Thesis (Master's Degree (Medical Technology)-- Cape Technikon, Cape Town, 1997 / There is, at present, no recognised diagnostic biochemical marker of Alzheimer's Disease (AD). Recently, Gunnerson and Haley, (1992), reported that the presence of glutamine synthetase (GS) in cerebrospinal fluid (CSF) samples showed a 97% correlation with patients diagnosed as having AD. GS was detected by photolabelling with [y32P]2-azido-ATP or [y32P]8azido- ATP and visualisation following sodium dodecyl sulphate polyacrylamide gel electrophoresis (SOS-PAGE) and autoradiography. This study set out to reproduce Gunnerson and Haley's methodology for labelling sheep GS in CSF using [y32P]8-azidoATP, to develop this assay or possibly another, using a fluorescent probe of ATP binding sites, into a robust procedure suitable for a routine diagnostic laboratory, and finally to assess whether the presence of GS in CSF is indeed a marker of AD.

Background: Diagnostic imaging plays an expanding and central role in patients' medical care. Radiographer clinical reporting is being increasingly used in patient focused services. There is a paucity of research that has examined radiographer chest X-ray reporting. Aim: To determine the diagnostic accuracy of reporting radiographer chest X-ray (CXR) reporting and the influence that CXR reports have on clinicians' diagnostic decision-making. Method: A quasi-experimental study determined the diagnostic accuracy of a cohort of reporting radiographers in CXR interpretation, using a free-response methodology. The influence of CXR reports on clinicians' diagnostic decision-making was determined with a cohort study. A non-inferiority approach was used, in line with Royal College of Radiologists and College of Radiographers guidance that reporting radiographers must be comparable to consultant radiologists. Results: The diagnostic accuracy of reporting radiographers (RR) was non-inferior to consultant radiologists (CR) for all measures, all p < 0.0001; unweighted JAFROC (RR Figure of Merit [FoM]=0.828, 95%CI 0.808-0.847; CR FoM=0.788, 95%CI 0.766-0.811), weighted JAFROC (RR FoM=0.830, 95%CI 0.811-0.849; CR FoM=0.786, 95%CI 0.764-0.808) and inferred ROC (RR Area Under the Curve [AUC]=0.909, 95%CI 0.887-0.931; CR AUC=0.903, 95%CI 0.882-0.924). No difference was found in the number of CXR reports that produced a correct most likely and/or most serious diagnosis (RR 876 of 1337 cases; CR 810 of 1368; p=0.103). Uncorrected most likely diagnostic confidence (RR 72.5 to 80.2; CR 71.0 to 80.4) and uncorrected most serious diagnostic confidence (RR 34.0 to 41.9; CR 33.5 to 39.2) of reporting radiographer CXR reports was non-inferior to consultant radiologists (p < 0.001). Corrected most likely diagnostic confidence, calculated using the Tsushima methodology, was lower (RR 4.61; CR 5.02) with no apparent difference, but noninferiority was not confirmed (p > 0.05). Conclusion: With appropriate postgraduate education, reporting radiographers are able to interpret chest X-rays at a level comparable to consultant radiologists.

This study explores the day-to-day application of digital radiography (DR) within the X-ray environment. This study presents the voices of the radiographers' untold views, attitudes and experiences of DR through the process of observing, listening, retelling and interpreting junior and senior radiographers' responses. There were three stages to this ethnographic study. Firstly, exploring 'what radiographers did' environment by observing clinical practices. This provided 'first-hand' experience of action-in-process. Secondly, 22 semi-structured interviews were undertaken, directed by emerging themes and informal discussions from the clinical observations. Semi-structured interviews provided an understanding of the experiences, behaviours and attitudes of radiographers providing a deeper understanding of the relationship between practice and context. Thirdly, X-ray experiments were undertaken contributing to 'what had been seen and said by participants'. This data was later triangulated to support the research objectives outlined in this PhD research. Observation and interview data were analysed using thematic analysis and grouped into four overarching categories; learning, radiographer challenges, ionising radiation and patient care delivery. X-ray experimental data was inputted into SPSS and later coded. The qualitative data had numerous codes, which generated themes and could be linked in order to generate theoretical descriptions. Multiple-linear regression analysis and Pearson's Correlation provide statistically significant values (p < 0.001) for the experimental models contributing to 'what had been seen and said' by radiographers in the clinical environment. This thesis provides new insights into general radiographic practices using advancing technology. The conclusions that can be drawn from the empirical data is that advancing technology has impacted the day-to-day practices of diagnostic radiographers. Complex phenomena include; current knowledge and understanding, the practice of keeping doses 'as low as reasonably practicable' and impact on patient care delivery. These insights suggest that healthcare and academic environments may require additional support in the aim of delivering optimum patient care.

