The effects of glare and inhomogeneous visual fields on contrast detection in the context of driving

An experiment was carried out to investigate how contrast threshold for target detection is affected by the presence of glare and by extraneous light sources using the method of ascending limits. The target was located at either a foveal or a peripheral (10° right) location, glare was adjacent to the foveal location, simulating the headlamps of an oncoming vehicle, and extraneous light sources were at either foveal or peripheral (10° right or left) locations. Contrast threshold for a foveal target without glare was affected mainly by the surrounding local luminance distribution. However, in the presence of glare and also for the peripheral target (both with and without glare) the global luminance distribution matters. Glare increased the contrast needed for detection of the foveal target, but this effect was reduced by the presence of extraneous light sources that were peripheral to the target. For peripheral targets, contrast threshold was also reduced by the presence of extraneous light at a non-target location and this effect was increased in the presence of glare. Glare equations tend to be based on tests using uniform, homogenous fields: these data indicate that, in the presence of extraneous light sources, the influence of glare is overestimated.BMBF, 13N10815, Messung und Simulation des photopischen und mesopischen Sehens: Psychophysiologische Maße zur Beurteilung von Beleuchtungseinrichtunge

Social interaction in local public squares after dark

This paper explores social interaction in local public squares under different lighting conditions. At its best public squares are social spaces that engender a sense of belonging, increase the quality of life and wellbeing of individuals. It is proposed that outdoor lighting would be essential to the use of the public realm after dark, but empirical results regarding lighting conditions and social aspects of life in public squares are limited. Based on a socio-physical conceptual model of the transactional relationship of the user, the lit environment andthe behavioural outcome, this study investigated active social interaction in daylight compared to after dark. A field study was conducted in two local public squares in Malmö, Sweden. The occurrences of which visitors were being alone, in pairs, or in groups of three or more (N=2522), and verbal or non-verbal interaction amongst those in company of another person were recorded.The lit appearance of the two squares after dark, was assessed with HDR-photography and photometric measurements; portraying dissimilar spatial, spectral and intensity characteristics.The results of social interaction show dissimilar patterns of the two squares; an increase in social interaction in EL after dark was observed in one of the squares, while a decrease in the afternoon and no significant difference was displayed in the evening after dark in the other square. It is suggested that lighting may sustain patterns of social interaction after dark, however it might be, that the company of another is especially important after dark

Review of a published article (Kakitsuba N. Comfortable Indoor Lighting Conditions Evaluated from Psychological and Physiological Responses.)

This note is a critical review of the spatial brightness experiment reported by Kakitsuba [Kakitsuba 2015]. There are several reasons why I think the study is flawed and therefore that the results should not be considered credible. In particular, the results can largely be explained by a stimulus range bias, the ‘boundary’ illuminances tending to lie near the centre of each range of illuminances reported. Therefore the results are a product of the illuminance ranges chosen by the experimenter and do not indicate observers’ preferences for light level

Comment on empirical evidence for the design of public lighting

A recent article (Peña-García et al., 2015) presented conclusions regarding the benefits of road lighting for pedestrians. Here it is demonstrated that those conclusions were drawn from incomplete evidence, in one case because the experimental designs leads only to a trivial solution and in a second case because of an incomplete search of the literature

Causal relevance of blood lipid fractions in the development of carotid atherosclerosis: Mendelian randomization analysis.

