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Laboratory studies of successional patterns in assemblages of attached estuarine diatomsBerglund, Lisette Aline 28 June 1972 (has links)
Successional patterns of attached estuarine diatoms were investigated
using laboratory model ecosystems. Artificial substrates
of acrylic plastic were exposed to 0, 4, and 10 hours of desiccation
per day. Diatom assemblages that developed under temperatures
normal for Yaquina Bay, Oregon (control ecosystem) were compared
to assemblages that developed at temperatures elevated 10 C (heated
ecosystem).
Continuously submerged substrates were quickly invaded by solitary,
motile and attached diatoms. By the end of the experiment,
filamentous and tube dwelling colonial diatoms had become established
with many motile and epiphytic diatoms interspersed among the colonies.
However, planktonic taxa were the first to settle on the substrates
exposed to 4 and 10 hours of desiccation. These taxa were
gradually replaced in prominence by solitary, motile and attached taxa
that had previously colonized the continuously submerged substrates
and by several species that were tolerant of desiccation and high air
temperatures. Again, filamentous and tube dwelling forms began to
establish colonies at the end of the experiment.
A total of 21,569 diatoms was counted in 42 samples, and 136
species were identified. The most abundant diatoms found in the
control ecosystem included Navicula directa, Thalassiosira no. 1,
Thalassionema nitzschioides, Nitzschia no. 2, and Navicula diserta.
Thalassiosira no. 1, Thalassionema nitzschioides, Nitzschia aerophila,
Nitzschia sigma, and Navicula no. 2 were the most abundant
species in the heated ecosystem. Of these taxa, Navicula directa
and Thalassionema nitzschioides were the most evenly distributed
over the samples. Species diversity was higher in the heated ecosystem
than in the control ecosystem. / Graduation date: 1973
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Growth control of a marine diatom by low and limiting levels of nitrate-nitrogenLarsen, David Phillips 25 March 1974 (has links)
Graduation date: 1975
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Population dynamics of Skeletonema costatum in high dilution rate chemostatsDonaghay, Percy L. 30 August 1973 (has links)
A chemostatic system was developed for the long term studies
of population dynamics of chain forming diatoms. Vessel volume
rather than flow rate was varied in these systems to obtain different
growth rates at steady state in systems with an equal capacity to
produce.
Population level responses to high dilution rates were examined
for Skeletonema costatum both in long term steady state and under
non-steady state conditions. Development of populations were observed
from small innocula through steady state dilution rates
approaching the maximum growth rate of the population. Populations
were characterized in terms of particulate carbon and nitrogen,
particle numbers and volumes, particle size distributions, and the
relationship of production and specific growth rate to biomass.
Qualitative observations were made on cell dimensions, morphology,
and bouyancy.
Four phases of growth were identified in some or all of the
systems: selection phase in which population concentrations declined,
but significant changes in population characteristics occurred; exponential
phase in which populations increased in a uniform and density-independent
fashion; transition phase in which adjustments were made
in population characteristics; and, finally, steady state in which populations
were stable. Selection phase was observed when small innocula
were placed in high dilution rate systems or when steady state
cultures were transfered to higher dilution rates. Those cultures
experiencing selection phase showed changes in physical cell
dimensions and in nutrient cell size.
Physical cell dimensions and nutrient cell size and their relationship
to growth rate are discussed. The work of Caperon (1968) is
examined for similar selectional effects. A method using curves of
nutrient per cell versus residence time of a particle in a chemostat
is suggested to separate selection and dilution rate effects in dynamic
systems. A model summarizing the ides of nutrient reservoirs is
suggested. / Graduation date: 1975
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Distributional patterns and taxonomic structure of diatom assemblages in Netarts Bay, Oregon /Whiting, Mark Carlos. January 1983 (has links)
Thesis (Ph. D.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 118-127). Also available online.
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Phylogeny of Aulacoseira (Bacillariophyta)Edgar, Stacy McBride. January 2003 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.
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Growth, reproduction, and survival of diatomsHostetter, Heber Peart, 1940- January 1969 (has links)
No description available.
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The life cycle of the centric diatom Thalassiosira weissflogii: control of gametogenesis and cell size /Armbrust, Elisabeth Virginia. January 1990 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1990.
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Role of nutrient limitation and competition in controlling the populations of a diatom and a blue-green algaPeterson, Nancy Lee. January 1979 (has links)
Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 123-131).
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Investigation of the liquid vapour shift in the infra-red absorption frequency of diatomic moleculesRoss, William LeBreton January 1953 (has links)
The changes in the infra-red absorption frequency of three diatomic molecules, HCl, HBr and CO, on the transition between the gaseous and the solution phase have been investigated experimentally. The magnitude of this shift has been predicted using a purely electrostatic interaction. The experimental values and predicted values for HCl agree within 17%. The experimental and predicted values for HBr and CO agree within an order of magnitude. The investigation provides a method for independently checking the variation of the dipole moment of these molecules with internuclear distance against values previously determined by infra-red intensity measurements. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
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Metabolic responses of diatoms to a changing environment : pathways for energy dissipation in high light /Parker, Micaela Schnitzler. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 92-110).
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