946 research outputs found

    Standardized Assessment of Concussion in football players

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    This is the publisher's version, also available electronically from http://www.neurology.org/content/48/3/586.Article abstract-The recent formulation of guidelines for the management of concussion in sports adopted by the American Academy of Neurology specifically calls for the development of a standardized, systematic sideline evaluation for the immediate assessment of concussion in athletes. The present study involved the preliminary investigation of the feasibility and clinical validity of a standardized version of a brief sideline examination complied in accordance with these guidelines. This examination, intended for use by athletic trainers, was administered by three trainers to 141 nonconcussed high school football players at three separate schools. All players suspected of suffering a concussion (N = 6) during the fall 1995 season were also tested immediately following their injury. The examination was easily administered and scored. The concussed players as a group scored significantly below the nonconcussed controls and below their own baseline (pre-injury) performance, despite their all having been considered by the trainers to have suffered mild, grade 1 concussions. Although preliminary, these data suggest that a standardized sideline examination of this type can be useful in detecting concussion and determining fitness to return to play

    Let's talk about varying G

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    It is possible that fundamental constants may not be constant at all. There is a generally accepted view that one can only talk about variations of dimensionless quantities, such as the fine structure constant αee2/4πϵ0c\alpha_{\rm e}\equiv e^2/4\pi\epsilon_0\hbar c. However, constraints on the strength of gravity tend to focus on G itself, which is problematic. We stress that G needs to be multiplied by the square of a mass, and hence, for example, one should be constraining αgGmp2/c\alpha_{\rm g}\equiv G m_{\rm p}^2/\hbar c, where mpm_{\rm p} is the proton mass. Failure to focus on such dimensionless quantities makes it difficult to interpret the physical dependence of constraints on the variation of G in many published studies. A thought experiment involving talking to observers in another universe about the values of physical constants may be useful for distinguishing what is genuinely measurable from what is merely part of our particular system of units.Comment: 6 pages, Gravity Research Foundation essa

    Study of diffusion weighted MRI as a predictive biomarker of response during radiotherapy for high and intermediate risk squamous cell cancer of the oropharynx: The MeRInO study

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    Introduction and background: A significant proportion of patients with intermediate and high risk squamous cell cancer of the oropharynx (OPSCC) continue to relapse locally despite radical chemoradiotherapy (CRT). The toxicity of the current combination of intensified dose per fraction radiotherapy and platinum based chemotherapy limits further uniform intensification. If a predictive biomarker for outcomes from CRT can be identified during treatment then individualised and adaptive treatment strategies may be employed. Methods/design: The MeRInO study is a prospective observational imaging study of patients with intermediate and high risk, locally advanced OPSCC receiving radical RT or concurrent CRT Patients undergo diffusion weighted MRI prior to treatment (MRI_1) and during the third week of RT (MRI_2). Apparent diffusion coefficient (ADC) measurements will be made on each scan for previously specified target lesions (primary and lymph nodes) and change in ADC calculated. Patients will be followed up and disease status for each target lesion noted. The primary aim of the MeRInO study is to determine the threshold change in ADC from baseline to week 3 of RT that may identify the sub-group of non-responders during treatment. Discussion: The use of DW-MRI as a predictive biomarker during RT for SCC H&N is in its infancy but studies to date have found that response to treatment may indeed be predicted by comparison of DW-MRI carried out before and during treatment. However, previous studies have included all sub-sites and biological sub-types. Establishing ADC thresholds that predict for local failure is an essential step towards using DW-MRI to improve the therapeutic ratio in treating SCC H&N. This would be done most robustly in a specific H&N sub-site and in sub-types with similar biological behaviour. The MeRInO study will help establish these thresholds in OPSCC

    New Path Equations in Absolute Parallelism Geometry

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    The Bazanski approach, for deriving the geodesic equations in Riemannian geometry, is generalized in the absolute parallelism geometry. As a consequence of this generalization three path equations are obtained. A striking feature in the derived equations is the appearance of a torsion term with a numerical coefficients that jumps by a step of one half from equation to another. This is tempting to speculate that the paths in absolute parallelism geometry might admit a quantum feature.Comment: 4 pages Latex file Journal Reference: Astrophysics and space science 228, 273, (1995

    The Association Between Persistent White-Matter Abnormalities and Repeat Injury After Sport-Related Concussion

