OBJECTIVES : This work studies the indications, methods, results , satisfaction and partner relationships in immediate (IBR ) and deferred breast reconstruction ( DBR ) to objectively consider the benefits and indications IBR . METHOD : IBR between 1/2002-12/2012 underwent 51 ( 33.33 %) women ( 29-58 years, mean 41.5 , median 40.5 ) ; DBR 102 ( 66.67 %) ( 31-64 , mean 47.5 , median 47 ), data were obtained from medical records , questionnaires interviews and questionnaires , processed by statistical analysis RESULTS : Indications IBR : ≤ pT2N0M0 , low grade tumor ; DBR : ≥ 1 year of remission. Age at IBR was lower than the DBR ( p- 0.0004 ) Statistical differences in the modes of life after reconstruction the IBR a DBR were observed ( p- 0.1935-0.9659 ) predominates full and prevailing contentment. IBR does not burden patients ( 55 to 160 min, average 91.1 and 139.3 min, median 75 and 135 min ) between unilateral and bilateral operations are not statistically significant differences ( p -value 0.1065 ) . Complications prolonging healing rare - IBR 5 ( 8.33 %) , DBR 6 ( 5.8 % ) and mortality generalization low - IBR and 1 ( 1.96 % s ) DBR 1 and 2 ( 0.98 % and 1 , 96%) . Satisfaction with IBR was reported by 84.09 % , with 86.11 % DBR . The DBR was found 4 times greater risk of life or relationship. SUMMARY:...

The aim of this study is the three-dimensional structural characterization of the genome packaging inside viral capsids via cryo-electron microscopy and three-dimensional reconstruction. The genome of some single-stranded viruses can be densely packaged within their capsid shells. Several stretches of the genome are known to adopt stable secondary structures, however, to date, little is known about the three-dimensional organization of the genome inside their capsid shells. Two techniques have been developed to facilitate the structural elucidation of genome packaging: the asymmetric random-model method, and the symmetry-mismatch, random model method. Both techniques were successfully tested with model and experimental data. The new algorithms were applied to study the genome structure of poliovirus and satellite tobacco mosaic virus. We have not yet found a consistent structure for the two genomes. Nevertheless, we have found that the genome of satellite tobacco mosaic genome is very stable, supporting a model where the RNA acts as a scaffold, with potential implications in capsid stability and assembly.

No description available.

