2,097 research outputs found

    Marked central nervous system pathology in CD59 knockout rats following passive transfer of Neuromyelitis optica immunoglobulin G.

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    Neuromyelitis optica spectrum disorders (herein called NMO) is an inflammatory demyelinating disease of the central nervous system in which pathogenesis involves complement-dependent cytotoxicity (CDC) produced by immunoglobulin G autoantibodies targeting aquaporin-4 (AQP4-IgG) on astrocytes. We reported evidence previously, using CD59-/- mice, that the membrane-associated complement inhibitor CD59 modulates CDC in NMO (Zhang and Verkman, J. Autoimmun. 53:67-77, 2014). Motivated by the observation that rats, unlike mice, have human-like complement activity, here we generated CD59-/- rats to investigate the role of CD59 in NMO and to create NMO pathology by passive transfer of AQP4-IgG under conditions in which minimal pathology is produced in normal rats. CD59-/- rats generated by CRISPR/Cas9 technology showed no overt phenotype at baseline except for mild hemolysis. CDC assays in astrocyte cultures and cerebellar slices from CD59-/- rats showed much greater sensitivity to AQP4-IgG and complement than those from CD59+/+ rats. Intracerebral administration of AQP4-IgG in CD59-/- rats produced marked NMO pathology, with astrocytopathy, inflammation, deposition of activated complement, and demyelination, whereas identically treated CD59+/+ rats showed minimal pathology. A single, intracisternal injection of AQP4-IgG in CD59-/- rats produced hindlimb paralysis by 3 days, with inflammation and deposition of activated complement in spinal cord, optic nerves and brain periventricular and surface matter, with most marked astrocyte injury in cervical spinal cord. These results implicate an important role of CD59 in modulating NMO pathology in rats and demonstrate amplification of AQP4-IgG-induced NMO disease with CD59 knockout

    Shear wave generation using a spiral electromagnetic acoustic transducer

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    A spiral electromagnetic acoustic transducer (EMAT) is efficient in eddy current generation and has been used for surface defect inspection using Rayleigh waves or thickness gauging based on plane waves in echo mode. Measured and calculated particle velocities and directivities are presented. It is found that the shear wave is not predominantly a plane wave. It has zero amplitude on the axis of the generation EMAT and has maximum amplitude at the critical angle. The shear wave could be used in the steel industry for both internal and surface defect inspections together with Rayleigh wave

    Communications protocol

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    The present invention relates to an improved communications protocol which increases the efficiency of transmission in return channels on a multi-channel slotted Alohas system by incorporating advanced error correction algorithms, selective retransmission protocols and the use of reserved channels to satisfy the retransmission requests

    The Impact of Severe Obesity on Post-Acute Rehabilitation Efficiency, Length of Stay, and Hospital Costs

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    Background and Objective. The purpose of this retrospective observational study was to examine the influence of severe obesity on length of stay (LOS), rehabilitation efficiency, and hospital costs post-acute rehabilitation in a population-based, tertiary care, publicly-funded regional rehabilitation center. Participants. 42 severely obese subjects (mean age 53 y; mean BMI 50.9 kg/m2) and 42 nonobese controls (mean age 59 y; mean BMI 23.0 kg/m2) matched by sex and admitting diagnosis. Main Outcome Measures. Total LOS, rehab LOS, waiting for transfer LOS, Fuctional Independence Measure (FIM) efficiency, and hospital costs. Results. Compared to controls, severely obese subjects experienced longer total LOS (98.4 vs. 37.4 days; P=0.03), rehabilitation LOS (55.8 vs. 37.4 days; P=0.04), and waiting for transfer LOS (42.6 vs. 0 days; P=0.006); increased hospital costs (115,822vs.115,822 vs. 43,969; P=0.03); and similar FIM efficiency (0.58 vs. 0.67; P=0.27). Severe obesity was an independent predictor of total LOS (beta-coefficient 0.51; P=0.03), rehab LOS (0.46; P=0.02) but not FIM efficiency (−0.63; P=0.06). Conclusion. Severe obesity adversely affects rehabilitation LOS and expenditures. Targeted interventions in severely obese individuals to optimize post-acute rehabilitation care delivery are needed

    To Branch Out or Stay Focused?: Affective Shifts Differentially Predict Organizational Citizenship Behavior and Task Performance

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    We draw from personality systems interaction theory (PSI; Kuhl, 2000) and regulatory focus theory (Higgins, 1997) to examine how dynamic positive and negative affective processes interact to predict both task and contextual performance. Using a twice-daily diary design over the course of a three-week period, results from multi-level regression analysis revealed that distinct patterns of change in positive and negative affect optimally predicted contextual and task performance among a sample of 71 individuals employed at a medium-sized technology company. Specifically, within persons, increases (upshifts) in positive affect over the course of a work day better predicted the subsequent day’s organizational citizenship behavior (OCB) when such increases were coupled with decreases (downshifts) in negative affect. The optimal pattern of change in positive and negative affect differed, however, in predicting task performance. That is, upshifts in positive affect over the course of the work day better predicted the subsequent day’s task performance when such upshifts were accompanied by upshifts in negative affect. The contribution of our findings to PSI theory and the broader affective and motivation regulation literatures, along with practical implications, are discussed
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