185,888 research outputs found

    Association between one-hour post-load plasma glucose levels and vascular stiffness in essential hypertension

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    Objectives: Pulse wave velocity (PWV) is a surrogate end-point for cardiovascular morbidity and mortality. A plasma glucose value 155mg/dlforthe1hourpostloadplasmaglucoseduringanoralglucosetolerancetest(OGTT)isabletoidentifysubjectswithnormalglucosetolerance(NGT)athighriskfortype2diabetes(T2D)andforsubclinicalorgandamage.Thus,weaddressedthequestionif1hourpostloadplasmaglucoselevels,affectsPWVanditscentralhemodynamiccorrelates,asaugmentationpressure(AP)andaugmentationindex(AI).Methods:Weenrolled584newlydiagnosedhypertensives.AllpatientsunderwentOGTTandmeasurementsofPWV,APandAI.InsulinsensitivitywasassessedbyMatsudaindex.Results:Amongparticipants,424wereNGTand160hadimpairedglucosetolerance(IGT).Of424NGT,278had1hpostloadplasmaglucose,155mg/dl(NGT,155)and146had1hpostloadplasmaglucose155 mg/dl for the 1-hour post-load plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high-risk for type-2 diabetes (T2D) and for subclinical organ damage. Thus, we addressed the question if 1-hour post-load plasma glucose levels, affects PWV and its central hemodynamic correlates, as augmentation pressure (AP) and augmentation index (AI). Methods: We enrolled 584 newly diagnosed hypertensives. All patients underwent OGTT and measurements of PWV, AP and AI. Insulin sensitivity was assessed by Matsuda-index. Results: Among participants, 424 were NGT and 160 had impaired glucose tolerance (IGT). Of 424 NGT, 278 had 1-h postload plasma glucose ,155 mg/dl (NGT,155) and 146 had 1-h post-load plasma glucose 155 mg/dl (NGT155).NGT155). NGT155 had a worse insulin sensitivity and higher hs-CRP than NGT,155, similar to IGT subjects. In addition, NGT 155incomparisonwithNGT,155hadhighercentralsystolicbloodpressure(134612vs131610mmHg),aswellasPWV(8.463.7vs6.761.7m/s),AP(12.567.1vs9.865.7mmHg)andAI(29.4611.9vs25.1612.4regressionanalysis,1hpostloadplasmaglucoseresultedthemajordeterminantofallindicesofvascularstiffness.Conclusion:HypertensiveNGT155 in comparison with NGT,155 had higher central systolic blood pressure (134612 vs 131610 mmHg), as well as PWV (8.463.7 vs 6.761.7 m/s), AP (12.567.1 vs 9.865.7 mmHg) and AI (29.4611.9 vs 25.1612.4%), and similar to IGT. At multiple regression analysis, 1-h post-load plasma glucose resulted the major determinant of all indices of vascular stiffness. Conclusion: Hypertensive NGT155 subjects, compared with NGT,155, have higher PWV and its hemodynamic correlates that increase their cardiovascular risk profile

    The effect of age on the relationship between cardiac and vascular function

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    Age-related changes in cardiac and vascular function are associated with increased risk of cardiovascular mortality and morbidity. The aim of the present study was to define the effect of age on the relationship between cardiac and vascular function. Haemodynamic and gas exchange measurements were performed at rest and peak exercise in healthy individuals. Augmentation index was measured at rest. Cardiac power output, a measure of overall cardiac function, was calculated as the product of cardiac output and mean arterial blood pressure. Augmentation index was significantly higher in older than younger participants (27.7 ± 10.1 vs. 2.5 ± 10.1%, P < 0.01). Older people demonstrated significantly higher stroke volume and mean arterial blood pressure (P < 0.05), but lower heart rate (145 ± 13 vs. 172 ± 10 beats/min, P < 0.01) and peak oxygen consumption (22.5 ± 5.2 vs. 41.2 ± 8.4 ml/kg/min, P < 0.01). There was a significant negative relationship between augmentation index and peak exercise cardiac power output (r = −0.73, P = 0.02) and cardiac output (r = −0.69, P = 0.03) in older participants. Older people maintain maximal cardiac function due to increased stroke volume. Vascular function is a strong predictor of overall cardiac function in older but in not younger people

