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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.
61

Differential density lipoprotein profiling for the characterization of Lipoprotein(a)

Espinosa Garcia, Irma Leticia 30 October 2006 (has links)
Lipoprotein(a) (Lp(a)) has been described as an emerging risk factor for cardiovascular disease. The complexity of the Lp(a) molecule sets a challenge for the determination of the risk it represents for the cardiovascular system. The objective of the present study was to develop a rapid method for the separation, purification, density measurement, and characterization of Lp(a) from serum using a procedure that is isoform independent. The objective was met by linking ultracentrifugation with affinity separations for the specific separation of Lp(a) from other lipoproteins. The mean density distribution of Lp(a) was determined by a differential density lipoprotein profile (DDLP). For DDLP, the lipoprotein density distribution of a serum sample with elevated Lp(a) levels was determined by ultracentrifugation using NaBiEDTA complex as a density gradient. Lp(a) was removed from a second aliquot of the same serum sample by carbohydrate affinity using wheat germ agglutinin (WGA). WGA was demonstrated to have high specificity for Lp(a) in serum. The Lp(a)-depleted sample was ultracentrifuged to obtain a lipoprotein density distribution in the absence of Lp(a). A DDLP was obtained after subtracting the Lp(a)-depleted lipoprotein density profile from the untreated lipoprotein density profile. DDLP gives relevant information of the lipoproteins in serum such as density, Lp(a) isoform, and subclass characteristics. Lp(a) was quantitatively removed from serum with a recovery efficiency of more than 80%. Lp(a) was purified by ultracentrifugation. Lp(a) obtained in this way retained its inherent density and immunoreactivity. Lp(a) was further characterized by gel electrophoresis and Western blot as well as by capillary electrophoresis. Capillary electrophoresis demonstrated to be a powerful analytical technique for the characterization of Lp(a) and apoprotein(a) isoforms. The major outcome of this research was the effectiveness of using affinity separations coupled with density ultracentrifugation for the isolation of pure Lp(a) from serum and its isoform characterization based on density and electromobility. The methodology developed and described here are relevant in a clinical setting for the analysis of Lp(a).
62

Distribution and abundance of endangered Florida Key deer on outer islands

Watts, Dominque Elijah 25 April 2007 (has links)
Status assessments are compulsory to efficacious management of large-mammal populations, particularly for endangered species such as the Florida Key deer (Odocoileus virginianus clavium). However, a dearth of data regarding basic demographic parameters has limited status assessment and management of Key deer on outer islands. Traditional survey techniques for Key deer on Big Pine and No Name keys include road-counts, strip-counts, and mark-recapture methods. However, practical limitations render traditional survey techniques impractical for application on outer islands. Thus, assessment of current status and appropriate management is limited by a paucity of information regarding Key deer on outer islands. The purpose of my study was to evaluate the utility of infrared-triggered cameras and forward-looking infrared thermography (FLIR) to monitor occupancy and abundance of Key deer on outer islands, and to obtain baseline information regarding current distribution and abundance of Key deer in these areas. In addition, I wanted to further evaluate the advantages and disadvantages inherent in using baited camera-stations to estimate abundance of large mammal populations. I compared 3 frequently applied methods to estimate abundance from camera-based survey data. All outer islands exhibited estimated abundances considerably below carrying capacities, with larger populations occurring closer to Big Pine Key. Results indicated that other islands and complexes such as Ramrod Key, Water Key, and the Annette complex maintain only small sub-populations (e.g., ≤5 individuals) and other previously inhabited island complexes (i.e., Johnson complex and Summerland Key) no longer maintain sub-populations. Additionally, I compared abundance estimates from FLIR-based surveys to camera-based estimates. Although no test of accuracy was possible, camera-based survey methods consistently produced higher estimates of Key deer abundance on outer islands. Results indicate that aerial FLIR-based survey methods may be unreliable for the survey of large mammals in tropical habitats or areas exhibiting dense vegetation, and camera-based surveys should be the preferred method to survey Key deer abundance on outer islands.
63

Spatial inequality of urban poverty in Hong Kong

Poon, Fu-kit, Benson. January 2009 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 126-132).
64

Localized-denisty-matrix method and its application to nano-size systems

Liang, Wanzhen. January 2001 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 148-161).
65

Some properties on doubly-stochastic matrices and the distribution of density on a numerical range /

Ng, Kam-chuen. January 1982 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1982.
66

A study of the 'equatorial anomaly' in the topside of the ionosphere during the northern winter at sunspot maximum.

Chan, Chang-sing. January 1974 (has links)
Thesis--M. Phil., University of Hong Kong, 1975.
67

A comparison between the northern and southern crests of the 'equatorial anomaly' within the Asian region.

Poon, Chiu-bong, Edward. January 1976 (has links)
Thesis--M. Phil., University of Hong Kong, 1977.
68

The 'equatorial anomaly' in electron content at sunspot minimum and sunspot maximum within the Asian region.

Ma, Hung-kin, John. January 1976 (has links)
Thesis--Ph. D., University of Hong Kong, 1977.
69

Proton acceleration experiment by high intensity laser pulse interaction with solid density target at the Texas Petawatt Laser Facility

Kuk, Donghoon 20 February 2012 (has links)
In recent, high intensity laser pulse interaction with solid density matter has been studied in several laboratory and facilities. Multi-MeV proton and ion beams from plasma produced by this interaction is one important application research area of HEDP. In this thesis, the basic theory of hot electron generation associated with proton acceleration will be introduced. A basic proton acceleration mechanism called TNSA will be introduced with supplemental free plasma expansion model. To investigate proton acceleration at the Texas Petawatt Facility, the experimental set up and target alignmen will be introduced in the chapter 5. While the analysis of data acquired from this experiment is still unfinished, a brief result with RCF image will be introduced in chapter 6. / text
70

Development of new technology for the accurate determination of the density of high value fluids

Hutchison, Craig McGregor January 2003 (has links)
The development and validation of new technology for the accurate and traceable metering of high value fluids is presented here. The focus of this doctoral submission is on the determination of fluid density by the measurement of relative permittivity. A prototype cell, comprising a re-entrant cavity resonator, for the precise determination of the relative permittivity of gases and hydrocarbon liquids over a wide range of both pressures and temperatures has been developed for this work. Accuracies of measurement of relative permittivity with the re-entrant cavity resonator technique of better than 1 ppm may be achieved. Reference quality relative permittivity measurements were performed and expressions developed for ethylene which are specific to industrial metering applications ( 0 ≤ t ≤ 30°C and 5 ≤ p ≤ 10 MPa). The uncertainty in values of density calculated from the mapping relationship is approximately 0.03 % in density at a 95 % confidence level. The laboratory facility used to perform the fluid mapping or characterisation was based around a high-performance RF network analyser as the principle measuring instrument. However, an on-line instrument must be simple to operate, relatively compact, robust and considerably less expensive; particularly if it is to be widely deployed. The aimed accuracy in the measurement of relative permittivity of the on-line instrument was 5 ppm; a factor of five lower than the laboratory instrument. For the on-line instrument, the re-entrant cavity resonator was incorporated into a feedback oscillator circuit as the frequency determining element. The accuracy of measurement of relative permittivity of the on-line instrument was 2.5 ppm; a factor of two greater than the aimed accuracy. This accuracy of frequency measurement is only achievable over a relatively narrow range of operating conditions, which is ultimately a limiting factor in the applicability of the on-line instrument for high precision relative permittivity measurements in the field.

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