Spelling suggestions: "subject:"[een] FERTILITY"" "subject:"[enn] FERTILITY""
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Vliv vzdělání na reprodukční chování v kontextu nízké plodnosti na Slovensku po roce 1992 / The effect of education on reproductive behaviour in low-fertility settings in Slovakia after 1992Fekiačová, Eva January 2019 (has links)
Vzťah medzi realizovanou reprodukciou a najvyšším dosiahnutým vzdelaním je v súčasnosti jeden z hlavných faktorov reprodukčného správania. V postmoderných spoločnostiach je všeobecne spájaný s negatívnym efektom vyššej vzdelanostnej úrovne na počet narodených detí. Úroveň vzdelania neovplyvňuje len konečnú plodnosť žien, či čas vstupu do materstva. Rovnako vplýva aj na preferencie jedinca, normatívne orientácie a vývoj hodnôt. Spojitosť vzdelania a reprodukcie sa dá uchopiť vo viacerých rovinách. Predkladaná práca preto poukazuje na postojové rozdiely medzi jedincami jednotlivých vzdelanostných kategórií a ponúka na príklade Slovenska v období po roku 1992 analytické i teoretické vysvetlenie vývoja a diferencie reprodukčného správania. Kľúčové slová: vzdelanie, plodnosť, reprodukcia
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Phosphorus and Potassium Fertility Management for Maximizing Tart Cherry Fruit Quality and Productivity on Alkaline SoilsRowley, Sean D. 01 May 2013 (has links)
Suitable orchard land in regions of high elevation, arid climates, and alkaline soil conditions is becoming more limited due to urban sprawl. With the loss of suitable farmland, increasing input costs, and the lack of sound fertility information for these regions, fruit growers face challenges in producing high quality fruit to meet local and general market demand. The question that arises is whether fruit growers can supply sufficient quantities of quality fruit to take full advantage of local and global demand. Government data for population, fruit production, and fruit consumption in Utah were reviewed to determine the potential size of the local market, and determine whether growers have opportunities to increase production to meet unsatisfied demand for high quality local produce. In addition to market analysis, fertility-based management strategies are needed to optimize yield and fruit quality in production areas of high elevation, arid climates, and alkaline soils. Three different approaches were used to investigate the effect of phosphorus (P) and potassium (K) on tart cherry fruit quality and yield at high elevations, arid climate conditions, and in alkaline soils. The approaches of this study include: a rate-response evaluation using the industry-standard Triple-16 fertilizer (16-16-16), and comparison of P and K fertilizer formulations to determine the most cost effective sources of these nutrients with regard to yield and fruit quality. Additions of P and K maintained adequate yield and fruit quality, but showed no significant difference among treatments, where historically aggressive nutrient management had been practiced. Fertilizer additions did result in a significant increase in yield and fruit quality where nutrient management programs were historically much less aggressive. There is no advantage of higher cost fertilizer formulations over standard low-cost sources (i.e.; Triple-16). Moreover, there is no significant advantage to splitting fertilizer application over time during the growing season. An analysis of government data indicates that, over the past 40 years, Utah has become a net importer of apples (1997), peaches (1987), and sweet cherries (2005), indicating increased local market opportunities. Increasing the fruit supply to the local market can best be accomplished by increasing yields and fruit quality on existing orchard acreage. Optimizing annual P and K nutrient management is an important key to maximizing yield and fruit quality. The results provide foundational guidelines of nutrient management for optimizing tart cherry production and fruit quality under regionally specific conditions.
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The quite revolution : an analysis of the change toward below-replacement-level fertility in Addis AbabaKinfu Ashagrea, Yohannes. January 2001 (has links)
No description available.
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Studies on the relationship between characteristics of ram semen and fertilityQuintana Casares, Pablo Ignacio. January 1991 (has links) (PDF)
Includes bibliographical references (leaves 274-316) Examines several aspects of male reproduction in the sheep, and how these are related to fertility in the female when semen is introduced by natural mating or artificial insemination.
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Genetical control of blood group substances in body secretionsBoettcher, Barry. January 1965 (has links) (PDF)
Typewritten ms. Includes bibliographical references
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The spatial distribution of Maori fertility in the North Island, 1955-1967.Kyle, G. D, n/a January 1974 (has links)
Summary:
In the past population geographers have tended to concentrate excessively on the task of mapping, discussing, and explaining the geographical distribution and pattern of change associated with demographical distribution and pattern of change associated with demographic problems and situations found in the developed world, namely Europe and the Americas. (Zelinsky: 1961). During the past decade, however, increasing attention has been given to the dynamics of population structure. This is particularly evident in the case of geographical mobility, and a considerable body of knowledge has already been accumulated on the spatial distribution of mortality.
