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.
A genus of hamsters characterized by small size, very short tail, and short, broad feet with hairy soles.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
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).
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
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.
A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.
The total process by which organisms produce offspring. (Stedman, 25th ed)
Achievement of full sexual capacity in animals and in humans.
The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.
A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.
A genus of the subfamily SIGMODONTINAE consisting of 49 species. Two of these are widely used in medical research. They are P. leucopus, or the white-footed mouse, and P. maniculatus, or the deer mouse.
The reproductive organs of plants.
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.
A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.
The measurement of an organ in volume, mass, or heaviness.
A saclike, glandular diverticulum on each ductus deferens in male vertebrates. It is united with the excretory duct and serves for temporary storage of semen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
The absence of light.
Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.
The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.
A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.
A genus of the family Muridae having three species. The present domesticated strains were developed from individuals brought from Syria. They are widely used in biomedical research.
A state in which the environs of hospitals, laboratories, domestic and animal housing, work places, spacecraft, and other surroundings are under technological control with regard to air conditioning, heating, lighting, humidity, ventilation, and other ambient features. The concept includes control of atmospheric composition. (From Jane's Aerospace Dictionary, 3d ed)
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.
Molecule produced in plant leaves that acts like a hormone by inducing flowering in the shoot apical meristem of buds and growing tips.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.
The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.
The functions and activities of living organisms that support life in single- or multi-cellular organisms from their origin through the progression of life.
Adaptation to a new environment or to a change in the old.
A state of decreased activity in animals characterized by depressed metabolism, reduced body temperature, and low sensitivity to external stimuli.
Sexual activities of animals.
The family Sturnidae, in the order PASSERIFORMES. The starling family also includes mynahs and oxpeckers.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
An infraclass of MAMMALS, also called Metatheria, where the young are born at an early stage of development and continue to develop in a pouch (marsupium). In contrast to Eutheria (placentals), marsupials have an incomplete PLACENTA.
A state of sexual inactivity in female animals exhibiting no ESTROUS CYCLE. Causes of anestrus include pregnancy, presence of offspring, season, stress, and pathology.
The gamete-producing glands, OVARY or TESTIS.
Bouts of physical irritability or movement alternating with periods of quiescence. It includes biochemical activity and hormonal activity which may be cellular. These cycles are shorter than 24 hours and include sleep-wakefulness cycles and the periodic activation of the digestive system.
The family Passeridae comprised of small, mainly brown and grey seed-eating birds with conical bills.
Periodic casting off FEATHERS; HAIR; or cuticle. Molting is a process of sloughing or desquamation, especially the shedding of an outer covering and the development of a new one. This phenomenon permits growth in ARTHROPODS, skin renewal in AMPHIBIANS and REPTILES, and the shedding of winter coats in BIRDS and MAMMALS.
The functional hereditary units of PLANTS.
A plant family of the order Caryophyllales, subclass Caryophyllidae, class Magnoliopsida. There are no true petals; each flower has two to six sepals. They produce betacyanin and betaxanthin pigments and lack anthocyanins.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
The male reproductive organs. They are divided into the external organs (PENIS; SCROTUM;and URETHRA) and the internal organs (TESTIS; EPIDIDYMIS; VAS DEFERENS; SEMINAL VESICLES; EJACULATORY DUCTS; PROSTATE; and BULBOURETHRAL GLANDS).
A mammalian order which consists of 29 families and many genera.
The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.
The horn of an animal of the deer family, typically present only in the male. It differs from the HORNS of other animals in being a solid, generally branched bony outgrowth that is shed and renewed annually. The word antler comes from the Latin anteocularis, ante (before) + oculus (eye). (From Webster, 3d ed)
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.
Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.
Highly keratinized processes that are sharp and curved, or flat with pointed margins. They are found especially at the end of the limbs in certain animals.
An order of insects comprising three suborders: Anisoptera, Zygoptera, and Anisozygoptera. They consist of dragonflies and damselflies.
Elements of limited time intervals, contributing to particular results or situations.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
A genus of aquatic newts in the Salamandridae family. During breeding season many Triturus males have a dorsal crest which also serves as an accessory respiratory organ. One of the common Triturus species is Triturus cristatus (crested newt).
Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
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.
A small, unpaired gland situated in the SELLA TURCICA. It is connected to the HYPOTHALAMUS by a short stalk which is called the INFUNDIBULUM.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
The surgical removal of one or both ovaries.
Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
Surgical removal or artificial destruction of gonads.
A class of plant growth hormone isolated from cultures of Gibberella fujikuroi, a fungus causing Bakanae disease in rice. There are many different members of the family as well as mixtures of multiple members; all are diterpenoid acids based on the gibberellane skeleton.
The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.
The withholding of food in a structured experimental situation.
An absence of warmth or heat or a temperature notably below an accustomed norm.
A family of the order PRIMATES, suborder Strepsirhini (PROSIMII), containing five genera. All inhabitants of Madagascar, the genera are: Allocebus, Cheirogaleus (dwarf lemurs), Microcebus (mouse lemurs), Mirza, and Phaner.
Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.
The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.
The surgical removal of one or both testicles.
The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.
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.
A blue-green biliprotein widely distributed in the plant kingdom.
A family of herbivorous leaping MAMMALS of Australia, New Guinea, and adjacent islands. Members include kangaroos, wallabies, quokkas, and wallaroos.
The dormant state in which some warm-blooded animal species pass the winter. It is characterized by narcosis and by sharp reduction in body temperature and metabolic activity and by a depression of vital signs.
An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.
A plant photo regulatory protein that exists in two forms that are reversibly interconvertible by LIGHT. In response to light it moves to the CELL NUCLEUS and regulates transcription of target genes. Phytochrome B plays an important role in shade avoidance and mediates plant de-etiolation in red light.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
Any of numerous agile, hollow-horned RUMINANTS of the genus Capra, in the family Bovidae, closely related to the SHEEP.

Prolactin replacement fails to inhibit reactivation of gonadotropin secretion in rams treated with melatonin under long days. (1/1549)

This study tested the hypothesis that prolactin (PRL) inhibits gonadotropin secretion in rams maintained under long days and that treatment with melatonin (s.c. continuous-release implant; MEL-IMP) reactivates the reproductive axis by suppressing PRL secretion. Adult Soay rams were maintained under long days (16L:8D) and received 1) no further treatment (control, C); 2) MEL-IMP for 16 wk and injections of saline/vehicle for the first 8 wk (M); 3) MEL-IMP for 16 wk and exogenous PRL (s.c. 5 mg ovine PRL 3x daily) for the first 8 wk (M+P). The treatment with melatonin induced a rapid increase in the blood concentrations of FSH and testosterone, rapid growth of the testes, an increase in the frequency of LH pulses, and a decrease in the LH response to N-methyl-D,L-aspartic acid. The concomitant treatment with exogenous PRL had no effect on these reproductive responses but caused a significant delay in the timing of the sexual skin color and growth of the winter pelage. These results do not support the hypothesis and suggest that PRL at physiological long-day concentrations, while being totally ineffective as an inhibitor of gonadotropin secretion, acts in the peripheral tissues and skin to maintain summer characteristics.  (+info)

The localisation of 2-carboxy-D-arabinitol 1-phosphate and inhibition of Rubisco in leaves of Phaseolus vulgaris L. (2/1549)

A recent controversial report suggests that the nocturnal inhibitor of Rubisco, 2-carboxy-D-arabinitol 1-phosphate (CAIP), does not bind to Rubisco in vivo and therefore that CA1P has no physiological relevance to photosynthetic regulation. It is now proved that a direct rapid assay can be used to distinguish between Rubisco-bound and free CA1P, as postulated in the controversial report. Application of this direct assay demonstrates that CA1P is bound to Rubisco in vivo in dark-adapted leaves. Furthermore, CA1P is shown to be in the chloroplasts of mesophyll cells. Thus, CA1P does play a physiological role in the regulation of Rubisco.  (+info)

Intrapreoptic microinjection of GHRH or its antagonist alters sleep in rats. (3/1549)

Previous reports indicate that growth hormone-releasing hormone (GHRH) is involved in sleep regulation. The site of action mediating the nonrapid eye movement sleep (NREMS)-promoting effects of GHRH is not known, but it is independent from the pituitary. GHRH (0.001, 0. 01, and 0.1 nmol/kg) or a competitive antagonist of GHRH (0.003, 0.3, and 14 nmol/kg) was microinjected into the preoptic area, and the sleep-wake activity was recorded for 23 hr after injection in rats. GHRH elicited dose-dependent increases in the duration and in the intensity of NREMS compared with that in control records after intrapreoptic injection of physiological saline. The antagonist decreased the duration and intensity of NREMS and prolonged sleep latency. Consistent alterations in rapid eye movement sleep (REMS) and in brain temperature were not found. The GHRH antagonist also attenuated the enhancements in NREMS elicited by 3 hr of sleep deprivation. Histological verification of the injection sites showed that the majority of the effective injections were in the preoptic area and the diagonal band of Broca. The results indicate that the preoptic area mediates the sleep-promoting activity of GHRH.  (+info)

Hypoglycemia and torpor in Siberian hamsters. (4/1549)

We tested whether reduced blood glucose concentrations are necessary and sufficient for initiation of torpor in Siberian hamsters. During spontaneous torpor bouts, body temperature (Tb) decreases from the euthermic value of 37 to <31 degrees C. Among hamsters that displayed torpor during maintenance in a short-day length (10 h light/day) at an air temperature of 15 degrees C, blood glucose concentrations decreased significantly by 28% as Tb fell from 37 to <31 degrees C and increased during rewarming so that by the time Tb first was >36 degrees C, glucose concentrations had returned to the value preceding torpor. Hamsters did not display torpor when maintained in a long-day length (16 h light/day) and injected with a range of insulin doses (1-50 U/kg body mass), some of which resulted in sustained, pronounced hypoglycemia. We conclude that changes in blood glucose concentrations may be a consequence rather than a cause of the torpid state and question whether induction of torpor by 2-deoxy-D-glucose is due to its general glucoprivic actions.  (+info)

Phenotypic differences in the GnRH neuronal system of deer mice Peromyscus maniculatus under a natural short photoperiod. (5/1549)

The neural mechanisms by which short photoperiod induces gonadal regression among seasonally breeding mammals are not well understood. One hypothesis suggests that the proximate cause of seasonal gonadal regression is a photoperiod-induced modification in GnRH secretion. This hypothesis is indirectly supported by our recent findings using immunocytochemistry which identified specific photoperiod-induced adjustments in the number and morphology of GnRH containing neurones between reproductively competent and reproductively regressed laboratory housed male deer mice. Herein, we report that the GnRH neuronal system is similarly affected in reproductively responsive and nonresponsive wild male deer mice Peromyscus maniculatus exposed to a natural short photoperiod. The distribution of immunoreactive (IR)-GnRH neurones was nearly identical in field caught animals and those housed under artificial photoperiod in the laboratory. Compared with reproductively nonresponsive males, reproductively responsive mice from the field population possessed a greater total number of IR-GnRH neurones, a greater number of IR-GnRH neurones within the lateral hypothalamus, and a greater proportion of bipolar IR-GnRH neurones. Each of these distributional and morphological characters was consistent with our findings in laboratory housed male deer mice exposed to an artificial short photoperiod. Taken together, these data underscore the validity of using an artificial photoperiod to evaluate seasonal adjustments in reproductive function in the laboratory.  (+info)

Annual cycle in LH and testosterone release in response to GnRH challenge in male woodchucks (Marmota monax). (6/1549)

