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Understanding Failure Mechanisms for Two Colorectal Anastomosis Techniques
No full textColorectal Surgery continues to be one of the most common gastrointestinal surgeries performed in the US. A common complication known as Anastomotic Leakage (AL) that threatens up to 30% of patients with this surgery. Many cases of AL can decrease the quality of life for patients or extensively extend hospital stays, and in many cases, lead to death. Researchers have studied this complication in clinical trials, yet few studied the mechanics of stapled anastomosis in controlled environments. The purpose of this research was to understand the mechanical interaction between the staples and the tissue, and to eventually apply it in a Finite Element Model (FEM). In doing so, the aim is to develop a resource “playground” for staple manufacturers to test and enhance current designs of staples and different anastomosis techniques before going to clinical trials. Firstly, to understand the colon tissue, an anisotropic -hyperelastic material model was introduced and calibrated to tensile testing data collected from freshly harvest porcine colon tissue. An initial FEM was developed to show the effectiveness of the model in predicting the stress and strain properties that were experimentally verified. Next, colon specimens were harvested from porcine tracts to compare two types of anastomosis techniques, End to End (EE) and End to Side (ES). Additionally, a control section of the tract was harvested to be used as a benchmark of a healthy colon tract. These specimens were subjected to burst testing to simulate the inflation of the colon, and burst pressures were recorded when AL occurred. The results showed no difference in the burst pressures of the EE and ES techniques, however showing more similar behavior of time to failure and expansion of ES and Control vs EE. Using this data, three FEM were developed to compare to the three specimens subjected to burst testing. The results showed a clear correlation to the experimental data
Understanding Levels of Perceived Racism and Discrimination When Utilizing Perinatal Care
No full textSocial and structural determinants of health, grounded in historical racism and discrimination, significantly influence maternal health outcomes. Because of this, communities of color experience a higher burden of maternal health disparities. In the last several decades, there has been an increased awareness of the need to integrate critical race theory into public health research to address maternal health disparities in the context of perinatal care delivery, policy, and funding decisions.
This three-manuscript dissertation utilized mixed methods to examine the ways in which systemic racism and discrimination are perceived and how it impacts the utilization of perinatal care services in historically marginalized communities. In the first two manuscripts, the perception of discrimination when utilizing perinatal care services among a sample of pregnant people and caregivers of children up to the age of three years old living in the West Las Vegas Promise Neighborhood (WLVPN) are examined and discussed. Taking into account these perceptions and experiences of discrimination, the third manuscript of this dissertation employs a person-centered approach to identify key components of community-based home-visiting perinatal care interventions that address social and structural barriers to care.
The findings of the two first manuscripts suggest that perceived discrimination in everyday and healthcare settings during perinatal care is significantly influenced by race/ethnicity and social and structural determinants of health within a historically marginalized community in Clark County, Nevada. The results of the third manuscript suggest key components, concepts, and areas such as community based participatory research principles, multisectoral collaboration, and sustainable funding sources for further exploration that may mitigate social and structural barriers to perinatal care utilization.
This study sheds light on the intricate relationship between experiences of racism and maternal health outcomes in perinatal settings. The findings emphasize the need for person-centered, culturally sensitive interventions aimed at addressing the unique social and structural barriers to care experienced by historically marginalized communities to improve maternal health outcomes across the lifespan
Implementing Radformation at Personalized Radiation Oncology: Enhancing Efficiency and Precision
No full textRadMachine is a data quality management application implemented at Personalized Radiation Oncology (PRO) to streamline quality assurance (QA) tests. It offers various functions assisting medical physicists in a radiation oncology clinic, including inputting, analyzing, managing, exporting, and monitoring QA data. Physicists create test lists following the recommendations provided by the American Association of Medical Physics (AAPM). These lists track results for units such as the Varian Edge, Varian BRAVOS, and Siemens SOMATOM go.Open Pro CT scanner. Ancillary equipment used for testing also has assigned test lists to store calibration factors and receive calibration expiration reminders. The primary goal of utilizing RadMachine is to standardize data management and tests performed, ensuring consistency evenwhen different physicists are covering duties. QA is conducted daily and monthly for the Varian Edge and Siemens SOMATOM go.Open Pro computer tomography (CT) scanner to verify proper unit performance. Therapists complete daily QA tasks in RadMachine, which physicists subsequently review. Monthly QA is