1,855 research outputs found

    Occasional essay: upper motor neuron syndrome in amyotrophic lateral sclerosis

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    The diagnosis of amyotrophic lateral sclerosis (ALS) requires recognition of both lower (LMN) and upper motor neuron (UMN) dysfunction.1 However, classical UMN signs are frequently difficult to identify in ALS.2 LMN involvement is sensitively detected by electromyography (EMG)3 but, as yet, there are no generally accepted markers for monitoring UMN abnormalities,4 the neurobiology of ALS itself, and disease spread through the brain and spinal cord,.5 Full clinical assessment is therefore necessary to exclude other diagnoses and to monitor disease progression. In part, this difficulty regarding detection of UMN involvement in ALS derives from the definition of ‘the UMN syndrome’. Abnormalities of motor control in ALS require reformulation within an expanded concept of the UMN, together with the neuropathological, neuro-imaging and neurophysiological abnormalities in ALS. We review these issues here

    Radiation chemistry in solvent etxraction: FY2011 research

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    This report summarizes work accomplished under the Fuel Cycle Research and Development (FCR&D) program in the area of radiation chemistry during FY 2011. The tasks assigned during FY 2011 included: (1) Continue measurements free radical reaction kinetics in the organic phase; (2) Continue development of an alpha-radiolysis program and compare alpha and gamma radiolysis for CMPO; (3) Initiate an effort to understand dose rate effects in radiation chemistry; and (4) Continued work to characterize TALSPEAK radiation chemistry, including the examination of metal complexed ligand kinetics. Progress made on each of these tasks is reported here. Briefly, the method developed to measure the kinetics of the reactions of the NO3 radical with solvent extraction ligands in organic solution during FY10 was extended here to a number of compounds to better understand the differences between radical reactions in the organic versus aqueous phases. The alpha-radiolysis program in FY11 included irradiations of CMPO solutions with 244Cm, 211At and the He ion beam, for comparison to gamma irradiations, and a comparison of the gamma irradiation results for CMPO at three different gamma dose rates. Finally, recent results for TALSPEAK radiolysis are reported, summarizing the latest in an effort to understand how metal complexation to ligands affects their reaction kinetics with free radicals

    Detecting disordered eating among recreational exercisers; exploring the role of personal trainers

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    This study aimed to understand how personal trainers identify and manage disordered eating among their clients. Semi-structured interviews were undertaken with eleven UK based personal trainers to document their experiences of working with clients exhibiting symptoms of disordered eating. The interviews were recorded, fully transcribed and subjected to a thematic analysis. The findings suggest that personal trainers rely on external cues to identify disordered eating among clients such as changes to physical appearance, exercise behaviours and performance. The findings also revealed that personal trainers lack knowledge and hold misconceptions about disordered eating. Such misconceptions influenced their ability to identify and manage potential problems among their clients. Participants described the need for further education and guidelines to increase their knowledge and confidence in identifying and managing disordered eating among their clients. The findings from this study will be useful for professional bodies and practitioners in the development of guidelines and educational material for personal trainers

    Mid-Infrared Spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 2. Determination of the Mean Composition of the Upper Troposphere and Stratosphere

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    Mid-infrared spectral observations Uranus acquired with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope are used to determine the abundances of C2H2, C2H6, CH3C2H, C4H2, CO2, and tentatively CH3 on Uranus at the time of the 2007 equinox. For vertically uniform eddy diffusion coefficients in the range 2200-2600 cm2 s-1, photochemical models that reproduce the observed methane emission also predict C2H6 profiles that compare well with emission in the 11.6-12.5 micron wavelength region, where the nu9 band of C2H6 is prominent. Our nominal model with a uniform eddy diffusion coefficient Kzz = 2430 cm2 sec-1 and a CH4 tropopause mole fraction of 1.6x10-5 provides a good fit to other hydrocarbon emission features, such as those of C2H2 and C4H2, but the model profile for CH3C2H must be scaled by a factor of 0.43, suggesting that improvements are needed in the chemical reaction mechanism for C3Hx species. The nominal model is consistent with a CH3D/CH4 ratio of 3.0+-0.2x10-4. From the best-fit scaling of these photochemical-model profiles, we derive column abundances above the 10-mbar level of 4.5+01.1/-0.8 x 10+19 molecule-cm-2 for CH4, 6.2 +- 1.0 x 10+16 molecule-cm-2 for C2H2 (with a value 24% higher from a different longitudinal sampling), 3.1 +- 0.3 x 10+16 molecule-cm-2 for C2H6, 8.6 +- 2.6 x 10+13 molecule-cm-2 for CH3C2H, 1.8 +- 0.3 x 10+13 molecule-cm-2 for C4H2, and 1.7 +- 0.4 x 10+13 molecule-cm-2 for CO2 on Uranus. Our results have implications with respect to the influx rate of exogenic oxygen species and the production rate of stratospheric hazes on Uranus, as well as the C4H2 vapor pressure over C4H2 ice at low temperatures

    Thermodynamics and Kinetics of Advanced Separations Systems ? FY 2010 Summary Report

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    This report presents a summary of the work performed in the area of thermodynamics and kinetics of advanced separations systems under the Fuel Cycle Research and Development (FCR&D) program during FY 2010. Thermodynamic investigations into metal extraction dependencies on lactate and HDEHP have been performed. These metal distribution studies indicate a substantial deviation from the expected behavior at conditions that are typical of TALSPEAK process operational platform. These studies also identify that no thermodynamically stable mixed complexes exist in the aqueous solutions and increasing the complexity of the organic medium appears to influence the observed deviations. Following on from this, the first calorimetric measurement of the heat of extraction of americium across a liquid-liquid boundary was performed

    Relative preservation of triceps over biceps strength in upper limb-onset ALS: the 'split elbow'

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    OBJECTIVE Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the motor system. The split hand sign in ALS refers to observed preferential weakness of the lateral hand muscles, which is unexplained. One possibility is larger cortical representation of the lateral hand compared with the medial. Biceps strength is usually preserved relative to triceps in neurological conditions, but biceps has a larger cortical representation and might be expected to show preferential weakness in ALS. METHODS Using the South-East England Register for Amyotrophic Lateral Sclerosis, we performed a retrospective longitudinal cohort study and extracted the modified Medical Research Council (MRC) muscle strength score for biceps and triceps in patients with a diagnosis of upper limb-onset ALS in the 19-year period 1996-2015. A Wilcoxon signed-rank test was used to assess the relative strength of the muscles within the total sum of the upper limbs involved in the study. RESULTS There were 659 people with upper limb onset of weakness. In 215 there were insufficient data to perform the analysis, and a further 33 were excluded for other reasons, leaving 411 for analysis. Biceps was stronger than triceps in 87 limbs, and triceps was stronger than biceps in 258 limbs, with no difference seen in the remaining 477. Triceps strength scores (mean rank=186.1) were higher than ipsilateral biceps strength scores (mean rank=134.2), Z=-10.1, p<0.001 (two-tailed). CONCLUSION Triceps strength is relatively preserved compared with biceps in ALS. This is consistent with a broadly corticofugal hypothesis of selective vulnerability, in which susceptibility might be associated with larger cortical representation
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