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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

Longitudinal kinematic study of master's aged distance runners

Walters, William A. January 1994 (has links)
The purpose of this study was to compare selected kinematic characteristics of distance runners over a twenty year period. The subjects in the investigation were 14 long distance runners who at the time of the first observation were considered highly trained (running more than 50 miles per week). The second observation occurred approximately 20-23 years after the first observation. At this time the average weekly mileage per runner had decreased to 37 miles per week. The first observation's data were collected with a Locam camera at film speeds ranging from 60 to 120 frames/second. The film data were digitized at the same time as the second observation's data. The second observation's data were collected with a Panasonic 5000 shutter video camera. The Peak Performance Motion Measurement System video interface allowed a 60 frame/second field rate. Ten subjects ran at a speed of 3.4 m/s; two subjects at the speeds of 3.1 and 3.6 m/s; and one subject at each of the following speeds: 4.0, 4.5, and 4.9 m/s. Statistical analyses (ANOVA) of the stride length, stride frequency, support and non-support time, and joint angular displacement indicated no significant difference (p > .05) between the first observation and the second observation. The results of this study indicated that the kinematics of continually active long distance runners do not change with an increase in age. / School of Physical Education
312

Bivariate meta-analysis of sensitivity and specificity of radiographers' plain radiograph reporting in clinical practice

Brealey, S., Hewitt, C., Scally, Andy J., Hahn, S., Godfrey, C., Thomas, N. January 2009 (has links)
Studies of diagnostic accuracy often report paired tests for sensitivity and specificity that can be pooled separately to produce summary estimates in a meta-analysis. This was done recently for a systematic review of radiographers' reporting accuracy of plain radiographs. The problem with pooling sensitivities and specificities separately is that it does not acknowledge any possible (negative) correlation between these two measures. A possible cause of this negative correlation is that different thresholds are used in studies to define abnormal and normal radiographs because of implicit variations in thresholds that occur when radiographers' report plain radiographs. A method that allows for the correlation that can exist between pairs of sensitivity and specificity within a study using a random effects approach is the bivariate model. When estimates of accuracy as a fixed-effects model were pooled separately, radiographers' reported plain radiographs in clinical practice at 93% (95% confidence interval (CI) 92-93%) sensitivity and 98% (95% CI 98-98%) specificity. The bivariate model produced the same summary estimates of sensitivity and specificity but with wider confidence intervals (93% (95% CI 91-95%) and 98% (95% CI 96-98%), respectively) that take into account the heterogeneity beyond chance between studies. This method also allowed us to calculate a 95% confidence ellipse around the mean values of sensitivity and specificity and a 95% prediction ellipse for individual values of sensitivity and specificity. The bivariate model is an improvement on pooling sensitivity and specificity separately when there is a threshold effect, and it is the preferred method of choice.
313

La cooperación internacional medioambiental y su incidencia en el ordenamiento jurídico chileno. Especial referencia al impacto del Tratado de Libre Comercio Chile/Estados Unidos y al acuerdo de asociación Chile/Unión Europea

Guevara Cortés, Daniel 04 February 2015 (has links)
Aquest treball planteja com a hipòtesi que, davant el canvi jurídic que comporta per a un país de desenvolupament mitjà com Xile la incorporació al seu ordenament intern dels tractats internacionals multilaterals mediambientals i els tractats bilaterals amb abast en matèria mediambiental, el paper de la cooperació internacional resulta fonamental per complir els nous elevats estàndards mediambientals que requereix el nostre planeta i Xile en particular. Per verificar aquesta Tesi, abordem especialment la cooperació internacional continguda en el Tractat de Lliure Comerç de Xile amb els Estats Units d'Amèrica, i l'Acord d'Associació amb la Unió Europea. Tots dos Tractats contemplen accions de cooperació que han permès avançar la legislació xilena en aspectes tan rellevants com la Llei de tancament de feines mineres, o la reforma a la Llei ambiental, incorporant l'avaluació ambiental estratègica, amb experiències en la regió minera d' Antofagasta. / El presente trabajo plantea como hipótesis que, ante el cambio jurídico que conlleva para un país de desarrollo medio como Chile la incorporación a su ordenamiento interno de los Tratados Internacionales Multilaterales Medioambientales y los Tratados Bilaterales con alcance en materia medioambiental, el rol de la cooperación internacional resulta fundamental para cumplir los nuevos elevados estándares medioambientales que requiere nuestro planeta y Chile en particular. Para verificar esta Tesis, abordamos especialmente la cooperación internacional contenida en el Tratado de Libre Comercio de Chile con Estados Unidos de América, y el Acuerdo de Asociación con la Unión Europea. Ambos Tratados contemplan acciones de cooperación que han permitido avanzar la legislación chilena en aspectos tan relevantes como la Ley de cierre de faenas mineras, o la reforma a la Ley Ambiental, incorporando la evaluación ambiental estratégica, con experiencias en la región minera de Antofagasta. / This study hypothesized that, given the legal change that entails for a country of average development as Chile incorporation into national law of International Treaties and Bilateral Multilateral Environmental Agreements with scope on the environment, the role of international cooperation is essential to meet the new high environmental standards required by our planet and Chile in particular. To verify this thesis, we address especially international cooperation contained in the FTA between Chile and USA, and Association Agreement with the European Union. Both Agreements provide for cooperative actions that have allowed Chilean law in aspects such as the Law of mine closure or amendments to the Environmental Law, incorporating strategic environmental assessment, and experience in the mining region of Antofagasta.
314

