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Biomedical subjects

D C Glass

Publications and source records attributed to D C Glass.

At least 37 records · Page 2Linked to original sources
PubMed1992

Occupational exposure to carbon black in its manufacture.

Carbon black is manufactured by the vapour phase pyrolysis of heavy aromatic hydrocarbon feedstocks. Its manufacture is worldwide and the majority of its production is for use in the rubber industry especially tyre manufacture. Its carbonaceous nature has led many to investigate the occurrence of exposure-related medical conditions. To quantify any such relationships, it is necessary to assess exposure accurately. As part of such an epidemiological investigation survey involving the measurement both of respirable and of total inhalable carbon black was undertaken in 18 plants in seven European countries between mid-1987 and mid-1989. A total of 1298 respirable samples (SIMPEDS cyclone) and 1317 total inhalable samples (IOM head) were taken and deemed of sufficient quality for inclusion in the study. The distributions of the time-weighted average values were assessed and found to be best described by a log-normal distribution, and so exposure is characterized by geometric means and standard deviations. The data are presented in terms of 13 separate job titles for both dust fractions and shows a wide variation between job titles, with the highest mean exposure experienced by the site cleaners, and 30% of the samples taken from the warehouse packers being in excess of the relevant countries' occupational exposure limits for total inhalable dust. The quality and extent of this data allows both for comparison with exposure standards and for generation of occupational exposure indices, which will be presented in another paper (Gardiner et al., in preparation).

Carbon↗
PubMed1991

Effects of emotional imagery on physiological and facial responses in Type A and Type B individuals.

Type A behavior was examined in relation to physiologic and facial-expressive changes associated with anger, fear and distress. Affect was induced by an imagery procedure in which subjects recalled and described actual, emotion-related episodes. Type A was assessed by a structured interview. Subjects were healthy men, 21 Type As and 21 Type Bs, whose mean age was 39 yr. Type Bs showed higher systolic blood pressure responses and greater expression of negative affect than Type As. Data analysis also revealed a tendency for enhanced physiologic and facial responses of Type Bs relative to Type As to be greater during fear and distress than during anger. These results appear to reflect a coping process whereby Type A individuals show attenuated facial-expressive and physiologic reactivity as a means of maintaining a sense of control over aversive conditions.

Adult↗
PubMed1990

An assessment of the exposure of water reclamation workers to hydrogen sulphide.

The paper describes a 4-month study of water reclamation workers in a rural area. Workers were chosen randomly from each of three groups: permanent site workers, mobile workers and tanker drivers. The exposure to H2S of each of these workers was monitored with pumped long-term colorimetric tubes over 4 days. The reclamation sites were visited over the period of the study and monitored with a hand-held H2S-measuring instrument to identify sources of possible exposure. Data on the weather conditions were also collected. Routine exposure to H2S was found to be low; only 14% of exposures were above the minimum detection limit of 0.1 ppm 8-h time-weighted average (TWA). None of the 190 valid samples were above the 8-h TWA occupational exposure standard (OES) of 10 ppm. If all the exposure had occurred in a 10 min period, 6% of exposures would have been above the 10 min TWA limit. The hand-held readings and knowledge of the work pattern suggest that this was unlikely to have been the case. Most of the positive personal exposure measurements were associated with tanker drivers who were not dealing with treated sludge only. There was a statistically significant difference between the likelihood of exposure to H2S occurring in warmer, drier weather and in cooler, wetter weather. Sites and jobs which can result in transient exposure to H2S are identified.

Environmental Monitoring↗
PubMed1982

Psychological and physiological responses of individuals displaying type A behaviour.

Earlier findings on the relationship between the coronary-prone behaviour pattern Type A and coronary heart disease (CHD) are briefly reviewed, with particular reference to the underlying pathophysiological mechanisms linking the two. Results obtained during the playing of competitive games with or without harassment from the opponent suggest that competition alone does not distinguish between Type A and Type B individuals. The Type A pattern appears to be associated with exaggerated cardiovascular responses only as the result of hostile interactions. The primary need to study the Type A pattern as psychological construct is emphasized. Analysis of structured interview responses suggests that hostility and competitive drive are the two components of the pattern associated with cardiovascular disease. A model is proposed in which Type A subjects, faced with threats of their control, exhibit first hyper-responsive and then hypo-responsive efforts to regain it, and experimental evidence in support of this model is presented. However, such hyper-responsive reactions might be linked more closely to coping and defence mechanisms than they are to Type A. It is proposed that the Type A pattern be regarded as an aspect of the person-situation interaction and that efforts be made to establish those classes of environmental stimuli likely to elicit it.

