From Euler to Navier–Stokes: A Spatial Analysis of Conceptual Changes in Nineteenth-century Fluid Dynamics

This article provides a spatial analysis of the conceptual framework of fluid dynamics during the nineteenth century, focusing on the transition from the Euler equation to the Navier–Stokes equation. A dynamic version of Peter Gärdenfors's theory of conceptual spaces is applied which distinguishes changes of five types: addition and deletion of special laws; change of metric; change in importance; change in separability; addition and deletion of dimensions. The case instantiates all types but the deletion of dimensions. We also provide a new view upon limiting case reduction at the conceptual level that clarifies the relation between the predecessor and successor conceptual framework. The nineteenth-century development of fluid dynamics is argued to be an instance of normal science development.     

UNCERTAINTY AND GOD: A JAMESIAN PRAGMATIST APPROACH TO UNCERTAINTY AND IGNORANCE IN SCIENCE AND RELIGION

This article picks up from William James's pragmatism and metaphysics of experience, as expressed in his “radical empiricism,” and further develops this Jamesian pragmatist approach to uncertainty and ignorance by connecting it to phenomenological thought. The Jamesian pragmatist approach avoids both a “crude naturalism” and an “absolutist rationalism,” and allows for identification of intimations of the sacred in both scientific and religious practices—which all, in their respective ways, try to make sense of a complex world. Analogous to religious practices, emotion and the metaphysics of experience play a central role in science, especially the emotion of wonder. Engaging in scientific or religious practices may create opportunities for individuals to realize that they are co‐creators of the world in partnership with God, in full awareness of uncertainty and ignorance and filled with the emotion of wonder.     

POST-TRAUMATIC STRESS REACTIONS AMONGST RESCUE WORKERS AFTER A MAJOR RAIL ACCIDENT

Abstract

Rescue tasks under heavy strain may act as traumatic events creating stress reactions among the rescue workers. After a major rail accident the rescue workers were examined by questionnaire at 3 and 7 months postaccident using the General Health Questionnaire-28 (GHQ), Impact of Event Scale (IES) and a structured questionnaire made for the purpose. Eighteen percent of the 77 rescue workers who participated in the study had GHQ-case-score and 10% had IES-case-score at 7 months using the usual GHQ-cut-off (4/5) and a low IES-cut-off (19/20). For the case-scorers there was a tendency towards increased GHQ- and IES-scores from 3 to 7 months. Five (6%) had post-traumatic stress disorders (PTSD) of low to moderate severity at 7 months.     

Assessing the quality of life of HIV infected persons: Clinical and descriptive information from studies with the hopes

Abstract

We have recently developed and psychometrically evaluated an HIV-specific quality of life instrument. The new instrument is called the HIV Overview of Problems-Evaluation System (HOPES) which was adapted from an established cancer-specific quality of life instrument called the CARES. In this paper we review the psychometric properties of the HOPES, examine the quality of life impact of HIV infection in a cross-sectional evaluation of 318 patients using data from the HOPES and describe other work in progress or planned using the HOPES.     

Beyond the Individual: Promoting Mental and Behavioural Health in Low- and Middle-income Countries

This brief report describes a programmatic approach to health promotion that can help address the social determinants of mental-health and associated risky behaviours. Using a South African case example, we illustrate that while micro-system interventions help to strengthen individual resilience and immediate proximal protective influences, group system interventions can assist to promote health enhancing social identities and representations. We conclude that multi-level interventions that assume a systemic focus can strengthen community transformative efforts to address social determinants of mental and behavioural health.     

Age-associated memory impairment diagnoses: problems of reliability and concerns for terminology.

Objective memory criteria for diagnosing age-associated memory impairment (AAMI), age-consistent memory impairment, and late-life forgetfulness (LLF) were applied to 523 cognitively normal older persons divided into 2 groups on the basis of the clinical memory assessment battery they received. Seventy-seven percent of Group 2 and 98% of Group 1 met the Crook et al. (1986) cognitive criteria for AAMI on at least 1 test. Rates based on individual tests varied from 7% to 96%. Objective-cognitive criteria for LLF were met by no members of Group 1 but by 31% of Group 2. Results suggest that, as proposed, the criteria for age-related diagnoses lack reliability. Concerns regarding the diagnosis of normal memory in older populations are considered.     

Solutions to some problems in the implementation of conjoint analysis

Methodological problems encountered in implementing conjoint analysis include (1) the impractically large set of multiattribute choice alternatives created by the factorial combination of more than a few attributes, (2) the hypothetical nature of the alternatives in the choice set, and (3) the assumption that each individual’s preferences can be described by the same composition rule. The techniques of tailoring, belief matching, and axiom testing are suggested as solutions to these problems, and their use is demonstrated in a conjoint analysis study of individuals’ contraceptive preferences. It is noted that tailoring and belief matching can also be used as methodological enhancements in functional measurement studies.     

Contextual control of letter perception

This study examined the hypothesis that the type of list context in which a given item is embedded may affect the way in which it is perceptually processed. In the first experiment, subjects matched four types of test items inserted in four types of lists. The types of test items and the types of lists in which they were embedded were two-letter words, two-letter spelling clusters, unrelated letter pairs, and pairs of novel letters. The first experiment indicated that only unrelated letter pairs were significantly affected by type of list in which they were inserted. The pattern of the effect was confirmed in the latency data of the second experiment and the interpretation was that only unrelated letter and related letter-group contexts were operating in the first two experiments. The third and fourth experiments were concerned with contrasting contexts at the feature and letter levels of processing. By using lists in which type of catch trial either emphasized local features or global aspects of a pattern, the processing times of both familiar and unfamiliar letters were affected. The results of these experiments suggest that information processing models should incorporate structures which represent the way that context selectively facilitates processing of items at particular levels.     

Adolescents' expectancies of success,self-evaluations,and attributions about performance on spatial and verbal tasks

The present study examined the expectancies of success, evaluations of performance, and achievement-related attributions that high school students made about verbal and spatial tasks that typically show sex differences. Although no sex differences were found in task performance, boys expected to do better than girls on both the spatial and verbal tasks. After completing the task, the girls continued to evaluate their performance more negatively than did boys on the spatial tasks. On spatial tasks girls also attributed to themselves less ability and saw the tasks as being more difficult than did boys. The results suggest that there are generalized, rather than task-specific, sex differences in achievement expectancies, evaluations, and attributions. These findings are discussed in terms of their implications for sex-related differences in cognitive functioning and subsequent achievement behaviors.The authors gratefully acknowledge support from the Judith Offer Fund and from the Spencer Foundation.