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    Objective: A recent systematic review determined that the physiological effects of concussion may persist beyond clinical recovery. Preclinical models suggest that ongoing physiological effects are accompanied by increased cerebral vulnerability that is associated with risk for subsequent, more severe injury. This study examined the association between signal alterations on diffusion tensor imaging following clinical recovery of sport-related concussion in athletes with and without a subsequent second concussion. Methods: Average mean diffusivity (MD) was calculated in a region of interest (ROI) in which concussed athletes (n = 82) showed significantly elevated MD acutely after injury (<48 h), at an asymptomatic time point, 7 days post-return to play (RTP), and 6 months relative to controls (n = 69). The relationship between MD in the identified ROI and likelihood of sustaining a subsequent concussion over a 1-year period was examined with a binary logistic regression (re-injured, yes/no). Results: Eleven of 82 concussed athletes (13.4%) sustained a second concussion within 12 months of initial injury. Mean MD at 7 days post-RTP was significantly higher in those athletes who went on to sustain a repeat concussion within 1 year of initial injury than those who did not (p = 0.048; d = 0.75). In this underpowered sample, the relationship between MD at 7 days post-RTP and likelihood of sustaining a secondary injury approached significance [χ2 (1) = 4.17, p = 0.057; B = 0.03, SE = 0.017; OR = 1.03, CI = 0.99, 1.07]. Conclusions: These preliminary findings raise the hypothesis that persistent signal abnormalities in diffusion imaging metrics at RTP following concussion may be predictive of a repeat concussion. This may reflect a window of cerebral vulnerability or increased susceptibility following concussion, though understanding the clinical significance of these findings requires further study

    Pressure as a Source of Gravity

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    The active mass density in Einstein's theory of gravitation in the analog of Poisson's equation in a local inertial system is proportional to ρ+3p/c2\rho+3p/c^2. Here ρ\rho is the density of energy and pp its pressure for a perfect fluid. By using exact solutions of Einstein's field equations in the static case we study whether the pressure term contributes towards the mass

    A Dynamical Study of the Friedmann Equations

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    Cosmology is an attracting subject for students but usually difficult to deal with if general relativity is not known. In this article, we first recall the Newtonian derivation of the Friedmann equations which govern the dynamics of our universe and discuss the validity of such a derivation. We then study the equations of evolution of the universe in terms of a dynamical system. This sums up the different behaviors of our universe and enables to address some cosmological problems.Comment: Needs IOP LaTeX class; 17 pages, 9 figure

    Education for Sustainable Development: Towards the Sustainable University

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    We  planned  this  conference  in  anticipation  of  the  end  of  the  UN  Decade  of  Education  for  Sustainable   Development  (DESD),  and  the  start  of  the  next  phase  for  those  involved  in  ESD  here  and   internationally.    At  Plymouth  University,  2015  marks  ten  year  anniversary  since  cross-­‐institutional   work  on  sustainability  and  sustainability  education  was  spearheaded  by  the  founding  of  the  Centre  for   Sustainable  Futures  (CSF).    Coincidentally,  2015  also  marks  a  ten  years  since  the  influential  HEFCE   policy  document  ‘Sustainable  Development  in  Higher  Education’  was  released.   Holding  the  conference  in  January  –  named  after  the  Roman  god  of  doorways,  of  endings  and   beginnings  –  we  sought  to  look  at  some  of  what  has  been  achieved  in  sustainability  education  to  date   and  explore  its  prospects  as  we  move  forward.   Following  an  enthusiastic  response  to  the  call  for  abstracts,  the  conference  featured  a  diverse  range   of  research  papers,  posters,  and  roundtable  presentations  from  academics  and  practitioners  across   the  UK  and  beyond.  The  conference  was  arranged  around  three  overarching  themes:     ESD  Pedagogy:  Criticality,  Creativity,  and  Collaboration   What  are  the  teaching  and  learning  processes  that  enable  students  to  develop  their  own  capacity  to   think  critically  and  creatively  in  the  face  of  global  sustainability  challenges  and,  secondly,  to  act   collaboratively  in  ways  that  pursue  more  hopeful  and  sustainable  futures?   Innovative  Learning  Spaces  for  ESD   What  are  the  physical  environments  that  provide  opportunities  for  new  forms  of  sustainability   education  to  flourish?  What  lies  beyond  the  lecture  hall  that  is  conducive  to  student  learning  through   inquiry-­‐based,  active,  participatory,  interdisciplinary  and  experiential  methods?   Towards  the  Sustainable  University   What  are  effective  approaches  for  leading  institutional  change,  organisational  learning,  and  staff  CPD   towards  sustainability?  This  publication  focuses  on  the  last  theme  –  Towards  the  Sustainable  University.    The  previous   PedRIO  Occasional  Paper  8  looks  at  the  first  theme  ESD  Pedagogy:  Criticality,  Creativity,  and   Collaboration
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