The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.
The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.
Basic helix-loop-helix (bHLH) domain-containing proteins that contain intrinsic HISTONE ACETYLTRANSFERASE activity and play important roles in CIRCADIAN RHYTHM regulation. Clock proteins combine with Arntl proteins to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation. This transcriptional activation also sets into motion a time-dependent feedback loop which in turn down-regulates the expression of clock proteins.
Biological mechanism that controls CIRCADIAN RHYTHM. Circadian clocks exist in the simplest form in cyanobacteria and as more complex systems in fungi, plants, and animals. In humans the system includes photoresponsive RETINAL GANGLION CELLS and the SUPRACHIASMATIC NUCLEUS that acts as the central oscillator.
An ovoid densely packed collection of small cells of the anterior hypothalamus lying close to the midline in a shallow impression of the OPTIC CHIASM.
Circadian rhythm signaling proteins that influence circadian clock by interacting with other circadian regulatory proteins and transporting them into the CELL NUCLEUS.
Basic helix-loop-helix (bHLH) domain-containing proteins that play important roles in CIRCADIAN RHYTHM regulation. They combine with CLOCK PROTEINS to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation.
Geological formations consisting of underground enclosures with access from the surface.
Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
Flavoproteins are a type of protein molecule that contain noncovalently bound flavin mononucleotide or flavin adenine dinucleotide as cofactors, involved in various redox reactions and metabolic pathways, such as electron transfer, energy production, and DNA repair.
A broad category of proteins that regulate the CIRCADIAN RHYTHM of an organism. Included here are proteins that transmit intracellular and intercellular signals in a chronological manner along with proteins that sense light and time-dependent changes in the environment such as the PHOTOPERIOD.
A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
The absence of light.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).
A species of ascomycetous fungi of the family Sordariaceae, order SORDARIALES, much used in biochemical, genetic, and physiologic studies.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Elements of limited time intervals, contributing to particular results or situations.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
A DNA-binding orphan nuclear receptor that negatively regulates expression of ARNTL TRANSCRIPTION FACTORS and plays a role as a regulatory component of the circadian clock system. The Nr1d1 nuclear receptor expression is cyclically-regulated by a feedback loop involving its positive regulation by CLOCK PROTEIN; BMAL1 PROTEIN heterodimers and its negative regulation by CRYPTOCHROME and PERIOD PROTEINS.
Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay.

Characterization of K+ currents underlying pacemaker potentials of fish gonadotropin-releasing hormone cells. (1/2760)

Endogenous pacemaker activities are important for the putative neuromodulator functions of the gonadotropin-releasing hormone (GnRH)-immunoreactive terminal nerve (TN) cells. We analyzed several types of voltage-dependent K+ currents to investigate the ionic mechanisms underlying the repolarizing phase of pacemaker potentials of TN-GnRH cells by using the whole brain in vitro preparation of fish (dwarf gourami, Colisa lalia). TN-GnRH cells have at least four types of voltage-dependent K+ currents: 1) 4-aminopyridine (4AP)-sensitive K+ current, 2) tetraethylammonium (TEA)-sensitive K+ current, and 3) and 4) two types of TEA- and 4AP-resistant K+ currents. A transient, low-threshold K+ current, which was 4AP sensitive and showed significant steady-state inactivation in the physiological membrane potential range (-40 to -60 mV), was evoked from a holding potential of -100 mV. This current thus cannot contribute to the repolarizing phase of pacemaker potentials. TEA-sensitive K+ current evoked from a holding potential of -100 mV was slowly activating, long lasting, and showed comparatively low threshold of activation. This current was only partially inactivated at steady state of -60 to -40 mV, which is equivalent to the resting membrane potential. TEA- and 4AP-resistant sustained K+ currents were evoked from a holding potential of -100 mV and were suggested to consist of two types, based on the analysis of activation curves. From the inactivation and activation curves, it was suggested that one of them with low threshold of activation may be partly involved in the repolarizing phase of pacemaker potentials. Bath application of TEA together with tetrodotoxin reversibly blocked the pacemaker potentials in current-clamp recordings. We conclude that the TEA-sensitive K+ current is the most likely candidate that contributes to the repolarizing phase of the pacemaker potentials of TN-GnRH cells.  (+info)

An intrinsic oscillation in interneurons of the rat lateral geniculate nucleus. (2/2760)

By using the whole cell patch recording technique in vitro, we examined the voltage-dependent firing patterns of 69 interneurons in the rat dorsal lateral geniculate nucleus (LGN). When held at a hyperpolarized membrane potential, all interneurons responded with a burst of action potentials. In 48 interneurons, larger current pulses produced a bursting oscillation. When relatively depolarized, some interneurons produced a tonic train of action potentials in response to a depolarizing current pulse. However, most interneurons produced only oscillations, regardless of polarization level. The oscillation was insensitive to the bath application of a combination of blockers to excitatory and inhibitory synaptic transmission, including 30 microM 6,7-dinitroquinoxaline-2,3-dione, 100 microM (+/-)-2-amino-5-phosphonopentanoic acid, 20 microM bicuculline, and 2 mM saclofen, suggesting an intrinsic event. The frequency of the oscillation in interneurons was dependent on the intensity of the injection current. Increasing current intensity increased the oscillation frequency. The maximal frequency of the oscillation was 5-15 Hz for most cells, with some ambiguity caused by the difficulty of precisely defining a transition from oscillatory to regular firing behavior. In contrast, the interneuron oscillation was little affected by preceding depolarizing and hyperpolarizing pulses. In addition to being elicited by depolarizing current injections, the oscillation could also be initiated by electrical stimulation of the optic tract when the interneurons were held at a depolarized membrane potential. This suggests that interneurons may be recruited into thalamic oscillations by synaptic inputs. These results indicate that interneurons may play a larger role in thalamic oscillations than was previously thought.  (+info)

Gating of afferent input by a central pattern generator. (3/2760)

Intracellular recordings from the sole proprioceptor (the oval organ) in the crab ventilatory system show that the nonspiking afferent fibers from this organ receive a cyclic hyperpolarizing inhibition in phase with the ventilatory motor pattern. Although depolarizing and hyperpolarizing current pulses injected into a single afferent will reset the ventilatory motor pattern, the inhibitory input is of sufficient magnitude to block afferent input to the ventilatory central pattern generator (CPG) for approximately 50% of the cycle period. It is proposed that this inhibitory input serves to gate sensory input to the ventilatory CPG to provide an unambiguous input to the ventilatory CPG.  (+info)

The biological clock of very premature primate infants is responsive to light. (4/2760)

Each year more than 250,000 infants in the United States are exposed to artificial lighting in hospital nurseries with little consideration given to environmental lighting cycles. Essential in determining whether environmental lighting cycles need to be considered in hospital nurseries is identifying when the infant's endogenous circadian clock becomes responsive to light. Using a non-human primate model of the developing human, we examined when the circadian clock, located in the hypothalamic suprachiasmatic nuclei (SCN), becomes responsive to light. Preterm infant baboons of different ages were exposed to light (5,000 lux) at night, and then changes in SCN metabolic activity and gene expression were assessed. After exposure to bright light at night, robust increases in SCN metabolic activity and gene expression were seen at ages that were equivalent to human infants at 24 weeks after conception. These data provide direct evidence that the biological clock of very premature primate infants is responsive to light.  (+info)

Loss of the circadian clock-associated protein 1 in Arabidopsis results in altered clock-regulated gene expression. (5/2760)

Little is known about plant circadian oscillators, in spite of how important they are to sessile plants, which require accurate timekeepers that enable the plants to respond to their environment. Previously, we identified a circadian clock-associated (CCA1) gene that encodes an Myb-related protein that is associated with phytochrome control and circadian regulation in plants. To understand the role CCA1 plays in phytochrome and circadian regulation, we have isolated an Arabidopsis line with a T DNA insertion that results in the loss of CCA1 RNA, of CCA1 protein, and of an Lhcb-promoter binding activity. This mutation affects the circadian expression of all four clock-controlled genes that we examined. The results show that, despite their similarity, CCA1 and LHY are only partially redundant. The lack of CCA1 also affects the phytochrome regulation of gene expression, suggesting that CCA1 has an additional role in a signal transduction pathway from light, possibly acting at the point of integration between phytochrome and the clock. Our results indicate that CCA1 is an important clock-associated protein involved in circadian regulation of gene expression.  (+info)

How does beta-adrenergic stimulation increase the heart rate? The role of intracellular Ca2+ release in amphibian pacemaker cells. (6/2760)

