Analysis of an array of monopoles with the use of a radial waveguide approach

A radial guide field matching method (RGFMM) is used to analyze a circular array antenna consisting of one active monopole surrounded by a concentric array of passive monopoles terminated in arbarary loads. An equivalent admittance matrix for this antenna system is determined to study the input admittance of the active monopole when the peripheral elements are terminated in open or short circuits. RGFMM results are compared with free-space method of moments (FS-MoM) results for a small switched-beam array a seven monopoles. Good agreement is noted. (C) 2002 Wiley Periodicals, Inc.

Epizootic activity of Murray Valley encephalitis virus in an aboriginal community in the southeast Kimberley region of western Australia: Results of cross-sectional and longitudinal serologic studies

Murray Valley encephalitis (MVE) virus is a mosquito-borne flavivirus causing severe encephalitis with a resultant high morbidity and mortality. In the period 1989-1993. we undertook a cross-sectional and longitudinal studs by annually screening members of a small remote Aboriginal community in northwestern Australia for MVE virus antibodies. Of the estimated 250-300 people in the community. 249 were tested, and 52.6% had positive serology to MVE. The proportion testing positive increased with increasing age group. and males were slightly more likely to be positive than females. During the study period. a high proportion of the population seroconverted to MVE: the clinical/subclinical ratio seems to be lower than previously reported. Although MVE is mostly asymptomatic, the devastating consequences of clinical illness indicate that advice should be provided regarding the avoidance of mosquito bites. Our longitudinal study showed that the risk of seroconversion was similar for each age group. not just the young.

Tenuous threads, small miracles

With the new Noosa Youth Centre, Deborah Fisher Architects has woven a small yet sophisticated building out of highly constrained and complex circumstances. Douglas Neale explores a project that convinces through its modesty.

Partitioning sets of triples into small planes

We study partitions of the set of all ((v)(3)) triples chosen from a v-set into pairwise disjoint planes with three points per line. Our partitions may contain copies of PG(2, 2) only (Fano partitions) or copies of AG(2, 3) only (affine partitions) or copies of some planes of each type (mixed partitions). We find necessary conditions for Fano or affine partitions to exist. Such partitions are already known in several cases: Fano partitions for v = 8 and affine partitions for v = 9 or 10. We construct such partitions for several sporadic orders, namely, Fano partitions for v = 14, 16, 22, 23, 28, and an affine partition for v = 18. Using these as starter partitions, we prove that Fano partitions exist for v = 7(n) + 1, 13(n) + 1, 27(n) + 1, and affine partitions for v = 8(n) + 1, 9(n) + 1, 17(n) + 1. In particular, both Fano and affine partitions exist for v = 3(6n) + 1. Using properties of 3-wise balanced designs, we extend these results to show that affine partitions also exist for v = 3(2n). Similarly, mixed partitions are shown to exist for v = 8(n), 9(n), 11(n) + 1.

Ali v Hartley Poynton Limited

The decision in Ali v Hartley Poynton Limited has significant implications for the stockbroking industry and investment advisors - likely to encourage brokers to adopt a more cautious understanding of their obligations to clients - illustrates the ability and willingness of small investors to challenge the quality of service being provided by their stockbroker.

Characteristic zirconium-rich coring structures in Mg-Zr alloys

The most characteristic feature of the microstructure of a magnesium alloy that contains more than a few tenths per cent soluble zirconium is the zirconium-rich cores that exist in most grains. The morphology, distribution and composition of cores observed in a Mg-0.56%Zr alloy and the small particles present in them were investigated. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.

Levels of consensus and majority and minority influence

Three experiments are reported which examine the effects of consensus information on majority and minority influence. In all experiments two levels of consensus difference were examined; large (82% versus 18%) and small (52% versus 48%). Experiment 1 showed that a majority source had more influence than a minority source, irrespective of consensus level. Experiment 2 examined the cause of this effect by presenting only the source label ('majority' versus 'minority'), only the consensus information (percentages) or both. The superior influence of the majority was again found when either (a) both source label and consensus information were given (replicating Experiment 1) and (b) only consensus information was given, but not when (c) only the source label was given. The results showed majority influence was due to the consensus information indicating more than 50% of the population supported that position. Experiment 3 also manipulated message quality (strong versus weak arguments) to identify whether systematic processing had occurred. Message quality only had an impact with the minority of 18%. These studies show that consensus information has different effects' for majority and minority influence. For majority influence, having over 50% support is sufficient to cause compliance while for a minority there are advantages to being numerically small, in terms of leading to detailed processing of its message. Copyright (C) 2002 John Wiley Sons, Ltd.

Early reoperation for acute dysphagia following laparoscopic fundoplication

Background: A small number of patients develop acute severe dysphagia for which reoperation is necessary within 10 days of laparoscopic fundoplication. The aim of this study was to identify clinical variables that might predict the likelihood of this condition occurring, such that it could be avoided in the future. Methods: This was a prospective cohort study from three tertiary referral centres, using reoperation for acute dysphagia as the main outcome variable. Gastrointestinal symptom rating scale, and psychological well-being index questionnaires were undertaken before laparoscopic fundoplication, and dysphagia scores were determined before operation and 1 year later. Standard preoperative assessment included gastroscopy, oesophageal manometry and pH studies. Results: Twelve (1.9 per cent) of the 617 patients suffered acute dysphagia, which was predicted by older age and female sex, and resulted in a longer duration of hospital stay. This condition was not predicted by any other demographic, clinical, investigative or operative variables. Conclusions: The study did not identify useful criteria by which severe acute dysphagia could be anticipated and thereby avoided following laparoscopic fundoplication.