How should we assess the mechanical properties of lower-limb prosthesis technology used in elite sport?: An initial investigation

Despite recent controversy, it is not yet formally recognised how lower-limb prosthesis should be assessed for their performance. To assist in this process, experiments are undertaken to investigate the linearity, stiffness and assessment of feet based energy return prosthesis technology typically used for elite level high speed running. Through initial investigations, it is concluded that static load testing would not be recommended to specify or regulate energy return prostheses for athletes with a lower-limb amputation. Furthermore, an assessment of energy return technology when loaded under dynamic conditions demonstrates changes in mechanical stiffness due to bending and effective blade length variation during motion. Such radical changes of boundary conditions due to loading suggest that any assessment of lower-limb prosthesis technology in the future should use methods that do not assume linear mechanical stiffness. The research into such effects warrants further investigation in the future

Studies on molecular Oxo and Imido complexes of the group 6 metals and supported chromium oxide polymerisation catalysts

This thesis describes studies directed towards the preparation of bis (imido) complexes of the Group 6 metals containing olefin, phosphine, acetylene, and alkyl ligands with particular emphasis on their relationship with Group 4 bent metallocenes. The polymerisation mechanism of the Phillips catalyst (CrO(_3)/SiO(_2)) is examined using XPS (X-Ray Photoelectron Spectroscopy) and in situ mass spectroscopy. Chapter 1 highlights properties of some of the important ligand classes that are used throughout the remainder of this thesis. Chapter 2 describes a high yield one-pot synthesis of molybdenum bis (imido) complexes of the type Mo(NR')(NR")Cl(_2).DME. In addition a number of attempts to extend this strategy to other metals are described, including a novel synthesis of the chromium complex [Cr(_2)Cl(_9)] [NHEt(_3)](_3). Chapter 3 describes the synthesis, characterisation, and reactivity of the bis (imido) bis (phosphine) complexes Mo(NAr)(_2)(PMe(_3))(_2) and [Mo(N(^t)Bu)(µ-N(^t)Bu)(PMe(_3))](_2). Further studies on bis (imido) olefin complexes of the type Mo(NAr)(_2)(PMe(_3))2(η(^2)-C(_2)H (_2)) and Mo(N(^t)Bu)(_2)(PMe(_3))(η(^2)-C(_2)H(_4)) was undertaken and concentrated on their structural relationship to Group 4 metallocene species. Chapter 4 describes the preparation, structure, and reactivity of some bis (imido) acetylene complexes Mo(NR)(_2)(PMe(_3)) (PhC=CR’) (R= Ar, (^t)Bu; R'= Ph, H). Preparation of bis (imido) alkyls was undertaken in attempts to generate benzyne and alkylidene derivatives. Chapter 5 studies the Phillips polymerisation catalyst using XPS and mass spectroscopy. Model systems were used to probe reactive surface species their use reveals a number of features that are difficult to observe with the actual catalyst. Aspects of molecular chemistry have been examined which are believed to relate directly to the heterogeneous system allowing a possible polymerisation mechanism to be postulated. Chapter 6 gives experimental details for Chapters 2-5. Philip William Dyer (November 1993

Investigating the Relationship Between High School Technology Education and Test Scores for Algebra 1 and Geometry

The standards-based reform movement in education that began in the 1980s has evolved. In the 1990s, the focus was on producing subject-area content standards and modifying instruction. Today, the focus has shifted to assessment, and for technology education, demonstrating the impact on children and the efficacy of the discipline within general education. The purpose of this study was to compare the Standards of Learning (SOL) End-of-Course mathematics performance of high school students who completed courses in illustration and design technology to students who have not completed an illustration and design technology course. The following research questions were developed for this study: (1) Did students who had taken illustration and design technology courses perform better on their mathematics SOL tests than students who did not take illustration and design technology courses?; and (2) Did students who had not passed the mathematics SOL tests do better on their retake examinations after they took an illustration and design course? The population for this study was composed of 996 students in the 10th, 11th, and 12th grades who had taken the Algebra I and/or the Geometry end-of-course SOL examinations during the 2002-2003 school year. A t test was used to validate the first research question, and a Chi-square test was used to validate the second research question. The means and standard deviations were used to show the quality of testing between the Non-Illustration and Design Technology group and the Illustration and Design Technology group. The Illustration and Design Technology group had a 78% passing rate, while the Non-Illustration and Design Technology group had a passing rate of 73%. The Illustration and Design Technology group scored 14 points higher on average than the Non-Illustration and Design Technology group. The researchers recommend that this study be replicated with a larger sample in order to include more students. Technology educators must insure that planning at all levels implements contextual practice and includes meaningful assessment. The profession\u27s long tradition of contextual practice is meaningless if it cannot delineate the impact it is having on students

