Rate Control Approaches Research Articles

RNxQuest: An Extension to the xQuest Pipeline Enabling Analysis of Protein-RNA Cross-Linking/Mass Spectrometry Data.

Cross-linking and mass spectrometry (XL-MS) workflows are increasingly popular techniques for generating low-resolution structural information about interacting biomolecules. xQuest is an established software package for analysis of protein-protein XL-MS data, supporting stable isotope-labeled cross-linking reagents. Resultant paired peaks in mass spectra aid sensitivity and specificity of data analysis. The recently developed cross-linking of isotope-labeled RNA and mass spectrometry (CLIR-MS) approach extends the XL-MS concept to protein-RNA interactions, also employing isotope-labeled cross-link (XL) species to facilitate data analysis. Data from CLIR-MS experiments are broadly compatible with core xQuest functionality, but the required analysis approach for this novel data type presents several technical challenges not optimally served by the original xQuest package. Here we introduce RNxQuest, a Python package extension for xQuest, which automates the analysis approach required for CLIR-MS data, providing bespoke, state-of-the-art processing and visualization functionality for this novel data type. Using functions included with RNxQuest, we evaluate three false discovery rate control approaches for CLIR-MS data. We demonstrate the versatility of the RNxQuest-enabled data analysis pipeline by also reanalyzing published protein-RNA XL-MS data sets that lack isotope-labeled RNA. This study demonstrates that RNxQuest provides a sensitive and specific data analysis pipeline for detection of isotope-labeled XLs in protein-RNA XL-MS experiments.

Atrial flutter and fibrillation in patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension in the ASPIRE registry: Comparison of rate versus rhythm control approaches

BackgroundThe development of atrial flutter and fibrillation (AFL/AF) in patients with pre-capillary pulmonary hypertension has been associated with an increased risk of morbidity and mortality. Rate and rhythm control strategies have not been directly compared. MethodsEighty-four patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) with new-onset AFL/AF were identified in the ASPIRE registry. First, baseline characteristics and rates of sinus rhythm (SR) restoration of 3 arrhythmia management strategies (rate control, medical rhythm control and DC cardioversion, DCCV) in an early (2009–13) and later (2014–19) cohort were compared. Longer-term outcomes in patients who achieved SR versus those who did not were then explored. ResultsSixty (71%) patients had AFL and 24 (29%) AF. Eighteen (22%) patients underwent rate control, 22 (26%) medical rhythm control and 44 (52%) DCCV. SR was restored in 33% treated by rate control, 59% medical rhythm control and 95% DCCV (p < 0.001). Restoration of SR was associated with greater improvement in functional class (FC) and Incremental Shuttle Walk Distance (p both <0.05). It also independently predicted superior survival (3-year survival 62% vs 23% in those remaining in AFL/AF, p < 0.0001). In addition, FC III/IV independently predicted higher mortality (HR 2.86, p = 0.007). Right atrial area independently predicted AFL/AF recurrence (OR 1.08, p = 0.01). DCCV was generally well tolerated with no immediate major complications. ConclusionsRestoration of SR is associated with superior functional improvement and survival in PAH/CTEPH compared with rate control. DCCV is generally safe and is more effective than medical therapy at achieving SR.

Modelling of photovoltaic-thermal collectors for the provision of electricity and low temperature heat—Comparison of different flow rate control approaches to optimize the electrical yield

• Locally adapted flow rate control approaches can increase the electrical yield of PVT collectors by up to 2.80%. • Compared to a reference case, an increase in additional electrical yield of up to 27% is possible. • Constant flow rate control approaches provide a flat distribution of temperature increase. • Variable flow rate control approaches provide a distribution peak of temperature increase. Photovoltaic-thermal (PVT) collectors can provide heat and electricity. A quasi-stationary model of a PVT collector is presented and validated based on measured data. Subsequently, the electrical and thermal performance of such a collector is simulated for different locations. These simulations focus on different flow rate control approaches with the aim of maximizing the electrical yield. The simulation results show that the two control approaches presented in this paper have the potential to increase the electrical output for all locations. The increase in additional electrical output at locations with higher solar radiation is significantly higher than the increase in solar radiation between the locations investigated. Additionally, the cooling fluids’ temperature differences for such PVT collectors vary between the investigated control approaches, where variable flow rates lead to a steadier increase in cooling fluids’ temperature. In conclusion, the flow rate needs to be adopted to the pre-defined main goal of the respective PVT collector. The use of variable flow rates by providing low-temperature heat at a more constant temperature level appears to be advantageous in this context.

