Fabaceae is the second most speciose plant family in the Core Cape Subregion (CCR) of South Africa, a Mediterranean type ecosystem, with mostly nutrient-poor soils. A majority of the legumes occurring in this region belong to the predominantly nitrogen-fixing subfamily Papilionoideae and they employ a variety of strategies for nutrient acquisition. However, legumes are neither uniformly nor randomly distributed in the CCR landscape. Instead, distinct legume species assemblages tend to occupy particular habitats within the landscape. The drivers of this distribution pattern are yet to be determined. In this thesis, it was hypothesized that edaphic factors (soil chemical and physical characteristics) and the distribution of rhizobia have influenced legume distributions in the CCR landscape. The influence of edaphic factors on the distribution of legume species assemblages in the Cape Peninsula (a microcosm of the CCR) is the subject of the second chapter of the thesis. It was hypothesized that the composition of legume species assemblages is correlated with soil physical and chemical properties and that the interaction of Phosphorus (P) and the three cations that often bind P, i.e. Aluminium, Calcium and Iron, making it unavailable to plants, drive legume species assemblages in the landscape. Soils from 27 legume sites, spanning all major soil types of the Cape Peninsula, were analysed for 31 chemical and physical properties. Surveys of legume species present at each site were conducted to generate a presence/absence matrix. Canonical correspondence analysis was used to test for a correlation between legume species composition and edaphic factors. The strength of the association between legume species composition and site groupings based on edaphic properties was assessed using indicator species analysis. A significant correlation between edaphic factors and species composition was found and the key edaphic parameters driving the relationship were clay content, iron (Fe), potassium (K), sulphur (S) and zinc (Zn). Indicator species, characteristic of the various edaphic habitats were also identified. These findings indicate that distinct edaphic habitats are occupied by discrete legume species assemblages, implying a significant influence of edaphic factors on the legume distributions. Chapter three of the thesis sought to determine if the ecological parameters; altitude, pH and soil type influence the distribution of the two main rhizobial genera (Burkholderia and Mesorhizobium) that nodulate various legumes of the CCR, and to determine the diversity and phylogenetic position of rhizobia that associate with the narrowly distributed and rare Indigofera superba in the CCR. The first objective was pursued through molecular characterisation of rhizobial strains isolated from nodules of legume species collected in the field across the Cape Peninsula. DNA sequences for 16S rRNA, recA and nodA were combined with data from a previous study that sampled broadly within the CCR and phylogenetic analyses were conducted. Tests for phylogenetic signals for the three ecological parameters were conducted, using the D statistic for soil type and Pagel’s λ for altitude and pH. These analyses were used to test the hypothesis that closely related species occupy similar habitats with respect to each of the three ecological parameters. For the study of rhizobial symbionts of Indigofera superba, field nodules were sampled from multiple populations across its distribution range and a phylogeny of its symbionts was reconstructed in a matrix that included symbionts of diverse legumes from different habitats within the CCR. The results showed that Burkholderia is restricted to acidic habitats, while Mesorhizobium occurs in both acidic and alkaline habitats. Additionally, both rhizobial genera showed significant phylogenetic clustering for pH and most soil types. However, none of the genera showed a phylogenetic structure with respect to altitude. These findings indicate that pH and soil type influence the distribution of rhizobia in the CCR. Implications of these findings for the distribution of legumes in the landscape are discussed. For the narrowly distributed I. superba, the results showed that it associates with diverse strains within the genus Burkholderia and such strains are not phylogenetically distinct from strains isolated from localities outside its distribution range. These findings lead to the hypothesis that I. superba does not exhibit rhizobia specificity at the intrageneric level. Testing of this hypothesis through analysis of its nodulation capability on soils from outside its distribution range is recommended. The fourth chapter of the thesis determined the extent of horizontal gene transfer among rhizobial genera in the Core Cape Subregion (CCR) of South Africa and reconstructed the ancestral symbionts of the legumes. Phylogenies of two chromosomal genes (16S rRNA and recA) and one nodulation gene (nodA) of rhizobia, isolated from diverse legumes in the CCR, were reconstructed using Bayesian and Maximum Likelihood techniques. A cophylogenetic analysis was used to test for congruence between the chromosomal and the nodA phylogenies. Five genera of rhizobia (Bradyrhizobium, Burkholderia, Ensifer, Mesorhizobium and Rhizobium) were studied. A phylogeny of the legumes was reconstructed from matK and rbcL DNA sequences and it was used to reconstruct their ancestral rhizobia, using Bayesian methods. The chromosomal phylogeny of the rhizobia was mostly incongruent with that of nodA, indicating potential horizontal inheritance of the latter. The nodA genes of Burkholderia, Mesorhizobium and Rhizobium had different evolutionary histories from their counterparts in other parts of the globe. Burkholderia was reconstructed as the ancestral symbionts of the CCR legumes. Evidence of co-diversification between the legumes and their symbionts was observed and this highlights a potential role of the legume-rhizobia interaction to the high diversity of legumes in the CCR. Finally, the availability of compatible rhizobia and their competitive ability are discussed as possible drivers for the lack of shared legumes between the CCR’s Fynbos biome and the Kwongan of Australia. Overall, the study shows that edaphic factors and biotic interactions (rhizobia) have significant influence on the distribution of legumes in the Cape Peninsula and the larger Core Cape Subregion of southern Africa. These findings are consistent with the theory that edaphic factors and biotic interactions have a strong influence on species distributions at local and site spatial scales.

