View All Items
(1 - 5 of 5)
- Title
- SEAWINDS RADIOMETER BRIGHTNESS TEMPERATURE CALIBRATION AND VALIDATION.
- Creator
-
Rastogi, Mayank, Jones, Linwood, University of Central Florida
- Abstract / Description
-
The NASA SeaWinds scatterometer is a radar remote sensor which operates on two satellites; NASA's QuikSCAT launched in June 1999 and on Japan's ADEOS-II satellite launched in December 2002. The purpose of SeaWinds is to provide global measurements of the ocean surface wind vector. On QuikSCAT, a ground data processing algorithm was developed, which allowed the instrument to function as a QuikSCAT Radiometer (QRad) and measure the ocean microwave emissions (brightness temperature, Tb)...
Show moreThe NASA SeaWinds scatterometer is a radar remote sensor which operates on two satellites; NASA's QuikSCAT launched in June 1999 and on Japan's ADEOS-II satellite launched in December 2002. The purpose of SeaWinds is to provide global measurements of the ocean surface wind vector. On QuikSCAT, a ground data processing algorithm was developed, which allowed the instrument to function as a QuikSCAT Radiometer (QRad) and measure the ocean microwave emissions (brightness temperature, Tb) simultaneously with the backscattered power. When SeaWinds on ADEOS was launched, this same algorithm was applied, but the results were anomalous. The initial SRad brightness temperatures exhibited significant, unexpected, ascending/descending orbit Tb biases. This thesis presents an empirical correction algorithm to correct the anomalous SeaWinds Radiometer (SRad) ocean brightness temperature measurements. I use the Advanced Microwave Scanning Radiometer (AMSR) as a brightness temperature standard to calibrate and then, with independent measurements, validate the corrected SRad Tb measurements. AMSR is a well-calibrated multi-frequency, dual-polarized microwave radiometer that also operates on ADEOS-II. These results demonstrate that, after tuning the Tb algorithm, good quality SRad brightness temperature measurements are obtained over the oceans.
Show less - Date Issued
- 2005
- Identifier
- CFE0000689, ucf:46490
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000689
- Title
- IDENTIFICATION OF GENES ENCODING ACYL-COA REDUCTASES AND ALDEHYDE REDUCTASES IN MYCOBACTERIAL GENOME BY CHARACTERIZATION OF THE REDUCTASES EXPRESSED IN E.COLI.
- Creator
-
Singh, Harminder, Kolattukudy, Pappachan, University of Central Florida
- Abstract / Description
-
Mycobacterium tuberculosis has been long known to produce wax esters. However, the enzymes involved in their biosynthesis have not been identified. Here we report the identification of Rv3391 and Rv1543 as genes that encode fatty acyl-CoA reductases and Rv1544 as one that encodes an aldehyde reductase. When expressed in E.coli, the products of Rv3391 and Rv1543 catalyzed reduction of fatty acyl-CoA to fatty alcohol with the corresponding aldehyde as an intermediate with an optimal pH of 7.0....
Show moreMycobacterium tuberculosis has been long known to produce wax esters. However, the enzymes involved in their biosynthesis have not been identified. Here we report the identification of Rv3391 and Rv1543 as genes that encode fatty acyl-CoA reductases and Rv1544 as one that encodes an aldehyde reductase. When expressed in E.coli, the products of Rv3391 and Rv1543 catalyzed reduction of fatty acyl-CoA to fatty alcohol with the corresponding aldehyde as an intermediate with an optimal pH of 7.0. Both enzymes showed a strong preference for NADPH over NADH as a reductant. Apparent Km for NADPH was 38 M for Rv3391 product and 202 M for Rv1543 product. Both enzymes reduced saturated fatty acyl-CoA such as palmitoyl-CoA and stearyl-CoA but showed a preference for oleoyl-CoA. Apparent Km for oleoyl-CoA was 13 M for Rv3391 product and 7 M for Rv1543 product. The Rv1544 product catalyzed fatty aldehyde reduction to fatty alcohol but not acyl-CoA reduction. The optimal pH for aldehyde reduction was 8.0. This aldehyde reductase showed a strong preference for NADPH with an apparent Km of 83 M. All three reductases were inhibited by SH directed reagents.
