The purpose of the study was to determine if perceived severity of the consequences of physical inactivity is an important component for exercise motivation in college students. The participants of the study were 581 college students who had enrolled in HSC 160, Fundamentals of Human Health, at Ball State University during the spring semester of 2001. Using a cross-sectional data collection process, participants completed a survey instrument consisting of the stages of change for exercise scale, the perceived severity of the consequences of physical inactivity scale, and demographic questions.The data were analyzed using both univariate and bivariate analyses. Specific descriptive and inferential statistic analyses were used to: 1) determine the degree of association between the participants' perceived severity and their identified stages of change for exercise, 2) examine the relationship between the stages of change for exercise and the participants' demographic characteristics, and 3) determine the difference between perceived severity of consequences of physical inactivity and the Participants' demographic characteristics.The results indicated that those who perceived the threat of a health condition as a result of not being physically active to be high were more likely to exercise regularly. Males and females differed in their exercise stage of change with males being more likely in the maintenance stage whereas females were more likely to be in the preparation stage. Also, perceived severity of the consequences from the lack of physical activity was greater in females than males, suggesting that those men who exercise regularly do so, but not exclusively for preventing negative health conditions.The results of this study should be useful to health and physical education instructors to assist them with organizing and tailoring appropriate physical activity lecture topics and emphasizing the severity of the consequences to those who are not physically active.Finally, additional research should be conducted in order to determine what factors affect perceived severity of a health threat as it relates to physical inactivity such as demographics, sociopsychological, and structural variables, to help identify all the possible factors that could impact future program planning efforts. / Department of Biology

The aim of this research was to implement and evaluate guidelines that will be used by treatment support counsellors in an attempt to increase client adherence to antiretroviral treatment.

<p>Nevirapine (NVP) is a cheap anti-retroviral drug used in poor countries worldwide, administered to pregnant women at the onset of labour to inhibit HIV enzyme reverse transcriptase. Viruses which may get transmitted to newborns are deficient in this enzyme, and HIV-1 infection cannot be established, thereby preventing mother to child transmission (MTCT). In some cases, babies get infected and positive selection for viruses resistant to nevirapine may be inferred. Positive selection can be inferred from sequence data, when the rate of nonsynonymous substitutions is significantly greater than the rate of synonymous substitutions.</p> <p>Unfortunately, it is found that available positive selection methods should not be used to analyse before- and after- NVP treatment sequence pairs associated with MTCT. Methods which use phylogenetic trees to infer positive selection trace synonymous and nonsynonymous substitutions further back in time than the short time duration during which selection for NVP occurred. The other group of methods for inferring positive selection, the pairwise methods, do not have appreciable power, because they average susbtituion rates over all codons in a sequence pair and not just at single codons. We introduce a simple counting method which we call the Pairwise Homologous Codons (PHoCs) method with which we have inferred positive selection resulting from NVP treatment in longitudinal HIV-1 reverse transcriptase sequences. The PHoCs method estimates rates of substitutions between before- and after- NVP treatment codons, using a simple pairwise method.</p>

<p>The HIV/AIDS pandemic poses the greatest threat to Africa's efforts to achieve its full potential in the social, economical and political spheres. Cognizant of its devastating consequences, various mechanisms have been designed to address the issue of HIV/AIDS in Africa. This thesis addressed the question: 'Are the legislations and policies of Ethiopia, Botswana and Uganda providing for various modalities of HIV testing consistent with human rights as enshrined under African Human Rights system?' The author of this dissertation critically analyzed the African human rights instruments and the relevant domestic legislation and policies of the three countries.</p>

