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Effect Of Altitude On The Peripheral Degradation Of Thyroxine In The Uinta Ground Squirrel (Citellus Armatus), Stuart K. Ware

Theses and Dissertations

Various methods were employed to detect changes in the peripheral degradation of thyroxine (T4) in adult Uinta ground squirrels (Citellus armatus) collected at two different altitudes (5400 and 9000 feet.) Plasma half-life of injected T4-125I (tl/2) was significantly decreased with altitude, as was T4-125I distribution space (TDS) and T4 degradation and secretion rate (TSR). In vitro deiodination of T4-125I by heart homogenates was not affected, while urinary excretion of thyroxine derived iodide was increased at high altitude 44-70 hours post-injection. Both total and free serum T4 concentrations were reduced at high altitude, although not significantly. The cause of the reduced …

The Horse Population Of Utah And Its Impact, Scott Stewart Mckendrick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

PART I

The horse numbers of Utah had not been accurately counted since the early 1960's. It was estimated that horse and pony numbers were reaching heights as recorded before the age of tractors and automobiles. Horsemen in Utah were asking for financial assistance for public horse facilities from the Utah legislature. The first part of this study was to survey the horse population to determine an accurate count of Utah horses.

PART II

In order to be satisfied that the horse industry deserved the spending of public funds, it was necessary to know the economic contribution of the horse …

Modeling Studies Of Small Mammal Trapping Phenology, And Plant Succession In The Kaiparowits Region, Kane County, Utah, James A. Raines

Theses and Dissertations

This study makes use of simple statistical models which may be manipulated for projection of changes in the Kaiparowits Region of Southern Utah. A method of determining habitat preferences of small rodents from capture-recapture trapping data is proposed. It is suggested that some aspects of animal behavior regarding trapping may also be explained. Timing of flowering of Oryzopsis hymenoides and Hilaria jamesii as related to enviromental conditions was investigated, and models of the requisite conditions proposed. It is suggested that similar models may be used to describe the timing of other phenological events. Succession on disturbed sites is considered to …

Effect Of Supplemental Food On Population Estimates And Mortality Rates Of Desert Rodents In Utah, J. Steven Thiriot

Theses and Dissertations

The objective of this research is to assess the effects of various quantities of supplemental food (seed) on population estimates and mortality rates of desert rodents . The supplemental food is meant to stimulate natural vegetational productivity. If food availability significantly affects the population parameters methods of population estimators previously used may be in error. Hopefully this study will aid small mannnal research by designating whether, in part, population estimates and mortality rates are in error because of high vegetational productivity. The hypothesis of this study is that supplemental food in the natural environment decreases population estimates and mortality rates …