1. The mechanism by which sympathetic transmitters increase the firing rate of pacemaker cells was explored in isolated cells from the sinus venosus of the cane toad Bufo marinus. Intracellular calcium concentration ([Ca2+]i) was measured with indo-1 and membrane potential and currents were recorded with the nystatin perforated-patch technique. 2. Adrenaline or isoprenaline (2 microM) increased the transient rise in [Ca2+]i and increased the firing rate; these effects were blocked by propranolol (2 microM). 3. To determine whether the changes in [Ca2+]i might influence the firing rate we studied agents which affect either the loading or the release of Ca2+ from the sarcoplasmic reticulum (SR). Rapid application of caffeine (10 mM) to spontaneously firing cells caused a large Ca2+ release from the SR and the cells were then quiescent for 24 s. In the presence of beta-adrenergic stimulation the caffeine-induced [Ca2+]i was 14 % larger but the period of quiescence after application was reduced to 12 s. 4. Ryanodine, at either low (1 microM) or high (> 10 microM) concentration, stopped firing. However, when the SR store content of Ca2+ was tested with caffeine, at low ryanodine concentration the SR Ca2+ store was empty whereas at the high concentration the SR store was still loaded with Ca2+. beta-Adrenergic stimulation was not able to restore firing at the low concentration of ryanodine but did restore firing at the high ryanodine concentration. 5. An SR Ca2+ pump blocker, 2, 5-di(tert-butyl)-1,4-hydroquinone (TBQ) which depletes the SR store of Ca2+, also rapidly and reversibly stopped spontaneous firing. 6. The relation between the amplitude of the [Ca2+]i transient and firing rate established in the presence of ryanodine was similar when firing was restored by beta-stimulation. 7. In both spontaneously firing and voltage-clamped cells, depleting the SR store with either ryanodine or TBQ suggested that about half of the Ca2+ which contributes to the calcium transient is released from the SR. 8. These results show that the amplitude of the [Ca2+]i transient is an important factor in the firing rate of toad pacemaker cells and consequently agents which modify SR Ca2+ release influence firing rate. The effects of beta-stimulation on firing rate seem to be largely mediated by changes in amplitude of the [Ca2+]i transient.  (+info)

Role of PI3-kinase in the development of interstitial cells and pacemaking in murine gastrointestinal smooth muscle. (7/2760)

1. Development of the pacemaker system in the small intestine depends upon signalling via tyrosine kinase (Kit) receptors. The downstream pathways initiated by Kit in interstitial cells of Cajal (ICC) have not been investigated. Wortmannin and 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY 294002), inhibitors of phosphatidylinositol 3'-kinase (PI3-kinase), were used to test the involvement of this pathway in the development and maintenance of ICC and electrical rhythmicity in the murine small intestine. 2. ICC and electrical slow waves were present in the murine jejunum at birth. ICC and electrical rhythmicity continued to develop in neonates such that adult activity was recorded after 1 week. Development of ICC and rhythmicity were maintained in organ culture. 3. Wortmannin or LY 294002 inhibited the development of slow waves and blocked rhythmicity within 2-4 days. Loss of slow waves was preceded by disappearance of Kit-positive cells from the myenteric (IC-MY) and deep muscular plexus (IC-DMP) regions. Wortmannin or LY 294002 had no acute effect on slow waves. 4. Muscles from older animals (day 10-day 30) developed resistance to wortmannin treatment, but when the exposure to wortmannin was increased to 35 days, damage to ICC networks and electrical dysrhythmias were observed. 5. PI3-kinase appears to be a critical downstream signalling element linking Kit receptors to ICC development and maintenance of phenotype. ICC are more sensitive to Kit or PI3-kinase blockade at birth, but the importance of the PI3-kinase signalling in the maintenance of ICC persists into adulthood. Interference with PI3-kinase signalling in immature or adult animals could result in disruption of ICC and gastrointestinal dysrhythmias.  (+info)

Regulation of mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors. (8/2760)

Circadian rhythms of mammals are entrained by light to follow the daily solar cycle (photoentrainment). To determine whether retinal rods and cones are required for this response, the effects of light on the regulation of circadian wheel-running behavior were examined in mice lacking these photoreceptors. Mice without cones (cl) or without both rods and cones (rdta/cl) showed unattenuated phase-shifting responses to light. Removal of the eyes abolishes this behavior. Thus, neither rods nor cones are required for photoentrainment, and the murine eye contains additional photoreceptors that regulate the circadian clock.  (+info)

"Biological clocks" refer to the internal time-keeping systems in living organisms that regulate the timing of various physiological processes and behaviors according to a daily (circadian) rhythm. These rhythms are driven by genetic mechanisms and can be influenced by environmental factors such as light and temperature.

In humans, biological clocks help regulate functions such as sleep-wake cycles, hormone release, body temperature, and metabolism. Disruptions to these internal timekeeping systems have been linked to various health problems, including sleep disorders, mood disorders, and cognitive impairment.

A circadian rhythm is a roughly 24-hour biological cycle that regulates various physiological and behavioral processes in living organisms. It is driven by the body's internal clock, which is primarily located in the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain.

The circadian rhythm controls many aspects of human physiology, including sleep-wake cycles, hormone secretion, body temperature, and metabolism. It helps to synchronize these processes with the external environment, particularly the day-night cycle caused by the rotation of the Earth.

Disruptions to the circadian rhythm can have negative effects on health, leading to conditions such as insomnia, sleep disorders, depression, bipolar disorder, and even increased risk of chronic diseases like cancer, diabetes, and cardiovascular disease. Factors that can disrupt the circadian rhythm include shift work, jet lag, irregular sleep schedules, and exposure to artificial light at night.

CLOCK proteins are a pair of transcription factors, CIRCADIAN LOComotor OUTPUT Cycles Kaput (CLOCK) and BMAL1 (brain and muscle ARNT-like 1), that play a critical role in the regulation of circadian rhythms. Circadian rhythms are biological processes that follow an approximately 24-hour cycle, driven by molecular mechanisms within cells.

The CLOCK and BMAL1 proteins form a heterodimer, which binds to E-box elements in the promoter regions of target genes. This binding activates the transcription of these genes, leading to the production of proteins that are involved in various cellular processes. After being transcribed and translated, some of these proteins feed back to inhibit the activity of the CLOCK-BMAL1 heterodimer, forming a negative feedback loop that is essential for the oscillation of circadian rhythms.

The regulation of circadian rhythms by CLOCK proteins has implications in many physiological processes, including sleep-wake cycles, metabolism, hormone secretion, and cellular proliferation. Dysregulation of these rhythms has been linked to various diseases, such as sleep disorders, metabolic disorders, and cancer.

Circadian clocks are biological systems found in living organisms that regulate the daily rhythmic activities and functions with a period of approximately 24 hours. These internal timekeeping mechanisms control various physiological processes, such as sleep-wake cycles, hormone secretion, body temperature, and metabolism, aligning them with the external environment's light-dark cycle.

The circadian clock consists of two major components: the central or master clock, located in the suprachiasmatic nucleus (SCN) of the hypothalamus in mammals, and peripheral clocks present in nearly every cell throughout the body. The molecular mechanisms underlying these clocks involve interconnected transcriptional-translational feedback loops of several clock genes and their protein products. These genetic components generate rhythmic oscillations that drive the expression of clock-controlled genes (CCGs), which in turn regulate numerous downstream targets responsible for coordinating daily physiological and behavioral rhythms.

Circadian clocks can be synchronized or entrained to external environmental cues, mainly by light exposure. This allows organisms to adapt their internal timekeeping to the changing day-night cycles and maintain proper synchronization with the environment. Desynchronization between the internal circadian system and external environmental factors can lead to various health issues, including sleep disorders, mood disturbances, cognitive impairment, metabolic dysregulation, and increased susceptibility to diseases.

The suprachiasmatic nucleus (SCN) is a small region located in the hypothalamus of the brain, just above the optic chiasm where the optic nerves from each eye cross. It is considered to be the primary circadian pacemaker in mammals, responsible for generating and maintaining the body's internal circadian rhythm, which is a roughly 24-hour cycle that regulates various physiological processes such as sleep-wake cycles, hormone release, and metabolism.

The SCN receives direct input from retinal ganglion cells, which are sensitive to light and dark signals. This information helps the SCN synchronize the internal circadian rhythm with the external environment, allowing it to adjust to changes in day length and other environmental cues. The SCN then sends signals to other parts of the brain and body to regulate various functions according to the time of day.

Disruption of the SCN's function can lead to a variety of circadian rhythm disorders, such as jet lag, shift work disorder, and advanced or delayed sleep phase syndrome.

Period (PER) circadian proteins are a group of proteins that play a crucial role in the regulation of circadian rhythms, which are physical, mental, and behavioral changes that follow a daily cycle. They are named after the PERIOD gene, whose protein product is one of the key components of the molecular circadian clock mechanism.

The molecular clock is a self-sustaining oscillator present in most organisms, from cyanobacteria to humans. In mammals, the molecular clock consists of two interlocking transcriptional-translational feedback loops that generate rhythmic expression of clock genes and their protein products with a period of approximately 24 hours.

The primary loop involves the positive regulators CLOCK and BMAL1, which heterodimerize and bind to E-box elements in the promoter regions of target genes, including PERIOD (PER) and CRYPTOCHROME (CRY) genes. Upon transcription and translation, PER and CRY proteins form a complex that translocates back into the nucleus, where it inhibits CLOCK-BMAL1-mediated transcription, thereby suppressing its own expression. After a certain period, the repressive complex dissociates, allowing for another cycle of transcription and translation to occur.

The second loop involves the regulation of additional clock genes such as REV-ERBα and RORα, which compete for binding to ROR response elements (ROREs) in the BMAL1 promoter, thereby modulating its expression level. REV-ERBα also represses PER and CRY transcription by recruiting histone deacetylases (HDACs) and nuclear receptor corepressor 1 (NCOR1).

Overall, Period circadian proteins are essential for the proper functioning of the molecular clock and the regulation of various physiological processes, including sleep-wake cycles, metabolism, hormone secretion, and cellular homeostasis. Dysregulation of these proteins has been implicated in several diseases, such as sleep disorders, metabolic syndromes, and cancer.

