575 research outputs found
A Case for Mental and Physical Rest in Youth Sports Concussion: It’s Never too Late
Over the past decade, there has been a considerable increase in research on, and media attention to, sports-related concussion. However, despite accurate diagnosis, effective treatment and management of sports-related concussion have remained a challenge. There are approximately 1.8 million traumatic brain injuries in the United States annually (Faul et al., 2010) and emergency department pediatric visits for suspected concussion have doubled in the past decade (Bakhos et al., 2010). However, health care providers and medical researchers have yet to offer an effective, reliable evidence-based treatment for concussive brain injury. The Zurich 2008 Consensus Statement on Concussion in Sport codified the prescription for cognitive and physical rest immediately following a concussion based on clinical acumen and common sense (McCrory et al., 2009). Currently, rest is the considered the best immediate treatment for concussion. Other supportive and anecdotal treatments are often applied throughout the post-concussive recovery process to address persistent symptoms. The need for empirical research to translate current guidelines for rest into evidence-based treatment protocols is essential. A recent study evaluated the efficacy of comprehensive rest and concluded that such rest may be helpful whether applied soon after a concussion or weeks to months later (Moser et al., 2012). Here, we present a case illustrating the effectiveness of rest in a youth athlete, commenced after experiencing 13 months of post-concussion symptoms. There appears to be value in applying a specific period of cognitive and physical rest following concussion, whether immediately or later in the recovery phase
Relative Periodic Solutions of the Complex Ginzburg-Landau Equation
A method of finding relative periodic orbits for differential equations with
continuous symmetries is described and its utility demonstrated by computing
relative periodic solutions for the one-dimensional complex Ginzburg-Landau
equation (CGLE) with periodic boundary conditions. A relative periodic solution
is a solution that is periodic in time, up to a transformation by an element of
the equation's symmetry group. With the method used, relative periodic
solutions are represented by a space-time Fourier series modified to include
the symmetry group element and are sought as solutions to a system of nonlinear
algebraic equations for the Fourier coefficients, group element, and time
period. The 77 relative periodic solutions found for the CGLE exhibit a wide
variety of temporal dynamics, with the sum of their positive Lyapunov exponents
varying from 5.19 to 60.35 and their unstable dimensions from 3 to 8.
Preliminary work indicates that weighted averages over the collection of
relative periodic solutions accurately approximate the value of several
functionals on typical trajectories.Comment: 32 pages, 12 figure
The Power Spectrum of Mass Fluctuations Measured from the Lyman-alpha Forest at Redshift z=2.5
We measure the linear power spectrum of mass density fluctuations at redshift
z=2.5 from the \lya forest absorption in a sample of 19 QSO spectra, using the
method introduced by Croft et al. (1998). The P(k) measurement covers the range
2\pi/k ~ 450-2350 km/s (2-12 comoving \hmpc for \Omega=1). We examine a number
of possible sources of systematic error and find none that are significant on
these scales. In particular, we show that spatial variations in the UV
background caused by the discreteness of the source population should have
negligible effect on our P(k) measurement. We obtain consistent results from
the high and low redshift halves of the data set and from an entirely
independent sample of nine QSO spectra with mean redshift z=2.1. A power law
fit to our measured P(k) yields a logarithmic slope n=-2.25 +/- 0.18 and an
amplitude \Delta^2(k_p) = 0.57^{+0.26}_{-0.18}, where is the
contribution to the density variance from a unit interval of lnk and k_p=0.008
(km/s)^{-1}. Direct comparison of our mass P(k) to the measured clustering of
Lyman Break Galaxies shows that they are a highly biased population, with a
bias factor b~2-5. The slope of the linear P(k), never previously measured on
these scales, is close to that predicted by models based on inflation and Cold
Dark Matter (CDM). The P(k) amplitude is consistent with some scale-invariant,
COBE-normalized CDM models (e.g., an open model with \Omega_0=0.4) and
inconsistent with others (e.g., \Omega=1). Even with limited dynamic range and
substantial statistical uncertainty, a measurement of P(k) that has no unknown
``bias factors'' offers many opportunities for testing theories of structure
formation and constraining cosmological parameters. (Shortened)Comment: Submitted to ApJ, 27 emulateapj pages w/ 19 postscript fig
19-element vertical cavity surface emitting laser arrays with inter-vertical cavity surface emitting laser ridge connectors
We achieve record concurrent combinations of bandwidth (18 GHz), optical output power (150 mW), and wall plug efficiency (30%) with a unique arrangement of 19-element, electrically parallel 980 nm vertical cavity surface emitting laser (VCSEL) arrays. We use a new two-dimensional, quasi honeycomb geometry with inter-VCSEL ridge connectors—made nonconducting by selective thermal oxidation—to improve heat dissipation and facilitate a single top surface anode contact. Via on-wafer probing we perform static and dynamic measurements over the wide temperature range of 23 °C to 85 °C and extract, report, and discuss key array figures-of-merit.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement
Koinonia
Best Practice FeaturesLife on Life Learning: Steps Towards Authentic Mentoring, Brian Jensen
The Heart of the Honor Code: I am My Brother\u27s Keeper, Emily J. Darnell
