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Mobile service robots employ vision systems to discern objects in their workspaces for navigation or object detection. The lighting conditions of the surroundings affect a robot's ability to discern and navigate in its work environment. Robot inclusivity principles can be used to determine the suitability of a site's lighting condition for robot performance. This paper proposes a novel framework for autonomously auditing the Robot Inclusivity Index of indoor environments based on the lighting condition (RII-lux). The framework considers the factors of light intensity and the presence of glare to define the RII-Lux of a particular location in an environment. The auditing framework is implemented on a robot to autonomously generate a heatmap visually representing the variation in RII-Lux of an environment. The applicability of the proposed framework for generating true-to-life RII-Lux heatmaps has been validated through experimental results. [ABSTRACT FROM AUTHOR]

In Rhodobacter capsulatus , hydrogen production is predominantly limited by nitrogenase activity and light conversion efficiency. Modifying related genes can potentially mitigate these limitations. In this study, partial deletions of the mopAB and mdtB genes were performed in the R. capsulatus JL1 (WT) genome. Resultant mutants, JL11 (mopAB - ) and JL15 (mopAB - , mdtB - ), demonstrated favorable growth on MedA in photosynthetic anaerobic conditions. However, the growth of JL12 (mdtB - ) was inhibited. Batch fermentation experiments revealed an augmented hydrogen production in JL15, achieving a remarkable 177.89 ± 9.98 mmol L−1. Furthermore, the light conversion efficiencies of JL15 reached 4.6% and 3.3% under 3 ± 0.5 klux and 7 ± 0.5 klux, respectively. In comparison, JL1 (WT) achieved efficiencies of 3.3% and 1.8% with nitrogenase activities of 6.16 ± 0.11 and 6.90 ± 0.30 nmol min−1·mg−1. These findings highlight the promising potential of co-deletion as a strategy for enhancing hydrogen production. • Double-gene inactivation of mopAB and mdtB was carried out to construct mutant JL15 with improved H 2 production. • The LCE of JL15 was increased up to 83.3% compared with that of wild-type at high light conditon. • The nitrogenease activity 6.90 ± 0.30 nmol min−1·mg−1 of JL15 was increased by 55.4% to JL1 (WT) at high light conditon. [ABSTRACT FROM AUTHOR]

Mobile service robots employ vision systems to discern objects in their workspaces for navigation or object detection. The lighting conditions of the surroundings affect a robot’s ability to discern and navigate in its work environment. Robot inclusivity principles can be used to determine the suitability of a site’s lighting condition for robot performance. This paper proposes a novel framework for autonomously auditing the Robot Inclusivity Index of indoor environments based on the lighting condition (RII-lux). The framework considers the factors of light intensity and the presence of glare to define the RII-Lux of a particular location in an environment. The auditing framework is implemented on a robot to autonomously generate a heatmap visually representing the variation in RII-Lux of an environment. The applicability of the proposed framework for generating true-to-life RII-Lux heatmaps has been validated through experimental results.

This study employs a data mining approach to discover hidden groups of crash-risk factors leading to each bus/minibus crash severity level on pothole-ridden/poor roads categorized under different lighting conditions namely daylight, night with streetlights turned on, and night with streetlights turned off/no streetlights. The bus/minibus data employed contained 2,832 crashes observed on poor roads between 2011 and 2015, with variables such as the weather, driver, vehicle, roadway, and temporal characteristics. The data was grouped into three based on lighting condition, and the association rule data mining approach was applied. Overall, most rules pointing to fatal crashes included the hit-pedestrian variable, and these crashes were more frequent on straight/flat roads at night. While median presence was highly associated with severe bus/minibus crashes on dark-and-unlighted roads, median absence was correlated with severe crashes on dark-but-lighted roads. On-street parking was identified as a leading contributor to property-damage-only crashes in daylight conditions. The study proposed relevant countermeasures to provide practical guidance to safety engineers regarding the mitigation of bus/minibus crashes in Ghana. [ABSTRACT FROM AUTHOR]

• Frequency of speeding was significantly lower in rain condition compared to clear condition. • The frequency of speeding was significantly higher under daylight. • Drivers had a significant higher number of correct signs recognition under daylight as compared to night. • Task completion time in clear weather was significantly shorter than that in rain and fog weather. • Workload in rain weather was significantly higher than that in clear and fog weather. Alongside human factors, contextual factors are believed to have an ongoing and complex impact on driving outcomes. However, how and to what extent the components of context influence driving outcomes (e.g. rule violations, crash, stress, fatigue) are far beyond full understanding. The purpose of this study is to explore the effects of weather condition, lighting condition and traffic density on driving outcomes. Thirty-six volunteers were enrolled to participate into a driving simulator-based experiment. Each participant was required to complete twelve trials of simulated driving under different sets of scenarios. Driving outcome was measured by five dependent variables: frequency of speeding, frequency of lane deviations, number of correct sign recognition, completion time and workload. The results showed the frequency of speeding was significantly affected by weather condition, lighting condition and traffic density. Lighting condition had a significant effect on number of correct sign recognition. Weather condition, lighting condition and traffic density had significant effects on task completion time. Weather condition and lighting condition had significant effects on driver's workload. The implications of the results could help traffic safety professionals better understand the risk factors that may lead to human errors during driving. Practically, countermeasures could be inspired and developed to mitigate the adverse impacts brought by driving context to minimum. [ABSTRACT FROM AUTHOR]

