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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.
61

Interpretation of clinical imaging examinations by radiographers : a programme of research

Piper, K. January 2014 (has links)
Background Studies which have investigated the interpretation of plain skeletal examinations by radiographers have demonstrated encouraging findings, however, the studies have not extended beyond this area of practice and radiographers' diagnostic performance for other more complex investigations has not been established. Comparisons of performance between groups of healthcare practitioners to date, has also been limited. Aim This research programme aimed to investigate the interpretation of clinical imaging examinations by radiographers, and other healthcare practitioners, in the provision of initial interpretations and/or definitive reports of plain imaging ( skeletal and chest) and crosssectional ( magnetic resonance imaging [MRI] – lumbar/thoracic spine, knees and internal auditory meati [IAM]) investigations. Methods The eight studies utilised a variety of methodological approaches and included quasiexperimental and observational studies. One quasi-experimental study compared the performance of radiographers, nurses and junior doctors in initial image interpretation and another similar study included a training intervention; both utilised alternate free-response receiver operating characteristic curve (AFROC) methodology. Three of the observational studies investigated the ability of radiographers to provide definitive reports on a wide range of clinical examinations, including chest and MRI investigations, in a controlled environment. One large multi-centre observational study investigated the performance of radiographers, in clinical practice (A/E: skeletal examinations) during the implementation of a radiographic reporting service. The agreement between consultant radiologists' MRI reports of lumbar/thoracic spine, knee and IAM examinations was investigated in another observational study. The final study compared the reports of trained radiographers and consultant radiologists, with those of an index radiologist, when reporting on MRI examinations of the knee and lumbar spine, as part of a prospective pre-implementation agreement study. Results The first AFROC study demonstrated statistically significant improvements after training, for radiographers (A1=0.55 - 0.72) and nurses (A1=0.65 - 0.63), although the radiographers maintained a better overall performance post training (p=0.004) in providing an initial image interpretation of trauma radiographs of the appendicular skeleton. Radiographers also achieved statistically higher (p<0.01) AUC values (A1=0.75) than nurses (A1=0.58) and junior doctors (A1=0.54) in the second AFROC study. Three studies, which examined 11155 reports, were conducted under controlled conditions in an academic setting and provided evidence of radiographers’ high levels of accuracy in reporting of skeletal A/E (93.9%); skeletal non A/E (92.5%); chest (89.0%); MRI lumbar/thoracic spine (87.2%), knees (86.3%) and IAM (98.4%) examinations. In the multi-centre clinical study, the mean accuracy, sensitivity and specificity rates of the radiographers reports (n=7179) of plain examinations of the skeletal system in the trauma setting was found to be 99%, 98% and 99%, respectively. The considerable range of values for agreement, between consultant radiologists reports of MRI examinations of the thoracic/lumbar spine (k=0 – 0.8), knee (k=0.3 – 0.8) and IAM (k=1.0) was similar to other studies and resulted in a reasonable estimation of the performance, in the UK, of an average non specialist consultant radiologist in MRI reporting. In the final study, radiographers reported in clinical practice conditions, on a prospective random sample of knee and lumbar spine MRI examinations, to a level of agreement comparable with non-musculoskeletal consultant radiologists (Mean difference in observer agreement <1%, p=0.86). Less than 10% of observers' reports (radiographers and consultant radiologists) were found to be sufficiently discordant to be clinically important. Conclusion The outcomes of this research programme demonstrate that radiographers can provide initial interpretations of radiographic examinations of the appendicular skeleton, in the trauma setting, to a higher level of accuracy than A/E practitioners. The findings also provide evidence that selected radiographers with appropriate education and training can provide definitive reports on plain clinical examinations (A/E and non A/E referral sources) of the skeletal system and the chest; and MRI examinations of the knee, lumbar/thoracic spine and IAM to a level of performance comparable to the average non specialist consultant radiologist. Wider implementation of radiographer reporting is therefore indicated and future multi-centre research, including economic evaluations, to further inform practice at a national level, is recommended.
62

