Saini, C., Hutton, P., Gao, S., Simpson, R. K., Giraudeau, M., Sepp, T., et al. (2019). Exposure to artificial light at night increases innate immune activity during development in a precocial bird. Comp Biochem Physiol A Mol Integr Physiol, in press.
Abstract: Humans have greatly altered Earth's night-time photic environment via the production of artificial light at night (ALAN; e.g. street lights, car traffic, billboards, lit buildings). ALAN is a problem of growing importance because it may significantly disrupt the seasonal and daily physiological rhythms and behaviors of animals. There has been considerable interest in the impacts of ALAN on health of humans and other animals, but most of this work has centered on adults and we know comparatively little about effects on young animals. We exposed 3-week-old king quail (Excalfactoria chinensis) to a constant overnight blue-light regime for 6weeks and assessed weekly bactericidal activity of plasma against Escherichia coli – a commonly employed metric of innate immunity in animals. We found that chronic ALAN exposure significantly increased bactericidal activity and that this elevation in immune performance manifested at different developmental time points in males and females. Whether this short-term increase in immune activity can be extended to wild animals, and whether ALAN-mediated increases in immune activity have positive or negative fitness effects are unknown and will provide interesting avenues for future studies.
|
Can Duman, A., & Güler, Ö. (2019). Techno-economic analysis of off-grid photovoltaic LED road lighting systems: A case study for northern, central and southern regions of Turkey. Building and Environment, in press.
Abstract: Street lighting is one of the sectors where off-grid energy systems are used, and in the past decade interest in these systems has increased due to recent developments occurred both in LED and PV technology. This paper presents a techno-economic analysis of off-grid PV LED road lighting systems for northern, central and southern regions of Turkey. Road lighting calculations are conducted using DIALux software for M4 and M5 road lighting classes to obtain optimal LED luminaires, pole sizes, and spacings. Among the obtained LED powers, load profiles are created using real lighting hours of operation of the selected regions. And then, the required PV-battery systems are optimized using HOMER software. Finally, sensitivity analysis is performed for future projections considering possible increases in electricity prices and decreases in component cost of the PV systems. The results showed that the levelized COE of the off-grid PV LED road lighting systems vary between 0.229 and 0.362 $/kWh. for M4, and 0.254–0.359 $/kWh for M5 road lighting class, depending on the solar potential of the region. And, the total NPC of the entire lighting installation per km vary between 24296 and 29123 $ for M5, and 33225–44318 $ for M4 road lighting class. According to the results, the systems are infeasible under current conditions in Turkey. Nonetheless, they have the added benefits of contributing to the reduction of CO2 emissions. Moreover, future projections show that the systems can be feasible if the declining trend in PV system costs continues and electricity prices increase.
|
Li, Y., Cheng, S., Li, L., Zhao, Y., Shen, W., & Sun, X. (2019). Light-exposure at night impairs mouse ovary development via cell apoptosis and DNA damage. Biosci Rep, .
Abstract: The alternation of light and dark rhythm causes a series of physiological, biochemical and metabolic changes in animals, which also alters the growth and development of animals, and feeding, migration, reproduction and other behavioral activities. In recent years, many studies have reported the effects of long-term (more than 6 weeks) illumination on ovarian growth and development. In this study, we observed the damage, repair and apoptosis of ovarian DNA in a short period of illumination. The results showed that, in short time (less than 2 weeks) illumination conditions, the 24 hrs-light treatment caused the reduction of total ovarian follicle number and downregulation of circadian clock related genes. Furthermore, the changed levels of serum sex hormones were also detected after 24 hrs-light exposure, of which the concentrations of LH (luteinizing hormone), FSH (follicle-stimulating hormone) and E2 (estradiol) were increased, but the concentration of PROG (progesterone) was decreased. Moreover, 24 hrs-light exposure increased the expression of DNA damage and repair related genes, the number of TUNEL and RAD51 positive cells. These results indicated that 24 hrs-light exposure for 4 days, 8days and 12 days increased DNA damage and cell apoptosis, thereby affecting the development of ovary.
|
Sánchez de Miguel, A., Bará, S., Aubé, M., Cardiel, N., Tapia, C. E., Zamorano, J., et al. (2019). Evaluating Human Photoreceptoral Inputs from Night-Time Lights Using RGB Imaging Photometry. J. Imaging, 5(4), 49.
Abstract: Night-time lights interact with human physiology through different pathways starting at the retinal layers of the eye; from the signals provided by the rods; the S-, L- and M-cones; and the intrinsically photosensitive retinal ganglion cells (ipRGC). These individual photic channels combine in complex ways to modulate important physiological processes, among them the daily entrainment of the neural master oscillator that regulates circadian rhythms. Evaluating the relative excitation of each type of photoreceptor generally requires full knowledge of the spectral power distribution of the incoming light, information that is not easily available in many practical applications. One such instance is wide area sensing of public outdoor lighting; present-day radiometers onboard Earth-orbiting platforms with sufficient nighttime sensitivity are generally panchromatic and lack the required spectral discrimination capacity. In this paper, we show that RGB imagery acquired with off-the-shelf digital single-lens reflex cameras (DSLR) can be a useful tool to evaluate, with reasonable accuracy and high angular resolution, the photoreceptoral inputs associated with a wide range of lamp technologies. The method is based on linear regressions of these inputs against optimum combinations of the associated R, G, and B signals, built for a large set of artificial light sources by means of synthetic photometry. Given the widespread use of RGB imaging devices, this approach is expected to facilitate the monitoring of the physiological effects of light pollution, from ground and space alike, using standard imaging technology.
|
Jørgensen, L. D., Tambo, T., & Xydis, G. (2019). An efficiency evaluation of radar‐based obstruction lights controlling at a wind turbine test site. Wind Energy, 22(4).
Abstract: In this study, an obstruction lights controlling (OLC) system based on a Terma SCANTER 5000 radar has been installed at a test centre for large wind turbines. The objective of this study was to evaluate the efficiency of the OLC system and to improve this efficiency by introducing new technological features. Once the first assessment had been carried out, new software with improved tracking functionalities was installed to the radar. With the new software, a second assessment was made to compare the new performance to the old one. To analyse the tracks, geographic information system (GIS) tools have been used. A new MATLAB script was developed to automate the assessment as well as to gather data on the tracks. These data sets were used to improve the system performance by introducing a radar cross section (RCS)/speed filter. The outcome of the study is a filter that can be implemented on the radar system to improve the efficiency of the system and reduce the time that obstruction lights need to be on for by 62.59%, without compromising the integrity of the system.
|