Show less - Date Issued
- 2007
- Identifier
- CFE0001903, ucf:47495
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001903
- Title
- DETECTION OF DRUG-RESISTANCE CONFERRING SINGLE NUCLEOTIDE POLYMORPHISMS IN MYCOBACTERIUM TUBERCULOSIS USING BINARY DNAZYMES.
- Creator
-
Addario, Marina, Rohde, Kyle, University of Central Florida
- Abstract / Description
-
Mycobacterium tuberculosis (Mtb) is the pathogen that causes Tuberculosis (TB) and is responsible for an average of 1.5 million deaths annually. Although a treatment regimen does exist, Multi-Drug Resistant (MDR-TB) and eXtremely Drug Resistant (XDR-TB) TB strains are becoming a more prevalent concern partly due to failure of patient compliance with the current six to nine month drug treatment regimen. The current diagnostic methods are not able to identify these MDR and XDR-TB strains...
Show moreMycobacterium tuberculosis (Mtb) is the pathogen that causes Tuberculosis (TB) and is responsible for an average of 1.5 million deaths annually. Although a treatment regimen does exist, Multi-Drug Resistant (MDR-TB) and eXtremely Drug Resistant (XDR-TB) TB strains are becoming a more prevalent concern partly due to failure of patient compliance with the current six to nine month drug treatment regimen. The current diagnostic methods are not able to identify these MDR and XDR-TB strains efficiently therefore more effective point-of-care (POC) diagnostics and drug susceptibility testing (DST) are urgently needed to detect drug resistance and facilitate prompt, appropriate treatment plans. In order to detect TB and efficiently identify drug resistance, this project seeks to develop a novel diagnostic technology based on deoxyribozyme (DNAzyme) sensors. The overall goal of this project is to create an assay which combines Polymerase Chain Reaction (PCR) and DNAzymes to identify drug resistance conferring Single Nucleotide Polymorphisms (SNPs). To safely test the ability of DNAzyme sensors to detect SNPs indicative of multi-drug resistant TB, we have constructed a panel of drug resistant (drugR) nonpathogenic M. bovis BCG. We have designed a multiplex PCR that amplifies 6 chromosomal regions of the genome necessary for the species specific detection of TB and determination of a drug susceptibility profile based on the presence of SNPs. To improve the sensitivity and selectivity of the detection and DST of Mtb, we have designed and optimized DNAzyme sensor assays combined with multiplex PCR analytes that will enable the rapid, POC detection of drug resistance. This work aims to develop novel tools for the prompt and specific diagnosis of TB allowing for the implementation of an iv effective treatment regimen that will ultimately lessen transmission and control the emerging global threat of MDR and XDR-TB.
Show less - Date Issued
- 2015
- Identifier
- CFH0004844, ucf:45435
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004844
- Title
- DEVELOPMENT OF NOVEL FLUORESCENT TOOLS FOR INVESTIGATING VIRULENCE FACTORS AND DRUG SUSCEPTIBILITY IN MYCOBACTERIUM TUBERCULOSIS.
- Creator
-
Wilburn, Kaley, Rohde, Kyle, University of Central Florida
- Abstract / Description
-
Mycobacterium tuberculosis (Mtb) is the causative agent of Tuberculosis (TB), a life-threatening disease primarily affecting the lungs that infects about one third of the world's population and causes 1.3 million deaths annually. It is estimated that TB has been infecting humans for around 70,000 years and has killed more people than any other infectious disease. The highly effective, persistent, and multifaceted virulence strategies that have allowed Mtb to continue to spread and thrive for...