Testosterone and LH concentrations were determined in serum samples obtained before and 15 min after injections of GnRH (1 microgram kg-1) administered at 4-7 week intervals over 20 months to groups of male woodchucks (n = 6-7) born and maintained in Northern Hemisphere (boreal) versus Southern Hemisphere (austral) simulated natural photoperiods, beginning at 18-24 months of age. Nadir and peak unstimulated testosterone (0.1 +/- 0.01 and 7.0 +/- 0.1 ng ml-1, respectively) and LH (0.8 +/- 0.2 and 8.1 +/- 1.1 ng ml-1, respectively) concentrations did not differ in boreal versus austral males. In the five boreal and five austral males that were confirmed to be photoentrained, basal (pre-GnRH) concentrations of LH and testosterone were lowest in summer, increased simultaneously in late autumn or early winter, and declined in the spring. GnRH stimulated some LH release throughout the year except for a 1-4 month period in the summer. The initial annual increase in the LH response to GnRH occurred in early autumn, and in 17 of 20 cycles it occurred 1-2 months before the initial increase in basal LH was detected. In the three free-running males not entrained to the photoperiod, the endocrine patterns were similar but were advanced by several months. The results demonstrate that in woodchucks there is a late autumn increase in LH secretion associated with the onset of testicular recrudescence, and an early autumn increase in pituitary response to GnRH before a detectable increase in serum testosterone.  (+info)

Abnormal photoresponses and light-induced apoptosis in rods lacking rhodopsin kinase. (7/1549)

Phosphorylation is thought to be an essential first step in the prompt deactivation of photoexcited rhodopsin. In vitro, the phosphorylation can be catalyzed either by rhodopsin kinase (RK) or by protein kinase C (PKC). To investigate the specific role of RK, we inactivated both alleles of the RK gene in mice. This eliminated the light-dependent phosphorylation of rhodopsin and caused the single-photon response to become larger and longer lasting than normal. These results demonstrate that RK is required for normal rhodopsin deactivation. When the photon responses of RK-/- rods did finally turn off, they did so abruptly and stochastically, revealing a first-order backup mechanism for rhodopsin deactivation. The rod outer segments of RK-/- mice raised in 12-hr cyclic illumination were 50% shorter than those of normal (RK+/+) rods or rods from RK-/- mice raised in constant darkness. One day of constant light caused the rods in the RK-/- mouse retina to undergo apoptotic degeneration. Mice lacking RK provide a valuable model for the study of Oguchi disease, a human RK deficiency that causes congenital stationary night blindness.  (+info)

Long-day up-regulation of a GAMYB gene during Lolium temulentum inflorescence formation. (8/1549)

Long-day exposure of the grass Lolium temulentum may regulate flowering via changes in gibberellin (GA) levels. Therefore, we have examined both GA levels and expression of a MYB transcription factor that is specific to the GA signal transduction pathway in monocots. This MYB gene from L. temulentum shows over 90% nucleotide identity with the barley and rice GAMYB genes, and, like them, gibberellic acid (GA3) up-regulates its expression in the seed. Furthermore, cDNAs of both the barley and L. temulentum GAMYB show the same simple patterns of hybridization with digests of L. temulentum genomic DNA. Compared with vegetative shoot apices of L. temulentum, the in situ mRNA expression of LtGAMYB does not change during the earliest steps of "floral" initiation at the apex. However, by 100 h (the double-ridge stage of flowering) its expression increased substantially and was highest in the terminal and lateral spikelet sites. Thereafter, expression declined overall but then increased within stamen primordia. Prior to increased LtGAMYB expression, long-day exposure sufficient to induce flowering led to increased (5- to 20-fold) levels of GA1 and GA4 in the leaf. Thus, increases first in GA level in the leaf followed by increased expression of LtGAMYB in the apex suggest important signaling and/or response roles in flowering.  (+info)

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.

"Phodopus" is not a medical term, but a taxonomic genus that includes several species of small rodents commonly known as hamsters. The most common species within this genus are the Campbell's dwarf hamster (Phodopus campbelli) and the Djungarian or Russian winter white hamster (Phodopus sungorus). These hamsters are often kept as pets and may be involved in biomedical research. However, they are not typically associated with medical conditions or treatments.

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'.

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.

I'm sorry for any confusion, but "seasons" is not a term that has a medical definition. Seasons refer to the four divisions of the year (spring, summer, autumn or fall, and winter) based on the position of the earth in its orbit around the sun. If you have any questions related to health or medicine, I'd be happy to try to help answer those!

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.

Arvicolinae is a subfamily of rodents that includes voles, lemmings, and muskrats. These small mammals are characterized by their short legs, rounded bodies, and short tails. They are primarily found in the northern hemisphere, with the majority of species living in North America and Eurasia.

Arvicolines are known for their high reproductive rate and ability to survive in a variety of habitats, including grasslands, forests, tundra, and wetlands. They have a unique set of teeth called hypsodont teeth, which continue to grow throughout their lives. This adaptation allows them to wear down their teeth as they gnaw on tough plant material.

Many arvicoline species are important prey animals for larger predators, such as hawks, owls, and foxes. Some species, like the muskrat, are also hunted by humans for their fur or meat. In recent years, some arvicoline populations have experienced dramatic fluctuations in size due to changes in their habitats and food supplies, leading to concerns about their conservation status.

Reproduction, in the context of biology and medicine, refers to the process by which organisms produce offspring. It is a complex process that involves the creation, development, and growth of new individuals from parent organisms. In sexual reproduction, this process typically involves the combination of genetic material from two parents through the fusion of gametes (sex cells) such as sperm and egg cells. This results in the formation of a zygote, which then develops into a new individual with a unique genetic makeup.

In contrast, asexual reproduction does not involve the fusion of gametes and can occur through various mechanisms such as budding, fragmentation, or parthenogenesis. Asexual reproduction results in offspring that are genetically identical to the parent organism.

Reproduction is a fundamental process that ensures the survival and continuation of species over time. It is also an area of active research in fields such as reproductive medicine, where scientists and clinicians work to understand and address issues related to human fertility, contraception, and genetic disorders.

Sexual maturation is the process of physical development during puberty that leads to the ability to reproduce. This process involves the development of primary and secondary sexual characteristics, changes in hormone levels, and the acquisition of reproductive capabilities. In females, this includes the onset of menstruation and the development of breasts and hips. In males, this includes the deepening of the voice, growth of facial hair, and the production of sperm. Achieving sexual maturation is an important milestone in human development and typically occurs during adolescence.

The testis, also known as the testicle, is a male reproductive organ that is part of the endocrine system. It is located in the scrotum, outside of the abdominal cavity. The main function of the testis is to produce sperm and testosterone, the primary male sex hormone.

The testis is composed of many tiny tubules called seminiferous tubules, where sperm are produced. These tubules are surrounded by a network of blood vessels, nerves, and supportive tissues. The sperm then travel through a series of ducts to the epididymis, where they mature and become capable of fertilization.

Testosterone is produced in the Leydig cells, which are located in the interstitial tissue between the seminiferous tubules. Testosterone plays a crucial role in the development and maintenance of male secondary sexual characteristics, such as facial hair, deep voice, and muscle mass. It also supports sperm production and sexual function.

Abnormalities in testicular function can lead to infertility, hormonal imbalances, and other health problems. Regular self-examinations and medical check-ups are recommended for early detection and treatment of any potential issues.

The pineal gland, also known as the epiphysis cerebri, is a small endocrine gland located in the brain. It is shaped like a pinecone, hence its name, and is situated near the center of the brain, between the two hemispheres, attached to the third ventricle. The primary function of the pineal gland is to produce melatonin, a hormone that helps regulate sleep-wake cycles and circadian rhythms in response to light and darkness. Additionally, it plays a role in the onset of puberty and has been suggested to have other functions related to cognition, mood, and reproduction, although these are not as well understood.

"Peromyscus" is not a medical term, but a genus of rodents commonly known as "deer mice." They are small mammals that belong to the family Cricetidae and are found in various parts of North America. Peromyscus mice can carry and transmit diseases, such as Hantavirus Pulmonary Syndrome (HPS), although they are not typically referred to in a medical context unless discussing potential zoonotic risks.

I'm sorry for any confusion, but "flowers" is not a term that has a medical definition. The term "flowers" is commonly used to refer to the reproductive structures of flowering plants (angiosperms), which are characterized by having both male and female reproductive organs or separate male and female flowers.

If you have any questions related to medical terminology or health conditions, I would be happy to try to help answer those for you!

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.

Prolactin is a hormone produced by the pituitary gland, a small gland located at the base of the brain. Its primary function is to stimulate milk production in women after childbirth, a process known as lactation. However, prolactin also plays other roles in the body, including regulating immune responses, metabolism, and behavior. In men, prolactin helps maintain the sexual glands and contributes to paternal behaviors.

Prolactin levels are usually low in both men and non-pregnant women but increase significantly during pregnancy and after childbirth. Various factors can affect prolactin levels, including stress, sleep, exercise, and certain medications. High prolactin levels can lead to medical conditions such as amenorrhea (absence of menstruation), galactorrhea (spontaneous milk production not related to childbirth), infertility, and reduced sexual desire in both men and women.

Organ size refers to the volume or physical measurement of an organ in the body of an individual. It can be described in terms of length, width, and height or by using specialized techniques such as imaging studies (like CT scans or MRIs) to determine the volume. The size of an organ can vary depending on factors such as age, sex, body size, and overall health status. Changes in organ size may indicate various medical conditions, including growths, inflammation, or atrophy.

The seminal vesicles are a pair of glands located in the male reproductive system, posterior to the urinary bladder and superior to the prostate gland. They are approximately 5 cm long and have a convoluted structure with many finger-like projections called infoldings. The primary function of seminal vesicles is to produce and secrete a significant portion of the seminal fluid, which makes up the bulk of semen along with spermatozoa from the testes and fluids from the prostate gland and bulbourethral glands.

The secretion of the seminal vesicles is rich in fructose, which serves as an energy source for sperm, as well as various proteins, enzymes, vitamins, and minerals that contribute to maintaining the optimal environment for sperm survival, nourishment, and transport. During sexual arousal and ejaculation, the smooth muscles in the walls of the seminal vesicles contract, forcing the stored secretion into the urethra, where it mixes with other fluids before being expelled from the body as semen.

Luteinizing Hormone (LH) is a glycoprotein hormone, which is primarily produced and released by the anterior pituitary gland. In women, a surge of LH triggers ovulation, the release of an egg from the ovaries during the menstrual cycle. During pregnancy, LH stimulates the corpus luteum to produce progesterone. In men, LH stimulates the testes to produce testosterone. It plays a crucial role in sexual development, reproduction, and maintaining the reproductive system.

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.

I apologize, but "sheep" is not a term that has a medical definition. It is a common animal with the scientific name Ovis aries. If you have any medical or health-related questions, I would be happy to try and help answer those for you.

I'm sorry for any confusion, but "lighting" does not have a specific medical definition. In a general context, lighting refers to the arrangement or use of light sources to achieve a particular effect or atmosphere. However, if you are referring to a term in medicine that may be similar to "lighting," you might be thinking of "lumination" or "illumination," which refer to the act of providing or admitting light, especially for medical examination or surgical procedures. I hope this helps! If you have any other questions, please don't hesitate to ask.

Testosterone is a steroid hormone that belongs to androsten class of hormones. It is primarily secreted by the Leydig cells in the testes of males and, to a lesser extent, by the ovaries and adrenal glands in females. Testosterone is the main male sex hormone and anabolic steroid. It plays a key role in the development of masculine characteristics, such as body hair and muscle mass, and contributes to bone density, fat distribution, red cell production, and sex drive. In females, testosterone contributes to sexual desire and bone health. Testosterone is synthesized from cholesterol and its production is regulated by luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

"Mesocricetus" is a genus of rodents, more commonly known as hamsters. It includes several species of hamsters that are native to various parts of Europe and Asia. The best-known member of this genus is the Syrian hamster, also known as the golden hamster or Mesocricetus auratus, which is a popular pet due to its small size and relatively easy care. These hamsters are burrowing animals and are typically solitary in the wild.

