<p> A critical factor for successful ovarian transplantation is the expeditious establishment of sufficient blood supply. Recommendations intended to improve recovery, reduce the effects of stress, and decrease the amount of pain for laboratory animals undergoing surgical procedures include post-operative analgesia. The two main types of drugs that are recommended for pain management are opioids and non-steroidal anti-inflammatory drugs (NSAIDs). Buprenorphine, an opioid, and meloxicam, an NSAID, are both widely used and have been shown to affect angiogenesis and vasculogenesis. This study was designed to examine the influence meloxicam and buprenorphine had on new blood vessel formation in the ovarian medullary region of aged female recipient CBA/J mice, transplanted with young ovaries from CBA/J donor females. Medullary vessel analysis was performed by viewing 40 &micro;m thick sections fluorescently labelled with the cell marker CD31/PECAM-1 via confocal microscopy. A multivariate analysis of variance (MANOVA) was performed between treatment groups to analyze how the independent variables of analgesic administration affected multiple dependent variables of deep microvessel quantities. Results demonstrated no significant endothelial microvessel growth or reduction among the meloxicam or buprenorphine-treated mice as compared to saline-treated mice. Results further suggested that neither type of analgesic drugs affected medullary ovarian angiogenesis and vasculogenesis after ovarian transplantation of young ovaries into aged females.</p>

<p> Ceratopsian dinosaurs are one of the most diverse dinosaur groups in the Cretaceous, and an outstanding question is how growth strategies of this group evolved in relation to their shift from small bipedal basal ceratopsians to larger quadrupedal ceratopsids. Previous bone histology studies have investigated several basal ceratopsians and centrosaurine ceratopsids (e.g., <i>Centrosaurus, Pachyrhinosaurus, Einiosaurus</i>), but no chasmosaurine ceratopsids have been investigated. I conducted histological analysis of humeri, ulnae, femora, tibiae, ribs, and ossified tendons from multiple specimens of two species of chasmosaurine ceratopsid dinosaurs from the late Campanian (Upper Cretaceous) Kaiparowits Formation of southern Utah, <i>Kosmoceratops richardsoni</i> and <i>Utahceratops gettyi</i>, to examine bone microstructure indicators of growth rate and maturity. I also reexamined the long-bone histology of the ceratopsian dinosaurs <i>Psittacosaurus mongoliensis, Protoceratops andrewsi</i>, and <i>Centrosaurus apertus </i>. All elements of <i>Utahceratops</i> and <i>Kosmoceratops </i> examined are dominated by densely vascularized tissue, indicative of sustained fast growth. Radially-oriented vascular canals as well as dense osteocytes from throughout ontogeny are further indicators of rapid growth. I identified juvenile (UMNH VP 20444, UMNH VP 20454), subadult (UMNH VP 16681) and adult (UMNH VP 16860, UMNH VP 16861, UMNH VP 12198) specimens of <i> Utahceratops</i>, and two subadult to adult specimens (UMNH VP 17000, UMNH VP 21339) of <i>Kosmoceratops</i>. </p><p> I conclude that basal ceratopsians grew more slowly than the large quadrupedal ceratopsids, as evidenced by a generally higher number of definitive growth lines prevalent throughout development. In contrast, the presence of dense osteocytes, and reticular and radially-oriented vascular canals are rapid growth indicators shared by all sampled large ceratopsids, and imply an elevated metabolism for all ceratopsians. Sampled specimens of <i>Utahceratops </i> and <i>Kosmoceratops</i> do not preserve any evidence of annual lines of arrested growth (LAGs). Placed in context with the number of LAGs observed in Alaskan <i>Pachyrhinosaurus, Centrosaurus</i> from Alberta, and <i>Einosaurus</i> from Montana, these data suggest a latitudinal gradient in the number of LAGs, which suggests that bone growth is reacting to the climate.</p>

<p> Spermatogenesis is governed by vitamin A, as shown by vitamin A deficient (VAD) testes, which lack advanced germ cells. Vitamin A signaling is mediated by retinoid receptors. There are two families of retinoid receptors, retinoic acid receptors (RARs) and retinoid X receptors (RXRs), each with alpha, beta and gamma subtypes. Retinoic acid receptor alpha (RARA), plays a significant role in the testis such that <i>Rara</i>-null males are infertile because of severe germ cell loss. </p><p> Striking similarities of the testicular phenotypes are detected between <i> Rara</i>-null and VAD mice: severely degenerated testes, lack of germ cells, sloughing of mature spermatids, and infertility. To discern the molecular function of RARA in germ cells, <i>Rara</i> was conditionally deleted using stimulated by retinoic acid 8 (STRA8)-iCRE. With RARA function disabled in germ cells, morphological abnormalities detected in the testes included lack of germ cell organization, lack of lumen, sloughing cells, and vacuolization. Not surprisingly, germ-cell specific <i>Rara</i> conditional knockout mice (cKO) had a dramatic reduction in epididymal sperm number. Further analysis of cKO testes demonstrated decreased spermatogonial proliferation and differentiation, while meiotic defects such as reduced synapsis, synaptonemal fragmentation, and unrepaired double strand breaks were increased. Furthermore, functional spermatogonial transplantation assays pointed to the possibility that RARA regulates spermatogonial stem cell colonization and proliferation, as shown by the reduction of donor-derived spermatogenesis from the cKO donor germ cells. The lack of RARA in the testes clearly shows quantifiable deficiencies during spermatogonial proliferation, differentiation, and meiosis. </p><p> Microarray gene expression studies of mRNAs from the enriched germ cells from wild type and cKO mice provided molecular evidence that RARA regulates spermatogonial differentiation at postnatal day 4 (P4) and meiosis at P8. Cell differentiation, cell adhesion, cell migration, and other pathways related to the early steps of spermatogonial differentiation were found to be functional categories significant in germ cells from P4. These were very distinct from synapsis, synaptonemal complex formation, and crossover formation related to meiosis, which were functional categories significant in germ cells from P8. In conjunction with phenotypic abnormalities, we provide gene expression evidence that RARA mediates retinoic acid function during spermatogonial proliferation, differentiation, and meiosis.</p>

Habitat loss is widely acknowledged as the leading cause of extinctions and is occurring at an alarming rate and affecting biodiversity globally. I measured the rate of habitat loss using satellite-based land cover change data. First, I modelled the potential suitable habitat of the Marbled Murrelet on Vancouver Island using two techniques and compared those results to in-situ field measurements. Both modelling techniques predicted declines in suitable habitat between the years, although one technique was better at predicting suitable habitat. I also compared rates of habitat loss in areas of high species endangerment to those with lower endangerment over a 15-year period in three Canadian ecozones. In two ecozones, rates of habitat loss were higher in sites of high species at risk richness than those with low richness. These results underscore the importance of using remote sensing data as a monitoring tool critical habitat for species at risk in Canada.

This research was designed to gain a better understanding of the oogenesis of the autogenous black-fly, Simulium vittatum and to compare it with studies on other Diptera. The autogenous character in S. vittatum showed only for the first gonadotropic cycle. Since the cytoblasts are first produced in the late larval period, the late larvae, early pupae, late pupae and adults of various ages were prepared separately for histological and histochemical examination. The adult female flies were fed only sugar and water. The changes in size, histology, and histochemistry of the oocyte, follicular cells and nurse-cells during oogenesis were described and the possible physiological role of these cells in oogenesis suggested. The amount and composition of larval fat-body remaining in females was compared with the stages of the oocyte development and the age of the flies. / Thesis / Master of Science (MS)