Monochromatic Leds For Vision Improvement in Foggy Roads

In India, foggy weather creates poor visibility, and this leads to several accidents and slows down normal traffic speed, which may lead to adverse effect on the economy of the country. The probable solution is the use of monochromatic light with other artificial vision system to increase the visibility for the drivers in these foggy areas. There are various kinds of monochromatic lights available in the market. In this study, it has been tried to find out the best working monochromatic LEDs for this particular application. In this study, two types of monochromatic radiation were compared (amber light with 600 nm and green light with 545 nm) with and without the camera-display setup (artificial visual system) for finding out best working system in the foggy area for increasing the visibility. The experiment shows that amber light monochromatic radiation with 600 nm works better for identification of objects. The amber light can be used in front of a car to illuminate the front environment in the foggy weather and increase the visibility. It has been observed that green light monochromatic radiation with 545 nm works better for identification of the source from a very long distance. It has been proposed to install both of these lights with amber and green monochromatic radiation in vehicles to reduce accidents in foggy weather.

Filtering Light-Emitting Diodes to Investigate Amber and Red Spectral Effects on Lettuce Growth

Red and blue light are the principal wavelengths responsible for driving photosynthetic activity, yet amber light (595 nm) has the highest quantum efficiency and amber-rich high pressure sodium lamps result in superior or comparable plant performance. On this basis, we investigated how lettuce plant growth and photosynthetic activity were influenced by broad and narrow light spectra in the 590–630 nm range, by creating amber and red light-emitting diode (LED) spectra that are not commercially available. Four different light spectra were outfitted from existing LEDs using shortpass and notch filters: a double peak spectrum (595 and 655 nm; referred to as 595 + 655-nm light) that excluded 630-nm light, 595-nm, 613-nm, and 633-nm light emitting at an irradiance level of 50 W·m−2 (243–267 µmol·m−2·s−1). Shifting LED wavelengths from 595 nm to 633 nm and from 595 nm to 613 nm resulted in a biomass yield decrease of ~50% and ~80%, respectively. When 630-nm light is blocked, lettuce displayed expanded plant structures and the absence of purple pigmentation. This report presents a new and feasible approach to plant photobiology studies, by removing certain wavelengths to assess and investigate wavelength effect on plant growth and photosynthesis. Findings indicate that amber light is superior to red light for promoting photosynthetic activity and plant productivity, and this could set precedence for future work aimed at maximizing plant productivity in controlled environment agriculture.

Exposure to Blue Wavelength Light Is Associated With Increases in Bidirectional Amygdala-DLPFC Connectivity at Rest

Blue wavelength light has been used successfully as a treatment method for certain mood disorders, but, the underlying mechanisms behind the mood enhancing effects of light remain poorly understood. We investigated the effects of a single dose of 30 min of blue wavelength light (n = 17) vs. amber wavelength light (n = 12) exposure in a sample of healthy adults on subsequent resting-state functional and directed connectivity, and associations with changes in state affect. Individuals who received blue vs. amber wavelength light showed greater positive connectivity between the right amygdala and a region within the left dorsolateral prefrontal cortex (DLPFC). In addition, using granger causality, the findings showed that individuals who received blue wavelength light displayed greater bidirectional information flow between these two regions relative to amber light. Furthermore, the strength of amygdala-DLPFC functional connectivity was associated with greater decreases in negative mood for the blue, but not the amber light condition. Blue light exposure may positively influence mood by modulating greater information flow between the amygdala and the DLPFC, which may result in greater engagement of cognitive control strategies that are needed to perceive and regulate arousal and mood.

Blue-wavelength Light Therapy for Post-traumatic Brain Injury Sleepiness, Sleep Disturbance, Depression, Fatigue: A Systematic Review and Network Meta-analysis

Background: We aimed to determine the efficacy of blue-wavelength light therapy (BWLT) for post-traumatic brain injury (TBI) sleepiness, sleep disturbance, depression, and fatigue.Methods: We searched six databases for randomized controlled trials of BWLT for adults with a history of TBI. Outcomes of interest included sleepiness, sleep disturbance, depression, or fatigue. We conducted random-effect frequentist network meta-analyses (NMA) to compare the efficacy and a pairwise meta-analysis to examine the dropout rates.Results: We included four randomized controlled trials that compared BWLT, amber light therapy, and no light therapy. BWLT was significantly superior in reducing depression as compared to amber light therapy (SMD = 0.57, 95% CI = 0.04 to 1.10) and no light therapy (SMD = 0.81, 95% CI = 0.20 to 1.43). BWLT was also significantly superior in reducing fatigue as compared to amber light therapy (SMD = 1.00, 95% CI = 0.14 to 1.86) and no light therapy (SMD = 1.09, 95% CI = 0.41 to 1.76). There was no significant heterogeneity of depression and fatigue data (I2 = 0% for both). The relative risk of dropout rates (95% CI) shows no significant difference between BWLT and amber light therapy groups (RR = 3.72, 95% CI = 0.66 to 21.34, I2 = 0%).Conclusion: BWLT may be effective for post-TBI depression and fatigue. Due to the risks of bias and the inability to exclude publication bias among included studies, the current evidence remains insufficient to support the clinical application of BWLT for post-TBI depression and fatigue. Protocol registration: The protocol of this systematic review is available at Open Science Framework (https://osf.io/yf2qe/).

