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  • 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.
301

Biologia reprodutiva de Leposternon microcephalum (Squamata, Amphisbaenidae) do Sudeste do Brasil / Reproductive biology of Leposternon microcephalum (Squamata, Amphisbaenia) from Southeastern Brazil

Santos, Lívia Cristina dos 02 February 2009 (has links)
Os Amphisbaenia (cobras de duas cabeças) têm sua biologia reprodutiva pouco conhecida, em parte devido à dificuldade de observações em campo e de coleta desses animais, que possuem hábitos fossórios. Leposternon microcephalum, da família Amphisbaenidae, é uma espécie amplamente distribuída no Brasil. Este trabalho teve como objetivo estudar aspectos da biologia reprodutiva de L. microcephalum do Sudeste do Brasil, tais como fecundidade, época de recrutamento, a ocorrência de oviposturas em formigueiros, tamanho de maturidade sexual, sintopia das gônadas, e dimorfismo sexual de comprimento e diâmetro do corpo, bem como analisar os ciclos folicular e espermatogênico e caracterizar a morfologia das gônadas e vias genitais. Para tanto, foram utilizados espécimes de coleção coletados em diferentes meses do ano para análise e medidas dos testículos, ductos deferentes, folículos ovarianos e ovidutos. Tais órgãos foram ainda analisados sob microscopia de luz, visando à descrição de sua estrutura e um estudo mais aprofundado do ciclo reprodutivo. Foram ainda escavados formigueiros para procura de ovos. Observou-se que o ciclo reprodutivo da fêmea dura pelo menos dois anos, sendo que o depósito mais substancial de vitelo é do tipo vernal (pré-nupcial), concentrado nos três meses que precedem a ovulação. Essa se dá provavelmente na mesma época da cópula, entre Novembro e Dezembro. A espermatogênese é do tipo misto, e o pico de produção de espermatozóides ocorre cerca de dois meses antes da cópula, havendo pequena fase de estocagem de esperma nos ductos deferentes. Nessa época, o epitélio desses ductos torna-se secretor. Após a fase espermatogênica, há uma acentuada involução dos testículos. O número de ovos produzido por fêmea provavelmente varia entre dois e seis. Os ovidutos dividem-se, segundo sua estrutura observada sob microscópio de luz, em vagina, útero, infundíbulo posterior e infundíbulo anterior. A maturidade sexual dos espécimes pode ser inferida com base na opacidade dos ductos genitais, e é atingida provavelmente aos três anos de idade. A gônada direita é normalmente mais cranial em relação à esquerda, e há uma região de sobreposição, na qual ambas se dispõem lado a lado. Não foi observado dimorfismo sexual, e a ovipostura em formigueiros não parece ser obrigatória. / The reproductive biology of the Amphisbaenia (worm lizards) is poorly known, in part because of their fossorial habits, which make difficult studies on the field and their capture. Leposternon microcephalum is a species widespread in Brazil, and accommodates in the family Amphisbaenidae. This work aimed to study features of the reproductive biology of L. microcephalum from Southeastern Brazil, such as fecundity, time of hatching, occurrence of oviposition in ant nests, size of sexual maturity, gonadal sintopy and sexual dimorphism on body length and width. It also aimed to analyze follicular and testicular cycles and to characterize the morphology of gonads and genital ducts. For that, museum specimens collected on different months of the year were used for analyses and measurements of testes, vas deferens, ovarian follicles and oviducts. Those organs were also analyzed histologically by light microscopy, to describe theirs structure and to better characterize the sexual cycle. Ant nests were excavated to look for eggs. The female reproductive cycle were estimated to take at least two years. The most part of yolk deposition occurs during the last three months before ovulation, and it is of the vernal type (pre-nuptial). Ovulation takes place approximately at the same time as mating, between November and December. Spermatogenesis is of the mixed type (type II B), and the peak of spermatozoa production occurs approximately two months before mating. There is a short phase of sperm storage in vas deferens. By that time, vas deferens epithelium becomes secretory. After the spermatogenesis, there is a great involution of testes. The number of eggs produced by each female probably varies between two and six. According to the structure seen under light microscope, the oviducts are divided in four regions: vagina, uterus, anterior infundibulum and posterior infundibulum. Sexual maturity can be inferred from the opacity of genital ducts, and it is probably attained in three years. The right gonad is usually anterior to the left one, and there is an overlapping region, in which the two gonads are arranged side by side. Sexual dimorphism was not observed, and oviposition in ant nests does not seem to be obligatory.
302

