The present study aims to develop a mechanistic understanding of the thermal-hydraulic processes in a vapor explosion, which may occur in nuclear power plants during a hypothetical severe accident involving interactions of high-temperature corium melt and volatile coolant. Over the past several decades, a large body of literature has been accumulated on vapor explosion phenomenology and methods for assessment of the related risk. Vapor explosion is driven by a rapid fragmentation of high temperaturemelt droplets, leading to a substantial increase of heattransfer areas and subsequent explosive evaporation of the volatile coolant. Constrained by the liquid-phase coolant, the rapid vapor production in the interaction zone causes pressurization and dynamic loading on surrounding structures. While such a general understanding has been established, the triggering mechanism and subsequent dynamic fine fragmentation have yet not been clearly understood. A few mechanistic fragmentation models have been proposed, however, computational efforts to simulate the phenomena generated a large scatter of results. Dynamics of the hot liquid (melt) droplet and the volatile liquid (coolant) are investigated in the MISTEE (Micro-Interactions in Steam Explosion Experiments) facility by performing well-controlled, externally triggered, single-droplet experiments, using a high-speed visualization system with synchronized digital cinematography and continuous X-ray radiography, called SHARP (Simultaneous High-speed Acquisition of X-ray Radiography and Photography). After an elaborate image processing, the SHARP images depict the evolution of both melt material (dispersal) and coolant (bubble dynamics), and their microscale interactions, i.e. the triggering phenomenology. The images point to coolant entrainment into the droplet surface as the mechanism for direct contact/mixing ultimately responsible for energetic interactions. Most importantly, the MISTEE data reveals an inverse correlation between the coolant temperature and the molten droplet deformation/prefragmentation during the first bubble dynamics cycle. The SHARP observations followed by further analysis leads to a hypothesis about a novel phenomenon called pre-conditioning, according to which dynamics of the first bubble-dynamics cycle and the ability of the melt drop to deform/pre-fragment dictate the subsequent explosivity of the so-triggered droplet. The effect of non-condensable gases on the perceived mechanisms was investigated on the MISTEE-NCG test campaign, in which a considerable amount of non-condensable gases (NCG) are present in the film that enfolds the molten droplet. The SHARP images for the MISTEE-NCG tests were analyzed and special attention was given to the morphology (aspect ratio) and dynamics of the air/ vapor bubble, as well as the melt drop preconditioning and interaction energetics. Analysis showed twomain aspects when compared to the MISTEE test series (withoutentrapped air). First, the investigation showed that the meltpreconditioning still strongly depends on the coolant subcooling. Second,in respect to the energetics, the tests consistently showed a reducedconversion ratio compared to that of the MISTEE test series. The effect of the melt material in the steam explosion triggerability was also summoned, since it would in principle directly implicate the melt preconditioning. Since a number of the thermo-physical properties of the material would influence the triggering process, we focused on the material properties by using the same dioxide material with difference concentrations, i.e. eutectic and non-eutectic. Unfortunately, due to the high melt superheat the possible differences were not perceived. Thus, inaddition to other materials, lower melt superheat tests were schedule inthe future. / QC 20101110

