Institutional Repository

The University of Houston Institutional Repository (UHIR) collects, preserves and distributes scholarly output and creative works produced by the University of Houston community. UHIR provides free and open online access to the university’s research and scholarship, including electronic theses and dissertations.


Recent Submissions

Enablers and Inhibitors to Implementing Tobacco Cessation Interventions within Homeless-Serving Agencies: A Qualitative Analysis of Program Partners’ Experiences
(2024-06-06) Martinez Leal, Isabel; Siddiqi, Ammar D.; Rogova, Anastasia; Britton, Maggie; Chen, Tzuan A.; Williams, Teresa; Casey, Kathleen; Sanchez, Hector; Reitzel, Lorraine R.
Despite the high tobacco use rates (~80%) and tobacco-related cancers being the second leading cause of death among people experiencing homelessness within the United States, these individuals rarely receive tobacco use treatment from homeless-serving agencies (HSAs). This qualitative study explored the enablers and inhibitors of implementing an evidence-based tobacco-free workplace (TFW) program offering TFW policy adoption, specialized provider training to treat tobacco use, and nicotine replacement therapy (NRT) within HSAs. Pre- and post-implementation interviews with providers and managers (n = 13) pursued adapting interventions to specific HSAs and assessed the program success, respectively. The organizational readiness for change theory framed the data content analysis, yielding three categories: change commitment, change efficacy and contextual factors. Pre- to post-implementation, increasing challenges impacted the organizational capacity and providers’ attitudes, wherein previously enabling factors were reframed as inhibiting, resulting in limited implementation despite resource provision. These findings indicate that low-resourced HSAs require additional support and guidance to overcome infrastructure challenges and build the capacity needed to implement a TFW program. This study’s findings can guide future TFW program interventions, enable identification of agencies that are well-positioned to adopt such programs, and facilitate capacity-building efforts to ensure their successful participation.
Experimental Study on Pulsed Plasma Stimulation and Matching with Simulation Work
(2024-05-31) Khalaf, Mina; Soliman, M.; Farouq-Ali, S. M.; Cipolla, Craig; Dusterhoft, Ron
Plasma stimulation is a form of waterless fracturing as it requires that only the wellbore be filled with an aqueous fluid. The technique creates multiple fractures propagating in different directions around the wellbore. The intent of this paper is to present an experimental and numerical investigation of the degree of competitiveness of plasma stimulation with hydraulic fracturing, especially in the case of stimulating tight formation. Several cases were run experimentally. The samples included limestone and sandstone to investigate plasma fracturing in different rock types. In addition, the main goal of the experiments was to study the creation of fracture(s) under confining stresses, the type of rock, the amount of electrical energy used in the experiment, and the length of the wire to generate the plasma reaction. A laboratory plasma equipment was designed and used to accomplish the experimental work. The experiments were then numerically matched using a finite element numerical simulator, HOSS developed by LANL (Los Alamos National Lab). HOSS was developed to simulate high-strain-rate fractures such as those created by plasma stimulation. It accounts for mixed-mode fracture mechanics which are tensile and shear fractures. The simulator governing equations obey the conservation of mass and momentum in a solid-mechanics sense and account for the nonlinear deformation of rock material. The matching of the experiment allowed us to validate the HOSS simulation of the process and showed that the numerical results are in good agreement with the experimental work. Using the HOSS simulator, we also investigated the effect of higher energy levels and/or short release time on a cement rock model. The pressure profile that is developed due to the energy release can vary in the peak pressure and the release time. The results showed that the plasma fracturing technique is an effective stimulation method in sandstone and limestone. Plasma fractures were developed in the rock samples and extended from the sample wellbore to the outer boundaries. The shape of the pressure pulse has an impact on the developed fractures. Moreover, the effect of plasma stimulation on natural fractures was studied numerically. It was found that natural fractures can arrest the plasma-generated fractures that propagate from the wellbore to the outer boundaries. However, new fractures may develop in the rock starting from the natural fracture tips.
Prevalence of Metabolic Syndrome Based on Activity Type and Dietary Habits in Extremely Low-Income Individuals
(2024-05-29) Su, Kunxia; Kim, Yonghwan; Park, Yoonjung
