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Biomedical subjects

G Lemasters

Publications and source records attributed to G Lemasters.

9 recordsLinked to original sources
PubMed2000

Menstrual disorders and occupational, stress, and racial factors among military personnel.

Few studies have assessed multiple stress factors as a potential risk for menstrual disorders. This study evaluated whether work-related stress or life event stress was associated with alterations in menstrual function of military personnel. The study is unique in that it evaluated the association between race and three job factors--job stress, handling chemical mixtures, and being a military or civilian employee of the US Air Force. A comprehensive questionnaire was administered to 170 healthy, premenopausal employed women to examine the relationship between work-related or life event stress and menstrual disorders. Multiple logistic regression analyses showed no statistically significant association between work-related stress and menstrual disorders, whereas life event stress was significantly associated with dysmenorrhea (odds ratio [OR], 2.20; 95% confidence interval [CI], 1.08 to 4.50) abnormal cycle length (OR, 3.42; CI, 1.12 to 10.50), and hypermenorrhea (OR, 2.99; 95% CI, 1.20 to 7.42). Having one or more menstrual disorders was significantly associated with life events by race interaction (OR, 6.52; 95% CI, 2.45 to 17.36). Non-Caucasians had significantly increased risks of hypermenorrhea (OR, 4.99; 95% CI, 2.07 to 12.05) and abnormal cycle length (OR, 4.12; 95% CI, 1.47 to 11.55). The prevalence of menstrual disorders in this military population was 31.2% for dysmenorrhea, 17.9% for hypermenorrhea, and 12.0% for abnormal cycle length. This study suggests that women in the military report less day-to-day job stress but more atypical life events, including those related to their jobs, and that these life events are associated with adverse menstrual consequences.

Adolescent↗
PubMed1999

Development and evaluation of a microprocessor-based ergonomic dosimeter for evaluating carpentry tasks.

This portable and self-contained lightweight microprocessor based Ergonomic Dosimeter is designed to collect continuously postural angles of the torso and the upper arm in the sagittal plane and the number of kneeling activities. Up to 4 h of task performance data can be stored in a non-volatile memory of the dosimeter, which can then be downloaded to a lap-top computer. The portable dosimeter was tested for test-retest reliability, compared with posture data obtained with a computer-based video analysis system and evaluated at a carpenter's apprentices school and at a construction site. The dosimeter was shown to be suitable for collecting posture and kneeling data for a prolonged period at construction sites.

Anthropometry↗
PubMed1997

An ergonomic education and evaluation program for apprentice carpenters.

Eighteen new apprentice carpenters received sixteen hours of ergonomics awareness education as a part of their regular apprenticeship training during 1994 and 1995. An equal number of apprentices received no training but served as controls. The training took place in the Southwest Ohio District Council of Carpenter's Joint Apprenticeship and Training School. The curriculum was designed to be "learner-centered." Instruction included short lectures presented by a journeyman carpenter and emphasized participatory activities in the school's carpentry shop. Ongoing program evaluation assessed trainees' reactions to the content and structure of the curriculum and its influence on their behavior. Trainees and controls completed brief quizzes on ergonomic knowledge. Hands-on exercises enabled trainees to apply recently acquired ergonomic knowledge in the school's carpentry shop. Trainees scored significantly higher on one-half of the post-session quizzes and the comprehensive test. Trainees preferred participatory teaching methods, especially those using redesigned tools (93%) and evaluating ergonomic risks (86%); and they supported continued safety and health education during apprentice training. The authors conclude that apprentice-ship programs should provide regular "learner-centered" occupational safety and health education that includes ergonomics, and these programs should be integrated with their shop-based manual arts instruction.

Ergonomics↗
PubMed1997

Effect of chronic low-level exposure to jet fuel on postural balance of US Air Force personnel.

This study used the postural stability technique to investigate the neurological effects of cumulative low-level exposure to raw JP-8 jet fuel vapor on aircraft maintenance personnel. All subjects performed two sets of four 30-second postural sway tests. The results of mean cumulative exposure levels (in parts per million +/- standard error of mean) were the following: naphthas, 1308 +/- 292; benzene, 21.2 +/- 5.7; toluene, 23.8 +/- 6.1; and m-,o-, p-xylene, 22.7 +/- 5.4. Covariate adjusted regression analysis of the exposed group data showed a statistically significant association (P < 0.05) between the solvents (benzene, toluene, and xylene) and increased postural sway response. For all solvent exposures, the "eyes closed, on foam" test provided the strongest association between sway length and JP-8 benzene (r2 range, 0.45 to 0.52), implying subtle influence on vestibular/proprioception functionalities.

