Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"Phototaxis"”.
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Phototaxis of Dictyostelium discoideum Slugs
… highly sensitive environmental reactions: phototaxis, chemotaxis and thermotaxis. Although many studies have investigated how Dictyostelium slugs move toward a light source, the mechanism of phototaxis is still unclear. It has been known that slugs turn towards the light at the anterior …
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Shedding light on E. coli phototaxis
My thesis work has been focused on phototaxis response in E. coli. I will review the current state of knowledge on chemotaxis and phototaxis and discuss the motivation behind this project in Chapter 1. In Chapters 2 and 3, I will describe a high-throughput framework for studying phototaxis in …
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Bioenergetics and dynamics of ciliary responses and systems biology of phototaxis in Chlamydomonas reinhardtii
… such as Ca2+, H+, and K+, and red light affect phototaxis of positively and negatively-phototactic cells (1117 and 806 respectively). I have tracked a cell population using the cell-tracking system for 10 s after stimulating them with green light (Chapter 4). Increasing [Ca2+]<sub>ext</sub> with …
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Negative phototaxis of mosquito larvae as a potential tool in the rapid biological monitoring of aquatic wastes (Diptera: Culicidae)
… approach to toxicity testing--based on negative phototaxis of larval <u>Aedes aegypti</u>--was investigated as a contribution to the search for rapid methods applicable to the field of water pollution control. Zinc and copper were the toxicants tested. All tests were conducted with a standard …
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Action Spectrum for Photoentrainment of the Circadian Clock in Wild-Type <i>Chlamydomonas reinhardtii</i>
… a circadian rhythm. Its circadian rhythm of phototaxis (swimming toward light) has been automated. Former action spectrum studies using the circadian phototaxis rhythm as an indicator surprisingly found that pulses of blue light were not effective in resetting the circadian clock of …
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Behavioral Analysis of a Digenetic Trematode Cercaria (Microphallus Turgidus) in Relation to The Microhabitat of Grass Shrimp (Palaemonetes Spp.)
… predicted that the cercariae would have negative phototaxis. For the control experiment, in the absence of light, I predicted an equal distribution of cercariae throughout the entire Petri dish. I also predicted that the cercariae would prefer the bottom of the water column, and that their …
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Pattern formation and hydrogen production in suspensions of swimming green algae
… viscous torque due to fluid flow gradients, and phototaxis, biased movement towards or away from a light source. In Chapters 2 and 3, a stochastic continuum model for gyrotaxis is extended to include phototaxis using three physically diverse and novel methods. A linear stability analysis is …
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Light-sensing in bacteria
… that has been shown to play a role in regulating phototaxis in Synechocystis sp. PCC6803. We were able to show that Slr1692, encoded by an ORF upstream of pixE-pixD might play a role in regulating phototaxis.
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Characteristics of cone-forming cyanobacteria and implications for the origin of conical stromatolites
… rock, may contain the earliest records of phototaxis, photosynthesis, and oxygenation of the environment. The reconstruction of the co-evolution of biology and the environment using stromatolites depends on the ability to recognize macroscopic shapes that arise uniquely as a consequence of …
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Development and application of control tools for use in optogenetics research
… and serve as sensory photoreceptors controlling phototaxis. Operationally, they contain the light-isomerizable chromophore all-trans-retinal that, upon absorption of a photon at or around 473nm, a conformational change to 13-cis-retinal is induced. This change opens the channel allowing cations …
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DISPERSAL MECHANISMS OF EMBRYONIC AND LARVAL BURBOT (LOTA LOTA)
… for embryonic buoyancy changes and larval phototaxis, startle response, temperature selection, rheotaxis, and lateral line development. Embryos showed a significant increase in buoyancy as they approach hatching but are negatively buoyant. Larvae showed a 25% increase in startle responses …
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cGMP -Dependent Protein Kinase, Behavioral Plasticity, and Foraging in Honey Bees and Fruit Flies
… the response of bees to light (positive phototaxis). In flies I show that individual variation in foraging intensity is mediated by both natural polymorphism in the for locus as well as environmentally-dependent temporal and spatial changes in for expression. Specifically, an animal with …
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Plant-Like Cryptochrome Does Not Promote Blue Light-Induced Resetting of the Circadian Clock in <i>Chlamydomonas Reinhardtii</i>
… of behavior, and the monitoring of its rhythm of phototaxis, or swimming towards light, has been automated. The receptors involved in entraining the clock to the daily light/dark cycle have not yet been identified in this organism. Previous research has shown that blue, green, and red light are …
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Investigating the role of rhomboid proteases in the development of Dictyostelium discoideum
… morphology which is consistent with phototaxis defects in slugs. rhmB null cells had slower growth rates, reaching stationary phase at a reduced density; a delayed response to folic acid stimulation; larger cell size in the unicellular phase and altered stalks in the multicellular …
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Homology Cloning, Heterologous Expression and Characterization of A New Channelrhodopsin
<p>Channelrhodopsins are phototaxis receptors in the plasma membranes of motile unicellular algae. They function as light-gated cation channels and this channel activity has been exploited to trigger action potentials in neurons with light to control neural circuits (“optogenetics"). Four …
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Charakterisierung des Zytoskelett-Proteins Villidin und einer dritten Profilin-Isoform in Dictyostelium discoideum
… development but are defective in motility and phototaxis in the multicellular slug stage. Based on this defect and the multidomain structure of the protein, villidin might be involved in signal transduction processes leading to phototactic movement. The second part of the project dealt with a …
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Dock180/Elmo proteins are critical regulators of phagocytosis,macropinocytosis and chemotaxis in Dictyostelium
… in macropinocytosis. dockA""ll slugs show poor phototaxis. dock8""`l cells grow slowly in the axenic medium and are defective in chemotaxis, macropinocytosis and phagocytosis. dockA/8 double mutant cells show stronger defects in chemotaxis than either mutant by itself. In the dockN8""ll double …
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Zooplankton Dynamics in Wastewater Treatment High Rate Algal Ponds and development of effective control methods
… 25-180 mg/L in laboratory experiments, and by phototaxis-induced migration in an 8 m³ HRAP. This suggested that mechanical treatments such as filtration and hydrodynamic stress could be performed to the upper layer of the pond water, reducing the amount of water processed and the overall …
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The Long-Rage Directional Behavior of the Nematode C. Elegans
… pathways for thermotaxis, olfaction, phototaxis, and aerotaxis, upstream of TAX-4, did not disrupt directional behavior. To get further insight into the nature of the stimulus directing the animals' behavior, if any, we performed rescue experiments of TAX-4 function in specific subsets …
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Factors Influencing Behavior of Overwintering Brown Marmorated Stink Bugs (Halyomorpha halys) in Human Dwellings
The brown marmorated stink bug (Halyomorpha halys) (Stål) is known for overwintering in human homes. Studies were conducted to understand the behavior of adult bugs in response to characteristics of potential overwintering structures including gap sizes, light, and presence of dead conspecifics. In …
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