• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 46
  • 44
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 111
  • 111
  • 46
  • 43
  • 31
  • 18
  • 16
  • 15
  • 13
  • 12
  • 12
  • 10
  • 10
  • 10
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The influence of sex chromosomes on the outcome of human embryo development /

Raja, Kimenthra. January 2005 (has links)
Thesis (MMedSc)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.
22

Estrogen receptor-[alpha] and -[beta] regulation of the testes, ovaries, and male and female mesonephric-derived efferent ductules

Rosenfeld, Cheryl Susan, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 137-162). Also available on the Internet.
23

Determining parental obligations to unborn children using a social contract theory

Sepinwall, Amy J. January 1999 (has links)
I use a brand of social contract theory derived from David Gauthier to delimit precisely what might be permissible in the methods of conception and gestation of a child. More specifically, Gauthier posits a rule that is supposed to govern behavior among individuals prior to but in anticipation of the rise of social interaction. I argue that this rule can be appropriately applied to the interactions between a parent and her unborn child. I review other social contract models in an effort to show that Gauthier's is preferable to these. I also address other accounts concerned with parental obligations to the unborn, to see how these fare against Gauthier's. I conclude that, because of its breadth of applicability, as well as its plausibility, Gauthier's model is a powerful force for guiding us through these issues.
24

Long-term romantic partner choice and sexual strategies in human evolution studies conducted in the United States and Ecuador /

Pillsworth, Elizabeth Grace, January 2008 (has links)
Thesis (Ph. D)--UCLA, 2008. / Vita. Includes bibliographical references.
25

Determining parental obligations to unborn children using a social contract theory

Sepinwall, Amy J. January 1999 (has links)
No description available.
26

Mothers of the nation the effect of nationalist ideology on women's reproductive rights in Ireland and Iran /

O'Mahoney, Sarah. January 1900 (has links)
Thesis (LL.M.). / Written for the Faculty of Law. Title from title page of PDF (viewed 2009/06/17). Includes bibliographical references.
27

Caracterização genômica de homens inférteis com falência espermatogênica primária / Genomic characterization of infertile men with primary spermatogenic failure

Lima, Maria Victoria Cortez de Oliveira 08 February 2019 (has links)
A infertilidade é uma doença do sistema reprodutivo considerada um problema de saúde pública global, afetando aproximadamente 15% dos casais e 7% dos homens. Falência espermatogênica primária é definida como incapacidade dos testículos produzirem espermatozoides, apesar do suporte hormonal adequado. Esse estudo é o primeiro a comparar dois grupos de pacientes com falência espermatogênica primária por meio da técnica array-CGH+SNP, utilizando a plataforma 4X180 (Agilent®). Adicionalmente, foram comparados os resultados obtidos por essa técnica com bancos de dados genômicos de expressão. Foram analisados vinte e três pacientes com falência espermatogênica primária, sendo sete com oligozoospermia extrema e dezesseis com azoospermia não obstrutiva, assim como seis homens comprovadamente férteis (grupo controle). A análise genômica foi realizada pelo software Nexus 8.0 e as análises de bancos de dados genômicos de expressão por meio do software Nexus Expression 3.0 com nível de significância de 5%. Os primeiros resultados evidenciaram diferenças de número e de tamanho das alterações genômicas (CNVs e LOHs) entre os dois grupos da amostra e o grupo controle, sendo a diferença do número de CNVs de perdas do grupo com oligozoospermia significativamente maior do que no grupo controle. O grupo de pacientes com azoospermia apresentou alterações genômicas de maior tamanho, entre 552pb a 11.3MB, quando comparado aos homens oligozoospérmicos e ao grupo controle. A análise descritiva permitiu identificação de um gene candidato a fenótipo de falência espermatogênica primária na região 12q21.1-q21.2, o gene GLIPR1L1. Por meio da análise individualizada, identificamos dois genes candidatos ao fenótipo de infertilidade, o SHH, localizado na região 7q21.3, e o TMEM184A, localizado na região 7p22.3. Foram também descritas oito novas regiões de CNVs e LOHs nos dois grupos da amostra, direcionando novos estudos para correlação entre genótipo e fenótipo. / Infertility is a disease of the reproductive system and a global public health problem affecting approximately 15% of couples and 7% of men. Primary spermatogenic failure is defined as the inability of the testes to produce sperm although there is adequate hormonal support. This study is the first to compare two groups of patients with primary spermatogenic failure using array-CGH + SNP technique with the 4X180 (Agilent®) platform. Also, we compared the results obtained by this technique with genomic expression databases. Twenty-three patients with primary spermatogenic failure were analyzed, seven with extreme oligozoospermia and sixteen with nonobstructive azoospermia. We used six proven fertile men as a control group. Genomic analysis was performed by Nexus 8.0 software and analysis of genomic databases of expression was performed using the Nexus Expression 3.0 software with 5% significance level. Initial results showed differences in both the number and size of genomic alterations (CNVs and LOHs) between the two sampled infertility groups and the control group. The main difference was that the number of overall CNVs losses which was significantly higher in the oligozoospermia group than in the control group. The group of patients with azoospermia showed larger genomic alterations, between 552bp and 11.3MB size, compared to oligozoospermic men and the control group. A descriptive analysis was used to identify a candidate gene, GLIPR1L1, for the primary spermatogenic failure phenotype in the region 12q21.1-q21.2. Through individualized analysis, we identified two other candidate genes that may have a relationship with the infertility phenotype, SHH, located in the 7q21.3 region, and TMEM184A, located on the 7p22.3 region. Eight new areas of CNV and LOHs have also been described in the two sample groups, for more extensive genotype and phenotype correlative studies.
28

