30 research outputs found
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Application of data fusion techniques and technologies for wearable health monitoring
Technological advances in sensors and communications have enabled discrete integration into everyday objects, both in the home and about the person. Information gathered by monitoring physiological, behavioural, and social aspects of our lives, can be used to achieve a positive impact on quality of life, health, and well-being. Wearable sensors are at the cusp of becoming truly pervasive, and could be woven into the clothes and accessories that we wear such that they become ubiquitous and transparent. To interpret the complex multidimensional information provided by these sensors, data fusion techniques are employed to provide a meaningful representation of the sensor outputs. This paper is intended to provide a short overview of data fusion techniques and algorithms that can be used to interpret wearable sensor data in the context of health monitoring applications. The application of these techniques are then described in the context of healthcare including activity and ambulatory monitoring, gait analysis, fall detection, and biometric monitoring. A snap-shot of current commercially available sensors is also provided, focusing on their sensing capability, and a commentary on the gaps that need to be bridged to bring research to market
NGTS-4b: A sub-Neptune transiting in the desert
We report the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a
13th magnitude K-dwarf in a 1.34d orbit. NGTS-4b has a mass M=M_E
and radius R=R_E, which places it well within the so-called
"Neptunian Desert". The mean density of the planet (g/cm^3) is
consistent with a composition of 100% HO or a rocky core with a volatile
envelope. NGTS-4b is likely to suffer significant mass loss due to relatively
strong EUV/X-ray irradiation. Its survival in the Neptunian desert may be due
to an unusually high core mass, or it may have avoided the most intense X-ray
irradiation by migrating after the initial activity of its host star had
subsided. With a transit depth of %, NGTS-4b represents the
shallowest transiting system ever discovered from the ground, and is the
smallest planet discovered in a wide-field ground-based photometric survey
The Irradiated Atmospheres Of Brown Dwarf Companions To White Dwarf Stars
Currently there are 1000’s of known exoplanets, many of which are hot-jupiters (Jupiter-like planets close in to their host star), but very few have had their atmospheres characterised. The study of close non-interacting white dwarf - brown dwarf binaries offers a unique opportunity to observe a planet-like atmosphere without the observational challenges faced when investigating exo-atmospheres. In this work I investigate two systems: WD0137-349 and NLTT5306. The former displays irradiation induced metal emission lines in a substellar atmosphere. I investigated the lines strengths of the H and Ca II line and found these to vary with orbital phase and almost completely disappear on the dark-side of the brown dwarf; implying that heat redistribution around this tidally locked companion is likely to be poor. replication of this result will be necessary in future planetary atmosphere models. NLTT6306 is almost identical to WD0137-349 in component mass and orbital period, the main difference being the age and temperature of the white dwarf primary. This system however, is very different. NLTT5306 displays H emission and Na I absorption associated with the white dwarf which indicates accretion is happening. However, there are no high energy emissions, Zeeman splitting, or evidence of a disc. An X-ray non-detection gives a maximum accretion rate of 2 x 10−15M⊙ yr−1 which would only require a magnetic field of 0.45 kG to prevent a disc from forming whilst still too low produce detectable Zeeman splitting. I have concluded that the observations can be explained by a light wind from the brown dwarf being magnetically funnelled onto the white dwarf surface. Finally, I have analysed Gemini near-infrared spectra from 8 white dwarfs with photometrically confirmed infrared excesses. I compared the spectra to composite models and I was able to spectroscopically confirm 3 new white dwarf - brown dwarf binaries
The role of activated coagulation factor XII in overall clot stability and fibrinolysis
Activated coagulation factor XII (α-FXIIa) is able to bind to fibrin(ogen) and increases the density and stiffness of the fibrin clot. Conversely, proteins of the contact system and the fibrinolytic system show a high degree of homology and α-FXIIa can convert plasminogen into plasmin resulting in fibrin degradation. Therefore, we studied the contribution of α-FXIIa to overall clot stability and plasmin driven fibrinolysis in the absence and presence of tissue plasminogen activator (tPA).
We observed that α-FXIIa directly converted plasminogen into plasmin and reduced clot lysis time at all tPA concentrations tested (15–1500 pM). Simultaneous assessment of plasmin generation (chromogenic substrate S-2251) and fibrin formation and degradation (absorbance at 405 nm), showed an earlier onset of fibrinolysis and plasmin formation in the presence of α-FXIIa. Fibrinolysis of clots formed under flow conditions, revealed that incorporation of α-FXIIa accelerated clot breakdown (fluorescence release of labeled fibrin) by additional plasmin generation on top of formation by tPA. Scanning electron microscopy (SEM) revealed that the surface area pore size increased in the presence compared with the absence of α-FXIIa when fibrinolysis was initiated by the conversion of plasminogen with tPA during clot formation.
α-FXIIa enhances fibrinolysis in the presence of plasminogen, irrespective of whether tPA was present during clot formation or was added afterwards to initiate fibrinolysis. We postulate that FXIIa first strengthens the clot structure during clot formation and thereafter contributes towards fibrinolysis
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
Search for the rare hadronic decay
A search for the rare hadronic decay Bs0→pp¯ is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb-1. No evidence of the decay is found and an upper limit on its branching fraction is set at B(Bs0→pp¯)<4.4(5.1)×10-9 at 90% (95%) confidence level; this is currently the world’s best upper limit. The decay mode B0→pp¯ is measured with very large significance, confirming the first observation by the LHCb experiment in 2017. The branching fraction is determined to be B(B0→pp¯)=(1.27±0.15±0.05±0.04)×10-8, where the first uncertainty is statistical, the second is systematic and the third is due to the external branching fraction of the normalization channel B0→K+π-. The combination of the two LHCb measurements of the B0→pp¯ branching fraction yields B(B0→pp¯)=(1.27±0.13±0.05±0.03)×10-8.A search for the rare hadronic decay is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb. No evidence of the decay is found and an upper limit on its branching fraction is set at at 90% (95%) confidence level; this is currently the world's best upper limit. The decay mode is measured with very large significance, confirming the first observation by the LHCb experiment in 2017. The branching fraction is determined to be , where the first uncertainty is statistical, the second is systematic and the third is due to the external branching fraction of the normalization channel . The combination of the two LHCb measurements of the branching fraction yields
Observation of sizeable contribution to decays
Resonant structures in the dipion mass spectrum from decays, produced via decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb. A sizeable contribution from the isospin conserving decay is established for the first time, , with a significance of more than . The amplitude of isospin violating decay, , relative to isospin conserving decay, , is properly determined, and it is a factor of six larger than expected for a pure charmonium state.Resonant structures in the dipion mass spectrum from χc1(3872)→π+π-J/ψ decays, produced via B+→K+χc1(3872) decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb-1. A sizeable contribution from the isospin conserving χc1(3872)→ωJ/ψ decay is established for the first time, (21.4±2.3±2.0)%, with a significance of more than 7.1σ. The amplitude of isospin violating decay, χc1(3872)→ρ0J/ψ, relative to isospin conserving decay, χc1(3872)→ωJ/ψ, is properly determined, and it is a factor of 6 larger than expected for a pure charmonium state.Resonant structures in the dipion mass spectrum from decays, produced via decays, are analyzed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 . A sizeable contribution from the isospin conserving decay is established for the first time, , with a significance of more than . The amplitude of isospin violating decay, , relative to isospin conserving decay, , is properly determined, and it is a factor of six larger than expected for a pure charmonium state