No abstract

This study is a comparison of several anthropometric variables in school children of the same age (7-10 years) and sex measured in two primary schools in Cagliari (Sardinia, Italy) at an interval of 20 years (1996 vs. 1975-1976). For both males and females of each age-class, there are significant differences in the following dimensions: weight, stature, estimated lower limb length, biacromial breadth, xiphoid chest circumference, xiphoid chest depth, and bicristal breadth, and also in relative sitting height, cephalic index, and facial index. The means of the relative sitting height, cephalic, and facial indexes are higher in the children measured in 1975-1976 than in those measured in 1996. There are no significant differences in sitting height and arm length. In addition, the estimated BMIs of the 1975-1976 sample are, on average, lower than those of the 1996 sample. The results suggest that urban Sardinian children sampled in 1996 are generally taller, heavier, and larger and have a longer head and wider face than their peers of 20 years earlier. The increase in stature is due more to an increase in lower limb length than in sitting height. Am J. Hum. Biol. 12:782-791, 2000. Copyright 2000 Wiley-Liss, Inc.

A Tabu Search optimisation technique is proposed for designing, planning and maintaining water distribution systems. As design and maintenance of pipe networks for water supply distribution require high costs, achieving the highest level of performance of existing networks at minimum costs is mandatory. The problem involves setting a lot of variables, as location and diameters of new pipes, operations on existing pipes, and so on. The domain of variables is discrete in nature, due to the fact that pipes are available with unified dimensions. Furthermore, the objective function to be minimised, i.e., the total cost of the plant, is non linear, non differentiable, highly illconditioned, and presents a huge amount of local minima. Recently, increasing attention has been paid to heuristic optimisation techniques, such as genetic algorithms (GA), simulated annealing (SA), and tabu-search (TS) for large combinatorial optimisation problems. In particular, GA has been applied to the problem of designing and maintaining water distribution networks. Results show good performance of the GA in terms of objective function values, but high computation time. One of the most promising approaches to combinatorial optimisation problems is the TS metaheuristic, that showed flexibility and effectiveness in a lot of applications. The aim of this paper is to present a TS based algorithm to the design of water distribution systems, and to demonstrate its validity in this field. 2 INTRODUCTIONA water distribution network is a system of hydraulic elements connected together to transfer predefined flow-rates of water from sources to demand centres. It has proved particularly useful to adopt a graph structure as a topological support to the model optimisation. Nodes can represent sources and demand centres as well as control elements in the network. Arcs represent connection pipes between nodes. Besides other well-known advantages, a graph structure allows the use of highly efficient data structure in the optimisation process.In this paper we consider the optimal design problem which has been extensively investigated in many research studies in past decades (Alperovits and Shamir, 1977; Quindry et al., 1981;Kessler and Shamir, 1989;Fujiwara and Khang, 1990; Eigher et al., 1994). Many investigative methods and solution techniques have been proposed and tested for this problem, but it seems generally accepted that, with general optimisation tools, it is not possible to solve the design problem with real-size systems complexity.An adequate approach to the design and maintenance optimisation of pipe networks for the water supply distribution should consider the nonlinear relations between head-losses in each pipe, its diameter, length, and hydraulic property. The literature on optimisation procedures of pipe networks is extensive.The mathematical models describing this kind of problem are typically characterised by difficulties in handling features, such as discrete variables, large dimensions and often the absence of those mathema...

trainees, and this will also spread the workload of teaching across the entire team rather than being consultant-led only. Our pilot study clearly emphasizes the need for incorporating more dedicated sessions in teaching schedules to assist medical students in achieving their intended learning outcomes and to empower them with the insight about the specialty to drive further interest for future career choices. References1 Murphy RJ, Gray SA, Straja SR, Bogert MC. Student learning preferences and teaching implications. J Dent Educ 2004; 68: 859-866. 2 Celenza A, Rogers IR. Qualitative evaluation of a bedside clinical teaching programme in an emergency department. Emerg Med J 2006; 23: 769-773. 3 Morrison J. ABC of learning and teaching in medicine: evaluation.

No abstract