Predictors of Breast Self-Examination Among Mexican American Women: A Path Analytic Model

González, Judith T. January 1990 (has links)
This paper is a test of several hypothesized predictors of frequency of breast self-examination among low-income Mexican American women. Current research points to several factors as important predictors of preventive care. Among these are self-efficacy – one’s perceived capacity to perform a given action – and social support from significant others. For Mexican Americans, environmental barriers to health care are important factors. While findings are inconclusive regarding the role of language proficiency as a predictor of preventive care, the model includes this as a hypothesized predictor of frequency of breast self-examination. The findings show a strong relationship between self-efficacy and frequency of breast self-examination. Barriers to health care have a weaker direct effect upon breast self-examination. The effects of English-language proficiency are indirect and mediated by self-efficacy.
63

MICROPROCESSOR BASED SYSTEM FOR THE ULTRASONIC MEASUREMENT OF URINARY BLADDER VOLUME.

Scott, Carl Alexander. January 1984 (has links)
No description available.
64

Assessing the effect of OFSTED inspections on GCSE school performance data from 1992 to 1997

Shaw, Iain Joseph January 2000 (has links)
No description available.
65

Anatomical, pathological and clinical study of donkey teeth

du Toit, Nicole January 2009 (has links)
Eighty normal cheek teeth and 26 normal incisors extracted from 14 donkeys (median age 19 years) at post mortem were anatomically examined including grossly and by computerised axial tomography (CAT) imaging. Decalcified histology was performed on 54 sections from 18 teeth (8 donkeys), undeclacified histology on 16 sections from 7 donkeys and scanning electron microscopy on 10 sections from 10 teeth (3 donkeys). The dental formulae and tooth number was found to be the same as in horses with a higher prevalence (17 %) of canine teeth in female donkeys. A decrease in tooth length, pulp horn length and pulp horn width with age was illustrated, as was an increase in occlusal secondary dentine depth with age, although not all these age changes were statistically significant. Normal histological and ultrastructural features of donkey teeth were identified and found to be similar to equine findings. Enamel was found to be thicker buccally in both maxillary and mandibular cheek teeth. Quantitative measurements of transverse dentine thickness around pulp cavities, dentinal tubule diameters and densities, and enamel prism diameters were made. Left lower incisors (301) were extracted from 7 donkeys and 6 horses for micro-hardness determination of enamel, primary and secondary dentine using a Knoop Hardness indenter. No significant difference between donkey and horse incisor microhardness was demonstrated. Examination of 19 donkey skulls at post mortem examination showed donkeys to have a higher degree of anisognathia (27%) compared to horses (23%). Post mortem dental examination of 349 donkeys (median age 31) demonstrated a high prevalence of dental disease (93%) and in particular cheek teeth diastemata (85%). Furthermore, age was associated with increasing prevalence of dental disease and diastemata. Diastemata were also associated with the presence of other dental disorders and with colic-related death in affected donkeys. Quantitative measurements of 45 diastemata from 16 donkeys showed no difference in the medial and lateral width of diastemata but periodontal pockets were deeper laterally. The definition of valve and open diastemata were confirmed. Pulp exposure, dental caries and periodontal disease were examined in detail (54 skulls) at post mortem. A total of 19 teeth were extracted for further detailed examination as performed in normal anatomy. Clinical dental examinations were performed on 357 donkeys in the U.K. that were selected for age distribution, and the prevalence of dental disease in different age groups was found to increase from 28% in the youngest group (age 0-10 years) to 98% in the oldest group (age > 35 years). An increased prevalence of most dental disorders with age was demonstrated as was an association between dental disease and weight loss, poor body condition score, supplemental feeding and previous episodes of colic. Clinical dental examination of 203 working donkeys in Mexico showed similar types of dental disorders as found in the U.K. study, with dental disease present in 62%, of which 18% required urgent dental treatment. There was a significant association between age groups and dental disease, and age groups and body condition score, but there was no association between dental disease and body condition score. However, body condition score was not associated with supplemental feeding or faecal egg counts either.
66

