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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.
411

Association Between Cardiovascular Risk Factors and the Diameter of the Thoracic Aorta in an Asymptomatic Population in the Central Appalachian Region

Paul, Timir K., Alamin, Ali E., Subedi, Pooja, Alamian, Arsham, Wang, Liang, Blackwell, Gerald, Budoff, Matthew, Mamudu, Hadii M. 01 February 2021 (has links)
Background: Effects of cardiovascular (CV) risk factors on the diameter of the thoracic aorta have not been fully studied. This study examined the associations between CV risk factors and diameter of thoracic aorta. Materials and Methods: Study population comprised of 1273 asymptomatic adults aged ≥18 years from Central Appalachia region of the United States who participated in a coronary artery screening between January 2014 and December 2016. Descriptive statistics and multiple linear regression analyses were performed to examine associations between multiple CV risk factors and diameters of the thoracic aorta. Results: Mean (±SD) age of participants was 57.9±9.7 years; that of body mass index (BMI) was 29.4±5.9. The mean aortic sinus, ascending aorta, and descending aorta diameter were 34.1±4.4 mm, 33.8±4.4 mm, and 26.0±3.6 mm, respectively. Increasing age, being male, and having a higher BMI were associated with wider aortic sinus, ascending aorta, and descending aorta diameters. Hypertension (p < 0.05) and obesity (p < 0.0001) were significantly associated with wider diameter for all measured aortic diameters. Participants with diabetes had wider descending aorta compared to those without (26.6±3.9 mm vs. 25.9±3.5 mm, P = 0.012). Participants who had ever smoked a cigarette had significantly wider descending aorta diameter compared to never smokers (26.3±3.6 mm vs. 25.9±3.5 mm, p = 0.031). Conclusions: The study results suggest that decreasing BMI and management of CV risk factors such as hypertension and modifying behavioral risk factors such as smoking are likely to be emphasized in order to decrease the rate of aortic dilatation and subsequent aortic dissection, if aortic dilatation is detected during a CT scan.
412

The Effects of Self-Efficacy, Process Feedback, and Task Complexity on Escalation of Commitment in New Product Development

Liang, Beichen 07 October 2019 (has links)
Purpose: The purpose of this paper is to investigate the effects of self-efficacy, process feedback and task complexity on decisions by managers to continue or discontinue a new product after receiving negative performance feedback. Design/methodology/approach: This paper uses a classroom experiment design and uses logistic regression and a chi-square test to analyze the data. Findings: The findings of this paper show that self-efficacy, process feedback and task complexity have not only main effects but also interactive effects on managers’ go or no-go decisions; further, the main effects are mediated by interactions. The effect of self-efficacy is moderated by process feedback and task complexity. Process feedback and task complexity also have an interactive effect on decisions about new products by decision-makers. Research limitations/implications: This paper extends the theory of escalation of commitment (EOC) by showing that self-efficacy, process feedback and task complexity can influence decision-makers’ go or no-go decisions after they have received negative performance feedback. Practical implications: This paper provides useful guidelines for managers on how to reduce the likelihood of EOC. Originality/value: The originality and value of this paper lie in its being the first to examine the effects of process feedback and task complexity on the EOC.
413

Variable Reduction for Past Year Alcohol and Drug Use in Unmet Need for Mental Health Services Among Us Adults

Wang, Nianyang, Ouedraogo, Youssoufou, Chu, Jun, Liu, Ying, Wang, Kesheng, Xie, Xin 01 September 2019 (has links)
Background: No previous study has focused on the inter-relationship among alcohol and drug use variables in the past year. This study aimed to classify the past year alcohol and drug use variables and investigate the selected variables in past year alcohol and drug use with the unmet need for mental health services among US adults. Methods: Data came from the 2015 National Survey on Drug Use and Health (NSDUH). Oblique principal component cluster analysis (OPCCA) was used to classify 37 variables on alcohol and drug use in the past year into disjoint clusters. Weighted multiple logistic regression analysis was used to examine the associations of selected variables with the unmet need. Results: 37 alcohol and drug use variables were divided into 7 clusters. The variable with the lowest 1-R2 ratio (R2 is the squared correlation) from each cluster was selected as follows: tobacco use, pain reliever use, tranquilizer use, stimulant use, zolpidem products use, illicit drug and alcohol use, and benzodiazepine tranquilizers misuse. Multiple logistic regression analysis showed that pain reliever use (OR = 1.33, 95% CI = 1.17–1.50), tranquilizer use (OR = 2.49, 95% CI = 2.16–2.86), stimulant use (OR = 1.22, 95% CI = 1.01–1.47), and illicit drug and alcohol use (OR = 1.54, 95% CI = 1.34–1.77) revealed positive associations with the unmet need for mental health services. Conclusion: This is the first study using OPCCA to reduce the dominations of alcohol and drug use; several alcohol and drug use variables in the past year were associated with unmet need of mental health services.
414

