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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.
531

Analysis of Weighted Fraction of Length for Interfacial Gap in Cervical Composite Restorations as a Function of the Number of B-Scans of OCT Volume Scans

Schneider, Hartmut, Meißner, Tobias, Rüger, Claudia, Haak, Rainer 26 April 2023 (has links)
In dental research, the morphometric assessment of restorations is a challenge. This also applies to the assessment of the length of interfacial adhesive defects in composite restorations as a measure of tooth-restoration bond failure. The determined mean fractions of interfacial gap length on enamel and dentin interfaces deviate from the true means (N → ∞), depending on the number (Ni) of object layers assessed. Cervical composite restorations were imaged with spectral domain optical coherence tomography (SD-OCT). The mean fractions of interfacial gap length on enamel and dentin were determined for an increasing number of OCT cross-sectional images (B-scans) per restoration and were graphically displayed as a function of the number of B-scans. As the number of B-scans increased, the calculated object means approached a range of ±2.5%. This analysis is appropriate for displaying the relationship between the determined mean fraction of interfacial gap length at the enamel/dentin-restoration interface and the number of B-scans.
532

Physical Fitness, Obesity, and Decision Making

Landers, Jacob David 01 September 2017 (has links)
No description available.
533

Nondestructive Evaluation of Deteriorated Prestressing Strands Using Magnetic Field Induction

Fernandes, Bertrand 14 June 2010 (has links)
No description available.
534

Building Resilience through Supply Chain Agility: Cross-sectional and Longitudinal Studies

Wen, Zhezhu 15 September 2022 (has links)
No description available.
535

Development and Implementation of an Automated SEM-EDX Routine for Characterizing Respirable Coal Mine Dust

Johann, Victoria Anne 02 November 2016 (has links)
This thesis describes the development and use of a computer-automated microscopy routine for characterization of respirable dust particles from coal mines. Respirable dust in underground coal mining environments has long been known to pose an occupational health hazard for miners. Typically following years of exposure, coal workers' pneumoconiosis (CWP) and silicosis are the most common disease diagnoses. Although dramatic reductions in CWP and silicosis cases were achieved across the US between about 1970-1999 through a combination of regulatory dust exposure limits, improved ventilation and dust abatement practices, a resurgence in disease incidence has been noted more recently – particularly in parts of Appalachia. To shed light on this alarming trend and allow for better understanding of the role of respirable dust in development of disease, more must be learned about the specific characteristics of dust particles and occupational exposures. This work first sought to develop an automated routine for the characterization of respirable dust using scanning electron microscopy with energy dispersive x-ray (SEM-EDX). SEM-EDX is a powerful tool that allows determination of the size, shape, and chemistry of individual particles, but manual operation of the instrument is very time consuming and has the potential to introduce user bias. The automated method developed here provides for much more efficient analysis – with a data capture rate that is typically 25 times faster than that of the manual method on which it was based – and also eliminates bias between users. Moreover, due to its efficiency and broader coverage of a dust sample, it allows for characterization of a larger and more representative number of particles per sample. The routine was verified using respirable dust samples generated from known materials commonly observed in underground coal mines in the central Appalachian region, as well as field samples collected in this region. This effort demonstrated that particles between about 1-9μm were accurately classified with respect to defined chemical categories, and suggested that analysis of 500 particles across a large area of a sample filter generally provides representative results. The automated SEM-EDX routine was then used to characterize a total of 210 respirable dust samples collected in eight Appalachian coal mines. The mines were located in three distinct regions (i.e., northern, mid-central and south-central Appalachia), which differed in terms of primary mining method, coal seam thickness and mining height, and coal and/or rock mineralogy. Results were analyzed to determine whether number distributions of particle size, aspect ratio, and chemistry classification vary between and within distinct mine regions, and by general sampling location categories (i.e., intake, feeder, production, return). Key findings include: 1) Northern Appalachian mines have relatively higher fractions of coal, carbonate, and heavy mineral particles than the two central Appalachian regions, whereas central Appalachian mines have higher fractions of quartz and alumino-silicate particles. 2) Central Appalachian mines tended to have more mine-to-mine variations in size, shape, and chemistry distributions than northern Appalachian mines. 3) With respect to particle size, samples collected in locations in the production and return categories have the highest percentages of very small particles (i.e., 0.94-2.0μm), followed by the feeder and then the intake locations. 4) With respect to particle shape, samples collected in locations in the production and return categories have higher fractions of particles with moderate (i.e., length is 1.5 to 3x width) to relatively high aspect ratios (i.e., length is greater than 3x width) compared to feeder and intake samples. 5) Samples with relatively high fractions of alumino-silicates have higher fractions of particles with moderate aspect ratios than samples with low alumino-silicate fractions. 6) Samples with relatively high fractions of quartz particles have higher fractions of particles with moderate aspect ratios and higher percentages of very small particles than samples with no identified quartz particles. 7) Samples with high fractions of carbonates have higher percentages of particles with relatively low aspect ratios (i.e., length and width are similar) than samples with no identified carbonate particles. / Master of Science
536

