Search results
Results From The WOW.Com Content Network
Although many researchers consider light to be the strongest cue for entrainment, it is not the only factor acting on circadian rhythms. Other factors may enhance or decrease the effectiveness of entrainment. For instance, exercise and other physical activity, when coupled with light exposure, results in a somewhat stronger entrainment response ...
The first published usage of the term "phase response curve" was in 1960 by Patricia DeCoursey. The "daily" activity rhythms of her flying squirrels, kept in constant darkness, responded to pulses of light exposure. The response varied according to the time of day – that is, the animals' subjective "day" – when light was administered.
In Drosophila there are two distinct groups of circadian clocks: the clock neurons and the clock genes. They act concertedly to produce the 24-hour cycle of rest and activity. Light is the source of activation of the clocks. The compound eyes, ocelli, and Hofbauer-Buchner eyelets (HB eyelets) are the direct external photoreceptor organs.
The fundamental elements of these loops are found across different phyla. In the mammalian circadian clock, for example, transcription factors CLOCK and BMAL1 are the positive regulators. [12] CLOCK and BMAL1 bind to the E-box of oscillating genes, such as Per1, Per2, and Per3 and Cry1 and Cry2, and upregulate their transcription. [12]
Here are things to know about daylight saving time, the origin of “spring forward, fall back” and when and why we change the clocks twice a year — like clockwork. Countdown clock to the end ...
Richard Caton discovered electrical activity in the cerebral hemispheres of rabbits and monkeys and presented his findings in 1875. [4] Adolf Beck published in 1890 his observations of spontaneous electrical activity of the brain of rabbits and dogs that included rhythmic oscillations altered by light, detected with electrodes directly placed on the surface of the brain. [5]
Clock signal and legend. In electronics and especially synchronous digital circuits, a clock signal (historically also known as logic beat) [1] is an electronic logic signal (voltage or current) which oscillates between a high and a low state at a constant frequency and is used like a metronome to synchronize actions of digital circuits.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!