• Nighttime crashes show a higher fatality risk for older pedestrians under no lighting. • High-speed zones (65–70 mph) and complex roads increase crash severity for pedestrians aged 65–74. • Rural roads with high speed pose greater fatal injury risks for pedestrians over 74. • Marked lane and urban areas with moderate speed (45–60 mph) increase crash risk for older pedestrians. Nighttime crashes involving older pedestrians pose a significant safety concern due to their age-related vulnerabilities such as reduced vision and slower reaction times. This study analyzes crash data from Texas for six years (2017–2022) using Association Rules Mining (ARM) to identify patterns and associations affecting crash severity for older pedestrians aged 65–74 years and those over 74 years under varying lighting conditions. The findings reveal that high-speed limits and complex road environments significantly increase the risk of fatal or severe injuries for both age groups, particularly under inadequate lighting. Additionally, demographic factors, adverse weather conditions, and specific road features further influence crash outcomes. These insights highlight the need for interventions, including lower speed limits, enhanced street lighting, and the implementation of advanced technologies such as modern pedestrian detection systems, sensor technology, pedestrian bags, accessible pedestrian signals, to improve the safety of older pedestrians. Policymakers should leverage these insights to formulate strategies that improve road safety for older pedestrians, addressing their unique vulnerabilities in various nighttime conditions. [ABSTRACT FROM AUTHOR]

Abstract Background The current study compared optical quality before and after implantation of a posterior chamber phakic intraocular lens with a central hole [V4c implantable collamer lens (ICL)] under bright and dark lighting conditions by means of the Optical Quality Analysis System™ (OQAS; Visiometrics, Terrassa, Spain). Methods This prospective study involved 91 eyes of 46 consecutive high myopia patients (15 males and 31 females, average spherical equivalent − 10.50 ± 0.33D) undergoing implantation of a V4c ICL. The modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and predicted visual acuities (PVAs; 100, 20, and 9%), under different lighting conditions, were measured before and 1 week, 1 month, and 3 months after surgery. Results All optical parameters showed significant improvements, at all time points, under dark condition after surgery. We observed no significant changes in PVA 9% at 1 week (mean value 0.539, P = 0.12) or 1 month after surgery (mean value 0.573, P = 0.08) under bright condition; but all other postoperative parameters improved significantly. Comparing the two lighting conditions, the OSI decreased more under dark conditions at 1 week (P = 0.02), 1 month (P = 0.004), and 3 months (P = 0.002), but there was no significant difference in any other parameter. In addition, patients were divided into super high myopia (group S, spherical equivalent greater than − 10 D) and high myopia (group H, spherical equivalent from − 6 D to − 10 D), the group S improved significantly more than group H in all parameters, under both bright and dark conditions. Conclusions V4c ICL implantation improved optical quality under both bright and dark lighting conditions, and had a better ability to reduce the extent of scattering in the dark. Furthermore, group S achieved greater improvement in visual quality, which should be considered by physicians before surgery.

The ability to quickly and accurately determine soil organic matter (SOM) content is critical for effective soil management decisions. Using the colour of soil images captured by smartphones to predict SOM content has emerged as a promising alternative to traditional wet chemistry methods. However, natural environments can present a complex array of light conditions that can compromise the accuracy and consistency of soil image colour acquisition, thus limiting the method's applicability. To address this issue, we propose five colour calibration patterns (C0 (no calibration), C1 (neutral grey), C2 (RGB), C3 (RGBCMY), and C4 (24 colours)), based on a 24-colour standard card. These patterns were used to calibrate the images of 352 original soil samples obtained from smartphones in three different lighting environments - L1 (100–2000 lx), L2 (35,000–40,000 lx), and L3 (75,000–80,000 lx). Random forest models were used to construct predictive models of soil organic matter (SOM) content based on images. Our findings indicate that smartphones exhibit complex spectral response characteristics, which result in poor image accuracy and stability of uncalibrated (C0) images under varying lighting conditions. The uncalibrated (C0) soil images in different lighting environments exhibited high colour difference (∆E mean = 14.11), resulting in poor SOM model sharing performance (R2 mean = 0.52 and RMSE mean = 20.33 g/kg). The use of colour calibration methods reduced the colour difference between soil images (∆E mean = 8.19) and improved the shared accuracy of the model (R2 mean = 0.61 and RMSE mean = 12.00 g/kg). The pattern of colour calibration has a key impact on the performance of the model application. The model sharing accuracy was found to be higher for the same or similar colour calibration pattern combination compared to different combinations of colour calibration patterns. Overall, the richer the colour calibration blocks, the better the model's shared performance. The findings of this research can enhance the application performance of soil attribute prediction models based on the colour of objects captured by smartphones in natural environments. • Differences in light intensity affect the colour stability of smartphone images. • Colour calibration reduces image colour differences in different light for phones. • Colour calibration boosts the shared ability of the attribute prediction model. • Colour calibration patterns with rich colours for better model-sharing ability. [ABSTRACT FROM AUTHOR]

