Risky intertemporal choice is a fairly new topic in the realm of behavioral economics that involves examining the interactions between individuals’ time and risk preferences. Previous research has looked at the gains and mixed domain, but little to no research has been done in the loss domain. This study aims to fill this gap by examining how people respond to risky gambles in the loss domain given real world time delays. The thesis focuses on changes in attitudes towards risk caused by temporal distance rather than how people discount risky prospects. Based on Construal Level Theory we predict that there will be a greater focus on outcomes over probabilities in delayed gambles compared to immediate ones, and hence, individuals will become more risk-averse for delayed gambles that are in the loss domain. We conducted two experiments to test this prediction. Results revealed that while subjects in the immediate resolution group were significantly more risk-seeking than future resolution groups in both experiments, the difference in risk attitudes between two delayed resolutions depend on how big the difference between two delays is.

Psychopathological conditions in which decision making is impaired are common and include schizophrenia, attention deficit hyperactivity disorder, and addiction, among others. This dissertation aimed to investigate the role of cholinergic signaling in risky and impulsive decision making. Rats were trained in either a “probability discounting” task in which they chose between small guaranteed and large probabilistically delivered food rewards (a measure of risky decision making), or a “delay discounting” task in which they chose between small immediate and large delayed food rewards (a measure of impulsive decision making). Rats were also divided into high and low “risk-taking” or “impulsive” groups on the basis of their performance in the tasks. Experiments 1 and 2 examined the effects of cholinergic drugs on performance in the probability and delay discounting task, respectively. In Experiment 1, acute administration of the acetylcholinesterase inhibitor donepezil decreased choice of the large risky reward in “risk-taking” rats. Acute administration of nicotine increased choice of the large risky reward in both groups, whereas administration of the nicotinic receptor antagonist mecamylamine decreased choice of the large risky reward in “risktaking” rats. In Experiment 2, nicotine increased choice of the large delayed reward and mecamylamine shifted impulsive choice in a non-specific manner in “impulsive” rats. The muscarinic receptor agonist oxotremorine decreased choice of the large delayed reward in “non-impulsive” rats and increased choice in “impulsive” rats, while treatment with the muscarinic receptor antagonist atropine increased impulsive choice in all rats. In Experiment 3, another group of rats was used to examine correlations between baseline performance in both discounting tasks and nicotinic receptor density levels in several brain regions. Impulsive choice was positively correlated with α4β2 receptor levels in ventral hippocampus and nucleus accumbens shell, and α7 receptor levels in the basolateral amygdala, such that greater impulsivity was associated with higher receptor levels. Additionally, risky choice was negatively correlated with α4β2 receptor levels in nucleus accumbens shell, such that greater risk was associated with lower receptor levels. These experiments suggest that cholinergic receptors are involved in cost-benefit decision making and that they may prove a useful target for treatment of psychopathological conditions in which decision-making deficits are present.

ABSTRACT Although sub-Saharan Africa continues to bear the brunt of the global HIV/AIDS pandemic and other sexually transmitted diseases (UNAIDS and WHO 2008; Fatusi and Wang 2009), very few studies in the region and for that matter Ghana have systematically and exclusively examined adolescent risky sexual behaviour in a manner that is theoretically consistent with the unique socio-cultural norms that govern sexuality in the society. Given that involvement in risky sexual behaviour constitutes sexual deviance in the Ghanaian context, and from the ontological position that behaviour is a product of structure and human agency (Sewell 1992), this study extends the theories of social control (Hirschi 1969), power control (Hagan et al. 1979, 1985,1987, 2002; McCarthy et al. 1999) and rational choice (Cornish and Clarke 1986) in examining the predictors of risky sexual behavior among Ghanaian adolescents. Using the 2004 Ghana National Adolescent Survey data (N=3985), the study employs descriptive statistics, measures of association and complementary log-log regression models in predicting the likelihood of being sexually active before marriage, having more than one lifetime sexual partner and condom use. Overall findings provide mixed support for the theoretical expectations. From the perspective of Hirschi’s control theory, the findings suggest among others that while some measures of conventional behaviour do not discourage premarital sex, they do so with respect to multiple sexual partnerships. A puzzle that needs further elaboration is the finding that highly educated adolescents who hold leadership positions have a higher significant taste for premarital sex and multiple sexual relations than their uneducated counterparts who are not leaders. Overall findings regarding the predictions of power control theory are consistent with the revised version offered by McCarthy and Colleagues (1999) and Hagan and colleagues (2002); that daughters in less patriarchal or matriarchal households are more likely than sons to have premarital sex and be in multiple sexual partnerships. Findings regarding the predictions of rational theory suggest a mixed rationality; condom use among adolescents in many instances is inconsistent with rational choice behaviour. General and specific policy implications of the findings and direction for future research are also discussed. / Thesis (Master, Sociology) -- Queen's University, 2010-07-31 02:18:09.013

