Circadian Rhythms Essay Example | Topics and Well Written Essays - 1000 words

Circadian Rhythms - Essay Example Circadian rhythm takes place in wide variety of organisms apart from humans and are controlled by environmental and internal factors. Temperature and light are the common environmental factors. The circadian cycle is controlled by suprachiasmatic nucleus located in hypothalamus region of brain that influences the sleep-wake cycle by receiving signals from retina of eye about light and dark. The photoreceptor cells in retina transmit signals on light activation and deactivation via neurons of retinohypothalamic tract to the SCN, which are further transmitted to pineal gland via the superior cervical ganglion.  Circadian rhythm takes place in wide variety of organisms apart from humans and are controlled by environmental and internal factors. Temperature and light are the common environmental factors. The circadian cycle is controlled by suprachiasmatic nucleus located in hypothalamus region of brain that influences the sleep-wake cycle by receiving signals from retina of eye about l ight and dark. The photoreceptor cells in retina transmit signals on light activation and deactivation via neurons of retinohypothalamic tract to the SCN, which are further transmitted to pineal gland via the superior cervical ganglion.   The superior cervical ganglion releases noradrenaline into pineal cells during dark, which is followed by transformation of serotonin into melatonin. The SCN leads to the release of more melatonin hormone from pineal gland when the light levels are low that in-turn influences the brainstem mechanisms.

Reveiwing the titanic movie Review Example | Topics and Well Written Essays - 750 words

Reveiwing the titanic - Movie Review Example Simon Adams writes, â€Å"The Titanic’s builders, Harland and Wolff, claimed that the ship’s system of watertight bulkheads made the vessel virtually unsinkable.†(8) But the power of the ocean was awesome, once the ship was caught in its watery trap. The shooting of the movie is the saga of the technical expertise of the highest order. Once the ship sank, it began to move towards its resting place in the ocean bed. Most of the underwater shots of the wreckage of the ship were real. â€Å"James Cameron hired in 1995 the Russian vessel Akademik Mstislav Keldysh and its two submersibles. The technical team worked at a depth of 12,500 feet below the North Atlantic. The special cameras and housings withstood the 6,000 pounds per square inch of water pressure. He made twelve dives of fifteen hours each and the cameras succeeded in storing 500 feet of film only. Twelve minutes of footage was shot per dive. (www.imdb.)So, one can see introduction of many fake underwater shots in the movie. The sinking process of Titanic has gathered momentum. The ship is moving towards its final destination in a rapid pace and grandeur in consistent with its gigantic size. Jack and Rose rush to the stern of the ship, along with many others, as it rises higher and higher. A priest is remembering God with the Rosary prayer. The passengers in freight, mob him. Jack and Rose reach out to the stern and are clustered together and lean on the railings. Rose looks to Jack and says to him, "Jack, this is where we first met!† (www.imdb)Cameron credits Kate Winslet with writing the heart-wrenching line during the final sinking. Jack kisses her forehead and presses her to him even more firmly. The ship now seems in a hurry to reach its final destination. It hangs in the air with a 30-degree angle between it and the water. People lose balance, slip and begin to fall/slide and crash into water. Many fall from the stern,