Association between the Fast-Food Environment and Obesity in Canada: A Cross-sectional Analysis

Frequent fast-food consumption is associated with weight gain therefore it is hypothesized that relative availability of fast-food is a risk factor for obesity. This thesis examined the association between the neighbourhood-level density of fast-food outlets and adult body mass index (BMI) in Canada. Population-based data on BMI and socio-economic variables from the 2008 Canadian Community Health Survey [CCHS] and selected neighbourhood-level socio-economic data from 2006 Canadian Census were merged with a commercial database containing geographic locations of all restaurants in Canada. The association between BMI and fast-food density (per 10,000 people in CCHS respondent’s FSA) was analyzed using ordinary least squares regression. Spatial clustering of BMI was also investigated and spatial-regression analysis was conducted. FSA-level fast-food density is significantly associated with BMI in Canadian adults, predominantly in females and non-rural area. This population-based analysis established that availability of fast-food restaurants is an important risk factor for obesity in Canada

Estimating the Effects of the ADA Amendments Act on the Hiring and Termination of Individuals with Disabilities, Using New Disability Categorizations

Disability discrimination laws are often used to potentially increase employment for individuals with disabilities. However, legal theory and empirical economics research do not provide conclusive answers as to how expansions in disability discrimination laws affect economic outcomes, namely hiring rates, for individuals with disabilities. We estimate the effect of the ADA Amendments Act (ADAAA) on employment transitions: hirings and terminations for individuals with disabilities relative to those without disabilities. To calculate employment transitions, we use data from the Survey of Income and Program Participation (SIPP). We also use the SIPP to develop additional measures and categorizations of disability based on whether the conditions are physical or mental, and whether they are salient to an employer at the hiring stage. We find that the ADAAA is generally associated with positive employment effects: increases or no effects on hiring rates, and decreases or no effects on termination rates. Our strongest and most robust results are that we find increases in hiring for those with nonsalient physical conditions and decreased terminations for those with salient physical conditions. Our results suggest that the effects of the ADAAA vary by disability type—especially by disability saliency—and are stronger for the groups most targeted by broader coverage of the ADAAA

Asymptotically simple solutions of the vacuum Einstein equations in even dimensions

We show that a set of conformally invariant equations derived from the Fefferman-Graham tensor can be used to construct global solutions of the vacuum Einstein equations, in all even dimensions. This gives, in particular, a new, simple proof of Friedrich's result on the future hyperboloidal stability of Minkowski space-time, and extends its validity to even dimensions.Comment: 25p

Association between neighbourhood fast-food and full-service restaurant density and BMI: A cross-sectional study of Canadian adults

OBJECTIVE: Frequent fast-food consumption is a well-known risk factor for obesity. This study sought to determine whether the availability of fast-food restaurants has an influence on body mass index (BMI). METHODS: BMI and individual-level confounding variables were obtained from the 2007-08 Canadian Community Health Survey. Neighbourhood socio-demographic variables were acquired from the 2006 Canadian Census. The geographic locations of all restaurants in Canada were assembled from a validated business registry database. The density of fast-food, full-service and non-chain restaurants per 10,000 individuals was calculated for respondents’ forward sortation area. Multivariable regression analyses were conducted to analyze the association between restaurant density and BMI. RESULTS: Fast-food, full-service and non-chain restaurant density variables were statistically significantly associated with BMI. Fast-food density had a positive association whereas full-service and non-chain restaurant density had a negative association with BMI (additional 10 fast-food restaurants per capita corresponded to a weight increase of 1 kilogram; p\u3c0.001). These associations were primarily found in Canada’s major urban jurisdictions. CONCLUSIONS: This research was the first to investigate the influence of fast-food and full-service restaurant density on BMI using individual-level data from a nationally representative Canadian survey. The finding of a positive association between fast-food restaurant density and BMI suggests that interventions aiming to restrict the availability of fast-food restaurants in local neighbourhoods may be a useful obesity prevention strategy

The impact of communicating genetic risks of disease on risk-reducing health behaviour: systematic review with meta-analysis.

