger than the Newtonian signal by a factor of the order (2πrν/c)4(2 \pi r \nu/ c)^4, where rr is the distance to the Sun, and cc is the velocity of light. The low order solar quadrupole pressure and gravity oscillation modes have not yet been detected above the solar background by helioseismic velocity and intensity measurements. We show that for frequencies ν2×104Hz\nu \lesssim 2\times 10^{-4} {\rm Hz}, the signal due to solar oscillations will have a higher signal to noise ratio in a LISA type space interferometer than in helioseismology measurements. Our estimates of the amplitudes needed to give a detectable signal on a LISA type space laser interferometer imply surface velocity amplitudes on the sun of the order of 1-10 mm/sec in the frequency range 1×1045×104Hz1\times 10^{-4} -5\times 10^{-4} {\rm Hz}. If such modes exist with frequencies and amplitudes in this range they could be detected with a LISA type laser interferometer.Comment: 16 pages, 6 figures, 1 table. A reworked and considerably improved version of ArXiv:astro-ph/0103472, Published in PR

    Simulations of core convection in rotating A-type stars: Differential rotation and overshooting

    Full text link
    We present the results of 3--D simulations of core convection within A-type stars of 2 solar masses, at a range of rotation rates. We consider the inner 30% by radius of such stars, thereby encompassing the convective core and some of the surrounding radiative envelope. We utilize our anelastic spherical harmonic (ASH) code, which solves the compressible Navier-Stokes equations in the anelastic approximation, to examine highly nonlinear flows that can span multiple scale heights. The cores of these stars are found to rotate differentially, with central cylindrical regions of strikingly slow rotation achieved in our simulations of stars whose convective Rossby number (R_{oc}) is less than unity. Such differential rotation results from the redistribution of angular momentum by the nonlinear convection that strongly senses the overall rotation of the star. Penetrative convective motions extend into the overlying radiative zone, yielding a prolate shape (aligned with the rotation axis) to the central region in which nearly adiabatic stratification is achieved. This is further surrounded by a region of overshooting motions, the extent of which is greater at the equator than at the poles, yielding an overall spherical shape to the domain experiencing at least some convective mixing. We assess the overshooting achieved as the stability of the radiative exterior is varied, and the weak circulations that result in that exterior. The convective plumes serve to excite gravity waves in the radiative envelope, ranging from localized ripples of many scales to some remarkable global resonances.Comment: 48 pages, 16 figures, some color. Accepted to Astrophys. J. Color figures compressed with appreciable loss of quality; a PDF of the paper with better figures is available at http://lcd-www.colorado.edu/~brownim/core_convectsep24.pd

    On general relativistic uniformly rotating white dwarfs

    Full text link
    The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of general relativity. Hartle's formalism is applied to construct the internal and external solutions to the Einstein equations. The WD matter is described by the relativistic Feynman-Metropolis-Teller equation of state which generalizes the Salpeter's one by taking into account the finite size of the nuclei, the Coulomb interactions as well as electroweak equilibrium in a self-consistent relativistic fashion. The mass MM, radius RR, angular momentum JJ, eccentricity ϵ\epsilon, and quadrupole moment QQ of RWDs are calculated as a function of the central density ρc\rho_c and rotation angular velocity Ω\Omega. We construct the region of stability of RWDs (JJ-MM plane) taking into account the mass-shedding limit, inverse β\beta-decay instability, and the boundary established by the turning-points of constant JJ sequences which separates stable from secularly unstable configurations. We found the minimum rotation periods 0.3\sim 0.3, 0.5, 0.7 and 2.2 seconds and maximum masses 1.500\sim 1.500, 1.474, 1.467, 1.202 MM_\odot for 4^{4}He, 12^{12}C, 16^{16}O, and 56^{56}Fe WDs respectively. By using the turning-point method we found that RWDs can indeed be axisymmetrically unstable and we give the range of WD parameters where it occurs. We also construct constant rest-mass evolution tracks of RWDs at fixed chemical composition and show that, by loosing angular momentum, sub-Chandrasekhar RWDs (mass smaller than maximum static one) can experience both spin-up and spin-down epochs depending on their initial mass and rotation period while, super-Chandrasekhar RWDs (mass larger than maximum static one), only spin-up.Comment: The Astrophysical Journal; in pres

    Numerical constraints on the model of stochastic excitation of solar-type oscillations

    Full text link
    Analyses of a 3D simulation of the upper layers of a solar convective envelope provide constraints on the physical quantities which enter the theoretical formulation of a stochastic excitation model of solar p modes, for instance the convective velocities and the turbulent kinetic energy spectrum. These constraints are then used to compute the acoustic excitation rate for solar p modes, P. The resulting values are found ~5 times larger than the values resulting from a computation in which convective velocities and entropy fluctuations are obtained with a 1D solar envelope model built with the time-dependent, nonlocal Gough (1977) extension of the mixing length formulation for convection (GMLT). This difference is mainly due to the assumed mean anisotropy properties of the velocity field in the excitation region. The 3D simulation suggests much larger horizontal velocities compared to vertical ones than in the 1D GMLT solar model. The values of P obtained with the 3D simulation constraints however are still too small compared with the values inferred from solar observations. Improvements in the description of the turbulent kinetic energy spectrum and its depth dependence yield further increased theoretical values of P which bring them closer to the observations. It is also found that the source of excitation arising from the advection of the turbulent fluctuations of entropy by the turbulent movements contributes ~ 65-75 % to the excitation and therefore remains dominant over the Reynolds stress contribution. The derived theoretical values of P obtained with the 3D simulation constraints remain smaller by a factor ~3 compared with the solar observations. This shows that the stochastic excitation model still needs to be improved.Comment: 11 pages, 9 figures, accepted for publication in A&

    Asteroseismic diagrams for solar-type stars

    Full text link
    We explore the feasibility of applying the Christensen-Dalsgaard diagram to real asteroseismic data and provide quantitative measures of the uncertainty associated with the results. We also propose a new kind of seismic diagram, based on the determination of the locations of sharp acoustic features inside a star. We show that by combining the information about the position of the base of the convective envelope or the HeII ionisation zone with a measure of the average large separation, it is possible to constrain the unknown chemical composition or the various parameters characterising the physical processes in the stellar interior. We demonstrate the application of this technique to the analysis of mock data for a CoRoT target star.Comment: Accepted for publication in A&

    Counselling in graphics - Visual aids for distressed patients and their doctors

    Get PDF
    Copyright to Australian Family Physician. Reproduced with permission. Permission to reproduce must be sought from the publisher, The Royal Australian College of General Practitioners.Distressed patients present to their general practitioners with a range of information which may overwhelm both patient and doctor. This article provides visual aids which give structure to counselling sessions, providing a grounding for both patient and doctor. Case studies are presented that demosntrate the use of these aids in counselling sessions.Anne Sved-Williams; Helen Roxburg
    corecore