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Title: RNA oxidative damage and ribosomal RNA surveillance under oxidative stress.
Creator: Liu, Min, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: We have studies oxidative damage of RNA, a major type of cellular macromolecules. RNA is a primary target of reactive oxygen species (ROS). Under oxidative stress, most nucleic acid damages in Escherichia coli (E.coli) are present in RNA as shown by high levels of 8-oxo-G, an oxidized form of guanine. Increased RNA oxidation is closely correlated to cell death under oxidative stress. Surprisingly, neither RNA structure nor association with proteins protects RNA from oxidation... Our results...
Show moreWe have studies oxidative damage of RNA, a major type of cellular macromolecules. RNA is a primary target of reactive oxygen species (ROS). Under oxidative stress, most nucleic acid damages in Escherichia coli (E.coli) are present in RNA as shown by high levels of 8-oxo-G, an oxidized form of guanine. Increased RNA oxidation is closely correlated to cell death under oxidative stress. Surprisingly, neither RNA structure nor association with proteins protects RNA from oxidation... Our results demonstrate a major role for RNA degradation in controlling oxidized RNA. We have identified activities that may work in specific pathways for selectively degrading damaged RNA. These activities may play pivotal rold in controlling oxidized RNA and protecting cells under oxidative stress.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3355620
Subject Headings: RNA, Metabolism, Cellular signal transduction, Genetic translation, Molecular biology
Format: Document (PDF)

Title: Quantifying the energetic cost of disorientation in loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle hatchlings.
Creator: Williams, Sean., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The photopollution of beaches caused by artificial light sources can interfere with sea turtle hatchlings' ability to orient properly towards the sea. Exhaustion due to extended disorientation crawling may then increase hatchling mortality. This study evaluated the energetic consequences of long-distance crawls in green and loggerhead sea turtle hatchlings. Turtles crawled for 200 m or 500 m on a treadmill, followed by a 30 minute evaluation of swim performance. Metabolic activity was...
Show moreThe photopollution of beaches caused by artificial light sources can interfere with sea turtle hatchlings' ability to orient properly towards the sea. Exhaustion due to extended disorientation crawling may then increase hatchling mortality. This study evaluated the energetic consequences of long-distance crawls in green and loggerhead sea turtle hatchlings. Turtles crawled for 200 m or 500 m on a treadmill, followed by a 30 minute evaluation of swim performance. Metabolic activity was quantified via measures of blood glucose, blood lactate, and oxygen consumption. No significant changes in metabolism resulted from long-distance crawling activity in loggerheads ; however, loggerheads rested for extended periods of time during the crawl trials, often unresponsive to stimuli. This behavior implies that loggerhead hatchlings would be vulnerable to predation or temperature stress due to exhaustion from extended periods of crawling. Further data is required to draw any significant conclusions about long-term disorientatin crawling in green hatchlings.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3356891
Subject Headings: Sea turtles, Nests, Protection, Sea turtles, Life cycles, Animal behavior, Predation (Biology)
Format: Document (PDF)

Title: Roles of troponin I in heart development and cardiac function.
Creator: Du, Jianfeng., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Two major troponin I (TnI) genes, fetal TnI (ssTnI) and adult TnI (cTnI), are expressed in the mammalian heart under the control of a developmentally regulated program. In this study, the up-stream domain (~1,800 bp) of mouse fetal TnI gene has been cloned and characterized. There is a high homology of this region among mouse, rat and human. Transfection assays indicated that conserved GA-rich sequences, CREB and a CCAAT box within the first 300 bp upstream of the transcription start site...
Show moreTwo major troponin I (TnI) genes, fetal TnI (ssTnI) and adult TnI (cTnI), are expressed in the mammalian heart under the control of a developmentally regulated program. In this study, the up-stream domain (~1,800 bp) of mouse fetal TnI gene has been cloned and characterized. There is a high homology of this region among mouse, rat and human. Transfection assays indicated that conserved GA-rich sequences, CREB and a CCAAT box within the first 300 bp upstream of the transcription start site were critical for the gene expression. Electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP) assays revealed binding proteins to CREB site in nuclear extracts from myocardial cells. Thyroid hormone (T3) caused a significant inhibitory effect on ssTnI expression in myocardial cells. Cardiac troponin I (cTnI) mutations have been linked to the development of restrictive cardiomyopathy (RCM) in human patients. We modeled one mutation in human cTnI Cv terminus, arginine1 92 histidine (R192H) by cardiac specific expression of the mutated protein (cTnI193His in mouse sequence) in transgenic mice. The main functional alteration detected in cTnI193His mice by ultrasound cardiac imaging examinations was impaired cardiac relaxation manifested by a decreased left ventricular end diastolic dimension (LVEDD) and an increased end diastolic dimension in both atria. Echocardiography revealed a series of changes on the transgenic mice including a reversed E-to-A ratio, increased deceleration time, and prolonged isovolumetric relaxation time. At the age of 12 months, cardiac output in cTnI193His mice was significantly declined, and some transgenic mice showed congestive heart failure. The negative impact of cTnI193His on ventricular contraction and relaxation was further demonstrated in isolated mouse working heart preparations., Dobutamine stimulation increased heart rate in cTnI193His mice but did not improve CO.The cTnI193His mice had a phenotype similar to that in human RCM patients carrying the cTnI mutation. The results demonstrate a critical role of the COOH-terminal domain of cTnI in the diastolic function of cardiac muscle. This mouse model provides us with a tool to further investigate the pathophysiology and the development of RCM.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/186287
Subject Headings: Mice as laboratory animals, Biochemical markers, Diagnostic use, Heart, Diseases, Molecular diagnosis, Cardiovascular system, Pathophysiology
Format: Document (PDF)

