Current Search: Charles E. Schmidt College of Science (x) » Florida Atlantic University (x)
View All Items
Pages
- Title
- Toward lanthanide containing coordination polymers and nanomaterials.
- Creator
- Greig, Natalie E., De Lill, Daniel T., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
The focus of this thesis is to develop lanthanide (Ln) luminescent materials through the exploration of coordination polymers and nanomaterials. Herein, dimethyl-3,4- furanedicarboxylate acid undergoes hydrolysis under hydrothermal conditions to form coordination polymers with lanthanide ions. The resulting coordination polymers exhibited luminescent properties, with quantum yields and lifetimes for the Eu-and Tb-CP of 1.14+-0.32% and 0.387=-0.0001 mx, and 3.33=-0.82% and 0.769=-0.006 ms,...
Show moreThe focus of this thesis is to develop lanthanide (Ln) luminescent materials through the exploration of coordination polymers and nanomaterials. Herein, dimethyl-3,4- furanedicarboxylate acid undergoes hydrolysis under hydrothermal conditions to form coordination polymers with lanthanide ions. The resulting coordination polymers exhibited luminescent properties, with quantum yields and lifetimes for the Eu-and Tb-CP of 1.14+-0.32% and 0.387=-0.0001 mx, and 3.33=-0.82% and 0.769=-0.006 ms, respectively. While the incorporation of lanthanides was not achieved in this work, progress toward the production of pure phase InP in the nanoregime has been made, using a low-cost, hydrothermal method. Through SEM and PXRD conflict, it is believed that pure INP particles with a size range of 58-81 nm were successfully synthesized.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358558
- Subject Headings
- Metallic composites, Speciation, Lanthanide shift reagents, Rare earth metals catalysts, Nanostructured materials
- Format
- Document (PDF)
- Title
- Anticancer ativities of topotecan-genistein combination in prostate cancer cells.
- Creator
- Hörmann, Vanessa P., Kumi-Diaka, James, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Prostate cancer is one of the leading causes of death in men aged 40-55. Genistein isoflavone (4', 5', 7-trihydroxyisoflavone) is a dietary phytochemical with demonstrated anti-tumor activities in a variety of cancers. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy drug, primarily used for secondary treatment of ovarian,cervical and small cell lung cancers. This study was to demonstrate the potential anticancer activities and synergy of topotecan-genistein combination in...
Show moreProstate cancer is one of the leading causes of death in men aged 40-55. Genistein isoflavone (4', 5', 7-trihydroxyisoflavone) is a dietary phytochemical with demonstrated anti-tumor activities in a variety of cancers. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy drug, primarily used for secondary treatment of ovarian,cervical and small cell lung cancers. This study was to demonstrate the potential anticancer activities and synergy of topotecan-genistein combination in LNCaP prostate cancer cells. The potential efficacy and mechanism of topotecan/genistein-induced cell death was investigated... Results: The overall data indicated that i) both genistein and topotecan induce cellular death in LNCaP cells, ii) topotecan-genistein combination was significantly more efficacious in reducing LNCaP cell viabiligy compared to either genistein or topotecan alone, iii) in all cases, cell death was primarily through apoptosis, via the activation of the intrinsic pathway, iv) ROS levels were increased and VEGF expression was diminished significantly with the topotecan-genistein combination treatment, v) genetic analysis of topotecan-genistein treatment groups showed changes in genetic expression levels in pathway specific apoptotic genes.... Conclusion: Treatments involving topotecan-genistein combination may prove to be an attractive alternative phytotherapy of adjuvant therapy for prostate cancer.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358553
- Subject Headings
- Apoptosis, Molecular aspects, Prostate, Cancer, Adjuvant treatment, Prostate, Cancer, Molecular aspects, Phytochemicals, Physiological effect, Antioxidants, Therapeutic use, Topotecan, Therapeutic use, Genistein, Therapeutic use, Cancer, Chemotherapy
- Format
- Document (PDF)
- Title
- Predicting leatherback sea turtle sex ratios using spatial interpolation of nesting beach temperatures.
