Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 381-400).

Thesis (Ph. D.)--University of Illinois, 1934. / Vita. Bibliography: p. 39-40.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 160-192).

Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-80).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1965. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Assisted reproductive technologies have become a common method used to treat infertility. These techniques have advanced quickly since the first birth of an in vitro fertilization (IVF) baby in 1978, at the Royal Oldham Hospital in the United Kingdom. Currently, IVF with or without intracytoplasmic sperm injection, is used throughout the world to achieve oocyte retrieval, fertilization, implantation of an embryo, clinical pregnancy, ongoing clinical pregnancy, and a live-born infant. The rationale for selecting one type of fertility treatment over another is multifactorial: the confirmed or unconfirmed cause of infertility, the age of the gamete donor and the recipient, the availability of the type of treatment, and the cost associated with the treatment. The ultimate goal of any fertility treatment is to achieve a successful pregnancy that results in a healthy infant. However, the literature is equivocal on the effects of fertility treatment cycles on the health outcomes of infants and mothers. Presently, there are thirty-six fertility treatment centres across Canada, eighteen of which reside in Ontario. A national, comprehensive database of assisted reproductive technology treatment cycles (Canadian Assisted Reproductive Technologies Register (CARTR) Plus) began collecting data in 2013, and has made the research objectives of this doctoral thesis feasible. Before this data collection system, population-wide studies involving fertility treatments were not possible in Canada. Two understudied issues associated with IVF are the impact of fertility treatments on the maternal serum screening markers used in prenatal screening programs to identify fetal aneuploidies; and the association between fertility treatments and adverse perinatal outcomes, such as preeclampsia and stillbirth. Given the increasing number of women who are using fertility treatments to conceive, it is imperative that studies investigating the association with adverse outcomes are conducted. As the science supporting fertility treatment procedure has advanced, so has prenatal screening. One of the first screening tests that are performed for newly pregnant women, including women who conceived following IVF, is maternal serum screening. The first objective of this doctoral thesis was to systematically review the literature on the association between IVF treatment and maternal serum screening marker levels and nuchal translucency (NT) thickness. After the search and screening of the literature there were 40 studies that were included in this systematic review. A decrease in pregnancy-associated plasma protein A (PAPP-A) and an increase in total human chorionic gonadotropin (hCG) was consistently reported for IVF pregnancies. However, since the levels of the other maternal serum screening markers reported also varied we were unable to generalize about the differences between prenatal screening results in the IVF population. These results led to investigating maternal serum screening marker levels among IVF patients in Ontario, Canada. The second objective of this thesis was three-fold: 1) to investigate the accuracy of IVF identification on the Ontario prenatal screening record, relative to reference standard on the CARTR Plus database; 2) to compare the prenatal screening markers in IVF versus non-IVF pregnancies in the population of Ontario; and 3) to propose updated IVF adjustment factors for prenatal screening in the Ontario population, based on the more accurate coding for IVF status in the CARTR Plus database. Significant differences between IVF and non-IVF groups, based on both the prenatal screening requisition information and CARTR Plus information, were found among the ethnicity adjusted mean multiple of the median (MoM)s for several prenatal screening markers: alpha-fetoprotein (AFP), PAPP-A, unconjugated estriol (µE3), first trimester hCG, total hCG, and dimeric inhibin A (DIA). When we developed the proposed adjustment factors for all CARTR Plus identified pregnancies we found that for PAPP-A, total hCG, and µE3 the mean adjusted marker MoMs were significantly closer to 1.00, as compared to the prenatal screening adjusted or the unadjusted mean marker MoMs. Currently, there is no adjustment made to the other maternal serum screening markers and NT measurement. The third objective was to examine the effect of type of infertility on placental-mediated adverse outcomes (preeclampsia, intrauterine growth restriction, placental abruption, and stillbirth). Type of infertility was classified as male factor (sperm count, poor sperm motility, and abnormal sperm morphology), female factor (ovulation disorders, tubal infertility, and uterine or cervical causes), and unexplained infertility. No significant associations were found between type of conception and the composite outcome, as well as each individual primary outcome. Similarly, the type of infertility was not associated with the composite outcome or any of the individual primary outcomes, except for female factor infertility, which was associated with increased probability of placental abruption. Overall, the results from this doctoral thesis suggest that there are substantial differences seen in maternal serum screening marker MoMs among women who use IVF to conceive, suggesting that appropriate adjustment factors should be employed to ensure accurate results for determining the risk of Down syndrome and trisomy 18. Additionally, although the literature has shown an association between fertility treatment and placental-mediated adverse outcomes no significant associations were found in the population of Ontario. Further studies should be performed to confirm the results of these observational studies.

