2,452 research outputs found

    Investigation and study of a multi-aperture antenna system final report, 1 jan. - 1 apr. 1964

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    Multiple aperture adaptive antenna system for telemetry reception from remote space vehicle

    Influences of Neural Pathway Integrity on Children's Response to Reading Instruction

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    As the education field moves toward using responsiveness to intervention to identify students with disabilities, an important question is the degree to which this classification can be connected to a student's neurobiological characteristics. A few functional neuroimaging studies have reported a relationship between activation and response to instruction; however, whether a similar correlation exists with white matter (WM) is not clear. To investigate this issue, we acquired high angular resolution diffusion images from a group of first grade children who differed in their levels of responsiveness to a year-long reading intervention. Using probabilistic tractography, we calculated the strength of WM connections among nine cortical regions of interest and correlated these estimates with participantsā€™ scores on four standardized reading measures. We found eight significant correlations, four of which were connections between the insular cortex and angular gyrus. In each of the correlations, a relationship with children's response to intervention was evident

    Controlling Light Through Optical Disordered Media : Transmission Matrix Approach

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    We experimentally measure the monochromatic transmission matrix (TM) of an optical multiple scattering medium using a spatial light modulator together with a phase-shifting interferometry measurement method. The TM contains all information needed to shape the scattered output field at will or to detect an image through the medium. We confront theory and experiment for these applications and we study the effect of noise on the reconstruction method. We also extracted from the TM informations about the statistical properties of the medium and the light transport whitin it. In particular, we are able to isolate the contributions of the Memory Effect (ME) and measure its attenuation length

    ā€œWe can all just get on a bus and goā€ : Rethinking independent mobility in the context of the universal provision of free bus travel to young Londoners

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    This paper uses qualitative data from interviews with 118 young Londoners (age 12-18) to examine how the universal provision of free bus travel has affected young peopleā€™s independent mobility. Drawing on Senā€™s ā€˜capabilities approachā€™, we argue that free bus travel enhanced young Londonersā€™ capability to shape their daily mobility, both directly by increasing financial access and indirectly by facilitating the acquisition of the necessary skills, travelling companions and confidence. These capabilities in turn extended both opportunity freedoms (e.g. facilitating non-ā€œnecessaryā€ recreational and social trips) and process freedoms (e.g. feeling more independent by decreasing reliance on parents). Moreover, the universal nature of the entitlement rendered buses a socially inclusive way for groups to travel and spend time together, thereby enhancing group-level capabilities. We believe this attention to individual and group capabilities for self-determination provides the basis for a broader and more child-centred view of ā€˜independent mobilityā€™ than the typical research focus upon ā€˜travelling without an adultā€™ and acquiring parental permissions.Peer reviewe

    Methods for Fine Scale Functional Imaging of Tactile Motion in Human and Nonhuman Primates

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    In the visual and auditory systems specialized neural pathways use motion cues to track object motion and self-motion, and use differential motion cues for figure-ground segregation. To examine the neural circuits that encode motion in the somatosensory system, we have developed neuroimaging methods to study motion processing in human and nonhuman primates. We have implemented stimulus presentation paradigms to examine neural encoding of apparent motion percepts. These paradigms are designed to be compatible with fMRI, optical imaging, and electrophysiological methods, thereby permitting direct comparison of data derived across neurofunctional scales. An additional motivation for using a common tactile motion stimulation paradigm is to bridge two disparate bodies of work, that derived from neuroimaging studies in humans and another from neuroimaging, neurophysiological and neuroanatomical studies in monkeys. Here, we demonstrate that such an approach through the use of optical imaging and 9.4 Tesla fMRI experiments in monkeys, and 7 Tesla fMRI experiments in humans is effective in revealing neural regions activated by tactile motion stimuli. These methods span spatial scales capable of detecting 100 Ī¼m sized domains to those that would reveal global whole brain circuits. Armed with such capabilities, our long-term goals are to identify directionally selective areas and directionally se-lective functional domains and understand the global pathways within which they reside. Such knowledge would have great impact on our thinking regarding not only tactile motion processing, but also general strategies underlying somatosensory cortical processing

    Hydrodynamic suppression of soot emissions in laminar diffusion flames

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77139/1/AIAA-23984-264.pd

    A retrospective study on the impact of comorbid depression or anxiety on healthcare resource use and costs among diabetic neuropathy patients

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    <p>Abstract</p> <p>Background</p> <p>Diabetic neuropathy (DN) is a common complication of diabetes that has significant economic burden, especially for patients with comorbid depression or anxiety. This study examines and quantifies factors associated with healthcare costs among patients diagnosed with diabetic neuropathy (DN) with or without a comorbid diagnosis of depression or anxiety (DA) using retrospective administrative claims data. No study has examined the differences in economic outcomes depending on the presence of comorbid DA disorders.</p> <p>Methods</p> <p>Over-age-18 individuals with 1+ diagnosis of DN in 2005 were selected. The first observed DN claim was considered the "index date." All individuals had a 12-month pre-index and follow-up period. For both under-age-65 commercially insured and over-age-65 individuals with employer-sponsored Medicare supplemental insurance, we constructed 2 subgroups for individuals with DA (DN-DA) or without (DN-only). Patients' clinical characteristics over pre-index period were compared. Multivariate regressions were performed to assess whether DN-DA patients had higher utilization of healthcare resources and costs than DN-only patients, controlling for demographic and clinical characteristics.</p> <p>Results</p> <p>We identified 16,831 DN-only and 1,699 DN-DA patients in the Medicare supplemental cohort, as well as 17,205 and 3,105 in the commercially insured. DN-DA patients had higher prevalence of diabetes-related comorbidities for cardiovascular disease, cerebrovascular/peripheral vascular disease, nephropathy, obesity, and hypoglycemic events than DN-only patients (all p < 0.05). Controlling for differences in demographic and clinical characteristics, DN-DA patients had 9,235(p<0.05)highertotalhealthcarecoststhanpatientswithDNāˆ’onlyamongthosewithMedicaresupplementalcoverage(9,235 (p < 0.05) higher total healthcare costs than patients with DN-only among those with Medicare supplemental coverage (26,718 vs. 17,483),and17,483), and 10,389 (p < 0.05) more total costs among commercially insured (29,775vs.29,775 vs. 19,386). Factors associated with increased costs included insurance type, geographical region, diabetes-related comorbidities, and insulin therapy.</p> <p>Conclusion</p> <p>These findings indicate that the healthcare costs were significantly higher for DN patients with depression or anxiety relative to those without such comorbid disorders.</p

    A hybrid radiation detector for simultaneous spatial and temporal dosimetry

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    In this feasibility study an organic plastic scintillator is calibrated against ionisation chamber measurements and then embedded in a polymer gel dosimeter to obtain a quasi-4D experimental measurement of a radiation field. This hybrid dosimeter was irradiated with a linear accelerator, with temporal measurements of the dose rate being acquired by the scintillator and spatial measurements acquired with the gel dosimeter. The detectors employed in this work are radiologically equivalent; and we show that neither detector perturbs the intensity of the radiation field of the other. By employing these detectors in concert, spatial and temporal variations in the radiation intensity can now be detected and gel dosimeters can be calibrated for absolute dose from a single irradiation
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