- Creator
- Weston, Emily G., Wyneken, Jeanette, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Sex determination in leatherback sea turtles is directed primarily by the temperatures a clutch experiences during the middle third of development. Warmer temperatures tend to produce females will cooler temperatures yield males. Nest temperatures can vary spatially and temporally. During the 2010 and 2011 nesting seasons, this study estimated the hatchling sex ratio of leatherback sea turtles on Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands. I measured sand...
Show moreSex determination in leatherback sea turtles is directed primarily by the temperatures a clutch experiences during the middle third of development. Warmer temperatures tend to produce females will cooler temperatures yield males. Nest temperatures can vary spatially and temporally. During the 2010 and 2011 nesting seasons, this study estimated the hatchling sex ratio of leatherback sea turtles on Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands. I measured sand temperatures from May- August and across the spatial range of leatherback nesting habitat. I spatially interpolated those temperatures to create maps that predicted temperatures for all nests incubating on SPWNR. Nest temperatures were also directly measured and compared with predicted nest temperatures to validate the prediction model. Sexes of dead-in-nest hatchlings and full term embryos were used to confirm the sex-temperature response. The model showed that microclimatic variation likely impacts the production of both sexes on SPNWR.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004071
- Subject Headings
- Leatherback turtle -- Habitat -- St. Croix -- Sandy Point National Wildlife Refuge (United States Virgin Islands), Loggerhead turtle -- Effect of temperature on, Sandy Point National Wildlife Refuge (United States Virgin Islands), Sea turtles -- Nests -- St. Croix -- Sandy Point National Wildlife Refuge (United States Virgin Islands), Sex determination, Genetic, Sex ratios, Vegetation dynamics
- Format
- Document (PDF)
- Title
- Computing automorphism groups of projective planes.
- Creator
- Adamski, Jesse Victor, Magliveras, Spyros S., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
The main objective of this thesis was to find the full automorphism groups of finite Desarguesian planes. A set of homologies were used to generate the automorphism group when the order of the plane was prime. When the order was a prime power Pa,a ≠ 1 the Frobenius automorphism was added to the set of homologies, and then the full automorphism group was generated. The Frobenius automorphism was found by using the planar ternary ring derived from a coordinatization of the plane.
- Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004000
- Subject Headings
- Combinatorial group theory, Finite geometrics, Geometry, Projective
- Format
- Document (PDF)
- Title
- Measurements of output factors for small photon fields up to 10 cm x 10 cm.
- Creator
- Bacala, Angelina, Pella, Silvia, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Field output factors (OF) for photon beams from a 6 MV medical accelerator were measured using five different detectors in a scanning water phantom. The measurements were taken for square field sizes of integral widths ranging from 1 cm to 10 cm for two reference source-to-surface distances (SSD) and depths in water. For the diode detectors, square field widths as small as 2.5 mm were also studied. The photon beams were collimated by using either the jaws or the multileaf collimators....
Show moreField output factors (OF) for photon beams from a 6 MV medical accelerator were measured using five different detectors in a scanning water phantom. The measurements were taken for square field sizes of integral widths ranging from 1 cm to 10 cm for two reference source-to-surface distances (SSD) and depths in water. For the diode detectors, square field widths as small as 2.5 mm were also studied. The photon beams were collimated by using either the jaws or the multileaf collimators. Measured OFs are found to depend upon the field size, SSD, depth and also upon the type of beam collimation, size and type of detector used. For field sizes larger than 3 cm x 3 cm, the OF measurements agree to within 1% or less. The largest variation in OF occurs for jawsshaped field of size 1 cm x 1cm, where a difference of more than 18% is observed.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004003
- Subject Headings
- Integrated circuits, Photonics, Quantum electrodynamics, Quantum theory
- Format
- Document (PDF)
- Title
- Morphology of Astarte borealis (Mollusca: bivalvia) of Camden bay, northern Alaska.
