A hibridação pode ter várias consequências, incluindo a manutenção ou aumento da diversidade resultando em zonas de hibridação estáveis; a introdução de nova variedade alélica que pode acarretar na origem ou transferência de adaptações, que pode ter efeito positivo no resgate de populações pequenas puras; o reforço do isolamento reprodutivo e a formação de novas linhagens híbridas. Além disso, a hibridação pode reduzir a diversidade, pois a quebra das barreiras reprodutivas e a mescla de populações anteriormente distintas pode acarretar na extinção de uma das populações ou espécies envolvidas na hibridação. Nesse cenário, nosso estudo teve como objetivo estudar uma zona de hibridação no estado da Bahia entre duas espécies de aves, Pyriglena atra (Swaison 1825) e P. leucoptera (Vieillot 1818). Foram analisados mais de 20.000 SNPs de 20 indivíduos de P. leucoptera, 22 de P. atra e seis indivíduos intermediários morfológicos. Encontramos pouca a nenhuma mistura genética nos intermediários morfológicos, o que indica um descompasso entre genótipo e fenótipo, o que poderia estar associado ao fato de os marcadores genéticos analisados terem.se mostrado neutros, enquanto a morfologia externa pode estar sob pressão de seleção sexual. Foi detectado que as localidades adjacentes à zona de hibridação apresentaram mistura genética na maioria dos indivíduos, um indicativo de que além de hibridação, esteja ocorrendo introgressão entre as espécies, sendo maior em P. leucoptera, o que pode ser consequência de \"genetic surfing\" / Hybridization can have many consequences, including maintenance or increase of diversity resulting in stable hybridization zones; introduction of a new allelic variety that can lead to the origin or transfer of adaptations, that may result on a positive effect on the rescue of small pure populations; enhancement of reproductive isolation and the origin of new species. In addition, hybridization may reduce diversity, as the break of reproductive barriers and the mixture of previously distinct populations may lead to the extinction of one of the populations or species. In this scenario, our study aimed to study a hybridization zone in the state of Bahia between two bird species, Pyriglena atra (Swaison 1825) and P. leucoptera (Vieillot 1818). We analyzed more than 20,000 SNPs from 20 individuals of P. leucoptera, 22 P. atra and six morphological intermediate individuals. We found little or no genetic mixture in the morphological intermediates, which indicates a mismatch between genotype and phenotype, possibly because these molecular markers were tested as neutral and these morphological characters could be under sexual selection. The majority of the individuals from localities adjacent to the hybrid zone have mixed ancestry, an indication that, besides hybridization, introgression among the species is occurring but higher into P. leucoptera as a possible consequence of genetic surfing

Begonia is one of the ten largest plant genera and is found throughout the tropics. I have used Begonia section Gireoudia to study the genetics underlying vegetative diversity in tropical herbaceous plants. Section Gireoudia is a large Central American group. The section is remarkably diverse in morphology and habitat preference. It ranges from wet rainforests to seasonally dry forests. I have investigated variation in morphological, anatomical and ecophysiological differences for 21 species in Begonia section Gireoudia. Based on the observed variation, species in Begonia section Gireoudia form a complex and unique group that stands out from currently analysed taxa in the global scale of variation on the basis of leaf function and resource use strategy traits as well as their peculiar leaf anatomy. Traits directly related to leaf function such as photosynthesis and stomatal conductance has very low values which overlap with those of CAM and aquatic plants. Values for traits indicative of resource use such as leaf mass area (LMA) and leaf dry matter content (LDMC) are also very low in Begonia when compared with the values observed globally. The trait- trait correlations across the species in section Gireoudia were also investigated and revealed patterns in micromorphology and ecophysiology. Some of the traits measured are correlated with each other in apparently straightforward, well charaterised biological relationships e.g., the variation among Begonia species in stomatal conductance and net assimilation rate are positively correlated. On the other hand, the linkage of high Amass with high Nmass which is in large part the result of a direct causal relationship, has been observed at the global scale but this relationship is not significant in Begonia section Gireoudia. I examined B. plebeja and B. conchifolia, two very closely related though ecologically divergent species from Meso-America, in more detail. I detected significant differences between the species for a number of phenotypic variables which may be related to their habitat preferences. This suggested that environmental conditions have driven divergent evolution of phenotypic traits for these two species. Using a mapping population generated from hybrids between these two species I was able to examine the genetic basis of these differences. This revealed that although some traits (such as anthocyanin accumulation) appear to be under simple genetic control, most of the variation between species has complex genetic inheritance patterns. I used QTL analysis to identify significant QTLs for 20 physiological, anatomical and morphological traits which varied between these two species. Leaf shape traits appear to be largely influenced by a few loci of large effect, making these good potential targets for further analysis. The study also identified clusters of coincident QTLs for different correlated traits identifying pleiotropic genes or suites of linked loci.