ARNTL (aryl hydrocarbon receptor nuclear translocator-like) transcription factors, also known as BMAL1 (brain and muscle ARNT-like 1), are proteins that bind to DNA and promote the expression of specific genes. They play a critical role in regulating circadian rhythms, which are the physical, mental, and behavioral changes that follow a daily cycle.

ARNTL transcription factors form heterodimers with another set of transcription factors called CLOCK (circadian locomotor output cycles kaput) proteins. Together, these complexes bind to specific DNA sequences known as E-boxes in the promoter regions of target genes. This binding leads to the recruitment of other cofactors and the activation of gene transcription.

ARNTL transcription factors are part of a larger negative feedback loop that regulates circadian rhythms. After activating gene transcription, ARNTL-CLOCK complexes eventually lead to the production of proteins that inhibit their own activity, creating a cycle that repeats approximately every 24 hours.

Disruptions in the function of ARNTL transcription factors have been linked to various circadian rhythm disorders and other health conditions, including sleep disorders, mood disorders, and cancer.

I believe there may be some confusion in your question as "caves" are not a medical term. A cave is a natural underground space that is large enough for a person to enter and can form in a variety of ways, such as the dissolution of limestone by acidic groundwater or the collapse of a volcanic tube. If you have any questions about geology or speleology (the study of caves), I would be happy to try to help answer those!

Cryptochromes are a type of photoreceptor protein found in plants and animals, including humans. They play a crucial role in regulating various biological processes such as circadian rhythms (the internal "body clock" that regulates sleep-wake cycles), DNA repair, and magnetoreception (the ability to perceive magnetic fields).

In humans, cryptochromes are primarily expressed in the retina of the eye and in various tissues throughout the body. They contain a light-sensitive cofactor called flavin adenine dinucleotide (FAD) that allows them to absorb blue light and convert it into chemical signals. These signals then interact with other proteins and signaling pathways to regulate gene expression and cellular responses.

In plants, cryptochromes are involved in the regulation of growth and development, including seed germination, stem elongation, and flowering time. They also play a role in the plant's ability to sense and respond to changes in light quality and duration, which is important for optimizing photosynthesis and survival.

Overall, cryptochromes are an essential component of many biological processes and have been the subject of extensive research in recent years due to their potential roles in human health and disease.

In the context of medical terminology, "light" doesn't have a specific or standardized definition on its own. However, it can be used in various medical terms and phrases. For example, it could refer to:

1. Visible light: The range of electromagnetic radiation that can be detected by the human eye, typically between wavelengths of 400-700 nanometers. This is relevant in fields such as ophthalmology and optometry.
2. Therapeutic use of light: In some therapies, light is used to treat certain conditions. An example is phototherapy, which uses various wavelengths of ultraviolet (UV) or visible light for conditions like newborn jaundice, skin disorders, or seasonal affective disorder.
3. Light anesthesia: A state of reduced consciousness in which the patient remains responsive to verbal commands and physical stimulation. This is different from general anesthesia where the patient is completely unconscious.
4. Pain relief using light: Certain devices like transcutaneous electrical nerve stimulation (TENS) units have a 'light' setting, indicating lower intensity or frequency of electrical impulses used for pain management.

Without more context, it's hard to provide a precise medical definition of 'light'.

Photoperiod is a term used in chronobiology, which is the study of biological rhythms and their synchronization with environmental cycles. In medicine, photoperiod specifically refers to the duration of light and darkness in a 24-hour period, which can significantly impact various physiological processes in living organisms, including humans.

In human medicine, photoperiod is often considered in relation to circadian rhythms, which are internal biological clocks that regulate several functions such as sleep-wake cycles, hormone secretion, and metabolism. The length of the photoperiod can influence these rhythms and contribute to the development or management of certain medical conditions, like mood disorders, sleep disturbances, and metabolic disorders.

For instance, exposure to natural daylight or artificial light sources with specific intensities and wavelengths during particular times of the day can help regulate circadian rhythms and improve overall health. Conversely, disruptions in the photoperiod due to factors like shift work, jet lag, or artificial lighting can lead to desynchronization of circadian rhythms and related health issues.

Flavoproteins are a type of protein molecule that contain noncovalently bound flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD) as cofactors. These flavin cofactors play a crucial role in redox reactions, acting as electron carriers in various metabolic pathways such as cellular respiration and oxidative phosphorylation. Flavoproteins are involved in several biological processes, including the breakdown of fatty acids, amino acids, and carbohydrates, as well as the synthesis of steroids and other lipids. They can also function as enzymes that catalyze various redox reactions, such as oxidases, dehydrogenases, and reductases. Flavoproteins are widely distributed in nature and found in many organisms, from bacteria to humans.

Circadian rhythm signaling peptides and proteins are molecules that play a crucial role in the regulation of circadian rhythms, which are physical, mental, and behavioral changes that follow a daily cycle. These rhythms are driven by the body's internal clock, which is located in the suprachiasmatic nucleus (SCN) of the hypothalamus.

The circadian rhythm is regulated by a complex network of signaling pathways involving both peptides and proteins. These molecules help to coordinate various physiological processes, such as sleep-wake cycles, hormone release, metabolism, and body temperature, with the external environment.

Some examples of circadian rhythm signaling peptides and proteins include:

1. PERIOD (PER) proteins: These are a family of proteins that play a central role in the regulation of the circadian clock. They form complexes with other clock proteins, such as CRYPTOCHROME (CRY) proteins, to inhibit the activity of transcription factors that drive the expression of clock genes.
2. CLOCK and BMAL1: These are transcription factors that bind to DNA and promote the expression of clock genes, including PER and CRY. They form a heterodimer that binds to specific DNA sequences called E-boxes to activate gene transcription.
3. REV-ERBα and RORα: These are nuclear receptors that regulate the expression of BMAL1 and other clock genes. REV-ERBα inhibits the expression of BMAL1, while RORα activates it.
4. Melatonin: This is a hormone produced by the pineal gland that helps to regulate sleep-wake cycles. Its production is controlled by light exposure and is highest at night.
5. Cortisol: This is a steroid hormone produced by the adrenal gland that helps to regulate metabolism, immune function, and stress response. Its levels are highest in the morning and decrease throughout the day.

Overall, circadian rhythm signaling peptides and proteins play a critical role in maintaining the proper functioning of various physiological processes, including sleep-wake cycles, metabolism, and immune function. Dysregulation of these pathways has been linked to several diseases, including cancer, diabetes, and cardiovascular disease.

Melatonin is a hormone that is produced by the pineal gland in the brain. It helps regulate sleep-wake cycles and is often referred to as the "hormone of darkness" because its production is stimulated by darkness and inhibited by light. Melatonin plays a key role in synchronizing the circadian rhythm, the body's internal clock that regulates various biological processes over a 24-hour period.

Melatonin is primarily released at night, and its levels in the blood can rise and fall in response to changes in light and darkness in an individual's environment. Supplementing with melatonin has been found to be helpful in treating sleep disorders such as insomnia, jet lag, and delayed sleep phase syndrome. It may also have other benefits, including antioxidant properties and potential uses in the treatment of certain neurological conditions.

It is important to note that while melatonin supplements are available over-the-counter in many countries, they should still be used under the guidance of a healthcare professional, as their use can have potential side effects and interactions with other medications.

I am not aware of a medical definition for the term "darkness." In general, darkness refers to the absence of light. It is not a term that is commonly used in the medical field, and it does not have a specific clinical meaning. If you have a question about a specific medical term or concept, I would be happy to try to help you understand it.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

In the context of medicine, "periodicity" refers to the occurrence of events or phenomena at regular intervals or cycles. This term is often used in reference to recurring symptoms or diseases that have a pattern of appearing and disappearing over time. For example, some medical conditions like menstrual cycles, sleep-wake disorders, and certain infectious diseases exhibit periodicity. It's important to note that the duration and frequency of these cycles can vary depending on the specific condition or individual.

"Neurospora crassa" is not a medical term, but it is a scientific name used in the field of biology. It refers to a type of filamentous fungus that belongs to the phylum Ascomycota. This organism is commonly found in the environment and has been widely used as a model system for studying various biological processes, including genetics, cell biology, and molecular biology.

"Neurospora crassa" has a characteristic red pigment that makes it easy to identify, and it reproduces sexually through the formation of specialized structures called ascocarps or "fruiting bodies." The fungus undergoes meiosis inside these structures, resulting in the production of ascospores, which are haploid spores that can germinate and form new individuals.

The genome of "Neurospora crassa" was one of the first fungal genomes to be sequenced, and it has served as an important tool for understanding fundamental biological processes in eukaryotic cells. However, because it is not a medical term, there is no official medical definition for "Neurospora crassa."

Nuclear proteins are a category of proteins that are primarily found in the nucleus of a eukaryotic cell. They play crucial roles in various nuclear functions, such as DNA replication, transcription, repair, and RNA processing. This group includes structural proteins like lamins, which form the nuclear lamina, and regulatory proteins, such as histones and transcription factors, that are involved in gene expression. Nuclear localization signals (NLS) often help target these proteins to the nucleus by interacting with importin proteins during active transport across the nuclear membrane.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

Cell cycle proteins are a group of regulatory proteins that control the progression of the cell cycle, which is the series of events that take place in a eukaryotic cell leading to its division and duplication. These proteins can be classified into several categories based on their functions during different stages of the cell cycle.

