Showing papers by "University of North Carolina at Greensboro published in 1991"

Stimulus equivalence and arbitrarily applicable relational responding.

Abstract: Subjects' responses to nonarbitrary stimulus relations of sameness, oppositeness, or difference were brought under contextual control. In the presence of the SAME context, selecting the same comparison as the sample was reinforced. In the presence of the OPPOSITE context, selecting a comparison as far from the sample as possible on the physical dimension defined by the set of comparisons was reinforced. Given the DIFFERENT context, selecting any comparison other than the sample was reinforced. Subjects were then exposed to arbitrary matching-to-sample training in the presence of these same contextual cues. Some subjects received training using the SAME and OPPOSITE contexts, others received SAME and DIFFERENT, and others received SAME, OPPOSITE, and DIFFERENT. The stimulus networks established allowed testing for a wide variety of derived relations. In two experiments it was shown that derived performances were consistent with relational responding brought to bear by the contextual cues. In contexts relevant to the relation of sameness, stimulus equivalence emerged. Other kinds of relational networks emerged in the other contexts. Arbitrarily applicable relational responding may give rise to a very wide variety of derived stimulus relations. The kinds of performances seen in stimulus equivalence do not appear to be unique.

Courtship violence: incidence in a national sample of higher education students.

Abstract: An approximately representative national sample of 2,602 women and 2,105 men was surveyed regarding their frequency of inflicting and sustaining verbal and physical aggression in a heterosexual relationship. Results revealed that approximately 81% of the men inflicted, as well as received, some form of verbal aggression at least once, while the comparable figure for women was 87-88%. The percentage experiencing some form of physical aggression was lower; about 37% of the men and 35% of the women inflicted some form of physical aggression and about 39% of the men and 32% of the women sustained some physical aggression. No differences were found as a function of ethnicity, family income, and institutional characteristics. Regional differences in the use of verbal and physical aggression, and in the receipt of physical aggression, were found for men.

Biogenesis of bacterial cellulose.

Abstract: Cellulose is the most abundant biological polymer on Earth. It is found in wood and cotton, and forms the basic structural foundation of the cell wall of almost all eukaryotic plants. Bacteria are ...

A Systematic Approach to Peer Group Supervision.

Abstract: The structured peer group format encourages skill development, conceptual growth, participation, instructive feedback, and self-monitoring. The procedure is described and illustrated.

Innovative behavior in small-sized firms

Abstract: This study compares aspects of innovative behavior among small-sized firms. The behavior considered is the acquisition of technical knowledge in the development of new products and production processes, the adoption of new production process technology, and the introduction of new innovative products as a competitive strategy. We find that among small-sized firms, size is important in determining the level of the first two aspects of innovative behavior, but not of the third.

Effects of Computer Programming on Cognitive Outcomes: A Meta-Analysis

Abstract: Although claims regarding the cognitive benefits of computer programming have been made, results from existing empirical studies are conflicting. To make a more reliable conclusion on this issue, a meta-analysis was performed to synthesize existing research concerning the effects of computer programming on cognitive outcomes. Sixty-five studies were located from three sources, and their quantitative data were transformed into a common scale—Effect Size. The analysis showed that 58 or 89 percent of the study-weighted effect sizes were positive and favored the computer programming group over the control groups. The overall grand mean of the study-weighted effect size for all 432 comparisons was 0.41; this suggests that students having computer programming experiences scored about sixteen percentile points higher on various cognitive-ability tests than students who did not have programming experiences. In addition, four of the seven coded variables selected for this study (i.e., type of publication, grade le...

Variability in running economy and mechanics among trained male runners.

Abstract: Data from two studies were analyzed to quantify intraindividual variability and reliability in running economy (RE) and mechanics. Following 30-60 min of treadmill accommodation, stride-to-stride and day-to-day biomechanical stability were assessed in 31 male runners (studies 1 and 2) who performed two level treadmill runs (3.33 m.s-1) at the same time of day, in the same footwear, and in a nonfatigued state. Under the same testing conditions, daily stability in RE was determined in 17 of the 31 subjects (study 2). RE demonstrated high day-to-day reliability (r = 0.95), and the mean coefficient of variation in RE was 1.32% (range = 0.30-4.40%). Stride-to-stride reliability for temporal (T), kinematic (KNM), and kinetic (KIN) measures was very high (mean r = 0.96; range = 0.91-0.99), but day-to-day reliability was lower for KIN (mean r = 0.67; range = 0.28-0.88) compared with T and KNM (mean r = 0.91; range = 0.68-0.98). Further analyses revealed no significant (P less than or equal to 0.05) mean stride-to-stride differences for any biomechanical variable, and only three of 22 variables (peak resultant velocity of the ankle joint, step length, and swing time) demonstrated statistically significant day-to-day differences. Viewed in concert, these results suggest that, if the testing environment is controlled, multiple trials are not required to obtain stable measures of running economy and basic mechanical characteristics in trained male runners if group data from adequate sample sizes are considered. However, if individual records are scrutinized or if small sample sizes cannot be avoided, at least two measures of individual performances should be secured.

