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- Title
- CONTROL OF STOMATAL FORMATION IN ARABIDOPSIS THALIANA INFLORESCENCE STEM.
- Creator
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Odapalli, Nalini, Nadeau, Jeanette, University of Central Florida
- Abstract / Description
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Stomata are cellular structures that control water loss and gas exchange through the plant epidermis. Stomata arise from special stem cells called meristemoids through a series of programmed asymmetric divisions that are controlled by cell signaling, or via multitude of regulatory pathways and intercellular communication between epidermal cells. In Arabidopsis thaliana, stomata are spaced non-randomly in the epidermis by cell-cell signaling of the receptor-like protein TOO MANY MOUTHS (TMM)...
Show moreStomata are cellular structures that control water loss and gas exchange through the plant epidermis. Stomata arise from special stem cells called meristemoids through a series of programmed asymmetric divisions that are controlled by cell signaling, or via multitude of regulatory pathways and intercellular communication between epidermal cells. In Arabidopsis thaliana, stomata are spaced non-randomly in the epidermis by cell-cell signaling of the receptor-like protein TOO MANY MOUTHS (TMM) as well as other proteins. Point mutation of the TMM gene prevents the development of stomata in some tissues like inflorescence stems. Investigation of tmm mutant stems showed that self-renewing stem cell-like precursors form by dividing asymmetrically but fail to form stomata. This is further supported by molecular markers of stomatal cell fate that show stomatal precursors form but do not differentiate as stomata. Therefore, TMM signaling is likely required to control expression of genes that are essential for the formation of stomata in stems. As a second approach, gene expression profiling was used to identify candidate genes involved in stomatal biogenesis. Differentially expressed genes were categorized by gene ontology and analyzed for statistically overrepresented classes to gain insight into functional processes. Comparison of stem expression data with previously published microarray data was used to narrow the list to genes involved in stomatal patterning. Mutants in these target genes have been obtained and phenotypic analysis revealed new stomatal regulators. Comparison of epidermal cells of the stem tip region from wild-type and tmm revealed that there are significantly more meristemoids formed in tmm stems compared to wild-type stems. In addition, the orientation of meristemoids formed in wild-type stems was random with respect to stem polarity and followed a spiral pattern of asymmetric divisions similar to leaves. This showed that stomatal patterning in dicots does not follow orientation in asymmetric cell division for spacing the adjacent stomata like monocots.
Show less - Date Issued
- 2008
- Identifier
- CFE0002179, ucf:47503
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002179
- Title
- A MATHEMATICAL STUDY OF TWO RETROVIRUSES, HIV AND HTLV-I.
- Creator
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Baxley, Dana, Mohapatra, Ram, University of Central Florida
- Abstract / Description
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In this thesis, we examine epidemiological models of two different retroviruses, which infect the human body. The two viruses under study are HIV or the human immunodefiency virus and HTLV-I, which is the human T lymphotropic virus type I. A retrovirus is a virus, which injects its RNA into the host, rather than it's DNA. We will study each of the different mathematical models for each of the viruses separately. Then we use MATLAB-SIMULINK to analyze the models by studying the...
Show moreIn this thesis, we examine epidemiological models of two different retroviruses, which infect the human body. The two viruses under study are HIV or the human immunodefiency virus and HTLV-I, which is the human T lymphotropic virus type I. A retrovirus is a virus, which injects its RNA into the host, rather than it's DNA. We will study each of the different mathematical models for each of the viruses separately. Then we use MATLAB-SIMULINK to analyze the models by studying the reproductive numbers in each case and the disease progression by examining the graphs. In Chapter 1, we mention basic ideas associated with HIV and HTLV-I. In Chapter 2 some of the basic mathematical model of epidemiology is presented. Chapter 3 is devoted to a model describing the intra-host dynamics of HIV. Here, we take into account how HIV infects and replicates in the CD4+ T cells. The model studied in this thesis examines the difference between cells, which are susceptible to the virus, and cells, which are not susceptible. Through the graphs associated with this model, we are able to see how this difference affects disease progression. In Chapter 4, we examine the effect of HTLV-I virus on human body. The HTLV-I virus causes a chronic infection in humans and may eventually lead to other diseases. In particular, the development of Adult T-cell Leukemia or ATL is studied in this thesis. The T-cell dynamics and progression to ATL is described using a mathematical model with coupled differential equations. Using mathematical analysis and SIMULINK, we obtain results on stability, asymptotic stability and the manner of progression of the disease. In Chapter 5 and appendices, we mention our inference and the MATLAB-SIMULINK codes used in this thesis, so that a reader can verify the details of the work carried out in this thesis.
Show less - Date Issued
- 2007
- Identifier
- CFE0001886, ucf:47398
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001886
- Title
- STUDY OF THE EGFR, SRC AND STAT3 PATHWAY IN PANCREATIC CANCER.
- Creator
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Jaganathan, Soumya, Turkson, James, University of Central Florida
- Abstract / Description
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Cancer is associated with many molecular aberrations that support the malignant phenotype. In that regard, aberrant activation of epidermal growth factor receptor (EGFR), Src, and signal transducer and activator of transcription 3 (Stat3) occur concurrently in pancreatic cancer and are implicated in the disease phenotype. Notwithstanding, increasing evidence indicates that therapies that target only EGFR or Src are rather ineffective in modulating the cancer phenotype. The poor therapeutic...