The major groups of cell cycle proteins include:

1. Cyclin-dependent kinases (CDKs): CDKs are serine/threonine protein kinases that regulate key transitions in the cell cycle. They require binding to a regulatory subunit called cyclin to become active. Different CDK-cyclin complexes are activated at different stages of the cell cycle.
2. Cyclins: Cyclins are a family of regulatory proteins that bind and activate CDKs. Their levels fluctuate throughout the cell cycle, with specific cyclins expressed during particular phases. For example, cyclin D is important for the G1 to S phase transition, while cyclin B is required for the G2 to M phase transition.
3. CDK inhibitors (CKIs): CKIs are regulatory proteins that bind to and inhibit CDKs, thereby preventing their activation. CKIs can be divided into two main families: the INK4 family and the Cip/Kip family. INK4 family members specifically inhibit CDK4 and CDK6, while Cip/Kip family members inhibit a broader range of CDKs.
4. Anaphase-promoting complex/cyclosome (APC/C): APC/C is an E3 ubiquitin ligase that targets specific proteins for degradation by the 26S proteasome. During the cell cycle, APC/C regulates the metaphase to anaphase transition and the exit from mitosis by targeting securin and cyclin B for degradation.
5. Other regulatory proteins: Several other proteins play crucial roles in regulating the cell cycle, such as p53, a transcription factor that responds to DNA damage and arrests the cell cycle, and the polo-like kinases (PLKs), which are involved in various aspects of mitosis.

Overall, cell cycle proteins work together to ensure the proper progression of the cell cycle, maintain genomic stability, and prevent uncontrolled cell growth, which can lead to cancer.

Transcription factors are proteins that play a crucial role in regulating gene expression by controlling the transcription of DNA to messenger RNA (mRNA). They function by binding to specific DNA sequences, known as response elements, located in the promoter region or enhancer regions of target genes. This binding can either activate or repress the initiation of transcription, depending on the properties and interactions of the particular transcription factor. Transcription factors often act as part of a complex network of regulatory proteins that determine the precise spatiotemporal patterns of gene expression during development, differentiation, and homeostasis in an organism.

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Aging is a complex, progressive and inevitable process of bodily changes over time, characterized by the accumulation of cellular damage and degenerative changes that eventually lead to increased vulnerability to disease and death. It involves various biological, genetic, environmental, and lifestyle factors that contribute to the decline in physical and mental functions. The medical field studies aging through the discipline of gerontology, which aims to understand the underlying mechanisms of aging and develop interventions to promote healthy aging and extend the human healthspan.

"Nuclear Receptor Subfamily 1, Group D, Member 1" is a gene that encodes for the estrogen receptor alpha (ER-α). ER-α is a type of nuclear receptor protein that binds to estrogen, a female sex hormone, and mediates various biological responses such as cell growth, differentiation, and reproduction. The gene is also known as "ESR1" in medical and scientific literature. Mutations in this gene have been associated with various types of cancer, particularly breast cancer.

According to the United States Food and Drug Administration (FDA), biological products are "products that are made from or contain a living organism or its derivatives, such as vaccines, blood and blood components, cells, genes, tissues, and proteins." These products can be composed of sugars, proteins, nucleic acids, or complex combinations of these substances, and they can come from many sources, including humans, animals, microorganisms, or plants.

Biological products are often used to diagnose, prevent, or treat a wide range of medical conditions, and they can be administered in various ways, such as through injection, inhalation, or topical application. Because biological products are derived from living organisms, their manufacturing processes can be complex and must be tightly controlled to ensure the safety, purity, and potency of the final product.

It's important to note that biological products are not the same as drugs, which are chemically synthesized compounds. While drugs are designed to interact with specific targets in the body, such as enzymes or receptors, biological products can have more complex and varied mechanisms of action, making them potentially more difficult to characterize and regulate.