The rule excluding evidence of opinion is traditionally stated in broad and general terms, subject to a more or less closed list of exemptions. Stephen says that a witness’s opinion is “deemed to be irrelevant”. A witness may depose to the facts which he has observed, but he may not ordinarily state any inferences which he has drawn from those facts, or opinions founded upon facts of which he has no personal knowledge. The general rule is that the evidence of opinion or belief of a witness is irrelevant because it is the function of a court to draw inferences and form its opinion from the facts; the witnesses give evidence as to the facts and the court forms its opinion from those facts. The opinion of an expert is admissible if it is relevant. It will be relevant if the witness’s skill, training or experience enables him materially to assist the court on matters in which the court itself does not usually have the necessary knowledge to decide. Where the topic is such that an ordinary judicial officer could be expected to be able, unassisted, to draw an inference, expert evidence is superfluous. In principle, there is no rule that a witness cannot give his opinion on an issue that the court has to decide ultimately. It is not experts alone who may give their opinions on ultimate issues but, in practice, there is a strong tendency to regard the evidence of lay persons on ultimate issues as constituting prima facie evidence only. If such lay testimony remains unchallenged, it may be of greater significance. It is generally true that relevant evidence is admissible and irrelevant evidence is inadmissible. At this stage the following question may be posed: is the opinion of any witness – whether from an expert or lay person – admissible evidence? Should an opinion be admitted for purposes of persuading the court to rely on it in deciding the issue at hand? The basic answer is that relevance remains the fundamental test for admissibility. Certain issues simply cannot be decided without expert guidance. Expert opinion evidence is therefore readily received on issues relating to ballistics, engineering, chemistry, medicine, accounting and psychiatry, to mention only a few examples. The problem which arises is this: what is the best way of cross-examining the expert witness? Although the concept of skilful cross-examination conjures up the image of the crossexaminer destroying the expert witness in the witness box, total annihilation of expert evidence in court occurs only rarely. In reality, lawyers who are expected to cross-examine experts are often at a disadvantage in that they do not possess sufficient in-depth knowledge of the specific field of expertise to enable them to cross-examine the witness. Despite the expert nature of the evidence, it is suggested that the true basis of crossexamination should not be abandoned when dealing with experts. The effectiveness of crossexamination is enhanced by keeping the number of questions to a minimum as well as opening and concluding with good strong points. At the outset it should be mentioned that there is a distinction between matters of scientific fact and matters of mere opinion. On matters of scientific fact experts seldom differ but within the province of opinion one encounters difficulties. Lengthy cross-examination concerning expert’s theoretical knowledge is usually inefficient and should rarely be attempted. Cross-examination should be directed at pure logic or scientific analysis. The cross-examiner should always have relevant authority with him in court so as to confront the expert with these. The whole effect of the testimony of an expert witness can also be destroyed by putting the witness to test at the trial as to his qualifications, his experience and his ability and discriminations as an expert. A failure to meet this test renders his evidence nugatory.

This study investigated the validity of excusing students from composition courses based upon an objective examination. Utah State University (USU) students who had taken freshman composition courses during the 1970-71 school year when these courses were required of all entering freshman students were divided into two groups: one group was composed of those who had received an "A" or "B" for three freshman composition courses, while the other group had received a- "C" or "D" for the same courses. USU students who had been excused from taking freshman composition courses based on the CLEP General Examination in English Composition (CLEP) during the 1971-72 school year when all entering freshman students were required to take the C LEP were divided into two groups: one group had scored above 449 on the CLEP and the other group had scored from 390-449. In addition, students who had been excused from the same composition requirement based on a score above 2 on the Advanced Placement Test in English Composition (AP) were included in the study. A random sample of 25 from each of the above groups participated in the study. All subjects completed an essay test (CLEP Subject Examination in English Composition--Essay Section) and an objective test (CLEP Subject Examination--Objective Section). The essay test was rated independently by three members of the USU English Department, and an inter-rater reliability coefficient of . 83 was obtained using analysis of variance techniques. Results showed that on the bases of both the essay test and the objective test there was no significant difference in the writing ability of the two groups of students who had completed freshman composition courses and the two groups of students who had been excused from freshman composition courses based on the C LEP. On the bases of both of these tests, the students who scored above 2 on the AP test scored above all other groups in the study; the students who scored above 449 on the CLEP scored second to the AP students and very much like the students who had received an average of "A" or "B" in freshman composition courses; the students who scored 390-449 and those who received a "C" or "D" in composition courses received virtually identical scores on the essay and objective tests. Based on multiple regression analysis, the objective test was found to be a much better predictor of freshman English grades than the essay test. In addition, the essay test was found to add little to the prediction of freshman composition grades provided by the objective test alone. Based on the findings of the study, it was concluded that the C LEP had been accurately applied at USU. Based upon the assumption that freshman composition grades are a valid measure of writing ability, it was also concluded that the objective test used in the study was a more valid measure of writing ability than the essay test, and further concluded that the objective test could predict writing ability quite accurately independent of the essay test. In consideration of the previous conclusions, it was concluded that a strictly objective test can validly be used to excuse students from freshman composition courses.