An assessment of the use of human samples in ancient DNA studies

Gilbert, Marcus Thomas Pius January 2003 (has links)
This thesis addresses gaps that exist in the theory and knowledge of ancient DNA (aDNA). Much of the underlying basis of the field has been neglected in the excitement that followed the first aDNA studies. Therefore the results of many studies have been based on untested assumptions about the nature of post mortem DNA damage, sample preservation, contamination, and the efficacy of sample decontamination techniques. The validity of such results is questionable if the assumptions prove false. Hydrolytic post mortem DNA damage may modify recovered aDNA sequences. This thesis reports new insights into the biochemical basis of, predisposition of certain sequences and nucleotide positions towards, and subsequent effects of, such damage. Parallels of post mortem damage with in vivo mutation also enable insights into DNA sequence evolution. The long-term survival of DNA, and contamination of samples with exogenous DNA are two related problems characteristic to aDNA. The survival of endogenous DNA within bone, teeth and hair samples, the susceptibility of such samples to contamination, and the efficacy of decontamination techniques used to remedy such problems are investigated. The results highlight serious flaws in using bone and teeth as a DNA source. In contrast, the results demonstrate that hair may present a valuable DNA source for future studies. Numerous studies have reported the retrieval of ancient pathogen DNA from human samples. Analyses of the DNA content within teeth extracted from putative victims of the 2<sup>nd</sup> plague argue that such studies are at great risk from DNA degradation, and contamination arising due to environmental microorganisms. An extrapolation of these results using basic physical and chemical theory is used to evaluate the potential survival of aDNA in ancient Egyptian remains. This suggests that positive results from such samples are unlikely.
315

Alkoholio vartojimo aspektai 20-mečių tarpe / Aspects of alcohol consumption among 20-year-old humans

