Transport in finite size systems: an exit time approach

In the framework of chaotic scattering we analyze passive tracer transport in finite systems. In particular, we study models with open streamlines and a finite number of recirculation zones. In the non trivial case with a small number of recirculation zones a description by mean of asymptotic quantities (such as the eddy diffusivity) is not appropriate. The non asymptotic properties of dispersion are characterized by means of the exit time statistics, which shows strong sensitivity on initial conditions. This yields a probability distribution function with long tails, making impossible a characterization in terms of a unique typical exit time.Comment: 16 RevTeX pages + 6 eps-figures include

Effect of silver nanoparticles and microbial ligands on the innate immune response of the human alveolar epithelium

Over the past decade there has been a rapid increase in the development and use of nanoparticles (NPs, <100nm). Silver (Ag) NPs, due to their antimicrobial activity, are the most commercialised NPs in the world and are incorporated into several consumer goods. However, little is known about the potential adverse effects of AgNPs in humans. Approximately 50% of inhaled NPs preferentially deposit in the alveoli, where alveolar epithelial type-I cells (AT1) form 95% of the alveolar surface, thus constituting a significant target for deposition. We hypothesised that (I) inhalation of AgNPs induces oxidative stress in AT1 cells, leading to a pro-inflammatory response, autophagy activation and DNA damage; (II) in the presence of a microbial infection, AgNP exposure potentiates the innate immune response, leading to increased inflammation and genotoxicity. An immortalised human transformed alveolar type1-like cell line (TT1) was used to investigate these hypotheses. TT1 cells were exposed to AgNPs in the presence/absence of Poly I:C (TLR-3 ligand) and LPS (TLR-4 ligand) prior to assaying cell viability, inflammatory mediator release, oxidative stress, autophagy and DNA damage. AgNPs induced oxidative stress in TT1 cells, as well as inflammation, autophagy activation and DNA damage. The AgNPs-Poly I:C combination further stimulated IL-6 release, DNA damage and delayed autophagic flux, whereas the AgNPs-LPS combination did not. We also discovered two different sources of AgNP-mediated oxidative stress, mitochondria and NADPH oxidase. Pre-treatment of TT1 cells with a TLR-4 inhibitor prevented AgNP-induced inflammation, autophagy activation and DNA damage. On the contrary, TLR-3 inhibition did not affect any of the pathways investigated. In conclusion, we showed that AgNPs induce oxidative stress and act via TLR-4, leading to a pro-inflammatory response, autophagy activation and DNA damage. These cellular pathways are potentiated by co-exposure with Poly I:C. This suggests that inhalation of AgNPs may exert deleterious effects on the lung and, in presence of a viral infection, a worsening of the pulmonary condition.Open Acces

Time Perspective, Coping Styles, Perceived Efficacy in Affect Regulation, and Creative Problem Solving in Adolescence and Youth

The study evaluated, in a sample of 230 adolescents (147 males and 83 females, mean age = 16.67) and a sample of 181 young people (21 males and 160 females, mean age = 22.57), the relationships between time perspective and the following personal skills: coping styles, perceived efficacy on affect regulation, and creative divergent problem solving. Results highlight that future time perspective increases in value from adolescence to youth, while present time perspective decreases. Future time perspective is correlated with creative problem solving and problem solving coping style in both age groups, while present time perspective is positively correlated with expression of positive emotions in both age groups. Results are discussed also for their relevance for school educational and training programs

Positive aging, Positive Psychology and Tourism. A challenging new area of investigation?