undertaken by the physicists themselves. The Varian Edge\u27s monthly QA comprises six test list types: dosimetry for photons and electrons, imaging, multileaf collimator (MLC), beam profile, and mechanical aspects. Monthly QA for the CT scanner evaluates its image quality characteristics and spatial accuracy. The Nuclear Regulatory Commission (NRC) oversees radioactive sources. The Varian BRAVOS, a high dose rate afterloader with a high dose rate Iridium-192 (192Ir) source used for treatment, undergoes tests created in RadMachine to verify source activity, dwell position, timer accuracy, and safety interlocks. PRO also employs the radioactive source Lutetium-177 (177Lu) for its radiopharmaceutical program, requiring accurate measurements before and after infusion. Quality control tests on ancillary equipment ensure accurate readings. RadMachine facilitates data accessibility for regulatory review in a clear and organized manner. A debugging phase ensured all test lists were functioning properly. Previous QA data, recorded using spreadsheets, were used to validate the test lists\u27 return values. Once all test lists were debugged, all previous QA performed before using RadMachine was inputted into the system. However, not all data were recorded in RadMachine. Some images did not meet RadMachine\u27s requirements, such as the phantom not being fully imaged or insufficient separation between the phantom and the stand. The next steps for RadMachine involve setting up a dedicated server to host RadMachine and its local agent. This will allow PRO to fully utilize RadMachine\u27s automation features. Full automation includes automatically downloading images and scans into RadMachine. Additionally, test lists will need to be built to record results for the annual QA
Institutional Design of Intergovernmental Organizations: Cooperation, Vitality, and Evolution
No full textIntergovernmental organizations (IGOs) are critical institutions in the international system through which states cooperate and compete. Much scholarship has examined the role and operation of IGOs, but many questions about how they facilitate cooperation, their vitality, and their evolution remain. The functions of IGOs are impacted by their institutional design, which then affects operation and vitality. IGO’s perform their roles through multiple mechanisms that facilitate state interaction. IGOs enable states to overcome credibility issues and cooperate. The institutional design of IGOs, their membership, their resources, and their institutionalization, all impact the functioning of the IGO. I examine empirically how joint membership in more institutionalized IGOs impacts general cooperation between member states. I then test how institutionalization affects the survival of IGOs comprised of non-democratic members. Finally, I examine IGO succession using a novel sample of 44 IGO pairs and show that institutional design evolves through successor institutions. These analyses provide evidence demonstrating the importance of institutional design on the functioning, vitality, and evolution of IGOs and contributes to our understanding of the important role that IGOs play in the international system
Prediction Of Cost and Schedule Changes in Transportation Projects Through Historical Bid and Change Order Document Analysis – Using Oklahoma Dot Project Cases.
No full textConstruction bid documents encompass project specifications, drawings, schedules, and other critical details and are the foundation for project bidding and execution. Accurate bid documents are essential to ensure project bids are competitive, realistic, and aligned with requirements. However, bid documents are susceptible to risks from various sources. Failure to identify and rectify these risks can result in inaccurate cost estimates and higher bids. Therefore, identifying and resolving risks within bidding or contract documents are of utmost importance. While prior research has shed light on potential risk factors within the bid documents, a noticeable gap remains in the literature regarding identifying bid document-related risks through document-based analysis. Moreover, quantifying project cost and schedule variation remains a challenge. This study identifies bid document-related risks by analyzing pre-bid Request for Information (RFI) and quantifies project cost and schedule changes from change order documents. This study has two primary objectives: 1) identifying substantial bid document-related risks and 2) developing an automated model using Natural Language Processing (NLP) to assess cost and schedule changes for new projects. Historical bid and change order documents obtained from the Transportation-related projects of the Oklahoma Department of Transportation (DOT) are used to fulfill these objectives. The findings of this study showed that \u27pay item omission\u27 and \u27incorrect quantities\u27 are the most significant bid document-related risks for these transportation-related projects. This study enhances our understanding of risk likelihood and the specific risk types before bidding. The study also proposed a prediction model that gives an F1 score of 79% to forecast changes in cost and 72% for predicting schedule changes, achieving an overall prediction accuracy of 75.5% for cost and schedule changes. This result shows that the proposed model adequately forecasts cost and schedule changes from bid and change order documents. Since the model training and validation are carried out using transportation projects from Oklahoma DOT, the findings might not universally apply to all projects and all locations. However, the proposed methodology can be extended to various projects and adapted to suit different contexts with necessary modifications