Monte Carlo is an important and well established research tool used in emission tomography. While used extensively in research applications, these techniques are not typically implemented clinically due to their low detection efficiency and long acquisition times. In order to make this computational tool faster, the variance reduction technique known as convolution-based forced detection (CFD) has been implemented into the SIMIND MC code (CFD-SIMIND) by our group. Briefly, at each site of interaction within the object, photons are forced to travel in a direction perpendicular to the detector and are then convolved with a distance dependent blurring kernel specific to that collimator and photon energy. A similar CFD method has already been implemented as an option in the SIMIND Monte Carlo program. The study presented in Chapter 2 performs a comparison between a well established, non-VRT Monte Carlo program, GATE, with our accelerated CFD-SIMIND. The intent of this work is to establish if CFD-SIMIND can either replace or be used in conjunction with GATE in order to gain significant reduction in simulation times for low and medium energy isotopes. A number of simulation studies were performed using point sources in air and water, along with the 3D XCAT phantom and a rectangular sheet source for Tc-99m with low and medium energy collimator and In-111 with medium energy collimator. A comparison in the projection domain was then performed in terms of spatial resolution, sensitivity, image profiles and energy spectra. The study has shown percent differences of between 3−5% in sensitivity between CFD-SIMIND and GATE with mean universal image quality index value of 0.994 ± 0.009 and spatial resolution within 0.2 mm of each other. CFD-SIMIND offers a significant reduction in simulation time by a factor of 5−6 orders of magnitude compared to GATE. This acceleration time is useful for many applications. This study also provides an objective tool that can help to determine if CFD-SIMIND can be used in place of GATE in order to achieve images of sufficient quality within a reduced time and at much lower computational cost. Simultaneous multi-isotope SPECT imaging has a number of applications in cardiac, brain and cancer imaging. The major concern however, is the significant crosstalk contamination due to photon scatter between the different isotopes. The second study (Chapter 3) focuses on a method of downscatter compensation between two isotopes iii in simultaneous dual isotope SPECT acquisition applied to cancer imaging using Tc-99m and In-111. We have developed an iterative image reconstruction technique that simulates the photon down-scatter from one isotope into the acquisition window of a second isotope. Our approach uses CFD-SIMIND for the forward projection step in an iterative reconstruction algorithm. The MC estimated scatter contamination of a radionuclide contained in a given projection view is then used to compensate for the photon contamination in the acquisition window of other nuclide. We use a modified ordered subset-expectation maximization (OS-EM) algorithm named simultaneous ordered subset-expectation maximization (Sim-OSEM), to perform this step. In this study, we have undertaken a number of simulation tests and phantom studies to verify this approach. The proposed reconstruction technique was also evaluated by reconstruction of experimentally acquired phantom data. Reconstruction using Sim- OSEM showed very promising results in terms of contrast recovery and uniformity of object background compared to alternative reconstruction methods implementing alternative scatter correction schemes (i.e., triple energy window or separately acquired projection data). In this study the evaluation is based on the quality of reconstructed images and activity estimated using Sim-OSEM. In order to quantitate the possible improvement in spatial resolution and signal to noise ratio (SNR) observed in this study, further simulation and experimental studies are required. It is perceived that in simultaneous dual-isotope breast SPECT studies using 123I-labelled Z-MIVE and Tc-99m sestamibi, I-123 labelled Z-MIVE not only detects the presence of estrogen receptor (ER) but, also thought to complement Tc-99m sestamibi in differentiating between benign and malignant breast lesions for patients with breast cancer (Chapter 4). The major concern in simultaneous Tc-99m/I-123 SPECT is the significant crosstalk contamination between the different isotopes used. The current study focuses on a method of crosstalk (downscatter and spillover) compensation between two isotopes with data acquired using Thallium activated Sodium Iodide (NaI(Tl)) detector (Energy resolution 9.8% at 140 keV ) and Cadmium Zinc Telluride (CZT) detector (Energy resolution 5% 140 keV ) respectively. The study uses Sim- OSEM for crosstalk compensation between the isotopes. We have undertaken a number of simulation studies using our modeled breast phantom to verify this approach. Reconstruction using Sim-OSEM showed very promising results in terms of crosstalk and scatter compensation and uniformity of background. In our case images obtained using Sim-OSEM were comparable or even better than the images reconstructed from separately acquired projection data using analytical attenuation based reconstruction. This may be due to better small angle scatter compensation in case of Sim-OSEM as CFD-SIMIND based MC forward projector was used. Compensation of the image degradation effects (i.e. attenuation, scatter and collimator-detector response) is necessary for an accurate quantification in SPECT imaging. We have previously proposed an accelerated Monte Carlo (MC) based iterative SPECT reconstruction algorithm that accurately corrects for attenuation and scatter once provided with attenuation information (Chapters 3 and 4). This algorithm uses SIMIND MC program accelerated through the implementation of a variance reduction technique known as, convolution forced detection (CFD), (CFD-SIMIND). With ever increasing number of hybrid SPECT/CT systems, CT-based attenuation correction is becoming a standard clinical protocol. This co-registered CT image with SPECT data can also be used to incorporate anatomical information as a prior into a maximum a-posteriori (MAP) SPECT image reconstruction algorithm. The study presented in Chapter 5 proposes a MAP reconstruction algorithm that includes CFD-SIMIND as a forward projector and a CT-image as an anatomical prior (CFD-AMAP) for simultaneous compensation of scatter and attenuation and, enhancement of spatial resolution during reconstruction. We have performed a number of simulation and experimental studies to elaborate the advantages of CFD-AMAP. These studies show an accurate quantification (within ±5% and ±8% for simulation and experimental studies respectively) accompanied by a significant reduction in coefficient of variation (CoV ). This reduction of CoV results in an improved boundary delineation and the Gibbs artifact compensation. However, this compensation comes at the cost of loss of an overall contrast in the reconstructed images due to a more uniform distribution of estimated activity over the regions of interest (ROI’s). Further studies with more complex phantoms and real patient data, task-based ROC studies, improvement in CFD-SIMIND in terms of speed and use of better Bayesian image reconstruction algorithms are needed to elaborate on the strengths and weaknesses of this proposed MC based forward projector and to pave the way for CFD-SIMIND based image reconstruction algorithms from research to clinic. / Thesis / Doctor of Philosophy (PhD)

