May 2014: This Month in JoVE - Bioengineering Limb Prostheses, Protecting Trees from Fungal Pathogens, and Investigating the Kinematics of Swallowing

Abstract

Here's a look at what's coming up in the May 2014 issue of JoVE: The Journal of Visualized Experiments. In JoVE Environment we examine beech bark disease, which affects susceptible trees after they are attacked by the beech scale insect. When it feeds on tree bark, the insect creates small fissures that allow the causative fungal species to establish infection. In the late 1890s, the beech scale insect was accidentally brought from Europe to Nova Scotia. By the 1930s, the insects and the associated fungal disease had reached the United States, subsequently spreading across the entire northeast towards the south and Midwest. Beech bark disease can kill up to 50% of infected trees, thus threatening biodiversity in hardwood forests. To address this concern, Koch and Carey adapt a technique of artificially inoculating seedlings with beech scale eggs, and present a method for screening disease resistance and susceptibility in American beech trees. This method can help to identify resistance and susceptibility genes or to screen mature trees in the field and help minimize the environmental impact of birch bark disease. Moving on to JoVE Bioengineering, much research is devoted to improving the design and function of prosthetics. This month, Smith et al. present techniques for directly estimating the inertial properties of below-knee prosthetics. The procedure is performed with the prosthesis fully intact, which reduces the measurement time and eliminates any additional time needed to realign the prosthesis after measurements. This technique allows rapid and direct measurements of the inertial properties of below-knee prosthetics, which could potentially benefit many patients who undergo lower-limb amputations. In JoVE Clinical & Translational Medicine, Thompson et al. use coordinate mapping to analyze the pharyngeal phase of swallowing, which is a complex process that involves over 20 muscles coordinated by the autonomic nervous system. To demonstrate this technique, they examine healthy subjects, without known swallowing impairments, who undergo a modified barium swallow. In this test, an X-ray of the throat is taken while the subject ingests food or liquid containing barium. Using image analysis software, the authors record anatomical landmark coordinates during the modified barium swallow. These coordinates are then translated into kinematic variables of interest, which can be useful for studying dysphagia, or difficulty swallowing. In developing vertebrates, cranial neural crest cells (CNCCs) migrate from the dorsal neural tube to form craniofacial structures. This month in JoVE Biology, Fish and Schneider examine how these neural crest cells give rise to the wide range of beak patterns in birds. The authors head to Chinatown to obtain white Pekin duck eggs, which they grow to Hamburger-Hamilton stage 9.5. Then, they graft a quail neural fold into the mid- and anterior hindbrain of the duck embryo to generate a quail-duck chimera, or a quck. Because the quail and the duck have very different beak morphology, this quck can help uncover the mechanisms of species-specific craniofacial patterning. You've just had a sneak peek of the May 2014 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments.