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- Title
- CLIMATE CHANGE AND OCEAN ACIDIFICATION EFFECTS ON TROPICAL REEF MACROALGAE.
- Creator
- McNicholl, Conall, Koch, Marguerite S., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Tropical marine macroalgae perform an essential role in coral reef function and health, however, their persistence in a rapidly changing ocean remains uncertain. The rise in sea surface temperatures and decrease in pH (ocean acidification = OA) are predicted to have damaging effects on marine calcifiers. Calcifying macroalgae have varied, often negative, responses to these conditions, however our lack of understanding about the mechanisms involved with calcification prevent us from...
Show moreTropical marine macroalgae perform an essential role in coral reef function and health, however, their persistence in a rapidly changing ocean remains uncertain. The rise in sea surface temperatures and decrease in pH (ocean acidification = OA) are predicted to have damaging effects on marine calcifiers. Calcifying macroalgae have varied, often negative, responses to these conditions, however our lack of understanding about the mechanisms involved with calcification prevent us from interpreting these results fully. Thus, I conducted a series of experiments on five calcifying species, utilizing microsensors, radioisotopes, and mesocosms, in an attempt to define biotic and abiotic mechanisms involved in calcification and dissolution under OA. Microsensor work demonstrated that all species elevate the thalli surface pH 2-3X higher under OA, which promoted calcification. The use of a photosynthetic inhibitor revealed species-specific light-triggered thalli pH control that stimulated calcification, indicating strong biotic control over calcification. When exposed to OA conditions, stronger organismal control over calcification was shown to maintain calcification in the light. A major gap in our understanding of calcification under OA is whether it affects organismal capacity to form new calcium carbonate, or if dissolution occurs, reducing calcification rates. Using radioisotopes, I found that the ability to form new calcium carbonate under OA in the light was not affected in any species. This suggested that species with reduced net calcification were actually experiencing dissolution. This study also highlighted that all species were experiencing dissolution in the dark under OA. Finally, in a short-term growth experiment, I examined the combined effects of OA and increased temperature and found complex responses in species that are negatively affected by OA. This included a crustose coralline that appears to have an additive negative effect where temperature enhances the effect of OA but also a species that exhibited a negative effect which was evidently offset with increased temperature. Here, I define distinct abiotic (light, temperature, dissolution) and biotic (proton pump & photosynthesis), that are essential for understanding macroalgae persistence on future coral reefs.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013397
- Subject Headings
- Coral reefs, Seaweed, Climate Change, Ocean acidification
- Format
- Document (PDF)
- Title
- Cognitive and magnetosensory ecology of the yellow stingray, Urobatis jamaicensis.
- Creator
- Newton, Kyle C., Kajiura, Stephen M., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Elasmobranchs (sharks, skates, and rays) migrate across a wide range of spatiotemporal scales, display philopatry, seasonal residency, and maintain home ranges. Many animals use the Earth’s magnetic field to orient and navigate between habitats. The geomagnetic field provides a variety of sensory cues to magnetically sensitive species, which could potentially use the polarity, or intensity and inclination angle of the field, to derive a sense of direction, or location, during migration....
Show moreElasmobranchs (sharks, skates, and rays) migrate across a wide range of spatiotemporal scales, display philopatry, seasonal residency, and maintain home ranges. Many animals use the Earth’s magnetic field to orient and navigate between habitats. The geomagnetic field provides a variety of sensory cues to magnetically sensitive species, which could potentially use the polarity, or intensity and inclination angle of the field, to derive a sense of direction, or location, during migration. Magnetoreception has never been unequivocally demonstrated in any elasmobranch species and the cognitive abilities of these fishes are poorly studied. This project used behavioral conditioning assays that paired magnetic and reinforcement stimuli in order to elicit behavioral responses. The specific goals were to determine if the yellow stingray, Urobatis jamaicensis, could detect magnetic fields, to quantify the nature of the magnetic stimuli it could detect, and to quantify the learning and memory capabilities of this species. The results supported the original hypotheses and demonstrated that the yellow stingray could: discriminate between magnetic and non-magnetic objects; detect and discriminate between changes in geomagnetic field strength and inclination angle; and use geomagnetic field polarity to solve a navigational task. The yellow stingray learned behavioral tasks faster and retained the memories of learned associations longer than any batoid (skate or ray) to date. The data also suggest that this species can classify magnetic field stimuli into categories and learn similar behavioral tasks with increased efficiency, which indicate behavioral flexibility. These data support the idea that cartilaginous fishes use the geomagnetic field as an environmental cue to derive a sense of location and direction during migrations. Future studies should investigate the mechanism, physiological threshold, and sensitivity range of the elasmobranch magnetic sense in order to understand the effects of anthropogenic activities and environmental change on the migratory ability of these fishes.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004883, http://purl.flvc.org/fau/fd/FA00004883
- Subject Headings
- Animal behavior., Animal migration., Magnetic fields--Physiological effect., Senses and sensation., Adaptation (Biology)
- Format
- Document (PDF)
- Title
- Comparative ecophysiology of bloom-forming macroalgae in the Indian River Lagoon, Florida: Ulva lactuca (Chlorophyta), Hypnea musciformis, and Gracilaria tikvahiae (Rhodophyta).
