Sample Student Day (image) PLOS Caption Sample student day with measured CO2 concentrations and GPS locations (A-H). Credit Richardson et al.:10.1371/journal.pone.0096334.g004 Usage Restrictions CC-BY 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.