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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Taxonomy of the marine, luminous bacteria

Reichelt, John Lawrence January 1973 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1973. / Bibliography: leaves 78-83. / viii, 83 l illus., tables
2

Beiträge zur Biologie der fluorescierenden Bakterien Inauguraldissertation zur Erlangung der Doctorwürde einer hohen Universität Basel /

Thumm, Karl. January 1895 (has links)
Thesis (doctoral)--Universität Basel, 1895?.
3

Characterization of LuxA of novel strains of the genus Shewanella

Fulayfil, Nada Rashid 29 July 1994 (has links)
Bioluminescence is a trait observed among different genera and families of bacteria. In this study part of the luxA gene was characterized from the new MS isolates and compared to luxA of other bacteria. The polymerase chain reaction (PCR) was used to amplify a fragment of the luxA gene of strain MS32 and Vibrio harveyi. These fragments were used as probes in hybridization experiments with luminous and nonluminous bacteria. The results from these experiments suggest that some nonluminous species may possess lux like regions in their chromosomal DNA and that luxA probes can demonstrate species identity. The MS32 luxA fragment was also sequenced and used in a phylogenetic analysis to identify the taxonomic affinities of MS strains. It was found that MS1 and MS32 were closely related, however, Shewanella hanedai was not. Thus there was a concordance between the phenotypic and genotypic approaches, which will help in establishing a consistent taxonomic affinity between these bacteria.
4

Solar illuminance models based on other meteorological data

Kinghorn, David Martin January 1999 (has links)
No description available.
5

Variation of Outer Membrane Protein of Symbionts Photobacterium leiognathi in Five Leiognathid Species

Ho, Yi-jing 05 February 2009 (has links)
Leiognathid fish (Perciformes: Leiognathidae) contain 17 species in Taiwan in three genera: Gaza, Leiognathus, and Secutor. Leiognathid fish form mutualistic bio- luminescent symbiosis with the luminous bacteria Photobacterium leiognathi and have developed a specialized light organ to harbor bacteria and other structures to control light emission. The ecological dependence of leiognathid fish to its symbiont for light production and the specialized adaptations suggest that there co-evolution might have taken place. A single symbiont species were thought to be harbored in the light organ of leiognathid fishes. However, different oxygen rates, light production, and cell morphology have been observed in bacteria culturing during previous studies. To investigate the co-evolutionary interaction between P. leiognathi and leiognathid species, I examined the 2-DE patterns of the outer membrane protein (OMP) of symbiotic bacteria from specimens of five leiognathid species; OMPs have been proposed to be essential in symbiotic interaction. The 2-DE results of the P. leiognathi OMP pattern from five leiognathid species displayed intra-specific similarity, when inter-specific differences also exist. Intra-specific consistence revealed five proteins that are essential in the symbiotic interaction. Spot differences between various leiognathid species have shown that closely related species have significant protein spots which may have effect on speciation. In Secutor ruconius absence of the protein responsible for motility might result the difficulty on bacteria culturing. Intra-specific similarity excludes the possible of individual differentiation, and the inter-specific differences of bacterial OMP suggested that P. leiognathi in various leiognathid species might have developed various OMPs to adapt to different host species.
6

Mineral ions in the growth and metabolism of marine luminous bacteria.

Srivastava, Vinod Shanker. January 1965 (has links)
The requirement of marine bacteria for seawater in the medium for growth has been observed to reflect their need for the inorganic ions in seawater for their growth and metabolism. Of these inorganic ions, the marine bacteria so far examined in contrast to most terrestrial bacterial species have been found to possess a specific requirement for Na+ for growth. The Na+ requirement for growth has been found to reflect a requirement for the transport of nutrients in marine bacterial cells. This and other information regarding the characteristics of marine bacteria have come from the studies of only a few representatives of a very small fraction of the bacterial population in the sea, and one may well ask how far these observations made with a few species are true for marine bacteria as a group of organisms? In this thesis observations made on non-luminous marine bacteria have been extended to include some representative luminous marine bacteria. In the course of these studies some similarities and differences in the nutrition and metabolism of the two groups of organisms have been noted.
7

