298 research outputs found
BERT with History Answer Embedding for Conversational Question Answering
Conversational search is an emerging topic in the information retrieval
community. One of the major challenges to multi-turn conversational search is
to model the conversation history to answer the current question. Existing
methods either prepend history turns to the current question or use complicated
attention mechanisms to model the history. We propose a conceptually simple yet
highly effective approach referred to as history answer embedding. It enables
seamless integration of conversation history into a conversational question
answering (ConvQA) model built on BERT (Bidirectional Encoder Representations
from Transformers). We first explain our view that ConvQA is a simplified but
concrete setting of conversational search, and then we provide a general
framework to solve ConvQA. We further demonstrate the effectiveness of our
approach under this framework. Finally, we analyze the impact of different
numbers of history turns under different settings to provide new insights into
conversation history modeling in ConvQA.Comment: Accepted to SIGIR 2019 as a short pape
Quantum correlations and synchronization measures
The phenomenon of spontaneous synchronization is universal and only recently
advances have been made in the quantum domain. Being synchronization a kind of
temporal correlation among systems, it is interesting to understand its
connection with other measures of quantum correlations. We review here what is
known in the field, putting emphasis on measures and indicators of
synchronization which have been proposed in the literature, and comparing their
validity for different dynamical systems, highlighting when they give similar
insights and when they seem to fail.Comment: book chapter, 18 pages, 7 figures, Fanchini F., Soares Pinto D.,
Adesso G. (eds) Lectures on General Quantum Correlations and their
Applications. Quantum Science and Technology. Springer (2017
Model Dispersive Media in Finite-Difference Time-Domain Method With Complex-Conjugate Pole-Residue Pairs
Abstract-In this letter, we show that both Debye poles and Lorentz pole pairs are special cases of complex-conjugate poleresidue pairs, and the general form of such pairs is in fact far more efficient than the commonly used Debye poles and Lorentz pole pairs for modeling real dispersive media with the finite-difference time-domain method. We first derive an alternative formulation of the auxiliary differential equation method for arbitrary dispersive media based on general complex-conjugate pole-residue pairs. We then numerically demonstrate the efficiency of using these pairs in modeling dispersive media. Index Terms-Auxiliary differential equation method, dispersive medium, finite-difference time-domain (FDTD)
Lensless Fourier-Transform Ghost Imaging with Classical Incoherent Light
The Fourier-Transform ghost imaging of both amplitude-only and pure-phase
objects was experimentally observed with classical incoherent light at Fresnel
distance by a new lensless scheme. The experimental results are in good
agreement with the standard Fourier-transform of the corresponding objects.
This scheme provides a new route towards aberration-free diffraction-limited 3D
images with classically incoherent thermal light, which have no resolution and
depth-of-field limitations of lens-based tomographic systems.Comment: 14 pages, 4 figures, comments are welcom
Transition Between Ground State and Metastable States in Classical 2D Atoms
Structural and static properties of a classical two-dimensional (2D) system
consisting of a finite number of charged particles which are laterally confined
by a parabolic potential are investigated by Monte Carlo (MC) simulations and
the Newton optimization technique. This system is the classical analog of the
well-known quantum dot problem. The energies and configurations of the ground
and all metastable states are obtained. In order to investigate the barriers
and the transitions between the ground and all metastable states we first
locate the saddle points between them, then by walking downhill from the saddle
point to the different minima, we find the path in configurational space from
the ground state to the metastable states, from which the geometric properties
