Mostrando recursos 1 - 20 de 12.316

  1. Retinal atrophy in relation to visual functioning and vision-related quality of life in patients with multiple sclerosis.

    Balk, LJ; Coric, D; Nij Bijvank, JA; Killestein, J; Uitdehaag, BM; Petzold, A
    BACKGROUND: Inner retinal layer atrophy in patients with multiple sclerosis (MS) has been validated as a structural imaging biomarker for neurodegeneration. OBJECTIVE: To determine how retinal layer thickness relates to high-contrast visual acuity (HCVA), low-contrast visual acuity (LCVA) and vision-related quality of life (QoL) and to investigate the effect of previous episodes on MS-associated optic neuritis (MSON). METHODS: Spectral-domain optical coherence tomography (SD-OCT) was performed in 267 patients with MS. Images were segmented for the peripapillary retinal nerve fiber layer (pRNFL) and the macular ganglion cell inner plexiform layer (GCIPL). Ophthalmological evaluations included history of MSON, HCVA, LCVA, and vision-related...

  2. Craniosynostosis

    Greig, AVH; Dunaway, DJ
    © 2015 John Wiley & Sons, Ltd. All rights reserved.Craniosynostosis is defined as the premature fusion of cranial sutures, which may be due to primary or secondary causes. Either a single suture or multiple sutures may be involved and these cause a change in head shape. Single suture synostosis is usually non-syndromic but craniosynostosis can be associated with several syndromes, including Apert, Crouzon, Pfeiffer, Saethre-Chotzen, Carpenter and Muenke syndromes. Syndromic craniosynostosis patients may present with elevated intracranial pressure, hydrocephalus, papilloedema, optic atrophy, corneal exposure or ulceration, globe herniation, amblyopia, astigmatism, squints and loss of vision. They may present with hearing...

  3. Measuring Primary and Secondary Degeneration of Retinal Ganglion Cells in the Rodent Partial Optic Nerve Transection Model

    Davis, B; Guo, L; Brenton, J; Langley, L; Normando, EM; Cordeiro, MF

  4. The Identification of Power-In Region in Vortex-Induced Vibration of Flexible Cylinders

    Rao, Zhibiao; Resvanis, Themistocles L; Vandiver, John Kim
    This paper proposes a novel method to identify the power-in regions of long flexible cylinders subjected to vortex-induced vibration (VIV). It also attempts to address a practical problem: “Will a secondary power-in region appear after the primary power-in region is covered with suppression devices?” The source of data is a recent model test on a 38 meter long flexible cylinder, densely instrumented with fiber optic strain gauges and accelerometers. For pipes with partial coverage of suppression devices in uniform flow, the bare region would be expected to be a power-in region and the section with suppression devices is expected to...

  5. Combined and three-dimensional rendered multimodal data for planning cranial base surgery: a prospective evaluation.

    Gandhe, AJ; Hill, DL; Studholme, C; Hawkes, DJ; Ruff, CF; Cox, TC; Gleeson, MJ; Strong, AJ
    Magnetic resonance (MR), X-ray computed tomography (CT), and angiographic images best depict soft tissue, bone, and blood vessels respectively. No one on its own is sufficient in the preoperative assessment of cranial base lesions. We have developed and evaluated a computational technique for the three-dimensional (3D) combination and display of multimodality images for planning cranial base surgery. This evaluation was prospective and performed in such a way that the results could be quantified. Eight patients (three acoustic neuromas, four subfrontal and suprasellar meningiomas, and one petrous apex meningioma) underwent MR, CT, and MR angiographic investigations. These images were registered with...

  6. A recurrent de novo mutation in ACTG1 causes isolated ocular coloboma.

    Rainger, J; Williamson, KA; Soares, DC; Truch, J; Kurian, D; Gillessen-Kaesbach, G; Seawright, A; Prendergast, J; Halachev, M; Wheeler, A; McTeir, L; Gill, AC; van Heyningen, V; Davey, MG; UK10K,; FitzPatrick, DR
    Ocular coloboma (OC) is a defect in optic fissure closure and is a common cause of severe congenital visual impairment. Bilateral OC is primarily genetically determined and shows marked locus heterogeneity. Whole exome sequencing was used to analyse twelve trios (child affected with OC and both unaffected parents), This identified de novo mutations in ten different genes in eight probands. Three of these genes encoded proteins associated with actin cytoskeleton dynamics: ACTG1, TWF1 and LCP1. Proband-only whole exome sequencing identified a second unrelated individual with isolated OC carrying the same ACTG1 allele, encoding p.(Pro70Leu). Both individuals have normal neurodevelopment with...

