Outdoor Light Research Articles

MDU‐sampling: Multi‐domain uniform sampling method for large‐scale outdoor LiDAR point cloud registration

AbstractSampling is a crucial concern for outdoor light detection and ranging (LiDAR) point cloud registration due to the large amounts of point cloud. Numerous algorithms have been devised to tackle this issue by selecting key points. However, these approaches often necessitate extensive computations, giving rise to challenges related to computational time and complexity. This letter proposes a multi‐domain uniform sampling method (MDU‐sampling) for large‐scale outdoor LiDAR point cloud registration. The feature extraction based on deep learning aggregates information from the neighbourhood, so there is redundancy between adjacent features. The sampling method in this paper is carried out in the spatial and feature domains. First, uniform sampling is executed in the spatial domain, maintaining local point cloud uniformity. This is believed to preserve more potential point correspondences and is beneficial for subsequent neighbourhood information aggregation and feature sampling. Subsequently, a secondary sampling in the feature domain is performed to reduce redundancy among the features of neighbouring points. Notably, only points on the same ring in LiDAR data are considered as neighbouring points, eliminating the need for additional neighbouring point search and thereby speeding up processing rates. Experimental results demonstrate that the approach enhances accuracy and robustness compared with benchmarks.

Towards a better understanding of light-glucose induced modifications on the structure and biological activity of formulated Nivolumab

In the last years, monoclonal antibodies (mAbs) have rapidly escalated as biopharmaceuticals into cancer treatments, mainly for their target specificity accompanied by less side effects than the traditional chemotherapy, and stimulation of reliable long-term anti-tumoral responses. They are potentially unstable macromolecules under shaking, temperature fluctuations, humidity, and indoor and outdoor light exposure, all stressors occurring throughout their production, transport, storage, handling, and administration steps. The chemical and physical modifications of mAbs can lead not only to the loss of their bioactivity, but also to the enhancement of their immunogenicity with increasing risk of severe hypersensitivity reactions in treated patients because of aggregation. The photostability of Nivolumab, the active principle of Opdivo®, has been here studied. The chemical modifications detected by LC-MS/MS after the light stressor showed Trp and Met mono and double oxidations as primary damage induced by light on this mAb. The oxidations were stronger when the mAb was diluted in sterile glucose solution where 5-HMF, a major heat glucose degradation product, acted as singlet oxygen producer under irradiation. However, no significant changes in the mAb conformation were found. On the contrary, formation of a significant extent of aggregates has been detected after shining high simulated sunlight doses. This again took place particularly when Nivolumab was diluted in sterile glucose, thus raising a direct correlation between the aggregation and the oxidative processes. Finally, the biological activity under light stress assessed by a blockade assay test demonstrated the maintenance of the PD-1 target recognition even under high light doses and in glucose solution, in line with the preservation of the secondary and tertiary structures of the mAb. Based on our results, as sterile glucose is mostly used for children's therapies, special warnings, and precautions for healthcare professionals should be included for their use to the pediatric population.

Self-Reported Outdoor Light Exposure Time and Incident Heart Failure.

A healthy lifestyle is an important factor for preventing heart failure. However, the association between outdoor light exposure time and heart failure is still unknown. The aim of this study was to examine the association between outdoor light exposure time and the incidence of heart failure. This cohort study included participants from the UK Biobank recruited from 2006 to 2010 who were 40 to 70 years of age and free of heart failure at baseline. The mean follow-up time was 12.61 years. The outdoor light exposure time was self-reported at baseline. A restricted cubic spline was performed to examine the potential nonlinear relationship between outdoor light exposure and the incidence of heart failure. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% CIs. During a mean follow-up of 12.61 years, 13 789 participants were first diagnosed with heart failure. There was a nonlinear (J-shaped) trend between outdoor light time and heart failure risk. Cox proportional hazard regression models showed that, compared with participants who received an average of 1.0 to 2.5 hours of outdoor light per day, those with <1.0 hours or >2.5 hours had a higher risk of heart failure after the model was adjusted for age and sex (<1.0 hours: HR, 1.27 [95% CI, 1.18-1.36]; >2.5 hours: HR, 1.11 [95% CI, 1.07-1.15]). These associations were still significant in the fully adjusted models (<1.0 hours: HR, 1.10 [95% CI, 1.03-1.18]; >2.5 hours: HR, 1.07 [95% CI, 1.03-1.11]). We found a J-shaped association between outdoor light exposure time and the risk of incident heart failure, suggesting that moderate exposure to outdoor light may be a prevention strategy for heart failure.