The aim of the current series of studies was to begin the process of examining whether a propensity to act rashly in response to positive affective states (positive urgency) increases the likelihood of engaging in risky, maladaptive, and harmful acts. We theorized that this trait may account for some types of risky drinking behavior not explained by other risk factors, particularly for college students. In the current series of studies, an internally consistent (=.94), unidimensional scale was developed. This scale was shown to have convergent validity across methods and discriminant validity from other types of impulsivity. For both alcohol use and risky behavior, positive urgency explained variance not explained by other forms of impulsivity. Cross-sectional tests were consistent with the hypothesis that positive urgency leads to positive alcohol expectancies, which lead to increased drinking, which leads to involvement in risky behavior. This possibility should be examined prospectively.

Sexual revictimization of college women is a relatively new area of study within the field of victimology. Although the link between childhood sexual assault (CSA) and adult revictimization has been examined, many aspects of why college-aged females are revictimized have gained little attention. This Master’s thesis will explore the current literature as well as analyze the possible link between risky behaviors, individual characteristics, and sexual revictimization. Using Jacquelyn W. White and Paige Hall Smith’s (2004) data, A Longitudinal Perspective on Physical and Sexual Intimate Partner Violence Against Women, bivariate analyses were conducted regarding the revictimization of college women. The findings suggest a few differences between single victims and revictims. The findings also suggested that nonvictims and revictims were found to have multiple differences across variables. Suggestions for future research will be discussed.

Few data are currently available regarding the extent to which older people (defined here as those aged >50 years): i) are sexually active; ii) engage in `risky' sexual behaviours; and iii) contract sexually transmitted diseases (STDs). It was the primary aim of research described in this thesis to address these specific knowledge deficits and to ascertain whether the exclusion of this age group as a research focus within this subject field can be reasonably justified. The dearth of previous research undertaken in this area necessitated that a secondary goal be addressed, namely the development of methodologies appropriate to the collection from older people of data concerning such issues. Using a combination of self-administered questionnaire studies and secondary data analyses, undertaken both in health care settings and within the community at large, the programme of research clearly indicates that: 1. Older people represent a consistent minority of patients attending specialised genitourinary (GUM) clinics. Members of this group are further regularly diagnosed with STDs. Moreover, older clinic attenders exhibit distinctive socio-demographic and clinical characteristics relative both to younger clinic attenders and to the general population of the same age group. 2. The majority of older GUM clinic attenders are first time attenders and have not been diagnosed with an STD before 3. In the community at large the majority of older adults are sexually active, of whom a small minority (approximately 7%) engage in behaviours that place them at risk of contracting STDs. 4. Most older people, recruited from both health care and non-health care settings, feel that they have received very little information about STDs and HIV, and many indicated that they would like to receive more information on these topics.

