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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.
241

Individual Differences in the Dopaminergic Reward System: The Effect of Genetic Risk on Neural Reward Sensitivity and Risky Choice

Soder, Heather E. 01 January 2015 (has links)
When making decisions, individuals evaluate several possible outcomes of their choice; however, some display heightened reward sensitivity, despite the potential for future negative consequences, which can lead one to make risky choices. Rewards are processed in the mesolimbic dopamine reward system, and this system is in part modulated by genetic polymorphisms that are associated with dopamine transmission. The current study tested if genetic polymorphisms that are associated with enhanced dopamine neurotransmission will be more neurally reward sensitive, score higher on self-reported impulsivity, and make riskier choices. In a sample of 85 participants, five genetic polymorphisms were genotyped and used to create a genetic risk score that represented dopamine transmission efficiency. Two groups (high and low efficiency) were created via median split and then compared on neural reward sensitivity (assessed by event-related potentials, specifically, the medial-frontal negativity [MFN] and the error-related negativity), impulsivity (assessed via self-report), and risky choice (measured using the Balloon Analogue Risk Task and self-report measures). Results indicated that individuals with higher levels of dopamine displayed a less negative MFN and more drinking behaviors than those with lower levels of dopamine. These results suggest that individuals with higher levels of dopamine are less sensitive to punishments, which could lead them to make riskier choices.
242

Sex Differences in Risky Adolescent Behavior

Jordan, Ashley C. January 2013 (has links)
Adolescence is a unique time during the human lifespan, where children develop into reproductively competent adults, and many behavioral and psychological changes develop. The goal of this dissertation is to examine the underlying functions related to the emergence of risky adolescent "behaviors," broadly defined to include both physical risks (e.g., drinking or physical fighting) and psychological risks (e.g., anxious or depressive symptoms). In this paper I (1) present a manuscript reviewing and synthesizing the relevant evolutionary theories, which bears testable hypotheses regarding sex differences in risky adolescent behavior, and (2) empirically assess these predictions in two separate but theoretically and conceptually related studies that test for theoretically-based hypothesized relations: one specific to males, one to females. Specifically, I test the proposition that males should be more likely to engage in physically risky behavior than females, and that females should be more likely to engage in affective risks (assessed as sensitivity to social evaluation). These hypotheses are generally supported, but shed light on important environmental factors that are associated with the prevalence of risk-taking, including the degree of closeness within the family, timing of pubertal development, and social status. In general, an early pubertal development and low social status are associated with risk-taking, while closeness to family buffers against the likelihood of engaging in later risky behaviors.
243

What's behind sexual risk taking? : exploring the experiences of chlamydia-positive, HIV-positive, and HIV-tested young women and men in Sweden

Christianson, Monica January 2006 (has links)
The overall aim was to explore the experiences of sexual risk taking among Chlamydia Trachomatis positive (CT+), HIV positive (HIV+), and HIV tested young women and men. The specific aims were to explore, from a gender perspective, the course of events, the norms, considerations and emotions involved in sexual risk taking in CT+, explore the perception of sexual risk taking in HIV+ youth, and their understanding of why they caught HIV and look at how the Law of Communicable Diseases Act impacts their sexuality. Moreover, to investigate why young adults test for HIV, how they construct the HIV risk, and what implications testing has for them. 42 informants between 17-24 years of age were recruited from a youth clinic in Umeå and from three infection clinics for HIV patients in Sweden. In depth interviews and focus group interviews were tape-recorded, transcribed verbatim and analyzed according to a Grounded Theory approach. The finding revealed that behind sexual risk taking, there was a drive to go steady, where lust and trust guided if sex would take place. In one-night stands women were expected to be less forward compared with men. We found an uneven responsibility concerning condom use where men expected women to be "condom promoters". By catching CT, women experienced guilt, while men felt content through knowing "the source of contamination". Among the HIV+ youth, socio-cultural factors such as; lack of adult supervision, naivité, love, alcohol, drugs, the macho ideal and cultures of silence blinded the informants to the risks and made them vulnerable. By grouping narratives according to degree of consensus in sexual encounters, this demonstrated that sexual risks happened in a context of gendered power relations where the informants had varied agency. The Law of Communicable Diseases Act implied both support and burden for these HIV+ youth. A lot of responsibility was put on them and to be able to handle the infromation duty they tried to switch off lust, switch off the disease, or balance lust and obedience. Among the HIV tested youth, HIV was seen a distant threat. Many had event-driven reasons for testing for HIV; multiple partners being one. Risk zones, like bars were perceived to be a milieu that often was expected to include one-night stands. Responsibility for testing was a gendered issue; "natural" for women, while men rather escaped from responsibility and had a testing resistance. Receiving a "green card" confirmed healthiness and provided relief, and made the informants felt "clean". They could restart with new ambitious, including reconsidering risk. The findings can be used in public health and in health care sectors that work with young people. We present suggestions on how to decrease the spread of STIs: To implement how men could play an equal part in sexual and reproductive health. Promote general CT screening for men. Liberal HIV testing among both young women and men. Promote safer sex behaviour from the uninfected youth, especially focusing on men??. Consider the role of gender and social background in the context of risky behaviours. Give lots of positive rewards concerning HIV disclosure to diminish the risk for HIV transmission.
244

