168 research outputs found

    Velocity-Based Channel Charting with Spatial Distribution Map Matching

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    Fingerprint-based localization improves the positioning performance in challenging, non-line-of-sight (NLoS) dominated indoor environments. However, fingerprinting models require an expensive life-cycle management including recording and labeling of radio signals for the initial training and regularly at environmental changes. Alternatively, channel-charting avoids this labeling effort as it implicitly associates relative coordinates to the recorded radio signals. Then, with reference real-world coordinates (positions) we can use such charts for positioning tasks. However, current channel-charting approaches lag behind fingerprinting in their positioning accuracy and still require reference samples for localization, regular data recording and labeling to keep the models up to date. Hence, we propose a novel framework that does not require reference positions. We only require information from velocity information, e.g., from pedestrian dead reckoning or odometry to model the channel charts, and topological map information, e.g., a building floor plan, to transform the channel charts into real coordinates. We evaluate our approach on two different real-world datasets using 5G and distributed single-input/multiple-output system (SIMO) radio systems. Our experiments show that even with noisy velocity estimates and coarse map information, we achieve similar position accuraciesComment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

    How to project a bipartite network?

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    The one-mode projecting is extensively used to compress the bipartite networks. Since the one-mode projection is always less informative than the bipartite representation, a proper weighting method is required to better retain the original information. In this article, inspired by the network-based resource-allocation dynamics, we raise a weighting method, which can be directly applied in extracting the hidden information of networks, with remarkably better performance than the widely used global ranking method as well as collaborative filtering. This work not only provides a creditable method in compressing bipartite networks, but also highlights a possible way for the better solution of a long-standing challenge in modern information science: How to do personal recommendation?Comment: 7 pages, 4 figure

    The effect of completeness of revascularization during CABG with single versus multiple arterial grafts

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    IntroductionIncomplete coronary revascularization is associated with suboptimal outcomes. We investigated the longâ term effects of Incomplete, Complete, and Supraâ complete revascularization and whether these effects differed in the setting of singleâ arterial and multiâ arterial coronary artery bypass graft (CABG).MethodsWe analyzed 15â year mortality in 7157 CABG patients (64.1â ±â 10.5 years; 30% women). All patients received a left internal thoracic artery to left anterior descending coronary artery graft with additional venous grafts only (singleâ arterial) or with at least one additional arterial graft (multiâ arterial) and were grouped based on a completeness of revascularization index (CRIâ =â number of grafts minus the number of diseased principal coronary arteries): Incomplete (CRIâ â ¤â â 1 [Nâ =â 320;4.5%]); Complete (CRIâ =â 0 [Nâ =â 2882;40.3%]; reference group); and two Supraâ complete categories (CRIâ =â +1[Nâ =â 3050; 42.6%]; CRIâ â ¥â +â 2 [Nâ =â 905; 12.6%]). Riskâ adjusted mortality hazard ratios (AHR) were calculated using comprehensive propensity score adjustment by Cox regression.ResultsIncomplete revascularization was rare (4.5%) but associated with increased mortality in all patients (AHR [95% confidence interval]â =â 1.53 [1.29â 1.80]), those undergoing singleâ arterial CABG (AHRâ =â 1.27 [1.04â 1.54]) and multiâ arterial CABG (AHRâ =â 2.18 [1.60â 2.99]), as well as in patients with 3â Vessel (AHRâ =â 1.37 [1.16â 1.62]) and, to a lesser degree, with 2â Vessel (AHRâ =â 1.67 [0.53â 5.23]) coronary disease. Supraâ complete revascularization was generally associated with incrementally decreased mortality in all patients (AHR [CRIâ =â +1]â =â 0.94 [0.87â 1.03]); AHR [CRIâ â ¥â +2]â =â 0.74 [0.64â 0.85]), and was driven by a significantly decreased mortality risk in singleâ arterial CABG (AHR [CRIâ =â +1]â =â 0.90 [0.81â 0.99]; AHR [CRIâ â ¥â +2]â =â 0.64 [0.53â 0.78]); and 3â Vessel disease patients (AHR [CRIâ =â +1]â =â 0.94 [0.86â 1.04]; and AHR [CRIâ â ¥â +2]â =â 0.75 [0.63â 0.88]) with no impact in multiâ arterial CABG (AHR [CRIâ =â +1]â =â 1.07 [0.91â 1.26]; AHR [CRIâ â ¥â +2]â =â 0.93 [0.73â 1.17]).ConclusionsIncomplete revascularization is associated with decreased late survival, irrespective of grafting strategy. Alternatively, supraâ complete revascularization is associated with improved survival in patients with 3â Vessel CAD, and in singleâ arterial but not multiâ arterial CABG.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146364/1/jocs13810.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146364/2/jocs13810_am.pd