Amorphous selenium based digital radiography has attracted much attention because of selenium's high X-ray absorption and excellent charge transport properties, and the ability to be created thick (typically 100 to 1000 micron) uniform layers over a large area (typically 30 cm X 30 cm) at low processing temperatures (typically at around 50 degree C substrate temperature). In this work, the excess noise in amorphous selenium has been studied. A number of device parameters were altered to study the noise characteristics, such as the metal of the electrodes, bulk material composition, device volume, surface conditions and substrate temperature. All the samples had a transverse geometry with 20 to 200- micron thick layers of amorphous selenium electroded with metal at the top and at the bottom. Sample devices were fabricated by conventional vacuum deposition.<p> Noise power was measured over a limited bandwidth of 1 kHz. The fluctuations for one sample amounted to 1% of the bias current. The excess noise was mainly 1/<i>f</i> noise with the slope ranging from -0.77 to -1.4. Interpretation of the noise spectra was complicated due to the samples' highly non-linear I-V relation and long time transients.<p> The metals of the electrode clearly showed a large effect on both the magnitude and shape of the noise spectrum. Of the metals studied, aluminum produced the least normalized noise and platinum the most. The addition of arsenic caused a decrease in the normalized noise. An additional 0.2% (% wt.) arsenic decreased the 1/<i>f</i> noise magnitude by more than a decade, but did not change the slope. The addition of chlorine did not affect the noise magnitude. Amorphous selenium is quite vulnerable to stress and in particular, external mechanical stress causes crystallization. The surface of the sample was gently abraded, applying the least possible amount of stress to the selenium layer. A change in the surface condition before the top electrode was deposited showed that a roughened surface decreased the noise magnitude substantially. These results strongly indicate that the noise is controlled by the metal-semiconductor interface.<p> Noise characteristics in multilayered samples were examined. The p-i-n and n-i-p structures consisted of 200 micron i-layer with 2 to 6 micron p- and n-like layers. The noise fluctuation in the current are typical of 1/<i>f</i> noise showing a power-law spectrum with slopes between -0.9 to -1.1. These samples showed a substantial decrease in the noise power compared to single layer samples; the additional n-like and p-like layers acted as carrier sources so that the current was not controlled by the metal interface. Hence, the measurements are closer to the intrinsic noise of a-Se. After exposure to 14 R (Roentgen) of X-rays, the normalized noise decreased by a factor of 1.6 for the n-i-p structure.

The dromedary camel has a very high economic importance in the Arabic countries. Nevertheless, there is a very little background literature on the use of ultrasound (US) and computed tomography (CT) in dromedaries in comparison to other domestic and farm animal species. Therefore, the tarsal region of six cadaver limbs, obtained from three orthopedic disease free dromedary camels, was evaluated via radiography, US and CT. The limbs were frozen and sectioned transversely, sagittaly and dorsally. The anatomic structures were identified and correlated to the analogous structures on the corresponding CT slices and US images and published in two manuscripts. Radiography was performed in both standard (0º and 90º) oblique (45º and 135º) radiographic projections. The tarsus was investigated via US in four planes (dorsal, medial, lateral and plantar) and each plane was scrutinized in four levels (calcaneal tuber, tibial malleoli, base of calcaneus and proximal head of metatarsus) in both transverse and longitudinal views. Radiography provided a good representation of the bony structures and articulations with little information on the soft tissues of the tarsus and superimposition of the tarsal bones. Ultrasonography furnished adequate delineation of the peri-articular tissues of the tarsus and was limited to the bone surface. Computed tomography provided cross sectional imaging of the dromedary tarsus without bone and soft tissue overlap and allowed visualization and differentiation of tissues in almost every situation. This work was undertaken to document the normal appearance of the dromedary camel tarsus via radiography, ultrasonography, and computed tomography which may be used as a resource for interpretation of dromedary tarsal pathology using various diagnostic imaging modalities.

