922 research outputs found
Processing of Synthetic Aperture Radar Images by the Boundary Contour System and Feature Contour System
An improved Boundary Contour System (BCS) and Feature Contour System (FCS) neural network model of preattentive vision is applied to two large images containing range data gathered by a synthetic aperture radar (SAR) sensor. The goal of processing is to make structures such as motor vehicles, roads, or buildings more salient and more interpretable to human observers than they are in the original imagery. Early processing by shunting center-surround networks compresses signal dynamic range and performs local contrast enhancement. Subsequent processing by filters sensitive to oriented contrast, including short-range competition and long-range cooperation, segments the image into regions. Finally, a diffusive filling-in operation within the segmented regions produces coherent visible structures. The combination of BCS and FCS helps to locate and enhance structure over regions of many pixels, without the resulting blur characteristic of approaches based on low spatial frequency filtering alone.Air Force Office of Scientific Research (90-0175); Defense Advanced Research Projects Agency (90-0083
Health-care resource use among patients who use illicit opioids in England, 2010–20: A descriptive matched cohort study
Background and aims:
People who use illicit opioids have higher mortality and morbidity than the general population. Limited quantitative research has investigated how this population engages with health-care, particularly regarding planned and primary care. We aimed to measure health-care use among patients with a history of illicit opioid use in England across five settings: general practice (GP), hospital outpatient care, emergency departments, emergency hospital admissions and elective hospital admissions.
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Design:
This was a matched cohort study using Clinical Practice Research Datalink and Hospital Episode Statistics.
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Setting:
Primary and secondary care practices in England took part in the study.
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Participants:
A total of 57 421 patients with a history of illicit opioid use were identified by GPs between 2010 and 2020, and 172 263 patients with no recorded history of illicit opioid use matched by age, sex and practice.
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Measurements:
We estimated the rate (events per unit of time) of attendance and used quasi-Poisson regression (unadjusted and adjusted) to estimate rate ratios between groups. We also compared rates of planned and unplanned hospital admissions for diagnoses and calculated excess admissions and rate ratios between groups.
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Findings:
A history of using illicit opioids was associated with higher rates of health-care use in all settings. Rate ratios for those with a history of using illicit opioids relative to those without were 2.38 [95% confidence interval (CI) = 2.36–2.41] for GP; 1.99 (95% CI = 1.94–2.03) for hospital outpatient visits; 2.80 (95% CI = 2.73–2.87) for emergency department visits; 4.98 (95% CI = 4.82–5.14) for emergency hospital admissions; and 1.76 (95% CI = 1.60–1.94) for elective hospital admissions. For emergency hospital admissions, diagnoses with the most excess admissions were drug-related and respiratory conditions, and those with the highest rate ratios were personality and behaviour (25.5, 95% CI = 23.5–27.6), drug-related (21.2, 95% CI = 20.1–21.6) and chronic obstructive pulmonary disease (19.4, 95% CI = 18.7–20.2).
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Conclusions:
Patients who use illicit opioids in England appear to access health services more often than people of the same age and sex who do not use illicit opioids among a wide range of health-care settings. The difference is especially large for emergency care, which probably reflects both episodic illness and decompensation of long-term conditions
Photoacclimation by arctic cryoconite phototrophs
© FEMS 2017. All rights reserved. Cryoconite is a matrix of sediment, biogenic polymer and a microbial community that resides on glacier surfaces. The phototrophic component of this community is well adapted to this extreme environment, including high light stress. Photoacclimation of the cryoconite phototrophic community on Longyearbreen, Svalbard, was investigated using in situ variable chlorophyll fluorescence. Rapid light curves (RLCs) and induction-recovery curves were used to analyse photosystem II quantum efficiency, relative electron transport rate and forms of downregulation including non-photochemical quenching (NPQ) and state transitions in cyanobacteria. Phototrophs used a combination of behavioural and physiological photochemical downregulation. Behavioural downregulation is hypothesised to incorporate chloroplast movement and cell or filament positioning within the sediment matrix in order to shade from high light, which resulted in a lack of saturation of RLCs and hence overestimation of productivity. Physiological downregulation likely consisted of biphasic NPQ, comprising a steadily induced light-dependent form and a light-independent NPQ that was not reversed with decreasing light intensity. State transitions by cyanobacteria were the most likely physiological downregulation employed by cyanobacteria within the mixed phototroph community. These findings demonstrate that cryoconite phototrophs combine multiple forms of physiological and behavioural downregulation to optimise light exposure and maximise photosynthetic productivity. This plasticity of photoacclimation enables them to survive productively in the high-light stress environment on the ice surface
