Thesis (M.S.)--Oregon State University, 1987. / Typescript (photocopy). Includes bibliographical references (leaves 65-71). Also available online.

Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains ix, 111 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

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Ion exchange membranes (IEMs) play an important role in a reverse electrodialysis (RED) system for salinity gradient power generation. Challenges exist in the selection of appropriate membrane materials in order to reduce the capital cost of membrane manufacturing and in the design of proper RED membranes to optimize the energy-producing process. This work presents the synthesis of hybrid cation exchange membranes by incorporating two well-known inexpensive organic polymers with great film-forming ability. Sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO) polymer mixed with sulfated polyvinyl alcohol (sPVA) has been proved to have great potential as a candidate for RED membranes. The prepared membranes with 2 to 10 wt% sPVA have improved the permselectivity up to 87 % and reduced area resistance down to 1.31 ohm cm-2, which is comparable to the commercially available FKS (Fumasep®, Germany) membranes. The best performance was achieved with hybrid membrane containing 5 wt% of sPVA which resulted in a gross power density at 0.46 W/m2. This power density is 14% greater than that achieved using commercial FKS membranes. This study shows a great potential of using organic-organic hybrid membranes for the RED power generation system.

A dilemma is posed by studies of galaxy evolution at intermediate redshifts. If evolutionary effects are neglected, simple models predict number densities of faint galaxies which are 2—5x lower than observed at z ≅ 0.4. Yet the faint galaxy redshift distribution appears to be well modelled by the same no—evolution models. If low-mass starbursting galaxies are responsible for the excess, then the excess faint galaxy population should have rotation velocities lower than those of quiescent galaxies with the same luminosity. This thesis describes the results of a limited survey of the internal kinematics of intermediate redshift (z = 0.25—0.45) field galaxies. The goal of this survey was to find the unmistakable kinematical signature of low-mass starbursting galaxies. Using the Canada-France-Hawaii Telescope, spatially resolved spectra of the [O II] λλ 3726—3729 Å doublet emission line have been obtained for 22 galaxies. High-spatial resolution has made it possible to extract [special characters omitted] and [O II] disk scale length from each galaxy spectrum using synthetic galaxy rotation curve fitting. It is found that about 25% of the galaxies in the sample have [OIl] kinematics unrelated to rotation. [OIl] emission is concentrated in the nucleus in these “kinematically anomalous" galaxies. A Doppler ellipse similar to those found in local dwarf irregular galaxies has been observed in a z = 0.35 galaxy. An intermediate redshift Tully-Fisher (TF) relation defined by 12 kinematically normal galaxies shows that these galaxies have a systematically lower rotation velocity (i.e. mass) for their luminosity than expected from the local TF relation. These galaxies would have to fade by ~ 1.5-2 mag to lie on the local TF relation. This is consistent with starbursting dwarf galeixy models. Although the sample is small, there is also a hint that massive galaxies do not lie as far off the local TF relation as low-mass ones. However, as shown using a large sample of local galaxies, the scatter in the local TF relation is large, especially for late-type galaxies. Selection effects, particularly [OIl] emission strength, could be responsible for part of the observed TF shift if different star formation rates are responsible for the local TF scatter. A comparison with other works indicates that the luminosity-dependent luminosity evolution scenario neatly explains all the available internal kinematics and surface brightness data. / Graduate