- Creator
- Vlaming, Lisa N.A., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Macroalgal blooms are responses to nutrient enrichment in shallow seagrass ecosystems like the Indian River Lagoon (IRL), Florida. Little is known about nitrogen (N) and phosphorus (P) limitation or the importance of morphological/physiological characteristics of bloom-forming macroalgae (Ulva lactuca, Hypnea musciformis, and Gracilaria tikvahiae) in the IRL. We hypothesized: 1) all species would proliferate in nutrient-rich Titusville, 2) opportunistic U. lactuca would dominate, 3) Rapid...
Show moreMacroalgal blooms are responses to nutrient enrichment in shallow seagrass ecosystems like the Indian River Lagoon (IRL), Florida. Little is known about nitrogen (N) and phosphorus (P) limitation or the importance of morphological/physiological characteristics of bloom-forming macroalgae (Ulva lactuca, Hypnea musciformis, and Gracilaria tikvahiae) in the IRL. We hypothesized: 1) all species would proliferate in nutrient-rich Titusville, 2) opportunistic U. lactuca would dominate, 3) Rapid Light Curves (RLCs) would assess nutrient status, and 4) nutrient concentrations would regulate growth more than N:P ratios. Field studies showed rapid biomass doubling times of 2 days (U. lactuca; November 2012) in urbanized Titusville. RLCs in a guano-enriched island off Big Pine Key (BPK) and Titusville (Ulva spp.) were similar due to P-saturation. Laboratory studies showed three-fold higher RLCs and two-fold faster growth at high nutrient concentrations of N and P. Reductions of both N and P will be required to moderate future blooms.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3361257
- Subject Headings
- Marine algae, Marine algae, Ecophysiology, Marine algae, Adaptation, Algal blooms
- Format
- Document (PDF)
- Title
- A comparison of stability in swimming loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle posthatchlings.
- Creator
- Dougherty, Erin., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Posthatchling green (Chelonia mydas) and loggerhead (Caretta caretta) turtles overlap ecologically but differ morphologically. This study compared hydrodynamic stability between the two species during swimming to test for functional differences in body shape. Flipper movement paths, four stability measures (yaw, pitch, heave, and sideslip), and the relative positions of the centers of buoyancy and gravity were compared between species. Both centers of buoyancy and gravity lie in the anterior...
Show morePosthatchling green (Chelonia mydas) and loggerhead (Caretta caretta) turtles overlap ecologically but differ morphologically. This study compared hydrodynamic stability between the two species during swimming to test for functional differences in body shape. Flipper movement paths, four stability measures (yaw, pitch, heave, and sideslip), and the relative positions of the centers of buoyancy and gravity were compared between species. Both centers of buoyancy and gravity lie in the anterior body; their positions relative to one another differed with species, but showed no functional consequences. Neither species demonstrated substantial yaw, sideslip, or pitch. Both experienced upward heave with the flippers' downstroke and downward heave with the upstroke; however phase relationships differed between these limb and body motions. No differences were found between the two species. Despite obvious morphological differences, loggerheads and green turtles were similarly stable during swimming, suggesting that the species use different mechanisms to achieve stability.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186689
- Subject Headings
- Sea turtles, Morphology, Sea turtles, Physiology, Animal locomotion, Marine ecology
- Format
- Document (PDF)
- Title
- Comparison of the Growth and Structure of the Pseudobranchs of Two Carangid Fishes.
- Creator
- Koenig, Christopher C., Courtenay, Walter R. Jr., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The growth and structure of the pseudobranchs of Trachinotus carolinus and Oligoplites saurus is described, illustrated, and discussed with respect to their histology and gross morphology. Morphological and histological differences between the pseudobranchs of the two species occur in the associated arteries, filament growth, mitochondrial form, and in the epithelium bordering the pseudobranchs. The pseudobranch of T. carolinus is contrasted with a typical carangid pseudobranch, characterized...
Show moreThe growth and structure of the pseudobranchs of Trachinotus carolinus and Oligoplites saurus is described, illustrated, and discussed with respect to their histology and gross morphology. Morphological and histological differences between the pseudobranchs of the two species occur in the associated arteries, filament growth, mitochondrial form, and in the epithelium bordering the pseudobranchs. The pseudobranch of T. carolinus is contrasted with a typical carangid pseudobranch, characterized by O. saurus is thick and heavily vascularized and shows a tendency to atrophy with growth of the fish. The results of bilateral pseudobranchectomy differed between adults and juveniles. All the fish became blind; however, only the adults displayed buoyancy problems and permanent chromatophore expansion.
