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A LOW-COST OPTIMIZATION APPROACH FOR SOLVING MINIMUM NORM LINEAR SYSTEMS AND LINEAR LEAST-SQUARES PROBLEMS

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Journal of Computational Mathematics 2024年第4期42卷 932-954页

作者： debora Cores Johanna Figueroa Defense University Center at the Spanish Naval Academy Plaza de Espana36920 MarinPontevedraSpain Departamento de Matematica Facultad de MatematicaPontificia Universidad Catolica de ChileAv.Vicuna Mackenna 4860San JoaquinSantiago 894000Chile

Recently,the authors proposed a low-cost approach,named Optimization Approach for Linear Systems(OPALS)for solving any kind of a consistent linear system regarding the structure,characteristics,and dimension of the coefficient matrix *** results obtained by this approach for matrices with no structure and with indefinite symmetric part were encouraging when compare with other recent and well-known *** this work,we proposed to extend the OPALS approach for solving the Linear Least-Squares Problem(LLSP)and the Minimum Norm Linear System Problem(MNLSP)using any iterative low-cost gradient-type method,avoiding the construction of the matrices AT A or AAT,and taking full advantage of the structure and form of the gradient of the proposed nonlinear objective function in the gradient *** combination of those conditions together with the choice of the initial iterate allow us to produce a novel and efficient low-cost numerical scheme for solving both ***,the scheme presented in this work can also be used and extended for the weighted minimum norm linear systems and minimum norm linear least-squares *** include encouraging numerical results to illustrate the practical behavior of the proposed schemes.

关键词： Nonlinear convex optimization Gradient-type methods Spectral gradient method Minimum norm solution linear systems Linear least-squares solution

THE ONE-DIMENSIONAL HUGHES MODEL FOR PEDESTRIAN FLOW:RIEMANN-TYPE SOLUTIONS

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Acta Mathematica Scientia 2012年第1期32卷 259-280页

作者： debora Amadori M.Di Francesco Dipartimento di Matematica Pura e Applicata Universita degli Studi dell'Aquila Departament de Matematiques Universitat Autonoma de Barcelona

This paper deals with a coupled system consisting of a scalar conservation law and an eikonal equation, called the Hughes model. Introduced in [24], this model attempts to describe the motion of pedestrians in a densely crowded region, in which they are seen as a ＇thinking＇（continuum） fluid. The main mathematical difficulty is the discontinuous gradient of the solution to the eikonal equation appearing in the flux of the conservation law. On a one dimensional interval with zero Dirichlet conditions （the two edges of the interval are interpreted as ＇targets＇）, the model can be decoupled in a way to consider two classical conservation laws on two sub-domains separated by a turning point at which the pedestrians change their direction. We shall consider solutions with a possible jump discontinuity around the turning point. For simplicity, we shall assume they are locally constant on both sides of the discontinuity. We provide a detailed description of the local- in-time behavior of the solution in terms of a ＇global＇ qualitative property of the pedestrian density （that we call ＇relative evacuation rate＇）, which can be interpreted as the attitude of the pedestrians to direct towards the left or the right target. We complement our result with explicitly computable examples.

关键词： pedestrian flow nonlocal conservation law eikonal equation

Alcoholic disease: Liver and beyond

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World Journal of Gastroenterology 2014年第40期20卷 14652-14659页

作者： Alba Rocco debora Compare debora Angrisani Marco Sanduzzi Zamparelli Gerardo Nardone Gastroenterology Unit Department of Clinical Medicine and Surgery University Federico Ⅱ of Naples 80131 Naples Italy

