Aline Roberta Aceituno da Costa

Naming New Stimuli After Selection by Exclusion

Responding by exclusion in matching-to-sample tasks is a robust behavioral pattern in humans. A single selection, however, does not ensure learning of the arbitrary relationship between the sample and the selected comparison stimulus. The present study aimed to investigate the amount of exposure required until eight preschoolers were able to name two undefined pictures, matched by exclusion, to two undefined words. After establishing a matching-to-sample baseline between pictures and dictated words, two new words were introduced in exclusion probes. On each probe, a new word was dictated and the matrix of comparison stimuli included a new picture and two experimentally defined pictures. Naming emerged after three to10 exclusion trials. Correct naming tended to occur more reliably when the teaching phase established stimulus control by selection.

Determination of Aflatoxin B1-Lysine in Pig Serum and Plasma by Liquid Chromatography–Tandem Mass Spectrometry

Aflatoxin B1 (AFB1) is a hepatocarcinogen produced by certain Aspergillus species growing on crops. After biotransformation in the liver, AFB1 generates several metabolites, one of which is AFB1 bound to lysine on serum albumin. AFB1-lysine (AFB1-lys) is a digest product of AFB1-albumin and is considered a biomarker of exposure to AFB1 in humans and animals. The objectives of this paper were to evaluate the performance characteristics of a new analytical method for determination of AFB1-lys levels in pig serum, heparinized and ethylenediaminetetraacetic acid (EDTA) plasma and to evaluate the interference of these anticoagulants in AFB1-lys quantification. Blank blood samples were obtained from eight crossbreed 91-day-old barrows fed AFB1-free diets. Pooled samples (n = 3) and individual samples of serum, EDTA and heparinized plasma collected from five pigs were enzymatically digested with pronase at 37°C for 4 h. AFB1-lys was isolated by solid-phase extraction and quantified by liquid chromatography coupled to tandem mass spectrometry. The analytical method was applied for determination of AFB1-lys in serum and EDTA plasma collected from five 49-day-old crossbreed barrows fed ad libitum diets containing 1.1 mg of AFB1 per kg of feed during 7 days (three animals) or 42 days (two animals). Samples of heparinized plasma were only available from animals intoxicated for 42 days. All animals had lower levels of AFB1-lys in EDTA plasma samples (24.78-37.40 ng/mL), when compared to serum (49.32-252.07 ng/mL-1) or heparinized plasma (176.81 and 264.24 ng/mL-1). EDTA did not interfere in AFB1-lys standard detection, but our findings suggest that EDTA should be avoided during blood collection since it affects the pronase activity in AFB1-albumin adduct digestion and, consequently, causes a reduction in the AFB1-lys levels. Hence, determination of AFB1-lys in serum and heparinized plasma is an approach to assess an individuals exposure of swine to AFB1.

Evaluating effectiveness of dynamic soundfield system in the classroom

Research has reported on the use of soundfield amplification devices in the classroom. However, no study has used standardized tests to determine the potential advantages of the dynamic soundfield system for normally hearing students and for the teacher′s voice. Our aim was to evaluate the impact of using dynamic soundfield system on the noise of the classroom, teacher′s voice and students′ academic performance. This was a prospective cohort study in which 20 student participants enrolled in the third year of basic education were divided into two groups (i.e., control and experimental); their teacher participated. The experimental group was exposed to the dynamic soundfield system for 3 consecutive months. The groups were assessed using standardized tests to evaluate their academic performance. Further, questionnaires and statements were collected on the participants′ experience of using the soundfield system. We statistically analyzed the results to compare the academic performance of the control group with that of the experimental group. In all cases, a significance level of P < .05 was adopted. Use of the dynamic soundfield system was effective for improving the students′ academic performance on standardized tests for reading, improving the teacher′s speech intelligibility, and reducing the teacher′s vocal strain. The dynamic soundfield system minimizes the impact of noise in the classroom as demonstrated by the mensuration of the signal-to-noise ratio (SNR) and pupil performance on standardized tests for reading and student and teacher ratings of amplification system effectiveness.