Risky intertemporal choice is a fairly new topic in the realm of behavioral economics that involves examining the interactions between individuals’ time and risk preferences. Previous research has looked at the gains and mixed domain, but little to no research has been done in the loss domain. This study aims to fill this gap by examining how people respond to risky gambles in the loss domain given real world time delays. The thesis focuses on changes in attitudes towards risk caused by temporal distance rather than how people discount risky prospects. Based on Construal Level Theory we predict that there will be a greater focus on outcomes over probabilities in delayed gambles compared to immediate ones, and hence, individuals will become more risk-averse for delayed gambles that are in the loss domain. We conducted two experiments to test this prediction. Results revealed that while subjects in the immediate resolution group were significantly more risk-seeking than future resolution groups in both experiments, the difference in risk attitudes between two delayed resolutions depend on how big the difference between two delays is.

The goal of this dissertation research is to model risk in delivery, operation and maintenance phases of infrastructure asset management. More specifically, the two main objectives of this research are to quantify and measure financial risk in privatizing and operational risks in maintenance and rehabilitation of infrastructure facilities. To this end, a valuation procedure for valuing large-scale risky projects is proposed. This valuation approach is based on mean-risk portfolio optimization in which a risk-averse decision-maker seeks to maximize the expected return subject to downside risk. We show that, in complete markets, the value obtained from this approach is equal to the value obtained from the standard option pricing approach. Furthermore, we introduce Coherent Valuation Procedure (CVP) for valuing risky projects in partially complete markets. This approach leads to a lower degree of subjectivity as it only requires one parameter to incorporate user's risk preferences. Compared to the traditional discounted cash flow analysis, CVP displays a reasonable degree of sensitivity to the discount rate since only the risk-free rate is used to discount future cash flows. The application of this procedure on valuing a transportation public-private partnership is presented. %and demonstrate that the breakeven buying price of a risky project is equal to the value obtained from this valuation procedure. Secondly, a risk-based framework for prescribing optimal risk-based maintenance and rehabilitation (M&R) policies for transportation infrastructure is presented. These policies guarantee a certain performance level across the network under a predefined level of risk. The long-term model is formulated in the Markov Decision Process framework with risk-averse actions and transitional probabilities describing the uncertainty in the deterioration process. Conditional Value at Risk (CVaR) is used as the measure of risk. The steady-state risk-averse M&R policies are modeled assuming no budget restriction. To address the short-term resource allocation problem, two linear programming models are presented to generate network-level polices with different objectives. In the first model, decision-maker minimizes the total risk across the network, and in the second model, the highest risk to the network performance is minimized.

Road trauma is recognized as a major public health problem worldwide (particularly for younger drivers), and risky driving has been identified as an important contributor to road crashes. It is often assumed that similar factors influence all risky driving behaviours, although direct and systematic examination of the differences between risky driving behaviours in terms of precipitating factors is lacking. The present thesis sought to undertake a systematic investigation of relevant factors in the prediction of four key risky driving behaviours (speeding, drink-driving, driving while fatigued, and not wearing seat belts). Four versions of a Risky Driving Questionnaire were developed to assess beliefs, personality factors and behavioural intentions, in relation to each of the four behaviours. Four versions of the Implicit Association Test were developed to assess attitudes toward each of the four behaviours, without reliance on self-report (in terms of the relative strength of pairs of associations). Data were collected from a student sample (N=215: Study 1), as well as urban (N=587) and rural (N=422) general population samples (Study 2), and regression models were examined for each of the four behaviours, with interaction terms to assess moderations involving perceived risk. Mediations involving gender were also assessed. Results indicate that different risky driving behaviours are predicted by different factors. For example, in the urban sample, speeding was predicted by driver anger and illusory invulnerability, drink driving was predicted by peer influence, driving while fatigued was predicted by the perceived benefits of not driving while fatigued, and not wearing seat belts was predicted by the (sensation seeking x illusory invulnerability) interaction. Results also suggest that different predictors of risky driving behaviours are relevant for different driver populations. For example, speeding was predicted by authority rebellion in the urban sample, and by sensation seeking in the rural sample. Observed moderations of perceived risk suggest that relationships between perceived risk and risky driving may differ for males versus females, and for low versus high sensation seekers. Findings suggest that future road safety interventions should be based on research of the determinants of individual risky driving behaviours, and in specific driver populations.

