189 research outputs found
Hikikomori. La solitudine degli adolescenti giapponesi
Il Giappone oggi rappresenta la terza potenza economica mondiale in cui il costo della vita è alto, il tasso di natalità basso e le patologie psichiche derivate da stress sono in forte aumento. Allarmante è il fenomeno hikikomori, una volontaria e ostinata forma di “ritiro sociale” (social withdrawal), di auto reclusione che si sviluppa nell’adolescenza e che nei casi più gravi dura anche più di dieci anni. L’eziologia del fenomeno è piuttosto complessa ma, tra le ipotesi plausibili avanzate, si parla di un disagio psichico dovuto ad una serie di fattori tra cui l’interdipendenza fra genitori e figli, la presenza di una figura materna iperprotettiva a fronte di un’assenza del padre e soprattutto il contesto sociale omologante, coartativo e frustrante. Si tratta di elementi in grado di generare nell’adolescente un angoscioso senso di inadeguatezza, alimentato dalla paura in cui il confronto con l’altro diventa insostenibile ed il silenzio la sola forma di comunicazione. Un disagio relazionale che conta nel Paese del Sol Levante più di un milione di adolescenti, ma che va diffondendosi anche negli Stati Uniti e nel Nord Europa.
Le Japon représente aujourd'hui la troisième puissance économique mondiale, où le coût de la vie est élevé, le taux de natalité bas et les pathologies psychiques causées par le stress en forte augmentation. Le phénomène de l’hikikomori, une forme volontaire et obstinée de "retrait social" (social withdrawal), devient de plus en plus alarmant. Il s’agit d’une auto-réclusion qui se développe dans l'adolescence et qui, dans les cas les plus graves, peut durer plus de dix ans. L’étiologie du phénomène est plutôt complexe mais, parmi les hypothèses plausibles avancées, l’on parle d’un trouble psychique du à une série de facteurs, parmi lesquels figurent l'interdépendance entre parents et enfants, la présence d'une figure maternelle hyper protectrice conjuguée à l’absence du père, et surtout le contexte social uniformisant, oppressif et frustrant. Il s'agit d'éléments capables de provoquer chez l'adolescent un sentiment angoissant d'inadéquation, alimenté par la peur et dans lequel la comparaison avec l'Autre devient insoutenable et le silence la seule forme de communication. C’est un trouble relationnel qui concerne plus d'un million d'adolescents au Pays du Soleil Levant, et qui commence également à se répandre aux États-Unis et en Europe du Nord.
Japan represents today the third world economic power with a high cost of life, a low birth-rate and a growth in psychological stress. It is quite worrying the phenomenon called “hikikomori”: it represents a volunteer and obstinate “social withdrawal”, an intentional imprisonment developing during the adolescence that, in the most serious cases, could last more then ten years. The phenomenon causes are complicated; for instance, it could be caused by a malaise due to the interdependence between parents and children; on the one hand the overprotection of the mother figure and on the other hand the absence of the father figure; a standardizing and frustrating social context. So, a teenager could develop feelings of inadequacy and a lack of communication. This phenomenon counts in Japan more than a million of teenagers and it is taking hold also in the United States and in North Europe
Feynman path integrals on compact Lie groups with bi-invariant Riemannian metrics and Schr\"odinger equations
In this work we consider a suitable generalization of the Feynman path
integral on a specific class of Riemannian manifolds consisting of compact Lie
groups with bi-invariant Riemannian metrics. The main tools we use are the
Cartan development map, the notion of oscillatory integral, and the Chernoff
approximation theorem. We prove that, for a class of functions of a dense
subspace of the relevant Hilbert space, the Feynman map produces the solution
of the Schr\"odinger equation, where the Laplace-Beltrami operator coincides
with the second order Casimir operator of the group.Comment: 50 page
Chernoff approximations of Feller semigroups in Riemannian manifolds
Chernoff approximations of Feller semigroups and the associated diffusion
processes in Riemannian manifolds are studied. The manifolds are assumed to be
of bounded geometry, thus including all compact manifolds and also a wide range
of non-compact manifolds. Sufficient conditions are established for a class of
second order elliptic operators to generate a Feller semigroup on a (generally
non-compact) manifold of bounded geometry. A construction of Chernoff
approximations is presented for these Feller semigroups in terms of shift
operators. This provides approximations of solutions to initial value problems
for parabolic equations with variable coefficients on the manifold. It also
yields weak convergence of a sequence of random walks on the manifolds to the
diffusion processes associated with the elliptic generator. For parallelizable
manifolds this result is applied in particular to the representation of
Brownian motion on the manifolds as limits of the corresponding random walks.Comment: 36 pages, no figures. Title and abstract changed. Minor corrections,
some proposition generalise
Gestão democrática : participação efetiva da comunidade escolar
Orientadora : Cristina CardosoMonografia (especialização) - Universidade Federal do Paraná, Setor de Educação, Curso de Especializaçao em Gestão Escola
Clinical Prognosis in BRAF-Mutated PTC