This is a work of local history examining the course of Reconstruction in Collin County, Texas. National and state level surveys of Reconstruction often overlook the experiences of communities in favor of simpler, broader narratives. The work proceeds chronologically, beginning with the close of the Civil War, and tells the story of Collin County as national Reconstruction progressed and relies on works of professional and non-academic historians, oral histories, census data, and newspapers to present a coherent picture of local life, work, and politics. The results exemplify the value of local history, as local conditions influenced the course of events in Collin County as much as those in Austin and Washington D.C. The story of Reconstruction in Collin County is one of anomalous political views resulting from geographical exclusion from the cotton culture of Texas followed by a steady convergence. As Reconstruction progressed, Collin County began to show solidarity with more solidly conservative Texas Counties. The arrival of railroads allowed farmers to move from subsistence agriculture to cash crop production. This further altered local attitudes toward government, labor, voting rights, and education for Freedmen. By the end of Reconstruction, Collin County had all but abandoned their contrarian social and political views of the 1850s and 1860s in favor of limited rights for blacks and Redemption. The results show the importance of local history and how Collin County’s Reconstruction experience enriches and deepens how historians view the years after the Civil War. The author recommends further research of this kind to supplement broader syntheses.

No description available.

Image-based 3D reconstruction has been employed in industrial metrology for micro measurements and quality control purposes. However, generating a highly-detailed and reliable 3D reconstruction of non-collaborative surfaces (textureless, shiny, and transparent) is still an open issue. This thesis presents various methodologies to successfully generate a highly-detailed and reliable 3D reconstruction of non-collaborative objects using the proposed photometric stereo image acquisition system. The first proposed method employs geometric construction to integrate photogrammetry and photometric stereo in order to overcome each technique's limitations and to leverage each technique's strengths in order to reconstruct an accurate and high-resolution topography of non-collaborative surfaces. This method uses accurate photogrammetric 3D measurements to rectify the global shape deviation of photometric stereo meanwhile uses photometric stereo to recover the high detailed topography of the object. The second method combines the high spatial frequencies of photometric stereo depth map with the low frequencies of photogrammetric depth map in frequency domain to produce accurate low frequencies while retaining high frequencies. For the third approach, we utilize light directionality to improve texture quality by leveraging shade and shadow phenomena using the proposed image-capturing system that employs several light sources for highlighting roughness and microstructures on the surface. And finally, we present two methods that effectively orient images by leveraging the low-contrast textures highlighted on object surfaces (roughness and 3D microstructures) using proper lighting system. Various objects with different surface characteristics including textureless, reflective, and transparent are used to evaluate different proposed approaches. To assess the accuracy of each approach, a comprehensive comparison between reference data and generated 3D points is provided.

High-resolution micro computed tomography (micro-CT) offers 3D image resolution of 1 um for non-destructive evaluation of various samples. However, the micro-CT performance is limited by several factors. Primarily, scan time is extremely long, and sample dimension is restricted by the x-ray beam and the detector size. The latter is the cause for the well-known interior problem. Recent advancement in image reconstruction, spurred by the advent of compressed sensing (CS) theory in 2006 and interior tomography theory since 2007, offers great reduction in the number of views and an increment in the volume of samples, while maintaining reconstruction accuracy. Yet, for a number of reasons, traditional filtered back-projection based reconstruction methods remain the de facto standard on all manufactured scanners. This work demonstrates that CS based global and interior reconstruction methods can enhance the imaging capability of micro-CT scanners. First, CS based few-view reconstruction methods have been developed for use with data from a real micro-CT scanner. By achieving high quality few-view reconstruction, the new approach is able to reduce micro-CT scan time to up to 1/8th of the time required by the conventional protocol. Next, two new reconstruction techniques have been developed that allow accurate interior reconstruction using just a limited number of global scout views as additional information. The techniques represent a significant progress relative to the previous methods that assume a fully sampled global scan. Of the two methods, the second method uses CS techniques and does not place any restrictions on scanning geometry. Finally, analytic and iterative reconstruction methods have been developed for enlargement of the field of view for the interior scan with a small detector. The idea is that truncated projections are acquired in an offset detector geometry, and the reconstruction procedure is performed through the use of a weighting function / weighted iteration updates, and projection completion. The CS based reconstruction yields the highest image quality in the numerical simulation. Yet, some limitations of the CS based techniques are observed in case of real data with various imperfect properties. In all the studies, physical micro-CT phantoms have been designed and utilized for performance analysis. Also, important guidelines are suggested for future improvements. / Ph. D.

