175 research outputs found
Reliability-Latency-Rate Tradeoff in Low-Latency Communications with Finite-Blocklength Coding
Low-latency communication plays an increasingly important role in
delay-sensitive applications by ensuring the real-time exchange of information.
However, due to the constraints on the maximum instantaneous power, bounded
latency is hard to be guaranteed. In this paper, we investigate the
reliability-latency-rate tradeoff in low-latency communications with
finite-blocklength coding (FBC). More specifically, we are interested in the
fundamental tradeoff between error probability, delay-violation probability
(DVP), and service rate. Based on the effective capacity (EC) and normal
approximation, we present several gain-conservation inequalities to bound the
reliability-latency-rate tradeoffs. In particular, we investigate the
low-latency transmissions over an additive white Gaussian noise (AWGN) channel,
over a Rayleigh fading channel, with frequency or spatial diversity, and over a
Nakagami- fading channel. To analytically evaluate the
quality-of-service-constrained low-latency communications with FBC, an
EC-approximation method is further conceived to derive the closed-form
expression of quality-of-service-constrained throughput. For delay-sensitive
transmissions in which the latency threshold is greater than the channel
coherence time, we find an asymptotic form of the tradeoff between the error
probability and DVP over the AWGN and Rayleigh fading channels. Our results may
provide some insights into the efficient scheduling of low-latency wireless
communications in which statistical latency and reliability metrics are
adopted.Comment: Submitted to IEEE Trans. Inf. Theor
Active cancellation of servo-induced noise on stabilized lasers via feedforward
Many precision laser applications require active frequency stabilization.
However, such stabilization loops operate by pushing noise to frequencies
outside their bandwidth, leading to large "servo bumps" that can have
deleterious effects for certain applications. The prevailing approach to
filtering this noise is to pass the laser through a high finesse optical
cavity, which places constraints on the system design. Here, we propose and
demonstrate a different approach where a frequency error signal is derived from
a beat note between the laser and the light that passes through the reference
cavity. The phase noise derived from this beat note is fed forward to an
electro-optic modulator after the laser, carefully accounting for relative
delay, for real-time frequency correction. With a Hz-linewidth laser, we show
dB noise suppression at the peak of the servo bump (
kHz), and a noise suppression bandwidth of MHz -- well beyond the
servo bump. By simulating the Rabi dynamics of a two-level atom with our
measured data, we demonstrate substantial improvements to the pulse fidelity
over a wide range of Rabi frequencies. Our approach offers a simple and
versatile method for obtaining a clean spectrum of a narrow linewidth laser, as
required in many emerging applications of cold atoms, and is readily compatible
with commercial systems that may even include wavelength conversion
Meat consumption and all-cause mortality in 5763 patients with inflammatory bowel disease: A retrospective cohort study
Background: Whether meat consumption is related to risk of mortality in patients with inflammatory bowel disease (IBD) remains poorly understood. Methods: In the UK Biobank, 5763 patients with IBD were recruited from 2007 to 2010 and finished a brief food frequency questionnaire at baseline. We followed them until March 13, 2021 to document all-cause death events. Cox proportional hazard models were used to estimate hazard ratios (HRs) for all-cause mortality associated with consumptions of fish, unprocessed poultry, unprocessed red meat, and processed meat among the patients. Findings: During 67,095 person-years (mean follow-up 11·7 years, mean age 57·3, 52·5% female), we documented 590 death events. Higher consumption of processed meat was associated with an increased risk of all-cause mortality in patients with IBD (HR comparing >4·0 with 0-0·9 time/week=1·52, 95% confidence interval (CI) 1·05-2·19), but the P-trend for each 25 g increment was 0·075. This association remained significant in patients with Crohn's disease (HR 1·77, 95% CI 1·01-3·10) but not in patients with ulcerative colitis (HR 1·34, 95% CI 0·82-2·20). Consumptions of fish (HR 1·27, 95% CI 0·84-1·91), unprocessed poultry (HR 0·59, 95% CI 0·28-1·21), or unprocessed red meat (HR 0·87, 95% CI 0·60-1·26) were not significantly associated with the mortality of patients with IBD. Interpretation: More frequent consumption of processed meat was associated with an increased risk of mortality in patients with IBD, while no associations were observed for consumption of other types of meat. Our exploratory and speculative findings should be cautiously interpreted and need further replication in other cohorts. Funding: The National Natural Science Foundation of China (81,970,494); Key Project of Research and Development Plan of Hunan Province (2019SK2041)
