Effect of flow fluctuations and nonflow on elliptic flow methods

We discuss how the different estimates of elliptic flow are influenced by flow fluctuations and nonflow effects. It is explained why the event-plane method yields estimates between the two-particle correlation methods and the multiparticle correlation methods. It is argued that nonflow effects and fluctuations cannot be disentangled without other assumptions. However, we provide equations where, with reasonable assumptions about fluctuations and nonflow, all measured values of elliptic flow converge to a unique mean v_{2,PP} elliptic flow in the participant plane and, with a Gaussian assumption on eccentricity fluctuations, can be converted to the mean v_{2,RP} in the reaction plane. Thus, the 20% spread in observed elliptic flow measurements from different analysis methods is no longer mysterious.Comment: one typo in Table I correcte

Capturing Public Opinion on Public Health Topics: A Comparison of Experiences from a Systematic Review, Focus Group Study, and Analysis of Online, User-Generated Content.

BACKGROUND: Capturing public opinion toward public health topics is important to ensure that services, policy, and research are aligned with the beliefs and priorities of the general public. A number of approaches can be used to capture public opinion. METHODS: We are conducting a program of work on the effectiveness and acceptability of health promoting financial incentive interventions. We have captured public opinion on financial incentive interventions using three methods: a systematic review, focus group study, and analysis of online user-generated comments to news media reports. In this short editorial-style piece, we compare and contrast our experiences with these three methods. RESULTS: Each of these methods had their advantages and disadvantages. Advantages include tailoring of the research question for systematic reviews, probing of answers during focus groups, and the ability to aggregate a large data set using online user-generated content. However, disadvantages include needing to update systematic reviews, participants conforming to a dominant perspective in focus groups, and being unable to collect respondent characteristics during analysis of user-generated online content. That said, analysis of user-generated online content offers additional time and resource advantages, and we found it elicited similar findings to those obtained via more traditional methods, such as systematic reviews and focus groups. CONCLUSION: A number of methods for capturing public opinions on public health topics are available. Public health researchers, policy makers, and practitioners should choose methods appropriate to their aims. Analysis of user-generated online content, especially in the context of news media reports, may be a quicker and cheaper alternative to more traditional methods, without compromising on the breadth of opinions captured.This work is produced under the terms of a Career Development Fellowship research training fellowship issued by the NIHR to JA, grant number: CDF-2011-04-001. The views expressed are those of the authors and not necessarily those of the NHS, The National Institute for Health Research or the Department of Health. ELG is funded in part, and FFS is funded in full by Fuse: the Centre for Translational Research in Public Health and JA is funded in part by The Centre for Diet and Activity Research (CEDAR). Fuse and CEDAR are UKCRC Public Health Research Centres of Excellence. Funding for Fuse and CEDAR from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It first appeared from Frontiers via http://dx.doi.org/10.3389/fpubh.2015.0020

Experimental Method Calibration (MECr): A new relative method for heat flux sensor calibration

Heat flux sensor calibration is often expensive, but it is also a fundamental step to obtain valid results. According to the needs, several calibration procedures could be considered. If experimental interpretations focus on heat flux values comparison rather than true values, a relative calibration with high accuracy can be performed. This paper focuses on a new relative calibration-type method of heat flux sensors (HFSs). In general, the HFSs were originally (even recently) factory and in-house-calibrated, but this method was used to calibrate them to an exact common reading to help in performing accurate experiments and eliminating errors that could result from differences between the HFSs. The developed methodology was adapted from a secondary calibration-type (i.e., absolute) generalization. This method aimed to present a simple, low cost, and accurate way to calibrate heat flux sensors. The proposed calibration method was relative, which means that it did not use any calibration reference. However, an absolute calibration adaptation of this method can easily be performed. In the method presented in this paper, calibration was made via sensor sensitivity correction. The experiment consisted of imposing an identical and homogeneous heat flux across four heat flux sensors during a sufficiently long time to be able to statistically subtract any unwanted influences, such as convective and radiative variation. More precisely, temperatures and heat flux levels of 30-35 °C and 60-70 W.m-2 , respectively, were used. Then, new sensor sensitivity values were found by basic statistical data manipulations. Although the focus of this methodology was for contenting thermopile-based HFSs that used differential temperature measurements, the set-up can be adapted for other types of HFSs. In this paper, the set-up, its conception, and guidelines for using this method are presented