Biologia reprodutiva do caranguejo simbionte Pachycheles monilifer (Crustacea, Decapoda, Anomura): relação entre potencial reprodutivo e substrato / Reproductive biology of the symbiotic crab Pachycheles monilifer (Crustacea, Decapoda, Anomura): relation between reproductive potential and substrate

Leone, Isabela Carnielli 27 May 2013 (has links)
Os crustáceos estão entre os invertebrados marinhos mais diversos e tendem a se associar com outros organismos a fim de encontrar abrigo, oferta de alimento e um lugar seguro para reprodução. Aspectos reprodutivos como fecundidade, tamanho dos embriões e energia investida na reprodução são os principais parâmetros para a compreensão da história natural de uma espécie e/ou população. Assim, esse trabalho foi desenvolvido no sentido de investigar tais parâmetros e a influência do tipo de substrato ocupado. A espécie utilizada como modelo de estudo foi o caranguejo porcelanídeo Pachycheles monilifer coletado em dois substratos biológicos diferentes, no briozoário Schizoporella errata no píer do Itaguá e no poliqueto Phragmatopoma caudata na praia Grande, ambas as paias localizadas em Ubatuba, litoral norte de SP. Somente os embriões em estágio inicial de desenvolvimento foram utilizados para os cálculos de fecundidade e investimento reprodutivo (RO). Os embriões foram contados e medidos sob esteromicroscópio. Para obtenção do RO foram utilizados os pesos secos das fêmeas ovígeras e das massas de embriões, previamente secos em estufa. Além dos aspectos reprodutivos, análises de distância genética também foram realizadas pelo sequenciamento de genes mitocôndrias (16S e COI) de exemplares de P. monilifer. A estimativa da porcentagem de variação genética intra e interespecífica, a possibilidade de fluxo gênico entre indivíduos de diferentes praias do estado de São Paulo foram verificadas. A partir desses dados confirmou-se a validade da espécie, assim como o fluxo gênico contínuo entre indivíduos dessas duas praias. A baixa divergência genética permite concluir que as diferenças reprodutivas encontradas são, portanto um reflexo das condições proporcionadas pelo ambiente. Os animais simbiontes do briozoário, assim como as fêmeas ovígeras, são maiores que os associados ao poliqueta e também possuem maior fecundidade e investimento reprodutivo, porém não foram encontradas diferenças em relação ao tamanho dos embriões. No substrato do briozoário o estresse reprodutivo parece ser menor que no substrato do poliqueto, já que aquele substrato proporciona um ambiente fisicamente mais estável para os organismos simbiontes. No substrato do poliqueto, além do alto hidrodinamismo local, o espaço disponível na colônia parece ser mais restrito e pode limitar o tamanho de seus habitantes. Os animais simbiontes do briozoário parecem não serem influenciados por fatores externos à colônia, entretanto o mesmo não foi observado nos simbiontes do poliqueto. Tais diferenças reprodutivas refletem o tipo de substrato ocupado, evidenciando a plasticidade fenotípica da espécie para uma melhor adaptação local. / The crustaceans are the most diverse of the marine invertebrates and many of them tend to associate with other organisms where they can find shelter, food supply and a safe place to reproduce. Reproductive traits as fecundity, egg size and reproductive output (RO) are the most important aspects to understand the species life history. This study aimed to investigate the reproductive traits in relation to the substrate that the organisms live. The studied species used as model was the porcellanid crab Pachycheles monilifer that was collected in two different substrates, one of them is the bryozoan Schizoporella errata at the Itaguá beach and the other is the polychaete Phragmatopoma caudata at Grande beach, both are located in Ubatuba, northern coast of São Paulo. Only the initial stage of eggs was used to estimate the crab fecundity and RO. The eggs were counted and measured in a stereomicroscope. To obtain the RO the female and the egg mass dry weight, which were previously dried in an oven, were used. Besides the reproductive aspects, the genetic distance between the organisms was valued with partial sequences of the mitochondrial genes 16S and COI. The estimate of the intra and interspecific genetic variation and the possibility of gene flow between the individuals from the beaches in SP were analyzed too. Therefore, with all these analyses it was possible to confirm that the species is valid and that there is gene flow among the populations. The low genetic divergence allowed us to conclude that the different reproductive traits found among the populations were due to the different substrates that the organisms inhabit. The bryozoan symbionts are larger than the polychaete symbionts as well as the females fecundity and the RO, but there is no difference in egg size. In the bryozoan substrate it seems like the physical stress is smaller than in polychaete and it promotes a more stable habitat for the crabs reproduce. In the polychaete substrate, beyond the high hydrodynamic location, the available space in the colony appears to be narrower, which could limit the size of its inhabitants. The bryozoan symbionts do not seem to be influenced by the external factors of the colony, though the same was not observed in the polychaete colony. Such differences in reproduction reflect the kind of substrate inhabited, highlighting the phenotypic plasticity of the species to a local better adaptation.
303

