Interpolating discrete advection-diffusion propagators at Leja sequences

We propose and analyze the ReLPM (Real Leja Points Method) for evaluating the propagator phi(DeltatB)nu via matrix interpolation polynomials at spectral Leja sequences. Here B is the large, sparse, nonsymmetric matrix arising from stable 2D or 3D finite-difference discretization of linear advection-diffusion equations, and phi(z) is the entire function phi(z) = (e(z) - 1)/z. The corresponding stiff differential system y(t) = By(t) + g,y(0) =y(0), is solved by the exact time marching scheme y(i+1) = y(i) + Deltat(i)phi(Deltat(i)B)(By(i) + g), i = 0, 1,..., where the time-step is controlled simply via the variation percentage of the solution, and can be large. Numerical tests show substantial speed-ups (up to one order of magnitude) with respect to a classical variable step-size Crank-Nicolson solve

A massively parallel exponential integrator for advection-diffusion models

This work considers the Real Leja Points Method (ReLPM) for the exponential integration of large-scale sparse systems of ODEs, generated by Finite Element or Finite Difference discretizations of 3-D advection-diffusion models. We present an efficient parallel implementation of ReLPM for polynomial interpolation of the matrix exponential propagators. A scalability analysis of the most important computational kernel inside the code, the parallel sparse matrix\u2013vector product, has been performed, as well as an experimental study of the communication overhead. As a result of this study an optimized parallel sparse matrix\u2013vector product routine has been implemented. The resulting code shows good scaling behavior even when using more than one thousand processors. The numerical results presented on a number of very large test cases gives experimental evidence that ReLPM is a reliable and efficient tool for the simulation of complex hydrodynamic processes on parallel architectures

TRENDS AND INNOVATIONS IN THE PET FOOD MARKET

Studies show that Brazil in the world ranking is the second country with the largest population of domestic animals, with the front only the US. These animals, which usually occupied a decorative space, were valued as a company and considered an integral part of the family.It is estimated that 59% of Brazilian households have some pets, spending an average of R $390,00 on products and services (pharmaceuticals, vaccines, beautification and accessories). In this survey we evaluate the current situation of the pet market, trends and innovations, especially on snacks/foods with high added value. In this research we have compiled national and international circulation periodicals for the last five years (2012-2017). It was found that the world market grew at an annual average of 17$ 1.5 billion since the year 95. The Brazilian market in 2014 reached R $ 16 billion, placing the country in the third position in the ranking world. The food segment is the main representative of the sector, with 67% of revenues. It is verified that the trend of the sector is directed towards health and animal welfare focused on health and practicality. It is generally seen that the market is susceptible to changing societal patterns and demands impose imposed by consumers, and to achieve competitive advantage must constantly be on the side of innovative technologie

Anisotropic osmosis filtering for shadow removal in images

We present an anisotropic extension of the isotropic osmosis model that has been introduced by Weickert et al.~(Weickert, 2013) for visual computing applications, and we adapt it specifically to shadow removal applications. We show that in the integrable setting, linear anisotropic osmosis minimises an energy that involves a suitable quadratic form which models local directional structures. In our shadow removal applications we estimate the local structure via a modified tensor voting approach (Moreno, 2012) and use this information within an anisotropic diffusion inpainting that resembles edge-enhancing anisotropic diffusion inpainting (Weickert, 2006, Gali\'c, 2008). Our numerical scheme combines the nonnegativity preserving stencil of Fehrenbach and Mirebeau (Fehrenbach, 2014) with an exact time stepping based on highly accurate polynomial approximations of the matrix exponential. The resulting anisotropic model is tested on several synthetic and natural images corrupted by constant shadows. We show that it outperforms isotropic osmosis, since it does not suffer from blurring artefacts at the shadow boundaries

PIRANESI PRIX DE ROME. PROGETTI PER LA GRANDE VILLA ADRIANA

In occasione del XIX centenario di Villa Adriana, datato 2018, l’Accademia Adrianea di Architettura e Archeologia, assieme all’Istituto di Villa Adriana e Villa d’Este, ha promosso una consultazione internazionale di progettazione all’interno della Buffer Zone UNESCO di Villa Adriana. L’obiettivo della Call è stato quello di misurare le possibilità e i limiti di gestione dei processi di sviluppo nel territorio caratterizzato dalla maggiore protezione offerta dalla perimetrazione della zona cuscinetto, relativa all’iscrizione di Villa Adriana nell’elenco dei siti patrimonio dell’umanità. Un sito che le stratificazioni di lunga durata e l’espansione incontrollata del tessuto edilizio abitativo e produttivo hanno reso oggi particolarmente problematico e fragil

Dissipation caused by a vorticity field and generation of singularities in Madelung fluid

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Melatonin reduces the severity of experimental amoebiasis

<p>Abstract</p> <p>Background</p> <p>Melatonin has immunomodulatory effects but very little is known about its influence in protozoan infections, such as <it>Entamoeba histolytica</it>, which causes amoebiasis, a disease with significant morbidity and mortality. In this study, we evaluated the effects of exogenous melatonin interference in experimental amoebiasis and on interactions between human blood cells and <it>E. histolytica </it>trophozoites.</p> <p>Methods</p> <p>The effect of melatonin was investigated in models of experimental amoebiasis in hamsters and rats by evaluating the area of necrosis induced by <it>E. histolytica</it>. The activity of melatonin on the interactions between leukocytes and amoebae was determined by examining leukophagocytosis. For <it>in vitro </it>tests, polymorphonuclear and mononuclear human blood leucocytes were incubated with <it>E. histolytica </it>trophozoites.</p> <p>Results</p> <p>The areas of amoebic necrosis were significantly reduced in animals treated with melatonin. Melatonin treatment increased leukophagocytosis but was associated with a greater number of dead amoebae.</p> <p>Conclusions</p> <p>These results suggest that melatonin may play a beneficial role in the control of amoebic lesions, raising the possibility that this drug may be used as an adjuvant in anti-amoebic therapy.</p