Multisynaptic neural and endocrine pathways from the suprachiasmatic nucleus of the hypothalamus have been hypothesized to communicate circadian and photic information to the adrenal glands. In humans, light exposure has been reported to have no effect, increase, or decrease cortisol levels. These inconsistent findings in humans may be related to differences among studies including the intensit...

Leaf initiation was previously thought to be self-regulated and not reliant on environmental cues. However, a recent study has revealed that light redirects meristem fate from maintenance to lateral organ initiation, through the regulation of the plant hormones auxin and cytokinin.

OBJECTIVES This study aimed to investigate the relationship between individual natural light exposure, sleep need, and depression at two latitudes, one extreme with a few hours of light per day during winter, and the other with equal hours of light and darkness throughout the year. METHODS This cross-sectional study included a sample of Brazilian workers (Equatorial, n = 488 workers) and a Sw...

PURPOSE Biochemical research has demonstrated that lutein and zeaxanthin, the two macular carotenoids, are bleachable pigments. Further, evidence suggests that exposure to UV light can degrade plasma carotenoid levels in vivo. The present study investigated the effects of exposure to normal levels of light on the levels of lutein and zeaxanthin in the retina. METHODS The optical density of ma...

In humans, light enhances both alertness and performance during nighttime and daytime [1-4] and influences regional brain function [5]. These effects do not correspond to classical visual responses but involve a non-image forming (NIF) system, which elicits greater endocrine, physiological, neurophysiological, and behavioral responses to shorter light wavelengths than to wavelengths geared towa...

PURPOSE This study aimed to quantify the pupillary light reaction during high altitude exposure using the state of the art Compact Integrated Pupillograph (CIP) and to investigate a potential correlation of altered pupil reaction with severity of acute mountain sickness (AMS). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. METHODS Parameters of pupil dynamics (...

persistence of benthiocarb in soil as affected by uv and sunlight exposure was studied. treated soil was placed in petri plate, brought to field capacity moisture and then exposed to uv and sunlight. residues of benthiocarb in soil dissipated with half lives of 2.10, 11.85 and 43.63 days under uv, sunlight and dark condition, respectively. soil samples kept under dark showed the slowest dissipa...

BACKGROUND The annual decrease of daylight duration initiates a depressive phase in patients with seasonal affective disorder (SAD), and light therapy treats it. How much bright light exposure in winter and summer these patients actually receive may help understand the pathogenetic factors initiating SAD. METHODS During a week in winter and summer, women with and without SAD kept daily logs o...

Introduction: There are general concerns about the hazardous impacts of the cell phones radiation on the human health. In this study, the structural and biochemical changes of the mice kidney were assessed after cell phone exposure in. Materials and methods: A total of 40 Balb/C mice were randomly divided into the control and experimental groups. The experimental group exposed to cell phon...