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Summary Coronavirus 19 (COVID‐19) has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand the prevalence of autoantibodies associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS‐CoV‐2, suffering from COVID‐19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on the intensive therapy unit (ITU) for non‐COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID‐19 ITU group compared with non‐COVID‐19 ITU disease control patients and that autoantibodies were also found in the serum 3–5 months post‐COVID‐19 infection. Non‐COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID‐19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that respiratory viral infection with SARS‐CoV‐2 is associated with the detection of a limited profile of tissue‐specific autoantibodies, detectable using routine clinical immunology assays. Further studies are required to determine whether these autoantibodies are specific to SARS‐CoV‐2 or a phenomenon arising from severe viral infections and to determine the clinical significance of these autoantibodies., Acute infection with COVID is associated with a pattern of autoantibodies including a high proportion with epidermal antibodies. This autoantibody pattern is more common in severe COVID and is persistent up to 6 months.

A technique has been developed to compensate pressure readings from arrays of highly sensitive membrane-type pressure sensors for deflections caused by acceleration normal to the plane of the membrane using a single inertial measurement unit. By normalizing the fourth-order unsteady Kirchoff-Love equation, it can be shown that inertial body pseudoforces and applied surface pressure elicit a similar and additive response from the sensors. Inertial effects arising from linear and angular acceleration as well as angular velocity may therefore be converted to ‘pseudopressures’ and eliminated by means of a simple linear compensation process which can be calibrated using only gravity. To demonstrate, signals from a conventional six-axis inertial measurement unit (including three orthogonal components each of angular velocity and linear acceleration) are used to provide an approximation of the acceleration of the sensing dies within a seven-channel distributed array of ultra-low pressure sensors. Applying the proposed correction reduces the maximum full-scale uncertainty of the measurements by as much as 50%.

Blue cone monochromacy (BCM) is an X-linked retinal disorder characterized by low vision, photoaversion, and poor color discrimination. BCM is due to the lack of long-wavelength-sensitive and middle-wavelength-sensitive cone photoreceptor function and caused by mutations in the

Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by impaired color discrimination, low visual acuity, photosensitivity, and nystagmus. To date, six genes have been associated with ACHM (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6), the majority of these being implicated in the cone phototransduction cascade. CNGA3 encodes the CNGA3 subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors and is one of the major disease-associated genes for ACHM. Herein, we provide a comprehensive overview of the CNGA3 variant spectrum in a cohort of 1060 genetically confirmed ACHM patients, 385 (36.3%) of these carrying "likely disease-causing" variants in CNGA3. Compiling our own genetic data with those reported in the literature and in public databases, we further extend the CNGA3 variant spectrum to a total of 316 variants, 244 of which we interpreted as "likely disease-causing" according to ACMG/AMP criteria. We report 48 novel "likely disease-causing" variants, 24 of which are missense substitutions underlining the predominant role of this mutation class in the CNGA3 variant spectrum. In addition, we provide extensive in silico analyses and summarize reported functional data of previously analyzed missense, nonsense and splicing variants to further advance the pathogenicity assessment of the identified variants.

Mean sensitivity (MS) derived from a standard test grid using microperimetry is a sensitive outcome measure in clinical trials investigating new treatments for degenerative retinal diseases. This study hypothesizes that the functional decline is faster at the edge of the dense scotoma (eMS) than by using the overall MS.Multicenter, international, prospective cohort study: ProgStar Study.Stargardt disease type 1 patients (carrying at least 1 mutation in the ABCA4 gene) were followed over 12 months using microperimetry with a Humphrey 10-2 test grid. Customized software was developed to automatically define and selectively follow the test points directly adjacent to the dense scotoma points and to calculate their mean sensitivity (eMS).Among 361 eyes (185 patients), the mean age was 32.9 ± 15.1 years old. At baseline, MS was 10.4 ± 5.2 dB (n = 361), and the eMS was 9.3 ± 3.3 dB (n = 335). The yearly progression rate of MS (1.5 ± 2.1 dB/year) was significantly lower (β = -1.33; P.001) than that for eMS (2.9 ± 2.9 dB/year). There were no differences between progression rates using automated grading and those using manual grading (β = .09; P = .461).In Stargardt disease type 1, macular sensitivity declines significantly faster at the edge of the dense scotoma than in the overall test grid. An automated, time-efficient approach for extracting and grading eMS is possible and appears valid. Thus, eMS offers a valuable tool and sensitive outcome parameter with which to follow Stargardt patients in clinical trials, allowing clinical trial designs with shorter duration and/or smaller cohorts.

