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Breeding System Evolution and Pollination Success in the Wind-Pollinated Herb <i>Plantago maritima</i>Nilsson, Emil January 2005 (has links)
<p>In this thesis, I examined variation in sex expression and mating patterns in the sexually polymorphic, wind-pollinated herb <i>Plantago maritima</i>. With a combination of field studies, greenhouse experiments, and genetic analyses, I (a) examined factors influencing sex ratio variation in gynodioecious plants (in which hermaphrodites and females coexist), (b) discovered variation in breeding system, (c) investigated density-dependence of seed production, and (d) documented genetic variation within and among populations close to the northern range margin in Europe. </p><p>In a survey of 104 <i>P. maritima</i> populations, I documented considerable variation in sex ratio (range 0-70% females, median 6.3% females). As predicted, females were more frequently missing from small than from large populations, and the variance in sex ratio increased with decreasing population size. Among twelve populations sampled for seed production, the frequency of females was positively related to relative fecundity of females and negatively related to population size. The results suggest that the local sex ratio is influenced both by the relative fecundity of females and hermaphrodites, and by stochastic processes in small populations.</p><p>A comparative field study showed that plant fecundity decreased with increasing distance to nearest pollen donor both within and among populations in an archipelago in southern Sweden, where self-incompatibility was confirmed in controlled crosses. In contrast, plant fecundity was overall higher and was not density-dependent in the Skeppsvik archipelago in northern Sweden, where controlled crosses showed that plants are self-compatible. The results were consistent with the prediction that evolution of self-fertility should reduce density-dependence of pollination success.</p><p>I quantified the genetic structure within and among populations from eastern Sweden and western Finland based on variation at four polymorphic microsatellite loci. The genetic diversity was low in northern Sweden, which may be the result of a history of small population sizes and periods of frequent self-fertilization.</p>
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Breeding System Evolution and Pollination Success in the Wind-Pollinated Herb Plantago maritimaNilsson, Emil January 2005 (has links)
In this thesis, I examined variation in sex expression and mating patterns in the sexually polymorphic, wind-pollinated herb Plantago maritima. With a combination of field studies, greenhouse experiments, and genetic analyses, I (a) examined factors influencing sex ratio variation in gynodioecious plants (in which hermaphrodites and females coexist), (b) discovered variation in breeding system, (c) investigated density-dependence of seed production, and (d) documented genetic variation within and among populations close to the northern range margin in Europe. In a survey of 104 P. maritima populations, I documented considerable variation in sex ratio (range 0-70% females, median 6.3% females). As predicted, females were more frequently missing from small than from large populations, and the variance in sex ratio increased with decreasing population size. Among twelve populations sampled for seed production, the frequency of females was positively related to relative fecundity of females and negatively related to population size. The results suggest that the local sex ratio is influenced both by the relative fecundity of females and hermaphrodites, and by stochastic processes in small populations. A comparative field study showed that plant fecundity decreased with increasing distance to nearest pollen donor both within and among populations in an archipelago in southern Sweden, where self-incompatibility was confirmed in controlled crosses. In contrast, plant fecundity was overall higher and was not density-dependent in the Skeppsvik archipelago in northern Sweden, where controlled crosses showed that plants are self-compatible. The results were consistent with the prediction that evolution of self-fertility should reduce density-dependence of pollination success. I quantified the genetic structure within and among populations from eastern Sweden and western Finland based on variation at four polymorphic microsatellite loci. The genetic diversity was low in northern Sweden, which may be the result of a history of small population sizes and periods of frequent self-fertilization.
