Rates of convergence to scaling profiles in a submonolayer deposition model and the preservation of memory of the initial condition

We establish rates of convergence of solutions to scaling (or similarity) profiles in a coagulation type system modelling submonolayer deposition. We prove that, although all memory of the initial condition is lost in the similarity limit, information about the large cluster tail of the initial condition is preserved in the rate of approach to the similarity profile. The proof relies in a change of variables that allows for the decoupling of the original infinite system of ordinary differential equations into a closed two-dimensional nonlinear system for the monomer--bulk dynamics and a lower triangular infinite dimensional linear one for the cluster dynamics. The detailed knowledge of the long time monomer concentration, which was obtained earlier by Costin et al. in (O. Costin, M. Grinfeld, K.P. O'Neill and H. Park, Long-time behaviour of point islands under fixed rate deposition, Commun. Inf. Syst. 13, (2), (2013), pp.183-200) using asymptotic methods and is rederived here by center manifold arguments, is then used for the asymptotic evaluation of an integral representation formula for the concentration of $j$-clusters. The use of higher order expressions, both for the Stirling expansion and for the monomer evolution at large times allow us to obtain, not only the similarity limit, but also the rate at which it is approached.Comment: Revised according to referee's suggestions; to be published in SIAM J. Math. Ana

On the convergence to critical scaling profiles in submonolayer deposition models

In this work we study the rate of convergence to similarity profiles in a mean field model for the deposition of a submonolayer of atoms in a crystal facet, when there is a critical minimal size $n\geq 2$ for the stability of the formed clusters. The work complements recently published related results by the same authors in which the rate of convergence was studied outside of a critical direction $x=\tau$ in the cluster size $x$ vs. time $\tau$ plane. In this paper we consider a different similarity variable, $\xi := (x-\tau)/\sqrt{\tau}$, corresponding to an inner expansion of that critical direction, and prove the convergence of solutions to a similarity profile $\Phi_{2,n}(\xi)$ when $x, \tau\to +\infty$ with $\xi$ fixed, as well as the rate at which the limit is approached.Comment: Dedicated to the memory of Jack Car

Statistical Audit via Gaussian Mixture Models in Business Intelligence Systems

A Business Intelligence (BI) System employs tools from several areas of knowledge for the collection, integration and analysis of data to improve business decision making. The Brazilian Ministry of Planning, Budget and Management (MP) uses a BI System designed with the University of Bras´ılia to ascertain irregularities on the payroll of the Brazilian federal government, performing audit trails on selected items and fields of the payroll database. This current auditing approach is entirely deterministic, since the audit trails look for previously known signatures of irregularities which are composed by means of an ontological method used to represent auditors concept maps. In this work, we propose to incorporate a statistical filter in this existing BI system in order to increase its performance in terms of processing speed and overall system responsiveness. The proposed statistical filter is based on a generative Gaussian Mixture Model (GMM) whose goal is to provide a complete stochastic model of the process, specially the latent probability density function of the generative mixture, and use that model to filter the most probable payrolls. Inserting this statistical filter as a pre-processing stage preceding the deterministic auditing showed to be effective in reducing the amount of data to be analyzed by the audit trails, despite the penalty fee intrinsically associated with stochastic models due to the false negative outcomes that are not further processed. In our approach, gains obtained with the proposed pre-processing stage overcome impacts from false negative outcomes

The enterobacterium <i>Trabulsiella odontotermitis</i> presents novel adaptations related to its association with fungus-growing termites

Fungus-growing termites rely on symbiotic microorganisms to help break down plant material and to obtain nutrients. Their fungal cultivar, Termitomyces, is the main plant degrader and food source for the termites, while gut bacteria complement Termitomyces in the degradation of foodstuffs, fixation of nitrogen, and metabolism of amino acids and sugars. Due to the community complexity and because these typically anaerobic bacteria can rarely be cultured, little is known about the physiological capabilities of individual bacterial members of the gut communities and their associations with the termite host. The bacterium Trabulsiella odontotermitis is associated with fungus-growing termites, but this genus is generally understudied, with only two described species. Taking diverse approaches, we obtained a solid phylogenetic placement of T. odontotermitis among the Enterobacteriaceae, investigated the physiology and enzymatic profiles of T. odontotermitis isolates, determined the localization of the bacterium in the termite gut, compared draft genomes of two T. odontotermitis isolates to those of their close relatives, and examined the expression of genes relevant to host colonization and putative symbiont functions. Our findings support the hypothesis that T. odontotermitis is a facultative symbiont mainly located in the paunch compartment of the gut, with possible roles in carbohydrate metabolism and aflatoxin degradation, while displaying adaptations to association with the termite host, such as expressing genes for a type VI secretion system which has been demonstrated to assist bacterial competition, colonization, and survival within hosts