Anger, impulsivity, sensation seeking and driver attitudes as correlates for self-reported acts of risky driving behaviour among young drivers.

Bachoo, Shaneel. January 2010 (has links)
The study used a cross-sectional survey design to investigate anger, impulsivity, sensation seeking and driver attitudes as correlates for self-reported acts of risky driving behaviour (RDB), among young drivers. A non-probability sample of 306 university students from two universities in the Durban region completed the self-administered questionnaire. A key focus area included an examination of age and gender differences in the above-mentioned constructs. Fifty four percent of the sample were male (N = 165) and 46% female (N = 141). The mean age of males and females in the sample was 29 years and 25 years respectively. The majority of the sample (75%) indicated that they drive either on a daily basis or 3-6 days a week. With regard to the relationship between the various personality constructs and selfreported acts of RDB, the results indicate that driver anger, sensation seeking, a sense of urgency and a lack of premeditation and perseverance were significantly related to self-reported acts of RDB. That is, drivers with higher driver anger, sensation seeking, urgency, and with a greater lack of premeditation and perseverance in daily activities were statistically more likely to report riskier driving acts. With respect to gender differences, males reported significantly more acts of RDB, while females displayed a significantly lower amount of premeditation in their general daily activities. However no other significant gender differences were observed. The results suggested that driver attitudes were significantly related to self-reported acts of RDB on most indicators. That is, drivers with a negative attitude towards RDB-related behaviours reported significantly less engagement in RDB-related actions.Finally, with respect to age differences, older drivers (25 years and older) reported significantly more negative attitudes towards rule violations/speeding and the careless driving of others. Also, older drivers reported a significantly lower sense of sensation seeking and urgency in life. / Thesis (M.Soc.Sci.)-University of KwaZulu-Natal, Durban, 2010.
245

Boys being boys : psychosocial factors associated with alcohol use among mid-adolescent males in a Durban boys' high school.

Payne, Kirsten L. January 2009 (has links)
The challenges of adolescence include negotiating risk behaviours such as alcohol use. The high prevalence and frequency of alcohol use among adolescents has been noted with concern, as has the rapidly decreasing age of initiation. Adolescent alcohol use has been found to be associated with numerous factors at intra-personal, inter-personal and contextual levels. This study aimed to explore qualitatively the perceived underlying factors related to alcohol use and binge drinking among adolescent boys, as identified and explained by the boys themselves. Exploration of these factors was guided by Brofenbrenner’s Ecological Systems Theory, the Prototype/Willingness Model and Bandura’s Social Cognitive Theory. The study population was comprised of male learners who were at that time in Grade 11 at the school and ranged in age from 16 to 18 years. Three focus group discussions were conducted, each comprising between 8-11 male learners, which were transcribed and analysed thematically in order to identify commonalties and variances among the responses of participants. The Nvivo software program was used to aid analysis. The findings of this study indicate that there are a variety of factors which influence adolescent alcohol use, and which operate individually as well as cumulatively. While adolescent boys are aware of the consequences of alcohol use and binge drinking, they often do not perceive themselves to be vulnerable to these risks. Protective factors include the school identity, team activities such as sports, and a sense of future. In conclusion, adolescent alcohol use is extremely complicated as it is impacted by multiple factors, and thus an awareness and greater understanding of the nature in which these factors interact are important for future interventions. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2009.
246

