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Information about Biological Rhythm

Chronobiology is a field of science that examines periodic (cyclic) phenomena in living organisms and their adaptation to solar and lunar related rhythms.[1] These cycles are known as biological rhythms. "Chrono" pertains to time and "biology" 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.

Chrobiological studies include but are not limited to comparative anatomy, physiology, genetics and molecular biology of organisms within biological rythms mechanics.[1]

Description

The variations of the duration of biological activity in living organisms occur for many essential biological processes. These occur (a) in animals (eating, sleeping, mating, hibernating, migration, cellular regeneration, etc), and (b) in plants (leaf movements, photosynthetic reactions, etc.). The most important rhythm in chronobiology is the circadian rhythm, a roughly 24 hour cycle shown by physiological processes in plants and animals. (The term circadian comes from the Latin circa, meaning "around" and dies, "day", meaning literally, "around a day."). This and other many other important cycles are also studied, including:
  • Infradian rhythms, which are long-term cycles, such as the annual migration or reproduction cycles found in certain animals or the human menstrual cycle.
  • Ultradian rhythms, which are short cycles, such as the 90-minute REM cycle, the 4-hour nasal cycle, or the 3-hour cycle of growth hormone production. They have periods of less than 24 hours.
  • Tidal rhythms, commonly observed in marine life, which follow the (roughly) 12-hour transition from high to low tide and back.

History

Franz Halberg of the University of Minnesota is widely considered the "father of chronobiology".

A circadian cycle was initially discovered, in the 1700s, in the movement of plant leaves by the French scientist Jean-Jacques d'Ortous de Mairan. For a description of circadian rhythms in plants by de Mairan, Linnaeus, and Darwin see [1]. In 1751 Swedish botanist and naturalist Carolus Linnaeus designed a floral clock using certain diurnal species of flowering plants. By arranging the selected species in a circular pattern, he designed a clock that indicated the time of day by observing which flowers were open and which ones were closed. For example, he discovered that the hawk's beard plant, opened its flowers at 6:30 am, whereas another species, the hawkbit, did not open its flowers until 7 am. More recently, light therapy and melatonin administration have been explored by Dr. Alfred J. Lewy (OHSU) and other researchers as a means to reset abnormal animal and human circadian rhythms.

More recent research by William Rowe in the UK has discovered another colour/light clock called Chromo[2] that helps the body understand what time it is based on a very simple colour and time standard. The theory allows you to control your circadian rhythm by using colour to release different hormones in your body, the two main ones being seratonin and melatonin.

In the second half of 20th century, substantial contributions and formalizations have been made by Europeans such as Jürgen Aschoff and Colin Pittendrigh, who pursued different but complementary views on the phenomenon of entrainment of the circadian system by light (parametric, continuous, tonic, gradual vs. nonparametric, discrete, phasic, instantaneous, respectively; see this historical article).

Assessment tools

In 1976, the Morningness-Eveningness Questionnaire was developed by Horne and Ostberg (1976), to assess whether people are more likely to be maximally alert in the morning or the evening. In their article, they distinguished between morning people and evening people, although other authors sometimes refer to these types as "larks" and "owls" respectively. These authors note how, although distinctions between morning and evening types go back as far as 1900, it was not until the work of Freeman and Hovland (1934) and Kleitman (1939) (cited in Horne and Ostberg, 1976) that systematic research began into these different types. Oquist (1970; cited in Horne & Ostberg, 1976) produced a Swedish questionnaire to distinguish evening from morning types. This questionnaire was modified by Ostberg (1973), and this formed the basis for the English language Morningness - Eveningness Questionnaire of Horne and Ostberg (1976). Using this questionnaire, Horne and Ostberg found statistically significant differences between evening and morning types in times of retiring to bed and waking, but they did not find statistically significant differences between these two types in terms of sleep length. They also note that age should be considered in assessments of morningness and eveningness, noting how a "bed time of 23: 30 may be indicative of a Morning type within a student population, but might be more related to an Evening type in the 40-60 years age group" (Horne & Ostberg, 1976, p109). These authors also note how temperature peaks vary between morning and evening types. Since these authors devised their scale, other authors have also developed scales to assess these constructs, and there is some evidence that morningness and eveningness may actually be orthogonal.

Other fields

Not a part of chronobiology is the unsubstantiated theory of biorhythms. These are said to describe a set of cyclic variations in human behaviour based on physiological and emotional cycles.

Chronobiology is a truly interdisciplinary interacting field of investigation. Jetlag is one of the medical conditions in which Chronobiology research is deeply involved, having also interaction in many other medical fields as sleep disorders, endocrinology, geriatrics, sports medicine, space medicine and more.[2][3][4]

References

1. ^ Patricia J. DeCoursey, Jay C. Dunlap, Jennifer J. Loros (2003). Chronobiology. Sinauer Associates Inc. ISBN 978-0878931491. 
2. ^ Postolache, Teodor T. (2005). Sports Chronobiology, An Issue of Clinics in Sports Medicine. Saunders. ISBN 978-1416027690. 
3. ^ Ernest Lawrence Rossi, David Lloyd (1992). Ultradian Rhythms in Life Processes: Inquiry into Fundamental Principles of Chronobiology and Psychobiology. Springer-Verlag Berlin and Heidelberg GmbH & Co. K. ISBN 978-3540197461. 
4. ^ Hayes, D.K. (1990). Chronobiology: Its Role in Clinical Medicine, General Biology, and Agriculture. John Wiley & Sons. ISBN 978-0471568025. 

