Showing papers by "York University published in 1989"

Parent Styles Associated with Children's Self-Regulation and Competence in School.

Abstract: This study assessed three dimensions of parent style, autonomy support, involvement, and provision of structure in 64 mothers and 50 fathers of elementary-school children in Grades 3-6, using a structured interview. Aspects of children's self-regulation and competence were measured through children's self-reports, teacher ratings, and objective indices. Results are discussed in terms of the motivational impact of the parent on school competence and adjustment and in terms of transactional models of influence

Has anything changed? Current characterizations of men, women, and managers.

Abstract: Replication et extension de la recherche de Schein (1973) sur la description des hommes, des femmes, en tant que tels ou comme managers ou managers a succes, par 268 managers utilisant un inventaire d'attributs a 92 items pour evaluer un des sept groupes cibles. La proximite de l'image de manager avec celle de chaque role sexuel est en particulier commentee

Effects of daily workload on subsequent behavior during marital interaction: the roles of social withdrawal and spouse support.

Abstract: This article examines daily variability in 2 marital behaviors, social withdrawal and the expression of anger, as a function of daily taskload at work. Thirty-three air traffic controllers (ATCs) and 27 wives completed surveys on 3 consecutive days. Subjective and objective indicators of daily workload (air traffic volume and visibility at the airport) were related to the couples' descriptions of the ATCs' behavior after work. Despite a positive association between withdrawal and anger, workload seemed to influence these 2 behaviors in opposite ways. On high spouse-support evenings, work overload was associated with increased social withdrawal and less expression of anger. Social withdrawal may help an aroused individual return to a baseline emotional and physiological state. By facilitating their stressed partner's social withdrawal, supportive spouses may buffer the effects of minor daily stressors. People usually think of behavior in close relationships as being determined by stable personality and situational variables. However, as everyone in a close relationship knows, there is substantial day-to-day variability in a couple's behavior. These variations and the factors that influence them are often overlooked in psychological research. Some of the variability in marital interaction may be due to conditions that an employed person faces at work each day. The study reported here addresses two questions: How do married people behave when they return home after a stressful day at work, and how does a spouse's behavior influence the employee's delayed response to job-related stress? A growing body of research investigates the relation between an individual's habitual experiences at work and typical patterns of social interaction within the family (Bronfenbrenner & Crouter, 1982; Hoffman, 1985; Piotrkowski, Rapoport, & Rapoport, 1987). Much of the literature has focused on a spillover model, which proposes that psychological responses to work, such as gratification or emotional depletion, carry over into the home (Piotrkowski, 1979). Almost all of the relevant studies have examined job stress as an individual difference variable. Using between-subjects designs, investigators have found that

Employment and women's health: Effects of paid employment on women's mental and physical health.

Abstract: This article reviews empirical evidence con- cerning the effects of paid employment on women's mental and physical health, with special attention to variations in the effects of employment depending on the character- istics of women and their jobs. We highlight methodolog- ical issues and focus primarily on studies with longitudinal data for representative samples of women. We conclude that women's employment does not have a negative effect on their health, on the average. Indeed, employment ap- pears to improve the health of unmarried women and married women who have positive attitudes toward em- ployment. Possible mediators linking employment to health outcomes are discussed. Current evidence suggests that increased social support from co-workers and super- visors may be one important mediator of the beneficial health effects of employment. Given the paucity of avail- able longitudinal studies, we encourage additional pro- spective research examining the mental and physical health consequences of employment according to job characteristics, personal characteristics, and disease out- come. We also recommend research on several promising mediators of employment-health relationships.