Liquid phase microextraction of hallucinogenic compounds from human urine samples based on single hollow fibre followed by chromatographic determination

Ncube, Somandla January 2016 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand in fulfilment of the requirements for the degree of Master of Science. University of the Witwatersrand, Johannesburg, March 2016 / A liquid phase microextraction based on single hollow fibre followed by liquid chromatographic determination was developed for the extraction and quantification of the hallucinogenic muscimol and its two precursors, tryptophan and tryptamine from urine samples. A multivariate design of experiment was used in which a half fractional factorial approach was applied to screen six potential factors (donor phase pH, acceptor phase concentration, supported liquid membrane composition, stirring rate, extraction time and salt content) for their extent of vitality on the extraction of muscimol, tryptophan and tryptamine using the developed method. Four factors were identified as essential for an enhanced enrichment of each of the three research analytes from diluted urine samples. The paired vital factors were then optimized using central composite designs where empirical quadratic response models were used to visualize the response surface through contour plots, surface plots and optimization plots of response output. When the muscimol-based optimum factor levels were applied for the simultaneous extraction of the three research analytes, a composite desirability of 0.687 was obtained implying that the set conditions were ideal for a combined extraction of the analytes from the donor phase into the acceptor phase across a supported liquid membrane impregnated with a carrier molecule. This was an acceptable result considering that only the optimized muscimol factor levels were set as universal factor values. Muscimol was the analyte of interest in this research. The composite desirability value was predicted by setting the extraction conditions to 20% (w/w) di-(2-ethylhexyl) phosphoric acid (DEHPA) in dihexyl ether (DHE) supported on the walls of a hollow fibre into a 200 mM HCl acceptor phase inside the hollow fibre from a 20% (v/v) diluted urine donor phase spiked in the 0.1 – 10 μg mL-1 analyte concentration range maintained at pH 4 and stirred at 800 rpm for 60 mins. Experimentally, average enrichments of 4.1, 19.7 and 24.1 were obtained for muscimol, tryptophan and tryptamine, respectively. iv The complexity of urine and the anionic nature of the carrier molecule embedded on the supported liquid membrane resulted in interfering peaks that could not be completely resolved from the analyte peaks. Thus matrix-based calibration curves were used to address matrix effects. Various statistical approaches were used to validate suitability of the developed method for its potential use in quantifying muscimol and its precursors from urine samples. These validation measures were used as a way of determining the method’s ability to maintain the extraction process at equilibrium over a specific range of analyte concentrations over a period of analyte existence in a urine sample. The r² values of the matrix-based linear regression prediction models ranged from 0.9933 to 0.9986. The linearity of the regression line of the matrixbased calibration for each analyte was directly linked to the analyte enrichment repeatability. Simultaneous analyte enrichment repeatability over a 0.1 – 10 μg mL-1 analyte spiking concentration ranged from an RSD value of 8.3% to 13.1%. Limits of detection were 0.021 μg mLˉ¹, 0.061 μg mL-1 and 0.005 μg mL-1 for muscimol, tryptophan and tryptamine, respectively. Other validation parameters that were considered included specificity (and selectivity), accuracy, robustness, extraction range and system suitability. The accuracy of the developed method was reported as the reproducibility of enrichment factor values over six spiking concentrations used in constructing matrix-based calibration curves. System suitability was limited to an HPLC-UV approach. Method suitability was addressed through a comparative summary in which the LOD, LOQ and r² values for the developed method were compared to other methods that have been used to extract muscimol from urine samples. The relevance or acceptability of the enrichment factor values obtained for the extraction of the three analytes was achieved by comparison with enrichment factor values of several compounds with similar polarity that have been extracted from urine samples using carrier-mediated hollow fibre liquid phase microextraction. / GR2016
67

the practice and usefulness of bone marrow examinations in a cohort of human immunodeficiency virus infected children in South Africa: a descriptive study

