Emergence of chaotic behaviour in linearly stable systems

Strong nonlinear effects combined with diffusive coupling may give rise to unpredictable evolution in spatially extended deterministic dynamical systems even in the presence of a fully negative spectrum of Lyapunov exponents. This regime, denoted as ``stable chaos'', has been so far mainly characterized by numerical studies. In this manuscript we investigate the mechanisms that are at the basis of this form of unpredictable evolution generated by a nonlinear information flow through the boundaries. In order to clarify how linear stability can coexist with nonlinear instability, we construct a suitable stochastic model. In the absence of spatial coupling, the model does not reveal the existence of any self-sustained chaotic phase. Nevertheless, already this simple regime reveals peculiar differences between the behaviour of finite-size and that of infinitesimal perturbations. A mean-field analysis of the truly spatially extended case clarifies that the onset of chaotic behaviour can be traced back to the diffusion process that tends to shift the growth rate of finite perturbations from the quenched to the annealed average. The possible characterization of the transition as the onset of directed percolation is also briefly discussed as well as the connections with a synchronization transition.Comment: 30 pages, 8 figures, Submitted to Journal of Physics

Mediterranean diet adherence and synergy with acute myocardial infarction and its determinants. a multicenter case-control study in Italy.

Cardiovascular diseases are the leading causes of mortality and morbidity in Western countries. The possible synergistic effect of poor adherence to a Mediterranean diet (MD) and other risk factors for acute myocardial infarction (AMI) such as hypertension, cholesterol, ever smoker, BMI> 25, diabetes, has not been deeply studied. Design Case-control study. Methods Patients with first AMI and controls from four tertiary referral Italian centers were screened for enrolment. Dietary information was collected through a questionnaire and a MD adherence score was calculated. Physical activity and smoking habits were also registered. The Synergy Index was calculated according to Rothman. Results 127 cases and 173 controls were enrolled. The analysis was conducted using a dichotomous variable for the MD score with values 7 representing good adherence. Multivariate analysis showed the following variables associated to AMI: ever smoker (OR = 2.08), diabetes (OR = 1.42), hypertension (OR = 2.08), hypercholesterolemia (OR = 2.47), BMI> 25 (OR = 1.99), while a protective effect emerged both in subjects scoring > 7 on the MD score(OR = 0.55) and in subjects resident of Southern Italy (OR = 0.38). A synergistic effect does exist between poor adherence to the MD and the following risk factors: hypertension, hypercholesterolemia, BMI >25, diabetes and being a resident in central and northern Italy. Conclusion Synergy between heart disease risk factors and MD underlines the need to enlarge the list of known modifiable cardiovascular risk factors to include and promote adherence to Mediterranean dietary habits

Determinants associated with obesity and physical activity in the public and private schools of the city of palermo

Introduction: Obesity is a medical condition associated with premature death and it is a risk factor for many chronic diseases. In this context, performing a regular physical activity promotes a healthy lifestyle, with significant health benefits. The aim of the study was to investigate behaviors that increase the risk of obesity and the determinants that encourage physical activity among adolescents. Materials and methods: The HBSC (Health Behavior in School-aged Children) questionnaire was administered to students in Palermo's private and public schools. For the sampling of public schools the protocol of the HBSC Surveillance System was followed; for the private ones it was opportunistic. Results: Private school students are more likely to exercise more than 3 days per week (OR 1.58) and are more likely to exercise more than 2 times a week (OR 2.08). Obese students in private schools in Palermo are more likely to perform physical activity for less than 3 days a week (OR 3.52) and a higher risk of not having breakfast (OR 10.11) and a snack between main meals (OR 3.82) every day. For all the schools examined, it emerged that obese subjects are more likely not to consume fruit (OR 3.13), to stay more than 6 hours a day in front of PCs and video games (OR 3.24) and more than 2 hours a day in front of TV (OR 3.79). Male students are more likely to perform physical activity for more than 3 days per week (OR 1.48) and intense physical activity at least 2 times per week (OR 1.76) Conclusions: It is necessary to intervene early with training on school and family in order to promote correct and responsible food choices and increase the level of physical activity among students. Therefore prevention interventions must be an integral part of coherent strategies based on tests of agreed effectiveness in order to minimize the risk linked to the development of diseases

