Non-equilibrium Phase-Ordering with a Global Conservation Law

In all dimensions, infinite-range Kawasaki spin exchange in a quenched Ising model leads to an asymptotic length-scale $L \sim (\rho t)^{1/2} \sim t^{1/3}$ at $T=0$ because the kinetic coefficient is renormalized by the broken-bond density, $\rho \sim L^{-1}$. For $T>0$, activated kinetics recovers the standard asymptotic growth-law, $L \sim t^{1/2}$. However, at all temperatures, infinite-range energy-transport is allowed by the spin-exchange dynamics. A better implementation of global conservation, the microcanonical Creutz algorithm, is well behaved and exhibits the standard non-conserved growth law, $L \sim t^{1/2}$, at all temperatures.Comment: 2 pages and 2 figures, uses epsf.st

Comment on ``Theory of Spinodal Decomposition''

I comment on a paper by S. B. Goryachev [PRL vol 72, p.1850 (1994)] that presents a theory of non-equilibrium dynamics for scalar systems quenched into an ordered phase. Goryachev incorrectly applies only a global conservation constraint to systems with local conservation laws.Comment: 2 pages LATeX (REVTeX macros), no figures. REVISIONS --- more to the point. microscopic example added, presentation streamlined, long-range interactions mentioned, to be published in Phys. Rev. Let

Numerical Simulation of Nano Scanning in Intermittent-Contact Mode AFM under Q control

We investigate nano scanning in tapping mode atomic force microscopy (AFM) under quality (Q) control via numerical simulations performed in SIMULINK. We focus on the simulation of whole scan process rather than the simulation of cantilever dynamics and the force interactions between the probe tip and the surface alone, as in most of the earlier numerical studies. This enables us to quantify the scan performance under Q control for different scan settings. Using the numerical simulations, we first investigate the effect of elastic modulus of sample (relative to the substrate surface) and probe stiffness on the scan results. Our numerical simulations show that scanning in attractive regime using soft cantilevers with high Qeff results in a better image quality. We, then demonstrate the trade-off in setting the effective Q factor (Qeff) of the probe in Q control: low values of Qeff cause an increase in tapping forces while higher ones limit the maximum achievable scan speed due to the slow response of the cantilever to the rapid changes in surface profile. Finally, we show that it is possible to achieve higher scan speeds without causing an increase in the tapping forces using adaptive Q control (AQC), in which the Q factor of the probe is changed instantaneously depending on the magnitude of the error signal in oscillation amplitude. The scan performance of AQC is quantitatively compared to that of standard Q control using iso-error curves obtained from numerical simulations first and then the results are validated through scan experiments performed using a physical set-up

Enfermedad carcinoide cardiaca multivalvular

ResumenHombre de 67 años de edad, enviado a valoración ecocardiográfica por cuadro clínico de 6meses de evolución con: disnea de esfuerzo, edemas de miembros inferiores y fatiga. Se encuentra doble lesión de la válvula tricúspide con: estenosis e insuficiencia severa, insuficiencia pulmonar severa; y compromiso valvular izquierdo con: insuficiencia mitral y aórtica severas, asociadas a engrosamiento y rigidez valvular. El paciente tenía como antecedente tumor neuroendocrino de íleon, metastásico a pulmón e hígado.En este caso se discuten los hallazgos ecocardiográficos característicos del síndrome carcinoide con compromiso multivalvular como hallazgo inusual de este raro síndrome.AbstractA 67 year-old man is sent to echocardiographic assessment for 6 month history of exertional: dyspnea, edema of the lower extremities, fatigue, double lesions in tricuspid valve with: severe stenosis and severe regurgitation, severe pulmonary valve regurgitation; and left side valvular disease with: severe aortic regurgitation and severe mitral regurgitation, all of them associated with valvular thickening, rigidity, in a patient with history of neuroendocrine tumor, with lung and liver metastases.This case discuss the echocardiographic findings suggestive of carcinoid multivalvular and left side valvular disease as unusual finding in this rare syndrome

Digital skills, ICTs and students’ needs: a case study in social work degree, University of Zaragoza (Aragón-Spain)

Technological innovations are related to information and communication technologies (ICTs), which in turn have become a fundamental pillar in the field of education. Social work professionals require new approaches to take on the new type of work demanded by the digital society, specializing in research into the innovation of these new forms of action through technology. This article analyses whether university training is in tune with the new skills and abilities required for professional interventions in the twenty-first century. A total of 288 surveys were carried out on 309 students. Each survey consisted of 25 questions on the five digital skills areas. The results indicate that training in digital skills must gain space in university training plans, just as the pandemic became a starting point for the massive use of ICTs. The conclusions point to the importance of improving training in digital competences and skills for future generations of social workers, who, although they are digital natives, will need to know how to use ICTs in their social work

Profilaxis antibiótica en cirugía

Existe una abundantísima documentación en la literatura acerca de la eficacia de los antibióticos utilizados profilácticamente en cirugía (1-10). Probablemente lo más útil para el trabajo diario de un hospital sea la adopción de pautas concretas que permitan ser evaluadas periódicamente a través de la colaboración, entre otros, de anestesistas, cirujanos y microbiólogos (11,12). En esta línea hemos revisado, de una manera intencionadamente esquemática, diversas facetas relativas a la profilaxis antibiótica en cirugía. Para ello comentaremos algunos aspectos generales de profilaxis de la infección postquirúrgica, unas breves normas para la utilización profiláctica de antibióticos y resumiremos determinadas indicaciones en función del tipo de intervención

Elucidation of Directionality for Co-Expressed Genes: Predicting Intra-Operon Termination Sites

We present a novel framework for inferring regulatory and sequence-level information from gene co-expression networks. The key idea of our methodology is the systematic integration of network inference and network topological analysis approaches for uncovering biological insights. We determine the gene co-expression network of Bacillus subtilis using Affymetrix GeneChip time series data and show how the inferred network topology can be linked to sequence-level information hard-wired in the organism's genome. We propose a systematic way for determining the correlation threshold at which two genes are assessed to be co-expressed by using the clustering coefficient and we expand the scope of the gene co-expression network by proposing the slope ratio metric as a means for incorporating directionality on the edges. We show through specific examples for B. subtilis that by incorporating expression level information in addition to the temporal expression patterns, we can uncover sequence-level biological insights. In particular, we are able to identify a number of cases where (i) the co-expressed genes are part of a single transcriptional unit or operon and (ii) the inferred directionality arises due to the presence of intra-operon transcription termination sites.Comment: 7 pages, 8 figures, accepted in Bioinformatic

Análisis e identificación de los volátiles procedentes del barrenillo del olivo Phloetribus scarabaeoides. Contribución a la determinación de los semioquímicos asociados

Se ha llevado a cabo un estudio sistemático de los semioquímicos asociados al barrenillo del olivo Phloeotribusscarabaeoides (Bern.) Que implica el análisis por CG y CG-EM de los volátiles procedentes de diferentes materiales(leños de poda, ramas del árbol, serrines e insectos)a fin de determinar las posibles kairomonas, feromonas yrepelentes