Ultraviolet spectrometer observations of Neptune and Triton

Abstract: Results from the occultation of the sun by Neptune imply a temperature of 750 + or - 150 kelvins in the upper levels of the atmosphere (composed mostly of atomic and molecular hydrogen) and define the distributions of methane, acetylene, and ethane at lower levels The ultraviolet spectrum of the sunlit atmosphere of Neptune resembles the spectra of the Jupiter, Saturn, and Uranus atmospheres in that it is dominated by the emissions of H Lyman alpha (340 + or - 20 rayleighs) and molecular hydrogen The extreme ultraviolet emission in the range from 800 to 1100 angstroms at the four planets visited by Voyager scale approximately as the inverse square of their heliocentric distances Weak auroral emissions have been tentatively identified on the night side of Neptune Airglow and occultation observations of Triton's atmosphere show that it is composed mainly of molecular nitrogen, with a trace of methane near the surface The temperature of Triton's upper atmosphere is 95 + or - 5 kelvins, and the surface pressure is roughly 14 microbars

Memory for action events: The power of enactment

Abstract: Memory researchers have traditionally made use of verbal materials in their empirical studies. During the last decade or so, there has been a burgeoning interest in memory for other classes of materials — in particular, memory for action events. This report reviews briefly some of the research in this area. The emphasis is on the recall of series of instructions, such aslift the pen, put on the ring. The core finding in those studies is that enactment of the instructions during the study phase, either by the subject or by the experimenter, improves performance on a subsequent recall test. Some explanations for the mnemonic effect of enactment are examined, as also are subsidiary issues, such as population and individual differences in the recall of action events. Implications for education are discussed, including the possibility of a two-way interaction between enactment and cognition.

On measures of flexibility in manufacturing systems

Abstract: SUMMARY This paper presents measures which quantify the notion of how well manufacturing systems, in which machines are assigned to participate in tasks, can absorb changes in the environment. Several measures are proposed and their properties discussed. This paper takes the viewpoint that such measures are relative to reference task-sets.

The Newtonian Mechanistic Paradigm, Special Education, and Contours of Alternatives An Overview

Abstract: The concept of paradigm as a set of ontological and epistemological benchmarks is the basis for a discussion of the influence the Newtonian mechanistic paradigm has exerted over special education theory, research, and practice. Discussions of “malcontents” with the mechanistic paradigm across the social sciences and within special education are noted. Recent literature in the field of special education is critiqued for renaming theories as paradigms, thereby leaving mechanistic assumptions in place. The contours are then drawn of theoretical reorientations and of the emerging alternative holistic paradigm and its importance for special education. It is concluded that we do not have paradigms or paradigm shifts within the field, but that the field is part of a paradigm that is undergoing change across the sciences and social sciences.

Managers Handling Disputes: Third-Party Roles and Perceptions of Fairness

Abstract: This study investigated how managers resolve disputes in organizations, comparing a typology of managerial third-party dispute-resolution behavior drawn from prior research to the behavior of manag...

An assessment of appraisal, anxiety, coping, and procrastination during an examination period

Abstract: High School students responded to an inventory which included dispositional measures of procrastination and social evaluation trait anxiety. Subsequently, and 7 days prior to their first examination (Stage 1), each of the 40 female and 23 male students completed measures of state anxiety, perception of the stressor situation, and ways of coping, all with regard to their approaching exam period. These judgments were repeated 1 day prior to their first examination (Stage 2), and again 5 days after their last examination (Stage 3). Correlational analyses indicated that threat and harm perceptions were highly positively related to state anxiety, whereas challenge and gain were moderately and negatively related. State anxiety was linked to emotion-focused coping, but was independent of problem-focused coping. In an analysis of variance, high procrastination, high trait anxious subjects felt the least challenged at Stage 1. In a ‘maverick’, post hoc analysis, high procrastinators were more likely than low procrastinators at each stage to promise themselves ‘that things will be different next time’. Discussion included an assessment of the need for specificity when using the Ways of Coping (Folkman and Lazarus, 1985) scale.

