Large-Scale Structure at z~2.5

We have made a statistically complete, unbiased survey of C IV systems toward a region of high QSO density near the South Galactic Pole using 25 lines of sight spanning $1.5<z<2.8$. Such a survey makes an excellent probe of large-scale structure at early epochs. We find evidence for structure on the $15-35h^{-1}$ proper Mpc scale ($H_0 \equiv 100$ km $s^{-1}$ Mpc${-1}$) as determined by the two point C IV - C IV absorber correlation function, and reject the null hypothesis that C IV systems are distributed randomly on such scales at the $\sim 3.5\sigma$ level. The structure likely reflects the distance between two groups of absorbers subtending $\sim~ 13 \times 5 \times 21h^{-3}$ and $\sim 7 \times 1 \times 15h^{-3}$ Mpc$^3$ at $z\sim 2.3$ and $z \sim 2.5$ respectively. There is also a marginal trend for the association of high rest equivalent width C IV absorbers and QSOs at similar redshifts but along different lines of sight. The total number of C IV systems detected is consistent with that which would be expected based on a survey using many widely separated lines of sight. Using the same data, we also find 11 Mg II absorbers in a complete survey toward 24 lines of sight; there is no evidence for Mg II - Mg II or Mg II - QSO clustering, though the sample size is likely still small to detect such structure if it exists.Comment: 56 pages including 32 of figures, in gzip-ed uuencoded postscript format, 1 long table not included, aastex4 package. Accepted for publication in ApJ Supplement

Real-world trials to answer real-world questions

Currently, there is a discrepancy between clinical trials designed to assess the efficacy and safety of a new medication under investigation and the real-life questions that need to be addressed regarding the clinical use of the medication by patients, healthcare professionals and society. The data necessary to obtain regulatory approval may be of limited relevance to policy makers when calculating economic parameters such as value for money or cost effectiveness. 'Real-world' studies examine questions relevant to health policy and reimbursement. There are many different forms of clinical trials, but in designing trials incorporating realistic budget impact estimates the important issue is to ensure we are asking a sensible question and attempting to answer it with an appropriate experimental design. As an example, a real-world trial currently underway that examines scenarios of introducing inhaled insulin into clinical practice is described