Thesis (M.D.)--University of Hong Kong, 1977. / Also available in print.

Thesis (M.Sc.)--University of Alberta, 2010. / Title from PDF file main screen (viewed on July 2, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Soil Science, Department of Renewable Resources, University of Alberta. Includes bibliographical references.

Thesis (Ph.D.)--Northwestern University, 2003. / Source: Dissertation Abstracts International, Volume: 64-04, Section: A, page: 1316. Adviser: Caroline Bledsoe.

Thesis (Ph.D.)--Brown University, 2005. / Vita. Thesis advisor: Frances Goldscheider. Includes bibliographical references (leaves 275-285). Also available online.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 121-130).

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 262-284).

Low soil fertility has been identified to be among the major causes of low pasture quantity and quality. Scarcity of high quality forage mainly during the dry season threatens animal productivity in some areas of South Africa, thus the need for identifying livestock feed alternatives. Pigeon pea is a woody legume that has continually been an important shrub in agroforestry and can provide protein-rich livestock feed during times of shortage. Soil fertility to support the production of pigeon pea can be enhanced by application of fertilisers. Therefore, this study was carried out firstly, to determine the effect of phosphorus fertiliser on the growth performance and biomass production of three pigeon pea varieties, and secondly, to investigate the influence of phosphorus application on the nutrient and anti-nutrient content of three pigeon pea varieties. The field experiment was done at the University of Fort Hare research farm in Alice, South Africa. The factors investigated were three pigeon pea varieties namely Chitedze 1, Chitedze 2 and CIMMYT 1 and three phosphorus fertiliser application rates of 0, 40 and 60 kg P/ha. The study was a 3× 3 factorial experiment set up in a randomised complete block design and was replicated three times. The growth performance attributes evaluated in this study include the number of branches, plant height and root collar diameter. Root collar diameter was not significantly (p>0.05) different among the pigeon pea varieties and phosphorus levels. Likewise, the application of phosphorus was not significant (p>0.05) on plant height and the number of branches of all the varieties. However, when P level was varied, there were significant differences among the varieties, and so were the interaction (p<0.05) between variety and phosphorus on plant height and the number of branches. There was no significant (p>0.05) difference among the phosphorus levels on the fresh leaf yield of Chitedze 1 and Chitedze 2, but phosphorus application at 40 kg P/ha increased the fresh leaf yield of CIMMYT 1. Phosphorus application at 60 kg P/ha increased (p<0.05) the dry matter content of Chitedze 1 and Chitedze 2. Furthermore, the results of the trial show that the application of 40 kg P/ha and 60 kg P/ha increased (p<0.05) the dry matter yield of the varieties CIMMYT 1 and Chitedze 2, respectively. The effects of phosphorus application on the nutrient composition of the three pigeon pea varieties varied. The composition of hemicellulose of all the varieties was significantly (p<0.05) increased by the application of 40 kg P/ha. Conversely, the concentration of crude protein, phosphorus, copper and iron, and the calcium to phosphorus ratio of all the pigeon pea varieties was not significantly (p>0.05) affected by phosphorus application and there was no interactive effect of variety and phosphorus. The proximate compositions of fat, total non-structural carbohydrates, ash, neutral detergent fibre, acid detergent fibre, cellulose, neutral detergent insoluble nitrogen, acid detergent insoluble nitrogen of the pigeon pea varieties varied significantly (p<0.05) at different phosphorus application levels. There was an interactive (p<0.05) effect of variety and the level of phosphorus on the concentration of calcium (Ca), potassium (K), magnesium (Mg), sodium, zinc, manganese, and the K/(Ca+Mg) ratio. The digestible dry matter, dry matter intake and the relative feed value were significantly (p<0.05) different among the pigeon pea varieties at varying phosphorus levels. The anti-nutrient composition of Chitedze 2 was not significantly (p>0.05) affected by phosphorus application but the concentration of phenols and saponins of Chitedze 1 was significantly (p<0.05) increased when 60 kg P/ha was applied, but these anti-nutrients were reduced (p<0.05) for CIMMYT 1 at 60 kg P/ha. It can be concluded that phosphorus application influences the biomass production and chemical composition while the optimum phosphorus level vary among the pigeon pea varieties.