A realistically inserted virtual object in the real-time physical environment is a desirable feature in augmented reality (AR) applications and mixed reality (MR) in general. This problem is considered a vital research area in computer graphics, a field that is experiencing ongoing discovery. The algorithms and methods used to obtain dynamic and real-time illumination measurement, estimating, and rendering of augmented reality scenes are utilized in many applications to achieve a realistic perception by humans. We cannot deny the powerful impact of the continuous development of computer vision and machine learning techniques accompanied by the original computer graphics and image processing methods to provide a significant range of novel AR/MR techniques. These techniques include methods for light source acquisition through image-based lighting or sampling, registering and estimating the lighting conditions, and composition of global illumination. In this review, we discussed the pipeline stages with the details elaborated about the methods and techniques that contributed to the development of providing a photo-realistic rendering, visual coherence, and interactive real-time illumination results in AR/MR. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the optical quality of highly myopic eyes under light and dark conditions and correlate it with other relevant parameters. Materials and Methods: A cross-sectional, observational study was performed on 180 eyes of 90 highly myopic patients (29 males and 61 females; mean age: 27.833 ± 0.364 years [range: 18–45 years]). The modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and predicted visual acuity (PVA; 100%, 20%, and 9%) under different lighting conditions were measured to evaluate the optical quality, which was correlated with probable relevant factors, including, axis length, spherical equivalent (SE), uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), astigmatism, and corneal curvature. The relationship between these visual parameters and optical quality was analyzed using a generalized linear model. Results: The OSIs were 1.241 ± 0.068 and 1.515 ± 0.076; the MTF cutoff frequencies were 37.725 ± 0.559 and 30.238 ± 0.550 cpd; the Strehl ratios were 0.219 ± 0.004 and 0.175 ± 0.003; and the PVAs at 100%, 20%, and 9% were 1.257 ± 0.019 and 1.001 ± 0.018, 0.949 ± 0.017 and 0.719 ± 0.015, and 0.579 ± 0.011 and 0.439 ± 0.010, under bright and dark conditions respectively. The optical quality parameters were correlated with age, SE, BDVA, corneal astigmatism, and curvature to different degrees under different lighting conditions. Conclusions: The optical quality declined in highly myopic eyes under both bright and dark lighting conditions. SE, BDVA, corneal astigmatism, and curvature were correlated with optical quality to different degrees under different lighting conditions. [ABSTRACT FROM AUTHOR]

Background: The current study compared optical quality before and after implantation of a posterior chamber phakic intraocular lens with a central hole [V4c implantable collamer lens (ICL)] under bright and dark lighting conditions by means of the Optical Quality Analysis System™ (OQAS; Visiometrics, Terrassa, Spain).Methods: This prospective study involved 91 eyes of 46 consecutive high myopia patients (15 males and 31 females, average spherical equivalent - 10.50 ± 0.33D) undergoing implantation of a V4c ICL. The modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and predicted visual acuities (PVAs; 100, 20, and 9%), under different lighting conditions, were measured before and 1 week, 1 month, and 3 months after surgery.Results: All optical parameters showed significant improvements, at all time points, under dark condition after surgery. We observed no significant changes in PVA 9% at 1 week (mean value 0.539, P = 0.12) or 1 month after surgery (mean value 0.573, P = 0.08) under bright condition; but all other postoperative parameters improved significantly. Comparing the two lighting conditions, the OSI decreased more under dark conditions at 1 week (P = 0.02), 1 month (P = 0.004), and 3 months (P = 0.002), but there was no significant difference in any other parameter. In addition, patients were divided into super high myopia (group S, spherical equivalent greater than - 10 D) and high myopia (group H, spherical equivalent from - 6 D to - 10 D), the group S improved significantly more than group H in all parameters, under both bright and dark conditions.Conclusions: V4c ICL implantation improved optical quality under both bright and dark lighting conditions, and had a better ability to reduce the extent of scattering in the dark. Furthermore, group S achieved greater improvement in visual quality, which should be considered by physicians before surgery. [ABSTRACT FROM AUTHOR]

The depth information performs a very important role in a production of three-dimensional (3D) video content. One way to acquire this information is a stereo matching method. The stereo matching method searches for correspondences from a stereo image that has two different viewpoints. Subsequently, it estimates the depth information by calculating a disparity value between two corresponding points. Generally, a relatively accurate result is obtained from the correspondence search when the stereo image is captured under uniform illumination and exposure conditions. However, it is difficult to estimate accurate correspondences if each viewpoint image is captured under varying illumination and exposure conditions. In this paper, we analyze conventional pixel-wise and block-wise stereo matching methods that are robust to lighting condition changes. Subsequently, we propose an adaptive pixel-wise and block-wise stereo matching method based on the analysis result. [ABSTRACT FROM AUTHOR]

Facial expressions recognition (FER) is an important modality in the future assessing teaching skill system (ATS). The fundamental difference with FER is in its low resolution image, unique occlusion of veiled teachers, and varied lighting conditions. However, it is still able to solve the problem of variations in head poses. This study, overall, began with the collection of articles from Scopus, created the FER taxonomy class and mapped the use of datasets. After finding out which datasets were suitable for the image of expression in teaching, a deeper discussion about classifier-classifier (using the same CK+ dataset) was capable of solving problems (low resolution image, occlusion, variation in lighting conditions and head poses). Finally, from the discussion conducted, it is known the potential for modification of algorithms, appropriate datasets and research opportunities for future FER in ATS. [ABSTRACT FROM AUTHOR]