Title: Role of methionine sulfoxide reductase in thermal-induced spreading depression coma in Drosophila melanogaster.
Creator: Schey, Karin., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Drosophila melanogaster encounter periods of increased temperature or decreased oxygen in its native environment. One consequence of these environmental stresses is increased production of reactive oxygen species that damage major molecules within cells. Another consequence is that flies fall into a protective coma where biological functions are minimized to conserve energy expenditures. This biological phenomenon is called spreading depression. The overarching aim of this project is to...
Show moreDrosophila melanogaster encounter periods of increased temperature or decreased oxygen in its native environment. One consequence of these environmental stresses is increased production of reactive oxygen species that damage major molecules within cells. Another consequence is that flies fall into a protective coma where biological functions are minimized to conserve energy expenditures. This biological phenomenon is called spreading depression. The overarching aim of this project is to determine if methionine sulfoxide reductases affect entrance or exit from the protective coma induced by acute thermal stress. The data revealed that complete deficiency of Msr in young flies causes a faster induction of the coma. In both young and old flies, Msr does not affect average recovery time but does affect the pattern of recovery from coma. Entrance into the coma is age dependent with young flies maintaining activity longer than before entering into the coma as compared to old flies.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3355873
Subject Headings: Cellular signal transduction, Proteins, Chemical modification, Spreading cortical depression, Oxidation-reduction reaction, Aging, Molecular aspects, Mutation (Biology)
Format: Document (PDF)

Title: Patterns of inorganic phosphate and carbohydrate allocation in sawgrass (Cladium jamaicense Crantz) and southern cattail (Typha domingensis Pers.) grown at low and high phosphate levels.
Creator: Hill, Brian, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: In recent history, C. jamaicense has been displaced by another native monocot, T. domingensis, predominantly resulting from increased phosphorous enrichment in the Everglades. This study aimed to elucidate these two species responses to low and high [Pi] in terms of allocation, photosynthate partitioning and growth. C. jamaicense growth was independent of Pi, while T. domingensis growth increased with [Pi]. Under high [Pi], allocation to younger T. domingensis shoots occurred, while C....
Show moreIn recent history, C. jamaicense has been displaced by another native monocot, T. domingensis, predominantly resulting from increased phosphorous enrichment in the Everglades. This study aimed to elucidate these two species responses to low and high [Pi] in terms of allocation, photosynthate partitioning and growth. C. jamaicense growth was independent of Pi, while T. domingensis growth increased with [Pi]. Under high [Pi], allocation to younger T. domingensis shoots occurred, while C. jamaicense shoots retained more [Pi], while low [Pi] resulted in homogeneous allocation patterns for both species. Additionally, Pi deficiencies induced carbohydrate levels in older shoots of T. domingensis, while [Pi] had no effect on photosynthate partitioning patterns in C. jamaicense. ACP activity was induced by Pi deficiency in all T. domingensis shoots and increased with shoot age, while no effect was observed in C. jamaicense. Results indicate these two species differ in allocation strategies when [Pi] is altered.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/238480
Subject Headings: Nitrogen-fixing algae, Biogeochemical cycles, Phosphorus, Psychological transport, Soil stabilization, Ecosystem management, Vegetation dynamics
Format: Document (PDF)

