Phase separation and critical percolation in bidimensional spin-exchange models

Binary mixtures prepared in an homogeneous phase and quenched into a two-phase region phase-separate via a coarsening process whereby domains of the two phases grow in time. With a numerical study of a spin-exchange model we show that this dynamics first takes a system with equal density of the two species to a critical percolation state. We prove this claim and we determine the time-dependence of the growing length associated to this process with the scaling analysis of the statistical and morphological properties of the clusters of the two phases.Comment: 6 pages, 9 figure

Critical percolation in the dynamics of the 2d ferromagnetic Ising model

We study the early time dynamics of the 2d ferromagnetic Ising model instantaneously quenched from the disordered to the ordered, low temperature, phase. We evolve the system with kinetic Monte Carlo rules that do not conserve the order parameter. We confirm the rapid approach to random critical percolation in a time-scale that diverges with the system size but is much shorter than the equilibration time. We study the scaling properties of the evolution towards critical percolation and we identify an associated growing length, different from the curvature driven one. By working with the model defined on square, triangular and honeycomb microscopic geometries we establish the dependence of this growing length on the lattice coordination. We discuss the interplay with the usual coarsening mechanism and the eventual fall into and escape from metastability.Comment: 67 pages, 33 figure

Quenched dynamics of classical isolated systems: the spherical spin model with two-body random interactions or the Neumann integrable model

We study the Hamiltonian dynamics of the spherical spin model with fully-connected two-body interactions drawn from a Gaussian probability distribution. In the statistical physics framework, the potential energy is of the so-called $p=2$ spherical disordered kind. Most importantly for our setting, the energy conserving dynamics are equivalent to the ones of the Neumann integrable system. We take initial conditions in thermal equilibrium and we subsequently evolve the configurations with Newton dynamics dictated by a different Hamiltonian. We identify three dynamical phases depending on the parameters that characterise the initial state and the final Hamiltonian. We obtain the {\it global} dynamical observables with numerical and analytic methods and we show that, in most cases, they are out of thermal equilibrium. We note, however, that for shallow quenches from the condensed phase the dynamics are close to (though not at) thermal equilibrium. Surprisingly enough, for a particular relation between parameters the global observables comply Gibbs-Boltzmann equilibrium. We next set the analysis of the system with finite number of degrees of freedom in terms of $N$ non-linearly coupled modes. We evaluate the mode temperatures and we relate them to the frequency-dependent effective temperature measured with the fluctuation-dissipation relation in the frequency domain, similarly to what was recently proposed for quantum integrable cases. Finally, we analyse the $N-1$ integrals of motion and we use them to show that the system is out of equilibrium in all phases, even for parameters that show an apparent Gibbs-Boltzmann behaviour of global observables. We elaborate on the role played by these constants of motion in the post-quench dynamics and we briefly discuss the possible description of the asymptotic dynamics in terms of a Generalised Gibbs Ensemble

The Compound Muscle Action Potential as Neurophysiological Marker for Amyotrophic Lateral Sclerosis.

Objectives: To definite the peripheral nervous involvement in ALS through the repeated use of the compound motor action potential (CMAP) to test the progression of disease, to determine different change of phrenic CMAP and forced vital capacity (FVC) in spinal and bulbar onset, and to establish clinical and neurophysiological features of patients with poor prognosis. Material & Methods: CMAP from phrenic, ulnar, and medial plantar nerves, Medical Research Council (MRC) score, revised ALS functional rating scale (ALSFRS-R) and FVC were evaluated in 117 ALS patients every three months in one year-period. Results: Bulbar onset patients had lower FVC but similar amplitude of phrenic CMAP at baseline compared to spinal onset patients. The patients with poor prognosis had lower phrenic CMAP and FVC at baseline. CMAP values, when compared to the rate found in the previous visit, reduced significantly in both poor and good prognosis groups during the entire follow-up period, while the FVC reduced significantly only in the first three months. Conclusions: CMAP is a reproducible sensitive marker for motor neurons loss and collateral reinnervation in ALS also in a short period of time. The changes in CMAP, MRC, FVC and ALSFRS-R score resulted correlated, but CMAP is the only parameter with the advantage to demonstrate objectively the progression of disease in both patients with poor and good prognosis for the entire period of follow-up. It should be used as clinical outcome of ALS in clinical trials, taking advantage of its objectivity and selectivity for peripheral nervous system study

3D Cephalometric Normality Range: Auto Contractive Maps (ACM) Analysis in Selected Caucasian Skeletal Class I Age Groups

The objective of this paper is to define normal values of a novel 3D cephalometric analysis and to define the links through an artificial neural network (ANN)

