The Effect of Interstellar Absorption on Measurements of the Baryon Acoustic Peak in the Lyman-{\alpha} Forest

In recent years, the autocorrelation of the hydrogen Lyman-{\alpha} forest has been used to observe the baryon acoustic peak at redshift 2 < z < 3.5 using tens of thousands of QSO spectra from the BOSS survey. However, the interstellar medium of the Milky-Way introduces absorption lines into the spectrum of any extragalactic source. These lines, while weak and undetectable in a single BOSS spectrum, could potentially bias the cosmological signal. In order to examine this, we generate absorption line maps by stacking over a million spectra of galaxies and QSOs. We find that the systematics introduced are too small to affect the current accuracy of the baryon acoustic peak, but might be relevant to future surveys such as the Dark Energy Spectroscopic Instrument (DESI). We outline a method to account for this with future datasets.Comment: MNRAS accepted. Minor change

‘1-8 interferon inducible gene family': putative colon carcinoma-associated antigens

Db−/−xβ2 microglobulin (β2m) null mice transgenic for a chimeric HLA-A2.1/Db-β2m single chain (HHD mice) are an effective biological tool to evaluate the antitumour cytotoxic T-lymphocyte response of known major histocompatibility-restricted peptide tumour-associated antigens, and to screen for putative unknown novel peptides. We utilised HHD lymphocytes to identify immunodominant epitopes of colon carcinoma overexpressed genes. We screened with HHD-derived lymphocytes over 500 HLA-A2.1-restricted peptides derived from colon carcinoma overexpressed genes. This procedure culminated in the identification of seven immunogenic peptides, three of these were derived from the ‘human 1-8D gene from interferon inducible gene' (1-8D). The 1-8D gene was shown to be overexpressed in fresh tumour samples. The three 1-8D peptides were both antigenic and immunogenic in the HHD mice. The peptides induce cytotoxic T lymphocytes that were able to kill a colon carcinoma cell line HCT/HHD, in vitro and retard its growth in vivo. One of the peptides shared by all the 1-8 gene family primed efficiently normal human cytotoxic T lymphocyte precursors. These results highlight the 1-8D gene and its homologues as putative immunodominant tumour-associated antigens of colon carcinoma