introduction: discoloration of resin composites is a common reason for replacement of these restorations. the aim of this study was to eva-luate the influence of different light curing de-vices on color stability of a microhybrid resin composite. materials and methods: 80 disc-shaped speci-mens (8 mm in diameter, 2-mm height) were fabricated from filtek z250 resin composite. specimens were divid...

co2 enrichment in greenhouse is a suitable way which reduces production time, better growth vigor and also higher plant quality. the main aim of this study was to find out the effects of artificial co2 enrichment under different light levels on rooting of the ornamental foliage codiaeum variegatum. the experiment was planned as a split plot based on a completely randomized design. co2 was consi...

In addition to attention to natural light as a renewable, costless and environment-friendly source of energy in the late 20th century, numerous studies have been conducted into the effect of natural light on human being’s soul and body and all such studies reiterate the undeniable role of natural lighting on people’s behavior, attitudes, and efficiency. However, in spite of the awareness of the...

Light is a major cue for nearly all life on Earth. However, most of our knowledge concerning the importance of light is based on organisms' response to light during daytime, including the dusk and dawn phase. When it is dark, light is most often considered as pollution, with increasing appreciation of its negative ecological effects. Using an Autonomous Surface Vehicle fitted with a hyperspectr...

Since the early days of human life on the Earth, our skin has been exposed to different levels of light. Recently, due to inevitable consequences of modern life, humans are not exposed to adequate levels of natural light during the day but they are overexposed to relatively high levels of artificial light at night. Skin is a major target of oxidative stress and the link between aging and oxidat...

The physical properties of light, both natural and artificial, play a significant role in its interaction with humans. Although there is a yet-to-be-explained duality between light as waves and light as photons, we do understand many of the characteristics of light that affect living things. Here I review the general history of light and its properties, especially those that affect human health.

In this study we assessed the ability of the C4 plant maize to perform long-term photosynthetic acclimation in an artificial light quality system previously used for analyzing short-term and long-term acclimation responses (LTR) in C3 plants. We aimed to test if this light system could be used as a tool for analyzing redox-regulated acclimation processes in maize seedlings. Photosynthetic param...

This study was designed to test the hypothesis that patients with SAD have significantly different physiological responses to light than healthy age- and sex-matched controls. We studied retinal contrast sensitivity, visual evoked EEG responses, and melatonin suppression by, and cerebral blood flow response to, full-spectrum artificial daylight. There was no significant difference between 10 pa...