Survival from breast cancer has significantly improved over the past years. Therefore, survivorship issues are an area of crucial importance to be addressed as early as possible by all health care providers dealing with breast cancer patients. Fertility and pregnancy-related issues represent a priority area of concern for young women with breast cancer. Despite a growing attention towards these issues has been given over the past years and is currently provided to young breast cancer patients, several grey zones persist in many domains of this field and some physicians are still uncomfortable to deal with this topic. In this thesis, we aimed at providing evidence on several unmet fertility and pregnancy-related issues faced by young breast cancer patients with the ultimate goals to further improve their quality of life and to help physicians during the oncofertility counseling of these women.In Chapter 1 of this thesis, we addressed questions related to the factors with a potential negative or protective impact on the ovarian function of young breast cancer patients. First, we assessed the influence of carrying a germline BRCA mutation on the reproductive potential of young breast cancer patients and the performance of fertility preservation strategies in this setting. We conducted a retrospective analysis within two prospective studies that involved young women with newly diagnosed breast cancer who underwent oocyte cryopreservation or ovarian tissue cryopreservation for fertility preservation at CUB-Hôpital Erasme in Brussels (Belgium) between January 2006 and December 2016. A total of 101 patients were included, of whom 29 had germline deleterious BRCA mutations. We observed a consistent trend for reduced reproductive potential and performance of both oocyte and ovarian tissue cryopreservation in BRCA-mutated patients.Second, we evaluated the gonadotoxicity of anticancer treatments focusing particulary on the risk of treatment-related amenorrhea (TRA) with the addition of taxanes to anthracycline-based chemotherapy and with the administration of chemotherapy plus the anti-human epidermal growth factor receptor 2 (HER2) agents trastuzumab and/or lapatinib. This analysis was conducted in 2,862 premenopausal patients with early-stage HER2-positive breast cancer enrolled in the ALTTO randomized trial (NCT00490139) by assessing menopausal status at week 37 visit following the initiation of anti-HER2 treatment. Addition of taxanes to anthracycline-based chemotherapy led to a statistically significantly higher risk of TRA. No difference in TRA rates was observed between the four anti-HER2 treatment arms (trastuzumab alone, lapatinib alone, their sequence or their combination); the absence of higher TRA rates in the dual blockade arm as compared to single agent arms may suggest the gonadal safety of these agents. TRA was associated with statistically significant improved disease-free survival (DFS) and overall survival (OS) in patients with hormone receptor-positive/HER2-positive disease. Third, we provided evidence on the efficacy and safety of temporary ovarian suppression with gonadotropin-releasing hormone agonists (GnRHa) during chemotherapy as an option for ovarian function preservation in young breast cancer patients undergoing (neo)adjuvant chemotherapy. We performed a meta-analysis including individual patient-level data from the 5 major trials (PROMISE-GIM6, POEMS/SWOG S0230, Anglo Celtic Group OPTION, GBG-37 ZORO, Moffitt-led trial) that investigated the role of this strategy. A total of 873 breast cancer patients were included. Concurrent administration of GnRHa and chemotherapy significantly reduced the risk of developing chemotherapy-induced premature ovarian insufficiency (POI), and was associated with a higher number of subsequent pregnancies. Similar DFS and OS were observed between groups irrespective of the estrogen receptor (ER) status of the disease suggesting the safety of administering GnRHa concurrently with chemotherapy.In Chapter 2 of this thesis, we aimed to address questions related to the safety of pregnancy following prior history of breast cancer including the impact of timing of pregnancy, induction of abortion or breastfeeding, as well as to investigate the pregnancy outcomes in these patients. First, we assessed if there were differences in survival outcomes between patients who conceived following breast cancer diagnosis as compared to those who did not have a subsequent pregnancy with a particular focus to women with ER-positive tumors. In addition, we investigated the potential impact of timing of pregnancy, induction of abortion and breastfeeding on patients’ prognosis. For this purpose, a multicenter retrospective case-control study was conducted. A total of 1,207 breast cancer patients with known ER status were included in the analysis, of whom 333 conceived after prior breast cancer and 874 had no subsequent pregnancies. Long-term results from this study confirmed that pregnancy after breast cancer can be considered safe irrespectively of ER status and should not be discouraged. This was observed independently of pregnancy outcome, pregnancy interval, and breastfeeding status. Second, we assessed the safety of pregnancy following prior history of HER2-positive breast cancer, and the pregnancy outcomes in women who conceived during or after chemotherapy plus anti-HER2 treatment. We collected all the pregnancy events that occurred in the NeoALTTO (NCT00553358) and ALTTO (NCT00490139) trials. These are two randomized studies that explored the role of trastuzumab and/or lapatinib in patients with HER2-positive early breast cancer as neoadjuvant and adjuvant treatment, respectively. A total of 92 patients had at least one pregnancy after inclusion in the two trials, of whom 12 patients conceived during anti-HER2 targeted therapy (exposed group) while 80 after the end of treatment (unexposed group). We observed that having a pregnancy after prior history of HER2-positive early breast cancer did not appear to impact on DFS. A high rate of induced abortion was observed among women in the exposed group; nevertheless, despite only 5 live births being described in this group, unintentional exposure to trastuzumab and/or lapatinib during gestation did not seem to affect newborn outcomes. Patients in the unexposed group appeared to have normal pregnancy outcomes. Therefore, overall, having a pregnancy following completion of chemotherapy plus anti-HER2 therapy showed to be safe without compromising fetal outcome or maternal prognosis.In conclusion, taken together, we believe that our findings can serve as a rational basis to improve the oncofertility counseling of young breast cancer patients facing concerns related to TRA risk, preservation of ovarian function and/or fertility as well as for those willing to consider a future pregnancy. Several ongoing and upcoming projects from our group have been started based on the results presented in this thesis and are expected to provide further evidence on these crucial topics. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

