Verification of the proteus two-dimensional Navier-Stokes code for flat plate and pipe flows

The Proteus Navier-Stokes Code is evaluated for 2-D/axisymmetric, viscous, incompressible, internal, and external flows. The particular cases to be discussed are laminar and turbulent flows over a flat plate, laminar and turbulent developing pipe flows, and turbulent pipe flow with swirl. Results are compared with exact solutions, empirical correlations, and experimental data. A detailed description of the code set-up, including boundary conditions, initial conditions, grid size, and grid packing is given for each case

Investigating The Dysregulation And Therapeutic Potential Of Neuroprotective Stress Response Proteins In Huntington’s Disease

Huntington’s disease (HD) is a fatal, genetic neurodegenerative disease that shares many features with other common neurological disorders, including early synapse loss. In both human HD brain and murine models, apoptotic pathways are dysregulated and mammalian target of rapamycin complex 1 (mTORC1) activity is reduced. These pathways are of particular interest because they regulate cell survival and metabolism, and enhancing mTORC1 is protective in HD models. RNA binding motif protein 3 (RBM3) is a stress response protein that promotes synaptic plasticity and cell survival, and is dysregulated in Alzheimer, prion and HD models. Hippocampal overexpression of RBM3 in Alzheimer and prion murine models is neuroprotective and in the setting of prion disease is mediated by reticulon 3 (RTN3), a downstream target of RBM3. Here, I show that RBM3 and RTN3 are dysregulated in in vitro and in vivo models of HD. I find that overexpressing RBM3 isoform 1 or RTN3 in the striatum of HD mice does not rescue disease phenotypes. I also find that overexpressing RBM3 isoform 1 or 2 in the striatum does not increase RTN3 levels as expected. Further, I provide evidence that cold stress and RBM3 overexpression enhances components of the mTORC1 pathway in vitro and in vivo. My combined work indicates that the RBM3-RTN3 axis may function differently in the striatum, possibly contributing to striatal vulnerability in HD, and that while RBM3 enhances components of the mTORC1 pathway, it is insufficient to rescue HD phenotypes

The Efficacy of STEMI Networks and Systems of Coordinated STEMI Care: An Evaluation of the Implementation of a STEMI Network

Purpose: The purpose of this project was to evaluate the implementation of an ST-elevation myocardial infarction (STEMI) Network into a large metropolitan healthcare system in Kentucky. The objectives of this project were to (1) determine if (and to what extent) the implementation of the STEMI Network decreased walk-in, emergency medical services (EMS), and transfer door to balloon (D2B) times at a STEMI receiving center at a metropolitan Kentucky academic hospital, (2) determine if there is a difference in treatment times for those individuals who present during working hours compared to non-working hours of the day, and (3) examine the associations between STEMI processes and specific patient characteristics (age, gender, race, body mass index, and various co-morbidities). Setting: This project was conducted in an in-hospital invasive cardiovascular laboratory at a large metropolitan tertiary care and multi-organ transplant center located in Kentucky. Population: Among the sample 69.9 % were male and 30.1 % were female. 80.1 % of the sample was Caucasian and 17.9 % were African American. Those included had an average age of 59 years (SD= 13.8), the mean body mass index (BMI) was 29.0% (SD=7.5), and 65.5% percent presented during non-working hours, while 34.5 % presented during working hours. Inclusion criteria: Patients 18 years or older with the principal diagnosis of a STEMI who presented as a walk-in to the ED, via EMS directly to the receiving facility or as a transfer patient from one of the referring hospitals within a 35 mile radius of the receiving hospital during three separate time periods. Design & Methods: A retrospective study of electronic medical record data was conducted to evaluate the efficacy of a STEMI Network during three separate four consecutive month long time frames. ICD-9 codes 410.0-410.9 and medical record numbers were obtained by the Information Technology Department at a large metropolitan hospital in Kentucky. The data review included age, gender, race, height, weight; history of hypertension, diabetes mellitus, prior MI; zip code of patient presenting via EMS; FMC time, door time, first medical contact time, EKG time, cardiac catheterization lab door time, and device time, and time of day categorized into working and non-working hours. Results: When examining the comparison between the two cohorts pre-implementation (n=32) versus post-implementation (n=82) the overall mean D2B time dropped from a pre-implementation mean time of 136.3 minutes to 80.5 minutes (log p-value = .005). The interaction between D2B times and pre/post cohort group was statistically significant with a p-value = .017. Walk-in and transfer patients all had D2B times that decreased when comparing pre to post-implementation D2B times. While EMS patients did not show a statistically significant decrease in times, there was still a decrease from mean of 85 minutes to a mean of 76 minutes with those patients exhibiting the lowest overall D2B times. Furthermore, patients who presented during non-working hours (pre-implementation log mean time of 202 minutes and a post-implementation log mean time of 88 minutes) and as transfers (pre-implementation log mean time of 238.6 minutes and post-implementation log mean time of 88.8 minutes) seemed to have the greatest benefits of the STEMI Network

