12 research outputs found
A detailed Hapmap of the Sitosterolemia locus spanning 69 kb; differences between Caucasians and African-Americans
BACKGROUND: Sitosterolemia is an autosomal recessive disorder that maps to the sitosterolemia locus, STSL, on human chromosome 2p21. Two genes, ABCG5 and ABCG8, comprise the STSL and mutations in either cause sitosterolemia. ABCG5 and ABCG8 are thought to have evolved by gene duplication event and are arranged in a head-to-head configuration. We report here a detailed characterization of the STSL in Caucasian and African-American cohorts. METHODS: Caucasian and African-American DNA samples were genotypes for polymorphisms at the STSL locus and haplotype structures determined for this locus RESULTS: In the Caucasian population, 13 variant single nucleotide polymorphisms (SNPs) were identified and resulting in 24 different haplotypes, compared to 11 SNPs in African-Americans resulting in 40 haplotypes. Three polymorphisms in ABCG8 were unique to the Caucasian population (E238L, INT10-50 and G575R), whereas one variant (A259V) was unique to the African-American population. Allele frequencies of SNPs varied also between these populations. CONCLUSION: We confirmed that despite their close proximity to each other, significantly more variations are present in ABCG8 compared to ABCG5. Pairwise D' values showed wide ranges of variation, indicating some of the SNPs were in strong linkage disequilibrium (LD) and some were not. LD was more prevalent in Caucasians than in African-Americans, as would be expected. These data will be useful in analyzing the proposed role of STSL in processes ranging from responsiveness to cholesterol-lowering drugs to selective sterol absorption
Vases flamulés du VendÎmois
Plat . Vases flamulés du VendÎmois. In: Bulletin de la Société Nationale des Antiquaires de France, 1945-1947, 1950. pp. 37-38
La Touraine, berceau des Ă©coles romanes du sud-ouest
Plat Gabriel. La Touraine, berceau des écoles romanes du sud-ouest. In: Bulletin Monumental, tome 77, année 1913. pp. 347-378
Les charpentes de la Trinité de VendÎme
Plat Gabriel. Les charpentes de la Trinité de VendÎme. In: Bulletin Monumental, tome 89, n°2, année 1930. pp. 386-390
L'omphalos gallique. Quelques considérations sur son emplacement probable
Plat Gabriel. L'omphalos gallique. Quelques considérations sur son emplacement probable. In: Comptes rendus des séances de l'Académie des Inscriptions et Belles-Lettres, 59ᔠannée, N. 4, 1915. pp. 285-294
A variable active galactic nucleus at z = 2.06 triply-imaged by the galaxy cluster MACS J0035.4â2015
We report the discovery of a triply imaged active galactic nucleus (AGN), lensed by the galaxy cluster MACS J0035.4â2015 (z d = 0.352). The object is detected in Hubble Space Telescope imaging taken for the RELICS program. It appears to have a quasi-stellar nucleus consistent with a point-source, with a de-magnified radius of re âČ 100 pc. The object is spectroscopically confirmed to be an AGN at z spec = 2.063 ± 0.005 showing broad rest-frame UV emission lines, and detected in both X-ray observations with Chandra and in ALCS ALMA band 6 (1.2 mm) imaging. It has a relatively faint rest-frame UV luminosity for a quasar-like object, MUV, 1450 = â19.7 ± 0.2. The object adds to just a few quasars or other X-ray sources known to be multiply lensed by a galaxy cluster. Some diffuse emission from the host galaxy is faintly seen around the nucleus, and there is a faint object nearby sharing the same multiple-imaging symmetry and geometric redshift, possibly an interacting galaxy or a star-forming knot in the host. We present an accompanying lens model, calculate the magnifications and time delays, and infer the physical properties of the source. We find the rest-frame UV continuum and emission lines to be dominated by the AGN, and the optical emission to be dominated by the host galaxy of modest stellar mass Mⶠâ 109.2 Mâ. We also observe some variation in the AGN emission with time, which may suggest that the AGN used to be more active. This object adds a low-redshift counterpart to several relatively faint AGN recently uncovered at high redshifts with HST and JWST.</p
A variable active galactic nucleus at triply-imaged by the galaxy cluster MACS J0035.4-2015
International audienceWe report the discovery of a triply-imaged active galactic nucleus (AGN), lensed by the galaxy cluster MACS J0035.4-2015 (). The object is detected in Hubble Space Telescope (HST) imaging taken for the RELICS program. It appears to have a quasi-stellar nucleus consistent with a point-source, with a de-magnified radius of pc. The object is spectroscopically confirmed to be an AGN at showing broad rest-frame UV emission lines, and is detected in both X-ray observations with \textit{Chandra} and in ALCS ALMA band 6 (1.2 mm) imaging. It has a relatively faint rest-frame UV luminosity for a quasar-like object, . The object adds to just a few quasars or other X-ray sources known to be multiply lensed by a galaxy cluster. Some faint, diffuse emission from the host galaxy is also seen around the nucleus, and nearby there is another fainter object sharing the same multiple-imaging symmetry and geometric redshift, which may be an interacting galaxy or a star-forming knot in the host. We present an accompanying lens model, calculate the magnifications and time delays, and infer physical properties for the source. We find the rest-frame UV continuum and emission lines to be dominated by the AGN, and the optical emission to be dominated by the relatively young ( Myr) host galaxy of modest stellar mass . We also observe variations in the AGN's emission, which may suggest that the AGN used to be more active. This object adds a low-redshift counterpart to several relatively faint AGN recently uncovered at high redshifts with HST and JWST
A supermassive black hole in the early universe growing in the shadows
International audienceEarly JWST observations have uncovered a new, substantial population of red sources that might represent a previously overlooked phase of actively growing supermassive black holes (Kocevski et al. 2023, Matthee et al. 2023, Labbe et al. 2023). One of the most intriguing examples is an extremely red, point-like object that was found to be triply-imaged by the strong lensing galaxy cluster Abell 2744 (Furtak et al. 2023), allowing an unprecedented detailed look into this enigmatic population. Here we present deep spectroscopic JWST/NIRSpec observations of this object, Abell2744-QSO1. The spectroscopy confirms that the three images are of the same object, and that it is a highly reddened () broad emission-line Active Galactic Nucleus (AGN) at a redshift of . From the width of H () we derive a black hole mass of . We infer a very high ratio of black hole to galaxy mass of at least 3% and possibly as high as 100%, an order of magnitude or more than is seen in local galaxies. The lack of strong metal lines in the spectrum together with the high bolometric luminosity () suggest that we are seeing the black hole in a phase of rapid growth, accreting at 30% of the Eddington limit. Based on early JWST imaging studies we estimate that such heavily reddened, low-mass black holes can be times more common than UV-selected ones at this epoch. The rapid growth and high black hole to galaxy mass ratio of A2744-QSO1 suggests that it may represent the missing link between black hole seeds (Inayoshi et al. 2020; Greene et al. 2020; Volonteri 2021) and the first luminous quasars (Fan et al. 2023)