The Usage and Associated Factors of Alternative Tobacco Products Among School-Going Youth in Central Appalachia

Owusu, Daniel, Mamudu, Hadii M., Collins, Candice, Robertson, Crystal, Wang, Liang, Rafie, Boghozian, Littleton, Mary 01 February 2019 (has links)
Objective. To examine alternative tobacco product (ATP) use and associated factors among middle school students in Appalachian Tennessee. Method. Data (2015– 2016; N=573) from school-based tobacco surveys in 11 middle schools in Appalachian Tennessee were analyzed. Multiple logistic regression model described factors associated with ATP use. Results. More than one-tenth (13.2%) of participants have ever used ATPs. Approximately 9%, 7%, 6%, and 2% of participants have ever used e-cigarettes, cigarettes, smokeless tobacco, and little cigars or cigarillos, respectively. The following were significantly associated with ever use of ATPs: believing tobacco users have more friends, owning tobacco-branded item(s), living with a tobacco user, having ever smoked cigarettes, and living in homes where smoking is allowed. Conclusion. More than one in 10 of participants have ever used at least one ATP, and association with desirable objects and situations may promote ATP use. Interventions should seek to reduce these positive images and make all tobacco products unappealing.
415

Association Between Cardiovascular Risk Factors and the Diameter of the Main Pulmonary Artery in Asymptomatic Population in the Appalachian Region

Paul, Timir K., Alamin, Ali E., Subedi, Pooja, Zhang, Michael, Diab, Mohamed M., Alamian, Arsham, Wang, Liang, Blackwell, Gerald, Mamudu, Hadii M. 01 January 2019 (has links)
Background: Pulmonary artery (PA) diameter may be altered in association with cardiovascular (CV) risk factors as noted in aorta in systemic hypertension. The flow of blood from the right ventricle to the PA and all the way to the capillary level depends on the pulmonary vascular resistance and to a lesser extent compliance and impedance of the PA, which are the fundamental conduit for maintenance of the right heart hemodynamics. Our objective is to determine the association between CV risk factors and the main pulmonary artery (MPA) diameter. Methods: The study population are asymptomatic individuals with no known diagnosis of CV diseases in central Appalachia (n=1,282). Adults aged 18 years or older were eligible for the screening if they were referred by a physician. For self-referral, only males aged ≥45 years and females aged ≥55 years were eligible. Unadjusted and adjusted linear regression analyses were performed. Results: The mean MPA diameter was significantly higher among males compared to females (27.19±4.20 vs. 24.99±3.91 mm, P<0.0001). Participants with diabetes also had wider MPA diameter (26.79±4.56 mm) compared to those without diabetes (25.93±4.11 mm) (P=0.015). Further, hypertensive (26.42±4.15 vs. 25.71±4.21 mm, P=0.002) and obese (27.25±4.11 vs. 25.28±4.07 mm, P<0.0001) participants had significantly wider MPA diameter compared to non-hypertensive and non-obese participants, respectively. Multivariable model showed that age, sex and body mass index (BMI) were significantly associated with MPA diameter. A 1-year increase in age increased MPA diameter by 0.046 mm (P<0.0001). The diameter of MPA was wider among males by 2.16 mm compared to females (P<0.0001). Finally, with one unit increase in BMI, the MPA diameter increased by 0.16 mm (P<0.0001). Conclusions: MPA diameter was significantly associated with age, sex, and BMI. Further prospective studies are needed to correlate computed tomography (CT) measurement of MPA diameter with pulmonary pressure as assessed by echocardiogram to diagnose pulmonary hypertension (PH).
416

The Use of E-cigarettes Among School-Going Adolescents in a Predominantly Rural Environment of Central Appalachia

