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Related to sleep fragmentation: polysomnography, polysomnogram


1. A means of production in which different parts of the supply chain are located in different countries. Fragmentation occurs to reduce costs of production. For example, the least expensive materials may be in India and the cheapest factory workers in China, while the target retail customer is in the United States or Canada. Fragmentation can occur most easily when there is free trade, or at least low tariffs between all the countries on the supply chain. See also: Globalization.

2. A situation in a decentralized market. This often renders investors unaware of the best price available for their trades, resulting in inefficiency in the market. Fragmentation has become less of a problem with the advent of electronic exchanges and other, similar products.
Farlex Financial Dictionary. © 2012 Farlex, Inc. All Rights Reserved


The lack of full interconnection of the various securities markets. Fragmentation can result in customer orders being sent to markets that do not offer the best available price. Critics claim the inefficiencies of fragmentation can be cured with a central order book that includes orders from all markets.
Wall Street Words: An A to Z Guide to Investment Terms for Today's Investor by David L. Scott. Copyright © 2003 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved. All rights reserved.
References in periodicals archive ?
The efficacy of various therapeutic approaches has been measured by the amount of improvement in polysomnographic parameters such as the respiratory disturbance index (apneas and hypopneas per hour) and the sleep fragmentation index (microarousals per hour).
In summary, narcolepsy is a complex disorder with multiple symptoms including excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, sleep paralysis and sleep fragmentation. The primary pharmaceutical intervention includes the use of different CNS stimulants for excessive daytime sleepiness.
These findings indicate the importance of differentiating between excessive daytime sleepiness in OSA (which is known to be secondary to hypoxemia and sleep fragmentation) and fatigue, and suggest the possible utility of addressing depression to deal with the latter, Dr.
The physiologic variables that are evaluated in a standard polysomnogram include changes in oxygen saturation, cardiac arrhythmias, arousals caused by respiratory events, and sleep fragmentation caused by frequent arousals.
We are not sure whether the LAI can serve as an indicator additional to the RAI, reflecting the extent of sleep fragmentation associated with changes in the severity of illness.
Twenty five percent of middle-aged men are affected by sleep apnoea, and almost three per cent of them experience a severe form of the condition characterised by extended pauses in breathing, repetitive asphyxia and sleep fragmentation.
Third, respiratory efforts can lead to sleep fragmentation, which may activate the sympathetic nervous system and increase arterial blood pressure, leading to hemodynamic disturbances.
"Although it is unlikely that OSA causes dementia, the lowered oxygen levels and sleep fragmentation associated with OSA might worsen cognitive function," said Lead researcher Sonia Ancoli-Israel, Ph.D., professor of psychiatry at the UC San Diego School of Medicine.
The previous results show that changes in HbA1c may be related to changes in sleep quality and sleep fragmentation.[sup][15] Whether CPAP therapy is beneficial to reduce the HbA1c levels in patients with T2DM is still controversial.
Nicotine increases sleep latency and sleep fragmentation. Other medications associated with insomnia are bronchodilators, corticosteroids, decongestants and some antidepressants.
Obstructive sleep apnea syndrome (OSAS) is a complex clinical syndrome characterized by apnea episodes, sleep fragmentation, oxygen desaturation, and increased daytime somnolence as a result of recurrent obstructive episodes in upper airways during sleep.[sup][1] Previous studies have revealed that OSAS is related with many cardiovascular diseases including hypertension, coronary artery disease, arrhythmias, and congestive heart failure.[sup][2] Basic hemodynamic mechanisms responsible from cardiovascular diseases are increased negative intrathoracic pressure, hypoxemia, and increased catecholamine release.[sup][2] In OSAS both ventricles are subjected to hemodynamic stress that induces various structural changes.[sup][3]
Repeated apnea, oxygen desaturation, and sleep fragmentation during sleep might cause autonomic dysfunction,[sup][25] which might impact vagus nerve function and subsequently, impact esophageal functions.