Show less - Date Issued
- 1969
- PURL
- http://purl.flvc.org/fau/fd/FA00000781
- Subject Headings
- Carangidae--Anatomy, Florida pompano--Anatomy
- Format
- Document (PDF)
- Title
- A comparison of the ontogeny of energy consumption in leatherback, Dermochelys coriacea and olive ridley, Lepidochelys olivacea sea turtle hatchlings.
- Creator
- Jones, T. Todd, Florida Atlantic University, Lutz, Peter L., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Changes in activity related oxygen consumption and energy partitioning were measured in leatherback and olive ridley sea turtle hatchlings over their first month after nest emergence. Leatherbacks emerge with about 75--90 KJ of energy in the residual yolk at their disposal for growth and movement. In comparison, the residual yolk energy reserves for the olive ridley are estimated to be much less (45 KJ). In leatherbacks resting specific oxygen consumption rates decreased by 53% over the first...
Show moreChanges in activity related oxygen consumption and energy partitioning were measured in leatherback and olive ridley sea turtle hatchlings over their first month after nest emergence. Leatherbacks emerge with about 75--90 KJ of energy in the residual yolk at their disposal for growth and movement. In comparison, the residual yolk energy reserves for the olive ridley are estimated to be much less (45 KJ). In leatherbacks resting specific oxygen consumption rates decreased by 53% over the first post-hatching month (0.0065 ml O2 min-1 g-1--0.0031 ml O2 min-1 g-1), while for ridleys the fall was 32% (0.0038 ml O2 min-1 g-1--0.0026 ml O2 min-1 g-1). Greater differences were seen in aerobic scope. For olive ridleys the factorial aerobic scope doubled over the first month but there was no significant increase in the leatherback's factorial aerobic scope. Leatherback hatchlings gained on average 33% body mass (10 g) over the first week however 70 to 80% of this increase was due to water accumulation. The differences in aerobic scope and energy reserves are related to differences in early life ecological stratagems of these species.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13139
- Subject Headings
- Sea turtles--Ecology, Animal behavior, Ontogeny, Developmental biology, Adaptation (Physiology), Ecophysiology
- Format
- Document (PDF)
- Title
- A comparison of the thermal bleaching response of the zoanthid Palythoa caribaeorum from three geographically different regions in south Florida.
- Creator
- Kemp, Dustin W., Florida Atlantic University, Cook, Clayton B., Brooks, W. Randy, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Coral bleaching involves the loss of symbiotic algae (zooxanthellae) from reef corals and other cnidarians during periods of environmental stress, particularly elevated temperature. In this study the thermal bleaching responses of the zoanthid Palythoa caribaeorum from three populations along the southeast coast of Florida were compared. Winter (2002--2003) and summer (2003) samples from three geographically separate sites were exposed to increased temperatures and the loss of zooxanthellae...
Show moreCoral bleaching involves the loss of symbiotic algae (zooxanthellae) from reef corals and other cnidarians during periods of environmental stress, particularly elevated temperature. In this study the thermal bleaching responses of the zoanthid Palythoa caribaeorum from three populations along the southeast coast of Florida were compared. Winter (2002--2003) and summer (2003) samples from three geographically separate sites were exposed to increased temperatures and the loss of zooxanthellae was measured. Zooxanthellae populations were sampled and identified using PCR-DGGE. The results showed that samples of P. caribaeorum from reefs that experience smaller annual thermal ranges released the most zooxanthellae. Seasonal comparisons revealed winter samples experienced a greater amount of zooxanthellae loss than summer samples. P. caribaeorum was found to harbor two genetic strains of zooxanthellae, C1 and D1a. Colonies either contained monotypic populations of these, or a combination of both.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13053
- Subject Headings
- Zoanthinaria, Seawater--Thermal properties, Zooxanthellales
- Format
- Document (PDF)
- Title
- A comprehensive study of mammalian SNAG transcription family members.
- Creator
- Chiang, Cindy Chung-Yue., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Transcriptional regulation by the family of SNAG (Snail/Gfi-1) zinc fingers has been shown to play a role in various developmental states and diseases. These transcriptional repressors have function in both DNA- and protein-binding, allowing for multiple interactions by a single family member. This work aims to characterize the SNAG members Slug, Smuc, Snail, Scratch, Gfi-1, Gfi-1B, and IA-1 in terms of both DNA-protein and protein-protein interactions. The specific DNA sequences to which the...
