The use of Grossone in Mathematical Programming and Operations Research

The concepts of infinity and infinitesimal in mathematics date back to anciens Greek and have always attracted great attention. Very recently, a new methodology has been proposed by Sergeyev for performing calculations with infinite and infinitesimal quantities, by introducing an infinite unit of measure expressed by the numeral grossone. An important characteristic of this novel approach is its attention to numerical aspects. In this paper we will present some possible applications and use of grossone in Operations Research and Mathematical Programming. In particular, we will show how the use of grossone can be beneficial in anti--cycling procedure for the well-known simplex method for solving Linear Programming Problems and in defining exact differentiable Penalty Functions in Nonlinear Programming

Guest editors’ preface to the special issue devoted to the 2nd International Conference “Numerical Computations: Theory and Algorithms”, June 19–25, 2016, Pizzo Calabro, Italy

This special issue of the Journal of Global Optimization contains twelve high-quality research papers devoted to different aspects of global optimization such as theory, numerical methods and real-life applications. The papers included in this special issue are based on the presentations carefully selected by the guest editors among the talks delivered at the 2nd International Conference “Numerical Computations: Theory and Algorithms (NUMTA)” held in June 19–25, 2016 in Pizzo Calabro, Italy (the first NUMTA conference took place in Falerna, Italy in 2013). The NUMTA 2016 has been organized by the University of Calabria, Rende (CS), Italy, in cooperation with the Society for Industrial and Applied Mathematics, USA. The guest editors actively participated in the organization of the conference: the Program Committee of the NUMTA 2016 was chaired by Yaroslav D. Sergeyev, in their turn, Renato De Leone and Anatoly Zhigljavsky took part in the Program Committee. The goal of the NUMTA 2016 was creation of a multidisciplinary round table for an open discussion on numerical modeling nature by using traditional and emerging computational paradigms. Participants of this conference discussed several aspects of numerical computations and modeling from foundations of mathematics and computer science to advanced numerical techniques. A large part of presentations has been dedicated to optimization. Selected papers presented at the conference in the field of numerical analysis and respective applications have been published in the special issue of the international journal Applied Mathematics and Computation, Volume 318 (2018). In its turn, the present special issue contains articles dealing with global optimization. Let us give a brief description of the papers included in this special issue

Insufficient weight at birth and preschool-age growth in children attending charitably funded crèches in the municipality of Santo André , in the State of São Paulo , Brazil

OBJETIVOS: comparar o crescimento alcançado e a prevalência de baixa estatura na idade pré-escolar entre recém-nascidos de peso insuficiente (PNI) e de peso adequado (PNA). MÉTODOS: foram estudadas 323 crianças com PNI e 886 com PNA de famílias de baixa renda de quinze creches filantrópicas de Santo André, São Paulo, Brasil, em 2001 e 2002. As variáveis foram o escore Z de peso e de estatura para a idade, pelo referencial Center for Disease Control (CDC) and National Center for Health Statistics (NCHS) 2000, comparando-se as médias dos dois grupos. Calculou-se a razão de prevalência (RP) de baixa estatura na idade pré-escolar em decorrência do peso insuficiente ao nascer. RESULTADOS: o escore z médio de peso foi -0,09 e 0,39 e o escore z médio de estatura foi de -0,06 e de 0,24 para as crianças de PNI e de PNA, respectivamente. A prevalência de baixa estatura foi de 2,78% para as crianças com PNI e de 0,79% para aquelas com PNA. A RP de baixa estatura na idade pré-escolar para as crianças de PNI foi de 3,5 (IC95% 1,3-9,4). CONCLUSÕES: as crianças com PNI apresentaram crescimento inferior e maior risco de falhas de crescimento até a idade pré-escolar, sugerindo um efeito negativo do peso insuficiente ao nascer sobre o crescimento infantil.OBJECTIVES: to compare rate of growth and prevalence of low stature at preschool age in children who were underweight at birth and in children born with a normal weight. METHODS: the study covered 323 children born underweight and 886 born with a normal weight from low-income families in fifteen charitably funded crèches in the municipality of Santo André, in the State of São Paulo, Brazil, in 2001 and 2002. The variables used were the z score for weight and height for age, using the Center for Disease Control (CDC) and National Center for Health Statistics (NCHS) 2000 benchmark, comparing the means for the two groups. The prevalence ratio was calculated for low stature in preschool age children resulting from insufficient weight at birth. RESULTS: the z score for weight was -0.09 and 0.39 and the average z score for height was -0.06 and 0.24 for underweight and normal weight at birth, respectively. The prevalence of low stature was 2.78% for children born underweight and 0.79% for normal weight. The PR for low stature at preschool age for children born underweight was 3.5 (CI95% 1.3-9.4). CONCLUSIONS: children born underweight had a lower rate of growth and greater risk of developing a growth disorder up to preschool age, suggesting a negative effect of insufficient birth weight on child growth

Preface

[No abstract available

Selenium Biofortification and the Problem of its Safety

Selenium is an essential mineral element to humans and animals because it is an important component of selenoproteins that are important for functioning of the metabolism. Because of poor soil conditions in various regions of the world, the enrichment of edible plants with selenium via the biofortification strategy has been implemented. However, selenium in the context of plant mineral nutrition appears twofold due to its biofortifying character at low concentrations and toxicity at high concentrations. In this sense, understanding of the functional mechanisms in which selenium is involved is important, ranging from its absorption and assimilation in organic compounds to its beneficial or harmful effects, considering its role in food security and human health. Therefore, this chapter addresses the key aspects related to selenium in the soil-plant-man environment and the narrow limit between biofortification and toxicity, as well as the main scientific findings on this mineral element in the biochemical, physiology and plant nutrition contexts

BACTERIAL EPIDEMIOLOGY AND ANTIMICROBIAL RESISTANCE IN THE SURGERY WARDS OF A LARGE TEACHING HOSPITAL IN SOUTHERN ITALY

Objectives: Surgical infections represent an increasingly important problem for the National Health System. In this study we retrospectively evaluated the bacterial epidemiology and antimicrobial susceptibility of the microorganisms concerned as well as the utilization of antibiotics in the General and Emergency Surgery wards of a large teaching hospital in southern Italy in the period 2011-2013. Methods: Data concerning bacterial isolates and antimicrobial susceptibility were retrieved from the Vitek II database. The pharmacy provided data about the consumption of antibiotics in the above reported wards. Chi-square or Fisher’s exact test were used to analyze categorical variables. Results: In all, 94 Gram-negative were isolated in 2011, 77 in 2012, and 125 in 2013, Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa always being the most frequently isolated microorganisms. In the same years, there were respectively 105, 93, and 165 Gram-positive isolated, Enterococcus faecalis, Staphylococcus epidermidis and Staphylococcus aureus being the most commonly found. No significant variation in the antibiotic susceptibility pattern was observed, either among Gram-negative or among Gram-positive pathogens; carbapenems (especially meropenem) consumption remained stable over time. Conclusions: Our results show no significant increase in antimicrobial resistance over the period in question, and a higher rate of both MRSA isolates and resistance to carbapenems in A. baumannii compared with other European data