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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

HIV in African American women: Evidence that elevated rate of infection cannot be explained solely on the basis of known individual risk behaviors.

Francois, Bermann 20 August 2013 (has links)
Objective: To compare known individual risk behaviors in African American, Whites, and Hispanic women as found in the literature and support those findings by analyzing data available through NHANES in order to find out if the higher rate of HIV infection in African American women is a direct result of higher risk behaviors. Those risk behaviors include lower rates of condom use, higher rates of drug use including those taken intravenously, higher rates of risky sex habits, higher number of sexual partners over their lifetime, and a more extensive history of sexually transmitted infections. This study also aims to draw attention to larger factors that may foster the conditions for increased HIV rates in African American women. Results: The perception that higher rate of HIV infection is the result of increased risk factors among African American women is not supported either in the literature or in the analysis of NHANES data. For instance, results from data analysis found that African American women had fewer average number of sexual partners (P ≤ 0.05), lower overall rate of drug use (P ≤ 0.01), lower rates of risky sexual practices (P ≤ 0.01), but more likely to report a history of STIs (P ≤ 0.01) than Whites. The literature also confirmed that current HIV testing recommendations do not cover a large enough portion of the population to make a significant impact on HIV incidence. In addition, socioeconomic situations further exacerbate the conditions favorable to the transmission of the disease in African American women. Conclusion: Prevention programs that rely on individual risk behaviors alone may not be enough to reduce HIV rates in African American women, though those same programs may be working in MSM. Programs that address socioeconomic disparities and testing recommendations that cover more people are needed in order to drive down HIV infection rates in African American women.
262

Low Fitness Phenotype and Cardiovascular Disease Risks in African American Women

Owen, Jurine H, Mrs 11 May 2012 (has links)
The purpose of this study is to determine if African American Women (AAW) with low fitness levels have low fitness related to a lifestyle choice of decreased physical activity (PA) or the cardiovascular disadvantage of greater proportion of Type II (FT) muscle fibers. Forty-eight apparently healthy AAW participated in the study. The women had no known risk factors for CVD; were sedentary (no structured fitness training program within last six months) or minimally fit (PA ≤ 3 x week for 20 minutes); and were not taking any prescription medications for blood pressure, diabetes, or lipid control. On the first visit the following measurements were taken: 1.) height and weight (electronic scale and stadiometer); 2.) body fat percentage (dual energy x-ray absorptiometry (DXA % body fat); and 3.) CRF (submaximal treadmill exercise test). On the second visit additional measurements included: 1.) blood pressure (stethoscope and sphygmomanometer); 2.) lipid profile and high sensitivity-C reactive protein (hs-CRP) (Cholestech LDX analyzer); 3.) thigh anthropometric measurements; 4.) isokinetic power and fatigue testing (KIN-COM dynamometer). Pearson product correlation coefficient (r) was used to analyze the relationship between the variables. The results indicated that gross oxygen consumption at 85% maximal heart rate (VO2) was not significantly related to PA (r = -.06, p = .67) or FT fibers (r = 0.14, p = 0.34). VO2 was negatively correlated with hs-CRP (r = -.31, p < 0.05), systolic blood pressure (r = -0.47, p < 0.01), diastolic blood pressure (r = -0.42, p < 0.01), and DXA % body fat (r = -0.64, p < 0.01). There were no significant relationships between PA and any of the variables. FT fibers were negatively correlated with low density lipoprotein (r = -0.30, p < 0.05) and DXA % body fat (r = -0.46, p < 0.01). In conclusion, low cardiorespiratory fitness in AAW does not seem to be a related to reported levels of PA or proportion of FT fibers. This suggests that there may be other factors that are contributing to the low levels of cardiorespiratory fitness observed in this sample of AAW.
263

The Role of Frontal Lobe White Matter Integrity and Executive Functioning in Predicting Adaptive Functioning in Alzheimer's Disease

Mumaw, Matthew A 09 September 2011 (has links)
Alzheimer’s disease (AD) is the most common form of dementia and is characterized by a gradual deterioration of the patients’ ability to independently perform day to day activities. Researchers have discovered significant changes in neuroanatomy, cognition and behavior that are related to the disease process of AD and researchers continue to uncover new variables, such as the presence of vascular risk factors, which may further increase our ability to understand and characterize the disease. The purpose of this study is to identify the neuroanatomical, cognitive and behavioral variables that best predict impairment of instrumental activities of daily living in individuals with probable AD. Reduced white matter integrity in the dorsolateral prefrontal cortex as well as the presence of vascular risk factors significantly predicted impairments in activities of daily living (ADLs). Executive functioning skills, typically described as frontal lobe system behaviors, were positively associated with ADLs. Further, executive functions fully mediated the relationship between frontal lobe white matter integrity and ADLs. A better understanding of the variables responsible for diminished ADLs in AD will allow researchers and clinicians to better target prevention and intervention strategies and ultimately help individuals with AD to maintain their independence for a longer duration.
264

