Testing Nelder-Mead based repulsion algorithms for multiple roots of nonlinear systems via a two-level factorial design of experiments

This paper addresses the challenging task of computing multiple roots of a system of nonlinear equations. A repulsion algorithm that invokes the Nelder-Mead (N-M) local search method and uses a penalty-type merit function based on the error function, known as 'erf', is presented. In the N-M algorithm context, different strategies are proposed to enhance the quality of the solutions and improve the overall efficiency. The main goal of this paper is to use a two-level factorial design of experiments to analyze the statistical significance of the observed differences in selected performance criteria produced when testing different strategies in the N-M based repulsion algorithm. The main goal of this paper is to use a two-level factorial design of experiments to analyze the statistical significance of the observed differences in selected performance criteria produced when testing different strategies in the N-M based repulsion algorithm.Fundação para a Ciência e Tecnologia (FCT

Mutagenic/genotoxic effect of pm0.5 collected in five italian towns in two seasons: results of the mapec study

PM can be considered as the atmospheric pollutant that mostly affects human health. The International Agency for Research on Cancer (IARC) has recently classified air pollution and fine PM as carcinogenic to human (1 Group) (Loomis et al. 2013). Different studies showed that PM induces several kinds of adverse cellular effects as cytotoxicity, mutagenicity, DNA damage and stimulation of cytokine production (Moller et al., 2015). The aim of the MAPEC study is to evaluate the association between air pollution (in particular PM) and early biomarkers in oral mucosa of children recruited from first grade schools of 5 Italian towns characterized by different PM levels. This work aims to evaluate children exposure to urban air pollution investigating the mutagenic and genotoxic effect of PM0.5 samples. PM0.5 samples (n=36) were collected (72h) in the school area on the same days of biological samplings in two different seasons (winter 2014-2015 and spring 2015) using a high-volume air sampler. PM0.5 organic extracts were chemically analyzed (PAH, Nitro-PAH) and tested on A549 by the comet assay and micronucleus test and on Salmonella strains (TA100, TA98, TA98NR and YG1021) by Ames test. Results showed that PM0.5 represents a very variable PM10 percentage (range 19.6-63% and 9.9-55.9% in winter and spring respectively). In winter PM10 concentration was generally lower than 50µg/m3 (EU daily limit) with highest values in the towns of the Padana plain. Generally lower values were observed in spring. In winter all PM0.5 extracts showed at least one mutagenic dose with the TA98 strain (net revertant/m3 range 0.3-1.5) suggesting the presence of indirect mutagens (+S9), while a lower effect was observed with the TA100 strain. The results obtained with the TA98NR and YG1021 strains in both seasons showed the presence of nitroaromatic compounds as confirmed by the chemical analysis. Lower effects and also a lower nitroaromatic compounds level were generally observed in spring. No genotoxic or oxidative effect of PM0.5 extracts was observed using the comet assay (with/without Fpg enzyme) and micronucleus test in both seasons except for some sporadic samples. The low biological effect observed in winter could be related to the low level of air pollution observed in this winter sampling associated to a high atmospheric instability. The high variability of PM0.5 observed in this study should be more investigated. Moreover for a greater understanding of the relationship between PM size, composition and biological effects, the results obtained in this study suggest to investigate also the biological effect of the other PM fractions and in particular of the PM0.5-1 fraction

Mutagenic and genotoxic effect of PM0.5 in different italian towns: the MAPEC (Monitoring Air Pollution Effects on Children for supporting public health policy) Study

Introduction Exposure to particulate matter (PM) is associated with respiratory and cardiovascular disease and lung cancer. The finest fractions of PM (PM2.5 µm and less) play the major role in causing chronic diseases. The structure and composition of PM influence the biological properties of particles. The aim of the MAPEC study is to evaluate the association between air pollution and early biomarkers in oral mucosa of children recruited from first grade schools of 5 Italian towns characterized by different PM levels. Methods To evaluate children exposure, PM0.5 samples (n=20) were collected (72h) in the school area on the same days of biological samplings (winter 2014-2015) using a high-volume air sampler. PM0.5 organic extracts were chemically analyzed (PAH, Nitro-PAH) and tested on A549 by the comet assay and micronucleus test and on Salmonella strains (TA100, TA98, TA98NR and YG1021) by Ames test. Results Results showed that PM0.5 represents a high variable PM10 percentage (range 19.6-63%). PM10 concentration were generally lower than 50µg/m3 (EU daily limit). All PM0.5 extracts showed a mutagenic effect with TA98 strain (net revertant/m3 range 0.3-1.5) and suggested the presence of indirect mutagens, while lower effect was observed with TA100 strain. The results with the TA98NR and YG1021 strains showed the presence of nitroaromatic compounds as confirmed by the chemical analysis. No genotoxic or oxidative effect of PM0.5 extracts was observed using the comet assay (with/without Fpg enzyme) and micronucleus test except for some sporadic samples. The low biological effect observed could be related to the low level of air pollution observed in this winter sampling associated to a high atmospheric instability. Conclusions For a greater understanding of the relationship between PM size, composition and biological effects the results obtained in this study suggest to investigate the biological effect of the other PM fractions and in particular of the PM0.5-1 fraction