Regulation of Wages and Hours Prior to 1938

Direct numerical simulations are performed to investigate the transient upstream propagation (flashback) of premixed hydrogen–air flames in the boundary layer of a fully developed turbulent channel flow. Results show that the well-known near-wall velocity fluctuations pattern found in turbulent boundary layers triggers wrinkling of the initially flat flame sheet as it starts propagating against the main flow direction, and that the structure of the characteristic streaks of the turbulent boundary layer ultimately has an important impact on the resulting flame shape and on its propagation mechanism. It is observed that the leading edges of the upstream-propagating premixed flame are always located in the near-wall region of the channel and assume the shape of several smooth, curved bulges propagating upstream side by side in the spanwise direction and convex towards the reactant side of the flame. These leading-edge flame bulges are separated by thin regions of spiky flame cusps pointing towards the product side at the trailing edges of the flame. Analysis of the instantaneous velocity fields clearly reveals the existence, on the reactant side of the flame sheet, of backflow pockets that extend well above the wall-quenching distance. There is a strong correspondence between each of the backflow pockets and a leading edge convex flame bulge. Likewise, high-speed streaks of fast flowing fluid are found to be always colocated with the spiky flame cusps pointing towards the product side of the flame. It is suggested that the origin of the formation of the backflow pockets, along with the subsequent mutual feedback mechanism, is due to the interaction of the approaching streaky turbulent flow pattern with the Darrieus–Landau hydrodynamic instability and pressure fluctuations triggered by the flame sheet. Moreover, the presence of the backflow pockets, coupled with the associated hydrodynamic instability and pressure–flow field interaction, greatly facilitate flame propagation in turbulent boundary layers and ultimately results in high flashback velocities that increase proportionately with pressure

An evaluation of hospital breastfeeding policies in the Philadelphia metropolitan area 1994-2009: a comparison with the baby-friendly hospital initiative ten steps.

OBJECTIVE: The purpose of this study was to describe current breastfeeding policies and practices among Philadelphia, PA metropolitan hospitals and changes in their policies and practices over time. METHODS: In-person group interviews were conducted to obtain a composite picture of actual breastfeeding policies and practices. One questionnaire per hospital was completed based on responses from group consensus. Twenty-five hospitals providing maternity care were contacted. Information was obtained from personnel representing different areas of maternity services. Hospitals were classified according to the degree to which they were implementing the Ten Steps to Successful Breastfeeding. RESULTS: Mean breastfeeding rates at suburban hospitals were significantly higher than urban hospitals (72% vs. 49%, p = 0.015). Most hospitals were classified as high or moderately high implementers on six of the Ten Steps, including staff training (67%), printed information distributed to breastfeeding mothers (94%), breastfeeding initiation (61%), oral breastfeeding instruction given to mothers (83%), infant feeding schedules (89%), and hospital postpartum support (83%). Most hospitals reported partial or low implementation on two maternity practices: infant formula supplementation (61%) and rooming-in (72%). CONCLUSIONS: In the past 15 years, hospitals in the Philadelphia area have an increased awareness about breastfeeding and enhanced support of breastfeeding by healthcare professionals. In spite of an increase in overall breastfeeding rates, formula supplementation in hospitals and contact time between mothers and their newborns continue to be areas of concern

Evaluating emotional distress and health-related quality of life in patients with heart failure and their family caregivers:Testing dyadic dynamics using the Actor-Partner Interdependence Model