- Creator
- Chrpa, Michelle E., Oleinik, Anton E., Charles E. Schmidt College of Science, Department of Geosciences
- Abstract/Description
-
The genus Astarte is known for variable shell morphology and polymorphism within living and fossil species. Astarte borealis, the most common living species, is recognizable and common among mid-to-high latitude North Pacific, Arctic Ocean and North Atlantic waters, and has been divided into many subspecies and varieties based on overall shell shape. A collection of recent A. borealis specimens from Camden Bay, northern Alaska (641 specimens) with outline intact were used for analyses....
Show moreThe genus Astarte is known for variable shell morphology and polymorphism within living and fossil species. Astarte borealis, the most common living species, is recognizable and common among mid-to-high latitude North Pacific, Arctic Ocean and North Atlantic waters, and has been divided into many subspecies and varieties based on overall shell shape. A collection of recent A. borealis specimens from Camden Bay, northern Alaska (641 specimens) with outline intact were used for analyses. Bivariate analysis of height vs. length and morphometric analysis of shell outline determined variants within a population of A. borealis, and then compared to Pliocene A. borealis and Oligocene A. martini. The computer program SHAPE uses elliptic Fourier coefficients of shell outline to evaluate and visualize shape variations. The multivariate outline analysis indicates that A. borealis intraspecies variation is based upon a common shape that grades into other shapes, rather than grade between two or more end-forms.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004010
- Subject Headings
- Bivalves -- Alaska -- Camden Bay -- Geographical distribution, Mollusks, Fossil -- Alaska -- Camden Bay -- Morphology
- Format
- Document (PDF)
- Title
- The multiple stress gradient hypothesis: expansion of the revised stress gradient hypothesis using a mangrove and salt marsh study system.
- Creator
- Coldren, Glenn A., Proffitt, C. Edward, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Plant interactions (e.g., competition, facilitation) are critical drivers in community development and structure. The Stress Gradient Hypothesis (SGH) provides a predictive framework for how plant species interactions vary inversely across an environmental stress gradient, predicting that facilitation is stronger with increasing levels of stress. The SGH has been supported in numerous ecosystems and across a variety of stress gradients, but recent research has demonstrated contradictory...
Show morePlant interactions (e.g., competition, facilitation) are critical drivers in community development and structure. The Stress Gradient Hypothesis (SGH) provides a predictive framework for how plant species interactions vary inversely across an environmental stress gradient, predicting that facilitation is stronger with increasing levels of stress. The SGH has been supported in numerous ecosystems and across a variety of stress gradients, but recent research has demonstrated contradictory results. These discrepancies have led to SGH revisions that expand its conceptual framework by incorporating additional factors, such as other stressor types and variations in species life history strategies. In this dissertation, I examine a further modification of the SGH by proposing and testing a Multiple Stress Gradient Hypothesis (MSGH) that considers how plant interactions vary along a continuous gradient of two co-occurring stressors using mangrove and salt marsh communities as a case study. In Chapter 1, I outline the predictive framework of a MSGH, by creating a series of predictions of species interactions. The components of the MSGH predict that stressors of similar types (e.g., resource and nonresource) will have similar effects and be additive. On the other hand, varying species life history strategies and life stages will lead to extremes of plant interactions. In Chapter 2, I performed a series of experiments to test the various components of the MSGH. In Chapter 3, I performed a large-scale observational study to test whether multiple co-occurring stressors altered the cumulative effects on plant interactions, and if these stressors should be grouped (e.g., resource and non-resource, abiotic and biotic, etc.) to enhance predictability. From a series of studies conducted herein, I concluded that co-occurring stressors are important factors that control complex species interactions as shown in my MSGH modeling approach. Further, future theories need to incorporate species-specific and stressor specific grouping when modeling how species interactions shape communities.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004011
- Subject Headings
- Coastal ecology, Ecophysiology, Mangrove ecology, Plant ecology, Salt marsh ecology
- Format
- Document (PDF)
- Title
- Friend influence on achievement during middle childhood.