Amorphous selenium based digital radiography has attracted much attention because of selenium's high X-ray absorption and excellent charge transport properties, and the ability to be created thick (typically 100 to 1000 micron) uniform layers over a large area (typically 30 cm X 30 cm) at low processing temperatures (typically at around 50 degree C substrate temperature). In this work, the excess noise in amorphous selenium has been studied. A number of device parameters were altered to study the noise characteristics, such as the metal of the electrodes, bulk material composition, device volume, surface conditions and substrate temperature. All the samples had a transverse geometry with 20 to 200- micron thick layers of amorphous selenium electroded with metal at the top and at the bottom. Sample devices were fabricated by conventional vacuum deposition.<p> Noise power was measured over a limited bandwidth of 1 kHz. The fluctuations for one sample amounted to 1% of the bias current. The excess noise was mainly 1/<i>f</i> noise with the slope ranging from -0.77 to -1.4. Interpretation of the noise spectra was complicated due to the samples' highly non-linear I-V relation and long time transients.<p> The metals of the electrode clearly showed a large effect on both the magnitude and shape of the noise spectrum. Of the metals studied, aluminum produced the least normalized noise and platinum the most. The addition of arsenic caused a decrease in the normalized noise. An additional 0.2% (% wt.) arsenic decreased the 1/<i>f</i> noise magnitude by more than a decade, but did not change the slope. The addition of chlorine did not affect the noise magnitude. Amorphous selenium is quite vulnerable to stress and in particular, external mechanical stress causes crystallization. The surface of the sample was gently abraded, applying the least possible amount of stress to the selenium layer. A change in the surface condition before the top electrode was deposited showed that a roughened surface decreased the noise magnitude substantially. These results strongly indicate that the noise is controlled by the metal-semiconductor interface.<p> Noise characteristics in multilayered samples were examined. The p-i-n and n-i-p structures consisted of 200 micron i-layer with 2 to 6 micron p- and n-like layers. The noise fluctuation in the current are typical of 1/<i>f</i> noise showing a power-law spectrum with slopes between -0.9 to -1.1. These samples showed a substantial decrease in the noise power compared to single layer samples; the additional n-like and p-like layers acted as carrier sources so that the current was not controlled by the metal interface. Hence, the measurements are closer to the intrinsic noise of a-Se. After exposure to 14 R (Roentgen) of X-rays, the normalized noise decreased by a factor of 1.6 for the n-i-p structure.

Given a known signal and perfect knowledge of the environment there exist few detection and estimation problems that cannot be solved. Detection performance is limited by uncertainty in the signal, an imperfect model, uncertainty in environmental parameters, or noise. Complex environments such as the ocean acoustic waveguide and the human anatomy are difficult to model exactly as they can differ, change with time, or are difficult to measure. We address the uncertainty in the model or parameters by incorporating their possibilities in our detection algorithm. Noise in the signal is not so easily dismissed and we set out to provide cases in which what is frequently termed a nuisance parameter might increase detection performance. If the signal and the noise component originate from the same system then it might be reasonable to assume that the noise contains information about the system as well. Because of the negative effects of ionizing radiation it is of interest to maximize the amount of diagnostic information obtained from a single exposure. Scattered radiation is typically considered image degrading noise. However it is also dependent on the structure of the medium and can be estimated using stochastic simulation. We describe a novel Bayesian approach to signal detection that increases performance by including some of the characteristics of the scattered signal. This dissertation examines medical imaging problems specific to mammography. In order to model environmental uncertainty we have written software to produce realistic voxel phantoms of the breast. The software includes a novel algorithm for producing three dimensional distributions of fat and glandular tissue as well as a stochastic ductal branching model. The image produced by a radiographic