Predictors of exception word and nonword reading in dyslexic children: the severity hypothesis

The classification of dyslexic children into discrete subtypes yields a poor description of the dyslexic population at large. Multiple regression methods were used to examine continuous variation in component reading subskills (nonword and exception word reading) and their underlying cognitive skills within a group of 59 9-15 year-old dyslexic children. Two measures of phonological skills contributed unique variance to nonword reading: phonological processing and verbal short-term memory skills. In contrast, the only unique predictor of exception word reading was reading experience. The results are discussed within a connectionist framework that views the decoding deficit in dyslexia as stemming from poorly specified phonological representations. The extent of the nonword reading deficit is determined by the severity of the underlying phonological impairment. In contrast, exception word reading is influenced more by print exposure

Writing the Cityscape: Narratives of Moscow since 1991

This thesis considers how continuity and transformation, the past and the future, are inscribed into the cityscape. Drawing on Roland Barthes’ image of the city as ‘a discourse’ and Michel de Certeau’s concept of the Wandersmänner, who write the city with their daily movements, this thesis takes urban space as both a repository of, and inspiration for, narratives. In few cities is the significance of writing narratives more visible than in Moscow. In the 1930s, it was conceived as the archetypal Soviet city, embodying the Soviet Union’s radiant future. Since the deconstruction of this grand narrative and the fall of the Soviet Union, competing ideas have flooded in to fill the void. With glass shopping arcades, a towering new business district, and reconstructed old churches, Moscow’s facelift offers only part of the picture. A number of other visions have been imprinted onto the post-Soviet city: nostalgic impulses for the simplicity of old Moscow; the search for a new, stable, powerful centre; desires for luxury, privatized gated communities; and feelings of abandonment in the grey, decaying, sprawling suburbs. Following an overview of recent changes to Moscow’s topography, these four major themes are investigated through the prism of post-Soviet Russian literature. Retro-detective fiction offers insight into nostalgia for the past and the temporal layers that build up the palimpsestic cityscape. Descriptions of Moscow after the apocalypse shed light on the city’s traditional concentric structure and the concomitant symbolism of hierarchy. Glamour literature challenges this paradigm by focusing on the gated community, a topographical form that splinters the city. Images of the supernatural and the Gothic lead to an alternative vision of the hybrid city, embracing multiplicity. In this way, fictional works defy the physical world’s constraints of time and space, revealing a kaleidoscope of different perspectives on post-Soviet Muscovite experiences

Aberrational Effects for Shadows of Black Holes

In this paper, we discuss how the shadow of a Kerr black hole depends on the motion of the observer. In particular, we derive an analytical formula for the boundary curve of the shadow for an observer moving with given four-velocity at given Boyer--Lindquist coordinates. We visualize the shadow for various values of parameters.Comment: 12 pages, 3 figures; Proceedings of the 524. WE-Heraeus-Seminar held at the Physikzentrum, Bad Honnef, Germany, 17.--23.2.201

Growth of non-polar InGaN quantum dots with an underlying AlN/GaN distributed Bragg reflector by metal-organic vapour phase epitaxy

Non-polar (11-20) InGaN quantum dots (QDs) have been grown using a modified droplet epitaxy method by metal-organic vapour phase epitaxy on top of a 15-period AlN/GaN distributed Bragg reflector (DBR) on a-plane GaN pseudo-substrate prepared by epitaxial lateral overgrowth (ELOG), in which the QDs are located at the centre of a ca. 180 nm GaN layer. The AlN/GaN DBR has shown a peak reflectivity of ~80% at a wavelength of ~454 nm with a 49 nm wide, flat stop-band. Variations in layer thicknesses observed by cross-sectional scanning transmission electron microscopy have been identified as the main source of degradation of the DBR reflectivity. The presence of trenches due to incomplete coalescence of the ELOG template and the formation of cracks due to relaxation of tensile strain during the DBR growth may distort the DBR and further reduce the reflectivity. The DBR top surface is very smooth and does not have a detrimental effect on the subsequent growth of QDs. Enhanced single QD emission at 20 K was observed in cathodoluminescence.This work has been funded by the EPSRC (Grant No. EP/H047816/1 and EP/J001627/1).This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.spmi.2015.10.00