Show moreTranscriptional regulation by the family of SNAG (Snail/Gfi-1) zinc fingers has been shown to play a role in various developmental states and diseases. These transcriptional repressors have function in both DNA- and protein-binding, allowing for multiple interactions by a single family member. This work aims to characterize the SNAG members Slug, Smuc, Snail, Scratch, Gfi-1, Gfi-1B, and IA-1 in terms of both DNA-protein and protein-protein interactions. The specific DNA sequences to which the zinc finger regions bind were determined for each member, and a general consensus of TGCACCTGTCCGA, was developed for four of the members. Via these studies, we also reveal thebinding affinities of E-box (CANNTG) sequences to the members, since this core is found for multiple members' binding sites. Additionally, protein-protein interactions of SNAG members to other biological molecules were investigated. The Slug domain and Scratch domain have unknown function, yet through yeast two-hybrid screening, we were able to determine protein interaction partners for them as well as for other full length SNAG members. These protein-interacting partners have suggested function as corepressors during transcriptional repression. The comprehensive information determined from these studies allow for a better understanding of the functional relationship between SNAG-ZFPs and other genes. The collected data not only creates a new profile for each member investigated, but it also allows for further studies to be initiated from the results.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/fcla/dt/3342041
- Subject Headings
- Cellular signal transduction, Zinc-finger proteins, Synthesis, Metalloproteins, Synthesis, Genetic transcription, Regulation
- Format
- Document (PDF)
- Title
- Comprehensive study of the ZAD family of zinc finger transcription factors in Drosophila melanogaster.
- Creator
- Krystel, Joseph., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The zinc finger associated domain (ZAD) family of transcription factors from Drosophila melanogaster is not well described in the literature, in part because it is very difficult to study by traditional mutagenesis screens. Bioinformatic studies indicate this is due to overlapping functions remaining after a recent evolutionary divergence. I set out to use in vitro-binding techniques to identify the characteristics of the ZAD family and test this theory. I have constructed glutathione S...
Show moreThe zinc finger associated domain (ZAD) family of transcription factors from Drosophila melanogaster is not well described in the literature, in part because it is very difficult to study by traditional mutagenesis screens. Bioinformatic studies indicate this is due to overlapping functions remaining after a recent evolutionary divergence. I set out to use in vitro-binding techniques to identify the characteristics of the ZAD family and test this theory. I have constructed glutathione S-transferase (GST)-ZAD domain chimeric proteins for use in pull down protein binding assays,and GST-Zinc finger (ZnF) array domain chimera for electrophoretic mobility shift assays (EMSA). Protein binding assays indicated two putative conserved interactors, similar to the analogous KRAB system in mammals. ... Competitive bindings were carried out to show a specificity of binding conferred by the identified conserved positions. While the consensus binding sites show relatively few similarities, the predicted target genes identified by the consensus binding sites show significant overlap. The nature of this overlap conforms to the known characteristics of the ZAD family but points to a more positive selection to maintain conservation of function.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3355627
- Subject Headings
- Cellular signal transduction, Drosophila melanogaster, Cytogenetics, Transcription factors, Zinc-finger proteins, Synthesis, Genetic transcription, Regulation, Gene expression
- Format
- Document (PDF)
- Title
- Constraints of landscape level prey availability on physiological condition and productivity of great egrets and white ibises in the Florida Everglades.
- Creator
- Herring, Garth, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Life history strategy suggests long lived bird species will adjust their nesting effort according to current conditions, balancing the costs of reproduction with their long-term needs for survival and future reproduction. The habitat conditions that produce these responses may differ between species, even within the same ecosystem, producing different nesting and population trends. I traced the pathway by which food availability influences the physiological condition of pre-breeding great...
Show moreLife history strategy suggests long lived bird species will adjust their nesting effort according to current conditions, balancing the costs of reproduction with their long-term needs for survival and future reproduction. The habitat conditions that produce these responses may differ between species, even within the same ecosystem, producing different nesting and population trends. I traced the pathway by which food availability influences the physiological condition of pre-breeding great egrets and white ibises through to reproductive measures, and the physiological condition of chicks. I focused on these two species with contrasting foraging strategies, in relation to foraging and habitat conditions to maximize the likelihood of application of these results to other wading bird species. Experimental food supplementation and physiology research on white ibis chicks demonstrated that in years with low prey availability white ibis were food limited, with increased levels of stress protein 60 and fecal corticosterone. This is the first study to demonstrate experimentally the response of stress protein 60 to changing levels of food availability. During a year with low prey availability (2007) white ibis adults and chick physiological condition was lower than that of great egrets. During the same year, fledging success was lower for both species (20% for white ibis versus 27% for great egret) but the magnitude of the decrease was particularly severe for the white ibis (76% decline versus 66% decline for the great egret). Results suggest white ibises modify their clutch size during years with poor habitat in accordance with life history traits of a long-lived species, whereas great egrets maintained their clutch size during years with poor habitat., Increasing recession rates, hydrological reversals, and prey densities influenced white ibis, whereas great egrets were most influenced by prey densities and recession rates, with no effect of hydrological reversal. During the same year, fledging success was lower for both species (20% for white ibis versus 27% for great egret) but the magnitude of the decrease was particularly severe for the white ibis (76% decline versus 66% decline for the great egret). Results suggest white ibises modify their clutch size during years with poor habitat in accordance with life history traits of a long-lived species, whereas great egrets maintained their clutch size during years with poor habitat. Increasing recession rates, hydrological reversals, and prey densities influenced white ibis, whereas great egrets were most influenced by prey densities and recession rates, with no effect of hydrological reversals. This study is the first to make the link between landscape hydrology patterns, prey availability, and responses in wading bird nesting. These linkages provide critical insight into how species' nesting patterns could differ given the same time and spatial constraints and how that may be related to long-term nesting trends. This knowledge could ultimately lead to novel predictions about population and community patterns of wetland birds.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/77643
- Subject Headings
- Bird populations, Water birds, Wetland ecology
- Format
- Document (PDF)
- Title
- Consumptive effects of predatory fish reduce wetland crayfish (Procambarus spp.) recruitment and drive species turnover.
