Conservation and management of the ecology of natural areas has become a prerequisite for mining companies in South Africa. Systematic conservation planning provides a useful tool for land–use planning and impact assessment, particularly in the mining industry. A study was therefore undertaken to provide sufficient, spatially explicit biodiversity and veld condition information to aid in the development and establishment of an official conservation plan for the leased mining area of Impala Platinum. By identifying areas with high plant diversity or endemism and by assessing veld conditions as well as grazing and browsing capacities, recommendations could be made towards management strategies and potential future land–use practices. The licensed mining area, north of Rustenburg, covers 29334 ha and includes 14 operational shafts. The area was stratified into three main categories based on landscape types namely: norite koppies; thornveld and rehabilitated areas. The Braun Blanquet approach was followed to sample 139 stratified random relevés. Additional computer software packages were used for capturing, processing and presentation of the phytosociological data (TURBOVEG) as well as a visual editor for phytosociological tables (MEGATAB). Ordinations were subsequently performed to confirm the plant communities and illustrate possible environmental gradients, using multivariate statistic analyses (CANOCO). Four plant communities with two subcommunities were identified and described in both the norite koppies and thornveld respectively while three plant communities with three sub–communities were identified in the rehabilitated areas. Specific environmental factors that influence plant community structure and composition in the norite koppies were the aspect and percentage of soil surface rockiness while soil types proved to be the distinguishing factor in the thornveld. The distribution of plant communities in the rehabilitated areas is mainly due to anthropogenic influences rather than any environmental factors. The Fixed Point Monitoring of Vegetation Methodology– FIXMOVE was then used to sample 32 stratified random survey plots in four selected plant communities in order to quantify and compare veld conditions as well as grazing and browsing capacities. The determination of landscape functionality served to support these quantitative results. The Landscape Function Analysis (LFA) method was used for this purpose. Multivariate statistic analyses (CANOCO) were used to indicate possible degradation gradients between the plant communities. Conclusions regarding conservation and management units were reached by interpreting the quantitative data in accordance with the phytosociological results and recommendations could then be made. All the norite koppies plant communities were recommended as areas for The Fixed Point Monitoring of Vegetation Methodology– FIXMOVE was then used to sample 32 stratified random survey plots in four selected plant communities in order to quantify and compare veld conditions as well as grazing and browsing capacities. The determination of landscape functionality served to support these quantitative results. The Landscape Function Analysis (LFA) method was used for this purpose. Multivariate statistic analyses (CANOCO) were used to indicate possible degradation gradients between the plant communities. Conclusions regarding conservation and management units were reached by interpreting the quantitative data in accordance with the phytosociological results and recommendations could then be made. All the norite koppies plant communities were recommended as areas for ii conservation because of unique and high biodiversity and anthropogenic threats. The Eragrostis rigidior–Ziziphus mucronata and Acacia caffra–Bothriochloa insculpta Communities in the thornveld showed the best potential for browsing and grazing practices but were also recommended for conservation because of their high species diversity and anthropogenic threats. The high landscape functionality, veld condition and grazing capacity of the Aristida bipartita–Bothriochloa insculpta Community indicated that the rehabilitation of the opencast mining areas had been relatively successful at the time of the surveys. Selected parts of the Indigofera heterotricha–Aristida bipartita Community were also recommended for conservation and management in the form of controlled and more effective grazing strategies were recommended for the rest of the thornveld. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2011.

