Methylphenidate modifies activity in the prefrontal and parietal cortex accelerating the time judgment.

Methylphenidate produces its effects via actions on cortical areas involved with attention and working memory, which have a direct role in time estimation judgment tasks. In particular, the prefrontal and parietal cortex has been the target of several studies to understand the effect of methylphenidate on executive functions and time interval perception. However, it has not yet been studied whether acute administration of methylphenidate influences performance in time estimation task and the changes in alpha band absolute power in the prefrontal and parietal cortex. The current study investigates the influence of the acute use of methylphenidate in both performance and judgment in the time estimation interpretation through the alpha band absolute power activity in the prefrontal and parietal cortex. This is a double-blind, crossover study with a sample of 32 subjects under control (placebo) and experimental (methylphenidate) conditions with absolute alpha band power analysis during a time estimation task. We observed that methylphenidate does not influence task performance (p > 0.05), but it increases the time interval underestimation by over 7 s (p < 0.001) with a concomitant decrease in absolute alpha band power in the ventrolateral prefrontal cortex and dorsolateral prefrontal cortex and parietal cortex (p < 0.001). Acute use of methylphenidate increases the time interval underestimation, consistent with reduced accuracy of the internal clock mechanisms. Furthermore, acute use of methylphenidate influences the absolute alpha band power over the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, and parietal cortex.

Chronic adaptations of lung function in breath-hold diving fishermen.

OBJECTIVES: The aim of this study was to verify and analyze the existence of chronic adaptations of lung function in free-diving fishermen whose occupation is artisanal fishing. MATERIAL AND METHODS: This was a cross-sectional study involving 11 breath-hold diving fishermen and 10 non-breath-hold diving fishermen (control) from the village of Bitupitá in the municipality of Barroquinha (Ceará - Brazil). Anthropometric measurements, chest and abdominal circumferences as well as spirometric and respiratory muscle strength tests were conducted according to the specifications of the American Thoracic Society/European Respiratory Society (ATS/ERS). In order to compare the measured values versus the predicted values, Student t test was used in the case of parametric test and Wilcoxon test in the case of nonparametric test. To compare the inter-group means Student t test was used for parametric test and Mann-Whitney test for the nonparametric one. The level of significance was set at α = 5%. RESULTS: The forced vital capacity (FVC) (4.9 ± 0.6 l vs. 4.3 ± 0.4 l) and forced expiratory volume in 1 s (FEV1) (4.0 ± 0.5 l vs. 3.6 ± 0.3 l) were, respectively, higher in the group of divers compared to the control group (p ≤ 0.05). Furthermore, in the group of free divers, the measured FVC, FEV1 and FEV1/FVC ratios were significantly greater than the predicted ones. No differences were found between the measured respiratory pressures. CONCLUSIONS: These results indicate that breath-hold diving seems to produce chronic adaptations of the respiratory system, resulting in elevated lung volumes with no airway obstruction.

Alterações do equilíbrio escapular em escolares de 10 a 12 anos no município de Parnaíba/PI / Changes in the scapular balance of 10 to 12 years old children at Parnaíba/PI

Crianças adaptam-se rapidamente a uma nova postura e, se esteposicionamento for inadequado, pode acarretar em comprometimentoscorporais, prejudicando sua postura. Os padrões posturaisassumidos na infância progressivamente podem formar a posturado adulto. São inúmeras as variáveis que influenciam a ergonomiacorporal, dentre elas estão os distúrbios no equilíbrio escapular.Este estudo objetivou analisar quantitativamente as alteraçõesescapulares em escolares no município de Parnaíba/PI. Trata-se deum estudo transversal, onde foi realizada uma avaliação posturalem 148 crianças entre 10 e 12 anos de ambos os sexos. O testeutilizado na análise da verificação da variação de frequências e dograu de associação entre as variáveis foi o Qui-Quadrado. O nívelde significância estabelecido foi o equivalente a p < 0,05. O presenteestudo observou as seguintes alterações no equilíbrio estáticoda cintura escapular: (5,2%) protusão, (16,5%) adução, (20,6%)abdução, (27,8%) elevação. A taxa de normalidade foi 29,9%. Aalteração escapular mais comum nos alunos avaliados foi a elevaçãoescapular com 27,8%. Concluiu-se que 66,2% dos escolaresavaliados apresentaram alterações do alinhamento escapular e aocompararmos as outras alterações, há variação significativamentedistinta na prevalência da adução e protusão escapular...

Children adapt quickly to a new position but, if this position isinadequate, can lead to physical impairments, affecting definitivelythe posture. The postural patterns in childhood can gradually modifythe adult posture. There are numerous variables that influence thebody posture, among which are disturbances in the scapular balance.This study aimed to quantitatively analyze the changes in scapularbalance in children at Parnaíba/PI. It was a cross-sectional study onpostural evaluation in 148 children of both genders, 10 to 12 yearsold. The tests used in the analysis of verification of frequency rangesand the degree of association between variables were chi-square. Thesignificance level was equivalent to p < 0.05. The present study observedthe following changes in static balance of the shoulder girdle:(5.2%) protrusion, (16.5%) adduction, (20.6%) abduction (27.8%)increase. The rate of normality was 29.9%. The most commonchange in scapular balance students was elevation with 27.8%. It wasconcluded that 66.2% of schoolchildren present scapular alignmentchanges and, comparing to other changes, they present a significantprevalence of scapular adduction and protrusion...