Thesis (M.S.)--Eastern Illinois University. / Vita. Includes bibliographical references (leaves 45-49).

Thèse--Méd.--Reims, 1973. N°: N° 13. / Bibliogr. ff. 52-60.

Th.--Musicologie--Paris, 1988. / Bibliogr. f. 308-337.

Morphogenesis in walled organisms represents a highly controlled process by which the variability of shapes arises through changes in the structure and mechanics of the cell wall. Despite taking different evolutionary paths, land plants and some brown algae exhibit great developmental and morphological similarities. In two brown algal model systems: the Sargassum muticum apex and the Fucus serratus embryo, I have used a combination of imaging techniques, growth analyses, surgical and pharmacological treatments, as well as molecular, biochemical and mechanical approaches to characterise the growth patterns and the cell wall contribution to shape change. To understand how the adult algal body is formed, I examined the branching strategy (phyllotaxis) in S. muticum. My results suggest that in S. muticum the spiral phyllotactic pattern and the apical cell division pattern are not linked. The phytohormone auxin and the biochemical changes of the cell wall do not seem to be correlated with the bud outgrowth, contrary to observations in plants. In summary, these results suggest Sargassum convergently developed a distinct growth mechanism with similar shape outcome as observed in plants. This dissertation is one of the first attempts to explore cell wall mechanics in brown algal development and its correlation with underlying cell wall biochemistry utilising the Fucus embryo as a known system. The results suggest a correlation between the wall mechanics and alginate biochemistry with the growing and non-growing regions of the embryo. In addition, altering cell wall deposition or composition has a strong effect on embryo rhizoid elongation and is, in certain cases, accompanied by significant increase in cell wall stiffness and reduction of alginate epitopes. Furthermore, preliminary results exploring transcriptomic changes during development indicate differential expression of particular alginate biosynthesis enzymes (mannuronan C5 epimerases) during development, suggesting alginate conformational modifications might be stage specific. These results contribute to the current knowledge addressing the importance of cell walls in brown algal development using novel tools and approaches. Understanding developmental processes in brown algae will provide a better insight how similar morphogenetic traits are established using different body-building mechanisms.

IBSP gene for bone sialoprotein plays an important role in bone mineralization. The aim of the study was to find out if there is an association between bone mineral composition and A211G polymorphism in gene for bone sialoprotein. PCR-RFLP method was used for polymorphism genotyping. Calcium and phosphorus content of bone tissue were determined photometrically. The three-point bending test was applied to measure bone strength. Results was evaluated by one-way ANOVA with Fisher LSD post-hoc testing. No statistically significant differences between genotypes were found. This findings shows no support for association between bone content and polymorphism. So A211G polymorphism cannot been recommended for MAS.

Submitted by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2017-07-26T14:38:10Z No. of bitstreams: 1 texto completo.pdf: 12251207 bytes, checksum: ced78226c04d431930b6d9934beacc56 (MD5) / Made available in DSpace on 2017-07-26T14:38:10Z (GMT). No. of bitstreams: 1 texto completo.pdf: 12251207 bytes, checksum: ced78226c04d431930b6d9934beacc56 (MD5) Previous issue date: 1988-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Com base em dados do Ensaio Ecológico de Milho realizado no CNPMS-EMBRAPA, nos anos agrícolas de 1976/77, 1977/78 e 1978/79, determinou-se o acúmulo, em graus-dias, pelo método de Brown, para três cultivares de milho atingirem os estádios fenológicos da emergência, do pendoamento e do espigamento. Fez-se a análise estatística dos dados, estabelecendo a ordem de precocidade dos cultivares. Para o período do plantio ao espigamento, os cultivares Phoenix, M. Amarillo e Pioneer 515 necessitaram de 2390 GD, 2201 GD e 2086 GD, respectivamente. Analisou-se a influência da água disponível no solo durante a estação de crescimento sobre a variação no acúmulo de graus-dias do plantio até o espigamento de três cultivares de milho, em oito diferentes datas de plantio. As épocas de plantio da cultura do milho foram analisadas em função das condições agroclimáticas na estação de crescimento em Sete Lagoas e das exigências térmicas e hídricas dos cultivares de milho.

No description available.

