971 resultados para Vertical pull-out failure


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Purpose To design and manufacture lenses to correct peripheral refraction along the horizontal meridian and to determine whether these resulted in noticeable improvements in visual performance. Method Subjective refraction of a low myope was determined on the basis of best peripheral detection acuity along the horizontal visual field out to ±30° for both horizontal and vertical gratings. Subjective refraction was compared to objective refractions using a COAS-HD aberrometer. Special lenses were made to correct peripheral refraction, based on designs optimized with and without smoothing across a 3 mm diameter square aperture. Grating detection was retested with these lenses. Contrast thresholds of 1.25’ spots were determined across the field for the conditions of best correction, on-axis correction, and the special lenses. Results The participant had high relative peripheral hyperopia, particularly in the temporal visual field (maximum 2.9 D). There were differences > 0.5D between subjective and objective refractions at a few field angles. On-axis correction reduced peripheral detection acuity and increased peripheral contrast threshold in the peripheral visual field, relative to the best correction, by up to 0.4 and 0.5 log units, respectively. The special lenses restored most of the peripheral vision, although not all at angles to ±10°, and with the lens optimized with aperture-smoothing possibly giving better vision than the lens optimized without aperture-smoothing at some angles. Conclusion It is possible to design and manufacture lenses to give near optimum peripheral visual performance to at least ±30° along one visual field meridian. The benefit of such lenses is likely to be manifest only if a subject has a considerable relative peripheral refraction, for example of the order of 2 D.

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Over the last decade advanced composite materials, like carbon fibre reinforced polymer (CFRP), have increasingly been used in civil engineering infrastructure. The benefits of advanced composites are rapidly becoming evident. This paper focuses on the comparative performance of steel and concrete members retrofitted by carbon fibre reinforced polymers. The objective of this work is a systematic assessment and evaluation of the performance of CFRP for both the concrete and steel members available in the technical literature. Existing empirical and analytical models were studied. Comparison is made with respect to failure mode, bond characteristics, fatigue behaviour, durability, corrosion, load carrying capacity and force transfer. It is concluded that empirical expressions for the concrete-CFRP composite are not readily suited for direct use in the steel-CFRP composite. This paper identifies some of the major issues that need further investigation.

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Background Trials of new technologies to remotely monitor for signs and symptoms of worsening heart failure are continually emerging. The extent to which technological differences impact the effectiveness of non-invasive remote monitoring for heart failure management is unknown. Objective To examine the effect of specific technology used for non-invasive remote monitoring of people with heart failure on all-cause mortality and heart failure-related hospitalisations. Methods A sub-analysis of a large systematic review and meta-analysis was conducted. Studies were stratified according to the specific type of technology used and separate meta-analyses were performed. Four different types of non-invasive remote monitoring technologies were identified including structured telephone calls, videophone, interactive voice response devices and telemonitoring. Results Only structured telephone calls and telemonitoring were effective in reducing the risk of all-cause mortality (RR 0.87; 95% CI=0.75-1.01; p=0.06 and 0.62; 95% CI=0.50-0.77; p<0.0001) and heart failure-related hospitalisations (RR 0.77; 95% CI=0.68-0.87; p<0.001) and 0.75; 95% CI=0.63-0.91; p=0.003). More research data is required for videophone and interactive voice response technologies. Conclusions This sub-analysis identified that only two of the four specific technologies used for non-invasive remote monitoring in heart failure improved outcomes. When results of studies that involved these disparate technologies were combined in previous meta-analyses, significant improvements in outcomes were identified. As such, this study has highlighted implications for future meta-analyses of randomised controlled trials focused on evaluating the effectiveness of remote monitoring in heart failure.