Dipoles in Graphene Have Infinitely Many Bound States

We show that in graphene charge distributions with non-vanishing dipole moment have infinitely many bound states. The corresponding eigenvalues accumulate at the edges of the gap faster than any power

The Effectiveness of Financial Incentives for Health Behaviour Change: Systematic Review and Meta-Analysis

Financial incentive interventions have been suggested as one method of promoting healthy behaviour change.To conduct a systematic review of the effectiveness of financial incentive interventions for encouraging healthy behaviour change; to explore whether effects vary according to the type of behaviour incentivised, post-intervention follow-up time, or incentive value.Searches were of relevant electronic databases, research registers, www.google.com, and the reference lists of previous reviews; and requests for information sent to relevant mailing lists.Controlled evaluations of the effectiveness of financial incentive interventions, compared to no intervention or usual care, to encourage healthy behaviour change, in non-clinical adult populations, living in high-income countries, were included.The Cochrane Risk of Bias tool was used to assess all included studies. Meta-analysis was used to explore the effect of financial incentive interventions within groups of similar behaviours and overall. Meta-regression was used to determine if effect varied according to post-intervention follow up time, or incentive value.Seventeen papers reporting on 16 studies on smoking cessation (n = 10), attendance for vaccination or screening (n = 5), and physical activity (n = 1) were included. In meta-analyses, the average effect of incentive interventions was greater than control for short-term (≤ six months) smoking cessation (relative risk (95% confidence intervals): 2.48 (1.77 to 3.46); long-term (>six months) smoking cessation (1.50 (1.05 to 2.14)); attendance for vaccination or screening (1.92 (1.46 to 2.53)); and for all behaviours combined (1.62 (1.38 to 1.91)). There was not convincing evidence that effects were different between different groups of behaviours. Meta-regression found some, limited, evidence that effect sizes decreased as post-intervention follow-up period and incentive value increased. However, the latter effect may be confounded by the former.The available evidence suggests that financial incentive interventions are more effective than usual care or no intervention for encouraging healthy behaviour change.PROSPERO CRD42012002393

Use of Online Food Delivery Services to Order Food Prepared Away-From-Home and Associated Sociodemographic Characteristics: A Cross-Sectional, Multi-Country Analysis

Online food delivery services like Just Eat and Grubhub facilitate online ordering and home delivery of food prepared away-from-home. It is poorly understood how these services are used and by whom. This study investigated the prevalence of online food delivery service use and sociodemographic characteristics of customers, in and across Australia, Canada, Mexico, the UK, and the USA. We analyzed online survey data (n = 19,378) from the International Food Policy Study, conducted in 2018. We identified respondents who reported any online food delivery service use in the past 7 days and calculated the frequency of use and number of meals ordered. We investigated whether odds of any online food delivery service use in the past 7 days differed by sociodemographic characteristics using adjusted logistic regression. Overall, 15% of respondents (n = 2929) reported online food delivery service use, with the greatest prevalence amongst respondents in Mexico (n = 839 (26%)). Online food delivery services had most frequently been used once and the median number of meals purchased through this mode of order was two. Odds of any online food delivery service use were lower per additional year of age (OR: 0.95; 95% CI: 0.94, 0.95) and greater for respondents who were male (OR: 1.50; 95% CI: 1.35, 1.66), that identified with an ethnic minority (OR: 1.57; 95% CI: 1.38, 1.78), were highly educated (OR: 1.66; 95% CI: 1.46, 1.90), or living with children (OR: 2.71; 95% CI: 2.44, 3.01). Further research is required to explore how online food delivery services may influence diet and health

