994 research outputs found
American Society of Biomechanics Journal of Biomechanics Award 2013: Cortical bone tissue mechanical quality and biological mechanisms possibly underlying atypical fractures
No full textThe biomechanics literature contains many well-understood mechanisms behind typical fracture types that have important roles in treatment planning. The recent association of "atypical" fractures with long-term use of drugs designed to prevent osteoporosis has renewed interest in the effects of agents on bone tissue-level quality. While this class of fracture was recognized prior to the introduction of the anti-resorptive bisphosphonate drugs and recently likened to stress fractures, the mechanism(s) that lead to atypical fractures have not been definitively identified. Thus, a causal relationship between these drugs and atypical fracture has not been established. Physicians, bioengineers and others interested in the biomechanics of bone are working to improve fracture-prevention diagnostics, and the design of treatments to avoid this serious side-effect in the future. This review examines the mechanisms behind the bone tissue damage that may produce the atypical fracture pattern observed increasingly with long-term bisphosphonate use. Our recent findings and those of others reviewed support that the mechanisms behind normal, healthy excavation and tunnel filling by bone remodeling units within cortical tissue strengthen mechanical integrity. The ability of cortical bone to resist the damage induced during cyclic loading may be altered by the reduced remodeling and increased tissue age resulting from long-term bisphosphonate treatment. Development of assessments for such potential fractures would restore confidence in pharmaceutical treatments that have the potential to spare millions in our aging population from the morbidity and death that often follow bone fracture.Peer reviewe
The resistance of cortical bone tissue to failure under cyclic loading is reduced with alendronate
No full textBisphosphonates are the most prescribed preventative treatment for osteoporosis. However, their long-term use has recently been associated with atypical fractures of cortical bone in patients who present with low-energy induced breaks of unclear pathophysiology. The effects of bisphosphonates on the mechanical properties of cortical bone have been exclusively studied under simple, monotonic, quasi-static loading. This study examined the cyclic fatigue properties of bisphosphonate-treated cortical bone at a level in which tissue damage initiates and is accumulated prior to frank fracture in low-energy situations. Physiologically relevant, dynamic, 4-point bending applied to beams (1.5 mm × 0.5 mm × 10 mm) machined from dog rib (n=12/group) demonstrated mechanical failure and micro-architectural features that were dependent on drug dose (3 groups: 0, 0.2, 1.0mg/kg/day; alendronate [ALN] for 3 years) with cortical bone tissue elastic modulus (initial cycles of loading) reduced by 21% (p<0.001) and fatigue life (number of cycles to failure) reduced in a stress-life approach by greater than 3-fold with ALN1.0 (p<0.05). While not affecting the number of osteons, ALN treatment reduced other features associated with bone remodeling, such as the size of osteons (-14%; ALN1.0: 10.5±1.8, VEH: 12.2±1.6, ×10(3) μm2; p<0.01) and the density of osteocyte lacunae (-20%; ALN1.0: 11.4±3.3, VEH: 14.3±3.6, ×10(2) #/mm2; p<0.05). Furthermore, the osteocyte lacunar density was directly proportional to initial elastic modulus when the groups were pooled (R=0.54, p<0.01). These findings suggest that the structural components normally contributing to healthy cortical bone tissue are altered by high-dose ALN treatment and contribute to reduced mechanical properties under cyclic loading conditions.NOTICE: this is the author's version of a work that was accepted for publication in Bone. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Bone, Volume 64 (July 2014) DOI: 10.1016/j.bone.2014.03.045Peer reviewe
Henry Fielding's Epistolary Voices: Polyphony and the Embedded Letter in Joseph Andrews, Tom Jones, and Amelia
No full textDegree awarded: Ph.D. English Language and Literature. The Catholic University of AmericaHenry Fielding's Epistolary Voices: Polyphony and the Embedded Letter in Joseph Andrews, Tom Jones, and AmeliaBridget Brennan, Ph.D.Director: Christopher Wheatley, Ph.D.This study explores the polyphonic nature of Henry Fielding's writing by analyzing the relationship between narrative voice and the embedded letter in his three major novels: Joseph Andrews, Tom Jones, and Amelia. More specifically, it establishes that the voices of the narrators, who have traditionally been considered Fielding's spokesmen, are not the only authoritative voices present in his works. Drawing on Mikhail Bakhtin's theories for its discussion of Joseph Andrews and Tom Jones, this dissertation demonstrates how the embedded letter, because of its inherent structural independence, not only allows other voices to enter the novels, it also grants these voices an authority equal to the narrator's. Fielding adopts a radically different narrative persona in his final novel, Amelia, and this change affects his use of the embedded letter. In Amelia, the most overtly polyphonic of the three novels, Fielding replaces the controlling narrator of the previous novels with an inconsistently-drawn figure who offers the reader little commentary or guidance. Consequently, the letter is no longer used as a way to give voice to opposing ideologies without undermining the consistency and authority of the narrator; instead, in the absence of a stable, moral guide, it becomes a forum through which the author's own voice and ideology enters the text. This study's exploration of the polyphonic nature of Fielding's novels brings to light previously unacknowledged complexities in the novels and refutes traditionally held beliefs that Fielding's works contain only a single narrow and clearly defined fictional universe.Made available in DSpace on 2012-09-11T17:08:17Z (GMT). No. of bitstreams: 1
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Joseph Conrad: "The Secret Sharer" and "An Outpost of Progress"
No full textCairney, Christopher T. (Dogus Author)..