- Creator
- DeLay, Dawn, Laursen, Brett, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
This study was designed to investigate friend influence on academic achievement and task avoidance during middle childhood in a sample of 794 participants in 397 stable same-sex friendship dyads (205 girl dyads and 192 boy dyads) from four municipalities in Finland: two in Central Finland, one in Western Finland, and one in Eastern Finland. Longitudinal data were collected during the spring of 3rd grade and 4th grade and reports were available from both members of each friendship dyad. The...
Show moreThis study was designed to investigate friend influence on academic achievement and task avoidance during middle childhood in a sample of 794 participants in 397 stable same-sex friendship dyads (205 girl dyads and 192 boy dyads) from four municipalities in Finland: two in Central Finland, one in Western Finland, and one in Eastern Finland. Longitudinal data were collected during the spring of 3rd grade and 4th grade and reports were available from both members of each friendship dyad. The Actor-Partner Interdependence Model (APIM; Kenny, Kashy & Cook, 2006) was used with a single sample of participants to estimate friend influence on academic achievement and task avoidance between two types of friendship dyads: (1) dyads that were distinguishable as a function of relative math achievement and relative peer acceptance and (2) dyads that were indistinguishable as a function of relative math achievement and relative peer acceptance. The results demonstrate that when friends are distinguished by math achievement the high achiever influences the low achiever’s math achievement, but not the reverse. When friends are distinguishable by peer acceptance the high accepted partner influences the low accepted partner’s math achievement, but not the reverse. When friends are indistinguishable on the basis of math achievement and peer acceptance there is mutual influence on math achievement. There was no evidence of friend influence on task avoidance. There was no evidence of friend influence from an individual’s own task avoidance predicting changes in friend math achievement, except among dyads that could not be distinguished on the basis of math achievement. Math achievement predicted within-individual changes in task avoidance for all friendship dyads, except those that could not be distinguished by relative math achievement. The findings suggest that friends influence math achievement during middle childhood. Furthermore, when friends are distinguished, relative math achievement and peer acceptance determines who is influencing whom within a friendship dyad. The use of the APIM for distinguishable and indistinguishable dyads on a single sample of participants illustrates that it is not sufficient to ignore differentiating features between friends, or to discard friendships that are more similar. Implications for teaching strategies and classroom interventions are discussed.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004015
- Subject Headings
- Achievement in education, Achievement motivation in adolescence, Achievement motivation in children, Motivation in education, Peer motivation in adolescence, Peer motivation in children
- Format
- Document (PDF)
- Title
- Best friend influence over adolescent problem behaviors: the role of perceived friendship quality.
- Creator
- Hiatt, Cody, Laursen, Brett, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
Close friends have been shown to influence adolescent problem behaviors, especially alcohol abuse (Urberg, Degirmencioglu, and Pilgrim, 1997). The degree of influence, however varies as a function of individual characteristics such as peer acceptance (Laursen, Hafen, Kerr, and Stattin, 2012) and age (Popp et al., 2008). The present study examines whether differences in influence extend to perceptions of friendship quality. Using a sample of 764 Swedish adolescents involved in stable samesex...
Show moreClose friends have been shown to influence adolescent problem behaviors, especially alcohol abuse (Urberg, Degirmencioglu, and Pilgrim, 1997). The degree of influence, however varies as a function of individual characteristics such as peer acceptance (Laursen, Hafen, Kerr, and Stattin, 2012) and age (Popp et al., 2008). The present study examines whether differences in influence extend to perceptions of friendship quality. Using a sample of 764 Swedish adolescents involved in stable samesex reciprocal best friend relationships that lasted at least one year, analyses used distinguishable dyad actor-partner interdependence model (APIM) analyses (Kenny, Kashy, & Cook, 2006) to track influence over two years of the friendship. More satisfied friends were more influential than less satisfied friends on intoxication frequency and truancy. The findings of this study indicate that influence accompanies perceptions of quality. Those with higher perceptions of quality exhibit more influence on friends who perceive relatively lower quality.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004025
- Subject Headings
- Adolescent psychology, Friendship in adolescence, Interpersonal relationships in adolescence, Peer pressure in adolescence, Web services -- Management
- Format
- Document (PDF)
- Title
- Changes in components of children’s self-reported gender identity over time.