Title: Pelvic fin locomotion in batoids.
Creator: Macesic, Laura Jane., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Although most batoids (skates and rays) are benthic, only the skates (Rajidae) have been described as performing benthic locomotion, termed 'punting'. While keeping the rest of the body motionless, the skate's specialized pelvic fins are planted into the substrate and then retracted caudally, which thrusts the body forward. This may be advantageous for locating and feeding on prey, avoiding predators, and reducing energetic costs. By integrating kinematic, musculoskeletal, material properties...
Show moreAlthough most batoids (skates and rays) are benthic, only the skates (Rajidae) have been described as performing benthic locomotion, termed 'punting'. While keeping the rest of the body motionless, the skate's specialized pelvic fins are planted into the substrate and then retracted caudally, which thrusts the body forward. This may be advantageous for locating and feeding on prey, avoiding predators, and reducing energetic costs. By integrating kinematic, musculoskeletal, material properties, and compositional analyses across a range of morphologically and phylogenetically diverse batoids, this dissertation (i) demonstrates that punting is not confined to the skates, and (ii) provides reliable anatomical and mechanical predictors of punting ability. Batoids in this study performed true punting (employing only pelvic fins), or augmented punting (employing pectoral and pelvic fins). Despite the additional thrust from the pectoral fins, augmented punters failed to exceed the punting c apabilities of the true punters. True punters' pelvic fins had greater surface area and more specialized and robust musculature compared to the augmented punters' fins. The flexural stiffness of the main skeletal element used in punting, the propterygium, correlated with punting ability (3.37 x 10-5 - 1.80 x 10-4 Nm2). Variation was due to differences in mineral content (24.4-48-9% dry mass), and thus, material stiffness (140-2533 MPa), and second moment of area. The propterygium's radius-to-thickness ratio (mean = 5.52 +-0.441 SE) indicated that the propterygium would support true and augmented punters, but not non-punters, in an aquatic environment. All propterygia would fail on land. Geometric and linear morphometric analyses of 61 batoid pelvic girdles demonstrated that pelvic girdle shape can predict punting and swimming ability and taxonomic attribution to Order., Characteristics of true punters' pelvic girdles, such as laterally facing fin articulations, large surface area formuscle attachment, and tall lateral pelvic processes are similar to characteristics of early sprawled-gait tetrapods' pelvic girdles. This dissertation demonstrates that punting is common in batoids, illustrates the convergent evolution of true punter and early tetrapod pelvic anatomy, and gives possible explanations for the restriction of elasmobranchs to aquatic habitats.
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Date Issued: 2011
PURL: http://purl.flvc.org/FAU/3171678
Subject Headings: Sharks, Ecology, Fins, Anatomy, Adaptation (Biology), Aquatic animals, Physiology, Fishes, Locomotion
Format: Document (PDF)

Title: Magnetic orientation of loggerhead sea turtle hatchlings: migratory strategies in the Gulf of Mexico.
Creator: Merrill, Maria W., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Loggerhead sea turtles nest on either the Atlantic or Gulf coast of Florida. The hatchlings from these nests migrate offshore in opposite directions. The purpose of my study was to determine if Gulf coast hatchlings use magnetic maps, as Atlantic coast hatchlings do, both to locate areas favorable for survival in the Gulf of Mexico and to orient appropriately within surface currents that could transport them into the Atlantic Ocean. To find out, I presented Gulf coast hatchlings with magnetic...
Show moreLoggerhead sea turtles nest on either the Atlantic or Gulf coast of Florida. The hatchlings from these nests migrate offshore in opposite directions. The purpose of my study was to determine if Gulf coast hatchlings use magnetic maps, as Atlantic coast hatchlings do, both to locate areas favorable for survival in the Gulf of Mexico and to orient appropriately within surface currents that could transport them into the Atlantic Ocean. To find out, I presented Gulf coast hatchlings with magnetic fields corresponding to different locations inside the Gulf, and within currents leading into (Florida Straits) and within (Gulf Stream) the western portion of the Atlantic Ocean. I conclude that Gulf coast hatchlings (i) use a high resolution magnetic map for navigation within the Gulf of Mexico, (ii) initially remain within the eastern Gulf, but later may (iii) gain entry into currents that transport them into Atlantic waters.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2138106
Subject Headings: Animal orientation, Magnetic fields, Sea turtles, Migration, Loggerhead turtle, Migration
Format: Document (PDF)

