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South Africa has one of the highest HIV+ prevalence rates in the world [1]. Furthermore, social support is beneficial to HIV+ people. Informational support is a type of social support which is used to increase one’s knowledge base [2]. Hayes et al. state that informational support is especially beneficial for those in the early stages of HIV infection [3]. Computer technologies have been used successfully in providing informational support to their users. However, virtual reality (VR) is a relatively unexplored technology in South Africa, and we feel it is a highly appropriate medium for a context where users have little or no prior computing experience. Traditionally, computer interfaces require users to have a learned skillset, but a VR interface does not necessarily require this as it maps more directly to users’ natural interaction techniques with the real world. A key benefit of a virtual environment (VE) is the interactivity and user involvement that it offers through a high degree of navigation and interaction with objects [4]. VR may, initially, seem to be an expensive technology to use in a developing country but it is possible to make use of desktop VR on a consumer-grade PC relatively affordably. This dissertation presents a comparison of the effects of two media, VR and paper (i.e. pamphlets) in communicating supportive information to an HIV+ sample group. We created a VE to provide social and informational support for HIV+ people in the South African context. The design of the VE placed emphasis on creating a typically South African space which users could recognize and find familiar. Our research focused on two rooms containing virtual agents and points of possible interaction: the lounge and the kitchen. In the lounge, a HIV/Aids support group was simulated while the kitchen contained two areas which presented nutritional informational support: Diet and Cleanliness & Hygiene. We conducted a pre- post-test study with 22 HIV+ women at two clinics in Cape Town. Participants were randomly assigned into one of three groups. One group experienced the informational VE (VE), one group received information pamphlets (Text), the control group who received no information until the end of the study (Ctrl). Participants attended three experiment meetings over a five week period. Participants completed two 3-day food diaries and completed questionnaires that provided measurement for two sets of variables: Food Safety Behaviours (a measure of knowledge of correct food and water safety practices to prevent food-borne illnesses) and Dietary Quality (measure of the diet quality – in terms of quantity, variety, water intake and vitamin supplements, as well as specific food items for the prevention of stomach ailments, a common complaint of HIV infection). While we found no differences between the Text and Ctrl groups, the VE group showed a significant improvement in consuming two (of three) specific food items recommended for the prevention of stomach complaints. This is a particularly striking result given that more than half the participants stated that they routinely did not have enough money to buy food let alone specific healthy foods. The area that contained the information related to stomach complaints was the last imagery experienced by all VE participants. That it was the only area that showed improvement highlights how careful VE authors should be in choosing the actual content for the environment, as well as how that content is delivered. Despite very minimal computing experience and only short training sessions, all participants mentioned that they found the VE easy to use and enjoyed their experience of it. Our results show that VR can indeed be used to deliver informational content to HIV+ women in South Africa.

Virtualisation is a method of partitioning one physical computer into multiple “virtual” computers, giving each the appearance and capabilities of running on its own dedicated hardware. Each virtual system functions as a full-fledged computer and can be independently shutdown and restarted. Xen is a form of paravirtualisation developed by the University of Cambridge Computer Laboratory and is available under both a free and commercial license. Performance results comparing Xen to native Linux as well as to other virtualisation tools such as VMWare and User Mode Linux (UML) were published in the paper "Xen and the Art of Virtualization" at the Symposium on Operating Systems Principles in October 2003 by (Barham et al, 2003). (Clark et al, 2004) performed a similar study and produced similar results. In this thesis, a similar performance analysis of Xen is undertaken and also extended to include the performance analysis of OpenVZ, an alternative open source virtualisation technology. This study made explicit use of open-source software and commodity hardware.

Darbo tikslas: nustatyti galimą nifumezino ir į jį panašių junginių struktūros-aktyvumo ryšį. Tyrimo metodai: susintetintų nifumezino analogų preliminarūs antimikrobinio aktyvumo tyrimai in vitro ir antimikrobinio aktyvumo prognozė PASS programa. Tyrimo rezultatai: atlikus antimikrobinio aktyvumo tyrimus in vitro nustatyta, kad junginiai AM-3 ir AM-4 yra praktiškai neaktyvūs, kai koncentracija 500 µg/ml. Junginiai AM-3-1 ir AM-4-1 veikia S. aureus, E. faecalis, S. epidermidis. AM-5 aktyvus prieš S. aureus ir B. subtillis. Nė vienas iš susintetintų junginių nėra aktyvus prieš P. aeruginosa, P. mirabilis ir E. coli. Atlikus kompiuterinį aktyvumo prognozavimą PASS programa, nustatyta, kad stipriausias antibakterinis poveikis prognozuojamas AM-3-1 ir AM-4-1 junginiams (Pa>0,4). Priešgrybelinis poveikis prognozuotas junginiui AM-3-1. Prognozuojamas didžiausias toksiškumas (Pa>0,6) AM-3-1 ir AM-4-1 junginiams. AM-4 prognozuojami 4 nepageidaujami farmakologiniai poveikiai, o AM-5 – 6. Tyrimo išvados: Nustatyta, kad antimikrobiniam poveikiui yra svarbus nitrofuraldehido pakaitas 5-oje padėtyje ir sulfadimidino pakaitas. Sulfadimidino vieta rodanino žiede (3-ia ar 4-a padėtis) reikšmingos įtakos neturi, tačiau dalinai skiriasi junginių aktyvumas prieš skirtingas bakterijų rūšis. PASS programa gali nuspėti junginių aktyvumą ir pagreitinti galimų veiklių junginių atranką ir kryptingą sintezę. / Aim of study: to identify potential nifumezine and similar compounds structure- activity relationship. Study methods: antimicrobial activity tests in vitro and prognosis of antimicrobial activity by PASS program. Study results: antimicrobial activity tests in vitro showed that the compouds AM-3 and AM-4 is inactive at concentration 500 µg/ml. Compounds AM-3-1 and AM-4-1 are active against S. aureus, E. faecalis, S. epidermidis. None of the synthesized compounds are not active against P. aeruginosa, P. mirabilis and E. coli. Activity prognosis by PASS program showed that the strongest antibacterial effect predisted compound AM-3-1 and AM-4-1, but these compouds have also the bigest risk to be toxic. Conclusions: it was found that the nitrofuraldehyde in 5-position is important to antimicrobial effects. The position of sulfadimidine (3rd or 4th position)is not significantly affected in rhodanine ring, bet different compounds could be active against different type of bacteria. PASS program can predict the activity of compounds.

