9,483 research outputs found
Categorizing stroke prognosis using different stroke scales
<p><b>Background and Purpose</b>: Stroke severity and dependency are often categorized to allow stratification for randomization or analysis. However, there is uncertainty whether the categorizations used for different stroke scales are equivalent. We investigated the amount of information retained by categorizing severity and dependency, and whether the currently used cut-offs are equivalent across different stroke scales.</p>
<p><b>Methods</b>: Stroke severity and dependency have been categorized as mild, moderate, or severe. We studied 2 acute stroke unit cohorts, measuring Scandinavian Stroke Scale (SSS), modified Rankin Scale (mRS), Barthel Index (BI), and modified National Institutes of Health Stroke Scale (mNIHSS). Receiver operating characteristic (ROC) curves were examined to determine the ability of full and categorized scales to predict death and dependency. A weighted kappa analysis assessed agreement between the categorized scales.</p>
<p><b>Results</b>: When scales are categorized, the area under the ROC curve is significantly reduced; however, the differences are small and may not be practically important. BI, mRS, and SSS all have excellent agreement with each other when categorized, whereas mNIHSS has substantial agreement with mRS and BI.</p>
<p><b>Conclusions</b>: Little predictive information is lost when stroke scales are categorized. There is substantial to almost perfect agreement among categorized scales. Therefore the use and categorization of a variety of stroke severity or dependency scales is acceptable in analyses.</p>
Dan P. Weir to Mr. Meredith (8 October 1962)
https://egrove.olemiss.edu/mercorr_pro/1013/thumbnail.jp
Gaussianity revisited: Exploring the Kibble-Zurek mechanism with superconducting rings
In this paper we use spontaneous flux production in annular superconductors
to shed light on the Kibble-Zurek scenario. In particular, we examine the
effects of finite size and external fields, neither of which is directly
amenable to the KZ analysis. Supported by 1D and 3D simulations, the properties
of a superconducting ring are seen to be well represented by analytic Gaussian
approximations which encode the KZ scales indirectly. Experimental results for
annuli in the presence of external fields corroborate these findings.Comment: 20 pages, 10 figures; submitted to J. Phys: Condens. Matter for the
special issue 'Condensed Matter Analogues of Cosmology'; v2: considerably
reduced length, incorporation of experimental details into main text,
discussion improved, references added, version accepted for publicatio
Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes
<p>Abstract</p> <p>Background</p> <p>Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC) technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2) BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. While the BAC mutagenesis procedure is a powerful method to generate HSV-2 recombinants, particularly in the absence of selective marker in eukaryotic culture, the mutagenesis procedure is still difficult and cumbersome.</p> <p>Results</p> <p>Here we describe the incorporation of a phage lambda recombination system into an allele replacement vector. This strategy enables any DNA fragment containing the phage <it>att</it>L recombination sites to be efficiently inserted into the <it>att</it>R sites of the allele replacement vector using phage lambda clonase. We also describe how the incorporation of <it>EGFP </it>into the allele replacement vector can facilitate the selection of the desired cross-over recombinant BACs when the allele replacement reaction is a viral gene deletion. Finally, we incorporate the lambda phage recombination sites directly into an HSV-2 BAC vector for direct recombination of gene cassettes using the phage lambda clonase-driven recombination reaction.</p> <p>Conclusion</p> <p>Together, these improvements to the techniques of HSV BAC mutagenesis will facilitate the construction of recombinant herpes simplex viruses and viral vectors.</p
From Dendritic Compartments to Neuronal Networks: A Multilevel Analysis of Motion Vision
Animals typically rely on vision to direct their locomotion through the environment. Flies, who move in three dimensions while in flight, have evolved the fastest visual system in the animal kingdom to help them stabilize their flight posture and trajectories (Autrum, 1958). Partly for this reason, they have been the subject of extensive research on the neuronal basis of motion vision, the component of visual function involved in detecting movement within a scene.
Using a variety of techniques, including electrophysiology, genetic manipulation, and behavioral analysis, researchers have started to unravel the earliest stages of motion processing (Clark et al., 2011; Eichner et al., 2011). Visual motion processing in the fly begins with the elementary motion detectors (EMDs), which are units sensitive to one direction of motion over a small receptive field. The identities of the cells involved in this computation are under active research, and a complete picture has yet to emerge. For over four decades, however, the identity of one set of downstream cells that receive input from the EMDs has been known (Braitenberg, 1972). These cells, located in the lobula plate of the optic lobe of the fly, are called the horizontal system (HS) and vertical system (VS) cells
The Effect of Postsurgical Edema of the Knee Joint on Reflex Inhibition of the Quadriceps Femoris
Journal of Sport Rehabilitation, 1996,5,172-182
© 1996 Human Kinetics Publishers, Inc.The purpose of this case study was to investigate reflex inhibition of the quadriceps
femoris in a subject with postsurgical edema of the left knee. The subject
was a 45-year-old male with a traumatic knee injury with resultant edema
who underwent elective arthroscopic surgery. Reflex inhibition was assessed
by H-reflex elicitation in the femoral nerve and surface electromyography of
the quadriceps. To assess the degree of edema, direct circumferential measurements
were taken. On the first presurgical visit, the left knee demonstrated
mild edema with a decrease in H-reflex amplitudes. Two days after surgery, a
further reduction in amplitudes and more swelling were demonstrated followed
by an increase in amplitudes and a reduction in edema on the 28th
postoperative day. These findings document a relationship between reflex inhibition
and joint swelling that was previously described in experimental
models where joint edema was simulated
- …