Personality traits and individual differences predict changes in postural control under conditions of height-induced postural threat

This thesis explored whether individual characteristics could predict changes in postural control in young adults under conditions of height-induced postural threat. Eighty-two young adults completed questionnaires to assess trait anxiety, trait movement reinvestment, physical risk-taking, and previous experience with height-related activities. Tests of static (quiet standing) and anticipatory (rise to toes) postural control were completed under conditions of low and high postural threat manipulated through changes in surface height. Individual characteristics were able to significantly predict changes in static, but not anticipatory postural control. Trait movement reinvestment and physical risk-taking were the most influential predictors. Evidence was provided that changes in fear and physiological arousal mediated the relationship between physical risk-taking and changes in static postural control. These results suggest that individual characteristics shape the postural strategy employed under threatening conditions and may be important for clinicians to consider during balance assessment and treatment protocols.

The effects of postural threat on cognitive strategies used to maintain upright stance

It is well established that postural threat modifies postural control, although little is known regarding the underlying mechanism(s) responsible. It is possible that changes in postural control under conditions of elevated postural threat result from alterations in cognitive strategies. The purpose of this study was to determine the influence of elevated postural threat on cognitive strategies and to determine the relationship between postural control, psychological, and cognitive measures. It was hypothesized that elevated postural threat would cause a shift to more conscious control of posture. It was also expected that a relationship between fear of falling and postural control would exist that could be explained by changes in conscious control of posture. Forty-eight healthy young adults stood on a force plate at two different surface heights: ground level (LOW) and 3.2m above ground level (HIGH). Center of pressure (COP) summary measures calculated to quantify postural control were the mean position (AP-COP MP), root mean square (AP-COP RMS) and mean power frequency (AP-COP MPF) in the anteriorposterior direction. Trunk sway measures calculated in the pitch direction were trunk angle and trunk velocity. Psychological measures including perceived balance confidence, perceived fear of falling, perceived anxiety, and perceived stability were self reported. As a physiological indicator of anxiety, electrodermal activity was collected. The cognitive strategies assessed were movement reinvestment and attention focus. A modified state-sp-ecific version of the Movement Specific Reinvestment Scale was used to measure conscious motor processing (CMP) and movement self-consciousness (MSC). An attention focus questionnaire was developed to assess the amount of attention directed to internal and external sources. An effect of postural threat on cognitive strategies was observed as participants reported more conscious control and a greater concern or worry about their posture at the HIGH postural threat condition as well as an increased internal and external focus of attention. In addition changes in postural control, psychological, and physiological measures were found. The participants leaned away from the edge of the platform, the frequency of their postural adjustments increased, and the velocity of their trunk movements increased. Participants felt less confident, more fearful, more anxious, and less stable with an accompanying increase in physiological anxiety. Significant correlations between perceived anxiety, AP-COP MP, and cognitive measures revealed a possible relationship that could be mediated by cognitive measures. It was found that with greater conscious motor processing, more movement self-consciousness, and a greater amount of attention focused externally there was a larger shift of the mean position away from the edge of the platform. This thesis provides evidence that postural threat can influence cognitive strategies causing a shift to more conscious control of movement which is associated with leaning away from the edge of the platform. Shifting the position of the body away from the direction of the postural threat may reflect a cognitive strategy to ensure safety in this situation due to the inability to employ a stepping strategy when standing on an elevated platform.

Permissivity of human HeLa cells to bovine adenovirus type 2 (BaV2 infection

Infection of hUlnan cells by bovine adenovirlls type 2 (BAV2) is abortive. To obtain a better understanding of this pllenomel1011, and in particular to identify Wllich steps in the viral replicative cycles are altered dllring this virlls-host cells interaction, we have llndertaken a detailed study of BAV2 infections of the nonpennissive hUlnan IIeLa cells. Using autoradiography and 3H-thymidine-labeled vvhole virus particles for infection of HeLa cells, vve determined that viral attachluent appears normal. Furthermore, Southern analysis revealed that internalization and transport to the nuclells occurs in BAV2 infected HeLa cells. To investigate viral DNi\ synthesis, infectivity assays involving hydroxyllrea, a viral DN-A synthesis inhibitor, were carried out. The results revealed that Bft:LV2 DNA synthesis does not occur in HeLa cells. Fllrtller investigations into viral early gene expression by northern blotting analyses indicated that HeLa cells fail to support expression of EIA. This suggested that abortive infection by BAV2 could be attributed to faiiure of EIA to express. To test the possibility that the failure to express ElA was due to the inability of the host cell to recognize the E lA prOlTIoter, ,ve carried out transient expression transfection experiments using plaslnids \vith the bacterial lacZ linder the control of either BAV2 or i\d5 EIA promoter. X-gal histochelIlical assays sho\ved expression of lacZ from the Ad5 ElA prOlnoter but no expression of lacZ [rOln the BAV2 EIA prOlTIoter. This further suggests that the abortive infection b:y BAV2 could be attributed to failure of EIA to express dlle to a nonfllnctional prOlTIoter in hlunan cells. Thus we speClllated that abortive infection of HeLa cells by adenoviruses may be averted by providing EtA functions in trans. To demonstrate this, we coinfected HeLa cells with Ad5 and BAV2, reasoning that Ad5 could cOlnpensate for EIA deficiency in BAV2. OUf results showed that BAV2 DNA synthesis was indeed Sllpported in HeLa cells coinfected with Ad5dlE3 as revealed by Southern analysis. In contrast, coinfection of HeLa cells \vith BAV2 and Ad5dlElE3 mutallt did not support BLt\V2 DNA synthesis. Interestingly, BAV2 failed to replicate in 293 cells which are constitlltively expressing the El genes. This could ilnply that El is necessary but not sufficient to avert the failllre ofBAV2 to undergo productive infection ofhulnan cells.

