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Advanced Sleep Phase Disorder
Advanced Sleep Phase Disorder (ASPD), also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder, is a condition that is characterized by a recurrent pattern of early evening (e.g. 7-9 PM) sleepiness and very early morning awakening (e.g. 2-4 AM). This sleep phase advancement can interfere with daily social and work schedules, and results in shortened sleep duration and excessive daytime sleepiness. The timing of sleep and melatonin levels are regulated by the body's central circadian clock, which is located in the suprachiasmatic nucleus in the hypothalamus. Symptoms Individuals with ASPD report being unable to stay awake until conventional bedtime, falling asleep early in the evening, and being unable to stay asleep until their desired waking time, experiencing early morning insomnia. When someone has advanced sleep phase disorder their melatonin levels and core body temperature cycle hours earlier than an average person. These symptoms must be pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronobiology
Chronobiology is a field of biology that examines timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronobiology comes from the ancient Greek χρόνος (''chrónos'', meaning "time"), and biology, which pertains to the study, or science, of life. The related terms ''chronomics'' and ''chronome'' have been used in some cases to describe either the molecular mechanisms involved in chronobiological phenomena or the more quantitative aspects of chronobiology, particularly where comparison of cycles between organisms is required. Chronobiological studies include but are not limited to comparative anatomy, physiology, genetics, molecular biology and behavior of organisms related to their biological rhythms. Other aspects include epigenetics, development, reproduction, ecology and evolution. The subject Chronobiology studies variations of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Clock
A circadian clock, or circadian oscillator, is a biochemical oscillator that cycles with a stable phase and is synchronized with solar time. Such a clock's ''in vivo'' period is necessarily almost exactly 24 hours (the earth's current solar day). In most living things, internally synchronized circadian clocks make it possible for the organism to anticipate daily environmental changes corresponding with the day–night cycle and adjust its biology and behavior accordingly. The term circadian derives from the Latin ''circa'' (about) ''dies'' (a day), since when taken away from external cues (such as environmental light), they do not run to exactly 24 hours. Clocks in humans in a lab in constant low light, for example, will average about 24.2 hours per day, rather than 24 hours exactly. The normal body clock oscillates with an endogenous period of exactly 24 hours, it entrains, when it receives sufficient daily corrective signals from the environment, primarily daylight and darkn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Clock Of Mammals
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment ( entrained by the environment). These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in animals, plants, fungi and cyanobacteria. The term ''circadian'' comes from the Latin ''circa'', meaning "approximately", and ''dies'', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjusted to the local environment by external cues called zeitgebers (German for "time givers"), which include light, temperature and redox cycles. In clinical settings, an abnormal circadian rhythm in humans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PER2
PER2 is a protein in mammals encoded by the ''PER2'' gene. ''PER2'' is noted for its major role in circadian rhythms. Discovery The ''per ''gene'' ''was first discovered using forward genetics in '' Drosophilla melanogaster'' in 1971. Mammalian Per2 was discovered by in 1997 through a search for homologous cDNA sequences to PER1. It is more similar to Drosophila '' per'' than its paralogs. Later experiments in also identified ''Per2 ''in humans. Function ''PER2'' is a member of the Period family of genes and is expressed in a circadian pattern in the suprachiasmatic nucleus, the primary circadian pacemaker in the mammalian brain. Genes in this family encode components of the circadian clock, which regulates the daily rhythms of locomotor activity, metabolism, and behavior. Circadian expression of these genes and their encoded proteins in the suprachiasmatic nucleus. Human PER2 is involved in human sleep disorder and cancer formation. Lowered ''PER2'' expression is common in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casein Kinase 1
The Casein kinase 1 family () of protein kinases are serine/threonine-selective enzymes that function as regulators of signal transduction pathways in most eukaryotic cell types. CK1 isoforms are involved in Wnt signaling, circadian rhythms, nucleo-cytoplasmic shuttling of transcription factors, DNA repair, and DNA transcription. Discovery By the early 1950s it was known from metabolic labeling studies using radioactive phosphate that phosphate groups attached to phosphoproteins inside cells can sometimes undergo rapid exchange of new phosphate for old. In order to perform experiments that would allow isolation and characterization of the enzymes involved in attaching and removing phosphate from proteins, there was a need for convenient substrates for protein kinases and protein phosphatases. Casein has been used as a substrate since the earliest days of research on protein phosphorylation. By the late 1960s, cyclic AMP-dependent protein kinase had been purified, and most attenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ying-Hui Fu
Ying-Hui Fu () is a Taiwanese-American biologist and human geneticist who has made important contributions to understanding the genetics of many neurological disorders. Her chief discoveries include describing Mendelian sleep phenotypes, identifying causative genes and mutations for circadian rhythm disorders, and characterizing genetic forms of demyelinating degenerative disorders. Fu is currently a professor of neurology at the University of California, San Francisco. She was elected to the US National Academy of Sciences in 2018. Background and education Early career In 1980, Fu received a degree in food science from National Chung-Hsing University in Taiwan. In her study of food sciences, she was introduced to biochemistry and microbiology, which led her to study DNA manipulation. She then received her Ph.D. in biochemistry and molecular biology from Ohio State University in 1986. She continued to work at OSU for three more years in a post-doctoral position studying gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroscience Of Sleep
