Multiple stellar populations in Globular Clusters: collection of information from the Horizontal Branch

The majority of the inhomogeneities in the chemical composition of Globular Cluster (GC) stars appear due to primordial enrichment by hot-CNO cycled material processed in stars belonging to a first stellar generation. Either massive AGB envelopes subject to hot bottom burning, or the envelopes of massive fastly rotating stars could be the progenitors. In both cases, the stars showing chemical anomalies must have also enhanced helium abundance, and we have proposed that this higher helium could be at the basis of the many different morphologies of GC horizontal branches (HB) for similar ages and metallicities. The helium variations have been beautifully confirmed by the splitting of the main sequence in the clusters omega Cen and NGC 2808, but this effect can show up only for somewhat extreme helium abundances. Therefore it is important to go on using the HB morphology to infer the number ratio of the first to the second generation in as many clusters as possible. We exemplify how it is possible to infer the presence of a He-rich stellar component in different clusters thanks to different HB features (gaps, RR Lyr periods and period distribution, ratio of blue to red stars, blue tails). In many clusters at least 50% of the stars belong to the second stellar generation, and in some cases we suspect that the stars might all belong to the second generation. We shortly examine the problem of the initial mass function required to achieve the observed number ratios and conclude that: 1) the initial cluster must have been much more massive than today's cluster, and 2) formation of the second stellar generation mainly in the central regions of the cluster may help in obtaining the desired values.Comment: to appear in the Proceedings of IAU Symposium 246 ``Dynamical Evolution of Dense Stellar Systems", E. Vesperini, M. Gierzs & A. Sills, eds., Cambridge University Pres

Understanding preferences for nature based and sustainable tourism. The role of personal values and general and specific environmental attitudes

This paper reports the results of a study which investigated the social psychological correlates of people’s preferences for sustainable and unsustainable tourism activities. Two-hundred-eighty-two participants from two Italian cities responded to a questionnaire which recorded their tourism preferences, their general pro-environmental attitudes and values, and their specific attitudes towards sustainable tourism. Results showed positive correlations among the constructs considered. Groups of participants differing in their tourism preferences were also identified and the paper discusses the way in which the social psychological variables considered here may be used to plan adequate strategies and management instruments able to address crucial issues of sustainability in tourism, including, for example, tourists’ ecological behaviors “on site” and their educational needs

Time trends of dietary and lifestyle factors and their potential impact on diabetes burden in China

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Web Health Monitoring Survey: a new approach to enhance effectiveness of telemedicine systems

Aging of the European population and interest in a healthy population in western countries have contributed to an increase in the number of health surveys, where the role of survey design, data collection, and data analysis methodology is clear and recognized by the whole scientific community. Survey methodology has had to couple with the challenges deriving from data collection through information and communications technology (ICT). Telemedicine systems have not used patients as a source of information, often limiting them to collecting only biometric data. A more effective telemonitoring system would be able to collect objective and subjective data (biometric parameters and symptoms reported by the patients themselves), and to control the quality of subjective data collected: this goal be achieved only by using and merging competencies from both survey methodology and health research. The objective of our study was to propose new metrics to control the quality of data, along with the well-known indicators of survey methodology. Web questionnaires administered daily to a group of patients for an extended length of time are a Web health monitoring survey (WHMS) in a telemedicine system. We calculated indicators based on paradata collected during a WHMS study involving 12 patients, who signed in to the website daily for 2 months. The patients’ involvement was very high: the patients’ response rate ranged between 1.00 and 0.82, with an outlier of 0.65. Item nonresponse rate was very low, ranging between 0.0% and 7.4%. We propose adherence to the chosen time to connect to the website as a measure of involvement and cooperation by the patients: the difference from the median time ranged between 11 and 24 minutes, demonstrating very good cooperation and involvement from all patients. To measure habituation to the questionnaire, we also compared nonresponse rates to the items between the first and the second month of the study, and found no significant difference. We computed the time to complete the questionnaire both as a measure of possible burden for patient, and to detect the risk of automatic responses. Neither of these hypothesis was confirmed, and differences in time to completion seemed to depend on health conditions. Focus groups with patients confirmed their appreciation for this “new” active role in a telemonitoring system. The main and innovative aspect of our proposal is the use of a Web questionnaire to virtually recreate a checkup visit, integrating subjective (patient’s information) with objective data (biometric information). Our results, although preliminary and if need of further study, appear promising in proposing more effective telemedicine systems. Survey methodology could have an effective role in this growing field of research and applications

Is mass loss along the red giant branch of globular clusters sharply peaked? The case of M3

