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Biomedical subjects

L J Chapman

Publications and source records attributed to L J Chapman.

At least 19 recordsLinked to original sources
PubMed2003

Musculoskeletal discomfort, injuries, and tasks accomplished by children and adolescents in Wisconsin fresh market vegetable production.

Little or no research is available about the tasks that children and adolescents perform in small scale, fresh market vegetable production. A mail questionnaire was administered in an exploratory study to an age-stratified, convenience sample of children and adolescents age 5 to 18 (n = 81) who were working on Wisconsin fresh market vegetable operations. Children and adolescents reported averaging 349 hours of farm work last year. Youths completed over 1/5 of all the tractor operation and produce loading and unloading that was completed by adults or children on their farms; 1/7 of the weeding, produce washing, and packing; and 1/12 of the hand harvesting during typical weeks when they worked. Fifty percent of 15-18 year olds reported experiencing low back discomfort in the last year, and 25% reported disabling discomfort. Children and adolescents performed the same range of tasks and often the same scope of work as adults. Further investigation with larger, more representative youth samples is needed to confirm these findings.

Adolescent↗
PubMed2003

Evaluation of an occupational injury intervention among Wisconsin dairy farmers.

OBJECTIVES: Dairy farming injury rates are high. Previous agricultural research has shown that better information flow can speed adoption of more profitable practices. We conducted and evaluated an intervention to increase voluntary adoption of three production practices that were safer and more profitable than typical practices: barn lights, bag silos, and a mixing site for calf feed. METHODS: Print mass media, public events, university Extension, and dairy farmers already using the practices were all enlisted to disseminate information to 4,300 northeast district Wisconsin dairy farmers. Evaluation questionnaires were mailed to independent samples of farm managers before (n = 582) and after (n = 572) the 12 month long intervention. RESULTS: After the intervention, more managers reported getting information about barn lights from public events (12% vs. 23%) and private consultants (8% vs. 17%) and about silo bags from print media (79% vs. 87%) and private consultants (9% vs. 14%). More managers were aware of barn lights (48% vs. 72%) and the calf feed mixing site (44% vs. 56%). There was a nonsignificant tendency for more managers to report adopting barn lights (12% vs. 23%). CONCLUSIONS: Improving information flow to operation managers about safer, more profitable production practices may be a relatively easy way to supplement conventional injury control efforts in high-hazard industries.

Accidents, Occupational↗
PubMed2001

Commentary on two articles concerning generalized and specific cognitive deficits.

This is a commentary on essays in this journal issue by M. E. Strauss (2001) and R. A. Knight and S. M. Silverstein (2001) on research methodology for studying cognitive deficits. Concentrating mostly on Knight and Silverstein's article, the authors review the psychometric issues in the matched-task design, analyze Knight and Silverstein's "process-oriented" objections to that design, and scrutinize their methods for studying cognitive deficits, examining 2 of their empirical studies as examples of those methods.

Case-Control Studies↗
PubMed2000

A longitudinal study of high scorers on the hypomanic personality scale.

Former college students (n = 36) identified by high scores on the Hypomanic Personality Scale (HYP; Eckblad & Chapman, 1986) were compared with control participants (n = 31) at a 13-year follow-up assessment. As hypothesized, the HYP group reported more bipolar disorders and major depressive episodes than the control group. The HYP group also exceeded the control group on the severity of psychotic-like experiences, symptoms of borderline personality disorder, and rates of substance use disorders. HYP group members with elevated scores on the Impulsive-Nonconformity Scale (Chapman et al., 1984) experienced greater rates of bipolar mood disorders, poorer overall adjustment, and higher rates of arrest than the remaining HYP or control participants.

Adult↗
PubMed1999

Validity and usefulness of the Wisconsin Manual for Assessing Psychotic-like Experiences.