- Creator
- Kellogg, Christopher M., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Trade-offs in traits conferring success in permanent and ephemeral habitats are often at odds with few species being able to persist in both types of environments. I examined the effect of sunfish predators on two species of south Florida crayfish to establish the mechanism that limits one species, Procambarus alleni, to short-hydroperiod environments. The crayfish assemblage response to a gradient of sunfish predators and the effect of predation on P. fallax alone was examined. I also...
Show moreTrade-offs in traits conferring success in permanent and ephemeral habitats are often at odds with few species being able to persist in both types of environments. I examined the effect of sunfish predators on two species of south Florida crayfish to establish the mechanism that limits one species, Procambarus alleni, to short-hydroperiod environments. The crayfish assemblage response to a gradient of sunfish predators and the effect of predation on P. fallax alone was examined. I also examined the effects of sunfish on crayfish growth and quantified activity levels and risky behaviors of both crayfish species. P. alleni dominated at low sunfish densities but dominance shifted with increasing sunfish density. P. alleni was more active and likely to initiate risky behaviors, suggesting that sunfish predators remove the more active P. alleni, reducing their numbers disproportionally to those of P. fallax and allowing P. fallax to dominate crayfish assemblages in long-hydroperiod wetlands.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3171400
- Subject Headings
- Wetland ecology, Habitat selection, Marine ecosystem management, Predatory marine animals, Ecology
- Format
- Document (PDF)
- Title
- Coral-Algal Symbioses in Mesophotic Montastraea cavernosa in the Gulf of Mexico.
- Creator
- Polinski, Jennifer, Voss, Joshua, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Mesophotic reefs represent biodiverse ecosystems that may act as a refuge for depth-generalist coral species threatened in shallow habitats. Despite the importance of coral-algal symbioses, few studies focus on mesophotic zooxanthellae assemblages and their influence on connectivity. This study compared zooxanthellae in Montastraea cavernosa at shallow and mesophotic depths at Flower Garden Banks National Marine Sanctuary and McGrail Bank. Mesophotic corals contained more zooxanthellae and...
Show moreMesophotic reefs represent biodiverse ecosystems that may act as a refuge for depth-generalist coral species threatened in shallow habitats. Despite the importance of coral-algal symbioses, few studies focus on mesophotic zooxanthellae assemblages and their influence on connectivity. This study compared zooxanthellae in Montastraea cavernosa at shallow and mesophotic depths at Flower Garden Banks National Marine Sanctuary and McGrail Bank. Mesophotic corals contained more zooxanthellae and more chlorophyll a and c2 per unit area coral. Increased zooxanthellae within mesophotic corals may represent an adaptive strategy to optimize light capture in low-light environments. Genetic profiles for zooxanthellae assemblages from shallow and mesophotic corals showed similar diversity across banks and between depths. The dominant sequence making up assemblages was identified as Symbiodinium type C1. Similar assemblage diversity suggests that zooxanthellae assemblages will not limit connectivity potential between shallow and mesophotic corals at these reefs.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004665, http://purl.flvc.org/fau/fd/FA00004665
- Subject Headings
- Adaptation (Biology), Coral reef biology, Coral reef ecology -- Research, Coral reefs and islands -- Monitoring, Corals -- Habitat, Marine biodiversity, Marine resources conservation
- Format
- Document (PDF)
- Title
- aB- crystallin/sHSP is required for mitochondrial function in human ocular tissue.
- Creator
- McGreal, Rebecca., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The central premise of this dissertation is that the small heat shock protein (sHSP), (Sa(BB-crystallin is essential for lens and retinal pigmented epithelial (RPE) cell function and oxidative stress defense. To date, the mechanism by which it confers protection is not known. We hypothesize that these functions could occur through its ability to protect mitochondrial function in lens and RPE cells. To test this hypothesis, we examined the expression of (Sa(BB-crystallin/sHSP in lens and RPE...