Conservation and management of the ecology of natural areas has become a prerequisite for mining companies in South Africa. Systematic conservation planning provides a useful tool for land–use planning and impact assessment, particularly in the mining industry. A study was therefore undertaken to provide sufficient, spatially explicit biodiversity and veld condition information to aid in the development and establishment of an official conservation plan for the leased mining area of Impala Platinum. By identifying areas with high plant diversity or endemism and by assessing veld conditions as well as grazing and browsing capacities, recommendations could be made towards management strategies and potential future land–use practices. The licensed mining area, north of Rustenburg, covers 29334 ha and includes 14 operational shafts. The area was stratified into three main categories based on landscape types namely: norite koppies; thornveld and rehabilitated areas. The Braun Blanquet approach was followed to sample 139 stratified random relevés. Additional computer software packages were used for capturing, processing and presentation of the phytosociological data (TURBOVEG) as well as a visual editor for phytosociological tables (MEGATAB). Ordinations were subsequently performed to confirm the plant communities and illustrate possible environmental gradients, using multivariate statistic analyses (CANOCO). Four plant communities with two subcommunities were identified and described in both the norite koppies and thornveld respectively while three plant communities with three sub–communities were identified in the rehabilitated areas. Specific environmental factors that influence plant community structure and composition in the norite koppies were the aspect and percentage of soil surface rockiness while soil types proved to be the distinguishing factor in the thornveld. The distribution of plant communities in the rehabilitated areas is mainly due to anthropogenic influences rather than any environmental factors. The Fixed Point Monitoring of Vegetation Methodology– FIXMOVE was then used to sample 32 stratified random survey plots in four selected plant communities in order to quantify and compare veld conditions as well as grazing and browsing capacities. The determination of landscape functionality served to support these quantitative results. The Landscape Function Analysis (LFA) method was used for this purpose. Multivariate statistic analyses (CANOCO) were used to indicate possible degradation gradients between the plant communities. Conclusions regarding conservation and management units were reached by interpreting the quantitative data in accordance with the phytosociological results and recommendations could then be made. All the norite koppies plant communities were recommended as areas for The Fixed Point Monitoring of Vegetation Methodology– FIXMOVE was then used to sample 32 stratified random survey plots in four selected plant communities in order to quantify and compare veld conditions as well as grazing and browsing capacities. The determination of landscape functionality served to support these quantitative results. The Landscape Function Analysis (LFA) method was used for this purpose. Multivariate statistic analyses (CANOCO) were used to indicate possible degradation gradients between the plant communities. Conclusions regarding conservation and management units were reached by interpreting the quantitative data in accordance with the phytosociological results and recommendations could then be made. All the norite koppies plant communities were recommended as areas for ii conservation because of unique and high biodiversity and anthropogenic threats. The Eragrostis rigidior–Ziziphus mucronata and Acacia caffra–Bothriochloa insculpta Communities in the thornveld showed the best potential for browsing and grazing practices but were also recommended for conservation because of their high species diversity and anthropogenic threats. The high landscape functionality, veld condition and grazing capacity of the Aristida bipartita–Bothriochloa insculpta Community indicated that the rehabilitation of the opencast mining areas had been relatively successful at the time of the surveys. Selected parts of the Indigofera heterotricha–Aristida bipartita Community were also recommended for conservation and management in the form of controlled and more effective grazing strategies were recommended for the rest of the thornveld. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2011.

Software to display and analyse DNA sequences is a crucial tool for bioinformatics research. The data of a DNA sequence has a relatively simple format but the length and sheer volume of data can create difficulties in navigation while maintaining overall context. This is one reason that current bioinformatics applications can be difficult to use. This research examines techniques for navigating through large single DNA sequences and their annotations. Navigation in DNA sequences is considered here in terms of the navigational activities: exploration, wayfinding and identifying objects. A process incorporating user-centred design was used to create prototypes involving panning and zooming of DNA sequences. This approach included a questionnaire to define the target users and their goals, an examination of existing bioinformatics applications to identify navigation designs, a heuristic evaluation of those designs, and a usability study of prototypes. Three designs for panning and five designs for zooming were selected for development. During usability testing, users were asked to perform common navigational activities using each of the designs. The “Connected View” design was found to be the most usable for panning while the “Zoom Slider” design was best for zooming and most useful zooming tool for tasks involving browsing. For some tasks the ability to zoom was unnecessary. The research provides important insights into the expectations that researchers have of bioinformatics applications and suitable methods for designing for that audience. The outcomes of this type of research can be used to help improve bioinformatics applications so that they will be truly usable by researchers.

Diss. (sammanfattning). Umeå : Sveriges lantbruksuniv., 2003. / Härtill 6 uppsatser.

Diss. (sammanfattning). Umeå : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Pretoria, 2008. / Title from PDF title page (viewed on Nov. 11, 2008). Includes bibliographical references.

