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Search Results: 1 - 10 of 72476 matches for " Maria Rosaria Russo "
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A GCV based Arnoldi-Tikhonov regularization method
Paolo Novati,Maria Rosaria Russo
Mathematics , 2013,
Abstract: For the solution of linear discrete ill-posed problems, in this paper we consider the Arnoldi-Tikhonov method coupled with the Generalized Cross Validation for the computation of the regularization parameter at each iteration. We study the convergence behavior of the Arnoldi method and its properties for the approximation of the (generalized) singular values, under the hypothesis that Picard condition is satisfied. Numerical experiments on classical test problems and on image restoration are presented.
Epiphytic Diatom Communities on Sub-Fossil Leaves of Posidonia oceanica Delile in the Graeco-Roman Harbor of Neapolis: A Tool to Explore the Past  [PDF]
Paola Cennamo, Paolo Caputo, Mario De Stefano, Elda Russo Ermolli, Maria Rosaria Barone Lumaga
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.55070

The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history of the marine biodiversity. In fact, the digs expose fossil leaf of Posidonia oceanica with epiphytic communities of microorganisms. Posidonia oceanica is a seagrass endemic to theMediterraneanthat forms large meadows whose remains can persist in the sediment for thousands of years. In this communication, we report results of analyses carried out using both molecular and morphological techniques on sub-fossil leaves of P. oceanica and their associated epiphytic communities.

Embedded techniques for choosing the parameter in Tikhonov regularization
Silvia Gazzola,Paolo Novati,Maria Rosaria Russo
Mathematics , 2013,
Abstract: This paper introduces a new strategy for setting the regularization parameter when solving large-scale discrete ill-posed linear problems by means of the Arnoldi-Tikhonov method. This new rule is essentially based on the discrepancy principle, although no initial knowledge of the norm of the error that affects the right-hand side is assumed; an increasingly more accurate approximation of this quantity is recovered during the Arnoldi algorithm. Some theoretical estimates are derived in order to motivate our approach. Many numerical experiments, performed on classical test problems as well as image deblurring are presented.
Generalizations of Sylvester's determinantal identity
Anna Karapiperi,Michela Redivo-Zaglia,Maria Rosaria Russo
Mathematics , 2015,
Abstract: In this paper we deal with the noteworthy Sylvester's determinantal identity and some of its generalizations. We report the formulae due to Yakovlev, to Gasca, Lopez--Carmona, Ramirez, to Beckermann, Gasca, M\"uhlbach, and to Mulders in a unified formulation which allows to understand them better and to compare them. Then, we propose a different generalization of Sylvester's classical formula. This new generalization expresses the determinant of a matrix in relation with the determinant of the bordered matrices obtained adding more than one row and one column to the original matrix. Sylvester's identity is recovered as a particular case.
Preconditioning linear systems via matrix function evaluation
Paolo Novati,Michela Redivo-Zaglia,Maria Rosaria Russo
Mathematics , 2011,
Abstract: For the solution of discrete ill-posed problems, in this paper a novel preconditioned iterative method based on the Arnoldi algorithm for matrix functions is presented. The method is also extended to work in connection with Tikhonov regularization. Numerical experiments arising from the solution of integral equations and image restoration are presented.
Semilinear Venttsel’ Problems in Fractal Domains  [PDF]
Maria Rosaria Lancia, Paola Vernole
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.512175
Abstract: We study a semilinear parabolic problem with a semilinear dynamical boundary condition in an irregular domain with fractal boundary. Local existence, uniqueness and regularity results for the mild solution, are established via a semigroup approach. A sufficient condition on the initial datum for global existence is given.