Show moreCancer is associated with many molecular aberrations that support the malignant phenotype. In that regard, aberrant activation of epidermal growth factor receptor (EGFR), Src, and signal transducer and activator of transcription 3 (Stat3) occur concurrently in pancreatic cancer and are implicated in the disease phenotype. Notwithstanding, increasing evidence indicates that therapies that target only EGFR or Src are rather ineffective in modulating the cancer phenotype. The poor therapeutic outcome of the monotherapies targeting EGFR or Src may in part be due to the increased incidence of signaling cross-talks among aberrant signaling pathways in cancer. Molecular details of the signaling integration between EGFR, Src and Stat3, however, are lacking. Understanding how the aberrant EGFR, Src and Stat3 pathways are integrated in pancreatic cancer would facilitate the design of effective multiple-targeted, clinically feasible therapeutic modalities. Our study shows that in pancreatic cancer cell lines, aberrant Src activity promotes abnormal EGFR activation through the phosphorylation of the EGFR motifs, Tyr845, Tyr1068 and Tyr1086. Furthermore, aberrantly-active EGFR and Src together induce constitutive activation of Stat3 in pancreatic cancer cells. Evidence further shows that EGFR, Src and Stat3 physically associated into a heteromeric complex. Significantly, the EGFR, Src and Stat3 heteromeric complex is detectable in the nucleus and functions as a transcriptionally-active complex to induce the c-Myc gene. Of therapeutic significance, the concurrent inhibition of Stat3 and EGFR or Src promoted greater viability loss and apoptosis of pancreatic cancer cells in vitro, and induced stronger tumor growth inhibition in xenografts of human pancreatic cancer. Altogether, our studies suggest that the heteromeric EGFR, Src, and Stat3 complex may serve as an additional novel mechanism of support of the pancreatic cancer phenotype. Furthermore, our studies provide evidence that the concurrent targeting of Stat3 and EGFR or Stat3 and Src could be a more effective therapeutic approach for human pancreatic cancer.
Show less - Date Issued
- 2010
- Identifier
- CFE0003417, ucf:48383
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003417
- Title
- A Proposed Approach to Protect Wastewater Biological Treatment Plants Against Toxic Contaminants.
- Creator
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Phillips, Joseph M., Evans, Ronald D., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis
- Date Issued
- 1972
- Identifier
- CFR0011998, ucf:53081
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011998
- Title
- EVALUATION OF PREFERMENTATION AS A UNIT PROCESS UPON BIOLOGICAL NUTRIENT REMOVAL INCLUDING BIOKINETIC AND WASTEWATER PARAMETERS.
- Creator
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McCue, Terrence, Randall, Andrew, University of Central Florida
- Abstract / Description
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The objective of this dissertation was to provide a controlled comparison of identical continuous flow BNR processes both with and without prefermentation in order to provide a stronger, more quantitative, technical basis for design engineers to evaluate the potential benefits of prefermentation to EBPR in treating domestic wastewater. In addition, the even less understood effect of prefermentation on denitrification kinetics and anoxic phosphorus (P) uptake was studied and quantified. Other...
Show moreThe objective of this dissertation was to provide a controlled comparison of identical continuous flow BNR processes both with and without prefermentation in order to provide a stronger, more quantitative, technical basis for design engineers to evaluate the potential benefits of prefermentation to EBPR in treating domestic wastewater. In addition, the even less understood effect of prefermentation on denitrification kinetics and anoxic phosphorus (P) uptake was studied and quantified. Other aspects of BNR performance, which might change due to use of prefermentation, will also be addressed, including anaerobic stabilization. Potential benefits to BNR processes derived from prefermentation are compared and contrasted with the more well-known benefits of primary clarification. Finally, some biokinetic parameters necessary to successfully model both the activated sludge systems and the prefermenter were determined and compared for the prefermented versus the non-prefermented system. Important findings developed during the course of this dissertation regarding the impact of prefermentation upon the performance of activated sludge treatment systems are summarized below: For a septic COD-limited (TCOD:TP < 40:1) wastewater, prefermentation was found to enhance EPBR by 27.7% at a statistical significance level of alpha=0.05 (95% confidence level). For septic P-limited (TCOD:TP > 40:1) wastewaters, prefermentation was not found to improve EBPR at a statistical significance level of alpha=0.05 (95% confidence level). The increased anaerobic P release and aerobic P uptakes due to prefermentation correlated with greater PHA formation and glycogen consumption during anaerobiosis of prefermented influent. Improvements in biological P removal of septic, non-P limited wastewater occurred even when all additional VFA production exceeded VFA requirements using typical design criteria (e.g. 6 g VFA per 1 g P removal). Prefermentation increased RBCOD content by an average of 28.8% and VFA content by an average of 18.8%, even for a septic domestic wastewater. Prefermentation increased specific anoxic denitrification rates for both COD-limited (14.6%) and P-limited (5.4%) influent wastewaters. This increase was statistically significant at alpha=0.05 for COD-limited wastewater, but not for P-limited wastewater.
Show less - Date Issued
- 2006
- Identifier
- CFE0001418, ucf:47052
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001418
- Title
- Quantifying the impacts of oyster reef restoration on oyster coverage, wave attenuation and seagrass fragment retention in Mosquito Lagoon, Florida.
- Creator
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Garvis, Stephanie, Walters, Linda, Weishampel, John, Virnstein, Robert, University of Central Florida
- Abstract / Description
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The goal of this project was to determine the effects of oyster reef restoration on oyster coverage, wave height dissipation and seagrass recruitment. First, to assess the current versus historical coverage of natural, dead and restored oyster reefs within Mosquito Lagoon, aerial photographs from 2009, provided by Saint Johns River Water Management District, were digitized using ArcGIS software. Live reefs, restored reefs and dead reefs were screen digitized using a reef 'signature' in order...