The Importance and achievement of work values and locus of control as factors in work motivation

The present research study examined the relationships in a work motivation context among perceived importance and achievement of work values, locus of control and internal work motivation. The congruence of a work value was considered to be the discrepancy between the importance of a work value and the perceived achievement of that value. The theoretical framework utilized was based on a self-perpetuating cycle of motivation which included the perceived importance and achievement of work values and internal work motivation as separate and distinct, yet interrelated factors. It was hypothesized that individuals who experienced high congruence of work values would experience higher levels of internal work motivation than individuals who had low congruence of work values. It was also hypothesized that individuals who had an internal locus of control would experience more internal work motivation individuals well, the and have higher congruence of work values than who had an external locus of control. As possibility of locus of control as a moderator between importance of work values and internal work motivation was explored. Survey data were collected from 184 managerial level employees of the XYZ company during an ongoing training session. The following instruments were employed to measure the variables: Elizur's (1984) Importance of Work Values, Hunt and Saul's (1985) Achievement of Work Values, Hatfield, Robinson and Huseman's (1975) Job Perception Scale, a modified version of Rotter's (1966) I-E Locus of Control Scale and the Internal Work Motivation Scale (Hackman & Oldham, 1980) which is a part of the Job Diagnostic Survey. The findings indicated that locus of control was not a significant factor in determining congruence between work values or internal work motivation for this sample. Furthermore, locus of control was also found not to be a moderator between the importance of work values and internal work motivation. All individuals in this study had relatively high levels of internal work motivation. However, individuals who had higher congruence of work values did have significantly higher internal work motivation than those who had low congruence of work values for a majority of the 21 values. This was particularly true for the intrinsic values which included responsibility, meaningfulness and use of abilities. In addition, the data were analysed into a hierarchy of needs to indicate possible organizational development or human resource development needs for the XYZ corporation.

"Re-huminization": the role of human-animal similarity in predicting prejudice towards immigrants and non-human animals

Research implies that there ~ay be an association between attitudes toward margil1alized human outgroups and non-human animals. Very few studies, however, have specifically tested this relation empirically. The general purpose of the present research was to determine if such a relation exists and if perceptions of human-animal similarity avail as a common predictor of both types of attitudes. Ideological orientations associated with prejudiced attitudes (Social Dominance Orientation, Right-Wing Authoritarianism, and Universal Orientation) were also examined as individual differences in predicting perceptions of human-animal similarity. As predicted, people who endorsed prejudiced attitudes toward human outgroups (Study 1) and immigrants in particular (Studies 2 and 3), were more likely to endorse prejudiced attitudes toward non-human animals. In Study 2, perceptions that humans are superior (versus similar) to other animals directly predicted higher levels of prejudice toward non-human animals, whereas the effect of human superiority beliefs on immigrant prejudice was mediated by dehumanization. In other words, greater perceptions of humans as superior (versus similar) to other animals "allowed for" greater dehumanization of immigrants, which in turn resulted in heightened immigrant prejudice. Furthermore, people higher in Social Dominance Orientation or Right-Wing Authoritarianism were particularly likely to perceive humans as superior (versus similar) to other animals, whereas people characterized by a greater Universal Orientation were more likely to perceive humans and non-human animals as similar. Study 3 examined whether inducing perceptions of human-animal similarity through experimental manipulation would lead to more favourable attitudes toward non-human animals and immigrants. Participants were randomly assigned to read one of four 11 editorials designed to highlight either the similarities or differences between humans and other animals (i.e., animals are similar to humans; humans are similar to animals;~~nimals are inferior to humans; humans are superior to animals) or to a neutral control condition. Encouragingly, when animals were described as similar to humans, prejudice towards non-human animals and immigrants was significantly lower, and to some extent this finding was also true for people naturally high in prejudice (i.e., high in Social Dominance Orientation or Right-Wing Authoritarianism). Inducing perceptions that nonhuman animals are similar to humans was particularly effective at reducing the tendency to dehumanize immigrants ("re-humanization"), lowering feelings of personal threat regarding one's animal-nature, and at increasing inclusive intergroup representations and empathy, all of which uniquely accounted for the significant decreases in prejudiced attitudes. Implications for research, theory and prejudice interventions are considered.

Perceived Deservingness and the Toleration of Human Rights Violations: The Problem and a Possible Solution

Despite general endorsement of universal human rights, people continue to tolerate specific human rights violations. I conducted a two-part study to investigate this issue. For Part I, I examined whether people tolerated torture (a human rights violation) based on the morality and deservingness of the target. Participants tolerated torture more when the target had committed a highly morally reprehensible transgression. This effect was mediated by the target’s perceived deservingness for harsh treatment, and held over and above participants’ abstract support for the right to humane treatment. For Part II, hypocrisy induction was used in an attempt to reduce participants’ toleration of the torture. Participants were assigned to either the hypocrisy induction or control condition. Unexpectedly, participants who tolerated the torture more in Part I reduced their toleration the most in the control condition, possibly because of consistency and floor effects. Limitations and implications of the findings are discussed.