Typescript (photocopy) / xiii, 209 leaves : ill., (1 col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Genetics, 1983

Porous inorganic materials that can be used in applications such as catalysis and separations have been intensely studied due to their potential stability, ease of recovery and high surface areas. Organic-inorganic hybrid materials meet these criteria by exploiting the physical robustness of porous inorganic materials and the chemical functionality of organic materials. While amorphous oxides are widely used industrially as inorganic supports, disordered pore structures make them difficult to characterize. Ordered-mesoporous-silica (OMS), such as SBA-15, that have ordered pores structures simplify characterization and are useful models for studying hybrid materials. Dendrimers, once appropriately functionalized, have high densities of uniformly distributed functional groups. In this thesis, melamine-based dendrimer/SBA-15 hybrids were synthesized and characterized using a wide range of analytical techniques. This thesis shows that the porosity can be independently altered by varying 1) the dendrimer generation, 2) the linker molecule, and 3) the surface amine loading. Cu(II) sequestration results demonstrate that the peripheral functional groups of the dendrimer are readily accessible for binding. This thesis also describes preliminary work toward preparing an enantioselective catalyst using L-proline supported on OMS. This work includes the synthesis and testing of three dendrimer-like proline derivatives. Future work in this area is outlined and will include synthesizing catalysts based on the dendrimer hybrid system previously described. Solution dendrimer syntheses will also be performed to create solution-based catalysts.

This dissertation focuses on the development of integrated circuits that employ InAs quantum well electronic devices. There are two InAs quantum well electronic devices studied in this work, the first being the pseudomorphic InAs/In₀.₅₃Ga₀.₄₇As/AlAs resonant tunneling diode (RTD) grown on an InP substrate, and the second being the InAs/AlSb HEMT. Because of there is no semi-insulating substrate near the InAs lattice constant of 6.06 Å this work develops monolithic and hybrid integration methods to realize integrated circuits. For the case of hybrid RTD circuits, a thin-film integration method was developed to integrate InAs/In₀.₅₃Ga₀.₄₇As/AlAs RTDs to prefabricated CMOS circuits, and this technique was employed to demonstrate a novel RTD-CMOS comparator. To achieve higher speed circuit operation, a next-generation RTD fabrication process was developed to minimize the parasitic capacitance associated with the thin-film hybridization process. This improved fabrication process is detailed and yield and uniformity analysis is included. Similar InP-based tunnel diodes can be integrated with InP-based HEMTs in monolithic RTD-HEMT integrated circuits, and in this work elementary microwave circuit components were characterized that co-integrate InP-based tunnel diodes with HEMTs. In the case of the InAs/AlSb HEMT, the monolithic approach grows the HEMT on a metamorphic buffer on a GaAs substrate. The semiconductor material and process development of the InAs/AlSb HEMT MMIC technology is described. The remarkable microwave and RF noise properties of the InAs/AlSb HEMT were characterized and analyzed, with special attention given to the strong effects of impact ionization in the narrow bandgap InAs channel. Results showed the extent to which impact ionization affects the small-signal gain and noise figure of the HEMT, and that these effects become less prevalent as the frequency of operation increases.