"Controlled Environment" is a term used to describe a setting in which environmental conditions are monitored, regulated, and maintained within certain specific parameters. These conditions may include factors such as temperature, humidity, light exposure, air quality, and cleanliness. The purpose of a controlled environment is to ensure that the conditions are optimal for a particular activity or process, and to minimize the potential for variability or contamination that could affect outcomes or results.

In medical and healthcare settings, controlled environments are used in a variety of contexts, such as:

* Research laboratories: To ensure consistent and reproducible experimental conditions for scientific studies.
* Pharmaceutical manufacturing: To maintain strict quality control standards during the production of drugs and other medical products.
* Sterile fields: In operating rooms or cleanrooms, to minimize the risk of infection or contamination during surgical procedures or sensitive medical operations.
* Medical storage: For storing temperature-sensitive medications, vaccines, or specimens at specific temperatures to maintain their stability and efficacy.

Overall, controlled environments play a critical role in maintaining safety, quality, and consistency in medical and healthcare settings.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Estrus is a term used in veterinary medicine to describe the physiological and behavioral state of female mammals that are ready to mate and conceive. It refers to the period of time when the female's reproductive system is most receptive to fertilization.

During estrus, the female's ovaries release one or more mature eggs (ovulation) into the fallopian tubes, where they can be fertilized by sperm from a male. This phase of the estrous cycle is often accompanied by changes in behavior and physical appearance, such as increased vocalization, restlessness, and swelling of the genital area.

The duration and frequency of estrus vary widely among different species of mammals. In some animals, such as dogs and cats, estrus occurs regularly at intervals of several weeks or months, while in others, such as cows and mares, it may only occur once or twice a year.

It's important to note that the term "estrus" is not used to describe human reproductive physiology. In humans, the equivalent phase of the menstrual cycle is called ovulation.

Florigen is not a term used in human medicine, but it is a concept in plant biology. It refers to a hypothetical mobile flowering hormone that is produced in leaves and translocated to the shoot apical meristem to promote flowering. The exact chemical identity of florigen is still under investigation, but recent research suggests that it may consist of a complex of proteins called FLOWERING LOCUS T (FT) and FD.

Gene expression regulation in plants refers to the processes that control the production of proteins and RNA from the genes present in the plant's DNA. This regulation is crucial for normal growth, development, and response to environmental stimuli in plants. It can occur at various levels, including transcription (the first step in gene expression, where the DNA sequence is copied into RNA), RNA processing (such as alternative splicing, which generates different mRNA molecules from a single gene), translation (where the information in the mRNA is used to produce a protein), and post-translational modification (where proteins are chemically modified after they have been synthesized).

In plants, gene expression regulation can be influenced by various factors such as hormones, light, temperature, and stress. Plants use complex networks of transcription factors, chromatin remodeling complexes, and small RNAs to regulate gene expression in response to these signals. Understanding the mechanisms of gene expression regulation in plants is important for basic research, as well as for developing crops with improved traits such as increased yield, stress tolerance, and disease resistance.

Body weight is the measure of the force exerted on a scale or balance by an object's mass, most commonly expressed in units such as pounds (lb) or kilograms (kg). In the context of medical definitions, body weight typically refers to an individual's total weight, which includes their skeletal muscle, fat, organs, and bodily fluids.

Healthcare professionals often use body weight as a basic indicator of overall health status, as it can provide insights into various aspects of a person's health, such as nutritional status, metabolic function, and risk factors for certain diseases. For example, being significantly underweight or overweight can increase the risk of developing conditions like malnutrition, diabetes, heart disease, and certain types of cancer.

It is important to note that body weight alone may not provide a complete picture of an individual's health, as it does not account for factors such as muscle mass, bone density, or body composition. Therefore, healthcare professionals often use additional measures, such as body mass index (BMI), waist circumference, and blood tests, to assess overall health status more comprehensively.

Physiological processes refer to the functional activities or functions of living organisms and their parts, including cells, tissues, and organs. These processes are necessary for the maintenance of life and include various functions such as:

1. Metabolism: the sum of all chemical reactions that occur in the body to maintain life, including anabolic (building up) and catabolic (breaking down) processes.
2. Circulation: the movement of blood and other fluids throughout the body, which helps transport nutrients, oxygen, and waste products.
3. Respiration: the process of gas exchange between the body and the environment, involving the inhalation of oxygen and the exhalation of carbon dioxide.
4. Digestion: the breakdown of food into smaller molecules that can be absorbed and utilized by the body for energy and growth.
5. Nerve impulse transmission: the electrical signals that transmit information between neurons and other cells in the body.
6. Endocrine regulation: the release and transport of hormones that regulate various physiological processes, such as growth, development, and metabolism.
7. Immune function: the body's defense system against foreign invaders, such as bacteria, viruses, and toxins.
8. Reproduction: the process of producing offspring through sexual or asexual means.
9. Maintenance of homeostasis: the ability of the body to maintain a stable internal environment despite changes in external conditions.

Physiological processes are regulated by complex systems of feedback and control, involving various hormones, nerves, and other signaling molecules. Understanding these processes is essential for understanding how the body functions and how to diagnose and treat various medical conditions.

Acclimatization is the process by which an individual organism adjusts to a change in its environment, enabling it to maintain its normal physiological functions and thus survive and reproduce. In the context of medicine, acclimatization often refers to the body's adaptation to changes in temperature, altitude, or other environmental factors that can affect health.

For example, when a person moves from a low-altitude area to a high-altitude area, their body may undergo several physiological changes to adapt to the reduced availability of oxygen at higher altitudes. These changes may include increased breathing rate and depth, increased heart rate, and altered blood chemistry, among others. This process of acclimatization can take several days or even weeks, depending on the individual and the degree of environmental change.

Similarly, when a person moves from a cold climate to a hot climate, their body may adjust by increasing its sweat production and reducing its heat production, in order to maintain a stable body temperature. This process of acclimatization can help prevent heat-related illnesses such as heat exhaustion and heat stroke.

Overall, acclimatization is an important physiological process that allows organisms to adapt to changing environments and maintain their health and well-being.

Torpor is a state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and metabolic rate. This state is often entered into as a way for the animal to survive periods of reduced food availability or harsh environmental conditions. Torpor enables animals to save energy during these periods by reducing their need for food and oxygen. It is a short-term hibernation-like state that can last for several hours to days, depending on the species and environmental conditions. This phenomenon is observed in various animal groups, including mammals, birds, and reptiles.

Sexual behavior in animals refers to a variety of behaviors related to reproduction and mating that occur between members of the same species. These behaviors can include courtship displays, mating rituals, and various physical acts. The specific forms of sexual behavior displayed by a given species are influenced by a combination of genetic, hormonal, and environmental factors.

In some animals, sexual behavior is closely tied to reproductive cycles and may only occur during certain times of the year or under specific conditions. In other species, sexual behavior may be more frequent and less closely tied to reproduction, serving instead as a means of social bonding or communication.

It's important to note that while humans are animals, the term "sexual behavior" is often used in a more specific sense to refer to sexual activities between human beings. The study of sexual behavior in animals is an important area of research within the field of animal behavior and can provide insights into the evolutionary origins of human sexual behavior as well as the underlying mechanisms that drive it.

I'm sorry for any confusion, but "starlings" is not a medical term. It is a common name used to refer to a type of bird, specifically the species Sturnus vulgaris, also known as the European Starling. If you have any questions about medical terminology or concepts, I would be happy to help with those!

Follicle-Stimulating Hormone (FSH) is a glycoprotein hormone secreted and released by the anterior pituitary gland. In females, it promotes the growth and development of ovarian follicles in the ovary, which ultimately leads to the maturation and release of an egg (ovulation). In males, FSH stimulates the testes to produce sperm. It works in conjunction with luteinizing hormone (LH) to regulate reproductive processes. The secretion of FSH is controlled by the hypothalamic-pituitary-gonadal axis and its release is influenced by the levels of gonadotropin-releasing hormone (GnRH), estrogen, inhibin, and androgens.

I'm sorry for any confusion, but "Marsupialia" is not a medical term. It is a taxonomic category in biology, specifically an order that includes mammals known as marsupials. These are mammals that carry their young in a pouch after birth. Examples of marsupials include kangaroos, koalas, and opossums. If you have any medical questions or terms you would like defined, I'd be happy to help!

Anestrus is a term used in veterinary medicine to describe the period of sexual quiescence in female animals, during which they do not exhibit estrous cycles. This phase is characterized by low levels of reproductive hormones and is seen in some species as a part of their natural reproductive cycle, while in others it may indicate an abnormality or underlying health issue.

For example, in dogs, anestrus is the period between heat cycles when the reproductive system is relatively inactive. In contrast, in domestic cats, continuous estrous cycling is the norm, and they do not typically exhibit an anestrus phase.

In some cases, anestrus may be induced by factors such as poor nutrition, stress, or illness, and it can have negative consequences for an animal's reproductive health if it persists for too long. If an animal is experiencing prolonged anestrus or other reproductive issues, it is important to consult with a veterinarian for proper diagnosis and treatment.

Gonads are the reproductive organs that produce gametes (sex cells) and sex hormones. In males, the gonads are the testes, which produce sperm and testosterone. In females, the gonads are the ovaries, which produce eggs and estrogen and progesterone. The development, function, and regulation of the gonads are crucial for reproductive health and fertility.

'Activity cycles' is a term that can have different meanings in different contexts, and I could not find a specific medical definition for it. However, in the context of physiology or chronobiology, activity cycles often refer to the natural rhythms of behavior and physiological processes that occur over a 24-hour period, also known as circadian rhythms.

Circadian rhythms are biological processes that follow an approximate 24-hour cycle and regulate various functions in living organisms, including sleep-wake cycles, body temperature, hormone secretion, and metabolism. These rhythms help the body adapt to the changing environment and coordinate various physiological processes to optimize function and maintain homeostasis.

Therefore, activity cycles in a medical or physiological context may refer to the natural fluctuations in physical activity, alertness, and other behaviors that follow a circadian rhythm. Factors such as sleep deprivation, jet lag, and shift work can disrupt these rhythms and lead to various health problems, including sleep disorders, mood disturbances, and impaired cognitive function.

I'm sorry for any confusion, but "sparrows" is not a term used in medical definitions. Sparrows are small, common birds that belong to the family Passeridae. If you have any questions about medical terminology or concepts, I would be happy to help with those instead!

"Molting" is not a term typically used in medical contexts. It is primarily used to describe the shedding and replacement of feathers, hair, or skin in animals, including birds, reptiles, insects, and other invertebrates. In humans and other mammals, this process is more commonly referred to as "shedding" or "growing new hair/skin."

However, if you are referring to the medical term "molt," it is a rare genetic disorder that affects the skin's pigmentation and causes it to shed in patches. It is also known as "congenital ichthyosiform erythroderma" or "non-bullous congenital ichthyosiform erythroderma." The condition is present at birth, and affected individuals have red, scaly skin that sheds in a pattern similar to snake skin. Molting is not contagious and has no known cure, but various treatments can help manage its symptoms.

A gene in plants, like in other organisms, is a hereditary unit that carries genetic information from one generation to the next. It is a segment of DNA (deoxyribonucleic acid) that contains the instructions for the development and function of an organism. Genes in plants determine various traits such as flower color, plant height, resistance to diseases, and many others. They are responsible for encoding proteins and RNA molecules that play crucial roles in the growth, development, and reproduction of plants. Plant genes can be manipulated through traditional breeding methods or genetic engineering techniques to improve crop yield, enhance disease resistance, and increase nutritional value.

Portulacaceae is not a medical term, but a taxonomic category in botany. It refers to the purslane family of flowering plants, which contains around 20-30 genera and about 400-500 species. Some members of this family have been used in traditional medicine, such as Portulaca oleracea (common purslane), which has been used to treat various ailments including gastrointestinal disorders and skin conditions. However, it's important to note that the use of plants for medicinal purposes should be done under the guidance of a healthcare professional, as they can have potential side effects or interact with other medications.