Rowe, Biance 11 January 2012 (has links)
INTRODUCTION: Bone marrow examination (BME) is performed in Human Immunodeficiency Virus-infected (HIV+) children with haematologic abnormalities to exclude specific disease (SD). AIMS: To describe the: (1) indications for BME , (2) utility of BME to diagnose SD, (3) patient characteristics associated with SD or non-specific disease (NSD). METHODS: Design: Retrospective review. Definitions: SD: BME positive for opportunistic infection (OI) or HIV-related malignancy. NSD: HIV-related changes only. RESULTS: Eighty six BME’s were done. Suspected SD in 56/86(65.1%) was the most common clinical indication. Bicytopaenia(n=32) and isolated cytopaenia(n=31) were the most common haematologic indications. NSD 48/86 (55.8%) was a more common finding than SD 32/86 (37.2%). Granulomas, pure red cell aplasia and malignancy were the SD identified. Pre- highly active antiretroviral therapy (HAART), advanced stage, and not being virally suppressed were significantly associated with NSD. CONCLUSION: The yield of SD (37.2%) on BME is comparable to adult studies. HAART should be instituted before BME as NSD will be the most likely finding.
68

Stress inför examination : En kvantitativ studie bland högskolestudenter

Karlsson, Greta January 2019 (has links)
Stress är ett vanligt förekommande problem som drabbar många individer. Bland studenter upplever ungefär en tredjedel stress. Stress kan uppstå i olika situationer och för studenter kan en sådan situation vara förberedelse inför examination. Syftet med studien är att undersöka stress i relation till examinationsformer samt att undersöka om det finns något samband mellan ålder och stress bland högskolestudenter. I denna kvantitativa studie har en tvärsnittsdesign tillämpats och data har samlats in med hjälp av enkäter. Populationen var studenter vid Mälardalens högskola och urvalet bestod av 101 respondenter. Resultatet visar att majoriteten av studenter upplever stress inför skriftlig examination och ungefär hälften av studenterna upplever stress inför muntlig examination. Resultatet påvisar även att hälften av studenterna upplever stress lång tid innan skriftlig examination och att ungefär en av sju studenter upplever stress lång tid innan muntlig examination. Det finns dessutom ett svagt samband mellan ålder och stress. / Stress is a common issue that affects many individuals. Among students, approximately one third experience stress. Stress can arise from different situations, and for students, one of those situations can be preparation for an examination. The aim of this study is to examine stress in relation to examination and to examine the correlation between age and stress among university students. In this quantitative study, a cross-sectional study design was applied and data was obtained using surveys. The study population existed of students at Mälardalen University and the sample existed of 101 respondents. The results reviled that the majority of students experience stress before a written examination, while approximately half of students experience stress before an oral examination. Furthermore, results reviled that half of the students experience stress long before a written examination, while one of seven students experience stress long before an oral examination. Also, there is a weak correlation between age and stress.
69