Human fertility, too, has become a major focal point for research. Part of this interest has been stimulated by the world-wide problem of excessive and unevenly distributed population growth. This has been coupled with the realization that fertility is the paramount influence on population growth rates, both in situations of sharply declining mortality, as in the economically advanced nations, and already low death rates, as in much of the rest of the world. Indeed, it has been demonstrated that, in a closed population, it is only when substantial changes in fertility occur that major shifts in age-structure become evident.
Theory relating to population dynamics, especially fertility, has developed largely from studies of Western populations. According to Zelinsky there are as few as two identifiable demographic paradigms in current use. These are the so-called Laws of Migration (Ravenstein: 1883) and the Theory of Demographic Transition. This concept appears to have been introduced by Thompson (1929) and has since been restated in numerous forms. Perhaps the most elaborate is that presented by Cowgill: 1962-63)...
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The physiological significance of insemination in programming pregnancy outcomeBromfield, John James January 2006 (has links)
The cellular and molecular environment of the uterus during the pre - and peri - implantation period of early pregnancy is critical for implantation success and optimal fetal and placental development. Perturbations to this environment not only have consequences for the success of pregnancy and neonatal health and viability, but can also drive adverse health outcomes in the offspring after birth, particularly the development of metabolic disorders such as obesity, hypertension and insulin resistance. The influence of seminal plasma on the cytokine and immune uterine environment has been previously well characterised in mice, however the effects of disruption in uterine seminal plasma exposure for pregnancy outcome have not been investigated. The studies described in this thesis employed the use of surgical seminal vesicle ablation in males and embryo transfer experiments to investigate the physiological significance of uterine seminal plasma exposure on programming fetal and neonatal outcomes, and growth and metabolic status in adult offspring. We demonstrate that in the absence of seminal plasma, oocyte fertilisation and embryo implantation are reduced, showing that seminal plasma acts primarily to facilitate fertilisation, possibly by promoting sperm transport and survival in the reproductive tract. In addition we show that pregnancies initiated in the absence of seminal plasma give rise to offspring which display accelerated growth after birth and increased adiposity in adulthood, compared to those developed in a tract exposed to seminal plasma at the time of conception. Offspring conceived in the absence of seminal plasma also displayed alterations in serum leptin and adiponectin content, similar to those known to be associated with obesity in the mouse. Using embryo transfer experiments, we showed that some, but not all aspects of the perturbed postnatal development are recapitulated when embryos fertilised in the presence of what semen are transferred to a recipient tract which has not been exposed to seminal plasma. More severe perturbations were seen in 2 - cell transfer than in blastocyst transfer experiment. Additionally, there was a significant effect of the embryo transfer procedure, irrespective of seminal plasma exposure, on fetal and postnatal development that confounded interpretation of these experiments. In addition, we investigated the potential mechanisms by which the influence of seminal plasma is exerted. Mediators of pre - implantation embryo development, implantation and the modulation of the maternal immune response to pregnancy were all assessed for regulation by seminal plasma using QRT - PCR. It was demonstrated that seminal plasma exposure induces the up - regulation of key embryotrophic factors, LIF, GM - CSF and IL - 6, in the oviduct following insemination. Factors important in tissue remodelling required for implantation and angiogenesis, MMP - 2, MMP - 3 and VEGF - C, were also shown to be increased at the time of implantation after seminal plasma exposure. Additionally the generation of T - regulatory cells in uterine tissues, demonstrated by the up - regulation of the transcription factor FOXp3 was shown to be dependent on semen exposure. The influence of seminal plasma on embryonic development, implantation and modulation of the maternal immune response to pregnancy may therefore be mechanisms which contribute to the adverse outcomes seen in pregnancies initiated in the absence of seminal plasma. Together these experiments show a role for seminal plasma signalling at the time of insemination in influencing the pre - implantation embryo to program later fetal and neonatal development, thereby impacting on the metabolic health of offspring. We conclude that seminal plasma is not simply a transport medium for sperm, but acts also as a key regulator of a female tract environment providing optimal support for the developing embryo. / Thesis (Ph.D.)--School of Paediatrics and Reproductive Health, 2006.
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Bone morphogenetic proteins are involved in controlling mammalian fertilityYoung, Julia, n/a January 2008 (has links)
Transforming growth factor beta (TGFβ) superfamily members are involved in controlling mammalian fertility. The largest subset of the TGFβ superfamily are the bone morphogenetic proteins (BMP). BMP ligands signal through the type I and II BMP receptors and utilise the Smads1/5/8 phosphorylation cascade to control gene expression in the cell nucleus. Although BMPs act through the same pathway, they have the ability to activate unique sets of genes dependant on the identity of the ligand. In this study, HEK293T cells were challenged with BMP ligands for four hours and gene expression profiles were compared using microarray technology. The genes upregulated in the presence of BMP2, BMP4, BMP6 and BMP7 play roles in cellular proliferation and differentiation. These functions are critical stages in the successful development of an ovarian follicle whilst undergoing folliculogenesis. All of the BMP ligands investigated in this study were also observed to upregulate the expression of a small group of common genes indicating that a shared regulatory pattern occurs within the BMP pathway. Of these genes, Smad6 and Smad7, inhibitor of DNA binding proteins 1-4 (ID 1-4), and msh homeobox homolog 2 (MSX2) were previously known BMP target genes. However, none of the remaining genes upregulated by all BMPs were previously shown to be BMP targets.