For measuring three components of velocity in unknown flow fields, multi-hole pressure probes possess a significant advantage. Unlike methods such as hot-wire anemometry, laser-Doppler velocimetry and particle-image velocimetry, multi-hole pressure probes can provide not only the three components of local velocity, but also static and stagnation pressures. However, multi-hole probes do require exhaustive calibration. The traditional technique for calibrating these probes is based on either look-up tables or polynomial curve fitting, but with the low cost and easy availability of powerful computing resources, neural networks are increasingly being used. Here, we explore the possibility to further reduce measurement uncertainty by implementing neural-network-based methods that have not been previously used for probe calibration, including supervised and unsupervised learning neural networks, regression models and elastic-map methods. We demonstrate that calibrating probes in this way can reduce the uncertainty in flow angularity by as much as 50% compared to conventional techniques.

More than 200 different mutations in peripherin-2 (PRPH2) are associated with multiple subtypes of inherited retinal diseases (IRDs), including retinitis pigmentosa and cone or macular diseases. Our goal was to understand how the poorly characterized PRPH2 mutation p.Pro210Arg (P210R) affects visual function and retinal structure as well as gain insight into the mechanism driving the clinical pathology.Eleven patients had clinical assessments including best-corrected visual acuity (BCVA), full field and multifocal electroretinography (ERG), static (spot size V) and kinetic perimetry (Octopus 900), and dark-adapted chromatic (DAC; Medmont; spot size V) perimetry. Images were acquired with the Optos ultra-wide field camera and spectral-domain optical coherence tomography (SD-OCT). Molecular characteristics of the P210R mutant protein were evaluated in vitro.Patients with the P210R mutation had BCVA (Snellen) ranging from 20/15 to 20/80. Perimetry showed a reduction in sensitivity, while ERG findings suggested that cone function was more impaired than rod function. Scotomas were identified corresponding to atrophic retinal lesions. Imaging revealed heterogeneous outer retinal changes such as hyperfluorescent flecks, hypo-autofluorescence (AF) regions of atrophy, and thinning of the photoreceptor layer on SD-OCT. In vitro findings suggested that P210R-Prph2 retains the ability to interact with binding partner Rom1 but abnormally accumulates in the endoplasmic reticulum (ER), suggesting the protein does not fold properly.Rod and cone sensitivities were decreased in subjects with the P210R mutation in PRPH2. There was scotomatous vision loss that occurred within the macula, likely due to atrophy that occurs after drusen have formed and have begun to resolve. This suggests that although rod and cone photoreceptors are dependent on PRPH2, preventing blindness in this specific subgroup of patients could involve therapeutics that impede the formation or lifecycle of drusen.

Transposable elements (TEs) are widespread across eukaryotic genomes, yet their content varies widely between different species. Factors shaping the diversity of TEs are poorly understood. Understanding the evolution of TEs is difficult because their sequences diversify rapidly and TEs are often transferred through non‐conventional means such as horizontal gene transfer. We developed a method to track TE evolution using network analysis to visualise TE sequence and TE content across different genomes. We illustrate our method by first using a monopartite network to study the sequence evolution of Tc1/mariner elements across focal species. We identify a connection between two subfamilies associated with convergent acquisition of a domain from a protein‐coding gene. Second, we use a bipartite network to study how TE content across species is shaped by epigenetic silencing mechanisms. We show that the presence of Piwi‐interacting RNAs is associated with differences in network topology after controlling for phylogenetic effects. Together, our method demonstrates how a network‐based approach can identify hitherto unknown properties of TE evolution across species., A novel network‐based method is used to study transposable element (TE) evolution, revealing new insights into how epigenetic silencing mechanisms affect TE content across species.