Atrial Fibrillation and Dementia.

Atrial fibrillation is associated with multiple adverse comorbidities, including the development of dementia in patients with and without a history of stroke. Mechanistic models have been proposed to explain the association of AF and dementia. Alterations of brain perfusion from embolic events, bleeding, and rhythm-related hypoperfusion underlie many of these models. Multiple mediators such as oxidative injury, inflammatory and autoimmune mechanisms, and genetic predisposition also interplay in the disease association. There are potential therapeutic opportunities to reduce dementia risk, including early and effective use of anticoagulation and strategies to improve brain perfusion through rhythm and rate control approaches. Prospective trials are needed to evaluate these therapeutic opportunities that carefully measure cognitive function and dementia incidence.

A Novel Rate-Control for Predictive Image Coding With Constant Quality

Predictive image coding systems yield a high-compression performance at low computational complexity, and are therefore popular in standards and prominent coding techniques for both lossless and near-lossless compression. However, few prediction-based coding techniques include rate-control approaches because of the difficulty in properly combining the prediction feedback loop and the quantization. None of the rate-control approaches for predictive image coding are focused on delivering homogeneous quality along the whole image. The main objective of this paper is to define a novel rate-control approach based on prediction that homogenises the quality over the entire image. The extensive experimental results, on medical, remote sensing, and natural images, suggest that our proposal attains more regular image quality and lower peak absolute error than the state-of-the-art approaches based on prediction and also transform-based techniques such as JPEG2000 and CCSDS-122.

Pharmacological Therapy for Rate and Rhythm Control for Atrial Fibrillation in 2017

In spite of the emergence of non-pharmacological approaches, medical therapy remains the primary modality of treatment for most patients with atrial fibrillation (AF). This review will look at evidence for rate and rhythm control approaches, and at factors that would help in choosing the appropriate treatment strategy for individual patients.

A New Rate Control Scheme For Video Coding Based On Region Of Interest

The quality fluctuation of video is significant in human visual system, and thus, many rate control schemes are widely developed in the area of video communication. In recent years, researchers show more interests in region of interest (ROI)-based encoding, and it is widely applied in the latest video codecs, such as HEVC and VP9. This paper presents a new rate control scheme for ROI mode coding based on discrete fourier transform coefficient model and radial basis function neuron network. A new R-D model is proposed by classifying blocks into different depth, ROI groups, and so on. Then, rate and distortion are described based on the Laplacian distribution model using mathematical ways. A machine learning approach is induced to enhance the accuracy of the distortion estimation. By utilizing the new R-D model, a new rate control scheme is designed for ROI mode coding from the group of picture layer to coding unit layer. By comparisons with other rate control approaches, the proposed one has a better result in terms of visual quality, R-D performance, bitrate accuracy, and so on. Hence, it outperforms the conventional schemes especially for sequences with obvious ROI details.

