Browsing by Author "Salcedo, Mary"

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    First person - Mary Salcedo
    Salcedo, Mary (2019-10)
    First Person is a series of interviews with the first authors of a selection of papers published in Biology Opens, helping early-career researchers promote themselves alongside their papers. Mary Salcedo is first author on 'Computational analysis of size, shape and structure of insect wings', published in BiO. Mary conducted the research described in this article while a Graduate Student in L. Mahadevan's lab at Harvard University, Cambridge, USA. She is now a NSF Postdoctoral Researcher in Biology in the lab of Jake Socha at Virginia Tech, USA, investigating insect wing shapes, venation patterns and circulation within the wings.
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    Reconsidering tympanal-acoustic interactions leads to an improved model of auditory acuity in a parasitoid fly
    Staples, Anne E.; Mikel-Stites, Max; Salcedo, Mary; Marek, Paul E.; Socha, John J. (2023-03)
    Although most binaural organisms locate sound sources using neurological structures to amplify the sounds they hear, some animals use mechanically coupled hearing organs instead. One of these animals, the parasitoid fly Ormia ochracea, has astoundingly accurate sound localization abilities. It can locate objects in the azimuthal plane with a precision of 2°, equal to that of humans, despite an intertympanal distance of only 0.5 mm, which is less than 1/100th of the wavelength of the sound emitted by the crickets that it parasitizes. Ormia ochracea accomplishes this feat via mechanically coupled tympana that interact with incoming acoustic pressure waves to amplify differences in the signals received at the two ears. In 1995, Miles et al. developed a model of hearing mechanics in O. ochracea that represents the tympana as flat, front-facing prosternal membranes, though they lie on a convex surface at an angle from the flies’ frontal and transverse planes. The model works well for incoming sound angles less than ±30° but suffers from reduced accuracy (up to 60% error) at higher angles compared to response data acquired from O. ochracea specimens. Despite this limitation, it has been the basis for bio-inspired microphone designs for decades. Here, we present critical improvements to this classic hearing model based on information from three-dimensional reconstructions of O. ochracea’s tympanal organ. We identified the orientation of the tympana with respect to a frontal plane and the azimuthal angle segment between the tympana as morphological features essential to the flies’ auditory acuity and hypothesized a differentiated mechanical response to incoming sound on the ipsi- and contralateral sides that depend on these features. We incorporated spatially-varying model coefficients representing this asymmetric response to explore this, making a new quasi-two-dimensional (q2D) model. The q2D model has high accuracy (average errors of under 10%) for all incoming sound angles. This improved biomechanical model may inform the design of new microscale directional microphones and other small-scale acoustic sensor systems.