Health and safety of the older worker

This is the author's pre-copyedited accepted manuscript. The final published article is available from the link below. Copyright @ 2012 The Authors.Background - In the UK, increasing numbers of paid employees are over 60 years with further increases expected as the state pension age rises. Some concern surrounds possible increased work-related illness and accidents for people working beyond the age of 60. Aims - To identify the available evidence for health and safety risks of workers over age 60 years with respect to factors associated with injuries and accidents. Methods - Databases searched included PUBMED, OSHUpdate, National Institute for Occupational Safety and Health (NIOSHTIC-2), SafetyLit, the UK The Health and Safety Executive (HSELINE) and the Canadian Centre for Occupational Health and Safety until December 2009. Inclusion criteria were workers aged over 60 years. Findings were grouped into occupational accidents and injuries and individual and workplace factors that may have influenced risk of injury to the over-60s. Results - Very little direct evidence was found concerning safety practices and health risks of workers over age 60. Some safety risks were associated with specific physical declines such as age-related hearing loss. Overall, these workers had fewer accidents and injuries but these were more likely to be serious or fatal when they occurred. There was no strong evidence that work patterns, including shift work or overtime, affected safety. Protective, compensatory strategies or experience may maintain safe working practices. Conclusions - Implications for health and safety risks cannot be assessed without longitudinal research on workforces with substantial numbers of workers over age 60 in order to address the healthy worker effect.Institution of Occupational Health and Safet

Vitamins and Perinatal Outcomes Among HIV-Negative Women in Tanzania.

Prematurity and low birth weight are associated with high perinatal and infant mortality, especially in developing countries. Maternal micronutrient deficiencies may contribute to these adverse outcomes. In a double-blind trial in Dar es Salaam, Tanzania, we randomly assigned 8468 pregnant women (gestational age of fetus, 12 to 27 weeks) who were negative for human immunodeficiency virus infection to receive daily multivitamins (including multiples of the recommended dietary allowance) or placebo. All the women received prenatal supplemental iron and folic acid. The primary outcomes were low birth weight (<2500 g), prematurity, and fetal death. The incidence of low birth weight was 7.8% among the infants in the multivitamin group and 9.4% among those in the placebo group (relative risk, 0.82; 95% confidence interval [CI], 0.70 to 0.95; P=0.01). The mean difference in birth weight between the groups was modest (67 g, P<0.001). The rates of prematurity were 16.9% in the multivitamin group and 16.7% in the placebo group (relative risk, 1.01; 95% CI, 0.91 to 1.11; P=0.87), and the rates of fetal death were 4.3% and 5.0%, respectively (relative risk, 0.87; 95% CI, 0.72 to 1.05; P=0.15). Supplementation reduced both the risk of a birth size that was small for gestational age (<10th percentile; 10.7% in the multivitamin group vs. 13.6% in the placebo group; relative risk, 0.77; 95% CI, 0.68 to 0.87; P<0.001) and the risk of maternal anemia (hemoglobin level, <11 g per deciliter; relative risk, 0.88; 95% CI, 0.80 to 0.97; P=0.01), although the difference in the mean hemoglobin levels between the groups was small (0.2 g per deciliter, P<0.001). Multivitamin supplementation reduced the incidence of low birth weight and small-for-gestational-age births but had no significant effects on prematurity or fetal death. Multivitamins should be considered for all pregnant women in developing countries. (ClinicalTrials.gov number, NCT00197548 [ClinicalTrials.gov].)

Manipulating infrared photons using plasmons in transparent graphene superlattices