Temperature, in a medical context, is a measure of the degree of hotness or coldness of a body or environment. It is usually measured using a thermometer and reported in degrees Celsius (°C), degrees Fahrenheit (°F), or kelvin (K). In the human body, normal core temperature ranges from about 36.5-37.5°C (97.7-99.5°F) when measured rectally, and can vary slightly depending on factors such as time of day, physical activity, and menstrual cycle. Elevated body temperature is a common sign of infection or inflammation, while abnormally low body temperature can indicate hypothermia or other medical conditions.

'Arabidopsis' is a genus of small flowering plants that are part of the mustard family (Brassicaceae). The most commonly studied species within this genus is 'Arabidopsis thaliana', which is often used as a model organism in plant biology and genetics research. This plant is native to Eurasia and Africa, and it has a small genome that has been fully sequenced. It is known for its short life cycle, self-fertilization, and ease of growth, making it an ideal subject for studying various aspects of plant biology, including development, metabolism, and response to environmental stresses.

"Male genitalia" refers to the reproductive and sexual organs that are typically present in male individuals. These structures include:

1. Testes: A pair of oval-shaped glands located in the scrotum that produce sperm and testosterone.
2. Epididymis: A long, coiled tube that lies on the surface of each testicle where sperm matures and is stored.
3. Vas deferens: A pair of muscular tubes that transport sperm from the epididymis to the urethra.
4. Seminal vesicles: Glands that produce a fluid that mixes with sperm to create semen.
5. Prostate gland: A small gland that surrounds the urethra and produces a fluid that also mixes with sperm to create semen.
6. Bulbourethral glands (Cowper's glands): Two pea-sized glands that produce a lubricating fluid that is released into the urethra during sexual arousal.
7. Urethra: A tube that runs through the penis and carries urine from the bladder out of the body, as well as semen during ejaculation.
8. Penis: The external organ that serves as both a reproductive and excretory organ, expelling both semen and urine.

"Rodentia" is not a medical term, but a taxonomic category in biology. It refers to the largest order of mammals, comprising over 40% of all mammal species. Commonly known as rodents, this group includes mice, rats, hamsters, gerbils, guinea pigs, squirrels, prairie dogs, capybaras, beavers, and many others.

While "Rodentia" itself is not a medical term, certain conditions or issues related to rodents can have medical implications. For instance, rodents are known to carry and transmit various diseases that can affect humans, such as hantavirus, leptospirosis, salmonellosis, and lymphocytic choriomeningitis (LCMV). Therefore, understanding the biology and behavior of rodents is important in the context of public health and preventive medicine.

"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.

Antlers are defined in medical terminology as the continuously growing, branched bony appendages that arise from the skull of members of the Cervidae family, which includes deer, elk, and moose. Antler growth and development are unique to this group of animals and are under the control of hormones and genetics. They serve as a means of defense, dominance display, and sexual selection.

During the growth phase, antlers are covered with highly vascular skin called "velvet," which provides nutrients for the rapid growth of bone. Once growth is complete, typically in late summer, the velvet is shed, revealing the hard, bony antler structure. The antlers are then used by males during the mating season as a tool to compete for females and establish dominance hierarchies.

In some species, only males grow antlers, while in others, both males and females develop them. After the mating season, the animals shed their antlers, which regenerate the following year. The study of antlers is known as palynology.

I believe there may be a slight misunderstanding in your question. "Plant leaves" are not a medical term, but rather a general biological term referring to a specific organ found in plants.

Leaves are organs that are typically flat and broad, and they are the primary site of photosynthesis in most plants. They are usually green due to the presence of chlorophyll, which is essential for capturing sunlight and converting it into chemical energy through photosynthesis.

While leaves do not have a direct medical definition, understanding their structure and function can be important in various medical fields, such as pharmacognosy (the study of medicinal plants) or environmental health. For example, certain plant leaves may contain bioactive compounds that have therapeutic potential, while others may produce allergens or toxins that can impact human health.

The hypothalamus is a small, vital region of the brain that lies just below the thalamus and forms part of the limbic system. It plays a crucial role in many important functions including:

1. Regulation of body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.
2. Production and regulation of hormones through its connection with the pituitary gland (the hypophysis). It controls the release of various hormones by producing releasing and inhibiting factors that regulate the anterior pituitary's function.
3. Emotional responses, behavior, and memory formation through its connections with the limbic system structures like the amygdala and hippocampus.
4. Autonomic nervous system regulation, which controls involuntary physiological functions such as heart rate, blood pressure, and digestion.
5. Regulation of the immune system by interacting with the autonomic nervous system.

Damage to the hypothalamus can lead to various disorders like diabetes insipidus, growth hormone deficiency, altered temperature regulation, sleep disturbances, and emotional or behavioral changes.

Arabidopsis proteins refer to the proteins that are encoded by the genes in the Arabidopsis thaliana plant, which is a model organism commonly used in plant biology research. This small flowering plant has a compact genome and a short life cycle, making it an ideal subject for studying various biological processes in plants.

Arabidopsis proteins play crucial roles in many cellular functions, such as metabolism, signaling, regulation of gene expression, response to environmental stresses, and developmental processes. Research on Arabidopsis proteins has contributed significantly to our understanding of plant biology and has provided valuable insights into the molecular mechanisms underlying various agronomic traits.

Some examples of Arabidopsis proteins include transcription factors, kinases, phosphatases, receptors, enzymes, and structural proteins. These proteins can be studied using a variety of techniques, such as biochemical assays, protein-protein interaction studies, and genetic approaches, to understand their functions and regulatory mechanisms in plants.

I'm sorry for any confusion, but "Hoof and Claw" is not a medical term or condition. The term "hoof" refers to the hard covering on the toes of animals such as horses, cows, and other ungulates, while "claw" refers to the sharp nail-like structure found on the toes of animals such as cats, dogs, and birds.

If you have any questions related to medical terminology or health concerns, I would be happy to try to help answer them for you.

Odonata is not a medical term, but rather an order in the classification system used in zoology and entomology. It refers to a group of insects commonly known as dragonflies and damselflies. These insects are characterized by their large, multifaceted eyes, two pairs of strong wings that are similar in size and shape, and elongated bodies.

While Odonata is not directly related to medical terminology or human health, it is worth noting that dragonflies and damselflies play a beneficial role in controlling the populations of various insects that can be pests or vectors of diseases. For example, some species feed on mosquitoes, which can transmit harmful pathogens to humans and animals.

In summary, Odonata is an order of insects that includes dragonflies and damselflies, and while not a medical term itself, these insects contribute to the ecosystem by helping control other insect populations that may impact human health.

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.

An ovary is a part of the female reproductive system in which ova or eggs are produced through the process of oogenesis. They are a pair of solid, almond-shaped structures located one on each side of the uterus within the pelvic cavity. Each ovary measures about 3 to 5 centimeters in length and weighs around 14 grams.

The ovaries have two main functions: endocrine (hormonal) function and reproductive function. They produce and release eggs (ovulation) responsible for potential fertilization and development of an embryo/fetus during pregnancy. Additionally, they are essential in the production of female sex hormones, primarily estrogen and progesterone, which regulate menstrual cycles, sexual development, and reproduction.

During each menstrual cycle, a mature egg is released from one of the ovaries into the fallopian tube, where it may be fertilized by sperm. If not fertilized, the egg, along with the uterine lining, will be shed, leading to menstruation.

I'm sorry for any confusion, but "Triturus" is not a medical term. It is actually the genus name for newts that are native to Europe. These newts belong to the family Salamandridae and are known for their ability to regenerate various body parts. If you have any questions related to medical terminology or healthcare, I would be happy to try and help answer those for you.

"Plant proteins" refer to the proteins that are derived from plant sources. These can include proteins from legumes such as beans, lentils, and peas, as well as proteins from grains like wheat, rice, and corn. Other sources of plant proteins include nuts, seeds, and vegetables.

Plant proteins are made up of individual amino acids, which are the building blocks of protein. While animal-based proteins typically contain all of the essential amino acids that the body needs to function properly, many plant-based proteins may be lacking in one or more of these essential amino acids. However, by consuming a variety of plant-based foods throughout the day, it is possible to get all of the essential amino acids that the body needs from plant sources alone.

Plant proteins are often lower in calories and saturated fat than animal proteins, making them a popular choice for those following a vegetarian or vegan diet, as well as those looking to maintain a healthy weight or reduce their risk of chronic diseases such as heart disease and cancer. Additionally, plant proteins have been shown to have a number of health benefits, including improving gut health, reducing inflammation, and supporting muscle growth and repair.

Spermatogenesis is the process by which sperm cells, or spermatozoa, are produced in male organisms. It occurs in the seminiferous tubules of the testes and involves several stages:

1. Spermatocytogenesis: This is the initial stage where diploid spermatogonial stem cells divide mitotically to produce more spermatogonia, some of which will differentiate into primary spermatocytes.
2. Meiosis: The primary spermatocytes undergo meiotic division to form haploid secondary spermatocytes, which then divide again to form haploid spermatids. This process results in the reduction of chromosome number from 46 (diploid) to 23 (haploid).
3. Spermiogenesis: The spermatids differentiate into spermatozoa, undergoing morphological changes such as the formation of a head and tail. During this stage, most of the cytoplasm is discarded, resulting in highly compacted and streamlined sperm cells.
4. Spermation: The final stage where mature sperm are released from the seminiferous tubules into the epididymis for further maturation and storage.

The entire process takes approximately 72-74 days in humans, with continuous production throughout adulthood.

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.

The pituitary gland is a small, endocrine gland located at the base of the brain, in the sella turcica of the sphenoid bone. It is often called the "master gland" because it controls other glands and makes the hormones that trigger many body functions. The pituitary gland measures about 0.5 cm in height and 1 cm in width, and it weighs approximately 0.5 grams.

The pituitary gland is divided into two main parts: the anterior lobe (adenohypophysis) and the posterior lobe (neurohypophysis). The anterior lobe is further divided into three zones: the pars distalis, pars intermedia, and pars tuberalis. Each part of the pituitary gland has distinct functions and produces different hormones.

The anterior pituitary gland produces and releases several important hormones, including:

* Growth hormone (GH), which regulates growth and development in children and helps maintain muscle mass and bone strength in adults.
* Thyroid-stimulating hormone (TSH), which controls the production of thyroid hormones by the thyroid gland.
* Adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol and other steroid hormones.
* Follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate reproductive function in both males and females.
* Prolactin, which stimulates milk production in pregnant and lactating women.

The posterior pituitary gland stores and releases two hormones that are produced by the hypothalamus:

* Antidiuretic hormone (ADH), which helps regulate water balance in the body by controlling urine production.
* Oxytocin, which stimulates uterine contractions during childbirth and milk release during breastfeeding.

Overall, the pituitary gland plays a critical role in maintaining homeostasis and regulating various bodily functions, including growth, development, metabolism, and reproductive function.

Progesterone is a steroid hormone that is primarily produced in the ovaries during the menstrual cycle and in pregnancy. It plays an essential role in preparing the uterus for implantation of a fertilized egg and maintaining the early stages of pregnancy. Progesterone works to thicken the lining of the uterus, creating a nurturing environment for the developing embryo.

During the menstrual cycle, progesterone is produced by the corpus luteum, a temporary structure formed in the ovary after an egg has been released from a follicle during ovulation. If pregnancy does not occur, the levels of progesterone will decrease, leading to the shedding of the uterine lining and menstruation.

In addition to its reproductive functions, progesterone also has various other effects on the body, such as helping to regulate the immune system, supporting bone health, and potentially influencing mood and cognition. Progesterone can be administered medically in the form of oral pills, intramuscular injections, or vaginal suppositories for various purposes, including hormone replacement therapy, contraception, and managing certain gynecological conditions.

