76 research outputs found

    Accurate Range-Only Tracking in Wireless Sensor Networks

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    This work presents initial results from a novel Range-Only Tracking System tailored for implementation in Wireless Sensor Networks. The system utilizes range estimates from a number of anchor nodes, positioned in known locations to infer the trace and velocity of a moving target. To include support for manoeuvring targets, the target’s movement is modeled using a multiple model state-space representation. A Particle Filter inspired tracking algorithm operates on the acquired ranging data to online estimate the target's position and two-axis velocity [1]. Preliminary results from simulating the system under realistic conditions, reveal that good accuracy (<10m) can be achieved, even under cluttered conditions

    The effects of an experimental programme to support students’ autonomy on the overt behaviours of physical education teachers

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    Although the benefits of autonomy supportive behaviours are now well established in the literature, very few studies have attempted to train teachers to offer a greater autonomy support to their students. In fact, none of these studies has been carried out in physical education (PE). The purpose of this study is to test the effects of an autonomy-supportive training on overt behaviours of teaching among PE teachers. The experimental group included two PE teachers who were first educated on the benefits of an autonomy supportive style and then followed an individualised guidance programme during the 8 lessons of a teaching cycle. Their behaviours were observed and rated along 3 categories (i.e., autonomy supportive, neutral and controlling) and were subsequently compared to those of three teachers who formed the control condition. The results showed that teachers in the experimental group used more autonomy supportive and neutral behaviours than those in the control group, but no difference emerged in relation to controlling behaviours. We discuss the implications for schools of our findings

    Boundary critical behavior at m-axial Lifshitz points for a boundary plane parallel to the modulation axes

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    The critical behavior of semi-infinite dd-dimensional systems with nn-component order parameter ϕ\bm{\phi} and short-range interactions is investigated at an mm-axial bulk Lifshitz point whose wave-vector instability is isotropic in an mm-dimensional subspace of Rd\mathbb{R}^d. The associated mm modulation axes are presumed to be parallel to the surface, where 0≀m≀d−10\le m\le d-1. An appropriate semi-infinite âˆŁÏ•âˆŁ4|\bm{\phi}|^4 model representing the corresponding universality classes of surface critical behavior is introduced. It is shown that the usual O(n) symmetric boundary term ∝ϕ2\propto \bm{\phi}^2 of the Hamiltonian must be supplemented by one of the form λ˚∑α=1m(∂ϕ/∂xα)2\mathring{\lambda} \sum_{\alpha=1}^m(\partial\bm{\phi}/\partial x_\alpha)^2 involving a dimensionless (renormalized) coupling constant λ\lambda. The implied boundary conditions are given, and the general form of the field-theoretic renormalization of the model below the upper critical dimension d∗(m)=4+m/2d^*(m)=4+{m}/{2} is clarified. Fixed points describing the ordinary, special, and extraordinary transitions are identified and shown to be located at a nontrivial value λ∗\lambda^* if Ï”â‰Ąd∗(m)−d>0\epsilon\equiv d^*(m)-d>0. The surface critical exponents of the ordinary transition are determined to second order in Ï”\epsilon. Extrapolations of these Ï”\epsilon expansions yield values of these exponents for d=3d=3 in good agreement with recent Monte Carlo results for the case of a uniaxial (m=1m=1) Lifshitz point. The scaling dimension of the surface energy density is shown to be given exactly by d+m(ξ−1)d+m (\theta-1), where Ξ=Îœl4/Îœl2\theta=\nu_{l4}/\nu_{l2} is the anisotropy exponent.Comment: revtex4, 31 pages with eps-files for figures, uses texdraw to generate some graphs; to appear in PRB; v2: some references and additional remarks added, labeling in figure 1 and some typos correcte

    Cognitive Interview-Based Validation of the Patient-Reported Outcomes Version of the Common Terminology Criteria for Adverse Events in Adolescents with Cancer

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    Context The National Cancer Institute created the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) to allow direct input on symptomatic adverse events (AEs) from adult patients in oncology trials. Objectives This study sought to determine the youngest age to complete the PRO-CTCAE, evaluated comprehension of PRO-CTCAE among adolescents, tested new items not currently in PRO-CTCAE, and tested a parent-proxy version. Methods From seven pediatric cancer hospitals, 51 adolescents (13–20 years) receiving cancer treatment participated, along with 40 parent proxies. We evaluated 55 AEs from the PRO-CTCAE library (97 questions) and seven new AEs not in PRO-CTCAE that assess symptom frequency, severity, interference, or presence. Questions were distributed across three forms to reduce burden. Cognitive interviews with retrospective probing were completed in age groups of 13–15 and 16–20 year olds. Proxies were interviewed independently. Results In general, the 16–20 year olds and the parent proxies were able to understand and complete the PRO-CTCAE and newly designed AE questions. Five PRO-CTCAE terms (bloating of the abdomen, anxiety, flashing lights in front of your eyes, hot flashes, and bed sores) and the wording of the questions about AE severity were challenging for a few adolescents and proxies. The 13–15 year olds had greater challenges completing the PRO-CTCAE. Conclusion This study extends use of the adult PRO-CTCAE for adolescents as young as 16 years and proposes new questions for seven new symptomatic AEs and a parent-proxy version of PRO-CTCAE. Additional testing of the new questions and alternative language for more challenging PRO-CTCAE items is recommended in adults

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele

    Prevalence of Frailty in European Emergency Departments (FEED): an international flash mob study

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    Introduction Current emergency care systems are not optimized to respond to multiple and complex problems associated with frailty. Services may require reconfiguration to effectively deliver comprehensive frailty care, yet its prevalence and variation are poorly understood. This study primarily determined the prevalence of frailty among older people attending emergency care. Methods This cross-sectional study used a flash mob approach to collect observational European emergency care data over a 24-h period (04 July 2023). Sites were identified through the European Task Force for Geriatric Emergency Medicine collaboration and social media. Data were collected for all individuals aged 65 + who attended emergency care, and for all adults aged 18 + at a subset of sites. Variables included demographics, Clinical Frailty Scale (CFS), vital signs, and disposition. European and national frailty prevalence was determined with proportions with each CFS level and with dichotomized CFS 5 + (mild or more severe frailty). Results Sixty-two sites in fourteen European countries recruited five thousand seven hundred eighty-five individuals. 40% of 3479 older people had at least mild frailty, with countries ranging from 26 to 51%. They had median age 77 (IQR, 13) years and 53% were female. Across 22 sites observing all adult attenders, older people living with frailty comprised 14%. Conclusion 40% of older people using European emergency care had CFS 5 + . Frailty prevalence varied widely among European care systems. These differences likely reflected entrance selection and provide windows of opportunity for system configuration and workforce planning

    A Range-Only Tracking Algorithm for Wireless Sensor Networks

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    Over the last few years, target tracking in wireless sensor networks has become a topic of particular interest. This paper presents a tracking system intended for deployment in distributed Wireless Sensor Networks. The approach is inspired from the concept of deploying sensor nodes in an adhoc manner and based on the aggregate amount of information they provide, perform tracking of mobile objects. Static sensor nodes, with known locations, act as anchor nodes providing range-only measurements at each time step. The proposed system is modeled using a nonlinear state-space model which reflects a real world tracking scenario. The batch of range measurements made available at each sampling step, is used to estimate the target’s desired kinematic properties. In order to infer the state of the target at each time step, a Particle Filter algorithm has been designed to approximate the required posterior distribution of the state vector. The system’s operation was simulated and execution examples demonstrate the algorithm’s accuracy as well as the ability to effectively cope with manoeuvring targets
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