Although the X chromosome is usually similar to the autosomes in size, gene density and cytogenetic appearance, theoretical models predict that its hemizygosity in males may cause unusual patterns of evolution. The sequencing of several genomes has indeed revealed differences between the X chromosome and the autosomes in the rates of gene divergence, patterns of gene expression and rates of gene movement between chromosomes. In this thesis, I have attempted to investigate some of these patterns and their possible causes. The first two chapters consist of theoretical and empirical work intended to analyse the rates of evolution of coding sequences of X-linked and autosomal loci, with particular emphasis on faster-X evolution, the theory that more effective selection on the X can lead to higher rates of adaptive evolution on this chromosome. By analyzing X-linked and autosomal coding sequence in several species of Drosophila, we found some evidence for more effective selection on the X, particularly evident in the higher levels of codon usage bias detected at X-linked loci. We argue that this could be due to higher levels of recombination on the X chromosome increasing its effective population size (NeX) relative to the autosomal effective population size (NeA). To further investigate this hypothesis, we have modeled the effect of increased NeX/NeA on rates of evolution and confirmed that this can contribute to faster-X evolution. The last two chapters deal with the evolution of sex-biased genes and the possible causes for their differential accumulation on the X. We used EST data to create expression profiles for D. melanogaster male-, female- and unbiased genes. Our results suggest that the expression levels of sex-biased genes are incompatible with the accepted iii model of sex-biased gene evolution. We also show that the deficit of testis-expressed genes that is observed in Drosophila seems to be stronger for highly expressed genes. In fact, for very lowly expressed genes, we observe a small excess of testis-expressed genes on the X. We attempt to discuss this pattern in view of what is currently known about the evolution of sex-biased gene expression.

Thesis (Ph. D.)--University of Michigan.