Show moreThe goal of this project was to determine the effects of oyster reef restoration on oyster coverage, wave height dissipation and seagrass recruitment. First, to assess the current versus historical coverage of natural, dead and restored oyster reefs within Mosquito Lagoon, aerial photographs from 2009, provided by Saint Johns River Water Management District, were digitized using ArcGIS software. Live reefs, restored reefs and dead reefs were screen digitized using a reef 'signature' in order to estimate the area of each type of reef. The 2009 maps were used as a guide to digitizing the historical aerial photographs (1943, 1951, 1967, 1971, 1984, 1995, 2006). Dead reefs increased both in number and aerial extent during the study period (1943 (-) 2009), with 2009 having over 10 acres of dead reef coverage. Dead reefs were more likely to be found along major boating channels. Several dead reefs exhibited migration into the mangrove islands located landward of the 1943 footprint, with some dead reefs completely washing up into the shoreline. Restoration of dead reefs added 0.5 acres of live oysters to the Mosquito Lagoon area as of January 2009. Second, I examined how different oyster reef types (natural reef, restored reef, dead reef) reduced wave height. To determine wave height attenuation on each reef type, experiments were conducted in a 9 meter long wave tank using sensors that measured changes in wave height. For each reef type, replicate reefs were created in the wave tank. Shoreline sediment without oysters was used as a control. Using the wave generator, wave heights similar to Mosquito Lagoon boat wakes were created. Restored reefs reduced the incoming wave height by 25% compared to sediment without oysters. Lastly, I examined the potential link between oyster reef restoration and recruitment of seagrass fragments. Monthly surveys were performed to quantify the number of seagrass fragments encountering the three oyster reef types: dead reefs, natural reefs and restored reefs. The quantity of seagrass fragments was found to be similar on the three different reef types, but did show a significant trend of seasonality, which corresponds with the growing season of Halodule wrightii. Next, I tested retention of experimentally manipulated seagrass fragments on five natural and five restored reefs. Restored reefs retained seagrass fragments for significantly longer than natural reefs. I also measured seagrass fragment entanglement on each reef type inside the wave tank. I found that seagrass fragments were significantly more likely to become entangled and retained on restored reefs compared to dead and natural reefs. Overall, these metrics are important for determining the success of long-term oyster restoration project in Mosquito Lagoon, Florida. This project has found that oyster restoration is increasing the area of oyster habitat as well as providing important ecosystem services.
Show less - Date Issued
- 2012
- Identifier
- CFE0004538, ucf:49250
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004538
- Title
- An Investigation of the Impacts of Face-to-Face and Virtual Laboratories in an Introductory Biology Course on Students' Motivation to Learn Biology.
- Creator
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Reece, Amber, Butler, Malcolm, Boote, David, Chini, Jacquelyn, Fedorka, Kenneth, University of Central Florida
- Abstract / Description
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The objective of this study was to evaluate and compare the effects of face-to-face and virtual laboratories in a large-enrollment introductory biology course on students' motivation to learn biology. The laboratory component of post-secondary science courses is where students have opportunities for frequent interactions with instructors and their peers (Seymour (&) Hewitt, 1997; Seymour, Melton, Wiese, (&) Pederson-Gallegos, 2005) and is often relied upon for promoting interest and...
Show moreThe objective of this study was to evaluate and compare the effects of face-to-face and virtual laboratories in a large-enrollment introductory biology course on students' motivation to learn biology. The laboratory component of post-secondary science courses is where students have opportunities for frequent interactions with instructors and their peers (Seymour (&) Hewitt, 1997; Seymour, Melton, Wiese, (&) Pederson-Gallegos, 2005) and is often relied upon for promoting interest and motivation in science learning (Hofstein (&) Lunetta, 2003; Lunetta, Hofstein, (&) Clough, 2007). However, laboratory courses can be resource intensive (Jenkins, 2007), leading post-secondary science educators to seek alternative means of laboratory education such as virtual laboratories. Scholars have provided evidence that student achievement in virtual laboratories can be equal to, if not higher than, that of students in face-to-face laboratories (Akpan (&) Strayer, 2010; Finkelstein et al., 2005; Huppert, Lomask, (&) Lazarowitz, 2002). Yet, little research on virtual laboratories has been conducted on affective variables such as motivation to learn science.Motivation to learn biology was measured at the beginning and end of the semester using the Biology Motivation Questionnaire (&)copy; (Glynn, Brickman, Armstrong, (&) Taasoobshirazi, 2011) and compared between the face-to-face and virtual laboratory groups. Characteristics of the two laboratory environments were measured at the end of the semester by the Distance Education Learning Environment Survey (Walker (&) Fraser, 2005). Interviews with 12 participants were conducted three times throughout the semester in the phenomenological style of qualitative data collection. The quantitative survey data and qualitative interview and observation data were combined to provide a thorough image of the face-to-face and virtual laboratory environments and their impacts on students' motivation to learn biology.Statistical analyses provided quantifiable evidence that the novel virtual laboratory environment did not have a differential effect on students' motivation to learn biology, with this finding being supported by the qualitative results. Comparison of the laboratory environments showed that students in the face-to-face labs reported greater instructional support, student interaction and collaboration, relevance of the lab activities, and authentic learning experiences than the students in the virtual labs. Qualitative results indicated the teaching assistants in the face-to-face labs were an influential factor in sustaining students' motivation by providing immediate feedback and instructional support in and out of the laboratory environment. In comparison, the virtual laboratory students often had to redo their lab exercises multiple times because of unclear directions and system glitches, potential barriers to persistence of motivation. The face-to-face students also described the importance of collaborative experiences and hands-on activities while the virtual laboratory students appreciated the convenience of working at their own pace, location, and time. According to social cognitive theory (Bandura, 1986, 2001), the differences in the learning environments reported by the students should have had ramifications for their motivation to learn biology, yet this did not hold true for the students in this study. Therefore, while these laboratory environments are demonstrably different, the virtual laboratories did not negatively impact students' motivation to learn biology and could be an acceptable replacement for face-to-face laboratories in an introductory biology course.
Show less - Date Issued
- 2015
- Identifier
- CFE0005872, ucf:50876
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005872
- Title
- Does the journey matter more than the destination? The contribution of geospatial characteristics and local variables to invasive Pomacea maculata distribution across ranchland wetlands.
- Creator
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Pierre, Steffan, Quintana-Ascencio, Pedro, Jenkins, David, Boughton, Elizabeth, University of Central Florida
- Abstract / Description
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Geospatial characteristics such as isolation and avenues of connectivity influence an invader's pattern of dispersal and distribution. However many examinations of invasion success ignore the contribution of dispersal to patterns of invasion and focus only on the local environmental/habitat factors. This study examines the interaction of geospatial characteristics, that may influence dispersal, and local environmental factors, that may govern successful occupation, on the likelihood of...