The harmful use of alcohol is a worldwide problem. It has been estimated that alcohol abuse represents the world’s third largest risk factor for disease and disability; it is a causal factor of 60 types of diseases and injuries and a concurrent cause of at least 200 others. Liver is the main organ responsible for metabolizing ethanol, thus it has been considered for long time the major victim of the harmful use of alcohol. Ethanol and its bioactive products, acetaldehyde-acetate, fatty acid ethanol esters, ethanol-protein adducts, have been regarded as hepatotoxins that directly and indirectly exert their toxic effect on the liver. A similar mechanism has been postulated for the alcohol-related pancreatic damage. Alcohol and its metabolites directly injure acinar cells and elicit stellate cells to produce and deposit extracellular matrix thus triggering the “necrosis-fibrosis” sequence that finally leads to atrophy and fibrosis, morphological hallmarks of alcoholic chronic pancreatitis. Even if less attention has been paid to the upper and lower gastrointestinal tract, ethanol produces harmful effects by inducing: (1) direct damaging of the mucosa of the esophagus and stomach; (2) modification of the sphincterial pressure and impairment of motility; and (3) alteration of gastric acid output. In the intestine, ethanol can damage the intestinal mucosa directly or indirectly by altering the resident microflora and impairing the mucosal immune system. Notably, disruption of the intestinal mucosal barrier of the small and large intestine contribute to liver damage. This review summarizes the most clinically relevant alcohol-related diseases of the digestive tract focusing on the pathogenic mechanisms by which ethanol damages liver, pancreas and gastrointestinal tract.

关键词： Alcoholic liver disease Alcoholic pancreatitis Alcohol and gastrointestinal tract

Assessment of effectiveness of oral supplementation of isolated fiber of carrot on metabolic parameters in mature rats

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Food Science and Human Wellness 2023年第6期12卷 2022-2028页

作者： Maria Rosana Ramirez debora Manuale Juan Carlos Yori Instituto Universitario de Ciencias de la Salud Fundación BarcelóCONICETCenteno 710CP 3340Santo TomeCorrientesArgentina Consejo Nacional de Investigaciones Científi cas Técnicas(CONICET) Buenos Aires C1033AAJArgentina Instituto de Investigaciones en Catálisis y Petroquímica(INCAPE)FIQ-UNL-CONICET Parque Tecnológico Litoral Centro 3000Santa FeArgentina Facultad de Ingeniería Química Universidad nacional del Litoral 3000Santa FeArgentina

This present study was conducted to evaluate the metabolic effects of isolated fi ber of carrot supplementation in *** properties of fi ber were *** groups were as follows:animals fed a standard diet,control group;high fi ber supplementation(70 mg);low fi ber supplementation(35 mg);for 12 *** samples were collected at the time of sacrifi *** weights of heart,liver,kidneys and spleen of the experimental rats with respect to body weight were *** kits were used to determine serum glucose concentration,lipid profi le(cholesterol,HDL-cholesterol,triglycerides),and the two main aminotransferases glutamic-oxalacetic transaminase(GOT)/glutamate-pyruvate transaminase(GPT).A histopathological assay was performed on the heart,liver,and spleen tissues of *** with fi ber favors weight loss in female((242.03±23.73)-(197.81±10.45)g);and male rats((262.50±32.21)-(213.96±12.56)g and induces a decrease in glucose levels in the supplemented *** the exception of total high-density lipoprotein cholesterol,the other lipid fractions decrease signifi cantly in rats *** supplementation did not induce changes in the dissected organs of the supplemented *** conclusion supplementation of fiber,improves glucose control,lower plasma lipid concentrations and reduced body weight in normal rats.

关键词： Carrot fiber Oral supplementation Animal studies

Screening for and surveillance of gastric cancer

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World Journal of Gastroenterology 2014年第38期20卷 13681-13691页

作者： debora Compare Alba Rocco Gerardo Nardone Department of Clinical Medicine and Surgery Gastroenterology UnitUniversity Federico Ⅱ of Naples