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Irrigação contínua e intermitente em arroz irrigado: uso de água, eficiência agronômica e dissipação de imazethapyr, imazapic e fipronil / Intermittent and continuos flooding in rice: water use, agronomic efficiency and imazethapyr, imazapic and fipronil dissipationMezzomo, Rafael Friguetto 19 February 2009 (has links)
Every anthropogenic activity causes environmental impact in some extent. Rice paddy fields area are pointed out as an activity with high potential of pollution due to the large amount of water used to maintain the flooding and the intensive use of pesticides and nutrients that can be transported to the environment. Though, there are other irrigation management practices that can reduce the environmental impact caused by the rice farming. Based on that, the objective of this study was to investigate the effect of the continuous and intermittent flooding on the amount of water applied and the amount of water transported to the environment, on water use efficiency, on weed control, on agronomic parameters of the rice plants and on dissipation of imazethapyr, imazapic and fipronil. The intermittent flooding resulted in
crop yield similar to continuous irrigation. In addition, it reduced in 32% the amount of water applied, resulting in a better water use efficiency (1.68 kg m-3) than the
continuous flooding (1.14 kg m-3). Water saving is promoted by the higher amount of rainfall stored in the intermittent flooding. The intermittent flooding reduces 40% of the run-off and less environmental contamination, resulting, on the average of the three pesticides a reduction higher than 90% on the mass of pesticide transported to the environment in comparison to the total applied on the rice Field. / Toda a atividade antrópica causa impacto ambiental de algum nível. A lavoura de arroz irrigado é apontada como uma atividade com alto potencial poluidor por usar grande volume de água para manter a lâmina de irrigação e também por ser um cultivo que demanda o intenso uso de agrotóxicos e nutrientes que podem ser transportados para o ambiente. Entretanto existem alternativas de manejar a lâmina
de irrigação que podem diminuir esse impacto ocasionado pela orizicultura. Nesse sentido, o presente trabalho tem por objetivo avaliar o efeito do manejo de irrigação
contínua e intermitente no balanço de água (lâmina de água aplicada e lâmina de água extravasada), na eficiência do uso da água, no controle de plantas daninhas, nos parâmetros agronômicos e na dissipação de imazethapyr, imazapic e fipronil. A irrigação intermitente ocasiona produtividade de grãos semelhante à irrigação contínua. Além disso, proporciona economia de 32% do volume de água aplicado,
resultando em uma maior eficiência do uso de água (1,68 kg m-3) do que a irrigação contínua (1,14 kg m-3). Essa economia está relacionada devido ao maior volume de
água da chuva armazenada. Dessa forma, a irrigação intermitente também promove redução de 40% no volume de água escoada superficialmente e menor contaminação ambiental, proporcionando uma redução, na média dos três
agrotóxicos avaliados, de 90% da massa de ingrediente ativo de agrotóxicos transportados para o ambiente em relação ao total aplicado na lavoura.
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Alterações fisiológicas e morfológicas de duas cultivares de arroz irrigado após aplicação do herbicida imazamox na fase reprodutiva / Physiological and morphological changes of two rice cultivars after imazamox herbicide application in reproductive phaseMoraes, Bibiana Silveira 01 March 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Weed control is one of the main agricultural practices indispensable to ensure
profitability and crop success. In paddy rice field, red rice is the most important weed due to
its difficult control. A widespread control method is the use of rice cultivars resistant to
herbicides which are inhibitors of ALS, since it is possible to have a selective chemical
control. Studies showed that the late control with imazamox promotes efficient control of red
rice escapes. Thus, the objective of this research was to check the effects of imazamox
application in the reproductive phase of two rice cultivars that differ in the level of resistance