Review: Joseph Urban: Unlocking an Art Deco Bedroom
No full textReview of Joseph Urban: Unlocking an Art Deco Bedroom by Amy Miller Dehan. Cincinnati Art Museum in association with D Giles Limited, February 2022. 128 p. ill. ISBN 978-1-911282-56-3 (h/c), $49.95. Reviewed July 2022 by Sara Mautino, Librarian, Oklahoma State University School of Architecture - Cunningham Architecture Library, Oklahoma State University Libraries, [email protected]
Telling realities : the story of Winnie Verloc in Joseph Conrad's The secret agent
No full textThis dissertation will investigate how Conrad's "purely artistic purpose" comes under ethical review as reader, character and author renegotiate the terms of the story's telling - specifically (to pursue the novel's haunting reference to Othello) with regard to "the pity of it"
Zinc has insulin-mimetic properties which enhance spinal fusion in a rat model
No full textBACKGROUND CONTEXT: Previous studies have found that insulin or insulin-like growth factor treatment can stimulate fracture healing in diabetic and normal animal models, and increase fusion rates in a rat spinal fusion model. Insulin-mimetic agents, such as zinc, have demonstrated antidiabetic effects in animal and human studies, and these agents that mimic the effects of insulin could produce the same beneficial effects on bone regeneration and spinal fusion.
PURPOSE: The purpose of this study was to analyze the effects of locally applied zinc on spinal fusion in a rat model.
STUDY DESIGN/SETTING: Institutional Animal Care and Use Committee-approved animal study using Sprague-Dawley rats was used as the study design.
METHODS: Thirty Sprague-Dawley rats (450-500 g) underwent L4-L5 posterolateral lumbar fusion (PLF). After decortication and application of approximately 0.3 g of autograft per side, one of three pellets were added to each site: high-dose zinc calcium sulfate (ZnCaSO4), low-dose ZnCaSO4 (half of the high dose), or a control palmitic acid pellet (no Zn dose). Systemic blood glucose levels were measured 24 hours postoperatively. Rats were sacrificed after 8 weeks and the PLFs analyzed qualitatively by manual palpation and radiograph review, and quantitatively by micro-computed tomography (CT) analysis of bone volume and trabecular thickness. Statistical analyses with p-values set at .05 were accomplished with analysis of variance, followed by posthoc tests for quantitative data, or Mann-Whitney rank tests for qualitative assessments.
RESULTS: Compared with controls, the low-dose zinc group demonstrated a significantly higher manual palpation grade (p=.011), radiographic score (p=.045), and bone formation on micro-CT (172.9 mm3 vs. 126.7 mm3 for controls) (p3 vs. 126.7 mm3) (p<.01) versus controls, and was trending toward higher manual palpation scores (p=.058).
CONCLUSIONS: This study demonstrates the potential benefit of a locally applied insulin-mimetic agent, such as zinc, in a rat lumbar fusion model. Previous studies have demonstrated the benefits of local insulin application in the same model, and it appears that zinc has similar effects.Peer reviewe
Compositions for Trumpet by Joseph Turrin: A Historical and Musical Overview
No full textabstract: Joseph Turrin’s compositions for trumpet are frequently performed, and have
become a large part of the trumpet repertoire. His trumpet works are played at events
such as International Trumpet Guild conferences, have been featured with many well-known
orchestras and bands, and are standard recital works. Many of Turrin’s trumpet
works have been performed and recorded by well-established musicians, which include
Philip Smith, Joseph Alessi, David Hickman, Robert Sullivan, Brian Shaw, Thomas
Hooten, Terry Everson, Wynton Marsalis, and Alison Balsom.
This study examines in detail each of Joseph Turrin’s twenty-four published
works for trumpet. Turrin’s pieces include Elegy, Caprice, Concerto for Trumpet, Intrada,
Two Portraits, Someone to Watch Over Me, Chronicles, Two Gershwin Portraits,
Fandango, and Three Episodes, and include pieces written for Philip Smith, Joseph
Alessi, Wynton Marsalis, Harold Lieberman, Lew Soloff, Brian Shaw, Robert Sullivan,
and Thomas Hooten. A complete history of each composition and arrangement, and
information relating to their premieres are presented. Technical elements from the music
are discussed, such as range, articulation, melodic contour, endurance, and difficult
fingerings. Biographical information such as youth, education, and career about Turrin
are incorporated, along with a discussion of his compositional characteristics and
influences. In addition, a list of each work with an assigned difficulty grade, as well as a
current discography, is included.Dissertation/ThesisDoctoral Dissertation Music 201
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