Outdoor artificial light at night and incident cardiovascular disease in adults: A national cohort study across China

Cardiovascular diseases (CVDs) become a major public health concern. Evidence concerning the effects of outdoor artificial light at night (ALAN) on CVD in adults is scarce. We aimed to investigate the extent to which outdoor ALAN could affect the risk of CVD over a exposure range. Data from the China Health and Retirement Longitudinal Study, a population-based longitudinal study, launched in 2011–2012 and follow up till 2018, covering 28 provinces, autonomous regions and municipalities across mainland China. This study included 14,097 adults aged ≥45 years. Outdoor ALAN exposure (in nanowatts per centimeters squared per steradian) within 500 m of each participant's baseline residence was obtained from satellite image data. CVD was defined from medical diagnosis. The population was divided into three groups based on outdoor ALAN exposure from low to high. Cox regression model was used to estimate the association between outdoor ALAN exposure and incident CVD with hazard ratios (HRs) and 95 % confidence intervals (CIs). The mean (SD) age of the cohort was 57.6 (9.1) years old and 49.3 % were males. Outdoor ALAN exposure of study participants ranged from 0.02 to 39.79 nW/cm2/sr. During 83,033 person-years of follow-up, 2190 (15.5 %) cases of CVD were identified. Both low (HR: 1.21; 95 % CI: 1.02—1.43) and high (HR: 1.23; 95 % CI: 1.04—1.46) levels of outdoor ALAN exposure group were associated with higher risk of CVD compared with intermediate levels of outdoor ALAN exposure group. Body mass index was a significant effect modifier in the association between outdoor ALAN and risk of CVD, with stronger effects among those who was overweight or obese. The findings of this study suggest that low and high outdoor ALAN exposure were associated with a higher risk for CVD. More attention should be given to the cardiovascular effects associated with outdoor ALAN exposure.

Self-Powered Dual-Band Electrochromic Supercapacitor Devices for Smart Window Based on Ternary Dielectric Triboelectric Nanogenerator.

A dual-band electrochromic supercapacitor device (DESCD) can be driven by an external power supply to modulate solar radiation, which is a promising energy-saving strategy and has broad application prospects in smart windows. However, traditional power supplies, such as batteries, supercapacitors, etc., usually face limited lifetimes and potential environmental issues. Hence, we propose a self-powered DESCD based on TiO2/WO3 dual-band electrochromic material and a ternary dielectric rotating triboelectric nanogenerator (TDR-TENG). The TDR-TENG can convert mechanical energy from the environment into electrical energy to obtain a high output of 840 V, 23.9 µA, and 327 nC. The as-prepared TDR-TENG can drive the TiO2/WO3 film to store energy with a high dual-band modulation amplitude of 41.6% in the visible (VIS) region and 84% in the near-infrared (NIR) region, decreasing the indoor-outdoor light-heat interaction and thereby reducing the building energy consumption. The self-powered DESCD demonstrated in this study has multiple functions of energy harvesting, energy storage, and energy saving, providing a promising strategy for the development of self-powered smart windows.

LASU: An efficient and stable phthalocyanine dye with tolerable safety profile for self-disinfecting anti-COVID textiles activated by ambient light

BackgroundRecent COVID crisis has demonstrated that modern society urgently needs an accessible protection against mass infections, especially viruses, as the new strains are appearing at an ever-increasing pace and cause severe harm to the population and the world economy. MethodsWe have developed an efficient phthalocyanine photosensitizer LASU, that is suitable for dyeing textiles and allows to prepare reusable self-disinfecting fabrics with strong antiviral properties. The safety profile of LASU was evaluated in accredited laboratories by several in vitro assays according to the OECD-guidelines. ResultsThe textiles impregnated with LASU phthalocyanine showed a significant antiviral photodynamic effect even under moderate indoor and outdoor light. The dye did not show any genotoxic potential in human lymphocyte micronucleus assay. It showed a possible indication for eye irritation in human EpiOcular™ model and was phototoxic when tested in mouse BALB/c 3T3 cell test in the presence and absence of UVA-irradiation. ConclusionNovel phthalocyanine-dyed textiles are suitable for general use as self-disinfecting antiviral barriers and materials in hospitals, households, and public places. The safety profile of LASU is the phototoxic effect which is related to LASU´s mode of action.