Show moreGeospatial characteristics such as isolation and avenues of connectivity influence an invader's pattern of dispersal and distribution. However many examinations of invasion success ignore the contribution of dispersal to patterns of invasion and focus only on the local environmental/habitat factors. This study examines the interaction of geospatial characteristics, that may influence dispersal, and local environmental factors, that may govern successful occupation, on the likelihood of invasion (invasability) of wetlands within an agriculturally modified landscape. I examined the current invasion of seasonal wetlands in south-central Florida ranchland by non-native apple snails (Pomacea maculata (Ampullariidae)) as a model system for understanding this interaction. I surveyed spatial occurrence of P. maculata in 171 wetlands in 2014 and found they occurred in 43% of wetlands surveyed. I evaluated how occurrence was related to geospatial variables (proximity to propagule sources, shoreline complexity, interwetland distance, elevation, area and ditch presence) and wetland characteristics (pH, water hardness, conductivity and soil type) for 95 wetlands. Presence of ditch connections and more neutral water pH were associated with P. maculata occurrence. I did not find evidence that Euclidean distance and minimum ditch distance were associated with P. maculata occurrence. I also performed a 5 month field experiment where I translocated snails to previously occupied and non-occupied wetlands and measured snail survival and growth (20 wetlands from November to March). This experiment evaluated if non-occurrence during survey was more likely to be associated with unfavorable habitat conditions or dispersal limitation. Wetland pH and water hardness explained variation in P. maculata survival, and wetland pH best explained growth. I did not find evidence that prior occupancy affected the snail survival and growth, which suggests previously unoccupied wetlands are due to dispersal limitation. These results emphasize that man-made conduits can increase permeability of the landscape, facilitating the dispersal and introduction of nonnative species and the need for the inclusion of dispersal metrics in understanding invasive species distribution.
Show less - Date Issued
- 2015
- Identifier
- CFE0006374, ucf:51527
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006374
- Title
- EFFECTS OF REDUCED RAS AND VOLUME ON ANAEROBIC ZONE PERFORMANCE FOR A SEPTIC WASTEWATER BIOLOGICAL PHOSPHOROUS REMOVAL SYSTEM.
- Creator
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Magro, Daniel, Randall, Andrew, University of Central Florida
- Abstract / Description
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Enhanced Biological Phosphorous Removal (EBPR) performance was found to be adequate with reduced Return Activated Sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller than typical anaerobic zone volume (1.08 hours hydraulic retention time or HRT). Three identical parallel biological nutrient removal (BNR) pilot plants were fed with strong, highly fermented (160 mg/L VFAs), domestic/industrial wastewater from a full scale wastewater treatment facility (WWTF). The pilot...
Show moreEnhanced Biological Phosphorous Removal (EBPR) performance was found to be adequate with reduced Return Activated Sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller than typical anaerobic zone volume (1.08 hours hydraulic retention time or HRT). Three identical parallel biological nutrient removal (BNR) pilot plants were fed with strong, highly fermented (160 mg/L VFAs), domestic/industrial wastewater from a full scale wastewater treatment facility (WWTF). The pilot plants were operated at 100%, 50%, 40% and 25% RAS (percent of available RAS) flows to the anaerobic tank with the remaining RAS to the anoxic tank. In addition, varying anaerobic HRT (1.08 and 1.5 hours), and increased hydraulic loading (35% increase) was examined. The study was divided in four Phases, and the effect of these process variations on EBPR were studied by having one different variable between two identical systems. The most significant conclusions were that only bringing part of the RAS to the anaerobic zone did not decrease EBPR performance, instead changing the location of P release and uptake. Bringing less RAS to the anaerobic and more to the anoxic tank decreased anaerobic P release and increased anoxic P release (or decreased anoxic P uptake). Equally important is that with VFA rich influent wastewater, excessive anaerobic volume was shown to hurt overall P removal even when it resulted in increased anaerobic P release. Computer modeling with BioWin and UCTPHO was found to predict similar results to the pilot test results. Modeling was done with reduced RAS flows to the anaerobic zone (100%, 50%, and 25% RAS), increased anaerobic volume, and increased hydraulic loading. The most significant conclusions were that both models predicted EBPR did not deteriorate with less RAS to the anaerobic zone, in fact, improvements in EBPR were observed. Additional scenarios were also consistent with pilot test data in that increased anaerobic volume did not improve EBPR and increased hydraulic loading did not adversely affect EBPR.
Show less - Date Issued
- 2005
- Identifier
- CFE0000329, ucf:46285
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000329
- Title
- THE ROLE OF INTESTINAL SWEET TASTE RECEPTORS (STRS) IN THE REGULATION OF GLUCOSE ABSORPTION: EFFECTS OF SHORT TERM HIGH SUCROSE DIET (HSD).
- Creator
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Hussain, Tania, Borgon, Robert, University of Central Florida
- Abstract / Description
-
Sweet taste receptors are primarily found in the oral cavity of the mammalian species. However, recent studies have shown that sweet taste receptors can be found in extraoral tissues such as the pancreas, intestines, and adipose tissue. Our lab has previously found that sweet taste receptors are down-regulated on the pancreas in the presence of high plasma glucose levels. In order to assess the possibility that sweet taste receptors respond to high levels of glucose by suppressing its...
Show moreSweet taste receptors are primarily found in the oral cavity of the mammalian species. However, recent studies have shown that sweet taste receptors can be found in extraoral tissues such as the pancreas, intestines, and adipose tissue. Our lab has previously found that sweet taste receptors are down-regulated on the pancreas in the presence of high plasma glucose levels. In order to assess the possibility that sweet taste receptors respond to high levels of glucose by suppressing its expression, we wanted to see if they reacted similarly on the intestines. We found that intestinal sweet taste receptors are down regulated in the presence of a 24 hour high sucrose diet (60% sucrose), and a 7 day high sucrose diet in both wild type (WT) mice on the high sucrose diet, and T1R2-KO (lacking sweet taste receptors) mice. We also examined their glucose excursion levels, and found that these mice are lacking a normal response to dietary glucose via an oral glucose tolerance test (OGTT). This led us to conclude that the mice lacking sweet taste receptor expression exhibit abnormal glucose absorption, possibly indicating that sweet taste receptors regulate glucose absorption in the intestines.
Show less - Date Issued
- 2014
- Identifier
- CFH0004686, ucf:45236
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004686
- Title
- Preliminary Investigation into Biological Sex Estimation Using Trace Element Analysis in Human Hair.
