Thesis (M.S.)--University of Florida, 2003. / Title from title page of source document. Includes vita. Includes bibliographical references.

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Factors affecting catch, trap fishing power and reef fish trappability were investigated by experimental fishing with Antillean fish traps on west coast fringing reefs in Barbados. Commercial (small mesh) traps caught significantly more fish (by number and weight), caught significantly smaller fish, and caught a higher proportion of immature fish, than large mesh traps. Fishing power was significantly higher for commercial traps than for large mesh traps. These catch differences between trap types have serious implications for the management of the reef fish resource by the imposition of larger mesh sizes in the commercial fishery. / The squeezability hypothesis and the visual image hypothesis were investigated as explanations for the lower fishing power of large mesh traps. The lower fishing power of large mesh traps results primarily from lower catch rates of fish in the 5.5-6.0 cm body depth size class. This result is strong support for the squeezability hypothesis as an explanation for the lower fishing power of large mesh traps. Differences in the visual images of traps created by structural differences and biotic differences did not produce definitive differences in ingress rates to traps, suggesting that the visual image hypothesis is an inadequate explanation for the lower fishing power of large mesh traps. / The trappability of reef fish differed substantially between species, but trappability differences were not correlated with species mobility, activity of the species in traps, gregariousness, or capacity of the species to squeeze through meshes. Predator-prey effects on trappability were negligible, but trappability was negatively correlated with percent reef cover of the substratum and with substratum rugosity. This suggests that traps are more attractive to fishes in areas where natural structural complexity is lower. (Abstract shortened by UMI.)

This thesis is concerned with various aspects of ion traps and their use as a quantum simulation and computation device. In its first part we investigate various sources of noise and decoherence in ion traps. As quantum information is very fragile, a detailed knowledge of noise and decoherence sources in a quantum computation device is essential. In the special case of an ion trap quantum computer we investigate the effects of intensity and phase noise in the laser, which is used to perform the gate operations. We then look at other sources of noise which are present without a laser being switched on. These are fluctuations in the trapping frequency caused by noise in the electric potentials applied to the trap and fluctuating electrical fields which will cause heating of the centre-of-mass vibrational state of the ions in the trap. For the case of fluctuating electrical fields we estimate the effect on a quantum gate operation. We then propose a scheme for performing quantum gates without having the ions cooled down to their motional ground state. The second part deals with various aspects of the use of ion traps as a device for quantum computation. We start with the use of ionic qubits as a measurement device for the centre-of-mass vibrational mode and investigate in detail the effect these measurements will have on the vibrational mode. If one wants to use quantum computation devices as systems to simulate quantum mechanics, it is of interest to know how to simulate say a k-level system with N qubits. We investigate the easiest case of this wider problem and look at how to simulate a three-level system (a so called trit) with two qubits in an ion trap quantum computer. We show how to get and measure a SU (3) geometric phase with this toy model. Finally we investigate how to simulate collective angular momentum models with a string of qubits in an ion trap. We assume that the ionic qubits are coupled to a thermal reservoir and derive a master equation for this case. We investigate the semiclassical limit of this master equation and, in the case for two qubits in the trap, determine the entanglement of the steady state. We also outline a way to find the steady state for the master equation using coherence vectors.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references (p.54-61).

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Mark G. Raizen. Vita. Includes bibliographical references.

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No description available.

Harris County Mosquito Control Division (HCMCD) is responsible for surveillance of mosquito species that are vectors of St. Louis Encephalitis (SLE) virus and West Nile Virus (WNV) within Harris County, Texas, including the Houston metroplex. The metroplex area has some unique attributes and a vast variety of environmental habitats that are attractive to vectors of arboviruses and for the transmission of arboviruses to the human population. Data describing the efficacy of Gravid (GV) and Underhouse (UH) CO2 traps were analyzed to determine if there is a significant difference between these two trap types with respect to the number of mosquitoes and the variety of mosquito species caught. This study was conducted during the off-peak HCMCD trapping season, to gain information in preparation for a yearround trapping program utilizing Underhouse CO2 traps for WNV and SLE virus surveillance. Adjusting for the week of collection, results suggest that Gravid traps caught significantly (P = 0.009) more mosquitoes (mean = 23.134 per trap) in the study area than Underhouse traps (mean = 3.616 per trap), and that Underhouse Traps caught a larger variety of mosquito species (n = 13) than Gravid Traps (n = 11), out of 15 total different species caught. Gravid and Underhouse traps caught 9 out of 15 of the same mosquito species during the study period. Culex quinquefasciatus mosquito catches in Gravid traps and temperature were strongly correlated (Spearman's Correlation Coefficient = 0.707, P = 0.005). Geographic Information System spatial analysis indicated clustering of Culex quinquefasciatus mosquito catches in both Gravid traps, week 9 and 21 (Moran's I = 0.69, P = 0.040 and 0.74, P = 0.021, respectfully ) and Underhouse traps, week 13 and 19 (Moran's I = 0.92, P = 0.002, and 0.89, P = 0.011, respectfully). It is recommended that Harris County Mosquito Control Division continue to utilize gravid traps as a primary method of surveillance. Gravid traps (16,194) caught 85% more mosquitoes than Underhouse traps (2,531) over the fourteen week study period. Their overall success far outweighs the additional materials or labor required for their use in a successful surveillance program.

No description available.