169,881 research outputs found
Towards Foundational Semantics - Ontological Semantics Revisited -
No full textCimiano P, Reyle U. Towards Foundational Semantics - Ontological Semantics Revisited -. In: Bennett B, Fellbaum C, eds. Formal Ontology in Information Systems, Proceedings of the Fourth International Conference, FOIS 2006. Frontiers in Artificial Intelligence and Applications, 150. IOS Press; 2006: 51-62
UDRT-based Semantics Construction for LTAG - and what it tells us about the role of adjunction in LTAG
No full textCimiano P, Frank A, Reyle U. UDRT-based Semantics Construction for LTAG - and what it tells us about the role of adjunction in LTAG. In: Proceedings of the 7th International Workshop on Computational Semantics. 2007
Talking about trees, scope and concepts
No full textCimiano P, Reyle U. Talking about trees, scope and concepts. In: Bunt H, Geertzen J, Thijse E, eds. Proceedings of the 6th Workshop on Computational Semantics (IWCS). 2005
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Constraining the Milky Way potential using the dynamical kinematic substructures
No full textWe present a method to constrain the potential of the non-axisymmetric components of the Galaxy using the kinematics of stars in the solar neighborhood. The basic premise is that dynamical substructures in phase-space (i.e. due to the bar and/or spiral arms) are associated with families of periodic or irregular orbits, which may be easily identified in orbital frequency space. We use the “observed” positions and velocities of stars as initial conditions for orbital integrations in a variety of gravitational potentials. We then compute their characteristic frequencies, and study the structure present in the frequency maps. We find that the distribution of dynamical substructures in velocity- and frequency-space is best preserved when the integrations are performed in the “true” gravitational potential
Kinematic groups across the MW disc: Insights from models and from the RAVE catalogue
No full textWith the advent of the Gaia data, the unprecedented kinematic census of great part of the Milky Way disc will allow us to characterise the local kinematic groups and new groups in different disc neighbourhoods. First, we show here that the models predict a stellar kinematic response to the spiral arms and bar strongly dependent on disc position. For example, we find that the kinematic groups induced by the spiral arm models change significantly if one moves only ~0.6kpc in galactocentric radius, but ~2kpc in azimuth. There are more and stronger groups as one approaches the spiral arms. Depending on the spiral pattern speed, the kinematic imprints are more intense in nearby vicinities or far from the Sun. Secondly, we present a preliminary study of the kinematic groups observed by RAVE. This sample will allow us, for the first time, to study the dependence on Galactic position of the (thin and thick) disc moving groups. In the solar neighbourhood, we find the same kinematics groups as detected in previous surveys, but now with better statistics and over a larger spatial volume around the Sun. This indicates that these structures are indeed large scale kinematic features
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Mercer 5: A probable new globular cluster in the Galactic bulge
No full textWe present a detailed study of a dust-obscured Galactic star cluster Mercer 5 ([MCM2005b] 5) in an extremely crowded field in the Milky Way. Near-infrared (near-IR) photometry from United Kingdom Infrared Digital Sky Surveys (UKIDSS) and the Son of ISAAC on the New Technology Telescope (SofI/NTT), combined with near-IR spectroscopy also from SofI, indicates that it is almost certainly a Galactic globular cluster, located at the edge of the Galactic bulge. The cluster suffers ~9 mag of visual extinction, with strong evidence for an extinction gradient across the cluster. A simulation of the differential reddening in the cluster using empirical data from NGC 6539 (chosen because it had high signal-to-noise ratio data and low field star contamination) as a template mimics the observations extremely well. This simulation and other arguments are used to indicate that the most prominent clump of stars in the colour-magnitude diagrams is a horizontal branch clump. On this basis we conclude that the cluster is at a distance of ~5.5kpc and suffers from visual extinction ranging from ~8.5 to ~12.5 mag. Alternative explanations for its nature, such as a young cluster or an old open cluster, are much less likely, on the grounds of no visible main sequence or stars with IR excesses for the former and location versus lifetime arguments for the latter. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS
The shape of dark matter haloes in the Aquarius simulations: Evolution and memory
No full textWe use the high resolution cosmological N-body simulations from the Aquarius project to investigate in detail the mechanisms that determine the shape of Milky Way-type dark matter haloes. We find that, when measured at the instantaneous virial radius, the shape of individual haloes changes with time, evolving from a typically prolate configuration at early stages to a more triaxial/oblate geometry at the present day. This evolution in halo shape correlates well with the distribution of the infalling material: prolate configurations arise when haloes are fed through narrow filaments, which characterizes the early epochs of halo assembly, whereas triaxial/oblate configurations result as the accretion turns more isotropic at later times. Interestingly, at redshift z = 0, clear imprints of the past history of each halo are recorded in their shapes at different radii, which also exhibit a variation from prolate in the inner regions to triaxial/oblate in the outskirts. Provided that the Aquarius haloes are fair representatives of Milky Way-like 1012M☉ objects, we conclude that the shape of such dark matter haloes is a complex, time-dependent property, with each radial shell retaining memory of the conditions at the time of collapse
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