Greenhouse gas emissions have been a growing concern throughout the world, particularly in the Western society. Agriculture has been identified as both a major source of greenhouse gas emissions and a potential solution in mitigating emissions through carbon sequestration. Changing agriculture current production practices (called conventional production system) to an organic production system can reduce the need for synthetically produced agricultural inputs, and thereby reduce these emissions. However, this may generate other co-benefits (or costs) to the society. The focus of this study was to evaluate the implications of converting conventional agriculture production system to an organic one for greenhouse gas emissions, level of agricultural production, farmer net income, regional and national level changes (in terms of gross domestic product, household income, and employment levels). The scope of the study was limited to the Prairie Provinces in Canada. This area was selected because it contained a majority of area under organic production system in Canada. Since there are several types of changes resulting from the conversion, a trade-off analysis was used to evaluate the overall desirability of the two options - conventional production system and the organic production system.<p> Multiple models were used to estimate various criteria. These included: the Canadian Regional Agriculture Model (CRAM), the Greenhouse Gas Emissions Model (GHGEM), and the Canadian Agriculture Regional Development Input-Output Model (CARDIOM).<p> The study concluded that converting land under conventional production system to an organic production system reduces greenhouse gas emissions and improves regional gross domestic product, household income, and employment. However, it results in a reduction in quantity of agricultural production, national gross domestic product, national household income, and national employment.

As the health care system experienced a complex tapestry of transitions in the past decade, first-line managers (FLMs) strived to maintain a sense of stability for themselves and their staff in chaotic work environments. Individuals across the nation are striving to ensure health care team members have quality work environments. The paucity of literature examining the perceptions FLMs have of their work environment prompted this study. <p>This study provided FLMs employed in regional and provincial hospitals in Saskatchewan a voice to share their perceptions of their work environments with others. It is an adaptation of the descriptive survey design used by Remus, Smith, and Schissel (2000) in their study of staff nurses. The adaptation was based on the literature, making it applicable to FLMs, and incorporating the six Quality Worklife Indicators (QWI) of the Canadian Nurses Associations (CNAs) Quality Professional Practice Environments framework. The questionnaire also incorporated open-ended questions that enabled respondents to elaborate on their perceptions of their work environments.<p>The total population of 113 FLMs in regional (FLMRs) and provincial (FLMPs) hospitals in Saskatchewan was invited to participate in this study. Sixty-nine respondents (61.1%) chose to do so. FLMRs had a higher, although not significant, response rate, (67.6% n=23) than did FLMPs (58.2% n=46). The researcher attempted to make personal contact and correspond with each invited participant when distributing the questionnaires. In the open ended questions, participants in this study described intertwined multidimensional roles and responsibilities resulting in unmanageable workloads. They faced daily challenges involving relationships, putting out fires, balancing system/personnel relationships, staffing issues, resources, time, and salary. FLMs who successfully resolved their challenges felt a sense of accomplishment or reward, increasing their self confidence in their ability to successfully fill their roles as a FLM. FLMs described that being a change agent, teamwork, recognition by others, relationships, working with patients, and control over practice as the most rewarding elements within in their practice environments. The Environment Perception Scale responses reflected positive perceptions of work environments on all subscales except control over workload. Overall, FLMPs had a slightly more positive perception of their work environments than did FLMRs, except on the control over workload subscale. However, there were no significant differences between the groups except on the innovation and creativity subscale, where FLMRs scored significantly lower.<p>Study results offer senior administrators, professional associations, government, educators, and others an opportunity to increase their understanding and awareness of the perceptions FLMs have of their practice environment. Awareness of these perceptions will facilitate supporting or strengthening the rewards FLMs perceive in their practice environments, resulting in a richer practice environment. Identification and awareness of the perceived challenges is the first step in addressing them. Educators will find these results useful in better preparing future leaders of nursing for formal management roles.

With the popularity of the Internet and the wider bandwidth, more and more people watch streaming movies online. The larger the scale of the web site, the more load it has to handle. Thus, how to efficiently process users' queries, reduce network latency and packet loss, and improve data reliability at once are top issues. Cloud environments, in this thesis, are used to solve these problems. Also, a cloud-based streaming system that enables users query movie information and watch movies streaming online is designed and implemented to deliver compelling user experiences.

Radiation risks to humans in space will be better understood if ground-based mixed field irradiations are developed and used to measure the overall effectiveness of proposed space radiation shielding. The space environment is composed of wide range of particles containing various energies. Existing measurements illustrate the properties of galactic cosmic rays (GCR) in particle fluence and species. However, it is nearly impossible to simulate a radiation environment corresponding to both properties at once. Since the final objective of this thesis research is to understand radiation risks, and radiation risks are more directly related to the energy deposited in the human tissue than to fluence and charge, the more likely goal would be reproducing the linear energy transfer (LET) spectrum found in the GCR. The purpose of this thesis research is to use a Monte Carlo transport code to study the fragmentation of a combined iron and proton beam source using a multi-depth moderator block to reproduce the LET component of the GCR. To study mixed-field radiation exposures, the Monte Carlo transport code - Particle and Heavy Ion Transport code System (PHITS) will be used. Calculations showed it is necessary to design a moderator block that contains two different thicknesses - one with a length less than 23 cm and one with a length greater than 23 cm. The thinner moderator will allow high-Z particles to pass through and produce heavy-ion fragments that contribute mostly in the high-LET range. The thicker moderator will stop most of fragments and only allow lighter ions to penetrate and contribute to the mid-range and low-LET portion of the GCR spectrum. Since iron beams along will not produce enough low-LET particles, proton beams were employed to increase the abundance of the low-LET portion of the GCR spectrum. After series of studies, it was concluded that a 17 cm and 49 cm thickness will be most effective. The initial conclusion of this project was that it is possible to produce the GCR environment using a multi-depth moderator block and a combined iron and proton beam.

