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Let X be a real Banach space. The rectangular constant $\mu (X)$ and some generalisations of it, $\mu _p(X)$ for $p \geq 1$, were introduced by Gastinel and Joly around half a century ago. In this paper we make precise some characterisations of inner product spaces by using $\mu _p(X)$, correcting some statements appearing in the literature, and extend to $\mu _p(X)$ some characterisations of uniformly nonsquare spaces, known only for $\mu (X)$. We also give a characterisation of two-dimensional spaces with hexagonal norms. Finally, we indicate some new upper estimates concerning $\mu (l_p)$ and $\mu _p(l_p)$.
For some adolescents surfing the web can turn into a psychological defense and to be in contrast with a healthy mental development. It happen if the internet surfing becomes a compulsive need (Drusian, 2005). Massive use of the internet can promote the development of behavioral addictions such as pathological gambling (Cantelmi, D’Andrea, 2000).
Objectives and Aims:
The study investigates the correlation between social introversion, modality of the internet surfing and propensity to pathological gambling in a sample of Italian adolescents.
The research used a questionnaire divided into four areas: school performance, use of the internet, social introversion (SI scale of the MMPI-A); experiences of gambling (LIE/BET Questionnaire). 583 adolescents (45% males and 54% females, mean age 17 years) responded to the questionnaire.
Adolescents with high social introversion (high scores on Si scale) are 7.4% of the sample. These teenagers use the Internet many hours per day. They state that surfing the internet is a way to drive away negative thoughts about their lives. They think that life would be boring without the internet. Many adolescents with social introversion have high scores to LIE/BET Questionnaire. The study does not show a correlation between school performance and the others variables (social introversion, use of internet and propensity to pathological gambling).
Social introversion seems to be a predictor of psychological disease such as internet addiction and pathological gambling.
The Internet provides adolescents the chance to experience autonomy through the collection of information and contact with peers with whom to share experiences, emotions and thoughts. A misuse of the Internet can occur if a teenager avoids real relationships and surfing the web turns into a psychological defense, in contrast with a healthy mental development.
and Aims The research investigates forms and motivations of misuse of the internet among a group of Italian teenagers. Objective of the work is the hypothesis of a correlation between massive use of internet and behaviours of social retreat.
The research used a questionnaire. The areas of investigation were: school performance, hours of internet surfing, activity on the Internet (social networks, games, information research, gambling online), psychological reasons of the Internet use, behaviours of social retreat. 583 adolescents (45% males and 54% females, mean age 17 years) responded to the questionnaire.
The 6% of adolescents sample responded to always think the Internet even when not on the computer or gets irritated and reacts impulsively if someone bothers him while it is connected. The 5% prefer surfing rather then going out with friends. Hours of internet sulfing and responses of social retreat were correlated.
The social retreat can be one of consequences of the Internet misuse, with difficulties in socializing and use of the Internet as a psychological defense.
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