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PubMed2001

Repeatability of in vitro measurements of the ultraviolet protection factor (UPF) by spectrophotometry with automatic sampling.

BACKGROUND/AIMS: Spectrophotometric assessment (in vitro) is the most established method for determining the ultraviolet protection factor (UPF) of textiles. Apart from stringent requirements for measurement precision, practical methods are required for the routine determination of the UPF. We report here spectrophotometric measurements of textiles using a newly developed autosampler. Measurement precision was evaluated under repeatable conditions. METHODS: Fifteen different textiles were spectrophotometrically assessed for the determination of the UPF. Sample handling inside the spectrophotometer was performed with a computer-controlled sampling device, capable of loading and unloading a textile sample from a magazine as well as rotating the sample perpendicular to the spectrometer beam. In order to evaluate the repeatability of measurements, one sample of each textile was assessed eight times under the same conditions in the same laboratory. RESULTS: A mean percentage of the standard error of 1% [E(UPF)] was calculated for the UPF measurements. For UPFs >30, a significantly higher E(UPF) was found (r=0.78; P<0.001). E(UV) (3.9%) of ultraviolet A (UVA) transmission differed significantly from E(UV) (1.1 %) of ultraviolet B (UVB) transmission (P<0.05). CONCLUSIONS: Though a slight decrease of repeatability was observed for UVA transmission measurements and UPFs higher than 30, our data indicate a high measurement precision under repeatable conditions. In conclusion, spectrophotometric measurements of textiles with the aid of the autosampler presented have been shown to be highly practical, time saving and precise.

Automation↗
PubMed1990

Preventing drug use in adolescents through media interventions.

The communications media, and the broadcast media in particular, have been disseminating an increasing volume of antidrug messages over the past several years. Many American business leaders believe that the media can help to reduce drug use, and they have supported a nationwide effort to highlight the dangers of illicit drug use on the airwaves and in newspapers and magazines. This article considers the efficacy of media-based efforts to prevent adolescent drug use. Selected theories and research are reviewed, and suggestions are made for integrating social and behavioral theory and research into media prevention strategies. The authors conclude that scientists and interventionists could do much to improve on current research and development in this prevention arena, within the limits of what is possible to achieve through mass communications as presently constituted in the United States.

Adolescent↗
PubMed1983

More aggressive cartoons are funnier.

Independent rankings of humor and aggressiveness were obtained for sets of cartoons drawn randomly from two different magazines. The correlation of median humor and median aggressiveness rankings ranged from .49 to .90 in six studies involving six different sets of cartoons and six different groups of subjects, including children and adults, high and low socioeconomic status (SES) individuals, and native- and foreign-born individuals. This correlation is consistent with Freudian, arousal, and superiority theories of humor. Another prediction of Freudian theory, that high-SES subjects should be more appreciative of aggressive humor than low-SES subjects, was not supported.

Adolescent↗
PubMed1993

A retrieval cue for extinction attenuates spontaneous recovery.

Four experiments with rats in an appetitive conditioned magazine entry preparation examined spontaneous recovery after extinction. Spontaneous recovery was obtained 6 days but not 5 hr following extinction; recovery depended on the passage of time but not on the removal of a cue that was featured in extinction or on the reintroduction of early-session cues. A cue featured in extinction attenuated recovery when presented on the test. The attenuation effect depended on the cue's correlation with extinction; a cue featured in conditioning did not attenuate recovery. The extinction cue did not evoke responding on its own, suggesting that it was not a conditioned excitor. Retardation tests and a summation test did not reveal that it was a conditioned inhibitor. The cue might work by retrieving a memory of extinction. Spontaneous recovery thus occurs because the subject fails to retrieve an extinction memory. Other accounts of spontaneous recovery are discussed.

Animals↗
PubMed1996

Sign tracking versus goal tracking in the sexual conditioning of male Japanese quail (Coturnix japonica).