Ocorrência de Classes Gramaticais na Fala Espontânea de Crianças de 18 a 41 Meses com Pares

This study aimed to investigate the occurrences of different grammatical categories in 21 children (18 to 41 months) in situations of spontaneous speech with their peers and compare these data with studies that employ the observation of adult/child interaction in the context of elicited speech. Each child was videotaped during 15 minutes interacting with classmates. It happened for five times with intervals of one month between them. Records were joined into four groups. The most frequent grammatical categories in all age groups were verbs and nouns. The frequency of different types of verbs and nouns were equivalent among younger groups, but verbs were more frequently used in older groups. We discuss the role of observation context and the method of data sampling.

Communicative performance and vocabulary domain in preschool preterm infants

Abstract Objective The objective of this study was to evaluate and compare the performance of children in preschool age who were born premature and term, without neurological injury, regarding receptive and expressive language skills, and to reflect on the importance of these skills for performance in preschool. Materials and Methods Two groups named Preterm Group and Comparison Group, each composed by 40 children, as well as 80 legal representatives (mothers) and 80 teachers of the participants. To pair the groups, we considered chronological age (months), sex, educational level, type of school (public or private) and socioeconomic status. To assess the groups we used structured and semi-structured Observation of Communicative Behavior and applied the ABFW Child Language Test - Part B-Vocabulary and the Peabody Picture Vocabulary Test. To assess the legal representatives we applied an anamnesis questionnaire and the MacArthur Communicative Development Inventory. The assessment of the teachers consisted of the MacArthur Communicative Development Inventory and a Student Assessment Protocol developed by the authors. Results For the observation of communicative behavior, the categories with the highest losses were: narrative, maintaining dialogic activities and attention difficulties. In the ABFW Child Language Test and Peabody Picture Vocabulary Test there were statistically significant differences. In the MacArthur Communicative Development Inventory there were statistically significant differences in expressive vocabulary, but no differences in receptive vocabulary, for both the mothers and the teachers. Conclusion Children born prematurely with low risk of neurological sequelae in preschool age may have greater difficulties in linguistic performance than their peers born to term.

Emparelhamento com o modelo simultâneo e atrasado: implicações para a demonstração de equivalência de estímulos por crianças

Delayed matching to sample (DMTS) has been used to teach conditional relations, to test emergent relations between stimuli and to test the maintenance of these performances. The literature, however,

Nomeacao de Estimulos Novos a Partir da Selecao por Exclusao

Responding by exclusion in matching-to-sample tasks is a robust behavioral pattern in humans. A single selection, however, does not ensure learning of the arbitrary relationship between the sample and the selected comparison stimulus. The present study aimed to investigate the amount of exposure required until eight preschoolers were able to name two undefined pictures, matched by exclusion, to two undefined words. After establishing a matching-to-sample baseline between pictures and dictated words, two new words were introduced in exclusion probes. On each probe, a new word was dictated and the matrix of comparison stimuli included a new picture and two experimentally defined pictures. Naming emerged after three to10 exclusion trials. Correct naming tended to occur more reliably when the teaching phase established stimulus control by selection.

Nombramiento de Nuevos Estimulos Despues de la Seleccion por Exclusion

Responding by exclusion in matching-to-sample tasks is a robust behavioral pattern in humans. A single selection, however, does not ensure learning of the arbitrary relationship between the sample and the selected comparison stimulus. The present study aimed to investigate the amount of exposure required until eight preschoolers were able to name two undefined pictures, matched by exclusion, to two undefined words. After establishing a matching-to-sample baseline between pictures and dictated words, two new words were introduced in exclusion probes. On each probe, a new word was dictated and the matrix of comparison stimuli included a new picture and two experimentally defined pictures. Naming emerged after three to10 exclusion trials. Correct naming tended to occur more reliably when the teaching phase established stimulus control by selection.