College students experience high levels of stress, especially those in health care programs. The purpose of this study was to determine what factors contribute to Tennessee radiography student stress levels and the methods by which they cope with stress. Additionally, do demographic factors affect radiography student stress levels? The research was conducted February 4 to March 30, 2016. A survey was distributed to students in a radiography program at two and four year colleges in Tennessee. Participants were asked questions on factors that influence their stress levels, coping strategies, and health issues experienced in the past year. Descriptive statistics, independent samples t-test, and Pearson correlations were used to determine what factors influenced student stress levels, the most effective coping strategies, and if demographics affected student stress levels. This analysis revealed that school causes students the most stress, while taking a break was the most used stress coping strategy.

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From an engineering background, it is often believed that the human anatomy has already been fully described. Radiology has greatly contributed to understand the inside of the human body without surgical intervention. Despite great advances in clinical CT scanning, image quality is still related to a limited amount X-ray exposure for the patient safety. This limitation prevents fine anatomical structures to be visible and, more importantly, to be detected. Where such modality is of great advantage for screening patients, extracting parameters like surface area and volume implies the bone structure to be large enough in relation to the scan resolution. The mastoid, located in the temporal bone, houses an air cell system whose cells have a variation in size that can go far below current conventional clinical CT scanner resolution. Therefore, the mastoid air cell system is only partially represented on a CT scan. Any statistical analysis will be biased towards air cells of smaller size. To allow a complete representation of the mastoid air cell system, a micro-CT scanner is more adequate. Micro-CT scanning uses approximately the same amount of X-rays but for a much longer exposure time compared to what is normally allowed for patients. Human temporal bone specimens are therefore necessary when using such scanning method. Where the conventional clinical CT scanner lacks level of minutes details, micro-CT scanning provides an overwhelming amount of fine details. Prior to any image analysis of medical data, visualization of the data is often needed to learn how to extract the structures of interest for further processing. Visualization of micro-CT scans is of no exception. Due to the high resolution nature of the data, visualization of such data not only requires modern and powerful computers, but also necessitates a tremendous amount of time to adjust the hiding of irrelevant structures, to find the correct orientation, while emphasising the structure of interest. Once the quality of the data has been assessed, and a strategy for the image processing has been decided, the image processing can start, to in turn extract metrics such as the surface area or volume and draw statistics from it. The temporal bone being one of the most complex in the human body, visualization of micro-CT scanning of this bone awakens the curiosity of the experimenter, especially with the correct visualization settings. This thesis first presents a statistical analysis determining the surface area to volume ratio of the mastoid air cell system of human temporal bone, from micro-CT scanning using methods previously applied for conventional clinical CT scannings. The study compared current resul s with previous studies, with successive downsampling the data down to a resolution found in conventional clinical CT scanning. The results from the statistical analysis showed that all the small mastoid air cells, that cannot be detected in conventional clinical CT scans, do heavily contribute to the estimation of the surface area, and in consequence to the estimation of the surface area to volume ratio by a factor of about 2.6. Such a result further strengthens the idea of the mastoid to play an active role in pressure regulation and gas exchange. Discovery of micro-channels through specific use of a non-traditional transfer function was then reported, where a qualitative and a quantitative preanalysis was performed are described. To gain more knowledge about these micro-channels, a local structure tensor analysis was applied where structures are described in terms of planar, tubular, or isotropic structures. The results from this structural tensor analysis, also reported in this thesis, suggest these micro-channels to potentially be part of a more complex framework, which hypothetically would provide a separate blood supply for the mucosa lining the mastoid air cell system.

Musculoskeletal injuries are the most common injuries sustained by athletes and military recruits and can result in decreased performance and lifelong disability. So common and costly are these injuries that the American Academy of Orthopedic Surgeons has provided guidelines for future research, including recommendations for the development of a large animal model of bone injury (USDA 2001). In human and veterinary medicine, digital radiography represents the primary diagnostic tool the physician uses to diagnose skeletal injury. Advances in digital radiography have provided the veterinarian with opportunities to make both simple and complex radiographic assessments. We investigated a simple quantitative measurement of the solar, concave aspect of the distal phalanx in the horse, termed the Palmar-Metric (PM). The PM was a significant predictor of solar cup volume (p < 0.001) and negatively correlated with age (r2 = 0.28, p < 0.05) as determined from 544 radiographs of the distal phalanx from the left and right front feet. Therefore, veterinarians should be aware of the age related change in the solar, concave aspect of the distal phalanx in the horse. We hypothesized that the decrease in the degree of concavity with age may be due to demineralization and subsequent loss of bone density along the solar margin of the distal phalanx. Therefore, we investigated the quantification of optical bone density (bone OD) via complex radiographic calibration. By developing a brightness/darkness index (BDI), the greyscale of radiographs, calibrated with an aluminum marker of varying known thickness, can be compared to the average density of a cross-section of bone. At varying radiographic exposure intensity (kV) and exposure time (mAs), Al BDI was a significant predictor of bone BDI (r2 = 0.960, p < 0.001) and bone OD (r2 = 0.971, p < 0.001). This method of calibration can be utilized by the radiologist to accurately assess bone OD regardless of technique, and allow direct comparison of radiographs taken under different exposure settings. This method successfully quantifies bone OD via measurement of BDI from standardized digital radiographs, allowing for the opacity of radiographs to be truly comparable when taken under different circumstances.

