The s-mote: a versatile heterogeneous multi-radio platform for wireless sensor networks applications

This paper presents a novel architecture and its implementation for a versatile, miniaturised mote which can communicate concurrently using a variety of combinations of ISM bands, has increased processing capability, and interoperability with mainstream GSM technology. All these features are integrated in a small form factor platform. The platform can have many configurations which could satisfy a variety of applications’ constraints. To the best of our knowledge, it is the first integrated platform of this type reported in the literature. The proposed platform opens the way for enhanced levels of Quality of Service (QoS), with respect to reliability, availability and latency, in addition to facilitating interoperability and power reduction compared to existing platforms. The small form factor also allows potential of integration with other mobile platforms including smart phones.

FLT3-driven redox signalling in acute myeloid leukaemia

Acute myeloid leukaemia refers to cancer of the blood and bone marrow characterised by the rapid expansion of immature blasts of the myeloid lineage. The aberrant proliferation of these blasts interferes with normal haematopoiesis, resulting in symptoms such as anaemia, poor coagulation and infections. The molecular mechanisms underpinning acute myeloid leukaemia are multi-faceted and complex, with a range of diverse genetic and cytogenetic abnormalities giving rise to the acute myeloid leukaemia phenotype. Amongst the most common causative factors are mutations of the FLT3 gene, which codes for a growth factor receptor tyrosine kinase required by developing haematopoietic cells. Disruptions to this gene can result in constitutively active FLT3, driving the de-regulated proliferation of undifferentiated precursor blasts. FLT3-targeted drugs provide the opportunity to inhibit this oncogenic receptor, but over time can give rise to resistance within the blast population. The identification of targetable components of the FLT3 signalling pathway may allow for combination therapies to be used to impede the emergence of resistance. However, the intracellular signal transduction pathway of FLT3 is relatively obscure. The objective of this study is to further elucidate this pathway, with particular focus on the redox signalling element which is thought to be involved. Signalling via reactive oxygen species is becoming increasingly recognised as a crucial aspect of physiological and pathological processes within the cell. The first part of this study examined the effects of NADPH oxidase-derived reactive oxygen species on the tyrosine phosphorylation levels of acute myeloid leukaemia cell lines. Using two-dimensional phosphotyrosine immunoblotting, a range of proteins were identified as undergoing tyrosine phosphorylation in response to NADPH oxidase activity. Ezrin, a cytoskeletal regulatory protein and substrate of Src kinase, was selected for further study. The next part of this study established that NADPH oxidase is subject to regulation by FLT3. Both wild type and oncogenic FLT3 signalling were shown to affect the expression of a key NADPH oxidase subunit, p22phox, and FLT3 was also demonstrated to drive intracellular reactive oxygen species production. The NADPH oxidase target protein, Ezrin, undergoes phosphorylation on two tyrosine residues downstream of FLT3 signalling, an effect which was shown to be p22phox-dependent and which was attributed to the redox regulation of Src. The cytoskeletal associations of Ezrin and its established role in metastasis prompted the investigation of the effects of FLT3 and NADPH oxidase activity on the migration of acute myeloid leukaemia cell lines. It was found that inhibition of either FLT3 or NADPH oxidase negatively impacted on the motility of acute myeloid leukaemia cells. The final part of this study focused on the relationship between FLT3 signalling and phosphatase activity. It was determined, using phosphatase expression profiling and real-time PCR, that several phosphatases are subject to regulation at the levels of transcription and post-translational modification downstream of oncogenic FLT3 activity. In summary, this study demonstrates that FLT3 signal transduction utilises a NADPH oxidase-dependent redox element, which affects Src kinase, and modulates leukaemic cell migration through Ezrin. Furthermore, the expression and activity of several phosphatases is tightly linked to FLT3 signalling. This work reveals novel components of the FLT3 signalling cascade and indicates a range of potential therapeutic targets.

A novel and miniaturized 433/868MHz multi-band wireless sensor platform for body sensor network applications

Body Sensor Network (BSN) technology is seeing a rapid emergence in application areas such as health, fitness and sports monitoring. Current BSN wireless sensors typically operate on a single frequency band (e.g. utilizing the IEEE 802.15.4 standard that operates at 2.45GHz) employing a single radio transceiver for wireless communications. This allows a simple wireless architecture to be realized with low cost and power consumption. However, network congestion/failure can create potential issues in terms of reliability of data transfer, quality-of-service (QOS) and data throughput for the sensor. These issues can be especially critical in healthcare monitoring applications where data availability and integrity is crucial. The addition of more than one radio has the potential to address some of the above issues. For example, multi-radio implementations can allow access to more than one network, providing increased coverage and data processing as well as improved interoperability between networks. A small number of multi-radio wireless sensor solutions exist at present but require the use of more than one radio transceiver devices to achieve multi-band operation. This paper presents the design of a novel prototype multi-radio hardware platform that uses a single radio transceiver. The proposed design allows multi-band operation in the 433/868MHz ISM bands and this, together with its low complexity and small form factor, make it suitable for a wide range of BSN applications.