system cannot be determined analytically since the interactions of particles are a random process. We have developed a particle transport software package to model a complete radiographic system including a realistic x-ray spectrum model, an arbitrary voxel-based medium, and an accurate material library. Novel features include an efficient voxel ray tracing algorithm that reflects the true statistics of the system as well as the ability to produce separable images of scattered and direct radiation. Similarly, the ocean environment includes a high degree of uncertainty. A pressure wave propagating through a channel produces a measurable collection of multipath arrivals. By modeling changes in the pressure wave front we can estimate the expected pattern that appears at a given location. For this purpose we have created an ocean acoustic ray tracing code that produces time-domain multipath arrival patterns for arbitrary 3-dimensional environments. This iterative algorithm is based on a generalized recursive ray acoustics algorithm. To produce a significant gain in computation speed we model the ocean channel as a linear, time invariant system. It differs from other ocean propagation codes in that it uses time as the dependent variable and can compute sound pressure levels along a ray path effectively measuring the spatial impulse response of the ocean medium. This dissertation also investigates Bayesian approaches to source localization in a 3-D uncertain ocean environment. A time-domain-based optimal a posteriori probability bistatic source localization method is presented. This algorithm uses a collection of acoustic time arrival patterns that have been propagated through a 3-D acoustic model as the observable data. These replica patterns are collected for a possible range of unknown environmental parameters. Receiver operating characteristics for a bistatic detection problem are presented using both simulated and measured data. / Dissertation

Das Ziel dieser Untersuchung ist es, Aspekte der Strukturqualität (technische Untersuchungs- und Bildqualität), Prozessqualität (Angemessenheit der Indikation) und der Ergebnisqualität (Richtigkeit der Befunderhebungen) von Röntgenaufnahmen aus der tierärztlichen Praxis zu erörtern und häufige Fehlerquellen festzustellen. Dazu werden alle Röntgenaufnahmen von Kleintieren, die im Zeitraum von Anfang Dezember 2003 bis Ende Dezember 2004 als Original in die Klinik für Kleintiere der Universität Leipzig gelangen auf praxisrelevante Merkmale der Struktur-, Prozess- und Ergebnisqualität hin untersucht. Die Ermittlung der Daten erfolgt auf subjektiver Grundlage anhand eines Befundbogens durch Konsensbeurteilung von zwei Unter-suchern. Zur Auswertung gelangen 1259 Röntgenaufnahmen aus 600 verschiedenen Untersuchungen. Diese Aufnahmen stammen zu 86,9 % aus den Bundesländern Sachsen, Sachsen-Anhalt und Thüringen von 216 verschiedenen Tierarztpraxen. 80,3 % der untersuchten Tiere sind Hunde, 18,9 % Katzen. In der Gesamtbeurteilung der Bildqualität erweisen sich 48,7 % der Aufnahmen ohne Bean-standung. 29,2 % zeigen geringfügige Mängel, 16,0 % sind bedingt diagnostisch geeignet und 6,1 % sind unzureichend. 22,1 % der ausgewerteten Aufnahmen sind somit mangelhaft. Sie weisen Defizite in der diagnostischen Eignung auf oder sind hierfür ungeeignet. Die wichtigsten Fehlerquellen der Strukturqualität sind Mängel der Lagerung und Projektion, des Bildkontrastes und der Bildschärfe. Abweichungen der Lagerung und Projektion, meist durch nicht winkelgerechte Lagerung des Patienten im Direktstrahl verursacht, sind mit 11,4 % aller Aufnahmen im Vergleich zu anderen Fehlerquellen relativ selten. Die Auswirkungen auf die diagnostische Eignung sind jedoch oft schwerwiegend: 69,9 % der von Mängeln in der Lagerung betroffenen Aufnahmen zeigen Einschränkungen hinsichtlich der diagnostischen Eignung. 33,3 % aller Aufnahmen weisen Abweichungen des Bildkontrastes auf. Die häufigste Ursache dafür ist der Umgang mit verbrauchter Entwicklerlösung, gefolgt von Unter- und Überbelichtung. Betrachtet man die Gesamtheit der Kontrastabweichungen kann festgestellt werden, dass 47,7 % auf Fehler in der Filmentwicklung zurückzuführen sind. Auswirkungen auf die Eignung zur Diagnosestellung sind weniger gravierend als bei Mängeln der Lagerung und Projektion: 35,1 % der von Kontrastabweichungen betroffenen Aufnahmen zeigen Einschränkungen des diagnosti-schen Nutzens. 