269 research outputs found
The Return of the White Buffalo: Taxation Issues Facing American Indian Tribes Conducting Gambling Enterprises on Tribal Lands
Anderson Localization in Disordered Vibrating Rods
We study, both experimentally and numerically, the Anderson localization
phenomenon in torsional waves of a disordered elastic rod, which consists of a
cylinder with randomly spaced notches. We find that the normal-mode wave
amplitudes are exponentially localized as occurs in disordered solids. The
localization length is measured using these wave amplitudes and it is shown to
decrease as a function of frequency. The normal-mode spectrum is also measured
as well as computed, so its level statistics can be analyzed. Fitting the
nearest-neighbor spacing distribution a level repulsion parameter is defined
that also varies with frequency. The localization length can then be expressed
as a function of the repulsion parameter. There exists a range in which the
localization length is a linear function of the repulsion parameter, which is
consistent with Random Matrix Theory. However, at low values of the repulsion
parameter the linear dependence does not hold.Comment: 10 pages, 6 figure
Anderson Localization Phenomenon in One-dimensional Elastic Systems
The phenomenon of Anderson localization of waves in elastic systems is
studied. We analyze this phenomenon in two different set of systems: disordered
linear chains of harmonic oscillators and disordered rods which oscillate with
torsional waves. The first set is analyzed numerically whereas the second one
is studied both experimentally and theoretically. In particular, we discuss the
localization properties of the waves as a function of the frequency. In doing
that we have used the inverse participation ratio, which is related to the
localization length. We find that the normal modes localize exponentially
according to Anderson theory. In the elastic systems, the localization length
decreases with frequency. This behavior is in contrast with what happens in
analogous quantum mechanical systems, for which the localization length grows
with energy. This difference is explained by means of the properties of the re
ection coefficient of a single scatterer in each case.Comment: 15 pages, 10 figure
Mortality, greenhouse gas emissions and consumer cost impacts of combined diet and physical activity scenarios: a health impact assessment study
To quantify changes in mortality, greenhouse gas (GHG) emissions and consumer costs for physical activity and diet scenarios.
For the physical activity scenarios, all car trips from <1 to <8 miles long were progressively replaced with cycling. For the diet scenarios, the study population was assumed to increase fruit and vegetable (F&V) consumption by 1–5 portions of F&V per day, or to eat at least 5 portions per day. Health effects were modelled with the comparative risk assessment method. Consumer costs were based on fuel cost savings and average costs of F&V, and GHG emissions to fuel usage and F&V production.
Working age population for England.
Data from the Health Survey for England, National Travel Survey and National Diet and Nutrition Survey.
Changes in premature deaths, consumer costs and GHG emissions stratified by age, gender and socioeconomic status (SES).
Premature deaths were reduced by between 75 and 7648 cases per year for the physical activity scenarios, and 3255 and 6187 cases per year for the diet scenarios. Mortality reductions were greater among people of medium and high SES in the physical activity scenarios, whereas people with lower SES benefited more in the diet scenarios. Similarly, transport fuel costs fell more for people of high SES, whereas diet costs increased most for the lowest SES group. Net GHG emissions decreased by between 0.2 and 10.6 million tons of carbon dioxide equivalent (MtCOe) per year for the physical activity scenarios and increased by between 1.3 and 6.3 MtCOe/year for the diet scenarios.
Increasing F&V consumption offers the potential for large health benefits and reduces health inequalities. Replacing short car trips with cycling offers the potential for net benefits for health, GHG emissions and consumer costs.MT, PM, NJ and JW were supported by 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. JW is also supported by an MRC Population Health Scientist fellowship (grant number: MR/K021796/1). CB is supported by the UK Research Councils (grant number: EPSRC EP/L024756/1) as part of the Decision Making Theme of the UK Energy Research Centre Phase 3
Persistent financial hardship, 11-year weight gain, and health behaviors in the Whitehall II study.
