Human responses to bright light of different durations

Simultaneous brightness contrast for flashes of light of different durations.

Measurements have been made of the magnitude of simultaneous brightness contrast on two young adult male observers by a binocular brightness matching method. Five different luminances of the inducing pattern were studied and the duration of the exposure was varied between 5 and 150 msec, along an arithmetic scale. For low inducing flash luminances, the longer exposures show the greater contrast...

Effects of ascorbic acid on physiological and biochemical responses of Zinnia elegans L. to different levels of light intensity

The aim of this study was to investigate the effect of different light intensities and ascorbic acid on some physiological and biochemical characteristics of Zinnia elegans L. The experiment was designed as a completely randomized design in a form of split-plot with three replications. The treatments were consisted of three light intensity levels (600, 1200 and 1800 μmol m-2 s-1) as the main fa...

Bright Storage of Light

Antioxidative Responses of Eucalyptus camaldulensis to Different Concentrations of Copper

Anthropogenic activities have caused important increases in soil Cu levels not only in urban areas but also in croplands. This study was designed to find out the effect of different concentration of copper on physiological and biochemical changes in Eucalyptus camaldulensis seedlings. Seeds of Eucalyptus camaldulensis were grown in marble chips and irrigated with nutrient solution mixed with co...

Isoforms of Melanopsin Mediate Different Behavioral Responses to Light

Melanopsin (OPN4) is a retinal photopigment that mediates a wide range of non-image-forming (NIF) responses to light including circadian entrainment, sleep induction, the pupillary light response (PLR), and negative masking of locomotor behavior (the acute suppression of activity in response to light). How these diverse NIF responses can all be mediated by a single photopigment has remained a m...