Philosophiae Doctor - PhD / Recently, a great deal of interest has developed towards the isolation of bioactive compounds from marine sources due to their numerous health benefits. Furthermore, marine algae are valuable sources of structurally diverse metabolites with scientifically proven therapeutic claims. The cell walls are rich in sulfated polysaccharides such as fucoidans in brown algae, carrageenans in red algae and ulvans in green algae. These sulfated polysaccharides exhibit many beneficial biological activities such as anticoagulant, antiviral, antioxidative, anticancer and immunomodulating activities. They have great potential for further development as products in cosmeceutical, pharmaceutical and nutraceutical areas. Although the mechanism of action is still not clear, their biological activities could be mainly attributed to their major secondary metabolites namely; phlorotannins, terpenoids and fucoidans. There was use of comprehensive chromatographic separations and a full analysis of isolates using one or other of the spectroscopic techniques. Antioxidant and cytotoxicity tests were perfomed in details for Ecklonia maxima. Furthermore, structural and electronic features of the phlorotannins were compared in an attempt to provide an explanation for the differences in their radical scavenging properties. In this regard, two main radical scavenging mechanisms, hydrogen atom transfer (HAT) and electron transfer (ET), were assessed in order to determine the preferred mode of radical scavenging. Fully relaxed geometry optimizations of the neutral and the radical species were performed utilizing DFT/B3LYP and DFT/UB3LYP methods respectively. In further studies, the structural and functional properties of sulfated polysaccharides from the three brown and one red seaweeds were investigated. This was through detailed analysis of chemical composition of crude and purified polysaccharides using PMP - derivatization of hydrolysed sugars, anion exchange, molecular weight determination, ion chromatography , FT-IR, NMR to methylation analysis. The work reports isolation and characterization of compounds from four algae: Ecklonia maxima, phlorotannin derivatives, namely phloroglucinol (22), eckol (23), 7-phloroeckol (24), 2-phloroeckol (25) and a sterol, 24-ethylidine cholesterol (26); Splachinidium rugosum, 24-ethylidine cholesterol ( 26), 1, 3-Dicapryloyl-2-oleoylglycerol (27), E-3,7,11,15-tetramethylhexa dec-2-en-1-ol (phytol) (2 8); Macrocystis angustifolia, 24-ethylidine cholesterol (26); a red seaweed Aeodes orbitosa, and E -3, 7, 11, 15-tetramethylhexad ec-2-en-1-ol (28) and 17-(5-Ethyl-6-methylheptan-2-yl)-10,13-dimethyl-2,3,4,7, 8,9,11,12,14,15,16,17-dodecahydro-1 H-cyclopenta[a]phenanthren-3-ol (β-sitosterol) (29). Experimental findings and theoretical predictions of phlorotannins indicated that the radical scavenging activities followed the order 22< 23 < 25 < 24. Theoretical studies further indicated the ET mechanism is more significant than the HAT mechanism due to the high BDE values. Their polysaccharide structures were tentatively shown to have a backbone of (1-3) and (1-4) linkages with sulfate groups at O-2 and O-2, 3 positions. The only red algae studied contained, 2-O-methyl-D-galactose with (1-3) and (1-4)-glycosidic linkages possessing sulfate groups at positions 2 and 6.

Abstract Maintaining connectivity in boreal streams by rehabilitation procedures is a challenging task that requires ecological understanding based on empirical research. In this thesis, I examined the effects of stream rehabilitation on densities and growth of brown trout (Salmo trutta L.), as well as on benthic biodiversity. As streams are known to be closely connected to their watersheds, I also examined the effects of watershed drainage activities on stream organisms. The results of this thesis have implications for enhancing salmonid populations, as well for maintaining stream biodiversity. First, regional climatic variability was shown to override local impacts of watershed management on stream biota. This highlights the importance of placing results from local studies in a regional context. Second, increased sedimentation that typically follows anthropogenic actions in the watershed did not only cause direct mortality on the early life stages of brown trout, but also forced them to emerge earlier from gravel and constrained their development. Thus, sedimentation may have far-reaching fitness consequences on juvenile salmonids. Third, while instream rehabilitation did enhance habitat diversity for salmonid fish, there were only marginal effects on juvenile fish and benthic biodiversity. Therefore, the factors limiting stream biota, and obscuring positive effects of rehabilitation, are to be found elsewhere. For this purpose, my thesis offers at least three potential, not mutually exclusive explanations: (i) land use changes have altered watersheds and this can be seen as decreased stream biodiversity that cannot be corrected through local-scale restoration efforts; (ii) a habitat-forming organism group, stream bryophytes, is dispersal limited, slowing down any positive responses to restoration by fish or invertebrates that depend strongly on bryophytes; and (iii) changes to stream habitat heterogeneity caused by channelization for timber floating were rather modest to start with, and therefore any effects of stream habitat rehabilitation on stream biota are likely to be subtle. Based on these findings, I suggest that future restoration efforts should be prioritized according to a comprehensive watershed assessment. Also, monitoring of projects should be more rigorous and preferably multidisciplinary, documenting the ecological as well as hydrological and socioeconomic outcomes of rehabilitation projects.

Abstract For effective management of stream salmonids, it is essential to (i) assess the productive potential of a stream in relation to species-specific habitat requirements, and to (ii) identify the key factors underlying any bottleneck periods during the life cycle of a fish. For this purpose, this PhD-thesis focuses on the mechanisms of habitat selection by juvenile salmonids in boreal streams. Habitat preference curves for depth, water velocity, substrate and instream cover for brown trout (Salmo trutta L.) in river Kuusinkijoki, northeastern Finland, indicated that larger trout preferred deeper stream areas than age-0 trout did. In summer, all size-classes of trout preferred small substrates, whereas in winter, areas with cobble-boulder substrates were preferred. Winter presents a bottleneck period for trout in boreal streams; therefore winter habitat curves should be incorporated into habitat-hydraulic models when estimating habitat suitable for riverine trout in areas with severe winter conditions. The preference curves of age-0 trout were validated by correlating age-0 trout density with habitat availability at multiple sites in two boreal rivers where trout densities were monitored in 1988-1995. Substrate preference curve was effective in predicting trout densities among sites, whereas among-year variation in trout densities was best predicted by depth-related preference curves. The responses of age-0 brown trout and grayling (Thymallus thymallus (L.)) to enhancement structures were investigated in artificial stream flumes. For both species a crucial habitat factor was the availability of flow refuges, especially in winter. In another experiment, age-1 trout dominated over age-0 trout when competing for velocity and overhead cover they both found suitable, emphasizing the role of intraspecific interactions in habitat selection by trout. These results suggest that the provision of a broad diversity of microhabitats should be a major goal in rehabilitation programs for fishery purposes. A new method, combining GIS-assisted (Geographical Information System) approach with geostatistical tools, facilitated the detection of fish distribution patterns in a spatially heterogenous stream habitat. The method will likely prove valuable when determining appropriate sampling scale(s) for future studies of fish habitat selection in relation to benthic prey. Unlike Arctic bullhead (Cottus poecilopus, Heckel), trout did not show any aggregation with their benthic prey according to spatially-referenced data on the distribution of lotic fishes and benthic macroinvertebrates within a stream reach.