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Analysis of Betta splendens erythrophore responses to Bacillus cereus cultured in different media /Austin, Melissa J. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 73-81). Also available on the World Wide Web.
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Localization and organization of fin chromatophore motoneurons in the European cuttlefish sepia officinalis /Gaston, Michelle Renee, January 2004 (has links)
Thesis (Ph. D.)--University of Oregon, 2004. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 83-91). Also available for download via the World Wide Web; free to University of Oregon users.
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IONIC REQUIREMENTS FOR MELANOPHORE REGULATIONVesely, David L., 1943- January 1972 (has links)
No description available.
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Processing sequences of chromatophore images with application to a signal transduction pathway modeling /Orhanovic, Iva. January 2004 (has links)
Thesis (Ph. D.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 100-102). Also available on the World Wide Web.
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Chemical and spectroscopic studies of chromone derivativesDavidson, Deborah Nicole January 1992 (has links)
Various chromone derivatives have been used in asthma therapy, and their biological activity is apparently related to certain chemical features which include conformation and acidity. In the present study, substituent effects on conformation and acidity have been explored in chromone systems with potential biological activity. A range of variously substituted symmetrical chromone-2-carboxamides (including a series of N,N-dimethylchromone-2-carboxamides) have been prepared via chromone-2-carboxylic acids, which, in turn, were prepared from the corresponding o-hydroxyacetophenones. The N,N-dimethylchromone-2-carboxamides were prepared by reacting the appropriate chromone-2-carbonyl chlorides with dimethylammonium chloride in pyridine, in an approach which resolved various problems encountered in the preparation of these compounds. Substituent effects on the conformation of chromone-2-carboxamides have been explored using dynamic NMR spectroscopy, and the observed splitting of the N-alkyl signals has been attributed to slow site-exchange of the N-alkyl substituents. Dynamic NMR frequency separations and coalescence temperatures have been used to calculate rotational energy barriers, and substituent effects on these rotational energy barriers have been analysed. The possible implication of ring-opening of chromones in chromone pharmacology has also been examined. A range of 3-(2-hydroxybenzoyl)acrylamides has been prepared via the dimethylamine-mediated ring-opening of N,N-dimethylchromone-2-carboxamides and the E-double-bond configuration of the ring-opened products has been unambiguously established by single crystal analysis of the parent system. The configuration and conformation of the crystal structure of the parent system have been shown, using IR and NMR spectroscopic, and molecular graphics techniques, to be maintained in solution and to characterise the whole series. ¹H and ¹³C NMR spectroscopy have also been used to study the dimethylamine-mediated ring-opening of disodium cromoglycate. The kinetics of the dimethylamine-mediated ring-opening of N,N-dimethylchromone-2-carboxamides have been studied using UV spectroscopy. These reactions have been shown to follow third-order kinetics overall and a mechanism accommodating the observed third-order kinetics has been proposed. Substituent effects have been further investigated by the potentiometric determination of the pKa (pK [subscript a]) values for a series of chromone-2-carboxylic acids. The relationship between acidity and the observed rate constants has been explored and has verified that the observed rate constants are sensitive to the influence of meta-substituents on the stability of the phenoxide ion "leaving group" rather than C-2 electrophilicity.
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A comparative study of fish coloration and toxicant responses in a chromatophore cell-based biosensorRoach, Holly B. 03 1900 (has links)
Detection of both biological and chemical environmental toxicants is essential in the assessment of risk to human health. Cell-based biosensors are capable of activity- based detection of toxicity. Chromatophore cells, responsible for the pigmentation of poikilothermic animal, have shown immense potential as cell-based biosensors in the detection of a broad range of environmental toxicants. Chromatophore cells possess the motile pigment granules that intracellularly aggregate or disperse in response to external stimuli. Previous studies have assessed chromatophore cells isolated from red Betta splendens and grey Oncorhynchus tschawytscha fish for use as a biosensor. The objective of this study was to describe blue B. splendens chromatophore cells in tissue culture. Blue B. splendens chromatophore cells were assessed for their longevity in tissue culture and their responses to previously established control agents. Blue B. splendens chromatophore cells were exposed to select chemicals and pathogenic bacteria to assess their ability to respond to environmental toxicants. Three concentrations of mercuric chloride, methyl mercuric chloride, paraquat, sodium arsenite, sodium cyanide chemicals were tested. Bacillus cereus, Bacillus subtilis, Salmonella enterica serovar Enteritidis, and Salmonella enterica serovar Typhimurium were tested. Red B. splendens chromatophore cells were subjected to the select chemical and bacterial toxicants, and observed for their responses. The data collected in this and previous studies were compiled to compare chromatophore cell responses to a broad range of environmental toxicants. Chromatophore cells isolated from both blue and red B. splendens were responsive to methyl mercuric chloride and sodium arsenite. Grey O. tschawytscha chromatophore cells have shown responsiveness to mercuric chloride and sodium arsenite. Blue and red B. splendens chromatophore cells were both responsive to B. cereus and both Salmonella serovars. Grey O. tschawytscha have previously been shown to respond to B. cereus as well.
