Indiana University-Purdue University Indianapolis (IUPUI) / Impulsivity is associated with addiction in many human studies. Delay discounting (DD) is often used to measure impulsive choice in humans and animals. In DD testing, a small immediate reward is pitted against a larger delayed reward, and relative preference is assessed. The relative contribution of ethanol to impulsivity in alcoholism is not well-understood, therefore I will test the hypothesis that ethanol exposure will increase impulsivity in High Alcohol Preferring (HAP) mice as measured in an adjusting amount DD task. Selectively bred HAP mice were exposed to ethanol and tested in DD in 3 different experiments. Experiment 1: ad lib homecage ethanol drinking for 21 days and 17 days were used to expose mice to ethanol. Additionally, mice were tested in DD while “currently drinking” vs. “abstinent”. In experiment 2, to achieve higher blood alcohol concentrations, mice were injected with 3.5 g/kg ethanol 8 times and tested before and after in DD. In both experiments 1 and 2, mice were tested at only 2 delays (0.5 sec and 10 sec), to maximize sensitivity to detect shifts in choice behavior. In experiment 3, mice responded for 8% ethanol or 0.01% saccharin at a full range of delays: 0, 1, 2, 4, and 8 sec. Experiment 1 did not reveal any impact of ethanol drinking on impulsivity. Experiment 2 revealed a strong trend of reduced impulsivity in the 10 sec delay group after ethanol injections. Experiment 3 revealed reduced impulsivity at the 8 sec delay in the group responding for ethanol, and also revealed a significant correlation between higher ethanol drinking and reduced impulsivity. These data were unexpected, and imply that the a priori hypothesis not only should be rejected, but that the opposite hypothesis may be true: ethanol decreases impulsivity, at least with high dose exposure and in responding for it as a reinforcer. This effect was similar to the effect observed in other studies with amphetamine, which consistently decreases impulsivity. Ethanol may have been exerting an amphetamine-like effect on impulsivity at the doses tested here. There is no evidence in the data generated in these studies that ethanol increases impulsivity.

Automobile accident reconstruction has been facilitated by the development of computer based modules to allow evaluation of evidence gathered at the accident scenes. Although the computer modules are based in fundamental physical laws, an understanding of these laws by the user is required for proper application of the computer model in a given accident scenario. Vehicle collision analysis techniques generally separate the collision into three phases: pre-impact, impact, and post impact. The intent of the research is to provide a generalized model to reconstruct two dimensional impact problems in the area of accident reconstruction. There are currently two modeling techniques used to reconstruct the impact phase: the first technique relying exclusively on impulse-momentum theory coupled with friction and restitution, while the second method combines impulse momentum with a relationship between crush geometry and energy loss. Because each method requires very different inputs, the literature would have us believe that both methods are different. We will show that both methods are derived using the same fundamental physical principles and for any given accident scenario, both methods will provide identical results. Each method will be presented in the form of a MathCAD spread sheet that will allow the user to reconstruct a wide variety of accidents controlling just a few parameters (i.e. mass, rotational inertia, angle of approach, etc...). Both methods will provide step by step graphical representation to assure a solid approach to physical fundamentals. The governing equations to the generalized energy approach will be non-dimensionalized and used to define all of the changes in energy (i.e. also referred to as an impulse in power) as a function of a characteristic velocity. Finally, different methods to consistently determine the direction of the force will be presented when additional information from the accident scene is provided.

General uncertainty analysis was used to evaluate the performance of a Rocket-Based Combined Cycle (RBCC) engine system. To estimate the uncertainties of test results, uncertainties of basic measurements such as temperature, pressure, mass flow rate, and thrust were determined. The desired test results of interest included specific impulse and characteristic velocity. Various possible test facilities were reviewed to obtain background information and example test run conditions. Based on the test run conditions, five methods of determining specific impulse were evaluated. Also, theoretical and actual characteristic velocities were analyzed to evaluate C* efficiency. Initially, general uncertainty analyses were completed relative to 1% accuracy for each measured variable. Then, cases were run using more realistic uncertainty estimates. The relative contributions of the different variables? uncertainties to the overall uncertainty of the selected performance parameters were also calculated. This process helps to identify the critical measurements from an uncertainty standpoint and can be a significant guide in the cost effective use of resources to reduce the test uncertainty.

No description available.

No description available.

No description available.

