2017 MU dissertations - Freely available online
https://hdl.handle.net/10355/61878
2024-03-28T13:53:42Z3D imaging for brachytherapy patient and mold applicator positioning verification
https://hdl.handle.net/10355/66740
3D imaging for brachytherapy patient and mold applicator positioning verification
Pokhrel, Sagar
We developed a stereo vision method for 3D imaging of HDR brachytherapy skin cancer applicator positioning and tracking with respect to patients' anatomical features. The setup consists of two high-resolution scientific scan cameras (3840 x 2748 pixels) mounted on high-precision 4D of freedom optical mounts for submillimeter and sub degree positioning. A Rando phantom was used as a surrogate for patients' skin cancer and keloid treatments using a 3D printed applicator. Stereo images were recorded and analyzed using an in-house developed LabVIEW interface to determine the relative position of the applicator with respect to skin reference markers. Oncentra treatment planning system was used to perform reference applicator positioning in X, Y and Z coordinate to evaluate the stereo system accuracy and resolution. Calibration of the system spatial resolution shows optimal performance at 1000mm from the camera imaging plane to the imaged object. Calibrated screen target measurements show that positional error in the XY-plane is less than 0.39[plus or minus]0.21mm and a discrepancy in depth measurement within 0.48[plus or minus]0.32mm. Rando phantom experiments were performed to mimic skin cancer facial treatments. Tracking several reference points at the applicator we validate an average localization precision of 0.41[plus or minus]0.32mm, 0.46[plus or minus]0.38mm, and 0.3[plus or minus]0.21mm for the X, Y, and Z coordinates respectively. Applicator misplacement was simulated to determine dosimetric errors originated by applicator positioning inaccuracies. Misalignment of applicator by 5mm caused dosimetric shift up to 2.6% for overall PTV and 6.45% in reference points in treated region. The developed 3D imaging system was validated as a high-resolution and accurate stereo vision solution capable of submillimeter pre-treatment, intra and inter-fraction applicator positioning, and repeatability. This system can be used to continuously track the intra-fraction motion of the skin applicator with respect to the patient's anatomical surface to enhance treatment accuracy, safety, and quality.
2017-01-01T00:00:00ZAdvancements in evaluating reliability of nondestructive technologies for the detection of subsurface fracture damage in R.C. bridge decks
https://hdl.handle.net/10355/65442
Advancements in evaluating reliability of nondestructive technologies for the detection of subsurface fracture damage in R.C. bridge decks
Sultan, Ali Abed
During the last few decades, many efforts have been made to assess the reliability of nondestructive evaluation (NDE) technologies used for the detection of subsurface damage in concrete bridge decks. During these efforts, reliability of NDE technologies has either been described anecdotally, or been solely relegated to the probability of detection (POD) or accuracy estimation. Although these indices are important, most of the previous work did not take into account the probability of false alarm (POFA) of NDE technologies, nor did they investigate the reliability considering multiple threshold settings throughout test results. In addition, the existing body of research has used a limited physical sampling such as coring to validate NDE results. Consequently, the assessments were rather controversial, and there was no general agreement about the reliability of such technologies. Because most diagnosis systems are characterized by noisy data and less than perfect detection characteristics, reliability is to be carefully assessed considering all possible diagnosis output with multiple threshold settings within practical range of applications. In other words, when NDE data do not fall into either of the two obviously defined categories: true positive (TP), meaning the NDE data indicates a defect and there is a defect, or true negative (TN), meaning the NDT data indicates no defect and there is no defect, reliability analysis should also include the two types of incorrect indications: failure to give a positive indication in the presence of a defect (false negative, FN) and giving a positive indication when there is no defect (a false alarm or false positive, FP). The \three decades of NDI reliability assessments" report developed by Karta Technologies, Inc. in 2000 under supervision of the Air Force NDI Office stated that POD alone cannot describe the reliability of NDE technologies unless the probability of false alarm (POFA) is also considered in the analysis. POFA may be induced by noise with several possible sources: human, nature of phenomenon to be measured, and environmental conditions. The report covered nearly 150 reports and manuscripts from over 100 authors. However, a review of research literature reveals that little theoretical work on the reliability assessment in terms of both POD and POFA has been undertaken since then. In this research, the reliability of impact echo (IE), infrared thermography (IRT), and ground penetration radar (GPR) technologies for the detecting of subsurface damage in concrete plate-like members is assessed by using a statistical analysis method called receiver operating characteristic (ROC). The proposed analysis method has the capability to integrate POD and POFA indices over a wide range of decision threshold settings in a single curve, which is useful in assessing trade-off in choosing a threshold and for quantitatively comparing the performance of NDE technologies. This methodology for assessing NDE reliability is intended to provide a more effective means of comparing different technologies used in civil engineering applications, to make the evaluation process of a quantitative scheme, to reduce subjectivity and variability in interpreting NDE data, and to improve sensitivity to extract more information from NDE data. Area under ROC curve (AUC), which is interpreted as the probability of correctly classifying an arbitrarily pair of negative and positive test points, can provide for the desired quantitative reliability index, which can be used to compare the performance of one NDE technology to another. Results of this research obtained from ROC analysis indicate a great ability of IE and IR in detecting subsurface fracture damage such as delamination and debonding. In both technologies, there exist some threshold settings that can provide for a relatively high POD with very low POFA, and consequently, the areas under their ROC curves were very high. Data obtained from GPR testing, on the other hand, indicates that GPR technology has a very limited ability to detect physical damage such as subsurface delamination. This conclusion contrasts with that been argued by a large body of the previous work. However, GPR showed a good sensitivity to the presence of corrosive environments such as moisture and chloride when the concentrations of these factors are above some threshold values that may facilitate the initiation of steel reinforcement corrosion.