Title: Limitations on macroinvertebrate populations in South Florida weltands.
Creator: Knorp, Natalie E., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: It can be difficult to disentangle the factors that determine population success in freshwater systems, particularly for organisms with disturbance-resistant life stages like aquatic invertebrates. Nevertheless, the effects of environmental variation and habitat structure on animal population success in wetlands are important for understanding both trophic interactions and biodiversity. I performed two experiments to determine the factors limiting crayfish (Procambarus fallax) and dragonfly ...
Show moreIt can be difficult to disentangle the factors that determine population success in freshwater systems, particularly for organisms with disturbance-resistant life stages like aquatic invertebrates. Nevertheless, the effects of environmental variation and habitat structure on animal population success in wetlands are important for understanding both trophic interactions and biodiversity. I performed two experiments to determine the factors limiting crayfish (Procambarus fallax) and dragonfly (Family: Libellulidae) populations in wetland environments. A simulation of a dry-disturbance and subsequent sunfish (Family: Centrarchidae) re-colonization revealed that crayfish populations are sensitive to sunfish, while dragonfly naiads seemed to be limited by other drying-related factors. A second manipulation revealed that small-bodied fishes and habitat structure (submerged vegetation) shaped dragonfly communities primarily through postcolonization processes.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362485
Subject Headings: Wetland ecology, Wildlife conservation, Freshwater invertebrates, Ecology, Predation (Biology), Marine ecosystem management
Format: Document (PDF)

Title: Highwire's characterization and signaling roles in Drosophila central synapse formation.
Creator: Rowland, Kimberly Diane., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The assembly and maintenance of central synapses is a complex process, requiring myriad genes and their products. Highwire is a large gene containing a RING domain, characteristic of ubiquitin E3 ligases. Highwire has been shown to restrain axon growth and control synaptogenesis at a peripheral synapse. Here I examine the roles of Highwire at a central synapse in the adult Drosophila Giant Fiber System (GFS). Highwire is indeed necessary for proper axonal growth as well as synaptic...
Show moreThe assembly and maintenance of central synapses is a complex process, requiring myriad genes and their products. Highwire is a large gene containing a RING domain, characteristic of ubiquitin E3 ligases. Highwire has been shown to restrain axon growth and control synaptogenesis at a peripheral synapse. Here I examine the roles of Highwire at a central synapse in the adult Drosophila Giant Fiber System (GFS). Highwire is indeed necessary for proper axonal growth as well as synaptic transmission in the GFS. Differences arise between the central synapse and the neuromuscular junction (NMJ), where highwire was initially characterized : expresion from the postsynaptic cell can rescue highwire synaptic defects, which is not seen at the NMJ. In addition, a MAP kinase signaling pathway regulated by highwire at the NMJ has differing roles at a central synapse. Wallenda MAPK can rescue not only the highwire anatomical phenotype but also the defects seen in transmission. Another distinction is seen here : loss of function basket and Dfos enhance the highwire anatomical phenotype while expression of dominant negative basket and Dfos suppress the highwire phenotype. As a result we have compared the signaling pathway in flies and worms and found that the NMJ in the two organisms use a parallel pathway while the central synapse uses a distinct pathway.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3352826
Subject Headings: Cellular control mechanisms, Cellular signal transduction, Cell differentiation, Gene expression, Genetic transcription, Transcription factors, Drosophila melanogaster, Cytogenetics
Format: Document (PDF)

Title: Home on the range: spatial ecology of Atlantic spotted dolphins (Stenella frontalis) in the Bahamas.
Creator: Augliere, Bethany., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: I examined summer home range use of Altantic spotted dolphins in the Bahamas from 1991-2004. Home ranges for 86 dolphins using the 95% Fixed Kernel Density (FKD) estimator averages 62.o km2+=22.96 km2 and ranged from 24.8 km2 to 148.4 km2. Older animals and males had the largest ranges. Home range size did not vary with female reproductive status. core areas were defined by the 50% FKD contour and averaged 10.32 km2 +=5.47 km2. Habitat use was different between reproductive states for females...
Show moreI examined summer home range use of Altantic spotted dolphins in the Bahamas from 1991-2004. Home ranges for 86 dolphins using the 95% Fixed Kernel Density (FKD) estimator averages 62.o km2+=22.96 km2 and ranged from 24.8 km2 to 148.4 km2. Older animals and males had the largest ranges. Home range size did not vary with female reproductive status. core areas were defined by the 50% FKD contour and averaged 10.32 km2 +=5.47 km2. Habitat use was different between reproductive states for females. Non-reproductively active (NRA) females used deeped habitat. Behavioral use of the home range varied spatially. The core area was an important foraging area for males and reproductively active females. NRA females foraged more outside their core area compared to the core area.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3358277
Subject Headings: Social behavior of animals, Dolphins, Geographical distribution, Dolphins, Habitat
Format: Document (PDF)

