(n.) A cleaving, splitting, or breaking up into parts.
(n.) A method of asexual reproduction among the lowest (unicellular) organisms by means of a process of self-division, consisting of gradual division or cleavage of the into two parts, each of which then becomes a separate and independent organisms; as when a cell in an animal or plant, or its germ, undergoes a spontaneous division, and the parts again subdivide. See Segmentation, and Cell division, under Division.
(n.) A process by which certain coral polyps, echinoderms, annelids, etc., spontaneously subdivide, each individual thus forming two or more new ones. See Strobilation.
Example Sentences:
(1) Primer extension experiments show that in fission yeast transcripts are initiated at the same starting point as in tomato, indicating for the first time that a plant promoter can be correctly recognized in fission yeast.
(2) When the reactor is running, high-speed particles called neutrons strike the uranium atoms and cause them to split in a process known as nuclear fission.
(3) On the basis of hystological studies a description of fission and gastrulation in Microsomacanthus paramicrosoma (gasowska, 1931) is given.
(4) However, in conical cells the new oral apparatus and fission line form well posterior to the cell equator, so the opisthes are invariably smaller than proters.
(5) We have cloned the gene for the resident luminal ER protein BiP from the fission yeast, Schizosaccharomyces pombe.
(6) A strain of fission yeast carrying replicating instability (RI) will segregate mitotically three types of cells: unstable (still RI-carrying) cells, stable identical mutants and stable non-mutants.
(7) The present data demonstrate that whereas most ssb caused by exposure to fission-spectrum neutrons can be rapidly repaired by both cell lines, a small but statistically significant fraction of the ssb induced by exposure to 6 Gy of neutrons is refractory to repair.
(8) 1965.-Thin sections of filterable hemolytic anemia agent of rat, now identified as Haemobartonella muris, revealed (i) that the agent is spherical or ellipsoidal and 350 to 700 mmu in size, (ii) that it has a single limiting membrane enclosing granules and some filaments (neither cell wall nor nucleoid was found), and (iii) that it is found preferentially at the surface and sometimes within the cytoplasmic vacuoles of erythrocytes in the circulating blood and bone marrow, and multiplies there through binary fission.
(9) The cyclin of fission yeast is the product of the cdc13 gene, which is known to interact with cdc2, a gene required for the entry into mitosis.
(10) of fission neutrons for the induction of yellow-green sectors in maize.
(11) Comparison of the identified fission sites of the B. subtilis neutral proteinase with the known substrate-specificity of the enzyme indicated that they were in agreement, showing a preference for the generation of fissions at the N-terminal side of large hydrophobic residues, such as leucine, isoleucine and methionine.
(12) These acrocentrics were also suggested to be originated from Robertsonian fission of the large metacentric M1 chromosome.
(13) In fission yeast the ability to undergo meiosis and sporulation is conferred by the matP+ and matM+ genes of the mating-type locus.
(14) Furthermore, the protein is highly similar to the fission yeast spi1 gene product [Matsumoto and Beach, Cell 66 (1991) 347-360].
(15) However, energy will either be provided from fossil fuels, nuclear fission or renewables.
(16) The ring-fission product of catechol was formed from phenol by a fluorescent Pseudomonas, that of 3-methylcatechol was formed from o-cresol and m-cresol, and the ring-fission product of 4-methylcatechol was given from p-cresol.
(17) The pho4 gene of the fission yeast Schizosaccharomyces pombe is regulated by thiamin.
(18) The author interprets the formation of exposure factors in a nuclear reactor accident, causes of the formation of a separated mixture of nuclear fission fragments and their principal radionuclide composition.
(19) A model of fission into subdivisions is superimposed on the previous branching process, and variation between subdivisions is considered.
(20) As measured by sectors per krad, mutagenic efficiency increased with increased dose of gamma-radiation; the opposite was true for fission neutrons.
Nucleus
Definition:
(n.) A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively.
(n.) The body or the head of a comet.
(n.) An incipient ovule of soft cellular tissue.
(n.) A whole seed, as contained within the seed coats.
(n.) A body, usually spheroidal, in a cell or a protozoan, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see Nucleoplasm). See Cell division, under Division.
(n.) The tip, or earliest part, of a univalve or bivalve shell.
(n.) The central part around which additional growths are added, as of an operculum.
(n.) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks.
