Modelling of epitaxial film growth with a Ehrlich-Schwoebel barrier dependent on the step height

The formation of mounded surfaces in epitaxial growth is attributed to the presence of barriers against interlayer diffusion in the terrace edges, known as Ehrlich-Schwoebel (ES) barriers. We investigate a model for epitaxial growth using a ES barrier explicitly dependent on the step height. Our model has an intrinsic topological step barrier even in the absence of an explicit ES barrier. We show that mounded morphologies can be obtained even for a small barrier while a self-affine growth, consistent with the Villain-Lai-Das Sarma equation, is observed in absence of an explicit step barrier. The mounded surfaces are described by a super-roughness dynamical scaling characterized by locally smooth (faceted) surfaces and a global roughness exponent $\alpha>1$. The thin film limit is featured by surfaces with self-assembled three-dimensional structures having an aspect ratio (height/width) that may increase or decrease with temperature depending on the strength of step barrier.Comment: To appear in J. Phys. Cond. Matter; 3 movies as supplementary materia

Um Cálculo Aproximado do Poder das Pontas

Pétion de Villeneuve Jérome. L'Assemblée se retire pour la nomination d'un nouveau président, lors de la séance du 19 décembre 1790. In: Archives Parlementaires de 1787 à 1860 - Première série (1787-1799) Tome XXI - Du 26 novembre 1790 au 2 janvier 1791. Paris : Librairie Administrative P. Dupont, 1885. p. 568

Thrombus Formation on a Left Atrial Appendage Closure Device

info:eu-repo/semantics/publishedVersio

Covariant and Heavy Quark Symmetric Quark Models

There exist relativistic quark models (potential or MIT-bag) which satisfy the heavy quark symmetry (HQS) relations among meson decay constants and form factors. Covariant construction of the momentum eigenstates, developed here, can correct for spurious center-of-mass motion contributions.Proton form factor and M1 transitions in quarkonia are calculated. Explicit expression for the Isgur-Wise function is found and model determined deviations from HQS are studied. All results depend on the model parameters only. No additional ad hoc assumptions are needed.Comment: 34 pages (2 figures not included but avaliable upon request), LATEX, (to be published in Phys.Rev.D

Electromagnetic transition form factors of negative parity nucleon resonances

We have calculated the transition form factors for the electromagnetic excitation of the negative parity resonances of the nucleon using different models previously proposed and we discuss their results and limits by comparison with experimental data.Comment: 13 pages, 6 figures, to be published on Journal of Physics

Three-Dimensional Speckle-Tracking Echocardiography for the Global and Regional Assessments of Left Ventricle Myocardial Deformation in Breast Cancer Patients Treated with Anthracyclines

Background: Assessment of 2D/3D left ventricular ejection fraction (LVEF) and 2D global longitudinal strain (GLS) is the gold standard for diagnosing cancer therapeutics-related cardiac dysfunction (CTRCD). Although 3D speckle-tracking echocardiography (STE) has several advantages, it is not used in this setting. Methods: 105 breast cancer patients who underwent serial echocardiographic assessment during anthracycline therapy were included. STE was used to estimate 2D GLS, 3D GLS, 3D global circumferential strain (GCS), 3D global radial strain (GRS), and 3D global area strain (GAS). CTRCD was defined as an absolute decrease in 2D/3D LVEF > 10% to a value 15%. Results: 24 patients developed CTRCD. There was a significant worsening of all 3D strain parameters during chemotherapy. 3D strain regional analysis showed impaired contractility in the anterior, inferior, and septal walls. Variations of 3D GRS and 3D GCS were associated with a higher incidence of CTRCD and the variation of 3D GRS was an independent predictor of CTRCD. Variations of 3D GCS and 3D GRS had a good discrimination for predicting CTRCD, with optimal cutoff values of - 34.2% for 3D GCS and - 34.4% for 3D GRS. These variations were observed 45 and 23 days before the diagnosis of CTRCD, respectively. Conclusion: Variations of 3D strain parameters were predictive of and preceded CTRCD, and thus have added value over currently recommended 2D/3D LVEF and 2D GLS. Routine application of this technique should be considered to offer targeted monitoring and timely initiation of cardioprotective treatment.info:eu-repo/semantics/publishedVersio

Tecnologias e métodos que auxiliam na comunicação de surdocegos: uma revisão bibliográfica

Este artigo descreve a primeira análise de uma pesquisa bibliográfica que explora as abordagens dos trabalhos realizados na temática de deficiências múltiplas focado em pessoas com surdocegueira. Com a finalidade de identificar as tecnologias, as linguagens e os tipos de dispositivos utilizados na comunicação dos surdocegos e, que de alguma forma, auxiliem a sua educação. Como resultado inicial, identificou-se como principal linguagem para estabelecer a comunicação, o braile e suas derivações: bodybraile, fingerbraile, e uma predominância de recursos para a comunicação bidirecional na interação de indivíduos surdocegos. Foram poucos trabalhos que exploraram métodos ou recursos para aprendizagem

Multi-scale assessment of human-induced changes to Amazonian instream habitats

Context Land use change and forest degradation have myriad effects on tropical ecosystems. Yet their consequences for low-order streams remain very poorly understood, including in the world´s largest freshwater basin, the Amazon. Objectives Determine the degree to which physical and chemical characteristics of the instream habitat of low-order Amazonian streams change in response to past local- and catchment-level anthropogenic disturbances. Methods To do so, we collected field instream habitat (i.e., physical habitat and water quality) and landscape data from 99 stream sites in two eastern Brazilian Amazon regions. We used random forest regression trees to assess the relative importance of different predictor variables in determining changes in instream habitat response variables. Results Multiple drivers, operating at multiple spatial scales, were important in determining changes in the physical habitat and water quality of the sites. Although we found few similarities in modelled relationships between the two regions, we observed non-linear responses of specific instream characteristics to landscape change; for example 20 % of catchment deforestation resulted in consistently warmer streams. Conclusions Our results highlight the importance of local riparian and catchment-scale forest cover in shaping instream physical environments, but also underscore the importance of other land use changes and activities, such as road crossings and upstream agriculture intensification. In contrast to the property-scale focus of the Brazilian Forest code, which governs environmental regulations on private land, our results reinforce the importance of catchment-wide management strategies to protect stream ecosystem integrity