A comparison of green space indicators for epidemiological research

<p><b>Background</b> The potential for natural environments to be salutogenic has received growing interest from epidemiologists, but there has been no critical examination of the extent to which associations between green space and health might vary according to the indicator of green space coverage used.</p> <p><b>Methods</b> Three different indicators of green space coverage were derived for a set of 268 small areas in four cities within Britain. The indicators had different origins and provided a spectrum of sensitivity from larger spaces only, through to ambient greenery. Two indicators reproducible for anywhere in Europe were included. Agreement between the indicators on the quantity of green space in a small area, and their independent association with measures of mortality and self-reported morbidity, were compared.</p> <p><b>Results</b> Overall, the indicators showed relatively close overall agreement (all r2>0.89, p<0.001). However, agreement varied by level of area socioeconomic deprivation (p<0.001). The indicator that detected larger spaces only found less green space in areas of socioeconomic deprivation than the other two. Despite this difference, all indicators showed similar protective associations with the risk of mortality and self-reported morbidity suggesting that larger green spaces may be more important for health effects than smaller spaces.</p> <p><b>Conclusions</b> Associations between green space indicator and health were not sensitive to indicator origin and type. This raises the possibility of trans-European epidemiological studies. Larger green spaces may be the most important for health effects, but may also be less prevalent in more deprived areas.</p&gt

High performance architecture design for large scale fibre-optic sensor arrays using distributed EDFAs and hybrid TDM/DWDM

A distributed amplified dense wavelength division multiplexing (DWDM) array architecture is presented for interferometric fibre optic sensor array systems. This architecture employs a distributed erbium doped fibre amplifier (EDFA) scheme to decrease the array insertion loss, and employs time division multiplexing (TDM) at each wavelength to increase the number of sensors that can be supported. The first experimental demonstration of this system is reported including results which show the potential for multiplexing and interrogating up to 4096 sensors using a single telemetry fibre pair with good system performance. The number can be increased to 8192 by using dual pump sources

Green cities and health: a question of scale?

<p><b>Background:</b> Cities are expanding and accommodating an increasing proportion of the world's population. It is important to identify features of urban form that promote the health of city dwellers. Access to green space has been associated with health benefits at both individual and neighbourhood level. We investigated whether a relationship between green space coverage and selected mortality rates exists at the city level in the USA.</p> <p><b>Methods:</b> An ecological cross-sectional study. A detailed land use data set was used to quantify green space for the largest US cities (n=49, combined population of 43 million). Linear regression models were used to examine the association between city-level ‘greenness’ and city-level standardised rates of mortality from heart disease, diabetes, lung cancer, motor vehicle fatalities and all causes, after adjustment for confounders.</p> <p><b>Results:</b> There was no association between greenness and mortality from heart disease, diabetes, lung cancer or automobile accidents. Mortality from all causes was significantly higher in greener cities.</p> <p><b>Conclusions:</b> While considerable evidence suggests that access to green space yields health benefits, we found no such evidence at the scale of the American city. In the USA, greener cities tend also to be more sprawling and have higher levels of car dependency. Any benefits that the green space might offer seem easily eclipsed by these other conditions and the lifestyles that accompany them. The result merits further investigation as it has important implications for how we increase green space access in our cities.</p&gt

Models and Materials for Exercise Promotion in Comprehensive Multiple Sclerosis Care: Completion of the ‘Exercise in Medicine’ Development Process

