Bioimpedance: Is it a predictor of true water volume?

Bioelectrical impedance analysis (BIA) has been reported to be insensitive to changes in water volumes in individual subjects, This study was designed to investigate the effect on the intra- and extracellular resistances (Ri and Re) of the segments of subjects for whom body water was changed without significant change to the total amount of electrolyte in the respective fluids, Twelve healthy adult subjects were recruited. Ri and Re of the leg, trunk, and arm of the subjects were determined from BIA measures prior to commencement of two separate studies that involved intervention, resulting in a loss/gain of body water effected either bt a sauna followed by water intake (study 1) or by ingestion (study 2). Ri and Re of the segments were also determined at a number of times following these interventions, The mean change in body water, expressed as a percentage of body weight, was 0.9% in study 1 and 1.25% in study 2. For each study, the results for each subject were normalized for each limb to the initial (prestudy) value and then the normalized results for each segment were pooled for all subjects, ANOVA of these pooled results failed to demonstrate any significant differences between the normalized mean values of Ri or Re of the segments measured through the course of each study, The failure to detect a change in Ri or Re is explained in terms of the basic theory of BIA.

True measures of GDP and convergence

Widely used ''purchasing power parity'' comparisons of per capita GDP are not true quantity indexes and are subject to systematic substitution bins. This bias may distort measurement of convergence and divergence. Extending Varian's nonparametric construction of a true index gives the set of true indexes, including the new Ideal Afriat Index. These indexes are utility-consistent and independent of arbitrary reference price vectors. We establish bounds on the dispersion of true multilateral indexes, hence bounds on convergence. International price indexes understate both true GDP dispersion and, where prices are converging over time, the rate of true quantity convergence.

The Fa,b,c conjecture is true, II

In 1977 a five-part conjecture was made about a family of groups related to trivalent graphs and subsequently two parts of the conjecture were proved. The conjecture completely determines all finite members of the family. Here we complete the proof of the conjecture by giving proofs for the remaining three parts. (c) 2006 Elsevier Inc. All rights reserved.

Merton's true self and the psychology of the dialogical self

Thomas Merton pursued a life-long quest to grasp the nature of the “true self.” This is the self that lives in and through Christ. Opposed to this is the false self that is expressive of infidelity. It is argued that the interaction between the true and false selves constitutes a dialogical process. The thesis of the essay is that this interaction expresses the dynamics associated with what some psychologists refer to as the “dialogical self.” The dialogical self is a model of the inner life that draws attention to the interpretive process required to deal with the many voices that get internalized in an engagement with the world.

Modelling Java concurrency with Object-Z

In this paper, we present a formal model of Java concurrency using the Object-Z specification language. This model captures the Java thread synchronization concepts of locking, blocking, waiting and notification. In the model, we take a viewpoints approach, first capturing the role of the objects and threads, and then taking a system view where we capture the way the objects and threads cooperate and communicate. As a simple illustration of how the model can, in general be applied, we use Object-Z inheritance to integrate the model with the classical producer-consumer system to create a specification directly incorporating the Java concurrency constructs.

A classification of concurrency failures in java components

The Java programming language supports concurrency. Concurrent programs are hard to test due to their inherent non-determinism. This paper presents a classification of concurrency failures that is based on a model of Java concurrency. The model and failure classification is used to justify coverage of synchronization primitives of concurrent components. This is achieved by constructing concurrency flow graphs for each method call. A producer-consumer monitor is used to demonstrate how the approach can be used to measure coverage of concurrency primitives and thereby assist in determining test sequences for deterministic execution.