- Creator
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Woltering, Abigail, Dupras, Tosha, Williams, Lana, Schultz, John, Starbuck, John, Baudelet, Matthieu, University of Central Florida
- Abstract / Description
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In forensic anthropology the estimation of biological sex of unidentified human remains is critical, as it essentially halves the number of potential identities. Sex estimation is also important in bioarchaeology, because the creation of the biological profile is critical to the interpretation of different sociocultural aspects of past populations. Furthermore, certain aspects of the biological profile are sex specific, so it is important to be able to accurately determine biological sex ...
Show moreIn forensic anthropology the estimation of biological sex of unidentified human remains is critical, as it essentially halves the number of potential identities. Sex estimation is also important in bioarchaeology, because the creation of the biological profile is critical to the interpretation of different sociocultural aspects of past populations. Furthermore, certain aspects of the biological profile are sex specific, so it is important to be able to accurately determine biological sex (France 1998). Typically, biological sex is estimated by assessing sexually dimorphic differences within the pelvis and skull. However, because sexually dimorphic differences arise during puberty it is difficult, and oftentimes impossible, to use these traditional techniques on juveniles. Recently, human hair has gained prominence in anthropological research. This is particularly evident in bioarchaeology, where hair can be used to discern information concerning health, toxicology, culture, and diet of past populations. This study focuses on the relationship between the content of trace elements in hair and biological sex to determine if biological sex can be assessed from the content of trace elements in human head hair. Hair was collected from three human sample groups: modern living individuals, modern cadavers, and archaeological remains. Data on trace elements was collected using laser-induced breakdown spectroscopy (LIBS). The statistical relationship between the content of trace elements and sex was then analyzed using a multivariate analysis of variance (MANOVA), post-hoc analysis of variance (ANOVAs), and stepwise binary logistic regression. The MANOVA revealed a statistically significant multivariate main effect for sample group using mean values (p-value (<) 0.0001) and mean variance values (MVs) (p-value = 0.018). Given the significant results of the MANOVA test, the univariate main effects were examined with post-hoc ANOVA tests. Significant univariate main effects were obtained for mean values for C/Mg (p-value (<) 0.0001), C/Fe (p-value (<) 0.0001), C/Ca (p-value (<) 0.0001), and C/Sr (p-value (<) 0.0001). Significant univariate main effects were obtained for MVs for C/Mg (p-value = 0.016), C/Fe (p-value = 0.010), and C/Sr (p-value = 0.042). These preliminary results demonstrate that biological sex of humans can be accurately estimated through trace elemental analysis approximately 85% of the time in living samples, and 79% of the time overall. The results also demonstrate the viability of this technique for sex estimation in juvenile remains with approximately 83% success in predicting juvenile biological sex. This sets the stage establishing trace elemental analysis of hair as a technique for estimating biological sex which is critical to forensic individuation and identification as well as further contextualization of archaeological remains.
Show less - Date Issued
- 2016
- Identifier
- CFE0006705, ucf:51928
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006705
- Title
- Computational Methods for Comparative Non-coding RNA Analysis: From Structural Motif Identification to Genome-wide Functional Classification.
- Creator
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Zhong, Cuncong, Zhang, Shaojie, Hu, Haiyan, Hua, Kien, Li, Xiaoman, University of Central Florida
- Abstract / Description
-
Non-coding RNA (ncRNA) plays critical functional roles such as regulation, catalysis, and modification etc. in the biological system. Non-coding RNAs exert their functions based on their specific structures, which makes the thorough understanding of their structures a key step towards their complete functional annotation. In this dissertation, we will cover a suite of computational methods for the comparison of ncRNA secondary and 3D structures, and their applications to ncRNA molecular...
Show moreNon-coding RNA (ncRNA) plays critical functional roles such as regulation, catalysis, and modification etc. in the biological system. Non-coding RNAs exert their functions based on their specific structures, which makes the thorough understanding of their structures a key step towards their complete functional annotation. In this dissertation, we will cover a suite of computational methods for the comparison of ncRNA secondary and 3D structures, and their applications to ncRNA molecular structural annotation and their genome-wide functional survey.Specifically, we have contributed the following five computational methods. First, we have developed an alignment algorithm to compare RNA structural motifs, which are recurrent RNA 3D structural fragments. Second, we have improved upon the previous alignment algorithm by incorporating base-stacking information and devise a new branch-and-bond algorithm. Third, we have developed a clustering pipeline for RNA structural motif classification using the above alignment methods. Fourth, we have generalized the clustering pipeline to a genome-wide analysis of RNA secondary structures. Finally, we have devised an ultra-fast alignment algorithm for RNA secondary structure by using the sparse dynamic programming technique.A large number of novel RNA structural motif instances and ncRNA elements have been discovered throughout these studies. We anticipate that these computational methods will significantly facilitate the analysis of ncRNA structures in the future.
Show less - Date Issued
- 2013
- Identifier
- CFE0004966, ucf:49580
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004966
- Title
- The behavior of humans and wildlife with respect to roads: insights for mitigation and management.
- Creator
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Grace, Molly, Noss, Reed, Weishampel, John, Hoffman, Eric, Johnson, Steve, University of Central Florida
- Abstract / Description
-
Road ecology is the study of how roads and wildlife interact. Traditionally, road ecologists have primarily focused on one effect of roads: roadkill. Though roadkill can have devastating effects on wildlife populations, roads have sub-lethal impacts that are gaining more and more attention from the scientific community. These sub-lethal impacts include noise, light, and chemical pollution as well as altered habitat structure, which can all influence animal behavior. In this dissertation, I...
