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X-ray grating interferometry allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, resulting from X-ray attenuation, refraction, and small-angle scattering, respectively. The modulated phase grating (MPG) interferometer is a recently developed grating interferometry system capable of generating a directly resolvable interference pattern using a relatively large period grating envelope function that is sampled at a pitch that is small enough that X-ray spatial coherence can be achieved by using a microfocus X-ray source or G0 grating. We present the theory of the MPG interferometry system for a 2-dimensional staggered grating, derived using Fourier optics, and we compare the theoretical predictions with experiments we have performed with a microfocus X-ray system at Pennington Biomedical Research Center, LSU. The theoretical and experimental fringe visibility is evaluated as a function of grating-to-detector distance. Additionally, quantitative experiments are performed with porous carbon and alumina compounds, and the mean normalized dark-field signal is compared with independent porosimetry measurements. Qualitative analysis of attenuation and dark-field images of a dried anchovy are shown.

As a growing number of states and municipalities consider reparative policies for Black Americans, it is important to understand what shapes support for and opposition to these policies. We explore the role that awareness of racial inequality plays in shaping attitudes. Drawing on data from a large, representative survey in Detroit and one national survey, we find that awareness of racial inequality plays a powerful role in the likelihood of supporting reparative policies. Yet, in follow-up surveys, we find that exposing respondents to information on the rationale for and importance of reparations does not shift public support. These findings suggest that it is the awareness of racial inequality that is cultivated over time that appears to be the dominant force in building support for reparations. These findings are particularly important during a time when many school districts are severely restricting access to information about the history of Black Americans.

Purpose:Modulated Phase Grating (MPG) interferometry has been shown in theory and simulations to produce observable fringes on a clinical detector without requiring fluence absorbing analyzer. In this work, we will experimentally show that the MPG X-ray system produces observable fringes and multi-modal X-ray images. Motivation:Nearly 1 in 8 women in the US will develop invasive breast cancer in their lifetime, accounting for approximately 40,000 deaths each year [1-2]. In order to pursue the best treatment option available, cancer itself must be adequately imaged and staged, based on size and level of metastasis, on the order of Stage I-IV. Currently, the most used imaging modality for breast cancer screening is mammography. Along with the traditional x-ray absorption images from mammography, the effects created from scattered x-rays at small angles (SAXS) can be utilized in the creation of multiple modalities generated from the same scan. Incorporating phase-shift and SAXS images in addition to the traditional attenuation images allow for an overall increase in contrast and the better detection of micro-calcifications, a risk factor for breast cancer. The advantage of MPG over prevalent Talbot Lau interferometry system is that MPG does not require fluence absorbing analyzer and therefore dose to patient can be maintained similar to conventional X-ray. Thus, MPGcan be usedfor breast cancer screening mammography. Methods: Experiments were performed with 8 keV test MPG gratings as well as two 25 keV MPG gratings, all manufactured by Microworks, GmbH. At LSU’s CAMD, the 8keV beamline was used to test the preliminary8 keV grating. We implemented both a deconvolution and linear optimization estimation method to remove the G0 grating effects seen in the detected fringe patterns. Experiments at Pacific Northwest National Lab (PNNL) were done using 25 keV design energy gratings placed in a X-ray tomography machine to test various constraints and limits of the proposed MPG system, leading us to the Pennington Biomedical Research Center (PBRC, LSU) experiments. Here, the Keck x-ray tomography machine (at PBRC) was used to measure the visibility at various set-up distances and imaged various samples (anchovy, chicken bone, seeds). Results:For the CAMD experiments, we successfully removed the G0 effects to get similar results from the deconvolution and linear optimization methods. The PNNL experiments showed the limit of larger detector pixel size for MPG system set-up. The PBRC experiments showed that we were again able to view fringe patterns of MPG, calculate visibility and also see attenuation and small angle X-ray scattering images of samples. Conclusion: The CAMD experiments yielded recovered fringe patterns with period lengths of 208um− 264um, roughly twice the period of the MPG used. At the PBRC, the visibility calculations illustrated that the farther the MPG is from the detector, the more the visibility increased. We obtained attenuation, differential phase and small angle x-ray scattering images of samples. The triangular MPG also yielded better results than the rectangular MPG used.