    Exenatide as an Adjunct to Nicotine Patch for Smoking Cessation and Prevention of Postcessation Weight Gain Among Treatment-Seeking Smokers With Pre-Diabetes and/or Overweight: Study Protocol for a Randomised, Placebo-Controlled Clinical Trial

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    INTRODUCTION: Obesity and smoking are the two leading causes of preventable death in the USA. Unfortunately, most smokers gain weight after quitting. Postcessation weight gain (PCWG) is frequently cited as one of the primary barriers to a quit attempt and a common cause of relapse. Further, excessive PCWG may contribute to the onset or progression of metabolic conditions, such as hyperglycaemia and obesity. The efficacy of the current treatments for smoking cessation is modest, and these treatments have no clinically meaningful impact on mitigating PCWG. Here, we outline a novel approach using glucagon-like peptide 1 receptor agonists (GLP-1RA), which have demonstrated efficacy in reducing both food and nicotine intake. This report describes the design of a double-blind, placebo-controlled, randomised clinical trial that evaluates the effects of the GLP-1RA exenatide as an adjunct to nicotine patches on smoking abstinence and PCWG. METHODS AND ANALYSIS: The study will be conducted at two university-affiliated research sites in Houston, Texas, the UTHealth Center for Neurobehavioral Research on Addiction and Baylor College of Medicine Michael E. DeBakey VA Medical Centre. The sample will consist of 216 treatment-seeking smokers with pre-diabetes (haemoglobin A1c of 5.7%-6.4%) and/or overweight (body mass index of 25 kg/m ETHICS AND DISSEMINATION: The study has been approved by the UTHealth Committee for the Protection of Human Subjects (HSC-MS-21-0639) and Baylor College of Medicine Institutional Review Board (H-50543). All participants will sign informed consent. The study results will be disseminated via peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT05610800

    Pollen exposure is associated with risk of respiratory symptoms during the first year of life.

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    BACKGROUND Pollen exposure is associated with respiratory symptoms in children and adults. However, the association of pollen exposure with respiratory symptoms during infancy, a particularly vulnerable period, remains unclear. We examined whether pollen exposure is associated with respiratory symptoms in infants and if maternal atopy, infant's sex or air pollution modify this association. METHODS We investigated 14,874 observations from 401 healthy infants of a prospective birth cohort. The association between pollen exposure and respiratory symptoms, assessed in weekly telephone interviews, was evaluated using generalized additive mixed models (GAMM). Effect modification by maternal atopy, infant's sex and air pollution (NO2 , PM2.5 ) was assessed with interaction terms. RESULTS Per infant 37±2 (mean±SD) respiratory symptom scores were assessed during the analysis period (January through September). Pollen exposure was associated with increased respiratory symptoms during the daytime (RR [95% CI] per 10% pollen/m3 : combined 1.006 [1.002, 1.009]; tree 1.005 [1.002, 1.008]; grass 1.009 [1.000, 1.23]) and nighttime (combined 1.003 [0.999, 1.007]; tree 1.003 [0.999, 1.007]; grass 1.014 [1.004, 1.024]). While there was no effect modification by maternal atopy and infant's sex, a complex crossover interaction between combined pollen and PM2.5 was found (p-Value 0.002). CONCLUSION Even as early as during the first year of life, pollen exposure was associated with an increased risk of respiratory symptoms, independent of maternal atopy and infant's sex. Because infancy is a particularly vulnerable period for lung development, the identified adverse effect of pollen exposure may be relevant for the evolvement of chronic childhood asthma

    Optimized algorithm for speed-of-sound-based infant sulfur hexafluoride multiple-breath washout measurements.

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    INTRODUCTION Major methodological issues with the existing algorithm (WBreath) used for the analysis of speed-of-sound-based infant sulfur hexafluoride (SF6) multiple-breath washout (MBW) measurements lead to implausible results and complicate the comparison between different age groups and centers. METHODS We developed OASIS-a novel algorithm to analyze speed-of-sound-based infant SF6 MBW measurements. This algorithm uses known context of the measurements to replace the dependence of WBreath on model input parameters. We validated the functional residual capacity (FRC) measurement accuracy of this new algorithm in vitro, and investigated its use in existing infant MBW data sets from different infant cohorts from Switzerland and South Africa. RESULTS In vitro, OASIS managed to outperform WBreath at FRC measurement accuracy, lowering mean (SD) absolute error from 5.1 (3.2) % to 2.1 (1.6) % across volumes relevant for the infant age range, in variable temperature, respiratory rate, tidal volume and ventilation inhomogeneity conditions. We showed that changes in the input parameters to WBreath had a major impact on MBW results, a methodological drawback which does not exist in the new algorithm. OASIS produced more plausible results than WBreath in longitudinal tracking of lung clearance index (LCI), provided improved measurement stability in LCI over time, and improved comparability between centers. DISCUSSION This new algorithm represents a meaningful advance in obtaining results from a legacy system of lung function measurement by allowing a single method to analyze measurements from different age groups and centers

