35 research outputs found

    Relationships between gross motor skills, cardiovascular fitness, and visuospatial working memory-related brain activation in 8-to 10-year-old children

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    Relationships between gross motor skills and cardiovascular fitness with visuospatial working memory (VSWM) in children are hypothesized to be mediated by underlying functional brain mechanisms. Because there is little experimental evidence to support this mechanism, the present study was designed to investigate the relationships of gross motor skills and cardiovascular fitness with VSWM-related brain activation in 8- to 10-year-old children. Functional magnetic resonance imaging data obtained during a VSWM-task were analyzed for 80 children from grades 3 (47.5%) and 4 of 21 primary schools in the Netherlands (51.3% girls). Gross motor skills (Korper Koordinationstest für Kinder and Bruininks-Oseretsky Test of Motor Proficiency - 2nd Edition) and cardiovascular fitness (20-meter Shuttle Run Test) were assessed. VSWM-related brain activation was found in a network involving the angular gyrus, the superior parietal cortex, and the thalamus; deactivation was found in the inferior and middle temporal gyri. Although behavioral results showed significant relations of gross motor skills and cardiovascular fitness with VSWM performance, gross motor skills and cardiovascular fitness were not related to VSWM-related brain activation. Therefore, we could not confirm the hypothesis that brain activation underlies the relationship of gross motor skills and cardiovascular fitness with VSWM performance. Our results suggest that either the effects of physical activity on cognition do not necessarily go via changes in gross motor skills and/or cardiovascular fitness, or that brain activation patterns as measured with the blood-oxygen-level dependent (BOLD) signal may not be the mechanism underlying the relationships of gross motor skills and cardiovascular fitness with VSWM

    ß1/ß2/ß3-adrenoceptor knockout mice are obese and cold-sensitive but have normal lipolytic responses to fasting

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    Catecholamines are viewed as major stimulants of diet- and cold-induced thermogenesis and of fasting-induced lipolysis, through the &beta;-adrenoceptors (&beta;1/&beta;2/&beta;3). To test this hypothesis, we generated &beta;1/&beta;2/&beta;3-adrenoceptor triple knockout (TKO) mice and compared them to wild type animals. TKO mice exhibited normophagic obesity and cold-intolerance. Their brown fat had impaired morphology and lacked responses to cold of uncoupling protein-1 expression. In contrast, TKO mice had higher circulating levels of free fatty acids and glycerol at basal and fasted states, suggesting enhanced lipolysis. Hence, &beta;-adrenergic signalling is essential for the resistance to obesity and cold, but not for the lipolytic response to fasting.<br /

    Relevance of neuroimaging for neurocognitive and behavioral outcome after pediatric traumatic brain injury

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    RF+TBI and moderate/severe TBI are at risk of persistent white matter abnormality. Furthermore, DTI has superior predictive value for neurocognitive out-come relative to conventional neuroimagin

    Earnings Management of Acquiring Firms in Stock-for-Stock Takeovers in the Telecommunications Industry

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    This article investigates whether acquiring telecommunications firms managed their earnings by means of discretionary accruals prior to the announcement of stock-for-stock takeovers in the U.S. telecommunications industry during the period of 1990 to 2006. The results show that acquiring telecommunications firms manage earnings upward prior to stock-for-stock takeovers. In addition, this article finds that there is a negative short-term wealth effect over the days surrounding stock-for-stock takeover announcements, and there is an inverse relation between earnings management and short-term wealth.

    Pediatric Traumatic Brain Injury Affects Multisensory Integration

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    To investigate the impact of pediatric traumatic brain injury (TBI) on multisensory integration in relation to general neurocognitive functioning. Method: Children with a hospital admission for TBI aged between 6 and 13 years (n = 94) were compared with children with trauma control (TC) injuries (n = 39), while differentiating between mild TBI without risk factors for complicated TBI (mildRF-; n = 19), mild TBI with ≥1 risk factor (mildRF+; n = 45), and moderate/severe TBI (n = 30). We measured set-shifting performance based on visual information (visual shift condition) and set-shifting performance based on audiovisual information, requiring multisensory integration (audiovisual shift condition). Effects of TBI on set-shifting performance were traced back to task strategy (i.e., boundary separation), processing efficiency (i.e., drift rate), or extradecisional processes (i.e., nondecision time) using diffusion model analysis. General neurocognitive functioning was measured using estimated full-scale IQ (FSIQ). Results: The TBI group showed selectively reduced performance in the audiovisual shift condition (p = .009, Cohen's d = -0.51). Follow-up analyses in the audiovisual shift condition revealed reduced performance in the mildRF+ TBI group and moderate/severe TBI group (ps ≤ .025, ds ≤ -0.61). These effects were traced back to lower drift rate (ps ≤ .048, ds ≤ -0.44), reflecting reduced multisensory integration efficiency. Notably, accuracy and drift rate in the audiovisual shift condition partially mediated the relation between TBI and FSIQ. Conclusion: Children with mildRF+ or moderate/severe TBI are at risk for reduced multisensory integration efficiency, possibly contributing to decreased general neurocognitive functioning
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