of the energy landscape are obtained. The sensitivity of the ground-state
configuration on the functional form of the inter-particle interaction and on
the confinement potential is also investigated
Intracellular β\u3csub\u3e1\u3c/sub\u3e-Adrenergic Receptors and Organic Cation Transporter 3 Mediate Phospholamban Phosphorylation to Enhance Cardiac Contractility
Rationale:
β1ARs (β1-adrenoceptors) exist at intracellular membranes and OCT3 (organic cation transporter 3) mediates norepinephrine entry into cardiomyocytes. However, the functional role of intracellular β1AR in cardiac contractility remains to be elucidated. Objective:
Test localization and function of intracellular β1AR on cardiac contractility. Methods and Results:
Membrane fractionation, super-resolution imaging, proximity ligation, coimmunoprecipitation, and single-molecule pull-down demonstrated a pool of β1ARs in mouse hearts that were associated with sarco/endoplasmic reticulum Ca2+-ATPase at the sarcoplasmic reticulum (SR). Local PKA (protein kinase A) activation was measured using a PKA biosensor targeted at either the plasma membrane (PM) or SR. Compared with wild-type, myocytes lacking OCT3 (OCT3-KO [OCT3 knockout]) responded identically to the membrane-permeant βAR agonist isoproterenol in PKA activation at both PM and SR. The same was true at the PM for membrane-impermeant norepinephrine, but the SR response to norepinephrine was suppressed in OCT3-KO myocytes. This differential effect was recapitulated in phosphorylation of the SR-pump regulator phospholamban. Similarly, OCT3-KO selectively suppressed calcium transients and contraction responses to norepinephrine but not isoproterenol. Furthermore, sotalol, a membrane-impermeant βAR-blocker, suppressed isoproterenol-induced PKA activation at the PM but permitted PKA activation at the SR, phospholamban phosphorylation, and contractility. Moreover, pretreatment with sotalol in OCT3-KO myocytes prevented norepinephrine-induced PKA activation at both PM and the SR and contractility. Conclusions:
Functional β1ARs exists at the SR and is critical for PKA-mediated phosphorylation of phospholamban and cardiac contractility upon catecholamine stimulation. Activation of these intracellular β1ARs requires catecholamine transport via OCT3
Direct-acting antiviral agents for liver transplant recipients with recurrent genotype 1 hepatitis C virus infection: Systematic review and meta-analysis
Background: Comprehensive evaluation of safety and efficacy of different combinaâ
tions of directâacting antivirals (DAAs) in liver transplant recipients with genotype 1
(GT1) hepatitis C virus (HCV) recurrence remains limited. Therefore, we performed
this systematic review and metaâanalysis in order to evaluate the clinical outcome of
DAA treatment in liver transplant patients with HCV GT1 recurrence.
Methods: Studies were included if they contained information of 12 weeks sustained
virologic response (SVR12) after DAA treatment completion as well as treatment reâ
lated complications for liver transplant recipients with GT1 HCV recurrence.
Results: We identified 16 studies comprising 885 patients. The overall pooled estiâ
mate proportion of SVR12 was 93% (95% confidence interval (CI): 0.89, 0.96), with
moderate heterogeneity observed (Ď
2 = 0.01, P < 0.01, I
2
=75%). High tolerability was
observed in liver transplant recipients reflected by serious adverse events (sAEs) with
pooled estimate proportion of 4% (95% CI: 0.01, 0.07; Ď2 = 0.02, P < 0.01, I
2 = 81%).
For subgroup analysis, a total of five different DAA regimens were applied for treating
these patients. Sofosbuvir/Ledipasvir (SOF/LDV) led the highest pooled estimate
SVR12 proportion, followed by Paritaprevir/Ritonavir/Ombitasivir/Dasabuvir (PrOD),
Daclatasvir (DCV)/Simeprevir (SMV) Âą Ribavirin (RBV), and SOF/SMV Âą RBV,
Asunaprevir (ASV)/DCV. There was a tendency for favoring a higher pooled SVR12
proportion in patients with METAVIR Stage F0âF2 of 97% (95% CI: 0.93, 0.99) comâ
pared to 85% (95% CI: 0.79, 0.90) for stage F3âF4 (P < 0.01). There was no significant
difference between LT recipients treated with or without RBV (P = 0.23).
Conclusions: Directâacting antiviral treatment is highly effective and wellâtolerated
in liver transplant recipients with recurrent GT1 HCV infection
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