The Impact of the Atlantic Slave Trade on Africa: A Review of the Literature

Abstract: Recent revisions of estimates for the volume of the trans-Atlantic slave trade suggest that approximately 11,863,000 slaves were exported from Africa during the whole period of the Atlantic slave trade, which is a small upward revision of my 1982 synthesis and still well within the range projected by Curtin in 1969. More accurate studies of the French and British sectors indicate that some revision in the temporal and regional distribution of slave exports is required, especially for the eighteenth century. First, the Bight of Biafra was more important and its involvement in the trade began several decades earlier than previously thought. Secondly, the French and British were more active on the Loango coast than earlier statistics revealed. The southward shift of the trade now appears to have been more gradual and to have begun earlier than I argued in 1982. The greater precision in the regional breakdown of slave shipments is confirmed by new data on the ethnic origins of slaves. The analysis also allows a new assessment of the gender and age profile of the exported population. There was a trend toward greater proportions of males and children. In the seventeenth century, slavers purchased relatively balanced proportions of males and females, and children were under-represented. By the eighteenth century, west-central Africa was exporting twice as many males as females, while West Africa was far from attaining such ratios. In the nineteenth century, by contrast, slavers could achieve those ratios almost anywhere slaves were available for export, and in parts of west-central and south-eastern Africa the percentage of males reached unprecedented levels of 70 per cent or more. Furthermore, increasing numbers of slaves were children, and again west-central Africa led the way in this shift while West Africa lagged behind considerably.This review of the literature on the demography of the slave trade provides a context to assess the revisionist interpretation of David Eltis, who has argued recently that the slave trade and its suppression were of minor importance in African history. It is shown that Eltis' economic arguments, based on an assessment of per capita income and the value of the export trade, are flawed. The demography of the trade involved an absolute loss of population and a large increase in the enslaved population that was retained in Africa. A rough comparison of slave populations in West Africa and the Americas indicates that the scale of slavery in Africa was extremely large.

Assessment of state and trait anxiety: Endler multidimensional anxiety scales

Abstract: The Endler Multidimensional Anxiety Scales (EMAS) are self-report measures of multidimensional trait anxiety, state anxiety and perception of situations. The scales were administered to samples of students, adults, and clinical patients. Normative data and reliabilities of the EMAS are reported. Concurrent and construct validity studies are discussed. In general, the data support the conclusion that the EMAS are reliable and valid measures of multidimensional trait and state anxiety. Theoretical and practical uses of the scales are discussed, including their relationship to the interaction model of personality and their uses in clinical and other applied settings.

AIDS: a syndrome of immune dysregulation, dysfunction, and deficiency.

Abstract: Acquired immune deficiency syndrome (AIDS) is a disease caused by the human immunodeficiency virus (HIV) in which cellular immune functions are severely impaired. Acute infection and subsequent destruction of helper T cells, although occurring readily in cell cultures, do not appear to be the only mechanisms mediating helper T cell loss. Other mechanisms that may account for the loss of helper T cells include: T cell syncytia formation, decreased T cell production, and autoimmune-related destruction of helper T cells. Immune abnormalities seen early in the course of HIV infection include immune hyperactivation and autoimmune phenomena suggestive of immune dysregulation rather than immune deficiency. Many changes in immune function are, in fact, seen in HIV-seropositive patients who possess a normal number of helper T cells. Mechanisms (other than the loss of helper T cells) that may contribute to the immune abnormalities seen in these patients include noninfectious effects of HIV and HIV proteins, effects...

Psychological Burnout among Men and Women in Teaching: An Examination of the Cherniss Model

Abstract: This investigation examined psychological burnout among 833 men and women in teaching using a framework developed by Cherniss (1980). Work setting characteristics in concert with person variables (both individual differences and extra-work factors) were hypothesized to result in experienced stress. Some individuals cope with these sources of stress by developing the negative attitude change termed psychological burnout. Respondents provided data by completing questionnaires anonymously. The data provide strong preliminary support for the model and produced findings consistent with previous research. Suggestions for organizational intervention are offered.

The role of transverse secondary instabilities in the evolution of free shear layers

Abstract: Linear stability analyses and nonlinear flow simulations reveal several important features of transverse secondary instabilities of two-dimensional Kelvin–Helmholtz billows and Stuart vortices. Vortex pairing is found to be the most rapidly amplified mode in a continuous spectrum of vortex merging instabilities. In certain not uncommon circumstances it is possible for more than two vortices to amalgamate in a single interaction, demonstrating that the phenomenon that has become known as the pairing resonance in fact has a rather low quality factor. Another form of merging instability in which a vortex is deformed and drained by its neighbours has been revealed by our linear stability analyses of nonlinear shear-layer disturbances. It appears, however, that this vortex draining instability may be important only in unstratified or very weakly stratified flows, since in moderately stratified Kelvin–Helmholtz flow, it is replaced by a highly localized instability which leads to a temporary distortion of the braids. Nonlinear simulations of vortex merging events in moderately stratified, high-Reynolds-number shear layers are compared to the theoretical predictions of our stability analyses. We investigate and quantify the sensitivity of merging events to variations in the initial conditions. The character of the flow after merging instability saturates and the nonlinear aspects of multiple merging events are also considered.

