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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.
91

Affect intensity, drug motivations, and polysubstance use

Seymore, Candice, Moore, kelly 12 April 2019 (has links)
People often use substances to cope with intense emotions, but more research is needed in this area. The scale we used to measure affect intensity was the Affect Intensity Measure (AIM). The participants self-reported their substance use. Drawing from a sample of adults in substance use treatment (n=118), we used regression analysis to examine the relationship between affect intensity, drug use motivations, and polysubstance use. Having this information is crucial to understanding how emotional experiences can be related to substance use. By knowing this we can also alter treatment to be specific to the individual, in order to improve the success rate of treatment facilities. More research is needed examining the relationship between affect intensity, motivation for substance use, and substance use patterns among people who are receiving substance use treatment.
92

Prospective Associations of Pain Intensity and Substance Use in the United States Population: A Cross-Lagged Panel Analysis

Roberts, Walter, Moore, Kelly E., Verplaetse, Terril L., Zakiniaeiz, Yasmin, Burke, Catherine, Peltier, Mackenzie R., McKee, Sherry A. 01 September 2021 (has links)
Objective: Pain is associated with increased risk for harmful substance use. Substance use also may increase levels of pain, suggesting that these two factors may reciprocally increase risk. The current study examined the reciprocal association between pain and substance use outcomes (i.e., alcohol, cannabis, and painkillers/seda-tives/tranquilizers [PSTs]) longitudinally in a nationally representative cohort of non-incarcerated U.S. citizens. Method: Adult (≥18 years old) survey data from Waves 2–4 of the Population Assessment of Tobacco and Health (PATH) study were used. The PATH is a nationally representative multiwave cohort survey (Wave 2: October 2014–October 2015, Wave 3: October 2015–October 2016, Wave 4: December 2016–January 2018). Cross-lagged panel models were used to estimate the reciprocal effects of pain intensity and substance use on subsequent changes in both variables. Substance use outcomes were substance use problems and greater-than-weekly use for cannabis and PSTs, total past-month drinks, and alcohol use exceeding moderate drinking guidelines. All models controlled for autoregressive effects and demographic covariates. Results: Pain intensity showed a positive prospective association with all substance use outcomes. All cannabis and PST use were positively associated with subsequent pain intensity. Alcohol use problems also predicted higher levels of pain intensity. Neither total past-month drinks nor exceeding moderate drinking guidelines predicted subsequent pain intensity. Conclusions: Pain and substance use show a reciprocal association and may act in a positive feedback loop to worsen both conditions over time in people with a history of use.
93

The role of acoustic cavitation in enhanced ultrasound-induced heating in a tissue-mimicking phantom

Edson, Patrick Lee January 2001 (has links)
A complete understanding of high-intensity focused ultrasound-induced temperature changes in tissue requires insight into all potential mechanisms for heat deposition. Applications of therapeutic ultrasound often utilize acoustic pressures capable of producing cavitation activity. Recognizing the ability of bubbles to transfer acoustic energy into heat generation, a study of the role bubbles play in tissue hyperthermia becomes necessary. These bubbles are typically less than 50μm. This dissertation examines the contribution of bubbles and their motion to an enhanced heating effect observed in a tissue-mimicking phantom. A series of experiments established a relationship between bubble activity and an enhanced temperature rise in the phantom by simultaneously measuring both the temperature change and acoustic emissions from bubbles. It was found that a strong correlation exists between the onset of the enhanced heating effect and observable cavitation activity. In addition, the likelihood of observing the enhanced heating effect was largely unaffected by the insonation duration for all but the shortest of insonation times, 0.1 seconds. Numerical simulations were used investigate the relative importance of two candidate mechanisms for heat deposition from bubbles as a means to quantify the number of bubbles required to produce the enhanced temperature rise. The energy deposition from viscous dissipation and the absorption of radiated sound from bubbles were considered as a function of the bubble size and the viscosity of the surrounding medium. Although both mechanisms were capable of producing the level of energy required for the enhanced heating effect, it was found that inertial cavitation, associated with high acoustic radiation and low viscous dissipation, coincided with the the nature of the cavitation best detected by the experimental system. The number of bubbles required to account for the enhanced heating effect was determined through the numerical study to be on the order of 150 or less.
94

Analyse stochastique de processus ponctuels : au-delà du processus de Poisson / Stochastic analysis of point processes : beyond the Poisson process

