4,401 research outputs found
The Machine as Data: A Computational View of Emergence and Definability
Turing’s (Proceedings of the London Mathematical Society 42:230–265, 1936) paper on computable numbers has played its role in underpinning different perspectives on the world of information. On the one hand, it encourages a digital ontology, with a perceived flatness of computational structure comprehensively hosting causality at the physical level and beyond. On the other (the main point of Turing’s paper), it can give an insight into the way in which higher order information arises and leads to loss of computational control—while demonstrating how the control can be re-established, in special circumstances, via suitable type reductions. We examine the classical computational framework more closely than is usual, drawing out lessons for the wider application of information–theoretical approaches to characterizing the real world. The problem which arises across a range of contexts is the characterizing of the balance of power between the complexity of informational structure (with emergence, chaos, randomness and ‘big data’ prominently on the scene) and the means available (simulation, codes, statistical sampling, human intuition, semantic constructs) to bring this information back into the computational fold. We proceed via appropriate mathematical modelling to a more coherent view of the computational structure of information, relevant to a wide spectrum of areas of investigation
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Day 1. Posters – Sport and Performance
Background: Exercise tests are one of the most commonly used tools within sports science research. Therefore, the reliability of such exercise tests is of critical importance when investigating the efficacy of nutritional, physiological, psychological or training interventions. Purpose: The aim of this experiment was to measure the reliability of a 20 km cycling time trial performance test when performed by mounting the cyclists own bicycle frame on an electronic turbo trainer. Methods: Twenty one male cyclists (age 35 ± 8 y, height 1.82 ± 0.05 m, body mass 80.7 ± 9.0 kg) completed the 20 km time trial on three separate occasions; the initial visit was a habituation trial and was followed by two main trials. All laboratory visits were conducted at the same time of day, following a 24h diet and activity standardisation period, and at least 2 h postprandial. The time trial was completed on a Cyclus2 (RBM Electronic, Germany) ergometer. The cyclists mounted their own bike frames on to the ergometer and the settings on the Cyclus2 were adjusted for each individual bike, ensuring an accurate measurement of distance and performance. During the exercise trial, participants were deprived of any performance information other than distance covered and gear selection; no encouragement was provided by experimenters. Results: There was no order effect of the trials, inclusive of the habituation trial (p = 0.901). There was no significant difference in the time taken to complete the 20 km between trials 1 and 2 (trial 1: 1969 ± 112 s; trial 2: 1975 ± 119 s; p = 0.222). The intra-class correlation between trial 1 and 2 was r = 0.99, with the coefficient of variation being 0.7%. Conclusions: The use of a 20 km cycling time trial, in which the cyclists bicycle frame is mounted on a cycle ergometer, is highly reproducible. Such a test can, therefore, be reliably used to detect changes in performance due to various interventions
High-intensity intermittent exercise: effect on young people’s cardiometabolic health and cognition
With only a quarter of young people currently meeting physical activity guidelines, two key areas of concern are the effects of exercise on cardio-metabolic health and cognition. Despite the fact that physical activity in young people is typically high intensity and intermittent in nature; much of the literature examines traditional endurance type exercise. This review provides an update on the effects of high intensity intermittent exercise on young people’s cardio-metabolic health and cognition. High intensity intermittent exercise has acute beneficial effects on endothelial function and postprandial lipemia and chronic positive effects on weight management. In addition, there is emerging evidence regarding chronic benefits on blood lipid profile, blood pressure and pro- and anti-inflammatory cytokines. Furthermore, emerging evidence suggests beneficial acute and chronic effects of high intensity intermittent exercise on cognition. However, further research is required in both cardio-metabolic health and cognition, particularly regarding the impact of school-based interventions in adolescents
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Breakfast consumption and cognitive function in adolescent school children
This study examined the effects of breakfast consumption on cognitive function, mood and blood glucose concentration in adolescent schoolchildren. With the institution's ethical advisory committee approval, 96 adolescents (12 to 15 years old) completed two randomly assigned trials (one following breakfast consumption and one following breakfast omission), scheduled 7 days apart. Cognitive function tests (visual search test, Stroop test and Sternberg paradigm), a mood questionnaire and a finger prick blood sample (in a subgroup of 60 participants) were completed immediately following breakfast and 120 min after the baseline measures.
Following breakfast consumption, accuracy on the more complex level of the visual search test was higher than following breakfast omission (p=0.021). Similarly, accuracy on the Stroop test was better maintained across the morning following breakfast consumption when compared to breakfast omission (p=0.022). Furthermore, responses on the Sternberg paradigm were quicker later in the morning following breakfast consumption, particularly on the more complex levels (p=0.012). Breakfast consumption also produced higher self-report energy and fullness, lower self-report tiredness and hunger and higher blood glucose concentrations (all p<0.0005). Overall, the findings of the present study suggest that breakfast consumption enhances cognitive function in an adolescent population when compared to breakfast omission
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Effects of different solutions consumed during exercise on cognitive function of male college soccer players
Background/Objectives: The present study aimed to investigate the effects of three solutions, i.e. carbohydrate-electrolyte-solution (CES), carbohydrate-electrolyte-protein-solution (CEPS), and placebo (PLA), on cognitive function of college soccer players.
