position effect


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effect

 [ĕ-fekt´]
a result produced by an action.
additive effect the combined effect produced by the action of two or more agents, being equal to the sum of their separate effects.
adverse effect a symptom produced by a drug or therapy that is injurious to the patient.
Bainbridge effect Bainbridge reflex.
Bohr effect decreased affinity of hemoglobin for oxygen caused by an increase of carbon dioxide; the oxyhemoglobin dissociation curve is displaced to the right because of higher partial pressure of carbon dioxide and lower pH. See also Haldane effect.
The Bohr effect causing a shift to the right in the oxyhemoglobin dissociation curve.
Crabtree effect the inhibition of oxygen consumption on the addition of glucose to tissues or microorganisms having a high rate of aerobic glycolysis; the converse of the Pasteur effect.
cumulative effect the action of a drug or treatment resulting from repeated use.
Doppler effect see doppler effect.
experimenter e's demand characteristics.
extrapyramidal e's the side effects caused by neuroleptic medications, including dystonias, parkinsonism, akathisia, and tardive dyskinesia.
Haldane effect increased oxygenation of hemoglobin promotes dissociation of carbon dioxide; see also Bohr effect.
Hawthorne effect a psychological response in which the subjects in a research study change their behavior simply because they are subjects in a study, not because of the research treatment.
heel effect variation in x-ray beam intensity and projected focal spot size along the long axis of the x-ray tube from cathode to anode.
parallax effect the position of the image on each emulsion of dual emulsion film; it is accentuated by tube-angled x-ray techniques.
Pasteur effect the decrease in the rate of glycolysis and the suppression of lactate accumulation by tissues or microorganisms in the presence of oxygen.
photoelectric effect ejection of electrons from matter as a result of interaction with photons from high frequency electromagnetic radiation, such as x-rays; the ejected electrons may be energetic enough to ionize multiple additional atoms.
placebo effect the total of all nonspecific effects, both good and adverse, of treatment; it refers primarily to psychological and psychophysiological effects associated with the caregiver-patient relationship and the patient's expectations and apprehensions concerning the treatment. See also placebo.
position effect in genetics, the changed effect produced by alteration of the relative positions of various genes on the chromosomes.
pressure effect the sum of the changes that are due to obstruction of tissue drainage by pressure.
proarrhythmic effect any new, more advanced form of arrhythmia caused by an antiarrhythmic agent, especially those that produce hemodynamically important symptoms. These arrhythmias occur less than 30 days after initiation of treatment and are not due to a new event such as acute myocardial infarction or hypokalemia.
side effect a consequence other than that for which an agent is used, especially an adverse effect on another organ system.
Somogyi effect see somogyi effect.

po·si·tion ef·fect

a change in the phenotypic expression of one or more genes due to a change in its physical location with respect to other genes; may result from change in chromosome structure or from crossing-over.

position effect

n.
Variation in the expression of a gene resulting from changes in its location within a chromosome or genome.

po·si·tion ef·fect

(pŏ-zish'ŏn e-fekt')
A change in the phenotypic expression of one or more genes due to a change in physical location with respect to other genes; may result from change in chromosome structure or from crossing over.

position effect

The effect on the expression of a gene resulting from its translocation to a different part of the genome. A gene may, for instance, be inactivated if moved to a region that is permanently in a highly condensed condition (heterochromation).

position effect

an alteration to the expression of a gene due to a change in its location within the GENOME.
References in periodicals archive ?
Such a swamping strategy is compatible with the serial position effect. Because investors will recall the end of the text best (recency effect), CEOs will increase the number of positive words toward the last bins.
The results of the AIC and BIC are in agreement: they reveal that the LLTM that includes position effects has the best fit.
Resolving the limb position effect in myoelectric pattern recognition.
With the four ads four advertising blocks were formed by combining the position of each of the ads in order to be able to measure the serial position effect. To avoid forming very similar blocks, the versions of the ads were combined in such a way that none of the blocks was formed of only highdensity or low-density ads.
The NAR-Mediated Reduction in Position Effect can be uncoupled from Copy Number-Dependent Expression in Transgenic Plants.
Atkinson and Shiffrin's model proposes a different explanation for the serial position effect, suggesting that the primacy effect would be stronger than the recency effect because items at the beginning of the list have more time to be rehearsed, coded, and consolidated, providing an opportunity to create a stronger stimulus-response bond for the earlier information.
Several hypotheses have been suggested to explain why these phenotypic anomalies are seen in balanced chromosome rearrangements, lt may be possible that the gene is broken and the position effects of gene or change in euchromatin structure, loss or small deletions or duplications were not seen with normal cytogenetic methods (6).
In the study of human memory it has been reliably found that words present at the beginning and end of a serial list are recalled at a significantly higher rate than words in the middle of the list; a finding called the serial position effect. Given its robust nature, the serial position effect is a great in-class demonstration, and results provide an opportunity to apply the classic "stages of processing" theory of human memory.
The serial position effect was again significant (F(6, 174) = 27.57, p < .0005), and these two factors interacted (F(6, 174) = 3.84, p < .01).
Flowering and fruiting lasted a mean of [approximately]40 d, but species differed significantly in their duration of reproduction (DURATION; [ILLUSTRATION FOR FIGURE 5 OMITTED]; [F.sub.9, 24] = 26.0, P = 0.001 for species effect, tested over the species X year interaction in factorial ANOVA with plot position effects removed).
One prediction from Eysenck's Hullian-based theory of extrtaversion, which made use of Hull's concept of reactive inhibition ([I.sub.R]), was that, since extraverts build up [I.sub.R] faster than do introverts, extraverts should show a more steeply peaked serial position effect in serial rote learning.

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