The Wisconsin Manual for Assessing Psychotic-like Experiences is an interview-based assessment system for rating psychotic and psychotic-like symptoms on a continuum of deviancy from normal to grossly psychotic. The original manual contained six scales, assessing thought transmission, passivity experiences, thought withdrawal, auditory experiences, personally relevant aberrant beliefs, and visual experiences. A seventh scale assessing deviant olfactory experiences was subsequently added. The rating scales have good interrater reliability when used by trained raters. Cross-sectional studies indicated that the frequency and deviancy of psychotic-like experiences are elevated among college students who were identified, hypothetically, as psychosis prone by other criteria. Psychotic-like experiences of moderate deviancy in college students successfully predicted the development of psychotic illness and poorer overall adjustment 10 years later. The manual is useful for identifying psychosis-prone individuals and is recommended for use in linkage and treatment outcome studies. The present article provides an interview schedule for collecting information required for rating psychotic-like experiences.

Delusions↗
PubMed1997

Magical ideation and social anhedonia as predictors of psychosis proneness: a partial replication.

The authors compared college students identified by high scores on the Magical Ideation Scale (M. Eckblad & L. J. Chapman, 1983) and the Revised Social Anhedonia Scale (MagSoc; n = 28; M. Eckblad, L. J. Chapman, J. P. Chapman, & M. Mishlove, 1982) with control participants (n = 20) at a 10-year follow-up assessment in an attempt to replicate L. J. Chapman, J. P. Chapman, T. R. Kwapil, M. Eckblad, and M. C. Zinser's (1994) report of heightened psychosis proneness in MagSoc individuals. The MagSoc group exceeded the control group on severity of psychotic-like experiences; ratings of schizotypal, paranoid, and borderline personality disorder symptoms; and rates of mood and substance use disorders. Two of the MagSoc participants but none of the control participants developed psychosis during the follow-up period (a nonsignificant difference). Consistent with L. J. Chapman et al.'s findings, the groups did not differ on rates of personality disorders or relatives with psychosis.

Adult↗
PubMed1996

An improved model for professional conferences and workshops.

A cooperative learning method designed to increase learning and other benefits to participants is presented. Small group problem-solving from case studies or story narratives provides a way to overcome the limitations of conventional lecture presentations. An example that used a case study in small groups during a breakout session at a scientific conference to improve skills in intervention design and research evaluation is described.

Congresses as Topic↗
PubMed1996

An occupational health and safety intervention research agenda for production agriculture: does safety education work?

It is clear that agriculture has not kept pace with other hazardous industries in reducing its injury rate. For example, between 1960 and 1990 the work death rate for agriculture decreased only 28% while the work death rates decreased 65% for mining and 55% for construction [Purschwitz (1992)]. A national conference in Iowa in 1988 came to the forceful conclusion that "America's most productive workforce was being systematically liquidated by an epidemic of occupational disease and traumatic death and injury" [NCASH (1988)]. In 1991, the nation's top public health officer, the U.S. Surgeon General, convened a conference titled "FarmSafe 2000-A National Coalition for Local Action," to formally address agricultural safety and health issues. Importantly, conferees recognized that preventing injury and disease was superior to trying to rehabilitate people after an injury occurred. But does participation in farm safety and health educational programs lead to a reduction in risk of injury from farm work? Questions are being raised about the value of farm safety and health educational information, campaigns, programs, and related activities. The questions have identified a critical gap in the literature of farm safety and health education. There is currently no good evidence demonstrating that farm safety and health education, campaigns, programs, or related activities lead to a relatively stable reduction of risk on the farm. In other words, do farmers and their families actually put to use, in a relatively permanent or stable manner, the educational information regarding elimination, reduction, or control of physical hazards and the modification of work behavior that may cause injury?

Agriculture↗
PubMed1996

Deviant olfactory experiences as indicators of risk for psychosis.

