Physical Electronics and Surface Physics

Contains reports on one research project.Joint Services Electronics Program (Contract DAAB07-71-C-0300

Physical Electronics and Surface Physics

Contains report on one research project.National Aeronautics and Space Administration (Grant NGL 22-009-091)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

Physical Electronics and Surface Physics

Contains report on one research project.National Aeronautics and Space Administration (Grant NGR 22-009-091)Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E

Physical Electronics and Surface Physics

Contains reports on two research projects.National Aeronautics and Space Administration (Grant NGR 22-009-091)Joint Services Electronics Programs (U.S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

Functional Morphology and Fluid Interactions During Early Development of the Scyphomedusa Aurelia aurita

Scyphomedusae undergo a predictable ontogenetic transition from a conserved, universal larval form to a diverse array of adult morphologies. This transition entails a change in bell morphology from a highly discontinuous ephyral form, with deep clefts separating eight discrete lappets, to a continuous solid umbrella-like adult form. We used a combination of kinematic, modeling, and flow visualization techniques to examine the function of the medusan bell throughout the developmental changes of the scyphomedusa Aurelia aurita. We found that flow around swimming ephyrae and their lappets was relatively viscous (1 < Re < 10) and, as a result, ephyral lappets were surrounded by thick, overlapping boundary layers that occluded flow through the gaps between lappets. As medusae grew, their fluid environment became increasingly influenced by inertial forces (10 < Re < 10,000) and, simultaneously, clefts between the lappets were replaced by organic tissue. Hence, although the bell undergoes a structural transition from discontinuous (lappets with gaps) to continuous (solid bell) surfaces during development, all developmental stages maintain functionally continuous paddling surfaces. This developmental pattern enables ephyrae to efficiently allocate tissue to bell diameter increase via lappet growth, while minimizing tissue allocation to inter-lappet spaces that maintain paddle function due to boundary layer overlap

Physical Electronics and Surface Physics

Contains research objectives, summary of research and reports on two research projects.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-0300National Aeronautics and Space Administration (Grant NGR 22-009-091

Physical Electronics and Surface Physics

Contains reports on two research projects.National Aeronautics and Space Administration (Grant NGR 22-009-091)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

Traumatic Brain Injury and the Neuronal Microenvironment: A Potential Role for Neuropathological Mechanotransduction

Traumatic brain injury (TBI) is linked to several pathologies for which there is a lack of understanding of disease mechanisms and therapeutic strategies. To elucidate injury mechanisms, it is important to consider how physical forces are transmitted and transduced across all spatial scales of the brain. Although the mechanical response of the brain is typically characterized by its material properties and biological structure, cellular mechanotransduction mechanisms also exist. Such mechanisms can affect physiological processes by responding to exogenous mechanical forces directed through sub-cellular components, such as extracellular matrix and cell adhesion molecules, to mechanosensitive intracellular structures that regulate mechanochemical signaling pathways. We suggest that cellular mechanotransduction may be an important mechanism underlying the initiation of cell and sub-cellular injuries ultimately responsible for the diffuse pathological damage and clinical symptoms observed in TBI, thereby providing potential therapeutic opportunities not previously explored in TBI

Julie Williams crowned Miss OBU 2019

Ouachita Baptist University hosted the 51st annual Miss Ouachita Baptist University Pageant on Saturday, Feb. 2, and crowned Arkadelphia, Ark., native Julie Williams as Miss OBU 2019

Propulsion in cubomedusae : mechanisms and utility

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS ONE 8 (2013): e56393, doi:10.1371/journal.pone.0056393.Evolutionary constraints which limit the forces produced during bell contractions of medusae affect the overall medusan morphospace such that jet propulsion is limited to only small medusae. Cubomedusae, which often possess large prolate bells and are thought to swim via jet propulsion, appear to violate the theoretical constraints which determine the medusan morphospace. To examine propulsion by cubomedusae, we quantified size related changes in wake dynamics, bell shape, swimming and turning kinematics of two species of cubomedusae, Chironex fleckeri and Chiropsella bronzie. During growth, these cubomedusae transitioned from using jet propulsion at smaller sizes to a rowing-jetting hybrid mode of propulsion at larger sizes. Simple modifications in the flexibility and kinematics of their velarium appeared to be sufficient to alter their propulsive mode. Turning occurs during both bell contraction and expansion and is achieved by generating asymmetric vortex structures during both stages of the swimming cycle. Swimming characteristics were considered in conjunction with the unique foraging strategy used by cubomedusae.This work was supported by an ONR MURI award (N000140810654) and National Science Foundation grant OCE 0623508 to JHC, SPC, JOD. And the work was supported by the Roger Williams University Foundation to Promote Scholarship