Mathematical modelling of the embolization process in the treatment of arteriovenous malformations

Arteriovenous malformations (AVMs) are neurological defects where the arte rial and venous systems are connected directly with no intervening capillaries. The absence of capillaries means that blood at high pressure is entering the venous system directly and so a venous haemorrhage is possible. AVMs can be treated by embolization in which a glue is injected into a local artery with the aim of diverting the blood flow away from the AVM and so reducing the risk of haemorrhage. The thesis introduces a mathematical model for the embolization process by considering a two phase fluid dynamical model. Both numerical and as ymptotic techniques are used to analyse the flow of the two fluids in different configurations. At the start of the thesis both the fluids are treated as inviscid and their interaction modelled using analytical techniques such as conformal mapping theory. Next, viscous effects are included in the model by assuming that both fluids are present in a thin wall layer as would be the case just be fore the glue has set. Finally the problem of both fluids being present in the core of the artery is treated numerically using the Volume of Fluid method. A detailed account of this method is given. The method essentially tracks the interface between the glue and the blood over time and thus can model how the glue spreads, for instance just after injection

Monolithically integrated tunable mode-locked laser diode source with individual pulse selection and post-amplification.

We report the generation of high-peak-power picosecond optical pulses in the 1.55 μm spectral band from a monolithically mode-locked laser integrated with a pulse selector and power booster. High-peak-power (>1  W) pulses with durations of 15.4 ps at a 55 MHz selected rate are demonstrated, indicating that this device shows promise as a high-peak-power pulsed light source for bio-photonic applications.Engineering and Physical Sciences Research Council (EPSRC) (MUSIC); Seventh Framework Programme (FP7) (EUROPIC, PARADIGM)

Computational modelling of the embolization process for the treatment of arteriovenous malformations (AVMs)

Arteriovenous malformations (AVMs) are neurological defects in which the arterial and venous systems are connected directly, with no intervening capillaries. The absence of capillaries allows blood at high pressure to enter the venous system directly, and so a venous haemorrhage or a stroke is possible. AVMs can be treated by embolization in which a glue is injected into a local artery with the aim of diverting the blood away from the AVM and so reducing the risk of haemorrhage. The present study introduces a novel mathematical model for the embolization procedure by considering a two-phase fluid dynamical approach for the glue/blood interaction. The two fluids are treated as incompressible and viscous, and their interaction is modelled using the volume-of-fluid method, with the aim of analysing the dynamics of the glue after injection and examining potential blocking strategies. The results obtained here include surface tension effects and point to advantageous placement, blocking and effective solidification in particular

Genomic analysis of heat-shock factor targets in Drosophila.

We have used a chromatin immunoprecipitation-microarray (ChIP-array) approach to investigate the in vivo targets of heat-shock factor (Hsf) in Drosophila embryos. We show that this method identifies Hsf target sites with high fidelity and resolution. Using cDNA arrays in a genomic search for Hsf targets, we identified 141 genes with highly significant ChIP enrichment. This study firmly establishes the potential of ChIP-array for whole-genome transcription factor target mapping in vivo using intact whole organisms.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

A MIQE-Compliant Real-Time PCR Assay for Aspergillus Detection

PMCID: PMC3393739This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Redesigning walking brochures using behaviour change theory: implications for walking intentions in natural environments

Summary Natural environments can be used to promote health through facilitating recreational walking. However, efforts to encourage this often neglect messages identified in psychological research that are effective at influencing intentions to walk. This is despite the National Institute for Health and Care Excellence stating that promotional efforts should utilize theoretical frameworks of behaviour change and be targeted towards less active adults. As an illustrative example, this experiment compared a prototypical recreational walking brochure with an “enhanced” version including such persuasive messages on people’s intentions to walk for recreation in natural environments. The enhanced brochure heightened intentions for inexperienced recreational walkers through our hypothesized mechanisms, but appeared to dissuade already-experienced walkers. Optimal messaging strategies in recreational walking brochures require tailoring to more and less active readerships. Guidelines are provided for authors of recreational walking brochures, though the principles and techniques could easily be extended to other means of outdoor walking promotion.</jats:p

Why do people fail to turn good intentions into action? : The role of executive control processes in the translation of healthy eating intentions into action in young Scottish adults

Non peer reviewedPublisher PD

A comprehensive map of insulator elements for the Drosophila genome.

Insulators are DNA sequences that control the interactions among genomic regulatory elements and act as chromatin boundaries. A thorough understanding of their location and function is necessary to address the complexities of metazoan gene regulation. We studied by ChIP-chip the genome-wide binding sites of 6 insulator-associated proteins-dCTCF, CP190, BEAF-32, Su(Hw), Mod(mdg4), and GAF-to obtain the first comprehensive map of insulator elements in Drosophila embryos. We identify over 14,000 putative insulators, including all classically defined insulators. We find two major classes of insulators defined by dCTCF/CP190/BEAF-32 and Su(Hw), respectively. Distributional analyses of insulators revealed that particular sub-classes of insulator elements are excluded between cis-regulatory elements and their target promoters; divide differentially expressed, alternative, and divergent promoters; act as chromatin boundaries; are associated with chromosomal breakpoints among species; and are embedded within active chromatin domains. Together, these results provide a map demarcating the boundaries of gene regulatory units and a framework for understanding insulator function during the development and evolution of Drosophila

How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program