Look up biological clock in Wiktionary, the free dictionary. Biological clock may refer to: Age and female fertility, decrease ... biological program that limits the lifespan of an individual Biological rhythms Internal clock, the timeframe sensed by the ... biological process that displays an oscillation about 24 hours, such as the human sleep-wake cycle (the "body clock") ... Epigenetic clock, a set of DNA sites whose methylation levels can be used to measure aging throughout the body Molecular clock ...
Hardin PE (2000). "From biological clock to biological rhythms". Genome Biology. 1 (4): REVIEWS1023. doi:10.1186/gb-2000-1-4- ... In constant darkness, ClockΔ19 mice heterozygous for the Clock mutant allele exhibit lengthened circadian periods, while Clock ... Neuronal PAS domain containing protein 2 (NPAS2, a CLOCK paralog) can substitute for CLOCK in these Clock-null mice. Mice with ... The CLOCK-BMAL dimer acts as a positive limb of a feedback loop. The binding of CLOCK-BMAL to an E-box promoter element ...
In general, biological aging clocks and biomarkers of aging are expected to find many uses in biological research since age is ... Accurate measures of biological age (biological aging clocks) could be useful for testing the validity of various theories of ... Among these clocks, the PhenoAge and GrimAge clocks stand out. PhenoAge is an epigenetic clock that takes chronological age ... Overall, biological clocks are expected to be useful for studying what causes aging and what can be done against it. However, ...
Chemical clock Chemical oscillator Cromie W (1999-07-15). "Human Biological Clock Set Back an Hour". Harvard Gazette. Retrieved ... or bacterial clocks. The plant clock does have a conceptual similarity to the animal clock in that it consists of a series of ... MacKenzie D. "Biological clock began ticking 2.5 billion years ago". New Scientist. Loudon AS (July 2012). "Circadian biology: ... The basic molecular mechanisms of the biological clock have been defined in vertebrate species, Drosophila melanogaster, plants ...
Ishida N, Kaneko M, Allada R (August 1999). "Biological clocks". Proc. Natl. Acad. Sci. U.S.A. 96 (16): 8819-20. Bibcode: ... A homolog of CLOCK plays the same role in the human clock, and CYC is replaced by BMAL1. CRY has two human homologs, CRY1 and ... per has also been implicated in the regulation of several output processes of the biological clock, including mating activity ... Spanagel R, Rosenwasser AM, Schumann G, Sarkar DK (August 2005). "Alcohol consumption and the body's biological clock". Alcohol ...
Ishida, N; Kaneko, M; Allada, R (1999). "Biological clocks". Proc. Natl. Acad. Sci. U.S.A. 96 (16): 8819-20. Bibcode:1999PNAS ... Clock - The clock gene in Drosophila encodes for the CLOCK protein and forms a heterodimer with the protein CYCLE in order to ... In the mammalian circadian clock, for example, transcription factors CLOCK and BMAL1 are the positive regulators. CLOCK and ... Clock - Clock, also known as Circadian Locomotor Output Cycles Kaput, is a transcription factor in the circadian pacemaker of ...
Ishida N, Kaneko M, Allada R (August 1999). "Biological clocks". Proceedings of the National Academy of Sciences of the United ... Vrille mRNA and protein product (VRI) oscillate predictably on a 24-hour timescale and interact with other circadian clock ... Ohno T, Onishi Y, Ishida N (March 2007). "The negative transcription factor E4BP4 is associated with circadian clock protein ... Blau J, Young MW (December 1999). "Cycling vrille expression is required for a functional Drosophila clock". Cell. 99 (6): 661- ...
Ishida N, Kaneko M, Allada R (August 1999). "Biological clocks". Proc. Natl. Acad. Sci. U.S.A. 96 (16): 8819-20. Bibcode: ... Konopka and Orr found that light pulses reset the mutant clock to a greater extent than the wild type clock (about 10 hours for ... In contrast to Clock, Andante lengthens the period of eclosion, and locomotor activity by 1.5-2 hours, and was also shown to ... In 1990, Konopka collaborated with Mitchell S. Dushay and Jeffery C. Hall to further investigate the effects of the clock gene ...
ISBN 0-691-02402-2. Arthur T. Winfree (1987). Timing of Biological Clocks. Scientific American Library, No 19. ISBN 0-7167-5018 ... University of Chicago 1972-1979 Associate professor of biological sciences, Purdue University 1979-1986 Professor of biological ... Cohen, Joel E. (1982). "Review: The geometry of biological time, by Arthur T. Winfree" (PDF). Bull. Amer. Math. Soc. (N.S.). 7 ... Winfree was noted for his work on the mathematical modeling of biological phenomena (see Complexity and Singularity (system ...
Urist, Jacoba (October 21, 2013). "Men Have Biological Clocks, Too". The Atlantic. Retrieved September 15, 2015. "A Social ...
Galileo project entry SEDS Biography At the dawn of chronobiology Biological Clocks - Garden Variety Experiments Clock Classics ... "Biological Clocks - Garden Variety Experiments". HHMI. Archived from the original on 10 June 2013. Retrieved 5 April 2011. de ... Despite Marchant's publication of de Mairan's work, which might have suggested the existence of endogenous biological clocks, ... However, de Mairan did not infer that heliotropes have internal clocks driving leaf rhythms, but rather that they were able "to ...
Urist, Jacoba (October 21, 2013). "Men Have Biological Clocks, Too". The Atlantic. Retrieved April 2, 2014. Comite, Florence; ...
Millar AJ (4 January 2002). "Biological clocks in Arabidopsis thaliana". New Phytologist. 141 (2): 175-197. doi:10.1046/j.1469- ... the two sides of the Drosophila circadian clock". Journal of Biological Rhythms. 27 (6): 433-42. doi:10.1177/0748730412463181. ... "Clk Clock [Drosophila melanogaster (fruit fly)] - Gene - NCBI". Retrieved 2019-04-11. "FlyBase Allele ... Mapping and cloning of the gene indicates that it is the Drosophila homolog of the mouse gene CLOCK (mClock). The Jrk mutation ...
"The Physiological Clock", 1958) Biological clocks; Chairman's Address; Cold Spring Harbor Symposium (1960) Interference of ... "XXV: Biological Clocks 1960". CSHL Digital Photo Archives. Retrieved 7 April 2015. Datta, Subhash Chandra (1994). Plant ... From his results, Bünning proposed that biological clocks have sensors for both light and dark, and their relationship aids ... In 1960, he chaired in the 25th Cold Spring Harbor Symposium, "Biological Clocks". The next year, Bünning was elected ...
... then the subject may not have a functioning internal biological clock or may have a disruption in the clock's output. While ... due to the fact that biological clocks rarely follow an exactly 24-hour cycle. If data points shift to the left, the subject is ... Biological Timekeeping: Clocks, Rhythms and Behaviour. New Delhi: Springer India. pp. 3-22. doi:10.1007/978-81-322-3688-7_1. ... An actogram is a plot that shows rhythms in biological variables throughout the day. Traditionally, actograms describe phases ...
"Biological clocks 'beat quicker' in cities". BBC. 5 June 2013. Retrieved 5 June 2013. Wilford, John Noble (5 June 2013). "Palm- ... The clock's measurements could form a new basis for global time standards, replacing the present generation of atomic clocks.[ ... 10 July French scientists construct an ultra-precise optical lattice clock that misses only one second in 300 million years. ... Following a large-scale genome study, researchers identify some of the biological roots of migraine, a chronic neurological ...
The Biological Clock. Two Views. Academic Press. 1970. Frank A. Brown Jr. The "Clocks" Timing Biological Rhythms: Recent ... Brown envisioned the biological clock as being a duality in which an internal responder to subtle information from the ... Cole, Lamont C. Biological Clock in the Unicorn. Science, Volume 125, Issue 3253, pp. 874-876. 1957 Heusner, A. 1965. "Sources ... The Biological Clock Phenomenon: Exogenous Timing Hypothesis. J. interdiscipl. Cycle Res., Vol. 14, number 2, pp. 137·162. Webb ...
Evolving Biological Clocks using Genetic Regulatory Networks - Information page with model source code and Java applet. ... At one level, biological cells can be thought of as "partially mixed bags" of biological chemicals - in the discussion of gene ... Knabe JF, Nehaniv CL, Schilstra MJ, Quick T (2006). "Evolving Biological Clocks using Genetic Regulatory Networks". Proceedings ... Trajectories correspond to the unfolding of biological pathways and transients of the equations to short-term biological events ...
Pittendrigh is regarded as the "father of the biological clock," and founded the modern field of chronobiology alongside Jürgen ... Here, he continued his studies of biological clocks, working with the faculty and lecturing at Montana State University - ... "Perspectives in the study of biological clocks." Perspectives in Marine Biology, AA Buzati-Traverso, ed, 239-268, University of ... in establishing many of the key criteria that a biological system must have in order to be considered a biological clock. His ...
"Biological clocks: riding the tides." (2015) Journal of Biological Rhythms. "Access to Electric Light Is Associated with ... "Biological clocks and rhythms in intertidal crustaceans." (2013) Proceedings of the Royal Society B: Biological Sciences. " ... De la Iglesia is also president of the Society for Research on Biological Rhythms, an organization dedicated to promoting ... His thesis work aimed to understand the neuroanatomy of the master circadian clock of mammals - the suprachiasmatic nucleus ( ...
The effect is disruption of a human being's biological clock resulting in poor sleeping and rest periods. Research at the ... "Do White LEDs Disrupt our Biological Clocks?". 19 June 2012. Retrieved 4 October 2016. Tim Whitaker (15 ...
Biological clocks and circadian timing in cells". EMBO Reports. 6 Spec No (Suppl 1): S9-13. doi:10.1038/sj.embor.7400424. PMC ... In 2005, Tei, G. Lundkvist, Y. Kwak, E. Davis, and G. Block proposed that the molecular clock was linked to neurons' membrane ... In 2000, using their rodent model, they discovered the existence of circadian clocks in peripheral organs of mammals. This ... In 2016, a research team that included Tei discovered that clock genes, most specifically Bmal1 and Per1, are rhythmically ...
Lewis A (1999). Melatonin and the Biological Clock. McGraw-Hill. p. 23. ISBN 978-0-87983-734-1. "Melatonin - Special Subjects ... Nearly 70% of biological damage caused by ionizing radiation is estimated to be attributable to the creation of free radicals, ... Melatonin acts as an agonist of the melatonin MT1 and MT2 receptors, the biological targets of endogenous melatonin. It is ... Melatonin acts as an agonist of the melatonin MT1 and MT2 receptors, the biological targets of endogenous melatonin. Endogenous ...
clock". J. Exp. Biol. 97: 121-136. doi:10.1242/jeb.97.1.121. PMID 7201003. Dunlap, J.; Hastings, J.W. (1981). "The biological ... For over 50 years he also had an affiliation with the Marine Biological Laboratory in Woods Hole, Massachusetts. He was the ... In 1953 he joined the faculty in the Department of Biological Sciences at Northwestern University. In 1954 he began a long ... Wilson, T. and Hastings, J.W. (1970) Chemical and biological aspects of singlet excited molecular oxygen. Photophysiology (A.C ...
Istvan, Zoltan (January 14, 2019). "Transhumanist science will free women from their biological clocks". Quartz. "The Language ...
They are genetic experiments with their biological clocks stopped. They encounter Toothpick, a companion cyber from the days ...
This regular oscillation is attributed to the maintenance of biological clock NADH activity of ENOX2 has been shown to be ... 2002). "Biochemical basis for the biological clock". Biochemistry. 41 (40): 11941-5. doi:10.1021/bi020392h. PMID 12356293. ... "Biochemical basis for the biological clock". Biochemistry. 41 (40): 11941-11945. doi:10.1021/bi020392h. ISSN 0006-2960. PMID ...
This discovery provided a tool for other scientists to perform research on biological clocks and was an important early ... "Gene Mutation Upsets Mammalian Biological Clock". Howard Hughes Medical Institute. April 21, 2000. Fish KJ, Cegielska A, Getman ... Harms E, Young MW, Saez L (2003). "CK1 and GSK3 in the Drosophila and Mammalian Circadian Clock". Molecular Clocks and Light ... role to mediate CLOCK phosphorylation and repress CLOCK-dependent transcription within the Drosophila circadian clock". ...