Ovariectomy is a surgical procedure in which one or both ovaries are removed. It is also known as "ovary removal" or "oophorectomy." This procedure is often performed as a treatment for various medical conditions, including ovarian cancer, endometriosis, uterine fibroids, and pelvic pain. Ovariectomy can also be part of a larger surgical procedure called an hysterectomy, in which the uterus is also removed.

In some cases, an ovariectomy may be performed as a preventative measure for individuals at high risk of developing ovarian cancer. This is known as a prophylactic ovariectomy. After an ovariectomy, a person will no longer have menstrual periods and will be unable to become pregnant naturally. Hormone replacement therapy may be recommended in some cases to help manage symptoms associated with the loss of hormones produced by the ovaries.

A plant stem is not typically defined in a medical context, but rather in the field of botany. However, I can certainly provide a general biological definition for you.

In plants, stems are organs that serve primarily as support structures, holding leaves, flowers, and fruits aloft where they can receive sunlight and exchange gases. They also act as conduits, transporting water, nutrients, and sugars made during photosynthesis between the roots and shoots of a plant.

The stem is usually composed of three main tissue systems: dermal, vascular, and ground. The dermal tissue system forms the outermost layer(s) of the stem, providing protection and sometimes participating in gas exchange. The vascular tissue system contains the xylem (which transports water and nutrients upward) and phloem (which transports sugars and other organic compounds downward). The ground tissue system, located between the dermal and vascular tissues, is responsible for food storage and support.

While not a direct medical definition, understanding the structure and function of plant stems can be relevant in fields such as nutrition, agriculture, and environmental science, which have implications for human health.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

Castration is a surgical procedure to remove the testicles in males or ovaries in females. In males, it is also known as orchiectomy. This procedure results in the inability to produce sex hormones and gametes (sperm in men and eggs in women), and can be done for various reasons such as medical treatment for certain types of cancer, to reduce sexual urges in individuals with criminal tendencies, or as a form of birth control in animals.

Gibberellins (GAs) are a type of plant hormones that regulate various growth and developmental processes, including stem elongation, germination of seeds, leaf expansion, and flowering. They are a large family of diterpenoid compounds that are synthesized from geranylgeranyl pyrophosphate (GGPP) in the plastids and then modified through a series of enzymatic reactions in the endoplasmic reticulum and cytoplasm.

GAs exert their effects by binding to specific receptors, which activate downstream signaling pathways that ultimately lead to changes in gene expression and cellular responses. The biosynthesis and perception of GAs are tightly regulated, and disruptions in these processes can result in various developmental abnormalities and growth disorders in plants.

In addition to their role in plant growth and development, GAs have also been implicated in the regulation of various physiological processes, such as stress tolerance, nutrient uptake, and senescence. They have also attracted interest as potential targets for crop improvement, as modulating GA levels and sensitivity can enhance traits such as yield, disease resistance, and abiotic stress tolerance.

Phytochrome A is a type of phytochrome, which is a photoreceptor protein that plants use to detect and respond to different wavelengths of light. Specifically, phytochrome A is responsible for mediating the response to red light. It exists in two interconvertible forms: Pr (the inactive form, absorbing red light) and Pfr (the active form, absorbing far-red light). The conversion between these two forms triggers a range of physiological responses in plants, such as seed germination, stem elongation, leaf expansion, and flowering. Phytochrome A is the most sensitive phytochrome to changes in light quality and quantity, making it a crucial photoreceptor for plants' adaptation to their environment.

Food deprivation is not a medical term per se, but it is used in the field of nutrition and psychology. It generally refers to the deliberate withholding of food for a prolonged period, leading to a state of undernutrition or malnutrition. This can occur due to various reasons such as famine, starvation, anorexia nervosa, or as a result of certain medical treatments or conditions. Prolonged food deprivation can have serious consequences on physical health, including weight loss, muscle wasting, organ damage, and decreased immune function, as well as psychological effects such as depression, anxiety, and cognitive impairment.

"Cold temperature" is a relative term and its definition can vary depending on the context. In general, it refers to temperatures that are lower than those normally experienced or preferred by humans and other warm-blooded animals. In a medical context, cold temperature is often defined as an environmental temperature that is below 16°C (60.8°F).

Exposure to cold temperatures can have various physiological effects on the human body, such as vasoconstriction of blood vessels near the skin surface, increased heart rate and metabolic rate, and shivering, which helps to generate heat and maintain body temperature. Prolonged exposure to extreme cold temperatures can lead to hypothermia, a potentially life-threatening condition characterized by a drop in core body temperature below 35°C (95°F).

It's worth noting that some people may have different sensitivities to cold temperatures due to factors such as age, health status, and certain medical conditions. For example, older adults, young children, and individuals with circulatory or neurological disorders may be more susceptible to the effects of cold temperatures.

Cheirogaleidae is a family of small primates also known as dwarf lemurs or mouse lemurs. They are native to Madagascar and are characterized by their rodent-like appearance and nocturnal behavior. This family includes several genera and species, such as Cheirogaleus, Microcebus, Mirza, and Allocebus. These primates are known for their ability to adapt to various environments, from forests to dry regions, and have a varied diet that includes fruits, insects, and small vertebrates. They are also known for their unique hibernation behavior during the dry season, where they lower their metabolic rate and body temperature to conserve energy.

A drug implant is a medical device that is specially designed to provide controlled release of a medication into the body over an extended period of time. Drug implants can be placed under the skin or in various body cavities, depending on the specific medical condition being treated. They are often used when other methods of administering medication, such as oral pills or injections, are not effective or practical.

Drug implants come in various forms, including rods, pellets, and small capsules. The medication is contained within the device and is released slowly over time, either through diffusion or erosion of the implant material. This allows for a steady concentration of the drug to be maintained in the body, which can help to improve treatment outcomes and reduce side effects.

Some common examples of drug implants include:

1. Hormonal implants: These are small rods that are inserted under the skin of the upper arm and release hormones such as progestin or estrogen over a period of several years. They are often used for birth control or to treat conditions such as endometriosis or uterine fibroids.
2. Intraocular implants: These are small devices that are placed in the eye during surgery to release medication directly into the eye. They are often used to treat conditions such as age-related macular degeneration or diabetic retinopathy.
3. Bone cement implants: These are specially formulated cements that contain antibiotics and are used to fill bone defects or joint spaces during surgery. The antibiotics are released slowly over time, helping to prevent infection.
4. Implantable pumps: These are small devices that are placed under the skin and deliver medication directly into a specific body cavity, such as the spinal cord or the peritoneal cavity. They are often used to treat chronic pain or cancer.

Overall, drug implants offer several advantages over other methods of administering medication, including improved compliance, reduced side effects, and more consistent drug levels in the body. However, they may also have some disadvantages, such as the need for surgical placement and the potential for infection or other complications. As with any medical treatment, it is important to discuss the risks and benefits of drug implants with a healthcare provider.

Lactation is the process by which milk is produced and secreted from the mammary glands of female mammals, including humans, for the nourishment of their young. This physiological function is initiated during pregnancy and continues until it is deliberately stopped or weaned off. The primary purpose of lactation is to provide essential nutrients, antibodies, and other bioactive components that support the growth, development, and immune system of newborns and infants.

The process of lactation involves several hormonal and physiological changes in a woman's body. During pregnancy, the hormones estrogen and progesterone stimulate the growth and development of the mammary glands. After childbirth, the levels of these hormones drop significantly, allowing another hormone called prolactin to take over. Prolactin is responsible for triggering the production of milk in the alveoli, which are tiny sacs within the breast tissue.

Another hormone, oxytocin, plays a crucial role in the release or "let-down" of milk from the alveoli to the nipple during lactation. This reflex is initiated by suckling or thinking about the baby, which sends signals to the brain to release oxytocin. The released oxytocin then binds to receptors in the mammary glands, causing the smooth muscles around the alveoli to contract and push out the milk through the ducts and into the nipple.

Lactation is a complex and highly regulated process that ensures the optimal growth and development of newborns and infants. It provides not only essential nutrients but also various bioactive components, such as immunoglobulins, enzymes, and growth factors, which protect the infant from infections and support their immune system.

In summary, lactation is the physiological process by which milk is produced and secreted from the mammary glands of female mammals for the nourishment of their young. It involves hormonal changes, including the actions of prolactin, oxytocin, estrogen, and progesterone, to regulate the production, storage, and release of milk.

Orchiectomy is a surgical procedure where one or both of the testicles are removed. It is also known as castration. This procedure can be performed for various reasons, including the treatment of testicular cancer, prostate cancer, or other conditions that may affect the testicles. It can also be done to reduce levels of male hormones in the body, such as in the case of transgender women undergoing gender affirming surgery. The specific medical definition may vary slightly depending on the context and the extent of the procedure.

Estradiol is a type of estrogen, which is a female sex hormone. It is the most potent and dominant form of estrogen in humans. Estradiol plays a crucial role in the development and maintenance of secondary sexual characteristics in women, such as breast development and regulation of the menstrual cycle. It also helps maintain bone density, protect the lining of the uterus, and is involved in cognition and mood regulation.

Estradiol is produced primarily by the ovaries, but it can also be synthesized in smaller amounts by the adrenal glands and fat cells. In men, estradiol is produced from testosterone through a process called aromatization. Abnormal levels of estradiol can contribute to various health issues, such as hormonal imbalances, infertility, osteoporosis, and certain types of cancer.

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.

Phytochrome is a photoreceptor protein responsible for detecting and mediating responses to different wavelengths of light, primarily red and far-red, in plants and some microorganisms. It plays a crucial role in various physiological processes such as seed germination, stem elongation, leaf expansion, chlorophyll production, and flowering.

The phytochrome protein exists in two interconvertible forms: Pr (the red-light-absorbing form) and Pfr (the far-red-light-absorbing form). The conversion between these forms regulates the downstream signaling pathways that control plant growth and development. Red light (around 660 nm) promotes the formation of the Pfr form, while far-red light (around 730 nm) converts it back to the Pr form. This reversible photoresponse allows plants to adapt their growth patterns based on the quality and duration of light they receive.

Macropodidae is not a medical term, but a taxonomic family in the order Diprotodontia, which includes large marsupials commonly known as kangaroos, wallabies, and tree-kangaroos. These animals are native to Australia and New Guinea. They are characterized by their strong hind legs, large feet adapted for leaping, and a long muscular tail used for balance. Some members of this family, particularly the larger kangaroo species, can pose a risk to humans in certain situations, such as vehicle collisions or aggressive encounters during breeding season. However, they are not typically associated with medical conditions or human health.

Hibernation is a state of significantly reduced metabolic activity in animals, generally characterized by a lower body temperature and slower breathing rate. This physiological adaptation allows animals to survive periods of extreme cold or food scarcity. During hibernation, an animal's body temperature can drop close to the ambient temperature, and its heart rate and respiratory rate can decrease significantly. Hibernating animals also store energy in the form of fat reserves, which they use up during this period of reduced activity. This state can last for days, weeks, or even months, depending on the species. Examples of animals that hibernate include bears, bats, and groundhogs.

Carnivora is an order of mammals that consists of animals whose primary diet consists of flesh. The term "Carnivora" comes from the Latin words "caro", meaning flesh, and "vorare", meaning to devour. This order includes a wide variety of species, ranging from large predators such as lions, tigers, and bears, to smaller animals such as weasels, otters, and raccoons.

While members of the Carnivora order are often referred to as "carnivores," it is important to note that not all members exclusively eat meat. Some species, such as raccoons and bears, have an omnivorous diet that includes both plants and animals. Additionally, some species within this order have evolved specialized adaptations for their specific diets, such as the elongated canines and carnassial teeth of felids (cats) and canids (dogs), which are adapted for tearing and shearing meat.