Einstein on the beach: A study in temporality

This is an Author's Accepted Manuscript of an article published in Performance Research, 17(5), 34 - 40, 2012, copyright @ Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/13528165.2012.728438.In this paper I seek to examine and analyse the sense of duration induced by performances of Einstein on the Beach, and the entailed sense of time which its internal structure creates. I initially sketch out the stylistic context and artistic intentions of this work's creators, Glass and Wilson, and I briefly describe the process of its creation. Certain features of this process indicate how the work may be interpreted. Having cited the creators' thoughts on structure and temporality, I address directly aspects of Einstein's temporal effects, comparing it to works of similar lengths. I give the briefest synopsis of its staging and motifs. I then outline three kinds of devices which seem to inform our temporal sense of this work as spectators. In the final section I invoke two ideas which serve as analogies to help characterise this work's overall effect on us: Heidegger's notion of the ‘hermeneutic circle’ and, more speculatively, Nietzsche's ‘theory’ of Eternal Recurrence

The dynamic elastic response to impulse synchronisation of composite prosthetic energy storing and returning feet

In this research, it is proven that perfect synchronisation between the input impulse (human effort) and the ground reaction impulse/impact can result in a phenomenon called the dynamic elastic response to impulse synchronisation with favourable consequences to the behaviour of the energy storing and returning foot. An energy storing and returning composite prosthetic foot was first used in elite competition at the 1988 Paralympic Games. Since its introduction, the prostheses have proven to be a source of controversy. In 2008, it was concluded that the athletes who use such technology when running are in advantageous position when compared to able-bodied athletes. However, these findings have since been disputed. There still remain unanswered questions regarding the level of contribution of energy storing and returning feet in the performance of amputee athletes. A series of investigations have previously been conducted to study the dynamic characteristics of a number of energy storing and returning composite prosthetic feet. It was found that if a sinusoidal input impulse, with a frequency close to one of the energy storing and returning feet’s natural frequencies, could be applied, it can make the energy storing and returning foot susceptible to resonance, which, in the case of bending mode, if sustained can lead to a gain in height or increased velocity

Recruiting participants with peripheral arterial disease for clinical trials: Experience from the Study to Improve Leg Circulation (SILC)

ObjectiveTo describe the success of diverse recruitment methods in a randomized controlled clinical trial of exercise in persons with peripheral arterial disease (PAD).MethodsAn analysis of recruitment sources conducted for the 746 men and women completing a baseline visit for the study to improve leg circulation (SILC), a randomized controlled trial of exercise for patients with PAD. For each recruitment source, we determined the number of randomized participants, the rate of randomization among those completing a baseline visit, and cost per randomized participant.ResultsOf the 746 individuals who completed a baseline visit, 156 were eligible and randomized. The most frequent sources of randomized participants were newspaper advertising (n = 67), mailed recruitment letters to patients with PAD identified at the study medical center (n = 25), and radio advertising (n = 18). Costs per randomized participant were $2750 for television advertising,$2167 for Life Line Screening, $2369 for newspaper advertising,$3931 for mailed postcards to older community dwelling men and women, and $5691 for radio advertising. Among those completing a baseline visit, randomization rates ranged from 10% for those identified from radio advertising to 32% for those identified from the Chicago Veterans Administration and 33% for those identified from posted flyers.ConclusionMost participants in a randomized controlled trial of exercise were recruited from newspaper advertising and mailed recruitment letters to patients with known PAD. The highest randomization rates after a baseline visit occurred among participants identified from posted flyers and mailed recruitment letters to PAD patients

The Early Stages of Pedaliodes poesia (Hewitson, 1862) in Eastern Ecuador (Lepidoptera: Satyrinae: Pronophilina)

We describe the immature stages Pedaliodes poesia Hewitson, 1862 from northeastern Ecuador. Chusquea scandens (Poaceae, Bambusoidea) is the larval food plant. Eggs are laid singly or in pairs on the bottom side of host plant leaves. The duration of the egg, larval, and pupal stages, combined, is 99–107 days

Corridor-based functional performance measures correlate better with physical activity during daily life than treadmill measures in persons with peripheral arterial disease

ObjectiveTo compare associations of physical activity during daily life with treadmill walking performance and corridor-based functional performance measures in persons with lower extremity peripheral arterial disease (PAD).Study DesignCross-sectional.SubjectsOne hundred fifty-six men and women with PAD who completed baseline measurements and were randomized into the study to improve leg circulation (SILC) exercise clinical trial.Main Outcome MeasuresParticipants completed a Gardner-Skinner treadmill protocol. Corridor-based functional performance measures were the 6-minute walk, walking velocity over four meters at usual and fastest pace, and the short physical performance battery (SPPB) (0-12 scale, 12 = best). Physical activity during daily life was measured continuously over 7 days with a Caltrac (Muscle Dynamics Fitness Network, Inc, Torrence, Calif) accelerometer.ResultsAdjusting for age, gender, and race, higher levels of physical activity during daily life were associated with greater distance achieved in the 6-minute walk (P trend = .001), faster fast-paced four-meter walking velocity (P trend < .001), faster usual-paced four-meter walking speed (P trend = .027) and a higher SPPB (P trend = .005). The association of physical activity level with maximum treadmill walking distance did not reach statistical significance (P trend = .083). There were no associations of physical activity with treadmill distance to onset of leg symptoms (P trend = .795).ConclusionFunctional performance measures are more strongly associated with physical activity levels during daily life than treadmill walking measures