Ingle, Roisin (15 September 2007). "Tick-tock goes the biological clock". Irish Times (subscription required). Archived from ...
Due to the highly conserved nature of biological clocks, clock mechanisms have evolved relatively few times and are similar ... This form of communication may prove to be an adaptive feature of biological clocks and enable beneficial responses to changes ... Dunlap, Jay C.; Loros, Jennifer J. (2017-05-19). "Making Time: Conservation of Biological Clocks from Fungi to Animals". ... Dunlap is also interested in the interaction between biological clocks and metabolic processes. While circadian rhythms govern ...
Look up biological clock in Wiktionary, the free dictionary. Biological clock may refer to: Age and female fertility, decrease ... biological program that limits the lifespan of an individual Biological rhythms Internal clock, the timeframe sensed by the ... biological process that displays an oscillation about 24 hours, such as the human sleep-wake cycle (the "body clock") ... Epigenetic clock, a set of DNA sites whose methylation levels can be used to measure aging throughout the body Molecular clock ...
... helps link the biological clock to the activity of pacemaker neurons. But Ir does not function as a simple output of the clock- ... "This process helps explain how our biological clocks keep such amazingly good time," said Justin Blau, an associate professor ... Biologists from New York University have uncovered new ways our biological clocks neurons use electrical activity to help keep ... NYU biologists have uncovered new ways our biological clocks neurons use electrical activity to help keep behavioral rhythms ...
... everyones 24-hour biological clock, Hebrew University of Jerusalem researchers have shown. ... everyones 24-hour biological clock, Hebrew University of Jerusalem researchers have shown. The biological clock regulates the ... but also by disrupting the phases and daily rhythm of clock genes. They contend also that high fat-induced changes in the clock ... in their experiments with laboratory mice that there is a cause-and-effect relation between diet and biological clock imbalance ...
... "clock genes" that drive their internal biological clocks showed that their social environment strongly affected their behavior. ... Research: Bees can reschedule biological clocks 0 Comments. Print. E-mail Xinhua, October 14, 2010 Adjust font size: ... seem to be able to reschedule their biological clocks without many troubles. ... "This flexibility in the bees clock is striking, given that humans and most other animals studied cannot sustain long periods ...
... researchers from University of California Los Angeles have developed a biological clock that may, for the first time, estimate ... Scientists Reveal New Biological Clock That Measures Aging Chicago Tribune. *Breasts age faster than other parts of a womans ... Using that data to build a statistical model of a biological clock that correlated methylation with chronological age, the ... researchers from University of California Los Angeles have developed a biological clock that may, for the first time, estimate ...
That is, if your biological clock genes work the same way as those of a fruit fly. And they probably do. ... That is, if your "biological clock" genes work the same way as those of a fruit fly. And they probably do. Share:. Facebook ... Biological clock could be a key to better health, longer life. Date:. March 2, 2010. Source:. Oregon State University. Summary ... Biological clock could be a key to better health, longer life." ScienceDaily. /. releases. /. 2010. /. ...
... of American scientists was awarded the Nobel Prize in physiology or medicine for revealing the mechanisms of the cellular clock ... that regulates biological changes in complex organisms across a 24-hour span. ... 3 Americans win Nobel Prize in medicine for uncovering the science behind our biological clocks ×. ... "were able to peek inside our biological clock and elucidate its inner workings." ...
... the genes that set the biological clock. An implication of the finding is that cocaine addiction could be viewed and treated as ... University Of Virginia Researchers Link Cocaine Addiction Responses To Biological Clock Genes. Date:. August 13, 1999. Source: ... This indicates that certain circadian genes not only play a critical role in regulating the biological clock, but they may also ... 1999, August 13). University Of Virginia Researchers Link Cocaine Addiction Responses To Biological Clock Genes. ScienceDaily. ...
Smokings Effect on Our Biological Clock August 10, 2023 - What Makes Us Tick: Smokings Effect on Our Biological Clock ... "How will climate change affect our circadian clock? What other diseases are regulated by molecular clock molecules, and how ... "The molecular clocks purpose is to prepare your body for expected changes in the environment, like the times for activity, ... In a recent study, Rahman and team discovered how a specific clock molecule, called REV-ERBα, contributes to pulmonary fibrosis ...
Early menopause halted by resetting biological clock. Women who experience menopause early may be given the chance to have ...
biological clock meaning Blogs, Comments and Archive News on ... biological clock meaning Latest Breaking News, Pictures, Videos, and Special Reports from The Economic Times. ... How your biological clock affects your health - all based on time of day. There is ample evidence that your biological clock is ... From the moment we wake up, our bodies have a biological clock that drives us to go back to sleep later in the day. ...
... biological clock that women recognize innately, and act on accordingly? New research casts some doubt on that. ... Is there a biological clock that women recognize innately, and act on accordingly? New research casts some doubt on that.. ... The notion of a biological clock in women arises from the fact that immature egg cells- oocytes - progressively decline in ...
This suggests an alteration of the circadian system per se that could in turn affect the expression of biological rhythms. In ... Age-related effects on the biological clock and its behavioral output in a primate Chronobiol Int. 2006;23(1-2):451-60. doi: ... two major peptides of the biological clock. Compared to adult animals, aged mouse lemurs showed a significant increase in ... This suggests an alteration of the circadian system per se that could in turn affect the expression of biological rhythms. In ...
But the idea of the biological clock is a recent invention. It first appeared in the late 1970s. "The Clock Is Ticking for the ... Yet, if we examine where the term came from, and how it came to be used, it becomes clear that the idea of the biological clock ... Biological clocks are certainly related to birth control, and I cant say Id ever thought about birth control for military ... Laurie and Debbies blogAngela Hovak Johnson, biological clock, birth control, Body Impolitic, colorism, Denise Oliver Velez, ...
Im Racing My Biological Clock and a Tight-Lipped Boyfriend. Help!. news via NYT , Style ...
Daniel Forger and Charles Peskin explain their mathematical model of the biological clock that replicates the hundreds of clock ... Researchers Simulate Biological Clock. By Will Parker on January 17, 2005 in News ... Biological circadian clocks time daily events with remarkable accuracy - often within seconds each day. However, understanding ... "Without the rapidity of molecular interactions within these cells, the precision of the biological clock would be lost. It is ...
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... because their internal clocks operate on a 20-hour cycle instead of being synchronized with the 24-hour cycle of day and night. ... A new study of molecular interactions central to the functioning of biological clocks explains how certain mutations can ... shorten clock timing, making some people extreme morning larks ... mechanism explains how mutations shorten biological clocks. ... A new study explains how mutations in either CK1 or PERIOD can throw off the timing of biological clocks in animals from fruit ...
... constantly tortured by the ticking clock inside the Crocodiles belly on their way to destroy Neverland. He… ... and the Crocodile is my uterus and its ticking biological clock. I can hear that clock no matter how fast I run, and someday it ... And as my friends continue to get married and have babies, my biological clock keeps ticking louder and louder. ... Listen, biological clock. I hear you, but YOU HAVE GOT TO CHILL. ... if he hadnt swallowed that alarm clock. But now, when hes ...
Men Who Wait to Have Kids Face a Ticking Biological Clock. Like women, a new study shows that mans age is a factor in the ... Your Biological Clock: Planning to Get Pregnant. Dealing with your body and your marriage gets into the picture when youre ... More Women Freeze Eggs to Freeze Biological Clock, says Study. Women have the option to freeze their eggs as a way to preserve ... For many aspiring parents planning to get pregnant, the persistent ticking of a biological clock does not always fall in line ...
Working overtime disturbs biological clock, say researchers. July. 11, 2018 08:17. [email protected]. People who work outside ... "Working overtime for three days is enough to destroy metabolism if the biological clock in the brain and digestive system is ... "Working overtime for three days is enough to destroy metabolism if the biological clock in the brain and digestive system is ... Working overtime disturbs biological clock, say researchers. Posted July. 11, 2018 08:17, ...
... estimate her egg count and provide a real-time assessment of her biological clock. "I just stuck with it over years and made ... but fertility experts now warn that the biological clock starts ticking much earlier than that. "Most women are infertile at 45 ... based upon the chemical structure of AMH will be introduced that slow the ticking of the female ovarian biological clock. " ...
Using a recently developed biomarker of aging known as an epigenetic clock, UCLA researchers working closely with a German team ... Horvath used the clock to measure the biological age of several tissues, and it proved accurate in matching biological to ... Using a novel biological clock, UCLA researchers find that obesity accelerates aging of the liver ... The epigenetic clock, which Horvath developed last year, uses a previously unknown time-keeping mechanism in the body to ...
Know the facts about your own biological clock and your particular ovarian reserve. Call to schedule a consult today. ... Beating Your Biological Clock - How It Works / Beating Your Biological Clock: Antrical Follicle Studies ... Such information would be of great help to young patients, who could relax somewhat about their biological clock if they knew ... Beating Your Biological Clock. Click Here to download Beating Your Biological Clock in PDF format. ...
10/21/2013 - Scientists Discover New Biological Clock With Age-Measuring Potential October 21, 2013. /in Longevity News 2013 / ... A team of scientists from UCLA have discovered a new biological clock with the potential to measure the age of human tissue. ... Scientists Discover New Biological Clock With Age-Measuring Potential. ...
... in vitro fertilization and third-party reproduction have made us rethink the biological clock concept. Recently, the successful ... have a biological fertility clock.". LaLiberte is referring to medical studies highlighting scientific evidence of a possible " ... in vitro fertilization and third-party reproduction have made us rethink the biological clock concept. Recently, the successful ...
Biological Clock Disruptions Sound Alzheimers Alarm. July 27, 2023• By Josh Barney, [email protected] Josh Barney, jdb9a@ ... While our biological clocks normally take cues from light, this adjustment happens gradually, as the body needs time to adapt. ... The new insights into the disruptions of the biological clock seen in Alzheimers could have important potential both for the ... Ferris and her collaborators used a mouse model of Alzheimers to better understand what happens to the biological clock in ...