Adaptation and Diversification in Bluebells (Mertensia spp., Boraginaceae)

Lin, Shang-Yao Peter 06 June 2019 (has links)
Examining the ecological processes generating evolutionary patterns is crucial to understanding how biodiversity arises and evolves. One of the most striking examples of evolutionary diversification is provided by the flowering plants (angiosperms) and their flowers. Pollinators are traditionally considered to be the most important selective agents and drivers of floral diversity. However, many angiosperms have a generalized floral morphology and are visited by a diverse and overlapping suite of pollinators, making it unclear how pollinators could have driven diversification in these taxa. In addition, flowers and plant reproductive success are likely to be influenced by factors other than pollinators, such as herbivores, precipitation, and temperature. These factors need to be considered along with pollinators in order to improve our understanding of angiosperm evolution and diversification. In my thesis, I focussed on the processes influencing adaptation and diversification in flowering plants in the genus Mertensia (Boraginaceae), which have relatively unspecialized flowers that attract a variety of nectar- and pollen-feeding insects. In Chapter One, I explored correlations among floral traits, vegetative traits, and flowering phenology across 12 Mertensia species. In Chapter Two, I assessed reproductive isolating barriers between related Mertensia species occurring in sympatry. In Chapter Three, I examined the ecological function of floral orientation in two Mertensia species with respect to pollinators and precipitation. First, across Mertensia species, I found that early-flowering species were shorter, produced fewer flowers, and occurred at higher altitudes than late-flowering species—suggesting a life-history trade-off between plant size and flowering phenology, as well as an altitudinal effect on both traits. Interspecific variation in floral traits was not strongly associated with variation in flowering phenology or plant size. Second, between sympatric M. brevistyla and M. fusiformis populations, I found weak reproductive isolating barriers and possible hybridization. Most pre-pollination barriers were weak, as the two Mertensia species shared similar habitats, flowering phenology, and pollinator assemblages. The two relatively strong barriers were floral (ethological and mechanical) isolation and post-pollination isolation: Pollinators transferred significantly more of a pollen analogue among conspecific than heterospecific plants in mixed-species arrays, and flowers yielded higher seed set when receiving conspecific rather than heterospecific pollen in hand-pollination experiments. Lastly, I found that floral orientation was more likely to be under selection by precipitation than by pollinators, in that paternal fitness (i.e., pollen germination) was reduced by contact with water and that pollinator-mediated selection via maternal fitness (i.e., seed set) was not detected. A more pendant floral orientation likely protects the relatively long and exposed anthers of M. fusiformis from rain, while the less pendant M. brevistyla does not require this protection because of its shorter, more concealed reproductive structures. Although I detected an effect of floral orientation on seed set, I was not able to identify the selective agents driving this effect. In summary, my results suggest that pollinators play a minor role in influencing floral adaptation and diversification in Mertensia. Instead, the dominant influences on the traits I examined appear to be life-history trade-offs, environmental conditions that vary along altitudinal gradients, and abiotic variables (e.g., precipitation). It is important to consider these factors and their influences on paternal and maternal fitness in order to gain a broader perspective on floral evolution in plants with generalized pollination systems.
304

