36,708 research outputs found
Unethical aspects of homeopathic dentistry
In the last year there has been a great deal of public debate about homeopathy, the system of alternative medicine whose main principles are that like cures like and that potency increases relative to dilution. The House of Commons Select Committee on Science and Technology concluded in November 2009 that there is no evidence base for homeopathy, and agreed with some academic commentators that homeopathy should not be funded by the NHS. While homeopathic doctors and hospitals are quite commonplace, some might be surprised to learn that there are also many homeopathic dentists practising in the UK. This paper examines the statements made by several organisations on behalf of homeopathic dentistry and suggests that they are not entirely ethical and may be in breach of various professional guidelines
Calibration of BVRI Photometry for the Wide Field Channel of the HST Advanced Camera for Surveys
We present new observations of two Galactic globular clusters, PAL4 and
PAL14, using the Wide-Field Channel of the Advanced Camera for Surveys (ACS) on
board the Hubble Space Telescope (HST), and reanalyze archival data from a
third, NGC2419. We matched our photometry of hundreds of stars in these fields
from the ACS images to existing, ground-based photometry of faint sequences
which were calibrated on the standard BVRI system of Landolt. These stars are
significantly fainter than those generally used for HST calibration purposes,
and therefore are much better matched to supporting precision photometry of ACS
science targets. We were able to derive more accurate photometric
transformation coefficients for the commonly used ACS broad-band filters
compared to those published by Sirianni, et al. (2005), owing to the use of a
factor of several more calibration stars which span a greater range of color.
We find that the inferred transformations from each cluster individually do not
vary significantly from the average, except for a small offset of the
photometric zeropoint in the F850LP filter. Our results suggest that the
published prescriptions for the time-dependent correction of CCD
charge-transfer efficiency appear to work very well over the ~3.5 yr interval
that spans our observations of PAL4 and PAL14 and the archived images of
NGC2419.Comment: 22 pages, 12 figures. Accepted for publication in PAS
Schroedinger Wheeler-DeWitt Equation In Multidimensional Cosmology
We study multidimensional cosmology to obtain the wavefunction of the
universe using wormhole dominance proposal. Using a prescription for time we
obtain the Schroedinger-Wheeler-DeWitt equation without any reference to WD
equation and WKB ansatz for WD wavefunction. It is found that the
Hartle-Hawking or wormhole-dominated boundary conditions serve as a seed for
inflation as well as for Gaussian type ansatz to Schroedinger-Wheeler-DeWitt
equation.Comment: 10 Pages, LaTeX, no figur
Experimental evaluation of shockless supercritical airfoils in cascade
Surface Mach number distributions, total pressure loss coefficients, and schlieren images of the flow are presented over a range of inlet Mach numbers and air angles. Several different trailing edge geometries were tested. At design conditions a leading edge separation bubble was observed resulting in higher losses than anticipated. The minimum losses were obtained at a negative incidence condition in which the flow was accelerating over most of the supercritical region. Relatively minor differences in losses were measured with the different trailing edge geometries studied
Interactions between empathy and resting heart rate in early adolescence predict violent behavior in late adolescence and early adulthood.
BackgroundAlthough resting heart rate (RHR) and empathy are independently and negatively associated with violent behavior, relatively little is known about the interplay between these psychophysiological and temperament-related risk factors.MethodsUsing a sample of 160 low-income, racially diverse men followed prospectively from infancy through early adulthood, this study examined whether RHR and empathy during early adolescence independently and interactively predict violent behavior and related correlates in late adolescence and early adulthood.ResultsControlling for child ethnicity, family income, and child antisocial behavior at age 12, empathy inversely predicted moral disengagement and juvenile petitions for violent crimes, while RHR was unrelated to all measures of violent behavior. Interactive effects were also evident such that among men with lower but not higher levels of RHR, lower empathy predicted increased violent behavior, as indexed by juvenile arrests for violent offenses, peer-reported violent behavior at age 17, self-reported moral disengagement at age 17, and self-reported violent behavior at age 20.ConclusionsImplications for prevention and intervention are considered. Specifically, targeting empathic skills among individuals at risk for violent behavior because of specific psychophysiological profiles may lead to more impactful interventions
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The interaction between monoamine oxidase A and punitive discipline in the development of antisocial behavior: Mediation by maladaptive social information processing.
Previous studies demonstrate that boys' monoamine oxidase A (MAOA) genotype interacts with adverse rearing environments in early childhood, including punitive discipline, to predict later antisocial behavior. Yet the mechanisms by which MAOA and punitive parenting interact during childhood to amplify risk for antisocial behavior are not well understood. In the present study, hostile attributional bias and aggressive response generation during middle childhood, salient aspects of maladaptive social information processing, were tested as possible mediators of this relation in a sample of 187 low-income men followed prospectively from infancy into early adulthood. Given racial-ethnic variation in MAOA allele frequencies, analyses were conducted separately by race. In both African American and Caucasian men, those with the low-activity MAOA allele who experienced more punitive discipline at age 1.5 generated more aggressive responses to perceived threat at age 10 relative to men with the high-activity variant. In the African American subsample only, formal mediation analyses indicated a marginally significant indirect effect of maternal punitiveness on adult arrest records via aggressive response generation in middle childhood. The findings suggest that maladaptive social information processing may be an important mechanism underlying the association between MAOA Ă— Parenting interactions and antisocial behavior in early adulthood. The present study extends previous work in the field by demonstrating that MAOA and harsh parenting assessed in early childhood interact to not only predict antisocial behavior in early adulthood, but also predict social information processing, a well-established social-cognitive correlate of antisocial behavior
Selection Effects, Biases, and Constraints in the Calan/Tololo Supernova Survey
We use Monte Carlo simulations of the Calan/Tololo photographic supernova
survey to show that a simple model of the survey's selection effects accounts
for the observed distributions of recession velocity, apparent magnitude,
angular offset, and projected radial distance between the supernova and the
host galaxy nucleus for this sample of Type Ia supernovae (SNe Ia). The model
includes biases due to the flux-limited nature of the survey, the different
light curve morphologies displayed by different SNe Ia, and the difficulty of
finding events projected near the central regions of the host galaxies. From
these simulations we estimate the bias in the zero-point and slope of the
absolute magnitude-decline rate relation used in SNe Ia distance measurements.
For an assumed intrinsic scatter of 0.15 mag about this relation, these
selection effects decrease the zero-point by 0.04 mag. The slope of the
relation is not significantly biased. We conclude that despite selection
effects in the survey, the shape and zero-point of the relation determined from
the Calan/Tololo sample are quite reliable. We estimate the degree of
incompleteness of the survey as a function of decline rate and estimate a
corrected luminosity function for SNe Ia in which the frequency of SNe appears
to increase with decline rate (the fainter SNe are more common). Finally, we
compute the integrated detection efficiency of the survey in order to infer the
rate of SNe Ia from the 31 events found. For a value of Ho=65 km/sec/Mpc we
obtain a SN Ia rate of 0.21(+0.30)(-0.13) SNu. This is in good agreement with
the value 0.16+/-0.05 SNu recently determined by Capellaro et al. (1997).Comment: 36 pages, 19 figures as extra files, to appear in the A
(Super)twistors and (super)strings
The Lagrangian formulation of the D=4 bosonic string and superstring in terms
of the (super)twistors is considered. The (super)twistor form of the equations
of motion is derived and the kappa-symmetry transformation for the
supertwistors is given. It is shown that the covariant kappa-symmetry gauge
fixation results in the action quadratic in the (super)twistor variables.Comment: LaTeX, 17 page
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