    ACGAN-based Data Augmentation Integrated with Long-term Scalogram for Acoustic Scene Classification

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    In acoustic scene classification (ASC), acoustic features play a crucial role in the extraction of scene information, which can be stored over different time scales. Moreover, the limited size of the dataset may lead to a biased model with a poor performance for records from unseen cities and confusing scene classes. In order to overcome this, we propose a long-term wavelet feature that requires a lower storage capacity and can be classified faster and more accurately compared with classic Mel filter bank coefficients (FBank). This feature can be extracted with predefined wavelet scales similar to the FBank. Furthermore, a novel data augmentation scheme based on generative adversarial neural networks with auxiliary classifiers (ACGANs) is adopted to improve the generalization of the ASC systems. The scheme, which contains ACGANs and a sample filter, extends the database iteratively by splitting the dataset, training the ACGANs and subsequently filtering samples. Experiments were conducted on datasets from the Detection and Classification of Acoustic Scenes and Events (DCASE) challenges. The results on the DCASE19 dataset demonstrate the improved performance of the proposed techniques compared with the classic FBank classifier. Moreover, the proposed fusion system achieved first place in the DCASE19 competition and surpassed the top accuracies on the DCASE17 dataset

    Non-Uniform Robust Network Design in Planar Graphs

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    Robust optimization is concerned with constructing solutions that remain feasible also when a limited number of resources is removed from the solution. Most studies of robust combinatorial optimization to date made the assumption that every resource is equally vulnerable, and that the set of scenarios is implicitly given by a single budget constraint. This paper studies a robustness model of a different kind. We focus on \textbf{bulk-robustness}, a model recently introduced~\cite{bulk} for addressing the need to model non-uniform failure patterns in systems. We significantly extend the techniques used in~\cite{bulk} to design approximation algorithm for bulk-robust network design problems in planar graphs. Our techniques use an augmentation framework, combined with linear programming (LP) rounding that depends on a planar embedding of the input graph. A connection to cut covering problems and the dominating set problem in circle graphs is established. Our methods use few of the specifics of bulk-robust optimization, hence it is conceivable that they can be adapted to solve other robust network design problems.Comment: 17 pages, 2 figure

    Contact homology and one parameter families of Legendrian knots

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    We consider S^1-families of Legendrian knots in the standard contact R^3. We define the monodromy of such a loop, which is an automorphism of the Chekanov-Eliashberg contact homology of the starting (and ending) point. We prove this monodromy is a homotopy invariant of the loop. We also establish techniques to address the issue of Reidemeister moves of Lagrangian projections of Legendrian links. As an application, we exhibit a loop of right-handed Legendrian torus knots which is non-contractible in the space Leg(S^1,R^3) of Legendrian knots, although it is contractible in the space Emb(S^1,R^3) of smooth knots. For this result, we also compute the contact homology of what we call the Legendrian closure of a positive braid and construct an augmentation for each such link diagram.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol9/paper46.abs.htm

    A scattering of orders

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    A linear ordering is scattered if it does not contain a copy of the rationals. Hausdorff characterised the class of scattered linear orderings as the least family of linear orderings that includes the class B \mathcal B of well-orderings and reversed well-orderings, and is closed under lexicographic sums with index set in B \mathcal B. More generally, we say that a partial ordering is κ \kappa -scattered if it does not contain a copy of any κ \kappa -dense linear ordering. We prove analogues of Hausdorff's result for κ \kappa -scattered linear orderings, and for κ \kappa -scattered partial orderings satisfying the finite antichain condition. We also study the Qκ \mathbb{Q}_\kappa -scattered partial orderings, where Qκ \mathbb{Q}_\kappa is the saturated linear ordering of cardinality κ \kappa , and a partial ordering is Qκ \mathbb{Q}_\kappa -scattered when it embeds no copy of Qκ \mathbb{Q}_\kappa . We classify the Qκ \mathbb{Q}_\kappa -scattered partial orderings with the finite antichain condition relative to the Qκ \mathbb{Q}_\kappa -scattered linear orderings. We show that in general the property of being a Qκ \mathbb{Q}_\kappa -scattered linear ordering is not absolute, and argue that this makes a classification theorem for such orderings hard to achieve without extra set-theoretic assumptions
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