An integrated optofluidic Bragg grating device to measure the dynamic composition of a fluid

Strong transitional mixing effects were observed by a planar Bragg grating sensor within a microfluidic system. This property was used to develop an integrated optofluidic sensor for detection of the composition of mixed solvent systems

Affective issues in learning technologies: emotional responses to technology and technology's role in supporting socio-emotional skills

This paper focuses on some of the author's research studies over the past thirty years and places these in a wider context to reflect on research into affective issues in learning technologies over this period, and to consider whether and how the issues uncovered by research have changed as technologies have developed over time. Three issues are given particular attention: firstly the reasons for learners' use or lack of use of technologies for their learning; secondly adult learners' attitudes towards using technology for learning and thirdly how technology might support socio-emotional development and expression in children. The discussion of these issues is framed by two of the author's research projects. For the first two issues this is an early study of students' perceptions and attitudes towards using computers for tutorial learning in 1980. The factors that influenced the students' use of the computer tutorials are discussed (including access, assessment and anxiety about using computers) and also the extent to which some of these factors persist for many learners using (or not using) technologies today. The discussion of the third issue draws on a series of studies conducted in the 1990s to investigate whether educational technology could support children and young people's emotional expression and communication and development of socio-emotional skills. Finally the paper considers how these kinds of issues have been taken forward and how they are represented in contemporary research and suggests that trust is an important factor in using learning technologies

Optofluidic integrated Bragg grating chemical sensor: Utilising a sodium-elective receptor surface to enhance detection

Planar waveguides can be written with a UV-laser into photosensitised silica to produce a wide range of optical devices. Careful modulation of two interfering beams allows Bragg gratings to be directly written into the channel. These Bragg gratings are inherently sensitive to temperature and strain, however etching away the surface exposes the mode within the grating to its surroundings. The corresponding observed shift in Bragg wavelength can be used to detect changes in this environment [1]. It has been previously reported [2] that the sensitivity of such a refractometer can be enhanced by over an order of magnitude through use of a high-index overlayer of tantalum pentoxide. This enhanced sensor has shown the potential to detect a single molecular monolayer upon the sensor surface [2]. This sensitivity was confirmed through the successful attachment and detection of a single molecular monolayer of a fluorescein-based organic dye to the sensor surface [3

An integrated Bragg grating oxygen sensor using a hydrophobic sol-gel layer doped with an organic dye

Oxygen sensing is required for the understanding of many chemical processes across a diverse set of fields including medicine, environmental science and chemical synthesis. Oxygen sensing can be achieved through the use of electronic sensors. However, there are limitations associated with electronic sensors including susceptibility to electromagnetic interference and presenting a spark risk in flammable environments. Optical fiber and integrated optical chemical sensors overcome these limitations of electrical based sensing methods

An integrated reconfigurable Bragg grating utilising a photoresponsive co-polymer

Reconfigurable Bragg grating devices are of significant interest for telecomm applications. Such devices can be fabricated by combining a UV-written silica Bragg grating with an azobenzene-based polymer - a photoresponsive material that undergoes reversible refractive index change on exposure to ultraviolet light. The preliminary 17 GHz tuning response suggests future applicability

Integrated temperature compensated Bragg grating refractometer

UV written planar Bragg grating sensors have been shown to form effective refractometers. Here we show that by using the birefringence of an integrated waveguide a temperature insensitive Bragg grating refractometer can be realised

Integrated planar Bragg grating oxygen sensor

We demonstrate an integrated planar Bragg grating sensor for the detection of oxygen by modification of the surface with a silica sol-gel containing immobilized methylene blue

Literature Mapping with PubAtlas — extending PubMed with a ‘BLASTing interface’ *

PubAtlas (www.pubatlas.org) is a web service and standalone program providing literature maps for the biomedical research literature. It accepts user-defined sets of terms (PubMed queries) as input, and permits ‘BLASTing’ of one set against another: for all terms x and y in these sets, deriving the results of the pairwise intersections x AND y. This all vs. all capability extends PubMed with a literature analysis interface. Correspondingly, the basic form of literature map that PubAtlas provides for exploring associations among sets of terms is an interactive tabular display, in heatmap/microarray format

Gene expression-phenotype associations in adults with eosinophilic esophagitis

Background: Gene expression patterns have not been extensively examined in the context of clinical features of eosinophilic esophagitis (EoE). Aims: To assess whether gene expression is associated with clinically defined phenotypes in adults with EoE. Methods: This was an analysis of prospectively collected esophageal biopsies in newly diagnosed EoE patients. We determined differential gene expression with a 94 gene panel in relation to clinical features and phenotypes. These included: endoscopic findings of esophageal rings, stricture, narrowing, linear furrows, exudates, edema, and dilation; an allergic phenotype; an inflammatory phenotype, and a fibrostenotic phenotype. Results: In 89 EoE cases analyzed, patients with exudates on endoscopy had multiple differences in gene expression compared to patients without exudates, though patients with exudates also had higher eosinophil counts (172 vs 106 eos/hpf; p =.01). Genes associated with esophageal narrowing included CCL26 (q-value = 0.028), ALOX15 (q = 0.011), GRK5 (q = 0.029), CPA3 (q = 0.012), and TRIM2 (q = 0.0027). TRIM2 was also associated with the fibrostenotic phenotype (q = 0.0051). No genes were associated with the inflammatory or atopic phenotypes, or with dilation. Conclusions: Multiple genes are associated with exudates, possibly related to higher eosinophil counts. However, a number of genes, including those related to both inflammation and remodelling, are associated with esophageal narrowing. In particular, TRIM2 is associated with clinical fibrotic phenotypes

Inflation, quantum fields, and CMB anisotropies

Inflationary cosmology has proved to be the most successful at predicting the properties of the anisotropies observed in the cosmic microwave background (CMB). In this essay we show that quantum field renormalization significantly influences the generation of primordial perturbations and hence the expected measurable imprint of cosmological inflation on the CMB. However, the new predictions remain in agreement with observation, and in fact favor the simplest forms of inflation. In the near future, observations of the influence of gravitational waves from the early universe on the CMB will test our new predictions.Comment: 11 pages, 1 figure, Awarded with the fourth prize in the Gravity Research Foundation 2009 Essay Competitio