Analysis of defect-related inhomogeneous electroluminescence in InGaN/GaN QW LEDs

The inhomogeneous electroluminescence (EL) of InGaN/GaN quantum well light emitting diode structures was investigated in this study. Electroluminescence hyperspectral images showed that inhomogeneities in the form of bright spots exhibited spectrally blue-shifted and broadened emission. Scanning electron microscopy combined with cathodoluminescence (SEM-CL) was used to identify hexagonal pits at the centre of approximately 20% of these features. Scanning transmission electron microscopy imaging with energy dispersive X-ray spectroscopy (STEM-EDX) indicated there may be p-doped AlGaN within the active region caused by the presence of the pit. Weak beam dark-field TEM (WBDF-TEM) revealed the presence of bundles of dislocations associated with the pit, suggesting the surface features which cause the inhomogeneous EL may occur at coalescence boundaries, supported by trends in the number of features observed across the wafer.The European Research Council has provided financial support under the European Community’s Seventh Framework Programme/ ERC grant agreement no. 279361 (MACONS).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.spmi.2016.03.03

Lack of association between glucocorticoid use and presence of the metabolic syndrome in patients with rheumatoid arthritis: a cross-sectional study

Introduction - Rheumatoid arthritis (RA) associates with excessive cardiovascular morbidity and mortality, attributed to both traditional and novel cardiovascular risk factors. The metabolic syndrome, a cluster of classical cardiovascular risk factors, including hypertension, obesity, glucose intolerance, and dyslipidaemia, is highly prevalent in RA. Reports suggest that long-term glucocorticoid (GC) use may exacerbate individual cardiovascular risk factors, but there have been no studies in RA to assess whether it associates with the metabolic syndrome. We examined whether GC exposure associates with the presence of metabolic syndrome in patients with RA. Methods - RA patients (n = 398) with detailed clinical and laboratory assessments were categorised into three groups according to GC exposure: no/limited (<3 months) exposure (NE), low-dose (<7.5 mg/day) long-term exposure (LE), and medium-dose (greater than or equal to 7.5 mg to 30 mg/day) long-term exposure (ME). The metabolic syndrome was defined using the National Cholesterol Education Programme III guidelines. The association of GC exposure with the metabolic syndrome was evaluated using binary logistic regression. Results - The metabolic syndrome was present in 40.1% of this population and its prevalence did not differ significantly between the GC exposure groups (NE 37.9% versus LE 40.7% versus ME 50%, P = 0.241). Binary logistic regression did not demonstrate any increased odds for the metabolic syndrome when comparing ME with LE (odds ratio = 1.64, 95% confidence interval 0.92 to 2.92, P = 0.094) and remained non significant after adjusting for multiple potential confounders. Conclusions - Long-term GC exposure does not appear to associate with a higher prevalence of the metabolic syndrome in patients with RA. The components of the metabolic syndrome may already be extensively modified by other processes in RA (including chronic inflammation and treatments other than GCs), leaving little scope for additive effects of GCs

Theoretical and experimental analysis of the photoluminescence and photoluminescence excitation spectroscopy spectra of m\textit{m}-plane InGaN/GaN quantum wells

