Coma (cometary)
The coma is the nebulous envelope around the nucleus of a comet. It is formed when the comet passes close to the Sun on its highly elliptical orbit; as the comet warms, parts of it sublimate. This gives a comet a "fuzzy" appearance when viewed in telescopes and distinguishes it from stars. The word coma comes from the Greek "kome" (κόμη), which means "hair" and is the origin of the word comet itself.
The coma is generally made of ice and comet dust. Water dominates up to 90% of the volatiles that outflow from the nucleus when the comet is within 3-4 AU of the Sun. The H2O parent molecule is destroyed primarily through photodissociation and to a much smaller extent photoionization. The solar wind plays a minor role in the destruction of water compared to photochemistry. Larger dust particles are left along the comet's orbital path while smaller particles are pushed away from the Sun into the comet's tail by light pressure.
On 11 August 2014, astronomers released studies, using the Atacama Large Millimeter/Submillimeter Array (ALMA) for the first time, that detailed the distribution of HCN, HNC, H2CO, and dust inside the comae of comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON). On 2 June 2015, NASA reported that the ALICE spectrograph on the Rosetta space probe studying comet 67P/Churyumov–Gerasimenko determined that electrons (within 1 km (0.62 mi) above the comet nucleus) produced from photoionization of water molecules by solar radiation, and not photons from the Sun as thought earlier, are responsible for the degradation of water and carbon dioxide molecules released from the comet nucleus into its coma.
Coma
In medicine, coma (from the Greek κῶμα koma, meaning "deep sleep") is a state of unconsciousness in which a person: cannot be awakened; fails to respond normally to painful stimuli, light, or sound; lacks a normal wake-sleep cycle; and does not initiate voluntary actions. A person in a state of coma is described as being comatose. Typically, a distinction is made in the medical community between a coma and a medically induced coma, the former is generally understood to be a result of circumstances beyond the control of the medical community, while the latter is generally understood to be a means by which medical professionals may allow a patient's injuries to heal in a controlled environment.
A comatose person exhibits a complete absence of wakefulness and is unable to consciously feel, speak, hear, or move. For a patient to maintain consciousness, two important neurological components must function. The first is the cerebral cortex—the gray matter that forms the outer layer of the brain. The other is a structure located in the brainstem, called reticular activating system (RAS). Injury to either or both of these components is sufficient to cause a patient to experience a coma. The cerebral cortex is a group of tight, dense, "gray matter" composed of the nuclei of the neurons whose axons then form the "white matter", and is responsible for perception, relay of the sensory input (sensation) via the thalamic pathway, and many other neurological functions, including complex thinking.
Coma (novel)
Coma is Robin Cook's first major published novel, published by Signet Book in 1977.Coma was preceded in 1973 by Cook's lesser known novel, The Year of the Intern (also published by Signet Book).
Synopsis
Susan Wheeler is an attractive, 23-year-old third-year medical student working as a trainee at Boston Memorial Hospital. Susan, along with four other students—George, Harvey, Geoffrey, and Paul—takes rounds in surgery rooms and ICUs making post-treatment notations on the health of patients. Mark Bellows, a surgery resident in the hospital, is the instructor and supervisor of this group.
The book is a journey into the inner workings of a hospital. As these students complete their three-month surgical rotation, the dilemmas and problems faced by a woman in a so-called "man's" profession are also highlighted.
It comes to Susan's attention that two patients, Nancy Greenly and Sean Berman, mysteriously went into comas immediately after their operations. These incidents were attributed to complications due to anesthesia. Nancy Greenly became comatose when her brain did not receive sufficient oxygen during surgery. Similarly, Sean Berman, a young man in his 30s in good physical condition, underwent a scheduled knee operation. Despite the operation's success, Sean failed to regain consciousness. Medically, the odds for such occurrences are one in 100,000; however, such odds seemed resolutely higher at the Boston Memorial Hospital.
List of Twin Peaks episodes
Twin Peaks, an American serial drama television series created by David Lynch and Mark Frost, premiered on April 8, 1990 on the ABC Network in the United States and ended on June 10, 1991. The show spans 30 episodes over two seasons. The original pilot and season 2 premiere are 90 minutes long, while all the other episodes are approximately 45 minutes long. ABC canceled the series due to declining ratings in the second season.
Both seasons of Twin Peaks were released on DVD in the U.S. in 2001 and 2007, respectively. A complete series DVD box set, titled "The Definitive Gold Box Edition", with additional features was released on October 30, 2007. The complete series (including the film) was released on Blu-ray with even further material on July 29, 2014.
Twin Peaks follows FBI Special Agent Dale Cooper, who is sent to the fictional town of Twin Peaks, Washington to investigate the murder of popular and respected high school student, Laura Palmer. A feature-length prequel film, titled Twin Peaks: Fire Walk with Me, was released on August 28, 1992, which depicts the events leading up to Laura's death.
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