Association between outdoor light at night and hypertension and high-normal blood pressure: A nationwide cross-sectional study among Chinese adults.

The authors aimed to investigate the association between outdoor light at night (LAN) intensity and blood pressure. The study included 13507 participants aged 45 and above from the 2011-2012 China Health and Retirement Longitudinal Study baseline survey. Blood pressure measurements were obtained by averaging the last two readings recorded (three measurements with an interval of 45-60 s between each measurement) during the survey. Outdoor LAN intensity was assessed using Defense Meteorological Satellite Program data. The study categorized participants based on quartiles of outdoor LAN intensity and employed statistical methods like linear regression, restricted cubic splines, and logistic models to analyze the connections. After adjusting for potential confounding factors, higher levels of outdoor LAN intensity were associated with increase in systolic blood pressure (0.592mmHg/interquartile range [IQR], 95% confidence interval [CI]: 0.027,1.157), diastolic blood pressure (0.853mmHg/IQR, 95% CI: 0.525,1.180) and mean arterial pressure (0.766mmHg/IQR, 95% CI: 0.385,1.147). Interestingly, the relationship between LAN intensity and odds of hypertension followed a non-linear pattern, resembling a reverse "L" shape on cubic splines. Participants with the highest quartile of outdoor LAN intensity had 1.31-fold increased odds of hypertension (95% CI: 1.08-1.58) compared to the lowest quartile. Additionally, there was an observable trend of rising odds for high-normal blood pressure with higher levels of LAN intensity in the crude model, but no statistically significant differences were observed after adjusting for confounding factors. In conclusion, this study underscores a significant connection between outdoor LAN intensity and the prevalence of hypertension.

Outdoor nighttime light exposure (light pollution) is associated with Alzheimer's disease.

Alzheimer's disease (AD) prevalence has increased in the last century which can be attributed to increased lifespan, but environment is also important. Exposure to artificial light at night is one environmental factor that may influence AD. This study evaluated the relationship between outdoor nighttime light exposure and AD prevalence in the United States using satellite acquired outdoor nighttime light intensity and Medicare data. Higher outdoor nighttime light was associated with higher prevalence of AD. While atrial fibrillation, diabetes, hyperlipidemia, hypertension, and stroke were associated more strongly with AD prevalence than nighttime light intensity, nighttime light was more strongly associated with AD prevalence than alcohol abuse, chronic kidney disease, depression, heart failure, and obesity. Startlingly, nighttime light exposure more strongly associated with AD prevalence in those under the age of 65 than any other disease factor examined. These data suggest light exposure at night may influence AD, but additional studies are needed.

Alleviate light pollution by recognizing urban night-time light control area based on computer vision techniques and remote sensing imagery

Light pollution caused by unreasonable and excessive use of outdoor artificial light at night (ALAN) has become one of the fastest growing and most urgent global environmental problems. Therefore, the International Dark-Sky Association advocated the more controlled use of ALAN in urban area to protect night-time environment and enable sustainable development. However, relevant research and lighting planning are still in the enlightenment stage. This study focused on a typical city experiencing significant ALAN growth, combining night-time remote sensing imagery, urban big data and other muti-source heterogeneous data to systematically research urban night-time light status. We first analyzed the spatio-temporal evolution pattern of ALAN. Subsequently, advanced computer vision algorithms were proposed to recognize the night-time light control area (NLCA) based on the perspective of supply and demand balance. Results suggest both the ALAN intensity and area have grown rapidly over the past decade in the study area, with the intensity increasing by 82 % and the area expanding by 42 %. And a 108.5-square-kilometre area of the NLCA was intelligently delineated, for where the ALAN intensity was more than the demand of population, indicating that the management of the night-time light environment an urgent matter. Therefore, this study proposed practical management solutions according to the different functional zones in city within the NLCA, for further promoting the green transformation and smart upgrading of urban outdoor lighting. To sum up, our research offers a novel approach to resolving the issue of urban light pollution by recognizing the NLCA, as well as facilitating energy conservation and emission reduction.

SFEMM: A cotton binocular matching method based on YOLOv7x.