Pairings of a conditioned (CS) and unconditioned (US) stimulus can result in approach to either the CS (sign tracking) or the US (goal tracking). Increasing the spatial or temporal separation between the CS and a US food has been reported to results in a decline in sign tracking and an increase in goal tracking. In the present experiments, sign tracking was the predominant response of male quail (Coturnix japonica) to a CS that was presented up to 91 cm from the door through which a female was presented as the US (Experiment 1). Contrary to reported results with food reinforcement, goal tracking was not facilitated by increasing the spatial separation between the CS and US (Experiment 2) or by introducing a trace interval between them (Experiment 3). The preponderance of sign tracking may reflect an adaptive specialization of sexual conditioning or may be related to the absence of magazine training and the use of a moving US in the sexual conditioning procedures.

Animals↗
PubMed1999

Associative changes in elements and compounds when the other is reinforced.

Four experiments investigated the symmetry of associative changes in stimulus compounds and elements in a Pavlovian conditioned magazine-approach situation with rats. Experiment 1 used multiple groups to examine the associative changes in a conditioned element (A) as a result of its subsequent reinforcement in compound with a neutral X. These were compared with the changes in an AX compound when one of its elements (A) was subsequently reinforced alone. Although reinforcing A enhanced responding to the AX compound, compared with a control compound, reinforcing AX failed to enhance responding to A, compared with a control element. Experiments 2 and 3 made similar comparisons in a fully within-subject design, finding greater changes in a previously trained AX compound when A was subsequently conditioned than in a B element when BY was subsequently conditioned. Experiment 4 found associative decrements in A when it was reinforced in the presence of a moderately conditioned X. The results observed in each of these experiments are more consistent with an elemental model of conditioning than with a recently proposed configural model.

Acoustic Stimulation↗
PubMed2000

Extinction can be enhanced by a concurrent excitor.

Five experiments used rat subjects to investigate the impact on extinction of the presence of other conditioned stimuli. In Experiments 1 (Pavlovian magazine approach) and 2 (instrumental discriminative training), an excitatory stimulus (X) was extinguished alone, in conjunction with a previously reinforced other stimulus (A), in conjunction with previously nonreinforced other stimulus (B), or it was spared extinction. Responding during extinction was greatest to AX, and subsequent testing of X alone showed AX extinction to have produced the most decrement to X. Experiment 3 found similar results using a within-subject design. Experiment 5 continued separate reinforced presentations of A during extinction. This procedure not only promoted extinction of X but also converted it into a conditioned inhibitor. These experiments bear on the mechanisms of overshadowing and stimulus processing, as well as provide information on the determinants of extinction.

Analysis of Variance↗
PubMed2000

Associative changes in excitors and inhibitors differ when they are conditioned in compound.

When an AB stimulus compound is reinforced or nonreinforced, there are associative changes in both A and B elements. In many contemporary theories those changes are viewed as governed by a common error term, computed as the discrepancy between the total associative strength of the AB compound and that supported by the trial consequence. This implies that if A and B are equally salient, then the magnitude of their associative change should be the same, whatever their strengths prior to the AB trial. This implication was explored for a compound consisting of an excitatory A and an inhibitory B. A novel assessment procedure avoided the difficulty of making comparisons at different locations on the performance scale. Three experiments using a magazine approach preparation in rats and 3 using autoshaping in pigeons found evidence contradicting this implication. The excitatory A changed less than the inhibitory B when the compound was reinforced but more than B when the compound was nonreinforced.

Animals↗
PubMed1992

Relation of level of exercise, age, and weight-cycling history to weight and eating concerns in male and female runners.

We examined the association between level of exercise and degree of weight preoccupation in a large sample of male and female runners, as well as risk factors posited to influence weight and eating concerns in the general population. Subjects were 2,459 males and 1,786 females who had completed a questionnaire on weight and eating concerns in a national running magazine. Eight percent of the males and 24% of the females had symptomatic scores on the Eating Attitudes Test (EAT). Exercise level, defined as weekly running mileage, was positively associated with excessive weight and eating concerns in males but not in females. Both sexes with a history of weight cycling were more likely to have symptomatic EAT scores than those with no such history. These results highlight the importance of studying these concerns in males as well as females and of examining the role of exercise level and weight-cycling history in the development of serious weight preoccupations.

