Deviancy as social problem: the answers of psychology [La devianza come problema sociale: le risposte della psicologia]

Scopo: Il comportamento deviante è tale in quanto infrange una serie di norme sociali più o meno consapevolmente riconosciute dai più. Scopo dello studio è descrivere e analizzare le caratteristiche di tale comportamento. Materiali e metodi: Si è tentato di individuare le cause della devianza in un rapporto complesso con le figure genitoriali, con l’Autorità generalmente intesa, con i Gruppi sociali che detengono il Potere ecc. valutando teorie a partire dalla psicoanalisi fino alla più recente sociologia. Risultati e conclusioni: Pur ammettendo la possibile presenza di un certo tipo di disturbi di personalità nella struttura psichica del deviante, non si può non puntare l’attenzione sulle metodiche che le varie società utilizzano per l’integrazione dei cittadini, soprattutto nelle agenzie fondamentali preposte all’educazione del minore: famiglia e scuola. Metodi didattici all’avanguardia, che senz’altro forniscano al discente griglie comportamentali e regole di condotta, che però al tempo stesso non dimentichino la dimensione fondamentale del gioco, dello svago e della ricerca personale, sono da incentivare fortemente. Con la consapevolezza che, nel bambino e nell’adolescente, “trasgredire” determinate regole con coscienza critica e capacità di discernimento, aiuta a formare un cittadino consapevole, responsabile e rivolto all’innovazione di paradigmi comportamentali spesso datati e inadeguati, anche se comunemente accettati con passività dai più.Scope: Deviant behaviour is the one that breaks those rules most people regard as social. The study describes and analyzes the characteristics of this behavior. Materials and Methods: Psychology and also the latest Sociological Theories have tried to find the causes of deviance in the complex and difficult relationship with parental figures, with Authority in general, with the Part of society that holds Power etc. Results and Conclusions: While admitting the possible presence of some kinds of personality disorders in the deviant’s psychic structure we cannot avoid focusing on the methodologies used for the integration of citizen above all in those fundamental units in charge of minors’ education: Family and School. Advanced teaching methods which can provide behavioural models and rules are to be strongly encouraged, without forgetting the essential dimension of playing, of research and also of individual personal growth. Nevertheless we must be aware that ‘breaking’ the rules with a sense of responsibility and discernment helps a young man to grow informed and responsible, able to renew his behavioural patterns often dated and deficient albeit mainly passively accepted

An atlas for tridiagonal isospectral manifolds

Let ${\cal T}_\Lambda$ be the compact manifold of real symmetric tridiagonal matrices conjugate to a given diagonal matrix $\Lambda$ with simple spectrum. We introduce {\it bidiagonal coordinates}, charts defined on open dense domains forming an explicit atlas for ${\cal T}_\Lambda$. In contrast to the standard inverse variables, consisting of eigenvalues and norming constants, every matrix in ${\cal T}_\Lambda$ now lies in the interior of some chart domain. We provide examples of the convenience of these new coordinates for the study of asymptotics of isospectral dynamics, both for continuous and discrete time.Comment: Fixed typos; 16 pages, 3 figure

The Asymptotics of Wilkinson's Iteration: Loss of Cubic Convergence

One of the most widely used methods for eigenvalue computation is the $QR$ iteration with Wilkinson's shift: here the shift $s$ is the eigenvalue of the bottom $2\times 2$ principal minor closest to the corner entry. It has been a long-standing conjecture that the rate of convergence of the algorithm is cubic. In contrast, we show that there exist matrices for which the rate of convergence is strictly quadratic. More precisely, let $T_X$ be the $3 \times 3$ matrix having only two nonzero entries $(T_X)_{12} = (T_X)_{21} = 1$ and let $T_L$ be the set of real, symmetric tridiagonal matrices with the same spectrum as $T_X$. There exists a neighborhood $U \subset T_L$ of $T_X$ which is invariant under Wilkinson's shift strategy with the following properties. For $T_0 \in U$, the sequence of iterates $(T_k)$ exhibits either strictly quadratic or strictly cubic convergence to zero of the entry $(T_k)_{23}$. In fact, quadratic convergence occurs exactly when $\lim T_k = T_X$. Let $X$ be the union of such quadratically convergent sequences $(T_k)$: the set $X$ has Hausdorff dimension 1 and is a union of disjoint arcs $X^\sigma$ meeting at $T_X$, where $\sigma$ ranges over a Cantor set.Comment: 20 pages, 8 figures. Some passages rewritten for clarit

An X-ray Survey in SA 57 with XMM-Newton

The maximum number density of Active Galactic Nuclei (AGNs), as deduced from X-ray studies, occurs at z<~1, with lower luminosity objects peaking at smaller redshifts. Optical studies lead to a different evolutionary behaviour, with a number density peaking at z~2 independently of the intrinsic luminosity, but this result is limited to active nuclei brighter than the host galaxy. A selection based on optical variability can detect low luminosity AGNs (LLAGNs), where the host galaxy light prevents the identification by non-stellar colours. We want to collect X-ray data in a field where it exists an optically-selected sample of "variable galaxies'', i.e. variable objects with diffuse appearance, to investigate the X-ray and optical properties of the population of AGNs, particularly of low luminosity ones, where the host galaxy is visible. We observed a field of 0.2 deg^2 in the Selected Area 57, for 67ks with XMM-Newton. We detected X-ray sources, and we correlated the list with a photographic survey of SA 57, complete to B_J~23 and with available spectroscopic data. We obtained a catalogue of 140 X-ray sources to limiting fluxes 5x10^-16, 2x10^-15 erg/cm^2/s in the 0.5-2 keV and 2-10 keV respectively, 98 of which are identified in the optical bands. The X-ray detection of part of the variability-selected candidates confirms their AGN nature. Diffuse variable objects populate the low luminosity side of the sample. Only 25/44 optically-selected QSOs are detected in X-rays. 15% of all QSOs in the field have X/O<0.1.Comment: 13 pages, 6 figures, 4 tables, A&A in pres

Dynamics of the symmetric eigenvalue problem with shift strategies

A common algorithm for the computation of eigenvalues of real symmetric tridiagonal matrices is the iteration of certain special maps $F_\sigma$ called shifted $QR$ steps. Such maps preserve spectrum and a natural common domain is ${\cal T}_\Lambda$, the manifold of real symmetric tridiagonal matrices conjugate to the diagonal matrix $\Lambda$. More precisely, a (generic) shift s \in \RR defines a map $F_s: {\cal T}_\Lambda \to {\cal T}_\Lambda$. A strategy \sigma: {\cal T}_\Lambda \to \RR specifies the shift to be applied at $T$ so that $F_\sigma(T) = F_{\sigma(T)}(T)$. Good shift strategies should lead to fast deflation: some off-diagonal coordinate tends to zero, allowing for reducing of the problem to submatrices. For topological reasons, continuous shift strategies do not obtain fast deflation; many standard strategies are indeed discontinuous. Practical implementation only gives rise systematically to bottom deflation, convergence to zero of the lowest off-diagonal entry $b(T)$. For most shift strategies, convergence to zero of $b(T)$ is cubic, $|b(F_\sigma(T))| = \Theta(|b(T)|^k)$ for $k = 3$. The existence of arithmetic progressions in the spectrum of $T$ sometimes implies instead quadratic convergence, $k = 2$. The complete integrability of the Toda lattice and the dynamics at non-smooth points are central to our discussion. The text does not assume knowledge of numerical linear algebra.Comment: 22 pages, 4 figures. This preprint borrows heavily from the unpublished preprint arXiv:0912.3376 but is adapted for a different audienc