87 research outputs found

    Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae

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    Acknowledgements We thank Marco Thiel for assistance with data interpretation, Peter Sudbery for the provision of strains and Jeremy Craven for useful discussions. This work was supported by a BBSRC-DTG to D. D. T., NIH award DK083592 to F. J. B. and P. A. J., and a Royal Society URF UF080611 and MRC NIRG 90671 to A. C. B.Non peer reviewedPublisher PD

    Neural network decoder for near-term surface-code experiments

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    Neural-network decoders can achieve a lower logical error rate compared to conventional decoders, like minimum-weight perfect matching, when decoding the surface code. Furthermore, these decoders require no prior information about the physical error rates, making them highly adaptable. In this study, we investigate the performance of such a decoder using both simulated and experimental data obtained from a transmon-qubit processor, focusing on small-distance surface codes. We first show that the neural network typically outperforms the matching decoder due to better handling errors leading to multiple correlated syndrome defects, such as YY errors. When applied to the experimental data of [Google Quantum AI, Nature 614, 676 (2023)], the neural network decoder achieves logical error rates approximately 25%25\% lower than minimum-weight perfect matching, approaching the performance of a maximum-likelihood decoder. To demonstrate the flexibility of this decoder, we incorporate the soft information available in the analog readout of transmon qubits and evaluate the performance of this decoder in simulation using a symmetric Gaussian-noise model. Considering the soft information leads to an approximately 10%10\% lower logical error rate, depending on the probability of a measurement error. The good logical performance, flexibility, and computational efficiency make neural network decoders well-suited for near-term demonstrations of quantum memories.Comment: 15 pages, 8 figures, 1 tabl

    Mass-loaded spherical accretion flows

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    We have calculated the evolution of spherical accretion flows undergoing mass-loading from embedded clouds through either conduction or hydrodynamical ablation. We have observed the effect of varying the ratios of the mass-loading timescale and the cooling timescale to the ballistic crossing timescale through the mass-loading region. We have also varied the ratio of the potential energy of a particle injected into the flow near the outer region of mass-loading to the temperature at which a minimum occurs in the cooling curve. The two types of mass-loading produce qualitatively different types of behaviour in the accretion flow, since mass-loading through conduction requires the ambient gas to be hot, whereas mass ablation from clumps occurs throughout the flow. Higher ratios of injected to accreted mass typically occur with hydrodynamical ablation, in agreement with previous work on wind-blown bubbles and supernova remnants. We find that mass-loading damps the radiative overstability of such flows, in agreement with our earlier work. If the mass-loading is high enough it can stabilize the accretion shock at a constant radius, yielding an almost isothermal subsonic post-shock flow. Such solutions may be relevant to cooling flows onto massive galaxies. Mass-loading can also lead to the formation of isolated shells of high temperature material, separated by gas at cooler temperatures

    Reduction in endothelial tip cell filopodia corresponds to reduced intravitreous but not intraretinal vascularization in a model of ROP

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    To determine the effect of a vascular endothelial growth factor receptor 2 tyrosine kinase (VEGFR2) inhibitor on intravitreous neovascularization (IVNV), endothelial tip cell filopodia, and intraretinal vascularization in a rat model of retinopathy of prematurity (ROP)

    Consumer understanding of terms used in imaging reports requested for low back pain: a cross-sectional survey

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    OBJECTIVES: To investigate (1) self-reported societal comprehension of common and usually non-serious terms found in lumbar spine imaging reports and (2) its relationship to perceived seriousness, likely persistence of low back pain (LBP), fear of movement, back beliefs and history and intensity of LBP. DESIGN: Cross-sectional online survey of the general public. SETTING: Five English-speaking countries: UK, USA, Canada, New Zealand and Australia. PARTICIPANTS: Adults (age >18 years) with or without a history of LBP recruited in April 2019 with quotas for country, age and gender. PRIMARY AND SECONDARY OUTCOME MEASURES: Self-reported understanding of 14 terms (annular fissure, disc bulge, disc degeneration, disc extrusion, disc height loss, disc protrusion, disc signal loss, facet joint degeneration, high intensity zone, mild canal stenosis, Modic changes, nerve root contact, spondylolisthesis and spondylosis) commonly found in lumbar spine imaging reports. For each term, we also elicited worry about its seriousness, and whether its presence would indicate pain persistence and prompt fear of movement. RESULTS: From 774 responses, we included 677 (87.5%) with complete and valid responses. 577 (85%) participants had a current or past history of LBP of whom 251 (44%) had received lumbar spine imaging. Self-reported understanding of all terms was poor. At best, 235 (35%) reported understanding the term ‘disc degeneration’, while only 71 (10.5%) reported understanding the term ‘Modic changes’. For all terms, a moderate to large proportion of participants (range 59%–71%), considered they indicated a serious back problem, that pain might persist (range 52%–71%) and they would be fearful of movement (range 42%–57%). CONCLUSION: Common and usually non-serious terms in lumbar spine imaging reports are poorly understood by the general population and may contribute to the burden of LBP. TRIAL REGISTRATION NUMBER: ACTRN12619000545167

    Neutralizing VEGF Decreases Tortuosity and Alters Endothelial Cell Division Orientation in Arterioles and Veins in a Rat Model of ROP: Relevance to Plus Disease

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    To study the effects of vascular endothelial growth factor (VEGF) on endothelial nitric oxide synthetase (eNOS) and retinal vascular tortuosity and cleavage planes in a rat model of retinopathy of prematurity (ROP)

    Using unoccupied aerial vehicles (UAVs) to map seagrass cover from Sentinel-2 imagery

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    Seagrass habitats are ecologically valuable and play an important role in sequestering and storing carbon. There is, thus, a need to estimate seagrass percentage cover in diverse environments in support of climate change mitigation, marine spatial planning and coastal zone management. In situ approaches are accurate but time-consuming, expensive and may not represent the larger spatial units collected by satellite imaging. Hence, there is a need for a consistent methodology that uses accurate point-based field surveys to deliver high-quality mapping of percentage seagrass cover at large spatial scales. Here, we develop a three-step approach that combines in situ (quadrats), aerial (unoccupied aerial vehicle—UAV) and satellite data to map percentage seagrass cover at Turneffe Atoll, Belize, the largest atoll in the northern hemisphere. First, the optical bands of four UAV images were used to calculate seagrass cover, in combination with in situ data. The seagrass cover calculated from the UAV was then used to develop training and validation datasets to estimate seagrass cover in Sentinel-2 pixels. Next, non-seagrass areas were identified in the Sentinel-2 data and removed by object-based classification, followed by a pixel-based regression to calculate seagrass percentage cover. Using this approach, percentage seagrass cover was mapped using UAVs (R2 = 0.91 between observed and mapped distributions) and using Sentinel-2 data (R2 = 0.73). This work provides the first openly available and explorable map of seagrass percentage cover across Turneffe Atoll, where we estimate approximately 242 km2 of seagrass above 10% cover is located. We estimate that this approach offers 30 times more data for training satellite data than traditional methods, therefore presenting a substantial reduction in cost-per-point for data. Furthermore, the increase in data helps deliver a high-quality seagrass cover map, suitable for resolving trends of deteriorating, stable or recovering seagrass environments at 10 m2 resolution to underpin evidence-based management and conservation of seagrass.publishedVersio
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