23,0 % der Aufnahmen sind durch Abweichungen der Bildschärfe gekennzeichnet. Am häufigs-ten ist Bewegungsunschärfe (67,7 % der betroffenen Aufnahmen) zu ermitteln. Weiterhin wer-den oft Materialunschärfe und Unschärfe durch Streustrahlung beobachtet, die auf den falschen Umgang mit dem Streustrahlenraster und der Film-Folien-Kombination zurückzuführen sind. Die Auswirkungen auf die diagnostische Eignung zeigen, dass 29,6 % der Röntgenaufnahmen mit Abweichungen der Bildschärfe Einschränkungen des diagnostischen Nutzens nach sich ziehen. Artefakte, vor allem verursacht durch Kratzer, Risse oder Brüche in Film oder Folie sowie durch Verunreinigungen durch Entwickler-, Fixierlösung oder Wasser, sind bei 20,7 % aller Röntgen-aufnahmen zu finden. Einschränkungen der diagnostischen Eignung ergeben sich dadurch bei 1,2 % der analysierten Aufnahmen. Zur Untersuchung der Prozessqualität wird die Angemessenheit der Indikation ermittelt, die nach RöV § 2a für jede Röntgenaufnahme gegeben sein muss (ANON. 2003a). Eine absolute Indikation kann bei 94,7 % der ausgewerteten Aufnahmen festgestellt werden. Bei knapp der Hälfte aller Aufnahmen dieser Arbeit kann die Ergebnisqualität erörtert werden. Die gestellte radiologische Verdachtsdiagnose ist bei 85,5 % dieser Fälle medizinisch nachvoll-ziehbar. Aus den Ergebnissen dieser Arbeit lässt sich ableiten, dass ein wesentlicher Teil der vorkom-menden Mängel der Bildqualität auf ungenügende Sorgfalt bei der Anfertigung und Verarbeitung der Röntgenaufnahme zurückzuführen ist. Allerdings liegen auch Defizite bei der Interpretation der gewonnenen Information durch die Röntgenuntersuchung vor. Da jeder Anwender ionisierender Strahlen verpflichtet ist, jede unnötige Strahlenexposition von Mensch und Umwelt zu vermeiden, müssen bestehende Defizite in Bezug auf die Anwendung der Projektionsradio-grafie abgebaut werden und die Vermittlung von Wissen und praktischen Fertigkeiten auf diesem Gebiet während der tierärztlichen Ausbildung verbessert werden. Ebenso sollte eine Feh-lerbeseitigung durch Ausnutzung oder Verbesserung der technischen Möglichkeiten erfolgen. Eine erneute Untersuchung zur Qualität von Röntgenaufnahmen in der tierärztlichen Praxis auf der Grundlage dieser Studie erscheint zur Überprüfung der getroffenen Maßnahmen zur Ver-besserung der Bildqualität sinnvoll. / The aim of this study is to evaluate aspects of structural quality (technical examination and im-age quality), quality of the process (adequacy of indication) and the outcome (correctness of findings) of radiographs from the veterinary practice and to indentify frequent radiographic er-rors. For this purpose all radiographs of small animals that are received at the Department of Small Animal Medicine of the University of Leipzig between December 1st 2003 and December 31th 2004 as an original are examined for relevant features of structural quality, process quality and outcome. The data collection is done subjectively based on the consensus examination of the radiographs by two independent examiners. The evaluation includes 1259 radiographs from 600 different examinations. 86.9 % of these images come from the federal states of Germany Saxony, Saxony-Anhalt and Thuringia from 216 different veterinary practices. 80.3 % of the examined animals are dogs, 18.9 % are cats. Concerning the over-all evaluation of the image quality, 48.7 % of the radiographs are without restrictions. Minor faults are detected in 29.2 % of the radiographs, 16.0 % are diagnostically compromised and 6.1 % are insufficient. Thus, 22.1 % of the examined radiographs are unsatis-factory. They show either deficits in their diagnostic suitability or are completely useless. The most important sources of errors are faults in positioning of the patient and the following projec-tion, of image contrast and sharpness. Deviations in positioning and projection, mostly caused by a suboptimal angle in the position of the patient in the x-ray, are with 11.4 % of all radiographs in comparison to other errors relatively rare. However the effect on the diagnostic use is severe: 69.9 % of the images with positioning faults show deficits with regard to the diagnostic suitability. Regarding the contrast of the image, 33.3 % of all radiographs display deficits. The most com-mon cause is the use of exhausted developer, followed by under- and overexposure. Consider-ing the overall deviations of image contrast, 47.7 % are attributed to errors during the x-ray film development. Consequences for the diagnostic use are less serious compared to errors in posi-tioning and projection: 35.1 % of the images with contrast deviations are of limited diagnostic use. 23.0 % of the radiographs are characterized by deviations in the sharpness: motion haziness occurs most frequently (in 67.7 %) of the images concerned. Receptor unsharpness and scat-tered