A thermophone-based bridge circuit for the measurement of electrical and thermal properties of thin films

This is the final version. Available from the IOP Publishing via the DOI in this record. Data availability statement: The data that support the findings of this study are available upon reasonable request from the authors.Sound can be generated via modulated Joule heating of thin conductive films. Its amplitude and phase are sensitive to the electrical and thermal properties of the film. Here we show how such sound can be used to measure and quantify these properties. In particular, we experimentally determine the relative conductances of electrical paths in a multi-branched thin film, which can then be used to find the temperature dependence of the film conductance. This is achieved by nullifying the sound at a given point in the sound field using simple voltage control. This method, essentially an acoustic analogue of an electrical bridge circuit, is advantageous since it allows for electrical and thermal properties to be measured simultaneously. These attributes benefit the characterisation of complex circuit architectures, as well as thermal sensing.Engineering and Physical Sciences Research Council (EPSRC)Engineering and Physical Sciences Research Counci

Risk factors for visual field deterioration in the United Kingdom Glaucoma Treatment Study

OBJECTIVE: The United Kingdom Glaucoma Treatment Study (UKGTS) investigated the visual field (VF) preserving effect of medical treatment in open-angle glaucoma (OAG). The objective of this analysis was to identify risk factors associated with VF deterioration. DESIGN: Randomized, double masked, placebo-controlled, multicentre trial. PARTICIPANTS: Five hundred sixteen participants with previously untreated OAG were prospectively recruited in 10 UK centres. METHODS: Eligibility criteria were modeled on those for the Early Manifest Glaucoma Trial. Study participants were randomized to either latanoprost 0.005% or placebo eye drops. The observation period was 2 years and involved, among other procedures, VF testing and intraocular pressure (IOP) measurement at 11 scheduled visits, with clustering of tests at baseline, 18 months, and 24 months. Guided Progression Analysis pattern deviation maps were used to determine VF deterioration. Cox regression was used to compute the hazard ratios (HRs) and respective 95% confidence intervals (CIs) whilst accounting for the correlation within sites. Model selection was guided by backwards stepwise selection conducted on the model containing all variables which were significant at the 0.2 level in the univariable analysis. Follow-up variables which showed collinearity with baseline values were not retained in the final model. MAIN OUTCOME MEASURES: Time-to-VF deterioration. RESULTS: Treatment with latanoprost reduced the HR for VF deterioration by 58% (HR 0.42; 95% CI 0.27-0.67, P=0.001). Factors associated with deterioration were bilateral disease (HR 1.59 for yes versus no; 95% CI 1.02-2.50, P=0.041), higher baseline IOP (HR 1.07 per mmHg; 95% CI 1.02-1.12, P=0.008) and disc haemorrhage at visit 1 (HR 2.08; 95% CI 1.07-4.04, P=0.030). Smoking (current or previous) was associated with a reduced HR for VF deterioration (HR 0.59; 95% CI 0.37-0.93, P=0.023). No other evaluated factors were found to be statistically significant in the multivariable analysis. CONCLUSIONS: In the UKGTS, treatment with latanoprost halved VF deterioration risk. Bilateral disease, higher IOP and disc haemorrhage were confirmed as risk factors for deterioration; smoking history appeared to be protective against VF deterioration

Coupling and confinement of current in thermoacoustic phased arrays

This is the final version. Available on open access from the American Association for the Advancement of Science via the DOI in this recordData and materials availability: All data are available in the manuscript or the Supplementary Materials.When a medium is rapidly heated and cooled, heat transfers to its surroundings as sound. A controllable source of this sound is realized through joule heating of thin, conductive films by an alternating current. Here, we show that arrays of these sources generate sound unique to this mechanism. From the sound alone, we spatially resolve current flow by varying the film geometry and electrical phase. Confinement concentrates heat to such a degree that the film properties become largely irrelevant. Electrical coupling between sources creates its own distinctive sound that depends on the current flow direction, making it unusually sensitive to the interactions of multiple currents sharing the same space. By controlling the flow, a full phased array can be created from just a single film.Engineering and Physical Sciences Research Council (EPSRC)Royal Societ

A Common Glaucoma-risk Variant of SIX6 Alters Retinal Nerve Fiber Layer and Optic Disc Measures in a European Population: The EPIC-Norfolk Eye Study

PURPOSE: A common missense variant in the SIX6 gene (rs33912345) is strongly associated with primary open-angle glaucoma (POAG). We aimed to examine the association of rs33912345 with optic disc and retinal nerve fiber layer (RNFL) measures in a European population. METHODS: We examined participants of the population-based EPIC-Norfolk Eye Study. Participants underwent confocal laser scanning tomography (Heidelberg Retina Tomograph II, HRT) to estimate optic disc rim area and vertical cup-disc ratio (VCDR). Scanning laser polarimetry (GDxVCC) was used to estimate average RNFL thickness. The mean of right and left eye values was considered for each participant. Genotyping was performed using the Affymetrix UK Biobank Axiom Array. Multivariable linear regression with the optic nerve head parameter as outcome variable and dosage of rs33912345 genotype as primary explanatory variable was used, adjusted for age, sex, disc area, axial length and intraocular pressure. We further repeated analyses stratified into age tertiles. RESULTS: In total, 5433 participants with HRT data and 3699 participants with GDxVCC data were included. Each "C" allele of rs33912345 was associated with a smaller rim area (-0.030▒mm [95% CI -0.040, -0.020], P=5.4×10), a larger VCDR (0.025 [95% CI 0.017, 0.033], P=3.3×10) and a thinner RNFL (-0.39▒μm [95% CI -0.62, -0.15], P=0.001). The RNFL association was strongest in the oldest age tertile, whereas rim area and VCDR associations were strongest in the youngest and oldest age tertiles. CONCLUSIONS: The protein coding SIX6 variant rs33912345, previously associated with POAG, has a functional effect on glaucoma-associated optic nerve head traits in Europeans

