1,031 research outputs found

    Horizontal Conflict Resolution Maneuvers with a Cockpit Display of Traffic Information

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    Pilot resolution of potential conflicts in the horizontal plane when the only information available on the other aircraft was presented on a Cockpit Display of Traffic Information (CDTI) is investigated. The pilot's task was to assess the situation and if necessary maneuver so as to avoid the other aircraft. No instructions were given on evasive strategy or on what was considered to be an acceptable minimum separation. The results indicate that pilots had a strong bias of turning toward the intruder aircraft in order to pass behind it. In more than 50% of the encounters with a 90 degree crossing angle in which the intruder aircraft was programmed to pass behind the aircraft, the pilots maneuvered so as to pass behind the intruder. This bias was not as strong with the display which showed a prediction of the intruder's relative velocity. The average miss distance for all encounters was about 4500 feet

    Impossible Worlds

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    Designing a physical activity parenting course : parental views on recruitment, content and delivery

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    Background Many children do not engage in sufficient levels of physical activity (PA) and spend too much time screen-viewing (SV). High levels of SV (e.g. watching TV, playing video games and surfing the internet) and low levels of PA have been associated with adverse health outcomes. Parenting courses may hold promise as an intervention medium to change children’s PA and SV. The current study was formative work conducted to design a new parenting programme to increase children’s PA and reduce their SV. Specifically, we focussed on interest in a course, desired content and delivery style, barriers and facilitators to participation and opinions on control group provision. Methods In-depth telephone interviews were conducted with thirty two parents (29 female) of 6–8 year olds. Data were analysed thematically. An anonymous online survey was also completed by 750 parents of 6–8 year old children and descriptive statistics calculated. Results Interview participants were interested in a parenting course because they wanted general parenting advice and ideas to help their children be physically active. Parents indicated that they would benefit from knowing how to quantify their child’s PA and SV levels. Parents wanted practical ideas of alternatives to SV. Most parents would be unable to attend unless childcare was provided. Schools were perceived to be a trusted source of information about parenting courses and the optimal recruitment location. In terms of delivery style, the majority of parents stated they would prefer a group-based approach that provided opportunities for peer learning and support with professional input. Survey participants reported the timing of classes and the provision of childcare were essential factors that would affect participation. In terms of designing an intervention, the most preferred control group option was the opportunity to attend the same course at a later date. Conclusions Parents are interested in PA/SV parenting courses but the provision of child care is essential for attendance. Recruitment is likely to be facilitated via trusted sources. Parents want practical advice on how to overcome barriers and suggest advice is provided in a mutually supportive group experience with expert input

    Towards a Spatial Reconsideration of “West Coast” and “East Coast” in Jazz: Hip Hop Parallels and Notions of the Local

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    West Coast jazz practices following World War II have often been positioned as diametrically opposed to jazz practices in New York and other Eastern cities. In comparison to the dominant New York scene, the “West Coast sound” has routinely been dismissed as being too laid back, too informed by Western art music, too unswinging, and, more often than not, too white. Yet, it seems rather obvious that sociocultural and environmental factors unique to California would have had an affective impact upon musicians and musical expression in the region; an attitude frequently reflected in discussions of popular music. In an exploration of the West Coast sound that attempts to reach beyond considerations of racial authenticity, this paper draws attention to the similar ways in which notions of authenticity and differences in sound and expression in the debate surrounding East Coast versus West Coast hip hop (1980s-1990s) can be seen to mirror those surrounding the West Coast/East Coast jazz divide some 40 years earlier, and suggests that the aesthetic and regional concerns expressed by the hip hop community may provide a means to reconsider and reassess the jazz sounds emerging from California in the 1940s–1950s

    Mothers’ views of their preschool child’s screen-viewing behaviour:a qualitative study

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    Abstract Background Research on screen-viewing in preschool children has predominantly focused on television viewing. The rapid development of mobile devices (e.g. tablets, smart phones and e-readers) and the increase in their use by preschool children means there is a need to understand how and why these devices are used by this age group. The aim of this study was to explore mothers’ views of their preschool children’s screen viewing behaviour (including mobile devices) and investigate how preschool children use different screen-viewing devices. Methods One-to-one, semi-structured interviews with mothers of preschool children (aged between 2 and 4 years old). Mothers were recruited through preschools, nurseries, and mother and toddler groups located within four areas of varying socio-economic status within Bristol, UK. Data were analysed thematically using a framework approach. Results Twenty-six mothers were interviewed. Mobile devices were regularly used as a form of screen-viewing for most children but were used on an ad hoc basis rather than being a habitual activity. The reasons and influences of mobile device use described by mothers were similar to that of television viewing. However, the portability of mobile devices meant that they were often used outside of the home as a distraction tool. Their multi-functionality meant that they could be used as a portable television, or for purposeful learning through educational games and applications. Some mothers showed concerns over mobile device use by their child, whilst others felt it was an important and useful educational tool. Although the majority of mothers felt they needed to set rules and restrictions for mobile device use, many mothers felt that they are also a necessary and unavoidable part of life. Conclusions Mothers in this study suggested that mobile device use by preschool children is common. More research is needed to determine the impact of mobile device use in preschool children, how much time preschool children spend using mobile devices and which activities their use may be replacing