Nuclear Fuel Cycle Chemistry: A Density Functional Study
No full textThe nuclear fuel cycle aptly describes the life cycle of nuclear fuel sources such as uranium. From its early forms in naturally bearing ores, to its high-temperature sintering into a fuel pellet, the chemistry uranium experiences throughout the fuel cycle is diverse, driving many experimental efforts towards understanding its chemistry to both improve nuclear technologies and advance the safety and handling of nuclear materials. Computing techniques and methodologies can be used to supplement experimental research and are readily available to researchers interested in utilizing computing-based data to support experimental findings. Density functional theory (DFT) is commonly practiced, reliably predicting the electronic ground states of molecular and crystal structures. The work presented in this thesis utilizes computational modeling for scenarios or simulations related to the nuclear fuel cycle, primarily employing DFT-coded programs to gather data that is then compared to or accompanied with experimental data. The ion-exchange behavior of a simple silicotitanate structure is examined, where the formation energies are compared to determine the favorability of the exchanged ion. A candidate crystal structure for an ammonium fluorouranate species is optimized to gather a theoretical diffraction pattern that is then compared to experimental sources. The optimization of a UO2 structure doped with CsI is replicated experimentally for comparisons of both research methods. Lastly, an early uranium oxide phase found in the fuel cycle is intentionally tagged with transition metals that are compared for their proclivity to imbed in the crystal matrix of the oxide
Projected Climate Change Impacts on the Number of Dry and Very Heavy Precipitation Days by Century’s End: A Case Study of Iran’s Metropolises
No full textThis study explores the impacts of climate change on the number of dry days and very heavy precipitation days within Iran’s metropolises. Focusing on Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz, the research utilizes the sixth phase of the Coupled Model Intercomparison Project (CMIP6) Global Circulation Models (GCMs) to predict future precipitation conditions under various Shared Socioeconomic Pathways (SSPs) from 2025 to 2100. The study aims to provide a comprehensive understanding of how climate change will affect precipitation patterns in these major cities. Findings indicate that the SSP126 scenario typically results in the highest number of dry days, suggesting that under lower emission scenarios, precipitation events will become less frequent but more intense. Conversely, SSP585 generally leads to the lowest number of dry days. Higher emission scenarios (SSP370, SSP585) consistently show an increase in the number of very heavy precipitation days across all cities, indicating a trend towards more extreme weather events as emissions rise. These insights are crucial for urban planners, policymakers, and stakeholders in developing effective adaptation and mitigation strategies to address anticipated climatic changes
\u3cem\u3eA Poetics of Handel’s Operas\u3c/em\u3e, by Nathan Link
No full textTextbooks and program notes summarize the relationship between story and music in opera seria with tidy bullet points: recitatives = action; arias = reflection; ensembles sometimes contribute to a story’s progression, while instrumental pieces typically do not. Nathan Link’s A Poetics of Handel’s Operas dismisses such generalizations as caricatures, going so far as to assert that opera seria is “easily among the most complex forms of storytelling yet devised” (p. 7). The author turns to narratological theory, with occasional forays into opera studies and cinema studies (including film music scholarship), to explain the “semantic decoding” (p. 2) that audiences must master to make sense of these drammi per musica
Top Tier 2.0: Community Partnership
No full textCommunity Partnerships have a positive long-term impact on our local communities. UNLV leverages resources for the public good to advance the university and the communities it serves. The value of the university is demonstrated through collaboration and engagement with the community to provide expertise, service, and support.https://oasis.library.unlv.edu/top_tier_focus/1030/thumbnail.jp
Agri-Tecture Aesthetic Designs Addressing Food Resilience in Urban Environments
No full textFood resilience in urban centers is increasing at risk due to climate change, economic costs, diminishing resources and ultimately the evolution of human society. As our way of life changes we must also adapt in how we grow, harvest and transport food. Hydroponic farms and innovative urban agriculture have proven to yield more food production with fewer resources than traditional agriculture methods. Urban centers throughout the world have been more of food deserts and rely on importation of over 90% of food. Proven urban farming methods can be integrated into existing buildings, such as rooftops, walls, warehouses, or vertical structures, to address food security resilience and create more green spaces in the city. City planners need to incorporate creative solutions to the changing needs of society. Architects will need to lead the design principles and strategies that incorporate Building Integrated Agriculture (BIA) as an everyday part of all design practices.
Note: the term “ Agri-tecture” has been used within the industry to fuse the concepts of agriculture and architecture. Its usage here is not intended to be original nor trademarked.https://oasis.library.unlv.edu/arch_grad_capstones/1053/thumbnail.jp