BACKGROUND: Whole-body MRI (WB-MRI) could be an alternative to multimodality staging of colorectal cancer, but its diagnostic accuracy, effect on staging times, number of tests needed, cost, and effect on treatment decisions are unknown. We aimed to prospectively compare the diagnostic accuracy and efficiency of WB-MRI-based staging pathways with standard pathways in colorectal cancer.METHODS: The Streamline C trial was a prospective, multicentre trial done in 16 hospitals in England. Eligible patients were 18 years or older, with newly diagnosed colorectal cancer. Exclusion criteria were severe systemic disease, pregnancy, contraindications to MRI, or polyp cancer. Patients underwent WB-MRI, the result of which was withheld until standard staging investigations were complete and the first treatment decision made. The multidisciplinary team recorded its treatment decision based on standard investigations, then on the WB-MRI staging pathway (WB-MRI plus additional tests generated), and finally on all tests. The primary outcome was difference in per-patient sensitivity for metastases between standard and WB-MRI staging pathways against a consensus reference standard at 12 months, in the per-protocol population. Secondary outcomes were difference in per-patient specificity for metastatic disease detection between standard and WB-MRI staging pathways, differences in treatment decisions, staging efficiency (time taken, test number, and costs), and per-organ sensitivity and specificity for metastases and per-patient agreement for local T and N stage. This trial is registered with the International Standard Randomised Controlled Trial registry, number ISRCTN43958015, and is complete.FINDINGS: Between March 26, 2013, and Aug 19, 2016, 1020 patients were screened for eligibility. 370 patients were recruited, 299 of whom completed the trial; 68 (23%) had metastasis at baseline. Pathway sensitivity was 67% (95% CI 56 to 78) for WB-MRI and 63% (51 to 74) for standard pathways, a difference in sensitivity of 4% (-5 to 13, p=0·51). No adverse events related to imaging were reported. Specificity did not differ between WB-MRI (95% [95% CI 92-97]) and standard pathways (93% [90-96], p=0·48). Agreement with the multidisciplinary team's final treatment decision was 96% for WB-MRI and 95% for the standard pathway. Time to complete staging was shorter for WB-MRI (median, 8 days [IQR 6-9]) than for the standard pathway (13 days [11-15]); a 5-day (3-7) difference. WB-MRI required fewer tests (median, one [95% CI 1 to 1]) than did standard pathways (two [2 to 2]), a difference of one (1 to 1). Mean per-patient staging costs were £216 (95% CI 211-221) for WB-MRI and £285 (260-310) for standard pathways.INTERPRETATION: WB-MRI staging pathways have similar accuracy to standard pathways and reduce the number of tests needed, staging time, and cost.FUNDING: UK National Institute for Health Research.

A two-component micropillar system has been developed for use in flow characterization and control applications. It is shown that the piezoresistive elements in a conventional pressure sensing die can be used to measure moments directly applied to the die with reasonable sensitivity. The concept is then demonstrated by bonding a small, rigid pillar to the centre of a commercially-available, off-the-shelf doped silicon pressure sensing membrane with integrated piezoresistive bridge elements. The signal response of the system is then calibrated against aerodynamic loading, and a typical sensitivity of 70 mV/ ${\mu }$ Nm is demonstrated. The functionality of the micropillars in flow control applications is verified by recessing the pillar below a flat surface on which a model boundary layer is developed. By processing the signals through the membrane bridge-arms independently, directionally-resolved forces may also be obtained.

Scalable resolution display environments, including immersive data observatories, are emerging as equitable and socially engaging platforms for collaborative data exploration and decision making. These environments require specialized middleware to drive them, but, due to various limitations, there is still a gap in frameworks capable of scalable rendering of data visualizations. To overcome these limitations, we introduce a new modular open-source middleware, the Open Visualization Environment (OVE). This framework uses web technologies to provide an ecosystem for visualizing data using web browsers that span hundreds of displays. In this paper, we discuss the key design features and architecture of our framework as well as its limitations. This is followed by an extensive study on performance and scalability, which validates its design and compares it to the popular SAGE2 middleware. We show how our framework solves three key limitations in SAGE2. Thereafter, we present two of our projects that used OVE and show how it can extend SAGE2 to overcome limitations and simplify the user experience for common data visualization use-cases.

Purpose To investigate the natural history of Stargardt disease (STGD1) using fixation location and fixation stability. Design Multicenter, international, prospective cohort study. Methods Fixation testing was performed using the Nidek MP-1 microperimeter as part of the prospective, multicenter, natural history study on the Prog ression of Star gardt disease (ProgStar). A total of 238 patients with ABCA4-related STGD1 were enrolled at baseline (bilateral enrollment in 86.6%) and underwent repeat testing at months 6 and 12. Results Outcome measures included the distance of the preferred retinal locus from the fovea (PRL) and the bivariate contour ellipse area (BCEA). After 12 months of follow-up, the change in the eccentricity of the PRL from the anatomic fovea was −0.0014 degrees (95% confidence interval [CI], −0.27 degrees, 0.27 degrees; P = .99). The deterioration in the stability of fixation as expressed by a larger BCEA encompassing 1 standard deviation of all fixation points was 1.21 degrees squared (deg2) (95% CI, −1.23 deg2, 3.65 deg2; P = .33). Eyes with increases and decreases in PRL eccentricity and/or BCEA values were observed. Conclusions Our observations point to the complexity of fixation parameters. The association of increasingly eccentric and unstable fixation with longer disease duration that is typically found in cross-sectional studies may be countered within individual patients by poorly understood processes like neuronal adaptation. Nevertheless, fixation parameters may serve as useful secondary outcome parameters in selected cases and for counseling patients to explain changes to their visual functionality.

