An electrophysiological investigation of power-amplification in the ballistic mantis shrimp punch

Author Posting. © Faculty for Undergraduate Neuroscience, 2019. This article is posted here by permission of Faculty for Undergraduate Neuroscience for personal use, not for redistribution. The definitive version was published in Journal of Undergraduate Neuroscience Education 17(1), (2019): T12-T19.Mantis shrimp are aggressive, burrowing crustaceans that hunt using one the fastest movements in the natural world. These stomatopods can crack the calcified shells of prey or spear down unsuspecting fish with lighting speed. Their strike makes use of power-amplification mechanisms to move their limbs much faster than is possible by muscles alone. Other arthropods such as crickets and grasshoppers also use power-amplified kicks that allow these animals to rapidly jump away from predator threats. Here we present a template laboratory exercise for studying the electrophysiology of power-amplified limb movement in arthropods, with a specific focus on mantis shrimp strikes. The exercise is designed in such a way that it can be applied to other species that perform power-amplified limb movements (e.g., house crickets, Acheta domesticus) and species that do not (e.g., cockroaches, Blaberus discoidalis). Students learn to handle the animals, make and implant electromyogram (EMG) probes, and finally perform experiments. This integrative approach introduces the concept of power-amplified neuromuscular control; allows students to develop scientific methods, and conveys high-level insights into behavior, and convergent evolution, the process by which different species evolve similar traits.Author GJG declares a commercial interest in the SpikerBox used here as a co-owner in Backyard Brains. Authors ES and SM are employed by Backyard Brains. DJP and GJG were supported by a National Institute of Mental Health (NIMH) Small Business Innovative Research (SBIR) award #R44MH093334. Author KDF is funded by European Commission Marie Sklodowska-Curie Independent Postdoctoral Research Fellowship and the Grass Foundation

Parallel multi-block computations of incompressible flows for industrial applications

The influence of allelochemical stress and population origin on the patterns of phenotypic and genetic correlations among life history traits and digestive enzyme activities were investigated in larvae of the gypsy moth (Lymantria dispar L.; Lepidoptera: Lymantriidae). Thirty-two full-sib families from oak (suitable host plant, Quercus population), and twenty-six full-sib families from locust-tree (unsuitable host plant, Robinia population) forests were reared on an artificial diet, with or without a 5% tannic acid supplement. Comparison of correlation matrices revealed significant similarity between the two populations in the structure of phenotypic and genetic correlations of life history traits and of digestive enzyme activities. The patterns of correlations of the examined traits, within each of the two locally adapted populations and in the presence of allelochemical stress, remained stabile despite the different selection pressures that mold these traits.Projekat ministarstva br. 17302