Summary
Abstract
The October 2011 issue of the Journal of Visualized Experiments (JoVE) presents the journal’s first effort to explore oceanographic physics and engineering. Investigators at the Woods Hole Oceanographic Institute demonstrate the use of a self-contained underwater velocimetry apparatus, or SCUVA. Principle components of this instrument include an HD camera and laser, which when aligned with an optical lens, produces a vertical sheet of light. Following alignment and testing for a watertight seal, these researchers seek out inhabitants the water column for analysis. Nightly experimentation is necessary, so that natural light does not interfere with the laser sheet. SCUVA is specifically designed to capture the movement of particles in the water, so that the velocity fields – a vector field that describes the movement of fluid – can be determined around an organism in their natural environment.
In Clinical and Translational Medicine, orthodontic researchers from the University of Graz determine the composition of the oral biofilms – a surface-adhering aggregate of microorganisms – that form on their patient’s palatal expanders. These authors use fluorescent in situ hybridization combined with confocal microscopy to detect specific bacteria within the biofilm as well as visualize its 3-dimensional structure.
JoVE also visits Graz for Immunology and Infection, where researchers at the University of Graz and the Graz institute of technology use transmission electron microscopy, or TEM, to analyze the ultrastructural changes that take place in the plant leaf as a result of viral infection. Small sections of leaves are cut from the plant and subjected to a microwave-assisted fixation procedure, which drastically reduces sample preparation time for TEM. Following embedding and sectioning, samples are loaded into the electron microscope, and imaged. Aided by image analysis software, these authors can calculate the dimensions of virus particles as well as assess the ultrastructural changes in the plant leaf, which is critical for identifying the infecting virus.
In Neuroscience, researchers from the University of California, Irvine, present a series of behavioral paradigms aimed to measure the degree of cognitive impairment in rodents treated with cranial radiotherapy. These authors demonstrate a novel place recognition task (for spatial recognition memory), an elevated plus maze task (for measurement of anxiety), a fear-conditioning task (learning and memory), and the Morris Water Maze (for spatial learning). The cognitive deficits in rodents resemble those manifested in cancers survivors following cranial radiotherapy, and therefore standardization of such cognitive behavioral paradigms is critical to assess therapy. One potential therapy is stem cell transplantation into the hippocampus, which the authors demonstrate in a separate video-article in October.
On the topic of stem cells, researchers from the University of California, Riverside demonstrate methods for genetic manipulation of human induced pluripotent stem cells. Induced pluoripotent stem cells, IPSCs, can be derived from somatic cells, like the fibroblasts you see here, following forced expression of certain transcription factors, which cause the cells to be transformed into a pluripotent state. These authors show how iPSCs can be cultured in feeder-free conditions and provide helpful hints for lifting and seeding the cells at concentrations optimal for transfection and nucleofection
In addition to these featured publications, JoVE presents methods for taking physiological measurements in individuals under psychosocial stress, tracking bacterial lysis following infections with phage, imaging in the olfactory bulb via a cranial window, and dozens more video-articles of complex methods.