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Structural Dynamics is the study of the response of structures to dynamic or time varying loads. This topic has emerged to be one of importance to all structural engineers due to three important issues with structural engineering in the new millennium. These are: (1) vibration and problems in slender structures that have emerged due to new material technology and aesthetic requirements, (ii) ageing structures such as bridges whoese health needs to be monitored and appropriate retrofitting carried out to prevent failure and (iii) increased vulnerability of structures to random loads such as seismic, impact and blast loads. Knowledge of structural dynamics is necessary to address these issues and their consequences. During the past two decades, research in structural dynamics has generated considerable amount of new information to address these issues. This new knowledge is not readily made available to practicing engineers and very little or none of it enters the classrooms. There is no universal emphasis on including structural dynamics and their recently generated new knowledge into the civil/structural curriculum. This paper argues for the need to include structural dynamics into the syllabus of all civil engineering courses especially those having a first or second major in structural engineering. This will enable our future structural engineers to design and maintain safe and efficient structures.

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Genetic studies are revealing the pathway for RNA-mediated gene silencing. Short RNA molecules are the key, giving sequence specificity for RNA degradation and mediating communication within and between cells; these short RNAs are common to transcriptional and post-transcriptional silencing pathways. The expression of transgenes in plants varies between independent transformants and there are many examples where the transgenic trait is not expressed, or disappears in subsequent generations, despite the presence of the transgene. This loss of a trait, but not of the transgene, has become known as gene silencing and can take two forms, transcriptional or post-transcriptional. As their names imply, transcriptional gene silencing occurs when a transgene is not transcribed, whereas in post-transcriptional gene silencing, the transgene mRNA is produced but degraded before it is translated (reviewed in [1]). Both forms of silencing seem to be the result of inherent mechanisms for protecting plants against mobile or invading DNA — for example, transposable elements or the T-DNA of Agrobacterium — or RNA viruses. Plants are not alone in their capacity for transgene silencing; both forms of silencing occur in flies and fungi, where it is known as RIP or quelling, while nematodes exhibit post-transcriptional silencing, generally referred to as RNA interference (RNAi). A clearer picture of the mechanisms and relationships of the different types of transgene silencing is beginning to emerge from a number of recent studies [2], [3], [4], [5], [6], [7] and [8]. Some of these studies [2], [3], [4] and [5] have enhanced our understanding of the steps within the post-transcriptional silencing pathway, and others [6], [7] and [8] have demonstrated that the two forms of silencing may be mechanistically linked.

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Background Foot ulcers are a common reason for diabetes-related hospitalisation. Foot ulcer simulation training (FUST) programs have increased podiatry participants self-confidence to manage foot ulcers. However, supervisors’ perspectives on their participants attending these simulation programs have not been investigated. This mixed method (quantitative and qualitative) study aimed to investigate home clinical supervisors’ perspectives on any changes to their participants’ competence and practice following FUST. Methods Clinical supervisors of fifteen podiatrists, who participated in a two-day Foot Ulcer Simulation Training (FUST) course, were recruited. Supervisors completed quantitative surveys evaluating their participants’ foot ulcer competence pre-FUST and 6-months post-FUST, via a purposed designed 21-item survey using a five-point Likert scale (1=Very limited, 5=Highly competent). Supervisors also attended a semi-structured qualitative group interview to investigate supervisors’ perspectives on FUST. Results Supervisors surveys returned were pre-FUST (n=10) and post-FUST (n=12). Significant competence improvements were observed at the 6-month survey (mean scores 2.84 cf. 3.72, p < 0.05). Five supervisors attended the group interview. Five sub-themes emerged: i) FUST provided a good foundation for future learning, ii) FUST modelled good clinical behaviour, iii) clinical practice improvement was evident in most participants, iv) clinical improvements were dependent on participant’s willingness to change and existing workplace culture, v) FUST needs to be reinforced back in the home clinic. Conclusion Overall, supervisors of FUST participants indicated that the course improved their participants’ competence and clinical practice. However, the degree of improvement appears dependant on the participants’ home workplace culture and willingness to embrace change.