radiation are often observed, caused by improper use of radiographic grids and film-screen combinations. The effects on the diagnostic suitability show that 29.6 % of the radiographs with deviations in the sharpness are of limited diagnostic use. Artifacts, most frequently caused by scratches, tears and breaks of the film or the intensifying screen as well as by splashes of the developing resp. fixation reagent or water, are found on 20.7 % of all radiographs. As a result of artifacts 1.2 % of the radiographs examined show defi-cits in their diagnostic suitability. To evaluate the quality of the process the adequacy of indication is determined, which is required for every radiographic examination according to RöV § 2a (ANON. 2003a). An absolute indication can be found in 94.7 % of all images. The quality of the outcome can be discussed in almost halve of all radiographs. The referral diagnosis is medically plausible in 85.5 % of these cases. The results of this study reveal that a considerable portion of the occurring errors in the image quality are caused by a lack of care during taking and processing of the radiographic images. Deficits in the interpretation of the gained information from the radiographic examination occur as well. Since avoidance of unnecessary exposure of humans and the environment to radiation is a major obligation of every user of ionizing radiation, existing deficits regarding the use of projection radiography should be reduced and the transfer of knowledge and practical capabili-ties in this area during the veterinary training should be improved. Furthermore, the elimination of errors by use or improvement of the technical possibilities is important. A new evaluation of the quality of radiographic images from the veterinary practice on the basis of this study seems useful to examine the effects of the steps taken to improve the image quality.

Thesis--University of London. / At head of title: Community Dentistry Unit, The London Hospital Medical College Dental School. Includes bibliographical references (p. 248-269).

As part of a state-funded Gopher Tortoise (Gopherus polyphemus Daudin) translocation project, I monitored actively grazed improved pastures to determine if they could serve as suitable recipient sites for the threatened Gopher Tortoise displaced by human development. For cattle ranches to be considered suitable recipient sites females must be able to acquire sufficient energy to produce a clutch of viable eggs, and sufficiently high quality vegetation must be available to support juvenile recruitment into the population. Vegetation surveys were conducted to determine the composition and percent cover of plant species, especially those containing high amounts of nutrients, specifically nitrogen. Resident and relocated females were radiographed during the 2010 and 2011 nesting seasons for the presence of shelled eggs. I was able to determine clutch size and egg diameter for both relocated and resident gravid females. Mean clutch sizes were not significantly different between years. Resident females had larger mean clutch sizes than relocated females in both years, significantly so in 2011, suggesting a period of stress and adjustment for relocated females. Egg diameters were significantly larger by 2.5 to 4.5 mm in 2010 for relocated and resident females, respectively, compared to 2011. Three females were recaptured in both years and exhibited the same trend of similar clutch sizes between years but significantly smaller eggs in 2011. A total of 68 unique taxa from 31 families were found, grasses (Poaceae) were the most dominant and covered a mean of 57% of the total sampled area. Four forb species occurred at much greater percent covers than all others. However, only two species (Richardia and Desmodium) were found to have adequate nutritional content and occur at percent covers greater than five percent, indicating that forage availability may be high, but forage quality may be inadequate to support growing juveniles. Burrow surveys indicate that at least some hatchlings are able to successfully leave the nest by the presence of hatchling size burrows scattered throughout the fields, but the ratio of juveniles to eggs laid is especially low. Survivorship of eggs, hatchlings and juveniles may be too low to support a sustainable Gopher Tortoise population in improved pasture possibly because of lack of adequate forage, burrow compaction by cows, lack of available natural shelter material for protection from desiccation, and the reduced ability of movement in thick pasture grasses, especially by hatchling and yearling tortoises.

