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Fertility preferences of wives and husbands in Hong Kong : spousal agreement and women's statusYu, Kam Lun 01 January 2002 (has links)
No description available.
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Avaliação do estado nutricional e da fertilidade do solo na cultura do plátano (Musa AAB subgrupo Plátano cv. Hárton). / Evaluation of the nutritional status and of the soil fertility for the plantain crop (Musa AAB subgroup plantain cv. Hárton).Vianel de Jesus Rodriguez Perez 26 June 2003 (has links)
Este trabalho teve o objetivo de propor uma metodologia adequada ao diagnostico nutricional e à avaliação da fertilidade do solo, dentro do contexto do balanço nutricional da cultura do plátano (Musa AAB subgrupo plátano cv. Hárton) no Sul do Lago do Maracaibo, Venezuela. O procedimento inicial foi, estratificar a área de amostragem por series semelhantes de solos da região. Desta maneira, selecionaram-se quatro lavouras com um histórico de melhor rendimento, na serie de solos de texturas francas. Em seguida fez-se a amostragem completamente ao acaso, entre os meses de julho a dezembro dos anos 2000 e 2001. O tamanho da amostra tirada por lavoura, foi de 30 unidades experimentais. Entretanto, por segurança acrescentaram-se cerca de 25%, dadas as possibilidades de perdas por rajadas de vento e chuva e outros infortúnios. A unidade experimental foi formada pela planta "mãe" e seu broto lateral "filho" em pleno desenvolvimento. Em cada unidade coletou-se a amostra foliar, na planta "mãe" de acordo a norma estabelecida pelo Método de Amostragem Internacional de Referencia (MEIR). Concomitantemente, tomou-se a amostra de solo, na faixa de adubação, em frente do "filho" em duas profundidades 0 20 cm e 21 40 cm. As amostras de folhas foram analisadas para N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn. Nas amostras de solo se determinou-se pH, condutividade elétrica, matéria orgânica, areia, silte, argila, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. Os dados foram avaliados por analises de regressão com as combinações lineares dos componentes principais, regressão múltipla e obtenção da media aritmética das plantas com maior rendimento. Os resultados demonstraram que o modelo de regressão das combinações lineares com o rendimento deu uma melhor avaliação e predição do rendimento do plátano Hárton, dentro do contexto do balanço nutricional. Com esse modelo, posteriormente estimou-se o rendimento e se separou a população em classes desde o menor até o maior rendimento. Observaram-se nos dados dos analises de solos e folhas, incrementos, decréscimos ou ausência da variação nas concentrações de nutrientes em relação com o rendimento. Isto permitiu realizar interpretações simultâneas das análises de solos e folhas sem a necessidade de valores de referência. Por conseguinte vê-se que o modelo de regressão do rendimento com as combinações lineares vai além do uso de valores de referência isolados, pois permitiu determinar e utilizar o balanço nutricional entre todas as variáveis estudadas. Os resultados assim obtidos, permitem que a metodologia utilizada, seja indicada como una proposta de interpretação dos resultados de análises de solos e folhas. / The aim of this work is to suggest an adequate methodology for the evaluation of the nutritional status and of the fertility of soil for plantain grown in the South of Lake Maracaibo, Venezuela. Initially the area to sample was split into similar soil series. Four high yielding plantations were selected within a soil series of intermediate texture. Afterwards a random sampling was carried out from July to December 2000 and 2001. The sample per plantation had 30 experimental units, plus 25 % for safety reasons, since losses could occur due to weather conditions and other adverse factors. The experimental unit consisted of the "mother" plant and its fully developed "daughter". In each unit leaf sampling was done according to the "Method of International Sampling for Reference"(MEIR). Soil Samples were colleted in front of he daughter in the fertilization band at the depths of 0-20 and 21-40 cm. Leaf samples were analysed for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo and Zn. pH, conductivity, organic matter, sand, silt, clay, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn were determined in the soil samples. Data were evaluated by regression analysis with the lineal combinations of the main components, and by multiple regression. Results have shown that the regression model of the lineal combination with yield gave a better evaluation and prediction of the plantain crop, within the context of nutritional balance. This, on its turn allowed for the assessment of yield and for the separation of the population in yield classes. It was possible to observe both in the soils and leaves concentrations of nutrients related and not related to yield. It was possible, therefore, to conduct simultaneous interpretation of soil and leaf analyses obviating the need for reference values. The model of regression of yield against lineal combinations goes farther the than the isolated reference values since it allowed for the determination and utilization of nutritional balance among all variables. This methodology could be proposed for the interpretation of the results of soil and plant analyses.