The homotopy type of the loops on (n−1)(n-1)-connected (2n+1)(2n+1)-manifolds

For $n\geq 2$ we compute the homotopy groups of $(n-1)$-connected closed manifolds of dimension $(2n+1)$. Away from the finite set of primes dividing the order of the torsion subgroup in homology, the $p$-local homotopy groups of $M$ are determined by the rank of the free Abelian part of the homology. Moreover, we show that these $p$-local homotopy groups can be expressed as a direct sum of $p$-local homotopy groups of spheres. The integral homotopy type of the loop space is also computed and shown to depend only on the rank of the free Abelian part and the torsion subgroup.Comment: Trends in Algebraic Topology and Related Topics, Trends Math., Birkhauser/Springer, 2018. arXiv admin note: text overlap with arXiv:1510.0519

Strangeness and the discovery of quark-gluon plasma

Strangeness flavor yield s and the entropy yield S are the observables of the deconfined quark-gluon state of matter which can be studied in the entire available experimental energy range at AGS, SPS, RHIC, and, in near future, at the LHC energy range. We present here a comprehensive analysis of strange, soft hadron production as function of energy and reaction volume. We discuss the physical properties of the final state and argue how evidence about the primordial QGP emerges.Comment: 16 pages: Invited talk at 5th International Conference on Physics and Astrophysics of Quark Gluon Plasma, February 8 - 12, 2005, Salt Lake City, Kolkata, India, to appear in: Journal of Physics: Conference Serie

Nonalcoholic and Alcoholic Beverage Intakes by Adults across 5 Upper-Middle- and High-Income Countries.

BACKGROUND: Despite considerable public health interest in sugary drink consumption, there has been little comparison of intake across countries. OBJECTIVES: This study aimed to compare the consumption frequency and amounts of commonly consumed beverages among adults in 5 upper-middle- and high-income countries, and examine differences in consumption between population subgroups. METHODS: Adults aged 18-65 y completed online surveys in December 2017 in Australia (n = 3264), Canada (n = 2745), Mexico (n = 3152), the United Kingdom (n = 3221), and the USA (n = 4015) as part of the International Food Policy Study. The frequency of consuming beverages from 22 categories in the past 7 d was estimated using the Beverage Frequency Questionnaire. Regression models were used to examine differences in the likelihood of any consumption and in the amounts consumed of sugar-sweetened beverages (SSBs), sugary drinks (SSBs and 100% juice), diet, and alcoholic beverages between countries and across sociodemographic subgroups. RESULTS: The prevalence of reported SSB consumption in the past 7 d ranged from 47% (United Kingdom) to 81% (Mexico), and that of sugary drinks ranged from 62% (United Kingdom) to 87% (Mexico). Rates of consumption of diet drinks ranged from 26% (Mexico) to 37% (United Kingdom), whereas alcoholic drink consumption rates ranged from 45% (USA) to 52% (Canada). Respondents in Mexico were more likely to consume SSBs and sugary drinks, and in greater amounts, than those in other countries. Respondents in the United Kingdom were more likely to consume diet drinks than those in Australia, Canada, and Mexico, and greater amounts of diet drinks were consumed in the United Kingdom and the USA. Across countries, younger respondents and males were more likely to consume greater amounts of SSBs and sugary drinks. CONCLUSIONS: Most adult respondents across all countries consumed SSBs and sugary drinks, with greater consumption in Mexico and the USA. Consumption varied greatly across countries, but patterns of association among subpopulations were relatively similar.The first two waves of the International Food Policy Study were funded by a population health intervention research operating grant from the Canadian Institutes of Health Research (CIHR). Additional support was provided by a CIHR – Public Health Agency of Canada (PHAC) Applied Public Health Chair held by David Hammond. JA receives funding from the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. GS is supported by a Heart Foundation Future Leader Fellowship (102035) from the National Heart Foundation of Australia. He is also a researcher within National Health and Medical Research Council (NHMRC) Centres for Research Excellence entitled Reducing Salt Intake Using Food Policy Interventions (APP1117300) and a Centre of Research Excellence in Food Retail Environments for Health (RE-FRESH) (APP1152968) (Australia). He has also received other funding from the NHMRC, Australian Research Council (ARC) and the World Health Organization (WHO). Data described in the manuscript, code book, and analytic code will be made available upon request pending application and approval by DH