The sigma-isotypic decomposition and the sigma-index of reversible-equivariant systems

This work is concerned with dynamical systems in presence of symmetries and reversing symmetries. We describe a construction process of subspaces that are invariant by linear Gamma-reversible-equivariant mappings, where Gamma is the compact Lie group of all the symmetries and reversing symmetries of such systems. These subspaces are the sigma-isotypic components, first introduced by Lamb and Roberts in (1999) [10] and that correspond to the isotypic components for purely equivariant systems. In addition, by representation theory methods derived from the topological structure of the group Gamma, two algebraic formulae are established for the computation of the sigma-index of a closed subgroup of Gamma. The results obtained here are to be applied to general reversible-equivariant systems, but are of particular interest for the more subtle of the two possible cases, namely the non-self-dual case. Some examples are presented. (C) 2011 Elsevier BM. All rights reserved.

Host-guest interactions between xanthones and water: the role of O-H center dot center dot center dot O, C-H center dot center dot center dot O, and pi center dot center dot center dot pi contacts in the channel- and cage-type frameworks

In this article were studied two xanthone derivatives known as 1,5-dihydroxy-8-methoxyxanthone (I) and 1,3,7-trihydroxy-8-methoxyxanthone (II), which show one water molecule into their crystal structures. In xanthone I, there are water wires contributing to build up channel-like cavities along the c axis, whereas in xanthone II the water is surrounded by three xanthone molecules forming a cage-type structure. The geometries of I and II were optimized using the density functional theory method with B3LYP functional, and the results were compared with crystal structure. Both theoretical and experimental investigations reveal a concordance between structural parameters, with the xanthone core presenting an almost flat conformation and substituents adopting the more stable orientations. In the two compounds, the hydroxyl group linked at position 1 is involved in a resonance-assisted hydrogen bond with the carbonyl group. Besides, the supramolecular arrangement of the host/guest systems are stabilized mainly by classical intermolecular hydrogen bonds (O-H center dot center dot center dot O) involving xanthone-to-water and xanthone-to-xanthone. In addition, C-H center dot center dot center dot O weak hydrogen bonds, as well as pi-pi interactions play an important role to stabilize the crystal self-assembly of xanthones I and II. The results reported here underline the role of inclusion of water molecules and their different arrangement into the crystal structure of two xanthone host/guest systems.

Influence of Genomic Ancestry on the Distribution of SLCO1B1, SLCO1B3 and ABCB1 Gene Polymorphisms among Brazilians

The frequency distribution of SNPs and haplotypes in the ABCB1, SLCO1B1 and SLCO1B3 genes varies largely among continental populations. This variation can lead to biases in pharmacogenetic studies conducted in admixed populations such as those from Brazil and other Latin American countries. The aim of this study was to evaluate the influence of self-reported colour, geographical origin and genomic ancestry on distributions of the ABCB1, SLCO1B1 and SLCO1B3 polymorphisms and derived haplotypes in admixed Brazilian populations. A total of 1039 healthy adults from the north, north-east, south-east and south of Brazil were recruited for this investigation. The c.388A>G (rs2306283), c.463C>A (rs11045819) and c.521T>C (rs4149056) SNPs in the SLCO1B1 gene and c.334T>G (rs4149117) and c.699G>A (rs7311358) SNPs in the SLCO1B3 gene were determined by Taqman 5'-nuclease assays. The ABCB1 c.1236C>T (rs1128503), c.2677G>T/A (rs2032582) and c.3435C>T (rs1045642) polymorphisms were genotyped using a previously described single-base extension/termination method. The results showed that genotype and haplotype distributions are highly variable among populations of the same self-reported colour and geographical region. However, genomic ancestry showed that these associations are better explained by a continuous variable. The influence of ancestry on the distribution of alleles and haplotype frequencies was more evident in variants with large differences in allele frequencies between European and African populations. Design and interpretation of pharmacogenetic studies using these transporter genes should include genomic controls to avoid spurious conclusions based on improper matching of study cohorts from Brazilian populations and other highly admixed populations.

