Confidence and the Stock Market: An Agent-Based Approach

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variance partitioning of deconstructed periphyton communities: does the use of biological traits matter?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinants of bird species richness, endemism, and island network roles in Wallacea and the West Indies: is geography sufficient or does current and historical climate matter?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Usinabilidade e integridade superficial de implantes dentários

Pós-graduação em Engenharia Mecânica - FEIS

Soluções do tipo vórtice em um modelo de Maxwell-Chern-Simons-Higgs com campos de Gauge distintos

Pós-graduação em Física - FEG

Acromyrmex charruanus: a new inquiline social parasite species of leaf-cutting ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A família e o indivíduo no curso vital: compreensão trigeracional sobre a morte e o morrer

The death has been considered a forbidden issue. To develop studies that promote reflections about it allows the enlargement of the understanding as regarding the death as about life in that both are related during the human existence. This research aimed to understand the death’s conceptions and family meanings to three different generations. For this goal, through phenomenological methodology, were achieved individual interviews with adolescents, both his parents and the grandfather, all belonging to the same family. After to understand the participant’s experiences, six thematic categories were created: a) Death’s meanings; b) The death of himself; c) The death of another and/or its possibility; d) Sources of support; e) The family in the death’s presence; f) The life in the death’s inevitability presence. From these categories, the dates were phenomenologically. The participants showed similar reports in several times, confirming the literature that says that the daily life experiences among the family members take the family to form a peculiar way to understand and an interpret their experiences. This identity family, however, did not prevent each participant to develop his particular history based in idiosyncratic elements and associated with the stage of life cycle that it is. The reports showed that the prohibition of death in society is still very present, which prevents that discussions about the issue are present in daily life. This study provided for participants to reflect on their experiences around the phenomenon of death and, consequently, about the inseparable relationship between living and dying. It has also reiterated the literature, showing the similarity of views among the family members of three generations face a vital phenomenon potentially impacting the life cycle of individual and family.

Concepção de criança na pós-modernidade

O artigo apresenta uma perspectiva sintética da concepção de criança, pontuando questões relacionadas à pós-modernidade e ao problema da violência sexual intrafamiliar, o que faz parte da revisão bibliográfica para a elaboração de dissertação do Mestrado em Psicologia Clínica e Social da UFPA. As reflexões são articuladas através dos pontos de vista da Psicologia e da terapia ocupacional, pois a primeira é a base do nosso mestrado, e a segunda, do campo de atuação. O pensamento pós-moderno valoriza o singular e o idiossincrático, assim, apreender o discurso sobre a criança nos remete à importância de compreender o que elas próprias pensam e sentem sobre a sua condição infantil. A Psicologia da qual nos valemos oferece, para as análises, o conceito de nutrição psicológica, que diz respeito ao provimento, pelos cuidadores, de alimentos positivos capazes de permitir à criança desenvolver-se de modo criativo e saudável; além desse conceito, a terapia ocupacional apresenta o de atividades expressivas.

The Kumaraswamy Gumbel distribution

The Gumbel distribution is perhaps the most widely applied statistical distribution for problems in engineering. We propose a generalization-referred to as the Kumaraswamy Gumbel distribution-and provide a comprehensive treatment of its structural properties. We obtain the analytical shapes of the density and hazard rate functions. We calculate explicit expressions for the moments and generating function. The variation of the skewness and kurtosis measures is examined and the asymptotic distribution of the extreme values is investigated. Explicit expressions are also derived for the moments of order statistics. The methods of maximum likelihood and parametric bootstrap and a Bayesian procedure are proposed for estimating the model parameters. We obtain the expected information matrix. An application of the new model to a real dataset illustrates the potentiality of the proposed model. Two bivariate generalizations of the model are proposed.

An extension of the half-normal distribution

In this paper we introduce a new distribution, namely, the slashed half-normal distribution and it can be seen as an extension of the half-normal distribution. It is shown that the resulting distribution has more kurtosis than the ordinary half-normal distribution. Moments and some properties are derived for the new distribution. Moment estimators and maximum likelihood estimators can computed using numerical procedures. Results of two real data application are reported where model fitting is implemented by using maximum likelihood estimation. The applications illustrate the better performance of the new distribution.

Robust modeling using the generalized epsilon-skew-t distribution

In this paper, an alternative skew Student-t family of distributions is studied. It is obtained as an extension of the generalized Student-t (GS-t) family introduced by McDonald and Newey [10]. The extension that is obtained can be seen as a reparametrization of the skewed GS-t distribution considered by Theodossiou [14]. A key element in the construction of such an extension is that it can be stochastically represented as a mixture of an epsilon-skew-power-exponential distribution [1] and a generalized-gamma distribution. From this representation, we can readily derive theoretical properties and easy-to-implement simulation schemes. Furthermore, we study some of its main properties including stochastic representation, moments and asymmetry and kurtosis coefficients. We also derive the Fisher information matrix, which is shown to be nonsingular for some special cases such as when the asymmetry parameter is null, that is, at the vicinity of symmetry, and discuss maximum-likelihood estimation. Simulation studies for some particular cases and real data analysis are also reported, illustrating the usefulness of the extension considered.

