Pure Extensions, Proof Rules, and Hybrid Axiomatics

In this paper we argue that hybrid logic is the deductive setting most natural for Kripke semantics. We do so by investigating hybrid axiomatics for a variety of systems, ranging from the basic hybrid language (a decidable system with the same complexity as orthodox propositional modal logic) to the strong Priorean language (which offers full first-order expressivity).We show that hybrid logic offers a genuinely first-order perspective on Kripke semantics: it is possible to define base logics which extend automatically to a wide variety of frame classes and to prove completeness using the Henkin method. In the weaker languages, this requires the use of non-orthodox rules. We discuss these rules in detail and prove non-eliminability and eliminability results. We also show how another type of rule, which reflects the structure of the strong Priorean language, can be employed to give an even wider coverage of frame classes. We show that this deductive apparatus gets progressively simpler as we work our way up the expressivity hierarchy, and conclude the paper by showing that the approach transfers to first-order hybrid logic.A preliminary version of this paper was presented at the fifth conference on Advances in Modal Logic (AiML 2004) in Manchester. We would like to thank Maarten Marx for his comments on an early draft and Agnieszka Kisielewska for help with the proof reading.Special Issue Ways of Worlds II. On Possible Worlds and Related Notions Edited by Vincent F. Hendricks and Stig Andur Pedersen     

Relevance of the Tripartite Dimensions of Affect for Anxiety and Depression in Youth: Examining Sex and Psychopathology Status

Using a combined sample (N = 1,215) of referred children and children from the general population aged between 8 and 14 years, the present study addressed two research goals: First, latent mean differences (depending on the individual’s sex or psychopathology level) in anxiety, depression, Positive Affect (PA), Negative Affect (NA) and Physiological Hyperarousal (PH) were examined. Secondly, the structure of anxiety and depression was investigated from a tripartite model perspective in boys and girls with high versus low levels of psychopathology respectively. When relating the latent mean level differences in NA, PA, and PH with those in anxiety and depression, the results suggest that higher levels (depending on the individual’s sex and psychopathology status) of anxiety or depression are associated with higher levels of PH and lower levels of PA, whereas no consistent pattern was found between mean level differences in NA on the one hand and mean level differences in anxiety/depression on the other. Results further demonstrated that a better fit was obtained for the dual than for the unitary construct representation in boys or girls with high or low levels of psychopathology, thereby suggesting that a valid distinction can be made between anxiety and depression in children between 8 and 14 years old, irrespective of their sex or level of psychopathology. However, when looking at the structural relations of the dual construct representation of anxiety and depression with NA, PA and PH in each of the four groups separately, it became evident that the PH and PA tripartite dimensions could not account for the unique aspects of anxiety and depression respectively. Moreover, PH rather than NA was found to be common for anxiety and depression.     

The Application of Behavior Change Theory to Family-Based Services: Improving Parent Empowerment in Children’s Mental Health

We describe the development of a parent empowerment program (PEP) using a community-based participatory research approach. In collaboration with a group of dedicated family advocates working with the Mental Health Association of New York City and state policy makers, academic researchers took an iterative approach to crafting and refining PEP to better prepare family advocates to help bridge the gaps in service access among children with emotional and behavioral problems. Despite the growth of family-led, family support programs nationally, research that demonstrates the positive benefits of such programs is scarce in the children’s mental health literature. The PEP model is based on research data about barriers families face in mental health service utilization (e.g., stigma, perceptions of providers, attitudes towards mental illness, service availability, etc.). PEP is premised on (a) the concept of empowerment as a process, (b) the need to engage parents in becoming active agents of change, and (c) the application of an integrated framework to empower parents, called the Parents as Agents of Change model. Our paper focuses on describing the application of a Unified Theory of Behavior Change as a theoretical framework to help activate parents as change agents in meeting their children’s mental health needs. Based on an integrated model of grassroots driven Principles of Parent Support and research-based Unified Theory of Behavior Change, PEP’s Parents as Agents of Change model provides a conceptual framework for testing the effectiveness of family support services in children’s mental health, a much-needed area for future research.     

