170,285 research outputs found
Separating inner and outer contributions in gravitational lenses with the perturbative method
No full textContext. This paper presents a reconstruction of the gravitational lens
SL2S02176-0513 with the singular perturbative method presented in
Alard (2007, MNRAS, 382, L58) and Alard (2008, MNRAS, 388, 375).
Aims. The ability of the perturbative method to separate the inner
and outer contributions of the potential in gravitational lenses is
tested using SL2S02176-0513. The gravitational field of the central galaxy is dominated by a nearby group of galaxies located at a distance of a few critical radius in this lens.
Methods. The perturbative functionals are re-constructed using local polynomials. The polynomial interpolation is smoothed by Fourier series, and numerically fitted to the Hubble Space Telescope data with a non linear minimization procedure. The potential inside and outside the critical circle is derived from the reconstruction of the perturbative fields.
Results. The inner and outer potential contours are very different.
The inner contours are consistent with the central galaxy, while the
outer contours are fully consistent with the perturbation introduced
by the group of galaxies.
Conclusions. The ability of the perturbative method to
separate the inner and outer contribution is confirmed, and
indicates that in the perturbative approach the field of the central
deflector can be separated from outer perturbations. The separation of
the inner and outer contribution is especially important to study
the shape of dark matter halos and for the statistical
analysis of the effect of dark matter substructures
Moses Güldenes Kalb
No full textM. L. A. P. S. A. C. M. bedeutet Magister Lambert Alard Pastor Süderoviensis Assessor Consistorii Munsterdorpiensis. - Enth. Th. I - III mit jeweils dem Sachtitel: Moses Güldenes Kalb nebst dem Magischem-Astralischem-Philosophischem- absonderlich dem Cabalistischem Feuer, Erscheinungsjahr jeweils 172
Perturbative reconstruction of a gravitational lens: when mass does not follow light
No full textAims. The structure and potential of a complex gravitational lens is reconstructed using the perturbative method presented in Alard (2007, MNRAS, 382, L58;
2008, MNRAS, 388, 375). This lens is composed of 6 galaxies belonging to a small group.
Methods. The lens inversion is reduced to the problem of reconstructing
non-degenerate quantities: the 2 fields of the perturbative theory of strong gravitational lenses. Since in the perturbative theory the circular source solution is analytical, the general properties of the perturbative solution can be inferred directly from the data. As a consequence, the reconstruction of the perturbative fields is not affected by degeneracy, and finding the best solution is only a matter of numerical refinement.
Results. The local shape of the potential and density of the lens are
inferred from the perturbative solution, revealing the existence
of an independent dark component that does not follow light.
Conclusions. The most likely explanation is that the particular shape of the dark
halo is due to the merging of cold dark matter halos. This is a
new result illustrating the structure of dark halos on the scale of
galaxies
Les Bengalis. 1, Armide / Gluck ; [extrait, arr. pour piano] par C. Alard ; [ill. par] P. Borie
No full textTitre uniforme : Gluck, Christoph Willibald von (1714-1787). Compositeur. [Armide. GluckWV 1.47]. Extrait ; arr. pour pianoPiano, Musique de (musique
Les Bengalis. 6, Les moutons / Martini[arr. pour piano] par C. Alard ; [ill. par] P. Borie
No full textPiano, Musique de (musique
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
Les Bengalis. 2, Couplets de l'épreuve villageoise / Grétry ; [extrait arr. pour piano] par C. Alard ; [ill. par] P. Borie
No full textTitre uniforme : Grétry, André-Ernest-Modeste (1741-1813). Compositeur. [L'épreuve villageoise]. Extrait ; arr. pour pianoPiano, Musique de (musique
Les Bengalis. 4, Rose et Colas / Monsigny ; [extrait arr. pour piano] par C. Alard ; [ill. par] P. Borie
No full textTitre uniforme : Monsigny, Pierre-Alexandre (1729-1817). Compositeur. [Rose et Colas]. Extrait ; arr. pour pianoPiano, Musique de (musique
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
Carte routière et hydrographique de Maine-et-Loire / dressée sous la direction de M. Alard...
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