Abstract: Rapid urbanisation has altered the vulnerability of urban areas to heat wave disasters. There is an urgent need to identify the factors underlying the effect of heat waves on human health and the areas that are most vulnerable to heat waves. In this study, we plan to integrate indices associated with heat wave vulnerability based on meteorological observation data, remote sensing data and point of interest (POI) data; analyse the influence of urbanisation on the urban vulnerability environment; and explore the relationship between the vulnerability environment and heat-wave-related mortality. Finally, we attempt to map the spatial distribution of high heat-wave-related mortality risk based on the results of heat wave vulnerability study and artificial society. The results reveal that 1) there are differences in the influence of urbanisation on heat wave exposure, sensitivity and adaptability; 2) the exposure and sensitivity level effects on the lower limit of health impacts and the adaptability level effects on the upper limit of the health impact from heat wave in a given study area; and 3) areas vulnerable to the effects of heat waves are not confined to the city centre, which implies that residents living in suburban areas are also vulnerable to heat waves. Finally, this study not only explores the factors contributing to the impacts of heat waves but also describes the spatial distribution of the risk of disaster-associated mortality, thereby providing direct scientific guidance that can be used by cities to address heat wave disasters in the future.

Abstract: Light is an indispensable part of routine laboratory works in which conventional light is generally used. Light-emitting diodes (LEDs) have come to replace the conventional light thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from African green monkey kidney, we assessed the possible consequences of blue spectra of LED light in future animal experiments and proposed a potent mitigation against light induced damages. COS-7 cells were exposed to blue LED light (450 nm) and the growth and DNA damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as light exposure time was prolonged. Reactive oxygen species generation was also elevated in accordance to the extension of light exposure times. A comparison to dark-maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time-dependent manner. In turn, antioxidant treatment has shown to improve the cell growth and viability under blue LED light conditions. This indicates that antioxidants are potential against blue LED light-induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and to maximize the beneficial use of LED light in future animal experiments. This article is protected by copyright. All rights reserved.

Abstract: The city emission function (CEF), describing the angular emission from an entire city as a light source, is one of the key elements in night-sky radiance models. The CEF describes the rate at which skyglow depends on distance and is indispensable in any prediction of light-pollution propagation into nocturnal environments. Nevertheless, the CEF remains virtually unexplored because appropriate retrieval tools have been unavailable until very recently. A CEF has now been obtained from ground-based night-sky observations and establishes an experiment successfully conducted in the field to retrieve the angular emission function for an urban area. The field campaign was conducted near the city of Los Mochis, Mexico, which is well isolated from other cities and thus dominates all light emissions in its vicinity. The experiment has proven that radiometry of a night sky can provide information on the light output pattern of a distant city and allows for systematic, full-area, and cost-efficient CEF monitoring worldwide. A database of CEFs could initiate a completely new phase in light-pollution research, with significant economy and advanced accuracy of night-sky brightness predictions. The experiment and its interpretation represent unique progress in the field and contribute to our fundamental understanding of the mechanism by which direct and reflected uplight interact while forming the CEF.