The aerodynamic characteristics of an aft-body, in-line mounted, boundary layer ingesting, electric ducted fan, propulsion installation system has been investigated through experimental and computational analysis. A modular wind-tunnel model allows variation in the geometry of the propulsion installation system to be assessed, in combination with fan speed. Various experimental measurement techniques, including LDA, seven-hole-probe and surface pressures are employed. The propulsion installation system has also been investigated using RANS CFD and comparison with experimental data is presented. An investigation of the boundary conditions for efficiently representing the fan in CFD is described. Initial results show reasonably good agreement between CFD and experiment, in terms of velocity profiles and surface pressures, but highlight remaining differences for cases exhibiting flow separation.

Summary Background Whole-body magnetic resonance imaging (WB-MRI) could be an alternative to multi-modality staging of non-small-cell lung cancer (NSCLC), but its diagnostic accuracy, effect on staging times, number of tests needed, cost, and effect on treatment decisions are unknown. We aimed to prospectively compare the diagnostic accuracy and efficiency of WB-MRI-based staging pathways with standard pathways in NSCLC. Methods The Streamline L trial was a prospective, multicentre trial done in 16 hospitals in England. Eligible patients were 18 years or older, with newly diagnosed NSCLC that was potentially radically treatable on diagnostic chest CT (defined as stage IIIb or less). Exclusion criteria were severe systemic disease, pregnancy, contraindications to MRI, or histologies other than NSCLC. Patients underwent WB-MRI, the result of which was withheld until standard staging investigations were complete and the first treatment decision made. The multidisciplinary team recorded its treatment decision based on standard investigations, then on the WB-MRI staging pathway (WB-MRI plus additional tests generated), and finally on all tests. The primary outcome was difference in per-patient sensitivity for metastases between standard and WB-MRI staging pathways against a consensus reference standard at 12 months, in the per-protocol population. Secondary outcomes were difference in per-patient specificity for metastatic disease detection between standard and WB-MRI staging pathways, differences in treatment decisions, staging efficiency (time taken, test number, and costs) and per-organ sensitivity and specificity for metastases and per-patient agreement for local T and N stage. This trial is registered with the International Standard Randomised Controlled Trial registry, number ISRCTN50436483, and is complete. Findings Between Feb 26, 2013, and Sept 5, 2016, 976 patients were screened for eligibility. 353 patients were recruited, 187 of whom completed the trial; 52 (28%) had metastasis at baseline. Pathway sensitivity was 50% (95% CI 37–63) for WB-MRI and 54% (41–67) for standard pathways, a difference of 4% (−7 to 15, p=0·73). No adverse events related to imaging were reported. Specificity did not differ between WB-MRI (93% [88–96]) and standard pathways (95% [91–98], p=0·45). Agreement with the multidisciplinary team's final treatment decision was 98% for WB-MRI and 99% for the standard pathway. Time to complete staging was shorter for WB-MRI (13 days [12–14]) than for the standard pathway (19 days [17–21]); a 6-day (4–8) difference. The number of tests required was similar WB-MRI (one [1–1]) and standard pathways (one [1–2]). Mean per-patient costs were £317 (273–361) for WBI-MRI and £620 (574–666) for standard pathways. Interpretation WB-MRI staging pathways have similar accuracy to standard pathways, and reduce the staging time and costs. Funding UK National Institute for Health Research.

Design is a balancing act between people’s competing concerns, design options and design performance. Recently collecting data on such concerns such as sustainability or aesthetics has become possible through online crowdsourcing, particularly in 3d. However, such systems rarely present more than a single design alternative or allow users to change the design and seldom provide quantitative design analysis to gauge design performance. This precludes a more participatory approach including a wider audience and their insight in the design process. To improve the design process we propose a system to assist the design team in exploring the balance of concerns, design options and their performance. We augment a 3d visualisation crowdsourcing environment with quantitative on-demand assessment of design variants run in the cloud. This enables crowdsourced exploration of the design space and its performance. Automated participant tracking and explicit submitted feedback on design options are collated and presented to aid the design team in balancing the demands of urban master planning. We report application of this system to an urban masterplan with Arup.