Owusu, Daniel, Aibangbee, Jocelyn, Collins, Candice, Robertson, Crystal, Wang, Liang, Littleton, Mary A., Boghozian, Rafie, Casenburg, Vicki, Mamudu, Hadii M. 01 June 2017 (has links)
E-cigarette use among youth in the United States (U.S.) continues to increase. In the rural Northeast Tennessee, where prevalence of tobacco use is higher than national and state averages, there is no literature on e-cigarette use to inform policies and programs. This study aimed to estimate the prevalence of e-cigarette use and examine association of e-cigarette use with two tobacco products among school-going adolescents. Data from 894 participants of a school-based survey conducted in 2016 in Northeast Tennessee were analyzed. Descriptive statistics and logistic regression analyses were conducted to estimate the prevalence and delineate the associations between e-cigarette use and other tobacco products. Approximately 11% of the participants currently used e-cigarettes, and 35% had ever used e-cigarettes. About 6% of the participants were current users of both e-cigarettes and cigarettes; 4% were current users of e-cigarettes and smokeless tobacco; 3% were current users of all three products, and 15% had ever tried all three products. More than one-half of current e-cigarette users (52%) also smoked cigarettes. Adjusting for covariates, current e-cigarette use was positively associated with cigarette smoking [Odds Ratio (OR) 27.32, 95% confidence interval (CI) 14.4–51.7] and smokeless tobacco use [OR 7.92, 95% CI 3.8–16.5]. E-cigarette use was more common among the high school students than cigarette and smokeless tobacco use, and a significant proportion of users either smoked cigarettes, used smokeless tobacco, or both. Thus, there is a critical need for preventive policies and programs to address dual and poly-use of these products.
417

Gender Differences in HIV Sexual Risk Behaviors Among Clients of Substance Use Disorder Treatment Programs in the U.S.

Pan, Yue, Metsch, Lisa R., Wang, Weize, Wang, Ke Sheng, Duan, Rui, Kyle, Tiffany L., Gooden, Lauren K., Feaster, Daniel 01 May 2017 (has links)
This study examined differences in sexual risk behaviors by gender and over time among 1281 patients (777 males and 504 females) from 12 community-based substance use disorder treatment programs throughout the United States participating in CTN-0032, a randomized control trial conducted within the National Drug Abuse Treatment Clinical Trials Network. Zero-inflated negative binomial and negative binomial models were used in the statistical analysis. Results indicated significant reductions in most types of sexual risk behaviors among substance users regardless of the intervention arms. There were also significant gender differences in sexual risk behaviors. Men (compared with women) reported more condomless sex acts with their non-primary partners (IRR = 1.80, 95 % CI 1.21–2.69) and condomless anal sex acts (IRR = 1.74, 95 % CI 1.11–2.72), but fewer condomless sex partners (IRR = 0.87, 95 % CI 0.77–0.99), condomless vaginal sex acts (IRR = 0.83, 95 % CI 0.69–1.00), and condomless sex acts within 2 h of using drugs or alcohol (IRR = 0.70, 95 % CI 0.53–0.90). Gender-specific intervention approaches are called for in substance use disorder treatment.
418

Polymorphisms in PDLIM5 Gene Are Associated With Alcohol Dependence, Type 2 Diabetes, and Hypertension

Owusu, Daniel, Pan, Yue, Xie, Changchun, Harirforoosh, Sam, Wang, Ke Sheng 01 January 2017 (has links)
The PDZ and LIM domain 5 (PDLIM5) gene may play a role in alcohol dependence (AD), bipolar disorder, and major depressive disorder; however, no study has identified shared genetic variants within PDLIM5 gene among AD, type 2 diabetes (T2D), and hypertension. This study investigated the association of 72 single nucleotide polymorphism (SNPs) with AD (1066 AD cases and 1278 controls) in the Study of Addiction - Genetics and Environment (SAGE) sample and 47 SNPs with T2D (878 cases and 2686 non-diabetic) and hypertension (825 cases and 2739 non-hypertensive) in the Marshfield sample. Multiple logistic regression models in PLINK software were used to examine the associations of genetic variants with AD, T2D, and hypertension and SNP x alcohol consumption interactions for T2D and hypertension. Twenty-five SNPs were associated with AD in the SAGE sample (p < 0.05); rs1048627 showed the strongest association with AD (p = 5.53 × 10−4). Of the 25 SNPs, 5 SNPs showed associations with both AD in the SAGE sample and T2D in the Marshfield sample (top SNP rs11097432 with p = 0.00107 for T2D and p = 0.0483 for AD) while 6 SNPs showed associations with both AD in the SAGE sample and hypertension in the Marshfield sample (top SNP rs12500426 with p = 0.0119 for hypertension and p = 1.51 × 10−3 for AD). SNP (rs6532496) showed significant interaction with alcohol consumption for hypertension. Our results showed that several genetic variants in PDLIM5 gene influence AD, T2D and hypertension. These findings offer the potential for new insights into the pathogenesis of AD, T2D, and hypertension.
419