Coronary Disease↗
PubMed1979

Harm-doing and victim's racial or orthopedic stigma as determinants of helping behavior.

Three experiments tested a prediction derived from an ambivalence theory of behavior toward the stigmatized. The prediction was that unintentional harm-doers would be more likely to make restitution by doing a favor for a stigmatized victim than for a nonstigmatized one. In Experiment 1 it was upheld for black versus white victims. In Experiment 2, where the victim of harm-doing was either physically handicapped or normal, the prediction was upheld only among older subjects, following the post hoc introduction of an age variable. Experiment 3 also used a physical disability variable. The data were consistent with the prediction, although the adequacy of the harm-doing manipulation was not checked empirically. On the whole, these results are seen as complementing previous findings of amplified post-harm-doing denigration of black and disabled victims. An assumption that the relationship between harm-doing and altruism was mediated by guilt arousal received only fragmentary support. That is, self-reports of guilt were highest in the harm-doing black confederate condition in Experiment 1, and self-reports of negative affect were highest in the harm-doing/wheelchair confederate condition in Experiment 3, but there were no significant relationships between individual differences in guilt or negative affect on the one hand, and amount of helping, on the other.

Adolescent↗
PubMed1978

When courtesy offends: effects of positive and negative behavior by the pbysically disabled on altruism and anger in normals.

The initial hypothesis was that physically disabled help-seekers will receive more aid from normal people than will help-seekers when both types of actors display positive personal qualities, whereas the reverse outcome will occur when both display negative qualities. In the first experiment a wheelchair-bound or normal confederate was either friendly and achievement oriented (positive condition) or caustic and apathetic (negative condition) while administering verbal tasks to subjects who were later asked to help the confederate. Contrary to prediction, subjects offered more help to the normal than to the disabled tester in the positive condition, and showed the reverse pattern in the negative condition. It was conjectured that subjects in the positive condition were annoyed by the disabled person's display of "normal" characteristics, whereas in the negative condition they sympathetically accepted the disabled person's inadequacies as befitting a victim of severe misfortune. A new experiment was done, which replicated the independent variables of the first study, but substituted two new dependent variables: covert anger arousal and perception of the confederate as happy-unhappy. As expected, covert anger was greater in the wheelchair-positive condition than in the normal-positive condition, and greater in the normal-negative condition than in the wheelchair-negative condition. Regardless of the confederate's physical status, subjects perceived negative behavior as a sign of unhappiness.

Adolescent↗
PubMed1976

The coronary-prone behavior pattern and the suppression of fatigue on a treadmill test.

A study was conducted to test the hypothesis that Type A (coronary-prone) individuals would show greater suppression of subjective fatigue than Type B (non-coronary-prone) individuals in order to persist at a tiring but challenging task. Type A and Type B college students completed a Balke treadmill test (at a walking pace) while rating their fatigue at 2-minute intervals. Each subject also completed another treadmill test (at a running pace) that was designed to assess maximum aerobic capacity. Subjects' aerobic capacities and their aerobic performance levels attained on the Balke test were determined by analysis of expired air. Each subject's walking performance was scored as a proportion of his maximum aerobic capacity. Analysis of the resulting percentage values indicated greater effort among A's than B's. Moreover, the subjective fatigue ratings of A's were lower than those of B's. The results were discussed in terms of fatigue suppression as an instrumental response for attaining mastery over the environment. consideration was also given to the role of fatigue in the onset of coronary heart disease.

Attitude to Health↗
PubMed1976

The self-consciousness scale: a discriminant validity study.

A recent Self-Consciousness Scale (SCS) measures Private and Public Self-Consciousness and Social Anxiety. The present research was intended to establish discriminant validity for the two Self-consciousness components with respect to several other variables. 105 male undergraduates completed the SCS, the Otis Test of Mental Ability, an abbreviated Edwards Personal Preference Schedule (measuring need for achievement), a Test Anxiety Questionnaire, and the EASI Temperament Survey. Private Self-consciousness did not correlate significantly with any other measure. Public Self-consciousness correlated weakly with the temperaments of Sociability and Emotionality. The Self-consciousness components of the SCS thus appear to be relatively independent of the other measures tested.

Journal Article↗