There has been much recent interest in the combined structural and aerodynamic properties of porous metal foams, but there does not yet appear to be a consensus on the aerodynamic behaviour of these foam materials. A comprehensive analytical and experimental study with special attention to scaling was carried out in order to examine the flow around cylinders coated with porous metal foam and characterize the effects upon the mechanisms governing shear layer separation, vortex shedding and wake formation. Results have yielded a correlation between the distance separating the detaching shear layers and the vorticity losses in the near-wake. It seems that it is the coating configuration, rather than geometry, that influences vortex shedding, and therefore foams affect the flow in a similar way as shrouds or bleeding systems.

Research under the Managing Air for Green Inner Cities (MAGIC) project uses measurements and modelling to investigate the connections between external and internal conditions: the impact of urban airflow on the natural ventilation of a building. The test site was chosen so that under different environmental conditions the levels of external pollutants entering the building, from either a polluted road or a relatively clean courtyard, would be significantly different. Measurements included temperature, relative humidity, local wind and solar radiation, together with levels of carbon monoxide (CO) and carbon dioxide (CO2) both inside and outside the building to assess the indoor–outdoor exchange flows. Building ventilation took place through windows on two sides, allowing for single-sided and crosswind-driven ventilation, and also stack-driven ventilation in low wind conditions. The external flow around the test site was modelled in an urban boundary layer in a wind tunnel. The wind tunnel results were incorporated in a large-eddy-simulation model, Fluidity, and the results compared with monitoring data taken both within the building and from the surrounding area. In particular, the effects of street layout and associated street canyons, of roof geometry and the wakes of nearby tall buildings were examined.

A generalized calibration process is presented for multi-hole, pressure-based velocity probes which is independent of the number of holes and probe geometry, allowing the use of probes with large numbers of holes. The calibration algorithm is demonstrated at low speeds with a conventional seven-hole pressure probe and a novel nineteen-hole pressure probe. Because the calibration algorithm is independent of probe configuration, it is very tolerant of data corruption and imperfections in the probe tip geometry. The advantages of using probes with large numbers of holes is demonstrated in a conventional wing wake survey. The nineteen-hole probe offers a higher angular sensitivity than a conventional seven-hole probe, and can accurately measure velocity components even when an analytical calibration scheme is used. The probe can also provide local estimates of the diagonal components of the cross-flow velocity gradient tensor in highly vortical flows.

We present a case of an elderly female patient who presented with a 6-month history of progressive slurred speech, vertigo, unsteadiness and falls. She underwent an extensive battery of neurological and cardiovascular investigations, none of which demonstrated a diagnostic cause for her symptoms. She was referred to the stroke and neurology teams and was started on treatment for presumed anxiety. As her symptoms continued to progress, she was referred to the falls service. Following a multidisciplinary team discussion, she was reviewed by the consultant geriatrician who felt this may be due to a malignancy so the consultant geriatrician arranged blood testsand CT scan of her chest, abdomen and pelvis. These demonstrated a large left adnexal mass and a raised Ca-125 level. The patient was diagnosed with an ovarian tumour, which was treated surgically. A provisional diagnosis of paraneoplastic cerebellar degeneration, secondary to ovarian carcinosarcoma, was made.

A case of a 37-year-old female primagravida who attended the emergency department (ED) via ambulance in hypotensive shock. She was 10 weeks pregnant, but had an inevitable miscarriage confirmed in the local Early Pregnancy Unit 3 weeks previously. She was hypotension (90/60 mm Hg), bradycardic (45 bpm) and was peripherally shut down. A provisional diagnosis of haemorrhagic shock was made, but despite intravenous fluid challenges, she appeared to be deteriorating, so a major haemorrhage protocol was activated. On examination, there was some vaginal bleeding and a protruding sac noted. The gynaecology registrar was informed and performed an Evacuation of the Retained Products of Conception in the ED. This gave instant relief to the patient and her blood pressure and heart rate became normal over a few minutes. She went on to make a full recovery. This case provides useful learning points for doctors working in the ED and other urgent care settings.