The neuroscience of sleep is the study of the neuroscientific and physiological basis of the nature of sleep and its functions. Traditionally, sleep has been studied as part of psychology and medicine. The study of sleep from a neuroscience perspective grew to prominence with advances in technology and proliferation of neuroscience research from the second half of the twentieth century. The importance of sleep is demonstrated by the fact that organisms daily spend hours of their time in sleep, and that sleep deprivation can have disastrous effects ultimately leading to death in animals. For a phenomenon so important, the purposes and mechanisms of sleep are only partially understood, so much so that as recently as the late 1990s it was quipped: "The only known function of sleep is to cure sleepiness". However, the development of improved imaging techniques like EEG, PET and fMRI, along with high computational power have led to an increasingly greater understanding of the mechan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllis C
Phyllis is a feminine given name which may refer to: People * Phyllis Bartholomew (1914–2002), English long jumper * Phyllis Drummond Bethune (née Sharpe, 1899–1982), New Zealand artist * Phyllis Calvert (1915–2002), British actress * Phyllis M. Christian (born 1956), Ghanaian lawyer and consultant * Phyllis Coates (born 1927), American actress * Phyllis Diller (1917–2012), American actress/comedian * Phyllis Dillon (1944–2004), Jamaican rocksteady and reggae singer * Phyllis Eisenstein (1946–2020), American writer * Phyllis Gotlieb (1926–2009), Canadian writer * Phyllis Hyman (1949–1995), American jazz singer * Phylis Lee Isley, birth name of Jennifer Jones (1919–2009), American film actress * P. D. James (1920–2014), English crime fiction writer * Phyllis Logan (born 1956), Scottish actress * Phyllis Newman (1933–2019), American actress * Phyllis Pearsall (1906–1996), British creator of the ''A to Z'' map of London * Phyllis Quek (born 1973), Mala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedigree Chart
A pedigree chart is a diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors from one generation to the next, most commonly humans, show dogs, and race horses. Definition The word pedigree is a corruption of the Anglo-Norman French ''pé de grue'' or "crane's foot", either because the typical lines and split lines (each split leading to different offspring of the one parent line) resemble the thin leg and foot of a crane or because such a mark was used to denote succession in pedigree charts. A pedigree results in the presentation of family information in the form of an easily readable chart. It can be simply called as a "family tree". Pedigrees use a standardized set of symbols, squares represent males and circles represent females. Pedigree construction is a family history, and details about an earlier generation may be uncertain as memories fade. If the sex of the person is unknown a diamond is used. Someone with the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morningness–eveningness Questionnaire
The morningness–eveningness questionnaire (MEQ) is a self-assessment questionnaire developed by researchers James A. Horne and Olov Östberg in 1976. Its main purpose is to measure whether a person's circadian rhythm (biological clock) produces peak alertness in the morning, in the evening, or in between. The original study showed that the subjective time of peak alertness correlates with the time of peak body temperature; morning types ( early birds) have an earlier temperature peak than evening types ( night owls), with intermediate types having temperature peaks between the morning and evening chronotype groups. The MEQ is widely used in psychological and medical research and has been professionally cited more than 4,000 times. MEQ questions The standard MEQ consists of 19 multiple-choice questions, each having four or five response options. Some example questions are: Responses to the questions are combined to form a composite score that indicates the degree to which the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actigraphy
Actigraphy is a non-invasive method of monitoring human rest/activity cycles. A small actigraph unit, also called an actimetry sensor, is worn for a week or more to measure gross motor activity. The unit is usually in a wristwatch-like package worn on the wrist. The movements the actigraph unit undergoes are continually recorded and some units also measure light exposure. The data can be later read to a computer and analysed offline; in some brands of sensors the data are transmitted and analysed in real time. Purpose Sleep Sleep actigraphs are generally watch-shaped and worn on the wrist of the non-dominant arm for adults and usually on the ankle for children. They are useful for determining sleep patterns and circadian rhythms and may be worn for several weeks at a time. In the medical setting, traditional polysomnography has long been cited as "the 'gold standard' for sleep assessment." Since the 1990s, however, actigraphy has increasingly been used to assess sleep/wake ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Ptáček
Louis Ptáček (Czech origin, Ptáček means a Little Bird) is an American neurologist and professor who contributed greatly to the field of genetics and neuroscience. He was also an HHMI investigator from 1997 to 2018. His chief areas of research include the understanding of inherited Mendelian disorders and circadian rhythm genes. Currently, Ptáček is a neurology professor and a director of the Division of Neurogenetics in University of California, San Francisco, School of Medicine. His current investigations primarily focus on extensive clinical studies in families with hereditary disorders, which include identifying and characterizing the genes responsible for neurological variations. __TOC__ Background and education In 1982, Louis Ptáček earned his Bachelor of Science degree in mathematics from the University of Wisconsin-Madison. In 1986, he received his Doctor of Medicine degree from the University of Wisconsin-Madison Medical School. During his neurology residency at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
