The effects of feeding rats a fat which contained approximately 46.6% trans fatty acids (trans fat) on the mutagenic potential of 2-aminofluorene (AF), benzo(a)pyrene (BP), dimethylbenz(a)anthracene (DMBA), and azoxymethane (AOM) were evaluated in the Ames assay. The corresponding control fat (cis fat) had a similar fatty acid composition, consisting only of cis isomers. Since both the cis and trans fats contained approximately 40% saturated fatty acids a comparison was made between these two types of fat and corn oil. All three fats were incorporated into a high fat, 20%, and moderate fat, 5%, diet and fed to male Sprague-Dawley rats for three weeks. / The effects of the level and type of fat on mutagenicity varied with the specific mutagen under investigation. The 20% level of fat whether cis, trans, or corn oil resulted in greater mutagenic activity with BP and AF when compared to the 5% level. At the 5% fat level the results for BP and AF were in conflict. The 5% trans fat resulted in the highest mutagenic response for AF, while the 5% corn oil resulted in the highest mutagenic response for BP. The trans fat produced a higher mutagenic potential at the 5% level with AF than the 5% cis fat, but at the 20% level no difference was found between the cis and trans fats. These findings indicate that not only does the quantity and type of fat alter the mutagenic response found in the Ames/Salmonella microsome assay, but also the effect of the fat in the assay varies with the mutagen tested. / Only with DMBA did type of fat affect the positive and negative outcomes of the assays. DMBA gave a positive response only in the assays using livers from rats fed corn oil diets, with no differences between the 5% and 20% level of corn oil. No positive responses were found with DMBA in the assays with liver homogenates from rats fed trans fat or cis fat. This suggests that DMBA required a moderate to high level of polyunsaturated corn oil to produce a positive mutagenic response. / Source: Dissertation Abstracts International, Volume: 47-03, Section: B, page: 0871. / Thesis (Ph.D.)--The Florida State University, 1986.

Thesis (M.S.)--Boston University

Practitioners of ecological restoration are increasingly adopting a genetic perspective when recreating historical landscapes. Genes are often endowed with the capacity to reveal specific and distinct relationships between organisms and environments. In this dissertation, I examine how genetic technologies and concepts are shaping ecological restoration practices. This research is based on two and a half years of fieldwork in Chicago. I employed participant observation and semi-structured interviews to compare how restorationists in two plant science institutions employ genetic concepts in their projects. One institution uses high-tech genetic methods to guide practice while the other uses lower-tech genetic approaches. Each group has distinct, yet internally diverse ways of deciding which seeds are ‘local enough’ to be included in a project. This research theorizes how classification differences regarding native seeds are part of a broader set of genetic logics I refer to as ‘genetic epistemologies’. Specifically, I ask how genetic technologies circumscribe different ways of seeing and making landscapes. I compare how restorationists delineated valid seed sourcing regions for restoration projects based on their genetic definitions of ‘native’ species. Drawing from science & technology studies, political ecology, and cultural landscape geography, I illustrate how restorationists incorporate cultural preferences, funding imperatives, aesthetics, and discourses about nature into their particular genetic epistemology. From this research, I offer the following conclusions. By incorporating genetic technology into ecological restoration, many practitioners feel their work will achieve more precision. Yet this perspective is typical of those who do not directly use genetic technologies. Scientists using direct genetic analyses are much more reserved about the potential of their technologies to match organisms to environments. Second, individuals or groups often come into conflict when attempting to apply different genetic epistemologies to the same problem. These conflicts are resolved in the course of planning and implementing a restoration project. Finally, direct genetic methods are only useful in restoration work involving rare or endangered species. Despite the limited utility of genetic technology in restoration, this approach is becoming influential. Chicago’s high-tech plant science institution is discursively reshaping the goals and approaches of native plant institutions that do not use these technologies.

Direct-to-Consumer advertisements allow pharmaceutical companies to advertise prescription drugs directly to consumers. Increasingly, marketing executives employed by pharmaceutical companies are shifting the focus of these advertisements from promoting the drug as a product, to promoting illness in general. Pharmaceutical companies defend this movement saying the advertisements have an educational function to "inform" consumers.

This paper analyzes the founding rate of bioengineering departments in the United States. It takes the density dependence model from organizational ecology literature as the starting point of the analysis. This model predicts that founding rates of organizational populations are driven by population density, which represents processes of legitimation and competition, and by external environmental factors. The analysis finds support for density dependence predictions about the effect of population density on the founding rate of bioengineering departments. Further, this analysis finds that funding from the Whitaker Foundation has a significant positive impact on the founding rate of departments. The density dependence model is based on assumptions that individual actors are limited in their ability to act strategically and that competition is diffuse. In light of these assumptions and the threat to validity that would be posed if they were incorrect, the paper presents a discussion of strategic interaction and direct competition. I use an acceleration analysis comparison to conduct an initial study of the existence of endogenous interaction within the population of bioengineering departments. I find evidence of endogenous interaction through a process of cumulative social learning.

In 1999, the Chinese Academy of Sciences realized that there was a need for a better public understanding of science. For the public to have better accessibility and comprehension of China's significance to the world, the Computer Network Information Center (CNIC), under the direction of the Chinese Academy of Sciences, combined resources from thousands of experts across the world to develop online science exhibits housed within the Virtual Science Museum of China. Through an analysis of historical documents, this descriptive dissertation presents a research project that explores a dimension of the development of the Giant Panda Exhibit. This study takes the reader on a journey, first to China and then to a classroom within the United States, in order to answer the following questions: (1) What is the process of the development of a virtual science exhibit; and, (2) What role do public audiences play in the design and implementation of virtual science museums? The creation of a virtual science museum exhibition is a process that is not completed with just the building and design, but must incorporate feedback from public audiences who utilize the exhibit. To meet the needs of the museum visitors, the designers at CNIC took a user-centered approach and solicited feedback from six survey groups. To design a museum that would facilitate a cultural exchange of scientific information, the CNIC looked at the following categories: visitor insights, the usability of the technology, the educational effectiveness of the museum exhibit, and the cultural nuances that existed between students in China and in the United States. The findings of this study illustrate that the objectives of museum designers may not necessarily reflect the needs of the visitors and confirm previous research studies which indicate that museum exhibits need a more constructivist approach that fully engages the visitor in an interactive, media-rich environment. Even though the world has moved forwards with digital technology, classroom instruction in both China and in the United States continues to reflect traditional teaching methods. Students were shown to have a lack of experience with the Internet in classrooms and difficulty in scientific comprehension when using the virtual science museum--showing a separation between classroom technology and learning. Students showed a greater interest level in learning science with technology through online gaming and rich multimedia suggesting that virtual science museums can be educationally valuable and support an alternative to traditional teaching methods if designed with the end user in mind.

Thesis (M.S.)--Lehigh University, 2009. / Adviser: John P. Coulter.

Thesis (Ph. D.)--Union Institute (Randolph County, N.C.), 1989. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M. Arch.)--University of Hong Kong, 1995. / Includes special report entitled: Environmental conscious sports architecture. Includes bibliographical references.

Thesis (Ph. D.)--Institute of Paper Science and Technology, 1990. / Bibliography: leaves 92-96.