Graphical abstractDisplay Omitted HighlightsBetter graph-sensemaking through fuzzy queries and large-scale visualisation.Fuzzy logic to identify interesting nodes.Illustrative examples of such data exploration provided. This work presents three case-studies of how fuzzy logic can be combined with large-scale immersive visualisation to enhance the process of graph sensemaking, enabling interactive fuzzy filtering of large global views of graphs. The aim is to provide users a mechanism to quickly identify interesting nodes for further analysis. Fuzzy logic allows a flexible framework to ask human-like curiosity-driven questions over the data, and visualisation allows its communication and understanding. Together, these two technologies successfully empower novices and experts to a faster and deeper understanding of the underlying patterns in big datasets compared to traditional means in a desktop screen with crisp queries. Among other examples, we provide evidence of how these two technologies successfully enable the identification of relevant transaction patterns in the Bitcoin network.

In many universities, admissions decisions are made based upon the advanced-level (A-Level) results. The purpose of this study was to assess the value of A-level and international equivalents as a predictor of early achievement in higher education. About 135 UK and 92 international undergraduate engineering students from 35 countries were assessed at different stages of their instruction. The results show that the key predictor for academic performance is whether or not the students received a British education. The implications are that more policies and awareness are needed in order to effectively support international students in engineering during their transitional process.

The measurement of vortex flows with particle-image velocimetry (PIV) is particularly susceptible to error arising from the finite mass of the tracer particles, owing to the high velocities and accelerations typically experienced. A classical model of Stokes-flow particle transport is adopted, and an approximate solution for the case of particle transport within an axisymmetric, quasi-two-dimensional Batchelor $q$-vortex is presented. A generalized expression for the maximum particle tracking error is proposed for each of the velocity components, and the importance of finite particle size distributions is discussed. The results indicate that the tangential velocity component is significantly less sensitive to tracking error than the radial component, and that the conventional particle selection criterion (based on the particle Stokes number) may result in either over- or under-sized particles for a specified allowable error bound. Results were demonstrated by means of PIV measurements carried out in air and water using particles with very different properties.

To examine the association between characteristics of Stargardt disease and visual acuity (VA), to estimate the longitudinal rate of VA loss, and to identify risk factors for VA loss.Retrospective, multicenter cohort study.A total of 176 patients (332 eyes) with molecularly and clinically confirmed Stargardt disease enrolled from the United States and Europe.Standardized data report forms were used to collect retrospective data on participants' characteristics and best-corrected or presenting VA from medical charts. Linear models with generalized estimating equations were used to estimate the cross-sectional associations, and linear mixed effects models were used to estimate the longitudinal VA loss.Yearly change in VA.The median duration of observation was 3.6 years. At baseline, older age of symptom onset was associated with better VA, and a longer duration of symptoms was associated with worse VA. Longitudinal analysis estimated an average of 0.3 lines loss (P0.0001) per year overall, but the rate varied according to baseline VA: (1) eyes with baseline VA ≥20/25 (N = 53) declined at a rate of approximately 1.0 line per year; (2) eyes with VA between 20/25 and 20/70 (N = 65) declined at a rate of approximately 0.9 lines per year; (3) eyes with VA between 20/70 and 20/200 (N = 163) declined at a rate of 0.2 lines per year; and (4) eyes with VA worse than 20/200 (n = 49) improved at a rate of 0.5 lines per year. Older age of onset was associated with slower VA loss: Patients with onset age30 years showed 0.4 lines slower change of VA per year (P = 0.01) compared with patients with onset age ≤14 years.Given the overall slow rate of VA loss, VA is unlikely to be a sensitive outcome measure for treatment trials of Stargardt disease. However, given the faster decline in younger patients and those with no or mild visual impairment, VA may be a potential outcome measure for trials targeting such subgroups of patients. These observations will need to be assessed in a prospective study bearing in mind the inherent limitations of retrospective datasets.

PurposeThis paper aims to reflect briefly on some of the major principles that have emerged from the developing policies, practices and debates about corporate citizenship in the last ten years or so.Design/methodology/approachConsiderable scholarly work has been conducted on corporate citizenship in the past, and will continue to be done in the future. This paper is deliberately written for a non‐scholarly audience.FindingsTen principles are outlined, all of them focusing on developing a cultural aspect of corporate citizenship as good business.Originality/valueThe basic premise of this paper is that significant cultural change, through corporate citizenship will only take place by business implementing policies, and practices based on the sort of sound (but basic) principles presented here. These ten principles, in this format, are original to this paper.