Validation of a Measure of Perfectionism

Abstract: This article describes perfectionism, or the holding of and striving for unrealistically high standards, and presents two studies undertaken to investigate the convergent, discriminant, and predictive validity of the Perfectionism Scale (PS; Burns, 1980) College students in the first study completed the PS, several other measures of high standards, and measures of constructs that, conceptually, are differentially related to perfectionism Correlational analyses indicated that the Perfectionism Scale has convergent and discriminant validity and seems to measure self-oriented perfectionism The second study attempted to determine the predictive validity of the PS by testing a vulnerability model of subclinical depression outlined in Hewitt and Dyck (1986) PS scores were used to predict depressed mood changes in female college students following failure on important and unimportant tasks As expected, the results indicated that perfectionism interacted with failure on important versus unimportant tasks to produce dysphoric mood Evidence for the predictive validity of the PS was thus shown Several directions for future research are discussed

The Adjustment of Students with Learning Disabilities to University and Its Relationship to Self-Esteem and Self-Efficacy

Abstract: Using self-report questionnaires, this study found that a sample of 34 university students with learning disabilities reported significantly poorer self-esteem, academic adjustment, and personal-emotional adjustment than a sample of 31 non-learning-disabled students. For both groups, self-esteem correlated positively with general self-efficacy. Both variables correlated positively with adjustment to university.

Kinetic depth effect and identification of shape.

Abstract: We introduce an objective shape-identification task for measuring the kinetic depth effect (KDE). A rigidly rotating surface consisting of hills and valleys on an otherwise flat ground was defined by 300 randomly positioned dots. On each trial, 1 of 53 shapes was presented; the observer's task was to identify the shape and its overall direction of rotation. Identification accuracy was an objective measure, with a low guessing base rate of the observer's perceptual ability to extract 3D structure from 2D motion via KDE. (1) Objective accuracy data were consistent with previously obtained subjective rating judgments of depth and coherence. (2) Along with motion cues, rotating real 3D dot-defined shapes inevitably produced a cue of changing dot density. By shortening dot lifetimes to control dot density, we showed that changing density was neither necessary nor sufficient to account for accuracy; motion alone sufficed. (3) Our shape task was solvable with motion cues from the 6 most relevant locations. We extracted the dots from these locations and used them in a simplified 2D direction-labeling motion task with 6 perceptually flat flow fields. Subjects' performance in the 2D and 3D tasks was equivalent, indicating that the information processing capacity of KDE is not unique. (4) Our proposed structure-from-motion algorithm for the shape task first finds relative minima and maxima of local velocity and then assigns 3D depths proportional to velocity.

Method and apparatus for the generation of reports

Abstract: A method and apparatus for generating, and storing for later retrieval, selected voice messages in response to selected verbal input trigger phrases. The voice signals including predetermined trigger phrases are transmitted from an input device such as a multiline telephone to a voice recognition system. The voice recognition system associates the trigger phrases with predetermined blocks of text message and in response to a sequence of trigger phrases, creates a report. The text is then output to a voice synthesizer system for the creation of synthetic voice signals corresponding to the full text of the report and the synthetic voice signals are output to a voice storage and forward system for later retrieval. The system also provides a printed copy of the full text of the report. In one embodiment of the system, an exception dictionary is provided which substitutes replacement words having a modified spelling for exception words whose pronunciation, as synthesized by the voice synthesizer, is not considered acceptable.

Acquired protein C deficiency in patients with breast cancer receiving cyclophosphamide, methotrexate, and 5-fluorouracil.