Adolescent↗
PubMed1990

Cortical, hippocampal, and striatal mediation of schedule-induced behaviors.

The sequential occurrence of licking, locomotor activity, entries into the food magazine (panel pressing), and nonreenforced lever pressing engendered by a periodic schedule of food presentation were measured in each 60-s interreenforcement interval in normal and brain-damaged rats. The development of these responses was measured over 20 days in different groups of food-deprived rats that had received aspirations of the hippocampus, small lesions of the cortex overlying the hippocampus (hippocampal-operated control group), decortication, or 6-hydroxy-dopamine lesions of the caudate nucleus or nucleus accumbens. All lesions produced distinctive patterns of change in the measured behaviors, and dissociations as well as similarities in their effects were evident. These results are discussed with respect to dissociations in the motor and motivational effects of the various lesions and in terms of contemporary hypotheses of schedule-induced behavior.

Animals↗
PubMed1997

Autonomic and behavioral correlates of appetitive conditioning in rats.

The cardiac responses accompanying conditioned stimulus- (CS)-generated (orienting) and unconditioned stimulus- (US)-generated appetitively motivated behaviors (P. C. Holland, 1977) were investigated. On the basis of contemporary psychophysiological research, CS-generated responses were predicted to produce bradycardia, and US-generated responses to produce tachycardia. Pairing a 10-s visual CS with food delivery produced conditioned behavioral orienting (rearing) during the initial portion of the CS, followed by magazine approach (US-generated) responses as the CS progressed. CS onset produced a decrease in heart rate, mediated by an increase in parasympathetic stimulation of the heart, which persisted throughout the 10-s CS; no support for a biphasic cardiac response was observed. These data are discussed with respect to other conditioned autonomic responses and their relevance to foraging and food ingestion.

Animals↗
PubMed2006

Hugo Münsterberg's attack on the application of scientific psychology.

No individual in the early history of American psychology is more identified with the promotion of applied psychology than Hugo Münsterberg, whose books and articles on applied topics such as industrial psychology, forensic psychology, psychotherapy, and educational psychology made him one of the most visible psychologists of his day. But there is an earlier chapter to Münsterberg's life that tells a very different story of a Münsterberg opposed to application. The story begins in 1898 when he wrote an article for an American magazine in which he told teachers that the findings of experimental psychology had no relevance for education, setting off a firestorm of controversy among his colleagues in psychology and education. This article describes Münsterberg's early denigration of applied psychology and his subsequent transformation as applied psychologist. Reasons for that transformation are discussed as well as issues involving the stigma associated with applied psychology and the popularization of psychology.

Attitude↗
PubMed2003

Choice and self-expression: a cultural analysis of variety-seeking.

Three studies examined whether the tendency to seek variety in choices depends in part on cultural assumptions of choice and uniqueness. Study 1 showed that people from different cultures where different assumptions of choice and uniqueness dominate show different levels of variety in their choice rule use. Study 2 primed participants with magazine ads highlighting different representations of uniqueness dominant in individualist versus collectivist cultures to show the influence of cultural meanings of uniqueness on the variety-seeking tendency. Study 3 manipulated the motivation to display variety to demonstrate that variety-seeking in the United States partly hinges on cultural meanings of choice as self-expression. Variety-seeking in choice rule use was eliminated when participants had the chance to self-express through choice listing. The research illustrates the role of cultural assumptions in the variety-seeking tendency.

Adult↗
PubMed2003

More rapid associative change with retraining than with initial training.

Retraining was compared with initial acquisition in 4 magazine approach experiments with rats and 1 autoshaping experiment with pigeons. The levels of performance were matched prior to reinforcement and nonreinforcement for stimuli with a history of both training and extinction and stimuli with only a minimal history of training. Under these conditions, a previously extinguished stimulus was more vulnerable both to the incremental effects of reinforcement and to the decremental effects of nonreinforcement compared with a stimulus that had only been minimally trained.

