4,561 research outputs found

    Psychological functioning in adolescents referred to specialist gender identity clinics across Europe : a clinical comparison study between four clinics

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    Adolescents seeking professional help with their gender identity development often present with psychological difficulties. Existing literature on psychological functioning of gender diverse young people is limited and mostly bound to national chart reviews. This study examined the prevalence of psychological functioning and peer relationship problems in adolescents across four European specialist gender services (The Netherlands, Belgium, the UK, and Switzerland), using the Child Behavioural Checklist (CBCL) and the Youth Self-Report (YSR). Differences in psychological functioning and peer relationships were found in gender diverse adolescents across Europe. Overall, emotional and behavioural problems and peer relationship problems were most prevalent in adolescents from the UK, followed by Switzerland and Belgium. The least behavioural and emotional problems and peer relationship problems were reported by adolescents from The Netherlands. Across the four clinics, a similar pattern of gender differences was found. Birth-assigned girls showed more behavioural problems and externalising problems in the clinical range, as reported by their parents. According to self-report, internalising problems in the clinical range were more prevalent in adolescent birth-assigned boys. More research is needed to gain a better understanding of the difference in clinical presentations in gender diverse adolescents and to investigate what contextual factors that may contribute to this

    Unique Identification of Graviton Exchange Effects in e^+ e^- Collisions

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    Many types of new physics can lead to contact interaction-like modifications in e^+ e^- processes below direct production threshold. We examine the possibility of uniquely identifying the effects of graviton exchange, which are anticipated in many extra dimensional theories, from amongst this large set of models by using the moments of the angular distribution of the final state particles. In the case of the e^+ e^- --> f bar{f} process we demonstrate that this technique allows for the unique identification of the graviton exchange signature at the 5 sigma level for mass scales as high as 6 sqrt(s). The extension of this method to the e^+ e^- --> W^+ W^- process is also discussed.Comment: 21 pages, 3 figs, LaTe

    Transverse Polarization Signatures of Extra Dimensions at Linear Colliders

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    If significant longitudinal polarization of both the electrons and positrons becomes feasible at a future linear collider(LC), it may be possible to use spin rotators to produce transversely polarized beams. Using the transverse polarization of both beams, new azimuthal spin asymmetries can be formed which will be sensitive probes for new physics beyond the Standard Model. Here we demonstrate that these asymmetries are particularly sensitive to the exchange of Kaluza-Klein towers of gravitons, or other spin-2 fields, that are predicted to exist in higher dimensional theories which address the hierarchy problem. These new asymmetries are shown to be able to extend the search reach for such new physics by more than a factor of two, provide an additional tool for isolating the signatures for spin-2 exchange up to mass scales in excess of 10s10\sqrt s, and can be used to help differentiate among the proposed solutions to the hierarchy problem below the production threshold for new particles.Comment: 22 pages, 6 figs. LaTe

    Precision Measurements and Fermion Geography in the Randall-Sundrum Model Revisited

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    We re-examine the implications of allowing fermion fields to propagate in the five-dimensional bulk of the Randall-Sundrum (RS) localized gravity model. We find that mixing between the Standard Model top quark and its Kaluza Klein excitations generates large contributions to the rho parameter and consequently restricts the fundamental RS scale to lie above 100 TeV. To circumvent this bound we propose a `mixed' scenario which localizes the third generation fermions on the TeV brane and allows the lighter generations to propagate in the full five-dimensional bulk. We show that this construction naturally reproduces the observed m_c / m_t and m_s / m_b hierarchies. We explore the signatures of this scenario in precision measurements and future high energy collider experiments. We find that the region of parameter space that addresses the hierarchies of fermion Yukawa couplings permits a Higgs boson with a mass of 500 GeV and remains otherwise invisible at the LHC. However, the entire parameter region consistent with electroweak precision data is testable at future linear colliders. We briefly discuss possible constraints on this scenario arising from flavor changing neutral currents.Comment: 44 pages, 20 ps files; VII, typos fixed and refs adde

    Wake Development behind Paired Wings with Tip and Root Trailing Vortices: Consequences for Animal Flight Force Estimates

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    Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV) of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body), angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals

    Efficiency of Lift Production in Flapping and Gliding Flight of Swifts

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    Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing with an elliptical planform. In flapping flight, on the other hand, the wing tip travels faster than the root, creating a spanwise velocity gradient. To compensate, the optimal wing shape should taper towards the tip (reducing the local chord) and/or twist from root to tip (reducing local angle of attack). We hypothesised that, if a bird is limited in its ability to morph its wings and adapt its wing shape to suit both flight modes, then a preference towards flapping flight optimization will be expected since this is the most energetically demanding flight mode. We tested this by studying a well-known flap-gliding species, the common swift, by measuring the wakes generated by two birds, one in gliding and one in flapping flight in a wind tunnel. We calculated span efficiency, the efficiency of lift production, and found that the flapping swift had consistently higher span efficiency than the gliding swift. This supports our hypothesis and suggests that even though swifts have been shown previously to increase their lift-to-drag ratio substantially when gliding, the wing morphology is tuned to be more aerodynamically efficient in generating lift during flapping. Since body drag can be assumed to be similar for both flapping and gliding, it follows that the higher total drag in flapping flight compared with gliding flight is primarily a consequence of an increase in wing profile drag due to the flapping motion, exceeding the reduction in induced drag

    Systematic review of context-aware digital behavior change interventions to improve health

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    Health risk behaviors are leading contributors to morbidity, premature mortality associated with chronic diseases, and escalating health costs. However, traditional interventions to change health behaviors often have modest effects, and limited applicability and scale. To better support health improvement goals across the care continuum, new approaches incorporating various smart technologies are being utilized to create more individualized digital behavior change interventions (DBCIs). The purpose of this study is to identify context-aware DBCIs that provide individualized interventions to improve health. A systematic review of published literature (2013-2020) was conducted from multiple databases and manual searches. All included DBCIs were context-aware, automated digital health technologies, whereby user input, activity, or location influenced the intervention. Included studies addressed explicit health behaviors and reported data of behavior change outcomes. Data extracted from studies included study design, type of intervention, including its functions and technologies used, behavior change techniques, and target health behavior and outcomes data. Thirty-three articles were included, comprising mobile health (mHealth) applications, Internet of Things wearables/sensors, and internet-based web applications. The most frequently adopted behavior change techniques were in the groupings of feedback and monitoring, shaping knowledge, associations, and goals and planning. Technologies used to apply these in a context-aware, automated fashion included analytic and artificial intelligence (e.g., machine learning and symbolic reasoning) methods requiring various degrees of access to data. Studies demonstrated improvements in physical activity, dietary behaviors, medication adherence, and sun protection practices. Context-aware DBCIs effectively supported behavior change to improve users' health behaviors

    Preliminary investigation of plasma levels of sex hormones and human growth factor(s), and P300 latency as correlates to cognitive decline as a function of gender

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    <p>Abstract</p> <p>Background</p> <p>Aging is marked by declines in levels of many sex hormones and growth factors, as well as in cognitive function. The P300 event-related potential has been established as a predictor of cognitive decline. We decided to determine if this measure, as well as 2 standard tests of memory and attention, may be correlated with serum levels of sex hormones and growth factors, and if there are any generalizations that could be made based on these parameters and the aging process.</p> <p>Findings</p> <p>In this large clinically based preliminary study several sex-stratified associations between hormone levels and cognition were observed, including (1) for males aged 30 to 49, both IGF-1 and IGFBP-3 significantly associated negatively with prolonged P300 latency; (2) for males aged 30 to 49, the spearman correlation between prolonged P300 latency and low free testosterone was significant; (3) for males aged 60 to 69, there was a significant negative correlation between P300 latency and DHEA levels; (4) for females aged 50 to 59 IGFBP-3 significantly associated negatively with prolonged P300 latency; (5) for females at all age periods, estrogen and progesterone were uncorrelated with P300 latency; and (6) for females aged 40 to 69, there was significant negative correlation between DHEA levels and P300 latency. Moreover there were no statistically significant correlations between any hormone and Wechsler Memory Scale-III (WMS-111). However, in females, there was a significant positive correlation between estrogen levels and the number of Attention Deficit Disorder (ADD) complaints.</p> <p>Conclusion</p> <p>Given certain caveats including confounding factors involving psychiatric and other chronic diseases as well as medications, the results may still have important value. If these results could be confirmed in a more rigorously controlled investigation, it may have important value in the diagnosis, prevention and treatment of cognitive impairments and decline.</p
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