Overall, the medical definition of Carnivora refers to an order of mammals that have a diet primarily consisting of flesh, although not all members exclusively eat meat.

Phytochrome B is a type of phytochrome photoreceptor found in plants that regulates various physiological and developmental processes in response to red and far-red light. It plays a crucial role in seed germination, de-etiolation, shade avoidance responses, and flowering time regulation. Phytochrome B exists in two interconvertible forms: Pr (the inactive, red light-absorbing form) and Pfr (the active, far-red light-absorbing form). The conversion between these forms allows phytochrome B to act as a molecular switch that mediates plant responses to different light conditions.

Physiological adaptation refers to the changes or modifications that occur in an organism's biological functions or structures as a result of environmental pressures or changes. These adaptations enable the organism to survive and reproduce more successfully in its environment. They can be short-term, such as the constriction of blood vessels in response to cold temperatures, or long-term, such as the evolution of longer limbs in animals that live in open environments.

In the context of human physiology, examples of physiological adaptation include:

1. Acclimatization: The process by which the body adjusts to changes in environmental conditions, such as altitude or temperature. For example, when a person moves to a high-altitude location, their body may produce more red blood cells to compensate for the lower oxygen levels, leading to improved oxygen delivery to tissues.

2. Exercise adaptation: Regular physical activity can lead to various physiological adaptations, such as increased muscle strength and endurance, enhanced cardiovascular function, and improved insulin sensitivity.

3. Hormonal adaptation: The body can adjust hormone levels in response to changes in the environment or internal conditions. For instance, during prolonged fasting, the body releases stress hormones like cortisol and adrenaline to help maintain energy levels and prevent muscle wasting.

4. Sensory adaptation: Our senses can adapt to different stimuli over time. For example, when we enter a dark room after being in bright sunlight, it takes some time for our eyes to adjust to the new light level. This process is known as dark adaptation.

5. Aging-related adaptations: As we age, various physiological changes occur that help us adapt to the changing environment and maintain homeostasis. These include changes in body composition, immune function, and cognitive abilities.

I'm sorry for any confusion, but "goats" is not a term commonly used in medical definitions. It is a common noun referring to the domesticated animal species Capra aegagrus hircus. If you have any questions about a specific medical condition or term, please provide that and I would be happy to help.