Highlights • Factors affecting machine vision parameters were optimised. • The artificial cloud lighting condition was outperformed than natural lighting condition. • Luminance colour plane was not able to increase detection accuracy. • Image acquisition speeds (1 and 1.5 km h−1) and working depth (300 mm) showed promising results. Abstract Strawberry plants have been facing a significant proportion of diseases during cultivation, scattered throughout the field, emphasizing the need for proper diseases management. Powdery mildew is one of the major fungal strawberry disease which is typically responsible for approximately 30–70% loss of yields. The aim of this study was to develop a machine vision based artificial cloud lighting condition system for detecting strawberry powdery mildew leaf disease. The artificial cloud lighting condition system was developed consisting of custom software, two µEye colour cameras, a black cloth cover, real time kinematics-global positioning system and a ruggedized laptop computer and mounted on a mobile platform. The custom software was developed in C# programming language. The colour co-occurrence matrix based texture analysis was used to extract image features and discriminant analysis (quadratic) for classification. The study proposed mobile platform of artificial cloud lighting condition for image acquisition is beneficial. It showed higher detection accuracies of 95.26%, 95.45% and 95.37% for recall, precision and F-measure, respectively compared to 81.54%, 72% and 75.95% of recall, precision and F-measure, respectively with acquired images at natural cloud lighting condition. The feature selection results suggested the PM_GHSI feature model was best fit for this study. This study also revealed that the image acquisition speed (1.5 km h−1) and working depth (300 mm) are suitable for strawberry powdery mildew disease detection in real-time field condition. [ABSTRACT FROM AUTHOR]

• Injury severity of pedestrian walking-along-the-road crashes in different lighting conditions is explored. • Correlated and uncorrelated random parameters logit models are applied for the analysis. • Out-of-sample predictions underscored the shifts in factor effects between different lighting conditions. • Significant variation in factor effects on injury severity outcomes in different lighting conditions was established. Pedestrians walking along the road's edge are more exposed and vulnerable than those on designated crosswalks. Often, they remain oblivious to the imminent perils of potential collisions with vehicles, making crashes involving these pedestrians relatively unique compared to others. While previous research has recognized that the surrounding lighting conditions influence traffic crashes, the effect of different lighting conditions on walking-along-the-road pedestrian injury severity outcomes remains unexplored. This study examines the variations in the impact of risk factors on walking-along-the-road pedestrian-involved crash injury severity across various lighting conditions. Preliminary stability tests on the walking-along-the-road pedestrian-involved crash data obtained from Ghana revealed that the effect of most risk factors on injury severity outcomes is likely to differ under each lighting condition, warranting the estimation of separate models for each lighting condition. Thus, the data were grouped based on the lighting conditions, and different models were estimated employing the random parameter logit model with heterogeneity in the means approach to capture different levels of unobserved heterogeneity in the crash data. From the results, heavy vehicles, shoulder presence, and aged drivers were found to cause fatal pedestrian walking-along-the-road severity outcomes during daylight conditions, indicators for male pedestrians and speeding were identified to have stronger associations with fatalities on roads with no light at night, and crashes occurring on Tuesdays and Wednesdays were likely to be severe on lit roads at night. From the marginal effect estimates, although some explanatory variables showed consistent effects across various lighting conditions in pedestrian walking-along-the-road crashes, such as pedestrians aged < 25 years and between 25 and 44 years exhibited significant variations in their impact across different lighting conditions, supporting the finding that the effect of risk factors are unstable. Further, the out-of-sample simulations underscored the shifts in factor effects between different lighting conditions, highlighting that enhancing visibility could play a pivotal role in significantly reducing fatalities associated with pedestrians walking along the road. Targeted engineering, education, and enforcement countermeasures are proposed from the interesting insights drawn to improve pedestrian safety locally and internationally. [ABSTRACT FROM AUTHOR]

Colourful signals are usually honest indicators of mate quality since they are energetically costly. However, how colours are perceived by choosers is highly affected by the environmental light condition. Amazon black waters are strongly red-biased while clear waters show no apparent colour bias. The sailfin tetra Crenuchus spilurus is a sexually dimorphic Amazon fish species; males have hyperallometric dorsal and anal fins conspicuously ornamented with red and yellow markings. The species has two main lineages, which inhabit black and clear waters. A comparison of the red colouration of the ornaments of males from different lineages indicates that red bias increases the perceived intensity of red colouration but decreases the perceived among-individual variation in red colour. In mate choice experiments, females from all lineages preferred males with larger ornaments. Clear water lineage females were more likely to accept males under red-biased lighting, which increases the apparent red colouration, suggesting the importance of the red colouration in their mate choice. On the other hand, male acceptance by females from black waters did not change under different light conditions, suggesting that signals other than the red colouration (e.g. size of ornaments) were more important in their mate choice. • Black water light condition increased the intense of red coloured ornaments. • However, it decreased the among-individual variation in ornaments colouration. • Mating acceptance from black waters females was not affected by lighting condition. • Males with larger ornaments were more likely to be accepted as mating partners. • Black-water lighting conditions might have caused the shift of mate-choice signals. [ABSTRACT FROM AUTHOR]