Show moreRoad ecology is the study of how roads and wildlife interact. Traditionally, road ecologists have primarily focused on one effect of roads: roadkill. Though roadkill can have devastating effects on wildlife populations, roads have sub-lethal impacts that are gaining more and more attention from the scientific community. These sub-lethal impacts include noise, light, and chemical pollution as well as altered habitat structure, which can all influence animal behavior. In this dissertation, I applied a behavioral ecology framework to study specific lethal and sub-lethal road effects with the goal of improving mitigation efforts. In Chapters 1 and 2, I evaluated how human behavior may be modified to reduce wildlife-vehicle collisions; traditionally efforts have been made to modify wildlife road crossing behavior. I found that Roadside Animal Detection Systems, which warn drivers when animals are near the road, are successful in reducing crash risk; however, care must be taken to ensure that drivers do not become acclimated to the warning system. In Chapters 3 and 4, I evaluated how traffic noise affects subadult growth and adult abundance and communication of anuran amphibians (frogs and toads), a taxon widely recognized as one of the most negatively impacted by roads. I found that through traffic noise alters tadpole behavior, it does not appear to have a negative effect on their growth. Traffic noise does, however, negatively affect adult anuran abundance. My results indicate that this reduction in abundance is caused by the interference of traffic noise with anuran communication.
Show less - Date Issued
- 2017
- Identifier
- CFE0006595, ucf:51275
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006595
- Title
- Biological Nutrient Removal (BNR) Process Optimization and Recovery of Embedded Energy Using Biodiesel By-product.
- Creator
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Salamah, Sultan, Randall, Andrew, Duranceau, Steven, Chopra, Manoj, University of Central Florida
- Abstract / Description
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Enhanced biological phosphorus removal (EBPR) as well as biological nitrogen removal require a carbon source to be carried out. Volatile fatty acid (VFAs) (mainly acetic and propionic acids) are the major driving force for EBPR. Many domestic wastewaters have an insufficient amount of VFAs. However, carbon sources such as acetic and propionic acids can be produced using primary solids fermentation process. Due to the cost of VFA production, an external carbon source can be added to the...
Show moreEnhanced biological phosphorus removal (EBPR) as well as biological nitrogen removal require a carbon source to be carried out. Volatile fatty acid (VFAs) (mainly acetic and propionic acids) are the major driving force for EBPR. Many domestic wastewaters have an insufficient amount of VFAs. However, carbon sources such as acetic and propionic acids can be produced using primary solids fermentation process. Due to the cost of VFA production, an external carbon source can be added to the biological nutrient removal (BNR) system that can be fermented to provide the desired VFAs. Glycerol (biodiesel by-product) offers a solution to reduce carbon addition cost if can be fermented to acetic and propionic acid or can be used directly as an external carbon substrate for EBPR and denitrification. Using glycerol in wastewater treatment can also offset the biodiesel plant disposal cost and reduce the BNR chemical cost. The main objective of this study was to optimize the prefermentation process and optimize the BNR system using glycerol as an external carbon source. In this work, Optimization of the prefermentation process using glycerol, mixing, and hydrogen gas addition was evaluated. EBPR performance within an A2O-BNR system was evaluated using either a direct glycerol method to the anaerobic zone or by co-fermentation with primary solids. Also, optimization of the nitrogen removal (specifically denitrification) efficiency of a 5-stage BardenphoTM BNR system using either a direct glycerol method to the second anoxic zone or by co-fermentation with primary solids was evaluated. It was found in this study that glycerol was an efficient external carbon substrate for EBPR as well as biological nitrogen removal. The prefermentation experiment showed that glycerol co-fermentation with primary solids produced significantly higher (p(<)0.05) VFAs than primary solids fermentation alone, even more than the possible value from the added glycerol (427 mg-COD/L). The increased VFAs imply that the glycerol addition stimulated additional fermentation of primary solids. Lowering the prefermenter mixing energy (50 to 7 rpm) resulted in a significant increase in VFAs production (80%). Also, purging the headspace of the prefermenter with hydrogen gas did not lead to more VFAs, but significantly (p(<)0.05) increased the propionic acid to acetic acid ratio by 41%. In the A2O-BNR pilot plant experiment, it was found that glycerol is a suitable renewable external substrate to drive enhanced EBPR as well as denitrification. The results from both locations of glycerol addition (direct vs. fermented) were beneficial to the BNR system. Both systems had similar effluent quality and achieved total nitrogen (TN) and total phosphorus (TP) removals up to 86% and 92% respectively. The 5-stage BardenphoTM BNR experiment investigated the location of glycerol addition (direct vs. fermented) on the performance of denitrification in the second anoxic zone and the overall performance. The results from both systems were that glycerol was beneficial to the BNR system and had virtually similar effluent quality. Both systems achieve complete denitrification and excellent removal of TN and TP up to 95% and 89% respectively. Also, the pilot that received fermented glycerol had significantly higher VFAs loading and lower observed yield. The side-stream prefermenter effluent flowing to the second anoxic reactor did not cause high effluent ammonia (NH3) concentration. In summary, the location at which glycerol was added did not affect effluent quality for nitrogen and phosphorus. However, glycerol addition and mixing energy did impact prefermenter performance and effluent quality.
Show less - Date Issued
- 2017
- Identifier
- CFE0006788, ucf:51826
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006788
- Title
- Investigating Novel Water Treatment Methods and Monitoring Techniques for Sulfide-Laden Groundwater Supplies.
- Creator
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Yoakum, Benjamin, Duranceau, Steven, Lee, Woo Hyoung, Sadmani, A H M Anwar, Moore, Sean, University of Central Florida
- Abstract / Description
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This dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water...