Animals↗
PubMed2005

Spontaneous recovery of excitation but not inhibition.

Five magazine approach experiments with rats and 1 sign-tracking experiment with pigeons explored the possibility of an analogue to spontaneous recovery of excitatory conditioning from extinction: spontaneous recovery of inhibitory conditioning from training. Stimuli were 1st treated as conditioned inhibitors and then as conditioned exciters or as irrelevant to reinforcement. At issue was whether the passage of time after the 2nd treatment would allow partial restoration of the initial conditioned inhibition. The experiments differed in the design used to study recovery, the manner of reinforcing the inhibitor, the means of testing for recovery, the time interval allowed for recovery, and the species used. None of the experiments found evidence for recovery of the inhibitory learning with time, despite the concurrently measured presence of spontaneous recovery of excitatory conditioning after extinction. These experiments suggest that changes with time may be preferential to the learning that occurs during extinction.

Acoustic Stimulation↗
PubMed2006

Deepened extinction from compound stimulus presentation.

Three experiments with rats and 2 with pigeons explored the effect of presenting 2 extinguished excitatory stimuli in compound. Four learning situations were used: Pavlovian magazine approach, Pavlovian fear conditioning, and instrumental discriminative instrumental learning in rats, as well as Pavlovian sign tracking in pigeons. All 5 experiments confirmed D. Reberg's (1972) observation that even after extinction of the individual stimuli, presenting them in compound evoked substantial responding. Moreover, nonreinforcement of that compound deepened extinction of an element more substantially than did additional presentation of that element alone. Such compound exposure reduced spontaneous recovery, reduced reinstatement, and slowed subsequent reconditioning. The primary determinant seemed to be the enhanced associative strength rather than the enhanced conditioned responding that occurred during the nonreinforced compound.

Animals↗
PubMed1975

Effect of ventromedial hypothalamic procaine injections on feeding, lever pressing, and other behavior in rats.

Rats were given bilateral injections of 1-2 mul procaine HCl solution (50 mug/mul) in the region of the ventromedial hypothalamus. Normal-sized meals occurred reliably with a latency of 16-120 sec, indicating that this region has the function of inhibiting onset of eating, not just the function of stopping a meal. Food-rewarded fixed-ratio-of-one (FR 1; continuous reinforcement) lever pressing was elicited by 2-mul but not by 1-mul procaine. The FR 64 pressing appeared to be disrupted during a period of increased activity following procaine injection, although visual observations indicated that the pressing which did occur was normal in topography and was significantly associated in temporal sequence with approaches of the food magazine.

Animals↗
PubMed2002

Dietary restraint and stress-induced snacking in youth.

OBJECTIVE: To determine whether dietary restraint modifies stress-induced eating in youth. RESEARCH METHODS AND PROCEDURES: Snacking was measured in boys (9.5 +/- 0.3 years) and girls (9.0 +/- 0.3 years), with and without dietary restraint, across a control day after reading children's magazines and/or coloring, and on a stress day after giving a videotaped speech, with order of conditions counterbalanced. Children were divided into four groups based on dietary restraint and changes in perceived stress: low-restraint/low-reactive (n = 9), low-restraint/high-reactive (n = 13), high-restraint/low-reactive (n = 10), and high-restraint/high-reactive (n = 8). Body composition was estimated by skinfolds. RESULTS: Energy intake of snack foods was influenced differently by dietary restraint and stress reactivity in the stress and control conditions (p < 0.01). After being stressed, low-restraint/low-reactive children ate fewer snacks and high-restraint/high-reactive children ate more snacks compared with the control condition. After covarying for percentage of body fat, the interactions remained (p < 0.01). Girls ate less than boys (p < 0.001), but sex did not influence eating in control and stress conditions. DISCUSSION: Dietary restraint occurs in children and may influence the effect of stress on eating. Interpersonal stress decreases snacking in low dietary restrained youth but increases snacking in high dietary restrained children, perhaps because of stress-induced disinhibition.

Body Mass Index↗