Adult↗
PubMed1996

Refractory ceramic fiber exposure and pleural plaques.

Refractory ceramic fibers (RCF) are manmade vitreous fibers (MMVF) manufactured for high-temperature applications. Between 1987 and 1992, a retrospective cohort and nested case-control study evaluated chest radiographs from 652 workers involved in the manufacture of these fibers for plausibility of a causal relationship between exposure to RCF and chest-radiographic changes. The exposure-response relationship was modeled with three variables: years since first fiber production job, years in fiber production, and cumulative fiber exposure to date of study X-ray. The case-control study used a comprehensive characterization of possible asbestos exposure to investigate asbestos as the potential causative agent of chest-radiographic changes. Chest radiographs of 20 workers (3.1%) demonstrated 19 pleural plaques and one diffuse pleural thickening. Nine of 72 workers (12.5%) with more than 20 yr since their first fiber-production job had plaques (odds ratio [OR] = 9.5; 95% confidence interval [CI] = 1.9 to 48.2). Five of 19 workers with more than 20 yr in fiber-production work (26.3%) had plaques (OR = 22.3; 95% CI = 3.6 to 137.0). Similarly, adjusted ORs demonstrated a progressive relationship between cumulative fiber-months per milliliter (fiber-mo/ml) exposure and plaques. The case-control study confirmed that asbestos exposure did not account for the observed association between fiber exposure and plaques. A validity review of historical films demonstrated biologic plausibility for the association, since sufficient latency existed from the time of first RCF exposure to the development of plaques. There was no significant increase in parenchymal changes consistent with interstitial fibrosis.

Asbestosis↗
PubMed1993

Nature and prevalence of ribavirin aerosol administration in U.S. pediatric hospitals.

A survey was undertaken to determine the nature and prevalence of ribavirin aerosol administration in pediatric hospitals. Ribavirin was administered in 79.4% of the respondents' hospitals. The majority used head hoods for aerosol administration. Ventilators were the primary method used by 6% of the respondents. This study demonstrates typical types of ribavirin exposure and the need to evaluate effects of chronic exposure.

Administration, Inhalation↗
PubMed1975

Do boys with a low-average I.Q. actually have a low self-esteem?

The purpose of this study was to gain an understanding of the needs, fears, aspirations, and attitudes of the low-average elementary and junior high age boy. The settings were two schools, a junior high (grades 9-12) and an elementary school (grades 5-6), located in a working class community. Two separate groups involving boys ages 11 and 12 years, and boys ages 14 and 15 years, met for five consecutive meetings. The structured interview in a group setting was chosen to increase the likelihood of a spontaneous, open interchange, as opposed to a more restricted response pattern. All subjects had failed at least one year, had maintained a stable I.Q. of 80-90 during their school years and were level in one or more subjects. The findings suggest caution in automatically equating low-average intelligence in boys with low self-concept, lack of career plans, family problems, and other similar stereotypes.

Achievement↗
PubMedDate not supplied

Exertion and body discomfort perceived symptoms associated with carpentry tasks: an on-site evaluation.

The purpose of this study was to determine how carpenters subjectively perceived the exertion level and body discomfort associated with their daily tasks. Two psychophysical instruments were utilized. The Borg Whole Body Physical Exertion Instrument, a measure of overall physical demand, and the Body Segment instrument (modified Bishop-Corlett Scale), a measure of body discomfort, were given to 73 carpenters at the end of a shift. Carpentry specialties evaluated included ceiling, drywall, formwork, finishing work, pile driving, fixtures, welding, and scaffolding. The mean Borg's exertion score for the subjects combining all specialties was 14.4 (+/-2.51 standard deviation), a score between "somewhat hard" and "hard." The perception of whole body physical exertion appeared to be a consequence of the specific task. There was no significant correlation between whole body physical exertion perception and age or the number of years as a carpenter. The findings from the body discomfort scale for the total group indicated that the three primary discomfort frequencies by body segment were mid-to-lower back (65.8%), knees (45.2%), and the neck (28.8%). The next highest discomfort rating by body segment (back, knee, right wrist, right leg/foot, and right shoulder) for those subjects in the top three job specialties represented (drywall, ceiling, and formwork; n = 38) resulted in significantly higher ratings for back (60.5%) than right leg/foot (34.2%) and right shoulder (31.6%). All other body segment ratings were not significantly different from one another using Tukey's studentized range test.

Adult↗