Bubbles with constant mean curvature, and almost constant mean curvature, in the hyperbolic space

Given a constant $k>1$, let $Z$ be the family of round spheres of radius $extrm{artanh}(k^{-1})$ in the hyperbolic space $mathbb{H}^3$, so that any sphere in $Z$ has mean curvature $k$. We prove a crucial nondegeneracy result involving the manifold $Z$. As an application, we provide sufficient conditions on a prescribed function $phi$ on $mathbb{H}^3$, which ensure the existence of a ${cal C}^1$-curve, parametrized by $arepsilonapprox 0$, of embedded spheres in $mathbb{H}^3$ having mean curvature $k +arepsilonphi$ at each point

Testable polarization predictions for models of CMB isotropy anomalies

Anomalies in the large-scale CMB temperature sky measured by WMAP have been suggested as possible evidence for a violation of statistical isotropy on large scales. In any physical model for broken isotropy, there are testable consequences for the CMB polarization field. We develop simulation tools for predicting the polarization field in models that break statistical isotropy locally through a modulation field. We study two different models: dipolar modulation, invoked to explain the asymmetry in power between northern and southern ecliptic hemispheres, and quadrupolar modulation, posited to explain the alignments between the quadrupole and octopole. For the dipolar case, we show that predictions for the correlation between the first 10 multipoles of the temperature and polarization fields can typically be tested at better than the 98% CL. For the quadrupolar case, we show that the polarization quadrupole and octopole should be moderately aligned. Such an alignment is a generic prediction of explanations which involve the temperature field at recombination and thus discriminate against explanations involving foregrounds or local secondary anisotropy. Predicted correlations between temperature and polarization multipoles out to l = 5 provide tests at the ~ 99% CL or stronger for quadrupolar models that make the temperature alignment more than a few percent likely. As predictions of anomaly models, polarization statistics move beyond the a posteriori inferences that currently dominate the field.Comment: 17 pages, 15 figures; published in PRD; references adde

Feature Comment: Considering The Effects of Public Procurement Regulations on Competitive Markets

Professor Albert Sanchez Graells of the University of Hull (UK) recently published a vitally important book on procurement law, Public Procurement and the EU Competition Rules (Hart Publishing 2011). In his study, Sanchez Graells asked what seems like a simple question: Shouldn’t regulators, when writing procurement regulations, consider the likely impact of those regulations on competitive markets? Sanchez Graells pointed out that far too little attention has been paid to the anticompetitive impact of public procurement regulation. This article assesses Sanchez Graells’ thesis from a U.S. perspective. In many ways the U.S. federal procurement system stands at one end of a spectrum: Even when squarely addressing the intersection of procurement regulation and the commercial market, U.S. procurement regulators have not considered their rules’ likely effects on competitive commercial markets. The article points out that this is in sharp contrast to the European Union’s strong emphasis on using procurement rules to integrate a broader European market. The article notes that there is substantial legal authority in the United States for assessing, as part of the rulemaking process, the likely competitive impact of proposed procurement rules -- and that doing so could integrate the $500 billion federal procurement system much more efficiently into the commercial marketplace

Feature Comment: Considering The Effects of Public Procurement Regulations on Competitive Markets

Professor Albert Sanchez Graells of the University of Hull (UK) recently published a vitally important book on procurement law, Public Procurement and the EU Competition Rules (Hart Publishing 2011). In his study, Sanchez Graells asked what seems like a simple question: Shouldn’t regulators, when writing procurement regulations, consider the likely impact of those regulations on competitive markets? Sanchez Graells pointed out that far too little attention has been paid to the anticompetitive impact of public procurement regulation. This article assesses Sanchez Graells’ thesis from a U.S. perspective. In many ways the U.S. federal procurement system stands at one end of a spectrum: Even when squarely addressing the intersection of procurement regulation and the commercial market, U.S. procurement regulators have not considered their rules’ likely effects on competitive commercial markets. The article points out that this is in sharp contrast to the European Union’s strong emphasis on using procurement rules to integrate a broader European market. The article notes that there is substantial legal authority in the United States for assessing, as part of the rulemaking process, the likely competitive impact of proposed procurement rules -- and that doing so could integrate the $500 billion federal procurement system much more efficiently into the commercial marketplace

Electrical Control of Linear Dichroism in Black Phosphorus from the Visible to Mid-Infrared

The incorporation of electrically tunable materials into photonic structures such as waveguides and metasurfaces enables dynamic control of light propagation by an applied potential. While many materials have been shown to exhibit electrically tunable permittivity and dispersion, including transparent conducting oxides (TCOs) and III-V semiconductors and quantum wells, these materials are all optically isotropic in the propagation plane. In this work, we report the first known example of electrically tunable linear dichroism, observed here in few-layer black phosphorus (BP), which is a promising candidate for multi-functional, broadband, tunable photonic elements. We measure active modulation of the linear dichroism from the mid-infrared to visible frequency range, which is driven by anisotropic quantum-confined Stark and Burstein-Moss effects, and field-induced forbidden-to-allowed optical transitions. Moreover, we observe high BP absorption modulation strengths, approaching unity for certain thicknesses and photon energies