Rationale: Impulse control deficits are thought to underlie criminal offending. Impulsive choice is a facet of impulse control that refers to a preference for immediate over delayed rewards. This facet of impulse control has been measured empirically using the Iowa Gambling Task (IGT), which provides a metric of overall disadvantageous decision-making, as well as metrics of specific maladaptive decision-making strategies. Purpose: To investigate impulsive choice as a measure of impairment in offenders as reflected by performance on the IGT, and to examine maladaptive decision-making strategies that may mimic real-life decisions to engage in illegal behaviour. Methods: 100 Canadian federal offenders (34% female, mean age = 39.14 ± 9.74) and 89 controls (39% female, mean age = 37.04 ± 10.79) completed the IGT. The IGT involves repeatedly choosing cards from four decks. Two decks are “good” and result in a net gain on the task, and two decks are “bad” and result in a net loss. Decks offer a fixed reward, but vary in loss magnitude and frequency. IGT data were analyzed for net score (number of good choices minus number of bad choices), learning across the task, and deck switching patterns. Other assessments included data on offenders’ current sentence and risk for reoffence level. Results: Offenders performed significantly poorer than controls in terms of net score. Controls learned the advantageous strategy across the task but offenders did not. Offenders also made greater use of a “win-stay/lose-shift” strategy. Low-risk offenders performed significantly better than medium- or high-risk offenders on the IGT. Conclusion: These results suggest that, compared with controls, offenders tend to make riskier choices and use maladaptive decision-making strategies that provide a larger immediate reward but are disadvantageous in the long term. The IGT, as part of a comprehensive assessment of risk, may provide valuable information for preventing criminal offending and recidivism. / Thesis / Master of Science (MSc) / Criminal offending is thought to be related to impulse control problems. Research has linked offending to poor performance on a decision-making task known as the Iowa Gambling Task (IGT). On the IGT, participants repeatedly choose cards from four decks that provide wins and losses of points. Two decks are “good” and result in an overall gain on the task, and two decks are “bad” and result in an overall loss. In this study, 100 Canadian federal offenders and 89 non-incarcerated control participants completed the IGT. Offenders performed worse than the control group overall, and control participants but not offenders learned the best strategy (i.e., choosing from good decks) over the course of the task. Additionally, offenders with a “Low” criminal risk rating did better than those at “Medium” or “High” risk levels. These results suggest that the IGT may provide important information about the cause and prevention of criminal offending.

No / The relationship between exports and economic growth has been analysed by a number of recent empirical studies. This paper re-examines the sources of growth for the period 1971-2001 for India. It builds upon Feder's (1983) model to investigate empirically the relationship between export growth and GDP growth (the export led growth hypothesis), using recent data from the Reserve Bank of India, and by focusing on GDP growth and GDP growth net of exports. We investigate the following hypotheses: (i) whether exports, imports and GDP are cointegrated using the Johansen approach and Breitung's nonparametric cointegration test; (ii) whether export growth Granger causes GDP growth; (iii) and whether export growth Granger causes investment. Finally, a VAR is constructed and impulse response functions (IRFs) are employed to investigate the effects of macroeconomic shocks.

An important element in retailing is the use of impulse purchases; generally small items that are bought by consumers on the spur of the moment. By some estimates, impulse purchases make up approximately 50 percent of all spending by consumers. While impulse purchases have been studied in the brick-and-mortar retail environment, they have not been researched in the online retail environment. With e-commerce growing rapidly and approaching $20 billion per year in the Canadian and US markets, this is an important unexplored area. Using real purchasing behaviour from visitors to the Reunion website of Huntsville High School in Ontario Canada, I explored factors that influence the likelihood of an impulse purchase in an online retail environment. Consistent with diminishing sensitivity (mental accounting and the psychophysics of pricing), the results indicate that the likelihood of a consumer purchasing the impulse item increases with the total amount spent on other items. The results also show that presenting the offer in a popup is a more effective location and presentation mode than embedding the offer into the checkout page and increases the likelihood of the consumer making an impulse purchase. In addition, the results confirm that providing a reason to purchase by linking a $1 donation for a charity to the impulse item increases the frequency of the impulse purchase.

An important element in retailing is the use of impulse purchases; generally small items that are bought by consumers on the spur of the moment. By some estimates, impulse purchases make up approximately 50 percent of all spending by consumers. While impulse purchases have been studied in the brick-and-mortar retail environment, they have not been researched in the online retail environment. With e-commerce growing rapidly and approaching $20 billion per year in the Canadian and US markets, this is an important unexplored area. Using real purchasing behaviour from visitors to the Reunion website of Huntsville High School in Ontario Canada, I explored factors that influence the likelihood of an impulse purchase in an online retail environment. Consistent with diminishing sensitivity (mental accounting and the psychophysics of pricing), the results indicate that the likelihood of a consumer purchasing the impulse item increases with the total amount spent on other items. The results also show that presenting the offer in a popup is a more effective location and presentation mode than embedding the offer into the checkout page and increases the likelihood of the consumer making an impulse purchase. In addition, the results confirm that providing a reason to purchase by linking a $1 donation for a charity to the impulse item increases the frequency of the impulse purchase.