304 research outputs found

    High-speed observation of sprite streamers

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    This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Sprites are optical emissions in the mesosphere mainly at altitudes 50–90 km. They are caused by the sudden re-distribution of charge due to lightning in the troposphere which can produce electric fields in the mesosphere in excess of the local breakdown field. The resulting optical displays can be spectacular and this has led to research into the physics and chemistry involved. Imaging at faster than 5,000 frames per second has revealed streamer discharges to be an important and very dynamic part of sprites, and this paper will review high-speed observations of sprite streamers. Streamers are initiated in the 65–85 km altitude range and observed to propagate both down and up at velocities normally in the 106–5 9 107 m/s range. Sprite streamer heads are small, typically less than a few hundreds of meters, but very bright and appear in images much like stars with signals up to that expected of a magnitude -6 star. Many details of streamer formation have been modeled and successfully compared with observations. Streamers frequently split into multiple sub-streamers. The splitting is very fast. To resolve details will require framing rates higher than the maximum 32,000 fps used so far. Sprite streamers are similar to streamers observed in the laboratory and, although many features appear to obey simple scaling laws, recent work indicates that there are limits to the scaling.Research funding has been provided by the US National Science Foundation grants to the University of Alaska Fairbanks, and the US Air Force Academy, and by DARPA through a grant to the University of Florida

    Screen Time and Executive Function in Toddlerhood: A Longitudinal Study.

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    Technology is pervasive in homes with young children. Emerging evidence that electronic screen-based media use has adverse effects on executive functions may help explain negative relations between media use and early academic skills. However, longitudinal investigations are needed to test this idea. In a sample of 193 British toddlers tracked from age 2 to 3 years, we test concurrent and predictive relations between screen use and children's executive function. We find no concurrent association between screen use and executive function; however, screen time at age 2 is negatively associated with the development of executive functions in toddlerhood from age 2 to 3, controlling for a range of covariates including verbal ability. Implications for parenting, education, and pediatric recommendations are discussed

    Self-reported suboptimal sleep and receipt of sleep assessment and treatment among persons with and without a mental health condition in Australia: a cross sectional study

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    Background Poor sleep and poor mental health go hand in hand and, together, can have an adverse impact on physical health. Given the already disproportionate physical health inequities experienced by people with a mental health condition worldwide, the need to consider and optimise sleep has been highlighted as a means of improving both physical and mental health status. Sleep recommendations recently developed by the United States’ National Sleep Foundation incorporate a range of sleep parameters and enable the identification of ‘suboptimal’ sleep. Among community-dwelling persons with and without a 12-month mental health condition in Australia, this study reports: [1] the prevalence of ‘suboptimal’ sleep and [2] rates of sleep assessment by a health care clinician/service and receipt of and desire for sleep treatment. Methods A descriptive study (N = 1265) was undertaken using self-report data derived from a cross-sectional telephone survey of Australian adults, undertaken in 2017. Results Fifteen per cent (n = 184) of participants identified as having a mental health condition in the past 12 months. Across most (7 of 8) sleep parameters, the prevalence of suboptimal sleep was higher among people with a mental health condition, compared to those without (all p < 0.05). The highest prevalence of suboptimal sleep for both groups was seen on measures of sleep duration (36–39% and 17–20% for people with and without a mental health condition, respectively). In terms of sleep assessment and treatment, people with a mental health condition were significantly more likely to: desire treatment (37% versus 16%), have been assessed (38% versus 12%) and have received treatment (30% versus 7%). Conclusions The prevalence of suboptimal sleep among persons with a mental health condition in Australia is significantly higher than those without such a condition, and rates of assessment and treatment are low for both groups, but higher for people with a mental health condition. Population health interventions, including those delivered as part of routine health care, addressing suboptimal sleep are needed

    Examining variation across treatment clinics in cancer patients' psychological outcomes: results of a cross sectional survey

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    Published online: 4 April 2018Purpose: The majority of research on psychological outcomes for cancer patients has focussed on the role of individual characteristics, and disease and treatment factors. There has been very little exploration of the potential contribution of the treatment clinic to these outcomes. This study explored whether there is variation among clinics in cancer patients’ psychological outcomes. Methods: Cancer outpatients were recruited from 22 medical oncology and haematology clinics in Australia. Participants completed a pen and paper survey including the Hospital Anxiety and Depression Scale (HADS), as well as sociodemographic, disease and treatment characteristics. Results: Of those eligible to participate, 4233 (82%) consented and 2811 (81% of consenters) returned the completed survey. There was no statistically significant variation in HADS depression scores across clinics. Some difference in anxiety scores derived from the HADS questionnaire between clinics (p = 0.03) was found with the percentage of between-clinic variation estimated to be 1.11%. However, once all demographic, disease and treatment predictors were adjusted for there was no statistical differences between clinics (percent of between-clinic variation = 0.53%; p = 0.1415). Conclusions: Psychological outcomes were not found to vary between clinics. Other sources of variation including patient characteristics may over-ride between-clinic variability, if it exists.Mariko Carey, Robert Sanson-Fisher, Tara Clinton-McHarg, Allison Boyes, Ian Olver, Christopher Oldmeadow, Christine Paul, Catherine D'Este, Frans Hensken