Finansiellt risktagande : En studie om svenska män och kvinnors finansiella riskbenägenhet

Lundström, Andrea, Nilsson, Johanna January 2013 (has links)
Syftet med studien är att identifiera om det finns någon skillnad i risk mellan svenska män och kvinnors aktieportföljer. I undersökningen av individernas riskbenägenhet används tre riskmått, total risk, marknadsrisk och unik risk, som enligt portföljteorin går att koppla till en individs aktieportfölj. Ålder och inkomst används som kontrollvariabler för att studera om eventuella skillnader i riskbenägenhet mellan könen kan förklaras av andra faktorer än kön. Studien baseras på en kvantitativ undersökning och sekundärdata från en unik databas. Urvalet för studien består av knappt 900 000 observationer av svenska individers aktieportföljer, med kontroll för kön, ålder och förvärvsinkomst. Resultatet av studien visar att det föreligger signifikanta skillnader mellan könens riskbenägenhet. Studien finner dock inga tydliga resultat för att män skulle vara mer riskbenägna än kvinnor, då könen tar olika hög risk beroende på vilket riskmått som avses. Resultaten visar på att skillnader mellan könens riskbenägenhet även existerar efter att variablerna ålder och inkomst studerats. / The purpose of this study is to identify whether there is any difference in risk between the stock portfolios of Swedish men and women. In the investigation of individual’ risk propensity, three measures of risk are used, total risk, market risk and unique risk, which according to the portfolio theory can be linked to an individual’s stock portfolio. Age and income are used as control variables to study whether any differences in risk propensity between the genders can be explained by other factors than gender. The study is based on a quantitative study and secondary data obtained from a unique database. The sample for the study consists of nearly 900 000 observations of Swedish individual’s stock portfolios, controlling for gender, age and income. The results of the study show that there are significant differences between the genders’ risk propensity. The study finds, however, no clear evidence that the men would be more risk-prone than women. The genders take different levels of high risk depending on which measure of risk involved. The results show that differences between the genders’ risk propensity also exists after studying the control variables age and income.
247

Skolhälsovårdens hälsofrämjande åtgärder för att förhindra sexuellt riskbeteende hos ungdomar / Health promotion methods in school health services to avoid sexual risk behavior among adolescents

Lindén Magnusson, Ann-Catrin January 2013 (has links)
I Sverige har förekomsten av klamydia ökat hos ungdomarna sedan 1997 och fortsatt stiga under 2000-talet. Den sexuella aktiviteten har förändrats till att ha fler tillfälliga partners och att skydda sig med kondom är inte alltid så självklart för de unga. Det kognitiva- och socioemotionella ssteme i hjärnan är inte färdigutvecklat hos tonåringarna vilket kan leda till spontana beslut och riskfyllt beteende. Syftet för denna litteraturstudie var att beskriva skolhälsovårdens hälsofrämjande omvårdnadsåtgärder för att påverka ungdomars sexuella risktagande. Event History Calendars, en metod för det individuella hälsosamtalet visade efter en månads postintervention en minskning av det sexuella riskbeteendet. Undervisning på gruppnivå är effektivt för att påverka ungdomars sexuella riskbeteende och för att höja åldern för den sexuella debuten. Men för yngre sexuellt aktiva tonåringar har dessa undervisningsmetoder ingen effekt. Metoder som stärker kommunikationen mellan de yngre tonåringarna och deras föräldrar har en skyddande effekt för utvecklingen av riskbeteenden. Familjeinterventionerna behöver undersökas närmare under svenska förhållanden. Metoder användbara i hälsosamtalen i skolhälsovården behöver också utvecklas i de svenska skolorna. Detta för att upptäcka de barn och ungdomar med behov av stöd. / The incidence of chlamydia in Swedish adolescents has increased in recent years. Sexual activity habits have changed and today´s teens have more partners and more casual contacts. Using condoms for protecting is not not always an obvious choice for the young. The cognitive ans socio-emotionell functions of the brain are not fully developed in young teens, and poor decision-making can and does lead to impulsive and risky beahaviors. The aim for this study of literature was to describe schhol health promotion nursing interventions to influence young peoples sexual risk-taking. Event History Calendars, a method used in individual health interviews, showed a reducation of risk behaviors after one month of post intervention. Teaching in groups is another effective method for influencing teens to reduce their risky behaviors and also leads to the additional positive outcome of raising the ages of sexual debut. Unfortunately these teaching methods have no positive effect on younger sexually active teens. A more productive methods for very young teens is to steengthen the communication between them and their parents. We need to examine closer the role of family interventions in Swedish schools as well as develope the methods shown to bee effective in health interviews in order to identify and assist children and young youth need of support.
248

