99 research outputs found

    Neurovascular relationship between abducens nerve and anterior inferior cerebellar artery

    Get PDF
    We aimed to study the neurovascular relationships between the anterior inferior cerebellar artery (AICA) and the abducens nerve to help determine the pathogenesis of abducens nerve palsy which can be caused by arterial compression. Twenty-two cadaveric brains (44 hemispheres) were investigated after injected of coloured latex in to the arterial system. The anterior inferior cerebellar artery originated as a single branch in 75%, duplicate in 22.7%, and triplicate in 2.3% of the hemispheres. Abducens nerves were located between the AICAs in all hemispheres when the AICA duplicated or triplicated. Additionally, we noted that the AICA or its main branches pierced the abducens nerve in five hemispheres (11.4%). The anatomy of the AICA and its relationship with the abducens nerve is very important for diagnosis and treatment. (Folia Morphol 2010; 69, 4: 201-203

    Lateral approach to the ankle and distal leg

    Get PDF
    Fractures of the distal tibia are usually high-energy injuries and are well known for their soft tissue complications after surgery. Various factors have been studied regarding the possibility of them reducing the incidence of such damage, including timing of surgery, staged surgery, fixation method, and surgical approach. Less invasive surgical techniques with vascularity preserving approaches were proposed as reasonable solutions to this problem. The aim of this study was to investigate the presence of minor vascular structures, which can be preserved during anterolateral approach, possibly contributing to the success of the approach. Lateral approach for the distal tibia was performed in 22 cadaver feet. The mean distance between the lateral malleolus and the superficial peroneal nerve was 12.2 cm. Two different vascular pedicles, from peroneal vessels to muscles of the anterior compartment, were 4.3 and 8.2 cm away from the lateral malleolus, respectively. We conclude that preserving greater vascularity was possible in the lateral approach for the distal tibia, placing the plate in a completely submuscular plane. (Folia Morphol 2011; 70, 2: 91–94

    Signal processing problems and algorithms in display side of 3DTV

    Get PDF
    Two important signal processing problems in the display side of a holographic 3DTV are the computation of the diffraction field of a 3D object from its abstract representation, and determination of the best display configuration to synthesize some intended light distribution. To solve the former problem, we worked on the computation of ID diffraction patterns from discrete data distributed over 2D space. The problem is solved using matrix pseudo-inversion which dominates the computational complexity. Then, the light field synthesis problem by a deflectable mirror array device (DMAD) is posed as a constrained linear optimization problem. The formulation makes direct application of common optimization algorithms quite easy. The simulations indicate that developed methods are promising. ©2006 IEEE

    Transit timing variation analysis of the low-mass brown dwarf KELT-1 b

    Get PDF
    We investigate whether there is a variation in the orbital period of the short-period brown dwarf-mass KELT-1 b, which is one of the best candidates to observe orbital decay. We obtain 19 high-precision transit light curves of the target using six different telescopes. We add all precise and complete transit light curves from open databases and the literature, as well as the available Transiting Exoplanet Survey Satellite (TESS) observations from sectors 17 and 57, to form a transit timing variation (TTV) diagram spanning more than 10 yr of observations. The analysis of the TTV diagram, however, is inconclusive in terms of a secular or periodic variation, hinting that the system might have synchronized. We update the transit ephemeris and determine an informative lower limit for the reduced tidal quality parameter of its host star of Q ′⋆>(8.5±3.9)×106 assuming that the stellar rotation is not yet synchronized. Using our new photometric observations, published light curves, the TESS data, archival radial velocities, and broadband magnitudes, we also update the measured parameters of the system. Our results are in good agreement with those found in previous analyses

    Reconstruction of computer generated holograms by spatial light modulators

    Get PDF
    Computer generated holograms generated by using three different numerical techniques are reconstructed optically by spatial light modulators. Liquid crystal spatial light modulators (SLM) on transmission and on reflection modes with different resolutions were investigated. A good match between numerical simulation and optically reconstructed holograms on both SLMs was observed. The resolution of the optically reconstructed images was comparable to the resolution of the SLMs. © Springer-Verlag Berlin Heidelberg 2006

    Can we rate public support for democracy in a comparable way? Cross-national equivalence of democratic attitudes in the World Value Survey

    Full text link
    In this study we examine the cross-cultural equivalence of two scales that measure attitudes toward democracy across 36 countries in the World Value Survey (WVS) 2000. We examine the equivalence of these scales in order to explore if we can meaningfully compare democratic attitudes across countries. Multiple group confirmatory factor analyses (MGCFA) is applied to answer this question. The analyses indicate that the scales may be compared but only to a certain extent and not across all the countries. We close this article by discussing the implications of the findings

    Homogeneous transit timing analyses of ten exoplanet systems

    Get PDF
    We study the transit timings of 10 exoplanets in order to investigate potential transit timing variations in them. We model their available ground-based light curves, some presented here and others taken from the literature, and homogeneously measure the mid-transit times. We statistically compare our results with published values and find that the measurement errors agree. However, in terms of recovering the possible frequencies, homogeneous sets can be found to be more useful, of which no statistically relevant example has been found for the planets in our study. We corrected the ephemeris information of all 10 planets we studied and provide these most precise light elements as references for future transit observations with space-borne and ground-based instruments. We found no evidence for secular or periodic changes in the orbital periods of the planets in our sample, including the ultra-short period WASP-103 b, whose orbit is expected to decay on an observable time-scale. Therefore, we derive the lower limits for the reduced tidal quality factors (Q(*)') for the host stars based on best-fitting quadratic functions to their timing data. We also present a global model of all available data for WASP-74 b, which has a Gaia parallax-based distance value similar to 25 per cent larger than the published value

    Times of Minima of Some Eclipsing Binaries

    Get PDF
    We present new times of minima in the light curves of some eclipsing binarie

    Transits of Known Planets Orbiting a Naked-Eye Star

    Get PDF
    © 2020 The American Astronomical Society. All rights reserved.Some of the most scientifically valuable transiting planets are those that were already known from radial velocity (RV) surveys. This is primarily because their orbits are well characterized and they preferentially orbit bright stars that are the targets of RV surveys. The Transiting Exoplanet Survey Satellite (TESS) provides an opportunity to survey most of the known exoplanet systems in a systematic fashion to detect possible transits of their planets. HD 136352 (Nu2 Lupi) is a naked-eye (V = 5.78) G-type main-sequence star that was discovered to host three planets with orbital periods of 11.6, 27.6, and 108.1 days via RV monitoring with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph. We present the detection and characterization of transits for the two inner planets of the HD 136352 system, revealing radii of 1.482-0.056+0.058 R ⊕ and 2.608-0.077+0.078 R ⊕ for planets b and c, respectively. We combine new HARPS observations with RV data from the Keck/High Resolution Echelle Spectrometer and the Anglo-Australian Telescope, along with TESS photometry from Sector 12, to perform a complete analysis of the system parameters. The combined data analysis results in extracted bulk density values of ρb = 7.8-1.1+1.2 g cm-3 and ρc = 3.50-0.36+0.41 g cm-3 for planets b and c, respectively, thus placing them on either side of the radius valley. The combination of the multitransiting planet system, the bright host star, and the diversity of planetary interiors and atmospheres means this will likely become a cornerstone system for atmospheric and orbital characterization of small worlds.Peer reviewe
    corecore