Exploring processes of indeterminate determinism in music composition, programming and improvisation

This portfolio consists of 15 original musical works. Taking the form of electronic and acousmatic music, multimedia, and scores, these chamber works serve as a result of experimentation and improvisation with individually built computer interfaces. The accompanying commentary provides discourse on the conceptual practice of these interfaces becoming a compositional entity that present a multi-interpretative opportunity to explore, engage, and personalise. Following this, the commentary examines the path of creative decisions and musical choices that formed both these interfaces and the resulting musical and visual works. This portfolio is accompanied by interfaces used, transcoded interfacing behavioural information, and documented improvisational findings.

Multi-parametric metabolic assessment of cells under stress conditions

Glycolysis, glutaminolysis, the Krebs cycle and oxidative phosphorylation are the main metabolic pathways. Exposing cells to key metabolic substrates (glucose, glutamine and pyruvate); investigation of the contribution of substrates in stress conditions such as uncoupling and hypoxia was conducted. Glycolysis, O2 consumption, O2 and ATP levels and hypoxia inducible factor (HIF) signalling in PC12 cells were investigated. Upon uncoupling with FCCP mitochondria were depolarised similarly in all cases, but a strong increase in respiration was only seen in the cells fed on glutamine with either glucose or pyruvate. Inhibition of glutaminolysis reversed the glutamine dependant effect. Differential regulation of the respiratory response to FCCP by metabolic environment suggests mitochondrial uncoupling has a potential for substrate-specific inhibition of cell function. At reduced O2 availability (4 % and 0 % O2), cell bioenergetics and local oxygenation varied depending on the substrate composition. Results indicate that both supply and utilisation of key metabolic substrates can affect the pattern of HIF-1/2α accumulation by differentially regulating iO2¬, ATP levels and Akt/Erk/AMPK pathways. Inhibition of key metabolic pathways can modulate HIF regulatory pathways, metabolic responses and survival of cancer cells in hypoxia. Hypoxia leads to transcriptional activation, by HIF, of pyruvate dehydrogenase (PDH) kinase which phosphorylates and inhibits PDH, a mitochondrial enzyme that converts pyruvate into acetyl-CoA. The levels of PDH (total and phosphorylated), PDH kinase and HIF-1α were analysed in HCT116 and HCT116 SCO2-/- (deficient in complex IV of the respiratory chain) grown under 20.9 % and 3 % O2. Data indicate that regulation of PDH can occur in a manner independent of the HIF-1/PDH kinase 1 axis, mitochondrial respiration and the demand for acetyl-CoA. Collectively these results can be applied to many diseases; reduced nutrient supply and O2 during ischemia/stroke, hypoglycaemia in diabetes mellitus and cancer associated changes in uncoupling protein expression levels.

Simplified PRBMs of spatial compliant multi-beam modules for planar motion

PRBMs (pseudo-rigid-body models) have been becoming important engineering technologies/methods in the field of compliant mechanisms to simplify the design and analysis through the use of the knowledge body of rigid-body mechanisms coupling with springs. This article addresses the PRBMs of spatial multi-beam modules for planar motion, which are composed of three or more symmetrical wire/slender beams parallel to each other where the planar twisting DOF (degree of freedom) is assumed to be very small for specific applications/loading conditions. Simplified PRBMs are firstly proposed through replacing each beam in spatial multi-beam module with a rigid-body link plus two identical spherical joints at its two ends. The characteristics factor, bending stiffness and twisting stiffness for the spherical joint are determined. Load-displacement equations are then derived for a class of spatial multi-beam modules and general spatial multi-beam modules using the virtual work principle and kinematic relationships. Finally, nonlinear FEA (finite element analysis) is employed with comparisons with the PRBMs. The present PRBMs have shown the ability to predict the primary nonlinear constraint characteristics such as load-stiffening effect, cross-axis coupling in the two primary translational directions and buckling load.

Diffusible Signal Factor (DSF)-dependent quorum sensing in pathogenic bacteria and its exploitation for disease control

Cell-to-cell signals of the Diffusible Signal Factor (DSF) family are cis-2-unsaturated fatty acids of differing chain length and branching pattern. DSF signalling has been described in diverse bacteria to include plant and human pathogens where it acts to regulate functions such as biofilm formation, antibiotic tolerance and the production of virulence factors. DSF family signals can also participate in interspecies signalling with other bacteria and interkingdom signaling such as with the yeast Candida albicans. Interference with DSF signalling may afford new opportunities for the control of bacterial disease. Such strategies will depend in part on detailed knowledge of the molecular mechanisms underlying the processes of signal synthesis, perception and turnover. Here, I review both recent progress in understanding DSF signalling at the molecular level and prospects for translating this knowledge into approaches for disease control.