The effect of sexual arousal on risky decision-making / Gillian Kennedy

Kennedy, Jillian, University of Lethbridge. Faculty of Arts and Science January 2011 (has links)
Sexual arousal is likely an important situational factor in date rape. Research shows that sexual arousal increases self-reported willingness to engage in sexually aggressive behaviour. Chapter One reviews the situational, perpetrator, and victim characteristics of date rape. Chapter Two describes an experiment that examined the effect of sexual arousal on measures of decision-making, including Risky Choice Task, Balloon Analogue Risk Task, Future Discounting, and on a measure of Viewing Time. Participants were 20 heterosexual men and 22 heterosexual women 18 to 25 years old. Results revealed that sexually aroused women preferred higher variance options compared to women who were not, and the opposite was observed for men. No other significant effects were observed. Chapter Three describes Experiment 2 which included another neutral condition and a measure of sexual decision-making. Results revealed no effect of condition on behavioural or sexual decision-making, nor on viewing times. Chapter Four provides a general discussion and directions for future research. / ix, 156 leaves; 29 cm
249

Competence satisfaction in action : risk taking and achievement by students with and without physical disabilities

Tsalavoutas, Ioannis January 2004 (has links)
The study compared competence satisfaction in a ball striking activity, as measured by risk taking and achievement, of individuals with ( N = 16) and without (N = 18) physical disabilities under mastery and performance orientation climates. The students ranged in age from 7-13 years. They were required to strike a ball into nets of three different size-distance combinations. Results supported the first hypothesis of no competence satisfaction differences between the groups under mastery and performance climates. The second hypothesis that the introduction of performance climate would increase risk taking and this would affect achievement accomplishments and competence satisfaction was also supported. Nonetheless, performance climate had a different effect on each ability group with regard to achievement accomplishments. Specifically, performance climate undermined achievement accomplishments for individuals with physical disabilities and encouraged achievement accomplishments for peers without disabilities. Hence, individuals with physical disabilities did not satisfy their need of competence in the same manner as peers without disabilities in the performance climate. For those with physical disabilities performance appears to be crucial, whereas for peers without disabilities risk taking is essential.
250

TWO ESSAYS ON CORPORATE FINANCE

Kim, Soohyung 01 January 2015 (has links)
This dissertation consists of two essays on corporate finance. The first essay investigates the relationship between dual-class shares and firm’s risk-taking. While costs associated with dual-class shares are widely documented, the benefits are seldom studied in the literature. We attempt to fill this gap and find that dual-class firms tend to have fewer business segments, higher volatilities in their cash flows, earnings, and investment opportunities compared to propensity-matched single-class firms. Business segments within a dual-class firm are also more positively correlated in their cash flows, earnings, or investment opportunities than those in single-class firms. The results are consistent with the hypothesis that dual-class shares can potentially shield insiders from short-term market pressure so they can focus on riskier projects to enhance long-term shareholder value. To provide a possible channel through which dual-class firms can increase corporate risk-taking, we examine one of the most important corporate investment decisions: mergers and acquisitions (M&As). Dual-class firms are more likely to engage in M&As, especially nondiversifying M&As. Corporate risks increase following M&As, and the increase is more for dual-class firms than for single-class firms. The second essay shows how CEO skills affect operating performance using a sample of 109 spin-offs from 1994 to 2009. Since a variety of studies indicate that firms in need of external financing are more likely to engage in spin-offs, we hypothesize that parent firms prefer to appoint financial experts as CEOs at spun-off units around spin-off transactions. We find that appointing spun-off unit CEOs with financial expertise brings significant and positive wealth effects. Furthermore, the CEOs with financial expertise significantly improve firms’ access to capital markets and subsequent operating performance. Conversely, we do not observe positive wealth effects at the spin-off announcement or improved operating performance following spin-offs when parent firms decide to assign non-financial experts as spun-off unit CEOs.

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