Political science scholars have long posited that Black Americans and women face penalties in terms of how they are evaluated by the American public. Some researchers emphasize intersectionality and have advanced the idea that Black female political figures are doubly disadvantaged due to their dual race-gender identity. This dissertation accordingly examines whether Black female political elites do indeed face a unique combination of disadvantages in the American political arena. I develop hypotheses based on previous studies that have examined the experiences of Black women in the political arena and beyond, particularly work suggesting the importance of intersectionality for understanding the combined effects of race and gender. And I examine both political attitudes and news coverage to identify the ways in which Americans’ beliefs about Black female political figures are (or are not) distinctive relative to White women, White men, and Black men. In order to test my hypotheses, I present a multi-methodological approach utilizing original survey and experimental data, as well as automated content analyses of media data. My findings reveal that voters are mostly (with some exceptions) unlikely to hold more negative attitudes toward Black women political elites relative to their counterpart groups. Additionally, I do not find that Black women political elites receive greater levels of negative news coverage when compared to their counterparts. At the same, I find that racial identity in and of itself is of great consequence for Black female political elites, even more so than gender identity; at times, Black female political elites experience penalties based on their racial identity alone, as opposed to their intersectional identity. Additionally, in the news, I find that Black women (and men) are also more likely to receive news coverage surrounding race and racial identity relative to their counterparts. Ultimately, this dissertation seeks to fill in the current gaps in the public opinion and political communication literatures, while also contributing critical knowledge surrounding Black women political elites, who remain understudied in these areas.

Political science scholars have long posited that Black Americans and women face penalties in terms of how they are evaluated by the American public. Some researchers emphasize intersectionality and have advanced the idea that Black female political figures are doubly disadvantaged due to their dual race-gender identity. This dissertation accordingly examines whether Black female political elites do indeed face a unique combination of disadvantages in the American political arena. I develop hypotheses based on previous studies that have examined the experiences of Black women in the political arena and beyond, particularly work suggesting the importance of intersectionality for understanding the combined effects of race and gender. And I examine both political attitudes and news coverage to identify the ways in which Americans’ beliefs about Black female political figures are (or are not) distinctive relative to White women, White men, and Black men. In order to test my hypotheses, I present a multi-methodological approach utilizing original survey and experimental data, as well as automated content analyses of media data. My findings reveal that voters are mostly (with some exceptions) unlikely to hold more negative attitudes toward Black women political elites relative to their counterpart groups. Additionally, I do not find that Black women political elites receive greater levels of negative news coverage when compared to their counterparts. At the same, I find that racial identity in and of itself is of great consequence for Black female political elites, even more so than gender identity; at times, Black female political elites experience penalties based on their racial identity alone, as opposed to their intersectional identity. Additionally, in the news, I find that Black women (and men) are also more likely to receive news coverage surrounding race and racial identity relative to their counterparts. Ultimately, this dissertation seeks to fill in the current gaps in the public opinion and political communication literatures, while also contributing critical knowledge surrounding Black women political elites, who remain understudied in these areas.

Controlled-release biodegradable polymers (CRBP’s) are an in-situ water remediation technology with potential use in managing the oxidation rate of contaminants in aquifer treatment systems. Hydrolysable polyesters are the key component to these structures, as their porosity and ester chain cleavage in aqueous environments allow for slow, sustained oxidant delivery to target sites while eliminating the need for physical removal of the CRBP system from the subsurface. Further slowing chemical release using multiple biodegradable polymers could improve the efficiency of these systems by providing a means of better controlling the chemical oxidation reaction and extending release duration. In this study, 3D printed poly-lactic acid (PLA) structures were used to partially coat a previously designed CRBP (which consisted of solid KMnO4 encapsulated in a poly-(ϵ-caprolactone), or PCL, matrix). Batch release studies were conducted in deionized water and were followed by a one-way ANOVA statistical analysis and post hoc Tukey test to assess significant differences in release kinetics due to PLA shells. A subsequent bacterial inactivation study was also conducted to investigate the ability for these designed structures to remediate high strength wastewater. Results from the statistical analysis revealed that by limiting PCL exposure to a single planar surface (Design 1) a statistically significant reduction in daily oxidant release can be achieved with p-values much lower than a 0.05 significance level. Additionally, it was found that changes in oxidant release rate compared to the control were dependent upon whether PLA shells facilitated KMnO4 diffusion through planar or curved PCL surfaces. Differences in bacteria reductions in wastewater samples treated with Design 1 and the control CRBP appeared to be insignificant following 48 hours of remediation. This suggested that these core and shell structures could be used to significantly reduce oxidant diffusion without significantly reducing remediation efficiency. While further research must be conducted to elucidate properties and limitations of these structures, these findings are promising for use in groundwater treatment systems requiring slower oxidant release due to aquifer properties (especially, natural oxidant demand).