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O estudo da função sexual e gonadal nas adolescentes com epilepsia / Evaluation of sexual and gonadal function in female adolescents with epilepsySílvia de Vincentiis 14 March 2008 (has links)
Em mulheres com epilepsia, sabe-se que a síndrome epiléptica, a freqüência de crises e as drogas antiepilépticas podem ter influência na função sexual, comportamento sexual e na capacidade reprodutora. Muitos fatores têm sido relacionados a estas alterações, tais como: duração e gravidade da epilepsia, tipo de droga antiepiléptica e localização da lesão epileptogênica. Baseado no conhecimento adquirido com as mulheres assume-se que as adolescentes sofram influência semelhante. Este estudo teve como objetivo avaliar aspectos relacionados à função e ao comportamento sexual, à educação sexual e à função gonadal em adolescentes do sexo feminino com epilepsia. Para isso, foram estudadas prospectivamente 35 pacientes do sexo feminino, com epilepsia parcial e generalizada, com idades entre 10 a 20 anos, com epilepsia ativa, sendo o diagnóstico da síndrome epiléptica realizado segundo os critérios da Liga Internacional Contra a Epilepsia (1989). Os critérios de exclusão foram: ausência de menarca; uso de contraceptivo hormonal ou dispositivo intra-uterino, no momento da avaliação ou nos últimos três meses; antecedente de cirurgia ginecológica ou distúrbio endocrinológico; presença de doença crônica associada, ou deficiência mental moderada a grave que impossibilitassem o seguimento do protocolo a ser instituído. As informações sobre a função sexual, comportamento sexual e a educação sexual das adolescentes com epilepsia foram avaliadas através de um questionário padrão. O protocolo de estudo da função gonadal incluiu a análise dos seguintes critérios: ciclo menstrual regular, presença de dismenorréia, dosagem dos níveis hormonais (FSH, LH, estradiol, progesterona, prolactina, testosterona, T3, T4 livre, TSH), ultra-sonografia pélvica, gestação em curso ou recente. A função gonadal foi considerada normal se pelo menos um ou mais parâmetros acima foi adequado. Não foi observada diferença entre a idade da primeira relação sexual (p=0,54), atividade sexual (p=0,23), libido (p=1,00) e orgasmo (p=0,23) entre as adolescentes com epilepsia, em relação ao grupo controle. Todas as adolescentes sexualmente ativas relataram o uso de métodos contraceptivos, porém apenas 20,1% com orientação de algum profissional de saúde. A idade da menarca nos dois grupos foi similar. No entanto, o uso de valproato próximo à menarca e crises freqüentes foram fatores antecipadores da menarca. As adolescentes com epilepsia apresentaram uma freqüência de ciclos menstruais irregulares superior à do grupo controle. A irregularidade menstrual relacionou-se com a presença de crises tônico-clônicas generalizadas (p=0,02), sem relação com a síndrome epiléptica. Houve uma tendência a irregularidades menstruais em adolescentes que apresentavam duração da doença mais prolongada (p=0,06), independente da freqüência de crises epilépticas. Observaram-se índices de gravidez superiores entre as adolescentes com epilepsia em comparação às controles (p<.0001). Não houve diferença na freqüência de aborto entre as adolescentes com epilepsia. Neste estudo, as adolescentes com epilepsia apresentaram comportamento e função sexual similares às adolescentes sem doenças crônicas. Embora a função gonadal destas pacientes estivesse preservada, os distúrbios menstruais foram significantes, sugerindo que estas adolescentes possam estar em um processo em evolução com ciclos anovulatórios e disfunção reprodutora na vida adulta. Portanto, os aspectos relacionados à função e comportamento sexual, contracepção e função gonadal, em adolescentes com epilepsia, requerem atenção especial por parte dos profissionais de saúde. / It is known that in women with epilepsy, the epileptic syndrome, seizure frequency and antiepileptic drugs may act on sexual function, sexual behavior and reproductive function. Several factors have been associated with these changes such as: duration and severity of the epilepsy, kind of antiepileptic drug and locality of the epileptogenic lesion. Based on knowledge acquired with studies in women, it is assumed that female adolescents suffer similar influences. This study aimed to evaluate several aspects related to sexual function, to sexual behavior, to sexual education and to gonadal function in female adolescents with epilepsy. We prospectively studied 35 females, with ages between 10 and 20 years, with active partial and generalized epilepsies and epileptic syndromes classified according to ILAE