The cotton-picking robot needs to locate the target object in space in the process of picking in the field and other outdoor strong light complex environments. The difficulty of this process was binocular matching. Therefore, this paper proposes an accurate and fast binocular matching method. This method used the deep learning model to obtain the position and shape of the target object, and then used the matching equation proposed in this paper to match the target object. Matching precision of this method for cotton matching was much higher than that of similar algorithms. It was 54.11, 45.37, 6.15, and 12.21% higher than block matching (BM), semi global block matching (SGBM), pyramid stereo matching network (PSMNet), and geometry and context for deep stereo regression (GC-net) respectively, and its speed was also the fastest. Using this new matching method, the cotton was matched and located in space. Experimental results show the effectiveness and feasibility of the algorithm.

Association of outdoor artificial light at night with myopia among Chinese adolescents: a representative cross-sectional study.

The association between the rapid increase in myopia among adolescents and the amount of outdoor artificial light at night (ALAN) remains unclear. The aim of this study was to investigate the association between outdoor ALAN and myopia in adolescents. Stratified cluster random sampling was used to obtain a sample of 33,160 students (age range: 9-18 years; mean: 13.51 years) with complete data from 120 primary and secondary schools across the Ningxia region in China in 2021. Myopia was defined as a spherical equivalent (SE) ≤-0.5 diopters (D) in at least one eye, determined by automated refractometers without cycloplegia. Outdoor ALAN data were obtained from satellite data and the two-year average outdoor ALAN exposure for each participant was determined by matching it to their school address (home addresses were not available). The association between ALAN and myopia was assessed using multiple logistic regression models and restricted cubic spline (RCS) regression. Stratified analyses were performed by age, sex, residence, school level, and outdoor exercise time. The myopia group had higher outdoor ALAN levels than the non-myopia group [median (interquartile spacing): 14.44 (3.88-26.56) vs. 6.95 (1.21-21.74) nanoWatts/cm2/sr]. After adjusting for covariates identified through stepwise regression, it was observed that the prevalence of myopia increased by 4% for every 10-unit change [95% confidence interval (CI): 1.02-1.07]. Compared to the first quantile (Q1) of outdoor ALAN exposure, the odds ratio (OR) of myopia was 1.20 (95% CI: 1.08-1.34) in the fourth quantile. RCS further showed a positive nonlinear relationship between outdoor ALAN exposure and myopia (p for nonlinear <0.001). Stronger effects were not found in subgroup analyses. Outdoor ALAN exposure is positively and nonlinearly associated with the prevalence of myopia in adolescents. Controlling outdoor light pollution may constitute a potential strategy to reduce the incidence of myopia in adolescents.

Identification and localization of transmission lines for live working in distribution network

In this paper, aiming at the current distribution network with power operation in the presence of outdoor bright light, the operating scene is complex and not fixed, the transmission lines and lead samples are small and uneven, leading to poor accuracy of machine learning and other methods of distribution network with power operation robot identification and localization, this paper selects three-dimensional LIDAR to design a set of support vector machine (SVM) classifier and correlation analysis based on the target recognition method. This paper selects three-dimensional LIDAR to design a set of support vector machine (SVM) classifier and correlation analysis based on the target recognition method. First, in the context of power distribution network operations, we have explored various filtering methods suitable for preprocessing transmission line data. These methods aim to remove outliers and clutter from point clouds, thus enhancing both point cloud quality and processing speed. This, in turn, improves the efficiency of real-time on-site detection. We conducted experimental comparisons of various clustering algorithms and opted for a region-based point cloud clustering algorithm to achieve the segmentation of individual point clouds. Secondly, we proposed a multi-feature composite approach based on the Viewpoint Feature Histogram (VFH) features, which helps maintain the scale-invariant characteristics of the features. We then introduced a multi-feature composite criterion based on VFH features to extract features from segmented point clouds. Subsequently, an SVM classifier based on this composite feature criterion was developed to achieve target identification and classification. Experimental results have demonstrated improved accuracy in target identification. Finally, we integrated this system with a bucket-arm vehicle for coordinate conversion and precise navigation of the robot to the target station. This method significantly improves the overall operational efficiency of power distribution tasks.

Research Progress of Outdoor Light and Exercise in the Prevention and Treatment of Myopia

Research Progress of Outdoor Light and Exercise in the Prevention and Treatment of Myopia

Robust Bi-anchoring carbon dot/BiOCl sheet heterojunction photocatalysts toward superior photocatalytic activity.