OBJECTIVE: To ascertain prospectively gender-specific associations between types and amounts of financial hardship and weight gain, and investigate potential behavioral mechanisms. METHODS: Prospective study of 3701 adult British civil servants with repeated measures of difficulty paying bills or insufficient money to afford adequate for food/clothing (1985-1988; 1989-1990; 1991-1993; 1997-1999), and weight (1985-1988; 1997-1999). RESULTS: Persistent hardships were associated with adjusted mean weight change in women over 10.9 years, but no consistent pattern was seen in men. During follow-up, 46% of women gained ≥5 kg. Women reporting persistent insufficient money for food/clothing had a significantly greater odds of gaining ≥5 kg (1.42 [1.05, 1.92]) compared to no hardship history, which remained after socioeconomic status (SES) adjustment (1.45 [1.05, 2.01]). The association between persistent difficulty paying bills and odds of excess weight gain was also significant (1.42 [1.03, 1.97]) but attenuated after considering SES (1.39 [0.98, 1.97]). Four health behaviors as single measures or change variables did not attenuate associations. CONCLUSIONS: Results suggested strategies to tackle obesity must address employed women's everyday financial troubles which may influence weight through more biological pathways than classical correlates of economic disadvantage and weight.This is the final version, originally published in the journal Obesity here: http://onlinelibrary.wiley.com/doi/10.1002/oby.20875/abstract;jsessionid=EDA4F761217B492D16E7384EB67A7399.f02t02
Marital transitions and associated changes in fruit and vegetable intake: Findings from the population-based prospective EPIC-Norfolk cohort, UK.
BACKGROUND: Diet is critical to health and social relationships are an important determinant of diet. We report the association between transitions in marital status and healthy eating behaviours in a UK population. METHODS: Longitudinal study of middle-age and older adults 39-78y (n = 11 577) in EPIC-Norfolk, a population-based cohort, who completed food frequency questionnaires in 1993-97 and 1998-2002. Multivariable linear regression analyses assessed gender-specific associations between five categories of marital transitions and changes in quantity (g/d), and variety (no/month) of fruits or vegetables. RESULTS: In 3.6 years of follow-up and relative to men who stayed married, widowed men showed significant declines (mean difference, 95% CI) in all four indicators of healthy eating including fruit quantity (-47.7, -80.6 to -14.9 g/d), fruit variety (-0.6, -1.1 to -0.2 no/month), vegetable quantity (-27.7, -50.5 to -4.9 g/d), and vegetable variety (-1.6, -2.2 to -0.9 no/month). Men who were separated or divorced or who remained single also showed significant declines in three of the indicators. Among women, only those who became separated/divorced or stayed single showed declines in one indicator, vegetable variety. CONCLUSION: Unhealthy changes to diet accompanying divorce, separation and becoming widowed may be more common among men than women. Moreover, deterioration in fruit and vegetable intakes was more apparent for variety rather than quantity consumed. Programmes to promote healthy eating among older adults need to recognise these social determinants of diet and consider prioritising people who live alone and in particular men who have recently left relationships or who have been widowed.AIC acknowledges PhD funding from the Gates Cambridge Trust. This work was undertaken by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research of Excellence and was funded by The British Heart Foundation, Economic and Social Research, Medical Research Council, National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration (grant number MR/K023187/1). We further acknowledge core MRC Epidemiology Unit support through Programme grant MC_UU_12015/1.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.socscimed.2016.04.00
Job-loss and weight gain in British adults: Evidence from two longitudinal studies.
