In JoVE (1)
Other Publications (1)
Articles by Casey Barr in JoVE
Quantifying Microorganisms at Low Concentrations Using Digital Holographic Microscopy (DHM) Manuel Bedrossian1, Casey Barr2, Chris A. Lindensmith3, Kenneth Nealson2, Jay L. Nadeau1 1Department of Medical Engineering, California Institute of Technology, 2Department of Earth Sciences, University of Southern California, 3Jet Propulsion Laboratory, California Institute of Technology Digital holographic microscopy (DHM) is a volumetric technique that allows imaging samples 50-100X thicker than brightfield microscopy at comparable resolution, with focusing performed post-processing. Here DHM is used for identifying, counting, and tracking microorganisms at very low densities and compared with optical density measurements, plate count, and direct count.
Other articles by Casey Barr on PubMed
Limits on Gravitational-wave Emission from Selected Pulsars Using LIGO Data Physical Review Letters. | Pubmed ID: 15904354 We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars.