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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"preovulatory"”.
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HEMODYNAMICS STUDIES OF THE PREOVULATORY FOLLICLE AND CORPUS LUTEUM IN CATTLE
… relationships between size and blood flow of the preovulatory follicle (POF) and corpus luteum (CL) with the subsequent systemic progesterone production, and the impact of those factors on fertility, would provide information to help maximize fertility in cattle reproduction. Three studies were …
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Studies of Iodinated Ovulatory Hormones and Their Interactions With Preovulatory Ovarian Tissues
Made available in DSpace on 2014-12-11T22:22:22Z (GMT). No. of bitstreams: 1 7405597.pdf: 6039933 bytes, checksum: d9b46651e5757c4ff1e373fd710f5afa (MD5) Previous issue date: 1973
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Physiology of the germinal disc region in preovulatory follicles of the chicken ovary
… hypothesized to be growth center of the avian preovulatory follicle. This investigation was undertaken to examine critical aspects of the physiology of the GDR with respect to its role in the proliferation and differentiation of the granulosa layer. Specifically, the objectives were: (1) to …
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Effects of Preovulatory Estradiol Concentration on Embryo Survival and Pregnancy Establishment in Beef Cows
<p>Estradiol exposure during the preovulatory period has been shown to affect the establishment and maintenance of pregnancy in beef cows. The mechanism by which estradiol affects pregnancy establishment and maintenance has not been well characterized. Previous studies have examined the effects of …
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The Role of Neurokinin B in the Regulation of the Preovulatory LH Surge in Ewes
Hypothalamic input is vital to the regulation of reproductive function. Gonadotropin-releasing hormone (GnRH) is secreted by hypothalamic GnRH neurons into the hypophysial portal circulation. When GnRH reaches the anterior pituitary, it stimulates gonadotropes to secrete luteinizing hormone (LH) …
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The Influence of Preovulatory Estradiol on Uterine Transcriptomics and Proteomics Around Maternal Recognition of Pregnancy in Beef Cattle
<p>Preovulatory estradiol has been reported to play a crucial role in pregnancy establishment and maintenance, but the mechanism by which estradiol exerts its effects has not been well characterized. Specifically, the interactions between the maternal uterine environment and the developing …
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The Effects of Preovulatory Estradiol on the Uterine Environment and Conceptus Survival From Fertilization to Maternal Recognition of Pregnancy
<p>Preovulatory estradiol has been reported to play a critical role in pregnancy establishment and embryonic survival, but the mechanism by which estradiol exerts its effects has not been well characterized. The objective of this thesis is to determine the effects of preovulatory estradiol on the …
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Steroidogenic cell populations in follicles of the chicken ovary
A two cell theory for steroidogenesis in preovulatory follicles of the chicken ovary states that the granulosa layer metabolizes cholesterol to progestins and progestins are, then, metabolized to androgens and estrogens by the theca layer. However, the precise site of steroidogenic cells in the …
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Regulation of Estradiol-17beta Synthesis by Small Follicles of the Domestic Hen Ovary
… in the domestic hen. Although steroidogenesis in preovulatory follicles has been studied extensively, regulation of steroidogenesis in small follicles has received little attention. Therefore, the aim of my dissertation was to investigate the regulation of E$\sb2$ synthesis by small follicles of …
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Factors Important to the Efficiency of Artificial Insemination in Single-Ovulating and Superovulated Cattle
… fixed. In Exp. 3, ultrastructural features of preovulatory, tubal-stage, and typical d 6 unfertilized ova were investigated. Preovulatory ova revealed normal ultrastructure; tubal-stage ova exhibited evidence of degeneration; typical d 6 ova were degenerated and contained no discernable …
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The effect of the human menstrual cycle on kilocalorie and nutrient intake
… higher in the postovulatory phase compared to preovulatory, but the difference was not significant. Mean carbohydrate and fat intakes were also increased, but not significantly, in the postovulatory phase. Protein intakes remained relatively stable when phases of the cycle were compared. A …
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Study of the pharmacological modification of neuroendocrine mechanisms controlling ovulation in the rat.
… at or before 01:00h on proestrus blocked the preovulatory LH surge, which was restored by LHRH or oestradiol plus progesterone. Administration of oestradiol alone restored ovulation to only 43% of RMI 12,936-treated rats. The negative feedback effect of testosterone on LH release showed …
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Evidence for the formation of supplementary corpora lutea in the pregnant and pseudopregnant rat
… into the presence of an appropriately-timed preovulatory surge of gonadotrophins in the early stages of pregnancy however, proved inconclusive. Supplementary ovulation occurs therefore between day 4 and 7 post-coitum in both pregnant and pseudopregnant Wistar and Sprague-Dawley rats, probably …
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The Effects of a GnRH Antagonist, Cetrorelix, on Ovarian Function in Cattle
… wave by inhibiting ovulation during the preovulatory phase (Experiment 1) and determined the effect of cetrorelix on the ovulatory ability of the dominant follicle to exogenous challenge of hCG (Experiment 2). In Experiment 1 of Study 2, heifers (n=6 per group) were given either a …
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The Reproductive Cycle of Sceloporus undulatus From Alabama Corresponding Plasma Steroid Levels and Comments on Reproductive Variation.
… and reached high levels during the last clutch. Preovulatory surges of plasma estrogen, progesterone, and testosterone were observed in yearling females captured in July. Whether similar surges occur with each clutch is unknown. Minimum levels of steroids were observed in overwintering …
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Computer-Assisted Image Analysis of Human Ovarian Follicles: Imaging Physiologic Selection
… determined. Identification of the timing of preovulatory selection is a key component in understanding natural and peri-menopausal ovarian function, ovarian suppression for contraception, and improvement of ovarian stimulation protocols. Morphologic characteristics obtained by ultrasonography …
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Fluorescence in Situ Hybridization Analysis of Human Embryos Derived From in Vitro and in Vivo Matured Oocytes
… display several levels of nuclear maturity. Preovulatory or mature oocytes, technically those that are Metaphase I or II, are inseminated shortly after aspiration and assessed for fertilization the following day. Prophase I oocytes, also called germinal vesicle-bearing or immature oocytes, …
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Genetic Profiling of the Bovine Pituitary Gland Using cDNA Microarray Technology
… to identify genes that were regulated during the preovulatory period as induced by the administration of prostaglandin F2α (PGF2α). This period is characterized by a decrease in circulating concentrations of P4 coincident with an increase in circulating concentrations of estradiol. Prior to the …
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Extraovarian and Intraovarian Control of Follicular Selection in the Chicken Ovary
… a pool of similar size follicles and becomes a preovulatory follicle. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) are primary regulators of follicular growth and differentiation. Epidermal growth factor (EGF), an intraovarian hormone, suppresses granulosa cell …
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IMPROVING REPRODUCTIVE PERFORMANCE THROUGH THE DEVELOPMENT OF A DAIRY HERD INDEX, INTRAUTERINE HORMONE DELIVERY OR INSEMINATION TECHNIQUE IN LACTATING COWS
… 200 µg of GnRH plus glycerol would result in the preovulatory release of LH comparable to the intramuscular administration of 100 µg of GnRH in lactating dairy cattle. Findings showed that increasing the concentration of GnRH (200 µg) and addition of glycerol (7% v/v) to enhance GnRH absorption …
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