Abstract: This study was conducted to test our hypothesis that intramuscular fat (IMF) accumulation increases in pigs fed on a low lysine diet during the dark period than those fed on the same diet during the light period. Using barrows aged 6 weeks, we monitored whether serum glucose and insulin levels were affected by light conditions. Two diets with different levels of lysine, 0.78% (LL diet) and 1.37% (control diet) were prepared. Eight pigs were fed on the diet during the light period, while the remaining pigs were fed during the dark period. The pigs were fed either the LL diet or the control diet. Although IMF contents of Longissimus dorsi (LD) muscle were higher in the pigs fed on a LL diet (p < .05), the light conditions had no effect. Low dietary lysine caused reduction in serum glucose levels (p < .05) and serum insulin levels (p = .0613). However, they were also unaffected by the lighting conditions. To gain further insights, we determined the messenger RNA levels of insulin receptor, insulin receptor substrate 1, acetyl CoA carboxylase, and fatty acid synthase in LD and Rhomboideus muscles and in the liver. [ABSTRACT FROM AUTHOR]

This paper investigates factors affecting injury severity of crashes involving trucks for different lighting conditions on rural and urban roadways. It uses 2009–2013 Ohio crash data from the Highway Safety Information System. The explanatory factors include the occupant, vehicle, collision, roadway, temporal and environmental characteristics. Six separate mixed logit models were developed considering three lighting conditions (daylight, dark, and dark-lighted) on two area types (rural and urban). A series of log-likelihood ratio tests were conducted to validate that these six separate models by lighting conditions and area types are warranted. The model results suggest major differences in both the combination and the magnitude of impact of variables included in each model. Some variables were significant only in one lighting condition but not in other conditions. Similarly, some variables were found to be significant in one area type but not in other area type. These differences show that the different lighting conditions and area types do in fact have different contributing effects on injury severity in truck-involved crashes, further highlighting the importance of examining crashes based on lighting conditions on rural and urban roadways. Age and gender of occupant (who is the most severely injured in a crash), truck types, AADT, speed, and weather condition were found to be factors that have significantly different levels of impact on injury severity in truck-involved crashes. [ABSTRACT FROM AUTHOR]

Based on a psychophysical experiment, this study aimed to investigate factors that influenced color emotion and color preference, as well as the correlations between color emotion and color preference. Some color chips of Munsell color order system were picked out to supply actual patterns with different sets to evaluate the factors of hue, chroma, lightness, then they were pasted at a baseplate with black and white backgrounds respectively to involve the influences of backgrounds. Thus, in total 6 groups of color patches were prepared, and 18 attributes were chosen for visual assessment, including 16 words to describe color emotion, together with 2 color preference descriptions, so that massive data of observers’ judgments were gathered. Afterwards, a quantitative analysis and a detailed discussion were carried out for each attribute. Moreover, the calculation of Pearson correlation coefficients indicated that backgrounds could influence the perception of color emotion and color preference in a certain degree, and hue played a more important role than chroma and lightness. Further factor analysis revealed that color emotions do not exist in an isolated manner, and color preference could be represented in three orthogonal dimensions. [ABSTRACT FROM AUTHOR]

Light is essential for plant growth. Light intensity, photoperiod and light quality all affect plant morphology and physiology. Compared to light intensity, photoperiod, little is known about the effects of different monochromatic lights on crop species. To investigate how different lighting conditions influence crops with heterogeneous colors in leaves, we examined photosynthetic characteristics and quality (regarding edibility and nutrition) of purple cabbage under different combinations of lights. Eight different treatments were applied including monochromic red (R), monochromic blue (B), monochromic yellow (Y), monochromic green (G) and the combination of red and blue (3/1, RB)， red/blue/yellow (3/1/1, RBY)， red /blue/green (3/1/1,RBG) and white light as the control. Our results indicate that RBY (3/1/1) treatment promotes the PSII activity of purple cabbage, resulting in improved light energy utilization. By contrast, both G and Y lights alone have inhibitory effect on the PSII activity of purple cabbage. In addition, RBY (3/1/1) significantly boosts the anthocyanin and flavonoids content compared with other treatments. Although we detected highest soluble protein and vitamin C content under B treatment (increased by 29.99% and 14.29% compared with the control respectively), RBY (3/1/1) appeared to be the second-best lighting condition (with soluble protein and vitamin C content increased by 8.63% and 4.07% respectively compared with the control). Thus we prove that the addition of yellow light to the traditional combination of red/blue lighting conditions is beneficial to synthesizing photosynthetic pigments and enables superior outcome of purple cabbage growth. Our results indicate that the growth and nutritional quality of purple cabbage are greatly enhanced under RBY (3/1/1) light, and suggest that strategical management of lighting conditions holds promise in maximizing the economic efficiency of plant production and food quality of vegetables grown in controlled environments.