Methods: Sixteen male college soccer players completed three main trials in a randomized cross-over study design. In each main trial, participants completed 90 min Loughborough Intermittent Shuttle Test (LIST) protocol and consumed one of three solutions. The cognitive function tests were performed; blood glucose and lactate concentrations, and several subjective measurements were also recorded in each trial.
Results: Compared with pre-exercise level, the accuracy of Rapid Visual Information Processing test (RVIPT) and the response time in Visual Search Test (VST, complex level) after LIST improved in CES and CEPS trials, but not in PLA trial. However, the accuracy of VST (complex level) decreased in both CES and CEPS trials, compared with PLA trial. CEPS consumption improved accuracy in VST (simple level), compared with CES consumption. Blood glucose concentrations were well maintained in CEPS trial, but not in CES and PLA trials.
Conclusion: It seems that both CES and CEPS consumption show certain benefits on some aspects of cognitive function in male college soccer players in Hong Kong. However, these effects may be specific to the cognitive domain tested
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The effects of a mid-morning bout of exercise on adolescents' cognitive function
The aim of the present study was to examine the effects of a mid-morning bout of exercise on adolescents’ cognitive function in a randomised crossover design where each participant completed two experimental trials. Forty-five adolescents (13.3±0.3 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test, 30s rest between repeats; exercise trial) or continued to rest (resting trial). A battery of cognitive function tests assessing visuo-motor speed, executive function and working memory (visual search test, Stroop test and Sternberg paradigm, respectively) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 172±17 beats/min. On the visual search test, there was a greater improvement in response times across the morning on the exercise trial (t=2.6, p=0.009). However, this improvement in response times was combined with a greater decrease in accuracy on the exercise trial (z=2.0, p=0.044). On the Sternberg paradigm there was a greater improvement in response times across the morning following exercise when compared to resting (t=2.6, p=0.010). The mid-morning bout of exercise did not affect Stroop test performance. These improvements in response times are most likely the result of a general speeding up of responses across several cognitive domains, because response times were improved similarly across two different domains and across all test complexity levels, rather than being restricted to the specific high cognitive load levels. Accordingly, exercise in school settings may help to improve cognitive function in adolescents during the school morning
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Breakfast glycaemic index and cognitive function in adolescent school children
It has been suggested that a low-glycaemic index (GI) breakfast may be beneficial for some elements of cognitive function (e.g. memory and attention), but the effects are not clear, especially in adolescents. Thus, the aim of the present study was to examine the effects of a low-GI breakfast, a high-GI breakfast and breakfast omission on cognitive function in adolescents. A total of fifty-two adolescents aged 12–14 years were recruited to participate in the study. Participants consumed a low-GI breakfast, a high-GI breakfast or omitted breakfast. A battery of cognitive function tests was completed 30 and 120 min following breakfast consumption and capillary blood samples were taken during the 120 min postprandial period. The findings show that there was a greater improvement in response times following a low-GI breakfast, compared with breakfast omission on the Stroop (P=0·009) and Flanker (P=0·041) tasks, and compared with a high-GI breakfast on the Sternberg paradigm (P=0·013). Furthermore, accuracy on all three tests was better maintained on the low-GI trial compared with the high-GI (Stroop: P=0·039; Sternberg: P=0·018; Flanker: P=0·014) and breakfast omission (Stroop: P<0·001; Sternberg: P=0·050; Flanker: P=0·014) trials. Following the low-GI breakfast, participants displayed a lower glycaemic response (P<0·001) than following the high-GI breakfast, but there was no difference in the insulinaemic response (P=0·063) between the high- and low-GI breakfasts. Therefore, we conclude that a low-GI breakfast is most beneficial for adolescents' cognitive function, compared with a high-GI breakfast or breakfast omission
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Sex differences in adolescents' glycaemic and insulinaemic responses to high and low glycaemic index breakfasts: a randomised control trial
During puberty young people undergo significant hormonal changes which affect metabolism and, subsequently, health. Evidence suggests there is a period of transient pubertal insulin resistance, with this effect greater in girls than boys. However, the response to everyday high and low glycaemic index (GI) meals remains unknown. Following ethical approval, forty adolescents consumed a high GI or low GI breakfast, in a randomised cross-over design. Capillary blood samples were taken during a 2-h postprandial period, examining the glycaemic and
insulinaemic responses. Maturity offset and homoeostatic model assessment (HOMA) were also calculated. The glycaemic response to the breakfasts was similar between boys and girls, as shown by similar peak blood glucose concentrations and incremental AUC (IAUC) following
both high and low GI breakfasts (all P> 0·05). Girls exhibited a higher peak plasma insulin concentration 30 min post-breakfast following both high GI (P=0·043, g=0·69) and low GI (P =0·010, g =0·84) breakfasts, as well as a greater IAUC following high GI (P=0·041, g =0·66) and low GI (P =0·041, g =0·66) breakfasts. HOMA was positively correlated with the insulinaemic responses (all P<0·0005) and maturity offset (P =0·037). The findings of the present study suggest that pubertal insulin resistance affects the postprandial insulinaemic responses to both high and low GI meals. Specifically, girls exhibit a greater insulinaemic response than boys to both meals, despite similar glycaemic responses.
