901 research outputs found
Hospital environment as a reservoir for cross transmission. Cleaning and disinfection procedures
Background. Healthcare associated infections (HAIs) represent a serious problem for public health, as they increase the morbidity and mortality rates, present a relevant financial burden, and significantly contribute to the antimicrobial resistance. Methods. The aim of this review was to investigate the literature about HAIs, with particular reference to hospital environments and the role of cleaning and disinfection procedures. Hospital environments are an essential reservoir for HAIs cross transmission, and the application of appropriate procedures related to hand hygiene and disinfection/sterilization of surfaces and instruments remain key strategies for controlling HAIs. Results. Different procedures, based on the risk associated with the healthcare procedure, are recommended for hand hygiene: washing with soap and water, antiseptic rubbing with alcohol-based disinfectants, antiseptic and surgical hand washing. Environmental surfaces can be treated with different products, and the mostly used are chlorine-based and polyphenolic disinfectant. The reprocessing of instruments is related to their use according to the Spaulding's classification. In addition, scientific evidence demonstrated the great relevance of the "bundles" (small set of practices performed together) in controlling HAIs. Conclusions. Research agenda should include the improvement of well-known effective preventive procedures and the development of new bundles devoted to high-risk procedures and specific microorganisms
Non-equilibrium dynamics of an active colloidal "chucker"
We report Monte Carlo simulations of the dynamics of a "chucker": a colloidal
particle which emits smaller solute particles from its surface, isotropically
and at a constant rate k_c. We find that the diffusion constant of the chucker
increases for small k_c, as recently predicted theoretically. At large k_c the
chucker diffuses more slowly due to crowding effects. We compare our simulation
results to those of a "point particle" Langevin dynamics scheme in which the
solute concentration field is calculated analytically, and in which
hydrodynamic effects can be included albeit in an approximate way. By
simulating the dragging of a chucker, we obtain an estimate of its apparent
mobility coefficient which violates the fluctuation-dissipation theorem. We
also characterise the probability density profile for a chucker which sediments
onto a surface which either repels or absorbs the solute particles, and find
that the steady state distributions are very different in the two cases. Our
simulations are inspired by the biological example of
exopolysaccharide-producing bacteria, as well as by recent experimental,
simulation and theoretical work on phoretic colloidal "swimmers".Comment: re-submission after referee's comment
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
Crystallization of hard-sphere glasses
We study by molecular dynamics the interplay between arrest and
crystallization in hard spheres. For state points in the plane of volume
fraction () and polydispersity (), we delineate states that spontaneously crystallize from those that do
not. For noncrystallizing (or precrystallization) samples we find
isodiffusivity lines consistent with an ideal glass transition at , independent of . Despite this, for , crystallization
occurs at . This happens on time scales for which the system is
aging, and a diffusive regime in the mean square displacement is not reached;
by those criteria, the system is a glass. Hence, contrary to a widespread
assumption in the colloid literature, the occurrence of spontaneous
crystallization within a bulk amorphous state does not prove that this state
was an ergodic fluid rather than a glass.Comment: 4 pages, 3 figure
Consumption patterns of social assistance (Bansos) recipients in the Bangka Belitung Islands Province
Poverty is one of the main problems in economic development, and various efforts are made to improve and expand social assistance programs (Bansos). This study aims to analyze the consumption patterns of Bansos recipients in Bangka Belitung Province. The data used are secondary data from various related agencies and primary data sourced from surveys on Bansos recipient households. The scope of the research covers two districts with the highest and lowest number of beneficiary households in the Province of Bangka Belitung Islands. The analytical method used is linear regression analysis. The results showed that Bansos significantly affected public spending, especially food spending, cellphone credit, and business capital. On the other hand, the provision of Bansos does not significantly affect expenditures such as non-food consumption, education, health, cigarettes, and debt paymen
Local structure of liquid carbon controls diamond nucleation
Diamonds melt at temperatures above 4000 K. There are no measurements of the
steady-state rate of the reverse process: diamond nucleation from the melt,
because experiments are difficult at these extreme temperatures and pressures.
Using numerical simulations, we estimate the diamond nucleation rate and find
that it increases by many orders of magnitude when the pressure is increased at
constant supersaturation. The reason is that an increase in pressure changes
the local coordination of carbon atoms from three-fold to four-fold. It turns
out to be much easier to nucleate diamond in a four-fold coordinated liquid
than in a liquid with three-fold coordination, because in the latter case the
free-energy cost to create a diamond-liquid interface is higher. We speculate
that this mechanism for nucleation control is relevant for crystallization in
many network-forming liquids. On the basis of our calculations, we conclude
that homogeneous diamond nucleation is likely in carbon-rich stars and unlikely
in gaseous planets
VECTOR AUTO REGRESSION ANALYSIS BETWEEN EXPORT, ECONOMIC GROWTH, AND JOB OPPORTUNITY IN BANGKA BELITUNG ISLANDS PROVINCE
Purpose of the study: The economic performance of Bangka Belitung Islands province has increased during the period of 2007-2016. This is marked by the increasing growth rate of Gross Regional Domestic Product (GRDP) measured at the constant price of 68 percent. These performance improvements should be accompanied by efforts to create job opportunities (for instance, by increasing exports) to boost the economic growth. The objective of the study was to examine and analyze the causality relationship between job opportunities, exports, and economic growth in the Bangka Belitung Islands province.
Methodology: This research used secondary data with Vector Auto Regression (VAR) analysis tool.
Main Findings: The test results indicated that job opportunities and exports are affected by job opportunity in the previous year (t-1). Furthermore, the results of the study show that in comparison to exports, job opportunity contributes more towards the economic growth.
Implications: This study implies that government may provide non-export oriented job opportunities in the province of Bangka Belitung Islands
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
Crystallization Mechanism of Hard Sphere Glasses
In supercooled liquids, vitrification generally suppresses crystallization.
Yet some glasses can still crystallize despite the arrest of diffusive motion.
This ill-understood process may limit the stability of glasses, but its
microscopic mechanism is not yet known. Here we present extensive computer
simulations addressing the crystallization of monodisperse hard-sphere glasses
at constant volume (as in a colloid experiment). Multiple crystalline patches
appear without particles having to diffuse more than one diameter. As these
patches grow, the mobility in neighbouring areas is enhanced, creating dynamic
heterogeneity with positive feedback. The future crystallization pattern cannot
be predicted from the coordinates alone: crystallization proceeds by a sequence
of stochastic micro-nucleation events, correlated in space by emergent dynamic
heterogeneity.Comment: 4 pages 4 figures Accepted for publication in Phys. Rev. Lett., April
201
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
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