Young people's perceptions of access to sexual and reproductive health services in Manzini, Swaziland

Fakudze, Simangele 05 1900 (has links)
The purpose of the study was to explore and describe young people’s perceptions of access to sexual and reproductive health (SRH) services in Swaziland. The study provided insights into the SRH services currently available to the young people of Swaziland and reveals the opportunities that can be used to improve accessibility and utilisation of the current reproductive health services. The findings will inform policy-making and appropriate future interventions for young people’s sexual and reproductive needs and services. Data were collected through a descriptive exploratory study design. Colaizzi’s seven steps of data analysis were used. The study provides ample evidence that young people face sexual health risks that justify their need to access and utilise SRH services. The findings revealed that access to service is an important but complex element of quality care, as it determines whether a client gets to the service provider. / Health Studies / M.A. (Health Studies)
305

Origin and evolution of social hybridogenesis in Cataglyphis ants: Origine et évolution de l'hybridogenèse sociale chez les fourmis Cataglyphis

Kuhn, Alexandre 29 May 2019 (has links) (PDF)
Hybridization and genetic introgression are significant evolutionary processes playing a keyrole in the adaptation and diversification of species. In desert ants of the genus Cataglyphis,some species have evolved a remarkable reproductive strategy, termed social hybridogenesis,that relies on a perpetual hybridization between two sympatric, yet genetically distinct lineages.The non-reproductive workers systematically result from mating between partners of differentlineages; in contrast, queens and males are both produced asexually by parthenogenesis.Consequently, workers are all interlineage hybrids, whereas reproductives are all pure-lineageindividuals. Although several studies have been carried out on the reproductive strategies ofCataglyphis desert ants, the origin and the mechanisms underlying social hybridogenesis in thegenus remain unclear.In this thesis, I first examined three aspects associated to the persistence of socialhybridogenesis using the ant Cataglyphis mauritanica as a model. (i) I showed that the tightcaste – genotype association stems from a strong genetic influence on female caste fate.However, some degree of phenotypic plasticity was retained in hybrid as well as pure-lineagegenomes, although not expressed in natural conditions. (ii) The genetic survey of a largehybridogenetic population of C. mauritanica reveals that the two lineages occur with equalfrequency. Furthermore, restricted dispersal and parthenogenetic production of queens result ina mosaic of clonal patches. In contrast, males disperse over patches, ensuring successfulinterlineage mating. (iii) To determine whether mating between partners from the same geneticlineage participate to queen production, I simulated genetic data under various rates of sexualvs. asexual queen production. I found that genetic diversity within each lineage fits with theoccurrence a few sex; however, the 100% clonality hypothesis could not be discarded.I then investigated the evolutionary origin of social hybridogenesis in Cataglyphis. Bycharacterizing the reproductive system of 11 Cataglyphis species, five new instances of socialhybridogenesis were discovered. Inferences from phylogenetic analyses, including thesespecies and all Cataglyphis species for which reproductive information was available, indicatedthat this reproductive system independently evolved multiple times in the genus Cataglyphis.Overall, the results of this thesis highlight the singularities of a hybridogenesic systemassociated to queen parthenogenesis, which may have facilitated the repeated evolution ofdependent-lineages in Cataglyphis ants. / L’hybridation et l’introgression génétique jouent