The flow structure of a tip vortex in the near field of a NACA 0015 wing with an effective aspect ratio of 5.04 undergoing a deep-stall oscillation with a(t) = 18 deg + 6 deg sin ωt at Re = 1.86 × 10 5 was investigated. The wing oscillation imposed a strong discrepancy in contour shapes and magnitudes between the pitch-up and pitch-down phases of the oscillation cycle. The vortex was more organized and nearly axisymmetric for x/c > 0.5 during pitch-up than during pitch-down. The peak tangential velocity and vorticity and the strength and size of the vortex increased with a(t), except in the vicinity of α max , and had higher values during pitch-up than during pitch-down. The axial flow was always wake like and the velocity deficit decreased with α(t), while exhibiting a sharp increase and decrease on the upstroke and downstroke in the vicinity of α max , respectively. The tangential velocity decreased slightly with the downstream distance. The vortex size increased rather significantly with x/c during pitch-down while remaining virtually unchanged during pitch-up. The inner region of the vortex exhibited a self-similar structure, similar to that of a stationary wing. The induced drag increased with a(t) and had a local maximum at 20 deg during pitch-up.

The effect of reduced frequency on the tip vortex in the near field behind a NACA 0015 wing oscillated sinusoidally within the static-stall angle (= 14 deg) was investigated at Re = 1.86 × × 10 5 . The nearly symmetric vortex was observed at 0.5 to 1.5 chords downstream of the trailing edge similar to the case of a stationary wing. The oscillating wing produced a less concentrated vortex of similar diameter and had a larger radial gradient in circulation strength, compared to that of a stationary wing, for reduced frequency less than about 0.1. The axial-flow velocity was always wake-like, with its minimum value increasing with the reduced frequency. The peak value of the vorticity and the vortex strength and the lift-induced drag were higher during pitch-down than during pitch-up. The normalized circulation in the inner part of the axisymmetric vortex also exhibited a self-similar structure, which was insensitive to the reduced frequency. The induced drag increased with the reduced frequency.

A 94 GHz imaging radar-based on the interrupted FMCW (FMICW) principles, with its associated gimbals for stabilization and scanning has been developed as an airborne test-bed to evaluate radar-aided navigation and guidance algorithms. Preliminary results from helicopter-based flight tests show sufficient contrast between selected features (including runways) and their surroundings for both computer- and human-pilot-based guidance. Feature extraction and matching algorithms have shown this system to be more accurate than GPS.

The near-wake tip vortex flow structure behind a NACA 0015 airfoil with a trailing-edge flap was investigated. Lift-induced drag was computed based on vorticity and was compared with force-balance data. The vortex strength reached a maximum immediately behind the trailing edge and remained nearly constant up to two chord lengths downstream (x/c = 3). The displaced flap produced a more concentrated vortex of similar diameter and a higher induced drag compared to that of a baseline airfoil and had a larger radial gradient in circulation strength for flap angle δ < 15 deg; the vortex radius increased significantly for δ =2 0deg. For δ < ‐ 15 deg, the axial flow velocity was jetlike with the peak values increased with the flap angle. The nearly symmetric vortex was observed at x/c =2 .25 fo ra displaced flap while at x/c =1 . 5f or a baseline airfoil. The stength and interaction of the secondary and main vortices along the tip were also found to increase with the flap angle, and the vortex flow (immediately downstream of the deflected flap) was dominated by the presence of multiple vortices. The normalized circulation in the inner part of the symmetric vortex exhibited a self-similar structure, insensitive to the flap angle.

A direct numerical simulation of a Batchelor vortex has been carried out in the presence of freely decaying turbulence, using both periodic and symmetric boundary conditions; the latter most closely approximates typical experimental conditions, while the former is often used in computational simulations for numerical convenience. The higher-order velocity statistics were shown to be strongly dependent upon the boundary conditions, but the dependence could be mostly eliminated by correcting for the random, Gaussian modulation of the vortex trajectory, commonly referred to as ‘wandering’, using a technique often employed in the analysis of experimental data. Once this wandering had been corrected for, the strong peaks in the Reynolds stresses normally observed at the vortex centre were replaced by smaller local extrema located within the core region but away from the centre. The distributions of the corrected Reynolds stresses suggest that the formation and organization of secondary structures within the core is the main mechanism in turbulent production during the linear growth phase of vortex development.

