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Son, K. - H., Jeon, Y. - M., & Oh, M. - M. (2016). Application of supplementary white and pulsed light-emitting diodes to lettuce grown in a plant factory with artificial lighting. Hortic. Environ. Biotechnol., 57(6), 560–572.
Abstract: Light-emitting diodes (LEDs) are currently undergoing rapid development as plant growth light sources in a plant factory with artificial lighting (PFAL). However, little is known about the effects of supplementary light and pulsed LEDs on plant growth, bioactive compound productions, and energy efficiency in lettuce. In this study, we aimed to determine the effects of supplementary white LEDs (study I) and pulsed LEDs (study II) on red leaf lettuce (Lactuca sativa L. ‘Sunmang’). In study I, six LED sources were used to determine the effects of supplementary white LEDs (RGB 7:1:1, 7:1:2, RWB 7:1:2, 7:2:1, 8:1:1, 8:2:0 [based on chip number] on lettuce). Fluorescent lamps were used as the control. In study II, pulsed RWB 7:2:1 LED treatments (30, 10, 1 kHz with a 50 or 75% duty ratio) were applied to lettuce. In study I, the application of red and blue fractions improved plant growth characteristics and the accumulation of antioxidant phenolic compounds, respectively. In addition, the application of green light increased plant growth, including the fresh and dry weights of shoots and roots, as well as leaf area. However, the substitution of green LEDs with white LEDs induced approximately 3.4-times higher light and energy use efficiency. In study II, the growth characteristics and photosynthesis of lettuce were affected by various combinations of duty ratio and frequency. In particular, biomass under a 1 kHz 75% duty ratio of pulsed LEDs was not significantly different from that of the control (continuous LEDs). Moreover, no significant difference in leaf photosynthetic rate was observed between any pulsed LED treatment utilizing a 75% duty ratio versus continuous LEDs. However, some pulsed LED treatments may potentially improve light and energy use efficiency compared to continuous LEDs. These results suggest that the fraction of red, blue, and green wavelengths of LEDs is an important factor for plant growth and the biosynthesis of bioactive compounds in lettuce and that supplementary white LEDs (based on a combination of red and blue LEDs) might be more suitable as a commercial lighting source than green LEDs. In addition, the use of suitable pulses of LEDs might save energy while inducing plant growth similar to that under continuous LEDs. Our findings provide important basic information for designing optimal light sources for use in a PFAL.
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Polivka, T. N., Wang, J., Ellison, L. T., Hyer, E. J., & Ichoku, C. M. (2016). Improving Nocturnal Fire Detection With the VIIRS Day-Night Band. IEEE Trans. Geosci. Remote Sensing, 54(9), 5503–5519.
Abstract: Building on existing techniques for satellite remote sensing of fires, this paper takes advantage of the day-night band (DNB) aboard the Visible Infrared Imaging Radiometer Suite (VIIRS) to develop the Firelight Detection Algorithm (FILDA), which characterizes fire pixels based on both visible-light and infrared (IR) signatures at night. By adjusting fire pixel selection criteria to include visible-light signatures, FILDA allows for significantly improved detection of pixels with smaller and/or cooler subpixel hotspots than the operational Interface Data Processing System (IDPS) algorithm. VIIRS scenes with near-coincident Advanced Spaceborne Thermal Emission and Reflection (ASTER) overpasses are examined after applying the operational VIIRS fire product algorithm and including a modified “candidate fire pixel selection†approach from FILDA that lowers the 4-μm brightness temperature (BT) threshold but includes a minimum DNB radiance. FILDA is shown to be effective in detecting gas flares and characterizing fire lines during large forest fires (such as the Rim Fire in California and High Park fire in Colorado). Compared with the operational VIIRS fire algorithm for the study period, FILDA shows a large increase (up to 90%) in the number of detected fire pixels that can be verified with the finer resolution ASTER data (90 m). Part (30%) of this increase is likely due to a combined use of DNB and lower 4-μm BT thresholds for fire detection in FILDA. Although further studies are needed, quantitative use of the DNB to improve fire detection could lead to reduced response times to wildfires and better estimate of fire characteristics (smoldering and flaming) at night.
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Rund, S., O'Donnell, A., Gentile, J., & Reece, S. (2016). Daily Rhythms in Mosquitoes and Their Consequences for Malaria Transmission. Insects, 7(2), 14.