Multilingualism and the risk of Alzheimer disease and dementia

Hack, Erica 09 June 2011 (has links)
Background: Alzheimer disease (AD) is a progressive, late-life neurodegenerative disorder. Given the aging population, AD is a significant health concern. According to the Alzheimer Society of Canada (Smetanin et al., 2009), in 25 years 2.8% of the Canadian population will have AD or a related dementia. Presently, there is no cure for AD; therefore, efforts to either delay AD onset or prevent AD altogether are a primary focus. The ability to proficiently speak many languages has been associated with certain cognitive advantages. Based on these findings, multilinguals are hypothesized to be more resistant to cognitive decline than monolinguals. More research is warranted in order to further this theory and to contribute to strategies to prevent or delay AD. Objectives: The first study objective was to evaluate whether multilingualism was associated with the development of AD. The second study objective was to assess whether multilingualism was associated with later dementia onset. Methods: Analyses were based on data from the Nun Study, a longitudinal study of aging in 678 participants 75+ years living in the United States. In order to address the first study objective, the association between multilingualism and AD was assessed in 157 participants using logistic regression models adjusted for age, education, apolipoprotein E-E4 (ApoE-E4) status, immigrant status, and occupation. Additional subgroup analyses also included covariates associated with career length and linguistic ability (grammatical complexity and idea density). AD was diagnosed based on criteria for both clinical dementia and AD neuropathology. Dementia was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition criterion (American Psychiatric Association, 1994) (based on the Consortium to Establish a Registry for Alzheimer’s Disease battery of tests (Morris, Heyman, Mohs, & Hughes, 1989) and performance on activities of daily living), while AD neuropathology was based on the National Institute on Aging and Reagan Institute criterion (The National Institute on Aging - Reagan Institute (NIA-RI) Working Group on Diagnostic Criteria for the Neuropathological Assessment of Alzheimer's Disease, 1997). In order to address the second study objective, dementia likelihood was assessed in 325 participants using discrete-time survival analyses adjusted for age, ApoE-E4 status, education, and linguistic ability. Results: When adjusted for age, education, ApoE-E4 status, occupation, and immigrant status, participants speaking two or more languages had similar AD risks compared to monolinguals (OR = 1.05; 95% CI = 0.45-2.50). However, when grammatical complexity was held constant across participants, speaking two or more languages was associated with a four-fold decrease in AD risk compared to speaking one language (OR = 0.25; 95% CI = 0.04-1.23), although this did not reach statistical significance. When the association between multilingualism and time of dementia onset was assessed, the dementia hazard function estimates for all participants were constant and persisted throughout the follow-up period of the study. When ApoE-E4 status and baseline age were held constant, participants speaking four or more languages were significantly less likely to develop dementia than monolingual participants (OR = 0.14; 95% CI = 0.01-0.66). An interaction between multilingualism and the other two covariates (ApoE-E4 status and baseline age) was observed: the oldest participants with an ApoE-E4 allele who spoke four or more languages had smaller dementia risks than younger participants without an ApoE-E4 allele who spoke one, two, or three languages. Participants speaking two or three languages were no less likely than monolinguals to develop dementia across the study duration. When idea density was held constant across participants, multilingualism was associated with a nonsignificant decreased risk of dementia for individuals speaking three (OR = 0.62; 95% CI = 0.16-2.41) or four or more languages (OR = 0.53; 95% CI = 0.06-4.91) while participants speaking two languages were no more at risk for dementia than monolinguals (OR = 1.08; 95% CI = 0.43-2.69). Discussion: Initially, multilingualism did not appear to confer protection against AD. After holding grammatical complexity constant across all participants, however, multilingualism was found to be associated with AD risk. Therefore, linguistic ability confounded the initial relationship measured by this study. When the association between multilingualism and time of dementia onset was evaluated, participants were no more likely to develop dementia in one time period than another, and monolingual participants were no more likely to develop dementia in earlier time periods than multilinguals. While a trend of decreasing dementia risk with ascending number of languages spoken was not observed, speaking four or more languages was consistently associated with decreased dementia risk compared to speaking one language. The presence of an ApoE-E4 allele and low linguistic ability had a strong and consistent significant association with increased AD and dementia risk. Therefore, the influence of these variables on the association of multilingualism with AD and dementia is worthy of further exploration. Overall, this study provided some support for a protective effect of multilingualism on AD and dementia. Some of the present investigation’s results differ, however, from those of previous studies. This is not surprising, considering the present study utilized different methodologies than other studies in this research area. For instance, our study employed a definition of multilingualism based on self-report data – participants were classified as multilingual based on the number of languages they reported proficiency with. Therefore, our definition of multilingualism was less strict than definitions used in previous studies. However, our study employed much stricter outcome criteria than those used in previous studies, as our study is the first in this area to confirm AD cases with AD neuropathology evaluations. Our study is also the first io utilize prospective data and to include participants who remained dementia-free in addition to participants developing AD and dementia. In addition, this is the only study in this research area to evaluate the relationship of multilingualism with AD and dementia in the context of important covariates such as ApoE-E4 status and linguistic ability. Therefore, while some of our results contrast with other findings in this area, this is understandable given our novel methodologies. A broad range of study methods must be used in the future if we are to generate the depth of evidence needed for a full understanding of the relationship of multilingualism with AD and dementia. A better understanding of this relationship may also provide insight into both cognitive and brain reserve mechanisms, which could help more individuals maintain cognitive function into late life.
265