Análise do imprinting e da expressão dos genes H19 e IGF2 em células de Sertoli humanas apos exposição in vitro ao 2,3,7,8-Tetraclorodibenzo-p-dioxina (TCDD) /

Ribeiro, Mariana Antunes. January 2013 (has links)
Orientador: Wellerson Rodrigo Scarano / Banca: Flávia Karina Delella / Banca: Glaura Scantamburlo / Resumo: A infertilidade acomete 10-15% dos casais em idade reprodutiva e o fator masculino pode ser responsável por 30-50% dos casos. A fertilidade masculina e o processo de espermatogênese estão diretamente relacionados à capacidade das células de Sertoli em produzir fatores determinantes para o desenvolvimento das células germinativas. Apenas as célulasde Sertolipossuem receptores paratestosteronaeFSHe, portanto, estascélulassão as principais reguladoras da espermatogênese. Estudos sugerem que 60-70% dos casos de infertilidade masculina são considerados idiopáticos, uma vez que os mecanismos moleculares envolvidos na espermatogênese ainda são desconhecidos. Estudos recentes relatam que homens oligozoospérmicos apresentam mudança no padrão de metilação do DNA nos espermatozoides,nas regiões que controlam a expressão dos genes regulados por imprintingH19 e IGF-2. Um dos grandes responsáveis para a alteração do padrão de metilação desses genes são os fatores ambientais, especialmente compostos orgânicos de alta toxicidade, como o 2,3,7,8- Tetraclorodibenzo-p-dioxina (TCDD). Modelos experimentais de exposição (camundongos) demonstraram que o TCDD ocasiona baixa contagem espermática e atraso na puberdade. O presente estudo correlacionou a ação do composto TCDD sobre as células de Sertoli humanas (in vitro) e sua ação na região controladoras de imprinting (ICR1) dos genes H19 e IGF-2. Inicialmente foi realizada a caracterização da amostra em estudo e foi constatado que esse tipo celular apresentrameilação entre 0 a 25% e é homozigota para os sítios polimórficos dos SNPsrs2839704 e rs10732516. Após 48 de exposição ao TCDD obervou-se tendência de aumento da metilação global do DNA da linhagem HSeC e discreto aumento da metilação dos sítios 4 e 7 de ligação do fator CTCF. A análise da expressão dos genes H19 e IGF2 deve ser finalizada... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Infertility affects 10-15% of couples on reproductive age and male factor may be responsible for 30-50% of cases. Male fertility and the spermatogenesis process are directly related to the ability of Sertoli cells to produce factors for germ cells development. Only Sertoli cells have receptors for testosterone and FSH, and therefore, these cells are the main regulators of spermatogenesis. Studies suggest that 60-70% of male infertility cases are considered idiophatic, once molecular mechanisms involved in spermatogenesis are still unknown. Recent studies report that oligozoospermic men showed an alteration of the DNA methylation pattern in the sperm, specifically in regions that control gene expression of genes regulated by imprinting: H19 and IGF2. Largely responsible for changing the methylation pattern of these genes are environmental factors, specialy organic compounds with high toxicity, such as 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD). Experimental models of exposure (mice) showed that TCDD causes low sperm count and delayed puberty. This study correlated the action of the compound TCDD on human Sertoli cells (in vitro) and its action on imprinted control region region (ICR1) of H19 and IGF-2 genes. It was initially performed the sample characterization and it was found that this cell type shows methylation between 0-25% and it is homozygous for the polymorphic sites of SNPs rs2839704 and rs10732516. After 48h of exposure to TCDD we observed a trend to increase global DNA methylation in HSEc lineage and also a slight increase in methylation status in the CTCF binding sites 4 and 7. Analysis of H19 and IGF2 expression must be completed to the best correlation between changes in the DNA methylation pattern and expression of these genes. Despite the important results obtained in this work, it is necessary to deepen the studies involving toxic agents such as TCDD and changes... (Complete abstract click electronic access below) / Mestre
29

