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published or submitted for publicatio

Online learning : towards enabling choice

Education is rapidly evolving from an opportunity that was provided mainly for an elite to one that is available to a mass markets and as such is prone to the forces generated by this environment. Where, in the established pattern, commercial interest was limited mainly to the use of skills developed during the educational process, the future model of educational provision will involve extensive commercial activity in the production, delivery and marketing of material. Already there are a number of commercial companies offering framework products enabling "off the shelf solutions" for the construction and delivery of web based courses in any subject area. The commercialisation of education is underway and it is inevitable that it will be viewed, by entrepreneurs and customers alike, as any other commercial product. It would seem reasonable that the consumer should be able to evaluate the performance of these new modes of working in a similar manner to other commercial products. This paper draws together current thinking on the problems associated with evaluating computer and communication based learning

Behavioural simulation of biological neuron systems using VHDL and VHDL-AMS

The investigation of neuron structures is an incredibly difficult and complex task that yields relatively low rewards in terms of information from biological forms (either animals or tissue). The structures and connectivity of even the simplest invertebrates are almost impossible to establish with standard laboratory techniques, and even when this is possible it is generally time consuming, complex and expensive. Recent work has shown how a simplified behavioural approach to modelling neurons can allow “virtual” experiments to be carried out that map the behaviour of a simulated structure onto a hypothetical biological one, with correlation of behaviour rather than underlying connectivity. The problems with such approaches are numerous. The first is the difficulty of simulating realistic aggregates efficiently, the second is making sense of the results and finally, it would be helpful to have an implementation that could be synthesised to hardware for acceleration. In this paper we present a VHDL implementation of Neuron models that allow large aggregates to be simulated. The models are demonstrated using a system level VHDL and VHDL-AMS model of the C. Elegans locomotory system

Doctor of Pharmacy

dissertationIn recent year, significant advances were made in the determination of optimal therapeutic dosage regimens for many drugs. Perhaps the main thrust in this area has been in the development of sensitive assay techniques allowing effective selection of dosage regimens on the basis of pharmacokinetic and biopharmaceutic knowledge. This has resulted in more accurate dosage selection with concomitant improvement in therapy and decreased incidence of adverse effects. Furthermore, the availability of serum assays for drugs has made it possible to maintain drug concentration in a therapeutic range for longer periods of time without risking the danger of serious toxicity, or subtherapeutic effect. This is especially important for those drugs having a narrow therapeutic index and a high variable half-life such as the seen with the digitalis glycosides. Digitalis glycoside serum assay utilization at its inception was low. However, as techniques of measurement improved and became increasingly more available, the frequency with which digitalis glycoside assays are ordered has dramatically risen. With this increase, much confusion has developed concerning assay interpretation resulting in severe criticism of the clinically utility of digitalis glycoside assays. It was the purpose of the presnet study to examine some of these problems with regard to the use of digitalis glycoside serum assays as they occur in a semi-private hospital setting. The study was designed to gain additional knowledge in the following areas: a) frequency of assay utilization , b) appropriateness of assay indication, c) appropriateness of assay use as measured by blood sampling time, d) actual assay levels, e) appropriateness of dosage adjustments, f) patient costs and g) physician understanding of digitalis glycoside assay utilization

Making a difference - the appropriate use of web technology

Much has been written elsewhere about how, different Information Technology tools, can in principle be used by groups or communities to make their web sites more effective for Continued Professional Development. In practice, complex use is not often the case. In particular, three sites were studied in Scotland, which provided web facilities for the over 60s. The sites, and the communities they served, used only simple Information Technology. Nevertheless, they enabled their communities to participate effectively, on the 'right side', of the European population's 'digital divide'

Effect of the renin-angiotensin system on limb circulation and metabolism during exercise in patients with heart failure

The maximal aerobic exercise capacity of patients with chronic heart failure is frequently decreased because of inadequate blood flow to working skeletal muscle. To investigate whether this reduced flow is in part due to interference by angiotensin II with arteriolar dilation in working muscle, the effect of the angiotensin-converting enzyme inhibitor captopril on leg blood flow, leg vascular resistance, leg oxygen consumption (V˙O2) and leg lactate release during maximal upright bicycle exercise was examined in 12 patients with heart failure (maximal V˙O210.7 ± 3.1 ml/min per kg). Captopril decreased leg resistance at rest (258 ± 115 to 173 ± 67 U, p < 0.01) and maximal exercise (68 ± 69 to 45 ± 29 U, p < 0.01) associated with proportionately similar decreases in systemic vascular resistance. However, maximal exercise duration and maximal V˙O2were unchanged and, at identical peak exercise work times, there was no improvement in leg blood flow (2.0 ± 0.9 to 2.0 ± 1.1 liters/min, p = NS), leg V˙O2(261 ± 104 to 281 ± 157 ml/min, p = NS) or leg lactate release (269 ± 149 to 227 ± 151 mg/min, p = NS). These data suggest that, during exercise in patients with heart failure, angiotensin II does not interfere with blood flow to working skeletal muscle

Approximation of Range in Materials as a Function of Incident Electron Energy

A simple composite analytic expression has been developed to approximate the electron range in materials. The expression is applicable over more than six orders of magnitude in energy (10 MeV) and range (10-9 m to 10-2 m), with uncertainty of ≤20% for most conducting, semiconducting and insulating materials. This is accomplished by fitting data from two standard NIST databases [ESTAR for the higher energy range and the electron IMFP (inelastic mean free path) for the lower energies]. In turn, these data have been fit with well-established semi-empirical models for range and IMFP that are related to standard materials properties (e.g., density, atomic number, atomic weight, stoichiometry, band gap energy). A single free parameter, the effective number of valence electrons per atom Nv, is used to predict the range over the entire energy span. Index Terms—range, inelastic mean free path, spacecraft chargin

Inferring muscle functional roles of the ostrich pelvic limb during walking and running using computer optimization

Owing to their cursorial background, ostriches (Struthio camelus) walk and run with high metabolic economy, can reach very fast running speeds and quickly execute cutting manoeuvres. These capabilities are believed to be a result of their ability to coordinate muscles to take advantage of specialized passive limb structures. This study aimed to infer the functional roles of ostrich pelvic limb muscles during gait. Existing gait data were combined with a newly developed musculoskeletal model to generate simulations of ostrich walking and running that predict muscle excitations, force and mechanical work. Consistent with previous avian electromyography studies, predicted excitation patterns showed that individual muscles tended to be excited primarily during only stance or swing. Work and force estimates show that ostrich gaits are partially hip-driven with the bi-articular hip–knee muscles driving stance mechanics. Conversely, the knee extensors acted as brakes, absorbing energy. The digital extensors generated large amounts of both negative and positive mechanical work, with increased magnitudes during running, providing further evidence that ostriches make extensive use of tendinous elastic energy storage to improve economy. The simulations also highlight the need to carefully consider non-muscular soft tissues that may play a role in ostrich gait