Cette thèse s’articule autour de 3 parties. Dans la première (épidémiologie descriptive), nous avons évalué, sur un large échantillon d’adultes français (cohorte NutriNet-Santé), la prise de compléments alimentaires et les facteurs associés en population générale et dans des groupes spécifiques (fumeurs, femmes enceintes, sujets atteints de cancer). La prise de compléments, souvent en automédication, était très répandue, en particulier chez les femmes enceintes et les sujets atteints de cancer. Nos travaux suggèrent que les pratiques « à risque » de consommation de compléments alimentaires étaient loin d’être négligeables dans certains groupes. Dans la seconde partie (épidémiologie étiologique), nous avons mis en évidence, pour la première fois, un potentiel effet modulateur d’une supplémentation en antioxydants (essai randomisé SU.VI.MAX) sur les relations prospectives entre consommation de charcuteries et risque de cancer du sein d’une part et taux d’acides gras plasmatiques et risque de cancer (toutes localisations et du sein) d’autre part, en cohérence avec les études mécanistiques. Nos résultats suggèrent que les antioxydants pourraient contrecarrer certains effets potentiellement pro-cancérigènes des charcuteries sur le risque de cancer du sein, et pourraient modifier les associations acides gras – cancer en s’opposant aux effets potentiels des acides gras sur la carcinogénèse. Enfin, la troisième partie de ma thèse a consisté en des travaux méthodologiques transversaux en e-épidémiologie portant sur les compétences informatiques des participants à la web-cohorte NutriNet-Santé. Ces travaux méthodologiques sont nécessaires à la bonne conduite des études épidémiologiques descriptives ou étiologiques en e-épidémiologie nutritionnelle. Les résultats de cette thèse soulignent l’importance de la prise en compte des consommations de compléments alimentaires en épidémiologie et contribuent plus généralement à une meilleure connaissance de l’étiologie des cancers. Ils permettront, à terme, d’améliorer les recommandations en matière de prévention nutritionnelle des cancers. / This thesis is structured in three parts. In the first part (descriptive epidemiology), we assessed dietary supplement use and associated factors in the general population and in specific subgroups (smokers, pregnant women and cancer survivors) of a large sample of French adults (the NutriNet-Santé cohort). Dietary supplement use was widespread, often in self-medication, particularly in pregnant women and in cancer survivors. Our findings suggest that the frequency of risky practices of dietary supplement use were su bstantial in several subgroups. In the second part (etiological epidemiology), we highlighted, for the first time, a potential modulatory effect of an antioxidant supplementation (SU.VI.MAX. trial) on prospective relationships between processed meat intake and breast cancer risk and between levels of plasma fatty acids and cancer risk (overall and breast), in line with mechanistic studies. Our results suggest that antioxidants may counteract the potential procarcinogenic effects of processed meat on breast cancer risk and may modify associations between fatty acids and cancer risk by counteracting the potential effects of these fatty acids on carcinogenesis. Finally, the third part of my thesis pertained to a methodological work in the field of e-epidemiology, related to computer literacy of participants of the NutriNet-Santé web-cohort. These results will be useful for optimizing descriptive and etiological epidemiological studies in nutritional e-epidemiology. Overall, these PhD findings underline the importance of taking into account dietary supplement use in epidemiological studies and contribute to a better understanding of cancer etiology. More general ly, they will also contribute to optimize nutritional recommendations for primary cancer prevention.

