1,496 research outputs found

    A multiple-access satellite relay system for low data rate users

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    Multiple access satellite relay system for low data rate user

    The Psychological Assessment of Language: A Philosophical Critique of the Illinois Test of Psycholinguistic Abilities.

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    It is argued in this paper that the Illinois Test of Psycholinguistic\ud Abilities (ITPA), a test widely used in the assessment\ud of certain language abilities in children, does not measure what it\ud purports to measure; in psychometric terminology, it does not have\ud construct validity. Specifically it is contended that the inferences\ud concerning the processing of language which are made on the basis of\ud children's performance on the tasks of the test are not warranted.\ud Three competing versions of the intended inferences are characterized •\ud at the outset of the paper, with particular attention being paid to\ud the logical relations obtaining between a given inference and the\ud test performance on which it is based. Central among these competing\ud interpretations is that wherein the psycholinguistic processes\ud postulated by Charles E. Osgood in his mediational response (neobehaviorist)\ud theory of communication are taken to be under assessment.\ud Considerable attention and criticism is brought to bear on Osgood's\ud theory because of the central role it played in the development of\ud the ITPA and because, at least on one interpretation of the test,\ud the processes specified by him are under assessment. The latter\ud interpretation is rejected on the grounds that Osgoodian theory is\ud incorrect, vitiated by an equivocation on his central theoretical\ud construct. The two other interpretations of the test, which do not\ud depend upon the correctness of Osgood's theory for their own validity,\ud are challenged and rejected independently. The conclusion reached\ud is that under none of the adopted formulations, all of which are\ud supported by the ITPA literature and have adherents amono the test's\ud many commentators, does the ITPA succeed in providing the information\ud about children's processinc of language which-it purports to provide.\ud The manifest consequences for educational decisions and programs\ud predicated on the belief that the test doeS do so are noted

    Preparation And Characterization Of Composite Hollow Fiber Reverse Osmosis Membranes By Plasma Polymerization. 1. Design Of Plasma Reactor And Operational Parameters

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    Composite hollow fiber reverse osmosis membranes were prepared by depositing a thin layer (10-50 nm) of plasma polymers on hollow fibers with porous walls (made of polysulfone). The coating was carried out in a semicontinuous manner with six strands of substrate fibers. Operational parameters which influence reverse osmosis characteristics of composite membranes were investigated. © 1984, American Chemical Society. All rights reserved

    The Monitoring and Assessment Plan (MAP) Greater Everglades Wetlands Module- Landscape Pattern- Ridge, Slough, and Tree Island Mosaics: Year 1 Annual Report

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    In the current managed Everglades system, the pre-drainage, patterned mosaic of sawgrass ridges, sloughs and tree islands has been substantially altered or reduced largely as a result of human alterations to historic ecological and hydrological processes that sustained landscape patterns. The pre-compartmentalization ridge and slough landscape was a mosaic of sloughs, elongated sawgrass ridges (50-200m wide), and tree islands. The ridges and sloughs and tree islands were elongated in the direction of the water flow, with roughly equal area of ridge and slough. Over the past decades, the ridge-slough topographic relief and spatial patterning have degraded in many areas of the Everglades. Nutrient enriched areas have become dominated by Typha with little topographic relief; areas of reduced flow have lost the elongated ridge-slough topography; and ponded areas with excessively long hydroperiods have experienced a decline in ridge prevalence and shape, and in the number of tree islands (Sklar et al. 2004, Ogden 2005)

    Lunar multispectral mosaics from Galileo's second Earth-Moon flyby

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    Galileo's Solid-State Imaging (SSI) experiment acquired about 800 images of the Moon from the second Earth-Moon flyby (EM2) in December of 1992. Ten major sequences were acquired; each consists of mosaics of the entire or nearly entire visible and illuminated surface from each viewing geometry in at least six spectral filters (effective wavelengths for the Moon of 420, 564, 660, 756, 890, and 990 nm). The geometries of LUNMOS numbers 3, 4, 5, and 6 were designed to provide stereo data at the best possible resolutions. The purpose of this abstract is to describe the sequences, calibration, processing, and mosaicking, and to present a set of color products in a poster session

    Saturable elimination of piperacillin in critically ill patients:implications for continuous infusion

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    The study aimed to evaluate saturation of piperacillin elimination in critically ill adult patients. Seventeen critically ill adult patients received continuous and intermittent infusion of piperacillin/tazobactam. Piperacillin plasma concentrations (n = 217) were analysed using population pharmacokinetic (PopPK) modelling. Post-hoc simulations were performed to evaluate the type I error rate associated with the study. Unseen data were used to validate the final model. The mean error (ME) and root mean square error (RMSE) were calculated as a measure of bias and imprecision, respectively. A PopPK model with parallel linear and non-linear elimination best fitted the data. The median and 95% confidence interval (CI) for the model parameters drug clearance (CL), volume of central compartment (V), volume of peripheral compartment (V-p) and intercompartmental clearance (Q) were 9 (7.69-11) L/h, 6.18 (4.93-11.2) L, 11.17 (7.26-12) L and 15.61 (12.66-23.8) L/h, respectively. The Michaelis-Menten constant (K-m) and the maximum elimination rate for Michaelis-Menten elimination (V-max) were estimated without population variability in the model to avoid overfitting and inflation of the type I error rate. The population estimates for K-m and V-max were 37.09 mg/L and 353.57 mg/h, respectively. The bias (ME) was -20.8 (95% CI -26.2 to -15.4) mg/L, whilst imprecision (RMSE) was 49.2 (95% CI 41.2-56) mg/L. In conclusion, piperacillin elimination is (partially) saturable. Moreover, the population estimate for K-m lies within the therapeutic window and therefore saturation of elimination should be accounted for when defining optimum dosing regimens for piperacillin in critically ill patients. (C) 2019 Elsevier B.V. and International Society of Chemotherapy. All rights reserved

    Success Factors of European Syndromic Surveillance Systems: A Worked Example of Applying Qualitative Comparative Analysis

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    Introduction: Syndromic surveillance aims at augmenting traditional public health surveillance with timely information. To gain a head start, it mainly analyses existing data such as from web searches or patient records. Despite the setup of many syndromic surveillance systems, there is still much doubt about the benefit of the approach. There are diverse interactions between performance indicators such as timeliness and various system characteristics. This makes the performance assessment of syndromic surveillance systems a complex endeavour. We assessed if the comparison of several syndromic surveillance systems through Qualitative Comparative Analysis helps to evaluate performance and identify key success factors. Materials and Methods: We compiled case-based, mixed data on performance and characteristics of 19 syndromic surveillance systems in Europe from scientific and grey literature and from site visits. We identified success factors by applying crisp-set Qualitative Comparative Analysis. We focused on two main areas of syndromic surveillance application: seasonal influenza surveillance and situational awareness during different types of potentially health threatening events. Results: We found that syndromic surveillance systems might detect the onset or peak of seasonal influenza earlier if they analyse non-clinical data sources. Timely situational awareness during different types of events is supported by an automated syndromic surveillance system capable of analysing multiple syndromes. To our surprise, the analysis of multiple data sources was no key success factor for situational awareness. Conclusions: We suggest to consider these key success factors when designing or further developing syndromic surveillance systems. Qualitative Comparative Analysis helped interpreting complex, mixed data on small-N cases and resulted in concrete and practically relevant findings
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