Flint, Ian 13 December 2013 (has links)
Les processus déterminantaux ont généré de l’intérêt dans des domaines très divers, tels que les matrices aléatoires, la théorie des processus ponctuels, ou les réseaux. Dans ce manuscrit, nous les considérons comme un type de processus ponctuel, c’est-à-dire comme un groupement de points aléatoires dans un espace très général. Ainsi, nous avons accès à une grande variété d’outils provenant de la théorie des processus ponctuels, ce qui permet une analyse précise d’un grand nombre de leur propriétés. Nous commençons par une analyse des processus déterminantaux d’un point de vue applicatif. Nous proposons ainsi différentes méthodes pour leur simulation dans un cadre général. Nous présentons une série de modèles dérivés du processus de Ginibre, et qui se trouvent être très utiles dans les applications. Troisièmement, nous introduisons un gradient différentiel sur l’espace des processus ponctuels. Grâce à des outils puissants de la théorie générale des formes de Dirichlet, nous montrons une formule d’intégration par parties pour un processus ponctuel général, et prouvons l’existence de diffusions correctement associées à ces processus. Nous sommes en mesure d’appliquer ces résultats aux processus déterminantaux, ce qui mènera à une caractérisation de ces diffusions en termes d’équations différentielles stochastiques. Enfin, nous nous intéressons au gradient différence. Dans un certain sens, nous définissons alors une intégrale de Skohorod qui satisfait une formule d'intégration par parties, c’est-à-dire que son adjoint est le gradient différence. Une application à l’étude d’une transformation aléatoire du processus ponctuel est présentée, dans laquelle nous caractérisons la distribution du processus ponctuel transformé sous certaines conditions. / Determinantal point processes have sparked interest in very diverse fields, such as random matrix theory, point process theory, and networking. In this manuscript, we consider them as random point processes, i.e. a stochastic collection of points in a general space. Hence, we are granted access to a wide variety of tools from point process theory, which allows for a precise study of many of their probabilistic properties. We begin with the study of determinantal point processes from an applicative point of view. To that end, we propose different methods for their simulation in a very general setting. Moreover, we bring to light a series of models derived from the well-known Ginibre point process, which are quite suited for applications. Thirdly, we introduce a differentiable gradient on the considered probability space. Thanks to some powerful tools from Dirichlet form theory, we discuss integration by parts for general point processes, and show the existence of the associated diffusion processes correctly associated to the point processes. We are able to apply these results to the specific case of determinantal point processes, which leads us to characterizing these diffusions in terms of stochastic differential equations. Lastly, we turn our attention to the difference gradient on the same space. In a certain sense, we define a Skohorod integral, which satisfies an integration by parts formula, i.e. its adjoint is the difference operator. An application to the study of a random transformation of the point process is given, wherein we characterize the distribution of the transformed point process under mild hypotheses.
95

Affect Intensity as a Moderator of the Relationship Between Emotional Intelligence and Transformational Leadership

Schaefer, Robert Taylor 01 January 2015 (has links)
Researchers have reported mixed findings on the relationship between emotional intelligence (EI) and transformational leadership, leading many to suspect the presence of moderating variables. This study was conducted to address the problem by analyzing the moderating effect that affect intensity may have upon this relationship. Based on a theoretical framework consisting of ability-based EI and the full-range theory of leadership, it was hypothesized that EI would be positively correlated with transformational leadership. In addition, based upon the arousal regulation theory of affect, it was hypothesized that affect intensity would be a statistically significant moderator of that relationship. A convenience sample of leaders (N = 142) working in the hospitality industry completed the Mayer Salovey Caruso Emotional Intelligence Test, the Multifactor Leadership Questionnaire form 5X, and the Affect Intensity Measure. Pearson's Product-Moment correlational analysis revealed that, consistent with expectations, total EI scores and the managing emotions branch scores of EI were positively correlated with transformational leadership; however, the branch scores for perceiving, using, and understanding emotion were not. Contrary to expectations, affect intensity was not a statistically significant moderator in this sample. Findings from this research support the proposition that EI may best predict transformational leadership within service-based environments where employees face intense emotional labor demands. A thorough understanding of the ways in which EI predicts leader behavior will not only help organizations improve leader selection and development, but also help to improve vital social outcomes, such as employee job satisfaction, engagement, and well-being.
96

Effect of Cultural Intensity and Planting Density on Wood Properties of Loblolly Pine (Pinus Taeda L.)

Aslezaeim, Nasrin 12 August 2016 (has links)
The effects of cultural intensity (operational and intensive) and planting densities (741, 1483, 2224, and 2965 ha-1) on modulus of elasticity (MOE), modulus of rupture (MOR) and specific gravity (SG) of small clear samples obtained from 15 and 16 year-old loblolly pine (Pinus taeda) from the Lower Coastal Plain and Piedmont region of the southeastern United State were examined. Planting density and distance from pith showed a significant (p < 0.0001) and strong main effect on stiffness (MOE) and strength (MOR) for the samples. Regardless of planting density, MOE, MOR and SG of samples increased significantly from pith toward bark. A significant culture × density interaction (p < 0.0001) was observed for the samples obtained from the Lower Coastal Plain. The project also determined the feasibility of measuring microfibril angle (MFA) on solid wood loblolly pine samples using scanning electron microscopy and transmission electron microscopy with the angle analyzed using image analysis. Measurements of MFA revealed minor differences (5⁰) between juvenile wood and mature wood.
97

Mood and Exercise Enjoyment of College Students When Jogging at Preferred Exercise Intensities

Zhang, Yu January 2013 (has links)
No description available.
98

The Effect of Active Workstation Use on Measures of Cognition, Attention and Motor Skill

Ohlinger, Christina M. 16 July 2009 (has links)
No description available.
99

An Investigation on the Stress Intensity Factor of Surface Micro-cracks

Arli, Sirisha Divya 31 May 2017 (has links)
No description available.
100

HIGH-INTENSITY, ORGANIC PHOTOCHEMISTRY: INVESTIGATIONS USING ARGON-ION AND EXCIMER LASER-JETS

Gamble, Bryan Matthew 11 October 2001 (has links)
No description available.

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