This study is the first to report the glycaemic and insulinaemic responses to everyday meals in boys and girls, supporting the recommendation for young people to base their diet on low GI carbohydrates
Selective Inhibitors of Kv11.1 Regulate IL-6 Expression by Macrophages in Response to TLR/IL-1R Ligands
The mechanism by which the platelet-endothelial cell adhesion molecule PECAM-1 regulates leukodiapedesis, vascular endothelial integrity, and proinflammatory cytokine expression in vivo is not known. We recently identified PECAM-1 as a negative regulator of Kv11.1, a specific voltage-gated potassium channel that functioned in human macrophages to reset a resting membrane potential following depolarization. We demonstrate here that dofetilide (DOF), a selective inhibitor of the Kv11.1 current, had a profound inhibitory effect on neutrophil recruitment in mice following TLR/IL-1R–elicited peritonitis or intrascrotal injection of IL-1β, but had no effect on responses seen with TNFα. Furthermore, inhibitors of Kv11.1 (DOF, E4031, and astemizole), but not Kv1.3 (margatoxin), suppressed the expression of IL-6 and MCP-1 cytokines by murine resident peritoneal macrophages, while again having no effect on TNFα. In contrast, IL-6 expression by peritoneal mesothelial cells was unaffected. Using murine P388 cells, which lack endogenous C/EBPβexpression and are unresponsive to LPS for the expression of both IL-6 and MCP-1, we observed that DOF inhibited LPS-induced expression of IL-6 mRNA following ectopic expression of wild-type C/EBPβ, but not a serine-64 point mutant. Finally, DOF inhibited the constitutive activation of cdk2 in murine peritoneal macrophages; cdk2 is known to phosphorylate C/EBPβ at serine-64. Taken together, our results implicate a potential role for Kv11.1 in regulating cdk2 and C/EBPβ activity, where robust transactivation of both IL-6 and MCP-1 transcription is known to be dependent on serine-64 of C/EBPβ. Our data might also explain the altered phenotypes displayed by PECAM-1 knockout mice in several disease models
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Manipulation of the duration of the initial self-control task within the sequential-task paradigm: effect on exercise performance
Self-control exertion on an initial task has been associated with impaired performance on subsequent physical tasks also requiring self-control; an effect suggested to be mediated by changes in perceptions of pain and motivation. However, the effects of spending longer on the initial self-control task are unknown. This study, therefore, explored the potential for the duration of the initial self-control task to influence subsequent physical performance, perceptions of pain, and perceived motivation; particularly during the early stages of the physical task. In a within-subject design, 29 participants (11 male, 18 female) completed a wall-sit task until volitional exhaustion, on four separate occasions. Prior to each wall-sit, participants completed either a non-self-control task (congruent Stroop task) for 4 min, or a self-control task (incongruent Stroop task) for 4 (short duration), 8 (medium duration), or 16 (long duration) min. Participant’s perceptions of pain and motivation were recorded every 30 s during the wall-sit. Wall-sit performance time was analyzed using one-way ANOVA and perceptions of pain and motivation analyzed using multi-level modeling. Wall-sit performance time was significantly longer on the non-self-control exertion trial compared to all other trials (all p < 0.01), as well as longer on both the short duration and medium duration self-control exertion trials compared to the long duration self-control exertion trial (both p < 0.001). Perceptions of initial (at 30 s) pain and motivation were different between the trials (main effect of trial: pain, p = 0.001; motivation, p < 0.001); whereby longer durations of self-control exertion increased perceptions of pain and decreased motivation. The decrease in motivation during the wall-sit task was greater on the long duration self-control exertion trial compared to all other trials (trial∗ time interactions, all p < 0.05). The present study provides novel evidence that spending longer on the initial self-control task led to greater detrimental effects on subsequent wall-sit performance time. Furthermore, longer duration self-control exertion tasks led to increased perceptions of pain and decreased motivation within the first 30 s of the wall-sit task, as well as a greater decrease in motivation across the wall-sit task. These attentional and motivational shifts may explain performance decrements following the exertion of self-control
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