Show moreMycobacterium tuberculosis (Mtb) is the causative agent of Tuberculosis (TB), a life-threatening disease primarily affecting the lungs that infects about one third of the world's population and causes 1.3 million deaths annually. It is estimated that TB has been infecting humans for around 70,000 years and has killed more people than any other infectious disease. The highly effective, persistent, and multifaceted virulence strategies that have allowed Mtb to continue to spread and thrive for so long are still poorly understood at the molecular level. This lack of knowledge contributes to ongoing challenges to curing TB. Although drugs capable of killing Mtb exist, even strains that are susceptible to these drugs remain so difficult to treat that stringent six- to nine-month courses of four-drug cocktails are required. Practical difficulties in administering full treatments and patient noncompliance have contributed to a rise in drug-resistant TB cases globally. To combat this increasing world health problem, new antibiotic treatments that kill Mtb and drug-resistant Mtb more effectively via new mechanisms of action are necessary. Discovering these antibiotics expediently requires that innovative Mtb-specific drug-screening assays are developed. An ideal and innovative TB drug screening method would target validated protein-protein interactions (PPI) essential to Mtb's pathogenesis and would be performed on whole Mtb cells under relevant in vivo-like conditions. This project focused on engineering several tools relevant to creating an ideal TB drug screen. A protein fragment complementation assay capable of studying PPI of the TB gyrase complex was created, and this assay was assessed for future HTS applications. To streamline the readout, this assay was re-engineered to include green fluorescent protein. Modifications to the red fluorescent protein mCherry, including the creation of a large Stokes shift mutant mCherry and an mCherry bimolecular fluorescence complementation assay, were also engineered and investigated.
Show less - Date Issued
- 2015
- Identifier
- CFH0004843, ucf:45473
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004843
- Title
- DEVELOPMENT OF A FLUORESCENT DRUG SCREENING PLATFORM FOR INHIBITORS OF MYCOBACTERIUM TUBERCULOSIS PROTEIN-PROTEIN INTERACTIONS.
- Creator
-
Versfeld, Zina, Rohde, Kyle, University of Central Florida
- Abstract / Description
-
Tuberculosis (TB) is a respiratory disease caused by Mycobacterium tuberculosis (Mtb) that kills around 1.3 million people annually. Multi-drug resistant TB (MDR-TB) strains are increasingly encountered, in part resulting from shortcomings of current TB drug regimens that last between six to nine months. Patients may stop taking the antibiotics during their allotted regimen, leading to drug resistant TB strains. Novel drug screening platforms are therefore necessary to find drugs effective...
Show moreTuberculosis (TB) is a respiratory disease caused by Mycobacterium tuberculosis (Mtb) that kills around 1.3 million people annually. Multi-drug resistant TB (MDR-TB) strains are increasingly encountered, in part resulting from shortcomings of current TB drug regimens that last between six to nine months. Patients may stop taking the antibiotics during their allotted regimen, leading to drug resistant TB strains. Novel drug screening platforms are therefore necessary to find drugs effective against MDR-TB. In order to discover compounds that target under-exploited pathways that may be essential only in vivo, the proposed screening platform will use a novel approach to drug discovery by blocking essential protein-protein interactions (PPI). In Mtb, PPI can be monitored by mycobacterial protein fragment complementation (M-PFC). This project will re-engineer the M-PFC assay to include the red fluorescent mCherry reporter for increased efficiency and sensitivity in high-throughput screening applications. To optimize the mCherry assay, we have developed fluorescent M-PFC reporter strains to monitor distinct PPI required for Mtb virulence: homodimerization of the dormancy regulator DosR. A drug screen will then identify novel compounds that inhibit this essential PPI. The screen will involve positional-scanning combinatorial synthetic libraries, which are made up of chemical compounds with varying side chains. This work will develop novel tools for TB drug discovery that could identify new treatments for the emerging world threat of MDR-TB.
Show less - Date Issued
- 2015
- Identifier
- CFH0004785, ucf:45369
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004785