un rôle majeur dans l’adaptation et ladiversification des espèces. Chez les fourmis du désert du genre Cataglyphis, certaines espècesont évolué une stratégie de reproduction remarquable, appelée hybridogenèse sociale, reposantsur l’hybridation systématique entre deux lignées génétiquement distinctes. Les ouvrières nonreproductricessont issues de l’accouplement entre des partenaires de lignées distinctes ;enrevanche, les reines et les mâles sont produits de façon asexuée par parthénogenèse. Lesouvrières sont donc toutes des hybrides des deux lignées, alors que les individus reproducteurssont de pure-lignées. Bien que plusieurs études aient analysé les stratégies de reproduction desfourmis Cataglyphis, l’origine et le fonctionnement de l’hybridogenèse sociale au sein du genrerestent obscurs.Dans cette thèse, trois aspects associés au maintien de ce système ont premièrement étéétudiés en prenant la fourmi Cataglyphis mauritanica comme modèle. (i) La forte associationentre génotype et caste des femelles est lié à une forte influence génétique sur le déterminismede la caste. Néanmoins, une certaine plasticité phénotypique est maintenue dans les génomeshybrides et pure-lignée mais elle ne s’exprime pas en conditions naturelles. (ii) L’analysegénétique d’une population hybridogène de C. mauritanica montre que les deux lignées sontéquifréquentes. De plus, une dispersion limitée des reines ainsi que leur production parparthénogenèse mènent à la formation d’une mosaïque de patches clonaux. A l’inverse, lesmâles dispersent d’un patch à l’autre assurant les accouplements interlignées. (iii) Afin dedéterminer si les accouplements intralignées participent à la production des reines, des donnéesgénétiques ont été simulées sous différents taux de reproduction sexuée et asexuée. Les résultatsmontrent que la diversité génétique au sein de chaque lignée correspond à une faible fréquencede reproduction sexuée, bien que qu’un scénario avec 100% de clonalité ne puisse être écarté.Ensuite, l’origine évolutive de l’hybridogenèse sociale chez les Cataglyphis a étéanalysée. L’étude des systèmes reproducteurs de 11 espèces de Cataglyphis a permis ladécouverte de 5 nouveaux systèmes hybridogènes. Des analyses phylogénétiques, basées surces espèces et sur toutes les espèces de Cataglyphis pour lesquels le système reproducteur a étéprécédemment étudié, indiquent que ce système reproducteur aurait évolué plusieurs foisindépendamment au sein du genre Cataglyphis.En conclusion, les résultats de cette thèse soulignent les singularités d’un systèmehybridogène associé à la parthénogénèse des reines, qui a pu faciliter l’évolution répétée delignées dépendantes chez les fourmis Cataglyphis. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
306

Reproductive Development of Female Bonefish (Albula spp.) from the Bahamas

Unknown Date (has links)
Bonefish (Albula spp.) support an economically important sport fishery, yet little is known regarding the reproductive biology of this genus. Analysis of oocytes histology and sex hormone levels was conducted on wild female bonefish sampled during and outside the spawning season in Grand Bahama, Central Andros, and South Andros, The Bahamas to assess reproductive state. Bonefish are commonly found along shallow water flats, or in pre-spawn aggregations (PSA) during spawning months. 17β-estradiol levels suggest vitellogenic consistency between habitats. However, fish are more reproductively developed at PSA based on the occurrence of larger, more prevalent vitellogenic oocytes and evidence of final maturation. Variability in hormone levels and spawning readiness existed between Grand Bahama and Andros PSAs, suggesting peak spawning may differ by region. Findings from this study will contribute baseline data to the captive bonefish restoration project at Harbor Branch Oceanographic Institute and to the limited ecological data regarding bonefish reproduction. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
307