to imidazolinones. Two studies were carried out at the Federal University of Santa Maria in
the years of 2009/10 and 2010/11. Imazamox was applied in different stadium of
development and doses. At the end of the application the final dose was 80 g a.i ha-1 for all
treatments. Results showed that independent of the date of the imazamox application in the
reproductive phase of rice, the grain yield reduced and spikelet sterility of IRGA 422 CL
increased. In general, the parameters 1000-grain weight, flag leaf length, panicule length,
fresh and dry weight of panicles, and panicles per m2 showed a reduction in practically all
imazamox treatments in the IRGA 422 CL cultivar. Changes in the biochemical parameters
(chlorophyll, carotenoids, thiobarbituric acid reactive substances, superoxide dismutase,
catalase and ascorbate peroxidase) were observed in leaves and panicles from main culm in
some treatments, demonstrating that the oxidative stress promoted by imazamox may have
contributed to grain yield reduction and the high percentage of sterile spikelet from IRGA 422
CL cultivar. Morphologic and anatomical changes showed that imazamox application in the
panicle differentiation promoted similar changes to homeotic changes observed in rice
mutant. Moreover, in the other treatments different morphologic and anatomical changes
were observed. Therefore, morphologic and anatomical changes were likely to be
responsible for grain yield reduction and high percentage of spikelet sterile from IRGA 422
CL. / O controle de plantas daninhas é uma das práticas agrícolas indispensáveis para
garantir rentabilidade e sucesso no cultivo. No cultivo de arroz irrigado, o arroz vermelho é a
planta daninha de maior importância, devido sua dificuldade de controle. Um método de
controle bastante difundido é o uso de cultivares resistentes aos herbicidas inibidores da
ALS, pois permite um controle químico seletivo. Estudos demonstram que o controle tardio
com o herbicida imazamox promove controle eficiente de escapes de arroz vermelho. Por
isso, o objetivo deste trabalho foi verificar os efeitos da aplicação do imazamox na fase
reprodutiva de duas cultivares de arroz irrigado (IRGA 422 CL e PUITÁ INTA CL) que
diferem quanto ao nível de resistência as imidazolinonas. Em vista do exposto, foram
conduzidos dois estudos na área experimental da Universidade Federal de Santa Maria
(2009/10 e 2010/11). O imazamox foi aplicado em diferentes estádios de desenvolvimento e
doses, sendo que a dose final foi de 80 g i.a ha-1. Com os resultados obtidos conclui-se que
independente da data de aplicação do imazamox na fase reprodutiva da cultura ocorreu
redução da produtividade de grãos e aumentou a esterilidade de espiguetas da cultivar
IRGA 422 CL. De maneira geral, os parâmetros: peso de mil grãos, comprimento da folha
bandeira, comprimento de panícula, peso fresco e seco de panículas, e número de
panículas por metro quadrado mostraram redução em praticamente todos os tratamentos na
cultivar IRGA 422 CL. Alterações nos parâmetros bioquímicos (clorofila, carotenoides,
substâncias reativas ao ácido tiobarbitúrico, superóxido dismutase, catalase e ascorbato
peroxidase) foram observadas em folhas e panículas do colmo principal em alguns
tratamentos, demonstrando que o estresse oxidativo provocado pela aplicação do imazamox
pode ter contribuído para a redução da produtividade de grãos e o elevado percentual de
espiguetas estéreis da cultivar IRGA 422 CL. A cultivar PUITÁ INTA CL não sofreu
alterações em todos os parâmetros avaliados neste estudo. As alterações morfológicas e
anatômicas demonstraram que a aplicação de 80 g i.a ha-1 imazamox na diferenciação da
panícula promoveu alterações semelhantes às alterações homeóticas observadas em arroz
mutante. Além disso, nas plantas que receberam a dose de 80 g i.a ha-1 após 14 dias da
diferenciação do primórdio floral (DPF) e as plantas que receberam a dose de 80 g i.a ha-1
em aplicação fracionada (metade da dose 7 dias após DPF e metade da dose aos 14 dias
após DPF) mostraram alterações morfológicas e anatômicas do grão de pólen. Dado o
exposto, os resultados obtidos sugerem que as alterações morfológicas e anatômicas foram
responsáveis pela redução da produtividade de grãos e alto percentual de espiguetas
estéreis da cultivar IRGA 422 CL.