PT194 Post Ablation Monitoring of Patients With Wolff-Parkinson-White Syndrome Associated With Spontaneous or Induced Atrial Fibrillation

Atrial fibrillation (AF) is a common arrhythmia and a risk factor for stroke and other, adverse events. Internationally there have been recent advancements in the therapies available for, stroke prevention in AF. Nurses will care for individuals with AF across a variety of primary and acute, care settings and should be familiar with evidence based therapies.This paper provides a review of the epidemiology of AF and stroke, stroke and bleeding risk, assessment tools and evidence based treatments for the prevention of stroke in AF including the use of, novel anti-thrombin agents.A review of key databases was conducted from 2002 to 2012 using the key search terms ‘atrial, fibrillation’ ‘anticoagulation’ ‘risk assessment’ and ‘clinical management’. The following electronic, databases were searched: CINAHL, Medline, Scopus, the Cochrane Library and Google Scholar., Reference lists were manually hand searched. Key clinical guidelines from National Institute for, Clinical Excellence (NICE, UK), American Heart Association (AHA, USA), American College of Cardiology, (ACC, USA) and the European Society of Cardiology (ESC) and key government policy documents were, also included. Articles were included in the review if they addressed nursing management with a focus, on Australia.Many treatment options exist for AF. Best practice guidelines make a variety of, recommendations which include cardioversion, ablation, pulmonary vein isolation, pharmacological, agents for rate or rhythm control approaches, and antithrombotic therapy (including anticoagulation, and antiplatelet therapy). Treatment should be patient centred and individualised based upon, persistency of the rhythm, causal nature, risk and co-morbid conditions.AF is a common and burdensome condition where treatment is complex and not without, risk. Nurses will encounter individuals with AF across a variety of primary and acute care areas, understanding the risk of AF and appropriate therapies is important across all care settings. Treatment, must be individually tailored to the needs of the patient and balanced with the best available evidence.

'Real-world' atrial fibrillation management in Europe: observations from the 2-year follow-up of the EURObservational Research Programme-Atrial Fibrillation General Registry Pilot Phase.

Atrial fibrillation (AF) is commonly associated with a high risk of stroke, thromboembolism, and mortality. The 1-year follow-up of the EURObservational Research Programme-Atrial Fibrillation (EORP-AF) Pilot Registry demonstrated a high mortality but good outcomes with European Society of Cardiology guideline-adherent therapy. Whether these 'real-world' observations on patients managed by European cardiologists extend to 2 years remains uncertain. In this report from the EORP-AF General Registry Pilot Phase, we provide data on the 2-year follow-up outcomes. Consistent with the 1-year follow-up report, only a small proportion of patients were symptomatic (24.9%), with minor differences between the different AF subtypes. Persistence of oral anticoagulant (OAC) therapy remains high at 2-years, with ∼80% of patients treated with OAC. The prescribing rates of non-vitamin K antagonist oral anticoagulants are progressively increasing (13.7% at 2 years). Rate and rhythm control approaches remained consistent across the entire follow-up observation. Overall mortality rates remained high, with 5.0% of patients dead during the 2-year follow-up, mostly due to cardiovascular causes (61.8%). Atrial fibrillation readmissions were frequent, particularly related to arrhythmias and heart failure. On multivariate analyses, any cardiovascular reason for admission rather than AF was significantly associated with increased mortality during the 2-year follow-up. In this 2-year follow-up report from EORP-AF, mortality rates with AF remain high from cardiovascular causes, despite the high prevalent use of OAC. Improved management strategies to reduce major adverse outcomes in AF patients are needed.

Low-Delay Rate Control for Consistent Quality Using Distortion-Based Lagrange Multiplier.

Video quality fluctuation plays a significant role in human visual perception, and hence, many rate control approaches have been widely developed to maintain consistent quality for video communication. This paper presents a novel rate control framework based on the Lagrange multiplier in high-efficiency video coding. With the assumption of constant quality control, a new relationship between the distortion and the Lagrange multiplier is established. Based on the proposed distortion model and buffer status, we obtain a computationally feasible solution to the problem of minimizing the distortion variation across video frames at the coding tree unit level. Extensive simulation results show that our method outperforms the rate control used in HEVC Test Model (HM) by providing a more accurate rate regulation, lower video quality fluctuation, and stabler buffer fullness. The average peak signal-to-noise ratio (PSNR) and PSNR deviation improvements are about 0.37 dB and 57.14% in the low-delay (P and B) video communication, where the complexity overhead is ∼4.44% .

