Bio-functionalised nanoparticles for enzyme sensing

Inorganic nanoparticles and their accompanying diverse physical properties are now virtually in routine use as imaging tools in cell-biology. In addition to serving as excellent contrast agents, their size- and environment-dependent optical and magnetic properties can be harnessed to create enzyme biosensor devices of extremely high sensitivity, whilst circumventing the numerous technical limitations associated with traditional enzyme assays. This thesis explores new applications of noble metal and semiconductor nanoparticles (quantum dots) for the detection of a range of medically-relevant enzymes. Here, water soluble colloidal gold nanoparticles and quantum dots are modified with peptides and antibodies to afford new reagents for enzyme sensing. These bio-functionalised nanoparticle probes exhibit numerous advantages over traditional enzyme sensing systems owing to their robust and size-tuneable optical properties. These enzyme-responsive nanoparticle systems are tailored to detect the activity of protein kinase and histone acetyltransferase activity in a simple homogeneous assay format based on Förster resonance energy transfer (FRET). Furthermore, these systems can be applied to screen for putative small-molecule modulators of enzyme function. These new assays should provide the basis for the development of a variety of new enzyme detection strategies based on nanoparticlespecific optical phenomena

Determining Device Position Using Ultrawideband to Customize Surround Sound

Traditional surround sound experiences require precise placement of speakers at positions that are optimal for audio playback. Even after a careful setup, the audio experience may suffer depending on where the user sits relative to the speakers, since there is no way to intelligently adjust the equalizers for the different speakers distributed in space without localization information about the speakers. The techniques described in this disclosure utilize ultrawideband ranging to determine the relative position of different audio playback devices in an environment and the position of the user. A central node customizes the audio streams provided to each speaker device based on the determined position. If any of the speaker devices are moved to a different position or removed from the environment, if new speaker devices are added, or if the user’s position changes significantly to a different fixed location during playback, the central node can automatically adjust the audio stream for the new environment, without the user having to perform manual reconfiguration

Use of Geotechnical Design Summary Report as a Management Tool for Resolving Disputes on Underground Construction Projects

The Los Angeles Metro Rail Subway project is initially planned for 30 km (18 mi) of twin, 6-m (20-ft) diameter bored tunnels under city streets and a total of 16 stations. This paper describes briefly the history of the project, the geologic setting, and the challenges encountered during design or anticipated during construction. It also introduces, as part of contract documentation, an interpretive geotechnical baseline report which establishes the basis for identification and recognition of site condition baselines . In so doing, this report (known as a GDSR ) has proven to be an effective tool for ameliorating contractual problems and facilitating conflict resolution

Dynamic changes in heparan sulfate during muscle differentiation and ageing regulate myoblast cell fate and FGF2 signalling

Satellite cells (SCs) are skeletal muscle stem cells residing quiescent around healthy muscle fibres. In response to injury or disease SCs activate, proliferate and eventually differentiate and fuse to one another to form new muscle fibres, or to existing damaged fibres to repair them. The sulfated polysaccharide heparan sulfate (HS) is a highly variable biomolecule known to play key roles in the regulation of cell fate decisions, though the changes that muscle HS undergoes during SC differentiation are unknown. Here we show that the sulfation levels of HS increase during SC differentiation; more specifically, we observe an increase in 6-O and 2-O-sulfation in N-acetylated disaccharides. Interestingly, a specific increase in 6-O sulfation is also observed in the heparanome of ageing muscle, which we show leads to promotion of FGF2 signalling and satellite cell proliferation, suggesting a role for the heparanome dynamics in age-associated loss of quiescence. Addition of HS mimetics to differentiating SC cultures results in differential effects: an oversulfated HS mimetic increases differentiation and inhibits FGF2 signalling, a known major promoter of SC proliferation and inhibitor of differentiation. In contrast, FGF2 signalling is promoted by an N-acetylated HS mimetic, which inhibits differentiation and promotes SC expansion. We conclude that the heparanome of SCs is dynamically regulated during muscle differentiation and ageing, and that such changes might account for some of the phenotypes and signalling events that are associated with these processes

Aminolysis of the 4-acetoxybenzoate anion catalysed by cyclodextrins

From the kinetic investigation of the cleavage of the 4-acetoxybenzoate anion (4-ABA) in the presence of three cyclodextrins (Ì-CD, Ý-CD, and Þ-CD) in basic aqueous solution, the results indicate that 4-ABA binds to Ì-CD fairly weakly while no binding is observed between 4-ABA and Ý-CD or Þ-CD. The effects of the three CDs on the kinetics of the aminolysis of 4-ABA by primary amines have been investigated. Rate constants for the nucleophilic attack by free and CD-bound amine are obtained. For Ì-CD, values of the reactivity ratios for the linear amines are low (1 for both n -alkyl and branched amines), implying modest catalysis. As for Þ-CD, the values of the reactivity ratios are >2, which also signifies modest catalysi

The Satellite Cell Niche Regulates the Balance between Myoblast Differentiation and Self-Renewal via p53

Satellite cells are adult muscle stem cells residing in a specialized niche that regulates their homeostasis. How niche-generated signals integrate to regulate gene expression in satellite cell-derived myoblasts is poorly understood. We undertook an unbiased approach to study the effect of the satellite cell niche on satellite cell-derived myoblast transcriptional regulation and identified the tumor suppressor p53 as a key player in the regulation of myoblast quiescence. After activation and proliferation, a subpopulation of myoblasts cultured in the presence of the niche upregulates p53 and fails to differentiate. When satellite cell self-renewal is modeled ex vivo in a reserve cell assay, myoblasts treated with Nutlin-3, which increases p53 levels in the cell, fail to differentiate and instead become quiescent. Since both these Nutlin-3 effects are rescued by small interfering RNA-mediated p53 knockdown, we conclude that a tight control of p53 levels in myoblasts regulates the balance between differentiation and return to quiescence

The development, standardisation and validation of an instrument designed to measure coping with chronic pain

The purpose of the study was to investigate the structure of coping with chronic pain and to develop a standardised, reliable and valid ~t to measure coping with chronic pain. The use of this instrument as a measure of change in the evaluation of a local Pain Management Programe was investigated. The Pain Coping Questionnaire was developed from analysis of responses of 298 chronic pain patients to a self-report questionnaire concerned with coping with chronic pain. Following empirical psychometric investigations of reliability and validity, four psychologically meaningful dimensions were identified. One dimension, the General Coping Measure, was a measure of psycho-social adjustment to chronic pain. Three dimensions measured beliefs in the use of cognitive and behavioural pain coping strategies. One dimension, Active Coping Strategies, measured active pain coping strategies. Two dimensions, Avoidance and Use of Drugs, measured passive pain coping strategies. Belief in the use of active pain coping strategies was predictive of good psycho-social adjustment. Belief in the use of passive pain coping strategies was predictive of poor psycho-social adjustment. The results from outco~e studies indicated that the Pain Coping Questionnaire was a sensitive measure of change. The Pain Manag~.ment Programne had beneficial effects with respect to short-term outcome. Limitations were discussed. It was concluded that the Pain Coping Questionnaire represents an original contribution that is likely to have broad applications in the assessment and treatment of chronic pain patients