criteria (1989). Criteria of exclusion were: patients that had not yet had their menarche, those in use of hormonal contraceptives or intrauterine devices, either at the moment of the evaluation or in the last three months; patients with previous gynecological surgery or endocrine disorders; patients with associated chronic disease or moderate to severe mental deficiency that might hinder completion of the study protocol. Information on sexual function and education were obtained with a standard questionnaire. Our study protocol for gonadal function included analysis of the following criteria: regular menstrual cycles, dysmenorrhea, hormonal levels (FSH, LH, stradiol, progesterone, prolactin, testosterone, T3, free T4, TSH), pelvic ultrasound study, and recent or ongoing pregnancy. Gonadal function was considered normal when at least one of the above parameters was found to be adequate. No significant differences were observed between age at first sexual intercourse (p=0.54), sexual activity (p=0.23), libido (p=1,00) and orgasm (p=0.23) among patients with epilepsy, when compared to controls. Sexually active adolescents reported the use of contraceptives, although only 20.1% with orientation done by a health professional. Age of menarche was similar in both groups, but the use of valproate close to menarche and frequent seizures were factors that anticipated this event. Moreover, adolescents with epilepsy presented irregular menstrual cycles more frequently than controls. Menstrual irregularity was correlated to the presence of tonic-clonic generalized seizures (p=0.02), regardless the epilepsy type or syndrome, and with longer disease duration (p=0.06), despite of seizure frequency. Higher rates of pregnancy were observed in adolescents with epilepsy compared to controls (p<.0001). Abortion rates were similar in both groups. In this study, adolescents with epilepsy presented sexual function and behavior similar to their peers without chronic diseases. Although the gonadal function of these patients was spared, menstrual disorders were significant, suggesting that these adolescents may be in an ongoing process with anovulatory cycles and reproductive dysfunction in later adulthood. Therefore, aspects related to sexual behavior and function, contraception and gonadal function in adolescents with epilepsy require special attention by health professionals.
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Caracterização das subpopulações e atributos espermáticos como método preditivo de desempenho na produção in vitro de embriões em bovinos / Characterization of subpopulations and spermatic features as a predictive method of performance in the in vitro production of embryos in cattleBicudo, Luana de Cássia 24 August 2018 (has links)
A predição do desempenho de touros na produção in vitro de embriões (PIVE), pela avaliação seminal, não está plenamente estabelecida. Com este estudo, objetivou-se caracterizar as diferenças nos atributos espermáticos de touros com baixo e alto desempenho, baseado nas taxas de clivagem e de blastocisto, visando estabelecer métodos preditivos de maior eficiência na PIVE. A partir do histórico de três anos da empresa In Vitro Brasil®, foram selecionados touros que haviam resultado nas menores e maiores taxas de clivagem e de blastocisto, estabelecendo-se 4 grupos experimentais: baixa taxa de clivagem (BC, n=5), alta taxa de clivagem (AC, n=5), baixa taxa de blastocisto (BB, n=5) e alta taxa de blastocisto (AB, n=5). Foram adquiridas palhetas de sêmen congelado dos touros de cada grupo, nas quais foram avaliados, antes (Pré-Percoll®) e após centrifugação em gradiente de Percoll® (Pós-Percoll®), os atributos espermáticos: cinética, em sistema CASA; integridade de membranas plasmática e acrossomal (FITC-PSA/PI), potencial de membrana mitocondrial (JC-1), status oxidativo (DHE, CellROXTM green/PI, MitoSox red), apoptose (FITC-FMK-VAD/PI) e DNA (SCSA), por citometria de fluxo; morfologia; atividade mitocondrial (DAB); capacitação (CTC); teste funcional e TBARS induzido. Diferenças entre grupos (BC vs. AC e BB vs. AB) foram estimadas pelo teste t. Para todas as análises estatísticas foi considerado nível de significância de 5%. Na ausência de interações significativas, o efeito dos grupos foi analisado ao fundir os momentos Pré e Pós-Percoll®. Os grupos AC e AB apresentaram valores superiores de VAP, VCL, ALH e DNC e valores inferiores de BCF, STR, LIN e WOB, cinética indicativa de hiperativação. Adicionalmente, estes grupos apresentaram indícios de menor ocorrência de estresse oxidativo, evidenciados pelo percentual de espermatozoides com membrana lesada e estresse oxidativo (CellROXTM green/PI) no grupo AC e nível de DHE no grupo AB. Para os demais atributos estudados, não se obteve diferença entre os grupos. Por meio de análise de regressão logística multivariada, constatou-se que a taxa de clivagem sofre efeito de: VCL, BCF e percentual de espermatozoides com integridade de membrana e sem estresse oxidativo; já a taxa de blastocisto, sofre efeito de: defeitos menores, VSL, DABIII e DHE, os quais foram inclusos nos respectivos modelos preditivos. As taxas obtidas com o modelo preditivo foram comparadas às taxas reais por análise de correlação de Pearson, que resultaram em intensidade moderada tanto para clivagem (r=0,56) quanto para blastocisto (r=0,44). Subpopulações espermáticas com diferentes perfis de cinética em CASA, foram determinadas em três etapas estatísticas segundo Núñez-Martínez et al. (2006). Foram detectadas 4 subpopulações: 1-Rápidos e progressivos; 2- Hiperativados; 3- Lentos e sinuosos; 4- Lentos e progressivos. Touros com alto desempenho (AC e AB) apresentaram maior percentual de subpopulação 2, Pré-Percoll®, e das subpopulações 1 e 2, Pós-Percoll®. Com isto, demonstra-se ser possível diferenciar touros de baixo e alto desempenho na PIVE, pela avaliação dos atributos espermáticos, com o estabelecimento de modelos preditivos para as taxas de clivagem e de blastocisto. Ademais, o estudo das subpopulações espermáticas constitui-se no método mais efetivo para a predição do desempenho in vitro. / The prediction of bull performance on the in vitro production (IVP) of bovine embryos, by the seminal evaluation, is not fully established. Thus, the aim of this study was to characterize the differences in the sperm features of bulls with low and high performance, based on cleavage and blastocyst rates, in order to establish predictive methods for a greater efficiency in the IVP. Based on the results obtained in three years from the company In Vitro Brasil®, bulls were selected by the lowest and highest cleavage and blastocyst rates, establishing 4 experimental groups: low cleavage rate (BC, n=5), high cleavage rate (AC, n=5), low blastocyst rate (BB, n=5) and high blastocyst rate (AB, n=5). Frozen semen were obtained from the bulls of each group, in which were evaluated, before (Pre-Percoll®) and after Percoll® gradient centrifugation (Post-Percoll®), the sperm features: kinetics, in CASA; integrity of plasma and acrosomal membranes (FITC-PSA/PI), mitochondrial membrane potential (JC-1), oxidative status (DHE, CellROXTM green/PI, MitoSox red), apoptosis (FITC-FMK-VAD/PI) and DNA (SCSA), by flow cytometry; morphology; mitochondrial activity (DAB); capacitation (CTC); functional test and induced TBARS. Differences between groups (BC vs. AC and BB vs. AB) were estimated by t test. A significance level of 5% was considered for all statistical analysis. In the absence of significant interactions, the effect of the groups was analyzed by merging the moments Pre and Post-Percoll®. The AC and AB groups presented higher values of VAP, VCL, ALH and DNC and lower values of BCF, STR, LIN and WOB, kinetics indicative of hyperactivation. In addition, these groups showed less evidence of oxidative stress, observed by the percentage of spermatozoa with damaged membrane and oxidative stress (CellROXTM green/PI) in the AC group and level of DHE in the AB group. For the others sperm features, there was no difference between groups. By multivariate logistic regression analysis, it was verified that the cleavage rate is affected by: VSL, BCF and percentage of spermatozoa with membrane integrity and without oxidative stress; and the blastocyst rate, is affected by: minor defects, VSL, DABIII and DHE, which were included in the respective predictive models. The rates obtained with the predictive model were compared to the real rates by Pearson correlation analysis, which resulted in moderate intensity for both cleavage (r=0.56) and blastocyst (r=0.44). Spermatic subpopulations with different kinetic profiles at CASA were determined in three statistical steps according to Núñez-Martínez et al. (2006). Four subpopulations were detected: 1-Fast and progressive; 2- Hyperactivated; 3- Slow and sinuous; 4- Slow and progressive. Bulls with high performance (AC and AB) presented higher percentage of subpopulation 2, Pre-Percoll®, and subpopulations 1 and 2, Post-Percoll®. In summary, it is possible to differentiate low and high-performance bulls at IVP by evaluating the sperm features, with the establishment of predictive models for the cleavage and blastocyst rates. Furthermore, the study of sperm subpopulations is the most effective method for predicting in vitro performance.