1158 Daytime Sleepiness, Depression, And Post-concussive Symptoms Improve Following Prescribed Morning Exposure To Blue Light

Introduction Long-term sleep disruption, fatigue, and depression are common after mild traumatic brain injuries (mTBIs). Efficacious treatments for these disturbances in the context of mTBIs are lacking. Morning blue light therapy (BLT) effectively treats sleep disruption and improves mood. This study evaluated the treatment effects of morning BLT on post-mTBI daytime sleepiness, depression, and post-concussion symptoms. Methods 62 individuals (Boston: n=31; age: 23.11±7.20y; 17 females; days post-injury: 236.00±121.40; Tucson: n=31; age: 26.35±8.08y; 20 females; days post-injury: 272.94±167.69) received either BLT (n=30) or placebo amber light therapy (ALT; n=32). All participants completed the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), and Rivermead Post-concussion Symptom Questionnaire (RPQ3 and RPQ13 subscales) pre- and post-treatment. Treatment consisted of direct exposure to either blue or amber light (30 minutes each morning), delivered via tabletop light-box, over six weeks. Baseline and post-treatment values were compared to a non-mTBI, non-treated control sample (Tucson: n=32, age: 23.94±5.41y; 19 females). Results Baseline scores were higher in both mTBI light groups (BLT, ALT, respectively) than controls for the ESS (Cohen’s d=0.83, 0.83), PSQI (d=1.45, 1.71), BDI (d=1.46, 1.62), RPQ3 (d=1.72, 1.62) and RPQ13 (d=1.86, d=1.76). BLT resulted in lower within-group ESS (d=-0.58), BDI (d=-0.50), PSQI (d=-0.57), and RPQ13 (d=-0.45, p=0.005) scores. No improvements were seen following ALT. Minimal ESS score differences between the BLT and controls were observed after treatment (d=0.25). Conclusion Daily morning BLT resulted in moderate improvements in post-mTBI daytime sleepiness, sleep quality, depression, and post-concussion symptoms. These improvements may contribute to enhanced academic and job performance, post-mTBI quality of life, and general recovery. Future work is needed to clarify optimal dosage and precision medicine factors indentifying those most likely to benefit from morning BLT. Support This research was supported by multiple grants from the US Army Medical Research and Materiel Command (USAMRMC) to Dr. William D. S. Killgore, including W81XWH-11-1-0056 and W81XWH-14-1-0571.

0070 The Effects of Acute Blue Wavelength Light Exposure on Functional Brain Connectivity and Mood

Introduction Blue wavelength light is an effective treatment for delayed sleep phase syndrome, seasonal affective disorder and bipolar depression. The role of blue light in regulating melatonin production has been extensively studied, but other potential neurophysiological effects remain poorly understood. Some studies have suggested that daily blue light exposure may modulate functional brain responses within the amygdala and prefrontal cortex (PFC), potentially explaining blue light’s antidepressant effect. In this study we investigated the effects of a single 30-minute session of blue light exposure on functional resting state connectivity between the amygdala and PFC. Methods Twenty-nine healthy 18–32 year olds were randomly assigned to either receive 30 minutes of blue (n=17) or non-blue (amber) light (n=12) exposure followed by a 7-minute resting state scan. Pre- and post light exposure, participants completed the Positive and Negative Affect Scale, as a measure of state affect. Results Individuals who received blue versus amber light showed greater positive connectivity between the right amygdala and the left dorsolateral prefrontal cortex (DLPFC) (x=-24, y=46, z=18, k=90, volume p-FDR corrected, p<0.001). Increased amygdala-DLFC connectivity correlated with greater decreases in negative mood for the blue (ρ=-.55, p=0.03), but not the amber group. Using Granger Causality, we found that the directionality of information flow between these two areas was bidirectional (p<0.0025). Conclusion Blue light exposure appears to facilitate greater information flow between the amygdala and the DLPFC at rest, potentially enhancing cognitive processes that regulate arousal and mood. As blue light exposure has been shown to enhance attention and learning, using blue light exposure during practice of emotional regulation strategies, such as reappraisal, may further increase the beneficial effects of blue light on mood. In order to use blue light exposure in a more targeted manner for sleep and mood disorders, further research into the underlying neurophysiological mechanisms is needed. Support This research was supported by a USAMRAA grant to WDSK (W81XWH-14-1-0571) as well as by an Arizona Health Education Centers (AHEC) Research Grant to AA.

Calculation and Analysis of the Amber Interval in Traffic Flow

According to the relationship between the speed of vehicle and the amber light, we establish the differential equation model of the amber light duration. And based on the relevant conditions given in the title, three differential equation models of amber light duration under different conditions are obtained. Considering the traffic condition and driver's habit, we calculate a value that is most suitable to the actual demand. The sensitivity and stability of the model and its related factors are analyzed. We improve the model for the problem of difficult area.