The results from the microarray experiment were used as founding data for the in silico mining of novel genes not present on the array that may be differentially expressed in response to these ligands. The expression levels of several of the novel genes identified by in silico mining were then measured in vitro, however the results showed no differential expression in the HEK293T cells.
To apply the knowledge of the microarray studies to the tissue of interest, eight genes were selected for assessment in ovine granulosa cells. Four of the genes upregulated in response to BMP6 in HEK293T cells were also differentially expressed in primary ovine granulosa cell cultures in response to BMP6 addition.
The identification of several sheep breeds with mutations in TGFβ superfamily members has enabled investigations into the roles that specific TGFβ components play in controlling fertility. The highly fertile Booroola sheep has a substitution mutation in the type IB BMP receptor that results in an additive effect on ovulation rate. The Booroola mutation causes precocious maturation of ovarian follicles with fewer granulosa cells surrounding an enlarged oocyte, and carriers of the mutation have higher levels of circulating follicle stimulating hormone (FSH). BMPs have previously been shown to influence the regulation of FSH synthesis and secretion in the pituitary gland. In this study, primary pituitary cells were harvested and cultured from homozygous Booroola ewes and from wildtype ewes to determine if the mutation caused alterations in FSH secretion in vitro. The cells were collected 24 h following induction of luteolysis and cultured for 72 h prior to being challenged for 24 h with bone morphogenetic proteins (BMP2, BMP4, BMP6), growth and differentiation factor-9 (GDF9), transforming growth factor β1 (TGFβ1), activin-A and gonadotropin releasing hormone (GnRH). The levels of FSH and luteinising hormone (LH) were measured by radioimmunoassay and compared to the untreated controls. Primary pituitary cell cultures from Booroola ewes secreted less FSH than wildtype cells in the presence of BMP2, BMP4 and BMP6. These BMPs did not affect the FSH stores within the cells, or the levels of LH released. GDF9 appeared to act in a BMP-like manner by suppressing FSH secretion. The BMPRIB receptor however, was not found to co-localise with gonadotroph cells in either Booroola or wildtype pituitary tissues. These findings imply that the increased sensitivity of Booroola cells to BMP2, BMP4, BMP6, and GDF9 cannot be due to the direct action of the BMPRIB mutant Booroola receptor in the cells that synthesize FSH. The alternative type I BMP receptor to BMPRIB that can act in BMP signal transduction is BMPRIA. This receptor was also not found in gonadotroph cells of wildtype orBooroola ewes This is in contrast to findings in other flocks which have been shown to express BMPRIA in gonadotroph cells.
This study has identified unique sets of differentially regulated genes in response to BMP-2, 4, 6, and 7 as well as TGFβ1 in a human HEK293T cell culture system. Among the differentially expressed genes, a common set of 12 genes were upregulated by all BMP ligands. None of these genes were present in the TGFβ1 set. Selected genes were validated in ovine primary granulosa cell cultures, showing that the human cell culture system functions similarly to cells of biologial relevance in fertility. Within the pituitary gland, BMPs are shown to influence FSH secretion. The presence of the Booroola mutation enhances the BMP effects on gonadotroph cells, however the lack of BMPRIB on gonadotroph cells indicates that the effects are indirect.
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Studies on the relationship between characteristics of ram semen and fertility / by Pablo Ignacio Quintana Casares.Quintana Casares, Pablo Ignacio January 1991 (has links)
Includes bibliographical references (leaves 274-316) / xxii, 333 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines several aspects of male reproduction in the sheep, and how these are related to fertility in the female when semen is introduced by natural mating or artificial insemination. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1991
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Social background, social mobility,and becoming a parent in SwedenCarlsson Dahlberg, Johan January 2010 (has links)
<p>The purpose of this study is to examine what effect social background may have on the timing of becoming a parent in Sweden. By applying event-history techniques to data from the Swedish level of living survey (LNU) we try to separate the direct from the indirect effect of social background on timing of first childbearing. Few previous studies have focused on characteristics of social background and analysis of intergenerational effects on the age of becoming a parent. In this study, we show that the risk of becoming a parent is different for those who are mobile than for the socially non-mobile. The effect of social background on the propensity of becoming a parent is not just indirect via persons own educational careers. When we control for own educational level much of the impact of social background on the propensity of becoming a parent remains. We clearly show the existence of a significant direct effect of social background on the propensity to become a parent.</p>
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