Example Sentences:
(1) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(2) The present results provide no evidence for a clear morphological substrate for electrotonic transmission in the somatic efferent portion of the primate oculomotor nucleus.
(3) In the caudal spinal trigeminal nucleus (Vc), the collaterals of one half of the periodontium afferent fibers terminated mainly in lamina V at the rostral and middle levels of Vc.
(4) It is concluded that in the mouse model the ability of buspirone to reduce the aversive response to a brightly illuminated area may reflect an anxiolytic action, that the dorsal raphe nucleus may be an important locus of action, and that the effects of buspirone may reflect an interaction at 5-hydroxytryptamine receptors.
(5) hypoglossal nucleus), whereas in other areas the angiotensinogen gene was expressed only in a certain population of glial cells.
(6) Local application of 8-OH-DPAT (0-5 micrograms) into the median raphe nucleus, facilitated male rat sexual behavior, as evidenced by a decrease in number of intromissions preceding ejaculation and in time to ejaculation.
(7) In addition, lightly immunostained cells were distinguished in the caudal portion of the hypothalamic arcuate nucleus, area of tuber cinereum, retrochiasmatic area, and rostral portion of the paraventricular thalamic nucleus after colchicine treatment.
(8) Arising of the nucleus from a polyheteronomous nucleoid of proeukaryotes.
(9) It is possible that the IgE that linked abnormally with the propofol had specific binding sites for the phenyl nucleus and the isopropyl groups, which are present in propofol and many other drugs.
(10) We conclude that neuronal activities in the region of the retrofacial nucleus are important both in the integration of stimuli from the central chemoreceptors and in defining the discharge patterns of respiratory neurons.
(11) A 68 year-old man with a history of right thalamic hemorrhage demonstrated radiologically in the pulvinar and posterior portion of the dorsomedian nucleus developed a clinical picture of severe physical sequelae associated with major affective, behavioral and psychic disorders.
(12) While the heaviest anterogradely labeled ascending projections were observed to the contralateral ventral posterolateral nucleus of the thalamus, pars oralis (VPLo), efferent projections were also observed to the contralateral ventrolateral thalamic nucleus (VLc) and central lateral (CL) nucleus of the thalamic intralaminar complex, magnocellular (and to a lesser extent parvicellular) red nucleus, nucleus of Darkschewitsch, zona incerta, nucleus of the posterior commissure, lateral intermediate layer and deep layer of the superior colliculus, dorsolateral periaqueductal gray, contralateral nucleus reticularis tegmenti pontis and basilar pontine nuclei (especially dorsal and peduncular), and dorsal (DAO) and medial (MAO) accessory olivary nuclei, ipsilateral lateral (external) cuneate nucleus (LCN) and lateral reticular nucleus (LRN), and to a lesser extent the caudal medial vestibular nucleus (MVN) and caudal nucleus prepositus hypoglossi (NPH), and dorsal medullary raphe.
(13) In contrast to this, adrenalectomy decreased ANP levels markedly in the organum vasculosum laminae terminalis and preoptic periventricular nucleus, which are reportedly involved in the central regulation of salt and water homeostasis.
(14) The shape of the nucleus changes from ovoid to a distinctive, radially splayed lobulated structure.
(15) Immunocytochemical analysis also suggested that bFGF immunoreactivity was present in the nucleus as well as the cytoplasm of astrocytes and CA2 neurons.
(16) The effect of Y-516 on the hyperactivity induced by dopamine injected bilaterally into the nucleus accumbens was compared with those of clocapramine (CCP), haloperidol (HPD) and chlorpromazine (CPZ).
(17) Moderately differentiated tumor revealed a wider range of nucleus size, less clustering (coefficient--3.59) and more hyperchromatic (70.1%) and "bare" (49.4%) nuclei and large nucleoli (22.2%).
(18) The majority of intensively stained and densely packed cells have been observed in tv nucleus.
(19) Following electrical stimulation of the hypothalamic paraventricular nucleus (PVN) area, 21% of the neurons were orthodromically excited, 6% were inhibited and 2.5% were antidromically activated.
(20) Proenkephalin A-related immunoreactive neuronal perikarya were detected in the central gray, reticular formation, nucleus raphes, trapezoid body, nucleus parabrachialis lateralis and medialis, nucleus spinalis nervi trigemini, nucleus dorsalis nervi vagi, and in the nucleus tractus solitarii.