Stressed caregivers. An observational study in a rehabilitation care home in western Sicily

Introduction: Caregiver is the person who takes care of the patient from the practical point of view, helping him in managing the disease and carrying out daily activities, but also supporting him on an emotional level. Caregiver burnout is a state of physical, emotional, and mental exhaustion that may be accompanied by a change in attitude from positive and caring to negative and unconcerned. The aim of the study was to understand what factors were associated with having panic attacks or crying crises in the caregivers of our study population. Materials and methods: The study design is observational. An anonymous questionnaire was administered to caregivers of the patients of a hospital for the intensive post-acute rehabilitation from April 2016 to December 2018. The statistical significance level chosen for the entire analysis was 0.05. The covariates to be included were selected using a stepwise backward selection process, with a univariate p-value <0.25 as the main criterion. Results are expressed as adjusted Odds Ratio (aOR) with 95% Confidence Intervals (CI). Results: The sample consists of 302 caregivers (60.93% was females and 39.07% was males). The mean age of the sample is 53.42 years old (SD ± 12.19). The multivariable logistic regression model shows that the risk to have panic or crying crisis is significantly associated with the following indipendent variables: female gender (aOR 27.06); living with the patient (aOR 4.38); had claimed that the problems related to the illness of their family member is a source of stress (aOR 23.54), smoking cigarettes (aOR 14.68); had claimed that taking care of their client affected their personal financial statement/career (aOR 5.95), having free time (aOR 7.68). Conclusions: In our study we found a greater probability of having panic attacks or crying crises in female subjects, smokers, who think they have sacrificed their careers to take care of the person they follow from a welfare point of view. Certainly in the light of what has emerged it is necessary to dedicate and pay close attention to the psychological and social aspects of the caregiver

Prevalence of sexually transmitted infections and enteric protozoa among homosexual men in western Sicily (south Italy)

Introduction. In recent years an increase in the number of sexu- ally transmitted infections (STIs) in men who have sex with men (MSM) has been reported in different industrialised countries. Because few epidemiological data on the STIs/MSM population in Sicily are available, a survey was conducted to assess the preva- lence of STIs/enteric protozoa and risky sexual behaviours among MSM in western Sicily. Methods. In 2010, 74 MSM with median age of 30 years old, were recruited via networks. All participants to the study were interviewed by anonymous self-administered questionnaire in order to collect social/demographic information, clinic data and STI-related risky sexual behaviours. After completing the ques- tionnaire, blood samples were collected to determine HIV, HCV, HHV8 and Treponema pallidum antibodies; presence of Giardia duodenalis and Cryptosporidium parvum was also investigated in faecal samples by immunofluorescence assay. Results. HIV, HHV8, T. pallidum and Giardia prevalence were 8.1%, 16.2%, 21.6% and 16.4% respectively; all patients were negative for HCV and Cryptosporidium infections. The median values of sexual anal intercourse and oral sex per week were 2 and 1, respectively. 7% of participants always had unprotected anal sex, 50.7% sometimes used condom during sexual anal inter- course and 42.3% always had protected anal sex. All MSM-HIV+ and 7 (43.7%) syphilis seropositives were unaware of their own infection. Discussion. MSM in western Sicily are a high risk group for important STIs. It seems necessary that continuous interventions for preventing HIV/AIDS and other STIs and for improving the level of knowledge of symptoms are needed

Cancer: New needs, new models. is it time for a community oncologist? another brick in the wall

Over the last few decades, thanks to early detection, effective drugs, and personalized treatments, the natural history of cancer has radically changed. Thanks to these advances, we have observed how survival of cancer patients has increased, becoming an ever more important goal in cancer care. Effective clinical governance of survivorship care is essential to ensure a successful transition between active and post-treatment life, identifying optimization of healthcare outcomes and quality of life for patients as the primary objectives. For these reasons, potential intervention models must consider these differences to rationalize the available resources, including economic aspects. In this perspective, analyzing the different models proposed in the literature to manage this type of patients, we focus on the possible role of the so-called “community oncologist”. As a trained health professional, also focused on longevity, he could represent the right management solution in all those “intermediate” clinical conditions that arise between the hospital specialist, frequently overworked, and the general practitioner, often biased by the lack of specific expertise