Show moreThe central premise of this dissertation is that the small heat shock protein (sHSP), (Sa(BB-crystallin is essential for lens and retinal pigmented epithelial (RPE) cell function and oxidative stress defense. To date, the mechanism by which it confers protection is not known. We hypothesize that these functions could occur through its ability to protect mitochondrial function in lens and RPE cells. To test this hypothesis, we examined the expression of (Sa(BB-crystallin/sHSP in lens and RPE cells, we observed its localization in the cells, we examined translocation to the mitochondria in these cells upon oxidative stress treatment, we determined its ability to form complexes with and protect cytochrome c (cyt c) against damage, and we observed its ability to preserve mitochondrial function under oxidative stress conditions in lens and RPE cells. In addition to these studies, we examined the effect of mutations of (Sa(BB-crystallin/sHSP on its cellular localization and translocation patterns under oxidative stress, its in vivo and in vitro chaperone activity, and its ability to protect cyt c against oxidation. Our data demonstrated that (Sa(BB-crystallin/sHSP is expressed at high levels in the mitochondria of lens and RPE cells and specifically translocates to the mitochondria under oxidative stress conditions. We demonstrate that (Sa(BB-crystallin/sHSP complexes with cyt c and protects it against oxidative inactivation. Finally, we demonstrate that (Sa(BB-crystallin/sHSP directly protects mitochondria against oxidative inactivation in lens and RPE cells. Since oxidative stress is a key component of lens cataract formation and age-related macular degeneration (AMD), these data provide a new paradigm for understanding the etiology of these diseases.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342242
- Subject Headings
- Mitochondrial pathology, Chemical mutagenesis, Oxidative stress, Prevention, Cellular signal transduction, Eye, Diseases, Etiology, Molecular chaperones
- Format
- Document (PDF)
- Title
- DECIPHERING NEURONAL SIGNALING WITHIN A SINGLE DENDRITIC SPINE IN LONG TERM POTENTIATION.
- Creator
- Tu, Xun, Yasuda, Ryohei, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Organization and function of neuronal circuits require not only the interaction between the intrinsic components of the individual neurons but also the synaptic interactions that incorporate them into functional entities. Dendritic spines are the major sites for excitatory synaptic transmission, and are considered as the basic unit of information transfer in nervous system. Structural plasticity of dendritic spines is highly associated with functional plasticity, playing critical roles in...
Show moreOrganization and function of neuronal circuits require not only the interaction between the intrinsic components of the individual neurons but also the synaptic interactions that incorporate them into functional entities. Dendritic spines are the major sites for excitatory synaptic transmission, and are considered as the basic unit of information transfer in nervous system. Structural plasticity of dendritic spines is highly associated with functional plasticity, playing critical roles in learning and memory. Here, we explored mechanisms underlying PKCα and structural plasticity of dendritic spines. We examined the spatiotemporal activation of actin regulators with 2pFLIM, including small GTPases Rac1, Cdc42 and Ras, in the presence or absence of PKCα during single-spine structural plasticity. Removal of PKCα expression in the postsynapse attenuated Rac1 activation during structural plasticity without affecting Ras or Cdc42 activity. Moreover, disruption of a PDZ binding domain within PKCα led to impaired Rac1 activation and deficits in structural spine remodeling. This work described that PKCα regulates the activation of Rac1, but not Ras or Cdc42, during sLTP of dendritic spines, and this modulation relies on PKCα’s PDZ-binding motif.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013974
- Subject Headings
- Dendritic Spines, Neuronal Plasticity, Long-Term Potentiation
- Format
- Document (PDF)
- Title
- Determining the Effects of Fire on Ridge Shape Complexity In the Central Everglades.
- Creator
- Dombrowski, Jacob, Benscoter, Brian, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Self-organized spatial patterning of microtopographic features is a trademark characteristic of the Everglades landscape. Anthropogenic modifications to Everglades’ hydrology have reduced and degraded pattern, where ridges occur at higher elevations and spread into open water sloughs under dryer conditions. Wildfire is an important ecological force in the central Everglades and may maintain ridge-slough patterning through reducing ridge size and complexity, and thus preserve habitat...
Show moreSelf-organized spatial patterning of microtopographic features is a trademark characteristic of the Everglades landscape. Anthropogenic modifications to Everglades’ hydrology have reduced and degraded pattern, where ridges occur at higher elevations and spread into open water sloughs under dryer conditions. Wildfire is an important ecological force in the central Everglades and may maintain ridge-slough patterning through reducing ridge size and complexity, and thus preserve habitat heterogeneity. To investigate fire as a patterning mechanism in the central Everglades I examined the shape complexity and area distribution of ridges along a chronosequence of time since fire. Shape complexity did not change following fire, but small and large ridges became more prominent and eventually spread as time since fire increased, suggesting fire may maintain ridge area distribution. Documentation of fires’ effect on ridge size will inform ecosystem and conceptual models detailing the complex interactions that maintain the Everglades ridge-slough patterning.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004683, http://purl.flvc.org/fau/fd/FA00004683
- Subject Headings
- Burning of land -- Environmental aspects, Everglades National Park (Fla.) -- Environmental conditions, Fire ecology -- Florida -- Everglades National Park, Landscape ecology
- Format
- Document (PDF)
- Title
- DEVELOPING PLASMA-BASED DIAGNOSTICS: FROM PANCREATIC DUCTAL ADENOCARCINOMA TO HIV.