In conclusion, this study reports the chromatophore cells isolated from blue B. splendens in tissue culture and showed similar responsiveness to the selected chemical and bacterial environmental toxicants as chromatophore cells isolated from red and grey colored fish. This study provides compelling evidence that the chromatophore response is not dependent on fish color and that chromatophore cells used for a cell-based detection system may be isolated from different colored fish. / Graduation date: 2012
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Advanced image segmentation and data clustering concepts applied to digital image sequences featuring the response of biological materials to toxic agentsRoussel, Nicolas 27 March 2003 (has links)
Image segmentation is the process by which an image is divided into number of
regions. The regions are to be homogeneous with respect to some property. Definition
of homogeneity depends mainly on the expected patterns of the objects of interest. The
algorithms designed to perform these tasks can be divided into two main families: Splitting
Algorithms and Merging Algorithms. The latter comprises seeded region growing
algorithms which provide the basis for our work.
Seeded region growing methods such as Marker initiated Watershed segmentation
depend principally on the quality and relevance of the initial seeds. In situations where
the image contains a variety of aggregated objects of different shapes, finding reliable
initial seeds can be a very complex task.
This thesis describes a versatile approach for finding initial seeds on images featuring
objects distinguishable by their structural and intensity profiles. This approach
involves the use of hierarchical trees containing various information on the objects in
the image. These trees can be searched for specific pattern to generate the initial seeds
required to perform a reliable region growing process. Segmentation results are shown
in this thesis.
The above image segmentation scheme has been applied to detect isolated living
cells in a sequence of frames and monitor their behavior through the time. The tissues
utilized for these studies are isolated from the scales of Betta Splendens fish family.
Since the isolated cells or chromatophores are sensitive to various kinds of toxic agents,
a creation of cell-based toxin detector was suggested. Such sensor operation depends on
an efficient segmentation of cell images and extraction of pertinent visual features.
Our ultimate objective is to model and classify the observed cell behavior in order
to detect and recognize biological or chemical agents affecting the cells. Some possible
modelling and classification approaches are presented in this thesis. / Graduation date: 2003
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A study of three photochemical activities of chloroplastsHinkson, Jimmy W. 23 April 1958 (has links)
Chloroplasts of sugar beet leaves were subjected to treatment by heating, by incubation at pH 8.5 and pH 5.5, by incubation in ion low water, by sonic oscillation, by digestion with enzymes (lysozyme, pancreatin, and lipase), by extraction with digitonin, and by chemical compounds including 8-hydroxy-quinoline, sodium azide, zinc sulfate, phenyl mercuric acetate, potassium cyanide, 1-allylthiourea, 2,4-dinitrophenol, thymol, and p-chloromercuribenzoate. A comparative study was made of the effects of these treatments upon three photochemical reactions (the photoreduction of 2,6- dichlorophenol indophenol, the photoreduction of indigo carmine in the presence of a couple composed of 2,6-dichlorophenol indophenol and ascorbic acid, and the photo-oxidation of the 2,6-dichlorophenol indophenol-ascorbic acid couple) and upon three enzymes (cytochrome oxidase, peroxidase, and catalase) present in the chloroplast preparations used.
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A network approach for the mechanistic classification of bioactive compoundsSiebert, Trina A. 22 November 2004 (has links)
Using network architecture to describe a biological system is an effective
organizational method. The utility of this approach, which generally applies to
qualitative models, is enhanced by the addition of quantitative models
characterizing the interactions between network nodes. A chromatophore-based
signal transduction network is developed, and the highly interconnected major
nodes of the network, guanine trisphosphate, adenylate cyclase, and protein kinase
A, are identified. These reference nodes serve to partition the network into
functional modules, and mechanistic models describing these modules are derived.
Three elicitor compounds, forskolin, melanocyte stimulating hormone (MSH), and
clonidine, were selected due to their ability to access the signal transduction
network at specific reference nodes, and the module configurations corresponding
to their mechanisms of action are presented.
The chromatophore responses to the three elicitors and to a negative
control, L-15 cell medium, were recorded for two experimental blocks consisting
of genetically different fish cells. Significant differences in cell responsiveness
were evident between the two blocks, but this variability was controlled by the
transformation and normalization of the data. The model parameters for each
agent were estimated, and the resulting response curves were highly accurate
predictors of the changes in apparent cell area, with R-squared values in the 0.88
to 0.96 range.
Two examples were presented for the application of a model discovery
algorithm, which selects modules from an existing library, generates model output
for all valid module configurations, and selects the configurations which best
satisfy a fitness function for a given set of target data. The algorithm proved
robust to the introduction of different levels of random error in the simulated data
sets when applied to a model of the desensitization of a cell membrane receptor,
and continued to classify the stochastic data sets correctly even when the
underlying rate constants differed significantly from those embedded in the
modules. When challenged with the chromatophore data, the model discovery
algorithm successfully matched the forskolin and MSH module configurations to
the data within the top three models proposed, with less precise classification for
the clonidine model. / Graduation date: 2005
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Pax6 and Six1/2 orthologs in leech ectodermal patterningQuigley, Ian Kirk. January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
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