Title: Hatchling sex ratios and nest temperature-sex ratio response of three South Florida marine turtle species (Caretta caretta L., Chelona mydas L., and Dermochelys coriacea V.).
Creator: Rogers, Micah Marie., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: South Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were...
Show moreSouth Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were estimated within biological limitations by both 50-65% of incubation and mean middle 1/3 temperature. The maximum middle 1/3 temperature was the best-fit predictor for green turtles. No best-fit sex ratio-temperature response could be identified for leatherbacks. Clutches incubating under natural conditions can vary greatly in SR ; TRT differences may account for differences among species' sex ratios.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3361062
Subject Headings: Sex ratio, Sex determination, Genetic, Sea turtles, Nests, Sea turtles, Embryology, Loggerhead turtle, Nests, Loggerhead turtle, Effect of temperature on
Format: Document (PDF)

Title: Hierarchical resource selection and movement of two wading bird species with divergent foraging strategies in the Everglades.
Creator: Beerens, James M., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Seasonal variation in food availability is one of the primary limitations to avian populations, particularly during the breeding season. However, the behavioral responses between species may differ based on foraging strategies. I examined the influence of food availability on landscape-level habitat selection, patch-level habitat selection, and movements of two wading bird species with divergent foraging strategies, the Great Egret and White Ibis. On a landscape scale, there appeared to be a...
Show moreSeasonal variation in food availability is one of the primary limitations to avian populations, particularly during the breeding season. However, the behavioral responses between species may differ based on foraging strategies. I examined the influence of food availability on landscape-level habitat selection, patch-level habitat selection, and movements of two wading bird species with divergent foraging strategies, the Great Egret and White Ibis. On a landscape scale, there appeared to be a relationship among resource availability, the temporal scale of the independent variable, and whether the response was similar or different between species. At the patch level, results demonstrated a relationship between resource availability and the spatial scale of the independent variables selected by birds. Species movements were consistent with the differing strategies. This study is the first to make the link between landscape hydrology patterns, prey availability, and responses in wading bird habitat selection at multiple spatial scales.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/172667
Subject Headings: Water birds, Habitat, Habitat selection, Bird populations, Wetland ecology
Format: Document (PDF)

Title: Maternal and alloparental discipline in Atlantic spotted dolphins (Stenella frontalis) in the Bahamas.
Creator: Weinpress, Meghan., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Discipline was implemented by mothers and alloparent spotted dolphins (Stenella frontalis) mothers and alloparents on Little Bahama Bank, Bahamas. Disciplinarians were significantly more likely to be adults than juveniles. Although most disciplinarians were female, males were also observed to perform discipline. The recipients of discipline were male and female, and significantly more likely to be calves than juveniles. Pursuit, contact, and display behaviors were used in discipline, however...
Show moreDiscipline was implemented by mothers and alloparent spotted dolphins (Stenella frontalis) mothers and alloparents on Little Bahama Bank, Bahamas. Disciplinarians were significantly more likely to be adults than juveniles. Although most disciplinarians were female, males were also observed to perform discipline. The recipients of discipline were male and female, and significantly more likely to be calves than juveniles. Pursuit, contact, and display behaviors were used in discipline, however pursuit behaviors were most often observed. Variables such as age class, sex, and parity were not found to influence how discipline was implemented. The durations of all disciplinary pursuits were under thirty seconds, and successful pursuits had slightly shorter duration than unsuccessful pursuits. Disciplinarian success was not significantly influenced by age class, sex, parity, or behavior used.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3361254
Subject Headings: Animal behavior, Behavior evolution, Atlantic mammals, Behavior, Parent-child relationships, Social behavior in animals, Discipline of children, Atlantic spotted dolphin
Format: Document (PDF)

