Showing papers by "Concordia University published in 1981"
TL;DR: The final experiment showed that a tone that had been paired with drug infusions acquired a statistically significant tendency to facilitate responding when tested during extinction but this effect disappeared after the first test presentation of the tone.
Abstract: Non-contingent “priming” drug injections and conditioned stimuli associated with drug injections led to reinstatement of responding after a period of extinction. Rats implanted with intravenous catheters were trained to self-administer cocaine (1 mg/kg/injection), and then given daily test sessions consisting of a period of self-administration followed by extinction conditions. Test drug injections or conditioned stimuli were presented during extinction and the latency to the first response and the total number of responses following the treatment were measured. Cocaine injections of 0.5, 1.0, and 2.0 mg/kg restored responding during extinction, regardless of the duration of the extinction period (between 10 min and 180 min) since drug self-administration. Amphetamine, apomorphine, and morphine but not ethanol, heroin, or methohexital reinstated previously cocaine-reinforced responding. Amphetamine, cocaine, and morphine did not increase responding in animals trained to bar press only for food reinforcement, suggesting that the reinstatement effect is specific to drug-reinforced responses. The final experiment showed that a tone that had been paired with drug infusions acquired a statistically significant tendency to facilitate responding when tested during extinction but this effect disappeared after the first test presentation of the tone.
923 citations
TL;DR: The idea that the equal sign is a "do-something signal" was first coined by Behr, Erlwanger and Nichols in their 1976 PMDC Technical Report as mentioned in this paper.
Abstract: This paper looks at recent research dealing with uses of the equal sign and underlying notions of equivalence or non-equivalence among preschoolers (their intuitive nitions of equality), elementary and secondary school children, and college students. The idea that the equal sign is a “do something signal”
This expression was first coined by Behr, Erlwanger and Nichols in their 1976 PMDC Technical Report (S. Erlwanger, personal communication, June 1980).
(an operator symbol) persists throughout elementary school and even into junior high school. High schoolers' use of the equal sign in algebraic equations as a symbol for equivalence may be concealing a fairly tenuous grasp of the underlying relationship between the equal sign and the notion of equivalence, as indicated by some of the “shortcut” errors they make when solving equations.
539 citations
TL;DR: Intracranial self-administration was effectively blocked by naloxone suggesting that this behavior is mediated through opiate receptors and is not the consequence of mechanical trauma, or changes in osmolarity or pH.
498 citations
TL;DR: Clear patterns in the development of sexual and agonistic behaviours in the rat were revealed and development toward the adult pattern of social behaviour was temporally associated with the period of sexual maturation.
394 citations
TL;DR: The use of difference scores as measures of organizational behavior variables is discussed in this paper, and several variations of the difference score paradigm have been discussed, including the constructs purportedly measured by difference scores, the source of component scores, and the means by which difference scores are expressed.
386 citations
TL;DR: The rewarding property of heroin was blocked by pretreatment with either naloxone or pimozide, suggesting that this opiate-receptor mediated effect is dependent on a dopaminergic substrate, supporting the notion that opiates and other sources of reward activate a similar neural substrate.
340 citations
TL;DR: The results of these experiments indicate that the sex difference in the social play of prepubescent rats is dependent on the neonatal exposure to testosterone or to its 5α-reduced metabolite, dihydrotestosterone.
196 citations
TL;DR: The most interesting finding was the high degree of variability in the restrictive syndrome associated with DMD.
Abstract: The purpose of this investigation was to compare the respiratory function of patients with different clinical types of muscular dystrophy (MD). A total of 190 patients representing facioscapulohumeral MD (n = 20), limb-girdle MD (n = 50), Becker MD (n = 20), Duchenne MD (n = 90), and the "intermediate" type of MD (n = 10) were studied using simple spirometric respiratory function tests. The respiratory modifications observed in the 3 adult forms indicate that pulmonary function was almost normal. Respiratory function in Duchenne muscular dystrophy (DMD) was always characterized by a restrictive syndrome which severely impaired pulmonary function. The vital capacity (VC) underwent ascending, plateau, and descending phases during the course of the disease. The VC at the plateau stage may be used as an estimate of life span. The most interesting finding was the high degree of variability in the restrictive syndrome associated with DMD. In the DMD group 30% presented a severe restrictive respiratory syndrome associated with a life span of less than 20 years (Type 1), 40% had a serious restrictive syndrome and variable mortality (Type 2), and the remaining 30% had a moderate restrictive respiratory syndrome (Type 3).
168 citations
TL;DR: Sex differences in the anatomy and physiology of the amygdala are discussed as a possible explanation of its apparent differential influence on the social play of male and female prepubertal rats.
121 citations
TL;DR: Primozide attenuates the response acquisition function as well as the previously studied response maintenance function of food reward in hungry rats.