In Vitro and In Vivo Assessment of a New Workflow for the Acquisition of Mandibular Kinematics Based on Portable Tracking System with Passive Optical Reflective Markers

Clinical use of portable optical tracking system in dentistry could improve the analysis of mandibular movements for diagnostic and therapeutic purposes. A new workflow for the acquisition of mandibular kinematics was developed. Reproducibility of measurements was tested in vitro and intra- and inter-rater repeatability were assessed in vivo in healthy volunteers. Prescribed repeated movements (n = 10) in three perpendicular directions of the tracking-device coordinate system were performed. Measurement error and coefficient of variation (CV) among repetitions were determined. Mandibular kinematics of maximum opening, left and right laterality, protrusion and retrusion of five healthy subjects were recorded in separate sessions by three different operators. Obtained records were blindly examined by three observers. Intraclass correlation coefficient (ICC) was calculated to estimate inter-rater and intra-rater reliability. Maximum in vitro measurement error was 0.54 mm and CV = 0.02. Overall, excellent intra-rater reliability (ICC > 0.90) for each variable, general excellent intra-rater reliability (ICC = 1.00) for all variables, and good reliability (ICC > 0.75) for inter-rater tests were obtained. A lower score was obtained for retrusion with “moderate reliability” (ICC = 0.557) in the inter-rater tests. Excellent repeatability and reliability in optical tracking of primary movements were observed using the tested portable tracking device and the developed workflow

Detection of bovine mitochondrial DNA in ruminant feeds: a molecular approach to test for the presence of bovine-derived materials.

A ban on ruminant-derived proteins in ruminant feeds has been introduced as a preventive measure to avoid the spread of bovine spongiform encephalopathy (BSE), as well as to minimize any potential risk of BSE transmission from bovines to humans. In the absence of commercially available efficient methods for identification of bovine-derived proteins in animal feeds, we developed a rapid and sensitive polymerase chain reaction (PCR)-based assay which allows detection and identification of a bovine-specific mitochondrial DNA sequence from feedstuffs. The amplified product encodes for the whole ATPase subunit 8 and the amino-terminal portion of the ATPase subunit 6 proteins, which are known to exhibit a relatively low degree of conservation among vertebrates. The specific amplification of such a bovine mitochondrial sequence from reference feedstuff samples was demonstrated by means of both direct sequencing and single-strand conformational analysis of the PCR product. Specificity was also confirmed by the absence of detectable homologous PCR product when using reference feedstuff samples lacking bovine-derived meat and bonemeals, or genomic DNA samples from vertebrates whose offals are commonly included in animal feeds. This method allows detection of the presence of bovine mitochondrial DNA in feedstuffs containing less than 0.125% of bovine-derived meat and bonemeals. Furthermore, it does not appear to be considerably affected by prolonged heat treatment. DpnII and SspI restriction endonuclease digestions of the unpurified PCR product may be used routinely to confirm the bovine origin of the amplified sequence. Since this method is specific, rapid, and sensitive, it could be successfully utilized as a routine control assay to evaluate the presence of bovine-derived meat and bonemeals in ruminant feeds

Whole exome sequencing in an Italian family with isolated maxillary canine agenesis and canine eruption anomalies

Objective: The aim of this study was the clinical and molecular characterization of a family segregating a trait consisting of a phenotype specifically involving the maxillary canines, including agenesis, impaction and ectopic eruption, characterized by incomplete penetrance and variable expressivity. Design: Clinical standardized assessment of 14 family members and a whole-exome sequencing (WES) of three affected subjects were performed. WES data analyses (sequence alignment, variant calling, annotation and prioritization) were carried out using an in-house implemented pipeline. Variant filtering retained coding and splice-site high quality private and rare variants. Variant prioritization was performed taking into account both the disruptive impact and the biological relevance of individual variants and genes. Sanger sequencing was performed to validate the variants of interest and to carry out segregation analysis. Results: Prioritization of variants “by function” allowed the identification of multiple variants contributing to the trait, including two concomitant heterozygous variants in EDARADD (c.308C>T, p.Ser103Phe) and COL5A1 (c.1588G>A, p.Gly530Ser), specifically associated with a more severe phenotype (i.e. canine agenesis). Differently, heterozygous variants in genes encoding proteins with a role in the WNT pathway were shared by subjects showing a phenotype of impacted/ectopic erupted canines. Conclusions: This study characterized the genetic contribution underlying a complex trait consisting of isolated canine anomalies in a medium-sized family, highlighting the role of WNT and EDA cell signaling pathways in tooth development