Porous inorganic materials that can be used in applications such as catalysis and separations have been intensely studied due to their potential stability, ease of recovery and high surface areas. Organic-inorganic hybrid materials meet these criteria by exploiting the physical robustness of porous inorganic materials and the chemical functionality of organic materials. While amorphous oxides are widely used industrially as inorganic supports, disordered pore structures make them difficult to characterize. Ordered-mesoporous-silica (OMS), such as SBA-15, that have ordered pores structures simplify characterization and are useful models for studying hybrid materials. Dendrimers, once appropriately functionalized, have high densities of uniformly distributed functional groups. In this thesis, melamine-based dendrimer/SBA-15 hybrids were synthesized and characterized using a wide range of analytical techniques. This thesis shows that the porosity can be independently altered by varying 1) the dendrimer generation, 2) the linker molecule, and 3) the surface amine loading. Cu(II) sequestration results demonstrate that the peripheral functional groups of the dendrimer are readily accessible for binding. This thesis also describes preliminary work toward preparing an enantioselective catalyst using L-proline supported on OMS. This work includes the synthesis and testing of three dendrimer-like proline derivatives. Future work in this area is outlined and will include synthesizing catalysts based on the dendrimer hybrid system previously described. Solution dendrimer syntheses will also be performed to create solution-based catalysts.

No description available.

Typescript (photocopy) / xiii, 209 leaves : ill., (1 col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Genetics, 1983

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / This research project was carried out using the ornamental species E. erythronema, E. stricklandii, their natural interspecific hybrid E. 'Urrbrae Gem', and artificial hybrids of these two species, with the aim of identifying a clonal propagation method for hybrid omamental eucalypts using the tissue culture techniques of micropropagation, organogenesis and somatic embryogenesis. Seeds of E. erythronema, E. stricklandii, and E. 'Urrbrae Gem' were decontaminated and germinated in culture for experiments on callus growth and response to plant growth regulators. Murashige and Skoog (1962) medium supplemented with 1 uM BAP, 10 uM NAA, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel® proved the most suitable callus growth medium when compared to those of Gamborg (1968), Lloyd and McCown (woody plant medium) (1980), Almehdi and Parfitt (1996) and de Fossard(1976) (Eucalyptus). A range and combination of plant growth regulators was used to investigate organogenesis, somatic embryogenesis and axillary shoot proliferation. A broad based experiment was first conducted to assess the response of the hybrid and its parental species to wide concentrations of commonly used auxins and cytokinins known to induce organogenesis and somatic embryogenesis. Callus growth was consistent across all genotypes and tissue types with soft and spongy callus growth in the presence of 2,4-D and hard and friable callus in the presence of NAA, while callus growth was greater with auxin or auxin/cytokinin (BAP or kinetin) combinations compared to cytokinin alone. Healthy root development was observed from treatments with NAA, while roots that developed from treatments with 2,4-D turned brown within 12 weeks. Bud development was observed with BAP alone or in combination with NAA with large bud clusters observed on E. erythronema and E. 'Urrbrae Gem' explants. Shoots, were observed in treatments with NAA alone, or in combination with BAP or kinetin, but not in treatments with 2,4-D. No somatic embryos were observed with any treatment or taxon. Light microscopy of explants treated with 2,4-D alone showed calli consisting only of large parenchyma cells, while 2,4¬D in combination with a cytokinin produced smaller parenchyma cells, with areas of vascular tissue and spherical growths. BAP, kinetin and NAA alone or in combination produced an increase in vascular tissue. Shoot and root initiation appeared to occur within the callus with connection to the vascular tissue. Shoot organogenesis from E. erythronema, E. stricklandii and E. 