The article examines the issue of positive aging and how it can be improved through traveling and environment exploration. Moving from the most relevant contemporary theoretical perspectives on positive aging, the first part of the article focuses the attention on the conceptualization of successful aging, and examines the theoretical basis that could support the thesis that traveling can be viewed as an hallmark of this condition. The second part of the article takes into consideration a recent new area of psychological science, the Positive Psychology, trying to briefly examine the potential of the “well-being approach” for reaching a positive aging also through the tourist activity

The Collective Traumatic Event of COVID-19 Pandemic and its Psychological Impact on Beliefs and Intentions of Senior Italian Tourists

Introduction. The COVID-19 Pandemic represents a traumatic collective event that has suddenly modified our future perception, representation and our lifestyle, including travel for tourism. Tourism is one of the major economic sectors that is suffering from it. Objectives, Method and Procedures. The study analyzed, through a purpose-built online questionnaire, in a sample of 311 Italian old people (m. age = 69.70) how much they believe that COVID-19 Pandemic will change their way of going on holidays. The possible perceived obstacles to continue to travel for tourism in and after Covid-19 Pandemic, and the beliefs about the relevance of tourism in general and cultural tourism for old people and the intention to continue the travel experience in the future are being effected. Results. Old people believe that this pandemic will change their way to go on holidays, and this belief is more pronounced for female than for males; the most critical obstacles are anxiety and fear about a sudden return of Coronavirus, the lack of safety systems in tourism hospitality structures, the lack of effective instruments by Tour Operators for dealing with Coronavirus in the touristic destinations, with 18% of explained variance. On the contrary, they possess very positive beliefs about the relevance of tourism in general and cultural tourism as a specific form of travel.Introduzione. La Pandemia di COVID-19 rappresenta un autentico trauma collettivo che ha modificato improvvisamente la nostra percezione e rappresentazione del futuro, il nostro stile di vita, incluso il modo di fare le vacanze. Il settore turistico risulta uno dei settori economici che oggi si trova in sofferenza causa la pandemia. Questa malattia infettiva ha serie conseguenze sulla salute, soprattutto nel segmento più anziano della popolazione, per il quale il turismo rappresenta una dimensione importante per il benessere psicologico e sociale, contribuendo a raggiungere un invecchiamento positivo. Obiettivi, Metodo e Procedure. Lo studio ha analizzato, attraverso un questionario online costruito ad hoc, in un campione di 311 anziani italiani (età m. = 69.70; 192 maschi e 112 femmine, con 7 dati mancanti per il genere; 5 in possesso della Licenza Elementare; 2 in possesso del diploma di Scuola Media, 90 in possesso del Diploma di Scuola Secondaria Superiore; 199 in possesso di Laurea, con due dati mancanti sulla scolarità), quanto essi ritengono che la Pandemia di COVID-19 modificherà il loro modo di fare le vacanze, gli ostacoli percepiti per continuare a viaggiare per turismo durante e dopo la Pandemia, le credenze sull’importanza del turismo in generale e del turismo culturale per le persone anziane e l’intenzione di continuare l’esperienza del viaggio turistico in futuro. Attraverso analisi Multivariate sono state analizzate le differenze di genere e scolarità per le credenze e le intenzioni; un modello di Regressione Gerarchica ha valutato il contributo offerto dagli ostacoli percepiti al cambiamento nel modo di viaggiare per turismo, dopo aver controllato l’età, il genere ed il livello di scolarità. Risultati. Gli anziani credono che questa pandemia modificherà il loro modo di fare le vacanze, e questa credenza risulta più pronunciata nelle femmine rispetto ai maschi; l’ostacolo più critico è indicato nell’ansia e nella paura per un ritorno improvviso del Coronavirus, la mancanza di sistemi di sicurezza nelle strutture ospitanti, la mancanza di strumenti efficaci da parte dei Tour Operator per gestire il Coronavirus nelle destinazioni turistiche, con il 18% della varianza spiegata. Conclusioni. Le istituzioni territoriali pubbliche e private ed i Tour Operator che saranno capaci di dotarsi di sistemi di sicurezza efficaci e sapranno utilizzare con gli anziani una comunicazione chiara ma al tempo stesso empatica e rassicurante sulle protezioni personali potranno aumentare la loro potenzialità turistica durante la Pandemia di COVID-19 e dopo la sua cessazione