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Mourning in feminine procreation and sterility: A psychodynarnic and projective approach / Duelo en la procreación y en la esterilidad femenina: enfoque psicodinámico y proyectivoClement, Anne K., Theis, Amandine, Tychey, Claude de 25 September 2017 (has links)
This paper uses a psychoanalytical framework to analyze women's mourning with regard to procreation and sterility. The psychodynamic factors related to this topic are described and illustrated with the presentation of a clinical case. This case was assessed with interviews and the Rorschach Inkblot Test according to the French system (de Tychey, 1994). The analysis of the data allows the discussion of the theoretical concepts and addresses the importance of the variety of conflicts that interfere with the desire of procreating. The findings are also discussed from an ethical point of view regarding the role that the clinician plays when he has to face these types of severe cases. / Se investiga sobre el trabajo en duelo de la procreación y en la esterilidad femenina dentro de un marco referencial psicoanalítico. Se describen desde el punto de vista teórico los factores psicodinámicos y se ejemplifica través de la presentación de un caso clínico evaluado con entrevistas y el test de Rorschach siguiendo el sistema francés (de Tychey 1994 ). Los resultados permiten discutir los conceptos teóricos y plantear la importancia de la variedad de conflictos que interfieren en el deseo de procrear. Se discuten los hallazgos desde un punto de vista ético en relación con la función del clínico para ayudar al cliente a enfrentar su severa problemática.
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Citometria de fase sólida aplicada ao teste de esterilidade do produto Cloreto de Sódio 0,9% Solução Injetável / Solid-Phase Cytometry applied to sterility test for Sodium chloride 0.9% Injectable Solution ProductSilva, Gisele Badauy Lauria 22 June 2015 (has links)
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Previous issue date: 2015-06-22 / The sterility test is a test that certificate the absence of viable microorganisms in pharmaceutical raw materials, drugs and medical device. The Solid Phase Cytometry method (SFC) is based on the detection of viable cells through the use of viability markers reagents, that permeate the cell membrane and are cleaved by nonspecific esterase enzymes, forming the fluorochromes that are detected by ChemScan RDI® equipment. It is a fast and innovative method for the sterile injecting drugs area. The objective of the study was to evaluate and validate this technology applied to the sterility test, of the product Sodium Chloride (NaCl) 0.9% Injectable Solution, using the ChemScan RDI® equipment (CS RDI®). Eight microorganisms were evaluated, being six compendial (Clostridium sporogenes NCTC 12935 (ATCC 11437), Pseudomonas aeruginosa NCTC 12924 (ATCC 9027), Staphylococcus aureus NCTC 10788 (ATCC 6538), Bacillus subtilis NCTC 10400 (ATCC 6633), Aspergillus brasiliensis NCPF 2275 (ATCC 16404) and Candida albicans NCPF 3179 (ATCC 10231)) and two "in house” microorganisms, obtained from bioburden monitoring of pre sterilization (Micrococcus luteus and Staphylococcus epidermidis). The Solid Phase Cytometry methodology through logistic regression statistical analysis and Chi-square test, showed to be more rapid than the sterility test by membrane filtration (MF) for all tested microorganisms, reducing the analysis time from 14 days to about 3 hours. The method was validated by the use of qualitative parameters: specificity, limit of detection and robustness. / O teste de esterilidade é um ensaio que certifica a ausência de micro-organismos viáveis em insumos farmacêuticos, medicamentos e produtos para saúde. A Citometria de Fase Sólida (CFS) é um método rápido e inovador para a área de medicamentos estéreis injetáveis e é fundamentado na detecção de células viáveis através da utilização de reagentes marcadores de viabilidade, que permeiam a membrana celular e são clivados por enzimas esterases não específicas, formando o fluorocromo, que são detectados pelo equipamento ChemScan RDI®. O objetivo do estudo foi avaliar e validar esta tecnologia aplicada para o teste de esterilidade, no produto Cloreto de Sódio (NaCl) 0,9% Solução Injetável, utilizando o equipamento ChemScan RDI® (CS RDI®). Os micro-organismos padrões utilizados para os testes foram Clostridium sporogenes NCTC 12935 (ATCC 11437), Pseudomonas aeruginosa NCTC 12924 (ATCC 9027), Staphylococcus aureus NCTC 10788 (ATCC 6538), Bacillus subtilis NCTC 10400 (ATCC 6633), Aspergillus brasiliensis NCPF 2275 (ATCC 16404) e Candida albicans NCPF 3179 (ATCC 10231), e dois micro-organismos “in house” obtidos do monitoramento da biocarga pré esterilização, o Micrococcus luteus e Staphylococcus epidermidis. O método de Citometria de Fase Sólida mostrou-se significativamente mais rápido em relação ao teste de esterilidade por filtração em membrana (FM) para todos os micro-organismos testados, reduzindo o tempo de análise de 14 dias para aproximadamente 3 horas. O método foi validado por meio da utilização dos parâmetros qualitativos: especificidade, limite de detecção e robustez.