Introduction Many studies have examined different factors contributing to the injury severity of crashes; however, relatively few studies have focused on the crashes by considering the specific effects of lighting conditions. This research investigates lighting condition differences in the injury severity of crashes using 3-year (2009–2011) crash data of two-lane rural roads of the state of Washington. Method Separate ordered-probit models were developed to predict the effects of a set of factors expected to influence injury severity in three lighting conditions; daylight, dark, and dark with street lights. A series of likelihood ratio tests were conducted to determine if these lighting condition models were justified. Results The modeling results suggest that injury severity in specific lighting conditions are associated with contributing factors in different ways, and that such differences cannot be uncovered by focusing merely on one aggregate model. Key differences include crash location, speed limit, shoulder width, driver action, and three collision types (head-on, rear-end, and right-side impact collisions). Practical Applications This paper highlights the importance of deploying street lights at and near intersections (or access points) on two-lane rural roads because injury severity highly increases when crashes occur at these points in dark conditions. [ABSTRACT FROM AUTHOR]

This paper models and mitigates the secondary crash (SC) risk for serial tunnels on the freeway which is incurred by traffic turbulence after primary crash (PC) occurrence and location-heterogeneous lighting conditions along serial tunnels. A traffic conflict approach is developed where SC risk is quantified using a surrogate safety measure based on the simulated vehicle trajectories after PC occurs from a lighting-related microscopic traffic model with inter-lane dependency. Numerical examples are presented to validate the model, illustrate SC risk pattern over time, and evaluate the countermeasures for SC, including adaptive tunnel lighting control (ATLC) and advanced speed and lane-changing guidance (ASLG) for connected vehicles (CVs). The results demonstrate that the tail of the stretching queue on the PC occurrence lane, the adjacent lane of the PC-incurred queue, and areas near tunnel portals are high-risk locations. In serial tunnels, creating a good lighting condition for drivers is more effective than advanced warnings in CVs to mitigate SC risk. Combined ATLC and ASLG is promising since ASLG informs CVs of an immediate response to traffic turbulence on the lane where PC occurs and ATLC alleviates SC risks on adjacent lanes via smoothing the lighting condition variations and reducing inter-lane dependency.

Building occupants' environmental comfort and physiological health conditions are significantly affected by workplace environmental quality, such as lighting, thermal, air, and acoustic conditions. Of all of these factors, lighting quality is the most significant in relation to the occupants' visual comfort and health, since its effect is almost instantaneous, and it is vulnerable due to its immediate sensitivity. This research investigated the possibility of using human eye pupil sizes to estimate visual sensations in office workplace environments. The human body, as a biological mechanism, naturally makes unconditioned responses using the parasympathetic nervous system in multiple physical organs, including pupils in human eyes. Based on this physiological principle, a human body automatically reacts to ambient conditions to minimize any environmental stressful condition. This study adopted this principle as a key factor for analyzing pupil sizes and their change patterns to assess each individual subject's visual sensations while generating various ranges of ambient lighting conditions in an environmental chamber. The chamber is located at the University of Southern California where researchers conducted a series of human subject experiments. The collected data were analyzed using statistical tools for interpreting research findings. The data were grouped by the subjects' gender, age, glasses-worn, eye color, in order to identify any differences in pupil sizes and change rates, depending on the physical characteristics of each individual. These research findings indicated that the use of pupil sizes to assess a subject's visual sensations has potential and would be applicable to individuals, regardless of their physical characteristics. [ABSTRACT FROM AUTHOR]

Highlights: [•] We use three exposure modes to explore the locomotion changes on 4–6dpf larvae. [•] Only 500μgL−1 PBDE-47 may decrease the locomotion significantly. [•] Interval exposure produced reversibility of the behavioral effects. [•] Only during dark period elicited hypoactivity. [ABSTRACT FROM AUTHOR]

The purpose of the several studies reported here was to improve the lighting conditions at industrial visual testing and inspection workplaces beyond the specifications given in technical standards. In this context, special emphasis was laid on the examination of the effects of directional and diffuse lighting as well as of sample-specific lighting scenarios with respect to the ability to detect three-dimensional (3D) details. The sample-specific lighting scenarios were designed according to ergonomic principles and adapted to different material surfaces. Landolt rings of various sizes were laser-engraved on several surface types, which are representative of the surfaces encountered in industrial final inspection tasks. The sample surfaces were fixed in a special object mount, which allowed defined and reproducible test arrangements. In a first step, the luminance distribution on the samples and the contrast between the Landolt rings and the background of the samples were measured depending on different illumination types and inclinations of the surface types. Additionally, laboratory tests were carried out in which the test subjects’ visual acuity was measured while detecting 3D details (e.g. the Landolt rings) on the surfaces of different materials illuminated in different ways. It turned out that all results were strongly dependent on the inclination of the samples rather than on the lighting scenarios applied. In a further study, the time-related performance in detecting surface flaws on samples under different lighting scenarios was measured. For this purpose, the average error quota was assessed, i.e. the proportion of wrongly identified Landolt rings among the overall number of optotypes and the response time to the identification of a presented optotype were determined. Both parameters gave evidence of the long-term advantage of the ergonomic sample-specific lighting scenarios. In a last step, the various illuminations were evaluated through a structured interview of the test subjects. The subjective assessment of the illuminations also indicated a high dependency on the geometric arrangement between light source and the sample under examination. Especially, in the context of long-term inspections, the subjects preferred the sample-specific lighting scenarios. The diffuse lighting was also assessed predominantly and positively. The illumination with directional lighting and with the lighting according to technical standards was, mostly, rated disadvantageously. [ABSTRACT FROM PUBLISHER]

The article discusses research on the effect of season and light intensity on core interthreshold zone (CIZ). It provides a definition for the CIZ and presents an overview on several studies covering CIZ. It explains the experimental protocol used in the study and describes the process of measuring rectal and skin temperatures using thermistors. The study demonstrated a seasonal difference and effect of light exposure on the CIZ.