Field of study: Civil engineering.; Dr. Glenn Washer, Dissertation Supervisor.; Includes vita.; "July 2017."
2017-01-01T00:00:00ZAdvancements in the understanding of staphylococcal mastitis through the use of molecular tools
https://hdl.handle.net/10355/63800
Advancements in the understanding of staphylococcal mastitis through the use of molecular tools
Adkins, Pamela Rae Fry
The objectives of this work were: 1) to complete a whole genome sequence of a Staphylococcus chromogenes isolate that is known to persist in the mammary gland of a cow, 2) to define a genetic target that could easily and reliably be used to differentiate Staphylococcus agnetis and Staphylococcus hyicus and to use this new assay along with pulsed-field gel electrophoresis (PFGE) strain typing to characterize a collection of non-Staphylococcus aureus coagulase positive staphylococci, 3) to determine if the recently described S. aureus Genotype B was present among previously characterized isolates from cases of bovine intramammary infection in the USA and to compare PFGE to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for strain typing of S. aureus, 4) to further the understanding of the association between body site colonization and intramammary infection before and after calving in heifers using molecular methods of speciation and strain typing, and 5) to describe the prevalence and distribution of Staphylococcus species on the teat and inguinal skin of dairy heifers throughout the heifer lifecycle using molecular speciation methods. A draft genome sequence of S. chromogenes MU 970, a strain that was isolated from the right rear quarter of a Holstein cow for 16 consecutive months, was completed. Whole genome sequences for S. chromogenes, S. hyicus, and S. agnetis were then used to construct a multiplex PCR used to differentiate S. hyicus, S. agnetis, and S. aureus. The multiplex PCR was then used to characterize a collection of isolates and found that S. agnetis was much more prevalent than S. hyicus. Furthermore, S. agnetis can cause persistent infections and can potentially be contagious. Next, RS-PCR plus toxin gene identification was explored as a possible strain typing method, however it was found to be less discriminatory than PFGE. Hence, PFGE was used as the strain typing method for the remainder of the dissertation research. The final two studies were conducted to characterize body site colonization with staphylococcal species and to explore the relationship of prepartum body site colonization to intramammary infections, both pre- and post-calving. MALDI-TOF was explored as a speciation method in these studies and was found to be accurate, rapid, and inexpensive. Overall, S. chromogenes was the most common species identified in prepartum mammary secretions and post-calving milk samples. Through PFGE strain typing, it was determined that many different strains of each species can be found on one heifer. Finally, it was determined that colonization of the inguinal region and teat skin was associated with age for S. agnetis, S. chromogenes, Staphylococcus devriesei, Staphylococcus equorum, Staphylococus haemolyticus, Staphylococcus lentus, Staphylococcus sciuri, Staphylococcus vitulinus, and Staphylococcus xylosus. Overall, these studies demonstrate that the staphylococcal species and subspecies associated with IMI are extremely abundant and diverse on dairy farms.
2017-01-01T00:00:00ZAdvancing single molecule fluorescence microscopy through the study of dynamic macromolecules
https://hdl.handle.net/10355/63672
Advancing single molecule fluorescence microscopy through the study of dynamic macromolecules
Menke, Drew Edwin
We took a two pronged approach to our investigation of protein synthesis by the ribosome: 1) the generation of a novel fluorescence enhancing substrates 2) the development of a method for the generation of fluorescent ribosome constructs. The development and application of fluorescence based diagnostics platforms for the detection of diseases represents a promising field of research. In collaboration with another lab, we established a method for the generation of a fluorescence enhancing substrate that does not require the use of expensive imaging equipment. During further testing of the fluorescence enhancing substrate with biologically relevant samples, our method proved promising for addition applications. Understanding how and why the ribosome synthesizes protein is important to all living organisms. One known challenge for the study of the ribosome has been the generation of complex samples. We developed a process for the generation of ribosomes that is quicker, easier, and cheaper than existing methods. We then applied our methods for the generation of ribosome constructs to investigate how the ribosome, the molecule responsible for protein synthesis, is coordinated during protein synthesis. Our experiments determined that specific interactions play different roles throughout protein synthesis.
Field of study: Biochemistry.; Dr. Peter V. Cornish, Dissertation Supervisor.; Includes vita.; "December 2017."
2017-01-01T00:00:00Z