345 research outputs found
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
Planejamento de redes de transmissão SDH dividido em camadas funcionais
Orientador: Raul Vinhas RibeiroTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoDoutorad
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
Manipulation of ovarian and uterine function to increase conception rates in cattle
In cattle, embryonic and fetal losses are the major causes of reproductive failure. Losses associated with failure in the process of maternal recognition of pregnancy can amount to as much as 30%. Successful estabblishment of pregnancy depends on a delicate balance between luteolytic mechanisms inherent to the endometrium at the end of diestrus and antiluteolytic mechanisms, orchestrated by the conceptus to change endometrial function and ultimately, block luteolysis. Antiluteolytic strategies are pharmacological, mechanical, nutritional and management manipulations of the process of maternal recognition of pregnancy that aim to increase the probability of succssful gestations. Objective of the present paper is to review the recent literature on antiluteolytic strategies in cattle. Specifically, we focused on strategies to simulate production of progesterone, strategies to reduce production of estradiol and other strategies. Future directions for research in this area are propose
The Homeless and Public Space: Urban Policy and Exclusion in Bologna
L’article porte sur le rapport des personnes sans domicile à l’espace urbain. Axée sur le contexte italien et notamment sur la ville de Bologna, l’analyse focalise l’attention sur les stratégies de politique urbaine visant à exclure ces sujets des espaces publics, ou à discipliner l’usage qu’ils font de ces mêmes espaces. Les réflexions des auteurs se développent sur trois axes: le premier concerne le rôle de l’espace public dans la vie quotidienne des sans domicile; le deuxième porte sur les changements des espaces publics provoqués par les processus de régénération urbaine; le dernier explore les mécanismes de contrôle de l’espace public qui, sous forme d’interventions urbanistiques ou d’arrêtés municipaux, produisent l’exclusion spatiale des sans domicile.This article addresses the relationship between homeless people and urban public space. The analysis, focusing on the Italian context and, in particular, on the city of Bologna, centres on urban policy strategies which tend to exclude the homeless from public spaces and to regulate their use of such spaces. Our considerations encompass three dimensions: the role of public space in the daily life of the homeless; the changes in public space following urban renewal processes; public space control mechanisms, in the form of urban design and local by-laws, which translate into a spatial exclusion of the homeless
Effect of an isotonic rehydration sports drink and exercise on urolithiasis in rats
The objective of the present study was to evaluate the role of physical exercise as well as the influence of hydration with an isotonic sports drink on renal function in male Wistar rats. Four groups were studied over a period of 42 days: 1) control (N = 9); 2) physical exercise (Exe, N = 7); 3) isotonic drink (Drink, N = 8); 4) physical exercise + isotonic drink (Exe + Drink, N = 8). Physical exercise consisted of running on a motor-driven treadmill for 1 h/day, at 20 m/min, 5 days a week. The isotonic sports drink was a commercial solution used by athletes for rehydration after physical activity, 2 ml administered by gavage twice a day. Urine cultures were performed in all animals. Twenty-four-hour urine samples were collected in metabolic cages at the beginning and at the end of the protocol period. Urinary and plasma parameters (sodium, potassium, urea, creatinine, calcium) did not differ among groups. However, an amorphous material was observed in the bladders of animals in the Exe + Drink and Drink groups. Characterization of the material by Western blot revealed the presence of Tamm-Horsfall protein and angiotensin converting enzyme. Physical exercise and the isotonic drink did not change the plasma or urinary parameters measured. However, the isotonic drink induced the formation of intravesical matrix, suggesting a potential lithogenic risk.Universidade Federal de São Paulo (UNIFESP) Departamento de Medicina Disciplina de NefrologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Farmacologia Disciplina de Fisiologia Cardiovascular e RespiratóriaUNIFESP, Depto. de Medicina Disciplina de NefrologiaUNIFESP, Depto. de Farmacologia Disciplina de Fisiologia Cardiovascular e RespiratóriaSciEL
Occupational Exposure to Metal-Based Nanomaterials: A Possible Relationship between Chemical Composition and Oxidative Stress Biomarkers
Efficacy of nilotinib therapy in patient with CML diagnosed in pre-TKI era and resistant to imatinib
Here we report a case of a 32-year-old man, who was diagnosed as having chronic myeloid leukaemia in 1998. After cytoreduction with hydroxyurea, the patient was submitted to high dose chemotherapy with haemopoietic stem cells rescue and reinfusion, and then he started therapy with IFNα without achievement of a cytogenetic response. On November 2000 he took imatinib 400 mg/day and he reached a complete cytogenetic response (CCyR) at 14 months, but not the major molecular response: therefore he was considered a sub-optimal responder according to European LeukemiaNet criteria of 2006. For this reason he increased imatinib dose to 800 mg/day, but after one year he lost CCyR. Considering the patient as a failure, at this time, he switched to second-generation tyrosine kinase inhibitor, nilotinib at the dose of 800 mg/day. After 3 months he reached complete CCyR and after 6 months the major molecular response, maintained until last molecular evaluation
Gli uccelli della provincia di Novara (Piemonte, Italia): distribuzione, abbondanza e stato di conservazione
In questo lavoro viene riportato un elenco commentato degli uccelli noti per la provincia di Novara (1.340 km2) aggiornato al 31/12/2016 e vengono forniti dati di sintesi relativi alle attività di monitoraggio condotte in anni recenti (2009-2016). I dati sono stati raccolti sia attraverso revisione bibliografica sia attraverso attività di ricerca diretta sul campo. L'avifauna della provincia di Novara annovera o ha annoverato (dal 1860 al 2016) 304 specie delle quali 135 nidificanti certe o probabili in tempi recenti (dopo il 2000), 85 di interesse comunitario (Allegato I della Direttiva "Uccelli"), 116 SPEC - Species of European Conservation Concern secondo BirdLife International e 53 inserite nella European Red List of Birds. L'area è di importanza europea e/o nazionale per la nidificazione di specie di interesse conservazionistico quali Egretta garzetta (650-1.100 nidi), Nycticorax nycticorax (200-300 nidi), Botaurus stellaris (5-7 maschi cantori), Ciconia nigra (1-2 coppie), Ciconia ciconia (4-6 coppie), Himantopus himantopus (300-500 coppie), Vanellus vanellus (500-600 coppie), Columba oenas (20-30 coppie), nonché per la migrazione di Philomachus pugnax (5.000-7.000 ind.) e Tringa glareola (500-1.500 ind.). Negli ultimi anni (2009-2016) si segnalano in particolare: la nidificazione accertata per la prima volta nel Novarese di Ardea alba, Galerida cristata e Lullula arborea; il ritorno di Burhinus oedicnemus e Chlidonias niger in periodo riproduttivo dopo decenni di assenza; la colonizzazione da parte di Dryocopus martius degli ambienti forestali di collina e di pianura.</p
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