47 research outputs found
A sharpened estimate on the pseudo-Gamma function
The pseudo-Gamma function is a key tool introduced recently by Cheng and
Albeverio in the proof of \break the density hypothesis. This function is
doubly symmetric, which means that it is reflectively symmetric about the real
axis by the Schwarz principle, whereas it is also reflectively symmmetric about
the half line where the real part of the variable is equal to .
In this article, we sharpen the estimate given in the proof of the density
hypothesis for this doubly symmetric pseudo-Gamma function on the real axis
near the symmetry center by taking a different approach from the way used in
the density hypothesis proof directly from the definition, reducing the error
caused by the fact that the difference of two pivotal parameters in the
definition of the pseudo-Gamma function is much larger than the difference of
the variables in this particular case.Comment: 8 pages, submitted to Journal of combinatorics and number theory,
June 11, 201
Interactive Data Analysis with Next-step Natural Language Query Recommendation
Natural language interfaces (NLIs) provide users with a convenient way to
interactively analyze data through natural language queries. Nevertheless,
interactive data analysis is a demanding process, especially for novice data
analysts. When exploring large and complex SQL databases from different
domains, data analysts do not necessarily have sufficient knowledge about
different data tables and application domains. It makes them unable to
systematically elicit a series of topically-related and meaningful queries for
insight discovery in target domains. We develop a NLI with a step-wise query
recommendation module to assist users in choosing appropriate next-step
exploration actions. The system adopts a data-driven approach to suggest
semantically relevant and context-aware queries for application domains of
users' interest based on their query logs. Also, the system helps users
organize query histories and results into a dashboard to communicate the
discovered data insights. With a comparative user study, we show that our
system can facilitate a more effective and systematic data analysis process
than a baseline without the recommendation module.Comment: 14 pages, 6 figure
Leveraging Historical Medical Records as a Proxy via Multimodal Modeling and Visualization to Enrich Medical Diagnostic Learning
Simulation-based Medical Education (SBME) has been developed as a
cost-effective means of enhancing the diagnostic skills of novice physicians
and interns, thereby mitigating the need for resource-intensive
mentor-apprentice training. However, feedback provided in most SBME is often
directed towards improving the operational proficiency of learners, rather than
providing summative medical diagnoses that result from experience and time.
Additionally, the multimodal nature of medical data during diagnosis poses
significant challenges for interns and novice physicians, including the
tendency to overlook or over-rely on data from certain modalities, and
difficulties in comprehending potential associations between modalities. To
address these challenges, we present DiagnosisAssistant, a visual analytics
system that leverages historical medical records as a proxy for multimodal
modeling and visualization to enhance the learning experience of interns and
novice physicians. The system employs elaborately designed visualizations to
explore different modality data, offer diagnostic interpretive hints based on
the constructed model, and enable comparative analyses of specific patients.
Our approach is validated through two case studies and expert interviews,
demonstrating its effectiveness in enhancing medical training.Comment: Accepted by IEEE VIS 202
THE PROTON SPIN PUZZLE AND DEPOLARIZATION IN
We point out that the measurement of target spin depolarization in
the reaction may test dynamical mechanisms
invoked to explain the proton spin puzzle revealed by polarized deep--inelastic
scattering experiments. In particular, models with {\it negatively} polarized
pairs in the proton wave function predict , whereas models
with {\it positively} polarized gluons would predict .Comment: LaTeX file, 4 figures appended as uuencoded, compressed PostScript
fil
Gauge bosons at zero and finite temperature
Gauge theories of the Yang-Mills type are the single most important building
block of the standard model and beyond. Since Yang-Mills theories are gauge
theories their elementary particles, the gauge bosons, cannot be described
without fixing a gauge. Beyond perturbation theory, gauge-fixing in non-Abelian
gauge theories is obstructed by the Gribov-Singer ambiguity. The construction
and implementation of a method-independent gauge-fixing prescription to resolve
this ambiguity is the most important step to describe gauge bosons beyond
perturbation theory. Proposals for such a procedure, generalizing the
perturbative Landau gauge, are described here. Their implementation are
discussed for two example methods, lattice gauge theory and the quantum
equations of motion. The most direct access to the properties of the gauge
bosons is provided by their correlation functions. The corresponding two- and
three-point correlation functions are presented at all energy scales. These
give access to the properties of the gauge bosons, like their absence from the
asymptotic physical state space, the absence of an on-shell mass pole,
particle-like properties at high energies, and their running couplings.
Furthermore, auxiliary degrees of freedom are introduced during gauge-fixing,
and their properties are discussed as well. These results are presented for
two, three, and four dimensions, and for various gauge algebras. Finally, the
modifications of the properties of gauge bosons at finite temperature are
presented. Evidence is provided that these reflect the phase structure of
Yang-Mills theory. However, it is found that the phase transition is not
deconfining the gauge bosons, although the bulk thermodynamical behavior is of
a Stefan-Boltzmann type. The resolution of this apparent contradiction is also
presented. This resolution also provides an explicit and constructive solution
to the Linde problem.Comment: v2: 153 pages, 45 figures, revised, updated, and extended version
submitted on invitation to Physics Reports; v3: Intermediate update, 152
pages, 45 figures, minor errors corrected, reference list extended; v3 minor
typographical changes and corrections, added references, version to appear in
Physics Report
Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data
Background: Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers. Methods: We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0–1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0–2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4–6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903. Findings: Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10–2·03]; p=0·011), with low heterogeneity across studies (I2=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05–1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06–2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4–6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52–1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03–4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22–25·50]; p=0·024). Interpretation: In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death. Funding: None