Thesis (M.S.)--University of Wisconsin, 1967. / Extension Repository Collection. Typescript (carbon copy). Includes autobiographical sketch of author. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 180-183).

Thesis (M.S.)--University of Wisconsin, 1958. / Extension Repository Collection. Typescript (carbon copy). Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 80).

Thesis (M.S.)--University of Wisconsin, 1966. / Extension Repository Collection. Typescript (carbon copy). Autobiographical sketch. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 131-137).

Thesis (M.S.)--University of Wisconsin, 1965. / Extension Repository Collection. Typescript (carbon copy). Autobiographical sketch. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 71-72).

Thesis (M.S.)--University of Wisconsin, 1967. / Extension Repository Collection. Typescript (carbon copy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 114-119).

Digital video games are an immensely popular form of entertainment. The meaningful positive experiences that games facilitate are fundamental to the activity; players are known to invest a lot of time playing games in search of those experiences. Digital games research is polarized. Some studies find games to be a healthy hobby with positive effects; games promote well-being through regular experience of positive psychological experiences such as flow and positive emotions. Others have identified rare problematic use in those players who devote excessive amounts of time to gaming, associating them with social dysfunction, addiction, and maladaptive aggression. While it remains unclear if games cause these effects, or merely coincide with play, the negative effects historically receive more attention in both popular media and academia. Some authorities attempt to reduce the harms associated with games to such an extent that their methods have become national policy affecting all players including those who exhibit no negative outcomes. In South Korea and Taiwan, policing authorities employ a behaviour policy that sets strict daily limits on session length, thereby controlling the amount of time people spend playing games each day. In China, the General Administration of Press and Publication employ a design policy requiring that games service-providers fatigue their games’ mechanics after a period to coax them to take a break sooner than they ordinarily would. Both policy types alter player interaction with games in any given session and it is unclear how these policies affect players in general. This research aims to compare sessions affected by the behaviour policy, design policy, and policy-free sessions in terms of session length, measurable subjective user-experience, the player's intention to return to the game, and their reasons for choosing to stop playing in a particular session. For use in a repeated-measures experiment, we modified the action RPG Torchlight II to simulate both policies. Participants had one session at the same time each week for three consecutive weeks. In varied sequences, participants played a control session unaffected by policy, a one-hour shutdown session representing behaviour policy, and a fatigue session representing design policy. After each session, we recorded their session's length, their user-experience in terms of flow and affect, their intention to return to the game, and their reason for ending the current session. We found that our shutdown condition successfully decreases session length, when compared to the other conditions. The condition facilitates strong flow, moderate positive-affect, and weak negative-affect. The shutdown event does not appear to degrade positive experiences and makes participants slightly more upset (statistically significant) than they would be after choosing to stop playing. This is because players do not get to make that decision, and because players are unable to complete the goals they have set for themselves. Most players intended to play the game again immediately or sometime later in that same day, much sooner (statistically significant) than they would after choosing to stop. This also may be due to satisfaction associated with choosing to stop, or being unable to complete their self-set goals. We found that our fatigue condition increases session length when compared to the other conditions. This result contradicts the intentions associated with design policies: shorter sessions. The fatigue mechanics make the game more difficult, which increases the time required for players to complete the goals they have set for themselves, whether it is to complete a level, quest, or narrative sequence. The condition facilitates high levels of flow, moderate positive-affect and low negative-affect; the condition does not appear to degrade these positive experiences, nor increase negative experience. Most players intended to take the longest breaks between sessions of at least one day, and although we observed that these were longer than the control condition, the differences is not statistically significant. We found that most participants chose to stop playing when the game stopped providing them with positive experiences, or begins to generate discomfort. A large group of participants chose to stop because another activity took priority. Few participants chose to stop because they were satisfied with their session. Less than one third of players explicitly referenced the fatigue mechanics in their decision to stop. Neither policy is holistically better than the other. Both provide strong positive experiences, and have different effects on session length. Whereas it appears that the fatigue condition fails to reduce session length, it also appears that players intend taking longer breaks between sessions, which may reduce total play-time across all sessions. Similarly, the shutdown condition may increase total play time, or at least bring it closer to normal amounts of play-time while also making players more upset. Our operational definition of user-experience is bi-dimensional, and does not include many experiential constructs commonly associated with digital games. During this research, several reliable and valid, and more representative experience measures became available. Any future work on this topic should make use of one of these. Our experiment tested the effects of player experience associated with a single game, genre, and context. Future research should reduce the variation of player factors by focusing on single personalities, typologies, or risk-factors rather than generalizing to all players. We tested out participants only as they played in the early stages of Torchlight II. It is possible that the game's narrative elements, rather than the gameplay mechanics fatigued by the design policy, motivated continued play. We suggest a longitudinal study of the individual policies to explore their effects over many sessions.