BRAF mutation has recently emerged as a potential prognostic marker for papillary thyroid carcinoma (PTC) due to several studies suggesting that it may condition the development of tumors with aggressive behavior. A study of the phenotypes of thyroid follicular cell lines and transgenic mice characterized by targeted expression of BRAF mutation indicates that, at variance with RET/PTC rearrangement, it induces or facilitates genomic instability and higher invasiveness and eventually deeper tumor de-differentiation and more significant suppression of apoptosis. An analysis of differential gene expression of PTCs harboring BRAF mutation versus PTCs characterized by other genetic alterations shows an important impairment of the expression of genes related to intra-thyroidal iodine metabolism machinery, up-regulation of Glut-1 mRNA, methylation-induced gene silencing of tumor suppressor genes and up-regulation of pro-angiogenetic proteins such as VEGF. Correlation of BRAF mutation with PTC clinico-pathological features yields controversial results, with several studies showing the association with unfavourable clinico-pathological qualities, while others do not confirm the findings. This review will summarize the studies in favor of or in contrast with a role of BRAF mutation as a prognostic marker in PTC. We will also indicate what information we still need in order to routinely introduce this indicator in clinical practice
Depletion of the SR-related protein TbRRM1 leads to cell cycle arrest and apoptosis-like death in Trypanosoma brucei
Arginine-Serine (RS) domain-containing proteins are RNA binding proteins with multiple functions in RNA metabolism. In mammalian cells this group of proteins is also implicated in regulation and coordination of cell cycle and apoptosis. In trypanosomes, an early branching group within the eukaryotic lineage, this group of proteins is represented by 3 members, two of them are SR proteins and have been recently shown to be involved in rRNA processing as well as in pre-mRNA splicing and stability. Here we report our findings on the 3rd member, the SR-related protein TbRRM1. In the present study, we showed that TbRRM1 ablation by RNA-interference in T. brucei procyclic cells leads to cell-cycle block, abnormal cell elongation compatible with the nozzle phenotype and cell death by an apoptosis-like mechanism. Our results expand the role of the trypanosomal RS-domain containing proteins in key cellular processes such as cell cycle and apoptosis-like death, roles also carried out by the mammalian SR proteins, and thus suggesting a conserved function in this phylogenetically conserved protein family.Fil: Levy, Gabriela Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Bañuelos, Carolina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Níttolo, Analía Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Ortiz, Gastón Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Mendiondo, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Moretti, Georgina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Tekiel, Valeria Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Sanchez, Daniel Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin
Molecular-Level Switching of Polymer/Nanocrystal Non-Covalent Interactions and Application in Hybrid Solar Cells
Hy brid composites obtained upon blending conjugated polymers and colloidal
inorganic semiconductor nanocrystals are regarded as attractive photo-active
materials for optoelectronic applications. Here we demonstrate that tailoring
nanocrystal surface chemistry permits to exert control on non-covalent bonding
and electronic interactions between organic and inorganic components. The
pendant moieties of organic ligands at the nanocrystal surface do not merely
confer colloidal stability while hindering charge separation and transport, but
drastically impact morphology of hybrid composites during formation from blend
solutions. The relevance of our approach to photovoltaic applications is
demonstrated for composites based on poly(3-hexylthiophene) and Pbs
nanocrystals, considered as inadequate before the submission of this
manuscript, which enable the fabrication of hybrid solar cells displaying a
power conversion efficiency that reaches 3 %. Upon (quasi)steady-state and
time-resolved analisys of the photo-induced processes in the nanocomposites and
their organic and inorganic components, we ascertained that electron transfer
occurs at the hybrid interface yielding long-lived separated charge carriers,
whereas interfacial hole transfer appears slow. Here we provide a reliable
alternative aiming at gaining control over macroscopic optoelectronic
properties of polymer/nanocrystal composites by acting at the molecular-level
via ligands' pendant moieties, thus opening new possibilities towards efficient
solution-processed hybrid solar cells
The space density of z>4 blazars
High redshift blazars are an important class of Active Galactic Nuclei (AGN)
that can provide an independent estimate of the supermassive black-hole mass
function in high redshift radio-loud AGN without the bias due to absorption
along the line-of-sight. Using the Cosmic Lens All Sky Survey (CLASS) we built
a complete radio flux-limited sample of high redshift (z>4) blazars suitable
for statistical studies. By combining dedicated optical observations and the
SDSS spectroscopic database, we obtained a sample of 26 blazar candidates with
a spectroscopic redshift above 4. On the basis of their radio spectrum we
distinguish between blazars and QSO with a Gigahertz Peaked Spectrum (GPS) like
spectrum. Out of the 18 confirmed blazars 14 constitute a completely
identified, flux-limited sample down to a magnitude of 21 (AB). Using this
complete sample we derive a space density of blazars with 4<z<5.5 of rho=0.13
(+0.05,-0.03) Gpc^-3. This is the first actual estimate of the blazar space
density in this range of redshift. This value is in good agreement with the
extrapolation of the luminosity function and cosmological evolution based on a
sample of flat-spectrum radio quasars selected at lower redshifts and it is
consistent with a cosmological evolution peaking at z2 similar to
radio-quiet QSO. We do not confirm, instead, the presence of a peak at z~4 in
the space density evolution, recently suggested using an X-ray selected sample
of blazars. It is possible that this extreme peak of the evolution is present
only among the most luminous blazars.Comment: 14 pages, accepted for publication on MNRAS
(https://doi.org/10.1093/mnras/sty3526
Editorial: Systemic cellular immune responses and immunological biomarkers in emerging and re-emerging viral infections: an evolving landscape
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