Dissertation (Ph.D.)--University of Michigan

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Though molecular phylogenetics has been very successful in reconstructing the evolutionary history of species, some phylogenies, particularly those involving ancient events, have proven difficult to resolve. One approach to improving the resolution of deep phylogenies is to increase the amount of data by including multiple genes assembled from public sequence databases. Using modern phylogenetic methods and abundant computing power, the vast amount of sequence data available in public databases can be brought to bear on difficult phylogenetic problems. In this thesis I outline the motivation for assembling large multigene datasets and lay out the obstacles associated with doing so. I discuss the various methods by which these obstacles can be overcome and describe a bioinformatics solution, TaxMan, that can be used to rapidly assemble very large datasets of aligned genes in a largely automated fashion. I also explain the design and features of TaxMan from a biological standpoint and present the results of benchmarking studies. I illustrate the use of TaxMan to assemble large multigene datasets for two groups of taxa – the subphylum Chelicerata and the superphylum Lophotrochozoa. Chelicerata is a diverse group of arthropods with an uncertain phylogeny. When a set of mitochondrial genes is used to analyse the relationships between the chelicerate orders, the conclusions are highly dependent upon the evolutionary model used and are affected by the presence of systematic compsitional bias in mitochondrial genomes. Lophotrochozoa is a recently-proposed group of protostome phyla. A number of distinct phylogenetic hypotheses concerning the relationships between lophotrochozoan phyla have been proposed. I compare the phylogenetic conclusions given by analysis of nuclear and mitochondrial protein-coding and rRNA genes to evaluate support for some of these hypotheses.

Thesis advisor: James M. O'Toole / This dissertation argues that the movement to restrict European immigration to the United States in the early 1900s was critically supported by a set of ideas that the dissertation refers to as "classic racialism." Derived from several intellectual traditions - such as anthropology, biology, criminology, eugenics and zoology - classic racialism posited that differences in human population groups were biologically determined and hereditary, and because of this fact, American nativists held that the "new" immigration to the United States had to be curtailed in order to save the American Anglo-Saxon racial stock. The dissertation uses Italian immigration to the United States as a case study for understanding the fluidity of racial and biological thought. While classic racialism played a key role in supporting nativists' calls for immigration restriction, advances in methods of scientific research were revolutionizing the fields of biology, genetics and anthropology. Research in these fields cast doubts on the veracity of intellectual claims made by classic racialists, which were increasingly untenable in the light of advancing scientific knowledge. The tensions between these competing intellectual paradigms of classic racialism and modern experimentalism in the late nineteenth- and early twentieth-centuries reveal the esoteric nature of scientific revolutions, in that the uncertainty and complexity of the developing biological and genetic sciences kept knowledge of scientific advances in these fields restricted to a narrow audience of professional scientists and academics. While modern experimental biology raised significant scientific doubts about the principles of classic racialism, it was the latter that influenced American immigration policy in the 1920s because of classic racialism's simplicity and the broad public recognition that "like produces like." / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: History.

This study is concerned with the teaching of biology in Utah secondary schools. It is based chiefly on analysis of: (1) the teaching procedures used by thirty-five teachers of biology in Utah who were designated by their principals as being outstanding teachers. and (2) the facilities and equipment these teachers think are essential.

The four year nursing programme is offered at the NEI in the EC province where this study was conducted. As early as 2009 the majority of first and second year nursing students of the NEI were academically unsuccessful in the subject biological science. This prompted the researcher to conduct a qualitative, contextual, exploratory and descriptive study to explore and describe the factors influencing the academic performance of students in the subject biological science at the NEI. Following an explanation of the Appreciative Inquiry (AI) process as the framework of the study and the purpose of the study, the consecutive sample of second year nursing students who consented to participate completed a written appreciative interview schedule. The findings of the content analysis process revealed factors influencing performance in the subject biological science as biological science content, nurse educator characteristics, study strategies, resources and biological science assessments. The recommendation was for all the stakeholders to play their various active roles towards influencing biological science performance positively. / Dissertation (MCur)--University of Pretoria, 2013. / gm2014 / Nursing Science / unrestricted

Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-15T14:27:16Z No. of bitstreams: 1 leandrobarretodutra.pdf: 1959699 bytes, checksum: 0e63c4aa2f87dd9180ea0af6a8410db0 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2015-12-15T15:46:50Z (GMT) No. of bitstreams: 1 leandrobarretodutra.pdf: 1959699 bytes, checksum: 0e63c4aa2f87dd9180ea0af6a8410db0 (MD5) / Made available in DSpace on 2015-12-15T15:46:50Z (GMT). No. of bitstreams: 1 leandrobarretodutra.pdf: 1959699 bytes, checksum: 0e63c4aa2f87dd9180ea0af6a8410db0 (MD5) Previous issue date: 2015-03-04 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Aprender como um exercício potente com a vida. Aprender a aprender no processo de viver. Usar a alegria como trilha de aprendizagens. Não havendo títulos e nem chefes. Amar como proposta: amor fati. Todo conhecimento se dá no corpo. Fica-se apavorado, certamente. É poético demais! É utópico! Mas segundo Eduardo Galeano, a utopia nos faz caminhar! Caminhemos! Nessas trilhas em invenções de formação de professores, a discussão da Ciência permeia a escrita. A tentativa de inventar ciências e modos de se viver na resistência pela alegria é o que move esta dissertação e para além dela, move a vida potente de quem ousa sonhar perigosamente com outros mundos possíveis. Augusto Boal nos dirige em sonhar quando diz que nós atores temos essa responsabilidade de inventar outro mundo, porque no fundo sabemos que outro mundo é possível. Acreditemos! Nessas trilhas de mestrar: fiz-me aluno e professor. Artistar aluno. Artistar professor. Num exercício contínuo. O palhaço foi chamado para professar a alegria da criança que vibra no presente. O palhaço que improvisa, que joga, que brinca, para nos ensinar a aprender com, a inventar com. O palhaço como professor dos professores. Ri dos medos e de suas ignorâncias. Ele que sempre está em relação, em jogo, vem alegre posicionarmo-nos em outra esfera de acontecimentos. Nesses imprevistos da vida, só o improviso dá conta provisoriamente do inesperado. Tudo que se quer é improvisar bem. Isso é exercício. Às vezes se acerta... mas, o treinar é questão fundante.O convite para a leitura desta dissertação é pensar outras biologias possíveis, outras relações entre professor-aluno, outros modos de resistir às intempéries e inventar-se outra coisa! Exercitar num nevoeiro povoado em conversações, numa peça teatral junto às metamorfoses nietzschianas e numa autobiografia presençada foram os modos arranjados para dar conta do problema, também, inventado: O que se pode fazer para se autoproduzir alegremente? A contação de histórias que se faz neste mestrado tenta responder essa questão eterna. Só tenta, outras respostas são possíveis. Se quer inventar métodos improvisados e singulares que servem para o presente e só. / Learn with life as a powerful exercise. Learning and learning in the living process. Use happiness as a path of apprenticeships. With no titles neither bosses. Love with a purpose: fati love. All the knowledge occurs in body. It gets certainly terrified. It is too much poetic. It is utopian! But according to Eduardo Galeano, the utopia makes us walking! So, let’s walk! In those tracks of teachers’ formation, the discussion of science permeates writing. The trying of inventing sciences and ways of living in the resistance of joy is what drives this thesis and far from that, it drives the powerful life of who dares dangerously to dream with other possible worlds. Augusto Boal guides us to dream when he says that we, the actors have the responsibility of inventing another world, because we know that another world is possible indeed. Let’s believe! On these tracks of teaching: I was a student and a teacher. An artist student.An artist teacher.In continuous exercise. The clown was called to profess the happiness of child which vibrates in the present. A clown who improvises and plays, to teach us with, to invent with.A clown as a professor of teachers. That laughs from his fearsand ignorance.He, who is always in relation to, in the game, joyfully comes to position ourselves in another sphere of events. In this unforeseen life, only improvisation gives provisionally account of unexpected. All that is wanted is to improvise well. It is exercise. We sometimes do it right…but, the training is fundamental. The invitation to the reading of this essay is to think about another possible biology, other student-teacher relations, and other ways to resist bad moments and invent other things! To exercise in a crowded talk, in a play with the nietzchianians metamorphosis and in an autobiography, those were the ways to handle with the problems, also invented: What we may do to happily produce ourselves? The stories telling we do in this master try to answer this eternal question. It only tries to, another answers are also possible. So invent makeshifts and singular methods which serve for the present and just it.