2,907 research outputs found
Constraining the Mass-Richness Relationship of redMaPPer Clusters with Angular Clustering
The potential of using cluster clustering for calibrating the mass-observable
relation of galaxy clusters has been recognized theoretically for over a
decade. Here, we demonstrate the feasibility of this technique to achieve high
precision mass calibration using redMaPPer clusters in the Sloan Digital Sky
Survey North Galactic Cap. By including cross-correlations between several
richness bins in our analysis we significantly improve the statistical
precision of our mass constraints. The amplitude of the mass-richness relation
is constrained to 7% statistical precision. However, the error budget is
systematics dominated, reaching an 18% total error that is dominated by
theoretical uncertainty in the bias-mass relation for dark matter halos. We
perform a detailed treatment of the effects of assembly bias on our analysis,
finding that the contribution of such effects to our parameter uncertainties is
somewhat greater than that of measurement noise. We confirm the results from
Miyatake et al. (2015) that the clustering amplitude of redMaPPer clusters
depends on galaxy concentration, and provide additional evidence in support of
this effect being due to some form of assembly bias. The results presented here
demonstrate the power of cluster clustering for mass calibration and cosmology
provided the current theoretical systematics can be ameliorated.Comment: 18 pages, 9 figure
Numerical Test of Disk Trial Wave function for Half-Filled Landau Level
The analyticity of the lowest Landau level wave functions and the relation
between filling factor and the total angular momentum severely limits the
possible forms of trial wave functions of a disk of electrons subject to a
strong perpendicular magnetic field. For N, the number of electrons, up to 12
we have tested these disk trial wave functions for the half filled Landau level
using Monte Carlo and exact diagonalization methods. The agreement between the
results for the occupation numbers and ground state energies obtained from
these two methods is excellent. We have also compared the profile of the
occupation number near the edge with that obtained from a field-theoretical
method. The results give qualitatively identical edge profiles. Experimental
consequences are briefly discussed.Comment: To be published in Phys. Rev. B. 9 pages, 6 figure
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Frame me if you must: PrEP framing and the impact on adherence to HIV Pre-exposure Prophylaxis
Abstract
Background
“PrEP whore” has been used both as a pejorative by PrEP opponents in the gay community and, reactively, by PrEP advocates as a method to reclaim the label from stigmatization and “slut-shaming.” The actual prevalence and impact of such PrEP-directed stigma on adherence have been insufficiently studied.
Methods
CCTG 595 was a randomized controlled PrEP demonstration project in 398 HIV-uninfected MSM and transwomen. Intracellular tenofovir-diphosphate (TFV-DP) levels at weeks 12 and 48 were used as a continuous measure of adherence. At study visits, participants were asked to describe how they perceived others’ reactions to them being on PrEP. These perceptions were categorized a priori as either “positively framed,” “negatively framed,” or both. We used Wilcoxon rank-sum to determine the association between positive and negative framing and TFV-DP levels at weeks 12 and 48.
Results
By week 4, 29% of participants reported perceiving positive reactions from members of their social groups, 5% negative, and 6% both. Reporting decreased over 48 weeks, but positive reactions were consistently reported more than negative. At week 12, no differences in mean TFV-DP levels were observed in participants with positively-framed reactions compared with those reporting no outcome or only negatively-framed (1338 [IQR, 1036-1609] vs. 1281 [946-1489] fmol/punch, P = 0.17). Additionally, no differences were observed in those with negative reactions vs. those without (1209 [977–1427] vs. 1303 [964–1545], P = 0.58). At week 48, mean TFV-DP levels trended toward being higher among those that report any reaction, regardless if positive (1335 [909–1665] vs. 1179 [841–1455], P = 0.09) or negative (1377 [1054–1603] vs. 1192 [838–1486], P = 0.10) than those reporting no reaction. At week 48, 46% of participants reported experiencing some form of PrEP-directed judgment, 23% reported being called “PrEP whore,” and 21% avoiding disclosing PrEP use.
Conclusion
Over 48 weeks, nearly half of participants reported some form of judgment or stigmatization as a consequence of PrEP use. However, individuals more frequently perceived positively framed reactions to being on PrEP than negative. Importantly, long-term PrEP adherence does not appear to suffer as a result of negative PrEP framing.