Title: Mathematical modeling of plankton patchiness.
Creator: Ather, Simantha S., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: In natural systems, it has been observed that plankton exist in patches rather than in an even distribution across a body of water. However, the mechanisms behind this patchiness are not fully understood. Several previous modeling studies have examined the effects of abiotic and biotic factors on patch structure. Yet these models ignore a key point: zooplankton often undergo diel vertical migration. I have formulated a model that incorporates vertical movement into the Rosezweig-MacArthur (R...
Show moreIn natural systems, it has been observed that plankton exist in patches rather than in an even distribution across a body of water. However, the mechanisms behind this patchiness are not fully understood. Several previous modeling studies have examined the effects of abiotic and biotic factors on patch structure. Yet these models ignore a key point: zooplankton often undergo diel vertical migration. I have formulated a model that incorporates vertical movement into the Rosezweig-MacArthur (R-M) predator-prey model. The R-M model is stable only at a carrying capacity below a critical value. I found that adding vertical movement stabilizes the system even at a high carrying capacity. By analyzing temporal stability and spatial structure, my results show that vertical movement interacts with carrying capacity to determine patch structure.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/368615
Subject Headings: Marine plankton, Vertical distribution, Marine ecology, Mathematical models, Macroecology, Mathematical models
Format: Document (PDF)

Title: Molecular mechanisms of neuroprotection in the anoxia tolerant freshwater turtle.
Creator: Kesaraju, Shailaja., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Cardiac ischemia, stroke and some neurodegenerative disorders are all characterized by cell damage and death due to low oxygen levels. Comparative studies show that anoxia tolerant model systems present a unique opportunity to study "survival" instead of death in the complete absence of oxygen. The freshwater turtle (Trachemys scripta elegans) is unique in its ability to survive total oxygen deprivation for hours to days, as well as reoxygenation insult after anoxia. The broad objective of...
Show moreCardiac ischemia, stroke and some neurodegenerative disorders are all characterized by cell damage and death due to low oxygen levels. Comparative studies show that anoxia tolerant model systems present a unique opportunity to study "survival" instead of death in the complete absence of oxygen. The freshwater turtle (Trachemys scripta elegans) is unique in its ability to survive total oxygen deprivation for hours to days, as well as reoxygenation insult after anoxia. The broad objective of this study is to understand the modulation of key molecular mechanisms involving stress proteins and VEGF that offer neuroprotection and enhance cell survival in the freshwater turtle through anoxia and reoxygenation. In vivo analyses have shown that anoxia induced stress proteins (Hsp72, Hsp60, Grp94, Hsp60, Hsp27, HO-1); modest changes in the Bcl2/Bax ratio and no change in cleaved caspase-3 expression suggesting resistance to neuronal damage. These results were corroborated with immunohistochemical evidence indicating no damage in turtle brain when subjected to the stress of anoxia and A/R. To understand the functional role of Hsp72, siRNA against Hsp72 was utilized to knockdown Hsp72 in vitro (neuronally enriched primary cell cultures established from the turtle). Knockdown cultures were characterized by increased cell death associated with elevated ROS levels. Silencing of Hsp72 knocks down the expression of Bcl2 and increases the expression of Bax, thereby decreasing the Bcl2/Bax ratio. However, there was no increase in cytosolic Cytochrome c or the expression levels of cleaved Caspase-3. Significant increase in AIF was observed in the knockdown cultures that increase through anoxia and reoxygenation, suggesting a caspase independent pathway of cell death., Expression of the master regulator of hypoxia, HIF1 alpha and its target gene, VEGF, were analyzed at the mRNA and protein levels. The results showed no significant increase in HIF-1 alpha levels but anoxia VE GF The levels of stress proteins and VEGF returned to control levels during reoxygenation suggesting robust ROS protection mechanisms through reoxygenation. The present study thereby emphasizes Trachemys scripta as an advantageous model to examine anoxia and reoxygenation survival without major damage to the brain due to it's modulation of molecular mechanisms.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/165943
Subject Headings: Turtles, Physiology, Anoxemia, Proteins, Chemical modification, Oxygen, Physiological effect, Molecular neurobiology
Format: Document (PDF)