A novel approach has been considered for the formal process of calibrating multiple hole pressure probes for use in wind tunnels. Rather than determining the attitude angles of a probe and subsequently flow angularity for a fixed probe, either by linear interpolation between sample points or through the use of piecewise functional fits, the outputs from the probe are mapped as continuous functions across the angular test space, using a set of sample points derived from Optimal Design of Experiments. This offers the potential of more accurate probe calibrations across a wider range of flow onset angles, with fewer sample points than currently used for the same purpose. Proof-of-concept tests using a five-hole probe have indicated that the approach is viable, while examination of fits to legacy data from prior tests indicates that the approach is easily extendable to probes with an arbitrary number of holes, and to multiple hot-wire installations.

Neuroimaging experiments can generate impressive volumes of data and many images of the results. This is particularly true of multi-modal imaging studies that use more than one imaging technique, or when imaging is combined with other assessments. A challenge for these studies is appropriate visualisation of results in order to drive insights and guide accurate interpretations. Next-generation visualisation technology therefore has much to offer the neuroimaging community. One example is the Imperial College London Data Observatory; a high-resolution (132 megapixel) arrangement of 64 monitors, arranged in a 313 degree arc, with a 6 metre diameter, powered by 32 rendering nodes. This system has the potential for high-resolution, large-scale display of disparate data types in a space designed to promote collaborative discussion by multiple researchers and/or clinicians. Opportunities for the use of the Data Observatory are discussed, with particular reference to applications in Multiple Sclerosis (MS) research and clinical practice. Technical issues and current work designed to optimise the use of the Data Observatory for neuroimaging are also discussed, as well as possible future research that could be enabled by the use of the system in combination with eye-tracking technology.

Trailing vortices have been repeatedly shown to exhibit a remarkably robust self-similarity independent of the Reynolds number and upstream boundary conditions. The collapse of the inner-scaled circulation profiles of a trailing vortex has even been previously demonstrated for the cases of highly unsteady and turbulent vortex systems, as well as for vortices which were incompletely developed. A number of factors which contribute to and may artificially promote this self-similarity are discussed. It is shown that the amplitude of vortex “wandering” (or the random modulations in the vortex trajectory) observed in some experimental measurements are of sufficient amplitude to cause any arbitrary finite and axisymmetric flow structure to collapse with an idealized trailing vortex when scaled on inner parameters. It is further shown that, for the case of an incompletely developed wing-tip vortex, similarity in the outer core region may be an artefact of the rate of roll-up of the vortex sheet. Great care must, therefore, be taken when interpreting experimental measurements of vortex flows.

A constant-temperature anemometer has been developed which uses a single high-fidelity speaker driver as a combined signal and power amplifier. Owing to its small size and simplicity of construction, the anemometer is well suited for applications requiring a large number of channels (such as hot-wire rakes) as well as applications requiring the embedding of instrumentation within confined experimental models (such as reduced-scale wind turbine blades). The anemometer is shown to have performance characteristics similar to those of a commercial anemometer when used under its design conditions. An operating bandwidth as high as 10 kHz can be achieved, which is greater than most available time-resolved digital particle-image velocimetry systems and is shown to be sufficient to track large-scale turbulence structures in channel flow.

The streamwise velocity component is studied in fully developed turbulent channel flow for two very rough surfaces and a smooth surface at comparable Reynolds numbers. One rough surface comprises sparse and isotropic grit with a highly non-Gaussian distribution. The other is a uniform mesh consisting of twisted rectangular elements which form a diamond pattern. The mean roughness heights (±) the standard deviation) are, respectively, about 76(±42) and 145(±150) wall units. The flow is shown to be two-dimensional and fully developed up to the fourth-order moment of velocity. The mean velocity profile over the grit surface exhibits self-similarity (in the form of a logarithmic law) within the limited range of 0.04≤y/h≤0.06, but the profile over the mesh surface does not, even though the mean velocity deficit and higher moments (up to the fourth order) all exhibit outer scaling over both surfaces. The distinction between self-similarity and outer similarity is clarified and the importance of the former is explained. The wake strength is shown to increase slightly over the grit surface but decrease over the mesh surface. The latter result is contrary to recent measurements in rough-wall boundary layers. Single- and two-point velocity correlations reveal the presence of large-scale streamwise structures with circulation in the plane orthogonal to the mean velocity. Spanwise correlation length scales are significantly larger than corresponding ones for both internal and external smooth-wall flows.