  7. Pontocerebellar hypoplasia type 2D and optic nerve atrophy further expand the spectrum associated with selenoprotein biosynthesis deficiency

    Pavlidou, E; Salpietro, V; Phadke, R; Hargreaves, LP; Batten, L; McElreavy, K; Pitt, M; Mankad, K; Wilson, C; Cutrupi, MC; Ruggieri, M; McCormick, D; Saggar, A; Kinali, M

  8. Author response: Gray matter MRI differentiates neuromyelitis optica from multiple sclerosis using random forest.

    Eshaghi, A; Ciccarelli, O

  9. A Period of Controlled Elevation of IOP (CEI) Produces the Specific Gene Expression Responses and Focal Injury Pattern of Experimental Rat Glaucoma

    Morrison, JC; Cepurna, WO; Tehrani, S; Choe, TE; Jayaram, H; Lozano, DC; Fortune, B; Johnson, EC
    PURPOSE: We determine if several hours of controlled elevation of IOP (CEI) will produce the optic nerve head (ONH) gene expression changes and optic nerve (ON) damage pattern associated with early experimental glaucoma in rats. METHODS: The anterior chambers of anesthetized rats were cannulated and connected to a reservoir to elevate IOP. Physiologic parameters were monitored. Following CEI at various recovery times, ON cross-sections were graded for axonal injury. Anterior ONHs were collected at 0 hours to 10 days following CEI and RNA extracted for quantitative PCR measurement of selected messages. The functional impact of CEI was assessed by electroretinography...

  10. Design of photovoltaics for modules with 50% efficiency

    Warmann, Emily C.; Flowers, Cristofer; Lloyd, John; Eisler, Carissa N.; Escarra, Matthew D.; Atwater, Harry A.
    We describe a spectrum splitting solar module design approach using ensembles of 2–20 subcells with bandgaps optimized for the AM1.5D spectrum. Device physics calculations and experimental data determine radiative efficiency parameters for III-V compound semiconductor subcells and enable modification of conventional detailed balance calculations to predict module efficiency while retaining computational speed for a wide search of the design space. Accounting for nonideal absorption and recombination rates due to realistic material imperfections allows us to identify the minimum subcell quantity, quality, electrical connection configuration, and concentration required for 50% module efficiency with realistic optical losses and modeled contact resistance losses....

  11. Characterizing microglia activation: a spatial statistics approach to maximize information extraction.

    Davis, BM; Salinas-Navarro, M; Cordeiro, MF; Moons, L; Groef, LD
    Microglia play an important role in the pathology of CNS disorders, however, there remains significant uncertainty about the neuroprotective/degenerative role of these cells due to a lack of techniques to adequately assess their complex behaviour in response to injury. Advancing microscopy techniques, transgenic lines and well-characterized molecular markers, have made histological assessment of microglia populations more accessible. However, there is a distinct lack of tools to adequately extract information from these images to fully characterise microglia behaviour. This, combined with growing economic pressures and the ethical need to minimise the use of laboratory animals, led us to develop tools to...

  12. Creating Automation to Couple Laser Light from an Optical Fiber to a Photonic Integrated Circuit

    Maharry, Aaron
    Coupling light between fiber optic cables and photonic devices on silicon chips is important for optical communications. Recently, vertically bent cantilever couplers have been developed that have better bandwidth and lower power loss than grating couplers, which are the current standard for fiber-to-chip coupling. A system that can perform butt-coupling between optical fibers and cantilever couplers on an integrated silicon photonic device is reported here. This system is able to perform butt coupling using vision processing and measured coupled power as feedback, and requires minimal human assistance. This system can be extended to automatically collect measurements from multiple devices on...

  13. Superconducting nanowire single-photon detectors on aluminum nitride photonic integrated circuits

    Zhu, Di, S.M. Massachusetts Institute of Technology
    With recent advances in integrated single-photon sources and quantum memories, onchip integration of high-performance single-photon detectors becomes increasingly important. The superconducting nanowire single-photon detector (SNSPD) is the leading single-photon counting technology for quantum information processing. Among various waveguide materials, aluminum nitride (AlN) is a promising candidate because of its exceptionally wide bandgap, and intrinsic piezoelectric and electro-optic properties. In this Master's thesis, we developed a complete fabrication process for making high-performance niobium nitride SNSPDs on AlN, and demonstrated their integration with AlN photonic waveguides. The detectors fabricated on this new substrate material have demonstrated saturated detection efficiency from visible to...