    Associations between Fatty Acid Intakes and Plasma Phospholipid Fatty Acid Concentrations in the European Prospective Investigation into Cancer and Nutrition

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    Background: The aim of this study is to determine the correlations between dietary fatty acid (FA) intakes and plasma phospholipid (PL) FA levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Methods: The dietary intake of 60 individual FAs was estimated using centre-specific validated dietary questionnaires. Plasma PL FA concentrations of these FAs were measured in non-fasting venous plasma samples in nested case-control studies within the EPIC cohort (n = 4923, using only non-cases). Spearman rank correlations were calculated to determine associations between FA intakes and plasma PL FA levels. Results: Correlations between FA intakes and circulating levels were low to moderately high (-0.233 and 0.554). Moderate positive correlations were found for total long-chain n-3 poly-unsaturated FA (PUFA) (r = 0.354) with the highest (r = 0.406) for n-3 PUFA docosahexaenoic acid (DHA). Moderate positive correlations were also found for the non-endogenously synthesized trans-FA (r = 0.461 for total trans-FA C16-18; r = 0.479 for industrial trans-FA (elaidic acid)). Conclusions: Our findings indicate that dietary FA intakes might influence the plasma PL FA status to a certain extent for several specific FAs. The stronger positive correlations for health-enhancing long-chain PUFAs and the health-deteriorating trans-FA that are not endogenously produced are valuable for future cancer prevention public health interventions

    A Systematic Approach to Multiple Breath Nitrogen Washout Test Quality

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    Background: Accurate estimates of multiple breath washout (MBW) outcomes require correct operation of the device, appropriate distraction of the subject to ensure they breathe in a manner representative of their relaxed tidal breathing pattern, and appropriate interpretation of the acquired data. Based on available recommendations for an acceptable MBW test, we aimed to develop a protocol to systematically evaluate MBW measurements based on these criteria. Methods: 50MBWtest occasions were systematically reviewed for technical elements and whether the breathing pattern was representative of relaxed tidal breathing by an experienced MBW operator. The impact of qualitative and quantitative criteria on inter-observer agreement was assessed across eight MBW operators (n = 20 test occasions, compared using a Kappa statistic). Results: Using qualitative criteria, 46/168 trials were rejected: 16.6%were technically unacceptable and 10.7% were excluded due to inappropriate breathing pattern. Reviewer agreement was good using qualitative criteria and further improved with quantitative criteria from (κ = 0.53– 0.83%) to (κ 0.73–0.97%), but at the cost of exclusion of further test occasions in this retrospective data analysis. Conclusions: The application of the systematic review improved inter-observer agreement but did not affect reported MBW outcomes

    Supine posture changes lung volumes and increases ventilation heterogeneity in cystic fibrosis

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    INTRODUCTION: Lung Clearance Index (LCI) is recognised as an early marker of cystic fibrosis (CF) lung disease. The effect of posture on LCI however is important when considering longitudinal measurements from infancy and when comparing LCI to imaging studies. METHODS: 35 children with CF and 28 healthy controls (HC) were assessed. Multiple breath washout (MBW) was performed both sitting and supine in triplicate and analysed for LCI, Scond, Sacin, and lung volumes. These values were also corrected for the Fowler dead-space to create 'alveolar' indices. RESULTS: From sitting to supine there was a significant increase in LCI and a significant decrease in FRC for both CF and HC (p<0.01). LCI, when adjusted to estimate 'alveolar' LCI (LCIalv), increased the magnitude of change with posture for both LCIalv and FRCalv in both groups, with a greater effect of change in lung volume in HC compared with children with CF. The % change in LCIalv for all subjects correlated significantly with lung volume % changes, most notably tidal volume/functional residual capacity (Vtalv/FRCalv (r = 0.54,p<0.001)). CONCLUSION: There is a significant increase in LCI from sitting to supine, which we believe to be in part due to changes in lung volume and also increasing ventilation heterogeneity related to posture. This may have implications in longitudinal measurements from infancy to older childhood and for studies comparing supine imaging methods to LCI
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