Purpose: 1) To compare levels of emotional symptoms and health-related quality of life between patients with heart failure and their family caregivers; and 2) to examine whether patients’ and caregivers’ emotional symptoms were associated with their own, as well as their partner’s health-related quality of life. Method: In this cross-sectional study, 41 patients-caregiver dyads (78% male patients, aged 68.6 years; and 83% female caregivers, aged 65.8 years) completed all nine dimensions of the Brief Symptom Inventory and the Minnesota Living with Heart failure Questionnaire. Dyadic data were analysed for 6 sub-scales of the Brief Symptom Inventory, using the Actor–Partner Interdependence Model. Results: There were no statistically significant differences in emotional symptoms and health-related quality of life between patients with heart failure and their caregivers. Patients’ and caregivers’ emotional symptoms were associated with their own health-related quality of life. Caregivers’ anxiety, phobic anxiety, obsession-compulsion, depression and hostility negatively influenced their partner’s (i.e. the patient’s) health-related quality of life. There were no partner effects of patients’ emotional symptoms on the health-related quality of life of caregivers. Conclusions: The results of this study suggest that patients may be particularly vulnerable to the emotional distress, i.e. thoughts, impulses and actions of their caregivers. It may be possible to improve patients’ health-related quality of life by targeting specific detrimental emotional symptoms of caregivers

Logistic regression models to predict solvent accessible residues using sequence- and homology-based qualitative and quantitative descriptors applied to a domain-complete X-ray structure learning set

A working example of relative solvent accessibility (RSA) prediction for proteins is presented. Novel logistic regression models with various qualitative descriptors that include amino acid type and quantitative descriptors that include 20- and six-term sequence entropy have been built and validated. A domain-complete learning set of over 1300 proteins is used to fit initial models with various sequence homology descriptors as well as query residue qualitative descriptors. Homology descriptors are derived from BLASTp sequence alignments, whereas the RSA values are determined directly from the crystal structure. The logistic regression models are fitted using dichotomous responses indicating buried or accessible solvent, with binary classifications obtained from the RSA values. The fitted models determine binary predictions of residue solvent accessibility with accuracies comparable to other less computationally intensive methods using the standard RSA threshold criteria 20 and 25% as solvent accessible. When an additional non-homology descriptor describing Lobanov–Galzitskaya residue disorder propensity is included, incremental improvements in accuracy are achieved with 25% threshold accuracies of 76.12 and 74.45% for the Manesh-215 and CASP(8+9) test sets, respectively. Moreover, the described software and the accompanying learning and validation sets allow students and researchers to explore the utility of RSA prediction with simple, physically intuitive models in any number of related applications

Evaluating perceptions of self-efficacy and quality of life in patients having coronary artery bypass grafting and their family caregivers

Background Self-efficacy is a critical factor for quality of life in patients who undergo coronary artery bypass grafting, as well as for their family caregivers. However, there is lack of knowledge about whether patients' self-efficacy and caregivers' perceptions of patient self-efficacy are associated with quality of life in patient and caregiver dyads. Objectives The aims of this study were to compare self-efficacy and quality of life between patients and family caregivers and to examine whether patients' and caregivers' perceptions of patient self-efficacy were associated with their own and their partner's quality of life in patient and caregiver dyads who were waiting for patients' coronary artery bypass grafting. Methods In this cross-sectional study, 84 dyads (85% male patients and 87% female caregivers) completed the Cardiac Self-efficacy Scale, which consists of self-efficacy for controlling symptoms and self-efficacy for maintaining function subscales, and the Short-Form 12 Health Survey for quality of life. Data were analyzed using the Actor-Partner Interdependence Model. Results Caregivers rated patient self-efficacy for maintaining function higher than did patients themselves and caregivers' perceptions were positively correlated with patients' physical health. Patients' self-efficacy for maintaining function exhibited an actor effect on their own mental health. There were no other actor or partner effects of self-efficacy on quality of life. Conclusions Differences between patients' and caregivers' perceptions of patient self-efficacy for maintaining function should be addressed before surgery to reduce discordance. Patients' self-efficacy for maintaining function was associated with their own quality of life. There was no partner (relationship) effect of self-efficacy on quality of life. More research is needed in this area

Transverse Chromatic Aberrations in Virtual Reality Devices

We demonstrate a method for measuring the transverse chromatic aberration (TCA) in a virtual reality head-mounted display (VR HMD). This procedure was used to characterize the optical performance of the Oculus Go VR HMD. Results show a measurable TCA for angles larger than approximately 6◦ from the center of the field of view. TCA can be thought of as a wavelength dependent magnification, and as a result, the relative size of objects vary based on the rendering color. In addition, this leads to color changes in the image due to mixing with neighboring pixels, which impacts image quality. The test results for the Oculus Go show promise for characterizing TCA across different HMDs