    Ecology good, aut-ecology better; Improving the sustainability of designed plantings

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    © 2015 European Council of Landscape Architecture Schools (ECLAS). This paper explores how contemporary ecological science, and aut-ecology in particular, can improve the sustainability of designed vegetation. It is proposed that ecological understanding can be applied to design at three levels: 1) as representation, 2) as process, and 3) as aut-ecology, representing a gradient from the least to the most profound. Key ecological interactions that determine the success of designed plantings are explored via a review of relevant ecological research, challenging some widely held but unhelpful constructs about how both semi-natural and designed vegetation actually function. The paper concludes that there are real benefits to integrating aut-ecological understanding in the design of vegetation at all scales but that this will require ecological theory to be taught as a design toolkit rather than largely as descriptive knowledge

    Widening access to medicine may improve general practitioner recruitment in deprived and rural communities:survey of GP origins and current place of work

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    BACKGROUND: Widening access to medicine in the UK is a recalcitrant problem of increasing political importance, with associated strong social justice arguments but without clear evidence of impact on service delivery. Evidence from the United States suggests that widening access may enhance care to underserved communities. Additionally, rural origin has been demonstrated to be the factor most strongly associated with rural practice. However the evidence regarding socio-economic and rural background and subsequent practice locations in the UK has not been explored. The aim of this study was to investigate the association between general practitioners’ (GPs) socio-economic and rural background at application to medical school and demographic characteristics of their current practice. METHOD: The study design was a cross-sectional email survey of general practitioners practising in Scotland. Socio-economic status of GPs at application to medical school was assessed using the self-coded National Statistics Socio-Economic Classification. UK postcode at application was used to define urban–rural location. Current practice deprivation and remoteness was measured using NHS Scotland defined measures based on registered patients’ postcodes. RESULTS: A survey was sent to 2050 Scottish GPs with a valid accessible email address, with 801 (41.5 %) responding. GPs whose parents had semi-routine or routine occupations had 4.3 times the odds of working in a deprived practice compared to those with parents from managerial and professional occupations (95 % CI 1.8–10.2, p = 0.001). GPs from remote and rural Scottish backgrounds were more likely to work in remote Scottish practices, as were GPs originating from other UK countries. CONCLUSION: This study showed that childhood background is associated with the population GPs subsequently serve, implying that widening access may positively affect service delivery in addition to any social justice rationale. Longitudinal research is needed to explore this association and the impact of widening access on service delivery more broadly

    Worrying in the wings? Negative emotional birth memories in mothers and fathers show similar associations with perinatal mood disturbance and delivery mode

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    Abstract: Negative birth experiences can lead to symptoms of post-traumatic stress disorder in new mothers but have received much less attention in new fathers. A sample of 314 first-time expectant couples rated their symptoms of anxiety and depression in the third trimester and at 4-month post birth (227 vaginal delivery, 87 caesarean section), when they also completed the emotional memories subscale of the BirthMARQ (Foley et al. BMC Pregnancy Childbirth, 14, 211, 2014). We first examined mode of delivery (vaginal birth versus caesarean section) as a predictor of mothers’ and fathers’ BirthMARQ scores. Next, we used actor-partner interdependence model (APIM) to investigate intra- and interpersonal associations between birth experiences and maternal/paternal latent factors for antenatal and postnatal depression/anxiety. Reports of negative birth experiences were more common for mothers than fathers and for parents of babies born by caesarean section than by vaginal delivery. Within-couple agreement was moderately strong and, for both parents at both time-points, individual differences in negative birth memories were associated with symptoms of depression and anxiety. Negative birth memories also played a mediating role in the association between birth via caesarean section and reduced postnatal maternal wellbeing. Given the striking similarities between mothers and fathers in links between birth experiences and wellbeing, our findings highlight the need for partner-inclusive intervention strategies

    Strategic green infrastructure planning in Germany and the UK: a transnational evaluation of the evolution of urban greening policy and practice

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    The evolution of Green Infrastructure (GI) planning has varied dramatically between nations. Although a grounded set of principles are recognized globally, there is increasing variance in how these are implemented at a national and sub-national level. To investigate this the following paper presents an evaluation of how green infrastructure has been planned for in England and Germany illustrating how national policy structures facilitate variance in application. Adopting an evaluative framework linked to the identification of GI, its development and monitoring/ feedback the paper questions the impacts on delivery of intersecting factors including terminology, spatial distribution and functionality on effective GI investment. This process reviews how changing policy structures have influenced the framing of green infrastructure policy, and subsequent impact this has on the delivery of green infrastructure projects
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