The Autonomy of the Health Professional: An Introduction

Theoretical Medicine and Bioethics -     

Illusory recouplings of onsets and terminations of glide tone components

We present a new auditory illusion, the gap transfer illusion, supported by phenomenological and psychophysical data. In a typical situation, an ascending frequency glide of 2,500 msec with a temporal gap of 100 msec in the middle and a continuously descending frequency glide of 500 msec cross each other at their central positions. These glides move at the same constant speed in logarithmic frequency in opposite directions. The temporal gap in the long glide is perceived as if it were in the short glide. The same kind of subjective transfer of a temporal gap can take place also when the stimulus pattern is reversed in time. This phenomenon suggests that onsets and terminations of glide components behave as if they were independent perceptual elements. We also find that when two long frequency glides are presented successively with a short temporal overlap, a long glide tone covering the whole duration of the pattern and a short tone around the temporal middle can be perceived. To account for these results, we propose an event construction model, in which perceptual onsets and terminations are coupled to construct auditory events and the proximity principle connects these elements.     

Matrix correlation

A correlational measure for ann byp matrixX and ann byq matrixY assesses their relation without specifying either as a fixed target. This paper discusses a number of useful measures of correlation, with emphasis on measures which are invariant with respect to rotations or changes in singular values of either matrix. The maximization of matrix correlation with respect to transformationsXL andYM is discussed where one or both transformations are constrained to be orthogonal. Special attention is focussed on transformations which causeXL andYM to ben bys, wheres may be any number between 1 and min (p, q). An efficient algorithm is described for maximizing the correlation betweenXL andYM where analytic solutions do not exist. A factor analytic example is presented illustrating the advantages of various coefficients and of varying the number of columns of the transformed matrices.This research was supported by grant APA 0320 from the Natural Sciences and Engineering Research Council of Canada. The authors wish to acknowledge valuable discussion of this problem with Jan de Leeuw, University of Leiden.     

A joint treatment of varimax rotation and the problem of diagonalizing symmetric matrices simultaneously in the least-squares sense

The present paper contains a lemma which implies that varimax rotation can be interpreted as a special case of diagonalizing symmetric matrices as discussed in multidimensional scaling. It is shown that the solution by De Leeuw and Pruzansky is essentially equivalent to the solution by Kaiser. Necessary and sufficient conditions for maxima and minima are derived from first and second order partial derivatives. A counter-example by Gebhardt is reformulated and examined in terms of these conditions. It is concluded that Kaiser's method or, equivalently, the method by De Leeuw and Pruzansky is the most attractive method currently available for the problem at hand.The author is obliged to Dirk Knol for computational assistance and to Dirk Knol, Klaas Nevels and Frits Zegers for critically reviewing an earlier draft of this paper.     

Understanding Respite Care Use by Families of Children Receiving Short-Term, In-Home Psychiatric Emergency Services

Respite care is widely believed to be an important support service for families raising a child with a disability. We report the findings of a respite care utilization study conducted within the context of a larger research and demonstration project examining three models of intensive, in-home services for children experiencing psychiatric crises. Respite care, both in-home and out-of-home, was a support service available to families in two of the three study conditions. Overall, 34% of 146 eligible families used in-home and or out-of-home respite care. Utilization was lower than the estimates developed prior to implementation, prompting an inquiry at the end of the first project year designed to maximize use and to gather more information on caregiver and service provider attitudes toward respite care. The inquiry included caregiver and provider focus groups, surveys, and enhanced data collection and analysis. Caregiver interviews indicated that many families did not fully understand what it meant to receive respite care or even that it was available to them. A comparative analysis of respite care users and non-users revealed that respite care users were more likely to have younger children, children who had a greater number of assessed functional impairments, and fewer social supports. Respite care users also reported greater difficulty managing their children's difficult behaviors.