Effects of Sodium Butyrate and Its Synthetic Amide Derivative on Liver Inflammation and Glucose Tolerance in an Animal Model of Steatosis Induced by High Fat Diet
Giuseppina Mattace Raso, Raffaele Simeoli, Roberto Russo, Anna Iacono, Anna Santoro, Orlando Paciello, Maria Carmela Ferrante, Roberto Berni Canani, Antonio Calignano, Rosaria Meli
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068626
Abstract: Background & Aims Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease. Insulin resistance (IR) appears to be critical in its pathogenesis. We evaluated the effects of sodium butyrate (butyrate) and its synthetic derivative N-(1-carbamoyl-2-phenyl-ethyl) butyramide (FBA) in a rat model of insulin resistance and steatosis induced by high-fat diet (HFD). Methods After weaning, young male Sprague-Dawley rats were divided into 4 groups receiving different diets for 6 weeks: 1. control group (standard diet); 2. HFD; 3. HFD plus butyrate (20 mg/kg/die) and 4. HFD plus FBA (42.5 mg/Kg/die, the equimolecular dose of butyrate). Liver tissues of the rats were analyzed by Western blot and real-time PCR. Insulin resistance, liver inflammation and Toll-like pattern modifications were determined. Results Evaluation of these two preparations of butyrate showed a reduction of liver steatosis and inflammation in HFD fed animals. The compounds showed a similar potency in the normalisation of several variables, such as transaminases, homeostasis model assessment for insulin resistance index, and glucose tolerance. Both treatments significantly reduced hepatic TNF-α expression and restored GLUTs and PPARs, either in liver or adipose tissue. Finally, FBA showed a higher potency in reducing pro-inflammatory parameters in the liver, via suppression of Toll-like receptors and NF-κB activation. Conclusions Our results demonstrated a protective effect of butyrate in limiting molecular events underlying the onset of IR and NAFLD, suggesting a potential clinical relevance for this substance. In particular, its derivative, FBA, could represent an alternative therapeutic option to sodium butyrate, sharing a comparable efficacy, but a better palatability and compliance.
Pain after earthquake
Chiara Angeletti, Cristiana Guetti, Roberta Papola, Emiliano Petrucci, Maria Laura Ursini, Alessandra Ciccozzi, Francesca Masi, Maria Rosaria Russo, Salvatore Squarcione, Antonella Paladini, Joseph Pergolizzi, Robert Taylor, Giustino Varrassi, Franco Marinangeli
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2012, DOI: 10.1186/1757-7241-20-43
Abstract: This observational retrospective study evaluated the prevalence and drug treatment of pain in the five weeks following the L'Aquila earthquake (April 6, 2009).958 triage documents were analysed for patients pain severity, pain type, and treatment efficacy.A third of pain patients reported pain with a prevalence of 34.6%. More than half of pain patients reported severe pain (58.8%). Analgesic agents were limited to available drugs: anti-inflammatory agents, paracetamol, and weak opioids. Reduction in verbal numerical pain scores within the first 24 hours after treatment was achieved with the medications at hand. Pain prevalence and characterization exhibited a biphasic pattern with acute pain syndromes owing to trauma occurring in the first 15 days after the earthquake; traumatic pain then decreased and re-surged at around week five, owing to rebuilding efforts. In the second through fourth week, reports of pain occurred mainly owing to relapses of chronic conditions.This study indicates that pain is prevalent during natural disasters, may exhibit a discernible pattern over the weeks following the event, and current drug treatments in this region may be adequate for emergency situations.
Asymmetric Friedel-Crafts Alkylation of Indole with Chalcones Catalyzed by Chiral Phosphoric Acids
Arrigo Scettri,Rosaria Villano,Maria Rosaria Acocella
Molecules , 2009, DOI: 10.3390/molecules14083030
Abstract: The reaction of indole with chalcones, to give Michael-type adducts, was found to occur with good efficiency (up to 98% yield) and moderate enantioselectivity (up to 52% e.e.) in the presence of a chiral BINOL-based phosphoric acid. Furthermore, the alkylation products can be obtained in much higher e.e.s after one only crystallization.
Eleonora de Fonseca Pimentel: morire per la rivoluzione
Maria Rosaria Pelizzari
Storia delle Donne , 2009,
Abstract: Eleonora de Fonseca Pimentel, poetess, scholar of jurisprudence, natural and mathematical sciences, at first, was an enthusiastic supporter of Ferdinand IV of Burbon’s enlightened politics reforms. After the French Revolution and the radical change of Neapolitan government policy, much more illiberal and repressive, she was an active protagonist of 1799’ Revolution and founded the “Neapolitan Republic”. Editor of Monitore napoletano , she was a free, courageous, journalist, committed in changing of “Neapolitan plebs” into “Civil people”. At fall of Republic, she showed herself fearless in meeting the death on the scaffold. Up to the Eighties of XXth century, her final sacrifice has been represented by Virile woman’ image, as a praise for meaning an extraordinary, and intellectually like a man, woman. Today writers represent Eleanor like a “Modern heroin”, far by nineteenth-century Virile woman’s characters. Intellectual virtues do not seem to be sexed any longer: they belong to men and to women at the same time.
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