Microelectrode array in mixed alkanethiol self-assembled monolayers: Electrochemical studies

We report an efficient alternative to obtain recessed microelectrodes device on gold electrode surface, in which mixed self-assembled monolayer of long and short carbon alkanethiol chains was used for this purpose. Development of the modified electrodes included the chemical adsorption of 11-mercaptoundecanoic acid and 2-mercaptoethanol solution, as well as their mixtures, on gold surface, resulting in the final mixed self-assembled monolayer configuration. For comparison, the electrochemical performance of self-assembled monolayer of 11-mercaptoundecanoic acid. 3-mercaptopropionic acid, 4-mercapto-1-butanol and 6-mercapto-1-hexanol modified electrodes was also investigated. It was verified that, in the mixed self-assembled monolayer, the 11-mercaptoundecanoic acid acts as a barrier for electron transfer while the short alkanethiol chair is deposited in an island-like shape through which electrons can be freely transferred to ions in solution, allowing electrochemical reactions to occur. The performance of the modified electrodes toward microelectrode behavior was investigated via cyclic voltammetry and electrochemical impedance spectroscopy measurements using [Fe(CN)(6)](3-/4-) redox couple as a probe. In this case, sigmoidal voltammetric responses were obtained, very similar to those observed for microelectrodes. Such behavior reinforces the proposition of electron transfer through the short alkanethiol chain layer and surface blockage by the long chain one. Electrochemical impedance results allowed calculated the mean radius value of each microelectrode disks of 3.8 mu m with about 22 mu m interval between them. The microelectrode environment provided by the mixed self-assembled monolayer can be conveniently used to provide an efficient catalytic conversion in biosensing applications. (C) 2012 Elsevier Ltd. All rights reserved.

Responsiveness to change for the Brazilian Scale of Oral Health Outcomes for 5-year-old children (SOHO-5)

Abstract Background The responsiveness of oral health-related quality of life (OHRQoL) instruments has become relevant, given the increasing tendency to use OHRQoL measures as outcomes in clinical trials and evaluations studies. The purpose of this study was to assess the responsiveness of the Brazilian Scale of Oral Health Outcomes for 5-year-old children (SOHO-5) to dental treatment. Methods One hundred and fifty-four children and their parents completed the child self- and parental’ reports of the SOHO-5 prior to treatment and 7 to 14 days after the completion of treatment. The post-treatment questionnaire also included a global transition judgment that assessed subject’s perceptions of change in their oral health following treatment. Change scores were calculated by subtracting post-treatment SOHO-5 scores from pre-treatment scores. Longitudinal construct validity was assessed by using one-way analysis of variance to examine the association between change scores and the global transition judgments. Measures of responsiveness included standardized effect sizes (ES) and standardized response mean (SRM). Results The improvement of children’s oral health after treatment are reflected in mean pre- and post-treatment SOHO-5 scores that declined from 2.67 to 0.61 (p < 0.001) for the child-self reports, and 4.04 to 0.71 (p < 0.001) for the parental reports. Mean change scores showed a gradient in the expected direction across categories of the global transition judgment, and there were significant differences in the pre- and post-treatment scores of those who reported improving a little (p < 0.05) and those who reported improving a lot (p < 0.001). For both versions, the ES and SRM based on change scores mean for total scores and for categories of global transitions judgments were moderate to large. Conclusions The Brazilian SOHO-5 is responsive to change and can be used as an outcome indicator in future clinical trials. Both the parental and the child versions presented satisfactory results.