- Creator
- Makler, Amy, Asghar, Waseem, Florida Atlantic University, Department of Biological Sciences
- Abstract/Description
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Plasma-based diagnostics are ideal for detecting a variety of diseases because they offer a method of detection that is minimally invasive, readily available, and easy to use for monitoring patients as they progress through a disease or respond to treatment. The only serum marker for PDAC is CA19-9 which lacks specificity, has limited sensitivity, and is unreliable for early detection. It is therefore of great importance to develop a diagnostic that is viable for screening and early detection...
Show morePlasma-based diagnostics are ideal for detecting a variety of diseases because they offer a method of detection that is minimally invasive, readily available, and easy to use for monitoring patients as they progress through a disease or respond to treatment. The only serum marker for PDAC is CA19-9 which lacks specificity, has limited sensitivity, and is unreliable for early detection. It is therefore of great importance to develop a diagnostic that is viable for screening and early detection. Exosomal miRNA were determined via bioinformatics analyses and then examined in PDAC cell lines to identify markers with greatest potential. These markers were then examined in plasma from PDAC patients and control groups. Four markers, miR-93-5p, miR-339-3p, miR-425-5p, and miR-425-3p, emerged as the most viable biomarker panel with the ability to detect PDAC in 100% of the early stages (N=5) compared to CA19-9 which showed increased levels in only one patient with early stage PDAC. Additionally, the diagnostic has a specificity of 80% and a sensitivity of 94.7%, making it comparable to CA19-9, and may even be beneficial for use in conjunction with CA19-9. A plasma-based diagnostic was also developed for multi-strain HIV-1 detection utilizing the loop-mediated isothermal amplification (LAMP) method. LAMP primers were developed against the integrase and vpr regions of the HIV-1 genome. They were tested first in cultured HIV samples and then examined for their ability to amplify HIV-1 subtypes A-G. The integrase primer set provided a reliable means of diagnosing all 55 strains and isolates in under 30 minutes, whereas vpr was inconsistent and exhibited high variability in detecting the HIV subtypes. Our limit of detection for B-subtype with integrase was 30 viral copies/reaction. This could provide the basis for a novel, point-of-care diagnostic for use in underdeveloped regions.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014141
- Subject Headings
- Plasma, Biomarkers, Carcinoma, Pancreatic Ductal, HIV-1, Diagnosis
- Format
- Document (PDF)
- Title
- DEVELOPMENT OF A GENETICALLY-ENCODED OXYTOCIN SENSOR TO DEFINE THE ROLE OF OXYTOCIN IN PREDICTING SOCIAL REWARD.
- Creator
- Mignocchi, Neymi Layne, Kwon, Hyung-Bae, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Oxytocin (OXT), a neuropeptide synthesized in the paraventricular nucleus (PVN) of the hypothalamus, functions to increase the precedence of social stimuli and promote the development of a wide range of social behaviors. However, whether OXT has a predicting role in social reward has yet to be examined. In this study, we developed a genetically encoded, scalable OXT sensor named OXTR-iTango2 and applied this technique to define the role of OXT in learned social behaviors. OXTR-iTango2 enables...
Show moreOxytocin (OXT), a neuropeptide synthesized in the paraventricular nucleus (PVN) of the hypothalamus, functions to increase the precedence of social stimuli and promote the development of a wide range of social behaviors. However, whether OXT has a predicting role in social reward has yet to be examined. In this study, we developed a genetically encoded, scalable OXT sensor named OXTR-iTango2 and applied this technique to define the role of OXT in learned social behaviors. OXTR-iTango2 enables the combination of light- and ligand- dependent gene expression both in vitro and in vivo neural systems. In order to study the predictive role of OXT during expected socially rewarding experiences, we first conditioned animals to a social environment, and then selectively labeled OXT-sensitive ventral tegmental area dopamine (VTA-DA) neurons when animals encountered a conditioned stimulus that stood to predict a familiar social reward. Recurrent exposure to the same social stimulus normally lowered the degree of social interaction, but this reduced interaction was not observed when OXT-sensitive DA neurons were optogenetically inhibited. Thus, our findings support the notion that OXT plays a role beyond promoting social interactions, leading for a new proposed hypothesis that OXT mediation also leads to active avoidance of mundane social interactions.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013509
- Subject Headings
- Oxytocin, Oxytocin--Research, Social Behavior, Oxytocin--physiology, Biosensing Techniques
- Format
- Document (PDF)
- Title
- DEVELOPMENT OF A MICROFLUIDIC DEVICE FOR EXOSOME ISOLATION IN POINT-OF-CARE SETTINGS.