A high prevalence of metabolic syndrome (MS) and cardiovascular disease among low-income individuals has often been reported. However, there is still a lack of research on the relationship between basic livelihood security (BLS) and MS. This study investigated the prevalence of MS according to activity type, dietary habits, and the nutrient intake characteristics of individuals receiving BLS. Data from 14,803 men and 20,299 women were analyzed to assess the association between receiving BLS and MS. The associations between MS and various factors were analyzed separately in men and women by logistic regression analysis. In this cohort, 5.9% of men and 6.8% of women received BLS; of these, 46.9% and 47.7% had MS, respectively. High caloric intake, low-frequency breakfast consumption, and no nutritional education were associated with MS in both men and women. Among those with a low-frequency walking habit and strength training activity type, MS increased by 1.58 and 1.57 times in men and by 1.47 and 2.16 times in women, respectively. Men who were sedentary for 8 h or more had an increased risk of MS, but there was no association between these in women. BLS nutritional intake characteristics were high in carbohydrates and fat and low in dietary fiber and vitamin C (p < 0.05). In conclusion, establishing a healthy eating pattern through nutritional education and increasing walking and strength training may reduce the risk of MS.
Availability of morphine sulfate and meperidine hydrochloride in total parenteral nutrition
(1984) Macias, Jean M.; Martin, William J.; Lloyd, Charles W.; Driever, Carl W.; Gupta, V. Das
At a comprehensive cancer center, patients experiencing severe chronic pain are managed by continuous infusion of narcotics via their TPN solutions. In some cases, patients have reported recurrence of pain when their narcotics were added to their TPN solutions shortly after titration in D5W. The purpose of this study was to evaluate the compatibility, stability and availability of two narcotics (morphine sulfate and meperidine hydrochloride) prepared in TPN and D5W. For this study a usual dose (300 mg) of each narcotic was mixed in the same types of products utilized with these patients (0.25 L bags of D5W and 3 L bags of TPN). Visually, each solution was examined immediately post-addition of drug to the bag and then every 12 hours for 36 hours. By high performance liquid chromatography (HPLC), the narcotic concentrations for each solution were determined prior to addition of drug to the bag, immediately post-addition of drug to the bag, and continuing every 4 hours for 36 hours. Results demonstrated no significant loss of morphine sulfate or meperidine hydrochloride due to adsorption to the polyvinyl chloride (PVC) bags. In addition, both narcotics were physically and chemically compatible, as well as, stable and available for at least 36 hours when stored at 21.5[degrees] C with no protection from environmental light.
Benzylamine oxidase activity in pathological states
(1984) Hayes, Barbara Elaine; Clarke, David E.; Lokhandwala, Mustafa F.; McCalden, Thomas A.; Miller, Harold H.; Ostrow, Peter T.
Benzylamine oxidase (BzAO) is an amine oxidase of unknown physiological significance. However, clinical studies show that BzAO activity is elevated in the serum of patients with fibrotic disorders and during growth spurts in children. Some workers have suggested, therefore, a functional association of BzAO in the biochemistry of connective tissue. The objective of the present research was to test this proposed association by measuring BzAO activity in conditions exhibiting enhanced connective tissue growth and proliferation. BzAO activity was measured in cellular systems as well as in serum, utilizing both human and animal tissues (human atherosclerotic aortae, bleomycin-induced lung fibrosis in rats, spontaneously hypertensive rats, and the hormonally manipulated rat uterus). No specific relationship between the activity of BzAO and connective tissue growth was found. BzAO activity was decreased significantly in plaque regions of atherosclerotic aortae, but this decrease was due to a reduced cell population density compared with nonplaque areas and normal aortae. In bleomycin-treated lungs, lysyl oxidase activity increased markedly, but again BzAO activity showed no specific change (lung and serum). Overall, similar negative results were found in hypertensive rats and in the rat uterus. In rat uteri (ovariecto-mized and estrogen-treated), BzAO activity was found to follow passively organ weight changes and, unlike monoamine oxidase, was unresponsive to direct hormonal influences. Since BzAO may be located predominantly in association with the smooth muscle cells of uterine blood vessels, changes in the activity of uterine BzAO may reflect changes in the vascularity of this organ (number of blood vessels per unit weight or wall thickness or both). An organ specific, disease dependent change in BzAO activity was found in diabetic rats where the activity of the serum and kidney enzyme was elevated in association with hyperglycemia. BzAO activity of lung, aorta and pancreas did not change significantly. Studies showed a different substrate profile for BzAO in the serum and kidney from that in aorta, lung and pancreas, indicating a possible heterogeneity of BzAO activity. It is speculated that elevations in the activity of serum BzAO may be reflective of renovascular damage associated with diabetes mellitus.