Typical Trees (IMAGE) DOE/Los Alamos National Laboratory Caption Using computational techniques, scientists at Los Alamos National Laboratory are working to more clearly understand how diseases such as HIV are spread. In this image, arrows indicate actual transmission; red and blue persons are sampled, and the grey outline person is an unsampled link discovered in the computer analysis of the phylogenetic trees of the disease agents. Credit Los Alamos National Laboratory. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.