Population dynamics advected by chaotic flows: a discrete-time map approach

A discrete-time model of reacting evolving fields, transported by a bidimensional chaotic fluid flow, is studied. Our approach is based on the use of a Lagrangian scheme where {\it fluid particles} are advected by a $2d$ symplectic map possibly yielding Lagrangian chaos. Each {\it fluid particle} carries concentrations of active substances which evolve according to its own reaction dynamics. This evolution is also modeled in terms of maps. Motivated by the question, of relevance in marine ecology, of how a localized distribution of nutrients or preys affects the spatial structure of predators transported by a fluid flow, we study a specific model in which the population dynamics is given by a logistic map with space-dependent coefficient, and advection is given by the standard map. Fractal and random patterns in the Eulerian spatial concentration of predators are obtained under different conditions. Exploiting the analogies of this coupled-map (advection plus reaction) system with a random map, some features of these patterns are discussed.Comment: 22 pages, 5 figure

Genitorialità: consapevolezza sul proprio ruolo come educatori e competenze per la cittadinanza

It is since a long time that the European Community highlights how parents – fundamental resource for the education of the “tomorrow’ citizens” – must be supported in the interpretation of their educative role and in the assumption of their whole responsibility with respect to the related functions.This paper presents the results of an ALICE pilot project dedicated to the training of parents with children aged 0-3 and realized as a laboratory of reflection through creative and informal languages. It comes to a formative proposal relative to empowerment interventions, aimed at sustaining parent competences and its conscious use from an educational point of view.Each meeting was organised in two phases: (a) self-reflection as parent and then as son/daughter; (b) realization of creative activities to enhance the educational quality of the relationship with their children. The participation of parents has been constantly active. The feedback obtained through a satisfaction survey and a questionnaire for self-evaluation to compare pre- and post- training has been very satisfactory.Da tempo la Commissione Europea sta mettendo in evidenza il fondamentale ruolo che genitori giocano in quanto risorsa per l’educazione cittadini del domani. Si sostiene che i genitori devono essere sostenuti nella comprensione e consapevolezza del proprio ruolo attraverso processi formativi che consentano agli adulti l’appropriazione responsabile di tale ruolo.Questo articolo presenta i risultati di una delle attività pilota svolte all’interno del progetto ALICE dedicati alla formazione dei genitori con bambini di età 0-3 e realizzati come laboratorio di riflessione attraverso linguaggi creativi e informali. Nello specifico, si tratta di una proposta formativa basata su interventi di empowerment volti a sviluppare competenze per la genitorialità, trasferite con successo nello svolgimento consapevole del ruolo di genitore. Ogni incontro è stato organizzato in due fasi: (a) auto-riflessione, come genitore e come figlio / figlia; (b) realizzazione di attività creative per migliorare la qualità educativa del rapporto con i figli. La partecipazione dei genitori è stata costantemente attiva. Il feedback ottenuto attraverso un sondaggio sulla soddisfazione e un questionario di auto-valutazione per confrontare pre e post-formazione ha mostrato positivi risultati

Behaviour-dependent predation risk in swimming zooplankters

Background: The survival of zooplanktonic organisms is determined by their capability of moving in a fluid environment, trading off between the necessities of finding prey and avoiding predators. In previous numerical experiments, we concentrated on the relationship between natatorial modality and encounter success of a virtual copepod swimming in the presence of prey distributed either in patches or uniformly in the environment. Results: In this contribution, we extend this simulation framework to the encounter with chaetognaths, the primary copepod predators, considering different motion rules as a proxy of different swimming strategies and looking at the influence of the concentration of predators and the size of their detection radius in posing a risk on copepod survival. The outcomes of our simulations indicate that more convoluted trajectories are more vulnerable to predator encounter while straighter motions reduce predation risk. Conclusions: Our results are then complemented with those obtained in our previous studies to perform a general cost-benefit analysis of zooplankton motion