Remarks on the development of computability

The purpose of this article is to examine aspects of the development of the concept and theory of computability through the theory of recursive functions. Following a brief introduction, Section 2 is devoted to the presuppositions of computability. It focuses on certain concepts, beliefs and theorems necessary for a general property of computability to be formulated and developed into a mathematical theory. The following two sections concern situations in which the presuppositions were realized and the theory of computability was developed. It is suggested in Section 3 that a central item was the problem of generalizing Gödel's incompleteness theorem. It is shown that this involved both the characterization of recursiveness and the attempt to clarify and formulate the notion of an effective process as it relates to the syntax of deductive systems. Section 4 concerns the decision problems which grew from the Hilbert program. Section 5 is devoted to the development of an informal' technique in the theory of computability often called ‘argument by Church's thesis’.     

A Debate About Anderson's Logic

This article is about the history of logic in Australia. Douglas Gasking (1911–1994) undertook to translate the logical terminology of John Anderson (1893–1962) into that of Ludwig Wittgenstein's (1921) Tractatus. At the time Gilbert Ryle (1900–1976), and more recently David Armstrong, recommended the result to students; but it is reasonable to have misgivings about Gasking as a guide to either Anderson or Wittgenstein. The historical interest of the debate Gasking initiated is that it yielded surprisingly little information about Anderson's traditional (syllogistic or Aristotelian) logic and its relation to classical (first-order predicate or Russellian) logic, the ostensible topic; but the materials now exist to interpret Anderson's logic in classical logic, possibly as an algebra of classes. This would be of little interest to contemporary logicians, but it might shed some light on Anderson's philosophy.     

Valedictory

Contingentism, generally contrasted with law necessitarianism, is the view that the laws of nature are contingent. It is often coupled with the claim that their contingency is knowable a priori. This paper considers Bird's [2001 Bird, Alexander 2001. Necessarily, Salt Dissolves In Water, Analysis 61/4: 267–74.[Crossref], [Web of Science ®] , [Google Scholar], 2002 Bird, Alexander 2002. On Whether Some Laws Are Necessary, Analysis 62/3: 257–70.[Crossref], [Web of Science ®] , [Google Scholar], 2005 Bird, Alexander 2005. Unexpected A Posteriori Necessary Laws of Nature, Australasian Journal of Philosophy 83/4: 533–48.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar], 2007 Bird, Alexander 2007. Nature's Metaphysics: Laws and Properties, Oxford: Clarendon Press.[Crossref] , [Google Scholar]] arguments for the thesis that, necessarily, salt dissolves in water; and it defends his view against Beebee's [2001] and Psillos's [2002 Psillos, Stathis 2002. Salt Does Dissolve In Water, But Not Necessarily, Analysis 62/3: 255–7.[Crossref], [Web of Science ®] , [Google Scholar]] contingentist objections. A new contingentist objection is offered and several reasons for scepticism about its success are raised. It is concluded that certain higher-level laws describing the behaviours of molecular compounds may be necessary due to their dependence on underlying physical laws, and that the modal status of laws of nature cannot be determined a priori, as the structural features of the substances and properties they govern must first be investigated.     

Cue competition effects in the planarian

The learning abilities of planarian worms (Dugesia tigrina) were assessed by using a number of Pavlovian conditioning paradigms. Experiment 1 showed that planaria were susceptible to basic conditioning in that they readily developed a conditioned response to a change in ambient luminance when it was consistently paired with an electric shock over a number of trials. In Experiment 2, the change in luminance was presented in a compound with a vibration stimulus during conditioning. Subsequent tests revealed poor conditioning of the elements compared with control groups in which the animals were conditioned in the presence of the elements alone, an instance of overshadowing. In Experiment 3, pre-training of one of the elements before compound conditioning resulted in blocking of learning about the other element. These results add to other studies that have reported cue competition effects in animal species belonging to different phyla (chordate, mollusk, arthropod), suggesting that learning in these phyla could be ruled by similar principles. The results are discussed adopting an evolutionary-comparative approach.     

Effects of lifestyle and stress on the employee and organization: Implications for promoting health at work

Abstract

This research was designed to determine the extent to which employee health and performance are predicted by lifestyle and stress. Data were collected from 345 employees working in a variety of organizations in southern California. Additionally, supervisors evaluated the work performance of the participating employees whom they directly supervised, and company records of employee health care costs were obtained. Hierarchical multiple regression analyses revealed (a) that physical lifestyle (i.e., exercise pattern, eating habits, and general health practices) predicted unique variance in vitality and positive well-being; (b) that psychosocial lifestyle (i.e., social relations, intellectual activity, occupational conditions, and spiritual involvement) predicted unique variance in vitality, positive well-being, anxiety, depression, lack of self-control, and somatic complaints; (c) that employee stress predicted unique variance in vitality, positive well-being, anxiety, depression, physician visits, somatic complaints, illness absences, and supervisory ratings of job performance, absenteeism and tardiness; (d) that physical lifestyle buffered the adverse consequences of stress for anxiety, depression, physician visits, and company health care costs; and (e) that there was a Physical x Psychosocial Lifestyle interaction for anxiety, depression, and lack of self-control. However, the employee lifestyle factors were not related to supervisory ratings of performance at work. The findings have direct implications for organizational health programs and policies.     

A Brief Parenting Intervention to Enhance the Parent–Child Relationship in Hong Kong: Harmony@Home

There is a dearth of high-level evidence for brief programs designed to promote positive parent–child relationships in nonwestern cultures. We present a pilot randomized controlled trial of a four-session intervention to enhance the parenting skills that promote a positive relationship with pre-adolescent children in Hong Kong. Our intervention, Harmony@Home, utilized Cunningham’s culturally appropriate coping modeling, problem-solving approach to change parental behavior. Our objective was to evaluate the feasibility, acceptability and initial evidence of benefit of the intervention. We blindly randomized 150 Hong Kong parents of children 10–13 years of age to (a) a Harmony@Home intervention group, (b) a waitlist control group, or (c) a third active intervention which shared the control group. Immediately following the intervention, we report increases in satisfaction with the parent–child relationship, one of the targeted parenting behaviors and family harmony, for the Harmony@Home group versus control group. However, only the results from satisfaction with the parent–child relationship were significant at 3-months post intervention. Most respondents reported high levels of program satisfaction. The results provide preliminary evidence that this parenting intervention is culturally acceptable for a nonwestern general population, is feasible for implementation in a community setting and shows evidence of benefit. This intervention is concordant with public health priorities because of the global importance of the parent–child relationship as a protective factor for adolescent outcomes, the need for culturally-appropriate interventions for nonwestern populations, and design characteristics that promote dissemination.     

A REVIEW OF THE CONTRIBUTION OF PERSONAL CONSTRUCT PSYCHOLOGY TO STAMMERING THERAPY

In the wake of Fransella's (1972) seminal application of Kellyian ideas to the understanding of stammering, the impact of personal construct psychology (PCP) upon speech and language therapists working in this area has been significant. This article reviews the literature and considers the developments in the management of stammering wrought through the application of PCP. A number of key issues relating to the meshing of traditional speech therapy methods and PCP are discussed and these are illustrated further by a specific personal clinical experience.