13,202 research outputs found
Change-point model on nonhomogeneous Poisson processes with application in copy number profiling by next-generation DNA sequencing
We propose a flexible change-point model for inhomogeneous Poisson Processes,
which arise naturally from next-generation DNA sequencing, and derive score and
generalized likelihood statistics for shifts in intensity functions. We
construct a modified Bayesian information criterion (mBIC) to guide model
selection, and point-wise approximate Bayesian confidence intervals for
assessing the confidence in the segmentation. The model is applied to DNA Copy
Number profiling with sequencing data and evaluated on simulated spike-in and
real data sets.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS517 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Product energy deposition of CN plus alkane H abstraction reactions in gas and solution phases
Protein adsorption on heterogeneous surfaces
The adsorption of the protein bovine serum albumin from an aqueous solution onto substrata made from pure silica, pure zirconia, and a mixture of the two has revealed that the adsorption behavior of the protein onto the mixture very significantly diverges from the corresponding mean of the behaviors with the pure substrata. A tentative explanation in terms of matching substratum heterogeneity with protein surface heterogeneity is offered
X-ray observations of the galaxy cluster PKS 0745-191: To the virial radius, and beyond
We measure X-ray emission from the outskirts of the cluster of galaxies PKS
0745-191 with Suzaku, determining radial profiles of density, temperature,
entropy, gas fraction, and mass. These measurements extend beyond the virial
radius for the first time, providing new information about cluster assembly and
the diffuse intracluster medium out to ~1.5 r_200, (r_200 ~ 1.7 Mpc ~ 15'). The
temperature is found to decrease by roughly 70 per cent from 0.3-1 r_200. We
also see a flattening of the entropy profile near the virial radius and
consider the implications this has for the assumption of hydrostatic
equilibrium when deriving mass estimates. We place these observations in the
context of simulations and analytical models to develop a better understanding
of non-gravitational physics in the outskirts of the cluster.Comment: 10 pages, 11 figures, accepted to MNRAS; expanded discussion of
analysis and uncertainties, results qualitatively unchange
Structural and electrostatic effects at the surfaces of size- and charge-selected aqueous nanodrops.
The effects of ion charge, polarity and size on the surface morphology of size-selected aqueous nanodrops containing a single ion and up to 550 water molecules are investigated with infrared photodissociation (IRPD) spectroscopy and theory. IRPD spectra of M(H2O) n where M = La3+, Ca2+, Na+, Li+, I-, SO42- and supporting molecular dynamics simulations indicate that strong interactions between multiply charged ions and water molecules can disrupt optimal hydrogen bonding (H-bonding) at the nanodrop surface. The IRPD spectra also reveal that "free" OH stretching frequencies of surface-bound water molecules are highly sensitive to the ion's identity and the OH bond's local H-bond environment. The measured frequency shifts are qualitatively reproduced by a computationally inexpensive point-charge model that shows the frequency shifts are consistent with a Stark shift from the ion's electric field. For multiply charged cations, pronounced Stark shifting is observed for clusters containing ∼100 or fewer water molecules. This is attributed to ion-induced solvent patterning that extends to the nanodrop surface, and serves as a spectroscopic signature for a cation's ability to influence the H-bond network of water located remotely from the ion. The Stark shifts measured for the larger nanodrops are extrapolated to infinite dilution to obtain the free OH stretching frequency of a surface-bound water molecule at the bulk air-water interface (3696.5-3701.0 cm-1), well within the relatively wide range of values obtained from SFG measurements. These cluster measurements also indicate that surface curvature effects can influence the free OH stretching frequency, and that even nanodrops without an ion have a surface potential that depends on cluster size
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Publication rates on the topic of racial and ethnic diversity in dermatology versus other specialties
Background: The population of the U.S. is becoming more diverse every year. The field of dermatology is not following the same trend. Objective: To assess the promotion of diversity in the field of dermatology by analyzing publications focused on diversity, compared to other specialties. Methods: The PubMed database was systematically searched to identify publications focused on diversity from January 2008 to July 2019. The search criteria were as follows: dermatology/radiology/ophthalmology/ anesthesiology/orthopedic surgery/family medicine/ internal medicine/general surgery AND diversity/ diverse/racial/race/ethnic/ethnicity/cultural/culture/competency/competence. Comparisons were made using single-factor ANOVA and two-group t-tests. A qualitative analysis was performed for publications in the field of dermatology. Results: From January 2016 to July 2019, there were 25 publications focused on diversity in dermatology (Mean=6.25, SD=2.06), compared to 6 in radiology (Mean=1.50, SD=1.29, P=0.01), two in ophthalmology (Mean=0.50, SD=0.58, P=0.01), two in anesthesiology (Mean=0.50, SD=1.00, P=0.01), 12 in orthopedic surgery (Mean=3.00, SD=1.41, P=0.04), 23 in family medicine (Mean=5.75, SD=2.22, P=0.75), 9 in internal medicine (Mean=2.25, SD=1.71, P=0.02), and 7 in general surgery (Mean=1.75, SD=0.50, P=0.02). Conclusions: Although the field of dermatology has suffered from a lack of racial/ethnic diversity, efforts to promote diversity via increased publications in the last four years have been stronger in dermatology compared to many other fields
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