A Multilevel File System for High Assurance

The designs of applications for multilevel systems cannot merely duplicate those of the untrusted world. When applications are built on a high assurance base they will be constrained by the underlying policy enforcement mechanism_ Consideration must be given to the creation and management of multilevel data structures by untrusted subjects_ Applications should be designed to rely upon the TCB s security policy enforcement services rather than build new access control services beyond the TCB perimeter The results of an analysis of the design of a general purpose le system developed to execute as an untrusted application on a high assurance TCB are presented. The design illustrates a number of solutions to problems resulting from a high assurance environment.Approved for public release; distribution is unlimited

School effects on adolescent pupils' health behaviours and school process associated with these effects

Eight schools, located in Scotland were involved in this study. Four different types of data were collected in the following order: first, 183 semi-structured interviews with a range of staff and pupils across the schools, the interviews covering questions relating to health education, promotion and ethos including quality of relationships; second, a school audit of health education and health promotion in all schools; third, Researcher observations for all schools; and, fourth, questionnaire data collected from 446 pupils across the schools. The Health Promoting School (HPS) concept is based on the belief that schools have the potential to influence their students' health and health behaviour through the school's social organisation, culture and physical environment, as well as through the formal curriculum. To date, there is little empirical evidence to test the effectiveness of the HPS, at least evidence that adjusts for known predictors of the behaviours, a standard set by the more advanced area of 'school effects' research on educational outcomes. This thesis will add to that evidence base. The aims of this study have three main components: first, to quantify 'school effects' on a range of pupils' health behaviours comprising current smoking, weekly alcohol drinking, ever tried drugs and physical activity: second, to assess the extent to which the health behaviour profile of schools are related to health promotion activity as evidenced by an audit: third, to select and analyse qualitative data from three case study schools. The purpose of the second and third aims is to investigate the extent to which school processes are associated with 'school effects' on pupils' health behaviours, triangulating data from different methodologies. The questionnaire data indicated that a strong school effect existed for smoking and drinking to a lesser degree, but not for drugs or physical activity. This addressed the first aim of this study and, in addition, provided the means by which three case study schools were selected. These were the two schools with the lowest (added value) and highest odds (lost value) for smoking after adjustment for known predictors of the health behaviours. Plus, a third school which was significantly different from the school with lowest smoking and located in the same town, as this eased interpretation of the results. Relating to the second aim, the pattern of the 'school effects' on smoking were triangulated with data from three different data sources. First, in the audit, higher levels of action on health education and health promotion were associated with lower (adjusted) rates of smoking. Second, the three case study schools were used to explore the Researcher's observations; the school with added value for smoking was rated more highly than the two with lost value. Regarding the third aim, based on qualitative data from a range of staff and pupils, the analysis showed that the school with added value had progressed furthest towards functioning as a whole school, performing best across all the areas explored. These findings theoretically triangulated with the schools low smoking rates according to the HPS concept. These results confirm the importance of school processes on students' health behaviour, particularly smoking, and support a school-wide or "Health Promoting School" approach to improving health behaviours

A comprehensive view on quantity based aggregation for cadastral databases

Quantity Based Aggregation (QBA) control is a subject that is closely related to inference control in databases. The goal is to enforce k out of n disclosure control. In this paper we work on QBA problems in the context of cadastral databases: how to prevent a user from knowing 1) the owners of all parcels in a region, and 2) all parcels belonging to the same owner. This work combines and extends our previous work on the subject [1, 2, 3]. We overview the legislative context surrounding cadastral databases. We give important definitions related to the QBA concept. We present a complete model for QBA control in cadastral databases. We show how to implement the security policy efficiently, and we present our prototype of secure cadastral databases with some performance evaluations

Parasitism of free-ranging Neotropical primates: examining parasite-host and parasite-parasite relationships