An Examination of the Structure of Affect in a Sample of Inpatient Adolescents

Veeder, Marietta A. 01 May 2007 (has links)
Multiple studies investigating the validity of the tripartite model of affect in youth have been supportive of the model; however, few studies have examined the model in narrow age bands or large clinical samples. The current study examined the structure of affect in a sample of psychiatrically hospitalized adolescents. Structural equation modeling was used to examine two-factor (negative affectivity [NA] and positive affectivity [PA]) and three-factor models (NA, PA, and physiological hyperarousal [PH]) with item level data from the Reynolds Adolescent Depression Scale (RADS) and Revised Children's Manifest Anxiety Scale (RCMAS), and from the Millon Adolescent Clinical Inventory (MACI), RADS, and RCMAS. Analyses were completed for the overall sample and for depressive, anxiety, comorbid depression, and anxiety, and other diagnostic groups. With data from the RADS and RCMAS, both the two- and three-factor models provided an equally good fit to the data for the overall sample. However, when tested for invariance across diagnostic groups, the two-factor model was invariant across groups, while the three-factor model yielded inadmissible solutions for the comorbid group, suggesting the two-factor solution provided the best fit to the data. For the data from the MACI, RADS, and RCMAS, one-, two-, and three-factor models were tested, but it was not possible to identify a model of acceptable fit. The t tests were used to examine the patterns of construct scores across diagnostic groups to determine if they were consistent with the tripartite model. Using data from the RCMAS and the RADS, the depressive and anxious diagnostic groups demonstrated similarly high levels of NA, while the anxious group demonstrated significantly higher levels of PA than the depressive group. Similar analyses could not be completed for the data from the MACI, RADS, and RCMAS because of the small sample size for the anxious diagnostic group. While the results of SEM and t-test analyses demonstrate support for the tripartite model and the associated constructs of NA and PA, support was not demonstrated for PH. Results suggest that the tripartite model may be dependent on the instruments used to assess it. Limitations of this study and implications and directions for future research are discussed.
70

Factors influencing children�s responses to cross-examination questioning

O'Neill, Sarah Christine, n/a January 2009 (has links)
Under an adversarial legal system, witnesses� testimony may be challenged by the opposing lawyer during cross-examination. Cross-examination has been shown to negatively affect the accuracy of children�s event reports, but as yet, the mechanisms driving this effect are unknown. Experiment 1 aimed to tease apart the roles of question type and repeated interviewing in mediating children�s cross-examination performance. Five- and 6-year-olds (N = 82) and 9- and 10-year-olds (N = 103) took part in a staged event, and 1 to 2 days later they took part in a direct examination interview. Next, either 1 to 3 days or 6 months later, all children were interviewed for a second time. For half of the children, this second interview was a repeat of their direct examination interview. The remaining children were interviewed in a cross-examination format. A second interview reduced response accuracy after both short and long delays, however, cross-examination questioning impaired the accuracy of children�s reports the most. Although, overall, children have considerable difficulty answering cross-examination questions correctly, variation in their performance has been observed. Experiment 2 assessed whether individual differences in cognitive abilities mediate cross-examination performance. Five- and 6-year-olds (N = 116) and 9- and 10-year-olds (N = 58) visited the police station and subsequently reported their experiences in direct examination and cross-examination interviews. Children�s memory, receptive language ability, expressive language ability, and intelligence were also measured. Age, intelligence, and memory predicted aspects of cross-examination performance. Overall, these cognitive factors accounted for between 16.6% and 19.5% of the variance in cross-examination outcome measures. Given the negative effect of cross-examination on children�s responding, and our inability to identify the children who are most at risk of poor performance during this interview, Experiment 3 assessed our ability to facilitate children�s responding to cross-examination questioning. Specifically, the effect of manipulating the timing of a pre-trial intervention, which gives children practice and feedback at cross-examination questioning, was investigated. Five- and 6-year-olds (N = 88) and 9- and 10-year-olds (N = 108) visited the police station. One to 3 days later they completed the direct examination interview and 6 months after the event, children were cross-examined. The timing of the preparation intervention was varied (1-day, 1-week, 1-month before cross-examination), and the children�s subsequent cross-examination performance was compared to that of children in the control group. When the preparation intervention was delivered 1 day or 1 week before the cross-examination interview, children�s cross-examination performance was significantly improved. The findings from the three experiments suggest that cross-examination is likely to pose considerable problems for children, especially younger children. Our greater understanding of factors that influence children�s responding to cross-examination questioning may guide reform of the cross-examination process for child witnesses. Bottom-up initiatives, such as pre-trial preparation, and top-down changes, including educating professionals, expert testimony, and reducing the delay to cross-examination, may improve the reliability of child witnesses� testimony during cross-examination.

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