Boredom in Young Adults Gender and Cultural Comparisons

Abstract: Little research has been done on boredom within or across cultures. The authors carried out comparisons of college students in Australia, Hong Kong, Lebanon and the United States with the Boredom Proneness (BP) Scale. A principal component analysis of the four samples revealed similar factor loadings and alpha coefficients. An ANOVA among groups showed a significant main effect of culture. A gender effect was also significant. Australian and U.S. samples were similar in their BP levels. Lebanese students, followed by the Hong Kong students, reported the highest amount of boredom proneness. Within all cultural groups males scored higher than females and significantly so in the United States and Australia. We identified 15 items that were transcultural in that they loaded on the first factor in all samples. Boredom proneness was found to share about half of its elements across cultures, leaving about half culturally specific. The authors explored the reasons for cultural and gender differences and pointed t...

Measurement-Related Course Work Requirements for Teacher Certification and Recertification.

Abstract: Do any state agencies require competence in assessment before certifying teachers? Do certification agencies permit measurement-related course work or continuing education credits meeting recertification requirements?

Mathematical Description of Operant Behavior: an Introduction

Abstract: Publisher Summary This chapter discusses mathematical description of operant behavior. The language of mathematics encourages descriptions that are precise, succinct, and general. An equation, for example, describes precisely and succinctly how the terms are related to one another. The term on the left specifies the dependent variable, and the term on the right specifies the independent variable. A common strategy for generating ideas for mathematical models is to conceptualize the behavioral phenomenon as analogous to some other phenomenon for which effective mathematical descriptions have already been developed. Then, with appropriate adjustments and translations, the mathematical description can be applied to the new case. Under many learning procedures, the probability of a response increases as a function of trials. But the size of the increase progressively decreases with each successive trial.

The Impact of Comparison Processes on Coactors' Frustration and Willingness to Expend Effort

Abstract: Subjects worked on an identical simple motor task that was described as being either rhigh or low in value. They worked alone or with a coactor whose performance rate was slightly superior or very superior to their own. When they performed with a very superior coactor on a high-value task, subjects were more frustrated and produced an inferior level of performance relative to those working with the same coactor on a low-value task. When subjects performed alone, however, they were not more frustrated while working on a high-than low-value task. Nevertheless, their performance scores reflected differences in motivation-subjects working on a high-value task tended to perform better than those working on a low-value task. These data are discussed within a social comparison framework and a resource investment analysis of goal value. The implications of this analysis for self-evaluation maintenance and modeling are discussed.

Why are governmental R&D and private R&D complements?

Abstract: It is well known that government R&D and private R&D have a complementary relationship. However, no previous study has provided an explanation for why that complementary relationship exists. This paper argues that infratechnology is the critical link between governmental and private R&D and that the observed complementarity is the result of technical complementarity at the production level between funding, infratechnology, and knowledge sharing. A theoritical framework based on this argument is developed and examined empirically for supporting evidence. Evidence of technical complementary is found as well as evidence that governmental R&D stimulates the sharing of knowledge.

The Computer Gender Gap: Children's Attitudes, Performance and Socialization

Abstract: A review of research studies on gender differences in computer-based education revealed significant discrepancies between equality of access and performance outcomes for female and male users. Begi...

Antiobesity effects of dehydroepiandrosterone are mediated by futile substrate cycling in hepatocytes of BHE/cdb rats.

Abstract: This study investigated the hypothesis that dehydroepiandrosterone (DHEA) functions as an antiobesity agent by promoting energy wastage via hepatic substrate cycling in prediabetic male BHE/cdb rats. Weanling BHE/cdb rats fed a 65% glucose diet were injected intraperitoneally daily with either DHEA (0.35 mol/kg body wt) or vehicle (1 mL/kg body wt) for 7 wk. The DHEA treatment significantly (P less than 0.05) reduced body weight gain. The DHEA-treated rats had epididymal and retroperitoneal fat pads that were 40% and 66% lighter, respectively, than those of control rats. The residual carcasses (i.e., minus fat pads, liver and ingesta) of DHEA-treated rats contained a significantly lower percentage of fat than those of control rats. The DHEA treatment significantly reduced fasting serum glucose and triglycerides without affecting total or HDL cholesterol. Isolated hepatocytes from DHEA-treated rats converted 2.5 times as much [U-14C]glucose to 14CO2 and one-half as much alanine to glucose as did hepatocytes from control rats. The DHEA treatment increased the specific activities of malic enzyme and lactate dehydrogenase 4.0- and 1.8-fold, respectively. Hepatocytes from DHEA-treated rats tended (P less than 0.08) to have lower phosphoenolpyruvate carboxykinase activities than hepatocytes from control rats. These data suggest that DHEA treatment exerts some of its antiobesity and antidiabetic effects in prediabetic, lipemic BHE/cdb rats by promoting hepatic glucose oxidation and reducing gluconeogenesis.