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Factors predisposing never-married women to have children in NamibiaNyathi, Cassandre Simphiwe 28 January 2016 (has links)
A RESEARCH REPORT SUBMITTED TO THE FACULTY OF HUMANITIES, SCHOOL OF SOCIAL SCIENCES, UNIVERSITY OF WITWATERSRAND, JOHANNESBURG, IN THE PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS IN THE FIELD OF DEMOGRAPHY AND POPULATION STUDIES
17 September 2015 / Context: Generally, marriage has been early and almost universal phenomenon in Sub-Saharan Africa, and this can be seen as an important factor in determining fertility. However, fertility among never-married women is no longer negligible. Non-marital childbearing has increased, as women spend much of their reproductive lives unmarried, while remaining sexually active. Although a number of studies have examined non-marital childbearing, the exploration has been largely on teenagers and adolescent youths. The purpose of this study is to identify the factors predisposing never-married women aged 25−49 to have children.
Methodology: This study was a secondary data analysis of the 2006-07 Namibian Demographic and Health Survey data. The study population was never-married women, aged 25−49, with a total weighted sample of 2,121. The dependent variable was never-married fertility, categorised into women who have had no birth and those who have had at least one birth. Age specific fertility rates were calculated using the TFR2 module. Bivariate and multivariate binomial logistic techniques were used to examine the association between independent variables of interest and never-married women’s childbearing experience.
Results: The study showed that 79% of never-married women, aged 25−49, had at least one child. Respondents from poor households, less educated respondents, rural dwellers and women from the Herero ethno-linguistic group, were more likely to be never-married mothers. The odds of being a never-married mother increased with age. The results further showed that the likelihood for being a never-married mother was higher among those women who reported ever having used contraception. Furthermore, the results showed that delaying age at sexual debut decreases the probability of being a never-married mother.
Conclusion: Childbearing among never-married women is common in Namibia, and with increasing age, the risk of having children outside of marriage increases. The consequences of never-married women’s childbearing should be studied, with a focus on the factors identified to influence their childbearing. Furthermore, policies and programmes addressing never-married women’s fertility should reflect the factors associated with never-married women’s fertility in a context where marriage levels are decreasing and fertility is happening outside of marriage.
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Challenges unique to adolescent and young adult cancer care: factors affecting barriers in access to careMobley, Erin M. 01 May 2019 (has links)
Adolescents and young adults (AYAs) ages 15-39 with cancer have experienced stagnant survival rates for the past 30 years in comparison to those older or younger diagnosed with cancer. Survival disparities for this population may be due to biologic factors, lack of consistent and effective access to care, and unique psychosocial needs of this age group, and taken together, present an opportunity for health policy intervention. Of particular interest are barriers most important to AYAs themselves, appropriate and timely clinical trial enrollment, and the ability to preserve fertility prior to initiating treatment. These barriers may be more difficult to overcome for AYAs that are from rural areas, those that may be un- or under- insured, of lower socioeconomic status or educational attainment, and other social determinant of health related-factors.
In this dissertation, I examined the factors that drive the challenges encountered by AYAs with cancer and discuss potential solutions to overcome these challenges. The first aim of this dissertation establishes which challenges or aspects of the cancer experience are most important to AYAs using a mixed methods approach. The second and third aims build off of challenges identified in aim one using quantitative methods. In aim two, AYA clinical trial enrollment in the United States is examined using a nationally-representative sample with a specific focus on rural disparities. In aim three, historical utilization of fertility preservation consultations and procedures are studied among AYAs treated a single institution serving a rural population.
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THE ELEGANT UNIVERSE: STORIESTighe-Pigott, Katharine 01 January 2018 (has links)
The Elegant Universe: Stories is a story collection featuring female characters unflinching in their self-appraisal, and wry in their humor, who explore the realities of their heterosexual relationships, particularly the weighty decision whether to have children or not in these dark and terrifying times. Sometimes funny, sometimes sad, the stories collected here explore the various, subtle modes of threat that are the palpable part of the experience of being a woman—not in society, or in the workplace, but primarily inside relationships with men. At the same time, the stories own that love can grow between men and women despite the near and present poison of misogyny. They own the miracle of motherhood while depicting the palpable fragility of new life and the proximity of mothers to unstoppable wreckage and ruin.
