The patterns of light intensity to which humans expose their circadian pacemakers in daily life are very irregular and vary greatly from day to day. The circadian pacemaker can adjust to such irregular exposure patterns by daily phase shifts, such as summarized in a phase response curve. It is demonstrated in this paper on the basis of computer simulations applying actually recorded human light...

in order to identify the effects of vitamin a and aspirin on reducing uv lightinduced retinopathy, erg waves were compared before and after uv light exposure in rabbits. 30 rabbits were divided into 3 groups: the first group received vitamin a, 50,000 units i.m., single dose, the second group received aspirin, 50 mg/ kg/day po and the third group did not receive any medication. all three groups...

Seasonal or photoperiodically sensitive animals respond to altered day length with changes in physiology (growth, food intake and reproductive status) and behaviour to adapt to predictable yearly changes in the climate. Typically, different species of hamsters, voles and sheep are the most studied animal models of photoperiodism. Although laboratory rats are generally considered nonphotoperiodi...

pyricularia oryzae (tel. magnaporthegrisea) is currently used as a fungal model for plantmicrobeinteraction studies as well as an indicative model for anticancer drug discovery. thepresent study introduces the optimal condition in which p. oryzae grows and sporulates beston common culture media. we have considered three fungal culture media, i.e. pda, pca andwa, based on which p. oryzae sporula...

The steady-state mRNA concentrations of two fcp genes encoding fucoxanthin chlorophyll a/c light-harvesting polypeptides of the centric diatom Cyclotella cryptica were investigated over a 4-day period by RNA dot-blotting experiments. Before and during the first day of the experiment, the cultures were grown under a 12-h light/12-h dark regime. On the following 3 days, the algae were kept in dar...

The objective of this study was to examine the impact of post-meal light exercise on the rise in blood glucose and insulin. After fasting overnight, nine healthy subjects (age 37.3 ± 12.2 years) participated in three experiments in a crossover design: Day 1 (no exercise), the subjects were given cornflakes, and blood glucose and plasma insulin were determined before meal, and each 15 min for th...

Circadian rhythms are physiological functions that cycle over a period of approximately 24 hours (circadian- circa: approximate and diem: day). They are responsible for timing our sleep/wake cycles and hormone secretion. Since this timing is not precisely 24-hours, it is synchronized to the solar day by light input. This is accomplished via photic input from the retina to the suprachiasmatic nu...