Let $(X,\chi)$ be a measurable space, let $M = M(X,\chi)$ be the space of nonnegative, bounded measures on $(X,\chi),$ let N be the subset of M with integer values, let ${\cal M}$ be the smallest $\sigma$-algebra on M with respect to which the coordinate functions$$\{f\sb A :M \to \Re\vert f\sb A (\mu) = \mu(A),\forall A \in \chi, \forall\mu \in M\}$$are measurable, and let ${\cal N}$ be the $\sigma$-algebra on N induced by its inclusion in $(M,{\cal M})$. A measurable map $\nu$ from a complete probability space ($\Omega,{\cal E},P)$ to $(M,{\cal M})$ is a random measure of $(X,\chi)$; such a map with range in $(N,{\cal N})$ is a point process. Let $\mu$ be a finite positive measure on $(X,\chi)$, random measure $\nu$ is a Poisson point process on $(X,\chi)$ with mean or directing measure $\mu$ if for all $A \in \chi\ \nu(A;\cdot)$ is a Poisson random variable with mean $\mu(A)$, $$P(\{\omega\vert\nu(A;\omega) = k\}) = e\sp{-\mu(A)}{\mu(A)\sp k\over k!},\ k = 0,1,2,\... ,$$and for any finite collection of pairwise disjoint sets $\{A\sb1,A\sb2,\...,A\sb p\} \subset \chi$ the random variables $\{\nu(A\sb1;\cdot),\nu(A\sb2;\cdot),\...,\nu(A\sb p;\cdot)\}$ are independent,$$P(\cap\sbsp{i = 1}{p}\{\omega\vert\nu(A\sb i;\omega) = k\sb i\}) = {\prod\limits\sbsp{i = 1}{p}}\ P(\{\omega\vert\nu(A\sb i;\omega) = k\sb i\}).$$ Following Peskin, Tranchina, and Hull, we use a Poisson point process to model the occurrence of $\gamma$-photons produced by the decay of a radioactive marker in the tissue of a given patient for a diagnostic procedure in nuclear medicine. The directing measure of the process represents the distribution of the marker during the scan; this directing measure can be estimated through a linear filtering technique. We prove the existence of a continuous, linear, least-squares filter and the approximability of this filter by a sequence of discrete filters of the kind developed by Peskin, Tranchina, and Hull. We also demonstrate techniques for filtering and filter error estimation at high resolution / acase@tulane.edu

Chinese hamster ovary cells were synchronized at the G$\sb1$/S boundary of the cell cycle and labeled for 10 min with $\sp{125}$I-iododeoxyuridine. Samples were frozen for decay accumulation between 15-480 min after labelling. Cells frozen within 1 h after labeling yielded a low LET survival response with a pronounced shoulder and a large D$\sb0$ (255 decays/cell). With longer chase periods the shoulder and the D$\sb0$ decreased progressively and cells harvested 5 h after labeling exhibited a high LET survival response (D$\sb0$: 65 decays/cell). If DNA is assumed to be the sole target for radiation-induced death, these results indicate that DNA maturation increases radiation damage to DNA or reduces repair. Alternatively, if radiation death involves damage to higher-order structures in the nucleus, the findings suggest that newly replicated DNA is not attached to these structures during the initial low LET period, but $\sp{125}$I starts to induce high LET effects as labeled DNA becomes associated with the target structure(s). On balance, our data favor the latter interpretation. / In related experiments, exponentially growing cells were labeled with $\sp{125}$I-iododeoxyuridine for 12 h. Mitotic cells were selected, plated for cell cycle traverse, and harvested during successive stages of the cell cycle for decay accumulation. $\sp{125}$I damage during G$\sb1$ resulted in shoulderless exponential survival curves with a D$\sb0$ of 60-65 decays/cell. Resistance to $\sp{125}$I decays increased as cells progressed through S and the survival curves of cells in late S/G$\sb2$ were characterized by a pronounced shoulder and a D$\sb0$ of 127-139 decays/cell. These findings suggest that the primary target for radiation death is duplicated during S with G$\sb1$ cells containing one set and G$\sb2$ cells two sets of targets. Dual targets, although located within a single cell, act independently, as if already distributed between separate daughter cells. Analysis of the data suggests that the emergence of a shoulder and doubling of the D$\sb0$ in late S/G$\sb2$ cells represents an artifact of the colony formation assay which systematically overstates cell survival when intracellular target multiplicity exceeds 1. / Source: Dissertation Abstracts International, Volume: 53-03, Section: B, page: 1235. / Major Professor: Kurt G. Holer. / Thesis (Ph.D.)--The Florida State University, 1992.

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