The Conboy research lab has outlined the problems with existing machine learning-based clocks and created a new clock based on ... the Conboy research lab has outlined the problems with existing machine learning-based clocks and created a new […] ... an artificial intelligence algorithm that powers the majority of biological clocks, including the Horvath biological clock [1 ... This work shifts the dominant paradigm of what is biological age, uncovers that it is not an evenly "ticking clock" or a ...
Women have a hard time deciding who they should see when they are having difficulty conceiving. Many women will first go to their Obstetrician/Gynecologist (OB/GYN). This is usually the first point of contact, when dealing with womens health issues. An OB/GYN cares for and treats the general population as well as a woman when she is pregnant. A Reproductive Endocrinologist, or Fertility Specialist, focuses exclusively on infertility. They work on evaluation, diagnosis, and treatment of all types of infertility. These specialists are best able to fully manage any fertility issues. For millions of women, the road to pregnancy can sometimes be difficult. This is why it is imperative to know when to see a Fertility Specialist and how they can help you.. When should you make an appointment with your Fertility Specialist?. If you are under 35 and have been unable to get pregnant after one year of unprotected intercourse or over 35 and have been unable to get pregnant after 6 months of unprotected ...
... Copertaro A.. Writing - Original Draft ... The master clock of the biological rhythm, located in the suprachiasmatic nucleus of the anterior hypothalamus, synchronizes ... Working against the biological clock: A review for the occupational physician / Copertaro, A.; Bracci, M.. - In: INDUSTRIAL ... The master clock of the biological rhythm, located in the suprachiasmatic nucleus of the anterior hypothalamus, synchronizes ...
  • Other concepts related to biological clock are senescence , circadian clock, epigenetic clock, and molecular clock. (
  • This study indicates that the epigenetic clock can be improved by increasing the training sample size and that its association with mortality attenuates with increased prediction of chronological age. (
  • Besides, whether the reported associations between AAR and health-related traits (e.g., mortality) are inflated (e.g., by potential confounders) and/or affected by the prediction accuracy of 'epigenetic clock' has not been investigated. (
  • One of the first to try, Steve Horvath , a biostatistician and biogerontologist, developed an epigenetic clock that assesses the state of DNA methylation . (
  • For example, the epigenetic clock (PMID: 24138928) is a multivariate age estimation method that applies to sorted cell types (CD4T cells or neurons), complex tissues, and organs and even prenatal brain samples. (
  • We know that our molecular circadian clocks work via biochemical feedback loops with the aptly name PERIOD (PER) protein at the center. (
  • This study reveals an underlying molecular link between our biological clock and the regulation of body weight. (
  • The complex dynamics of biological systems is primarily driven by molecular interactions that underpin the regulatory networks of cells. (
  • An NIH-funded team has some new clues based on evidence showing how a molecular "switch" wired into the biological clocks of extreme early risers leads them to operate on a daily cycle of about 20 hours instead of a full 24-hour, or circadian (Latin for "about a day"), cycle [1]. (
  • The molecular mechanism of circadian clocks has been uncovered by the use of phenotype-driven (forward) genetic analysis in a number of model systems. (
  • Professor David highlights that understanding these molecular mechanisms may provide scientists the essentials to develop therapies for intervening in the clock to alleviate disruptions, whether they are caused by inherited conditions or by shift work or jet lag. (
  • New research indicates this is because the body's 'master clock' in the brain uses different molecular mechanisms to make up for the gain or loss of time. (
  • By figuring out how biological clocks drive sleep and wake cycles, scientists might be able to identify new molecular targets for drugs that treat sleep-related disorders. (
  • Researchers have identified similar genes in people, fruit flies, mice, plants, fungi, and several other organisms that make the clocks' molecular components. (
  • It has been a long standing goal to develop molecular biomarkers of biological age. (
  • Members from the family of CK1 proteins cooperatively regulate the circadian clock. (
  • For example, while CK1D1 accelerates the circadian clock, CK1D2 slows it down. (
  • By shining a light on this key part of how these CK1 proteins work on the circadian clock, we have a better understanding of what we can do when our circadian clock breaks down and problems arise, and the treatments we can develop. (
  • Our body's daily rhythms are synchronized with the sun and coordinated by cells in the brain called a circadian clock. (
  • The body's circadian clock regulates our sleep, body temperature, eating habits and activity levels. (
  • Researchers at the University of Virginia and the Medical College of Wisconsin have found a new link between a circadian clock gene called Nocturnin and obesity. (
  • Circadian clock refers to the various mechanisms that result in a circadian rhythm . (
  • The system is complex, with central clock genes directing the body's rhythms, deciding which proteins are expressed in which tissues at different times of the day. (
  • In mammals, circadian oscillations are generated by a set of genes forming a transcriptional autoregulatory feedback loop: these include: Clock, Bmal1, Per1, Per2, Cry1, Cry2 and Casein kinase 1 epsilon. (
  • The discovery of 'clock genes' also led to the realization that the capacity for circadian gene expression is widespread throughout the body. (
  • Clock genes and clock cells : a new view / Joseph Takahashi. (
  • Genetic factors: several genes (collectively called "clock genes") are involved in this process and any genetic abnormality in them may make it difficult to sleep at certain times. (
  • Genes and proteins run biological clocks that help keep daily rhythms in synch. (
  • Researchers funded by the National Institutes of Health are identifying the genes and proteins that run biological clocks and figuring out exactly how they help keep daily rhythms in synch. (
  • Mutations or changes in certain genes can affect our biological clocks. (
  • Scientists learn about circadian rhythms by studying humans and by using organisms with similar biological clock genes, such as fruit flies and mice. (
  • Their 'ageing clock' was created in 2015 using data collected from 4846 adults and includes 16 blood biomarkers, including cholesterol and glucose levels, as well as gender, blood pressure, body mass index, and lung volume and capacity measurements. (
  • These clocks are intricately regulated by complex mechanisms, the details of which scientists are teasing out. (
  • A biological clock pertains to any of the various mechanisms that regulate biological rhythms such as sleep and wakefulness cycle, body temperature, patterns of hormone secretion, blood pressure, digestive secretions, alertness levels, reaction times, etc. 1 Biological rhythms is the synchronized cyclic pattern demonstrated by an organism as its response to a particular stimulus. (
  • Recent genomewide association studies shed light on the underlying biological mechanisms. (
  • These applications may have as their research focus the chronic, comorbid conditions themselves or TMJMDs, provided that the aims and goals of the project are to discover biological mechanisms linking the comorbidities. (
  • Caption: Casein kinase 1 (CK1) regulates PERIOD, a core protein in the biological clock of people. (
  • In this new study, our team focused on mutations in a protein called casein kinase 1 (CK1), which regulates a core clock protein called PERIOD (PER). (
  • These clocks, found in cells and tissues throughout the body, are composed of specialized sets of proteins. (
  • These molecules are proteins known as clock proteins which interact with cells throughout the body. (
  • A study led by scientists from Duke-NUS Medical School and the University of California Santa Cruz demonstrated how mutations in proteins are able to modify the timing of the biological clock. (
  • Mutations in these proteins that are able to shorten the biological clock timing will have a "morning lark" effect while those that make the clock run longer would cause a pronounced "night owl" effect. (
  • Mutations in either CK1 or PER proteins was able to alter the balance, favouring degradation, thereby disrupting the biological clock. (
  • It is important to understand how these clock proteins regulate our circadian rhythms, because those rhythms affect not only the sleep cycle but almost every aspect of our physiology. (
  • Despite the familiarity with ovarian aging effects on fertility, the male biological clock remains less studied and understood. (
  • While a region of the brain operates as the master biological clock, many tissues in our body have their own clocks. (
  • Individual organs and tissues may undergo different aging processes, but the real challenge is to define a biological clock that applies to the whole organism, and that translates into parameters that are easy to monitor and act upon. (
  • The Nrf2 pathway activation is the mechanism that turns back the biological time clock. (
  • Bruce - Obviously it's quite a complex issue when you're looking at what the actual protective mechanism is on the biological level. (
  • Just as we abide by an external time schedule to eat, sleep, and go to work, our body is similarly dictated by internal clocks. (
  • This biological clock seems to give the organism a sense of time as evidenced by a rhythmic pattern on its behavior. (
  • And at one level, that makes total sense-our planet has operated on a 24-hour clock for the entire span of evolutionary time. (
  • The years between puberty and menopause are the reproductive years most will refer to as the time your 'biological clock' begins ticking. (
  • Much more emotionally charged is the other common meaning of biological clock -- the amount of time a woman who desires pregnancy and childbirth has to achieve those goals before her body becomes unable to accommodate them. (
  • As Biological Clock Day celebrates, both men as well as women have a biological time. (
  • So celebrate Biological Clock Day and set aside some time to re-regulate it. (
  • It's time for us to start listening to our body's internal clock! (
  • In this way, it is the biological clock that sets the time at which the propensity for sleep increases and decreases. (
  • Birds of Prey gallery 2008-2014 is early book the physiological clock endogenous diurnal rhythms to card on date, time, digits, description, and offered seconds for more than 540 lymphocytes and Tools. (
  • By focusing on a clock gene that makes a potassium channel in fruit flies, scientists from New York University discovered that the gene is much more active at dusk than dawn in one biological clock: the key set of pacemaker neurons in the brain that help flies track time. (
  • When you pass through different time zones, your biological clock will be different from the local time. (
  • When you wake up at 7:00 a.m. on the East Coast, your biological clock is still running on West Coast time, so you feel the way you might at 4:00 a.m. (
  • It often takes a few days for your biological clock to align with a new time zone. (
  • Current light-therapy treatments for sleep disturbances include sitting in front of bright lights for hours at a time during the day, which allows you to transition your body clock to a new time zone in small steps prior to taking a trip. (
  • Meanwhile, jet lag, which occurs because your body's clock is still synced to your original time zone, can cause fatigue, lack of alertness, a general feeling of malaise and sometimes gastrointestinal problems. (
  • When these biological clocks fail to work as they should, our bodies are out of phase with the outside world and this leads to many problems, not only sleep disorders but obesity, cancer and mental health issues as well. (
  • When our biological clock is disrupted, it can cause sleep disorders and a host of other problems, including obesity, depression, heart disease, high blood pressure and diabetes. (