Olfactory hallucinations, although relatively rare, are reportedly indicative of serious psychopathology and poor prognosis in psychotic patients. This article describes the development of a rating scale for assessing olfactory experiences of psychotic and psychoticlike deviancy. The scale is modeled after Chapman and Chapman's rating scales for other psychoticlike experiences, which have been found to predict psychosis and psychosis-proneness. In a longitudinal study, college students who reported deviant olfactory experiences at their initial assessment (n = 31) exceeded the remaining subjects (n = 477) on DSM-III-R psychosis and on measures of psychosis proneness at a 10-year followup. Furthermore, hypothetically psychosis-prone subjects identified by the Perceptual Aberration and Magical Ideation scales exceeded control subjects on ratings of olfactory experiences at both initial and followup assessments.

Analysis of Variance↗
PubMed1995

Farm-work hazard prevention efforts by school-based agricultural education instructors.

OBJECTIVE: To assess current prevention efforts, we examined agricultural work-related safety and health activities by school-based agricultural education instructors in Wisconsin. METHODS: Questionnaires were administered to 284 high school agricultural education instructors. RESULTS: Instructors taught agricultural safety and health to 61.5 students during 20.4 hours during the previous year. Extension agents were used most often as resources during preparation and presentation of coursework. Only a minority of instructors (13.6%) agreed that modifying the work to eliminate hazards should be emphasized over training people to work safely around hazards. After issues of time pressures and lack of student interest, the most important problems the instructors felt they faced were the needs for materials and other resources. CONCLUSION: Safety education alone is unlikely to reduce injuries unless unsafe conditions are modified. Instructors need to emphasize teaching of skills in hazard recognition, identification, and control. Instructors felt they could be more effective with better materials and more time for injury and disease prevention.

Accidents, Occupational↗
PubMed1995

Psychometrically matched tasks for assessment of hemispheric asymmetries of function.

One of the best methods for studying subtle lateralizing signs of brain dysfunction is the use of psychometrically matched tasks. The current study reports the development and psychometric matching of two pairs of measures of language and visual-spatial functioning. We expanded and modified four existing neuropsychological measures in order to develop tasks with a wide range of item difficulty that could be administered to subjects with impaired attention or extreme fatigue. Using 413 subjects, a Word Finding and a Dot Localization task were matched on their distribution of item difficulty and item-scale correlations. Measures of Similarities and Line Orientation were matched similarly. The psychometric matching for both pairs of tests was cross-validated using an additional 413 subjects. The matched measures of Word Finding and Dot Localization have been used in several studies to date and have proven valuable for identifying subtle lateralized impairment that might otherwise be obscured by psychometric artifacts.

Adolescent↗
PubMed1995

Task difficulty and cognitive deficits in schizophrenia.

Investigators of schizophrenic cognition often produce 2 or more tasks of differing difficulty levels by manipulating a variable that affects the accuracy of both normal and schizophrenic individuals; the investigators find that the variable also affects the difference between the groups in accuracy and conclude that the variable taps a schizophrenic differential deficit. An alternative hypothesis is that task differences in true-score variance artifactually produce the finding. For free-response tasks, group differences tend to be larger when difficulty is near 50%. The authors illustrate a new method of controlling this artifact by selecting items for hard and easy tasks on opposite sides of 50% difficulty and equidistant from it. Using this design with an anagram task, they found that schizophrenic and normal individuals differ no more on hard anagrams than on easy ones, and they propose the design for testing hypotheses concerning schizophrenic deficit on tasks that differ in difficulty.

Cognition Disorders↗
PubMed1995

Agricultural work safety efforts by Wisconsin extension agricultural agents.

This study investigated the agricultural work-related safety and health programming of county-level cooperative extension agents who work through land grant universities to provide a range of educational programs to agricultural producers. A questionnaire was designed and administered to all 89 Wisconsin agriculture and agribusiness extension county faculty. The questionnaire obtained valid responses from 98.9 percent of the agents. Ninety percent of all agents conducted some occupational safety and health promotion programming in the last year. These activities occupied an average of 4.8 days per agent per year. Most of the reported activities were group programs for the agricultural labor force that involved other extension agents and included the use of videotapes. The greatest barrier to more programming was lack of time on the part of both the agricultural work force and the agents. Most extension agents placed greater emphasis on training in how to work safely around hazards than on how to recognize and permanently correct hazards. For future programs agents requested more short format materials to use in programming, such as fact sheets, videotapes, and farm hazard inspection checklists. Agents are important training delivery resources for controlling farm-related injury and disease. Agents could be more effective with more time, better materials, and with more emphasis on hazard correction in workplace safety programs.