Purpose: Health care providers have highlighted the need for tools and resources that support promotion of exercise behavior within comprehensive multiple sclerosis (MS) care. This study involved a final quality improvement evaluation of exercise promotion models and materials for inclusion within this setting. Methods and materials: Our research team distributed a paper-based survey containing Likert scales, open answer questions, and copies of the models for editing. We distributed this survey among health care providers across the United States. We conducted a novel mixed-methods analysis evaluating quantitative, qualitative, and creative data. Results: We received completed surveys from 13 health care providers who strongly rated the clarity and applicability of the models and materials, and reported that no major improvements were necessary. The minor improvements were specific per comprehensive MS care center. The feedback indicated that the “Exercise in Medicine” models and materials are guides such that the processes should be integrated into real world practice by amending roles and responsibilities with the team members and structure per comprehensive MS care center. Conclusion: This paper presents finalized models and materials for exercise promotion within comprehensive MS care that are ready to be tested for feasibility and efficacy in a clinical trial

Estimating Associations Between Annual Concentrations of Particulate Matter and Mortality in the United States, Using Data Linkage and Bayesian Maximum Entropy

Background: Exposure to fine particulate matter (PM2.5) is an established risk factor for human mortality. However, previous US studies have been limited to select cities or regions or to population subsets (e.g., older adults). Methods: Here, we demonstrate how to use the novel geostatistical method Bayesian maximum entropy to obtain estimates of PM2.5 concentrations in all contiguous US counties, 2000–2016. We then demonstrate how one could use these estimates in a traditional epidemiologic analysis examining the association between PM2.5 and rates of all-cause, cardiovascular, respiratory, and (as a negative control outcome) accidental mortality. Results: We estimated that, for a 1 log(μg/m3) increase in PM2.5 concentration, the conditional all-cause mortality incidence rate ratio (IRR) was 1.029 (95% confidence interval [CI]: 1.006, 1.053). This implies that the rate of all-cause mortality at 10 µg/m3 would be 1.020 times the rate at 5 µg/m3. IRRs were larger for cardiovascular mortality than for all-cause mortality in all gender and race–ethnicity groups. We observed larger IRRs for all-cause, nonaccidental, and respiratory mortality in Black non-Hispanic Americans than White non-Hispanic Americans. However, our negative control analysis indicated the possibility for unmeasured confounding. Conclusion: We used a novel method that allowed us to estimate PM2.5 concentrations in all contiguous US counties and obtained estimates of the association between PM2.5 and mortality comparable to previous studies. Our analysis provides one example of how Bayesian maximum entropy could be used in epidemiologic analyses; future work could explore other ways to use this approach to inform important public health questions

Full characterization and comparison of phase properties of narrow linewidth lasers operating in the C-band

We characterize and compare the performance of various commercially available lasers in terms of their absolute frequency stability, lineshape and linewidth, and frequency noise. The frequency stability, linewidth and lineshape are evaluated using an ‘optical ruler’ - a carrier-envelope stabilized optical comb. The frequency noise is measured over an extended spectral range starting from 2 Hz. The performed analysis gives data necessary when deciding which laser to use in a particular application

Using animations of risk functions to visualize trends in US all-cause and cause-specific mortality, 1968-2016

Objectives. To use dynamic visualizations of mortality risk functions over both calendar year and age as a way to estimate and visualize patterns in US life spans. Methods. We built 49 synthetic cohorts, 1 per year 1968 to 2016, using National Center for Health Statistics (NCHS) mortality and population data. Within each cohort, we estimated age-specific probabilities of dying from any cause (all-cause analysis) or from a particular cause (cause-specific analysis). We then used Kaplan–Meier (all-cause) or Aalen–Johansen (cause-specific) estimators to obtain risk functions. We illustrated risk functions using time-lapse animations. Results. Median age at death increased from 75 years in 1970 to 83 years in 2015. Risk by age 100 years of cardiovascular mortality decreased (from a risk of 55% in 1970 to 32% in 2015), whereas risk attributable to other (i.e., nonrespiratory and noncardiovascular) causes increased in compensation. Conclusions. Our findings were consistent with the trends published in the NCHS 2015 mortality report, and our dynamic animations added an efficient, interpretable tool for visualizing US mortality trends over age and calendar time

Moderate drinking before the unit: medicine and life assurance in Britain and the US c.1860–1930

