Iniciativas de comunicação na interação entre crianças com distúrbios do espectro autístico e suas mães: análise pragmática

OBJETIVOS: investigar as iniciativas de comunicação na interação entre crianças com distúrbios do espectro autístico (DEA) e suas mães, por meio de uma análise pragmática. MÉTODO: cinco crianças com DEA, de ambos os gêneros, idades entre cinco e 12 anos juntamente com suas mães. O grupo controle constou de cinco crianças com desenvolvimento normal, pareadas com as crianças com DEA de acordo com gênero e idade e suas respectivas mães, totalizando 20 participantes. Para a caracterização da amostra foram utilizadas uma Ficha informativa e a Escala de Avaliação de Traços Autísticos. Cada díade foi filmada por 30 minutos durante as interações lúdicas, analisadas a partir do Protocolo de Pragmática. Este instrumento avalia as iniciativas de comunicação, meios e funções comunicativas expressas. Os dados foram tratados estatisticamente (p < 0,05; foram utilizados os testes não-paramétricos de Wilcoxon e de Mann-Whitney). RESULTADOS: foram observadas diferenças estatisticamente significantes entre as iniciativas comunicativas das crianças com DEA e suas mães, quando comparadas ao grupo controle. As díades que envolveram crianças com DEA iniciaram menos a comunicação e utilizaram predominantemente gestos e vocalizações menos interativas. CONCLUSÕES: estes dados possibilitaram descrever aspectos fundamentais para compreensão das manifestações clínicas da população estudada e para a elaboração de programas de intervenção que visem melhorar a qualidade de vida da criança e sua família.

Time-dependent effects of lead on rat reproductive functions

The effects of exposure to lead on endocrine function and the reproductive parameters were studied in pubertal rats treated with 1.0 g l(-1) lead acetate in drinking water for 20 days (subacute group) or 9 months (chronic group) in addition to i.v. injections of lead acetate (0.1 mg 100 g(-1) body wt.) every 10 (subacute group) or 15 days (chronic group). Although basal levels of testosterone were higher both in plasma and in testes of acutely intoxicated animals, the circulating levels of luteinizing hormone (LH) were not affected in either group, nor was the LH-releasing hormone content of the median eminence. The density of [I-125]LH/human chorionic gonadotrophin (hCG) binding sites in testicular homogenates was reduced by saturnism in both groups, concomitant with a significantly increased apparent affinity constant of the hormone-receptor complex. These data can be viewed as the result of a mixture of specific lead toxicity (e.g. at the enzyme level) with other more general actions (e.g. at the level of the hypothalamus-pituitary-testicular axis).

CLASSICAL DISTRIBUTION-FUNCTIONS DERIVED FROM WIGNER DISTRIBUTION-FUNCTIONS

A mapping which relates the Wigner phase-space distribution function associated with a given stationary quantum-mechanical wavefunction to a specific solution of the time-independent Liouville transport equation is obtained. Two examples are studied.

Feedforward neural networks based on PPS-wavelet activation functions

Function approximation is a very important task in environments where computation has to be based on extracting information from data samples in real world processes. Neural networks and wavenets have been recently seen as attractive tools for developing efficient solutions for many real world problems in function approximation. In this paper, it is shown how feedforward neural networks can be built using a different type of activation function referred to as the PPS-wavelet. An algorithm is presented to generate a family of PPS-wavelets that can be used to efficiently construct feedforward networks for function approximation.

Green functions of the Dirac equation with magnetic-solenoid field

Various Green functions of the Dirac equation with a magnetic-solenoid field (the superposition of the Aharonov-Bohm field and a collinear uniform magnetic field) are constructed and studied. The problem is considered in 2+1 and 3+1 dimensions for the natural extension of the Dirac operator (the extension obtained from the solenoid regularization). Representations of the Green functions as proper time integrals are derived. The nonrelativistic limit is considered. For the sake of completeness the Green functions of the Klein-Gordon particles are constructed as well. (C) 2004 American Institute of Physics.