'Urrbrae Gem' seedlings and E. erythronema x E. stricklandii hybrid 2.5 was further investigated using apex and leaf explants with 1 uM and lower levels of BAP. Apex and leaf explants of E. erythronema and E. 'Urrbrae Gem' developed clusters of buds from the apex base and leaf petiole while apex and leaf explants of E. stricklandii and hybrid 2.5 produced individual buds. Bud and shoot development was greater on apex than leaf explants with 0.5 and 1 uM BAP producing the greatest shoot numbers. Light microscopy showed that meristem development had occurred within the callus and bud structures, but there were few shoot primordia considering the amount of meristem development (meristemoids). Somatic embryogenesis was further investigated in juvenile ad callus tissue using NAA, NAA/2,4-D combinations, and heat and smoked water treatments. Somatic embryogenesis was not observed macroscopically with 2,4-D and NAA treatments. Globular somatic embryo structures were observed on apex explants of 'Urrbrae Gem' seedlings at 2 wk on MS medium supplemented with 16.11 uM NAA but there was no development beyond the globular stage. Areas of defined callus development, which did not contain typical embryogenic cells, were observed on all treatments and genotypes. Root development was observed from all auxin treatments but was less on explants treated with 5.37 uM NAA/4.5 uM 2,4-D compared to NAA alone while roots and shoots developed simultaneously on apex explants after culture for 1 wk on MS medium supplemented with 80.55 uM NAA. Heat and smoked water were detrimental to E. 'Urrbrae Gem' callus and no somatic embryogenesis was observed. Explants from field trees of E. erythronema, E. stricklandii, E. 'Urrbrae Gem', E. erythronema x stricklandii hybrids 20E, 20P, 20R, 20T, 20V, 21A, 21G, 21U and potted plants of E. erythronema x E. stricklandii hybrids 35.2 and 2.5 growing under glasshouse conditions, were harvested and initiated into culture. Of the selected plants only explants from glasshouse grown material could be initiated into culture and multiplied. E. erythronema x stricklandii hybrids 35.2 and 2.5 . were multiplied by axillary shoot proliferation over 3 yr on Quoirin and Lepoivre medium (1977) with 2.2 uM BAP, 0.5 uM NAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. However root growth proved difficult as shoots developed short thick roots that failed to elongate and the plants could not be hardened off. By using zeatin in the multiplication medium and activated charcoal after the IBA pulse elongated roots suitable for hardening off were developed. By comparison seedlings of E. 'Urrbrae Gem' were successfully germinated in culture and multiplied by axillary shoot proliferation using WPM, 2.2 uM BAP, 0.5 uMNAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. They were rooted on 1/2WPM, 20 uM IBA, 10 g⁻¹ sucrose gelled with 7 g⁻¹ Phytagel® for 7 d, followed by subculture to PGR free medium. Following root initiation and growth plants were hardened off to the external environment. In conclusion genetic differences were observed between genotypes, in regards to initiation into culture, and response to nutrient medium, and plant growth regulators, with differences observed in explant deterioration, medium exudates, callus growth and appearance, somatic embryogenesis, bud, shoot and root organogenesis, axillary shoot development, and rooting of shoots. For organogenesis, juvenile explants were more responsive in culture than mature explants and potted plants more responsive than field plants for micropropagation. Shoot and root organogenesis was achieved from juvenile explants while shoot explants of E. erythronema x E, stricklandii hybrids were successfully micropropagated by axillary shoot proliferation. Somatic embryogenesis was observed with E. 'Urrbrae Gem' seedlings but was blocked at the globular stage. This research has provided a greater understanding of the clonal propagation requirements via tissue culture techniques for E. erythronema, E. stricklandii and their hybrids. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1177221 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2005