    Ultrafast Momentum Imaging of Pseudospin-Flip Excitations in Graphene

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    The pseudospin of Dirac electrons in graphene manifests itself in a peculiar momentum anisotropy for photo-excited electron-hole pairs. These interband excitations are in fact forbidden along the direction of the light polarization, and are maximum perpendicular to it. Here, we use time- and angle-resolved photoemission spectroscopy to investigate the resulting unconventional hot carrier dynamics, sampling carrier distributions as a function of energy and in-plane momentum. We first show that the rapidly-established quasi-thermal electron distribution initially exhibits an azimuth-dependent temperature, consistent with relaxation through collinear electron-electron scattering. Azimuthal thermalization is found to occur only at longer time delays, at a rate that depends on the substrate and the static doping level. Further, we observe pronounced differences in the electron and hole dynamics in n-doped samples. By simulating the Coulomb- and phonon-mediated carrier dynamics we are able to disentangle the influence of excitation fluence, screening, and doping, and develop a microscopic picture of the carrier dynamics in photo-excited graphene. Our results clarify new aspects of hot carrier dynamics that are unique to Dirac materials, with relevance for photo-control experiments and optoelectronic device applications.Comment: 23 pages, 12 figure

    Feasibility trial evaluation of a physical activity and screen-viewing course for parents of 6 to 8 year-old children : Teamplay

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    Background: Many children spend too much time screen-viewing (watching TV, surfing the internet and playing video games) and do not meet physical activity (PA) guidelines. Parents are important influences on children’s PA and screen-viewing (SV). There is a shortage of parent-focused interventions to change children’s PA and SV. Methods: Teamplay was a two arm individualized randomized controlled feasibility trial. Participants were parents of 6–8 year old children. Intervention participants were invited to attend an eight week parenting program with each session lasting 2 hours. Children and parents wore an accelerometer for seven days and minutes of moderate-to-vigorous intensity PA (MVPA) were derived. Parents were also asked to report the average number of hours per day that both they and the target child spent watching TV. Measures were assessed at baseline (time 0) at the end of the intervention (week 8) and 2 months after the intervention had ended (week 16). Results: There were 75 participants who provided consent and were randomized but 27 participants withdrew post-randomization. Children in the intervention group engaged in 2.6 fewer minutes of weekday MVPA at Time 1 but engaged in 11 more minutes of weekend MVPA. At Time 1 the intervention parents engaged in 9 more minutes of weekday MVPA and 13 more minutes of weekend MVPA. The proportion of children in the intervention group watching ≥ 2 hours per day of TV on weekend days decreased after the intervention (time 0 = 76%, time 1 = 39%, time 2 = 50%), while the control group proportion increased slightly (79%, 86% and 87%). Parental weekday TV watching decreased in both groups. In post-study interviews many mothers reported problems associated with wearing the accelerometers. In terms of a future full-scale trial, a sample of between 80 and 340 families would be needed to detect a mean difference of 10-minutes of weekend MVPA. Conclusions: Teamplay is a promising parenting program in an under-researched area. The intervention was acceptable to parents, and all elements of the study protocol were successfully completed. Simple changes to the trial protocol could result in more complete data collection and study engagement

    A qualitative exploration of English black adults’ views of strength and balance activities in mid-life

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    BACKGROUND: Public health guidelines state that all adults should undertake muscle and bone strengthening and balance training activities at least twice a week to support their physical function and maintain independent health. This is intended to maintain strength in adulthood and offset natural declines in bone density and muscle mass. Most older adults do not meet this guideline with low levels of compliance among older black people. This study explored the experiences of physical activity relating to strength and balance activities, amongst black men and women living in England, aged 50–70. METHODS: Participants were recruited by phone via a network of research recruitment specialists across England. In-depth qualitative interviews were conducted with 25 black people aged 50–70 living in England. An inductive thematic analysis was conducted. RESULTS: We found there was only a very general understanding of the importance of maintaining body strength and balance, and low salience: strength and balance activities were not seen to be an important part of participants’ lives. Most participants only wanted to be strong enough to get on with ‘normal life’ and not to build strength or balance. Participants aged 50–70 were likely to think they were too young to worry about strength and balance, which tended to be mentioned only if someone had experienced a problem. Participants reported that NHS staff, especially physiotherapists are a key source of information on the topic and could therefore be useful in future prevention strategies. CONCLUSION: Public health recommendations stress the importance of increasing participation in regular strength and balance activities as people age, to reduce the risk of falls and maintain independence. This study has shown that among the black middle-aged adults we interviewed, the knowledge and salience of this message is low. Public health approaches should be taken to communicate the importance of enhancing strength and balance as people approach older age, including communication and education programmes led by health professionals, who were viewed with authority amongst these participants
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