Designing an Energy-Efficient Cloud Messaging Service for Smartphones

This article compares two rate-control approaches that a cloud messaging service can use to deliver notifications for a variety of applications. The author reviews the pros and cons of the two approaches in terms of metrics such as latency, fairness, and overhead related to carrier network signaling and battery life of the user device.

Atrial fibrillation: Stroke prevention in focus

IntroductionAtrial fibrillation (AF) is a common arrhythmia and a risk factor for stroke and other, adverse events. Internationally there have been recent advancements in the therapies available for, stroke prevention in AF. Nurses will care for individuals with AF across a variety of primary and acute, care settings and should be familiar with evidence based therapies. AimThis paper provides a review of the epidemiology of AF and stroke, stroke and bleeding risk, assessment tools and evidence based treatments for the prevention of stroke in AF including the use of, novel anti-thrombin agents. MethodA review of key databases was conducted from 2002 to 2012 using the key search terms ‘atrial, fibrillation’ ‘anticoagulation’ ‘risk assessment’ and ‘clinical management’. The following electronic, databases were searched: CINAHL, Medline, Scopus, the Cochrane Library and Google Scholar., Reference lists were manually hand searched. Key clinical guidelines from National Institute for, Clinical Excellence (NICE, UK), American Heart Association (AHA, USA), American College of Cardiology, (ACC, USA) and the European Society of Cardiology (ESC) and key government policy documents were, also included. Articles were included in the review if they addressed nursing management with a focus, on Australia. ResultsMany treatment options exist for AF. Best practice guidelines make a variety of, recommendations which include cardioversion, ablation, pulmonary vein isolation, pharmacological, agents for rate or rhythm control approaches, and antithrombotic therapy (including anticoagulation, and antiplatelet therapy). Treatment should be patient centred and individualised based upon, persistency of the rhythm, causal nature, risk and co-morbid conditions. ConclusionAF is a common and burdensome condition where treatment is complex and not without, risk. Nurses will encounter individuals with AF across a variety of primary and acute care areas, understanding the risk of AF and appropriate therapies is important across all care settings. Treatment, must be individually tailored to the needs of the patient and balanced with the best available evidence.

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Region-Based Rate Control for H.264/AVC for Low Bit-Rate Applications

Rate-control plays an important role in video coding. However, in the conventional rate-control algorithms, the number and position of Macroblocks (MBs) inside one basic unit for rate-control is inflexible and predetermined. The different characteristics of the MBs are not fully considered. Also, there is no overall optimization of the coding of basic units. This paper proposes a new region-based rate-control scheme for H.264/AVC to improve the coding efficiency. The inter-frame information is explored to objectively divide one frame into multiple regions based on their rate-distortion behaviors. The MBs with the similar characteristics are classified into the same region, and the entire region instead of a single MB or a group of contiguous MBs is treated as a basic unit for rate-control. A linear rate-quantization stepsize model and a linear distortion-quantization stepsize model are proposed to accurately describe the rate-distortion characteristics for the region-based basic units. Moreover, based on the above linear models, an overall optimization model is proposed to obtain suitable Quantization Parameters (QPs) for the region-based basic units. Experimental results demonstrate that the proposed region-based rate-control approach can achieve both better subjective and objective quality by performing the rate-control adaptively with the content, compared to the conventional rate-control approaches.

Efficient rate control approach for JPEG2000 image coding

Abstract. JPEG2000, the new image coding standard, is more effi-cient when compared with the old JPEG standard. However, most ofthe computationsand memory usagein post-compressionrate distor-tion(PCRD)optimizationschemeinJPEG2000isredundant.Wepro-pose an efficient rate control approach for the JPEG2000 encoder. Inthis approach, optimal rate distortion (RD) slope threshold is selectedusing the minimum RD slope of lower level horizontally and verticallylow pass (LL 0 ) subband of the wavelet decomposed image. Also, thepasses of the code blocks of other subbands, whose RD slopes areless than the optimal RD slope, are skipped. The proposed approachreduces memory requirements and encoding time when comparedwith the existing rate control approaches for JPEG2000 standard,and also provides the same image quality as that of the PCRDapproach used in the JPEG2000 standard. © 2012 SPIE andIS&T. [DOI: 10.1117/1.JEI.21.3.033004] 1 IntroductionJPEG2000 is the new state-of-art image and video codingstandard. It has excellent coding performance and novel fea-tures such as superior low-bit rate compression performance,lossless and lossy compression, progressive transmission,region of interest coding, error resilience and randomcode stream access, and so on.