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Meiotická homologní rekombinace a hybridní sterilita / Meiotic homologous recombination and hybrid sterilityGergelits, Václav January 2020 (has links)
(English) Meiotic homologous recombination, homologous chromosomes synapsis, and F1 hybrid sterility (enabling formation of species) are mutually interconnected phenomenons, one being the prerequisite to the latter. In the present thesis, these phenomenons were investigated on a genetic and mechanistic level using a mouse subspecies as a model. Noncrossovers (NCOs, gene conversions), 90% prevalent resolution of Prdm9- determined meiotic double-strand breaks (DSBs), were uniquely identified and characterized on a chromosome-wide level. The mean gene conversion tract length, based on 94 NCOs events, was calculated to be 32 bp. On a local level, the NCOs overlapped the known hotspots of PRDM9-controlled histone trimethylation and DSB formation, indicating their origin in the standard meiotic DSB repair pathway. On chromosome-wide level, NCO and CO distributions differed, in particular COs being relatively preferred over NCOs in subtelomeric regions. A specific subset of nonparental/asymmetric NCOs and COs was underrepresented in our datasets, proposing their problematic repair, hypothetically enabled by sister chromatids, and thus not contributing to indispensable homologous synapsis. Genome-wide crossover (CO) rates, genetically and mechanistically crucial ~10% of DSB repair, were proven to be...
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National Insecurity in the Nuclear Age: Cold War Manhood and the Gendered Discourse of U.S. Survival, 1945-1960Steinmetz, Melissa A. 30 July 2014 (has links)
No description available.
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Genetika a genomika hybridní sterility / Genetics and Genomics of Hybrid SterilityBhattacharyya, Tanmoy January 2013 (has links)
Charles University in Prague Faculty of Science Ph.D. study program: Molecular and Cellular Biology, Genetics and Virology Abstract Genetics and genomics of hybrid sterility Mgr. Tanmoy Bhattacharyya Supervisor: Prof. MUDr. Jiří Forejt, DrSc. Praha 2013 Abstract Male-limited hybrid sterility restricts gene flow between the related species, an important pre- requisite of speciation. The F1 hybrid males of PWD/Ph female (Mus m. musculus subspecies) and C57BL/6J or B6 male (Mus m. domesticus) are azoospermic and sterile (PB6F1), while the hybrids from the reciprocal (B6PF1) cross are semi fertile. A disproportionately large effect of the X chromosome (Chr) on hybrid male sterility is a widespread phenomenon accompanying the origin of new species. In the present study, we mapped two phenotypically distinct hybrid sterility loci Hstx1 and Hstx2 to a common 4.7 Mb region on Chr. X. Analysis of meiotic prophase I of PB6F1 sterile males revealed meiotic block at mid-late pachynema and the TUNEL assay showed apoptosis of arrested spermatocytes. In sterile males over 95% of pachytene spermatocytes showed one or more unsynapsed autosomes visualized by anti SYCP1, HORMAD2 and SYCP3 antibodies. The phosphorylated form of H2AFX histone, normally restricted only to XY chromosome containing sex body decorated unsynapsed...
