Data are lacking to guide management of asymptomatic bacteriuria (ASB) in elderly patients with a fall. Comparing treated versus non-treated patients, we identified clear harm and no benefit from antibiotic treatment. Our data support IDSA recommendations to withhold antibiotics in elderly patients with ASB and evaluate alternative causes of falls.

The value of otoacoustic emissions as an objective screening test for normal peripheral auditory function in infants is currently the subject of extensive and promising research. Additionally the measurement of cochlear emissions is potentially useful when children cannot be tested reliably by traditional subjective methods but confirmation of normal hearing is diagnostically important. Three groups of children are described who present such audiological dilemmas: children with non-organic hearing loss, children with severe learning difficulties and more rarely children with an abnormal auditory brainstem response who also have damage to the central nervous system. In all three groups otoacoustic emission testing was found to be diagnostically useful in determining normal peripheral auditory function thereby resolving some of the dilemmas facing paediatric audiology and ENT clinics.

A mechanistic model of dairy cow metabolism is described. The model was constructed as part of a programme directed toward quantitative and dynamic analysis of concepts and data regarding factors which influence the partition of nutrients in lactating dairy cows. Sensitivity and behavioural analyses undertaken using the model indicate that concepts and data arising from tissue level experiments conducted in vitro can be used to structure and parameterize whole-animal models since the quantitative and dynamic behaviour of such a model is acceptable. These analyses indicate further that such models can be used to evaluate factors which influence patterns of nutrient utilization. By way of illustrating the model's utility regarding evaluation of concepts relating to the interpretation of energy balance experiments, results of a simulated energy balance experiment are presented. Apparent costs of milk synthesis are partitioned among biosynthetic costs, physiological costs, ion transport costs and the reductions in energy expenditures in synthesis of body components which accompany increasingly negative energy balances due to feed restriction.

TWO models of lactating dairy cows were constructed by combining mechanistic models of digestion and metabolism reported previously and by adding elements to allow simulation of changes in tissue metabolic capacities over time. One model (day version) had an integration interval of 0·005 d and was suitable for simulation of within-day dynamics of nutrient supply and partition. The other (lactation version) had an integration interval of 1 d and was suitable for simulation of full lactation cycles. A number of simulation analyses were conducted to characterize and evaluate the models, to examine quantitative and dynamic properties of mechanisms which influence partition of nutrients, to identify aspects requiring further study, and to illustrate the potential usefulness of mechanistic, as compared to empirical, models in analyses of energy balance in lactating dairy cows.