Čmukienė, Valda 18 June 2014 (has links)
Darbo tikslas – išanalizuoti dvidešimtmečių alkoholio vartojimo aspektus. Dvidešimtmečiai vyrai dažniausiai vartoja alų (82,9 proc.) ir degtinę (77,1 proc.), moterys dažniausiai vartoja vyną (73,7 proc.), alkoholinius kokteilius (65,8 proc.) ir šampaną (64,6 proc.). Kartu su draugais alkoholinius gėrimus vartoja 94,3 proc. vyrų, 87,1 proc. moterų. Noras atsipalaiduoti alkoholį vartoti skatina 74,3 proc. vyrų ir 73,7 proc. moterų. Dažniausiai vyrai alkoholį vartoja kartą per savaitę (42,9 proc.), bendraujant su draugais (48,6 proc.), bei dažniau išleidžia daugiau pinigų alkoholiui(22,9 proc.). Moterys dažniausiai alkoholį vartoja kartą per mėnesį (43,8 proc.), švenčių metu (65,4 proc.) ir išleidžia mažiau pinigų alkoholiui (83,3 proc.). Dažniausiai vyrai (40 proc.) ir moterys (39,2 proc.) teigia, kad pagrindinė problema susijusi su alkoholio vartojimu yra sugadinti daiktai ar drabužiai. Taip pat 32,5 proc. moterų nurodo sveikatos pablogėjimą. Vieniši respondentai dažniausiai alkoholį vartoja namuose (72,8 proc.), su draugais (91,5 proc.), kurie labiausiai ir skatina juos vartoti alkoholį (24,1 proc.). Vieniši respondentai labiau įsitikinę (42,9 proc.), kad jiems reikėtų mažiau vartoti alkoholinių gėrimų. 13,4 proc. vienišų respondentų jaučia gėdą dėl alkoholinių gėrimų vartojimo įpročių. 31,3 proc. vienišų respondentų alkoholį vartoja dažniau – kartą per savaitę. Su partneriais gyvenantys respondentai dažniau alkoholį vartoja švenčių metu (67 proc.), jie labiau įsitikinę (83... [toliau žr. visą tekstą] / The aim of this study was to analyze the aspects of alcohol consumption among 20-yearold humans. The men in their twenties usually consumes beer (82.9 %) and vodka (77.1 %), while women tend to consume wine (73.7 %), alcoholic cocktails (65.8 %) and champagne (64.6 %). Together with friends the alcohol consumes 94.3 % of men and 87.1 % of women. The wish to relax promotes the use of alcohol in 74.3 % of men and 73.7 % of women. The men consume the alcohol mostly once a week (42.9 %) while communicating with friends (48.6 %), and often spend more money on alcohol (22.9 %) than women. Women usually consume alcohol once a month (43.8 %), on holidays (65.4 %) and spend less money on alcohol (83.3 %) than man. The large part of the men (40 %) and women (39.2 %) argue that the main reason associated with alcohol consumption are damaged items or clothing. Aggravation of health conditions may become the reason for alcohol consumtion in 32.5 % of women. Single respondents most frequently consumed the alcohol at home (72.8 %), with friends (91.5 %), who causes the main motivation for alcohol consumption (24.1 %). The large part of single respondents (42.9 %) are confident that they should reduce the amount of alcohol. 13.4 % of single respondents feel shame for alcohol consumption habits. 31.3 % of single respondents have the alcohol more frequently (once a week). Respondents living with partners have more alcohol during the holidays (67 %) and they are more confident (83 %) that they... [to full text]
316

Anticipatory lower limb muscle activity during a turning task

Ngan-Hing, Lisa Unknown Date (has links)
Two experiments were undertaken. The objective of Experiment One was to identify the lower limb muscles that were most frequently active during the early period of a step turning task for further testing in Experiment Two. In Experiment Two participants undertook multiple trials of a step-turning task, 30 and 60° to the left and right of midline, at a self-selected pace in response to a visual cue. There were five objectives to Experiment Two. Firstly, to identify the predominant order in the onset of foot movement so that anticipatory muscle activity could be defined for this task. Secondly, to identify whether there is a consistent temporal order in movement onset between the head and the feet. Thirdly, to identify whether and how consistently anticipatory lower limb muscle activity is present bilaterally. Fourthly, to assess whether there is a consistent sequence in the onset of anticipatory muscle activity among muscles active in at least 80% of trials. The final objective was to identity whether there was a consistent temporal relationship in the onset of the anticipatory muscle activity present in at least 80% of trials, with the onset of head and foot movement. Study Design: A repeated measures design was used. Background: Anticipatory lower limb muscle activity in gait initiation and forward stepping studies has been reported to be consistently present, and associated with initial and important balance responses. Falls during turning are associated with a high incidence of hip fractures in the elderly population. The presence of anticipatory lower limb muscle activity turning has not been previously reported. Participants: There were five participants in Experiment One, and ten in Experiment Two. All were between 18 and 40 years of age and did not have neurological or musculoskeletal disorders, or severe visual loss. Results: In Experiment One, four muscles were consistently active bilaterally, during the early period of step-turning and were: tibialis anterior, gastrocnemius, biceps femoris and gluteus medius. In Experiment Two the ipsilateral foot moved before the contralateral foot in 68% of trials towards the left, and 79% of trials towards the right. The onset of head movement consistently occurred before the onset of foot movement during turns towards both directions. The percentage of trials in which the four muscles were active in an anticipatory manner was low bilaterally, ranging from 12 to 38% of trials. Objectives that involved the further analysis of muscles active in at least 80% of trials were unable to be completed. Conclusions: During a step-turning task young healthy adults predominantly move their ipsilateral foot before their contralateral foot. The consistent onset of head movement prior to that of the feet, indirectly suggests that the visual system might influence the temporal onset of the feet. The low levels of anticipatory muscle activity during step-turning suggest that the lower limbs are not involved with the initial balance responses for this task thus making it inherently different to gait initiation and forward stepping.
317