The objective of this study was to examine the relationships between Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) foliar nutrient status and forest floor chemical properties. Foliar nutrient analysis data were collected on 27, 50- to 140-year-old Douglas-fir stands, for which the forest floor chemical properties had previously been analysed. The 27 sites encompassed a broad geographical area within the Coastal Western Hemlock Biogeoclimatic Zone. Foliar samples were individually analysed for total S, N, P, K, Ca, Mg, B, Cu, Zn, Fe, Al, Mn and for AFe (active iron). Four foliar nutrient ratios (N/S, N/P, K/Ca, Ca/Mg) were additionally calculated. As the foliar sampling intensity was often below that recommended in the provincial sampling guidelines, the precision of the within-site foliar nutrient variable mean values was examined for the lowest sampling intensity used in this study (n=8). Foliar nutrient and ratio variances from 6 of the 27 sites, for which 15 trees per site had been sampled, were used as population variance estimates. A sampling intensity of n=8 was found to be sufficiently large to provide foliar nutrient variable mean estimates with an allowable error of 20% (∝ =0.5) for all but the following foliar nutrients and ratios: B, Cu, Ca/Mg and K/Ca. Two combinations of forest floor horizons were examined for possible relationships with foliar nutrient variables: L plus F and L plus F plus H. These two combinations of forest floor horizons were referred to as the LF and the LFH layers. The two criteria used to select forest floor chemical properties are as follows: (1) the precision of the forest floor chemical property site estimate was less than or equal to 20% (∝=0.5) for the field sampling intensity used, or (2) the forest floor chemical property was an established measure of nutrient availabilty. The 12 LF and 16 LFH chemical properties selected included: LF and LFH: pH (CaCl₂), total-S, -N, -P, -Cu, -Zn, -Mg, -K, -C, Min-N (anaerobic mineralizable N), KC1-N (KC1 extractable N, A (lipids), and LFH (only): exK, exCa, exMg (1M NH₄OAC exchangeable bases) and extP (Bray P₁ extractable P). Simple linear relationships between foliar nutrient variables and LF and LFH chemical properties were initially examined. Strong negative associations were found between foliar S and certain forest floor chemical properties, namely LF: pH, LMg and LFH: pH, LMg, LexMg, LexCa, LexK (here and following, L signifies the natural logarithm). It was hypothesized that these relationships reflected the effect of the different sources of plant available sulphur predominant on the higher (17 sites) and lower (10 sites) forest floor pH sites. Organic sulphur mineralization and mineral weathering were suggested as the major sources of plant available sulphur for the higher forest floor pH sites; anthropogenic atmospheric sulphur was suggested as the major source of plant available sulphur for the lower forest floor pH sites. The efficacy of forest floor (LF and LFH) chemical properties for predicting and classifying foliar nutrient status was examined through the use of multiple regression and discriminant analysis, respectively. These analyses were performed for the four foliar nutrient variables for which a range in sufficiency and possible deficiency (actual or inducible) was indicated for the stands sampled: foliar N, S, AFe and N/S. One regression model of potential predictive value was found for foliar LS. Together, LFH pH and LFH LCu statistically accounted for 79% of the observed variation in foliar LS. Several LF and LFH chemical properties were able to reliably classify stands into the following total foliar S groupings: sufficient and deficient (actual or inducible). LF LMg and LF A provided the best classification of stands into the groupings: S sufficiency and N-inducible S deficiency, as defined by foliar N/S. Three LFH chemical properties: P, S, and LexK provided the best classification of stands in terms of adequate and slight to severely deficient foliar N status. LF and LFH chemical properties were only poorly able to classify foliar AFe status. It was concluded that the relationships found in this study could not be extrapolated beyond the present study, due to the unforeseen, yet probable, influence of slightly acidic precipitation on both nutrient cycling and foliar nutrient status for 10 of the 27 stands examined. / Land and Food Systems, Faculty of / Graduate

No description available.

Capacitation of spermatozoa is essential for fertilization. Rabbit spermatozoa are particularly difficult to capacitate in vitro and require treatment with high-ionic-strength Brackett's defined medium. Spermatozoa treated with platelet activating factor had significantly higher fertilization rates when compared with nontreated (fresh, twice washed) spermatozoa (63% vs 34%). Fertilization rates of spermatozoa treated with platelet activating factor, although higher than those of high-ionic-strength capacitated spermatozoa, were not significantly different (63% vs 57%). Spermatozoa treated with lyso-platelet activating factor, the biologically inactive form of platelet activating factor, were noted to have fertilization rates similar to those of the untreated (noncapacitated) group. These data show that synthetic platelet activating factor treatment of uncapacitatedspermatozoa induces fertilization of rabbit oocytes in vitro in a manner similar to that for spermatozoa capacitated by high-ionic-strength media and significantly higher than that for untreated spermatozoa or after treatment with the biologically inactive form of platelet activating factor (lyso-platelet activating factor).