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Estudo do perfil proteico e epigenético do núcleo espermático bovino com influência na produção in vitro de embriões / Study of protein and epigenetic profile of bovine sperm nucleus with impact on in vitro embryo productionCastro, Letícia Signori de 31 January 2019 (has links)
A produção in vitro de embriões (PIVE) vem se destacado como biotecnologia reprodutiva nos rebanhos bovinos, porém ainda com algumas limitações. A diferença de fertilidade entre touros é uma delas e dentre os atributos espermáticos que podem impactar na PIVE, pouco se sabe sobre a composição do núcleo espermático. Sendo assim, este trabalho teve como objetivo principal identificar quais aspectos nucleares do espermatozoide caracterizam a diferença nos índices de PIVE. Para tanto, o estudo foi dividido em 3 experimentos nos quais foi utilizado o banco de dados da empresa In Vitro Brasil para seleção de touros de alta (AF) e baixa (BF) taxa de desenvolvimento embrionário (taxa de blastocisto/taxa de clivados; n=5 touros/grupo). No primeiro experimento, foi realizado a avaliação da cromatina para susceptibilidade ao desafio ácido (SCSA modificado), deficiência de protaminação (CMA3) e fragmentação do DNA (COMETA). Apenas a deficiência de protaminação apresentou diferença entre os grupos, entretanto a porcentagem de células positivas para o CMA3 foi baixa, não sendo possível atribuir a esta alteração as diferenças de fertilidade encontradas. No segundo experimento, foi realizada a avaliação de proteômica do núcleo espermático destes touros. Para tanto, as amostras foram incubadas com detergente CTAB para remoção de parte da membrana e cauda, extração das proteínas, digestão com tripsina e análise por espectrometria de massas. A quantificação das proteínas foi avaliada pelo índice iBAQ obtido após a identificação dos peptídeos e a média deste índice comparado entre os grupos para identificação das proteínas diferencialmente expressas. Foram identificadas 196 proteínas, 21 diferencialmente expressas, sendo 17 hiperexpressas no grupo AF e 4 hiperexpressas no grupo BF. Dentre elas, proteínas relacionadas ao processo de espermatogênese, fecundação e motilidade. No terceiro experimento, com objetivo de identificar as marcações epigenéticas relacionadas com a diferença de fertilidade in vitro, foi realizado a avaliação das estruturas de nucleossomos utilizando a enzima MNase para posteriormente utilização na técnica de imunoprecipitação das marcações de histona. Entretanto, não foi identificado a presença de nucleossomos no DNA espermático bovino, inviabilizando análises posteriores. Sendo assim, a avalição da metilação de DNA foi escolhida como marcação epigenética para ser estudada. Neste caso, foi utilizada a técnica de RRBS (reduced representation of bisulfite sequencing) para identificar as citosinas diferencialmente metiladas (CDM) entre os grupos AF e BF. Foram identificadas 440 CDM, sendo 327 hipometiladas e 113 hipermetiladas no grupo AF. Além disto, 184 genes contendo estas CDM foram identificados, entretanto nenhum processo biológico foi enriquecido por estes genes. Foi possível concluir com este trabalho que a fertilidade in vitro pode ser considerada de caráter multifatorial, sendo que alterações pequenas de integridade de cromatina não afetam diretamente, já proteínas relacionadas a espermatogênese, motilidade e fecundação podem ter relação com o fenótipo fertilidade estudado. Dentre as marcações epigenética estudadas, as estruturas de nucleossomo pareceram estar ausentes no espermatozoide bovino, e a metilação de DNA não apresenta impacto significativo no perfil de fertilidade. / In vitro embryo production (IVP) has been highlighted as reproductive biotechnique in bovine herds, but still with some limitations. The fertility difference between bulls is one of them and among the sperm attributes that can impact on IVP, little is known about the composition of the bovine sperm nucleus. Therefore, this work had as main goal to identify which sperm nuclear aspects characterize the difference in the IVP index. Then, the study was divided in 3 experiments in which the database of the company In Vitro Brasil was used for selection of bulls with high (HF) and low (LF) embryo development rate (blastocyst rate/cleavage rate; n=5 bulls/group). In the first experiment, chromatin analysis of susceptibility to acid denaturation (modified SCSA), protamine deficiency (CMA3) and DNA fragmentation (COMET assay) were performed. Only protamine deficiency presented difference between groups, however the percentage of CMA3 positive cells was low and it was not possible to attribute to this alteration the fertility difference between groups. In the second experiment, proteomic analysis of the sperm nucleus of these bulls was performed. For that, samples were incubated with CTAB detergent to remove part of the membrane and