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Purpose: To assess intrasessional and intersessional repeatability of two commercial partial coherence interferometry instruments for measuring peripheral eye lengths and to investigate the agreement between the two instruments. Methods: Central and peripheral eye lengths were determined with the IOLMaster (Carl-Zeiss Meditec AG, Jena, Germany) and the Lenstar (Haag Streit, Bern, Switzerland) in seven adults. Measurements were performed out to 35° and 30° from fixation for horizontal and vertical visual fields, respectively, in 5° intervals. An external fixation target at optical infinity was used. At least four measurements were taken at each location for each instrument, and measurements were taken at two sessions. Results: The mean intrasessional SDs for the IOLMaster along both the horizontal and vertical visual fields were 0.04 ± 0.04 mm; corresponding results for the Lenstar were 0.02 ± 0.02 mm along both fields. The intersessional SDs for the IOLMaster for the horizontal and vertical visual fields were ±0.11 and ±0.08 mm, respectively; corresponding limits for the Lenstar were ±0.05 and ±0.04 mm. The intrasessional and intersessional variability increased away from fixation. The mean differences between the two instruments were 0.01 ± 0.07 mm and 0.02 ± 0.07 mm in the horizontal and vertical visual fields, but the lengths with the Lenstar became greater than those with the IOLMaster as axial length increased (rate of approximately 0.016 mm/mm). Conclusions: Both the IOLMaster and the Lenstar demonstrated good intrasessional and intersessional repeatability for peripheral eye length measurements, with the Lenstar showing better repeatability. The Lenstar would be expected to give a slightly greater range of eye lengths than the IOLMaster across the visual field.

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For the last decade, one question has haunted me: what helps people to cope with large-scale organisational change in their workplace? This study explores the construct of personal change resilience, and its potential for identifying solutions to the problems of change fatigue and change resistance. The thesis has emerged from the fields of change management, leadership, training, mentoring, evaluation, management and trust within the context of higher education in Australia at the beginning of the twenty-first century. In this thesis I present a theoretical model of the factors to consider in increasing peoples’ personal change resilience as they navigate large-scale organisational change at work, thereby closing a gap in the literature on the construct of change resilience. The model presented is based on both the literature in the realms of business and education, and on the findings of the research. In this thesis, an autoethnographic case study of two Australian university projects is presented as one narrative, resulting in a methodological step forward in the use of multiple research participants’ stories in the development of a single narrative. The findings describe the experiences of workers in higher education and emphasise the importance of considerate management in the achievement of positive experiences of organisational change. This research makes a significant contribution to new knowledge in three ways. First, it closes a gap in the literature in the realm of change management around personal change resilience as a solution to the problem of change fatigue by presenting models of both change failure and personal change resilience. Second, it is methodologically innovative in the use of personae to tell the stories of multiple participants in one coherent tale presented as a work of ethnographic fiction seen through an autoethnographic lens. By doing so, it develops a methodology for giving a voice to those to whom change is done in the workplace. Third, it provides a perspective on organisational change management from the view of the actual workers affected by change, thereby adding to the literature that currently exists, which is based on the views of those with responsibility for leading or managing change rather than those it affects. This thesis is intended as a practical starting point for conversations by actual change managers in higher education, and it is written in such a way as to help them see how theory can be applied in real life, and how empowering and enabling the actual working staff members, and engaging with them in a considerate way before, during and even after the change process, can help to make them resilient enough to cope with the change, rather than leaving them burned out or disengaged and no longer a well-functioning member of the institution. This thesis shows how considerately managed large-scale organisational change can result in positive outcomes for both the organisation and the individuals who work in it.