Spotlight FeaturesOld People are Whole Persons, Too: Why Understanding Heritage is a Foundational Component of College Student Development, Philip Byers
Ministry and Learning in Residence Life, Josh Arnold
Shepherding in an Age of Edupunks, Drew Moser
The Gap in the Curtain: Seeing Pieces of a Residential Community\u27s Future, David Johnstone
InterviewsA Conversation with Juana Bordas, conducted by Rob Pepper
Looking Into the Future: Two Educators\u27 Perspectives on Christian Higher Education, by Kim Stave and Ken Heffner (edited by Kirstin Vander Giessen-Reitsma)
Book ReviewsThe Unlikely Disciple (by Kevin Roose), reviewed by Christopher Bohle
ReflectionsSeven Greek Words that Mean the World to Me, Bob Crow
FeaturesThe President\u27s Corner
Editor\u27s Deskhttps://pillars.taylor.edu/acsd_koinonia/1013/thumbnail.jp
A tall order: Small area mapping and modelling of adult height among Swiss male conscripts
Adult height reflects an individual's socio-economic background and offers insights into the well-being of populations. Height is linked to various health outcomes such as morbidity and mortality and has consequences on the societal level. The aim of this study was to describe small-area variation of height and associated factors among young men in Switzerland. Data from 175,916 conscripts (aged between 18.50 and 20.50 years) was collected between 2005 and 2011, which represented approximately 90% of the corresponding birth cohorts. These were analysed using Gaussian hierarchical models in a Bayesian framework to investigate the spatial pattern of mean height across postcodes. The models varied both in random effects and degree of adjustment (professional status, area-based socioeconomic position, and language region). We found a strong spatial structure for mean height across postcodes. The range of height differences between mean postcode level estimates was 3.40cm according to the best fitting model, with the shorter conscripts coming from the Italian and French speaking parts of Switzerland. There were positive socioeconomic gradients in height at both individual and area-based levels. Spatial patterns for height persisted after adjustment for individual factors, but not when language region was included. Socio-economic position and cultural/natural boundaries such as language borders and mountain passes are shaping patterns of height for Swiss conscripts. Small area mapping of height contributes to the understanding of its cofactors
85 °C error-free operation at 38 Gb/s of oxide-confined 980-nm vertical-cavity surface-emitting lasers
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 100, 081103 (2012) and may be found at https://doi.org/10.1063/1.3688040.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/224211/EU/VISIT - Vertically Integrated Systems for Information Transfer/VISI
Second primary cancer risk - the impact of applying different definitions of multiple primaries: results from a retrospective population-based cancer registry study
Background:
There is evidence that cancer survivors are at increased risk of second primary cancers. Changes in the prevalence of risk factors and diagnostic techniques may have affected more recent risks.<p></p>
Methods:
We examined the incidence of second primary cancer among adults in the West of Scotland, UK, diagnosed with cancer between 2000 and 2004 (n = 57,393). We used National Cancer Institute Surveillance Epidemiology and End Results and International Agency for Research on Cancer definitions of multiple primary cancers and estimated indirectly standardised incidence ratios (SIR) with 95% confidence intervals (CI).<p></p>
Results:
There was a high incidence of cancer during the first 60 days following diagnosis (SIR = 2.36, 95% CI = 2.12 to 2.63). When this period was excluded the risk was not raised, but it was high for some patient groups; in particular women aged <50 years with breast cancer (SIR = 2.13, 95% CI = 1.58 to 2.78), patients with bladder (SIR = 1.41, 95% CI = 1.19 to 1.67) and head & neck (SIR = 1.93, 95% CI = 1.67 to 2.21) cancer. Head & neck cancer patients had increased risks of lung cancer (SIR = 3.75, 95% CI = 3.01 to 4.62), oesophageal (SIR = 4.62, 95% CI = 2.73 to 7.29) and other head & neck tumours (SIR = 6.10, 95% CI = 4.17 to 8.61). Patients with bladder cancer had raised risks of lung (SIR = 2.18, 95% CI = 1.62 to 2.88) and prostate (SIR = 2.41, 95% CI = 1.72 to 3.30) cancer.<p></p>
Conclusions:
Relative risks of second primary cancers may be smaller than previously reported. Premenopausal women with breast cancer and patients with malignant melanomas, bladder and head & neck cancers may benefit from increased surveillance and advice to avoid known risk factors
Performance of Monolayer Graphene Nanomechanical Resonators with Electrical Readout
The enormous stiffness and low density of graphene make it an ideal material
for nanoelectromechanical (NEMS) applications. We demonstrate fabrication and
electrical readout of monolayer graphene resonators, and test their response to
changes in mass and temperature. The devices show resonances in the MHz range.
The strong dependence of the resonant frequency on applied gate voltage can be
fit to a membrane model, which yields the mass density and built-in strain.
Upon removal and addition of mass, we observe changes in both the density and
the strain, indicating that adsorbates impart tension to the graphene. Upon
cooling, the frequency increases; the shift rate can be used to measure the
unusual negative thermal expansion coefficient of graphene. The quality factor
increases with decreasing temperature, reaching ~10,000 at 5 K. By establishing
many of the basic attributes of monolayer graphene resonators, these studies
lay the groundwork for applications, including high-sensitivity mass detectors
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