6DOF Pose Estimation of a 3D Rigid Object based on Edge-enhanced Point Pair Features
The point pair feature (PPF) is widely used for 6D pose estimation. In this
paper, we propose an efficient 6D pose estimation method based on the PPF
framework. We introduce a well-targeted down-sampling strategy that focuses
more on edge area for efficient feature extraction of complex geometry. A pose
hypothesis validation approach is proposed to resolve the symmetric ambiguity
by calculating edge matching degree. We perform evaluations on two challenging
datasets and one real-world collected dataset, demonstrating the superiority of
our method on pose estimation of geometrically complex, occluded, symmetrical
objects. We further validate our method by applying it to simulated punctures.Comment: 16 pages,20 figure
Inhibition of epidermal growth factor receptor attenuates atherosclerosis via decreasing inflammation and oxidative stress
Atherosclerosis is a progressive disease leading to loss of vascular homeostasis and entails fibrosis, macrophage foam cell formation, and smooth muscle cell proliferation. Recent studies have reported that epidermal growth factor receptor (EGFR) is involved vascular pathophysiology and in the regulation of oxidative stress in macrophages. Although, oxidative stress and inflammation play a critical role in the development of atherosclerosis, the underlying mechanisms are complex and not completely understood. In the present study, we have elucidated the role of EGFR in high-fat diet-induced atherosclerosis in apolipoprotein E null mice. We show increased EGFR phosphorylation and activity in atherosclerotic lesion development. EGFR inhibition prevented oxidative stress, macrophage infiltration, induction of pro-inflammatory cytokines, and SMC proliferation within the lesions. We further show that EGFR is activated through toll-like receptor 4. Disruption of toll-like receptor 4 or the EGFR pathway led to reduced inflammatory activity and foam cell formation. These studies provide evidence that EGFR plays a key role on the pathogenesis of atherosclerosis, and suggests that EGFR may be a potential therapeutic target in the prevention of atherosclerosis development
A selective cascade reaction-based probe for colorimetric and ratiometric fluorescence detection of benzoyl peroxide in food and living cells
A novel colorimetric and ratiometric fluorescent probe (Cou-BPO) was readily prepared for specific
detection of harmful benzoyl peroxide (BPO). The probe Cou-BPO reacted with BPO via a selective
oxidation cleavage-induced cascade reaction of the pinacol phenylboronate group, which resulted in an
observable colorimetric and ratiometric fluorescence response towards BPO with a fast response time
(o15 min) and a low detection limit (56 nM). For practical application, facile, portable and sensitive test
paper of Cou-BPO has been prepared for visual detection of BPO. Furthermore, we employed Cou-BPO
as a probe to determine BPO in food samples and living cells.info:eu-repo/semantics/publishedVersio
Effectiveness of Educational Interventions for Health Workers on Antibiotic Prescribing in Outpatient Settings in China: A Systematic Review and Meta-Analysis
Educational interventions are considered an important component of antibiotic stewardship, but their effect has not been systematically evaluated in outpatient settings in China. This research aims to evaluate the effectiveness of educational interventions for health workers on antibiotic prescribing rates in Chinese outpatient settings. Eight databases were searched for relevant randomized clinical trials, non-randomized trials, controlled before-after studies and interrupted time-series studies from January 2001 to July 2021. A total of 16 studies were included in the systematic review and 12 in the meta-analysis. The results showed that educational interventions overall reduced the antibiotic prescription rate significantly (relative risk, RR 0.72, 95% confidence interval, CI 0.61 to 0.84). Subgroup analysis demonstrated that certain features of education interventions had a significant effect on antibiotic prescription rate reduction: (1) combined with compulsory administrative regulations (RR With: 0.65 vs. Without: 0.78); (2) combined with financial incentives (RR With: 0.51 vs. Without: 0.77). Educational interventions can also significantly reduce antibiotic injection rates (RR 0.83, 95% CI 0.74 to 0.94) and the inappropriate use of antibiotics (RR 0.61, 95% CI 0.51 to 0.73). The limited number of high-quality studies limits the validity and reliability of the results. More high-quality educational interventions targeting the reduction of antibiotic prescribing rates are needed
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