Variations in gait patterns and recovery of function following arthroscopic partial meniscectomy

Sturnieks, Daina Louise January 2004 (has links)
[Truncated abstract] Previous research has found that full recovery of knee function following arthroscopic partial meniscectomy (APM) is often not achieved, and in the long-term, over 50% of these patients will develop knee osteoarthritis (OA). Mechanical factors are believed to contribute largely to the development of knee OA. High frequency loading has been shown to lead to degenerative joint changes in animal models. In human gait, the knee adduction moment during stance phase, which tends to load the medial articular surface of the tibiofemoral joint, has been associated with the presence, severity and progression of knee OA. Quadriceps weakness, which is common in people with knee pathology, has been associated with abnormal sagittal plane knee moments during gait, yet no studies have investigated the effect of knee strength on frontal plane kinetics. This work aimed to investigate gait mechanics in a post-APM population, determine the influence of neuromuscular factors on gait, and assess recovery of function over 12 months while examining factors associated with recovery. One hundred and six APM subjects were examined between one and three months postsurgery. Data were compared to an age-matched control group of 49 healthy adults. Subjects were aged 20 to 50 years and had been screened for: clinical and radiographic evidence of knee OA; previous or current knee joint disease or injury (other than the current meniscus pathology); or any other previous or existing disease or injury that may have an effect on gait, or predispose to joint disease. Three-dimensional gait analysis was performed at a freely-chosen walking velocity, using a 50 Hz VICON three-dimensional motion analysis system, instrumented with two force platforms and 10-channel electromyography system. Subjects also underwent knee strength testing on a Biodex isokinetic dynamometer. Information was collected regarding subject’s physical activity levels, general health and knee function, as well as patient’s surgery specifics and rehabilitation regime.
318

Clinical and biomechanical outcomes following unicondylar knee arthroplasty with Preservation fixed and mobile bearing tibial components

Joss, Brendan Keith January 2007 (has links)
[Truncated abstract] Unicondylar knee arthroplasty (UKA) has re-emerged as a successful treatment option for isolated single compartment tibio-femoral joint osteoarthritis. However despite its increasing use, controversy still remains over fixed or mobile bearing tibial components, as there is a lack to prospective randomised studies reported in the literature. In addition, the theoretical advantages of the mobile bearing for knee kinematics, kinetics and clinical outcome have not been evaluated in vivo. The aim of this research study was to explore the clinical and biomechanical outcomes of the fixed and mobile bearing UKA. . . . When the results for the both studies were combined, utilising the Preservation and MG fixed bearing prostheses, there was a significant relationship between knee adduction moment, and a poor prognosis predicted from RSA. Those patients with translation or rotation of the tibial component in any direction above 1mm and 1.5 degrees respectively were considered to have a poor prognosis for long term fixation. Of the 28 patients, the 8 patients considered to have a poor prognosis, had increased knee adduction moments post-surgery (mean difference = 1.66Nm.kg-1, p = 0.007). There was no difference between the groups for knee flexion moment (mean difference 0.16Nm.kg-1, p = 0.844). Pre-surgery gait was unable to predict the post-surgery outcome, due to the significant changes in gait from pre- to post-surgery. Care must taken when implanting the Preservation mobile bearing prosthesis, as long term outcome is questionable. The mobile bearing prosthesis also produced the worst clinical outcome, however the theoretical advantages of the mobile bearing does not affect gait. Gait analysis is a useful tool to identify patient who are overloading their prosthesis, leading to potential early failure. Identification of these gait patterns can allow for early intervention to reduce joint load, and possible extend the longevity of the prosthesis.
319

The acute effect of treadmill running on overground running mechanics in a barefoot condition

Candelaria, Norma G., January 2007 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
320

The contribution of divided attention to tripping while walking

Dell'Oro, Lisa Ann. January 2008 (has links)
Thesis (Ph. D.)--Victoria University (Melbourne, Vic.), 2008. / Includes bibliographical references.

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