Title: Monitoring seasonal and annual changes in the mesozooplankton community of the Indian River Lagoon, Florida.
Creator: Kerr, Miranda Hoover., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: In estuaries, like the Indian River Lagoon, mesozooplankton have a vital role in the food web by connecting trophic levels. In this study, mesozooplankton abundance and species composition were monitored weekly on the incoming and outgoing tides from September 2006 to May 2009. For the incoming tide, the mean abundance was 2298.2 mesozooplankton/m3 (+/-325.2), and for the outgoing tide the mean abundance was 1180.0 mesozooplankton/m3 (+/-153.1). The mesozooplankton abundance on the incoming...
Show moreIn estuaries, like the Indian River Lagoon, mesozooplankton have a vital role in the food web by connecting trophic levels. In this study, mesozooplankton abundance and species composition were monitored weekly on the incoming and outgoing tides from September 2006 to May 2009. For the incoming tide, the mean abundance was 2298.2 mesozooplankton/m3 (+/-325.2), and for the outgoing tide the mean abundance was 1180.0 mesozooplankton/m3 (+/-153.1). The mesozooplankton abundance on the incoming tide was significantly greater than on the outgoing tide. The most abundant type of mesozooplankton was the copepod Acartia tonsa, representing 35.0% and 52.1% of the individuals on the incoming and outgoing tides respectively. Mesozooplankton abundance values were compared with environmental data obtained from the South Florida Water Management District. The strongest positive correlation was found between chlorophyll a concentrations and A. tonsa abundance, likely due to phytoplankton being the primary food source for A. tonsa.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/2783241
Subject Headings: Marine zooplankton, Ecology, Marine ecology, Marine ecosystem management
Format: Document (PDF)

Title: Molecular characterization of a subset of KRAB-ZFPs.
Creator: Chamoun, Alain., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: There are approximately 20,000 genes in the human genome. Around 2% of these genes code for transcriptional repressors known as KRAB-ZFPs. It is already known that Zinc-Finger Proteins contain two main functional domains at either end of the polypeptide. In today's database, you will find a KRAB (Kruppell-associated Box) domain at one end and a tandem array of Zinc-finger repeats at the other end. The carboxyl terminal tandem Zinc-finger repeats function as sequence-specific DNA-binding...
Show moreThere are approximately 20,000 genes in the human genome. Around 2% of these genes code for transcriptional repressors known as KRAB-ZFPs. It is already known that Zinc-Finger Proteins contain two main functional domains at either end of the polypeptide. In today's database, you will find a KRAB (Kruppell-associated Box) domain at one end and a tandem array of Zinc-finger repeats at the other end. The carboxyl terminal tandem Zinc-finger repeats function as sequence-specific DNA-binding domains. The amino terminal KRAB domain serves as a repressor domain, which will recruit a co-repressor termed KAP-1 (KRAB Associated Protein-1). Located in between these two domains is a region of uncharacterized DNA referred to as the "Linker Region". This thesis will explore the DNA-binding domains of 6 known KRAB-ZFPs, as well as utilize the linker regions to derive an evolutionary history for this superfamily.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2684313
Subject Headings: Zinc-finger proteins, Synthesis, Metalloproteins, Synthesis, Genetic transcription, Regulation, Gene expression
Format: Document (PDF)

Title: Methionine sulfoxide reductases: studies on the reducing requirements and role in the metabolism of sulindac.
Creator: Brunell, David J., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The methionine sulfoxide reductase (Msr) enzymes catalyze the reduction of methionine sulfoxide (Met(O)) to methionine. The Msr enzymes protect cells against oxidative stress and may have a role in aging. The MsrA family of enzymes reduces stereospecifically the S epimer of free and protein-bound Met(O) while the MsrB family reduces the R epimer of Met(O) in proteins. It has been generally accepted, primarily from studies on MsrA, that the biological reductant for the Msr enzymes is...
Show moreThe methionine sulfoxide reductase (Msr) enzymes catalyze the reduction of methionine sulfoxide (Met(O)) to methionine. The Msr enzymes protect cells against oxidative stress and may have a role in aging. The MsrA family of enzymes reduces stereospecifically the S epimer of free and protein-bound Met(O) while the MsrB family reduces the R epimer of Met(O) in proteins. It has been generally accepted, primarily from studies on MsrA, that the biological reductant for the Msr enzymes is thioredoxin (Trx), although high levels of dithiothreitol (DTT) can be used as the reductant in vitro. In contrast, certain MsrB enzymes show less than 10% of the activity with Trx as compared to DTT. This raises the possibility that in animal cells Trx may not be the direct hydrogen donor for the MsrB enzymes. Studies with bovine liver extracts have shown that thionein, the apoprotein of metallothionein, can function as a reductant for the Msr proteins. Certain selenium compounds such as selenocystamine and selenocystine can also serve as potent reducing agents for the Msr enzymes. Since an increased activity of Msr enzymes can reduce the level of oxidative damage in tissues, compounds that could activate Msr may have therapeutic potential. A high-throughput screening assay has been developed to screen large chemical libraries to find activators of MsrA, as well as specific inhibitors that could be useful research tools. This study will be done in collaboration with The Scripps Florida Research Institute. Sulindac was originally developed as a non-steroidal anti-inflammatory drug but has also shown efficacy in the treatment of certain cancers. The S epimer of sulindac is known to be reduced by MsrA, but the enzymes responsible for reduction of the R epimer are not known., An activity has been purified from rat liver which is capable of reducing the R epimers of sulindac, free Met(O) and a dabsylated Met(O) substrate, the latter suggesting that this enzyme may have properties similar t o the MsrB enzymes. The oxidation of the epimers of sulindac to sulindac sulfone has also been characterized, and the members of the cytochrome P450 family involved in the oxidation have been identified.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/227979
Subject Headings: Cellular signal transduction, Proteins, Chemical modification, Biochemical markers, Oxidation-reduction reaction
Format: Document (PDF)

