1,425 research outputs found
Electrostatic interactions between discrete helices of charge
We analytically examine the pair interaction for parallel, discrete helices
of charge. Symmetry arguments allow for the energy to be decomposed into a sum
of terms, each of which has an intuitive geometric interpretation. Truncated
Fourier expansions for these terms allow for accurate modeling of both the
axial and azimuthal terms in the interaction energy and these expressions are
shown to be insensitive to the form of the interaction. The energy is evaluated
numerically through application of an Ewald-like summation technique for the
particular case of unscreened Coulomb interactions between the charges of the
two helices. The mode structures and electrostatic energies of flexible helices
are also studied. Consequences of the resulting energy expressions are
considered for both F-actin and A-DNA aggregates
Does Incidental Disgust Amplify Moral Judgment? A Meta-Analytic Review of Experimental Evidence
The role of emotion in moral judgment is currently a topic of much debate in moral psychology. One specific claim made by many researchers is that irrelevant feelings of disgust can amplify the severity of moral condemnation. Numerous studies have found this effect, but there have also been several published failures to replicate this effect. Clarifying this issue would inform important theoretical debates between rival accounts of moral judgment. We meta-analyzed all available studies, published and unpublished, that experimentally manipulated incidental disgust prior to or concurrent with a moral judgment task (k = 50). We found that there is evidence for a small amplification effect of disgust (d = .11), which is strongest for gustatory/olfactory modes of disgust induction. However, there is also some suggestion of publication bias in this literature, and when this is accounted for, the effect disappears entirely (d = -.01). Moreover, prevalent confounds mean that the effect size that we estimate is best interpreted as an upper bound on the size of the amplification effect. The results of this meta-analysis argue against strong claims about the causal role of affect in moral judgment and suggest a need for new, more rigorous research on this topic
Cervical Screening at Age 50-64 Years and the Risk of Cervical Cancer at Age 65 Years and Older: Population-Based Case Control Study
This work was supported by Cancer Research UK [C8162/10406 and C8162/12537]
The Luminosity Function of Galaxies in the Las Campanas Redshift Survey
We present the -band luminosity function for a sample of 18678 galaxies,
with average redshift , from the Las Campanas Redshift Survey. The
luminosity function may be fit by a Schechter function with , , and $\phi^* = 0.019 \pm 0.001 \
h^3^{-3}-23.0 \leq M - 5 \log h \leq -17.5b_J \approx 20b_J \approx 20\alpha = -0.7\alpha = -1W_{\lambda} = 5\alphaM^* =
-20.03 \pm 0.03 + 5 \log h\alpha = -0.9 \pm 0.1M^* = -20.22 \pm 0.02 + 5 \log h\alpha = -0.3
\pm 0.1$.
(abridged abstract)Comment: 41 pages, including 13 postscript figures, uses AASTEX v4.0 style
files. Important clarification of R-band definition, plus correction of
luminosity densities and updated references. Main conclusions unchanged.
Final version to appear in Ap
Characteristics and screening history of women diagnosed with cervical cancer aged 20-29 years
This work is supported by Cancer Research UK (C8162/10406 and C8162/12537)
A statistical test of emission from unresolved point sources
We describe a simple test of the spatial uniformity of an ensemble of
discrete events. Given an estimate for the point source luminosity function and
an instrumental point spread function (PSF), a robust upper bound on the
fractional point source contribution to a diffuse signal can be found. We
verify with Monte Carlo tests that the statistic has advantages over the
two-point correlation function for this purpose, and derive analytic estimates
of the statistic's mean and variance as a function of the point source
contribution. As a case study, we apply this statistic to recent gamma-ray data
from the Fermi Large Area Telescope (LAT), and demonstrate that at energies
above 10 GeV, the contribution of unresolved point sources to the diffuse
emission is small in the region relevant for study of the WMAP Haze.Comment: 11 pages, 7 figures. Final version, accepted by Mon. Not. R. Astron.
Soc. The definitive version is available at www.blackwell-synergy.com
Line versus Flux Statistics -- Considerations for the Low Redshift Lyman-alpha Forest
The flux/transmission power spectrum has become a popular statistical tool in
studies of the high redshift () Lyman-alpha forest. At low redshifts,
where the forest has thinned out into a series of well-isolated absorption
lines, the motivation for flux statistics is less obvious. Here, we study the
relative merits of flux versus line correlations, and derive a simple condition
under which one is favored over the other on purely statistical grounds.
Systematic errors probably play an important role in this discussion, and they
are outlined as well.Comment: 6 pages, to appear in "The IGM/Galaxy Connection: The Distribution of
Baryons at z=0", eds. J. L. Rosenberg and M. E. Putma
Risk of preterm delivery with increasing depth of excision for cervical intraepithelial neoplasia in England: nested case-control study
Objective To determine the association between depth of excision of cervical intraepithelial neoplasia and risk of preterm birth. Design Case-control study nested in record linkage cohort study. Setting 12 hospitals in England. Participants From a cohort of 11 471 women with at least one histological sample taken at colposcopy and a live singleton birth (before or after colposcopy), 1313 women with a preterm birth (20-36 weeks) were identified and frequency matched on maternal age at delivery, parity, and study site to 1313 women with term births (38-42 weeks). Main outcome measures Risk of preterm birth and very/extreme preterm birth by depth of excisional treatment of the cervical transformation zone. Results After exclusions, 768 preterm births (cases) and 830 term births after colposcopy remained. The risk of preterm birth was no greater in women with a previous small (<10 mm) excision (absolute risk 7.5%, 95% confidence interval 6.0% to 8.9%) than in women with a diagnostic punch biopsy (7.2%, 5.9% to 8.5%). Women with a medium (10-14 mm) (absolute risk 9.6%; relative risk 1.28, 0.98 to 1.68), large (15-19 mm) (15.3%; 2.04, 1.41 to 2.96), or very large (≥20 mm) excision (18.0%; 2.40, 1.53 to 3.75) had a higher risk of preterm delivery than those with small excision. The same pattern was seen in 161 women with very/extremely preterm births (20-31 weeks) and with increasing volume excised. Most births were conceived more than three years after colposcopy, and the risk of preterm delivery did not seem to depend on time from excision to conception. Conclusions The risk of preterm birth is at most minimally affected by a small excision. Larger excisions, particularly over 15 mm or 2.66 cm(3), are associated with a doubling of the risk of both preterm and very preterm births. The risk does not decrease with increasing time from excision to conception. Efforts should be made to excise the entire lesion while preserving as much healthy cervical tissue as possible. Close obstetric monitoring is warranted for women who have large excisions of the cervical transformation zone
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