670 research outputs found

    Phase transition in a class of non-linear random networks

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    We discuss the complex dynamics of a non-linear random networks model, as a function of the connectivity k between the elements of the network. We show that this class of networks exhibit an order-chaos phase transition for a critical connectivity k = 2. Also, we show that both, pairwise correlation and complexity measures are maximized in dynamically critical networks. These results are in good agreement with the previously reported studies on random Boolean networks and random threshold networks, and show once again that critical networks provide an optimal coordination of diverse behavior.Comment: 9 pages, 3 figures, revised versio

    Estimation of Flame Temperature and Alkali Emission During the Combustion of Sugarcane Bagasse in Laboratory in Combustion Chamber Type Grate Using Spectroscopy Method

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     Knowing the temperature of the combustion of solid biomass residues and how alkaline gases must be supplied during combustion is an area currently under study in the international community. The correlation between temperature and concentration of alkaline gases in the combustion phases is an open research for some types of biomass, among which sugarcane bagasse. This information optimizes the operation of thermoelectric boilers that use solid biomass waste as fuel, improving its efficiency and maintenance costs. The aim of the study was to estimate the temperature of the flame during the combustion of sugarcane bagasse in a pilot chamber that simulates burning in a grid, as well as an estimate of the potassium concentration in the flue gases. Temperature estimates were made using the two-color spectrometry technique in the visible light range. The potassium concentrations in the flue gases were estimated through analysis of the emission lines present in the electromagnetic spectra collected by a spectrometer for different combustion temperatures. In the experiments, the biomass flame was of the diffusion flame type. Considered the combustion phases - devolatilization, char combustion and ash formation - temperature were varying in the range of 1000 K to 1700 K. The average emission of potassium in the flue gases was evaluated in the range of 0.126 ppm to 0.631 ppm, considering the combustion phases. For the combustion conditions, no alkaline sodium gases were detected

    Myalgic encephalomyelitis/chronic fatigue syndrome: A comprehensive review

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    Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown aetiology that is recognized by the World Health Organization (WHO) and the United States Center for Disease Control and Prevention (US CDC) as a disorder of the brain. The disease predominantly affects adults, with a peak age of onset of between 20 and 45 years with a female to male ratio of 3:1. Although the clinical features of the disease have been well established within diagnostic criteria, the diagnosis of ME/CFS is still of exclusion, meaning that other medical conditions must be ruled out. The pathophysiological mechanisms are unclear but the neuro-immuno-endocrinological pattern of CFS patients gleaned from various studies indicates that these three pillars may be the key point to understand the complexity of the disease. At the moment, there are no specific pharmacological therapies to treat the disease, but several studies’ aims and therapeutic approaches have been described in order to benefit patients’ prognosis, symptomatology relief, and the recovery of pre-existing function. This review presents a pathophysiological approach to understanding the essential concepts of ME/CFS, with an emphasis on the population, clinical, and genetic concepts associated with ME/CFS. © 2019 by the authors

    Asymptotics of relative heat traces and determinants on open surfaces of finite area

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    The goal of this paper is to prove that on surfaces with asymptotically cusp ends the relative determinant of pairs of Laplace operators is well defined. We consider a surface with cusps (M,g) and a metric h on the surface that is a conformal transformation of the initial metric g. We prove the existence of the relative determinant of the pair (Δh,Δg)(\Delta_{h},\Delta_{g}) under suitable conditions on the conformal factor. The core of the paper is the proof of the existence of an asymptotic expansion of the relative heat trace for small times. We find the decay of the conformal factor at infinity for which this asymptotic expansion exists and the relative determinant is defined. Following the paper by B. Osgood, R. Phillips and P. Sarnak about extremal of determinants on compact surfaces, we prove Polyakov's formula for the relative determinant and discuss the extremal problem inside a conformal class. We discuss necessary conditions for the existence of a maximizer.Comment: This is the final version of the article before it gets published. 51 page

    Consensus-based care recommendations for congenital and childhood-onset myotonic dystrophy type 1.

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    Purpose of review: Myotonic dystrophy type 1 is a multisystemic disorder caused by a noncoding triplet repeat. The age of onset is variable across the lifespan, but in its most severe form, the symptoms appear at birth (congenital myotonic dystrophy) or in the pediatric age range (childhood-onset myotonic dystrophy). These children have a range of disabilities that reduce the lifespan and cause significant morbidity. Currently, there are no agreed upon recommendations for caring for these children. Recent findings: The Myotonic Dystrophy Foundation recruited 11 international clinicians who are experienced with congenital and childhood-onset myotonic dystrophy to create consensus-based care recommendations. The experts used a 2-step methodology using elements of the single text procedure and nominal group technique. Completion of this process has led to the development of clinical care recommendations for this population. Summary: Children with myotonic dystrophy often require monitoring and interventions to improve the lifespan and quality of life. The resulting recommendations are intended to standardize and improve the care of children with myotonic dystrophy
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