Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1948. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1938. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-74).

Thesis (Ph. D.)--Washington State University, December 2006. / Includes bibliographical references.

No description available.

No description available.

Master of Science / Department of Human Nutrition / Kadri Koppel / Understanding the physiological activation and genetic variation of the sweet taste receptor (T1R) can improve formula optimization for products intended for a population of genetically diverse people. Computer modeling and cell culture techniques have thoroughly described the structure and binding sites of the T1R. The structure contains two subunits (T1R2 and T1R3) with multiple domains where sweet molecules can interact. The interaction takes place between individual molecules and amino acid residues of the T1R. The residues with which individual molecules interact differs between sweeteners. Person-to-person differences in the residue sequence of the T1R can arise from variation in the genes that encode the T1R (TAS1R), potentially effecting the function of the receptor. As a result of the specificity of binding interactions, genetic variation may affect sensitivity to some sweeteners, while sensitivity to other sweeteners remains normal. Therefore, it can be hypothesized that the level of person-to-person sweetness sensitivity variation may differ for each sweetener depending on the binding site of the molecule and site of T1R variation. The T1R structure, binding sites, and genetic variation will be reviewed, as well as potential parameters to predict the degree of sensitivity variation and formulation strategies to minimize the effects of sensitivity variation.

The sweet potato whitefly is an insect whose economic importance is continually expanding as it becomes a more efficient vector, increases its fecundity and broadens its host range. To keep pace with its ability to develop resistance to existing classes of pesticides, we have undertaken a program to examine the effectiveness of pesticides with novel chemistries and novel modes of action. Several have shown themselves to be very effective against the various life stages of the sweet potato whitefly. Once these are incorporated in to our arsenal of pesticides, we hope to be able to manage resistance by prudently using these new materials.

Populations of the sweet potato whitefly, Bemisia tabaci, have been shown to consist of both migratory and trivial flying morphs. The behavior of these forms as part of the process of short-range migration needed to be examined under field conditions. Insects were marked in a field of cantaloupes using fluorescent dust. During the first growing season traps, used to collect living whiteflies, were placed along 16 equally spaced transects (22.5° apart) radiating out from the field to a distance of up to 0.6 miles. Wind out of the northeast consistently carried migrating whiteflies to traps placed along transects in the southwestern quadrant because cold air drainages dictate wind direction during early morning hours. For this reason, during the second season traps were laid out in a rectangular grid extending 3 miles to the southwest of the marked field. If dispersal was entirely passive or wind directed patterns could be described using a diffusion model. Statistical examination of the data, however, demonstrate that the distribution on all days was patchy. Traps in the immediate vicinity of the marked field caught more whiteflies than the daily median. Large numbers were also collected from around the periphery of the grid. Whiteflies were far less prevalent in the grid's center. As a result, the distribution of captured whiteflies can be described as bimodal. These patterns confirm behavior observed in the laboratory, i.e., a portion of the population are trivial fliers that do not engage in migration and are consequently captured in traps near the field and a portion initially ignore vegetative cues and fly for a period of time before landing in distant traps. This second population comprises the second peak in the model that appeared 1.6 miles from the marked field. On a localized level, 1.6 miles seems to be how far whiteflies move in a day. Earlier studies indicate that whiteflies only fly one day.