Factors influencing Grade 7 teachers' implementation of outcomes-based approaches in the national curriculum when teaching 'human reproduction'

Doidge, Megan Caroline 01 September 2014 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2014. / Outcomes-based education was introduced into South Africa almost 20 years ago amidst much controversy. During the period of my study, a modified version of the outcomes-based curriculum was in use, i.e. the Revised National Curriculum Statement Grades R-9. In this curriculum, critical and learning outcomes were described and a learner-centred approach advocated which would enable learners to achieve the outcomes. Human reproduction was introduced as one of the content areas in the senior phase of the Natural Sciences. Human reproduction is a sensitive but very relevant topic in South Africa where HIV/AIDS, teenage pregnancy and child abuse are prevalent and so was selected as a Grade 7 topic in one educational district of Gauteng. In my study, I was interested in finding out what factors influenced Grade 7 teachers' implementation of outcomes-based approaches when teaching Human Reproduction. I explored the use of learner-centred approaches and the extent to which the critical and Natural Sciences learning outcomes could be achieved through these approaches. Firstly I wanted to know to what extent Grade 7 teachers used outcomes-based and learner-centred approaches when teaching human reproduction. Secondly I was interested in the factors that influenced the teaching of human reproduction. Thirdly I set out to find which factors affected the use of outcomes-based and learner-centred approaches during the teaching of human reproduction. Lastly the influence of teachers' behavioural, normative and control beliefs on their teaching of human reproduction in outcomes-based and learner-centred ways were of interest. My theoretical framework took into account the above-mentioned factors and beliefs about the influence of these factors and their possible impact on teaching human reproduction in outcomes-based and learner-centred ways. My research involved a workshop for Natural Sciences teachers on the teaching of human reproduction to Grade 7's, followed by a survey. Forty teachers completed the survey questionnaire in which they recorded their perceptions of the expected influence of the learners, the learning environment and support structures, as well as teachers' beliefs, on the teaching of human reproduction. Ten of these teachers participated as the case studies in my multiple case study, forming a convenience sample. I used a mixed methods approach in my investigation, starting with the survey questionnaire and then narrowing my focus to the ten case study teachers and becoming a participant observer in their classes. I recorded my data in field notes and as digital recordings of class discussions and when teachers had completed teaching human reproduction, I interviewed them. The data from the questionnaires, interview and lesson transcripts and field notes were analysed and conclusions drawn. I used profiles to assess the achievement of the critical and learning outcomes by each teacher and to assess the extent to which each teacher used learner-centred approaches when teaching human reproduction. A cross case analysis enabled me to compare the teachers with regard to each outcome and learner-centred feature. Some quantitative data from my surveys and mostly qualitative data from my observations and interviews were used to explore the influence of factors internal to the teacher, i.e. personal and professional factors, and those external to the teacher such as the learners, the iii learning environment and support structures. I also used the qualitative data to identify the influence of behavioural, normative and control beliefs about teaching human reproduction in outcomes-based ways on practice. My findings were that all teachers taught towards some outcomes and used some learner-centred approaches and these differed amongst teachers. The profiles enabled me to identify overall strengths of each teacher as an outcomes-based and learner-centred teacher, and the cross-case analysis indicated which outcomes were being met by learners through the teaching and learning approaches used. I found that the learning environment, and in particular the provision of or lack of learning support materials and other resources, impacted on the achievement of the outcomes. The school principals, colleagues, parents and friends proved to be mostly very supportive of the teaching of human reproduction and the need for strong communities of practice became evident. The choice of language was seen as a dilemma but my findings pointed to the use of home language or preferably code-switching to promote conceptual development and the development of English language skills. Cultural beliefs of learners contributed to their prior knowledge, and religious beliefs influenced some teachers who promoted more conservative values amongst their learners regarding sexuality. The need for clear boundaries on what could be discussed in class became evident, to protect both the teacher and learner from intrusion into their personal lives. Group work was seen as an important approach for this sensitive topic, and the need for workshops to strengthen teacher's subject content knowledge and thus their self efficacy when teaching human reproduction and to build strong communities of practice in which ideas and experiences could be shared amongst teachers, was a finding of this study. In conclusion, some teachers were more outcomes-based and learner-centred than others. Subject content knowledge, choice of an appropriate language or language mix for teaching and learning, suitable learning environments with adequate learning support materials, school, district and parental support for the teaching of human reproduction all promoted a teachers sense of self-efficacy and made a difference to their teaching of human reproduction using outcomes-based approaches.
30