Galaxy evolution and cosmology studies using luminous red galaxies

Ratsimbazafy, Ando January 2014 (has links)
Philosophiae Doctor - PhD / There have been a number of attempts to measure the expansion rate of the Universe using age-dating of Luminous Red Galaxies (LRGs). Assuming that stars in LRGs form at the same time, age-dating of two populations of LRGs at different redshifts can provide an estimate of the time different associated with the corresponding redshift interval (dz/dt). This gives a direct estimate of the Hubble parameter H (z) at the average redshift of the two populations. In this thesis, we explore the validity of this method by using two different sets of data. Firstly, we select a homogeneous sample of passively evolving galaxies over 0.10 < z < 0.40 from the Sloan Digital Sky Survey Data Release Seven (SDSS-DR7) catalogue by applying a refined criteria, which is based on absolute magnitude. Secondly, we carry out series of observations on the Southern African Large Telescope (SALT) to obtain spectra of LRGs at two narrow redshift ranges z ' 0.40 and z ' 0.55 in order to calculate the Hubble parameter H(z) at z ' 0.47. We utilise two distinct methods of age-dating including the use of absorption Lick index lines and full spectral fitting on high signal-to-noise galaxy spectra from our sample. By establishing the age-redshift relation of the quiescent, passively evolving galaxies from SDSS, we obtain three improved new observational H(z) data points which are H(z) = 76.8 5.3 km s􀀀1Mpc􀀀1 at z ' 0.28, H(z) = 78.5 6.8 km s􀀀1Mpc􀀀1 at z ' 0.30 and H(z) = 86.3 7.6 km s􀀀1Mpc􀀀1 at z ' 0.32 respectively. We also find another H(z) value of 105 39 km s􀀀1Mpc􀀀1 at z ' 0.47 when age-dating LRGs observed with SALT. Combining all 4 data points with another 25 data points in the literature, we place better constraints on cosmological models and find the matter density parameter to be constrained by m = 0:32+0:05 􀀀0:06 and the Hubble constant to be H0 =68.5 2.4. These results are very consistent with other studies. Through this work, we are able to demonstrate that the cosmic chronometers approach can potentially be used to explore the evolution of the Universe.
8

Mineral ions in the growth and metabolism of marine luminous bacteria.

Srivastava, Vinod Shanker. January 1965 (has links)
No description available.
9

Investigating Characteristics of Lightning-Induced Transient Luminous Events Over South America

Bailey, Matthew A 01 May 2010 (has links)
Sprites, halos, and elves are members of a family of short-lived, luminous phenomena known as Transient Luminous Events (TLEs), which occur in the middle atmosphere. Sprites are vertical glows occurring at altitudes typically ranging from ~40 to 90 km. In video imagery they exhibit a red color at their top, with blue tendril-like structure at low altitudes. Elves are disk-like glows that occur at the base of the ionosphere, with diameters of ~100-300 km, and have very short lifetimes (~2-3 ms). Halos are diffuse glows that occur at low altitudes, have diameters <100 >km, and have a duration that may last up to 10s of ms. A majority of the studies of TLEs have taken place over the Midwestern U.S. where they were first discovered. This area produces large thunderstorms, which in turn generate large lightning discharges that have been associated with the formation of TLEs. Studies have used the low frequency radiation that initiates with these strokes to study characteristics of these events. This low frequency radiation has been used to determine where large numbers of TLEs may occur. Extreme southern Brazil is a region of the globe believed to have many TLEs, but few studies on these phenomena. Two collaborative campaigns involving Utah State University proceeded in 2002- 2003, and in 2006. Multiple TLE images were made, proving this is, indeed, a region of the globe where these types of events are prominent. In particular, one storm in February 2003 produced over 440 TLEs imaged by USU video cameras. Of these events, over 100 of them had associated halos. Statistical studies for halos previously had been performed in the U.S., but never abroad. Also, several events from the February storm have been associated with negative cloud to ground lightning, a surprising occurrence, as to date, less than a handful of such events have ever been witnessed or published. In analyzing the TLEs from this campaign, we have shown the halos are similar to those seen in the U.S., even though the storms may be somewhat different. Also, detailed analyses of the negative events show both temporal and spatial morphology heretofore never reported on.
10

Illumination properties and energy savings of a solar fiber optic lighting system balanced by artificial lights

Lingfors, David January 2013 (has links)
A solar fiber optic lighting system, SP3 from the Swedish company Parans Solar Lighting AB, has been installed in a study area/corridor test site. A collector is tracking the sun during daytime, focusing the direct sun irradiance via Fresnel lenses into optical fibers, which guide the solar light into the building. The illumination properties of the system have been characterized. The energy saving due to reduced need of artificial lighting have been calculated and methods for balancing the artificial lights in the test site have been evaluated. The illumination at the test site using solar light was at least as high as when using the artificial lights and even higher at very clear days. The luminous flux output (500 lm) was somewhat lower than specified by the manufacturer (550 lm) at 100 000 lx direct sun illuminance. The output at 130 000 lx was high 767±33 lm the sunlight coupling efficiency 23 %. However, for a 20 m SP3 system the luminous flux output (400 lm) at 100 000 lx was higher than specified (350 lm). The SP3 system of Parans provides high quality solar light. It has a fuller spectrum close to the spectrum of the sun compared to the fluorescent lights at the test site. The correlated color temperature of the system was 5800±300 K and the color rendering index 84.9±0.5. The lighting energy saved due to decreased need for artificial light was estimated to 19 % in Uppsala which has 1790 annual sun hours. The savings in Italy, which has 3400 sun hours, is 46 %. Additional saving, especially in warmer countries can be obtained due to decreased need for cooling in the building as the solar luminaires provide negligible heat to the indoor air. Economical saving could also be realized by improved well-being of the occupants spending time under the solar luminaires. Three ways of balancing the artificial light due to sunshine fluctuations have been investigated. The global horizontal irradiance could not be used as a control signal for balancing the artificial lights but a pyranometer attached to the SP3 sun tracking collector was usable. Also the signal from an indoor luxmeter sensor could be used for balancing the light. However the signal from the light sensor which makes the SP3 collector to track the sun is probably the most cost effective method as it would serve two purposes; tracking the sun and balancing the artificial lights.

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