Although the prevalence of gastric cancer(GC) progressively decreased during the last decades,due to improved dietary habit,introduction of food refrigeration and recovered socio-economic level,it still accounts for 10% of the total cancer-related deaths. The best strategy to reduce the mortality for GC is to schedule appropriate screening and surveillance programs,that rises many relevant concerns taking into account its worldwide variability,natural history,diagnostic tools,therapeutic strategies,and cost-effectiveness. Intestinal-type,the most frequent GC histotype,develops through a multistep process triggered by Helicobacter pylori(H. pylori) and progressing from gastritis to atrophy,intestinal metaplasia(IM),and dysplasia. However,the majority of patients infected with H. pylori and carrying premalignant lesions do not develop GC. Therefore,it remains unclear who should be screened,when the screening should be started and how the screening should be performed. It seems reasonable that screening programs should target the general population in eastern countries,at high prevalence of GC and the high-risk subjects in western countries,at low prevalence of *** far as concern surveillance,currently,we are lacking of standardized international recommendations and many features have to be defined regarding the optimal diagnostic approach,the patients at higher risk,the best timing and the ***,patients with corpus atrophic gastritis,extensive incomplete IM and dysplasia should enter a surveillance *** present,screening and surveillance programs need further studies to draw worldwide reliable recommendations and evaluate the impact on mortality for GC.

关键词： Screening Surveillance Helicobacter pylori Gastric cancer Preneoplastic lesions Gastric atrophy Intestinal metaplasia Gastric dysplasia

SIRENE: A Spatial Data Infrastructure to Enhance Communities' Resilience to Disaster-Related Emergency

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International Journal of Disaster Risk Science 2018年第1期9卷 129-142页

作者： Simone Sterlacchini Gloria Bordogna Giacomo Cappellini debora Voltolina Institute for the Dynamics of Environmental Processes –National Research Council of Italy (CNR-IDPA) Institute for Electromagnetic Sensing of the Environment –National Research Council of Italy (CNR-IREA)

Planning in advance to prepare for and respond to a natural hazard-induced disaster-related emergency is a key action that allows decision makers to mitigate unexpected impacts and potential damage. To further this aim, a collaborative, modular, and information and communications technology-based Spatial Data Infrastructure(SDI)called SIRENE—Sistema Informativo per la Preparazione e la Risposta alle Emergenze(Information System for Emergency Preparedness and Response) is designed and implemented to access and share, over the Internet, relevant multisource and distributed geospatial data to support decision makers in reducing disaster risks. SIRENE flexibly searches and retrieves strategic information from local and/or remote repositories to cope with different emergency phases. The system collects, queries, and analyzes geographic information provided voluntarily by observers directly in the field(volunteered geographic information(VGI) reports) to identify potentially critical environmental conditions. SIRENE can visualize and cross-validate institutional and research-based data against VGI reports,as well as provide disaster managers with a decision support system able to suggest the mode and timing of intervention, before and in the aftermath of different types of emergencies, on the basis of the available information and in agreement with the laws in force at the national andregional levels. Testing installations of SIRENE have been deployed in 18 hilly or mountain municipalities(12 located in the Italian Central Alps of northern Italy, and six in the Umbria region of central Italy), which have been affected by natural hazard-induced disasters over the past years(landslides, debris flows, floods, and wildfire) and experienced significant social and economic losses.

关键词： Data retrieval Decision support system Disaster management Italy Spatial data infrastructure Susceptibility/hazard and risk maps Volunteered geographic information

Water evacuations in remote tourist regions: evaluating case studies from natural hazards in North Patagonian lakes, Argentina

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Journal of Mountain Science 2022年第6期19卷 1782-1807页

作者： SALGADO Pablo Agustin VILLAROSA Gustavo BEIGT debora OUTES Valeria IPATEC(Instituto Andino-Patagonico de Tecnologias Biologicas y Geoambientales) CONICET-UNCOAv.de los Pioneros 23508400 S.C.de BarilocheArgentina Centro Regional Uniuersitario Bariloche Universidad Nacional del ComahueQuintral 12508400 S.C.de BarilocheArgentina