This study was a comprehensive evaluation of population reconstruction techniques. Population reconstruction techniques are population estimation methods that calculate a minimum population size based on age-specific harvest data (Downing 1980, Roseberry and Woolf 1991). Population reconstruction techniques share the following characteristics: 1) utilization of catch-at-age data and 2) backward addition of cohorts to estimate a minimum population size. I developed a questionnaire to survey the biologists participating in this survey to determine the most common reconstruction technique used to estimate population sizes of exploited white-tailed deer (Odocoileus virginianus) and black bear (Ursus americanus). Downing reconstruction (Downing 1980) was the most commonly used reconstruction technique among biologists participating in this study. Based on a comprehensive literature review and discussions with state biologists, I decided to evaluate virtual reconstruction (Roseberry and Woolf 1991) and develop a new reconstruction technique: Reverse Order reconstruction. I developed a quantitative population model in Microsoft Visual Basic 6.0 to evaluate the ability of the 3 reconstruction techniques to estimate population sizes given a variety of conditions. I evaluated the effects of stochasticity on reconstruction population estimates by incorporating different levels of environmental stochasticity (i.e. process error) and measurement error in the generated or "known" population. I also evaluated the effects of collapsing age classes and aging biases on population estimates. In all conditions, Downing and virtual reconstruction were underestimates of the actual population size. Reverse Order reconstruction more closely estimated the actual population size, but is also more data-intensive than the other 2 methods. Measurement error introduces more uncertainty in the reconstructed population estimates than does process error. The population simulation model proved that Downing and virtual reconstruction are consistently underestimates and the percent underestimation is due to lack of inclusion of a natural mortality rates in population estimation. I used the results of the questionnaire to characterize the harvest datasets of the states participating in this study. From these results, I chose two harvest datasets to further analyze: a white-tailed deer harvest dataset from North Carolina and a black bear harvest dataset from Pennsylvania. I analyzed these datasets with Downing and virtual reconstruction. I also applied the quantitative population model to these datasets to evaluate the effect of increasing levels of measurement error on the variance of the population estimates. I found that Downing and virtual reconstruction estimated the population sizes very closely to one another, within 5%, for both datasets, and the reconstructed estimates closely tracked the actual harvest numbers. I also found that increasing levels of measurement error increased the variance associated with reconstructed population estimates and may decrease the ability of these techniques to accurately capture population trends. / Master of Science

Non-intrusive acoustic thermometry using an acoustic impulse generator and two microphones is developed and integrated with tomographic techniques to reconstruct temperature contours. A low velocity plume at around 450 °F exiting through a rectangular duct (3.25 by 10 inches) was used for validation and reconstruction. 0.3 % static temperature relative error compared with thermocouple-measured data was achieved using a cross-correlation algorithm to calculate speed of sound. Tomographic reconstruction algorithms, the simplified multiplicative algebraic reconstruction technique (SMART) and least squares method (LSQR), are investigated for visualizing temperature contours of the heated plume. A rectangular arrangement of transmitter and microphones with a traversing mechanism collected two orthogonal sets of acoustic projection data. Both reconstruction techniques have successfully recreated the overall characteristic of the contour; however, for the future work, the integration of the refraction effect and implementation of additional angled projections are required to improve local temperature estimation accuracy. The root-mean-square percentage errors of reconstructing non-uniform, asymmetric temperature contours using the SMART and LSQR method are calculated as 20% and 19%, respectively. / Master of Science / Computational tomography is an approach to reconstruct the cross-sectional planar image of a 3D object. This technique is widely used in the medical field using x-rays to visualize cross-sections of internal organs. Along with x-rays, acoustic rays can also be utilized with tomographic techniques. The speed of sound travelling through a gaseous medium, such as air, is depended on the density, humidity, and temperature of the medium. Using this relationship, the temperature of the medium can be calculated with known speed of sound, density, and humidity. The speed of sound can be found using the distance and time of flight of the acoustic ray using transmitter and microphones. Since the effect of density and humidity of the medium on speed of sound is relatively insignificant, those values were assumed to be constant. In this research, the acoustic temperature measuring technique using the speed of sound relationship was applied and validated, then the technique was integrated with tomography using two projection angles. A rectangular duct (3.25 by 10 inches) with a heated air at around 450 °F exiting the duct was tested. The calculated temperature from acoustics was compared with values measured with thermocouples. After the acoustic temperature measuring technique was validated, multiple acoustic rays arranged in two orthogonal projections were setup. The speed of sound values from the acoustic rays were utilized to reconstruct the temperature distribution of the duct exit using two tomographic reconstruction methods: LSQR and SMART. Both reconstruction techniques have captured overall contour of the temperature. More projection angles and sound refractive properties will be utilized in the future to overcome the limitations of detailed reconstruction.