Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011. / Vita. Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references. / Amyloid fibrils are insoluble, non-crystalline protein filaments associated with a number of diseases such as Alzheimer's and Type Il diabetes. They can have a functional role in different organisms and many proteins and peptides have been found to form amyloid fibrils in vitro. We have used magic angle spinning (MAS) NMR spectroscopy to investigate the structure of two amyloid fibril systems - an 11- residue segment from the disease-related protein transthyretin (TTR); and P2- microglobulin (32m), a 99-residue protein associated with dialysis-related amyloidosis. The TTR(105-115) case exemplifies our efforts to characterize the hierarchy of structures present in the fibril form, including the organization of the Pstrands into P-sheets (tertiary structure), the P-sheet interface that defines each protofilament (quaternary structure), and the protofilament-to-protofilament contacts that lead to the formation of the complete fibril. Our efforts were guided by information obtained from other methods such as cryo-electron microscopy and atomic force microscopy, and resulted in the very first atomic resolution structure of a complete amyloid fibril. We have extended the methods used in the TTR(105-115) structure determination procedure to the fibrils formed by 2m, a process complicated not only by the much larger size of the protein involved but also by the high degree of dynamics exhibited in these fibrils. Nevertheless, we were able to characterize the secondary structure of the protein in the fibril form, and the tertiary and quaternary interactions within the fibrils. In addition, we have compared at the molecular level @2m fibrils formed under different conditions, in an effort to characterize the origins of fibril polymorphism for this protein sequence. Our work on amyloid fibrils has also benefited extensively from the development of dynamic nuclear polarization, a method used to enhance the sensitivity of MAS NMR experiments, leading to unprecedented gains in signal-to-noise ratios and acquisition times. / by Galia Tzvetanova Debelouchina. / Ph.D.

Thesis (Ph.D.)--University of Wisconsin--Madison, 2006 / Includes bibliographical references (p. 492-506). Also available on the Internet.

During my introductory interview, the professional duties outlined to me included a broad spectrum of areas. I would be responsible for coordinating all components of the production and presentation process, handling such intricate details as the payment of the performers and the design of the program to the scheduling of security personnel and the maintenance of departmental instruments. It would also be my responsibility to serve as the reservation agent for all departmental facilities by coordinating both on and off campus bookings for Dixon Hall, Dixon Recital Hall, Dixon Reception Hall, The Weinmann Patio Theatre, and the Myra Clare Rogers Memorial Chapel. Most importantly, it would be my responsibility to actively promote and seek media coverage and audiences for all events of the department. (Only through this exposure can the department expect to fill its house and maintain its academic reputation thereby ensuring the continued financial support of the public.)

Thesis (M.A.)--Boston University Bibliography: leaves 290-316.

This item was digitized by the Internet Archive. Thesis (M.A.)--Boston University / https://archive.org/details/poeticaldramasof00alde

Thesis (M.M.E.)--Boston University, 1951

No description available.

There is no abstract available for this thesis.

Fire suppression has resulted in dramatic changes to species composition and structural diversity in the Sierra Nevada mixed-conifer forests of California. Advancing the ecological understanding and management of these forests requires a better understanding of changes that occurred during the fire suppression era, but empirical historical datasets are rare and methodologies for developing new historical reference information are subject to many limitations. I sought to develop historical reference information for the Yosemite Forest Dynamics Plot (YFDP), a research plot located in an old-growth mixed-conifer stand in Yosemite National Park. I performed a dendrochronological fire history analysis to characterize the historical fire regime of the YFDP (pre-1900 fire return interval: 29.5 years). I then developed two different forest reconstruction models to estimate pre-suppression forest conditions. Two alternative tree growth models, one regionally-parameterized and one locally-parameterized, and a decay model based on published estimates of tree decay rates were evaluated. Limited tree decay data available in the literature is a source of uncertainty in forest reconstructions, both for this study and other studies in the Sierra Nevada. Model analysis demonstrated that the regionally-parameterized growth model resulted in unreasonably fast tree growth rates. The site-specific growth model produced results similar to empirical historical datasets (84.5 trees ha-1 and 25.7 m2 ha-1 in 1900) I utilized these results to investigate patterns of tree establishment during the fire suppression era. I found evidence for spatial attraction between early ingrowth (trees that established between 1930 and 1970) sugar pine and legacy trees (trees established before 1930) and spatial repulsion between late ingrowth (trees that established after 1970) sugar pine and legacy trees. This indicates that fire suppression is driving changes to intertree relationships, causing current tree spatial patterns to be outside of their historical range and variability. These results highlight the need for a substantial increase in research efforts regarding tree decay data for Sierra Nevada mixed-conifer forests. When developing restoration targets, managers should avoid a one size fits all approach and consider site-specific factors, such as parent material and the historical fire regime, which have influenced changes to forest conditions during the fire suppression era.

Thesis--Teachers College, Columbia University, 1967. / Typescript; issued also on microfilm. Dissertation Committee: Francis Shoemaker, Margaret Mead, . Includes bibliographical references.