Disclosures
All authors: No reported disclosures
Design and Implementation of the UniProt Website
The UniProt consortium is the main provider of protein sequence and annotation data for much of the life sciences community. The "www.uniprot.org":http://www.uniprot.org website is the primary access point to this data and to documentation and basic tools for the data. This paper discusses the design and implementation of the new website, which was released in July 2008, and shows how it improves data access for users with different levels of experience, as well as to machines for programmatic access
Stochastic Mode-Reduction in Models with Conservative Fast Sub-Systems
A stochastic mode reduction strategy is applied to multiscale models with a
deterministic energy-conserving fast sub-system. Specifically, we consider
situations where the slow variables are driven stochastically and interact with
the fast sub-system in an energy-conserving fashion. Since the stochastic terms
only affect the slow variables, the fast-subsystem evolves deterministically on
a sphere of constant energy. However, in the full model the radius of the
sphere slowly changes due to the coupling between the slow and fast dynamics.
Therefore, the energy of the fast sub-system becomes an additional hidden slow
variable that must be accounted for in order to apply the stochastic mode
reduction technique to systems of this type
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Perceived Versus Calculated HIV Risk: Implications for Pre-exposure Prophylaxis Uptake in a Randomized Trial of Men Who Have Sex With Men.
BackgroundInaccurate HIV risk perception by men who have sex with men is a barrier to HIV prevention. Providing information about objective HIV risk could improve pre-exposure prophylaxis (PrEP) uptake.MethodsPrEP Accessibility Research & Evaluation 2 (PrEPARE2) was a randomized controlled trial of men who have sex with men to determine whether an objective risk score affects future PrEP uptake. Participants completed a baseline survey to assess demographics, risk behaviors, and HIV self-perceived risk (SPR). The survey generated a calculated HIV risk (CalcR) score, estimating HIV risk based on reported condomless anal intercourse and sexually transmitted infections, and was provided to individuals in the intervention arm. Participants were contacted 8 weeks later to determine whether they initiated PrEP.ResultsOf 171 participants (median age 32 years; 37% Hispanic or non-Hispanic Black; median 5 sexual partners in the past 6 months), 81% had heard of PrEP, and 57% believed they were good PrEP candidates. SPR had poor agreement with CalcR (kappa = 0.176) with 38% underestimating their HIV risk. At week 8, only 14 of 135 participants had initiated PrEP with no difference between arms (CalcR 11%, control 10%, P > 0.99). The most common reason for not starting PrEP was low HIV risk perception. There was a relative decrease in SPR over time (P = 0.06) but no difference between arms (P = 0.29).ConclusionProviding an objective HIV risk score alone did not increase PrEP uptake. HIV testing performed at testing sites may be a crucial time to correct misperceptions about risk and initiate same-day PrEP, given enthusiasm for PrEP on the testing day to facilitate greater uptake
Dipole superfluid hydrodynamics
We construct a theory of hydrodynamic transport for systems with conserved
dipole moment, U(1) charge, energy, and momentum. These models have been
considered in the context of fractons, since their elementary and isolated
charges are immobile by symmetry, and have two known translation-invariant
gapless phases: a ``p-wave dipole superfluid'' phase where the dipole symmetry
is spontaneously broken and a ``s-wave dipole superfluid'' phase where both the
U(1) and dipole symmetries are spontaneously broken. We argue on grounds of
symmetry and thermodynamics that there is no transitionally-invariant gapless
fluid with unbroken dipole symmetry. In this work, we primarily focus on the
hydrodynamic description of p-wave dipole superfluids, including leading
dissipative corrections. That theory has, in a sense, a dynamical scaling
exponent , and its spectrum of fluctuations includes novel subdiffusive
modes in the shear sector and magnon-like sound mode
. By coupling the fluid to background fields, we
find response functions of the various symmetry currents. We also present a
preliminary generalization of our work to s-wave dipole superfluids, which
resemble fluids and feature sound waves and diffusive shear modes, as in
an ordinary fluid. However, the spectrum also contains a magnon-like
second-sound mode with subdiffusive
attenuation.Comment: 53 pages plus appendices; we have appended a Mathematica notebook to
the arXiv submission which computes dispersion relations and response
function
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