BACKGROUND: Carotid intima-media thickness (CIMT), a subclinical measure of atherosclerosis, is associated with risk of coronary heart disease events. Statins reduce progression of CIMT and coronary heart disease risk in proportion to the reduction in low-density lipoprotein cholesterol. However, interventions targeting triglycerides (TGs) or high-density lipoprotein cholesterol (HDL-C) have produced inconsistent effects on CIMT and coronary heart disease risk, making it uncertain whether such agents are ineffective for coronary heart disease prevention or whether CIMT is an inadequate marker of HDL-C or TG-mediated effects. We aimed to determine the causal association among the 3 major blood lipid fractions and common CIMT using mendelian randomization analysis. METHODS AND RESULTS: Genetic scores specific for low-density lipoprotein cholesterol, HDL-C, and TGs were derived based on single nucleotide polymorphisms from a gene-centric array in ≈5000 individuals (Cardiochip scores) and from a genome-wide association meta-analysis in >100 000 individuals (Global Lipids Genetic Consortium scores). These were used as instruments in a mendelian randomization analysis in 2 prospective cohort studies. A genetically predicted 1 mmol/L higher low-density lipoprotein cholesterol concentration was associated with a higher common CIMT by 0.03 mm (95% confidence interval, 0.01-0.04) and 0.04 mm (95% confidence interval, 0.02-0.06) based on the Cardiochip and Global Lipids Genetic Consortium scores, respectively. HDL-C and TGs were not causally associated with CIMT. CONCLUSIONS: Our findings confirm a causal relationship between low-density lipoprotein cholesterol and CIMT but not with HDL-C and TGs. At present, the suitability of CIMT as a surrogate marker in trials of cardiovascular therapies targeting HDL-C and TGs is questionable and requires further study

Using the daylight savings clock change to show ambient light conditions significantly influence active travel

This article reports a novel procedure used to investigate whether ambient light conditions affect the number of people who choose to walk or cycle. Pedestrian and cyclist count data were analysed using the biannual daylight-saving clock changes to compare daylight and after-dark conditions whilst keeping seasonal and time-of-day factors constant. Changes in frequencies during a 1-h case period before and after a clock change, when light conditions varied significantly between daylight and darkness, were compared against control periods when the light condition did not change. Odds ratios indicated the numbers of pedestrians and cyclists during the case period were significantly higher during daylight conditions than after-dark, resulting in a 62% increase in pedestrians and a 38% increase in cyclists. These results show the importance of light conditions on the numbers of pedestrian and cyclists, and highlight the potential of road lighting as a policy measure to encourage active travel after-dark

Specifying enough light to feel reassured on pedestrian footpaths

This article discusses lighting for pedestrians and how investigation of reassurance might lead toward an understanding of the right amount of light. A conventional approach is to evaluate reassurance after dark under road lighting of different illuminance: this tends to show the trivial result that higher illuminances enhance reassurance, and that alone does not enable an optimum light level to be identified. One reason is that the category rating procedure widely used is prone to stimulus range bias; experimental results are presented that demonstrate stimulus range bias in reassurance evaluations. This article also recommends alternative methods for future research. One such method is the day–dark rating approach, which does not tend toward ever higher illuminances, and results are presented of two studies using this method

Variant rs10911021 that associates with coronary heart disease in type 2 diabetes, is associated with lower concentrations of circulating HDL cholesterol and large HDL particles but not with amino acids.

AIMS: An intergenic locus on chromosome 1 (lead SNP rs10911021) was previously associated with coronary heart disease (CHD) in type 2 diabetes (T2D). Using data from the UCLEB consortium we investigated the relationship between rs10911021 and CHD in T2D, whether rs10911021 was associated with levels of amino acids involved in the γ-glutamyl cycle or any conventional risk factors (CRFs) for CHD in the T2D participants. METHODS: Four UCLEB studies (n = 6531) had rs10911021 imputation, CHD in T2D, CRF and metabolomics data determined using a nuclear magnetic resonance based platform. RESULTS: The expected direction of effect between rs10911021 and CHD in T2D was observed (1377 no CHD/160 CHD; minor allele OR 0.80, 95 % CI 0.60-1.06) although this was not statistically significant (p = 0.13). No association between rs10911021 and CHD was seen in non-T2D participants (11218 no CHD/1274 CHD; minor allele OR 1.00 95 % CIs 0.92-1.10). In T2D participants, while no associations were observed between rs10911021 and the nine amino acids measured, rs10911021 was associated with HDL-cholesterol (p = 0.0005) but the minor "protective" allele was associated with lower levels (-0.034 mmol/l per allele). Focusing more closely on the HDL-cholesterol subclasses measured, we observed that rs10911021 was associated with six large HDL particle measures in T2D (all p < 0.001). No significant associations were seen in non-T2D subjects. CONCLUSIONS: Our findings are consistent with a true association between rs10911021 and CHD in T2D. The protective minor allele was associated with lower HDL-cholesterol and reductions in HDL particle traits. Our results indicate a complex relationship between rs10911021 and CHD in T2D