Abstract: This study was undertaken to develop machine vision-based raisin detection technology for various lighting conditions. Supervised color image segmentation using a permutation-coded genetic algorithm (GA) identifying regions in hue–saturation–intensity (HSI) color space (GAHSI) for desired and undesired raisin detection in various conditions was successfully implemented. Images from two extreme intensity lighting and dense conditions: under weak lighting and high-density product and under suitable lighting and low-density product, were mosaicked to explore the possibility of using GAHSI to locate desired raisin and undesired raisin regions in color space when these two extremes were presented simultaneously. The GAHSI results provided evidence for the existence and separability of such regions. In the experiment, GAHSI performance was measured by comparing the GAHSI-segmented image with a corresponding hand-segmented reference image. When compared with cluster analysis-based segmentation results, the GAHSI method showed no significant difference. [ABSTRACT FROM AUTHOR]

Abstract: Ethologically based animal models are widely used; however, results from different laboratories vary significantly which may partly be due to the lack of standardization. Here, we examined the effects of circadian rhythm, lighting condition and mouse strain (BALB/c and C57BL/6, known to differ in measures of avoidance and risk assessment behavior) on two well established behavioral tests in mice: the Elevated Plus Maze (EPM) and the Open Field (OF). Parameters from both paradigms are commonly used as indices of anxiety-like behavior. BALB/c mice and C57BL/6 mice were independently tested in the morning and at night, in regular laboratory lighting and in the dark. We developed a novel method based on infrared lighting from below, coupled to respective video-tracking equipment, which facilitates standard testing of behavior interference-free in complete darkness. The two mouse strains differed in anxiety-related variables for the EPM in the dark, and for the OF in regular laboratory lighting. Moreover, BALB/c displayed greater anxiety-like behavior than C57BL/6 in the OF but less anxiety-like behavior than C57BL/6 in the EPM. Lighting condition has a major influence on both behavioral tests and this to a considerably larger extent than circadian rhythm. In addition, the lighting condition interacts strongly with the genetic background, producing discriminative differences in the anxiety-related variables depending on mouse strain and lighting condition. These results challenge the comparability of not sufficiently standardized tests of anxiety-like behavior and emphasize the need for controlling environmental variables in behavioral phenotyping. [ABSTRACT FROM AUTHOR]

Many studies have examined the impact of factors affecting accident severity in rural areas; however, little attention has been paid to different lighting conditions (LCs), and less to the detailed categories and precise determining of twilight. In this paper, solar altitude angle (SAA), as a basis for differentiating and categorizing LCs, is proposed to investigate explanatory variables in much greater detail. For each LC, namely, dark, twilight, dark lit (dark with street lights) and daylight, separate random parameter models are developed to investigate the impacts of some factors on crash injury severity data of 2017 and 2018 in two lane rural roads of Texas. The model estimation results indicated that different LCs have various contributing factors, indeed, to each injury severity, further stressing the significance of investigating crashes based on SAA. The key differences include crash location, marked lane, grade direction, no passing zone, shoulder width, weekday and collision type. The important findings were that developing artificial lighting at intersections and LED raised pavement markers on two lane rural roads could lead to enhanced road safety under dark LCs. Furthermore, increasing shoulder width in straight segments of two lane rural roads is important for decreasing severe injury in daylight conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effects of artificial and natural lighting on photobioreactors were investigated. • COD removal of artificial lighting mode was 13.2% higher than that of natural one. • Nutrients removal between two lighting conditions were not significantly different. • Light intensity had strong positive correlation with biomass and DO concentration. • Natural lighting saved 57% energy consumption compared with artificial lighting. Co-culture using microalgae-activated sludge in Sequencing Batch Photobioreactors (PBRs) was investigated for wastewater treatment performance. This study evaluated the effect of natural and artificial lighting conditons on treatment performance under consideration of energy consumption. The results found that the removal of nutrients and COD of natural lighting condition was only 10% and 13% lower than those of artificial lighting respectively. Generally, artificial lighting mode took an advantage in pollutants removal. However, standing at 0.294 kWh L-1, the total energy consumption of natural lighting was over two times less than that of artificial lighting. It reveals the natural lighting system played a dominant role for cutting energy costs significantly compared to artificial lighting one (∼57%). As a practical viewpoint on energy aspect and treatment performance, a natural lighting PBR system would be a sustainable option for microalgae-activated sludge co-culture system treating wastewater. [ABSTRACT FROM AUTHOR]