Abstract: The 24-h day involves cycles in environmental factors that impact organismal fitness. This is thought to select for organisms to regulate their temporal biology accordingly, through circadian and diel rhythms. In addition to rhythms in abiotic factors (such as light and temperature), biotic factors, including ecological interactions, also follow daily cycles. How daily rhythms shape, and are shaped by, interactions between organisms is poorly understood. Here, we review an emerging area, namely the causes and consequences of daily rhythms in the interactions between vectors, their hosts and the parasites they transmit. We focus on mosquitoes, malaria parasites and vertebrate hosts, because this system offers the opportunity to integrate from genetic and molecular mechanisms to population dynamics and because disrupting rhythms offers a novel avenue for disease control.
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Keshet-Sitton, A., Or-Chen, K., Yitzhak, S., Tzabary, I., & Haim, A. (2016). Light and the City: Breast Cancer Risk Factors Differ Between Urban and Rural Women in Israel. Integr Cancer Ther, 16(2), 176–187.
Abstract: Women are exposed to indoor and outdoor artificial light at night (ALAN) in urban and rural environments. Excessive exposure to hazardous ALAN containing short wavelength light may suppress pineal melatonin production and lead to an increased breast cancer (BC) risk. Our objective was to address the differences in BC risks related to light exposure in urban and rural communities. We examined indoor and outdoor light habits of BC patients and controls that had lived in urban and rural areas in a 5-year period, 10 to 15 years before the time of the study. Individual data, night time sleeping habits and individual exposure to ALAN habits were collected using a questionnaire. A total of 252 women (110 BC patients and 142 controls) participated in this study. The sample was divided to subgroups according to dwelling area and disease status. Age matching was completed between all subgroups. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated for urban and rural women separately, using binary logistic regression. OR results of urban population (92 BC patients and 72 control) revealed that BC risk increases with daily use of cellphone (OR = 2.13, 95% CI = 1.01-4.49, P < .05) and residence near strong ALAN sources (OR = 1.51, 95% CI = 0.99-2.30, P < .06). Nevertheless, BC risk decreases if a woman was born in Israel (OR = 0.44, 95% CI = 0.21-0.93, P < .03), longer sleep duration (OR = 0.75, 95% CI = 0.53-1.05, P < .1), and reading with bed light illumination before retiring to sleep (OR = 0.77, 95% CI = 0.61-0.96, P < .02). Furthermore, in the rural population (18 BC patients and 66 control) BC risk increases with the number of years past since the last menstruation (OR = 1.12, 95% CI = 1.03-1.22, P < .01). However, BC risk decreases with longer sleep duration (OR = 0.53, 95% CI = 0.24-1.14, P < .1), reading with room light illumination before retiring to sleep (OR = 0.55, 95% CI = 0.29-1.06, P < .07), and sleeping with closed shutters during the night (OR = 0.66, 95% CI = 0.41-1.04, P < .08). These data support the idea that indoor and outdoor nighttime light exposures differ between urban and rural women. Therefore, we suggest that women can influence BC risk and incidence by applying protective personal lighting habits. Further studies with larger sample sizes are needed to strengthen the results.
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Keshet-Sitton, A., Or-Chen, K., Huber, E., & Haim, A. (2016). Illuminating a Risk for Breast Cancer: A Preliminary Ecological Study on the Association Between Streetlight and Breast Cancer. Integr Cancer Ther, .
Abstract: Artificial light at night (ALAN) for elongating photophase is a new source of pollution. We examined the association between measured ALAN levels and breast cancer (BC) standard morbidity ratio (SMR) at a statistical area (SA) level in an urban environment. Sample size consisted of 266 new BC cases ages 35-74. Light measurements (lux) were performed in 11 SAs. A new calculated variable of morbidity per SA size (SMR35-74/km2) was correlated with the light variables per road length, using Pearson correlations (P < .05, 1-tailed). Looking for a light threshold, we correlated percentage of light points above SA light intensity median with SMR35-74/km2 SMR35-74/km2 was significantly and positively strongly correlated with mean, median, and standard-deviation (SD) light intensity per road length (r = .79, P < .01, R2 = .63; r = .77, P < .01, R2 = .59; and r = .79, P < .01, R2 = .63). Light threshold results demonstrate a marginally significant positive moderate correlation between percentage of points above 16.3 lux and SMR35-74/km2 (r = .48, P < .07; R2 = .23). In situ results support the hypothesis that outdoor ALAN illumination is associated with a higher BC-SMR in a specific area and age group. Moreover, we suggest an outdoor light threshold of approximately 16 lux as the minimal intensity to affect melatonin levels and BC morbidity. To the best of our knowledge, our attempt is the first to use this method and show such association between streetlight intensity and BC morbidity and therefore should be further developed.
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