Medical imaging informatics is one of the important research areas in radiology that studies how information available on medical images is retrieved, analyzed, and enhanced. Recent development in medical imaging informatics has resulted in improvement of diagnostic accuracy based on imaging examinations, as well as efficiency in clinical workflow. Computer aided diagnosis (CAD) and electronic patient record system (ePR) are both topics in medical imaging informatics that have matured from research concepts into commercially available computerized systems in clinical environment. The current challenges are to further broaden their scope of applications. In this thesis project, I developed a CAD system for interpreting PET/CT examinations and an ePR system for patient data integration in neurosurgery suites. Specifically, the CAD system in this project was designed to automatically diagnose nasopharyngeal carcinoma (NPC) on Positron emission tomography/computed tomography (PET/CT) examinations, which aimed to detect and classify both the primary NPC and its nodal metastasis. The regions of interests (ROIs) were segmented from the PET images and registered onto the CT in order to combine the imaging features from both modalities and the a priori anatomical knowledge of the suspicious lesion. These combined features were then classified by a support vector machine (SVM) to generate the final diagnosis result. The system was validated with 25 PET/CT examinations from 10 patients suffering from NPC, and the result produced by the system was compared to the gold standard of lesions manually contoured by experienced radiologists. The results confirmed that the system successfully distinguished all 53 genuine lesions from the mimickers due to normal physiological uptake and artifacts that also produced potentially confusing signals. The second part of the project involved development of an electronic patient record system (ePR) that integrated all the myriad of images and different types of clinical information before, during, and after neurosurgery operations, in order to enhance efficiency of work flow in this unique clinical environment. The system comprises of pre-, intra-, and post-operation modules which correspond to the different stages of the neurosurgery. The pre-op module was developed to store and categorize all images and data before the procedure to assist the surgeons in planning operation. The intra-op module integrates all the input signals, waveforms, images and videos that are produced by different imaging and physiological monitoring devices in the operation room during the surgery, and displays all the relevant information in a single large screen in real time to ease monitoring of the procedure. The post-op module helps surgeons to review all the data acquired from all the prior stages for follow-up of the treatment outcome. One-tumor case was utilized to test the pre-op module, and the signals and waveforms simulators were used to evaluate the performance of the intra-op module. In summary, two different medical informatics systems, a CAD and an ePR system were developed. Both showed promising results in laboratory tests. Future work would involve performance enhancement and feedback of the systems, and ultimately evaluation of these systems in the clinical environment. / published_or_final_version / Diagnostic Radiology / Master / Master of Philosophy

Human-caused destruction of xeric habitats in Florida that support gopher tortoises (Gopherus polyphemus Daudin) is occurring at a rapid rate. One conservation strategy that has been used for numerous taxa is translocation. The effects of translocation on the health, reproductive activity, and movements of translocated and resident telemetered individuals was evaluated for a population of gopher tortoises in central-Florida from 2001 to 2004. Only one of the 13 individuals released left the site during the study. The home range estimates of resident individuals were not significantly different before and after the release of the translocated individuals on the site, and all mean home ranges fit within the range of estimates reported in the literature for natural populations of gopher tortoises. Habitat use of several individual resident gopher tortoises was significantly different after the translocation events. The degree that the home ranges of the residents were overlapped by other individuals in the study was not significantly different. The spatial locations of the home ranges of resident and translocated individuals were significantly different. There was evidence of reproduction for both resident and translocated females a year after the release of the translocates. The body condition of the resident individuals was higher at the end of the study relative to the start, although this may be explained by other factors. This study illustrates some of the problems associated with studies designed to assess translocation success, namely the lack adequate baseline data for the population and the challenge of balancing the sample sizes necessary for acceptable statistical power with the mechanics of translocation. The results of this study suggest that translocation is a potentially useful conservation strategy, although there are other potential consequences of translocation that need to be considered prior to its implementation.