This article describes the way in which “Anstie’s Limit” – a particular definition of moderate drinking first defined in Britain in the 1860s by the physician Francis Edmund Anstie (1833–1874) – became established as a useful measure of moderate alcohol consumption. Becoming fairly well-established in mainstream Anglophone medicine by 1900, it was also communicated to the public in Britain, North America and New Zealand through newspaper reports. However, the limit also travelled to less familiar places, including life assurance offices, where a number of different strategies for separating moderate from excessive drinkers emerged from the dialogue between medicine and life assurance. Whilst these ideas of moderation seem to have disappeared into the background for much of the twentieth century, re-emerging as the “J-shaped” curve, these early developments anticipate many of the questions surrounding uses of the “unit” to quantify moderate alcohol consumption in Britain today. The article will therefore conclude by exploring some of the lessons of this story for contemporary discussions of moderation, suggesting that we should pay more attention to whether these metrics work, where they work and why

Association Between Long-term Ambient PM2.5 Exposure and Cardiovascular Outcomes Among US Hemodialysis Patients

Rationale & Objective: Ambient PM2.5 (particulate matter with a diameter of 2.5 microns) is a ubiquitous air pollutant with established adverse cardiovascular (CV) effects. However, quantitative estimates of the association between PM2.5 exposure and CV outcomes in the setting of kidney disease are limited. This study assessed the association of long-term PM2.5 exposure with CV events and cardiovascular disease (CVD)–specific mortality among patients receiving maintenance in-center hemodialysis (HD). Study Design: Retrospective cohort study. Settings & Participants: 314,079 adult kidney failure patients initiating HD between 2011 and 2016 identified from the US Renal Data System. Exposure: Estimated daily ZIP code–level PM2.5 concentrations were used to calculate each participant's annual average PM2.5 exposure based on the dialysis clinics visited during the 365 days before the outcome. Outcome: CV event and CVD-specific mortality were ascertained based on ICD-9/ICD-10 diagnostic codes and recorded cause of death from Centers for Medicare & Medicaid Services form 2746. Analytical Approach: Discrete time hazards models were used to estimate hazards ratios per 1 μg/m3 greater annual average PM2.5, adjusting for temperature, humidity, day of the week, season, age at baseline, race, employment status, and geographic region. Effect measure modification was assessed for age, sex, race, and baseline comorbidities. Results: Each 1 μg/m3 greater annual average PM2.5 was associated with a greater rate of CV events (HR, 1.02 [95% CI, 1.01-1.02]) and CVD-specific mortality (HR, 1.02 [95% CI, 1.02-1.03]). The association was more pronounced for people who initiated dialysis at an older age, had chronic obstructive pulmonary disease (COPD) at baseline, or were Asian. Evidence of effect modification was also observed across strata of race, and other baseline comorbidities. Limitations: Potential exposure misclassification and unmeasured confounding. Conclusions: Long-term ambient PM2.5 exposure was associated with CVD outcomes among patients receiving maintenance in-center HD. Stronger associations between long-term PM2.5 exposure and adverse effects were observed among patients who were of advanced age, had COPD, or were Asian. Plain-Language Summary: Long-term exposure to air pollution, also called PM2.5, has been linked to adverse cardiovascular outcomes. However, little is known about the association of PM2.5 and outcomes among patients receiving dialysis, who are individuals with high cardiovascular disease burdens. We conducted an epidemiological study to assess the association between the annual PM2.5 exposure and cardiovascular events and death among patients receiving regular outpatient hemodialysis in the United States between 2011 and 2016. We found a higher risk of heart attacks, strokes, and related events in patients exposed to higher levels of air pollution. Stronger associations between air pollution and adverse health events were observed among patients who were older at the start of dialysis, had chronic obstructive pulmonary disease, or were Asian. These findings bolster the evidence base linking air pollution and adverse health outcomes and may inform policy makers and clinicians