Research publications

External articles

Science (from the Latin scientia, 'knowledge'), in the broadest sense, refers to any systematic knowledge or practice.[1] Examples of the broader use included political science and computer science, which are not incorrectly named, but rather named according to
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The Sun

Observation data
Mean distance
from Earth 1.4961011 m
(8.31 min at light speed)
Visual brightness (V) −26.74m [1]
Absolute magnitude 4.
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Moon  

The Moon as seen by an observer on Earth
Orbital characteristics
Periapsis: 363,104 km
0.0024 AU
Apoapsis: 405,696 km
0.0027 AU
Semi-major axis: 384,399 km
0.
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time.

One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured.
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Biology (from Greek: βίος, bio, "life"; and λόγος, logos, "knowledge"), also referred to as the biological sciences, is the scientific study of life.
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Life (Biota)

Domains and Kingdoms
  • Life on Earth (Gaeabionta)
  • Nanobes

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molecule is defined as a sufficiently stable electrically neutral group of at least two atoms in a definite arrangement held together by strong chemical bonds.[1][2] In organic chemistry and biochemistry, the term molecule
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Anatomy (from the Greek ἀνατομία anatomia, from ἀνατέμνειν
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Physiology (from Greek: φυσις, physis, “nature, origin”; and λόγος, logos, "knowledge") is the study of the mechanical, physical, and biochemical functions of living organisms.
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Genetics is the science of heredity and variation in living organisms.[1][2] Knowledge of the inheritance of characteristics has been implicitly used since prehistoric times for improving crop plants and animals through selective breeding.
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Molecular biology is the study of biology at a molecular level. The field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry. Molecular biology chiefly concerns itself with understanding the interactions between the various systems of a cell,
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A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. The term "circadian", coined by Franz Halberg,[1] comes from the Latin circa, "around", and diem or
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Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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An infradian rhythm is a biological rhythm with a period longer than 24 hours.

Menstrual Cycle

The menstrual cycle is an example of an infradian rhythm. The endogenous pacemaker of this is the actual biological cycle. Oestrogen and progesterone are released by the ovaries.
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The menstrual cycle is a recurring cycle of physiologic changes that occurs in the females of several mammals, including human beings and other apes.[1] Humans are the only species that has a menstrual cycle with concealed ovulation.
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Ultradian characterizes recurrent periods or cycles repeated frequently throughout a 24-hour day

The descriptive term ultradian is used in sleep research to describe individual stages of sleep that occur within intervals of an organism's circadian rhythm, and especially to
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REM atonia, a state in which the motor neurons are not stimulated and thus the body's muscles don't move. Lack of such REM atonia causes REM Behavior Disorder; sufferers act out the movements occurring in their dreams.
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The nasal cycle is the rhythmic, alternating side-to-side fluctuation in nasal airflow. It is known to be regulated by the autonomic nervous system probably from the centres located in brainstem.
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Growth hormone (GH) or somatotropin (STH) is a protein hormone which stimulates growth and cell reproduction in humans and other animals. It is a 191-amino acid, single chain polypeptide hormone which is synthesized, stored, and secreted by the somatotroph
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Tides are the cyclic rising and falling of Earth's ocean surface caused by the tidal forces of the Moon and the Sun acting on the oceans. More generally, tidal phenomena can occur in any object that is subjected to a gravitational field that varies in time and space, such as the
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Franz Halberg is a scientist and the founder of modern chronobiology. He first began his experiments in the 1940s and later founded the Chronobiology Laboratories at the University of Minnesota.
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University of Minnesota, Twin Cities is the oldest and largest part of the University of Minnesota system. It is located on two campuses in the cities of Minneapolis and St. Paul, Minnesota; the campuses are linked through a dedicated bus system.
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Jean-Jacques d'Ortous de Mairan (November 26, 1678 – February 20, 1771) was a French geophysicist.

He was born in the town of Béziers. His father, François d'Ortous, belonged to the landed gentry, but he died when Jean-Jacques was four.
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Botany is the scientific study of plant life. As a branch of biology, it is also called plant science(s), phytology, or plant biology. Botany covers a wide range of scientific disciplines that study plants, algae, and fungi including: structure, growth,
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Natural history or (in Latin) Naturalis Historia is the scientific study of plants or animals.

Natural History may also refer to:

In science and medicine:
  • Natural History (Pliny), Naturalis Historia

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Carolus Linnaeus (Carl von Linné)

Carl von Linné, Alexander Roslin, 1775. Currently owned by and hanging at the Royal Swedish Academy of Sciences.
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floral clock or flower clock may be one of two things:
  1. A large decorative clock set into a flower bed in a park or other public recreation area, the most famous being in Geneva, Switzerland, and the largest in the world being in Tehran, Iran;

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Diurnal ("daily") may refer to:
  • Diurnal animal, a plant or animal that is active in the daytime
  • Actions which are completed in 24 hours and are repeated every 24 hours, e.g. the sun reaching its zenith.

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Magnoliophyta

Classes

Magnoliopsida - Dicots
Liliopsida - Monocots

The flowering plants or angiosperms are the most widespread group of land plants. The flowering plants and the gymnosperms comprise the two extant groups of seed plants.
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