Magnetic Fields at First Order Phase Transition: A Threat to Electroweak Baryogenesis

The generation of the observed baryon asymmetry may have taken place during the electroweak phase transition, thus involving physics testable at LHC, a scenario dubbed electroweak baryogenesis. In this paper we point out that the magnetic field which is produced in the bubbles of a first order phase transition endangers the baryon asymmetry produced in the bubble walls. The reason being that the produced magnetic field couples to the sphaleron magnetic moment and lowers the sphaleron energy; this strengthens the sphaleron transitions inside the bubbles and triggers a more effective wash out of the baryon asymmetry. We apply this scenario to the Minimal Supersymmetric extension of the Standard Model (MSSM) where, in the absence of a magnetic field, successful electroweak baryogenesis requires the lightest CP-even Higgs and the right-handed stop masses to be lighter than about 127 GeV and 120 GeV, respectively. We show that even for moderate values of the magnetic field, the Higgs mass required to preserve the baryon asymmetry is below the present experimental bound. As a consequence electroweak baryogenesis within the MSSM should be confronted on the one hand to future measurements at the LHC on the Higgs and the right-handed stop masses, and on the other hand to more precise calculations of the magnetic field produced at the electroweak phase transition.Comment: 16 pages, 4 figures. Minor corrections and references added to match published versio

Design, engineering and utility of biotic games

Games are a significant and defining part of human culture, and their utility beyond pure entertainment has been demonstrated with so-called ‘serious games’. Biotechnology – despite its recent advancements – has had no impact on gaming yet. Here we propose the concept of ‘biotic games’, i.e., games that operate on biological processes. Utilizing a variety of biological processes we designed and tested a collection of games: ‘Enlightenment’, ‘Ciliaball’, ‘PAC-mecium’, ‘Microbash’, ‘Biotic Pinball’, ‘POND PONG’, ‘PolymerRace’, and ‘The Prisoner's Smellemma’. We found that biotic games exhibit unique features compared to existing game modalities, such as utilizing biological noise, providing a real-life experience rather than virtual reality, and integrating the chemical senses into play. Analogous to video games, biotic games could have significant conceptual and cost-reducing effects on biotechnology and eventually healthcare; enable volunteers to participate in crowd-sourcing to support medical research; and educate society at large to support personal medical decisions and the public discourse on bio-related issues

Two-year follow-up of macaques developing intermittent control of the human immunodeficiency virus homolog simian immunodeficiency virus SIVmac251 in the chronic phase of infection

Off-therapy control of viremia by HIV-infected individuals has been associated with two likely players: a restricted viral reservoir and an efficient cell-mediated immune response. We previously showed that a combination of highly suppressive antiretroviral therapy and two experimental drugs, i.e., auranofin and buthionine sulfoximine, was able to reduce the viral reservoir, elicit efficient cell-mediated antiviral responses, and induce intermittent posttherapy viral load control in chronically SIVmac251-infected macaques. We here show that the macaques that had received this drug combination and then stopped antiretroviral therapy were also able to maintain low numbers of activated CD4(+) T cells at viral rebound. Moreover, these macaques consistently displayed low-level simian immunodeficiency virus (SIV) diversity, which was in line with the strong and broadly reactive cell-mediated immune responses against conserved Gag antigens. Extended follow-up showed that the two macaques that had received the complete drug combination remained healthy and did not develop AIDS in 2 years of follow-up after therapy suspension. This disease-free survival is longer than twice the average time of progression to AIDS in SIVmac251-infected rhesus macaques. These results suggest that limited numbers of activated T cells at viral rebound and subsequent development of broadly reactive cell-mediated responses may be interrelated in reducing the viral reservoir