There is a growing evidence that several globular clusters must contain multiple stellar generations, differing in helium content. This hypothesis has helped to interpret peculiar unexplained features in their horizontal branches. In this framework we model the peaked distribution of the RR Lyr periods in M3, that has defied explanation until now. At the same time, we try to reproduce the colour distribution of M3 horizontal branch stars. We find that only a very small dispersion in mass loss along the red giant branch reproduces with good accuracy the observational data. The enhanced and variable helium content among cluster stars is at the origin of the extension in colour of the horizontal branch, while the sharply peaked mass loss is necessary to reproduce the sharply peaked period distribution of RR Lyr variables. The dispersion in mass loss has to be <~ 0.003 Msun, to be compared with the usually assumed values of ~0.02 Msun. This requirement represents a substantial change in the interpretation of the physical mechanisms regulating the evolution of globular cluster stars.Comment: Accepted for publication in The Astrophysical Journa

"UNDERSTANDING HUMAN VALUES IS A NEVER-ENDING PROCESS": CHALLENGES IN VALUES MEASUREMENT

L’obiettivo generale del progetto di ricerca è quello di riflettere sul tema della misurazione dei valori nell’ambito delle scienze psicosociali. Secondo la Teoria di Schwartz, i valori sono definiti come obiettivi desiderabili e transituazionali che servono come principi guida nella vita delle persone per guidare e determinare le azioni e gli atteggiamenti. I valori sono stati prevalentemente indagati tramite l’utilizzo di strumenti self-report per raccogliere dati quantitativi. Tuttavia, le risposte a questi strumenti possono essere influenzate da diversi bias, come ad esempio la desiderabilità sociale, oppure possono dipendere dalla tendenza a riflettere in modo introspettivo delle persone che rispondono. Ciò accade principalmente perché i valori sono per definizione ciò che è desiderabile e sono inoltre concetti astratti. Sulla base di queste riflessioni, i Capitoli 1 e 2 considerano in modo teorico ed empirico gli strumenti self-report di misura dei valori e i bias che possono influenzare le risposte a questi strumenti. I Capitoli 3, 4, 5 e 6 considerano invece un recente sviluppo nel campo della misurazione dei valori, ovvero la possibilità di studiare questo costrutto adottando la prospettiva della cognizione sociale implicita, utilizzando quindi strumenti indiretti per acquisire conoscenza sul tema. Nel presente lavoro sono stati sviluppati due strumenti indiretti utili alla misurazione di valori, il Values Implicit Association Task and the Values Lexical Decision Task; tali strumenti sono stati anche analizzati in funzione della loro relazione con gli strumenti self-report di valori e con un outcome comportamentale.The general aim of the present research project was to reflect on the measurement of values in the field of psychosocial sciences. According to Schwartz’s Theory, values are defined as desirable and trans-situational goals that serve as guiding principles in people's life to select modes, means, and actions. They have been mainly investigated using self-report instruments to gather quantitative data. However, respondents’ answers on these measures may be influenced by different response biases, such as for example socially desirable responding, or may depend on respondents’ tendency to introspection. This is mainly because values are by definition what is desirable, and they are abstract concepts. Based on this Chapters 1 and 2 theoretically and empirically deal with the available self-report measures of values and with the possible biases which are likely to influence respondents’ answers. Chapters 3 to 6 consider instead a recent trend in the field of values measurement, which is the possibility of studying values adopting an implicit social cognition perspective, that is using indirect measures to gain knowledge on the topic. Two indirect measures aimed at measuring values, namely the Values Implicit Association Test and the Values Lexical Decision Task, are here developed and considered in terms of their relations with self-report measures of values and with behavioural outcomes

Effects of Smoking on Oxidative Stress and Vascular Function

Tobacco smoking is the single most preventable risk factor related to the development of cardiovascular disease. It was demonstrated that tobacco smoke contains a thousand compounds potentially harmful to human health. As tobacco use declined over time, electronic cigarettes were introduced as an alternative. E-cigarettes are a modern and technological surrogate of traditional cigarettes and use heat to convert a nicotine solution or a flavored nicotine-free solution into vapor. Even though all the ingredients contained in the liquid of E-cigarettes are approved as food additives, the harmlessness of these electronic devices is still not fully proven in humans. The general mechanisms by which smoking results in cardiovascular events include the development of atherosclerotic changes with a hypercoagulable state and an increased risk of thrombosis. Endothelial dysfunction has been recognized as a hallmark of preclinical systemic atherosclerosis and as a useful marker to stratify the risk of cardiovascular disease. Based on these considerations, in this chapter, we (1) discussed the role of endothelial dysfunction and its contributing factors, such as oxidative stress and inflammation, in the development of cardiovascular diseases and (2) reported the studies which investigated the effect of tobacco and electronic smoking on the biomarkers of endothelial dysfunction, oxidative stress, and inflammation