Developing Spawning Protocols and Embryological Benchmarks for a Tropical Marine Fish (Albula spp.) in Captivity

Unknown Date (has links)
Relying on field research to complete the life history for certain fish species can be inadequate, but laboratory research can be used to fill these gaps. These gaps exist for Bonefish (Albula spp.), a tropical marine fish and popular sportfish. In this study, aquaculture techniques were applied to Bonefish in a captive setting at Harbor Branch Oceanographic Institute (HBOI) and Cape Eleuthera Institute (CEI) to induce spawning and describe early ontogeny. Photothermal manipulations and hormone injections were used to induce gonad maturation and spawning, which was achieved once at CEI and is the first record of hormone-induced spawning for Bonefish. From that spawn, egg and larval development were recorded and described through 26 hours and 56 hours respectively, representing the first record of these early life stages for Bonefish. This work expands upon what is known about Bonefish reproductive biology and will be useful for management and future captive research. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
308

The effect of cervical intraepithelial neoplasia and treatment surgeries on fecundability

Klann, Alexandra 24 October 2018 (has links)
INTRODUCTION: Approximately 6 million couples in the United States experience infertility. Because few risk factors for infertility are known, identification of modifiable determinants is an important public health goal. Cervical intraepithelial neoplasia, CIN, occurs when the surface cells of the cervical tissue begin to change, and is caused by infection with a high-risk type of human Papillomavirus (HPV). CIN may affect the cervix’s immunological function, resulting in changes in mucus production, reduced protection against infections, and alterations in sperm transport through the cervical canal. CIN can also progress to invasive cervical cancer. There are four main CIN treatment procedures that aim to remove pre-cancerous cells from the cervix; loop excisions, commonly known as electrosurgical excision procedure (LEEP) or large loop excision of the transformative zone (LLETZ); cryosurgery; conization; and laser ablation. Because the goal of these procedures is to remove abnormal cells, healthy cervical cells may inadvertently be removed as well, leading to further changes in cervical mucus production, sperm motility, and reduced protection against infection. Because of the changes to the cervical tissue and its function, CIN and its surgical treatments may affect fecundability. METHODS: We analyzed data from Pregnancy Study Online (PRESTO), a preconception cohort of 5,594 North American pregnancy planners enrolled and followed between 2013 and 2018. At baseline, participants reported whether they had abnormal Pap tests and their age at their first abnormal Pap test, as well as cervical procedures and their age at the procedure. We estimated fecundability ratios (FR) and 95% confidence intervals (CI) using proportional probabilities models adjusted for sociodemographics, smoking, number of sexual partners, history of sexually transmitted infections/ pelvic inflammatory disease, and HPV vaccination. RESULTS: A history of abnormal Pap test, which we used as a proxy for cervical dysplasia, was positively associated with current and past smoking, gravidity, parity, irregular menses, number of sexual partners, history of chlamydia, genital warts and herpes, as well as a history of pelvic inflammatory disease. Of the women with an abnormal Pap test, the average age at first abnormal Pap test was 23.0 (std=4.5) years and the average number of abnormal Pap tests was 2.1 (std=1.7). We found little association overall between a history of abnormal Pap test and fecundability (FR=1.03, 95% CI: 0.96, 1.11). The results did not differ when the data were examined by number of abnormal Pap tests, or type of procedure. There was also little association between time since the diagnosis or procedure and pregnancy attempt and fecundability. There was however a slight decrease in fecundability within the first 2 years of diagnosis/ procedure, with FRs that tended to increase with increasing time since diagnosis/procedure. DISCUSSION: We found little association overall between a history of abnormal Pap test or cervical dysplasia, including excisional surgeries, and fecundability. These results are consistent with most other studies demonstrating no clear adverse effects of CIN and treatments. Recency of diagnosis or procedure did not appreciably affect these findings. Although we found a very slight decrease in fecundability within the first two years since diagnosis or procedure, fecundability became similar to that of undiagnosed/untreated women after 2 years, and then increased slightly. CONCLUSION: We found little association between a history of abnormal Pap and CIN treatments and fecundability. A major limitation of our study is that the data were self-reported, which may have resulted in non-differential exposure misclassification.
309

