3,878 research outputs found

    Embedding of global attractors and their dynamics

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    Using shape theory and the concept of cellularity, we show that if AA is the global attractor associated with a dissipative partial differential equation in a real Hilbert space HH and the set A−AA-A has finite Assouad dimension dd, then there is an ordinary differential equation in Rm+1{\mathbb R}^{m+1}, with m>dm >d, that has unique solutions and reproduces the dynamics on AA. Moreover, the dynamical system generated by this new ordinary differential equation has a global attractor XX arbitrarily close to LALA, where LL is a homeomorphism from AA into Rm+1{\mathbb R}^{m+1}

    The independent association of overweight and obesity with breathlessness in adults: a cross-sectional, population-based study

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    Obesity is an independent risk factor for chronic breathlessness and should be assessed in people with this symptom

    Listening to the sound of dark sector interactions with gravitational wave standard sirens

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    We consider two stable Interacting Dark Matter -- Dark Energy models and confront them against current Cosmic Microwave Background data from the \textit{Planck} satellite. We then generate luminosity distance measurements from O(103){\cal O}(10^3) mock Gravitational Wave events matching the expected sensitivity of the proposed Einstein Telescope. We use these to forecast how the addition of Gravitational Wave standard sirens data can improve current limits on the Dark Matter -- Dark Energy coupling strength (ξ\xi). We find that the addition of Gravitational Waves data can reduce the current uncertainty by a factor of 55. Moreover, if the underlying cosmological model truly features Dark Matter -- Dark Energy interactions with a value of ξ\xi within the currently allowed 1σ1\sigma upper limit, the addition of Gravitational Wave data would help disentangle such an interaction from the standard case of no interaction at a significance of more than 3σ3\sigma.Comment: 16 pages, 3 tables, 4 figures; version published in JCA

    Experimental test of the no signaling theorem

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    In 1981 N. Herbert proposed a gedanken experiment in order to achieve by the ''First Laser Amplified Superluminal Hookup'' (FLASH) a faster than light communication (FTL) by quantum nonlocality. The present work reports the first experimental realization of that proposal by the optical parametric amplification of a single photon belonging to an entangled EPR pair into an output field involving 5 x 10^3 photons. A thorough theoretical and experimental analysis explains in general and conclusive terms the precise reasons for the failure of the FLASH program as well as of any similar FTL proposals.Comment: 4 pages, 4 figure

    Circulating SIRT1 inversely correlates with epicardial fat thickness in patients with obesity

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    Background and aim: Obesity is increasing worldwide and is related to undesirable cardiovascular outcomes. Epicardial fat (EF), the heart visceral fat depot, increases with obesity and correlates with cardiovascular risk. SIRT1, an enzyme regulating metabolic circuits linked with obesity, has a cardioprotective effect and is a predictor of cardiovascular events. We aimed to assess the relationship of EF thickness (EFT) with circulating SIRT1 in patients with obesity. Methods and results: Sixty-two patients affected by obesity and 23 lean controls were studied. Plasma SIRT1 concentration was determined by enzyme-linked immunosorbent assay (ELISA). EFT was measured by echocardiography. Body mass index (BMI), waist circumference, heart rate (HR), blood pressure, and laboratory findings (fasting glucose, insulin, HbA1c, cholesterol, and triglycerides) were assessed. SIRT1 was significantly lower (P = 0.002) and EFT was higher (P < 0.0001) in patients with obesity compared with lean controls. SIRT1 showed a negative correlation with EFT and HR in the obesity group (rho = -0.350, P = 0.005; rho = -0.303, P = 0.008, respectively). After adjustment for obesity-correlated variables, multiple linear regression analysis showed that EFT remained the best correlate of SIRT1 (beta = -0.352, P = 0.016). Conclusions: Circulating SIRT1 correlates with the visceral fat content of the heart. Serum SIRT1 levels might provide additional information for risk assessment of coronary artery disease in patients with obesity. (C) 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved
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