  14. Integrated optical quantum manipulation and measurement of trapped ions

    Mehta, Karan K. (Karan Kartik)
    Individual atomic ions confined in designed electromagnetic potentials and manipulated via lasers are strong candidates as physical bases for quantum information processing (QIP). This is in large part due to their long coherence times, in distinguishability, and strong Coulomb interactions. Much work in recent years has utilized these properties to implement increasingly precise quantum operations essential for QIP, as well as to conduct increasingly sophisticated experiments on few-ion systems. Many questions remain however regarding how to implement the significant classical apparatus required to control and measure many ions (and indeed any physical qubit under study) in a scalable way that...

  15. Architecture in the Afternet

    Ghantous, Sam N
    Tweeting from your couch, in your sweats, can be an architectural act. Architecture's ability to serve and shape a public has been weakened by its disciplinary exclusivity and the privatization of public space. Hope for architecture today is found, instead, in its ability to be shared online. There, its value is in its newfound velocity, intensity, and spread - an ability to "get around". Attention is a currency and the image, a visual byte that circulates, has already replaced the building in space, as such. Architecture is on and of the web, and it can shape public there. If you...

  16. Photoacoustic endoscopy probe using a coherent fibre optic bundle

    Ansari, R; Zhang, E; Mathews, S; Desjardins, AE; Beard, PC
    There is considerable interest in the development of photoacoustic endoscopy probes (PAE) for applications in foetal medicine, interventional surgery and gastroenterology. However, most previous PAE probes employ a combination of mechanical scanning and piezoelectric transducers at the distal end which can be technically complex and pose challenges in achieving the required level of miniaturisation and acoustic performance. To overcome these limitations, we present two novel all-optical forward-viewing endoscopic probes that use coherent fibre bundles to address a Fabry-Perot polymer film ultrasound sensor.

  17. Arl3 and RP2 regulate the trafficking of ciliary tip kinesins.

    Schwarz, N; Lane, A; Jovanovich, K; Parfitt, DA; Aguila, M; Thompson, CL; da Cruz, L; Coffey, PJ; Chapple, JP; Hardcastle, AJ; Cheetham, ME
    Ciliary trafficking defects are the underlying cause of many ciliopathies, including Retinitis Pigmentosa (RP). Anterograde intraflagellar transport (IFT) is mediated by kinesin motor proteins; however, the function of the homodimeric Kif17 motor in cilia is poorly understood, whereas Kif7 is known to play an important role in stabilising cilia tips. Here we identified the ciliary tip kinesins Kif7 and Kif17 as novel interaction partners of the small GTPase Arl3 and its regulatory GTPase activating protein (GAP) Retinitis Pigmentosa 2 (RP2). We show that Arl3 and RP2 mediate the localisation of GFP-Kif17 to the cilia tip and competitive binding of RP2...

  18. [Clinical spectrum associated with aquaporin-4 antibodies (NMO-IgG)].

    Blanco, Y; Hankiewicz, K; Llufriu, S; Sabater, L; Graus, F; Saiz, A; Grupo Español de Neuromielitis Optica,
    INTRODUCTION: The description of a highly sensitive and specific biomarker for neuromyelitis optica (NMO-IgG/aquaporin-4 antibody) extended the clinical spectrum of NMO to limited forms such as optic neuritis (ON) and longitudinally extensive myelitis (LEM). OBJECTIVE: To asses the sensitivity and specificity of our assay, and to describe the clinical characteristics of the patients who were tested for NMO-IgG. METHODS: NMO-IgG was analysed by immunohistochemistry and confirmed by assay on HEK cells transfected with aquaporin-4. The clinical information was obtained from forms filled in by the referring neurologists. RESULTS: A total of 580 samples from 518 patients were analysed from November...

  19. Musical interests and abilities of children with septo-optic dysplasia

    Ockelford, A; Welch, G; Pring, L
    Recent anecdotal evidence and appearances in the US media have indicated that children with septo-optic dysplasia (s.o.d.) may have a tendency to precocious musical development, in some cases leading to 'savant syndrome'. Here, initial evidence based on a questionnaire survey of parents suggests that a significant proportion of this group do appear to have an unusual predilection for music. However, significant differences in the perceived levels of musical interest and ability of blind children with s.o.d. as opposed to those who are partially sighted indicate that level of vision may be a particularly important factor in musical development. © 2005...

  20. Focus on Music: Exploring the Musical Interests and Abilities of Blind and Partially-Sighted Children with Septo-Optic Dysplasia

    Ockelford, A; Pring, L; Welch, G; Treffert, D

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