Parasites are infectious agents that require resources from host organisms to complete all or part of their lifecycles. It is customary for wild animals to acquire and maintain multiple parasitic infections during their lifetime. The effects of parasites on hosts vary across demographic and environmental variables, and in relation to each other. Moreover, the propensity for a host animal to acquire an infection can be influenced by other host species in the area that are susceptible to the same parasites. This dissertation describes and explores the natural parasite assemblage of a free-ranging community of nonhuman primates in the Peruvian Amazon rainforest. A mark-recapture program of sympatric saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarins (Callitrichidae) was implemented from June through August, 2012 – 2015, to collect repeat blood and fecal samples from known individuals. Seven other primates on site, belonging to the Pitheciidae, Cebidae, Atelidae, and Aotidae, were followed in 2014 and 2015 for noninvasive collection of fecal samples. Microscopy and molecular techniques were used to assess the degree of parasite–host specificity in gastrointestinal and blood parasites. I also explored individual differences in infection status engendered by various host factors, and tested for non-random associations of co-occurrence between multiple parasites. Patterns of infection were analyzed using multifactorial statistical models. In total, I collected 250 blood samples from 134 known tamarins, 208 fecal samples from 105 known tamarins, and 64 fecal samples distributed across the remaining hosts. Temporal variation of multiple parasite infections confirmed the necessity of a multi-year study to evaluate parasite-host relationships in this system. Individual age was a common predictor of parasite infection, and co-infections were significant predictors for blood parasites. No gastrointestinal parasites appeared to be host specific, but significant differences in prevalence were observed across hosts. I also report the presence of a natural, potentially zoonotic malarial parasite that for first time is demonstrated to chronically infect its nonhuman primate host. Collectively these data demonstrate the importance and need for broad spectrum and long-term screening of parasites from wildlife communities

The Centre of the Region Enterprise: The Effect of Transit Funding on Land Planning and Development

The Research Triangle Park was founded in 1959 as an economic development tool to slow the brain drain from the state of North Carolina by creating research opportunities for graduates of the three major universities nearby, North Carolina State University, Duke University, and the University of North Carolina at Chapel Hill. It was located in the hinterland between Raleigh, Durham, and Chapel Hill near Raleigh-Durham International Airport and was the only sizeable activity in the area for over three decades. The Research Triangle Park's success as a knowledge cluster has meant that it is largely in competition with similar research and technological agglomerations nationwide. Furthermore, the Triangle region of North Carolina is in competition with metropolitan areas much larger and more established than itself. Increasingly, the labour force that firms likely to locate in knowledge clusters attract have become more discerning in their location decisions, rating the region's quality of life as high or higher than the quality of the job they are being offered. As a result, firms are now considering local urban amenities when making their own location decisions. The Triangle region of North Carolina has always been at a disadvantage in this regard vis-a-vis its peer group. However, the Research Triangle is one of the best research and technology clusters in the world and needs to be able to attract new firms to the campus to remain successful for another 50 years. To this end, the Triangle J Council of Governments and the Research Triangle Foundation initiated a study of the area around the Research Triangle Park which was published in 2002. The project, known as the Centre of the Region Enterprise (CORE), sought to exhibit cooperative relationships between local governments, regional organisations, and private sector firms that drive future development to strengthen the existing linkages in the area while creating a coherent development pattern in the long term. Much had changed in the Triangle area since 2002 and the calls for greater convenience and accessibility for RTP employees had gotten louder. In 2005, a second study was launched to identify to the changes to the CORE since the publication of the original plan to determine how the participating municipalities could support and encourage the growth in the Research Triangle region. The original CORE area was 60 square miles but had been expanded in 2005 to over 100 square miles to include the rapidly expanding areas in southern Durham County and eastern Chatham County. Multiple clients exist for this project and will use it in different ways. Such an analysis will prove valuable to the Research Triangle Foundation as both a marketing and long-range planning tool. RTF has the responsibility to recruit research and development firms to the Park. Increasingly, these target firms are voicing their concerns about the quality of life of the region in which they choose to locate because the labour force is becoming more particular about issues of proximity to amenities and traffic congestion. RTF can use this project to determine where development opportunities exist inside the CORE region and cooperate with local planners and developers to design development nodes, similar to the original CORE study in 2002, and market these special planning districts to current and potential employers as obvious growth opportunities in which, early investment is prudent. The Triangle J Council of Governments will use this project to facilitate long-term planning across its jurisdiction and introduce coherence to the process of planning for infrastructure, transportation, and green spaces. Local governments in the Triangle region will also benefit significantly from this study. Currently, the seven municipalities that comprise the CORE region are disjointed in their planning and growth strategies. Some of these municipalities have quite adversarial relationships stemming from parochial competitive interests. The CORE area plan endeavours to concentrate development activity in a cohesive and sustainable fashion around the Research Triangle Park and the economic clusters it helped spawn, while respecting the desire of each constituent municipality to grow and prosper. Inter-jurisdictional cooperation is likely the only method to achieve this common goal across the entirety of the region. Employers currently in the region or interested in relocating to the Triangle have expressed interest in a development database to aid their own long-term corporate planning processes. With the help of the CORE project database, firms may determine the long-term viability of the Triangle as an attractive location for the employees they want to recruit.Master of City and Regional Plannin