Modification by photoperiod. Biological Bulletin 101:71-83. Frank A. Brown Jr. 1954. "Persistent Activity Rhythms in the Oyster ...
Modification by photoperiod. Biological Bulletin 101:71-83. Stephens, G.C. 1955. Induction of molting in the crayfish, Cambarus ... by modification of daily photoperiod. Biological Bulletin 108:235-241. Stephens, G.C. and R.A. Schinske. 1961. Uptake of amino ...
The photoperiod also significantly influences how fast the corms grow. Corms begin to develop much more slowly if the ... f.) Hensch) to photoperiod". The Journal of Horticultural Science and Biotechnology. 75 (1): 72-78. doi:10.1080/14620316.2000. ... photoperiod exceeds 12 hours. The corms are also the propagating material. Alternatively, transplants can be used. Machinery, ...
Photoperiod: (a.k.a. Day Length): The duration of light in an external light-dark cycle. Splitting: A phenomenon that occurs in ... it was discovered that both PRR9-1 and PRR90x-1 had changes of photoperiods under high light irradiance. This variation is ... "Quantitative Study of Dual Circadian Oscillator Models under Different Skeleton Photoperiods". Journal of Biological Rhythms. ...
The photoperiod also affects the oil content in sesame seed; increased photoperiod increases oil content. The oil content of ... Initiation of flowering is sensitive to photoperiod and sesame variety. ...
Overwintering is triggered by short photoperiod. Weed, A. S.; Casagrande, R. A. (2010). "Biology and larval feeding impact of ...
Moulting is affected by the photoperiod. Deer are also excellent jumpers and swimmers. Deer are ruminants, or cud-chewers, and ... doi:10.1111/j.1469-7998.1973.tb05044.x. Lincoln, G. A.; Guinness, F. E. (1972). "Effect of altered photoperiod on delayed ...
Werner, H. O. (1942). Relation of length of photoperiod and intensity of supplemental light to the production of flowers and ... Chrysanthemum was one of the plants used in experiments that led to the definitions of photoperiod and photoperiodism. Yet, ... 95-99). Adams, S. R., & Langton, F. A. (2005). Photoperiod and plant growth: a review. The Journal of Horticultural Science and ... Alden, M., & Faust, J. E. (2021). Unravelling the role of temperature and photoperiod on poinsettia heat delay. HortScience, 56 ...
Day-neutral plants are those that flower regardless of photoperiod. Plants that flower in response to photoperiod may have a ... In general, a "short-day" is one in which the photoperiod is no more than 12 hours. A "long-day" is one in which the ... An obligate response means that the plant will only flower if grown under a certain photoperiod. Lux and lumens are commonly ... A facultative response means that a plant will eventually flower regardless of photoperiod, but will flower faster if grown ...
Mice are nocturnal animals whose activity is compressed under long photoperiods and extended under short photoperiods. The dual ... This phenomena also shows the importance of E and M cells for adapting the activity of an organism different photoperiods. In ... Porcu A, Riddle M, Dulcis D, Welsh DK (February 28, 2018). "Photoperiod-Induced Neuroplasticity in the Circadian System". ...
Hansen PJ, Kamwanja LA, Hauser ER (October 1983). "Photoperiod influences age at puberty of heifers". J Anim Sci. 57 (4): 985- ... He subsequently did studies that, for the first time, demonstrated that photoperiod modified the processes leading to puberty ...
American elm is wholly insensitive to daylight length (photoperiod), and will continue to grow well into autumn until injured ... 30: 4-5. Downs, R. J.; Borthwick, H. A. (1956). "Effects of Photoperiod on Growth of Trees". Botanical Gazette. 117 (4): 310- ...
The effects of temperature, photoperiod and daily torpor. 1997 P.M. Meerlo: Behavioural and chronobiological consequences of ...
... photoperiod, drought, temperature, and other external environmental conditions; and exogenous sources of PGRs, e.g., externally ...
... photoperiod, drought, temperature, and other external environmental conditions; and exogenous sources of PGRs, e.g., externally ...
Masuda, Junichiro; Urakawa, Toshihiro; Ozaki, Yukio; Okubo, Hiroshi (2006-01-01). "Short Photoperiod Induces Dormancy in Lotus ...
In temperate regions, photoperiod is the most reliable cues of seasonal change. This informs entry into reproductive diapause ... Photoperiod is the most important stimulus initiating diapause. The initiation phase begins when morphological development ... Token stimuli can consist of changes in photoperiod, thermoperiod, or allelochemicals from food plants. These stimuli are not ... Sensitivity to certain stimuli which act to prevent termination of diapause, such as photoperiod and temperature, is increased ...
Photoperiod is controlled during sporulation and growth phases. A synthetic twine of about 2 - 6mm in diameter is placed on the ...
... photoperiod, drought, temperature, and other external environmental conditions; and exogenous sources of PGRs, e.g., externally ...
Response of California Annuals to Photoperiod and Temperature". American Journal of Botany. 32 (1): 1-12. doi:10.1002/j.1537- ... that of the response of 13 California annuals to photoperiod and temperature. Although they were not able to correlate the ...
For flowering, Capsicum is a non-photoperiod-sensitive crop. The flowers can self-pollinate. However, at extremely high ...
These refer to the day-length sensitivity of the plant and the type of photoperiod that induces flower formation. Day-neutral ... cultivars produce flowers regardless of the photoperiod. Strawberry cultivars vary widely in size, color, flavor, shape, degree ...
This diatom is more dependent on the water quality than photoperiod lengths for bloom formation, though it is especially common ... Rost, Björn; Riebesell, Ulf; Sültemeyer, Dieter (2006). "Carbon acquisition of marine phytoplankton: Effect of photoperiod ... responses of Skeletonema costatum to the interactions of seawater acidification and the combination of photoperiod and ...
Photoperiod (the length of daylight) affects overall plant uptake. When the length of daylight gets shorter, grass undergoes ...
This pattern is affected by age, photoperiod, and temperature. The daily rhythm of hormone production varies when the female ... Because PBAN can be produced independently of the moth's photoperiod, the circadian rhythm of pheromone production must be ...
Photoperiod flowering is controlled by output gene Gigantea (GI). GI is activated at night and activates the expression of ...
Sexual maturation depends on environmental temperature and photo-period. Longer days and warmer days stimulate brighter ...
To create artificial photoperiods, Bünning exposed plants to a light-dark cycle indicative of a specific season, such as the ... By entraining the plants to a spring or summer photoperiod, Bünning was able to induce flowering, even if the actual season ... In the early-1930s, Bünning proposed that organisms rely on a circadian rhythm of sensitivity to light to measure photoperiod. ... Bünning also demonstrated that an artificial photoperiod can induce flowering at inappropriate times, supporting his model of ...
Temte, J. L. (1994). Photoperiod control of birth timing in harbour seal (Phoca vitulina). Journal of Zoology (London) 233: 369 ...
Photoperiods affect the development period of larvae at 20 °C (68 °F) but not at 25 °C (77 °F) and 30 °C (86 °F). As ... Yi Chuan-Hui; Chen Xiao-Ming; Shi Jun-Yi; Zhou Cheng-Li (2008). "Influence of the Photoperiod on Larvae of Kallima inachus ... The low survival rate at 30 °C under most photoperiod gradients requires that artificial breeding of K. inachus be done below ... Increasing temperature also made an increase in the survival rate under different photoperiods. The survival rate of larvae at ...
... germinated fastest under 4-h photoperiods and slowest under 24-h photoperiods at 20 °C. No differences were found between total ... A photoperiod response in germination of western hemlock seeds. 1973. Edwards, D.G.W.; Olsen, P.E. Canadian Journal of Forest ... Stratification tended to reduce the degree of response to photoperiod. Several indices of germination rate and capacity were ...
VetSmoke85 - LSD Photoperiod - DYNOMYCO 2023 - Solo Cup Challenge. VetSmoke 4 strain grow with Mars Hydro & Geoflora - Complete ... VetSmoke85 - LSD Photoperiod - DYNOMYCO 2023 - Solo Cup Challenge. VetSmoke 4 strain grow with Mars Hydro & Geoflora - Complete ... VetSmoke85 - LSD Photoperiod - DYNOMYCO 2023 - Solo Cup Challenge. VetSmoke 4 strain grow with Mars Hydro & Geoflora - Complete ... VetSmoke85 - LSD Photoperiod - DYNOMYCO 2023 - Solo Cup Challenge. VetSmoke 4 strain grow with Mars Hydro & Geoflora - Complete ...
The result showed worms had 1.5 times faster oocyte growth rates when exposed to accelerated rate of change in photoperiod (2.5 ... In experiment II, worms collected in late autumn were under mimicked or shortened seasonal changes in photoperiod to evaluate ... In experiment I, worms collected during summer were reared under constant or decreasing photoperiod and temperatures to test ... It was concluded temperature and photoperiod transition can increase the oocyte development. ...
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Here we propose a model of adaptive starch metabolism in response to various photoperiods. We assume the three key metabolic ... Here we propose a model of adaptive starch metabolism in response to various photoperiods. We assume the three key metabolic ... We performed gradient descents for various photoperiod conditions to find the corresponding optimal sets of phase shifts that ... We performed gradient descents for various photoperiod conditions to find the corresponding optimal sets of phase shifts that ...
The coincidence of photoperiod-responsive vernalization genes with photoperiod QTL suggests vernalization genes should also be ... Photoperiod and vernalization regulate the vegetative to reproductive phase transition, and photoperiod regulates expression of ... Positional relationships between photoperiod response QTL and photoreceptor and vernalization genes in barley.. Title. ... Positional relationships between photoperiod response QTL and photoreceptor and vernalization genes in barley.. ...
Methods of photoperiod control. Photoperiod control is necessary for scheduling greenhouse crops such as mum, kalanchoe, ... For example, a 12-hour photoperiod consists of 12 hours of light and 12 hours of darkness, whereas an 8-hour photoperiod ... may make the actual photoperiod shorter than estimated photoperiod (Table 2). Another important question is, can moonlight ... Photoperiod Control Systems for Greenhouse Crops. Daylength exerts profound effects on the growth and flowering of many plant ...
Photo periods in bloom! Share your pics and advice. JavaScript is disabled. For a better experience, please enable JavaScript ...
To ensure that only new shoots and new floral buds produced after the photoperiod manipulation treatments were taken into ...
Male hamsters were gestated in long photoperiods and remained in long photoperiods postnatally, or were transferred to an ... Divergent reproductive responses to the same intermediate photoperiod depend on a photoperiod history, communicated during ... and immune function following exposure to short photoperiods. Photoperiods of intermediate-duration, encountered in nature by ... Effects of photoperiod history on immune responses to intermediate day lengths in Siberian hamsters (Phodopus sungorus).. ...
Influence of photoperiod, photosynthetic photon flux, and temperature on growth of Canary Island ivy. / Al-Juboory, Karim H.; ... Influence of photoperiod, photosynthetic photon flux, and temperature on growth of Canary Island ivy. HortScience. 1998;33(2): ... Influence of photoperiod, photosynthetic photon flux, and temperature on growth of Canary Island ivy. In: HortScience. 1998 ; ... title = "Influence of photoperiod, photosynthetic photon flux, and temperature on growth of Canary Island ivy", ...
Sorghum is known as a short day plant requiring short photoperiods (PP) to flower. However, in field experiments based on ... The results indicate that the common concepts of a gradual (linear, or quantitative) response of photoperiod-induced phase (PIP ... Does panicle initiation in tropical sorghum depend on day-to-day change in photoperiod? ... In order to investigate these contradictory results, three tropical sorghum varieties of different photoperiod sensitivity were ...
Increasing photoperiod[edit]. Cyanobacteria tend to consume nearly as much oxygen at night as they produce during the day. ... However, experiments demonstrate that cyanobacterial mats produce a greater excess of oxygen with longer photoperiods. The ...
... our exclusive photoperiod strain with a captivating lineage. This extraordinary cultivar is the result of a careful ... We have the Best Genetics and now carry photoperiod seeds. Now at an unbeatable 40% discount with code AUTO40 at checkout. To ... Autoflowers are great for indoor grows as well with much shorter seed to harvest time than traditional photoperiod seeds. In ... Explore our diverse menu below, and find the perfect autoflower and photoperiod strains to elevate your winter growing ...
Photoperiod. December 28, 2022 2022-12-28 14:55 « Back to Glossary Index. The amount of time that it is light or dark in a day ...
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We encourage all customers to follow the laws set forth by their Country, State / Province and local municipalities. All Seeds & Clones sold are FOR NOVELTY & PRESERVATION PURPOSES ONLY! By visiting this website you acknowledge that you are over 21 and you are going to adhere to whatever laws your state has on record. You also release Seed Canary LLC of any liability or legal issues as we are assuming that you are purchasing them strictly for legal uses.. EVERYTHING SOLD ON SEED CANARY CONTAINS LESS THAN 0.03% THC. #text-170074330 { font-size: 0.75rem; } @media (min-width:550px) { #text-170074330 { font-size: 0.9rem; } } @media (min-width:850px) { #text-170074330 { font-size: 1rem; } } ...
LEGALITY OF CANNABIS SEEDS IN THE UK AND IRELAND. WE SELL OUR SEEDS FOR SOUVENIR PURPOSES ONLY AND FOR GENETIC PRESERVATION IN CASE OF A FUTURE LAW CHANGE. IT IS ILLEGAL TO GERMINATE CANNABIS SEEDS IN THE UK AND IRELAND AND WE WILL NOT ANSWER QUESTIONS RELATING TO GERMINATION OR GROWING. IF YOUR INTENT IS TO GERMINATE SEEDS WE WILL REFUSE THE SALE. STRAIN DESCRIPTIONS ARE PROVIDED BY THE BREEDERS WHO OPERATE IN LEGAL LOCATIONS AND SHOW THE GENETIC TRAITS OF THE STRAIN ...
Photoperiod on the FLD or FFD was used as a proxy of photoperiod condition for the two phenological events (Fu, Zhang, et al., ... 1st quantile of photoperiod), medium (between 1st and 3rd quantiles) and long (,3rd quantile) photoperiod, and further checked ... Although photoperiod does not change with warming, plants experience shorter photoperiod prevailing at the earlier occurrence ... Fu, Y. H., Piao, S., Zhou, X., Geng, X., Hao, F., Vitasse, Y., & Janssens, I. A. (2019). Short photoperiod reduces the ...
Role of the photoperiod in altering the response of the hypothalamic hypophyseal axis to the inhibitory effects of testosterone ... Role of the photoperiod in altering the response of the hypothalamic hypophyseal axis to the inhibitory effects of testosterone ... Role of the photoperiod in altering the response of the hypothalamic hypophyseal axis to the inhibitory effects of testosterone ... Role of the photoperiod in altering the response of the hypothalamic hypophyseal axis to the inhibitory effects of testosterone ...
Photoperiod Cannabis Seeds. Photoperiod is a word that describes the amount of light vs. dark time that a plant needs to grow. ... This light cycle translates to a photoperiod of 18/6. This type of photoperiod imitates early spring conditions for our ... Typically, cannabis plant varieties begin their flowering stage growth based on photoperiod.. ...
Ana Sayfa / PHOTO-PERIOD SEEDS. Filtrele Gösterilen sonuç sayısı: 7. Varsayılan Sıralama. En çok incelenene göre sırala. En çok ...
... GREEN MOUNTAIN GENETICS Autoflower. GREEN MOUNTAIN CHEDDAR , 5-pack $60. ...
Many genes and biochemical processes control how a plant responds to the photoperiod. The creation and movement of the hormone ... In this essay, I will cover the current understanding of how plants respond to photoperiod and the molecular mechanisms ... or photoperiod. The physiological response of plants to the length of day or night is known as photoperiodism. The plant uses ... particularly variations in photoperiod or day length. Photoperiodism refers to a plants capacity to detect variations in day ...
Photoperiod, Seeds » Cannabis Seeds at North Atlantic Seed Co. » BLIMBURN SEEDS , ZOAP (RAINBOW SHERBET X PINK GUAVA) Origins ...
Effect of photoperiod on microalgae growth and biomass. Photoperiod affected the cell density and biomass of C. vulgaris (UMT- ... Photoperiod treatment. Microalgae inoculated from the stock cultures were grown under two photoperiod conditions; one was given ... Keyword: Growth biomass antioxidants photoperiod microalgae. Citation: Yusof NS, Yeong YS, Zakeri HA, Wahid MEA, Ghafar SNA, ... Table 1. Effect of photoperiod cycle on the wet and dry biomass of UMT-M1, CB, and CT.. [Click here to view] ...
Photoperiod manipulation is a common technique used in cannabis cultivation to control the plants growth and flowering cycle. ... How do you manipulate a photoperiod. Photoperiod manipulation is the practice of managing a plants exposure to light and dark ... A "photoperiod," from the Greek root photo meaning light, is a period of time exposed to light, generally a cycle of light and ... Photoperiod Manipulation for Marijuana. Equally important, if not more so than the color of light, is the duration of light ...
