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A Maury

Publications and source records attributed to A Maury.

8 recordsLinked to original sources
PubMed2006

Charon's size and an upper limit on its atmosphere from a stellar occultation.

Pluto and its satellite, Charon (discovered in 1978; ref. 1), appear to form a double planet, rather than a hierarchical planet/satellite couple. Charon is about half Pluto's size and about one-eighth its mass. The precise radii of Pluto and Charon have remained uncertain, leading to large uncertainties on their densities. Although stellar occultations by Charon are in principle a powerful way of measuring its size, they are rare, as the satellite subtends less than 0.3 microradians (0.06 arcsec) on the sky. One occultation (in 1980) yielded a lower limit of 600 km for the satellite's radius, which was later refined to 601.5 km (ref. 4). Here we report observations from a multi-station stellar occultation by Charon, which we use to derive a radius, R(C) = 603.6 +/- 1.4 km (1sigma), and a density of rho = 1.71 +/- 0.08 g cm(-3). This occultation also provides upper limits of 110 and 15 (3sigma) nanobar for an atmosphere around Charon, assuming respectively a pure nitrogen or pure methane atmosphere.

Journal Article↗
PubMed2003

Large changes in Pluto's atmosphere as revealed by recent stellar occultations.

Pluto's tenuous nitrogen atmosphere was first detected by the imprint left on the light curve of a star that was occulted by the planet in 1985 (ref. 1), and studied more extensively during a second occultation event in 1988 (refs 2-6). These events are, however, quite rare and Pluto's atmosphere remains poorly understood, as in particular the planet has not yet been visited by a spacecraft. Here we report data from the first occultations by Pluto since 1988. We find that, during the intervening 14 years, there seems to have been a doubling of the atmospheric pressure, a probable seasonal effect on Pluto.

Journal Article↗
PubMed1994

[Evaluation of individual dosimetric data on patients in an international radiotherapy trial].

A quality control programme has been developed in the radiotherapy department of the Institut Gustave-Roussy for an international clinical trial on the use of Etanidazole as a radiosensitizer in association with radiotherapy for head and neck tumors. Twenty-nine european centers belonging to Germany, United Kingdom, Austria, France and Italy contributed to this trial during 374 patients has been included from 1987 to 1988. This programme concerned the control of the external radiotherapy equipment available in the participating centers and the examination of the patient treatment data. The authors present, in this paper, the methods applied and the main results obtained during the analysis of the individual patient treatment data. This analysis shows that 83% of the evaluable treatments were done in compliance with the protocol recommendations and 17% contained a major deviation and among them only 3% were judged unacceptable.

Humans↗
PubMed1992

Anti-Trypanosoma-cruzi-proteinase antibodies and immunoprotection in experimental Chagas' disease.

To verify whether anti-Trypanosoma-cruzi-proteinase antibodies are able to play a role in the development of Chagas' disease, CBA/J and C57BL/6 mice were immunized with purified proteinase fractions: antibody production was studied and passive immunization experiments were carried out. No significant differences were observed in the titre, isotype composition and specificity of the antibodies produced by the mouse strains. Immune sera produced in one strain was able to protect mice of both strains, provided that the challenge did not exceed the number of parasites corresponding to 30-fold the LD50. The data presented suggest that anti-proteinase antibodies may play a role in immunoprotection.

Animals↗
PubMed1982

[Diagnosis of isolated hypereosinophilia in parasitology (378 cases)].

378 cases of isolated hypereosinophilia (eosinophils greater than 500 by mm3 of blood) are presented. The diagnosis was done for 189 cases: 184 parasitic diseases and 5 non parasitic diagnosis (3 neoplastic syndromes). The diagnosis was done more often if patients came back from a tropical area, if hypereosinophilia was observed on two samples of blood, if hypereosinophilia was major (greater than 2,500 eosinophils). The diagnosis was not done for 189 cases, but 49 patients have had an allergic disease. Drug etiologies are certainly underestimated.

Adult↗