The scale of repeat prescribing--time for an update

Petty, Duncan R., Zermansky, A.G., Alldred, David P. 2014 January 1929 (has links)
Yes / The NHS spends billions of pounds annually on repeat prescriptions in primary care, but data on their extent and use is out of date. Understanding the scale of repeat prescribing and for whom it is prescribed is important for the NHS to plan services and develop policies to improve patient care. Anonymous data on prescription numbers and practice population demographics was obtained from GP computer systems in a large urban area.Searches were conducted in November 2011 to identify the numbers of repeat items listed on individuals' repeat lists by sex and age.The proportion of all prescription items issued as repeats was identified by conducting searches on items issued as repeat and acute prescriptions. In the year of study 4,453,225 items were issued of which 3,444,769 (77%) were repeats (mean 13 items per patient/annum) and 1,008,456 (23%) acute prescriptions (mean 3.9 items per patient per annum). The mean number of repeat Items per patient was 1.87 (range 0.45 ages 0-9 years; 7.1 ages 80-89 years). At least one repeat medicine was prescribed to 43% of the population (range 20% for ages 0-9; over 75% for ages 60+). A significant proportion of the population receive repeat prescriptions and the proportion increases with age. Whilst the proportion of repeat items to acute items has remained unchanged over the last two decades the number of repeat prescriptions items issued has doubled (from 5.8 to 13.3 items/patient/annum). This has implications for general practice workload, patient convenience, NHS costs and risk.
537

En stillbild av paraprofessionella : En explorativ studie om skillnader i elever och lärares uppfattningar om sociala aspekter från två olika skonkontexter / A snapshot of paraprofessionals : An exploratory study on differences in students' and teachers' perceptions of social aspects from two different school contexts

Hallin, Joy January 2024 (has links)
I dagens skolmiljö är det alltmer erkänt att skolor kan variera avsevärt i sin struktur, elevsammansättning och personaluppsättning, vilket kan få betydelse för såväl elever som lärares uppfattningar om miljön i skolan. En yrkeskategori som blivit allt vanligare i skolans värld är paraprofessionella. Avsikten med införandet av denna yrkesgrupp och deras arbetsuppgifter kan variera från skola till skola, däremot kan arbetet i många fall innebära att främja sociala aspekter i skolmiljön samt ett elevsocialt arbete. Eftersom vissa skolor har infört paraprofessionella med dessa uppgifter, medan andra skolor inte har gjort det, har denna studie som syfte att med hjälp av data från TIMSS 2019 analysera och beskriva en ögonblicksbild av två olika skolkontexter. Mer specifikt är syftet att undersöka skillnader mellan skolkontexter med och utan paraprofessionella avseende elevernas och lärarnas uppfattningar om sociala aspekter i skolmiljön. För att utforska och beskriva dessa skillnader har en tvärsnitts- och explorativ design med kvantitativ ansats använts. Resultaten indikerar att det kan finnas skillnader i elevernas uppfattningar om klassrumsklimatet, samt i lärarnas arbetstillfredsställelse gällande tidsmässiga villkor. Dessa fynd betonar vikten av att förstå hur olika skolkontexter påverkar skolmiljön och kan bidra till att informera framtida skolutvecklingsinitiativ. / In today's educational environment, it is increasingly recognized that schools can vary significantly in their structure, student composition, and staffing, which can impact both students' and teachers' perceptions of the school environment. One professional category that has become more common in the school setting is paraprofessionals. The purpose and tasks assigned to this group can vary from school to school, but their work often involves promoting social aspects within the school environment and providing social support to students. Since some schools have implemented paraprofessionals with these roles while others have not, this study aims to analyze and describe a snapshot of two different school contexts using data from TIMSS 2019. Specifically, the aim is to examine differences between school contexts with and without paraprofessionals regarding students' and teachers' perceptions of social aspects in the school environment. To explore and describe these differences, a cross-sectional and exploratory design with a quantitative approach has been used. The results indicate that there may be differences in students' perceptions of classroom climate and in teachers' job satisfaction regarding time-related conditions. These findings underscore the importance of understanding how different school contexts affect the school environment and can contribute to informing future school development initiatives.
538