tail, submitted to protein extraction, trypsin digestion and mass spectrometry analysis. The amount of the proteins was evaluated by the iBAQ index obtained after the identification of peptides and the average of this index compared to identify the differentially expressed proteins. In this experiment, 196 proteins were identified, 21 differentially expressed, being 17 overexpressed in the HF and 4 overexpressed in LF group. Among them, proteins related to the spermatogenesis, fertilization and motility. In the third experiment, in order to identify the epigenetic marks related to in vitro fertility differences it was performed the evaluation of the nucleosome structures using the MNase enzyme to later utilization of immunoprecipitation of the histone marks technique. However, the presence of nucleosomes in bovine sperm DNA was not identified, unfeasible further analysis. Thus, the evaluation of DNA methylation was chosen as epigenetic mark to be studied. In this case, the RRBS (reduced representation of bisulfite sequencing) technique was used to identify the differentially methylated cytosines (DMC) between the two groups. In this experiment, it was identified 440 DMC, being 327 hypomethylated and 113 hypermethylated in HF group. In addition, 184 genes containing these DMCs were identified, however no biological process enrichment was identified with these genes. In conclusion, this study indicated that in vitro fertility characterization can be multifactorial; small changes in chromatin integrity do not directly affect, but proteins related to spermatogenesis, motility and fertilization may be related to the fertility phenotype studied. Among the epigenetic marks studied, nucleosome structures were absent in bovine spermatozoa, and DNA methylation did not have a significant impact on the fertility profile.
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Late childbearing continues to increase in developed countriesBeaujouan, Eva, Sobotka, Tomas January 2019 (has links) (PDF)
Broad societal and cultural changes since the 1970s have provided incentives for young people to postpone parenthood. The greater access to and longer pursuit of higher education, the greater involvement of women in the labour market, and changes in family behaviour have contributed to a long-term increase in age at parenthood. The spread of effective contraception and wider access to abortion have also played a part, helping women and couples better plan the timing of births. Using data from the Human Fertility Database, we document a rise in fertility rates among women aged 40 and older in low-fertility countries of Europe, East Asia, North America, and Australia.
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Fertility and Family Planning Among Navajo Indian of Public Welfare Assistance in Southeastern UtahShaffer, Gary Morris 01 May 1969 (has links)
A fertility and family planning survey was conducted among the recipients of pub lie welfare ass i stance in San Juan County, Utah. Two hundred twenty-five recipient families out of some 536 families on the list were interviewed during May and June of 1968 by nine graduate and undergraduate students in Sociology and Social Work with the help of Social Welfare workers and Navajo interpreters.
The study was primarily concerned with the following objectives: (1) to study the level and age patterns of fertility of a group of selected Navajo Indians, (2) to investigate the factors which might affect the fertility, desired fami.ly size, and ideal family size, (3) to study the knowledge of and the extent of the use of birth control methods among the selected group, (4) to compare the findings of previous fertility studies dealing with other groups to those found among the selected group of Navajos.
The data indicate that the fertility of Navajo women was very high, reaching the completed fertility rate of 9. 2 children for women aged 45-49 years as compared with that of 2.4 children and 2 .8 children for white and non-white women in the United States in 1960 respectively. The number of children ever born among the total ever married women was 6 .6 children . The number of children the Navajo women considered ideal for a couple in general and for the Navajo family in particular was 7 . 1 children and 7.7 children respectively.
A strong inverse relationship was observed among Navajo women between fertility level and several social variables. The fertility of women who knew English was as much as 3.9 percent below that of women who did not . Fertility was also lower among those who had more frequent contact with white people. Although the proportion of women who knew any methods of birth control was very low (only 50 percent of the total women), the fertility of these women was considerably lower than that of those who did not know anything about birth control.
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