Rate control algorithm based on intra-picture complexity for H.264/AVC

An efficient rate control algorithm based on the content-adaptive initial quantisation parameter (QP) setting scheme and the peak signal-to-noise ratio (PSNR) variation-limited bit-allocation strategy for low-complexity mobile applications is presented. This algorithm can efficiently measure the residual complexity of intra-pictures without performing the computation-intensive intra-prediction and mode decision in H.264/AVC, based on the structural and statistical features of local textures. This can adaptively set proper initial QP values for versatile video contents. In addition, this bit-allocation strategy can effectively distribute bit-rate budgets based on the monotonic property to enhance overall coding efficiency while maintaining the consistency of visual quality by limiting the variation of quantisation distortion. The experimental results reveal that the proposed algorithm surpasses the conventional rate control approaches in terms of the average PSNR from 0.34 to 0.95 dB. Moreover, this algorithm provides more impressive visual quality and more robust buffer controllability when compared with other algorithms.

Examination of the concept of degree of rate control by first-principles kinetic Monte Carlo simulations

The conceptual idea of degree of rate control (DRC) approaches is to identify the “rate limiting step” in a complex reaction network by evaluating how the overall rate of product formation changes when a small change is made in one of the kinetic parameters. We examine two definitions of this concept by applying it to first-principles kinetic Monte Carlo simulations of the CO oxidation at RuO 2(1 1 0). Instead of studying experimental data we examine simulations, because in them we know the surface structure, reaction mechanism, the rate constants, the coverage of the surface and the turn-over frequency at steady-state. We can test whether the insights provided by the DRC are in agreement with the results of the simulations thus avoiding the uncertainties inherent in a comparison with experiment. We find that the information provided by using the DRC is non-trivial: It could not have been obtained from the knowledge of the reaction mechanism and of the magnitude of the rate constants alone. For the simulations the DRC provides furthermore guidance as to which aspects of the reaction mechanism should be treated accurately and which can be studied by less accurate and more efficient methods. We therefore conclude that a sensitivity analysis based on the DRC is a useful tool for understanding the propagation of errors from the electronic structure calculations to the statistical simulations in first-principles kinetic Monte Carlo simulations.

Rate versus rhythm control in the management of patients with atrial fibrillation

The management of patients with atrial fibrillation involves three main areas: anticoagulation, rate control and rhythm control. Importantly, these are not mutually exclusive of each other. Anticoagulation is necessary for patients who are at a high risk of stroke; for example, those who are older than 75 years, or those who have hypertension, severe left ventricular dysfunction, previous cerebrovascular events, or diabetes. It is now clear that patients who are at a high risk of stroke require long-term anticoagulation with warfarin regardless of whether a rate-control or rhythm-control strategy is chosen. One possible exception might be patients who are apparently cured with catheter ablation. Several published trials comparing rate-control and rhythm-control strategies for the treatment of patients with atrial fibrillation have shown no difference in mortality between these approaches. The patients enrolled in these studies were typically over 65 years of age. Data comparing rate and rhythm strategies in patients who are younger than 60 years of age are limited. For more elderly patients, it seems reasonable to consider rate control as a primary treatment option and to reserve rhythm control for those who do not respond to rate control. For younger patients, we prefer to start with a rhythm-control approach and to reserve rate-control approaches for patients in whom antiarrhythmic drugs, ablation, or both, do not ameliorate the symptoms.