<p> To provide a logical framework for the comparison of various methods of kinematic flood routing a general method of kinematic flood routing is developed.</p> <p> After presenting the general framework, the properties of the numerical model are investigated by: l. Algebraic examination of the finite difference scheme. 2.Numerical experiments using a high speed digital computer. 3. Comparison of the kinematic flood routing results with results of simulations using the complete one dimensional dynamic representation.</p> <p> Particular facets of the numerical kinematic model that were studied included: 1. The stability of the numeric schematizations. 2. The degree of approximation with the finite difference system. 3. The applicability of kinematic methods to unsteady flow systems. 4. Methods of extending the kinematic solutions to predict attenuation as well as translation of the flood wave through the channel systems. </p> <p> The results indicate that kinematic flood routing methods differ primarily in the point about which the finite difference equation is formulated, hereafter termed the nucleus, and that the general framework is capable of emulating such methods as the Muskinghum Method, other non-linear kinematic methods and reservoir routing. By varying the location of the nucleus the stability and degree of approximation is significantly altered. This results in the outflow hydrograph being sensitive to the location of the nucleus and the size of the finite difference steps.</p> <p> To facilitate further research and application of the methods outlined in the thesis, a computer program was developed to enable kinematic flood routing to be performed in a natural channel with arbitrary geometry. Furthermore, the data is compatible with a program that is capable of performing a flood routing analysis using a numerical solution of the complete Saint-Venant equations. Documentation of the computer program for kinematic analysis is included with this thesis.</p> / Thesis / Master of Engineering (MEngr)

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No description available.

<p> Microstructural as well as structural analysis of amygdules and groundmass of the Catoctin F·ormation located in the overturned western limb of the South Mountain anticline permit interpretation pertaining to the nature of cleavage development. Various -metliods haye been employed in the structural analysis of amygdules, in order to ascertain their original shapes and also the nature of the tectonic strain ellipsoid. A deformation path has been constructed in logarithmic co-ordinates. This appears to be an improvement over the arithmatic graph of Wood (1974). Microstructural investigation allows recognition of two distinct domains within the groundmass and amygdules : i)an early schistosity and ii)a crenulation cleavage. Microstructural and structural analysis provide a logical explanation of this history. An initial flattening episode forming the early schistosity was followed by approximately plane strain deformation creating the crenulation cleavage. </p> / Thesis / Bachelor of Science (BSc)

A reduction in breast cancer mortality could be achieved by the regular practice of Breast Self-Examination (BSE), an early detection technique. · Based on interventions which have been successful in increasing compliance to other health-related behaviors, this study attempted to evaluate the efficacy of prompts on the monthly practice of BSE. Specifically, after exposure to a BSE teaching workshop, participants (N = 83), who were faculty and staff members at a state university, were assigned to one of three experimental conditions: telephoned prompts, mailed prompts, and no prompts. Compliance was measured during a 7 month period by means of an indirect behavioral measure. Results indicated that although experimental conditions did not differ with respect to mean frequency of BSE, they did differ in terms of proportion of noncompliers and high compliers. The prompt conditions contained a smaller proportion of noncompliers and a greater proportion of high compliers than the control group. In addition, the phoned prompts were more effective than the mailed prompts in increasing compliance. The proportion of compliance in all conditions decreased over time; compliance during the first half of the study accurately predicted compliance during the second half. The variables that accurately discriminated noncompliers from high compliers for all months of the study were educational level and perceived efficacy of BSE. The results are discussed in terms of cost-effectiveness and generalizability. Specific recommendations for future studies are presented. / Ph. D.