BiOCl has attracted much attention due to its robust layered structure, excellent photocatalytic activity and nontoxicity. However, its practical application is hindered by its narrowband UV photoresponse and rapid recombination of photocarriers. Herein, zero-dimensional Bi-anchoring carbon quantum dot (Bi-CD)/two-dimensional BiOCl heterojunction (Bi-CD/BiOCl) photocatalysts are designed and synthesized by a facile hydrothermal method. Under 190-1100 nm broadband light irradiation, the optimized Bi-CD/BiOCl sample exhibits a superb rhodamine B (RhB) degradation rate of nearly 100%, which is 2.3 (1.7) times that of pristine BiOCl (CD/BiOCl). Additionally, the optimized sample exhibits an RhB degradation rate of up to 88.1% even under direct outdoor light and robust durability in water solution. Experimental results combined with DFT calculations reveal that the superior photocatalytic activity arises from the synergetic effects of broader light absorption due to the incorporation of CD, extra hot electron excitation by the localized surface plasmon resonance (LSPR) effect of metallic Bi, and enhanced electron transfer across the heterojunction interface as well as the existence of more oxygen vacancy traps in BiOCl. This work gives insights into the structure and photocatalytic properties of Bi-CD/BiOCl and provides a new strategy for the design and fabrication of robust high-performance photocatalysts under wide spectrum light irradiation.

Developing a Performance-Based Approach to the Effect of Roof Features on Fire Safety in Buildings with Atriums

Developing technology, changing social structures, and the threat of resource depletion have changed the design of buildings. Therefore, design approaches are developed to increase user comfort and reduce energy consumption by utilizing natural ventilation and lighting. The design of the distribution of outdoor air and light into the spaces through vertical and horizontal gaps reduces the energy demand of the mechanical systems and increases occupant comfort. The atrium is the preferred vertical gap in modern buildings for distributing natural air and light to interior spaces under appropriate conditions. However, in buildings with atrium, there is a risk of fire spreading in the event of a fire due to the uninterrupted gaps between the rooms. It is necessary to ensure the operability of the design by monitoring the measures to be taken in the early stages of design using performance-based fire safety methods. This study develops design strategies for fire analysis in atrium buildings using computational fluid dynamics (CFD) simulation technology. Atrium height, roof type, and slope characteristics are analyzed for the stack effect, which is the main factor in the movement of smoke and flames. As a result of the numerical analyses consisting of flat, unidirectional, and bidirectional sloping roof type, 10, 20, 30-degree roof slope, and one-meter rising atrium roof variables, the effect degrees for smoke dispersal and temperature control are investigated. Fire Dynamic Simulator, which uses CFD capabilities, and Smokeview software, which can visualize the results, were used for the numerical analysis. Correlation analysis was used to determine the effect of variables on temperature. The results showed that flat roofs and designs with increasing height were effective in delaying the spread of smoke and increasing the stack effect in the atrium, while the contribution of roof slope to fire safety was weak.

THE ROLE OF OUTDOOR LIGHT EXPOSURE ON SLEEP QUALITY IN OLDER INDIVIDUALS WITH FRAILTY OF DIFFERENT LIVING TYPES

Abstract The study investigates the relationship between outdoor light exposure and sleep quality in older individuals with frailty in institutions and the community, where sleep disorders are common, and outdoor light exposure is inadequate.The study includes older individuals with frailty in community and institutions in Taiwan. Participants must be aged 65 or above and have a Clinical Frailty Scale score between 4 to 8. We collect sleep quality and outdoor light exposure data using questionnaires and actigraphy.The study includes 77 older individuals: 29 from day-care centers, 22 from conventional long-term care institutions, and 26 from unit care institutions. The average outdoor light exposure is 15 minutes per day, with an average Pittsburgh Sleep Quality Index (PSQI) score of 8, 74% sleep efficiency, and 125.8 minutes of wake after sleep onset. After controlling for multiple variables. Outdoor light exposure shows no relationship with PSQI, sleep efficiency, and wake after sleep onset.The average PSQI score is &amp;gt; 5, indicating poor subjective sleep quality. Additionally, Wake After Sleep Onset &amp;gt; 60 minutes, and sleep efficiency &amp;lt; 75%, suggesting poor objective sleep quality. The average outdoor light exposure time &amp;lt; 20 minutes, indicating a lack of outdoor light exposure. However, our study does not observe the effects of light exposure, possibly because the average daily light exposure is below the 30-minutes threshold. Older individuals with frailty experience poor sleep quality. It is possible that a longer duration of outdoor light exposure may be needed to observe its impact on sleep quality.

Association between exposure to outdoor artificial light at night and the risk of preterm birth.