Abstract: Pimozide pretreatment produced a dose-dependent attenuation of acquisition of a lever-pressing habit motivated by food reward in hungry rats. No evidence of learning was seen in animals treated at 1.0 mg/kg, minimal learning was seen at 0.5 mg/kg, and retarded learning which ultimately did reach normal asymptote was seen at 0.25 mg/kg. Thus primozide attenuates the response acquisition function as well as the previously studied response maintenance function of food reward.
114 citations
TL;DR: The substrate mediating rewarding actions of opiates and psychomotor stimulants also mediates the rewarding action of more natural rewards like food and water, which suggests that the brain has specialized circuitry for mediation of reward.
Abstract: 1. 1. Animals will work for stimulation of some parts of their own brains; this suggests that the brain has specialized circuitry for mediation of reward. 2. 2. Current evidence identifies two links in such circuitry: a myelinated, descending, medial forebrain bundle link and an ascending, dopaminergic, medial forebrain bundle link. The myelinated link makes probable synaptic contact with the dopaminergic cells of the ventral tegmental area and substantia nigra. These dopaminergic cells may receive other myelinated and reward-relevant afferents as well, particularly from the brainstem. 3. 3. Psychomotor stimulants facilitate intracranial self-stimulation by acting at terminals of the dopaminergic link, particularly in nucleus accumbens. Opiates facilitate self-stimulation by acting at the dopamine cell bodies in the ventral tegmentum. Facilitation of self-stimulation by other drugs of abuse has not been localized to a site of action. 4. 4. Psychomotor stimulants have rewarding actions of their own in nucleus accumbens. Opiates have rewarding actions at the dopaminergic cell body region of the ventral tegmentum. The sites of rewarding action have not been determined for other drugs of abuse. 5. 5. The substrate mediating rewarding actions of opiates and psychomotor stimulants also mediates the rewarding action of more natural rewards like food and water. The fact that some drugs of abuse can come to dominate behavior in relation to more natural rewards may stem from the more direct central actions of drugs on the reward substrate. The fact that the rewarding effects of food, water, opiates, and psychomotor stimulants feel subjectively dissimilar may simply reflect the fact that while a common rewarding action is shared by these agents, many other effects which are subjectively experienced differ between agents and obscure awareness of a common dimension of all positive rewards.
TL;DR: In this paper, the authors investigated the relationship between shift schedules and mental health, job satisfaction, social participation, organizational commitment, anticipated turnover, absenteeism and tardiness among nurses in two hospitals and among rank-and-file workers (N=383) in a manufacturing organization.
Abstract: The present study investigates the relationship between shift schedules and mental health, job satisfaction, social participation, organizational commitment, anticipated turnover, absenteeism and tardiness among nurses (N=440) in two hospitals and among rank-and-file workers (N=383) in a manufacturing organization. Results are generally supportive of the model which projected that workers on fixed work schedules (high routine-oriented) would be better off than workers on rotating work schedules (low routine-oriented) in terms of mental health, job satisfaction, organizational commitment and social participation. In addition, workers on fixed shift schedules are found to be lower on anticipated turnover, absenteeism and tardiness than workers on rotating shift schedules. Six potential moderators: age, marital status, place of socialization, cultural background, seniority and respondent's sex, were measured and their association with these relationships analyzed. Results are discussed in the light of the previous empirical evidence.
TL;DR: Data suggest a role for brain dopamine in behavior and reflect the same patterns as have been seen with food reinforcement and with several centrally-acting reinforcers.
Abstract: Rats were trained to lever-press for water on a schedule of continuous reinforcement, then tested every fourth session on five occasions either under conditions of non-reinforcement or following injections of the dopamine receptor blocker pimozide (0.5 or 1.0 mg/kg) or the injection vehicle. The low dose of pimozide did not significantly attenuate responding until the fifth session. The high dose attenuated responding on all occasions, with residual responding decreasing progressively across repeated drug sessions. Responding in the pimozide conditions was never less than that of the non-reinforced control group. Responding in each condition was strongest in the early minutes of a session. After five sessions, rats were switched from the pimozide condition to the non-reinforced condition (or vice-versa) for one additional test day. Decreased responding continued for rats transferred from non-reinforcement to pimozide though not for rats transferred from pimozide to non-reinforcement. These suggest a general role for brain dopamine in behavior; they reflect the same patterns as have been seen with food reinforcement and with several centrally-acting reinforcers.
TL;DR: The development of social play depends on the presence of testicular androgens for at least 6 days after birth, and castration on day 1 or 6 reduced male play to levels that were not reliably different from females.
TL;DR: It is reported that repeated exposure to brief pinches at the scruff in mice results in the development of long lasting cataleptic-like immobility, and naloxone fails to suppress the pinch-induced catalepsy when administered after this behavior has already been established.