Integrated associations of genotypes with multiple blood biomarkers linked to coronary heart disease risk

Individuals at risk of coronary heart disease (CHD) show multiple correlations across blood biomarkers. Single nucleotide polymorphisms (SNPs) indexing biomarker differences could help distinguish causal from confounded associations because of their random allocation prior to disease. We examined the association of 948 SNPs in 122 candidate genes with 12 CHD-associated phenotypes in 2775 middle aged men (a genic scan). Of these, 140 SNPs indexed differences in HDL- and LDL-cholesterol, triglycerides, C-reactive protein, fibrinogen, factor VII, apolipoproteins AI and B, lipoprotein-associated phospholipase A2, homocysteine or folate, some with large effect sizes and highly significant P-values (e.g. 2.15 standard deviations at P = 9.2 × 10−140 for F7 rs6046 and FVII levels). Top ranking SNPs were then tested for association with additional biomarkers correlated with the index phenotype (phenome scan). Several SNPs (e.g. in APOE, CETP, LPL, APOB and LDLR) influenced multiple phenotypes, while others (e.g. in F7, CRP and FBB) showed restricted association to the index marker. SNPs influencing six blood proteins were used to evaluate the nature of the associations between correlated blood proteins utilizing Mendelian randomization. Multiple SNPs were associated with CHD-related quantitative traits, with some associations restricted to a single marker and others exerting a wider genetic ‘footprint’. SNPs indexing biomarkers provide new tools for investigating biological relationships and causal links with disease. Broader and deeper integrated analyses, linking genomic with transcriptomic, proteomic and metabolomic analysis, as well as clinical events could, in principle, better delineate CHD causing pathways amenable to treatment

Sixty-five common genetic variants and prediction of type 2 diabetes.

We developed a 65 type 2 diabetes (T2D) variant-weighted gene score to examine the impact on T2D risk assessment in a U.K.-based consortium of prospective studies, with subjects initially free from T2D (N = 13,294; 37.3% women; mean age 58.5 [38-99] years). We compared the performance of the gene score with the phenotypically derived Framingham Offspring Study T2D risk model and then the two in combination. Over the median 10 years of follow-up, 804 participants developed T2D. The odds ratio for T2D (top vs. bottom quintiles of gene score) was 2.70 (95% CI 2.12-3.43). With a 10% false-positive rate, the genetic score alone detected 19.9% incident cases, the Framingham risk model 30.7%, and together 37.3%. The respective area under the receiver operator characteristic curves were 0.60 (95% CI 0.58-0.62), 0.75 (95% CI 0.73 to 0.77), and 0.76 (95% CI 0.75 to 0.78). The combined risk score net reclassification improvement (NRI) was 8.1% (5.0 to 11.2; P = 3.31 × 10(-7)). While BMI stratification into tertiles influenced the NRI (BMI ≤24.5 kg/m(2), 27.6% [95% CI 17.7-37.5], P = 4.82 × 10(-8); 24.5-27.5 kg/m(2), 11.6% [95% CI 5.8-17.4], P = 9.88 × 10(-5); >27.5 kg/m(2), 2.6% [95% CI -1.4 to 6.6], P = 0.20), age categories did not. The addition of the gene score to a phenotypic risk model leads to a potentially clinically important improvement in discrimination of incident T2D