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Full-Text Articles in Engineering
O&P, Arezoo Eshraghi
Upper Limb Orthoses, Arezoo Eshraghi
Fluoride Treatment Increased Serum Igf-1, Bone Turnover, And Bone Mass, But Not Bone Strength, In Rabbits, C. Turner, L. Garetto, A. Dunipace, W. Zhang, M. Wilson, Marc Grynpas, Debbie Chachra, R. Mcclintock, M. Peacock, G. Stookey
Fluoride Treatment Increased Serum Igf-1, Bone Turnover, And Bone Mass, But Not Bone Strength, In Rabbits, C. Turner, L. Garetto, A. Dunipace, W. Zhang, M. Wilson, Marc Grynpas, Debbie Chachra, R. Mcclintock, M. Peacock, G. Stookey
Debbie Chachra
We hypothesized that fluoride partly acts by changing the levels of circulating calcium-regulating hormones and skeletal growth factors. The effects of oral fluoride on 24 female, Dutch-Belted, young adult rabbits were studied. The rabbits were divided into two study groups, one control and the other receiving about 16 mg fluoride/rabbit/day in their drinking water. After 6 months of fluoride dosing, all rabbits were euthanized and bone and blood samples were taken for analyses. Fluoride treatment increased serum and bone fluoride levels by over an order of magnitude (P < 0.001), but did not affect body weight or the following serum biochemical variables: urea, creatinine, phosphorus, total protein, albumin, bilirubin, SGOT, or total alkaline phosphatase. No skeletal fluorosis or osteomalacia was observed histologically, nor did fluoride affect serum PTH or Vitamin D metabolites (P > 0.4). BAP was increased 37% (P < 0.05) by fluoride; serum TRAP was increased 42% (P < 0.05); serum IGF-1 was increased 40% (P < 0.05). Fluoride increased the vertebral BV/TV by 35% (P …
The Dynamics Of Legged Locomotion: Models, Analyses, And Challenges, Philip Holmes, Robert J. Full, Daniel E. Koditschek, John Guckenheimer
The Dynamics Of Legged Locomotion: Models, Analyses, And Challenges, Philip Holmes, Robert J. Full, Daniel E. Koditschek, John Guckenheimer
Daniel E Koditschek
Cheetahs and beetles run, dolphins and salmon swim, and bees and birds fly with grace and economy surpassing our technology. Evolution has shaped the breathtaking abilities of animals, leaving us the challenge of reconstructing their targets of control and mechanisms of dexterity. In this review we explore a corner of this fascinating world. We describe mathematical models for legged animal locomotion, focusing on rapidly running insects and highlighting past achievements and challenges that remain. Newtonian body–limb dynamics are most naturally formulated as piecewise-holonomic rigid body mechanical systems, whose constraints change as legs touch down or lift off. Central pattern generators …
Preliminary Analysis Of A Biologically Inspired 1-Dof "Clock" Stabilized Hopper, Haldun Komsuoglu, Daniel E. Koditschek
Preliminary Analysis Of A Biologically Inspired 1-Dof "Clock" Stabilized Hopper, Haldun Komsuoglu, Daniel E. Koditschek
Daniel E Koditschek
We investigate the stability of a one degree of freedom mechanical spring-mass system modulated by a feed-forward "clock" that stiffens and relaxes a Hooke's law potential force according to a periodic rhythm. At the present early stage of inquiry, we offer sufficient conditions for local asymptotic stability of an isolated periodic orbit when there is no feedback to the clock at all but some viscous friction in the mechanism. We conjecture that, absent feedback, a lossless mechanical system cannot exhibit an asymptotically stable limit cycle in response to such rhythmic excitation.