Impacto da IATF (inseminação artificial em tempo fixo) sobre características de importância econômica em bovinos Nelore /

Nogueira, Camilla de Souza. January 2017 (has links)
Orientador: Josineudson Augusto II de Vasconcelos Silva / Banca: Henrique Nunes de Oliveira / Banca: Joslaine Noely dos Santos Gonçalves Cyrillo / Resumo: A produção de carne no Brasil cresce constantemente, assim como as exigências do mercado e dos consumidores, que fazem a pecuária de corte estar sempre em busca de estratégias tecnológicas e de manejo para garantir maior retorno econômico da atividade. Aliado ao melhoramento genético, o uso da inseminação artificial em tempo fixo (IATF) ganha destaque na produção comercial. O objetivo deste estudo foi comparar grupos de progênies oriundas de IATF e de monta natural (MN), a fim de avaliar o impacto da tecnologia reprodutiva no peso a desmama (PD), ganho de peso pós-desmama (GPD), perímetro escrotal (PE) e musculatura (MUS), além de verificar a idade ao primeiro parto (IPP) e tempo de permanência (TP) das fêmeas em rebanhos Nelore criados em sistema extensivo. Os dados avaliados foram provenientes de seis fazendas participantes do programa de melhoramento genético Nelore Qualitas, utilizou-se registro de 65.086 animais. Análises estatísticas dos dados foram realizadas pelo procedimento GLM e as médias ajustadas foram comparadas entre os grupos, G_MN (grupo de progênies oriundas de MN) e G_IA (grupo de progênies oriundas de inseminação artificial), a partir do teste de Tukey-Kramer no programa SAS. A concentração de nascimentos, em ambos os grupos, ocorreu entre agosto e novembro, período com maior oferta de pastagem, o que resultou maior potencial de desempenho das progênies ao desmame. Os touros apresentaram papel fundamental no desempenho das progênies, sendo aquelas oriunda... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Meat production in Brazil is constantly growing, as well as the requirements of the market and consumers, which makes the making beef cattle to be always in search of technological strategies and management to ensure greater economic return to activity. Allied to genetic breeding, the use of fixed-time artificial insemination (FTAI) acquires emphasis in commercial production. The aim of this study was to compare progeny groups of FTAI and natural breeding (NB), in order to evaluate the reproductive technology impact in weaning weight (WW), postweaning weight gain (PWG), scrotal perimeter (SP) and musculature (MUS), besides checking the age at first calving (AFC) and time of permanency (TP) of females of Nelore herd created in extensive system. The data evaluated came from six farms that participate in the Nelore Qualitas breeding program, and it was used a register of 65,086 animals. Statistical analyzes of the data were performed by the GLM procedure and the adjusted means were compared between the groups, G_MN (group of progenies born by NB) and G_IA (group of progenies born by TFAI), by the Tukey-Kramer test in the SAS program. The concentration of births in both groups occurred between August and November, a period with greater pasture supply, which resulted in progeny's greater performance potential at weaning. The bulls presented a fundamental role in the progeny performance, and those from AI were more efficient (p<0.001) in the studied traits. The phenotypes of the G_IA group for WW, PWG, SP and MUS were 187.02 kg, 81.69 kg, 24.09 cm e 3.92, respectively, and with genetic values equal to 4.64 kg, 7.48 kg, 0.49 cm e 0.23, respectively. These results showed phenotypes and higher genetic values (p <0.001) than those of the G_MN group, 180.8 kg, 69.81 kg, 23.68 cm and 3.78 and 0.04 kg, 0.05 kg, -0.01 cm and 0.02, res... (Complete abstract click electronic access below) / Mestre
310

