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Te Kulve, M., Schlangen, L. J. M., & van Marken Lichtenbelt, W. D. (2019). Early evening light mitigates sleep compromising physiological and alerting responses to subsequent late evening light. Sci Rep, 9(1), 16064.
Abstract: The widespread use of electric light and electronic devices has resulted in an excessive exposure to light during the late-evening and at night. This late light exposure acutely suppresses melatonin and sleepiness and delays the circadian clock. Here we investigate whether the acute effects of late-evening light exposure on our physiology and sleepiness are reduced when this light exposure is preceded by early evening bright light. Twelve healthy young females were included in a randomised crossover study. All participants underwent three evening (18:30-00:30) sessions during which melatonin, subjective sleepiness, body temperature and skin blood flow were measured under different light conditions: (A) dim light, (B) dim light with a late-evening (22:30-23:30) light exposure of 750 lx, 4000 K, and (C) the same late-evening light exposure, but now preceded by early-evening bright light exposure (18.30-21.00; 1200 lx, 4000 K). Late-evening light exposure reduced melatonin levels and subjective sleepiness and resulted in larger skin temperature gradients as compared to dim. Interestingly, these effects were reduced when the late-evening light was preceded by an early evening 2.5-hour bright light exposure. Thus daytime and early-evening exposure to bright light can mitigate some of the sleep-disruptive consequences of light exposure in the later evening.
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Nguyen, C. N., & Noy, I. (2019). Measuring the impact of insurance on urban earthquake recovery using nightlights. Journal of Economic Geography, , in press.
Abstract: We measure the longer-term effect of a major earthquake on the local economy, using night-time light intensity, and focus on the role of insurance payments for damaged residential property in the recovery process. The destructive Canterbury Earthquake Sequence (2010–2011) in New Zealand is our case study. Uniquely, for this event, >95% of residential housing units were covered by insurance and almost all incurred some damage. However, insurance payments were staggered over 5 years, enabling us to identify their local impact on recovery. We find that night-time luminosity can capture the process of recovery; and that insurance payments contributed significantly to the process of local economic recovery after the earthquake. Cash settlement of claims was no more effective than insurance-managed repairs in generating local recovery. Notably, delayed payments were less affective in assisting recovery; this suggests an important role for the regulator in making sure insurance payments are made promptly after disaster events.
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Wallner, S. (2019). Usage of Vertical Fisheye-Images to Quantify Urban Light Pollution on Small Scales and the Impact of LED Conversion. J. Imaging, 5(11), 86.
Abstract: The aim of this work was to develop an easy and quick technique for characterizing various lighting situations, that is, single lamps or illuminated signs and to quantify impacts on small scales like streets, buildings and near areas. The method uses a DSLR-camera equipped with fisheye-lens and the software Sky Quality Camera, both commonly used as part of night sky imagery in the light pollution community, to obtain information about luminance and correlated colour temperature. As a difference to its usual build-up, observed light emitting sources were captured by pointing the camera towards analysed objects, that is, images were taken via vertical plane imaging with very short exposure times under one second. Results have proven that this technique provides a practical way to quantify the lighting efficacy in a certain place or area, as a quantitative analysis of the direct emission towards the observer and the illumination on surroundings, that is, street surfaces, sidewalks and buildings, was performed. When conducting lamp conversions, the method can be used to characterize the gradient of change and could be a useful tool for municipalities to find the optimal lighting solution. The paper shows examples of different lighting situations like single lamps of different types, also containing various luminaires, illuminated billboards or buildings and impacts of the lighting transition to LEDs in the city of Eisenstadt, Austria. The horizontal fisheye method is interdisciplinary applicable, for example, being suitable for lighting management, to sustainability and energy saving purposes.
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Li, X., Liu, Z., Chen, X., & Meng, Q. (2019). Assessment of the impact of the 2010 Haiti earthquake on human activity based on DMSP/OLS time series nighttime light data. J. Appl. Rem. Sens., 13(04), 1.
Abstract: Earthquake disasters and postdisaster reconstruction have profound impacts on human society. We use time series nighttime light images collected by the defense meteorological satellite program-operational linescan system sensors as a proxy data source for human activities (HAs). After calibration, a time series analysis method is used to study the distribution and intensity of the changes in HAs after an earthquake. We consider the Haiti earthquake an example to analyze the HA sequence patterns and the aggregation patterns of the HA centers. The results show the following: (1) postearthquake recovery and reconstruction efforts led to increases in the long-term HAs, but the level of increased HA was usually low. (2) The level of postearthquake HAs in the most affected areas (seismic intensity zone VIII+) increased, whereas the postearthquake HAs in severely affected areas (seismic intensity zones VI and VII) were more fragmented. (3) The recovery of HAs in seismic intensity zone VIII+ (mainly Port-au-Prince) required 2 years, but the actual time may be far longer.
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Liu, Z., Qian, M., Tang, X., Hu, W., Sun, S., Li, G., et al. (2019). SIRT7 couples light-driven body temperature cues to hepatic circadian phase coherence and gluconeogenesis. Nat Metab, 1(11), 1141–1156.
Abstract: The central pacemaker in the hypothalamic suprachiasmatic nucleus (SCN) synchronizes peripheral oscillators to coordinate physiological and behavioural activities throughout the body. How circadian phase coherence between the SCN and the periphery is controlled is not well understood. Here, we identify hepatic SIRT7 as an early responsive element to light that ensures circadian phase coherence in the mouse liver. The SCN-driven body temperature (BT) oscillation induces rhythmic expression of HSP70, which promotes SIRT7 ubiquitination and proteasomal degradation. Acute temperature challenge dampens the BT oscillation and causes an advanced liver circadian phase. Further, hepatic SIRT7 deacetylates CRY1, promotes its FBXL3-mediated degradation and regulates the hepatic clock and glucose homeostasis. Loss of Sirt7 in mice leads to an advanced liver circadian phase and rapid entrainment of the hepatic clock upon daytime-restricted feeding. These data identify a BT–HSP70–SIRT7–CRY1 axis that couples the mouse hepatic clock to the central pacemaker and ensures circadian phase coherence and glucose homeostasis.
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