(a.) Extinguished; put out; quenched; as, a fire, a light, or a lamp, is extinct; an extinct volcano.
(a.) Without a survivor; without force; dead; as, a family becomes extinct; an extinct feud or law.
(v. t.) To cause to be extinct.
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(8) When reinforcement for competing behavior was withdrawn, however, rats resumed their original behavior and there were no overall savings in total responses to extinction.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.
Vestigial
Definition:
(a.) Of or pertaining to a vestige or remnant; like a vestige.
Example Sentences:
(1) We describe herein, a new unstable mutant of the vestigial locus, isolated from a French natural population.
(2) The ischiocavernosus and bulbospongiosus muscles are vestigial in the female rat.
(3) Anal transitional epithelium is not highly specialized and incorporates features of both urothelium and squamous epithelium; slight urothelial differentiation is considered vestigial.
(4) The 17-DOS, while a vestigial pathway, may still cause disease, and provide clues to central organization of the adreno-cortical response to injury, stress, and disease.
(5) This leg was connected with two sets of coxae by a irregular-shaped bone considered the vestigial vertebrae and ribs.
(6) Two cases of idiopathic soft tissue calcification occurring in the vestigial fingers of infants with congenital brachydactyly are reported.
(7) The DNA-containing nucleomorph of cryptomonad algae appears to be the vestigial nucleus of such an algal endosymbiont.
(8) The short cysteine-containing motif represented the only evidence of a possible vestigial relationship between SP-40,40 and other complement components.
(9) The protamine-mRNA-coding region is flanked by AACA... TGTT sequences, which might represent vestigial traces of past recombination events and whose presence supports the notion that the protamine gene sequence was of foreign origin.
(10) We present a cyst arising from vestigial thymic remnants in the neck.
(11) The dorsal ommatidia have only four full-length typical cells, and one distal and three vestigial full-length cells.
(12) This is in spite of the lack of flight ability in both mutants, the reduced enzyme activity levels in the alpha-glycerophosphate mutant, and in the case of the vestigial flies, of reduced life-span.
(13) A third type characterized by its vestigial callus was found only in histologic sections.
(14) One patient had a vestigial radial artery that ended as muscular branches in the forearm.
(15) Vestigial mutants however, present several alterations including the absence of the ovoid projection, a fact consistent with the existence of very few marginal bristles.
(16) These data, together with the sequence homologies and identical cofactors and substrates, led us to propose that the AHAS enzymes are descended from pyruvate oxidase (or a similar protein) and, thus, that the flavin requirement of the AHAS enzymes is a vestigial remnant, which may have been conserved to play a structural rather than a chemical function.
(17) Goats with dependent ear types were infested more commonly than those with erect ears; no goats with vestigial ears were found to harbor mites.
(18) The hypothesis predicts that if IL-3 is a significant in vivo regulator of megakaryocyte formation and development, receptor for IL-3 should be present on megakaryocytes and may be vestigially on platelets.
(19) Urogenital cysts are retroperitoneal or mesenteric cysts that are derived from vestigial remnants of the embryonic urogenital apparatus.
(20) The absence of the lower portion of the orbicularis oris muscle, the death of tissue in the infralabial region, as well as the presence of only a vestigial lower lip has hitherto not been reported in the literature.