Show moreThis dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water column post-aeration. A recirculating spray aeration pilot unit was constructed to make this assessment. To assess the effect of multi-pass spray aeration on the TTHMFP, water was recirculated through a fabricated spray nozzle for various lengths of time. Results showed that multi-pass spray aeration can remove chloroform, dichlorobromomethane, dibromochloromethane and bromoform to below detection levels ((<) 0.7 ppb) for the waters investigated. Additionally, spray aeration reduced the TTHMFP of chlorinated water. Results suggest multi-pass spray aeration may be a viable treatment option for some bromide container waters. Results also indicate that multi-pass spray aeration removes bromide from the bulk water in the form of organically bound volatile compounds.The second investigation assessed the efficacy of using pre-existing tray aeration infrastructure to comply with disinfection by-product (DBP) regulations. To assess the efficacy of tray aerators to reduce the concentration TTHMs a pilot tray aerator was constructed. Results showed that after five tray passes (each pass consisting of water being passed over five trays) the concentration of TTHMs was below the detection limit ((<) 0.7 ppb) for the water investigated. To assess the efficacy of tray aeration at full-scale, a water treatment plant and the distribution system it serves were monitored for eight months. Results showed an approximate 40 ppb reduction in the TTHM concentration at two on-site monitoring locations and the one off-site monitoring location (initial concentrations being approximately 54 ppb, 60 ppb and 73 ppb, respectively). Results suggest that the utility managing the full-scale system could comply with DBP regulations by using the pre-existing tray aeration infrastructure to reduce formed THMs on-site where regulated haloacetic acids are not predominant.The third investigation assessed the efficacy of using biological activated carbon (BAC) to remove disinfection by-product precursor matter to comply with DBP regulations. To research this method, a pilot scale BAC filter was operated for three independent test runs. In addition, two full-scale WTPs using BAC were monitored over time. Results showed an approximate 40 percent removal of dissolved organic carbon (DOC) during the three pilot runs and an approximate 55 percent removal of DOC during full-scale monitoring. Results showed that the reduction in DOC reduced the TTHMFP of BAC treated water. Results suggest that BAC treatment could be a viable treatment option to comply with DBP regulations in the sulfide-laden water studied.The fourth investigation assessed the suitability of oxidation reduction potential (ORP) to monitor the effectiveness of an oxidizing media filter used to remove sulfur from a sulfide-laden groundwater. Results showed that ORP was more useful as a measurement technique as compared to free chlorine residual when assessing filter bed health and regeneration effectiveness. It was determined that when the ORP measurement taken from within the oxidative media layer was below 500 mV, the filter bed was not providing treatment, and manganese could be released. Results showed a significant increase in turbidity ((>) 2 NTU) and total manganese ((>) 0.05 mg/L) occurred when the ORP within the filter bed dropped below 400 mV. More frequent cycling of the filters was found to be an effective treatment option to maintain ORP values above an identified 400 mV operational threshold.
Show less - Date Issued
- 2017
- Identifier
- CFE0007141, ucf:52317
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007141
- Title
- Development of Micro Volume DNA and RNA Profiling Assays to Identify the Donor and Tissue Source of Origin of Trace Forensic Biological Evidence.
- Creator
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Morgan, Brittany, Ballantyne, John, Kolpashchikov, Dmitry, Ye, Jingdong, University of Central Florida
- Abstract / Description
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In forensic casework analysis it is necessary to obtain genetic profiles from increasingly smaller amounts of biological material left behind by perpetrators of crime. The ability to obtain profiles from trace biological evidence is demonstrated with so-called 'touch DNA evidence' which is perceived to be the result of DNA obtained from shed skin cells transferred from donor to an object or person during physical contact. However, the current method of recovery of trace DNA involves cotton...
Show moreIn forensic casework analysis it is necessary to obtain genetic profiles from increasingly smaller amounts of biological material left behind by perpetrators of crime. The ability to obtain profiles from trace biological evidence is demonstrated with so-called 'touch DNA evidence' which is perceived to be the result of DNA obtained from shed skin cells transferred from donor to an object or person during physical contact. However, the current method of recovery of trace DNA involves cotton swabs or adhesive tape to sample an area of interest. This (")blind-swabbing(") approach may result in the recovery of biological material from different individuals resulting in admixed DNA profiles which are often difficult to interpret. Profiles recovered from these samples are reported to be from shed skin cells with no biological basis for that determination. A specialized approach for the isolation of single or few cells from 'touch DNA evidence' is necessary to improve the analysis and interpretation of recovered profiles. Here we describe the development of optimized and robust micro volume PCR reactions (1-5 uL) to improve the sensitivity and efficiency of 'touch DNA' analysis. These methods will permit not only the recovery of the genetic profile of the donor of the biological material, but permit an identification of the tissue source of origin using mRNA profiling. Results showed that the 3.5 uL amplification volume, a fraction of the standard 25 uL amplification volume, was the most ideal volume for the DNA assay, as it had very minimal evaporation with a 50% profile recovery rate at a single cell equivalent input (~5 pg) with reducing amplification volume alone. Findings for RNA showed that by reducing both amplification steps, reverse transcriptase PCR (20 uL) and body fluid multiplex PCR (25 uL), to 5 uL, ideal results were obtained with an increase in sensitivity and detection of six different body fluids down to 50 pg. Once optimized at the trace level, the assays were applied to the collection of single and few cells. DNA findings showed that about 40% of a full profile could be recovered from a single buccal cell, with nearly 80% of a full profile recovered from only two cells. RNA findings from collected skin particles of (")touched(") surfaces showed accurate skin detection down to 25 particles and detection in one clump of particles. The profiles recovered were of high quality and similar results were able to be replicated through subsequent experiments. More studies are currently underway to optimize these developed assays to increase profile recovery at the single cell level. Methods of doing so include comparing different locations on touched surfaces for highest bio-particle recovery and the development of physical characteristics of bio-particles that would provide the most ideal results.
Show less - Date Issued
- 2013
- Identifier
- CFE0005385, ucf:50468
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005385
- Title
- REMOVAL OF REFRACTORY TKN FROM AN EFFLUENT WASTEWATER USING SODIUM FERRATE.
- Creator
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Lettie, Lucia, Reinhart, Debra, University of Central Florida
- Abstract / Description
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This research addresses refractory forms of nitrogen that, even with advanced biological nitrification-denitrification systems are not removed completely from domestic wastewater. TKN (Total Kjeldahl Nitrogen), ammonia plus organic nitrogen, is one of the forms to measure the levels of nitrogen present in effluent wastewaters. Ferrate, a strong oxidant, was used for the treatment of these nitrogen forms with the objective of producing nitrogen compounds that can be removed by subsequent...