- Creator
- Ramnauth, Natasha, Waseem Asghar, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Exosomes have gained recognition in cancer diagnostics and therapeutics. Most exosome isolation methods are time-consuming, costly and require bulky equipment, rendering them unsuitable for point-of-care (POC) settings. Microfluidics can be the key to solving these challenges. Here, we employ the development of a double filtration microfluidic device that can rapidly isolate exosomes in POC settings. The device can efficiently isolate exosomes from just 100 uL of plasma within 50 minutes. The...
Show moreExosomes have gained recognition in cancer diagnostics and therapeutics. Most exosome isolation methods are time-consuming, costly and require bulky equipment, rendering them unsuitable for point-of-care (POC) settings. Microfluidics can be the key to solving these challenges. Here, we employ the development of a double filtration microfluidic device that can rapidly isolate exosomes in POC settings. The device can efficiently isolate exosomes from just 100 uL of plasma within 50 minutes. The device was compared against Polyethylene glycol (PEG) based precipitation, and findings show that both methods yield comparable exosome sizes and purity, but the device can detect exosomal miRNA earlier than PEG. Finally, a comparative analysis of membrane filters with exosomes collected from pore sizes 15 nm and 30 nm showed a similarity in exosome size and miRNA expressions, with significantly increased sample purity. These findings suggest that this device has potential in POC settings.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014071
- Subject Headings
- Microfluidic devices, Exosomes, Point-of-care testing
- Format
- Document (PDF)
- Title
- Development of a novel assay for in vivo screening of neuromodulatory drugs and targeted disruption of cholinergic synaptic transmission in Drosophila melanogaster.
- Creator
- Mejia, Monica, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Finding novel compounds that affect neuronal or muscular function is of great interest, as they can serve as potential pharmacological agents for a variety of neurological disorders. For instance, conopeptides have been developed into powerful drugs like the painkiller PrialtTM. Most conopeptides, however, have yet to be characterized, revealing the need for a rapid and straightforward screening method. We have designed a novel bioassay, which allows for unbiased screening of biological...
Show moreFinding novel compounds that affect neuronal or muscular function is of great interest, as they can serve as potential pharmacological agents for a variety of neurological disorders. For instance, conopeptides have been developed into powerful drugs like the painkiller PrialtTM. Most conopeptides, however, have yet to be characterized, revealing the need for a rapid and straightforward screening method. We have designed a novel bioassay, which allows for unbiased screening of biological activity of compounds in vivo against numerous molecular targets on a wide variety of neurons and muscles in a rapid and straightforward manner. For this, we paired nanoinjection of compounds with electrophysiological recordings from the Giant Fiber System of Drosophila melanogaster, which mediates the escape response of the fly.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362560
- Subject Headings
- Drosophila melanogaster, Genetics, Drosophila melanogaster, Life cycles, Insects, Physiology, Developmental neurobiology, Neural transmission, Cholinergic mechanisms
- Format
- Document (PDF)
- Title
- DEVELOPMENT OF AN ACELLULAR EXTRACELLULAR MATRIX AS A THREE-DIMENSIONAL SCAFFOLD FOR ESOPHAGEAL TUMOR ENGINEERING.
- Creator
- Chaitin, Hersh, Kang, Yunqing, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Human esophageal squamous cell carcinoma (hESCC) is a very aggressive form of cancer due to its ability to easily metastasize into proximal lymph nodes and adjacent organs. The role of the extracellular matrix (ECM) and its stromal cells in metastasis remains unclear. To better understand the effect of the ECM and fibroblast cells on esophagus cancer cell migration and invasion, we propose a biomimetic human esophagus model cultured with hESCC and human primary fibroblast cells (fibroblast)....
Show moreHuman esophageal squamous cell carcinoma (hESCC) is a very aggressive form of cancer due to its ability to easily metastasize into proximal lymph nodes and adjacent organs. The role of the extracellular matrix (ECM) and its stromal cells in metastasis remains unclear. To better understand the effect of the ECM and fibroblast cells on esophagus cancer cell migration and invasion, we propose a biomimetic human esophagus model cultured with hESCC and human primary fibroblast cells (fibroblast). To mimic the extracellular matrix of human esophagus we use decellularized porcine esophagus matrix (DEM) to culture with hESCC and fibroblasts in static conditions. This DEM can recapitulate the human esophagus tumor microenvironment with relevant cues. This model will provide valuable information regarding esophagus cancer cell migration with respect to the heterogeneous extracellular matrix and stromal fibroblast cells. We expect to discover the mechanisms by which extracellular matrix and stromal cells affect cancer migration and invasion in vitro. Characterizing this process will provide vital insight towards the effects of fibroblasts cells on facilitating migration and invasion of esophageal cancer cells. This esophagus cancer model also provides promising potential to study drug screening and develop new strategies against esophagus metastasis.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013534
- Subject Headings
- Esophageal Squamous Cell Carcinoma, Extracellular matrix, Metastasis, Fibroblasts, Biomimetics, Stromal Cells
- Format
- Document (PDF)