The Effects of Specialized Pro-Resolving Mediator Lipoxin A4 on Pseudomonas aeruginosa Biofilms and Interactions with Monocytes

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor. The studies presented here suggest SPM inhibition of biofilm formation has selectivity, and that LxA4 can reduce P. aeruginosa biofilm formation, possibly through reducing quorum sensing virulence gene expression. LxA4 also shows improvement to the efficacy of antibiotics against P. aeruginosa infection. In combination, LxA4 and ciprofloxacin increase killing of biofilm-associated bacteria in established biofilms, which may be an effect of LxA4 reducing quorum sensing gene expression, thereby reducing biofilm formation, and allowing better penetration of ciprofloxacin into the biofilm. When co-incubated with established biofilms, untreated THP-1 monocytes induced a rise in the proportion of live bacteria. Importantly, LxA4 pre-treatment of monocytes abolished this induced reaction from the bacterial population. Also of great significance, LxA4 pre-treatment increases the adhesion ability of the monocytes to the established biofilms, suggesting an increased duration of direct contact to be a possible method for increased host immune response against biofilms. TNF-α production of pre-treated monocytes showed an initial hyper-inflammatory response to co-incubation with established biofilms but resolved to circulating levels roughly half that seen in untreated monocytes, suggesting LxA4 pre-treatment enhances the initial activation of immune response mechanisms, which then necessitates a quicker approach to inflammation resolution. In summary, these studies highlight the possibilities of LxA4 as an additive treatment against P. aeruginosa infections in two ways: by acting in conjunction with antibiotics directly on bacteria and biofilms; and by priming host immune cells to achieve infection resolution more effectively

Receipt of Health Information, Body Mass Index, And Physical Activity And Dietary Behaviors Among University Students

This study examined relationships between receipt of health information, body mass index (BMI), and dietary and physical activity behaviors in a sample of university students (n=1,799). A cross-sectional design assessed health-risk behaviors. Students were placed into dichotomous categories related to receipt of health information, then grouped by risk and non-risk for each dependent behavioral variable; descriptive statistics were then generated. Odds ratios assessed relationships between receipt of health information and activity, diet, and nutrition for normal-weight and overweight students; odds ratios also assessed associations between BMI and diet and activity behaviors. Post-hoc analyses were also conducted. Students who received health information were more likely to: attempt weight-loss; diet; exercise at recommended levels; and eat well. Normal-weight students behaved more optimally than overweight students after receiving health information. Health messages may provide limited benefits regarding health-promoting behaviors; information should be but one component of a comprehensive strategy to target high-risk students

Contributions of visual speech, visual distractors, and cognition to speech perception in noise for younger and older adults

Older adults report that understanding speech in noisy situations (e.g., a restaurant) is difficult. Repeated experiences of frustration in noisy situations may cause older adults to withdraw socially, increasing their susceptibility to mental and physical illness. Understanding the factors that contribute to older adults’ difficulty in noise, and in turn, what might be able to alleviate this difficulty, is therefore an important area of research. The experiments in this thesis investigated how sensory and cognitive factors, in particular attention, affect older and younger adults’ ability to understand speech in noise. First, the performance of older as well as younger adults on a standardised speech perception in noise task and on a series of cognitive and hearing tasks was assessed. A correlational analysis indicated that there was no reliable association between pure-tone audiometry and speech perception in noise performance but that there was some evidence of an association between auditory attention and speech perception in noise performance for older adults. Next, a series of experiments were conducted that aimed to investigate the role of attention in gaining a visual speech benefit in noise. These auditory-visual experiments were largely motivated by the idea that as the visual speech benefit is the largest benefit available to listeners in noisy situations, any reduction in this benefit, particularly for older adults, could exacerbate difficulties understanding speech in noise. For the first auditory-visual experiments, whether increasing the number of visual distractors displayed affected the visual speech benefit in noise for younger and older adults when the SNR was -6dB (Experiment 1) and when the SNR was -1dB (Experiment 2) was tested. For both SNRs, the magnitude of older adults’ visual speech benefit reduced by approximately 50% each time an additional visual distractor was presented. Younger adults showed the same pattern when the SNR was - 6dB, but unlike older adults, were able to get a full visual speech benefit when one distractor was presented and the SNR was -1dB. As discussed in Chapter 3, a possible interpretation of these results is that combining auditory and visual speech requires attentional resources. To follow up the finding that visual distractors had a detrimental impact on the visual speech benefit, particularly for older adults, the experiment in Chapter 4 tested whether presenting a salient visual cue that indicated the location of the target talker would help older adults get a visual speech benefit. The results showed that older adults did not benefit from the cue, whereas younger adults did. As older adults should have had sufficient time to switch their gaze and/or attention to the location of the target talker, the failure to find a cueing effect suggests that age related declines in inhibition likely affected older adults’ ability to ignore the visual distractor. The final experiment tested whether the visual speech benefit and the visual distraction effect found for older adults in Chapter 4 transferred to a conversationcomprehension style task (i.e., The Question-and-Answer Task). The results showed that younger and older adults’ performance improved on an auditory-visual condition in comparison to an auditory-only condition and that this benefit did not reduce when a visual distractor was presented. To explain the absence of a distraction effect, several properties of the visual distractor presented were discussed. Together, the experiments in this thesis suggest that the roles of attention and visual distraction should be considered when trying to understand the communication difficulties that older adults experience in noisy situations

