41 research outputs found
A Westervelt equation for acoustic wave propagation through weakly stratified, arbitrary Mach number atmospheres
Nonlinear distortion of infrasonic waves through atmospheres up to
thermospheric altitudes govern large-range ground-level observations of
explosive noise sources, causing large differences between the near and far
field. Propagation modelling in this scenario to include realistic nonlinear
effects has thus far been limited to high-fidelity, numerically intensive
Direct Numerical Simulations of the Navier-Stokes equations, or nonlinear
parabolic equations with restrictions on the mean flow Mach number. For the
accurate modelling of nonlinear waveform synthesis through realistic
atmospheric winds up to thermospheric altitudes, this work presents nonlinear
wave equation analysis which results in in a Westervelt equation for weakly
stratified, arbitrary Mach number atmospheres. This is intended to be used as a
benchmark for model development and numerical analyses such that alternative
low-fidelity numerical calculations to Direct Numerical Simulations can be
sought
Learning When to Speak: Latency and Quality Trade-offs for Simultaneous Speech-to-Speech Translation with Offline Models
Recent work in speech-to-speech translation (S2ST) has focused primarily on
offline settings, where the full input utterance is available before any output
is given. This, however, is not reasonable in many real-world scenarios. In
latency-sensitive applications, rather than waiting for the full utterance,
translations should be spoken as soon as the information in the input is
present. In this work, we introduce a system for simultaneous S2ST targeting
real-world use cases. Our system supports translation from 57 languages to
English with tunable parameters for dynamically adjusting the latency of the
output -- including four policies for determining when to speak an output
sequence. We show that these policies achieve offline-level accuracy with
minimal increases in latency over a Greedy (wait-) baseline. We open-source
our evaluation code and interactive test script to aid future SimulS2ST
research and application development.Comment: To appear at INTERSPEECH 202
Development of Electrodynamic Tethers for Propellantless Propulsion in Low-Earth Orbit
The Miniature Tether Electrodynamic Experiment-1 (MiTEE-1) is a University of Michigan faculty research project, backed by student research and leadership, consisting of a 3U CubeSat with a shortrigid boom electrodynamic tether (EDT) connecting a picosatellite providing enhanced current collection. It is the first of two satellite missions working towards a technology demonstration and increased knowledge of CubeSat spacecraft charging dynamics. This will thus allow for increased refinement and full operation of an EDT spacecraft system capable of station keeping activities on MiTEE-2. The mission of the MiTEE organization is to demonstrate and refine the technology needed to successfully use electrodynamic tethers on CubeSat and smaller platforms. With a final goal of producing a pico (100g-1000g) to femto (\u3c 100g) sized pair of satellites capable of complex station keeping activities further advancing the ability to create low cost, long term, and controllable satellite constellations. The following paper describes the MiTEE-1 spacecraft, proposed operations, and the hardware needed to demonstrate a miniature EDT housed in a 3U body
The effect of medications which cause inflammation of the gastro-oesophageal tract on cancer risk : a nested case–control study of routine Scottish data
Peer reviewedPostprin
Lessons Learned from the Development and Flight of the First Miniature Tethered Electrodynamics Experiment (MiTEE-1)
The Miniature Tether Electrodynamics Experiment (MiTEE) CubeSat team is a technological advancement project intended to evaluate technology for Electrodynamic Tether (EDT) propulsion on very small pico- and femto-satellite platforms. MiTEE is demonstrating this through a series of missions starting with MiTEE-1, a 3U CubeSat designed to characterize the electron current collection behavior of a biased, simulated picosat mounted at the end of a 1-meter deployable boom. In addition, a miniaturized Langmuir probe electronics board was flown to characterize the ambient plasma environment. MiTEE-1 was launched successfully with Virgin Orbit’s Launch Demo 2 flight on NASA’s 20th Educational Launch of Nanosatellites (ELaNa XX) mission, January 17, 2021
Medications that relax the lower oesophageal sphincter and risk of oesophageal cancer : An analysis of two independent population-based databases
Acknowledgements We acknowledge collaboration with the Research Applications and Data Management Team lead by Ms Katie Wilde, University of Aberdeen in conducting our study. This research has been conducted using the UK Bio-bank Resource under application number 34374.Peer reviewedPostprin
Endovascular management of pelvic trauma
Traumatic pelvic injuries are an important group of acquired pathologies given their frequent association with significant vascular compromise. Potentially fatal as a consequence of rapid hemorrhage, achievement of early hemostasis is a priority; endovascular management of traumatic pelvic arterial injuries is an important potential option for treatment. Precipitated by any number of mechanisms of trauma, pelvic vascular injury necessitates timely patient assessment. Variable patterns of arterial injury may result from blunt, penetrating or iatrogenic trauma. Selection of the most appropriate imaging modality is a priority, ensuring streamlined access to treatment. In the case of CT, this is complemented by acquisition of the most appropriate phase of imaging; review of both arterial and delayed phase imaging improves the accuracy of detection of low-flow hemorrhage. In cases where surgical intervention is not deemed appropriate, endovascular treatment provides an alternative means for cessation of hemorrhage associated with pelvic injuries. This may be achieved in a selective or nonselective manner depending on the patient's clinical status and time constraints. Consequently, a detailed understanding of vascular anatomy is essential, including an appreciation of the normal variant anatomy between males and females. Additional consideration must be given to variant anatomy which may co-exist in both sexes. This review article aims to provide a synopsis of endovascular management of pelvic vascular injury. Through case examples, available treatment options will be discussed, including thrombin injection and transcatheter arterial embolization. Furthermore, potential adverse complications of pelvic arterial embolization will be highlighted. Finally, in view of the potential severity of these injuries, a brief overview of initial management of the hemodynamically unstable patient is provided
Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial
Background
Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear.
Methods
RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047.
Findings
Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths.
Interpretation
Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population
Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial
Background
Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain.
Methods
RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and
ClinicalTrials.gov
,
NCT00541047
.
Findings
Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths.
Interpretation
Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy.
Funding
Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society