Title: Spatial and trophic ecology of the sawtooth eel, Serrivomer beanii, a biomass-dominant bathypelagic fish over the northern Mid-Atlantic ridge.
Creator: Geidner, Megan E., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The role of Serrivomer beanii in bathypelagic food webs is poorly known, but abundance and biomass estimates from the 2004 G.O. Sars MAR-ECO Expedition suggest it to have a high level of importance. MAR-ECO, a Census of Marine Life field project, has allowed us to increase our knowledge of S. beanii through spatial analysis, including the congeneric species Serrivomer lanceolatoides, and trophic analysis. Serrivomer beanii abundance and biomass exhibited a decreasing trend along the northern...
Show moreThe role of Serrivomer beanii in bathypelagic food webs is poorly known, but abundance and biomass estimates from the 2004 G.O. Sars MAR-ECO Expedition suggest it to have a high level of importance. MAR-ECO, a Census of Marine Life field project, has allowed us to increase our knowledge of S. beanii through spatial analysis, including the congeneric species Serrivomer lanceolatoides, and trophic analysis. Serrivomer beanii abundance and biomass exhibited a decreasing trend along the northern Mid-Atlantic Ridge from north to south. In terms of size, S. beanii was found to increase as distance from the ridge decreased, suggesting a topographic aggregation strategy. The diet of S. beanii consisted of crustaceans, cephalopods, and teleosts. The trophic results of this study reveal a likely "alternative" trophic pathway in the deep mid-North Atlantic, and perhaps other, bathypelagic ecosystems: higher trophic-level predators are supported by micronektonic invertebrates as primary prey.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/165941
Subject Headings: Plankton, Ecology, Coral reef animals, Ecology, Deep sea biology
Format: Document (PDF)

Title: Social play as a tool for developing social-cognitive skills in a wild population of Atlantic spotted dolphins (Stenella frontalis).
Creator: Bender, Courtney Elizabeth., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: The purposes of this dissertation were to identify complex social-cognitive behaviors in a population of wild Atlantic spotted dolphins (Stenella frontalis) using long-term video archives and identify developmental trends in those behaviors. Chapter One analyzed calf behavior during foraging events involving maternal teaching in order to identify mechanisms for sharing information between mother and calf... The calves' behavior was affected by the referencing cues, supporting the presence of...
Show moreThe purposes of this dissertation were to identify complex social-cognitive behaviors in a population of wild Atlantic spotted dolphins (Stenella frontalis) using long-term video archives and identify developmental trends in those behaviors. Chapter One analyzed calf behavior during foraging events involving maternal teaching in order to identify mechanisms for sharing information between mother and calf... The calves' behavior was affected by the referencing cues, supporting the presence of joint attention and true teaching behavior....Chapter Two observed the altered benthic foraging behavior of juvenile play groups, in which juveniles took turns chasing the fish and using referencing gestures to reference the position of the fish to other individuals during the chase, despite the ability of these young, independent dolphins to catch fish much more quickly and efficiently alson... The third chapter analyzed social object play in which dolphins passed pieces of seaweed between individuals. The data clarified developmental trends in the play, and suggested social-cognitive abilities needed for participation.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3358280
Subject Headings: Social behavior in animals, Cognition in animals, Dolphins, Behavior, Atlantic spotted dolphin
Format: Document (PDF)

FAU Theses and Dissertations (428)	+ -
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