OBJECTIVE: To assess the impact of communicating DNA based disease risk estimates on risk-reducing health behaviours and motivation to engage in such behaviours. DESIGN: Systematic review with meta-analysis, using Cochrane methods. DATA SOURCES: Medline, Embase, PsycINFO, CINAHL, and the Cochrane Central Register of Controlled Trials up to 25 February 2015. Backward and forward citation searches were also conducted. STUDY SELECTION: Randomised and quasi-randomised controlled trials involving adults in which one group received personalised DNA based estimates of disease risk for conditions where risk could be reduced by behaviour change. Eligible studies included a measure of risk-reducing behaviour. RESULTS: We examined 10,515 abstracts and included 18 studies that reported on seven behavioural outcomes, including smoking cessation (six studies; n=2663), diet (seven studies; n=1784), and physical activity (six studies; n=1704). Meta-analysis revealed no significant effects of communicating DNA based risk estimates on smoking cessation (odds ratio 0.92, 95% confidence interval 0.63 to 1.35, P=0.67), diet (standardised mean difference 0.12, 95% confidence interval -0.00 to 0.24, P=0.05), or physical activity (standardised mean difference -0.03, 95% confidence interval -0.13 to 0.08, P=0.62). There were also no effects on any other behaviours (alcohol use, medication use, sun protection behaviours, and attendance at screening or behavioural support programmes) or on motivation to change behaviour, and no adverse effects, such as depression and anxiety. Subgroup analyses provided no clear evidence that communication of a risk-conferring genotype affected behaviour more than communication of the absence of such a genotype. However, studies were predominantly at high or unclear risk of bias, and evidence was typically of low quality. CONCLUSIONS: Expectations that communicating DNA based risk estimates changes behaviour is not supported by existing evidence. These results do not support use of genetic testing or the search for risk-conferring gene variants for common complex diseases on the basis that they motivate risk-reducing behaviour. SYSTEMATIC REVIEW REGISTRATION: This is a revised and updated version of a Cochrane review from 2010, adding 11 studies to the seven previously identified.A previous version of this review was funded as part of a grant from the Medical Research Council, UK (Risk communication in preventive medicine: optimising the impact of DNA risk information; G0500274). Updating this review was funded by an NIHR Senior Investigator award to TMM. The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.This is the final version of the article. It first appeared from the BMJ Publishing Group via http://dx.doi.org/10.1136/bmj.i110

Pinpointing needles in giant haystacks: use of text mining to reduce impractical screening workload in extremely large scoping reviews.

In scoping reviews, boundaries of relevant evidence may be initially fuzzy, with refined conceptual understanding of interventions and their proposed mechanisms of action an intended output of the scoping process rather than its starting point. Electronic searches are therefore sensitive, often retrieving very large record sets that are impractical to screen in their entirety. This paper describes methods for applying and evaluating the use of text mining (TM) technologies to reduce impractical screening workload in reviews, using examples of two extremely large-scale scoping reviews of public health evidence (choice architecture (CA) and economic environment (EE)). Electronic searches retrieved >800,000 (CA) and >1 million (EE) records. TM technologies were used to prioritise records for manual screening. TM performance was measured prospectively. TM reduced manual screening workload by 90% (CA) and 88% (EE) compared with conventional screening (absolute reductions of ≈430 000 (CA) and ≈378 000 (EE) records). This study expands an emerging corpus of empirical evidence for the use of TM to expedite study selection in reviews. By reducing screening workload to manageable levels, TM made it possible to assemble and configure large, complex evidence bases that crossed research discipline boundaries. These methods are transferable to other scoping and systematic reviews incorporating conceptual development or explanatory dimensions

A new AF gravitational instanton

It has long been conjectured that the Euclidean Schwarzschild and Euclidean Kerr instantons are the only non-trivial asymptotically flat (AF) gravitational instantons. In this letter, we show that this conjecture is false by explicitly constructing a new two-parameter AF gravitational instanton with a U(1)xU(1) isometry group, using the inverse-scattering method. It has Euler number \chi=3 and Hirzebruch signature \tau=1, and its global topology is CP^2 with a circle S^1 removed appropriately. Various other properties of this gravitational instanton are also discussed.Comment: 10 pages, 2 figures, LaTe

Visualising health risks with medical imaging for changing recipients' health behaviours and risk factors: Systematic review with meta-analysis.

