Identification of criticality in neuronal avalanches: II. A theoretical and empirical investigation of the Driven case

The observation of apparent power laws in neuronal systems has led to the suggestion that the brain is at, or close to, a critical state and may be a self-organised critical system. Within the framework of self-organised criticality a separation of timescales is thought to be crucial for the observation of power-law dynamics and computational models are often constructed with this property. However, this is not necessarily a characteristic of physiological neural networks—external input does not only occur when the network is at rest/a steady state. In this paper we study a simple neuronal network model driven by a continuous external input (i.e. the model does not have an explicit separation of timescales from seeding the system only when in the quiescent state) and analytically tuned to operate in the region of a critical state (it reaches the critical regime exactly in the absence of input—the case studied in the companion paper to this article). The system displays avalanche dynamics in the form of cascades of neuronal firing separated by periods of silence. We observe partial scale-free behaviour in the distribution of avalanche size for low levels of external input. We analytically derive the distributions of waiting times and investigate their temporal behaviour in relation to different levels of external input, showing that the system’s dynamics can exhibit partial long-range temporal correlations. We further show that as the system approaches the critical state by two alternative ‘routes’, different markers of criticality (partial scale-free behaviour and long-range temporal correlations) are displayed. This suggests that signatures of criticality exhibited by a particular system in close proximity to a critical state are dependent on the region in parameter space at which the system (currently) resides

An acute bout of cycling does not induce compensatory responses in pre-menopausal women not using hormonal contraceptives

There is a clear need to improve understanding of the effects of physical activity and exercise on appetite control. Therefore, the acute and short-term effects (three days) of a single bout of cycling on energy intake and energy expenditure were examined in women not using hormonal contraceptives. Sixteen active (n = 8) and inactive (n = 8) healthy pre-menopausal women completed a randomised crossover design study with two conditions (exercise and control). The exercise day involved cycling for 1 h (50% of maximum oxygen uptake) and resting for 2 h, whilst the control day comprised 3 h of rest. On each experimental day participants arrived at the laboratory fasted, consumed a standardised breakfast and an ad libitum pasta lunch. Food diaries and combined heart rate-accelerometer monitors were used to assess free-living food intake and energy expenditure, respectively, over the subsequent three days. There were no main effects or condition (exercise vs control) by group (active vs inactive) interaction for absolute energy intake (P > 0.05) at the ad libitum laboratory lunch meal, but there was a condition effect for relative energy intake (P = 0.004, ηp2 = 0.46) that was lower in the exercise condition (1417 ± 926 kJ vs. 2120 ± 923 kJ). Furthermore, post-breakfast satiety was higher in the active than in the inactive group (P = 0.005, ηp2 = 0.44). There were no main effects or interactions (P > 0.05) for mean daily energy intake, but both active and inactive groups consumed less energy from protein (14 ± 3% vs. 16 ± 4%, P = 0.016, ηp2 = 0.37) and more from carbohydrate (53 ± 5% vs. 49 ± 7%, P = 0.031, ηp2 = 0.31) following the exercise condition. This study suggests that an acute bout of cycling does not induce compensatory responses in active and inactive women not using hormonal contraceptives, while the stronger satiety response to the standardised breakfast meal in active individuals adds to the growing literature that physical activity helps improve the sensitivity of short-term appetite control

Adopted children and the transition from primary to secondary school: an examination of pupil, parent and teacher views

Adopted children and the transition from primary to secondary school: an examination of pupil, parent and teacher views This research focuses upon the impact that the transition from primary to secondary school may have on adopted children, and the role schools could play in supporting adopted children during this time. Questionnaires were sent to adopted children and their adoptive parents: 20 parents and 11 children returned questionnaires. The questionnaires focused on attitudes towards the transition from primary to secondary school, the needs of adopted children compared to other children and the role of schools in supporting adopted children. Following the questionnaires, a focus group was held with six adoptive parents and then interviews with four secondary school teachers. The interviews and focus groups had seven key areas: • sharing information • curriculum issues • the perceived needs of adopted children • the transition process • pastoral support • homework • training for schools. Both parents and children alike felt that adopted children have additional educational needs, particularly around issues of self-organization. However,adoptive parents were often unclear about who to talk to in their child’s school, and how to ensure that information about their child’s adoption was subsequently passed on to all appropriate members of staff. Equally, schools were generally keen to support adopted children, but often had poor channels of communication for ensuring staff were well informed. Additionally, some teachers revealed a lack of awareness regarding the needs of adopted children and the types of support that might be useful. However, where school staff had worked closely with parents and other agencies, such as the Educational Psychology Service and the Post-Adoption Service, parents and pupils reported helpful outcomes. This would suggest that working with other agencies may be particularly useful in enabling schools to gain a better understanding of the needs of adopted children, and allow them to take a more proactive approach in offering support to these children

Personality as it Relates to Performance Among Primary Flight Students at Embry-Riddle Aeronautical University

The purpose of this study was to evaluate the relationship of primary flight students\u27 performance as it relates to personality. Previous research has provided the basis for the relationship between what an individual accomplishes and personality traits. The individual performance of 30 students were evaluated by two different techniques during an observer flight. One was an evaluation form developed by the researcher and the other, the flight instructor\u27s (P.I.C.) evaluation. The performance data gathered by the researcher was collected in order to provide a secondary set of performance data in case there was no discriminability amongst the flight instructor\u27s evaluation. The flight instructor\u27 s evaluation was the primary source of performance data. These two factors were compared against measures from a personality test. The researcher administered The Sixteen Personality Factor Questionnaire (16PF), under the supervision of the thesis chairperson, to every student who was observed after they had completed the flight course