  • They also may lead to new treatments designed to reset the clock in people struggling with sleep disorders, jet lag, or night-shift work. (
  • Mechanistic understanding of the regulators of the human biological clock can provide scientists with the key to developing therapies for sleep disorders. (
  • This knowledge could aid the development of remedies for a range of clock-related disorders, from insomnia and jet lag to diabetes. (
  • Scientists have long suspected that diabetes, obesity and other metabolic disorders could be linked to problems with biological clocks, and new scientific findings support this. (
  • The clock is ticking, and to make matters worse, Rachel's younger sister (Yamée Couture) finds herself pregnant by accident. (
  • Learn more about the ticking of your biological clock with this educational video. (
  • Is my biological clock ticking? (
  • As women, we know immediately that expression "your biological clock is ticking" and it can throw us into the fight or flight stress response. (
  • Feeling that the clock is ticking is inducing an unnecessary stress response and you will make poor decisions. (
  • Delaying pregnancy: can we test how fast the biological clock is ticking? (
  • There's no biological clock ticking. (
  • Scientists from the University of Massachusetts Medical School and the University of Washington learned this by exposing hamsters-another organism used in sleep research-to conditions that advanced or delayed the biological clock. (
  • The biological age of an organism is a significant indicator of health status and susceptibility to illness. (
  • Therefore, when one wants to pay attention to the ongoing aging processes in the organism in order to prevent and slow them down, one must refer to biological age Different from chronological age. (
  • Therefore, defining a biological clock that can measure the true ageing of an organism is complex. (
  • Feb. 17, 2022 An international team has discovered a protein that plays a key biological role in a parasite that causes malaria. (
  • It is composed of a central pacemaker located in the brain and additional biological clocks throughout the body and is key for coordinating many bodily functions. (
  • It builds on decades of research into biological clocks, which help to control sleeping and waking, rest and activity, fluid balance, body temperature, cardiac rate, oxygen consumption, and even the secretions of endocrine glands. (
  • In humans, a region in the hypothalamus called the Suprachiasmatic Nucleus controls our body clock. (
  • Variations in light levels help us to synchronize our circadian rhythms with the Earth's day/night cycle, keeping our body clocks accurate. (
  • Research has found that without day/night cues, our body clocks can drift, with different body functions falling out of synch with each other. (
  • The more complete files thought to act those that did their book the physiological clock endogenous diurnal body to the accessible language fanatics of their idea apparatus and submitted readers trying in their tax. (
  • That's because your body has its own network of tiny, coordinated biological clocks. (
  • These clocks are responsible for our circadian rhythms, the roughly 24-hour cycles of physical, mental and behavioral changes that influence sleep patterns, hormone release, body temperature, hunger and more. (
  • Researchers at Hong Kong start-up - Deep Longevity, from Stanford University and the Chinese University of Hong Kong, have created a digital model of human ageing, proving the importance of mental health to the biological age of the body. (
  • In addition, phthalates are a common environmental exposure (see sidebar), which when present in high concentrations in the body have been associated with sperm epigenetic profiles in biological pathways known to be important for early embryonic development. (
  • Related studies indicate that the clock-dependent nocturnal increase in AA-NAT mRNA requires gene expression but not de novo protein synthesis, and that AA-NAT mRNA levels are suppressed at all times of the day by a rapidly turning over protein. (
  • Clock-altering mutations in CK1 and PERIOD have been known for many years. (
  • Clock-altering mutations in CK1 had been known for years, but it was unclear how they changed the timing of the clock," said Dr Rajesh Narasimamurthy, Principal Research Scientist at the Duke-NUS' Cancer and Stem Cell Biology (CSCB) programme. (
  • An international team of researchers found that CK1 is the priming kinase that 'switches on' a key control point which plays an important role in regulating our biological clock. (
  • Researchers have identified a key role for the circadian system-the biological clock that controls your sleep/wake cycle-that may help explain why asthma symptoms worsen at night. (
  • Here we present evidence that the chick pineal clock generates a rhythm in the abundance of AA-NAT mRNA in cultured cells that parallels the rhythm in AA-NAT activity. (
  • More recently, they discovered that a small molecule dubbed KL001 controls cryptochrome in such a way that it can slow the liver's biological clock and prevent excess sugar production by liver cells, particularly during fasting states. (
  • In vertebrate animals, including humans, the master clock is a group of about 20,000 nerve cells (neurons) that form a structure called the suprachiasmatic nucleus, or SCN. (
  • Scientists report a new link between a gene that controls the body's biological clock and weight gain. (
  • A team of scientists from UCLA have discovered a new biological clock with the potential to measure the age of human tissue. (
  • Hormonal factors: different hormonal changes which occur during menstruation, menopause, but also in some endocrine diseases, can alter the function of the biological clock. (
  • When activated, the biological clock sends a signal to the pineal gland, located next to the brain, to begin the production of melatonin. (
  • Biological clock that synchronizes with biological rhythm may be endogenous or exogenous. (
  • An endogenous type is one in which the internal biological clock is the one that controls it. (
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  • Previous research has suggested that a 'priming' kinase is required to 'switch on' the FASP site, a key control point that plays an important role in regulating our biological clock. (
  • Arthur T. Winfree, 60, who was known for his studies of biological rhythms -- work that affected research in heart rhythms, arrhythmia and sleep patterns -- died of cancer Nov. 5 at his home in Tucson. (
  • However, it is not necessarily a good predictor of biological ageing since individuals with the same chronological age can vary in health, especially in later life [ 3 ]. (
  • These clocks utilize age acceleration residuals (AAR, defined as the residuals from regressing predicted age on chronological age) as a biomarker of ageing[ 7 ]. (
  • biological age Different from chronological age. (
  • Added to this, then, is the fact that each organ proceeds independently, may be subject to different risk factors, and may therefore have a different biological age Different from chronological age. (
  • In general, however, to calculate a person's biological age Different from chronological age. (
  • By studying fruit flies, which have a very similar genetic makeup to humans, they isolated a gene that helps control the body's clock. (
  • Many computing systems rely on switches and clocks as computational modules. (
  • An introduction to the mathematical, computational, and analytical techniques used for modeling biological rhythms, presenting tools from many disciplines and example applications. (
  • Biological clock may also pertain to female fertility wherein there is a gradual decrease of fertility from puberty to menopause. (
  • Winfree, a University of Arizona professor of ecology and evolutionary biology, helped develop an understanding of how the human biological clock could be synchronized and slightly reset, an idea that led to his designing a program by which travelers might avoid jet lag. (
  • Here we present a historical perspective on computation by biological systems, with a focus on switches and clocks, and discuss parallels between biology and computing. (
  • When speaking of the routine of daily life, and how we live it, biological clock is a plain-language synonym for the more scientific term circadian rhythm s . (
  • Nearly every tissue and organ contains biological clocks. (
  • In the latest paper, Partch and her colleagues focused on two core clock components: an enzyme known as casein kinase 1 (CK1) and a protein called PERIOD. (
  • Human biological clocks are a network of specific molecules that interact to produce the circadian rhythm. (
  • How do I know if my insomnia problem is due to the brain clock malfunctioning? (
  • A master clock in the brain coordinates all the biological clocks in a living thing, keeping the clocks in sync. (
  • It's a kind of "biological hacking" that fools the brain into thinking the day is longer while you get to sleep, Zeitzer said. (
  • With consistent NIH funding since 2007, he has studied how environmental tobacco smoke induces inflammation by disrupting biological processes known as circadian rhythms. (
  • I think my biological clock knows that and I do my work just fine during the night. (
  • Conversely, a switch that favors a slower breakdown will lengthen the clock, predisposing some to be night owls. (
  • Light from electronic devices at night can confuse our biological clocks. (
  • By conducting light therapy at night, the brain's biological clock gets tricked into adjusting to an awake cycle even when asleep. (
  • This may also help to explain difficulties such as SAD , where a lack of natural light in the winter months allows the body's clock to drift out of proper phase, causing depression and moodiness. (
  • The sciences that study biological living organisms. (
  • The study found that a sequence of 2-millisecond flashes of light, similar to a camera flash, 10 seconds apart elicited a nearly two-hour delay in the onset of sleepiness, the most efficient and fastest method of adjusting the internal clock. (
  • In this case, people easily and correctly align their internal clocks to the daily coming and going of daylight. (
  • Now, in paragraph E, the first few lines provide us with the answer, " If a life span is a genetically determined biological characteristic, it is logically necessary to propose the existence of an internal clock , which in some way measures and controls the ageing process and which finally determines death as the last step in a fixed programme. (
  • The biological clock is an alarming, continuous ghost that haunts many women who want to have children, especially those who are sailing through the business world and other priorities well into their 30s. (
  • These results suggest that clock-controlled changes in AA-NAT activity occur primarily through changes at the mRNA level, whereas cAMP-controlled changes occur primarily through changes at the protein level. (
  • 0001). For each 1-year increase in father's age, newborn LTL increased by 0.016 kb (95% confidence interval: 0.04 to 0.28) (P = .0086).The large LTL variation across newborns challenges the telomeric clock model. (
  • The Daily Mail tells us with giddy delight that 'it is not just women that have to worry about their biological clock' . (
  • The clock is an ominous reference to the fact that the number of viable eggs that women produce declines - rapidly for some - as they age. (
  • It is always important to keep in mind that insomnia may frequently be due to abnormal functioning of the biological clock, rather than inadequate relaxation or poor stress management. (
  • In essence, these molecules together act as a microscopic clock timed to waxing and waning sunlight. (
  • Thus, in natural conditions, the biological clock is activated at the end of the day by the decreasing light signal, so we notice the feeling of sleepiness a few hours later. (
  • Biological clocks are organisms' natural timing devices, regulating the cycle of circadian rhythms. (
  • Such shifts in clock timing can arise from alterations either to the CK1 enzyme or the PERIOD protein. (