Family resource management and family stress theories: Toward a conceptual integration

Abstract: Integration of concepts and models from family resource management and family stress theories can provide a comprehensive view of the crisis and stress management process. This article (a) presents and discusses the ABCD-XYZ Resource Management Model of Crisis/Stress, (b) discusses the concepts of coping, resource management, and adaptation as they pertain to crisis and stress, (c) shows how interpersonal resource exchange theory can be used to conceptualize the concept of social support, and (d) suggests how concepts from family resource management can provide better insight into family crisis/stress. According to the ABCD-XYZ model, crisis/stress management involves (a) perceiving the stressor, the demands of the situation, and the available coping resources to formulate a definition of the crisis/stress situation, (b) cognitive coping and managerial decision-making to create, use, or combine coping resources, and (c) activating those decisions through adaptive coping and management behavior.

Beta-endorphin time course response to intensity of exercise: effect of training status.

Abstract: The concentration of beta-endorphin (B-EP) was measured in 6 trained and 6 untrained cyclists during three intensities of exercise to determine the time course changes of B-EP. B-EP was determined by radioimmunoassay with less than 5% cross reactivity with beta-lipotrophin. A counter-balanced design was used to avoid an order effect from exercise intensity. Resting B-EP values were similar across visits. There were no differences in resting B-EP values comparing the trained (4.61 +/- 0.25 pmol.l-1) to the untrained (4.03 +/- 0.23 pmol.l-1) group. Cycling at 60% VO2max did not increase B-EP in either group at any time measured. Cycling at 70% VO2max increased B-EP by 10 min in both groups p less than 0.05. The rate and magnitude of increase of B-EP were similar for both groups. B-EP changes at 80% VO2max were significantly greater that at 70% VO2max and were identical for the two groups. Both groups demonstrated increases by 5 min and further increases at 30 min of exercise p less than 0.01. These changes occurred despite the fact that lactate levels were lower in the trained group at both 70 and 80% VO2max intensities. It is concluded that the time course change for B-EP is similar for trained and untrained individuals working at the same relative intensity of exercise and does not seem to be related to plasma lactate concentrations.

Developmental sequences for catching a small ball: a prelongitudinal screening.

Abstract: Developmental sequences are identified for many skills (e.g., hopping and throwing). Sequences are hypothesized but not validated for catching. Two purposes of this investigation were to validate hypothesized catching sequences and examine the importance of task constraints on catching performance. Seventy-two subjects (5-12 years of age) were videotaped as they attempted to catch a small (10-cm) ball, tossed to three locations: (a) directly to the body, (b) at the forehead, and (c) to various other locations. Trials were categorized using developmental sequences including four components: arm preparation, arm reception, hands, and body. The data were analyzed by catching condition using the prelongitudinal screening procedure described by Roberton, Williams, and Langendorfer (1980). Preliminary screening resulted in clarification of descriptions for several developmental levels. Movement sequences for hand and body components were comprehensive and age-related for the groups studied. Task condit...

DSM-IV: empirical guidelines from psychometrics.

Abstract: This commentary addresses the use of psychometric theory and methodology in the development of the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders ( DSM—IV ). Reliability issues include interdiagnostician reliability, temporally consistent diagnoses, and the relations of diagnostic criteria within categories. Validity issues include content validity of the diagnostic criteria, criterion-related validity (the relation between different criterion sets or their algorithms and alternative diagnostic criteria), and construct validity (the relation between diagnostic categories and external validators). Specific questions and methodology to investigate its utility vary with the different uses proposed for the diagnostic system. Specific psychometric methodologies that may be useful in developing the DSM—IV are noted, as are the limitations of psychometrics and their applicability to DSM—IV .

Centrality of the grandfather role among older rural black and white men.

Abstract: This study examined racial differences in the centrality of the grandfather role and in the factors related to its saliency. Rural men aged 65 years or older, 48 Black and 51 White, reported on their grandchild of most contact. Multiple Classification Analysis, t-tests, and hierarchical multiple regression were used to examine two hypotheses: (a) the grandfather role would be more central to Black than to White men, and (b) factors predicting interaction with grandchildren would vary by race. Strong support was found for both. Racial differences were observed in household structure, association with grandchildren, grand-filial expectations, help given to grandchildren, and in affection for grandchildren. Similarities, however, were seen in the ranked importance of the role, in the amount of help received from grandchildren, and in grandfather-grandchild consensus. The findings support a cultural rather than a structural/economic base for the grandfather role, thus validating the cultural variant perspective.

