Artificial light may have severe ecological consequences but there is limited experimental work to assess these consequences. We carried out an experimental study on a wild population of great tits (Parus major) to assess the impact of light pollution on daily activity patterns during the chick provisioning period. Pairs that were provided with a small light outside their nest box did not alter...

this study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets.fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: groups 1 (control) and 2: the brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. t...

The origin of light is a unsolved mystery in nature. Recently, it was suggested that light may originate from a new kind of order quantum order. To test this idea in experiments, we study systems of screened magnetic/electric dipoles in 2D and 3D lattices. We show that our models contain an artificial light – a photon-like collective excitation. We discuss how to design realistic devices that r...

background: light is an important and adjustable physical factor in the job environment.this study aimed to determine the intensity of natural and mixed light and also the level of ultraviolet radiation in libraries and computer sites of ilam universities in spring 2011.   methods: in this cross-sectional study, 10 libraries, 16 study saloons, and 7 computer sites were selected. luminosity asse...

Artificial light is gaining attention as a potential stressor to aquatic ecosystems. Artificial lights located near streams increase light levels experienced by stream invertebrates and we hypothesized light would depress night drift rates. We also hypothesized that the effect of light on drift rates would decrease over time as the invertebrates acclimated to the new light level over the course...

Since the 1970s nighttime satellite images of the Earth from space have provided a striking illustration of the extent of artificial light. Meanwhile, growing awareness of adverse impacts of artificial light at night on scientific astronomy, human health, ecological processes and aesthetic enjoyment of the night sky has led to recognition of light pollution as a significant global environmental...