Immediate Complications and Flow Volume Changes During Treatment Phases of Bronchial Thermoplasty: A Single-Center Descriptive Study

Vijayan, Karthik, Karakattu, Sajin M., Bansal, Apurva, Thomas, Akesh, Alazzeh, Ahmad, El Minaoui, Wael, Maisonet, Mildred 01 January 2021 (has links)
Introduction: Bronchial thermoplasty (B.T.) is a therapeutic bronchoscopic procedure in which controlled thermal energy is applied to the airway wall to decrease smooth muscle mass. Immediate complications of B.T. include acute exacerbation of bronchial asthma, upper and lower respiratory tract infection, hemoptysis, among others. Our study assessed these immediate adverse events and the changes in forced expiratory volume in one second (FEV1%) measured four hours after each procedure from baseline. The study also aimed to examine the number of activations during each cycle of treatment and its correlation to the corresponding change in FEV1% from baseline. Methods: A case-series analysis of 17 patients who underwent B.T. between 2014 and 2019 was done. Demographic, clinical characteristics, including pre and post-BT FEV1% measures, and the number of activations were obtained. Results: Acute exacerbation of asthma was the commonest complication accounting for 33%, 57%, and 75% after BT1, BT2, and BT3, respectively. There was deterioration in FEV1% after each treatment phase, the most significant being in BT3. There was no correlation between the number of heat activations with the change in FEV1% from baseline. Conclusion: The number of activations in B.T. does not correlate with the immediate deterioration in FEV1%, although exacerbation of asthma is the commonest complication post-B.T.
420

Secondhand Smoke Exposure Among Never-Smoking Youth in 168 Countries

Veeranki, Sreenivas P., Mamudu, Hadii M., Zheng, Shimin, John, Rijo M., Cao, Yan, Kioko, David, Anderson, James, Ouma, Ahmed E.O. 01 January 2015 (has links)
Purpose To estimate the prevalence of secondhand smoke (SHS) exposure among never-smoking adolescents and identify key factors associated with such exposure. Methods Data were obtained from nationally representative Global Youth Tobacco Surveys conducted in 168 countries during 1999-2008. SHS exposure was ascertained in relation to the location - exposure inside home, outside home, and both inside and outside home, respectively. Independent variables included parental and/or peer smoking, knowledge about smoke harm, attitudes toward smoking ban, age, sex, and World Health Organization region. Simple and multiple logistic regression analyses were conducted. Results Of 356,414 never-smoking adolescents included in the study, 30.4%, 44.2%, and 23.2% were exposed to SHS inside home, outside home, and both, respectively. Parental smoking, peer smoking, knowledge about smoke harm, and positive attitudes toward smoke ban were significantly associated with increased odds of SHS exposure. Approximately 14% of adolescents had both smoking parents and peers. Compared with never-smoking adolescents who did not have both smoking parents and peers, those who had both smoking parents and peers had 19 (adjusted odds ratio [aOR], 19.0; 95% confidence interval [CI], 16.86-21.41), eight (aOR, 7.71; 95% CI, 7.05-8.43), and 23 times (aOR, 23.16; 95% CI, 20.74-25.87) higher odds of exposure to SHS inside, outside, and both inside and outcome home, respectively. Conclusions Approximately one third and two fifths of never-smoking adolescents were exposed to SHS inside or outside home, and smoking parents and/or peers are the key factors. Study findings highlight the need to develop and implement comprehensive smoke-free policies consistent with the World Health Organization Framework Convention on Tobacco Control.

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