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Evolution de la gynodioécie-gynomonoécie : approches expérimentales chez Silene nutans & approche théorique / Evolution of gynodioecy-gynomonoecy : experimental approaches in Silene nutans & theoretical approachGarraud, Claire 11 March 2011 (has links)
Chez les plantes à fleurs, la gynodioécie -- système dans lequel coexistent des individus femelles et des individus hermaphrodites -- est le système de reproduction le plus commun après l'hermaphrodisme. La question de l'évolution et surtout du maintien de la gynodioécie et du polymorphisme génétique sous-jacent a intrigué les chercheurs depuis le 19e siecle. Aujourd'hui, les grands principes de son évolution sont posés mais beaucoup de zones d'ombres persistent. Durant ma thèse, j'ai exploré trois aspects de la gynodioécie en utilisant une approche expérimentale chez l'espèce Silene nutans et une approche théorique. Je me suis en premier lieu intéressée au déterminisme génétique de la gynodioécie grâce à la réalisation de croisements contrôlés qui m'ont permis de montrer que le déterminisme génétique du sexe était cytonucléaire, c'est à dire contrôlé par plusieurs gènes de stérilité mâle cytoplasmique (CMS) et plusieurs restaurateurs nucléaires de fertilité. En parallèle, j'ai porté une attention particulière aux plantes gynomonoïques -- celles où coexistent sur le même pied des fleurs pistillés (femelles) et des fleurs parfaites (hermaphrodites) -- fréquentes chez Silene nutans comme chez d'autres espèces gynodioïques. J'ai montré que les caractéristiques reproductrices et florales de ce troisième phénotype sexuel étaient souvent intermédiaires entre celles des femelles et des hermaphrodites mais pouvaient dépendre de la proportion de fleurs pistillées sur la plante. Par ailleurs et contrairement à ce qui avait été suggéré, la plasticité du phénotype gynomonoïque s'est révélée être relativement réduite, suggérant un déterminisme génétique dont la caractérisation est encore en cours. La troisième partie de ma thèse a été motivée par les preuves récentes d'hétéroplasmie -- coexistence de différents génomes mitochondriaux au sein d'un individu -- et de la transmission occasionnelle du génome mitochondrial par le pollen chez Silene vulgaris. J'ai montré théoriquement que la présence d'un gène de stérilité mâle cytoplasmique favorisait l'évolution de la fuite paternelle de mitochondries. J'ai également vérifié expérimentalement l'hérédité mitochondriale chez Silene nutans par le génotypage des descendances de croisements contrôlés. / In flowering plants, gynodioecy -- a system in which females and hermaphrodites coexist within populations -- is the most common sexual system after hermaphroditism. The evolution and maintenance of gynodiocy and its underlying polymorphism have puzzled evolutionary biologists since the 19th century. The main principles of its evolution are well known but some points remain vague. During my PhD, I explored three aspects of gynodioecy using an experimental approach in the species Silene nutans and a theoretical approach. First, I studied the genetic determination of gynodioecy using controlled crosses that showed that the genetic determination of sex was cytonuclear, i.e. controlled by several cytoplasmic male sterility (CMS) genes and several nuclear restorers of fertility. Second, I focused on gynomonoecious plants -- those that carry both pistillate (female) flowers and perfect (hermaphrodite) flowers -- that are frequently found in Silene nutans as in other gynodioecious species. I showed that the floral and reproductive traits of this third sex phenotype were often intermediate between those of females and hermaphrodites but varied with varying proportions of pistillate flowers on the plant. Contrary to what was previously thought, the plasticity of the gynomoneocious phenotype was found to be limited, suggesting a genetic determination whose characterization is still in progress. The third part of my PhD was motivated by recent evidences of heteroplasmy -- the coexistence of different mitochondrial genomes within an individual -- and occasional transmission of the mitochondrial genome through pollen in Silene vulgaris. I showed theoretically that the occurrence of a cytoplasmic male sterility gene can favor the evolution of paternal leakage of mitochondria. I also investigated mitochondrial inheritance in Silene nutans by genotyping progenies from controlled crosses.
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