La chasse – comme la prédation naturelle - induit des réponses comportementales par les individus chassés qui cherchent ainsi à éviter ou à reduire le risque. Il est en particulier fréquent d'observer un changement dans leur utilisation de l'espace, mais l'articulation et les déterminants des réponses aux différentes échelles spatiales restent mal compris. De même, s'il a été suggéré que ces modifications comportementales pouvaient affecter en cascade la végétation, cela reste à tester. Pour combler ces lacunes, j'ai, (1) étudié, dans un paysage agricole du sud de la France, une population chassée de chevreuils et leur utilisation des milieux ouverts risqués et des couverts boisés, au cours de périodes de risque contrasté ; (2) testé, sur une population canadienne de cerfs à queue noire dépourvue de prédateurs et exempte de chasse, l'influence d'une chasse expérimentale sur le comportement des animaux et sur la végétation. J'ai montré que les chevreuils répondaient à une augmentation du risque à plusieurs échelles spatiales. Ils réduisaient leur utilisation des habitats risqués, et dans certains cas se rapprochaient des couverts, de jour ces deux réponses étant couplées au niveau individuel. Le gradient paysager d'ouverture du milieu contraignait cependant les niveaux de réponses observées et les stratégies individuelles. Au Canada, j'ai observé un évitement de la zone chassée par les cerfs les plus sensibles à la présence humaine, corrélé à une diminution de l'abroutissement pour deux des quatre espèces de plantes étudiées. J'ai intégré ces résultats dans une discussion sur l'utilisation de la chasse pour gérer les populations d'herbivores et leurs impacts sur la végétation. / Hunting – similarly to natural predation – induces behavioural responses of hunted individuals which aims at avoiding or reducing risk. Particularly, changes in space use are frequently observed, but the articulation and determinants of these changes at multiple spatial scales are still poorly understood. Also, although it has been suggested that these changes might cascade on the vegetation, this remains to be tested. To fill these gaps, I (1) studied a hunted roe deer population living in an agricultural landscape in southern France where roe deer can find open risky habitats and woody covers; and (2) tested black-tailed deer behavioural response to an experimental hunt in a predator- and hunting-free population in the Haïda-Gwaii archipelago (BC, Canada). I also investigated the possible cascading effects on the vegetation. I showed that roe deer responded to increased hunting pressure at multiple scales, reducing their use of the risky habitats and, in specific situations, their distance to the nearest cover. At day-time those two responses were coupled at the individual level. Generally, landscape openness constrained individual responses and strategies. In the hunting-for-fear experiment conducted on Haida Gwaii, I found that only the deer less-tolerant to human disturbance avoided the hunting area. A simultaneous reduction in browsing pressure on two out of the four plant species monitored was found however. I integrated these results in a general discussion on the possible role of hunting as a tool to manage abundant deer populations and their impacts on the vegetation.

There has been an enormous growth in the Internet usage in recent years, fueled by the increasing number of multimedia applications and widespread availability of World Wide Web (WWW). The end-user generally accesses these applications through web browsing activities. These time-critical services often suffer from the delays ranging from small chunks to long peaks which can have severe implications on the Quality of Experience (QoE). Hence, it is worthwhile to identify the impact of different variations of delay on the end-user QoE. This research focused on the end-user QoE for three different distributions of delays occurring during an e-commerce shopping experiment. By keeping the overall waiting time of every sessions same, the study shows that the end-user QoE is different for different variety of delays. And the research also concludes that, the users prefer small frequently occurring delays as compared to the long rarely occurring delays within a task-driven web browsing session.

OpenSpace is an interactive data visualization software system that portrays the entire known universe in a 3D simulation. Current navigation interface requires explanations, which prohibits OpenSpace to be displayed effectively in public exhibitions. Research has been shown that using large tangible touch surfaces with a multi-touch navigation interface is more engaging to users than mouse and keyboard as well as enhances the understanding of navigation control, thus decreasing the required instructions to learn the systems user interface. This thesis shows that combining a velocity-based interaction model together with a screen-space direct-manipulation formulation produces a user-friendly interface. Giving the user precise control of objects and efficient travels in between in the vastness of space. This thesis presents the work of integrating a multi-touch navigation interface with a combined formulation of velocity-based interaction and screen-space direct-manipulation into the software framework OpenSpace.

User perceived latency is the most prominent performance issue influencing the World Wide Web (www) presently. Hyper-Text Transfer Protocol(HTTP) and Transmission Control Protocol (TCP) have been the backbone of web transport for decades, thus received a lot of attention recently due to end-to-end performance degradation in mobile environments. Inefficiencies of HTTP and TCP strongly affect web response time mainly in resource limited devices. HTTP compression reduces some of the burden imposed by TCP slow start phase. However, compression is still an underutilized feature of the web today [1]. In order to fulfill the end user expectations, we can optimize HTTP to improve Page Load Time (PLT), low memory usage and better network utilization. SPDY, a web latency reducing protocol and HTTP pipelining are a recent proposal to provide faster information exchange over web. Through the course of this work, we present a comprehensive study of new approaches to reduce mobile web latency. At first, we measure the PLT after implementing SPDY, HTTP and HTTP pipelining. Secondly, we also analyze the performance of these protocols after tuning the network parameters like bandwidth and round-trip time (RTT). Finally, we compare the performance of HTTP and other latency reducing protocols. We have conducted all experiments over DummyNet under user-configured network conditions. We critically discuss the challenges of shifting from HTTP to these latency-reducing protocols.