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Involvement of ovarian Câ†2â†1 steriods on oocyte final maturation in rainbow trout, (Salmo gairdeneri), plaice (Pleuronectes platessa) and dab (Limanda limanda)Canario, Adelino Vicente Mendonca January 1989 (has links)
No description available.
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Trade-offs in fish reproduction of the common goby to oxygen stressJones, J. C. January 1997 (has links)
No description available.
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The biology of Vitex (Verbenaceae) in Sri LankaSinghakumara, B. M. P. January 1990 (has links)
No description available.
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Comparative analyses of reproductive tacticsRead, Andrew F. January 1989 (has links)
No description available.
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A study of neosporosis in cattle and sheep in IrelandFerris, John F. January 2003 (has links)
No description available.
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Growth and reproduction in a dioecious tree, Salix cineraAlliende, Maria Catalina January 1986 (has links)
No description available.
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The role of androgens in testicular development and dysgenesisScott, Hayley M. January 2007 (has links)
Disorders of male reproductive health which manifest at birth (cryptorchidism, hypospadias) or in young adulthood (testicular germ cell cancer and low sperm counts), are common and may be increasing in incidence. These disorders have a common fetal origin and share risk factors; consequently they are hypothesized to comprise a testicular dysgenesis syndrome (TDS). TDS arises when maldevelopment (dysgenesis) of the fetal testis results in hormonal malfunctions and abnormal development and function of the somatic cells. It is thought that the suppressed intratesticular testosterone levels associated with TDS may account for subsequent low sperm counts, via a reduction in perinatal Sertoli cell proliferation/number. Sertoli cells do not express androgen receptors (AR) in fetal life in the human or rat, so it is hypothesised that any androgen effects on Sertoli cell number occur indirectly, via the AR positive peritubular myoid cells. Evidence from the di (n‐butyl) phthalate (DBP)‐treated rat model for TDS suggests that reduced androgen action may play a role in testicular dysgenesis as in patients with complete androgen insensitivity syndrome (CAIS; ‘testicular feminization’), in whom focal areas of testicular dysgenesis have been reported. The studies in this thesis sought to establish if reduced androgen levels/action in the fetal rat testis contribute to putative testicular dysgenetic features, namely reduced Sertoli cell number, occurrence of multinucleated gonocytes or abnormal aggregation of fetal Leydig cells, the precursor of focal dysgenesis. Pregnant rats were exposed to treatments or co‐treatments expected to manipulate testicular testosterone levels (DBP, testosterone propionate; TP) or action (flutamide, DMBA) or to induce intrauterine growth restriction (dexamethasone), another risk factor for TDS. The aforementioned endpoints were analysed in fetal testes and related to testicular testosterone levels and peripheral androgen action (anogenital distance). The same endpoints were evaluated in mice with inactivation of the androgen receptor (tfm or ARKO mice). As androgen action is assumed to be mediated indirectly, via the peritubular myoid cells, changes in peritubular myoid cell number and function were investigated in testes with suppressed androgens. In vitro studies were also used to investigate the role of androgens in Sertoli cell proliferation. Fetal rat testis explants were cultured with various chemicals designed to manipulate androgen action and Sertoli cell proliferation. Potential non‐androgen related mechanisms of DBP action were investigated using Taqman RT‐PCR to determine the mRNA expression of key developmental genes after exposure to DBP. Sertoli cell number was reduced after exposure to treatments that reduced testicular testosterone levels, i.e. DBP alone or as a co‐treatment, TP and dexamethasone. Sertoli cell numbers in ARKO mice were also significantly reduced. The occurrence of multinucleated gonocytes and large Leydig cell clusters were induced after exposure to DBP, alone or as a co‐treatment, but not after exposure to TP or dexamethasone, and these dysgenetic endpoints did not occur either in tfm or ARKO mice. Rats exposed in utero to DBP have reduced testicular testosterone levels, however peritubular myoid cell number was unaffected by DBP, though AR expression in the peritubular myoid cells was delayed, and laminin and vimentin expression in Sertoli cells was altered after DBP exposure. DMRT‐1 and DAX‐1 mRNA expression levels were significantly reduced after DBP exposure, but this reduction was no longer evident once mRNA expression was corrected for Sertoli cell number. In conclusion, these studies provide strong evidence that androgens play a role in regulation of Sertoli cell number/proliferation, and this is supported by a comparable reduction in Sertoli cell number in ARKO and tfm mice. However, since the treatments that reduce testicular testosterone in the rat, may also have a direct affect on the Sertoli cells, this alternate mechanism of action cannot be ruled out, and the administration of a treatment that reduces testicular testosterone without directly affecting Sertoli cells is required. These studies also show that reduced testicular testosterone levels are associated with multinucleated gonocyte formation and fetal Leydig cell aggregation, although this evidence it is not supported by parallel findings from the TP and dexamethasone exposed rats or the ARKO and tfm mice, as neither of these endpoints were identified as being affected in these animals. Aside from the delay in AR expression, there were no obvious changes in peritubular myoid cell number or the peritubular myoid cell markers examined in testes deprived of androgens, although there are other markers that could be investigated. mRNA analysis of the developmental genes investigated after DBP exposure, demonstrated no change in expression after correction for Sertoli cell number, suggesting that they do not play a role in the dysgenetic features observed in DBP exposed testes.
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Elicitation and application of preference values in economic evaluation : case studies in reproductive healthScotland, Graham January 2011 (has links)
Outcome valuation and economic evaluation in maternal and reproductive health care can be complicated by the fact that: 1. Alternative interventions can be geared towards enhancing the experience of women undergoing care, rather than improving health status; and 2. Alternative interventions can directly affect the health and wellbeing of both woman and infant(s) This thesis explores methods for overcoming these challenges. A review of the literature indicates that: 1) while stated preference techniques have been used to value patient experience in the context of reproductive health care, few studies have incorporated such values into full economic evaluations; 2) while health state valuation techniques have been adapted to value combined mother-infant health outcomes, these techniques have never been used to value outcomes of alternative approaches to assisted reproduction; and 3) no economic evaluations in this area have explicitly considered preferences for the distribution of benefits between women and newborn infants. These gaps are addressed though three empirical case studies. The first demonstrates a method for measuring and incorporating women’s preferences for patient experience factors into an economic evaluation comparing alternative approaches to labour management. The second assesses women’s preferences for mother-infant health outcomes in the context of an economic evaluation comparing alternative approaches to IVF treatment. The final case study adopts an approach to estimate the relative monetary value that community members place on the prevention of maternal and neonatal deaths, in the context of decisions between competing health care programmes that impact differentially on these outcomes. The case studies show that the challenges identified above can be overcome by adapting one or other of the stated preference valuation techniques available to health economists. DCEs in particular offer a flexible approach to dealing with the complexities and trade-offs that can arise when considering choices between alternative reproductive health care interventions in the context of scarce resources.
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Interactions between prostaglandins, phospholipids and spermatozoaCrosby, John January 1988 (has links)
No description available.
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Adrenal → gonad interactions in the male rat : studies on the influence of the adrenal gland on testicular steroidogenesisFeek, Colin Michael January 1987 (has links)
No description available.
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