Overweight and obesity have been associated with unemployment but less is known about changes in weight associated with changes in employment. We examined weight changes associated with job-loss, retirement and maintaining employment in two samples of working adults in the United Kingdom. This was a prospective study of 7201 adults in the European Prospective Investigation of Cancer (EPIC)-Norfolk study (aged 39-76 years) and 4539 adults in the British Household Panel Survey (BHPS) who were followed up over 43 months and 26 months, respectively. In both samples, changes in measured (EPIC) and self-reported (BHPS) weight were computed for each participant and assessed in relation to three employment transitions: maintaining paid employment, retirement and job-loss. Regression models adjusted for potential confounders. Further analyses evaluated the contribution of diet, physical activity and smoking to weight gain. In EPIC-Norfolk, weight change differed across the three employment transitions for women but not men. The mean (95% CI) annualised change in weight for women who became unemployed over the follow-up period was 0.70 (0.55, 0.85) kg/y while those who maintained employment gained 0.49 (0.43, 0.55) kg/y (P = 0.007). Accounting for changes in smoking, diet and physical activity did not substantially alter the difference in weight gain among groups. In BHPS, job-loss was associated with weight gain of 1.56 (0.89, 2.23) kg/y, while those who maintained employment 0.60 (0.53, 0.68) kg/y (P < 0.001). In both samples, weight changes associated with retirement were similar to those staying in work. In BHPS, job-loss was also associated with significant declines in self-reported well-being and increases in sleep-loss. Two UK-based samples of working adults reveal strong associations between job-loss and excess weight gain. The mediating behaviours are so far unclear but psychosocial mechanisms and sleep-loss may contribute to the excess weight gain among individuals who become unemployed.This work was undertaken by the Centre for Diet and Activity Research, a UK Clinical Research Collaboration Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, National Institute for Health Research, and Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged
Associations between exposure to takeaway food outlets, takeaway food consumption, and body weight in Cambridgeshire, UK: population based, cross sectional study.
OBJECTIVES: To examine the association between environmental exposure to takeaway food outlets, takeaway food consumption, and body weight, while accounting for home, work place, and commuting route environments. DESIGN: Population based, cross sectional study, using data on individual participants' diet and weight, and objective metrics of food environment exposure. PARTICIPANTS: Working adults participating in the Fenland Study, Cambridgeshire, UK (n = 5442, aged 29-62 years), who provided home and work addresses and commuting preferences. Takeaway food outlet exposure was derived using data from local authorities for individual environmental domains (at home, at work, and along commuting routes (the shortest route between home and work)), and for exposure in all three domains combined. Exposure was divided into quarters (Q); Q1 being the least exposed and Q4 being the most exposed. MAIN OUTCOME MEASURES: Self reported consumption of takeaway type food (g/day; pizza, burgers, fried foods, and chips) using food frequency questionnaires, measured body mass index, and cut-offs for body mass index as defined by the World Health Organization. RESULTS: In multiple linear regression models, exposure to takeaway food outlets was positively associated with consumption of takeaway food. Among domains at home, at work, and along commuting routes, associations were strongest in work environments (Q4 v Q1; β coefficient = 5.3 g/day, 95% confidence interval 1.6 to 8.7; P<0.05), with evidence of a dose-response effect. Associations between exposure in all three domains combined and consumption were greater in magnitude across quarters of exposure (Q4 v Q1; 5.7 g/day, 2.6 to 8.8; P<0.001), with evidence of a dose-response effect. Combined exposure was especially strongly associated with increased body mass index (Q4 v Q1; body mass index 1.21, 0.68 to 1.74; P<0.001) and odds of obesity (Q4 v Q1; odds ratio 1.80, 1.28 to 2.53; P<0.05). There was no evidence of effect modification by sex. CONCLUSIONS: Exposure to takeaway food outlets in home, work, and commuting environments combined was associated with marginally higher consumption of takeaway food, greater body mass index, and greater odds of obesity. Government strategies to promote healthier diets through planning restrictions for takeaway food could be most effective if focused around the workplace
Wannier-Stark ladders in one-dimensional elastic systems
The optical analogues of Bloch oscillations and their associated
Wannier-Stark ladders have been recently analyzed. In this paper we propose an
elastic realization of these ladders, employing for this purpose the torsional
vibrations of specially designed one-dimensional elastic systems. We have
measured, for the first time, the ladder wave amplitudes, which are not
directly accessible either in the quantum mechanical or optical cases. The wave
amplitudes are spatially localized and coincide rather well with theoretically
predicted amplitudes. The rods we analyze can be used to localize different
frequencies in different parts of the elastic systems and viceversa.Comment: 10 pages, 6 figures, accepted in Phys. Rev. Let
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