Estimación de caudales ecológicos basada en simulación del hábitat físico en un pequeño río del sudeste de Brasil

El método de simulación del hábitat físico, integrado en el marco de la metodología IFIM (Instream Flow Incremental Methodology) y en otros marcos metodológicos hoy día, utiliza variables hidráulicas e índices de idoneidad del hábitat (a escala de microhábitat) para predecir los cambios potenciales del hábitat al cambiar el caudal circulante. Este enfoque se ha utilizado para simular los cambios potenciales de idoneidad del hábitat para tres especies de peces tropicales de diferentes órdenes, Bryconamericus ornaticeps, Ancistrus multispinis y Geophagus brasiliensis. El estudio se realizó en dos tramos de un río en la zona de mata atlántica al sudeste de Brasil, durante el verano de 2013 e invierno de 2014. Se midieron las características topográficas e hidráulicas por transectos (calado, velocidad media, tipos de sustrato) y se estudió el uso del microhábitat por los peces mediante observación directa bajo el agua (snorkelling); esto permitió elaborar curvas de idoneidad de microhábitat para las tres especies. Mediante la simulación del hábitat físico se obtuvieron las curvas que relacionan dos indicadores, el HSI (indice medio de idoneidad en un tramo), y el HPU (Hábitat Potencial Útil) con el caudal del río. Sobre dichas curvas se observaron los caudales importantes para el mantenimiento de los hábitats de las tres especies. Los resultados indicaron un caudal mínimo-minimorum de 0.25 m3 s-1 en época seca para conservar el hábitat de los peces. También se determinó un rango óptimo de 0.65-0.85 m3 s-1 para el hábitat de las tres especies. Los resultados pueden apoyar la elaboración de una primera propuesta de régimen ecológico de caudales, en el marco de un proceso de gestión adaptativa de los recursos hídricos, para conservar la salud del río São Pedro y los diversos servicios ecosistémicos que aporta a la sociedad.Da Costa, M.; Moretti Mattos, T.; Muñoz Mas, R.; Martinez-Capel, F.; Fernandes, V.; Aráujo, F. (2015). Estimación de caudales ecológicos basada en simulación del hábitat físico en un pequeño río del sudeste de Brasil. Cuadernos de la Sociedad Española de Ciencias Forestales. (41):245-252. http://hdl.handle.net/10251/60209S2452524

The electron-furfural scattering dynamics for 63 energetically open electronic states

14 págs.; 15 figs.We report on integral-, momentum transfer- and differential cross sections for elastic and electronically inelastic electron collisions with furfural (CHO). The calculations were performed with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (N) at either the static-exchange (N ch-SE) or the static-exchange-plus-polarisation (N ch-SEP) approximation was employed to calculate the scattering amplitudes at impact energies lying between 5 eV and 50 eV, using a channel coupling scheme that ranges from the 1ch-SEP up to the 63ch-SE level of approximation depending on the energy considered. For elastic scattering, we found very good overall agreement at higher energies among our SMCPP cross sections, our IAM-SCAR+I cross sections and the experimental data for furan (a molecule that differs from furfural only by the substitution of a hydrogen atom in furan with an aldehyde functional group). This is a good indication that our elastic cross sections are converged with respect to the multichannel coupling effect for most of the investigated intermediate energies. However, although the present application represents the most sophisticated calculation performed with the SMCPP method thus far, the inelastic cross sections, even for the low lying energy states, are still not completely converged for intermediate and higher energies. We discuss possible reasons leading to this discrepancy and point out what further steps need to be undertaken in order to improve the agreement between the calculated and measured cross sections. ©2016 AIP Publishing LLCR.F.d.C., M.C.A.L., M.H.F.B., M.T.d.N.V., and M.A.P.L. acknowledge support from the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). M.T.d.N.V. acknowledges support from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). D.B.J. thanks the Australian Research Council (ARC) for financial support provided through a Discovery Early Career Researcher Award. M.J.B. thanks the ARC for some financial support and also thanks CNPq for his “Special Visiting Professor” award at the Federal University of Juiz de Fora. G.G. thanks the Spanish Ministerio de Economia y Competitividad under Project No. FIS2012- 31230 and the European Union COST Action No. CM1301 for funding.Peer Reviewe

LaMMos - Latching Mechanism based on Motorized-screw for Reconfigurable Robots and Exoskeleton Suits