The role of men in promoting women’s reproductive and maternal health in a matrilineal marriage system in Malawi: the case of Ntchisi District

Kapulula, Phillip Klemens January 2015 (has links)
Philosophiae Doctor - PhD / This research explored the role of men in efforts by the Malawi Ministry of Health to promote women’s reproductive and maternal health in accordance with Millennium Development Goal (MDG) number five, i.e. to reduce the maternal mortality ratio by three quarters between 1990 and 2015. The study was conceptualised in 2011 in an effort to contribute to the national strategy to reduce maternal mortality in Malawi, and it was done in the particular cultural context of a matrilineal marriage and kinship system in Ntchisi district, Malawi. At the inception of this study, the highest prevalence of maternal deaths in the country was reported in seven districts, including Ntchisi. A common understanding in public health circles worldwide is that male involvement in reproductive and maternal health activities is an important factor in achieving the above MDG goal. But historically, research on maternal health in Malawi has focused mostly on women and children. Consequently there are only a small number of relevant previous studies or extant literature to draw on for the current investigation. Malawi’s reproductive and maternal health policies largely lack locally-informed research on men and masculinities. My study aimed to explore the relationship between local constructions of masculinity, fatherhood and reproductive health in Malawi among Chichewa speakers who live in Ntchisi. It was guided by the social constructionist theory which recognises the role of the impersonal features of the social world like cultural, personal and group influences in the construction of ideas, knowledge and facts. In this study I adopted an inductive approach to learning in which the participants were the main players in describing and explaining social phenomena as they are constructed and experienced in the research site. I conducted multiple in-depth interviews and focus group discussions with 53 married men, key informant interviews with eight local leaders and traditional birth attendants, as well as focus group discussions with 12 married women who had given birth multiple times. Data analysis involved intensive scrutiny of transcripts to determine prevailing themes. Listening to the tapes and re-reading these transcripts enabled me to detect patterns and categorise different practices and constructions, to find associations between these practices and constructions of concepts. Malawi’s men are considered to be the traditional gatekeepers of maternal and social ideals. Therefore, as elders in a clan or as husbands, their prompt decisions can facilitate the access of their spouses to maternal and reproductive health services. Men as heads of households and decision makers can also support and enable their wives to follow the recommended maternal health counsel. However, men’s “lack of involvement” is not the principal reason why there is increasing maternal challenges among child-bearing women in Ntchisi. Although men are not entirely free of the blame for contributing to the status quo, they already work hard towards ensuring positive pregnancy outcomes for their spouses. The study found that husbands in Ntchisi have long been involved in pregnancy and child care. The study shows that pregnancy is regarded as a liminal state or as a kind of “sickness”. Male involvement in pregnancy means the man should take over the routine household chores of drawing water, fetching firewood and cooking, among other things. However, men construct their involvement in reproductive and maternal health matters in the framework of masculinity and femininity as dictated by the commonly held beliefs of a matrilineal Chewa grouping. The study showed that masculinities are constructed within the context of a matrilineal system, which has nonetheless been changing largely due to the colonial impact of the United Kingdom, the related influences of Christian and westernised social ideals and an education system based on the British model. Men’s gendered practices in reproduction and parenting have foundations in the initiation rites of the secret Nyau societies where the masculine ideals of sexuality and secrecy are inculcated. This research cannot be generally extrapolated to the wider population in Malawi but it is a starting point for understanding the responses of matrilineal Chichewa speaking men to reproductive and maternal health matters. Further and broader research on the construction of fatherhood and masculinity is needed in Malawi to make it possible for public health policy on reproductive and maternal health to be more culturally informed.

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