TL;DR: The lateral boundaries of the substantia nigra, zona compacta, were mapped for intracranial self-stimulation in rats and data strengthen the view that rewarding stimulation in this system activates the tegmental dopaminergic cells or, more likely, their immediate afferents.
TL;DR: In this paper, a model based on water flow was proposed to explain the preferential distribution of diatoms on slides oriented parallel to the current in a spring-fed stream near Lennoxville, Quebec.
Abstract: Glass microscope slides were submerged for two to six week periods at selected sites in a small, spring-fed stream near Lennoxville, Quebec. Slides were oriented parallel and perpendicular to the current. Qualitative and quantitative data from transects across slides show that diatoms are randomly distributed on slides perpendicular to the current but not on slides oriented parallel to the current. In the later case, most individuals first settled near the upstream or downstream edge of the slide. Non-random distribution is most pronounced on slides containing Cocconeis placentula. This species and two others, Achnanthes linearis and A. minutissima, are abundant and determine most distribution patterns found on slides. Preference of diatoms for the edges of slides appears to be affected by current. We propose a model, based upon water flow, to explain the preferential distribution of diatoms on slides oriented parallel to the current. Light appears not to affect settling patterns to a great extent in this study.
TL;DR: Examination of parameters lends credence to the argument that Mesostoma predation affects Daphnia dynamics in some circumstances, and suggests that benthic invertebrate predators may affect zooplankton dynamics, especially in shallow ponds.
Abstract: Experiments were performed in 1977 to determine which large zooplankton in a series of high altitude ponds can be consumed by the predatory flatworm Mesostoma ehrenbergii. This predator consumes Daphnia at a high rate and the fairy shrimp Branchinecta at a low rate, but does not consume Diaptomus. Experiments were performed in 1978 and 1979 to determined the rate of predation on Daphnia in 30 liter tubs and to determine if predation rate is correlated with surface to volume ratio of experimental containers. There is a clear correlation between surface to volume ratio and predation rate. Determinations of Mesostoma and Daphnia densities were made in a series of eight high altitude ponds, and pond surface to volume ratios were determined. Examination of these parameters lends credence to the argument that Mesostoma predation affects Daphnia dynamics in some circumstances. The results suggest that benthic invertebrate predators may affect zooplankton dynamics, especially in shallow ponds.
TL;DR: In this paper, the aim of the study was to determine whether blind children in a well-equipped modern institution are receiving enough physical education activities to maintain good physical condition, and the results showed that they did not.
Abstract: The aim of the study was to determine whether blind children in a well-equipped modern institution are receiving enough physical education activities to maintain good physical condition. Toward thi...
TL;DR: Data indicate correspondence between the reinforcing and the self-stimulation facilitating effects of heroin in relation to dose and time course parameters, and fit with the view that narcotic facilitation of self- Stimulation reflects the reinforcing value of the drugs.
TL;DR: Dietary restriction may retard lipofuscin accumulation by reducing the level of free radical-reactions and thus retard lipid peroxidation fluorescent products in brain and heart in male Swiss albino mice.
TL;DR: In this article, the sublimation problem with coupled heat and mass transfer taking place in a porous halfspace is defined and exact solutions for temperature and moisture distributions as well as the position of the moving sub-limation front are obtained.
Abstract: Sublimation problem with coupled heat and mass transfer taking place in a porous halfspace is defined and exact solutions for temperature and moisture distributions as well as the position of the moving sublimation front are obtained. The condition for the limitation of the sublimation process is also determined.
TL;DR: At all concentrations tested, widespread cyanide-induced degenerative necrosis of hepatocytes was observed; it was more intense at higher cyanide concentrations and well established even at 0.01 mg/L HCN.
Abstract: Cyanide markedly affected growth and resting metabolic rate while causing degenerative hepatic necrosis in juvenile rainbow trout (Salmo galrdneri, Richardson). This was revealed during two experiments performed in continuously renewed water at 12.5°C with fish fed a restricted artificial diet and exposed to assayed cyanide concentrations of 0.00, 0.01, 0.02, or 0.03 mg/L hydrogen cyanide (HCN) for 18 days.
TL;DR: In this paper, an experimental investigation of wind-induced pressure loads acting on two square-plan flat-roofed model structures (50ft and 225ft high in full scale) is described.
Abstract: An experimental investigation of wind-induced pressure loads acting on two square-plan flat-roofed model structures (50ft and 225ft high in full scale) is described. Measurements of mean, peak, and root mean square pressures acting on points and over larger roof areas have been made in turbulent boundary layer flow simulating wind over urban and open country terrains. Area loads on the roofs have been measured both by a pneumatic-averaging technique, and by using a large flush-diaphragm transducer. Correlation coefficients and spectra of effective pressure loads on various regions of the roofs are also presented. A significant overestimation of peak loads may occur for larger areas if full correlation of the worst point pressures acting over the area is assumed.