Articles by Robert D. M. Gray in JoVE
Open-source Single-particle Analysis for Super-resolution Microscopy with VirusMapper Robert D. M. Gray1,2, Jason Mercer1, Ricardo Henriques1,3 1MRC Laboratory for Molecular Cell Biology, University College London, 2Centre for Mathematics and Physics in Life Sciences and Experimental Biology (CoMPLEX), University College London, 3Department of Cell and Developmental Biology, University College London This manuscript uses the Fiji-based open-source software package VirusMapper to apply single-particle analysis to super-resolution microscopy images in order to generate precise models of nanoscale structure.
Other articles by Robert D. M. Gray on PubMed
VirusMapper: Open-source Nanoscale Mapping of Viral Architecture Through Super-resolution Microscopy Scientific Reports. Jul, 2016 | Pubmed ID: 27374400 The nanoscale molecular assembly of mammalian viruses during their infectious life cycle remains poorly understood. Their small dimensions, generally bellow the 300nm diffraction limit of light microscopes, has limited most imaging studies to electron microscopy. The recent development of super-resolution (SR) light microscopy now allows the visualisation of viral structures at resolutions of tens of nanometers. In addition, these techniques provide the added benefit of molecular specific labelling and the capacity to investigate viral structural dynamics using live-cell microscopy. However, there is a lack of robust analytical tools that allow for precise mapping of viral structure within the setting of infection. Here we present an open-source analytical framework that combines super-resolution imaging and naïve single-particle analysis to generate unbiased molecular models. This tool, VirusMapper, is a high-throughput, user-friendly, ImageJ-based software package allowing for automatic statistical mapping of conserved multi-molecular structures, such as viral substructures or intact viruses. We demonstrate the usability of VirusMapper by applying it to SIM and STED images of vaccinia virus in isolation and when engaged with host cells. VirusMapper allows for the generation of accurate, high-content, molecular specific virion models and detection of nanoscale changes in viral architecture.
A Method to Implement the Reservoir-wave Hypothesis Using Phase-contrast Magnetic Resonance Imaging MethodsX. 2016 | Pubmed ID: 28003965 The reservoir-wave hypothesis states that the blood pressure waveform can be usefully divided into a "reservoir pressure" related to the global compliance and resistance of the arterial system, and an "excess pressure" that depends on local conditions. The formulation of the reservoir-wave hypothesis applied to the area waveform is shown, and the analysis is applied to area and velocity data from high-resolution phase-contrast cardiovascular magnetic resonance (CMR) imaging. A validation study shows the success of the principle, with the method producing largely robust and physically reasonable parameters, and the linear relationship between flow and wave pressure seen in the traditional pressure formulation is retained. The method was successfully tested on a cohort of 20 subjects (age range: 20-74 years; 17 males). This paper: •Demonstrates the feasibility of deriving reservoir data non-invasively from CMR.•Includes a validation cohort (CMR data).•Suggests clinical applications of the method.