The impact of sleep on factual memory retention over 24 hr.

Although a period of sleep seems to benefit the retention of declarative memories, recent studies have challenged both the size of this effect and its active influence on memory consolidation. This study aimed to further investigate the effect of sleep and its time dependency on the consolidation of factual information. In a within-subjects design, 48 participants (M = 24.

Engineered swift equilibration of a Brownian gyrator.

In the context of stochastic thermodynamics, a minimal model for nonequilibrium steady states has been recently proposed: the Brownian gyrator (BG). It describes the stochastic overdamped motion of a particle in a two-dimensional harmonic potential, as in the classic Ornstein-Uhlenbeck process, but considering the simultaneous presence of two independent thermal baths. When the two baths have different temperatures, the steady BG exhibits a rotating current, a clear signature of nonequilibrium dynamics.

Efficacy of endoscopic triage during the Covid-19 outbreak and infective risk.

Objective: SARS-CoV-2 outbreak is spreading worldwide. As a consequence of the new circumstances, almost all endoscopic units underwent in-depth reorganization involving patients' selection. We analyzed the efficacy of the newly adopted endoscopic triage.

Breakdown of Scaling and Friction Weakening in Intermittent Granular Flow.

Many materials are produced, processed and stored as grains, while granularity of matter can be crucial in triggering potentially catastrophic geological events like landslides, avalanches and earthquakes. The response of grain assemblies to shear stress is therefore of utmost relevance to both human and natural environment. At low shear rate a granular system flows intermittently by distinct avalanches.

Dynamical Collective Memory in Fluidized Granular Materials.

Recent experiments with rotational diffusion of a probe in a vibrated granular media revealed a rich scenario, ranging from a dilute gas to a dense liquid with cage effects and an unexpected superdiffusive behavior at large times. Here we set up a simulation that reproduces quantitatively the experimental observations and allows us to investigate the properties of the host granular medium, a task not feasible in the experiment. We discover a persistent collective rotational mode which emerges at a high density and a low granular temperature: a macroscopic fraction of the medium slowly rotates, randomly switching direction after very long times.

Hydrodynamics of granular particles on a line.

We investigate a lattice model representing a granular gas in a thin channel. We deduce the hydrodynamic description for the model from the microscopic dynamics in the large-system limit, including the lowest finite-size corrections. The main prediction from hydrodynamics, when finite-size corrections are neglected, is the existence of a steady "uniform longitudinal flow" (ULF), with the granular temperature and the velocity gradient both uniform and directly related.

Preliminary safety and efficacy profile of prucalopride in the treatment of systemic sclerosis (SSc)-related intestinal involvement: results from the open label cross-over PROGASS study.

Background: Prokinetics are used to treat enteric dismotility symptoms in systemic sclerosis (SSc) patients, but they often lack adequate efficacy. The most effective prokinetics belonging to the serotonin (5-HT) receptor agonists class were withdrawn due to cardiac toxicity in relation to modest 5-HT receptor affinity. Prucalopride is a high-affinity 5-HT receptor agonist with no major cardiac issues, for which the efficacy in SSc has not yet been assessed.

Increasing 'ease of sliding' also increases friction: when is a lubricant effective?

We investigate experimentally the effective Coulomb friction exerted by a granular medium on a shearing plate, varying the medium depth. The plate is driven by a spring connected to a motor turning at a constant speed and, depending on the system configuration, performs continuous sliding or stick and slip in different proportions. We introduce an order parameter which discriminates between the different regimes expressing the fraction of time spent in slipping.

Is the subjective perception of lactose intolerance influenced by the psychological profile?

Background: Symptoms of lactose intolerance are often attributed to lactose malabsorption but, as this relationship has not been demonstrated when a small dose of lactose similar to that contained in one cup of milk is ingested by intolerant patients, psychological factors may play a role in altered symptom perception.

Aim: To assess the hypothesis that the psychological profile influences the symptoms of lactose intolerance.

Methods: One hundred and two consecutive patients underwent a 15 g lactose hydrogen breath test to assess lactose malabsorption.

Collective dynamics of social annotation.

The enormous increase of popularity and use of the worldwide web has led in the recent years to important changes in the ways people communicate. An interesting example of this fact is provided by the now very popular social annotation systems, through which users annotate resources (such as web pages or digital photographs) with keywords known as "tags." Understanding the rich emergent structures resulting from the uncoordinated actions of users calls for an interdisciplinary effort.

Brownian forces in sheared granular matter.

We present results from a series of experiments on a granular medium sheared in a Couette geometry and show that their statistical properties can be computed in a quantitative way from the assumption that the resultant from the set of forces acting in the system performs a Brownian motion. The same assumption has been utilized, with success, to describe other phenomena, such as the Barkhausen effect in ferromagnets, and so the scheme suggests itself as a more general description of a wider class of driven instabilities.

Self-stabilized fractality of seacoasts through damped erosion.

Erosion of rocky coasts spontaneously creates irregular seashores. But the geometrical irregularity, in turn, damps the sea waves, decreasing the average wave amplitude. There may then exist a mutual self-stabilization of the wave amplitude together with the irregular morphology of the coast.

Average trajectory of returning walks.

We compute the average shape of trajectories of some one-dimensional stochastic processes x(t) in the (t,x) plane during an excursion, i.e., between two successive returns to a reference value, finding that it obeys a scaling form.

Multicenter trial for the set-up of a MRI quality assurance programme.

Many international protocols related to RMI-QC program are focused on acquisition methods and analysis of several image quality parameters but rarely normality ranges or measurement frequencies are presented. To address this problem we investigated the variability of many magnetic resonance imaging (MRI) systems with the set-up of multicenter trial. The trial was set up to investigate short-and mid-term variability of two fundamental nongeometric image quality parameters: signal-to-noise (SNR) and integral percent uniformity (U%).

Average shape of a fluctuation: universality in excursions of stochastic processes.

We study the average shape of a fluctuation of a time series x(t), which is the average value (T) before x(t) first returns at time T to its initial value x(0). For large classes of stochastic processes, we find that a scaling law of the form (T) = T(alpha)f(t/T) is obeyed. The scaling function f(s) is, to a large extent, independent of the details of the single increment distribution, while it encodes relevant statistical information on the presence and nature of temporal correlations in the process.

Fluctuation-dissipation relations in driven granular gases.

We study the dynamics of a two-dimensional driven inelastic gas, by means of direct simulation Monte Carlo techniques, i.e., under the assumption of molecular chaos.

Possible protective effect of 5-aminosalicylic acid on Helicobacter pylori infection in patients with inflammatory bowel disease.

Goals: To evaluate the prevalence of (Hp) infection in a group of inflammatory bowel disease (IBD) outpatients and the possible influence of treatment.

Background: The low prevalence of Hp infection in these patients is usually attributed to environmental factors; the role of drugs has not been fully investigated.

Study: Seventy-two consecutive outpatients underwent a C13-urea breath test for Hp: 32 with Crohn's disease (13 men; mean age, 48 years; range, 20-72 years) and 40 with ulcerative colitis (25 men; mean age, 49 years; range, 25-71 years).

Cooling of a lattice granular fluid as an ordering process.

We present a microscopic model of granular medium to study the role of dynamical correlations and the onset of spatial order induced by the inelasticity of the interactions on the velocity field. In spite of its simplicity and intrinsic limitations, it features several aspects of the rich phenomenology observed in granular materials and allows to make contact with other topics of statistical mechanics such as diffusion processes, domain growth, aging phenomena. Interestingly, while local observables, being controlled by the largest wavelength fluctuations, seem to suggest a purely diffusive behavior, the formation of spatially extended structures and topological defects, such as vortices and shocks, reveals a more complex scenario.

Coarsening and slow dynamics in granular compaction.

We address the problem of the microscopic reorganization of a granular medium under a compaction process in the framework of Tetris-like models. We point out the existence of regions of spatial organization which we call domains, and study their time evolution. It turns out that after an initial transient, most of the activity of the system is concentrated on the boundaries between domains.

Driven granular gases with gravity.

We study fluidized granular gases in a stationary state determined by the balance between external driving and bulk dissipation. The two considered situations are inspired by recent experiments, where gravity plays a major role as a driving mechanism: in the first case, gravity acts only in one direction and the bottom wall is vibrated; in the second case, gravity acts in both directions and no vibrating walls are present. Simulations performed under the molecular chaos assumption show averaged profiles of density, velocity, and granular temperature that are in good agreement with the experiments.

Helicobacter pylori prevalence in patients with diabetes and its relationship to dyspeptic symptoms.

As available data on Helicobacter pylori infection in patients with diabetes are scattered and discordant, we evaluated the prevalence of H. pylori and its relationship to dyspeptic symptoms in adult patients with diabetes and subjects with dyspepsia. H.

Surface hardening and self-organized fractality through etching of random solids.

When a finite volume of etching solution is in contact with a disordered solid, complex dynamics of the solid-solution interface develop. If the etchant is consumed in the chemical reaction, the dynamics stop spontaneously on a self-similar fractal surface. As only the weakest sites are corroded, the solid surface gets progressively harder and harder.

Influence of caloric intake on gastric emptying of solids assessed by 13C-octanoic acid breath test.

Background: The 13C-octanoic breath test (13C-OBT), a recently developed technique to evaluate gastric emptying of solids, has been validated in comparison to scintigraphy with low caloric meals (250 kcal). However, there is consensus that for clinical studies total caloric load should be in excess of 300 kcal, but studies comparing 13C-OBT results after low and medium caloric meals are lacking.

Methods: Ten healthy subjects were given a 250-kcal and a 550-kcal meal in randomized order.

Scintigraphic imaging and absorption of a 5-aminosalicylic acid enema in patients with ileorectal anastomosis.

Unlabelled: Ileorectal anastomosis (IRA) is a possible surgical treatment for hyperacute and drug-unresponsive forms of ulcerative colitis (UC). UC relapses in the rectal remnant usually are prevented by chronic administration of 5-aminosalicylic acid (5-ASA) in topical formulations. The relationships between intestinal absorption and pattern of luminal spread of 5-ASA enemas are still unknown in patients with IRA.