Amino acids as transmitters of synaptic excitation in neocortical sensory processes.

Abstract: Few synaptic transmitters are known to exist that are not represented in some region or another, or at some layer or other, in the cerebral cortex of mammalian brain. The more difficult job than mere identification of which substances are present, is that of the assignment of particular functional role(s) of such substances, and as well, of determining upon exactly which element(s) of the known synaptic circuitry of neocortex, such transmitters operate. Current wisdom subscribes to the view that the excitatory amino acids, most likely L-glutamate, and L-aspartate but perhaps also L-cysteate, L-homocysteate, L-cysteine sulfinate or even (although much less likely) the endogenous dipeptide substance, N-acetyl-L-aspartyl-L-glutamate, are the major excitatory synaptic transmitters of intracortical (associational) fibres, of corticofugal projections, and, as this article will attest, of thalamocortical inputs, as well. What particular limits, or restrictions, are imposed upon these generalizations, such as whe...

Activation of reproduction in nulliparous and primiparous voles is blocked by vomeronasal organ removal.

Abstract: Chemical cues from male voles activate reproduction in female prairie voles (Microtus ochrogaster). Twelve hours of contact with a male, followed by exposure to his soiled bedding for 2 days, is sufficient to initiate follicular maturation and induce uterine hypertrophy. Our recent work indicates that the chemosensory vomeronasal organ (VNO) can mediate this response. Here, we examined whether other sensory systems can acquire the ability to activate female reproduction as a result of learning or experience

The involvement of alcohol dehydrogenase and aldehyde dehydrogenase in alcohol/aldehyde metabolism in Drosophila melanogaster.

Abstract: In this study we have examined the roles of alcohol dehydrogenase, aldehyde oxidase, and aldehyde dehydrogenase in the adaptation of Drosophila melanogaster to alcohol environments. Fifteen strains were characterized for genetic variation at the above loci by protein electrophoresis. Levels of in vitro enzyme activity were also determined. The strains examined showed considerable variation in enzyme activity for all three gene-enzyme systems. Each enzyme was also characterized for coenzyme requirements, effect of inhibitors, subcellular location, and tissue specific expression. A subset of the strains was chosen to assess the physiological role of each gene-enzyme system in alcohol and aldehyde metabolism. These strains were characterized for both the ability to utilize alcohols and aldehydes as carbon sources as well as the capacity to detoxify such substrates. The results of the above analyses demonstrate the importance of both alcohol dehydrogenase and aldehyde dehydrogenase in the in vivo metabolism of alcohols and aldehydes.

Using mental imagery to enhance gifted elementary students’ creative writing

Abstract: The purpose of the present research was to examine the effects of mental imagery instruction on gifted elementary students’ creative writing and development of imagery vividness. Thirty‐seven fourth‐and fifth‐grade students were assigned to either a treatment or a control group and then participated in four group lessons over a two‐week period. Treatment subjects received instruction and practice in imagery usage through researcher‐developed passages that embedded highly imaginal sensory descriptions. Control subjects listened and responded to children's stories. Following each lesson, both groups completed creative writing assignments. To assess the effects of the treatment, two pretest‐posttest tasks were given, a creative writing sample and a survey of imagery vividness. On the creative writing task, treatment subjects significantly outperformed control subjects on originality and use of sensory descriptions but not on writing length. In addition, both groups significantly improved on the vivi...

Underlying Dimensions of Apparel Involvement in Consumers' Purchase Decisions:

Abstract: The purposes of this study were (a) to determine if apparel involvement is composed of more than one dimension and, if composed of more than one dimension, (b) to determine if variation in apparel ...

The underside of slavery: The internal economy, self‐hire, and quasi‐freedom in Virginia, 1780–1865

Abstract: From the beginning of the twentieth century, scholars have shown an keen interest in various aspects of black life in Virginia. In 1902, J. C. Ballagh published A History of Slavery in Virginia in. Johns Hopkins Press series on race and slavery; and between 19t),; and 1930, Beverley Munford, Charles Ambler, John Russell, and Theodore Whitfield wrote on such subjects as the anti-slavery movement, the origin and legal status of free blacks, and the political crises following the publication of David Walker's Appeal and Nat Turner's slave revolt. During the 1930s and 1940s, black scholars Luther Porter Jackson and James. Hugo Johnston analyzed the economic, religious, social, and cultural condition of slaves and free Negroes in the state. Jackson's study, Free Free Negro Labor and Property Holding in Virginia, 1830-1860, culminated more than twenty years of research. In the past quarter-century, historians have explored such topics as slave rebelliousness, industrial slavery, free black slave owners, emigration, and the criminal justice system, among others.