- Creator
- Jackson, Emily, Perry, David G., Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
In past gender identity research, little attention has been paid to the determinants of the various dimensions of gender identity (felt pressure for gender differentiation, gender contentedness, and within-gender typicality). This study examined whether children’s self-perceptions and social behaviors influence changes in gender identity over time. One hundred and ninety-five fourth- through seventh-graders completed self-report and peer-report questionnaires during the fall and spring of a...
Show moreIn past gender identity research, little attention has been paid to the determinants of the various dimensions of gender identity (felt pressure for gender differentiation, gender contentedness, and within-gender typicality). This study examined whether children’s self-perceptions and social behaviors influence changes in gender identity over time. One hundred and ninety-five fourth- through seventh-graders completed self-report and peer-report questionnaires during the fall and spring of a school year. This study found that both felt pressure for gender differentiation and within-gender typicality are fluid, rather than stable, constructs during childhood. It also found that sex plays a significant role in not only which constructs influence gender identity, but which components of gender identity are influenced.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004027
- Subject Headings
- Gender identity -- Psychological aspects, Self perception in adolescence, Sex (Psychology)
- Format
- Document (PDF)
- Title
- A novel method to evaluate local control of lung cancer in stereotactic body radiation therapy (SBRT) treatment using 18f-Fdg positron emission tomography (PET).
- Creator
- Kathriarachchi, Vindu, Shang, Charles, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
An improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations...
Show moreAn improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations associated with SUVmax and objectively demonstrates a strong correlation between the low SUVcmax (< 2.5-3.0) and local control of post lung SBRT. The false positive rates of both SUVmax and SUVcmax increase with inclusion of early (<6 months) PET scans, therefore such inclusion is not recommended for assessing local tumor control of post lung SBRT.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004029
- Subject Headings
- Cancer -- Radiotherapy, Image guided radiation therapy, Lung cancer -- Treatment, Radiopharmaceuticals, Tomography, Emission
- Format
- Document (PDF)
- Title
- Electroencephalography in children with autism.
- Creator
- Lucas, Nikola N., Jones, Nancy Aaron, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
Autism is a neurodevelopmental disorder that is characterized by deficits involving social interaction, communication, and perception. Although there is much research that has examined functional neural connectivity in individuals with autism, few have conducted these studies in very young children while awake across EEG power and coherence measures. Anomalies in EEG coherence and power have been associated with deficits in executive function and mental activity. The present study examined...
Show moreAutism is a neurodevelopmental disorder that is characterized by deficits involving social interaction, communication, and perception. Although there is much research that has examined functional neural connectivity in individuals with autism, few have conducted these studies in very young children while awake across EEG power and coherence measures. Anomalies in EEG coherence and power have been associated with deficits in executive function and mental activity. The present study examined neural activation and functional connectivity with an EEG, in children ages 3 -5, during an eyesclosed baseline period. Discrete Fourier Transform was performed on artifact-free segments of EEG data to produce power density values. In addition, coherence measurements were examined to assess functional connectivity in the alpha bandwidth during the baseline recording. Children with autism spectrum disorder (ASD) demonstrated reduced alpha coherence in fronto-temporal regions and between right temporal sites when compared to typically developing (TD) children. In addition, the reduction in coherence was based on ASD severity, such that high-functioning children with ASD showed greater coherence than low-functioning children with ASD. Children with ASD also displayed reduced power in the alpha, beta, and theta frequency bandwidths in frontal, temporal, central, and occipital regions compared to TD children. Interestingly, delta power differentiated children based on developmental status such that high-functioning children with ASD demonstrated the greatest delta power, followed by TD children, and then low-functioning children with ASD. Finally, TD children demonstrated left anterior temporal EEG asymmetry in the alpha bandwidth, whereas children with high-functioning ASD exhibited left posterior temporal EEG asymmetry and right frontal EEG asymmetry. Thus, the results suggest that children with ASD exhibit atypical patterns of brain activity and functional connectivity compared to their typically developing counterparts.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004034
- Subject Headings
- Autism in children -- Research, Autism spectrum disorders, Cognition disorders in children, Cognitive neuroscience, Electroencephalography -- Therapeutic use
- Format
- Document (PDF)
- Title
- Netrin-Frazzled signaling instructs synaptogenesis and plasticity at an identified central synapse in Drosophila.
