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Catheter ablation is a safe and effective therapy for the treatment of supraventricular tachycardia in children. Current improvements in technology have allowed progressive reduction in radiation exposure associated with the procedure. To assess the impact of three-dimensional mapping, we compared acute procedural results collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to published results from the Prospective Assessment after Pediatric Cardiac Ablation study.
Inclusion and exclusion criteria from the Prospective Assessment after Pediatric Cardiac Ablation study were used as guidelines to select patient data from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to compare acute procedural outcomes between cohorts. Outcomes assessed include procedural and fluoroscopy exposure times, success rates of procedure, and complications.
In 786 ablation procedures, targeting 498 accessory pathways and 288 atrioventricular nodal reentrant tachycardia substrates, average procedural time (156.5 versus 206.7 minutes, p < 0.01), and fluoroscopy time (1.2 versus 38.3 minutes, p < 0.01) were significantly shorter in the study group. Success rates for the various substrates were similar except for manifest accessory pathways which had a significantly higher success rate in the study group (96.4% versus 93.0%, p < 0.01). Major complication rates were significantly lower in the study group (0.3% versus 1.6%, p < 0.01).
In a large, multicentre study, three-dimensional systems show favourable improvements in clinical outcomes in children undergoing catheter ablation of supraventricular tachycardia compared to the traditional fluoroscopic approach. Further improvements are anticipated as technology advances.
In recent years, global navigation satellite system (GNSS) precise point positioning (PPP) has become a standard positioning technique for many applications with typically favourable open sky conditions, e.g. precision agriculture. Unfortunately, the long convergence (and reconvergence) time of PPP often significantly limits its use in difficult and restricted signal environments typically associated with urban areas. The modernisation of GNSS will positively affect and improve the convergence time of the PPP solutions, thanks to the higher number of satellites in view that broadcast multifrequency measurements. The number and geometry of the available satellites is a key factor that impacts on the convergence time in PPP, while triple-frequency observables have been shown to greatly benefit the fixing of the carrier phase integer ambiguities. On the other hand, many studies have shown that triple-frequency combinations do not usefully contribute to a reduction of the convergence time of float PPP solutions.
This paper proposes novel GPS and Galileo triple-carrier ionosphere-free combinations that aim to enhance the observability of the narrow-lane ambiguities. Tests based on simulated data have shown that these combinations can reduce the convergence time of the float PPP solution by a factor of up to 2·38 with respect to the two-frequency combinations. This approach becomes effective only after the extra wide-lane and wide-lane ambiguities have been fixed. For this reason, a new fixing method based on low-noise pseudo-range combinations corrected by the smoothed ionosphere correction is presented. By exploiting this algorithm, no more than a few minutes are required to fix the WL ambiguities for Galileo, even in cases of severe multipath environments.
The integration of first-, second-, and third-personal information within joint intentional collaboration provides the foundation for broad-based second-personal morality. We offer two additions to this framework: a description of the developmental process through which second-personal competence emerges from early triadic interactions, and empirical evidence that collaboration with a concrete goal may provide an essential focal point for this integrative process.
Evidence suggests that dietary intake of UK children is currently suboptimal. It is therefore imperative to identify effective and sustainable methods of improving dietary habits and knowledge in this population, whilst also promoting the value of healthiness of food products beyond price. Schools are ideally placed to influence children's knowledge and health, and Project Daire, in partnership with schools, food industry partners and stakeholders, aims to improve children's knowledge of, and interest in, food to improve health, wellbeing and educational attainment.
Daire is a randomised-controlled, factorial design trial evaluating two interventions. In total, n = 880 Key Stage (KS) 1 and 2 pupils have been recruited from 18 primary schools in the North West of Northern Ireland and will be randomised to one of four 6-month intervention arms: i) ‘Engage’, ii) ‘Nourish’, iii) ‘Engage’ and ‘Nourish’ and iv) Delayed. ‘Engage’ is an age-appropriate, cross-curricular educational intervention on food, agriculture, science and careers linked to the current curriculum. ‘Nourish’ is an intervention aiming to alter schools’ food environments and increase exposure to local foods. Study outcomes include food knowledge, attitudes, trust, diet, behaviour, health and wellbeing and will be collected at baseline and six months. Qualitative data on teacher/pupil opinions will also be collected. The intervention phase is currently ongoing. We present baseline results from our involvement and food attitudes measure from all participating schools. Results were compared by Key Stage and sex using Pearson Chi-Squared test.
Baseline results from our food involvement and attitudes measure are presented for n = 880 KS1 (n = 454) and KS2 (n = 426) pupils. KS1 pupils were more likely to always or sometimes help with food shopping (89.0%) whilst KS2 pupils were more likely to always or sometimes help with food preparation (69.0%). A higher proportion of KS1 pupils reported liking to try new foods (66.1%) and that it was important that food looked (64.5%), tasted (71.1%) and smelled good (60.6%) compared with KS2 children (P < 0.01). Girls were more likely to always or sometimes help with food shopping (96.2%) and preparation (73%) when compared with boys; whilst a higher proportion of girls reported they liked to try new foods (48.2%) and that it was important that food looked (68%) smelled (50.5%) and tasted (71.8%) good compared with boys (P < 0.01).
Results suggest that involvement in food preparation and shopping, willingness to try new foods and attitudes towards food presentation varied by KS and sex in this cohort.