The human immunodeficiency virus type 1 (HIV-1) uses a mechanism of genetic recoding known as programmed ribosomal frameshifting to translate the proteins encoded by the pol gene. The pol gene overlaps the preceding gag gene in the -1 reading frame relative to gag. It contains neither a start codon nor an internal ribosome entry site (IRES) to initiate translation of its proteins. Rather the host ribosomes are forced to pause due to tension placed on the mRNA when they encounter a specific secondary structural element in the mRNA. This tension is relieved by disruption of the contacts between the mRNA codons and tRNA anticodons at a �slippery� sequence within the ribosomal decoding centre. Re-pairing of the tRNAs occurs in the new -1 frame after movement of the mRNA backwards by one nucleotide, allowing the ribosome to translate the pol gene as a Gag-Pol polyprotein. A change in ratio of Gag to Gag-Pol proteins affects viral assembly, and most significantly dramatically reduces viral infectivity. The prevailing model for the mechanism of -1 frameshifting has focussed on a pre-translocational event, where slippage occurs when the slippery sequence is within the ribosomal A and P sites. This model precludes a contribution from the codon immediately downstream of the slippery sequence leading into the secondary structural element. I have termed this the �intercodon�. Often at frameshifting sites it is a termination codon, whereas in HIV-1 it is a glycine codon, GGG. When the intercodon within the frameshift element was changed from the wild-type GGG to a termination codon UGA, the efficiency of frameshifting decreased 3-4-fold in an in vivo assay in cultured human cells. This result mimicked previous data in the group within bacterial cells and cultured monkey COS-7 cells. Changing the first nucleotide of the intercodon to each of the three other bases altered frameshifting to varying degrees, but not following expected patterns for base stacking effects. Such a result would support a post-translocational model for -1 frameshifting. It suggested that the intercodon might be within the ribosomal A site before frameshifting, and that the slippery sequence was therefore within the P and E sites. This was investigated by modulating the expression of decoding factors for the intercodon - the release factor eRF1 and cognate suppressor tRNAs when it was either of the UGA or UAG termination codons, and tRNA[Gly] for the native GGG glycine codon. These were predicted to affect frameshifting only if slippage were occurring when the ribosomal elongation cycle was in the post-translocational state. Overexpression of tRNA[Gly] gave inconsistent effects on frameshifting in vivo, implying that its concentration may not be limiting within the cell. When eRF1 was overexpressed or depleted by RNAi, significant functional effects of decreased or increased stop codon readthrough respectively were documented. Expression of suppressor tRNAs increased readthrough markedly in a stop codon-specific manner. These altered levels of eRF1 expression were able to modulate the +1 frameshifting efficiency of the human antizyme gene. Overexpression of eRF1 caused significant reduction of frameshifting of the HIV-1 element with the UAG or UGA intercodon. Depletion of the protein by contrast had unexplained global effects on HIV-1 frameshifting. Suppressor tRNAs increased frameshifting efficiency at the UAG or UGA specifically in a cognate manner. These results strongly indicate that a post-translocational mechanism of frameshifting is used to translate the HIV-1 Gag-Pol protein. A new model (�almost� post-translocational) has been proposed with -1 frameshifting occurring for 1 in 10 or 20 ribosomal passages during the end stages of translocation, because of opposing forces generated by translocation and by resistance to unwinding of the secondary structural element. With translocation still incomplete the slippery sequence is partially within the E and P sites, and the intercodon partially within the A site. The nature of the intercodon influences frameshifting efficiency because of how effectively the particular decoding factor is able to bind to the partially translocated intercodon and maintain the normal reading frame.

Thesis (PhD)--University of South Australia, 2001.

Bibliography: leaves 127-161. / x, 161, [94] leaves, [30] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Direct transmission from infected cells to uninfected cells, otherwise known as cell-to-cell infection, is one mode of viral spread adopted by HIV-1. Transcriptional aspects of HIV-1 replication were examined following cell-to-cell infection. / Thesis (Ph.D.)--University of Adelaide, Dept. of Microbiology and Immunology, 1997

Thesis (Ph.D.)--University of Adelaide, Dept. of Public Health, 2002. / Bibliography: p. 189-229.

Thesis (M.S.)--Rochester Institute of Technology, 2008. / Typescript. Includes bibliographical references (leaves 37-40).

Thesis (Ph.D.)--Murdoch University, 2006. / Thesis submitted to the Division of Health Sciences. Bibliography: leaves 138-177.