686 research outputs found
Strong Gravitational Lensing Parameter Estimation with Vision Transformer
Quantifying the parameters and corresponding uncertainties of hundreds of
strongly lensed quasar systems holds the key to resolving one of the most
important scientific questions: the Hubble constant () tension. The
commonly used Markov chain Monte Carlo (MCMC) method has been too
time-consuming to achieve this goal, yet recent work has shown that convolution
neural networks (CNNs) can be an alternative with seven orders of magnitude
improvement in speed. With 31,200 simulated strongly lensed quasar images, we
explore the usage of Vision Transformer (ViT) for simulated strong
gravitational lensing for the first time. We show that ViT could reach
competitive results compared with CNNs, and is specifically good at some
lensing parameters, including the most important mass-related parameters such
as the center of lens and , the ellipticities
and , and the radial power-law slope . With this promising
preliminary result, we believe the ViT (or attention-based) network
architecture can be an important tool for strong lensing science for the next
generation of surveys. The open source of our code and data is in
\url{https://github.com/kuanweih/strong_lensing_vit_resnet}.Comment: Accepted by ECCV 2022 AI for Space Worksho
Prevalence of latent tuberculosis infection in persons with and without human immunodeficiency virus infection using two interferon-gamma release assays and tuberculin skin test in a low human immunodeficiency virus prevalence, intermediate tuberculosis-burden country
BackgroundThe risk of tuberculosis (TB) is higher in human immunodeficiency virus (HIV)-infected patients and intravenous drug users (IDUs). We determined the prevalence and risk factors of latent TB infection (LTBI) in individuals with or without HIV infection, including IDUs, in a country with a low HIV prevalence, an intermediate TB burden, and a high Bacillus Calmette-Guérin (BCG) vaccine coverage using two interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST).MethodsFor this prospective, cross-sectional study, HIV-infected and -uninfected patients from a regional hospital and medical center in Taiwan were enrolled. Results of the two IGRAs [QuantiFERON-TB Gold (QFT-G) and QuantiFERON-TB Gold In-Tube (QFT-GIT)] and the TST were compared. Risk factors for positivity were analyzed.ResultsWe recruited 233 patients [198 (85%) men; mean age, 39.4 years]. Most patients (74%) were BCG vaccinated. The prevalence of LTBI was estimated to be 22.8% by TST, 15.9% by QFT-G, and 20.6% by QFT-GIT. HIV-infected individuals had fewer positive QFT-GIT [7.0% vs. 28.6%, p < 0.001, adjusted odds ratio (aOR) = 0.28, p = 0.05] and TST results, and more indeterminate QFT-G responses (9.3% vs. 0.7%, p = 0.002). Concordance between IGRAs and TST was very poor in HIV-infected patients (κ < 0.05). Independent risk factors for IGRA positivity were increasing age (QFT-G: aOR = 1.98, p = 0.03; QFT-GIT: aOR = 2.00, p = 0.01) and IDUs (aOR = 4.33, p = 0.05 by QFT-G).ConclusionHIV-infected persons had a significantly lower response to both IGRAs and TST. High discordance was found between the two generations of IGRAs and between IGRAs and TST. Increasing age, a known risk factor for LTBI, was significantly associated with IGRAs, but not with TST
Vision meets mmWave Radar: 3D Object Perception Benchmark for Autonomous Driving
Sensor fusion is crucial for an accurate and robust perception system on
autonomous vehicles. Most existing datasets and perception solutions focus on
fusing cameras and LiDAR. However, the collaboration between camera and radar
is significantly under-exploited. The incorporation of rich semantic
information from the camera, and reliable 3D information from the radar can
potentially achieve an efficient, cheap, and portable solution for 3D object
perception tasks. It can also be robust to different lighting or all-weather
driving scenarios due to the capability of mmWave radars. In this paper, we
introduce the CRUW3D dataset, including 66K synchronized and well-calibrated
camera, radar, and LiDAR frames in various driving scenarios. Unlike other
large-scale autonomous driving datasets, our radar data is in the format of
radio frequency (RF) tensors that contain not only 3D location information but
also spatio-temporal semantic information. This kind of radar format can enable
machine learning models to generate more reliable object perception results
after interacting and fusing the information or features between the camera and
radar
Surgical Outcomes and Predictive Factors in Patients With Detrusor Underactivity Undergoing Bladder Outlet Obstruction Surgery
Purpose This study was conducted to evaluate the efficacy of bladder outlet surgery in patients with detrusor underactivity (DU) and to identify factors associated with successful outcomes. Methods We conducted a retrospective review of men diagnosed with DU in urodynamic studies who underwent bladder outlet surgery for lower urinary tract symptoms between May 2018 and April 2023. The International Prostate Symptom Score (IPSS) questionnaire, uroflowmetry (UFM), and multichannel urodynamic studies were administered. Successful treatment outcomes were defined as either an IPSS improvement of at least 50% or the regaining of spontaneous voiding in patients urethral catheterization prior to surgery. Results The study included 93 male patients. Men diagnosed with significant or equivocal bladder outlet obstruction (BOO) experienced significant postoperative improvements in IPSS (from 20.6 to 6.0 and from 17.4 to 6.5, respectively), maximum urine flow rate (from 5.0 mL/sec to 14.4 mL/sec and from 8.8 mL/sec to 12.2 mL/sec, respectively) and voiding efficiency (from 48.8% to 86.0% and from 61.2% to 85.1%, respectively). However, in the group without obstruction, the improvements in IPSS and UFM results were not significant. The presence of detrusor overactivity (odds ratio [OR], 3.152; P=0.025) and preoperative urinary catheterization (OR, 2.756; P=0.040) were associated with favorable treatment outcomes. Conversely, an unobstructed bladder outlet was identified as a negative prognostic factor. Conclusions In men with DU accompanied by equivocal or significant BOO, surgical intervention to alleviate the obstruction may enhance the IPSS, quality of life, and UFM results. However, those with DU and an unobstructed bladder outlet face a comparatively high risk of treatment failure. Preoperative detrusor overactivity and urinary catheterization are associated with more favorable surgical outcomes. Consequently, active deobstructive surgery should be considered for patients with DU who are experiencing urinary retention
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