With the evolving Global Navigation Satellite System (GNSS) landscape, the International GNSS Service (IGS) has started the Multi-GNSS Experiment (MGEX) to produce precise products for new generation systems. Various analysis centres are working on the estimation of precise orbits, clocks and bias for Galileo, Beidou and Quasi-Zenith Satellite System (QZSS) satellites. However, at the moment these products can only be used for post-processing applications. Indeed, the IGS Real-Time service only broadcasts Global Positioning System (GPS) and Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) corrections. In this research, a simulator of multi-GNSS observations and real-time precise products has been developed to analyse the performance of GPS-only, Galileo-only and GPS plus Galileo Precise Point Positioning (PPP). The error models in the simulated orbits and clocks were based on the difference between the GPS Real-Time and the Final products. Multiple scenarios were analysed, considering different signals combined in the Ionosphere Free linear combination. Results in a simulated open area environment show better performance of the Galileo-only case over the GPS-only case. Indeed, up 33% and 29% of improvement, respectively, in the accuracy level and convergence time can be observed when using the full Galileo constellation compared to GPS. The dual constellation case provides good improvements, in particular in the convergence time (47% faster than GPS). This paper will also consider the impact of different linear combinations of the Galileo signals, and the potential of the E5 Alternative Binary Offset Carrier (AltBOC) signal. Even though it is significantly more precise than E5a, the PPP performance obtained with the Galileo E1-E5a combination is either better or similar to the one with Galileo E1-E5. The reason for this inconsistency was found in the use of the ionosphere free combination with E1. Finally, alternative methods of ionosphere error mitigation are considered in order to ensure the best possible positioning performance from the Galileo E5 signal in multi-frequency PPP.
As multi-core computing is now standard, it seems irresponsible for constraints researchers to ignore the implications of it. Researchers need to address a number of issues to exploit parallelism, such as: investigating which constraint algorithms are amenable to parallelisation; whether to use shared memory or distributed computation; whether to use static or dynamic decomposition; and how to best exploit portfolios and cooperating search. We review the literature, and see that we can sometimes do quite well, some of the time, on some instances, but we are far from a general solution. Yet there seems to be little overall guidance that can be given on how best to exploit multi-core computers to speed up constraint solving. We hope at least that this survey will provide useful pointers to future researchers wishing to correct this situation.
The development of algorithms for agile science and autonomous exploration has been pursued in contexts ranging from spacecraft to planetary rovers to unmanned aerial vehicles to autonomous underwater vehicles. In situations where time, mission resources and communications are limited and the future state of the operating environment is unknown, the capability of a vehicle to dynamically respond to changing circumstances without human guidance can substantially improve science return. Such capabilities are difficult to achieve in practice, however, because they require intelligent reasoning to utilize limited resources in an inherently uncertain environment. Here we discuss the development, characterization and field performance of two algorithms for autonomously collecting water samples on VALKYRIE (Very deep Autonomous Laser-powered Kilowatt-class Yo-yoing Robotic Ice Explorer), a glacier-penetrating cryobot deployed to the Matanuska Glacier, Alaska (Mission Control location: 61°42′09.3″N 147°37′23.2″W). We show performance on par with human performance across a wide range of mission morphologies using simulated mission data, and demonstrate the effectiveness of the algorithms at autonomously collecting samples with high relative cell concentration during field operation. The development of such algorithms will help enable autonomous science operations in environments where constant real-time human supervision is impractical, such as penetration of ice sheets on Earth and high-priority planetary science targets like Europa.
Reducing the excess nutrient and sediment pollution that is damaging habitat and diminishing recreational experiences in coastal estuaries requires actions by people and communities that are within the boundaries of the watershed but may be far from the resource itself, thus complicating efforts to understand tradeoffs associated with pollution control measures. Such is the case with the Chesapeake Bay, one of the most iconic water resources in the United States. All seven states containing part of the Chesapeake Bay Watershed were required under the Clean Water Act to submit detailed plans to achieve nutrient and sediment pollution reductions. The implementation plans provide information on the location and type of management practices making it possible to project not only water quality improvements in the Chesapeake Bay but also improvements in freshwater lakes throughout the watershed, which provide important ancillary benefits to people bearing the cost of reducing pollution to the Bay but unlikely to benefit directly. This paper reports the results of a benefits study that links the forecasted water quality improvements to ecological endpoints and administers a stated preference survey to estimate use and nonuse value for aesthetic and ecological improvements in the Chesapeake Bay and watershed lakes. Our results show that ancillary benefits and nonuse values account for a substantial proportion of total willingness to pay and would have a significant impact on the net benefits of pollution reduction programs.
Place has always been central to studies of language, variation and change. Since the eighteenth century, dialectologists have been mapping language features according to boundaries - both physical and institutional. In the twentieth century, variationist sociolinguists developed techniques to correlate language use with speakers' orientations to place. More recently, perceptual dialectologists are examining the cognitive and ideological processes involved in language-place correlations and working on ways to understand how speakers mentally process space. Bringing together research from across the field of language variation, this volume explores the extent of twenty-first century approaches to place. It features work from both established and influential scholars, and up and coming researchers, and brings language variation research up to date. The volume focuses on four key areas of research: processes of language variation and change across time and space; methods and datasets for regional analysis; perceptions of the local in language research; and ideological representations of place.