Abstract In this thesis we propose a match_based scheduling algorithm for heterogeneous environment. The major difference of our algorithm from other researches is that it considers the variation of computing power with time. In our algorithm the each host is regarded as a group, their computing powers are sorted in ascending way and the ratio of each computing power with the total computing power is calculated. Similarly, the workload of tasks is classified and is sorted to the relative computing power in ascending way, then is assigned to one of host groups depending on the balance of computing power. The execution cost for each node of the task group is calculated from the task load and the computing power of host been assigned. In order to determine the priority of execution, the rank of each task is calculated from the total of the execution costs, maximum execution cost of its immediate successor, and the summation of ranks of all immediate successors. Experiment results show that the proposed algorithm has better performance than DLS (Dynamic Level Scheduling)[12], HNF (Heavy Node First)[6], WLA (Weighted Length Algorithm)[6] and DPS (Dynamic Priority Scheduling)[18], especially, for heterogeneous environment.

This quantitative study investigates the adequacy and quality of middle school facilities in Humble ISD middle schools as reported by the primary users of these facilities, the teachers and administrators. These middle school educators also provide an assessment of the impact that these facilities have on the learning environment. This study also assesses the quality and adequacy of these middle school facilities through a purely quantitative evaluation conducted by an unbiased assessment team. Humble ISD is undergoing unprecedented growth at all levels and has addressed the burgeoning elementary and high school aged growth occurring in the district by constructing and renovating these facilities. At the middle level, however, new facility construction is occurring at a slower pace. The purpose of this research is to ascertain which factors in each of these six facilities have the greatest quality and adequacy and the impact that they have on the learning environment. Furthermore, it is the purpose of this research to provide valuable and practical data, to which Humble ISD and others can refer in developing future building plans, renovating existing facilities, allocating funds, and creating student centered learning environments. This study also investigates the relationship between what educators perceive as adequate and quality facility factors and their perception of the impact that these factors have on the learning environment. Finally, this study reviews any congruency or agreement between educator’s perception of adequacy and quality and architect assessment of adequacy and quality. Middle level students are the most influential group of adolescents and it is important that we provide facilities that meet their very specific needs. This research will ultimately and positively impact the learning environment for these children.

The red drum (Sciaenops ocellatus) is important for recreational fishing and aquacultural production in Texas' coastal waters and elsewhere in the nearshore Gulf of Mexico and in subtemperate to subtropical areas of the western North Atlantic Ocean. I performed indoor-tank and outdoor-pond experiments, in conjunction with automa ted respirometry and ecophysiological modeling, to assess interacting effects of temperature, dissolved-oxygen concentration (DO) and feed energy density on survival, growth, metabolism, and other measures of juvenile red drum performance. The main objective was to test an energy/metabolism tradeoff hypothesis, which states that growth of fish exposed to high temperatures can be limited by available feed energy; whereas, growth of fish exposed to lower temperatures can be limited by their metabolic capacity to exploit available feed energy. Also, I examined the influence of DO on this relationship and evaluated the effects of cyclical regimes of temperature and DO on fish performance. Insights from laboratory-based feeding trials were incorporated in experiments conducted in hatchery ponds to assess effects of oxygen supplementation and dietary additives - nucleotides and prebiotics - on performance in a more natural setting. In examining these issues, various technologies were developed. These included a computer-based apparatus for autonomously inducing cyclical regimes of temperature and DO in experimental tanks over an extended period of time. Additionally, I developed a soft feed with low energy-density to simulate natural forage. Experimental results supported the principal research hypothesis: At high temperature and DO, ecophysiological performance of juvenile red drum was enhanced by feeding to satiation with a high-energy feed (15.9 kJ/g) versus with a foragesimulating feed having lower energy density (4.1 kJ/g). Cyclical regimes of temperature and DO - as imposed in my particular laboratory experiments -did not impart growth benefits; however, the potential for enhanced growth via an appropriate cyclical environmental regime remains intact. Results from outdoor-pond experiments were consistent with laboratory results; however, the strong positive effect of feed energy density overwhelmed potential effects of dietary additives or oxygen supplementation on growth.

Thesis (M.A.)--Royal Roads University (Canada), 2007. / Includes bibliographical references.

Thesis (M.A.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 53-57).

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 493-561). Available also in a digital version from Dissertation Abstracts.