Reconfigurable robots refer to a category of robots that their components (individual joints and links) can be assembled in multiple configurations and geometries. Most of existing latching mechanisms are based on physical tools such as hooks, cages or magnets, which limit the payload capacity. Therefore, robots re- quire a latching mechanism which can help to reconfigure itself without sacrificing the payload capability. This paper presents a latching mechanism based on the flexible screw attaching principle. In which, actuators are used to move the robot links and joints while connecting them with a motorized-screw and dis- connecting them by unfastening the screw. The brackets used in our mechanism configuration helps to hold maximum force up to 5000N. The LaMMos - Latching Mechanism based on Motorized- screw has been applied to the DeWaLoP - Developing Water Loss Prevention in-pipe robot. It helps the robot to shrink its body to crawl into the pipe with minimum diameter, by recon- figuring the leg positions. And it helps to recover the legs positions to original status once the robot is inside the pipe. Also, LaMMos add stiffness to the robot legs by dynamically integrate them to the structure. Additionally, we present an application of the LaMMos mechanism to exoskeleton suits, for easing the mo- tors from the joints when carrying heavy weights for long periods of time. This mechanism offers many interesting opportunities for robotics research in terms of functionality, pay- load and size.Comment: 14 pages, 15 figure

Is age a risk factor for liver disease and metabolic alterations in ataxia Telangiectasia patients?

Background: Ataxia telangiectasia (A-T) is a neurodegenerative disease that leads to mitochondrial dysfunction and oxidative stress. Insulin resistance (IR), type 2 diabetes and the risk for development of cardiovascular disease was recently associated as an extended phenotype of the disease. We aimed to assess IRliver involvementcarotid intima-media thickness (cIMT) and metabolic alterations associated to cardiovascular risk in A-T patients, and relate them with age. Results: Glucose metabolism alterations were found in 54.6% of the patients. Hepatic steatosis was diagnosed in 11/17 (64.7%) A-T patients. AST/ALT ratio > 1 was observed in 10/17 (58.8%). A strong positive correlation was observed between insulin sum concentrations with ALT (r = 0.782, p < 0.004) and age (r = 0.818, p = 0.002). Dyslipidemia was observed in 55.5% of the patients. The apolipoprotein (Apo-B)/ApoA-I ratio (r = 0.619p < 0.01), LDL/HDL-c (r = 0.490p < 0.05) and the Apo-B levels (r = 0.545p < 0.05) were positively correlated to cIMT. Conclusions: Metabolic disorders implicated in cardiovascular and liver diseases are frequently observed in adolescent A-T patients and those tend to get worse as they become older. Therefore, nutritional intervention and the use of drugs may be necessary.CAPES Foundation, Ministry of Education of Brazil, Brasilia DF, BrazilFed Univ São Paulo UNIFESP, Escola Paulista Med, Dept Pediat, Rua Otonis 725, BR-04025002 São Paulo, SP, BrazilABC Fdn FMABC, Fac Med ABC, Dept Morphol & Physiol, Santo Andre, SP, BrazilFed Univ São Paulo UNIFESP, Escola Paulista Med, Dept Diagnost Imaging, São Paulo, SP, BrazilSanta Casa São Paulo Sch Med Sci FCMSCSP, São Paulo, SP, BrazilFed Univ Alfenas UNIFAL, Sch Nutr, Alfenas, MG, BrazilFed Univ São Paulo UNIFESP, Escola Paulista Med, Dept Pediat, Rua Otonis 725, BR-04025002 São Paulo, SP, BrazilFed Univ São Paulo UNIFESP, Escola Paulista Med, Dept Diagnost Imaging, São Paulo, SP, BrazilWeb of Scienc

The electron-furfural scattering dynamics for 63 energetically open electronic states

We report on integral-, momentum transfer-and differential cross sections for elastic and electronically inelastic electron collisions with furfural (C5H4O2). The calculations were performed with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (N-open) at either the static-exchange (N-open ch-SE) or the static-exchange-plus-polarisation (N-open ch-SEP) approximation was employed to calculate the scattering amplitudes at impact energies lying between 5 eV and 50 eV, using a channel coupling scheme that ranges from the 1ch-SEP up to the 63ch-SE level of approximation depending on the energy considered. For elastic scattering, we found very good overall agreement at higher energies among our SMCPP cross sections, our IAM-SCAR+I cross sections and the experimental data for furan (a molecule that differs from furfural only by the substitution of a hydrogen atom in furan with an aldehyde functional group). This is a good indication that our elastic cross sections are converged with respect to the multichannel coupling effect for most of the investigated intermediate energies. However, although the present application represents the most sophisticated calculation performed with the SMCPP method thus far, the inelastic cross sections, even for the low lying energy states, are still not completely converged for intermediate and higher energies. We discuss possible reasons leading to this discrepancy and point out what further steps need to be undertaken in order to improve the agreement between the calculated and measured cross sections. (C) 2016 AIP Publishing LLC