The ultrastructural characteristics of nematocysts from the cubozoan Carybdea alata Reynaud, 1830 (Hawaiian box jellyfish) were examined using light, scanning and transmission electron microscopy. We reclassified the predominant nematocyst in C. alata tentacles as a heterotrichous microbasic eurytele, based on spine, tubule and capsule measurements. These nematocysts exhibited a prominent and singular stylet, herein referred to as the lancet. Discharged nematocysts from fixed tentacle preparations displayed the following structures: a smooth shaft base, lamellae, a hemicircumferential fissure demarking the proximal end of a stratified lancet, and a gradually tapering tubule densely covered with large triangularly shaped spines. The lancet remained partially adjoined to the shaft base in a hinge-like fashion in rapidly fixed, whole-tentacle preparations. In contrast, this structure was not observed in discharged nematocyst preparations which involved multiple transfer steps prior to fixation. Various approaches were designed to detect this structure in the absence of fixative. Detached lancets were located in proximity to discharged tubules in undisturbed coverslip preparations of fresh tentacles. In addition, examination of embedded nematocysts from fresh tentacles laid on polyacrylamide gels revealed still-attached lancets. To examine the function of this structure in prey capture, Artemia sp. laden tentacles were prepared for scanning electron microscopy. While carapace exteriors exhibited structures proximal to the lancet, i.e., the nematocyst capsule and shaft base, neither tubule nor lancet structures were visible. Taken together, the morphological data suggested a series of events involved in the discharge of a novel eurytele from C. alata.

This paper describes the development of a Virtual Reality (VR) based therapeutic training system aimed at encourage stroke patients with upper limb motor disorders to practice physical exercises. The system contains a series of physically-based VR games. Physically-based simulation provides realistic motion of virtual objects by modelling the behaviour of virtual objects and their responses to external force and torque based on physics laws. We present opportunities for applying physics simulation techniques in VR therapy and discuss their potential therapeutic benefits to motor rehabilitation. A framework for physically-based VR rehabilitation systems is described which consists of functional tasks and game scenarios designed to encourage patients' physical activity in highly motivating, physics-enriched virtual environments where factors such as gravity can be scaled to adapt to individual patient's abilities and in-game performance.

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Hospital-acquired infections (HAI) are defined as infections that are neither present nor incubating when a patient enters the hospital (Bourn, 2000). Their effects vary from discomfort to prolonged or permanent disability and they may contribute directly or substantially to a patient’s death. HAI’s are estimated to cost the National Health Service (NHS) in England £1 billion annually (Bourn, 2000) with as many as 5,000 patients dying as a result of acquiring such an infection (Anon, 2001). Not all hospital-acquired infections are preventable but Infection Control Teams believe that they could be reduced by at least 15%, with yearly savings of £150 million (Anon, 2001). Central intravascular catheters have been found to be a common source of infection. Catheters can become infected via a number of different routes with the infection proliferating in multiple areas along the catheter surface. It has been reported that over 40% of the identified micro-organisms causing hospital-acquired infection were Staphylococci, an organism that is typically found on the natural skin flora (Bourn, 2000).

There is a need for accurate, reliable methods of detecting bacteria for a range of applications. One organism that is commonly found in urinary catheter infections is Staphylococcus epidermidis. Current methods to determine the presence of an infection require the removal of catheters. An alternative approach may be the use of in vivo sensing for bacterial/biofilm detection. This work investigates electrical impedance spectroscopy to detect the growth of Staphylococcus epidermidis RP62A on gold electrodes fabricated on a flexible substrate. Impedance spectra measured during biofilm formation on the electrode surface showed an increase in charge transfer resistance (RCT) with time.