Various aspects of the biology of the intertidal agarophyte, Gelidium pristoides, were investigated, with the aim of providing information that would assist in formulating a management policy for this economic seaweed resource. G.pristoides occurs as tufts comprising as many as 40 individual plants, representing all three conspicuous life history stages, that are linked by the intertwining of their basal creeping axes. Individual plants consist of a system of branched creeping axes, which is largely responsible for colonizing surrounding substrata, from which one or more erect flattened fronds arise. These erect fronds may reach a height of 15 cm, and are irregularly bipinnately branched. Internal vegetative anatomy is generally typical of the genus. Morphological variation in mature plants is limited to increased plant height and branch density during the summer season. A dorso-ventrally flattened creeping habit was seen during early recruitment on flat rock surfaces and limpet shells within grazer exclusion plots, which developed into typical erect plants. Although there is a close taxonomic affinity between G.pristoides and the low-growing Gelidium turf, which occurs on wave-cut platforms in the eastern Cape (both produce bispores), the turf appears to represent a genetically divergent ecotype of the typical G.pristoides habit. In the light of present observations, it is suggested that the recent inclusion of G.pristoides in the new Onikusa genus should be questioned. Reproduction in G.pristoides is typical of the genus, except for the production of bispores, instead of tetraspores, in the sporophyte generation. The smaller nuclei in the binucleate bispores, in comparison to carpospores, suggested they are the product of normal meiosis (meiospores). This was confi rmed by chromosome counts of germl i ngs deri ved from bispores (n = 13-17) and carpospores (2n = 28-33). Throughout the geographical range of the seaweed, the bisporophyte generation is dominant over the combined male and female gametophyte generati on by a ratio of about 3 : 1. This imbalance may be due to bispores. G.pristoides a greater germination success of carpospores over plants are fertile throughout the year, while at Port Alfred there is no apparent seasonality in spore release. Growth of carpospore and bispore germlings is similar under various temperature treatments in culture. Optimum temperatures for growth were from 15-23°C, which corresponds with the sea temperatures experienced within the geographical range of the species . At Port Alfred, growth (linear frond elongation) and standing crop levels were maximal during summer . Ory weight levels were significantly inversely related to both growth and ash levels. Agar contents (% of dry weight) were generally greater in summer (48% ) than in winter (30%), and were inversely correlated with thallus nitrogen levels. Agar contents of distal plant halves were higher (8-15%) than in proximal halves. Regrowth of G.pristoides to original biomass or standing crop levels after harvesting, is similar for plucking and shearing at different times of the year. Regrowth is more rapid after spring and summer harvests (2-3 months) than after winter harvests (4-5 months). During the summer season, harvesting at monthly intervals showed significantly greater total yields, and production rates (e.g . 3.13 g. dry wt. / m2 / day for plucking) than under 3-monthly intervals (1.42 g. dry wt. / m2 / day for plucking). In contrast, average yields per harvest were Significantly greater when recovery period was longer (e.g. 3 months). Quadrats that were completely denuded failed to recover after a year, while regrowth was also retarded with increased elevation on the shore. Agar contents did not differ Significantly between plucked (38%) and sheared (42%) plant material. G.pristoides is distributed from about 0 . 2-0.75 m above MLWS, with a reduction in stature and frequency corresponding to increased elevation on the shore. Frond elongation rates, germling survival and recruitment within grazer-exclusion plots, is retarded with increased elevation level. Plants transplanted above the normal vertical range of the seaweed became severely bleached and died, while plants transplanted below the normal range of the seaweed (sub littoral fringe) senesced due to overgrowth by the epiphytic encrusting coralline, Polyporolithon patena (Hook . et Harv . ) Mason . G.pristoides recrui t ment in the sublittoral fri nge was enhanced with the exclusion of grazers . However, successful recruits were displaced due to smothering by articulated corallines (e.g. Corallina sp. and Jania sp. ) . G.pristoides is largely restricted to cracks and crevices in the rock, and also occurs on a large proportion of the available shells of the limpet Patella oculus Born., and to a lesser extent, shells of the barnacle Tetraclita serrata. G.pristoides recruitment was significantly enhanced by the exclusion of grazers (using toxic antifouling paint barriers). G.pristoides recruitment within the exclusion plots was significantly greater on artificially attached limpet shells (almost 100% cover) than on rock surfaces (20-30% cover), which occurred largely within cracks and crevies in the rocky substratum. ly attached to limpet G.pristoides plants are significantly more strongand barnacle shells than to rock and epilithic encrusting corallines (Lithothamnion sp.). Removal of G.pristoides from limpet shells revealed pits of a uniform size in the surface of the shells, into which the rhizoidal attachment organs of the seaweed penetrate. It is concluded that the horizontal distribution of G.pristoides is largely controlled by grazers (and "escapes" from grazing) and resistance to dislodgement by wave action. Based on present results, and considering some of the socio-economic factors associated with the Gelidium industry in South Africa, suggestions are made concerning the management and long-term maintenance of G.pristoides resources in the eastern Cape.

The highly sulphated, methylated polysaccharide isolated from Pachymenia Carnosa, a red seaweed, was shown to contain D- galactose, 2-o (underscore) methyl-D- galactose, 6-o (underscore) -methyl- D- galactose and 4-o (underscore)-methylgalactose. The polysaccharide was desulphated with methanolic hydrogen chloride. Methylation of the desulphated polysaccharide revealed that it was composed entirely of (1→73) and (1→4) links in approximately equal amounts. Treatment of the polysaccharide with alkali showed that the majority of the ester sulphate groups were alkali-stable. Partial hydrolysis and acetolysis studies indicated that the polysaccharide was extremely complex, and contained alternate (1→3) and β (1→4) glycosidic linkages. There is evidence for the presence of D-galactose-6-sulphate.

Aeodes ulvoidea, a red seaweed of the Grateloupiaceae, yielded a highly sulphated polysaccharide which was shown to contain D- and L-galactose, 4-0-methy-L-galactose, 2-0-methyl - D- and L-galactose and 6-0-methyl-D-galactose, together with chromatographic traces of xylose and mannose. The sulphate was not labile to alkali, but it was largely removed with methanolic hydrogen chloride. Periodate oxidation of the polysaccharide, methylation of the de sulphated polysaccharide, and investigation of fifteen oligosaccharides from partial hydrolysis and acetolysis studies of the polysaccharide, indicate that (a) the polysaccharide is composed of a backbone of D-galactose residues which are 1,3- and 1,4-linked (b) at least some regions of alternating structure do occur (c) the 2-0-methylgalactose is linked through the 4-position (d) the 4-0-methyl-L-galactose is present as single unit side chains glycosidically linked to the galactose backbone at position 6, and (e) most of the 6-0-methyl-D-galactose is linked to the 4-position of 2-0-methyl-D-galactose.