The subjects were obtained from the TwinsUK (TUK) registry (http://www.twinsuk.ac.uk) at King's College London, United Kingdom, which has been ascertained by a national media campaign.
Sleep quality was assessed by the Athens Insomnia Scale (AIS), the consistency, reliability, and validity of which has been ascertained as a screening or diagnosis tool for insomnia (18).
We have assumed a discovery panel of 1,000 individuals from the same population from which the analysis cohort has been ascertained which may not always be the case.
These panels will miss rare variants specific to the population from which the analysis cohort has been ascertained, and may lead to genotyping of variants which are, in fact, monomorphic.
In their theoretical study entitled "Occurrence of cancer at multiple sites: Metastasis versus multigenesis?" and submitted to Biology Direct, Zhang et al. propose that de novo initiation of cancer in multiple sites may actually account for those clinical cases in which metastasis to "unusual" sites has been ascertained.
This matter has been ascertained to be of nonbiological origin.
One principle of classical epidemiologic study design is that the distribution of risk factors of interest in controls should be the same as the distribution in the population from which cases have been ascertained [13].
In this article, I have addressed the challenges of allelic effect heterogeneity posed by transethnic meta-analysis of GWAS by considering the relatedness between the populations from which they have been ascertained.
Antibodies of which the specificities have been ascertained by the modENCODE project [ 36, 54] were obtained from Abcam, Inc., and Active Motif, Inc. Enriched chromatin extracts were used to prepare bar-coded sequencing libraries.
Time at risk for a SPN began at 5-year survival and individuals exited from risk at the first occurrence of an SPN, emigration, death, or 31 December 2006 which was the most recent date up to which all potential SPNs had been ascertained and validated.
To investigate the nature of nucleotide misincorporations in ancient DNA, we have considered a set of ancient sequences obtained in our laboratory, the authenticity of which has been previously ascertained [24].