Show moreThis research addresses refractory forms of nitrogen that, even with advanced biological nitrification-denitrification systems are not removed completely from domestic wastewater. TKN (Total Kjeldahl Nitrogen), ammonia plus organic nitrogen, is one of the forms to measure the levels of nitrogen present in effluent wastewaters. Ferrate, a strong oxidant, was used for the treatment of these nitrogen forms with the objective of producing nitrogen compounds that can be removed by subsequent biological processes. Bench-scale experiments were performed on effluent samples taken prior to chlorination from an Orlando, FL wastewater treatment facility, using a biological nutrient removal process. The samples were treated with doses of ferrate ranging from 1 to 50 mg/L as FeO42 under unbuffered conditions. TKN removal as high as 70% and COD removal greater than 55% was observed. The TSS production after ferrate treatment was in a range of 12 to 200 mg/L for doses between 10 and 50 mg/L FeO4-2. After an optimum dose of ferrate was determined, three bench-scale reactors were operated under anoxic conditions for 10 to 12 days, two as duplicates containing the treated effluent and one as a control with untreated sample. Two different doses of ferrate were used as optimum dose for these experiments, 10 and 25 mg/L as FeO4-2. The purpose of these reactors was to determine the potential for biological removal of remaining nitrogen after ferrate oxidation of refractory nitrogen. Treated and raw samples were analyzed for Total Kjeldahl Nitrogen (TKN) (filtered and unfiltered), chemical oxygen demand (COD) (filtered and unfiltered), total suspended solids (TSS), nitrate (NO3-N), nitrite (NO2-N), and heterotrophic plate count (HPC). As a result, more than 70% of the soluble TKN was removed by chemical and biological oxidation for a sample treated with a dose of 25 mg/L FeO4-2, and less than 50% when treated with 10 mg/L FeO4-2. For the control samples run parallel to the ferrate treated samples, a maximum of 48% of soluble TKN and a minimum of 12% was removed. A three-log increase was observed in heterotrophic bacteria numbers for both doses during the operation of the reactors. Sodium ferrate was found to be an effective oxidant that can enhance the biodegradability of recalcitrant TKN present in municipal wastewaters. As mentioned before this research was develop using batch reactor units at bench-scale, therefore it is recommended to follow the investigation of the biodegradability of recalcitrant TKN of a ferrate treated sample under continuous flow conditions so that results can be extrapolated to a full-scale treatment facility.
Show less - Date Issued
- 2006
- Identifier
- CFE0001247, ucf:46936
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001247
- Title
- BLOODLINES.
- Creator
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toner, Pamela, Bartkevicius, Jocelyn, University of Central Florida
- Abstract / Description
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"Bloodlines" is a collection of personal essays that focus on the process of remembering, imagining, and reflecting on the past through the lens of a perpetually shifting present. They consider situations ranging from mental and physical illnesses, from cancer to alcohol addiction, to career changes, to the often dysfunctional and displaced family ties that distance and adulthood have not severed. In "Searching," I write the narrative of the ongoing search for my birthmother, and how the...
Show more"Bloodlines" is a collection of personal essays that focus on the process of remembering, imagining, and reflecting on the past through the lens of a perpetually shifting present. They consider situations ranging from mental and physical illnesses, from cancer to alcohol addiction, to career changes, to the often dysfunctional and displaced family ties that distance and adulthood have not severed. In "Searching," I write the narrative of the ongoing search for my birthmother, and how the search complicates the relationship with my adoptive mother, who always feared she'd lose me. Similarly, "Of Flesh and Blood" recounts and negotiates how hereditary and environmental factors have shaped my identity. Loss and betrayal are weaved throughout "Flight Patterns" when I trace the links between relationships among my family and my pets. In "Signs and Stars" and "Seeing Stars," I search for ways of dealing with my cancer diagnosis and alcoholism, weaving through my past as I fight for recovery. By exploring the subjective nature of memory and circumstance through sensory, expositional, structural, and even written documentation, I have attempted to capture what is, for me, the tenuous hold on intertwined moments in time by creating a palimpsest of perspectives.
Show less - Date Issued
- 2006
- Identifier
- CFE0001053, ucf:46819
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001053
- Title
- ATP-Induced Disassembly of CDTB/CDTC Heterodimer of Cytolethal Distending Toxin.
- Creator
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Huhn, George, Teter, Kenneth, Cole, Alexander, Jewett, Mollie, University of Central Florida
- Abstract / Description
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Cytolethal distending toxin (CDT) is a virulence factor produced by many Gram-negative bacteria, including Haemophilus ducreyi. This fastidious pathogen is the causative agent of genital cancroid. CDT is a heterotrimeric toxin with an AB2 structure consisting of a cell-binding (")B(") domain (CdtA + CdtC) and a catalytic (")A(") domain (CdtB) that has DNase activity. This toxin assembles in the bacterial periplasm that lacks ATP and is secreted into the extracellular environment. After cell...
Show moreCytolethal distending toxin (CDT) is a virulence factor produced by many Gram-negative bacteria, including Haemophilus ducreyi. This fastidious pathogen is the causative agent of genital cancroid. CDT is a heterotrimeric toxin with an AB2 structure consisting of a cell-binding (")B(") domain (CdtA + CdtC) and a catalytic (")A(") domain (CdtB) that has DNase activity. This toxin assembles in the bacterial periplasm that lacks ATP and is secreted into the extracellular environment. After cell binding, CDT is internalized by endocytosis and travels through the endosomes and Golgi before arriving in the endoplasmic reticulum (ER). CdtA is lost from the holotoxin before reaching the Golgi, and CdtB separates from CdtC in the ER. CdtB is then transported into the nucleus, inducing cell cycle arrest and apoptosis. Using disassembly of the AB5 pertussis toxin as a model, we explore that ATP, which is present in the ER lumen but not in the endosomes or Golgi, will cause dissociation of the CdtB/CdtC heterodimer. We have cloned and purified the three individual subunits of the H. ducreyi CDT. When combined, the subunits form a lethal holotoxin. Examining the individual toxin subunits, only CdtB binds with ATP but does not function as an ATPase. CdtB's binding to ATP also does not cause global changes to its secondary structure. After isolating the CdtB/CdtC heterodimer, we have shown the addition of ATP causes CdtC to dissociate from CdtB. The work presented in this Thesis provides a molecular basis for why the CdtB/CdtC heterodimer disassembles after reaching the ER and confirms the novel two-stage disassembly mechanism for CDT, a first in the AB toxin field.
Show less - Date Issued
- 2019
- Identifier
- CFE0007657, ucf:52488
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007657