Distribution patterns of a marsh vegetation metacommunity in relation to habitat configuration

The identification of the factors behind the distribution of plant communities in patched habitats may prove useful towards better understanding how ecosystems function. Plant assemblages are especially important for wetland productivity and provide food and habitat to animals. The present study analyses the distribution of a metacommunity of helophytes and phreatophytes in a wetland complex in oder to identify the effects of habitat configuration on the colonisation process. Ponds with wide vegetated shores and a short distance to a big (> 10 ha) wetland, had higher species richness. The average percentage of surface covered by each species in all the wetlands correlated positively with the number of patches occupied by that species. Moreover, the community presented a nested pattern (species-poor patches were subsets of species-rich patches), and this pattern came about by selective extinction and colonisation processes. We also detected the presence of some idiosyncratic species that did not follow nestedness. Conservation managers should attempt to maximise the vegetated shore width and to reduce the degree of isolation to enhance species richness. Furthermore, a single large and poorly isolated reserve may have the highest level of biodiversity in emergent vegetation species in this wetland complex, however, the particular ecological requirements of idiosyncratic species should also be taken into account when managing this type of community.

Generalized beta-generated distributions

This article introduces generalized beta-generated (GBG) distributions. Sub-models include all classical beta-generated, Kumaraswamy-generated and exponentiated distributions. They are maximum entropy distributions under three intuitive conditions, which show that the classical beta generator skewness parameters only control tail entropy and an additional shape parameter is needed to add entropy to the centre of the parent distribution. This parameter controls skewness without necessarily differentiating tail weights. The GBG class also has tractable properties: we present various expansions for moments, generating function and quantiles. The model parameters are estimated by maximum likelihood and the usefulness of the new class is illustrated by means of some real data sets. (c) 2011 Elsevier B.V. All rights reserved.

Assessment of variance components in nonlinear mixed-effects elliptical models

The issue of assessing variance components is essential in deciding on the inclusion of random effects in the context of mixed models. In this work we discuss this problem by supposing nonlinear elliptical models for correlated data by using the score-type test proposed in Silvapulle and Silvapulle (1995). Being asymptotically equivalent to the likelihood ratio test and only requiring the estimation under the null hypothesis, this test provides a fairly easy computable alternative for assessing one-sided hypotheses in the context of the marginal model. Taking into account the possible non-normal distribution, we assume that the joint distribution of the response variable and the random effects lies in the elliptical class, which includes light-tailed and heavy-tailed distributions such as Student-t, power exponential, logistic, generalized Student-t, generalized logistic, contaminated normal, and the normal itself, among others. We compare the sensitivity of the score-type test under normal, Student-t and power exponential models for the kinetics data set discussed in Vonesh and Carter (1992) and fitted using the model presented in Russo et al. (2009). Also, a simulation study is performed to analyze the consequences of the kurtosis misspecification.

Polyazomethine with vinylene and phenantridine moieties in the main chain: Synthesis, characterization, opto(electrical) properties and theoretical calculations

The opto(electrical) properties and theoretical calculations of polyazomethine with vinylene and phenantridine moieties in the main chain were investigated in the present study. 2,5-Bis(hexyloxy)-1,4-bis[(2,5-bis(hexyloxy)-4-formyl-phenylenevinylene]benzene was polymerized in solution with 3,8-diamino-6-phenylphenanthridine (PAZ-PV-Ph). The temperatures of 5% weight loss (T-5%) of the polyazomethine was observed at 356 degrees C in nitrogen. Electrochemical properties of thin film of the polymer were studied by differential pulse voltammetry. The HOMO level of the PAZ-PV-Ph was at -4.97 eV. The energy band gap (E-g) was detected of approximately similar to 1.9 eV. Energy band gap (E-gopt) was additionally calculated from absorption spectrum and absorption coefficient alpha. The absorption UV-vis spectra of polyazomethine recorded in solution showed a blue shift in comparison with the solid state. HOMO-LUMO levels and E-g were additionally calculated theoretically by density functional theory and molecular simulations of PAZ-PV-Ph are presented. Current density-voltage (J-U) measurements were performed on ITO/PAZ-PV-Ph/Al, ITO/TiO2/PAZ-PV-Ph/Al and ITO/PEDOT/PAZ-PV-Ph:TiO2/Al devices in the dark and during irradiation with light (under illumination of 1000 W m(-2)). The polymer was tested using AFM technique and roughness (R-a, R-ms) along with skew and kurtosis are presented.