  • Unstratified and stratified seeds of western hemlock (Tsugaheterophylla) germinated fastest under 4-h photoperiods and slowest under 24-h photoperiods at 20 °C. No differences were found between total darkness and an 8-h photoperiod. (gc.ca)
  • We have the Best Genetics and now carry photoperiod seeds. (autoflower.ca)
  • Autoflower's are great for indoor grows as well with much shorter seed to harvest time than traditional photoperiod seeds. (autoflower.ca)
  • Introducing Slusherz Feminized Photoperiod cannabis seeds - The extremely potent euphoric cannabis strain that stands out from the rest. (supernaturalseeds.uk)
  • Slusherz Feminized Photoperiod cannabis seeds - get them while you still can. (supernaturalseeds.uk)
  • There is a constant debate in the cannabis world about the difference between Autoflower vs Photoperiod seeds many experts discuss and tackle the possible harvest time, yields, effects, and ease of growth of both Autoflower vs Photoperiod seeds comparing them and having an understanding of which seeds are the best for every grower. (cropkingseeds.com)
  • Photoperiod seeds require specific light cycles to initiate flowering, making them ideal for indoor growers who can control light exposure. (organiccatalog.com)
  • Outdoor growers can also benefit from photoperiod seeds by planting during certain seasons to ensure optimal growth. (organiccatalog.com)
  • The result showed worms had 1.5 times faster oocyte growth rates when exposed to accelerated rate of change in photoperiod (2.5 times faster). (frontiersin.org)
  • Does panicle initiation in tropical sorghum depend on day-to-day change in photoperiod? (icrisat.org)
  • Given the change in photoperiod length (longer nights and shorter days) and that bright-light therapy has an antidepressant effect, circadian rhythms have been hypothesized to contribute to the onset of SAD. (medscape.com)
  • Plants are extremely sensitive to changes in their environment, particularly variations in photoperiod or day length. (who.int)
  • Siberian hamsters (Phodopus sungorus) are long-day breeders that adjust reproductive physiology and behavior, body mass, and immune function following exposure to short photoperiods. (duke.edu)
  • Sorghum is known as a short day plant requiring short photoperiods (PP) to flower. (icrisat.org)
  • This alters exposure to the regular photoperiod ical studies of night shift work and cancer since and may disrupt circadian rhythms in humans. (who.int)
  • The result showed females collected during summer showed the highest oocyte growth when exposed to constant temperatures combined with decreasing photoperiod and decreasing temperature combined with constant photoperiod. (frontiersin.org)
  • In summary, in this paper we describe, for the first time in the sea bass, the effect of constant photoperiod regimes on the 17β-oestradiol plasma profiles, the timing of spawning and the quality of the eggs. (eauetbiodiversite.fr)
  • Explore our diverse menu below, and find the perfect autoflower and photoperiod strains to elevate your winter growing endeavours. (autoflower.ca)
  • These strains are distinct from "photoperiod" strains, which require specific signals from the sun to start flowering and need special light schedules to produce buds. (cropkingseeds.com)
  • However, a breeder recognized that the autoflowering capability and short growing period of Ruderalis could benefit hobbyist cannabis growers, so they began breeding Ruderalis plants with photoperiod strains to increase bud potency while retaining autoflowering ability. (cropkingseeds.com)
  • Photoperiod strains need at least 12 hours of daily darkness to start budding, and outdoor growers must ensure that their plants are planted in the spring and will finish flowering before winter. (cropkingseeds.com)
  • This article reviews photoperiod manipulation for marijuana, the role of red light versus blue light, and explores autoflowering marijuana as an alternative. (potguide.com)
  • Autoflowering cannabis plants typically have a shorter growing period and are ready for harvest earlier than photoperiod plants. (cropkingseeds.com)
  • Unlike photoperiod plants, autoflowering plants continue to grow taller while buds are forming. (cropkingseeds.com)
  • Even when grown from seed, photoperiod plants take longer to reach maturity than autoflowering plants, and their yields are often lower. (cropkingseeds.com)
  • This article briefly reviews photoperiodism and photoperiod control systems for greenhouses. (umass.edu)
  • The terms photoperiod and photoperiodism are commonly used in extension bulletins and other literature, but what actually do these terms mean? (umass.edu)
  • Through a process known as photoperiodism, plants can detect and react to variations in the number of daylight hours, or photoperiod. (who.int)
  • The regulation of flowering in response to day length or photoperiod is called photoperiodism . (ufl.edu)
  • Thus, for photoperiodic responses, photoperiods are estimated by adding the periods of civil twilight to the duration of daylight. (umass.edu)
  • Scholars@Duke publication: Effects of photoperiod history on immune responses to intermediate day lengths in Siberian hamsters (Phodopus sungorus). (duke.edu)
  • Divergent reproductive responses to the same intermediate photoperiod depend on a photoperiod history, communicated during gestation. (duke.edu)
  • These experiments assessed whether photoperiod history during gestation likewise impacts immunological responses to intermediate photoperiods. (duke.edu)
  • Using long-term phenological records in Europe, we examined simultaneously the responses of both leaf-out and flowering of four common temperate tree species to climate warming and further examined the effects of winter chilling, spring forcing and photoperiod on the responses of the two events. (wiley.com)
  • The role of photoperiods in the development of antioxidants and their responses to microalgae, however, is poorly understood. (japsonline.com)
  • The goal of this study was to determine the effect of the photoperiod on growth and antioxidant responses of three species of marine microalgae, Chlorella vulgaris , Isochrysis galbana (CB) , and Tetraselmis chuii (CT), commonly found in tropical brackish and marine environments. (japsonline.com)
  • Genetic analysis and QTL detection of reproductive period and post-?owering photoperiod responses in soybean. (xjegi.com)
  • The effects of selected environmental factors [temperature, photosynthetic photon flux (PPF), and photoperiod] that contribute to optimal vegetative growth of Canary Island ivy (Hedera canariensis Willd. (illinois.edu)
  • Postflowering photoperiod regulates vegetative growth and reproductive development of soybean. (xjegi.com)
  • Winterhardiness has three primary components: photoperiod (day length) sensitivity, vernalization response, and low temperature tolerance. (oregonstate.edu)
  • In order to investigate these contradictory results, three tropical sorghum varieties of different photoperiod sensitivity were planted monthly in Mali and the dates of panicle initiation (PI) were recorded. (icrisat.org)
  • However, the photoperiod sensitivity is not observed in the cultivars of highlands such as Peru, Bolivia and coastal parts of Chile (Curti et al. (springer.com)
  • The sensitivity of the Nicotiana plumbaginifolia wild-type and phytochrome B (hlg) mutant to photoperiod was investigated. (illinois.edu)
  • Three different experiments were conducted to examine the oocyte development of the polychaete Hediste diversicolor in response to changing photoperiod and temperature at three different periods of oogenesis. (frontiersin.org)
  • In experiment I, worms collected during summer were reared under constant or decreasing photoperiod and temperatures to test the combined effects of the summer-autumn photoperiod and temperature transition on oogenesis. (frontiersin.org)
  • It was concluded temperature and photoperiod transition can increase the oocyte development. (frontiersin.org)
  • 11 h light) coupled with an endogenous timer synchronizes spawning of the first cohort of oocytes in Harmothoe imbricate L. The authors also mentioned that in H. imbricate vitellogenesis was favored by low temperature and increasing photoperiod. (frontiersin.org)
  • Bud endodormancy is induced by a decreasing photoperiod and/or low temperature during autumn. (sdstate.edu)
  • In Vitis there is considerable variation in response to photoperiod, with some genotypes becoming endodormant in response to a decreasing photoperiod (SD) and others requiring low temperature to induce dormancy. (sdstate.edu)
  • Seyval' ('Seyve Villard 5-276'), which has a higher chilling requirement and a short critical photoperiod and/or low temperature requirement for dormancy induction, their F 1 , and F 2 and BC populations. (sdstate.edu)
  • Photoperiod and vernalization regulate the vegetative to reproductive phase transition, and photoperiod regulates expression of key vernalization genes. (oregonstate.edu)
  • The Photoperiod-Driven Cyclical Secretion of Pineal Melatonin Regulates Seasonal Reproduction in Geese ( Anser cygnoides ). (bvsalud.org)
  • Using two barley mapping populations, we mapped six individual photoperiod response QTL and determined their positional relationship to the phytochrome and cryptochrome photoreceptor gene families and the vernalization regulatory genes HvBM5A, ZCCT-H, and HvVRT-2. (oregonstate.edu)
  • It was concluded that the B-type phytochrome absent in the hlg mutant is required for the measurement of photoperiod duration in N. plumbaginifolia, but is not required for entrainment of the circadian clock. (illinois.edu)
  • Hudson, M & Smith, H 1998, ' The phytochrome B encoded by the HLG locus of Nicotiana plumbaginifolia is required for detection of photoperiod: hlg mutants show altered regulation of flowering and circadian movement ', Plant Journal , vol. 15, no. 2, pp. 281-287. (illinois.edu)
  • It should be noted that local conditions, i.e., shading from trees or adjacent buildings, persistant cloudiness, or fog, may make the actual photoperiod shorter than estimated photoperiod (Table 2). (umass.edu)
  • Both photoperiod extension and night interruption are common practices used by greenhouse growers to inhibit flowering of short-day plants. (ufl.edu)
  • Achieving photoperiod manipulation for marijuana indoors , like in a grow tent , is much easier. (potguide.com)
  • Samples were incubated indoors for the photoperiod-specific to the time of the year. (cdc.gov)
  • Genetic Segregation for Indicators of Photoperiod Control of Dormancy " by Anne Fennell, Kathy Mathiason et al. (sdstate.edu)
  • This system includes: a long critical photoperiod (dormancy induction), cold hardy, lower chilling requirement V. riparia parent, a less cold hardy parent, Vitis sp. (sdstate.edu)
  • Let's begin with a crash course in earth science because to fundamentally understand photoperiod manipulation, growers should understand the photoperiod we are manipulating. (potguide.com)
  • Welcome to the enchanting realm of Sunset Sherbet, our exclusive photoperiod strain with a captivating lineage. (autoflower.ca)
  • Auxin, photoperiod and putrescine are factors involved in the control of the reproductive phase of the flowering process in planta. (uniroma1.it)
  • For example, a 12-hour photoperiod consists of 12 hours of light and 12 hours of darkness, whereas an 8-hour photoperiod consists of 8 hours of light and 16 hours of darkness. (umass.edu)
  • The effect of photoperiod after photostimulation on male broiler breeder fertility. (ukzn.ac.za)
  • Stratification tended to reduce the degree of response to photoperiod. (gc.ca)
  • Here we propose a model of adaptive starch metabolism in response to various photoperiods. (frontiersin.org)
  • Positional relationships between photoperiod response QTL and photoreceptor and vernalization genes in barley. (oregonstate.edu)
  • Of the six photoreceptors mapped in the current study (HvPhyA and HvPhyB to 4HS, HvPhyC to 5HL, HvCry1a and HvCry2 to 6HS, and HvCry1b to 2HL), only HvPhyC coincided with a photoperiod response QTL. (oregonstate.edu)
  • Each of these three vernalization genes is located in chromosome regions determining small photoperiod response QTL effects. (oregonstate.edu)
  • In this essay, I will cover the current understanding of how plants respond to photoperiod and the molecular mechanisms underpinning this response. (who.int)
  • Analysis of this trait indicates that it is heritable and may be controlled largely by a single locus with the longer critical photoperiod response of the V. riparia parent being dominant. (sdstate.edu)
  • Photoperiods of intermediate-duration, encountered in nature by juvenile hamsters born in early-spring and by those born in mid-summer, trigger gonadal development in the former cohort and inhibit the onset of puberty in the latter. (duke.edu)
  • At 51 weeks of age, testes weights were affected by the degree of photostimulation with a trend of lower testes weights from birds on longer photoperiods which suggests the earlier onset of adult photorefractoriness in birds on longer photoperiods. (ukzn.ac.za)
  • However, in field experiments based on monthly plantings reported elsewhere, panicle initiation took place during long days as well as during short days even for highly photoperiod-sensitive varieties thought to be of the absolute type, or was particularly early for the sowings in September, well before days were shortest. (icrisat.org)
  • Typically, cannabis plant varieties begin their flowering stage growth based on photoperiod. (joecettina.com)
  • The coincidence of photoperiod-responsive vernalization genes with photoperiod QTL suggests vernalization genes should also be considered candidates for photoperiod effects. (oregonstate.edu)
  • The data suggest that photoperiodic mechanisms that enhance and suppress several aspects of immunity in young-adult hamsters are not responsive to prenatally communicated photoperiod history information. (duke.edu)
  • This type of photoperiod imitates early spring conditions for our cannabis plants with long days and short nights. (joecettina.com)
  • Photoperiod plants require a vegetative stage before flowering and are not well-suited for quick harvests. (cropkingseeds.com)
  • At 42o N. latitude, the photoperiod (=daylight plus civil twilight) varies from 10 hours and 11 minutes on December 21 (winter solstice) to 16 hours and 25 minutes on June 23 (summer solstice) (Table 2). (umass.edu)
  • In experiment II, worms collected in late autumn were under mimicked or shortened seasonal changes in photoperiod to evaluate the effect of accelerated change on oocyte growth. (frontiersin.org)
  • A photoperiod is the duration of light within a particular time span, usually a 24-hour period. (umass.edu)
  • other males were gestated in short days and transferred to an intermediate-duration photoperiod at birth. (duke.edu)
  • In the stored data screen, it shows the DLI measurement, photoperiod, and which day the data was collected (up to 99 days ago). (hoskin.ca)
  • We performed gradient descents for various photoperiod conditions to find the corresponding optimal sets of phase shifts that minimize starvation. (frontiersin.org)
  • Leaf number at bolting and rosette-leaf movement were measured under conditions of different light quality and photoperiod. (illinois.edu)
  • In a replicated field planting of the F 2 and BC populations, summer lateral emergence was used for determining photoperiod responsiveness. (sdstate.edu)
  • Careful control of carbon partitioning, starch degradation, and sucrose export rates is crucial to avoid carbon starvation, insuring optimal growth whatever the photoperiod. (frontiersin.org)
  • Both DLI and photoperiod influence plant growth and development, and they are often measured in greenhouses and growth chambers to aid in light management and decision making. (hoskin.ca)
  • Photoperiod is a word that describes the amount of light vs. dark time that a plant needs to grow. (joecettina.com)
  • This light cycle translates to a photoperiod of 18/6. (joecettina.com)
  • Light and photoperiod affect microalgae accumulation of antioxidants. (japsonline.com)
  • A "photoperiod," from the Greek root photo meaning light, is a period of time exposed to light, generally a cycle of light and dark. (potguide.com)
  • In addition to measuring ePAR, the DLI-600 meter calculates daily light integral (DLI) and photoperiod. (hoskin.ca)
  • 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. (bvsalud.org)
  • Photoperiod is the total amount of time in which PAR or ePAR is incident on a plane during a 24-hour period and is expressed in units of hours (h). (hoskin.ca)
  • The numbers of sperm trapped in the perivitelline layer of a hen's egg, and the probability of the egg being fertile, were significantly affected by the photoperiod, age of the male and the time elapsed between artificial insemination and the laying of the egg. (ukzn.ac.za)
  • Behavioral tolerance to endotoxin is enhanced by adaptation to winter photoperiods. (uchicago.edu)
  • For example, cultivars grown close to equator, mainly in Colombia, are more photoperiod-sensitive. (springer.com)
  • Semen characteristics were generally not affected by the final photoperiod apart from the semen concentration measured at female ASM. (ukzn.ac.za)
  • HvBM5A and HvPhyC are closely linked on 5HL and therefore are currently both positional candidates for the same photoperiod effect. (oregonstate.edu)
  • By contrast, photoperiod during gestation did not affect most immune endpoints. (duke.edu)
  • We recently mapped the candidate genes for the 5HL VRN-H1 (HvBM5A) and 4HL VRN-H2 (ZCCT-H) loci, and in this study, we mapped HvVRT-2, the barley TaVRT-2 ortholog (a wheat flowering repressor regulated by vernalization and photoperiod) to 7HS. (oregonstate.edu)

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