Abstract: The increasing use of zebrafish (Danio rerio) in developmental research highlights the need for a detailed understanding of their behavior. We studied the locomotion of individual zebrafish larva (6 days post-fertilization) in 96-well microtiter plates. Movement was recorded using a video-tracking system. Time of day results indicated locomotion, tested in darkness (infrared), decreased gradually from early morning to a stable level between 13:00 and 15:30h. All further studies were conducted in early-to-late afternoon and lasted approximately 1h. Each study also began with a period of darkness to minimize any unintended stimulation caused by transferring the plates to the recording platform. Locomotion in darkness increased initially to a maximum at 4min, then decreased steadily to a low level by 20min. Locomotion during light was initially low and then gradually increased to a stable level after 20min. When 10-min periods of light and dark were alternated, activity was low in light and high in dark; curiously, activity during alternating dark periods was markedly higher than originally obtained during either extended dark or light. Further experiments explored the variables influencing this alternating pattern of activity. Varying the duration of the initial dark period (10–20min) did not affect subsequent activity in either light or dark. The activity increase on return to dark was, however, greater following 15min than 5min of light. Acute ethanol increased activity at 1 and 2% and severely decreased activity at 4%. One-percent ethanol retarded the transition in activity from dark to light, and the habituation of activity in dark, while 2% ethanol increased activity regardless of lighting condition. Collectively, these results show that locomotion in larval zebrafish can be reliably measured in a 96-well microtiter plate format, and is sensitive to time of day, lighting conditions, and ethanol. [Copyright &y& Elsevier]

In order to optimize the illumination of industrial visual testing and inspection workplaces, the limits of the detectability of 3-dimensional details have to be determined for different surfaces and lighting scenarios. For this reason, the influence of the inclination of samples on luminance and contrast was examined, and additionally laboratory tests were carried out to measure visual acuity when detecting flaws on the surfaces of different materials at various illuminations. The results were compared to the subjective assessment of test subjects (Ss) who participated in the laboratory tests. It turned out that all results are strongly dependent on the inclination of the samples rather than on the lighting scenarios applied. [ABSTRACT FROM AUTHOR]

Delayed sleep phase syndrome (DSPS) is very often seen among patients with sleep-wake rhythm disorders. Humans with the 3111C allele of the human Clock gene tend to demonstrate a higher evening preference on the morningness–eveningness (ME) preference test. DSPS is thought to be an extreme form of this evening preference. Clock-mutant mice have been proposed as an animal model of evening preference. In this study, we looked at whether constant light (LL) housing of Clock-mutant mice during lactation would result in evening preference and/or DSPS. Housed under light–dark (LD) or constant dark (DD) conditions during the lactation period, both wild-type and Clock-mutant mice did not show a phase-delay in the locomotor activity measured under light–dark conditions, whereas constant light housing during lactation significantly caused a delayed onset. The magnitude of the delay during the light–dark cycle was positively associated with free-running period measured during constant darkness. Among wild, heterozygote, and homozygote pups born from heterozygous dams, only homozygote pups showed a delayed onset. Constant light–housed Clock-mutant mice exhibited a lower number and delayed peak of phospho-MAPK-immunoreactive cells in core regions of the suprachiasmatic nucleus (SCN) compared to light–dark housed wild-type or Clock-mutant mice. Activity onset returned to normal with daily melatonin injection at the lights-off time for 5 days. The present results demonstrate that Clock-mutant mice exposed to constant light during lactation can function as an animal model of DSPS and can be used to gain an understanding of the ethological aspects of DSPS as well as to find medication for its treatment. [ABSTRACT FROM AUTHOR]

Microalgae have attracted wide attention as an alternative raw material for bioenergy. Microalgae cultivated in wastewater can reduce cultivation costs, and wastewater can be treated while the microalgal biomass accumulates. Here, the effects of nutrient composition, lighting conditions, and metal ions on the growth and lipid yield of Chlorella pyrenoidosa cultivated in synthetic wastewater and actual wastewater were investigated. The microalgae treated with NO 3 --N showed the best growth status, and microalgae treated with NH 4 +-N exhibited the highest lipid yield. The maximum lipid yield was 0.18 g/L at a total phosphorus concentration of 5 mg/L. The maximum lipid content of C. pyrenoidosa was obtained at 4000 lux and 9:15 h L/D. In the metal ion experiment, the dry weight and total lipid yield in microalgae were highest when the Fe3+ concentration was 28.8 × 10−3 mM, and the total lipid yield reached the maximum (0.25 g/L) when the Mg2+ concentration was 0.5 mM. The seven factors involved in C. pyrenoidosa cultivation were optimised using a uniform-design experiment. According to the model, the optimal culture conditions were as follows: photoperiodicity, 23:1 h L/D; ammonia nitrogen, 125 mg/L; Fe3+, 0 mM; light intensity, 9000 lux; phosphorus, 14 mg/L; Mg2+, 0.18 mM; and CO 2 , 1.3 vol%; furthermore, the maximum theoretical lipid yield was 0.31 g/L. Analysis of the fatty acid composition revealed a similar composition in both real and synthetic wastewater. [Display omitted] • NO 3 --N was more suitable for microalgal growth, while NH 4 +-N for lipid yield. • C. pyrenoidosa had a similar growth trend at different light conditions. • The culture conditions of C. pyrenoidosa were optimized by uniform design test. • Fatty acid composition in both real and synthetic wastewater were similar. [ABSTRACT FROM AUTHOR]