This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

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Indiana University-Purdue University Indianapolis (IUPUI) / Trained canines are commonly used as biological detectors for explosives; however, there are some areas of uncertainty that have led to difficulties in canine training and testing. Even though a standardized container for determining the accuracy of explosives-detecting canines has already been developed, the factors that govern the amount of explosive vapor that is present in the system are often uncertain. This has led to difficulties in comparing the sensitivity of canines to one another as well as to analytical instrumentation, despite the fact that this container has a defined headspace and degree of confinement of the explosive. For example, it is a common misconception that the amount of explosive itself is the chief contributor to the amount of odor available to a canine. In fact, odor availability depends not only on the amount of explosive material, but also the explosive vapor pressure, the rate with which the explosive vapor is transported from its source and the degree to which the explosive is confined. In order to better understand odor availability, headspace GC/MS and mass loss experiments were conducted and the results were compared to the Ideal Gas Law and Fick’s Laws of Diffusion. Overall, these findings provide increased awareness about availability of explosive odors and the factors that affect their generation; thus, improving the training of canines. Another area of uncertainty deals with the complexity of the odor generated by the explosive, as the headspace may consist of multiple chemical compounds due to the extent of explosive degradation into more (or less) volatile substances, solvents, and plasticizers. Headspace (HS) and solid phase microextraction (SPME) coupled with gas chromatography/mass spectrometry (GC/MS) were used to determine what chemical compounds are contained within the headspace of an explosive as well as NESTT (Non-Hazardous Explosive for Security Training and Testing) products. This analysis concluded that degradation products, plasticizers, and taggants are more common than their parent explosive.

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

Oocysts of Isospora canis, an important protozoan parasite of dogs, must sporulate in the external environment in order to become infective. To determine the tolerance of these oocysts to different temperatures, oocysts ware collected from freshly passed feces, cleaned, and subsequently stored in unsporulated, partially sporulated, and completely sporulated conditions at temperatures ranging from +50 C to -50 C. Observations on survival for each group were determined periodically thereafter at intervals up to 64 days. The rate of sporulation was followed at 6 hr intervals for temperatures of 20, 25, 30, and 38 C. Completely sporulated oocysts ware more resistant to temperature extremes than unsporulated or partially sporulated oocysts; the optimum storage temperature for all stages was 4 C. This suggests that the development and survival of this parasite would be higher during mild spring and fall months than during cold winter and hot summer periods. The sporulation time for I. canis was 102 hr at 20 C, 96 hr at 25 C, 60 hr at 30 C, and 54 hr at 38 C; however, at the upper limit tested, more abnormal development occurred.

Indiana University-Purdue University Indianapolis (IUPUI) / Previous research indicates that overall, bone turnover decreases with age. The effects of aging on the remodeling of the mandibular condyle have not been studied. As part of the temporomandibular joint, the mandibular condyle (MC) is exposed to a unique pattern of loading. As such, data obtained from studies of other bones may not be applicable to accurately explain the behavior of trabecular bone of the mandibular condyle and its relationship to aging. Recent research has led to the finding that cortical bone turnover in the mandible is much higher than that seen in tibia, and that both sites decline with age. The purpose of this study was to histomorphometrically quantify the effects of aging on the bone remodeling of the canine MC, and to determine whether site-specific differences due to age occur in the dynamic and static parameters between MC and tibial condyle (TC). Fluorochrome labels were used to mark sites of bone formation in ten old and five young dogs. Specimens were obtained from one MC and one TC for each dog and were prepared for analysis of static and dynamic histomorphometric indices. Mineral apposition and bone formation were totally absent in the old group, as shown by the lack of fluorochrome labels. In the young group, they were significantly higher in the MC than in the TC (p < 0.01). Aging resulted in a significant increase of volume density of the subchondral bone (p < 0.05). Trabecular bone volume was not significantly affected by age in the samples studied. The results indicate that bone remodeling is markedly higher in MC than in the TC in young dogs. With aging, it declines to zero in both sites. Whether the loss of remodeling activity in these elderly animals indicates that they are fully adapted to their mechanical environment or that they have lost the intrinsic ability to remodel, remains to be determined.

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