Faceted anomalous scaling in the epitaxial growth of semiconductor films

We apply the generic dynamical scaling theory (GDST) to the surfaces of CdTe polycrystalline films grown in glass substrates. The analysed data were obtained with a stylus profiler with an estimated resolution lateral resolution of $l_c=0.3 \mu$m. Both real two-point correlation function and power spectrum analyses were done. We found that the GDST applied to the surface power spectra foresees faceted morphology in contrast with the self-affine surface indicated by the local roughness exponent found via the height-height correlation function. This inconsistency is explained in terms of convolution effects resulting from the finite size of the probe tip used to scan the surfaces. High resolution AFM images corroborates the predictions of GDST.Comment: to appear in Europhysics Letter

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

Orientation dynamics of weakly Brownian particles in periodic viscous flows

Evolution equations for the orientation distribution of axisymmetric particles in periodic flows are derived in the regime of small but non-zero Brownian rotations. The equations are based on a multiple time scale approach that allows fast computation of the relaxation processes leading to statistical equilibrium. The approach has been applied to the calculation of the effective viscosity of a thin disk suspension in gravity waves.Comment: 16 pages, 7 eps figures include

Fuzzy logic as a decision-making support system for the indication of bariatric surgery based on an index (OBESINDEX) generated by the association between body fat and body mass index

Background: A Fuzzy Obesity Index (OBESINDEX) for use as an alternative in bariatric surgery indication (BSI) is presented. The search for a more accurate method to evaluate obesity and to indicate a better treatment is important in the world health context. BMI (body mass index) is considered the main criteria for obesity treatment and BSI. Nevertheless, the fat excess related to the percentage of Body Fat (%BF) is actually the principal harmful factor in obesity disease that is usually neglected. This paper presents a new fuzzy mechanism for evaluating obesity by associating BMI with %BF that yields a fuzzy obesity index for obesity evaluation and treatment and allows building up a Fuzzy Decision Support System (FDSS) for BSI.

Methods: Seventy-two patients were evaluated for both BMI and %BF. These data are modified and treated as fuzzy sets. Afterwards, the BMI and %BF classes are aggregated yielding a new index (OBESINDEX) for input linguistic variable are considered the BMI and %BF, and as output linguistic variable is employed the OBESINDEX, an obesity classification with entirely new classes of obesity in the fuzzy context as well is used for BSI.

Results: There is a gradual, smooth obesity classification and BSI when using the proposed fuzzy obesity index when compared with other traditional methods for dealing with obesity.

Conclusion: The BMI is not adequate for surgical indication in all the conditions and fuzzy logic becomes an alternative for decision making in bariatric surgery indication based on the OBESINDEX

Banco de sementes em sistemas de produção de agricultura com queima e sem queima no município de Marapanim, Pará.

Na agricultura de corte e queima, a capoeira tem como papel principal a fertilização da terra após a queima de sua biomassa vegetal. Geralmente as repetidas queimadas acabam destruindo todas as formas de regeneração, incluindo o banco de sementes. Pensando nessa problemática, o Projeto Studies of Human Impact on Forests and Floodplains in the Tropics (SHIFT), no qual esta pesquisa se insere, após uma série de estudos básicos sobre as capoeiras da região Bragantina, vem desenvolvendo uma alternativa de produção agrícola em que a capoeira é usada como fonte de nutrientes e matéria orgânica para o solo em sistemas de produção de ?agricultura sem queima?. O trabalho desenvolvido no município de Marapanim foi um experimento participativo, uma nova abordagem do projeto, onde as áreas foram definidas pelos agricultores. O objetivo do trabalho foi avaliar o potencial do banco de sementes de áreas submetidas a diferentes práticas agrícolas, caracterizando qualitativa e quantitativamente sua composição florística. Foram testadas as hipóteses de que o fogo diminui o potencial do banco de sementes e cria condições favoráveis à regeneração de espécies invasoras herbáceas. A cobertura triturada minimiza os impactos provocados pela queima sobre a diversidade vegetal e aumenta a regeneração de espécies acumuladoras de biomassa. O potencial de germinação do banco de sementes nos tratamentos foi monitorado durante 270 dias. Nos tratamentos queima e cobertura triturada, foram avaliadas a densidade, riqueza de espécies, famílias e formas de vida predominantes. No banco de sementes antes do manejo do solo, a densidade média na queima foi de 284 indivíduos/m2 e na cobertura triturada 328 indivíduos/m2. Depois do manejo do solo na queima, foram encontrados em média 23 indivíduos/m2 e na cobertura triturada 139 indivíduos/m2. As espécies mais freqüentes nos dois momentos e nos dois tratamentos foram Borreria latifolia, Fimbristylis meliacea e Cyperus diffusus. As famílias Cyperaceae, Rubiaceae e Poaceae apareceram em alta frequência em todas as áreas e nos dois tratamentos. Além dessas, destacaram-se as famílias Euphorbiaceae, Melastomataceae, Malvaceae, Lamiaceae, Scrophulariaceae e Asteraceae. As formas de vida mais comuns encontradas nos tratamentos foram as ervas. Os diferentes tratamentos afetaram a abundância e riqueza florística, diminuindo o número de sementes de espécies arbóreas e arbustivas, acumuladoras de biomassa

Factors associated with postpartum depressive symptomatology in Brazil: The Birth in Brazil National Research Study, 2011/2012

Background: Depression is one of the most common postpartum mental disorders. Many sociodemographic and individuals risk factors are associated with maternal depression but the impact of high levels of birth intervention is unclear. The Brazilian context is characterized by excessive intervention and frequent non-compliance with recommended obstetric protocols. This study therefore examined the impact of sociodemographic, individual, and obstetric risk factors in postpartum depression. Methods: The Birth in Brazil research study is a national study of 23,894 postpartum women. Information about depression was obtained by telephone interview at 6 to 18 months after birth and was measured using the Edinburgh Postnatal Depression Scale. Results: The prevalence of probable cases of depression was 26.3%. A multivariate model identified significant sociodemographic and individual risk factors as: brown skin color (OR = 1.15 CI 1.01-1.31), lower economic class (OR=1.70 CI 1.41-2.06), alcohol use (OR= 1.41 CI 1.09-1.84) and a history of mental disorders (OR= 3.13 CI 1.80-5.44). Significant obstetric factors were unplanned pregnancy (OR=1.22 CI 1.05-1.43 for wanted later and OR= 1.38 CI 1.20-1.60 for never wanted), multiparity (OR=1.97 CI 1.58-2.47 for 3 or more children), and poor care during birth (OR= 2.02 CI 1.28-3.20) or of the newborn (OR=2.16 CI 1.51-3.10). Obstetric interventions and complications were not associated with maternal depression. Limitations: Depression was measured only once so we are not able to examine the course over time. The associational and reverse causality cannot be ruled out for some variables. Conclusions: The prevalence of postpartum depression is high in Brazilian women six months after birth. Poor care of women and babies during birth is more important in postpartum depression than physical obstetric or neonatal intervention and complications

Produção de leite em pastagem de capim-elefante e em duas variedades de Panicum maximum.

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Promoção do consumo de frutas, legumes e verduras em escolas: diagnóstico inicial.

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