Risk and Predictive Factors for Liver Cancer : Analysis of Data from a Cohort Study

Sookthai, Disorn January 2011 (has links)
The association between the risk of liver cancer and blood chemistry was investigated in a cohort study with 95,150 men and women from two counties in Sweden. In 1963-65, blood tests and physical measurements were undertaken. All individuals were then followed up until 2007, and a total of 312 were diagnosed with liver cancer. Using survival analysis and logistic regression, significant risk factors were identified. Stepwise Cox proportional hazards regression applied to a main effect model revealed that Glutamic Pyruvate Transaminase (GPT) and Thymol Turbidity (TYM) were the most significant risk factors (p&lt;0.0001), followed by Protein-Bound Hexoses (HEX)  (p=0.002), sex (p=0.02), and Serum Iron (p= 0.03). Increasing the level of GPT expressed in U/L from normal (&lt;21) to slightly elevated (21, 31) or substantially elevated (&gt;31) raised the hazard of experiencing liver cancer by a factor of 1.45 and 4.09, respectively. In addition, GPT was found to be the most significant risk factor in almost all age groups among both men and women. However, there was no evidence that elevated GPT levels within the normal range (&lt;21), influenced the risk of liver cancer. Additional subgroup analyses revealed that TYM was highly significant within the group with normal GPT, and a high level of HEX (≥134 mg/dl) increased the hazard 1.55 times in comparison with the lowest HEX group (&lt;115 mg/dl). BMI was significant only in the male subgroup  (p&lt;0.01) and, in the obesity group, the hazard of experiencing liver cancer was 1.99 times higher than in the normal BMI group. A significant three-way interaction between GPT, BMI and gender was present (p=0.05) with a robust significant two-way interaction between GPT and BMI (p&lt;0.01) in the male subgroup.
266

The application of Multifactor model and VaR model in predicting market meltdown

Ni, Hao-Yu 21 June 2012 (has links)
With the progress of the times, the international financial market link is becoming more and more closely, while the probability of extreme events more and more high, if there are some indicators can be used as a prediction of the crash, as whether to sell the stocks, it can be very useful. The study process for the use of the Fama-French five-factor model, as well as the VaR model, with the cluster analysis method, and clustering for Taiwan 50 constituent stocks in accordance with the five-factor characteristics of the individual stocks, the similar nature of stock into the same group, the establishment of portfolio, the use of portfolio daily returns to calculate the the VaR, and observe the VaR spread before the crash, how the trend, and whether certain characteristics. Comparison of the cluster group for the predictive ability of the collapse events, as well as the relationship between risk factors and predictive ability. The results of VaR spread movements are often subject to fluctuations significantly change the situation before the crash occurs. By intense will be stable or from stable will be severe. Good predictive ability of the cluster, often its constituent stocks and the collapse of the reasons more closely the relationship. Financial stocks sensitive to the financial tsunami; Electronic stocks are subject to exchange rate affect.Overall, the group with the best predictive ability is more sensitive to momentum effects and investor sentiment indicators ,but non-sensitive to book-to-market factor.To use the Var spread as a predictor of reference,choosing to meet the aforementioned conditions of stocks to the portfolio is a nice way.
267

CARDIOVASCULAR DISEASE RISK FACTORS AMONG RURAL KAZAKH POPULATION

SAKAMOTO, JUNICHI, TULEBAYEV, KAZBEK, YOSHIDA, YOSHITOKU, HARUN-OR-RASHID, MD., KULKAYEVA, GULNARA 02 1900 (has links)
No description available.
268

Protective factors and risk factors of HIV infection of Mexican-American gay men a dissertation /

Meyer, Mark A. January 2008 (has links)
Dissertation (Ph.D.).--University of Texas Graduate School of Biomedical Sciences at San Antonio, 2008. / Vita. Includes bibliographical references.
269

Meta-analysis: racial disparities in prostate cancer survival and case-control study association between family history of cancers, obesity and prostate cancer /

Sridhar, Gayathri, January 1900 (has links)
Thesis (Ph.D.)--Virginia Commonwealth University, 2009. / Prepared for: Dept. of Epidemiology and Community Health. Title from title-page of electronic thesis. Includes bibliographical references.
270

Inflammation-associated risk factors for Alzheimer's disease and dementia

Eriksson, Ulrika K., January 2010 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

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