819 research outputs found
Ipotesi sul ciclo in stucco di palazzo Altieri a Roma.
Il saggio contestualizza un ciclo significativo della produzione a stucco della Roma della seconda metĂ del 17. secolo
Condotte compulsive in paziente con sindrome di Aicardi. agenesia del corpo calloso
The corpus callosum, which is the largest white matter structure in the brain of all placental mammals, connects the left and right
cerebral hemispheres. An alteration in its morphology, hypoconnectivity or hyperconnectivity is a common marker of various
neuropsychiatric pathologies. One of these is Aicardi syndrome, which is characterized by a triad of callosal agenesis, infantile
spasms and chorioretinal lacunae. Patients affected by Aicardi syndrome frequently display other malformations together with
congenital defects of the eyes, ribs and vertebrae. Based on the current clinical knowledge, this syndrome is now recognized as
a complex neurodevelopmental disorder that includes neurological and constitutional symptoms. However, literature data have
not yet defined the presence of a particular set of symptoms in psychiatric patients with this condition. The present case is the
first report in which an on-going compulsive behaviour focused on the insistence to order objects has been observed in Aicardi syndrom
Dissociative symptoms in female patients with mood and anxiety disorders: a psychopathological and temperamental investigation.
Abstract
OBJECTIVE:
Dissociative symptoms are frequent among psychiatric patients and may considerably affect patients' psychopathological condition and treatment outcomes. The objectives of the study are to assess the presence of dissociative symptoms in female patients with mood and anxiety disorders, to investigate their correlation with the clinical severity of the disorders and to investigate those personality traits that are more frequent in patients with high levels of dissociation.
PATIENTS AND METHODS:
50 Caucasian females were enrolled in the study. Patients were assessed through the Self-Report Symptom Check-List, the Dissociative Experiences Scale (DES) and rating scales for Depression and Anxiety.
RESULTS:
The mean DES score in the overall sample was 16.6. 32% of patients had a DES score > 20. Depressive symptoms positively correlated with the DES total scores. Dissociator patients presented some significantly different temperamental characteristics in comparison with non dissociator patients.
CONCLUSIONS:
Dissociative symptoms are highly present in patients with mood and anxiety disorders and correlate with the severity of depressive symptoms. Specific personality traits more frequently observed in dissociator people may represent predisposing factors; their early identification could be clinically relevant
Attracted Diffusion-Limited Aggregation
In this paper, we present results of extensive Monte Carlo simulations of
diffusion-limited aggregation (DLA) with a seed placed on an attractive plane
as a simple model in connection with the electrical double layers. We compute
the fractal dimension of the aggregated patterns as a function of the
attraction strength \alpha. For the patterns grown in both two and three
dimensions, the fractal dimension shows a significant dependence on the
attraction strength for small values of \alpha, and approaches to that of the
ordinary two-dimensional (2D) DLA in the limit of large \alpha. For
non-attracting case with \alpha=1, our results in three dimensions reproduce
the patterns of 3D ordinary DLA, while in two dimensions our model leads to
formation of a compact cluster with dimension two. For intermediate \alpha, the
3D clusters have quasi-2D structure with a fractal dimension very close to that
of the ordinary 2D-DLA. This allows one to control morphology of a growing
cluster by tuning a single external parameter \alpha.Comment: 6 pages, 6 figures, to appear in Phys. Rev. E (2012
A parameter-free, solid-angle based, nearest-neighbor algorithm
We propose a parameter-free algorithm for the identification of nearest
neighbors. The algorithm is very easy to use and has a number of advantages
over existing algorithms to identify nearest- neighbors. This solid-angle based
nearest-neighbor algorithm (SANN) attributes to each possible neighbor a solid
angle and determines the cutoff radius by the requirement that the sum of the
solid angles is 4{\pi}. The algorithm can be used to analyze 3D images, both
from experiments as well as theory, and as the algorithm has a low
computational cost, it can also be used "on the fly" in simulations. In this
paper, we describe the SANN algorithm, discuss its properties, and compare it
to both a fixed-distance cutoff algorithm and to a Voronoi construction by
analyzing its behavior in bulk phases of systems of carbon atoms, Lennard-Jones
particles and hard spheres as well as in Lennard-Jones systems with
liquid-crystal and liquid-vapor interfaces
Phase separation and rotor self-assembly in active particle suspensions
Adding a non-adsorbing polymer to passive colloids induces an attraction
between the particles via the `depletion' mechanism. High enough polymer
concentrations lead to phase separation. We combine experiments, theory and
simulations to demonstrate that using active colloids (such as motile bacteria)
dramatically changes the physics of such mixtures. First, significantly
stronger inter-particle attraction is needed to cause phase separation.
Secondly, the finite size aggregates formed at lower inter-particle attraction
show unidirectional rotation. These micro-rotors demonstrate the self assembly
of functional structures using active particles. The angular speed of the
rotating clusters scales approximately as the inverse of their size, which may
be understood theoretically by assuming that the torques exerted by the
outermost bacteria in a cluster add up randomly. Our simulations suggest that
both the suppression of phase separation and the self assembly of rotors are
generic features of aggregating swimmers, and should therefore occur in a
variety of biological and synthetic active particle systems.Comment: Main text: 6 pages, 5 figures. Supplementary information: 5 pages, 4
figures. Supplementary movies available from
httP://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1116334109/-/DCSupplementa
Forward Flux Sampling for rare event simulations
Rare events are ubiquitous in many different fields, yet they are notoriously
difficult to simulate because few, if any, events are observed in a conventiona
l simulation run. Over the past several decades, specialised simulation methods
have been developed to overcome this problem. We review one recently-developed
class of such methods, known as Forward Flux Sampling. Forward Flux Sampling
uses a series of interfaces between the initial and final states to calculate
rate constants and generate transition paths, for rare events in equilibrium or
nonequilibrium systems with stochastic dynamics. This review draws together a
number of recent advances, summarizes several applications of the method and
highlights challenges that remain to be overcome.Comment: minor typos in the manuscript. J.Phys.:Condensed Matter (accepted for
publication
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