Investigação das dificuldades na memória de trabalho em alunos do 2º ano do Ensino Fundamental em Manaus: um estudo com a Working Memory Rating Scale

Dissertação de mestrado em Educação Especial (área de especialização em Dificuldades de Aprendizagem Específicas)

Antibacterial Ag/a-C nanocomposite coatings: The influence of nano-galvanic a-C and Ag couples on Ag ionization rates

Biofilm formation has been pointed as a major concern in different industrial applications, namely on biomedical implants and surgical instruments, which has prompted the development of new strategies for production of efficient antimicrobial surfaces. In this work, nano âgalvanic couples were created to enhance the antibacterial properties of silver, by embedding it into amorphous carbon (a-C) matrix. The developed Ag/a-C nanocomposite coatings, deposited by magnetron sputtering, revealed an outstanding antibacterial activity against S.epidermidis, promoting a total reduction in biofilm formation with no bacteria counts in all dilution. The open circuit potential (OCP) tests in 0.9% NaCl confirmed that a-C shows a positive \OCP\ value, in contrast to Ag coating, thus enhancing the ionization of biocidal Ag+ due to the nano-galvanic couple activation. This result was confirmed by the inductively coupled plasma-optical emission spectroscopy (ICP-OES), which revealed a higher Ag ionization rate in the nanocomposite coating in comparison with the Ag coating. The surface of Ag/a-C and Ag coatings immersed in 0.9% NaCl were monitored by scanning electron microscopy (SEM) over a period of 24 hours, being found that the Ag ionization determined by ICP-OES was accompanied by an Ag nanoparticles coalescence and agglomeration in Ag/a-C coating.

Sex differences in the fetal heart rate variability indices of twins

Aims: To evaluate the differences in linear and complex heart rate dynamics in twin pairs according to fetal sex combination [male-female (MF), male-male (MM), and female-female (FF)]. Methods: Fourteen twin pairs (6 MF, 3 MM, and 5 FF) were monitored between 31 and 36.4 weeks of gestation. Twenty-six fetal heart rate (FHR) recordings of both twins were simultaneously acquired and analyzed with a system for computerized analysis of cardiotocograms. Linear and nonlinear FHR indices were calculated. Results: Overall, MM twins presented higher intrapair average in linear indices than the other pairs, whereas FF twins showed higher sympathetic-vagal balance. MF twins exhibited higher intrapair average in entropy indices and MM twins presented lower entropy values than FF twins considering the (automatically selected) threshold rLu. MM twin pairs showed higher intrapair differences in linear heart rate indices than MF and FF twins, whereas FF twins exhibited lower intrapair differences in entropy indices. Conclusions: The results of this exploratory study suggest that twins have sex-specific differences in linear and nonlinear indices of FHR. MM twins expressed signs of a more active autonomic nervous system and MF twins showed the most active complexity control system. These results suggest that fetal sex combination should be taken into consideration when performing detailed evaluation of the FHR in twins.

The alarm distress baby scale in a longitudinal Portuguese study reanalyzed with attachment data

Article first published online: 13 NOV 2013

Brazelton Neonatal Behavioral Assessment Scale: a psychometric study in a Portuguese sample

Background: The Neonatal Behavioral Assessment Scale (NBAS, Brazelton & Nugent, 1995) is an instrument conceived to observe the neonatal neurobehavior. Data analysis is usually performed by organizing items into groups. The most widely used data reduction for the NBAS was developed by Lester, Als, and Brazelton (1982). Objective: Examine the psychometric properties of the NBAS items in a sample of 213 Portuguese infants. Method: The NBAS was performed in the first week of infant life (3 days±2) and in the seventh week of life (52 days±5). Results: Principal component analyses yielded a solution of four components explaining 55.13% of total variance. Construct validity was supported by better neurobehavioral performance of 7-week-old infants compared with 1-week-old infants. Conclusion: Changes in the NBAS structure for the Portuguese sample are suggested compared to Lester factors in order to reach better internal consistency of the scale.

Estudo de validação da versão portuguesa da Alarm Distress Baby Scale (ADBB)

Contexto. O comportamento de retraimento social prolongado da criança é um importante sinal de alarme, quer tenha origem orgânica, psicológica e/ou social. A. Guédeney construiu a Alarm Distress Baby Scale (ADBB), para identificar este comportamento no contexto da consulta pediátrica ou da observação psicológica. Objectivos. Validação da versão portuguesa da ADBB destinada a avaliar o comportamento de retraimento social de crianças com idades compreendidas entre 2 e 24 meses. Metodologia A ADBB e as Bayley Scales of Infant Development (BSID) foram administradas a uma amostra de 130 lactentes com 3 meses de idade, cujas mães preencheram a versão portuguesa da Edinburgh Postnatal Depression Scale (EPDS); 51 bebés foram novamente avaliados aos 12 meses de idade. Resultados. Os itens da ADBB organizam-se satisfatoriamente em duas sub-escalas. A consistência interna do instrumento é razoável (alpha de Cronbach = .587). A validade externa é elevada: a correlação entre os resultados na ADBB e nas BSID é muito significativa - os bebés que aos 3 meses apresentam um resultado igual ou superior a 5 na ADBB evidenciam menor desenvolvimento nas BSID. Os resultados testemunham ainda que bebés de mães deprimidas (EPDS ≥ 12) mostram mais sinais de retraimento social do que os bebés das mães não deprimidas. Conclusão. A escala permite detectar crianças a necessitar de ajuda no sentido de contrariar o retraimento social que encetaram em relação ao meio. Desenhada para sinalizar tão precocemente quanto possível o retraimento social do lactente, e na medida em que este é um comprovado sinal da perturbação do desenvolvimento, a ADBB pode estimular os clínicos na procura das suas causas e na intervenção junto das mesmas. Estudos em amostras de crianças com mais idade são necessários. No entanto, os resultados obtidos apontam que a Versão portuguesa da ADBB é robusta e válida.

Combustion of alternative biomass fuels in a domestic boiler and in a large-scale furnace

Programa Doutoral em Engenharia Mecânica.