X-ray grating interferometry allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, resulting from X-ray attenuation, refraction, and small-angle scattering, respectively. The modulated phase grating (MPG) interferometer is a recently developed grating interferometry system capable of generating a directly resolvable interference pattern using a relatively large period grating envelope function that is sampled at a pitch that allows for X-ray spatial coherence using a microfocus X-ray source or by use of a source G0 grating that follows the Lau condition. We present the theory of the MPG interferometry system for a 2-dimensional staggered grating, derived using Fourier optics, and we compare the theoretical predictions with experiments we have performed with a microfocus X-ray system at Pennington Biomedical Research Center, LSU. The theoretical and experimental fringe visibility is evaluated as a function of grating-to-detector distance. Quantitative experiments are performed with porous carbon and alumina samples, and qualitative analysis of attenuation and dark-field images of a dried anchovy are shown.

The intensive care unit (IGU) is a busy, high stress, complex environment in which health care professionals routinely provide numerous forms of advanced life support and life sustaining measures to a wide mix of critically ill patients. Frontline ICU professionals directly involved in patient care may be subjected to considerable psychosocial stressors and be susceptible to moral distress and burnout. To describe and compare the prevalence and contributing factors to moral distress and burnout among ICUprofessionals in a large quaternary cardiovascular surgery ICU (CVICU). Web-based survey of ICU professionals (registered nurses [RN]/nurse practitioners [NP]; registered respiratory therapists [RRT]; allied health [AH] and physicians [MD]) working in a 24-bed CVICU at the Mazankowski Alberta Heart Institute, between June 15-29, 2015. The survey captured sociodemographic data and integrated the Moral Distress Scale-Revised, the Maslach Burnout Inventory', and a validated job satisfaction questionnaire. One hundred sixty-nine providers completed the sur- vey (response rate 88%). The majority of respondents were aged 26-34 years old (45%), female (79%), married or common law (50%), full-time employed (78%) and had been working in the CVICU for >5 years (46%). Moral distress scores were highest among RN/NP (med [IQR] 80 [57-110]) and RRT (85 [61-104]) compared to AH (54 [39-66]) and physicians (66 [43-82], p=0.05). The highest-ranked sources of moral distress were related to controversies on end-of-life care (\"Continue to participate in the care for a hopelessly ill person who is being sustained on a ventilator, when no one will make a decision to withdrawal support\") and poor communication (\"witness healthcare providers giving false hope' to a patient or family\"). High, moderate and low levels of burnout syndrome were found in 64.0%, 22.7% and 13.3% of respondents with significantly greater levels among non-physician professionals (p<0.001). Job satisfaction was highest for physicians compared with other professionals (p<0.001). The item \"the recognition you get for good work\" was consistently rated as poor across all groups. Moral distress and burnout scores were positively correlated (p<0. 001), whereas both were neg- atively correlated with job satisfaction (p<0.001 for both). This was primarily driven by RN/NP scores. Moral distress and burnout are common in health- care professionals in a large academic cardiovascular surgery ICU, in particular among nurses and respiratory therapists. Both moral distress and burnout have a negative perception on job satisfaction. These findings will direct strategies to mitigate moral distress and burnout along with enhancing patient care and improving the workplace environment.