Superlattices are artificial periodic nanostructures which can control the flow of electrons. Their operation typically relies on the periodic modulation of the electric potential in the direction of electron wave propagation. Here we demonstrate transparent graphene superlattices which can manipulate infrared photons utilizing the collective oscillations of carriers, i.e., plasmons of the ensemble of multiple graphene layers. The superlattice is formed by depositing alternating wafer-scale graphene sheets and thin insulating layers, followed by patterning them all together into 3-dimensional photonic-crystal-like structures. We demonstrate experimentally that the collective oscillation of Dirac fermions in such graphene superlattices is unambiguously nonclassical: compared to doping single layer graphene, distributing carriers into multiple graphene layers strongly enhances the plasmonic resonance frequency and magnitude, which is fundamentally different from that in a conventional semiconductor superlattice. This property allows us to construct widely tunable far-infrared notch filters with 8.2 dB rejection ratio and terahertz linear polarizers with 9.5 dB extinction ratio, using a superlattice with merely five graphene atomic layers. Moreover, an unpatterned superlattice shields up to 97.5% of the electromagnetic radiations below 1.2 terahertz. This demonstration also opens an avenue for the realization of other transparent mid- and far-infrared photonic devices such as detectors, modulators, and 3-dimensional meta-material systems.Comment: under revie

Difficult at dusk? Illuminating the debate on cricket ball visibility

Objectives: Investigate the visibility of new and old red, white and pink cricket balls under lighting and background conditions experienced during a day–night cricket match. Design: We modelled the luminance contrast signals available for a typical observer for a ball against backgrounds in a professional cricket ground, at different times of day. Methods: Spectral reflectance (light reflected as a function of wavelength) was derived from laboratory measurements of new and old red, white and pink balls. We also gathered spectral measurements from backgrounds (pitch, grass, sightscreens, crowd, sky) and spectral illuminance during a day–night match (natural afternoon light, through dusk to night under floodlights) from Lord's Cricket Ground (London, UK). The luminance contrast of the ball relative to the background was calculated for each combination of ball, time of day, and background surface. Results: Old red and old pink balls may offer little or no contrast against the grass, pitch and crowd. New pink balls can also be of low contrast against the crowd at dusk, as can pink and white balls (of any age) against the sky at dusk. Conclusions: Reports of difficulties with visibility of the pink ball are supported by our data. However, our modelling also shows that difficulties with visibility may also be expected under certain circumstances for red and white balls. The variable conditions in a cricket ground and the changing colour of an ageing ball make maintaining good visibility of the ball a challenge when playing day–night matches

Entropy Production in an Elementary, Light Driven Micro-Machine

This is the final version. Available on open access from Frontiers media via the DOI in this recordData Availability Statement: The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.We consider the basic, thermodynamic properties of an elementary micro-machine operating at colloidal length scales. In particular, we track and analyze the driven stochastic motion of a carefully designed micro-propeller rotating unevenly in an optical tweezers, in water. In this intermediate regime, the second law of macroscopic thermodynamics is satisfied only as an ensemble average, and individual trajectories can be temporarily associated with decreases in entropy. We show that our light driven micro-propeller satisfies an appropriate fluctuation theorem that constrains the probability with which these apparent violations of the second law occur. Implications for the development of more complex micro-machines are discussed.Czech Science FoundationEuropean Regional Development Fund (ERDF)Engineering and Physical Sciences Research Council (EPSRC)Royal Academy of Engineering (RAE

A systematic review and meta-analysis of the relationship between flow states and performance

This is the final version. Available on open access from Routledge via the DOI in this recordData availability: All relevant data and code is available online from https://osf.io/3hfcu/Flow is an optimal experience that has received particular interest within sport because of a possible relationship with enhanced athletic performances. Yet, the strength and direction of the putative flow–performance relationship remain unclear. Consequently, a PRISMA guided systematic review was conducted in May 2020 to examine the empirical evidence for a flow–performance relationship, to examine potential mechanisms, and to assess the quality of current evidence. Peer-reviewed articles that examined the relationship between flow and performance in sport or computer gaming tasks were searched for using five online databases. The results were collated into a narrative synthesis and a meta-analysis. Twenty articles met the inclusion criteria, featuring 22 studies that were appropriate for meta-analysis. The overall quality of the studies was fairly good, with a mean quality assessment score of 76.5% (SD = 9.7). The pooled effect size (r = 0.31, 95% CI [0.24; 0.38]) indicated that across a range of sport and gaming tasks there was a medium-sized flow–performance relationship. However, current evidence is unable to determine the causal direction of this relationship or the mechanisms that mediate it. A number of conceptual and methodological challenges facing the study of flow are discussed and recommendations for future work are outlined.Royal Academy of Engineering (RAE