Cross-cultural adaptation and psychometric properties of the Brazilian version of the scale of oral health outcomes for 5-year-old children (SOHO-5)

Abstract Background Most of the instruments available to measure the oral health-related quality of life (OHRQoL) in paediatric populations focus on older children, whereas parental reports are used for very young children. The scale of oral health outcomes for 5-year-old children (SOHO-5) assesses the OHRQoL of very young children through self-reports and parental proxy reports. We aimed to cross-culturally adapt the SOHO-5 to the Brazilian Portuguese language and to assess its reliability and validity. Findings We tested the quality of the cross-cultural adaptation in 2 pilot studies with 40 children aged 5–6 years and their parents. The measurement was tested for reliability and validity on 193 children that attended the paediatric dental screening program at the University of São Paulo. The children were also clinically examined for dental caries. The internal consistency was demonstrated by a Cronbach's alpha coefficient of 0.90 for the children’s self-reports and 0.77 for the parental proxy reports. The test-retest reliability results, which were based on repeated administrations on 159 children, were excellent; the intraclass correlation coefficient was 0.98 for parental and 0.92 for child reports. In general, the construct validity was satisfactory and demonstrated consistent and strong associations between the SOHO-5 and different subjective global ratings of oral health, perceived dental treatment need and overall well-being in both the parental and children’s versions (p < 0.001). The SOHO-5 was also able to clearly discriminate between children with and without a history of dental caries (mean scores: 5.8 and 1.1, respectively; p < 0.001). Conclusion The present study demonstrated that the SOHO-5 exhibits satisfactory psychometric properties and is applicable to 5- to 6-year-old children in Brazil.

Study of the Influence of Localized Vibrational Modes in Charge Transport Properties at Nanoscale Systems.

In molecular and atomic devices the interaction between electrons and ionic vibrations has an important role in electronic transport. The electron-phonon coupling can cause the loss of the electron's phase coherence, the opening of new conductance channels and the suppression of purely elastic ones. From the technological viewpoint phonons might restrict the efficiency of electronic devices by energy dissipation, causing heating, power loss and instability. The state of the art in electron transport calculations consists in combining ab initio calculations via Density Functional Theory (DFT) with Non-Equilibrium Green's Function formalism (NEGF). In order to include electron-phonon interactions, one needs in principle to include a self-energy scattering term in the open system Hamiltonian which takes into account the effect of the phonons over the electrons and vice versa. Nevertheless this term could be obtained approximately by perturbative methods. In the First Born Approximation one considers only the first order terms of the electronic Green's function expansion. In the Self-Consistent Born Approximation, the interaction self-energy is calculated with the perturbed electronic Green's function in a self-consistent way. In this work we describe how to incorporate the electron-phonon interaction to the SMEAGOL program (Spin and Molecular Electronics in Atomically Generated Orbital Landscapes), an ab initio code for electronic transport based on the combination of DFT + NEGF. This provides a tool for calculating the transport properties of materials' specific system, particularly in molecular electronics. Preliminary results will be presented, showing the effects produced by considering the electron-phonon interaction in nanoscale devices.

Base genética do hábito de crescimento e florescimento em tomateiro e sua importânciana agricultura

Hybrids or open pollinated tomato cultivars used for sauces and ketchups production usually has determinate growth habit, while most of the genotypes used in the production to salads (in natura consumption) has indeterminate growth habit. Additionally, growth habit can have influence on culture management, productivity and total soluble solids (TSS) in fruits. The growth habit is mainly controlled by the gene SELF-PRUNING (SP), which is a component of a small gene family which is also part of the gene SINGLE FLOWER TRUSS (SFT), currently considered one of the components so sought after 'florigin'. Understanding the biochemical function and physiological effect of such genes in interaction with the environment and other genes (epistasis), allows the manipulation of parameters such as precocity and TSS. It also provides subsidies to understand the genetic basis of semideterminate growth, which combines the advantages of determinate and indeterminate habit and can be used for plant breeders to development of new cultivars.