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The therapeutic value of play can be shown in spontaneous play situations following children’s experiences of traumatic events. Following the events of the Christchurch earthquakes in New Zealand in 2010 and 2011, an investigation was conducted of how children used the earthquake event as a catalyst in pretend play with peers and in discussions with teachers. Supporting children’s well-being is a focus area in New Zealand early childhood education as it is a strand of the national curriculum, Te Whāriki (Ministry of Education [MoE], 1996). In this article, children are observed engaging in pretend play episodes and with Learning Story books to explore personal reflections of the earthquake, prompting the children to make reference to things being ‘broken’ and needing 'fixing.' Analysis shows how the content of the pretend play experiences helped the children to come to terms with their experiences. Affording children time and interactional opportunities to play out and discuss traumatic experiences contributes to the psychological well-being of participants following a traumatic event.

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While video is recognised as an important medium for teaching and learning in the digital age, many video resources are not as effective as they might be, because they do not adequately exploit the strengths of the medium. Presented here are some case studies of video learning resources produced for various courses in a university environment. This ongoing project attempts to identify pedagogic strategies for the use of video; learning situations in which video has the most efficacy; and what production techniques can be employed to make effective video learning resources.

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Significant problems confront our child protection out-of-home care system including: high costs; increasing numbers of children and young people entering and remaining in care longer; high frequency of placement movement; and, negative whole-of-life outcomes for children and young people who have exited care. National policy and research agendas recognise the importance of enhancing the evidence base in out-of-home care to inform the development of policy, programs and practice, and improve longitudinal outcomes of children and young people. The authors discuss the concept of placement trajectory as a framework for research and systems analysis in the out-of-home context. While not without limitations, the concept of placement trajectory is particularly useful in understanding the factors influencing placement movement and stability. Increasing the evidence base in this area can serve to enhance improved outcomes across the lifespan for children and young people in the out-of-home care system.

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Anaemia is a chronic problem in patients with renal insufficiency, especially chronic renal failure (CRF). In patients with CRF, anaemia is primarily due to a deficiency in erythropoietin (EPO), a glycoprotein growth factor that stimulates RBC production. The long-term effects and burden of anaemia for patients with CRF can be physical, emotional and financial. With efficient, systematic management of anaemia, clinicians have the potential to realise not only better clinical outcomes for CRF patients but also significant cost savings for them and the health system. During the last decade, significant advances have been made in clinicians’ understanding of how best to manage anaemia in this vulnerable population. One of the most important efforts to improve clinical practice has been the development of best practice guidelines.

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This catalogue essay was written to accompany Clark Beaumont's 2014 exhibition at Kings Artist Run in Melbourne, 'Feeling It Out'. It contextualises Clark Beaumont's work within a history of women's participation and achievement in modern and contemporary art, and suggests that this body of work may work through issues of anxiety, ambivalence and doubt about the art world.

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Suspension bridges meet the steadily growing demand for lighter and longer bridges in today’s infrastructure systems. These bridges are designed to have long life spans, but with age, their main cables and hangers could suffer from corrosion and fatigue. There is a need for a simple and reliable procedure to detect and locate such damage, so that appropriate retrofitting can be carried out to prevent bridge failure. Damage in a structure causes changes in its properties (mass, damping and stiffness) which in turn will cause changes in its vibration characteristics (natural frequencies, modal damping and mode shapes). Methods based on modal flexibility, which depends on both the natural frequencies and mode shapes, have the potential for damage detection. They have been applied successfully to beam and plate elements, trusses and simple structures in reinforced concrete and steel. However very limited applications for damage detection in suspension bridges have been identified to date. This paper examines the potential of modal flexibility methods for damage detection and localization of a suspension bridge under different damage scenarios in the main cables and hangers using numerical simulation techniques. Validated finite element model (FEM) of a suspension bridge is used to acquire mass normalized mode shape vectors and natural frequencies at intact and damaged states. Damage scenarios will be simulated in the validated FE models by varying stiffness of the damaged structural members. The capability of damage index based on modal flexibility to detect and locate damage is evaluated. Results confirm that modal flexibility based methods have the ability to successfully identify damage in suspension bridge main cables and hangers.