Zero location for discrete-time linear system polynomials with respect to an orthogonal basis

The problem is considered of a discrete-time constant linear system whose characteristic polynomial is expressed in terms of an arbitrary basis of orthogonal polynomials. It is shown how the Jury-Marden tabular array can be generalized to determine the location of the zeros with respect to the unit circle, without conversion of the polynomial into power form.     

A new approach to testing the flammability characteristics of surface coatings

This paper describes the background information which led to the development of a technique specifically designed to test the flammability performance of coatings applied to metal substrates. Design parameters for the new test are discussed and the prototype apparatus is described in detail. The mode of operation is explained and some results are tabulated for a range of typical coating materials. Conclusions based on the behaviour of the coatings tested are drawn in the text. These conclusions are, however, biased towards the Naval environment and application, and may not be universally applicable. The main implications of this work so far are that it is possible to improve the performance of existing fire retardant paint systems by: (1) ensuring that only the minimum thickness is applied to non-flammable substrates; (2) that adequate time is allowed for solvent elimination before deliberate exposure to risk; (3) using a white coating if possible; (4) increasing the durability of the coating to reduce the need for cosmetic overcoating, (i.e. re-coating purely to improve appearance), e.g. by using a thermosetting resinous binder in place of the conventionally used alkyd resin.     

Men, family-role quality, job-role quality, and physical health.

[Correction Notice: An erratum for this article was reported in Vol 12(2) of Health Psychology (see record 2008-10479-001). In this article the title for Table 1 (p. 50) should be "Correlations Between Rewards and Concerns in the Job, Marital, and Parent Roles." Also, the last item in the first column of the table should read "6. Parent-role concerns."] The relationship between the quality of men's family roles, as spouse and as parent, and the quality of men's job role, on the one hand, and their reports of physical symptoms, on the other, was examined in men drawn from a random sample of 300 dual-earner couples. The main effect of marital-role quality (i.e., rewards and concerns) on physical health was estimated, as was the Marital-Role Quality&×&Job-Role Quality interaction effect. With respect to the present role, the effect of both parent-role occupancy and parent-role quality was estimated. After controlling for job-role quality, it was found that parent-role occupancy had neither main nor interactive effects. However, among the men who occupied all 3 roles (n&=&180), only parent-role concerns were a significant predictor of physical health reports. Thus, concerns in the parent role are a major unmeasured source of variance in studies of the stress–illness relationship in men. [An erratum concerning this article appears in Health Psychology, 1993(Mar), Vol 12(2), 92. Table 1 is corrected.] (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding and using the medical subject headings (MeSH) vocabulary to perform literature searches

The United States National Library of Medicine's (NLM) MEDLINE database is the largest and most widely used medical bibliographic database. MEDLINE is manually indexed with NLM's Medical Subject Headings (MeSH) vocabulary. Using MeSH, a searcher can potentially create powerful and unambiguous MEDLINE queries. This article reviews the structure and use of MeSH, directed toward the nonexpert, and outlines how MeSH may help resolve a number of common difficulties encountered when searching MEDLINE. The increasing importance of the MEDLINE database as an information resource and the trend toward individuals performing their own bibliographic searches makes it crucial that health care professionals become familiar with MeSH.     

Greater improvement in summer than with light treatment in winter in patients with seasonal affective disorder

OBJECTIVE: The authors sought to compare the degree of mood improvement after light treatment with mood improvement in the subsequent summer in patients with seasonal affective disorder. METHOD: By using the Seasonal Affective Disorder Version of the Hamilton Depression Rating Scale, the authors rated 15 patients with seasonal affective disorder on three occasions: during winter when the patients were depressed, during winter following 2 weeks of light therapy, and during the following summer. They compared the three conditions by using Friedman's analysis of variance and the Wilcoxon signed ranks test. RESULTS: The patients' scores on the depression scale were significantly higher after 2 weeks of light therapy in winter than during the following summer. CONCLUSIONS: Light treatment for 2 weeks in winter is only partially effective when compared to summer. Further studies will be necessary to assess if summer's light or other factors are the main contributors to this difference.     

Cerebral ischemic events associated with prolapsing mitral valve

Twelve patients who had no evidence of arteriosclerotic cerebral vascular disease, lacked hypertension or coagulation defect, and had not been receiving contraceptive therapy had recurrent transient cerebral ischemic attacks (TIAs) and partial nonprogressive strokes. All had prolapsing mitral valve proved by angiocardiography. The average age was 38 years, compared with 62 years in a larger series of patients with TIA associated with arteriosclerosis. We propose that the ischemic events are related to emboli emanating from the abnormal mitral valve with or without an associated paroxysmal cardiac arrhythmia.     

Asymptotic stability and the method of linear bounds

If x? = Ax is asymptotically stable, it is possible to find linear bounds for g(x); so that x? = Ax + g(x) is also asymptotically stable. An explicit expression is given for functions which satisfy these bounds.