A LEARNER INTERACTION STUDY OF DIFFERENT ACHIEVEMENT GROUPS IN MPOCS WITH LEARNING ANALYTICS TECHNIQUES

The purpose of this study was to conduct data-driven research by employing learning analytics methodology and Big Data in learning management systems (LMSs), and then to identify and compare learners’ interaction patterns in different achievement groups through different course processes in Massive Private Online Courses (MPOCs). Learner interaction is the foundation of a successful online learning experience. However, the uncertainties about the temporal and sequential patterns of online interaction and the lack of knowledge about using dynamic interaction traces in LMSs have prevented research on ways to improve interactive qualities and learning effectiveness in online learning. Also, most research focuses on the most popular online learning organization form, Massive Open Online Courses (MOOCs), and little online learning research has been conducted to investigate learners’ interaction behaviors in another important online learning organization form: MPOCs. To fill these needs, the study pays attention to investigate the frequent and effective interaction patterns in different achievement groups as well as in different course processes, and attaches importance to LMS trace data (log data) in better serving learners and instructors in online learning. Further, the learning analytics methodology and techniques are introduced here into online interaction research. I assume that learners with different achievements express different interaction characteristics. Therefore, the hypotheses in this study are: 1) the interaction activity patterns of the high-achievement group and the low-achievement group are different; 2) in both groups, interaction activity patterns evolve through different course processes (such as the learning process and the exam process). The final purpose is to find interaction activity patterns that characterize the different achievement groups in specific MPOCs courses. Some learning analytics approaches, including Hidden Markov models (HMMs) and other related measures, are taken into account to identify frequently occurring interaction activity sequence patterns of High/Low achievement groups in the Learning/Exam processes under MPOCs settings. The results demonstrate that High-achievement learners especially focused on content learning, assignments, and quizzes to consolidate their knowledge construction in both Learning and Exam processes, while Low-achievement learners significantly did not perform the same. Further, High-achievement learners adjusted their learning strategies based on the goals of different course processes; Low-achievement learners were inactive in the learning process and opportunistic in the exam process. In addition, despite achievements or course processes, all learners were most interested in checking their performance statements, but they engaged little in forum discussion and group learning. In sum, the comparative analysis implies that certain interaction patterns may distinguish the High-achievement learners from the Low-achievement ones, and learners change their patterns more or less based on different course processes. This study provides an attempt to conduct learner interaction research by employing learning analytics techniques. In the short term, the results will give in-depth knowledge of the dynamic interaction patterns of MPOCs learners. In the long term, the results will help learners to gain insight into and evaluate their learning, help instructors identify at-risk learners and adjust instructional strategies, help developers and administrators to build recommendation systems based on objective and comprehensive information, all of which in turn will help to improve the achievements of all learner groups in specific MPOC courses

The viability of coral populations in the Anthropocene

Andreas Dietzel examined demographic trends in corals at large spatial and temporal scales. He found that while few Pacific coral species face an elevated risk of global extinction, long-term shifts in colony sizes indicate declines in reproduction and the spatial scale of mass bleaching events jeopardizes population connectivity and recovery