Agricultural Workers' Diseases↗
PubMed1994

Putatively psychosis-prone subjects 10 years later.

The predictive validities of several indicators of psychosis proneness were evaluated in a 10-year longitudinal study (N = 508). As hypothesized, high scorers on the Perceptual Aberration Scale, Magical Ideation Scale, or both (n = 182), especially those who initially reported psychoticlike experiences of at least moderate deviance, exceeded control subjects (n = 153) on psychoses (revised 3rd edition of the Diagnostic and Statistical Manual of Mental Disorders), psychotic relatives, schizotypal symptoms, and psychoticlike experiences at follow up. Ss who initially scored high on the Magical Ideation Scale and above the mean on the Social Anhedonia Scale were especially deviant. The Physical Anhedonia Scale and the Impulsive Nonconformity Scale were not effective predictors of psychosis proneness.

Adult↗
PubMed1993

Slowness and the preceding preparatory interval effect in schizophrenia.

We measured the reaction times (RTs) of schizophrenic (n = 25), matched normal (n = 69), and bipolar (n = 14) subjects to a tone preceded by a preparatory interval (PI; the time between the warning signal and imperative stimulus) of varying length. RTs increase when the PI for the immediately preceding trial (the PPI) is longer than the PI for the current trial. Several studies have shown that this PPI effect (difference score) is heightened in schizophrenia. We replicated this finding. However, we found that the size of the PPI effect within groups increased with overall slowness and that the least squares regression line relating the PPI effect difference score to overall slowness did not differ between groups, nor did schizophrenic subjects' regression line differ from that of normal subjects. Group differences on the PPI effect were also analyzed by taking residuals for members of all groups from the normal subjects' regression line of the PPI effect difference score on overall slowness. Groups did not differ on these residuals, nor did schizophrenic subjects differ from normal subjects. We conclude that the heightening of the PPI effect in schizophrenia is like that observed in equally slow normal subjects. This finding suggests that the PPI effect does not appear to be a promising marker of a distinctive schizophrenic pathology.

Adult↗
PubMed1992

Monaural and binaural story recall by schizophrenic subjects.

P. Green and other investigators have reported that schizophrenic Ss have poorer recall of stories presented to both ears than to the single best ear (binaural deficit) and poorer recall of stories presented to the left ear than to the right ear (monaural asymmetry) than do normal control Ss. These studies are plagued by potential methodological problems, including differences in overall accuracy, which artifactually affect the difference scores, and scoring methods that are vulnerable to systematic bias. In this study, scores of schizophrenic, bipolar, and normal control Ss on the Auditory Comprehension Test were compared. Scoring bias was avoided by the use of blind scoring and a revised scoring manual, and artifactual effects of accuracy were considered in interpreting the results. Contrary to previous findings, the groups did not differ on either monaural asymmetry or binaural deficit.

Adult↗
PubMed1991

Finger tremor after carbon disulfide-based pesticide exposures.

Index finger tremor accompanying voluntary movement was studied in 19 age-matched control subjects and in 19 grain industry employees chronically exposed to carbon disulfide-based fumigants. Visual judgments of tremor amplitude made by neurologists during clinical examinations equaled the sensitivity of computerized tremor amplitude measurements. Tremor frequency variations detectable only with computerized measurement were present in grain workers with and without increased tremor amplitudes. Frequency differences discriminated between normal subjects and 74% of the grain workers. The distribution of tremor frequency power in the grain workers was often sequestered at 5 to 7 Hz, reminiscent of tremor in idiopathic Parkinson's disease. These findings suggest that the measurement of subtle tremor frequency changes may provide an early indication of chronic carbon disulfide poisoning.

Adult↗