(n.) The act of extinguishing or making extinct; a putting an end to; the act of putting out or destroying light, fire, life, activity, influence, etc.
(n.) State of being extinguished or of ceasing to be; destruction; suppression; as, the extinction of life, of a family, of a quarrel, of claim.
Example Sentences:
(1) The stages of mourning involve cognitive learning of the reality of the loss; behaviours associated with mourning, such as searching, embody unlearning by extinction; finally, physiological concomitants of grief may influence unlearning by direct effects on neurotransmitters or neurohormones, such as cortisol, ACTH, or norepinephrine.
(2) The effect upon ethanol responding was found not to resemble a pattern of extinction, but rather was best described as a general overall reduction in responding.
(3) In a recent study, Orr and Lanzetta (1984) showed that the excitatory properties of fear facial expressions previously described (Lanzetta & Orr, 1981; Orr & Lanzetta, 1980) do not depend on associative mechanisms; even in the absence of reinforcement, fear faces intensify the emotional reaction to a previously conditioned stimulus and disrupt extinction of an acquired fear response.
(4) We conclude that the procedure used in this study is a non-intrusive intervention that is an extension of the current literature pertaining to sensory extinction.
(5) After 40 programmed minutes of acquisition and 12 min of maintenance, without notice, both schedules changed to extinction for 28 min.
(6) This differential absorbance is linear with increasing concentrations of Na2MoO4 and was used to calculate the molar extinction coefficient of molybdochelin at 425 nm (epsilon similar to 6,200).
(7) However, during massed testing, all subjects trained with response contingent CS termination showed an overall extinction influence, which was most pronounced in the medial subgroup, although the laterals showed frequency control as well.
(8) When reinforcement for competing behavior was withdrawn, however, rats resumed their original behavior and there were no overall savings in total responses to extinction.
(9) The relative amount of the crystals was measured in both amoeba strains on the basis of the integral extinction value.
(10) Chronic extinction of chain closed conditioned reflex in intact rabbits took five to six days.
(11) The amounts of phosphatidylcholine and sphingomyelin could be determined by high-performance liquid chromatography and ultraviolet absorption if the apparent extinction coefficient of the material analyzed was established.
(12) In a number of neurones the extinction of reflexes either does not change the reaction to acetylcholine, or enhances it.
(13) In Experiment 3, following an unsignaled reinforcement delay, groups receiving either no event or signaled food in the context responded faster in extinction than groups receiving no context exposure or unsignaled food.
(14) The optical extinction decreases as the red cell agglutinates grow, giving a parametric estimate of the haemagglutination rate.
(15) By calculating for DNA standard solutions the value of the ratio between the extinction at 665 nm after 15 min to the extinction of 600 nm after 2 min of the orcinol reaction it is possible to increase specifiaty of the orcinol method for determination of the RNA content.
(16) To lose the Sundarbans would be to move a step closer to the extinction of these majestic animals," said ZSL tiger expert Sarah Christie.
(17) Values obtained for thebuoyant density, isoelectric point, and extinction coefficient differed minimally; major differences were observed in the molecular weight and the characterisitc width of cylinders formed by in vitro-assembled T-layer of the wild-type and variant.
(18) The CS+ preference persisted for several weeks during extinction tests when both the CS+ and CS- were paired with IG water or with no infusions.
(19) The extinction coefficient at 550 nm for the oxidized enzyme is about 5300 (M subunit)-1 X cm-1.
(20) On this planet, extinction is the norm – of the 4 billion species ever thought to have evolved, 99% have become extinct.
Scattering
Definition:
(p. pr. & vb. n.) of Scatter
(a.) Going or falling in various directions; not united or aggregated; divided among many; as, scattering votes.
(n.) Act of strewing about; something scattered.
Example Sentences:
(1) Using an in vitro culture system, light scatter analyses, and two-color flow cytometry, we provide evidence that the interleukin-2 (IL-2) and transferrin receptors can be induced within 48 hr on nonproliferating immature thymocytes.
(2) We identified four distinct clinical patterns in the 244 patients with true positive MAI infections: (a) pulmonary nodules ("tuberculomas") indistinguishable from pulmonary neoplasms (78 patients); (b) chronic bronchitis or bronchiectasis with sputum repeatedly positive for MAI or granulomas on biopsy (58 patients, virtually all older white women); (c) cavitary lung disease and scattered pulmonary nodules mimicking M. tuberculosis infection (12 patients); (d) diffuse pulmonary infiltrations in immunocompromised hosts, primarily patients with AIDS (96 patients).
(3) Proliferating cells were abundant and scattered throughout the stratified epithelium before the appearance of villi.
(4) Furthermore, experiments with the fluorescence-activated cell sorter revealed increased forward light scatter from resting exudate PMN compared to blood PMN.
(5) Quantitative measurements of image contrast were carried out for B-mode images of anechoic spheres (cysts) embedded in a random scattering medium.
(6) The angular distribution of the scattered light was obtained as a function of time and compared with the rates at which hydrolysis products were formed.
(7) It is found that, whereas the spatial resolution achievable with such a system is only dependent upon its temporal resolution, the scattering characteristics of the tissue being imaged will strongly affect the ultimate imaging performance of such a system.
(8) In these cells no autonomous periodic activities were observed by light scattering.
(9) The scatter measurement was made using a standard imaging geometry with both beam stops and an additional x-ray detector placed behind the standard imaging detector.
(10) Type C-like particles were found inter- and intracellularly in gland and vessel lumina and scattered in the connective tissue.
(11) Modifications in quaternary structure induced by variation of these physicochemical parameters were followed by means of X-ray and quasi-elastic light-scattering and quantified in terms of weight average molecular weight (M), radius of gyration (Rg) and hydrodynamic radius (Rh).
(12) Cape no longer has the monopoly on talent; the stars are scattered these days, and Franklin's "fantastically discriminating" deputy Robin Robertson can take credit for many recent triumphs, including their most recent Booker winner, Anne Enright.
(13) Dome-shaped, fungiform papillae were scattered among these filiform papillae.
(14) Visible light activates a large guanosine cyclic 3',5'-phosphate (cGMP)- and phosphodiesterase (PDE)-dependent infrared light-scattering change in suspensions of photoreceptor disk membranes.
(15) The angular distribution of the scattered acoustic field from an inosonifying source will directly relate to the distribution of surface fibrillatory changes.
(16) The electron spectroscopic diffraction (ESD) mode of operation of an energy-filtering electron microscope offers the possibility of being able to avoid the background from inelastic scattering in selected-area electron diffraction patterns.
(17) Single particles or small clusters were scattered across the cell membrane.
(18) Fibrinogen was scattered in the intercellular spaces, and located in the inner layer or edges of the thickened intima of the bifurcation with increasing plaque formation.
(19) From the different shapes of the scattering curves of the native phosphofructokinase at pH 7.5 in the presence of 15 mM ATP and of the cross-linked tetramer or octamer, it can be inferred that the shapes of the protomers are different: in the presence of ATP the protomers are elongated, having an axial ratio of 1.8 to 2.0; the cross-linked state reveals a spherical protomer of radius 33.0 A, similar to that of the native enzyme at pH 7.5 in the presence of fructose 6-phosphate or fructose 1,6-bisphosphate.
(20) Cells taking up label are found scattered throughout the large cartilaginous epiphyses.