Can cross sectional imaging contribute to the investigation of unexplained child deaths? A literature review

Beck, Jamie J.W. January 2014 (has links)
Yes / This review examines the factors that can influence an investigation into the unexpected death of a child before considering if using imaging techniques could be of benefit. Method A systematic search strategy was adopted to search databases using keywords, these results were then subjected to inclusion and exclusion criteria to filter and refine the evidence base further. Discussion More research is published on the use of MRI in comparison with other modalities. There is evidence in the case of MRI in particular that its use could be of benefit in identifying and ruling out potential causes of death in children. Conclusion More research is needed on the use of CT but the routine use of MRI in child death investigation could now be considered. Ethical considerations appear to be a barrier to research in this area and discussions as to how such considerations can be overcome is necessary.
539

A multi-country perspective on nurses' tasks below their skill level: Reports from domestically trained nurses and foreign trained nurses from developing countries

Bruyneel, L., Li, B., Aiken, L.H., Lesaffre, E., Van den Heede, K., Sermeus, W., McIntosh, Bryan January 2013 (has links)
No / Several studies have concluded that the use of nurses’ time and energy is often not optimized. Given widespread migration of nurses from developing to developed countries, it is important for human resource planning to know whether nursing education in developing countries is associated with more exaggerated patterns of inefficiency. Objectives First, to describe nurses’ reports on tasks below their skill level. Second, to examine the association between nurses’ migratory status (domestically trained nurse or foreign trained nurse from a developing country) and reports on these tasks. Design The Registered Nurse Forecasting Study used a cross-sectional quantitative research design to gather data from 33,731 nurses (62% response rate) in 486 hospitals in Belgium, England, Finland, Germany, Greece, Ireland, the Netherlands, Norway, Poland, Spain, Sweden and Switzerland. Methods For this analysis, nurse-reported information on migratory status and tasks below their skill level performed during their last shift was used. Random effects models estimated the effect of nurses’ migratory status on reports of these tasks. Results 832 nurses were trained in a developing country (2.5% of total sample). Across countries, a high proportion of both domestically trained and foreign trained nurses from developing countries reported having performed tasks below their skill level during their last shift. After adjusting for nurses’ type of last shift worked, years of experience, and level of education, there remained a pronounced overall effect of being a foreign trained nurse from a developing country and an increase in reports of tasks below skill level performed during the last shift. Conclusion The findings suggest that there remains much room for improvement to optimize the use of nurses’ time and energy. Special attention should be given to raising the professional level of practice of foreign trained nurses from developing countries. Further research is needed to understand the influence of professional practice standards, skill levels of foreign trained nurses from developing countries and values attached to these tasks resulting from previous work experiences in their home countries. This will allow us to better understand the conditions under which foreign trained nurses from developing countries can optimally contribute to professional nursing practice in developed country contexts. / Dr McIntosh is a member of the the RN4CAST Consortium.
540

Psychosocial aspects of coeliac disease: a cross-sectional survey of a UK population.

Ford, S., Howard, R.A., Oyebode, Jan 16 April 2012 (has links)
Yes / Objectives. Coeliac disease (CD) is an autoimmune condition managed by a lifelong therapeutic gluten-free diet. Previous research suggests that the chronicity of CD, the limitations imposed by the gluten-free diet, and the risk of other associated diseases can have a negative impact on health-related quality of life (HRQoL) and psychological well-being. The aim of this study was to explore the illness perceptions and self-efficacy beliefs of adults with CD in the United Kingdom and to report their subjective levels of HRQoL and psychological well-being. Design. The study employed a cross-sectional postal questionnaire design. Method. Participants (n= 288) were adults with CD recruited via Coeliac UK. Measures of well-being, HRQoL, self-efficacy, illness perceptions, and dietary self-management were analysed. Preliminary descriptive and univariate procedures were employed before bivariate tests of association or difference were carried out. Backward stepwise multiple regression analysis was used to investigate the predictive strength of variables on well-being, quality of life, and self-efficacy. Logistic regression was used to look at the influence of variables on adherence. Results. Results indicate that HRQoL and psychological well-being were comparable to those found in previous related studies. Participants with weak beliefs in the serious consequences of CD and poorer emotional reactions to the condition had a greater likelihood of having enhanced HRQoL, improved psychological well-being, and higher self-efficacy. Strong beliefs in personal control and a greater perceived understanding of CD were associated with greater self-efficacy. Conclusions. Perceived self-efficacy and illness perceptions could play a role in informing psychological interventions for individuals with CD.

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