First case of strong gravitational lensing by a QSO : SDSS J0013+1523 at z = 0.120

We present the first case of strong gravitational lensing by a QSO : SDSS J0013+1523, at z = 0.120. The discovery is the result of a systematic search for emission lines redshifted behind QSOs, among 22298 spectra of the SDSS data release 7. Apart from the z = 0.120 spectral features of the foreground QSO, the spectrum of SDSS J0013+1523 also displays the OII and Hbeta emission lines and the OIII doublet, all at the same redshift, z = 0.640. Using sharp Keck adaptive optics K-band images obtained using laser guide stars, we unveil two objects within a radius of 2 arcsec from the QSO. Deep Keck optical spectroscopy clearly confirms one of these objects at z = 0.640 and shows traces of the OIII, emission line of the second object, also at z = 0.640. Lens modeling suggests that they represent two images of the same z = 0.640 emission-line galaxy. Our Keck spectra also allow us to measure the redshift of an intervening galaxy at z = 0.394, located 3.2 arcsec away from the line of sight to the QSO. If the z = 0.120 QSO host galaxy is modeled as a singular isothermal sphere, its mass within the Einstein radius is M_E(r < 1 kpc) = 2.16e10 M_Sun and its velocity dispersion is sigma_SIS = 169 km/s. This is about 1 sigma away from the velocity dispersion estimated from the width of the QSO Hbeta emission line, sigma_*(M_BH) = 124 +/- 47 km/s. Deep optical HST imaging will be necessary to constrain the total radial mass profile of the QSO host galaxy using the detailed shape of the lensed source. This first case of a QSO acting as a strong lens on a more distant object opens new directions in the study of QSO host galaxies.Comment: 6 pages, 5 figures, accepted for publication in A&A Letters. Added new Keck spectroscop

Urea metabolism in the digestive tract of the pig ; preliminary quantitative and qualitative data

La méthode directe d’étude des échanges de nutriments entre le sang et les contenus digestifs, déjà exposée ici (Rerat, 1977) a été appliquée à l'étude du passage de l’urée sanguine vers la lumière intestinale et de sa métabolisation en ammoniac chez le porc au cours de cinq répétitions à niveaux alimentaires différents permettant de comparer chez un même animal des régimes à 12 p. 100 de protéines contenant ou non de l’urée (3 p. 100). Il se produit une sécrétion brute permanente d urée en provenance du sang vers le tube digestif qui s’élève à près d’un gramme par heure au cours de la digestion de repas équilibrés chez des sujets en bonne santé. L’urée sécrétée n’est que partiellement dégradée (moins de 50 p. 100) en ammoniac. L’urée fournie par voie alimentaire est rapi dement absorbée (en cinq heures environ), et son addition au régime ne se traduit pas par une élévation significative des quantités d’ammoniac produites au cours de la période d’étude postprandiale (8 h) chez des animaux non adaptés à cette addition d urée.The previously reported direct method of determination of the exchanges of nutriments between blood and digestive contents (Rerat, 1977) was applied to the study of the passage of blood urea towards the intestinal lumen and its meta- bolization into ammonia in the pig. Using five replications at different feeding levels it was possible to compare in one and the same animal diets containing 12 p. 100 protein and either no urea or 3 p. 100. The amount of blood urea permanently secreted in the gut during digestion of a balanced meal in healthy animals ranged around 1 gramme per hour. The urea secreted was only partially degraded ( less than 50 p. 100) into ammonia. Dietary urea was rapidly absorbed (within about 5 hours) and its addition to the diet did not lead to a significant elevation in the amounts of ammonia produced during the postprandial period (8 h) in animals non adapted to this addition of urea

La perfusion des organes digestifs. Méthode d'étude de l'absorption

Le Bars Henri, Mollé J., Rérat Alain, Simonnet Henri. La perfusion des organes digestifs. Méthode d'étude de l'absorption. In: Bulletin de l'Académie Vétérinaire de France tome 111 n°6, 1958. pp. 305-310

Absorption des acides aminés au niveau du rumen de l’intestin grêle et du caecum chez le mouton

Demaux G., Le Bars Henri, Mollé J., Rérat Alain, Simonnet Henri. Absorption des acides aminés, au niveau du rumen, de l’intestin grêle et du cæcum chez le Mouton. In: Bulletin de l'Académie Vétérinaire de France tome 114 n°2, 1961. pp. 85-88

Acidogenic Potential of “Sugar-Free” Cough Drops

A patient presented with extensive marginal ditching around restorations recently placed during whole-mouth rehabilitation. The patient was not xerostomic and was otherwise normal except for the self-reported excessive use of “sugar-free” cough drops sweetened with sorbitol and Isomalt® (an equimolar mix of glucosyl-mannitol and glucosylsorbitol). This prompted an in vitro investigation to determine whether Streptococcus sobrinus 6715, a cariogenic streptococcus, could grow and produce acid in growth medium containing an aqueous extract of such “sugar-free” cough drops. The results indicate that S. sobrinus 6715 uses Isomalt® and sorbitol extensively, producing terminal culture pH as low as 4.2 when grown on medium with cough drop extract containing these sugars. This pH is sufficient to demineralize dental enamel. Patients should be cautioned against the chronic overuse of “sugar-free” cough drops and other “sugar-free” confections sweetened with a mixture of Isomalt® and sorbitol