We present a combined theoretical and experimental analysis of the optical properties of $\textit{m}$-plane InGaN/GaN quantum wells. The sample was studied by photoluminescence and photoluminescence excitation spectroscopy at low temperature. The spectra show a large Stokes shift between the lowest exciton peak in the excitation spectra and the peak of the photoluminescence spectrum. This behavior is indicative of strong carrier localization effects. These experimental results are complemented by tight-binding calculations, accounting for random alloy fluctuations and Coulomb effects. The theoretical data explain the main features of the experimental spectra. Moreover, by comparison with calculations based on a virtual crystal approximation, the importance of carrier localization effects due to random alloy fluctuations is explicitly shown.This work was supported by Science Foundation Ireland (Project No. 13/SIRG/2210) and the United Kingdom Engineering and Physical Sciences Research Council (Grant Agreement Nos. EP\J001627\1 and EP\J003603\1). S.S. acknowledges computing resources provided by the SFI/HEA Irish Centre for High-End Computing. R.A.O. and F.T. acknowledge the support of the European Research Council under the European Community's 7th Framework Programme (FP7/2007–2013)/ERC Grant Agreement No. 279361 (MACONS)

The British antibiotic and silver-impregnated catheters for ventriculoperitoneal shunts multi-centre randomised controlled trial (the BASICS trial): study protocol

BACKGROUND: Insertion of a ventriculoperitoneal shunt (VPS) for the treatment of hydrocephalus is one of the most common neurosurgical procedures in the UK, but failures caused by infection occur in approximately 8% of primary cases. VPS infection is associated with considerable morbidity and mortality and its management results in substantial cost to the health service. Antibiotic-impregnated (rifampicin and clindamycin) and silver-impregnated VPS have been developed to reduce infection rates. Whilst there is some evidence showing that such devices may lead to a reduction in VPS infection, there are no randomised controlled trials (RCTs) to support their routine use. METHODS/DESIGN: Overall, 1,200 patients will be recruited from 17 regional neurosurgical units in the UK and Ireland. Patients of any age undergoing insertion of their first VPS are eligible. Patients with previous indwelling VPS, active and on-going cerebrospinal fluid (CSF) or peritoneal infection, multiloculated hydrocephalus requiring multiple VPS or neuroendoscopy, and ventriculoatrial or ventriculopleural shunt planned will be excluded. Patients will be randomised 1:1:1 to either standard silicone (comparator), antibiotic-impregnated, or silver-impregnated VPS. The primary outcome measure is time to VPS infection. Secondary outcome measures include time to VPS failure of any cause, reason for VPS failure (infection, mechanical failure, or patient failure), types of bacterial VPS infection (organism type and antibiotic resistance), and incremental cost per VPS failure averted. DISCUSSION: The British antibiotic and silver-impregnated catheters for ventriculoperitoneal shunts multi-centre randomised controlled trial (the BASICS trial) is the first multi-centre RCT designed to determine whether antibiotic or silver-impregnated VPS reduce early shunt infection compared to standard silicone VPS. The results of this study will be used to inform current neurosurgical practice and may potentially benefit patients undergoing shunt surgery in the future. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number: ISRCTN49474281

Assisted extraction of the energy level spacings and lever arms in direct current bias measurements of one-dimensional quantum wires, using an image recognition routine

A multiplexer technique is used to individually measure an array of 256 split gates on a single GaAs/AlGaAs heterostructure. This results in the generation of large volumes of data, which requires the development of automated data analysis routines. An algorithm is developed to find the spacing between discrete energy levels, which form due to transverse confinement from the split gate. The lever arm, which relates split gate voltage to energy, is also found from the measured data. This reduces the time spent on the analysis. Comparison with estimates obtained visually show that the algorithm returns reliable results for subband spacing of split gates measured at 1:4 K. The routine is also used to assess DC bias spectroscopy measurements at lower temperatures (50 mK). This technique is versatile and can be extended to other types of measurements. For example, it is used to extract the magnetic field at which Zeeman-split 1D subbands cross one another.This work was supported by the Engineering and Physical Sciences Research Council grant No. EP/IO14268/1.This is the accepted manuscript. The final version is available from AIP at http://scitation.aip.org/content/aip/journal/jap/117/1/10.1063/1.4905484