Genomic analysis reveals a tight link between transcription factor dynamics and regulatory network architecture

Although several studies have provided important insights into the general principles of biological networks, the link between network organization and the genome-scale dynamics of the underlying entities (genes, mRNAs, and proteins) and its role in systems behavior remain unclear. Here we show that transcription factor (TF) dynamics and regulatory network organization are tightly linked. By classifying TFs in the yeast regulatory network into three hierarchical layers (top, core, and bottom) and integrating diverse genome-scale datasets, we find that the TFs have static and dynamic properties that are similar within a layer and different across layers. At the protein level, the top-layer TFs are relatively abundant, long-lived, and noisy compared with the core- and bottom-layer TFs. Although variability in expression of top-layer TFs might confer a selective advantage, as this permits at least some members in a clonal cell population to initiate a response to changing conditions, tight regulation of the core- and bottom-layer TFs may minimize noise propagation and ensure fidelity in regulation. We propose that the interplay between network organization and TF dynamics could permit differential utilization of the same underlying network by distinct members of a clonal cell population

Evidence for the classical integrability of the complete AdS(4) x CP(3) superstring

We construct a zero-curvature Lax connection in a sub-sector of the superstring theory on AdS(4) x CP(3) which is not described by the OSp(6|4)/U(3) x SO(1,3) supercoset sigma-model. In this sub-sector worldsheet fermions associated to eight broken supersymmetries of the type IIA background are physical fields. As such, the prescription for the construction of the Lax connection based on the Z_4-automorphism of the isometry superalgebra OSp(6|4) does not do the job. So, to construct the Lax connection we have used an alternative method which nevertheless relies on the isometry of the target superspace and kappa-symmetry of the Green-Schwarz superstring.Comment: 1+26 pages; v2: minor typos corrected, acknowledgements adde

Dynamics of spiral spin waves in magnetic nanopatches: influence of thickness and shape

This is the final version. Available from American Physical Society via the DOI in this record. We explore the dynamics of spiral spin waves in permalloy nanoelements with variable aspect ratio of geometric dimensions, and their potential use as improved spin wave emitters with no or little biasing field required. Numerical results show that above a certain thickness, propagating spiral waves can be obtained in circular and square shaped elements in a flux closure state. VNA-FMR experiments on 20-nm (thin) and 80-nm (thick) samples confirm two type of spectra corresponding to different dispersions for thinner and thicker elements. We show that, for the thicker films, the vortex core region acts as a source of large amplitude spiral spin waves, which dominate over other modes. In case of the thinner elements, these modes are critically damped. For different shapes of the patch, we show that a rich collection of confined propagating modes can also be excited, modifying the final wave front and enriching the potential of the nanodot as a spin wave emitter. We give an explanation for the intense spiral modes from the perspective of a balance of dipolar and exchange energies in the sample.EPSRCSpanish MINECOComunidad de Madri

A frequentist framework of inductive reasoning

Reacting against the limitation of statistics to decision procedures, R. A. Fisher proposed for inductive reasoning the use of the fiducial distribution, a parameter-space distribution of epistemological probability transferred directly from limiting relative frequencies rather than computed according to the Bayes update rule. The proposal is developed as follows using the confidence measure of a scalar parameter of interest. (With the restriction to one-dimensional parameter space, a confidence measure is essentially a fiducial probability distribution free of complications involving ancillary statistics.) A betting game establishes a sense in which confidence measures are the only reliable inferential probability distributions. The equality between the probabilities encoded in a confidence measure and the coverage rates of the corresponding confidence intervals ensures that the measure's rule for assigning confidence levels to hypotheses is uniquely minimax in the game. Although a confidence measure can be computed without any prior distribution, previous knowledge can be incorporated into confidence-based reasoning. To adjust a p-value or confidence interval for prior information, the confidence measure from the observed data can be combined with one or more independent confidence measures representing previous agent opinion. (The former confidence measure may correspond to a posterior distribution with frequentist matching of coverage probabilities.) The representation of subjective knowledge in terms of confidence measures rather than prior probability distributions preserves approximate frequentist validity.Comment: major revisio

The effect of temperature, farm density and foot-and-mouth disease restrictions on the 2007 UK bluetongue outbreak

In 2006, bluetongue (BT), a disease of ruminants, was introduced into northern Europe for the first time and more than two thousand farms across five countries were affected. In 2007, BT affected more than 35,000 farms in France and Germany alone. By contrast, the UK outbreak beginning in 2007 was relatively small, with only 135 farms in southeast England affected. We use a model to investigate the effects of three factors on the scale of BT outbreaks in the UK: (1) place of introduction; (2) temperature; and (3) animal movement restrictions. Our results suggest that the UK outbreak could have been much larger had the infection been introduced into the west of England either directly or as a result of the movement of infected animals from southeast England before the first case was detected. The fact that air temperatures in the UK in 2007 were marginally lower than average probably contributed to the UK outbreak being relatively small. Finally, our results indicate that BT movement restrictions are effective at controlling the spread of infection. However, foot-and-mouth disease restrictions in place before the detection and control of BT in 2007 almost certainly helped to limit BT spread prior to its detection