The Spitzer Extragalactic Representative Volume Survey (SERVS): The Environments of High-z SDSS Quasi-Stellar-Objects

This paper presents a study of the environments of SDSS Quasi-Stellar-Objects (QSOs) in the Spitzer Extragalactic Representative Volume Survey (SERVS). We concentrate on the high-redshift QSOs as these have not been studied in large numbers with data of this depth before. We use the IRAC 3.6-4.5{\mu}m colour of objects and ancillary r-band data to filter out as much foreground contamination as possible. This technique allows us to find a significant (> 4-{\sigma}) over-density of galaxies around QSOs in a redshift bin centred on z ~ 2.0 and a (> 2-{\sigma}) over-density of galaxies around QSOs in a redshift bin centred on z ~ 3.3. We compare our findings to the predictions of a semi-analytic galaxy formation model, based on the {\Lambda}CDM millennium simulation, and find for both redshift bins that the model predictions match well the source-density we have measured from the SERVS data.Comment: 13 pages, 12 figures, Accepted by Ap

On lattice profile of the elliptic curve linear congruential generators

Lattice tests are quality measures for assessing the intrinsic structure of pseudorandom number generators. Recently a new lattice test has been introduced by Niederreiter and Winterhof. In this paper, we present a general inequality that is satisfied by any periodic sequence. Then, we analyze the behavior of the linear congruential generators on elliptic curves (EC-LCG) under this new lattice test and prove that the EC-LCG passes it up to very high dimensions. We also use a result of Brandstätter and Winterhof on the linear complexity profile related to the correlation measure of order k to present lower bounds on the linear complexity profile of some binary sequences derived from the EC-LCG

Gaia Universe Model Snapshot : A statistical analysis of the expected contents of the Gaia catalogue

Context. This study has been developed in the framework of the computational simulations executed for the preparation of the ESA Gaia astrometric mission. Aims. We focus on describing the objects and characteristics that Gaia will potentially observe without taking into consideration instrumental effects (detection efficiency, observing errors). Methods. The theoretical Universe Model prepared for the Gaia simulation has been statistically analyzed at a given time. Ingredients of the model are described, giving most attention to the stellar content, the double and multiple stars, and variability. Results. In this simulation the errors have not been included yet. Hence we estimate the number of objects and their theoretical photometric, astrometric and spectroscopic characteristics in the case that they are perfectly detected. We show that Gaia will be able to potentially observe 1.1 billion of stars (single or part of multiple star systems) of which about 2% are variable stars, 3% have one or two exoplanets. At the extragalactic level, observations will be potentially composed by several millions of galaxies, half million to 1 million of quasars and about 50,000 supernovas that will occur during the 5 years of mission. The simulated catalogue will be made publicly available by the DPAC on the Gaia portal of the ESA web site http://www.rssd.esa.int/gaia/.Comment: 21 pages, 21 figures, accepted for publication in Astronomy and Astrophysics, typos corrected in author name

Somatic mutations of KIT in familial testicular germ cell tumours

Somatic mutations of the KIT gene have been reported in mast cell diseases and gastrointestinal stromal tumours. Recently, they have also been found in mediastinal and testicular germ cell tumours (TGCTs), particularly in cases with bilateral disease. We screened the KIT coding sequence (except exon 1) for germline mutations in 240 pedigrees with two or more cases of TGCT. No germline mutations were found. Exons 10, 11 and 17 of KIT were examined for somatic mutations in 123 TGCT from 93 multiple-case testicular cancer families. Five somatic mutations were identified; four were missense amino acid substitutions in exon 17 and one was a 12bp in-frame deletion in exon 11. Two of seven TGCT from cases with bilateral disease carried KIT mutations compared with 3 out 116 unilateral cases (p = 0.026). The results indicate that somatic KIT mutations are implicated in the development of a minority of familial as well as sporadic TGCT. They also lend support to the hypothesis that KIT mutations primarily take place during embryogenesis such that primordial germ cells with KIT mutations are distributed to both testes

SIRNA-Directed In Vivo Silencing of Androgen Receptor Inhibits the Growth of Castration-Resistant Prostate Carcinomas

BACKGROUND: Prostate carcinomas are initially dependent on androgens, and castration or androgen antagonists inhibit their growth. After some time though, tumors become resistant and recur with a poor prognosis. The majority of resistant tumors still expresses a functional androgen receptor (AR), frequently amplified or mutated. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that AR is not only expressed, but is still a key therapeutic target in advanced carcinomas, we injected siRNA targeting AR into mice bearing exponentially growing castration-resistant tumors. Quantification of siRNA into tumors and mouse tissues demonstrated their efficient uptake. This uptake silenced AR in the prostate, testes and tumors. AR silencing in tumors strongly inhibited their growth, and importantly, also markedly repressed the VEGF production and angiogenesis. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that carcinomas resistant to hormonal manipulations still depend on the expression of the androgen receptor for their development in vivo. The siRNA-directed silencing of AR, which allows targeting overexpressed as well as mutated isoforms, triggers a strong antitumoral and antiangiogenic effect. siRNA-directed silencing of this key gene in advanced and resistant prostate tumors opens promising new therapeutic perspectives and tools