BACKGROUND: There is ongoing clinical and research interest in determining whether providing personalised risk information could motivate risk-reducing health behaviours. We aimed to assess the impact on behaviours and risk factors of feeding back to individuals' images of their bodies generated via medical imaging technologies in assessing their current disease status or risk. METHODS AND FINDINGS: A systematic review with meta-analysis was conducted using Cochrane methods. MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to July 28, 2021, with backward and forward citation searches up to July 29, 2021. Eligible studies were randomised controlled trials including adults who underwent medical imaging procedures assessing current health status or risk of disease, for which personal risk may be reduced by modifying behaviour. Trials included an intervention group that received the imaging procedure plus feedback of visualised results and assessed subsequent risk-reducing health behaviour. We examined 12,620 abstracts and included 21 studies, involving 9,248 randomised participants. Studies reported on 10 risk-reducing behaviours, with most data for smoking (8 studies; n = 4,308), medication use (6 studies; n = 4,539), and physical activity (4 studies; n = 1,877). Meta-analysis revealed beneficial effects of feedback of visualised medical imaging results on reduced smoking (risk ratio 1.11, 95% confidence interval [CI] 1.01 to 1.23, p = 0.04), healthier diet (standardised mean difference [SMD] 0.30, 95% CI 0.11 to 0.50, p = 0.003), increased physical activity (SMD 0.11, 95% CI 0.003 to 0.21, p = 0.04), and increased oral hygiene behaviours (SMD 0.35, 95% CI 0.13 to 0.57, p = 0.002). In addition, single studies reported increased skin self-examination and increased foot care. For other behavioural outcomes (medication use, sun protection, tanning booth use, and blood glucose testing) estimates favoured the intervention but were not statistically significant. Regarding secondary risk factor outcomes, there was clear evidence for reduced systolic blood pressure, waist circumference, and improved oral health, and some indication of reduced Framingham risk score. There was no evidence of any adverse effects, including anxiety, depression, or stress, although these were rarely assessed. A key limitation is that there were some concerns about risk of bias for all studies, with evidence for most outcomes being of low certainty. In particular, valid and precise measures of behaviour were rarely used, and there were few instances of preregistered protocols and analysis plans, increasing the likelihood of selective outcome reporting. CONCLUSIONS: In this study, we observed that feedback of medical images to individuals has the potential to motivate risk-reducing behaviours and reduce risk factors. Should this promise be corroborated through further adequately powered trials that better mitigate against risk of bias, such interventions could usefully capitalise upon the widespread and growing use of medical imaging technologies in healthcare

Stationary Black Holes: Uniqueness and Beyond

The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.Comment: Major update of the original version by Markus Heusler from 1998. Piotr T. Chru\'sciel and Jo\~ao Lopes Costa succeeded to this review's authorship. Significantly restructured and updated all sections; changes are too numerous to be usefully described here. The number of references increased from 186 to 32

Multiwavelength observations of the EUV variable metal-rich white dwarf GD 394

We present new Hubble Space Telescope (HST) ultraviolet and ground-based optical observations of the hot, metal-rich white dwarf GD394. Extreme-ultraviolet (EUV) observations in 1992-1996 revealed a 1.15 d periodicity with a 25 per cent amplitude, hypothesized to be due to metals in a surface accretion spot. We obtained phase resolved HST/Space Telescope Imaging Spectrograph high resolution far-ultraviolet spectra of GD394 that sample the entire period, along with a large body of supplementary data. We find no evidence for an accretion spot, with the flux, accretion rate, and radial velocity of GD394 constant over the observed time-scales at ultraviolet and optical wavelengths. We speculate that the spot may have no longer been present when our observations were obtained, or that the EUV variability is being caused by an otherwise undetected evaporating planet. The atmospheric parameters obtained from separate fits to optical and ultraviolet spectra are inconsistent, as is found for multiple hot white dwarfs. We also detect non-photospheric, high ionisation absorption lines of multiple volatile elements, which could be evidence for a hot plasma cocoon surrounding the white dwarf.European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013 / ERC Grant) [320964]; Leverhulme Trust Research Project Grant; NASA [NAS 5-26555]; NASA through a Space Telescope Science Institute [13719]; W. M. Keck FoundationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]