A Clinical Dashboard to Reduce Missed Opportunities to Measure Dialysis Adequacy

In the local department, pre-pilot dialysis adequacy data was housed in a spreadsheet with manually entered, month-old data, inaccessible to clinic staff. The inoperability of the local QAPI workbook and EHR as well as data inaccessibility to staff resulted in missed opportunities to measure Kt/V. Based on the synthesis of evidence, dashboards have been utilized in a variety of interdisciplinary clinical settings with positive outcomes in addressing patient care gaps. The purpose of this pilot was to implement the Epic Dashboard that displays automated, real-time quality metric data to reduce missed opportunities to measure Kt/V in the outpatient HD setting. To evaluate dashboard efficacy, the proportion of missed opportunities to measure Kt/V three months pre-implementation was compared to the proportion of missed opportunities three months post-implementation; results did not show a statistically significant difference in missed opportunities to measure Kt/V. Counterbalance surveys to assess perceived impact by local staff yielded themes of sufficient education, dashboard ease of use, and enhanced ability to impact patient outcomes. The results of this QI pilot demonstrated the need for further research to better understand the development, utilization, and associated benefits of data dashboard integration in the clinical setting

Testing LSST dither strategies for Survey Uniformity and Large-Scale Structure Systematics

The Large Synoptic Survey Telescope (LSST) will survey the southern sky from 2022{2032 with unprecedented detail. Since the observing strategy can lead to artifacts in the data, we investigate the eects of telescope-pointing osets (called dithers) on the r-band coadded 5 depth yielded after the 10-year survey. We analyze this survey depth for several geometric patterns of dithers (e.g.,random, hexagonal lattice, spiral) with amplitude as large as the radius of the LSST eld-of-view, implemented on dierent timescales (per season, per night, per visit). Our results illustrate that per night and per visit dither assignments are more eective than per season. Also, we find that some dither geometries (e.g., hexagonal lattice) are particularly sensitive to the timescale on whichthe dithers are implemented, while others like random dithers perform well on all timescales. We then model the propagation of depth variations to articial uctuations in galaxy counts, which are a systematic for large-scale structure studies. We calculate the bias in galaxy counts caused by the observing strategy, accounting for photometric calibration uncertainties, dust extinction, and magnitude cuts; uncertainties in this bias limit our ability to account for structure induced by the observing strategy. We nd that after 10 years of the LSST survey, the best dither strategies lead to uncertainties in this bias smaller than the minimum statistical floor for a galaxy catalog as deep asr<27.5. A few of these strategies bring the uncertainties close to the statistical floor for r<25.7 after only one year of survey.Fil: Awan, Humna. Rutgers University; Estados UnidosFil: Gawiser, Eric. Rutgers University; Estados UnidosFil: Kurczynski, Peter. Rutgers University; Estados UnidosFil: Lynne Jones, R.. University of Washington; Estados UnidosFil: Zhan, Hu. Chinese Academy of Sciences; República de ChinaFil: Padilla, Nelson David. Pontificia Universidad Católica de Chile; ChileFil: Muñoz Arancibia, Alejandra M.. Pontificia Universidad Católica de Chile; ChileFil: Orsi, Alvaro. Centro de Estudios de Fisica del Cosmos de Aragon; EspañaFil: Cora, Sofia Alejandra. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; ArgentinaFil: Yoachim, Peter. University of Washington; Estados Unido

Alterations to the Gastrointestinal Microbiome Associated with Methamphetamine Use among Young Men who have Sex with Men.

Methamphetamine (MA) use is a major public health problem in the United States, especially among people living with HIV (PLWH). Many MA-induced neurotoxic effects are mediated by inflammation and gut microbiota may play a role in this process, yet the effects of MA on the microbiome have not been adequately explored. Therefore, we performed 16S rRNA gene sequencing on rectal swab samples from 381 men who have sex with men, 48% of whom were PLWH and 41% of whom used MA. We compared microbiome composition between MA users and non-users while testing for potential interactions with HIV and controlling for numerous confounders using inverse probability of treatment weighting. We found that MA use explained significant variation in overall composition (R2 = 0.005, p = 0.008) and was associated with elevated Finegoldia, Parvimonas, Peptoniphilus, and Porphyromonas and reduced Butyricicoccus and Faecalibacterium, among others. Genera including Actinomyces and Streptobacillus interacted with HIV status, such that they were increased in HIV+ MA users. Finegoldia and Peptoniphilus increased with increasing frequency of MA use, among others. In summary, MA use was associated with a microbial imbalance favoring pro-inflammatory bacteria, including some with neuroactive potential and others that have previously been associated with poor HIV outcomes