The impact of lifestyle factors on the clinical outcomes of in vitro fertilisation-embryo transfer (IVF) treatment

Joesbury, Karen Ann January 2003 (has links)
Objectives: To determine the effect of female and male cigarette smoking, caffeine and alcohol consumption, stress and indicators of dietary status on the clinical outcomes of NF treatment. Design: Prospective cohort study. Setting: PIVET Medical Centre, Perth, Western Australia. Patients: Of 351 couples who commenced IVF treatment at PIVET Medical Centre between January 1997 and August 1998, 281 females and 247 males participated in this study, generating participation rates of 80.1% and 70.4%, respectively. Main Outcome Measures: Multivariate methods of data analyses were used to control for patient and treatment variables in the examination of the effect of lifestyle factors on the following clinical outcomes: 1) number of oocytes retrieved by transvaginal oocyte aspiration (oocyte production), 2) fertilisation, measured as the number of oocytes fertilised weighted by the number of oocytes inseminated, 3) B-hCG pregnancy, 16 days post-embryo transfer, and 4) <12 week pregnancy loss following confirmation of B-hCG pregnancy. As a measure of ovarian reserve, serum basal FSH levels were also investigated as a dependent variable. Lifestyle factors included years of cigarette smoking (smoke years), tobacco, alcohol, caffeine and fruit and vegetable consumption, and stress from daily living and NF treatment. Results: Daily stress, tobacco consumption and smoke years were the female lifestyle factors shown to have a significant effect on NF treatment. Oocyte production decreased with increasing levels of daily stress (P=0.039). However, female patients with high daily stress levels experienced higher than average rates of fertilisation in vitro (P=0.0059) and pregnancy (P--0.0207). Smoke years had an adverse effect on ovarian reserve (P=0.035), which in turn, compromised oocyte production. / Female smoke years was negatively associated with rates of fertilisation (P<0.0001), and this effect was exacerbated by cigarette smoking at the time of treatment (P=0.0187). Of the male lifestyle factors, caffeine, alcohol and fruit and vegetable consumption and IVF stress affected fertilisation in vitro. Fertilisation increased with alcohol consumption (P<0.0001), and with fruit and vegetable consumption (P<0.0001). A significant interaction term between these two factors (P=0.0144) implied a threshold of benefit from the combined effect of the consumption of alcohol and fruit and vegetables. Caffeine consumption negated the beneficial effect of alcohol consumption, as shown by a significant interaction term between alcohol consumption and caffeine consumption (P=0.0007). Male stress from NF treatment had an adverse effect on rates of fertilisation in vitro (P<0.0001). Cigarette smoking by the male partner increased the likelihood of the female partner experiencing a <12 week pregnancy loss (P=0.0084). Conclusions: In meeting with its principal objective, this study has demonstrated that specific lifestyle factors impact on the clinical outcomes of IVF treatment. It confirms the findings from former studies, namely the adverse effect of female smoking on ovarian reserve, and daily stress on ovulation. Moreover, this study has identified numerous new and unexpected relationships. Of note, the positive effect of male alcohol consumption on fertilisation in vitro and the elevated risk of early pregnancy loss associated with male smoking. This study has paved the way for future research into the identification of specific mechanisms of effect, including those suggested.

Page generated in 0.0676 seconds