Evolution of a dense neutrino gas in matter and electromagnetic field

We describe the system of massive Weyl fields propagating in a background matter and interacting with an external electromagnetic field. The interaction with an electromagnetic field is due to the presence of anomalous magnetic moments. To canonically quantize this system first we develop the classical field theory treatment of Weyl spinors in frames of the Hamilton formalism which accounts for the external fields. Then, on the basis of the exact solution of the wave equation for a massive Weyl field in a background matter we obtain the effective Hamiltonian for the description of spin-flavor oscillations of Majorana neutrinos in matter and a magnetic field. Finally, we incorporate in our analysis the neutrino self-interaction which is essential when the neutrino density is sufficiently high. We also discuss the applicability of our results for the studies of collective effects in spin-flavor oscillations of supernova neutrinos in a dense matter and a strong magnetic field. (C) 2011 Elsevier B.V. All rights reserved.

Social Skills and Psychological Disorders: Converging and Criterion-Related Validity for YSR and IHSA-Del-Prette in Adolescents at Risk

This study evaluated indexes of converging and criterion-related validity for the Social Skills Inventory for Adolescents (IHSA-Del-Prette) and the Youth Self-Report (YSR) in two samples: one referring to clinical service (CLIN), with 28 adolescents (64.3% boys), 11 through 17 years old (M = 13.75; SD = 1.74), and the other referring to a psycho-educational program (PME = 46.2%), mainly composed of boys (91.7%) aged 13 through 17 (M = 15.33; SD = 1.47). Both samples completed the two inventories. Results showed a high incidence of psychological disorders in both samples (between 4% and 79% in the borderline or clinical range on YSR scales) and accentuated deficits in the general and subscale scores of IHSA-Del-Prette, especially on the frequency scale (25% to 58%). The correlations between the instruments in the two groups supported criterion-related and converging validity. Some issues concerning the differences between the samples and about the construct of social competence, underlying these inventories, are discussed. Key words authors:

Percepções de um grupo de idosos frente ao fato de não consultarem regularmente o cirurgião-dentista

Ainda existe no imaginário coletivo a ideia de que idosos não necessitam de assistência odontológica, pois são em sua maioria desdentados e usuários de dentaduras. Assim, a pergunta desta pesquisa é: Qual o motivo que faz com que muitos idosos não consultem regularmente o cirurgião-dentista? O objetivo foi levantar e analisar os motivos que fazem com que idosos cadastrados em uma Unidade de Saúde da Família não consultem regularmente o dentista. Trata-se de uma pesquisa descritiva exploratória de abordagem metodológica quanti-qualitativa realizada por meio de entrevistas domiciliares semiestruturadas aplicadas em 149 idosos cadastrados em uma Unidade de Saúde da Família na cidade de Ribeirão Preto,SP. Os dados foram analisados e sistematizados por meio da técnica da Análise de Conteúdo, e para a análise quantitativa foram realizadas análises bivariadas com associações significantes baseadas em valor de p<0,05. Houve associação estatisticamente significante entre visita ao dentista e idade (p=0,025), e observou-se que idosos com idades mais avançadas relataram ir menos ao dentista. Alguns dos motivos alegados foram: medo, dificuldade financeira, falta de tempo, além de falta de sintomatologia dolorosa nos dentes devido ao uso de dentaduras. Concluiu-se que os motivos alegados estão associados a aspectos sociais e culturais que devem ser analisados frente ao cuidado na atenção primária à saúde.

Reasoning about shadows in a mobile robot environment

This paper describes a logic-based formalism for qualitative spatial reasoning with cast shadows (Perceptual Qualitative Relations on Shadows, or PQRS) and presents results of a mobile robot qualitative self-localisation experiment using this formalism. Shadow detection was accomplished by mapping the images from the robot’s monocular colour camera into a HSV colour space and then thresholding on the V dimension. We present results of selflocalisation using two methods for obtaining the threshold automatically: in one method the images are segmented according to their grey-scale histograms, in the other, the threshold is set according to a prediction about the robot’s location, based upon a qualitative spatial reasoning theory about shadows. This theory-driven threshold search and the qualitative self-localisation procedure are the main contributions of the present research. To the best of our knowledge this is the first work that uses qualitative spatial representations both to perform robot self-localisation and to calibrate a robot’s interpretation of its perceptual input.