The degradation of soil quality due to undesirable farming practices has reached alarming scales in the Eastern Cape and this has had negative repercussions on soil productivity and the environment in general. There is growing evidence that conservation agriculture (CA) practices involving minimal mechanical disturbance, maintaining permanent surface cover and embracing diverse crop rotations increase soil organic carbon (SOC) and therefore has potential to mitigate soil quality deterioration. A study was carried out at two sites located in two ecotopes to investigate the effects of crop residue retention and crop rotations in a no till system on overall soil quality using the Soil Management Assessment Framework (SMAF) as the soil quality assessment tool. The CA study trials were laid out in 2012 at two different locations, one at the Phandulwazi Agricultural High school within the Phandulwazi Jozini ecotope and the other one at University of Fort Hare Research Farm within the Alice Jozini ecotope. The experiment was laid out as a split-split plot arrangement in a randomized complete block design with three replicates. Tillage treatments were applied on the main plots while crop rotation treatments were applied as subplots. Crop residue retention treatments were applied as sub-sub plots. The rotational treatments were maize-fallow-maize (MFM), maize-fallow-soybean (MFS), maize-wheat-maize (MWM) and maize-wheat-soybean (MWS). The initial assessment of the overall soil quality of the two ecotopes using the SMAF soil quality index (SQI) revealed that the soils at the Alice site were functioning at 80% while the soils at the Phandulwazi site were functioning at 79 percent of their optimum capacity. The slight difference in the soil quality of the two ecotopes could be attributed to their different soil organic C contents where the Alice Jozini ecotope had significantly higher soil organic C contents than the Phandulwazi Jozini ecotope. After 3 years of continuous treatment application, crop residue retention significantly improved most of the measured soil quality parameters. Generally across the sites, more soil organic C, microbial biomass C (MBC), ß-glucosidase (BG) activity, mineral N, extractable P and K, Cu, Zn, Mn, Fe, and macro-aggregates were recorded in treatments where crop residues were retained. Crop rotations alone did not have a significant impact on most of the measured soil quality indicators. The crop rotations influenced significantly the availability of mineral N across the two sites, highlighting the importance of using a legume in rotations on available N for the subsequent crops. Most of the measured soil attributes were not significantly influenced after 3 years of continuously applying combined treatment of CA components. Mineral N (NO3 + NH4), K, Zn and Fe were significantly impacted on by the interactions of CA components at the Phandulwazi site, while N, Cu, Zn and Mn were significantly increased at the Alice site. Low response of SOC to combined CA treatments in the short-term prompted the need to examine treatment effects on individual soil carbon fractions. The interaction of crop rotation and residue management techniques were significant on the fine particulate organic matter – C fractions and microbially respired C. These soil C fractions were more sensitive to short-term treatments of combined CA components than SOC and MBC, therefore they can be used as short-term indicators of CA effects on SOM. Soil organic carbon, MBC, extractable P and K, soil pH, EC, b, AGS (aggregate stability) and BG activity were measured and the Soil Management Assessment Framework (SMAF) used to calculate soil quality index (SQI) values for each treatment. The combination of the crop rotations with crop residue retention showed the potential to significantly improve SQI values in the long term. The highest soil quality improvement at both sites was achieved by the maize-wheat-soybean (MWS) rotation with crop residue retention.

This research explores the concept of descendant insurance and its efficiency as a calculated estimate of a country's fertility rates based on the infant or child mortality rates of the same country. A database of 191 countries was used to evaluate the concept by nation. The results suggest that descendant insurance plays a significant roll in decreasing total fertility rates. Prediction strength for many countries can be increased greatly by incorporating time lags into the model. Adding a lag component produced strong results for predicting fertility rates in countries where many previous studies have failed to find significant fertility trends. The results of the analysis provide further evidence for the argument that preventing infant and child deaths is a driving factor for decreasing fertility rates.