Abstract: Recent reports have documented an increase of thrombotic complications in patients with carcinoma of the breast receiving chemotherapy regimens containing cyclophosphamide, methotrexate, and 5-fluorouracil. The authors studied blood from nine such patients screening for abnormalities that might predispose to thrombosis or indicate that the coagulation cascade had been activated. Six of the patients were in the adjuvant setting, and three had metastatic disease. Samples were collected from each patient before, during, and after completion of the chemotherapy in question. In each patient a statistically significant decline in functional protein C activity (P = 0.001) was demonstrated at midtherapy. In seven of nine patients functional protein C level normalized after the cessation of therapy. No other positive results were found. The authors conclude that the combination of cyclophosphamide, methotrexate, and 5-fluorouracil, when administered to patients with a diagnosis of carcinoma of the breast, causes a reversible decline in the activity of protein C.

The fast computation of disparity from phase differences

Abstract: Previous work has demonstrated that the task of recovering local disparity measurements can be reduced to the task of measuring the local phase between bandpass signals extracted from the left and right cameras. In computing this local phase difference, earlier algorithms expressed the computational task as a nonlinear differential equation to be solved at each image point. Although this approach has great appeal as a model for biological disparity measurement, the solving of a differential equation at a large number of image points and disparities makes the algorithm unsuitable for serial digital computer applications. Here, the authors demonstrate how the approach of recovering disparity from the measurement of local phase differences can be accomplished without the computational expense exhibited by previous algorithms. This disparity measurement technique is embedded within a simple coarse-to-fine stereopsis similar to the algorithm proposed by H.K. Nishihara (1984) and the resulting algorithm is applied to a number of stereo pairs. >

Incidence and risk factors for human immunodeficiency virus seroconversion in a cohort of Sydney homosexual men.

Abstract: By means of prospective cohort data from the Sydney AIDS Project, we report on 55 homosexual or bisexual men who have become infected with human immunodeficiency virus (HIV), as measured by the development of serum HIV antibodies (seroconversion). We have compared the sexual practices, recreational drug abuse, history of sexually-transmissible diseases, and antecedent immunological findings of the men who seroconverted with those of 588 subjects who persistently remained seronegative in the same time-period. The cumulative incidence rate of HIV infection over the three years of observation was 8.5%. The cumulative incidence rate ranged from less than 1% for the six months before August 1, 1984, to a peak of 5% in the six months before August 1, 1985. Of those subjects for whom we had data for the period of seroconversion, all but two of the subjects who seroconverted admitted to a recognized high-risk sexual practice in the six months before the first visit at which they were found to be seropositive. Univariate analysis found that men who seroconverted were significantly more likely to have had a greater number of recent sexual partners (relative risk per partner, 1.02; P less than 0.001), to have engaged in receptive anal intercourse (incidence rate ratio, 3.1; 95% confidence interval [CI], 1.3-7.6; P = 0.01) and to have used nitrite inhalant (incidence rate ratio, 2.6; 95% CI, 1.2-5.9; P = 0.02) and amphetamine (incidence rate ratio, 4.8; 95% CI, 2.2-10.5; P less than 0.001) drugs. The men who seroconverted were significantly (incidence rate ratio, 2.7; 95% CI, 1.2-6.1; P = 0.014) more likely to have antecedent T-suppressor-cell counts of greater than 800 cells/microL. Factors that retained significance in multivariate analysis were the number of recent sexual partners, recent amphetamine abuse and a T-suppressor-cell count of greater than 800 cells/microL.

Career Stages, Satisfaction, and Well-Being among Police Officers

Abstract: This study examined the relation of career stage to work experiences and satisfactions of police constables. 522 police officers participated by anonymously completing questionnaires. Five career stages were considered: less than 1 yr., 1–3 yr, 6–15 yr., 16–25 yr., and over 25 yr. in policing. Constables in the midcareer stage reported the most negative work setting, greatest stress, least job satisfaction, greatest psychological burnout, and most work-family conflict. Constables in the most advanced career stage reported the poorest physical health, a function of their greater age.