Logic and/of Truthmaking
The purpose of this paper is to explore the question of how truthmaker theorists ought to think about their subject in relation to logic. Regarding logic and truthmaking, I defend the view that considerations drawn from advances in modal logic have little bearing on the legitimacy of truthmaker theory. To do so, I respond to objections Timothy Williamson has lodged against truthmaker theory. As for the logic of truthmaking, I show how the project of understanding the logical features of the truthmaking relation has led to an apparent impasse. I offer a new perspective on the logic of truthmaking that both explains the problem and offers a way out
Final report on project SP1210: Lowland peatland systems in England and Wales – evaluating greenhouse gas fluxes and carbon balances
Lowland peatlands represent one of the most carbon-rich ecosystems in the UK. As a result of widespread habitat modification and drainage to support agriculture and peat extraction, they have been converted from natural carbon sinks into major carbon sources, and are now amongst the largest sources of greenhouse gas (GHG) emissions from the UK land-use sector. Despite this, they have previously received relatively little policy attention, and measures to reduce GHG emissions either through re-wetting and restoration or improved management of agricultural land remain at a relatively early stage. In part, this has stemmed from a lack of reliable measurements on the carbon and GHG balance of UK lowland peatlands. This project aimed to address this evidence gap via an unprecedented programme of consistent, multi year field measurements at a total of 15 lowland peatland sites in England and Wales, ranging from conservation managed ‘near-natural’ ecosystems to intensively managed agricultural and extraction sites. The use of standardised measurement and data analysis protocols allowed the magnitude of GHG emissions and removals by peatlands to be quantified across this heterogeneous data set, and for controlling factors to be identified. The network of seven flux towers established during the project is believed to be unique on peatlands globally, and has provided new insights into the processes the control GHG fluxes in lowland peatlands. The work undertaken is intended to support the future development and implementation of agricultural management and restoration measures aimed at reducing the contribution of these important ecosystems to UK GHG emissions
The new SIGCHI EC's values and strategic initiatives.
The SIGCHI EC has articulated the following 10 values. Specifically, these are instrumental values: They are our preferred methods of behavior. They are not an end goal, but they translate into a means by which an end goal is accomplished
Ultraviolet Spectroscopy and TARDIS Models of the Broad-lined Type-Ic Supernova 2014ad
Few published ultraviolet (UV) spectra exist for stripped-envelope
supernovae, and none to date for broad-lined Type Ic supernovae (SN Ic-bl).
These objects have extremely high ejecta velocities and are the only supernova
type directly linked to gamma-ray bursts (GRBs). Here we present two epochs of
HST/STIS spectra of the SN Ic-bl 2014ad, the first UV spectra for this class.
We supplement this with 26 new epochs of ground-based optical spectra,
augmenting a rich spectral time series. The UV spectra do not show strong
features, likely due to high opacity, and are consistent with broadened
versions of other SN Ic spectra observed in the UV. We measure Fe II 5169
Angstrom velocities and show that SN 2014ad has even higher ejecta velocities
than most SNe Ic both with and without observed GRBs. We construct models of
the SN 2014ad UV+optical spectra using TARDIS, a 1D Monte-Carlo
radiative-transfer spectral synthesis code. The models fit the data well at
multiple epochs in the optical but underestimate the flux in the UV. We find
that high densities at high velocities are needed to reproduce the spectra,
with 3 M of material at 22,000 km s, assuming
spherical symmetry. Our nebular line fits suggest a steep density profile at
low velocities. Together, these results imply a higher total ejecta mass than
estimated from previous light curve analysis and expected from theory. This may
be reconciled by a flattening of the density profile at low velocity and extra
emission near the center of the ejecta.Comment: 25 pages, 14 figures, submitted to AAS Journal
The design with intent method: A design tool for influencing user behaviour
The official published version can be found at the link below.Using product and system design to influence user behaviour offers potential for improving performance and reducing user error, yet little guidance is available at the concept generation stage for design teams briefed with influencing user behaviour. This article presents the Design with Intent Method, an innovation tool for designers working in this area, illustrated via application to an everyday human–technology interaction problem: reducing the likelihood of a customer leaving his or her card in an automatic teller machine. The example application results in a range of feasible design concepts which are comparable to existing developments in ATM design, demonstrating that the method has potential for development and application as part of a user-centred design process
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