The remote North Patagonian region is a sparsely populated territory and a world famous tourist destination located on the leeward side of the Andes Mountains. Recent disasters triggered by various types of geoenvironmental hazards(including volcanic eruptions, mass-wasting processes and extreme weather events) heavily disrupted ground transport networks in a region with already limited territorial accessibilities. All these catastrophes prompted the need to evacuate or assist a number of secluded visitors, locals and livestock extemporaneously on board of coastguards and tourist passenger-ships from the shores of the many glacial lakes that make up part of the regional attraction. Despite the recurrence of these types of events, water evacuations in the region continue to be spontaneous, improvised and hazardous procedures. This contribution reconstructs and assesses a number of recent local-scale cases of lake evacuations and assistances from a number of Patagonian urban centers, rural areas and tourist sites. For each case study, we systematically elaborated on the prime components of an evacuation process, which enabled us to recognize key achievements, failures and conditioning factors for managing emergencies via water transport, most of them inherent to the studied region. Some of the complexities to emerge from case studies referred to: complex hazard-related scenarios;limited ground-based accessibilities and risk of isolation;various inter-and intra-organizational issues, incidental to natural reserves and tourist regions;a wide range of particular demographic features;and the availability and vulnerability of water transport resources. We suggested fundamental and replicable recommendations for developing water evacuation plans, also identifying forthcoming problems to solve in order to improve the management of emergencies through this alternative means of transport.

关键词： Water transport Emergency management Accessibility problems Tourism activities Volcanic crises Mountain area

GLOBAL EXISTENCE OF SOLUTIONS FOR A MULTI-PHASE FLOW: A BUBBLE IN A LIQUID TUBE AND RELATED CASES

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Acta Mathematica Scientia 2015年第4期35卷 832-854页

作者： debora AMADORI Paolo BAITI Andrea CORLI Edda DAL SANTO Department of Engineering and Computer Science and Mathematics University of L'Aquila Department of Mathematics and Computer Science University of Udine Department of Mathematics and Computer Science University of Ferrara

In this paper we study the problem of the global existence （in time） of weak entropic solutions to a system of three hyperbolic conservation laws, in one space dimension, for large initial data. The system models the dynamics of phase transitions in an isothermal fluid; in Lagrangian coordinates, the phase interfaces are represented as stationary contact discontinuities. We focus on the persistence of solutions consisting in three bulk phases separated by two interfaces. Under some stability conditions on the phase configuration and by a suitable front tracking algorithm we show that, if the BV-norm of the initial data is less than an explicit （large） threshold, then the Cauchy problem has global solutions.

关键词： hyperbolic systems of conservation laws phase transitions wave-front trackingalgorithm

Cancer stem cell hypothesis and gastric carcinogenesis: Experimental evidence and unsolved questions

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World Journal of Gastrointestinal Oncology 2012年第3期4卷 54-59页

作者： Alba Rocco debora Compare Gerardo Nardone Department of Clinical and Experimental Medicine Gastroenterology Unit University Federico Ⅱ of Naples

Traditionally, the clonal evolution model has been used to explain gastric cancer (GC) growth dynamics. According to this model, GC cells result from multiple mutations over time resulting in a population of continually diversifying cells. This heterogeneity enables the survival of different clones under particular conditions allowing growth at metastatic locations or resistance to chemotherapeutics. Cancer stem cell (CSC) theory completely overturns this traditional understanding of cancer suggesting that only CSCs can self-renew and promote tumor growth. CSCs are relatively refractory to conventional therapies, thus explaining why anti-cancer therapies are far from curative and why relapses of cancer are frequent. The identification of the CSC component of a tumor might, thus, open new therapeutic perspective based on the selective targeting of this small population of cells. In this review we examine the current scientific evidence supporting the existence of CSC in gastric tumors and analyze the main unsolved questions of this difficult field of cancer research.

关键词： Cancer stem cells Gastric cancer CD133 CD44