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / This research project was carried out using the ornamental species E. erythronema, E. stricklandii, their natural interspecific hybrid E. 'Urrbrae Gem', and artificial hybrids of these two species, with the aim of identifying a clonal propagation method for hybrid omamental eucalypts using the tissue culture techniques of micropropagation, organogenesis and somatic embryogenesis. Seeds of E. erythronema, E. stricklandii, and E. 'Urrbrae Gem' were decontaminated and germinated in culture for experiments on callus growth and response to plant growth regulators. Murashige and Skoog (1962) medium supplemented with 1 uM BAP, 10 uM NAA, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel® proved the most suitable callus growth medium when compared to those of Gamborg (1968), Lloyd and McCown (woody plant medium) (1980), Almehdi and Parfitt (1996) and de Fossard(1976) (Eucalyptus). A range and combination of plant growth regulators was used to investigate organogenesis, somatic embryogenesis and axillary shoot proliferation. A broad based experiment was first conducted to assess the response of the hybrid and its parental species to wide concentrations of commonly used auxins and cytokinins known to induce organogenesis and somatic embryogenesis. Callus growth was consistent across all genotypes and tissue types with soft and spongy callus growth in the presence of 2,4-D and hard and friable callus in the presence of NAA, while callus growth was greater with auxin or auxin/cytokinin (BAP or kinetin) combinations compared to cytokinin alone. Healthy root development was observed from treatments with NAA, while roots that developed from treatments with 2,4-D turned brown within 12 weeks. Bud development was observed with BAP alone or in combination with NAA with large bud clusters observed on E. erythronema and E. 'Urrbrae Gem' explants. Shoots, were observed in treatments with NAA alone, or in combination with BAP or kinetin, but not in treatments with 2,4-D. No somatic embryos were observed with any treatment or taxon. Light microscopy of explants treated with 2,4-D alone showed calli consisting only of large parenchyma cells, while 2,4¬D in combination with a cytokinin produced smaller parenchyma cells, with areas of vascular tissue and spherical growths. BAP, kinetin and NAA alone or in combination produced an increase in vascular tissue. Shoot and root initiation appeared to occur within the callus with connection to the vascular tissue. Shoot organogenesis from E. erythronema, E. stricklandii and E. 'Urrbrae Gem' seedlings and E. erythronema x E. stricklandii hybrid 2.5 was further investigated using apex and leaf explants with 1 uM and lower levels of BAP. Apex and leaf explants of E. erythronema and E. 'Urrbrae Gem' developed clusters of buds from the apex base and leaf petiole while apex and leaf explants of E. stricklandii and hybrid 2.5 produced individual buds. Bud and shoot development was greater on apex than leaf explants with 0.5 and 1 uM BAP producing the greatest shoot numbers. Light microscopy showed that meristem development had occurred within the callus and bud structures, but there were few shoot primordia considering the amount of meristem development (meristemoids). Somatic embryogenesis was further investigated in juvenile ad callus tissue using NAA, NAA/2,4-D combinations, and heat and smoked water treatments. Somatic embryogenesis was not observed macroscopically with 2,4-D and NAA treatments. Globular somatic embryo structures were observed on apex explants of 'Urrbrae Gem' seedlings at 2 wk on MS medium supplemented with 16.11 uM NAA but there was no development beyond the globular stage. Areas of defined callus development, which did not contain typical embryogenic cells, were observed on all treatments and genotypes. Root development was observed from all auxin treatments but was less on explants treated with 5.37 uM NAA/4.5 uM 2,4-D compared to NAA alone while roots and shoots developed simultaneously on apex explants after culture for 1 wk on MS medium supplemented with 80.55 uM NAA. Heat and smoked water were detrimental to E. 'Urrbrae Gem' callus and no somatic embryogenesis was observed. Explants from field trees of E. erythronema, E. stricklandii, E. 'Urrbrae Gem', E. erythronema x stricklandii hybrids 20E, 20P, 20R, 20T, 20V, 21A, 21G, 21U and potted plants of E. erythronema x E. stricklandii hybrids 35.2 and 2.5 growing under glasshouse conditions, were harvested and initiated into culture. Of the selected plants only explants from glasshouse grown material could be initiated into culture and multiplied. E. erythronema x stricklandii hybrids 35.2 and 2.5 . were multiplied by axillary shoot proliferation over 3 yr on Quoirin and Lepoivre medium (1977) with 2.2 uM BAP, 0.5 uM NAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. However root growth proved difficult as shoots developed short thick roots that failed to elongate and the plants could not be hardened off. By using zeatin in the multiplication medium and activated charcoal after the IBA pulse elongated roots suitable for hardening off were developed. By comparison seedlings of E. 'Urrbrae Gem' were successfully germinated in culture and multiplied by axillary shoot proliferation using WPM, 2.2 uM BAP, 0.5 uMNAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. They were rooted on 1/2WPM, 20 uM IBA, 10 g⁻¹ sucrose gelled with 7 g⁻¹ Phytagel® for 7 d, followed by subculture to PGR free medium. Following root initiation and growth plants were hardened off to the external environment. In conclusion genetic differences were observed between genotypes, in regards to initiation into culture, and response to nutrient medium, and plant growth regulators, with differences observed in explant deterioration, medium exudates, callus growth and appearance, somatic embryogenesis, bud, shoot and root organogenesis, axillary shoot development, and rooting of shoots. For organogenesis, juvenile explants were more responsive in culture than mature explants and potted plants more responsive than field plants for micropropagation. Shoot and root organogenesis was achieved from juvenile explants while shoot explants of E. erythronema x E, stricklandii hybrids were successfully micropropagated by axillary shoot proliferation. Somatic embryogenesis was observed with E. 'Urrbrae Gem' seedlings but was blocked at the globular stage. This research has provided a greater understanding of the clonal propagation requirements via tissue culture techniques for E. erythronema, E. stricklandii and their hybrids. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1177221 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2005