Made available in DSpace on 2014-06-11T19:31:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-24Bitstream added on 2014-06-13T18:42:09Z : No. of bitstreams: 1 fonzar_ujv_dr_botfm.pdf: 1765649 bytes, checksum: aa5996c6a7991f5ddc704d8d95d78bf9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A leptospirose é uma importante zoonose que tem como hospedeiros primários os animais silvestres, sinantrópicos e domésticos. Os seres humanos comportam-se como hospedeiros terminais e acidentais. A sua distribuição é mundial, no entanto, na América Latina, África e Ásia, as prevalências são maiores devido às condições ambientais de ordem físico-química, bem como sócio-econômico-cultural, que favorecem a persistência e a disseminação da infecção. A distribuição geográfica da leptospirose está fortemente relacionada à questão ambiental e ao processo de urbanização das cidades. A prevalência deste agravo depende do animal portador que dissemina leptospiras, da sua sobrevivência ambiental e do contato de pessoas susceptíveis. Vários animais infectados podem ser hospedeiros ou reservatórios, e cada sorovar tem um ou mais hospedeiros com diferentes níveis de adaptação. A permanência de focos de leptospirose se deve aos animais infectados, doentes e assintomáticos, considerados como fontes permanentes de contaminação ambiental. O objetivo desta pesquisa foi determinar áreas de risco e possíveis componentes ecológicos da infecção leptospírica em cães errantes e pacientes com diagnóstico de leptospirose, entre os anos de 2006 e 2008, no municípío de Maringá-PR. Foram estudados 335 cães errantes e 25 pacientes. Amostras de soro, tanto dos animais como dos pacientes, foram examinadas pela prova de soroaglutinação microscópica-SAM, para pesquisa de anticorpos anti-leptospíricos. Para determinar as áreas de risco e a distribuição espacial da doença, foram elaborados mapas temáticos e avaliados os indicadores ambientais e sociais por setores do perímetro urbano. Foram observados 41(12,2%) cães positivos para um ou mais sorovares de leptospiras, e os mais freqüentes foram: Pyrogenes (43,9%), Canícola (21,9%) e Copennhageni (19,5%)... / Leptospirosis is an important zoonosis which has as primary hosts savage, synantropic and domestic animals. Human beings behave as terminal and accidental hosts. Its distribution is worldwide, notwithstanding, in Latin America, Africa and Asia the prevalence is higher due to the environmental conditions either of physical-chemical or social-economical-cultural order, which favor persistence and dissemination of the infection. The geographic distribution of leptospirosis is strongly related to the environmental question and the process of the cities urbanization. This prevalence depends on the animal carrier which disseminates the leptospirosis, its environmental survival and the contact with susceptible host. Many infected animals may be a host or a reservoir and each serovar has one or more different hosts or reservoirs with diverse levels of adaptation. The persistence of the leptospirosis focus is due to the infected animals, sick or non-syntomatic, that are considered as sources of permanent environmental infection. The aim of this work was to determine the risky areas and the possible ecologic components of the leptospirosis infection in wandering dogs and patients with leptospirosis diagnosis between the years of 2006 to 2008 in Maringá city, Paraná state. 335 wandering dogs and 25 patients were studied. Either animal or patients serum samples were examined by the microscopic serum agglutination – MAT for search of the anti-leptospira antibodies. To determine the risky areas and the special distribution of the disease thematic maps were elaborated and the environmental and social indicators were evaluated by the urban perimeter sectors. In the study, 41 (12,2%) positive dogs were observed, with for one or more leptospirosis serovars and the most common were: Pyrogenes (43,9%), Canícola (21,9%) and Copennhageni (19,5%). For humans the positiveness was of 2 (8%)... (Complete abstract click electronic access below)