This study aimed to investigate the association between outdoor artificial light at night (ALAN) exposure during pregnancy and the risk of preterm birth (PTB). A retrospective case-control study was conducted, and data were collected from pregnant women residing in Beijing, China. The level of ALAN exposure during pregnancy was estimated using remote sensing satellite data. Propensity score matching was utilized to match the control group. Logistic and multivariate linear regression were used to analyze the association between ALAN and the risk of PTB. The odds ratio (OR) and partial regression coefficient (β) with 95% confidence interval (CI) were utilized to assess the association. A total of 2,850 pregnant women were enrolled in this study. ALAN (nW/cm2/sr) exposure was higher in the PTB group than in the control group during first trimester (mean ± standard deviation: 25.30 ± 17.91 vs. 17.56 ± 14.74, p < 0.001) and second trimester (27.07 ± 18.10 vs. 21.93 ± 16.08, p < 0.001). A negative association was found between ALAN exposure and gestation day in the first (β = -0.151, 95%CI: -0.217 to -0.085, p < 0.001) and second trimesters (β = -0.077, 95%CI: -0.139 to -0.015, p = 0.015). ALAN was identified as a risk factor for PTB during the first trimester (OR = 1.032, 95%CI: 1.025-1.040, p < 0.001) and the second trimester (OR = 1.018, 95%CI: 1.011-1.025, p < 0.001), while no significant association was observed in the third trimester. Our study suggesting that exposure to outdoor ALAN, especially during first and second trimester, was associated with the risk of PTB. These findings highlight the potential impact of ALAN on pregnancy health and offer new insights into the risk of PTB.

An empirical study on the effect of outdoor illumination and exercise intervention on Children's vision.

To explore the relationship between outdoor lighting and sports and the development of myopia, and to analyze the effects of outdoor lighting and exercise on the diopter of children with normal vision and myopia, so as to provide guidance for the prevention and treatment of myopia in children and adolescents in the future. A total of 201 children were divided into two groups according to myopia or not. Each group was randomly divided into 4 groups: outdoor exercise group, outdoor control group, indoor exercise group and indoor control group. Among them, the outdoor exercise group and indoor exercise group received moderate and high intensity aerobic exercise 3 times a week for 60 min each time for 12 months, while the outdoor control group and indoor control group had normal study and life during the corresponding period of time. No additional exercise intervention. At the end of the experiment, the diopter of each group was compared. The diopter of all groups with normal vision and myopia decreased significantly after the experiment (p < 0.01). There were significant differences in diopter between outdoor exercise group and indoor control group (p < 0.01), between outdoor exercise group and indoor control group (p < 0.05), and between indoor exercise group and indoor control group (p < 0.01). There were significant differences in diopter between indoor exercise group and indoor control group (p < 0.01). The differences among myopic children after the experiment showed that there was significant difference in diopter between outdoor exercise group and indoor exercise group (p < 0.05), between outdoor exercise group and indoor control group (p < 0.01), and between outdoor control group and indoor control group (p < 0.05). There were significant differences in the changes of diopter between the outdoor control group and the indoor exercise group with normal vision and myopia before and after the experiment (p < 0.05). Outdoor light and exercise intervention can have a beneficial effect on children's vision, but because of whether children are myopic or not, the effect is different, outdoor light and exercise have a better effect on reducing the diopter of children with normal vision.

Time spent in outdoor light is associated with the risk of dementia: a prospective cohort study of 362094 participants

AbstractBackgroundFew epidemiological studies in the adult population related these outcomes to daytime sunlight exposure.MethodData were from a prospective cohort of 362094 UK Biobank participants. Questionnaire survey was conducted to investigate how many hours the participants spent outdoors on typical summer and winter days. Restricted cubic spline (RCS) was performed to explore the potential nonlinear relationship between sunlight exposure and the risk of dementia.ResultMore specifically, we prefer to describe this nonlinear relationship with J shape, the lowest risk at three change points (1.5 hours/day on average, 2 hours/day in summer, and 1 hour/day in winter). Since for sunlight exposure, a marked increase in risk was observed at low exposure, but a relatively slow elevation in risk at higher exposure.ConclusionThere is a J‐shaped correlation between outdoor sunlight exposure time and dementia risk.

Outdoor light at night and mortality in the UK Biobank: a prospective cohort study

BackgroundMore than 83% of the world’s population lives under light-polluted skies while information about health effects of outdoor light at night (LAN) is limited. We examined the association of LAN...