Eat Well, Live Actively: A Primary Care Interventional Program for the Treatment of Childhood Obesity

Over the last thirty years, childhood obesity has become one of the presiding diseases in the pediatric population. Last year the CDC (2012) reported that 12.5 million children under the age of five were not only overweight but also obese. This growing trend has been inadequately addressed by the United States preventive healthcare system. The pandemic has continued to spread: America’s obese children have substantially contributed to the ever-growing fiscal demands of health care in the United States. Olshansky et al. (2005) suggest this will in turn translate into the first generation of American adults that will be sicker and die younger than their parents. Utilizing the current practice guidelines for the screening, prevention, and treatment of childhood obesity reveals that the complexity of the problem necessitates an equally intricate solution. Adequate identification through screening and immediate initiation of conservative treatment is recommended. Increased family participation is also supported. The American Academy of Pediatrics, United States Preventive Services Task Force, and The Endocrine Society all support holistic primary care interventions as the most effective in treating and preventing childhood obesity. The “Eat Well, Live Actively” program was created in alliance with these clinical guideline recommendations. The “Eat Well, Live Actively” program was designed with four main components: two visits with the pediatrician, two visits with a dietician, bi-weekly classes at the YMCA, and weekly follow-up communication with the program coordinator. Anthropomorphic data was collected pre- and post-intervention: height, weight, and BMI percentage. A pre- and post- healthy lifestyle questionnaire was also completed. Lastly, participant and parent satisfaction surveys were collected at the conclusion of the program. Due to significant data variance and difficulty recruiting and retaining participants, the results from this program are not statistically significant and proved inconclusive. Additionally, the impact of poverty on the sample size of this study was unexpected and inadequately prepared for. This study confirmed the findings reflected in the literature: controlling for the many factors that influence childhood obesity is very difficult. Future research is needed in the primary care setting that focuses on supporting and minimizing the socioeconomic difficulties and disparities that convolute the path to establishing a model for the prevention and treatment of childhood obesity

From Victim to Volunteer: A Life Course Perspective and the Transition to Adulthood for Individuals Who Have Sold Sex

Under the United States definition of sex trafficking, one is considered a sex trafficking victim if she or he sells sex under 18 years old. Once someone turns 18, in order to claim trafficking status force, fraud, or coercion must be proven or that person falls under the illegal status of sex worker (VTVPA 2000). If one can go from being a victim of a crime to a perpetrator of a crime by having a birthday, what does the transition to adulthood and turning 18 look like for those who sell or exchange sex or are at risk of selling and exchanging sex? And how might institutional factors change upon the transition to adulthood that contribute to a pathway of selling sex? Using a life course perspective, this study explores the transition to adulthood for individuals who have sold or exchanged sex at any point in their lives to determine what role the institutions of the family, education system, work/economy, and the criminal justice have on this population along the life course and during the transition to adulthood. The study includes interviews with service providers working with individuals who have sold or exchanged sex in the City of Boston (N=13) and an original online national survey of individuals who have sold or exchanged sex (N=97). Using qualitative and quantitative data, results analyzed include an event history analysis of the predictors and timing for entering the commercial sex trade, discussion of labels about sex trafficking and sex work, and qualitative analysis from both service provider interviews and survey questions from individuals who have sold or exchanged sex. Life events through the stages of childhood, adolescence, and adulthood are framed as institutional influences to better understand the barriers and supports that exist for this population throughout the life course and where pathways into the commercial sex trade are formed