- Creator
- Orr, Brian, Murphey, Rodney K., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The classic guidance molecules, Netrin and its receptor Frazzled (Fra), dictate the strength of synaptic connections in the giant fiber system (GFS) of Drosophila melanogaster by regulating gap junction localization in the pre-synaptic terminal. In Netrin mutant animals the synaptic coupling between a giant interneuron and the jump motor neuron was weakened. Dye-coupling between these two neurons was severely compromised or absent. These mutants exhibited anatomically and physiologically...
Show moreThe classic guidance molecules, Netrin and its receptor Frazzled (Fra), dictate the strength of synaptic connections in the giant fiber system (GFS) of Drosophila melanogaster by regulating gap junction localization in the pre-synaptic terminal. In Netrin mutant animals the synaptic coupling between a giant interneuron and the jump motor neuron was weakened. Dye-coupling between these two neurons was severely compromised or absent. These mutants exhibited anatomically and physiologically defective synapses between the giant fiber (GF) and tergotrochanteral motor neuron (TTMn). In cases where Netrin mutants displayed apparently normal synaptic anatomy, half of the specimens exhibited physiologically defective synapses. Dye-coupling between the giant fiber and the motor neuron was reduced or eliminated, suggesting that gap junctions were disrupted in the Netrin mutants. When we examined the gap junctions with antibodies to Shaking-B Innexin (ShakB), they were significantly decreased or absent in the pre-synaptic terminal of the mutant GF. This data is the first to show that Netrin and Frazzled regulate placement of gap junctions pre-synaptically at a central synapse. In the Drosophila Giant Fiber System, we demonstrate a mechanism that ensures the monoinnervation of two homologous motor neurons by two homologous interneurons. In a scenario where both interneurons could synapse with both motor neuron targets, each interneuron exclusively synapsed with only one target and the circuit functions at normal physiological levels. This innervation pattern depended on the ratio of netrin-to-frazzled expression. When Netrin was over expressed in the system, shifting the ratio in favor of Netrin, both interneurons synapsed with both target motor neurons and physiological function was reduced. This resulted in the polyinnervationof a single target. In contrast, when Frazzled was over expressed in the system, one interneuron innervated both targets and excluded the remaining interneuron from making any synaptic contact. This resulted in a single interneuron mono-innervating both motor neurons and physiological function was mutant. The orphaned interneuron made no synaptic contact with either motor neuron target. Physiological function was only normal when the Netrin-Frazzled ratio was at endogenous levels and each GF monoinnervated one motor neuron. When we examined the gap junctions at this synapse in experimental animals, there was a significant reduction of gap junction hemichannels in the presynaptic terminal of axons that deviated from normal innervation patterns. While the synapse dyecoupled, the reduction in gap junction hemichannels reduced function in the circuit.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004041
- Subject Headings
- Cellular control mechanisms, Cellular signal transduction, Drosophila melanogaster -- Cytogenetics, Genetic transcription, Transcription factors
- Format
- Document (PDF)
- Title
- The hawksbill rookery at Antigua, W.I.: nest success, hatchling behavior, and hatchling survival during offshore migration.
- Creator
- Reising, Megan, Salmon, Michael, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The younger life history stages of marine turtles (eggs, hatchlings) often fail to survive. To compensate, sea turtles nest several times/season and produce large clutches of eggs. The hawksbill produces the largest clutches (150 eggs) and the smallest hatchlings of any marine turtle. My study, done at Jumby Bay in Antigua, West Indies, was designed to determine whether they did so to compensate for loss in the nest, hatchling loss in the water, or both factors. I found that most of the eggs ...
Show moreThe younger life history stages of marine turtles (eggs, hatchlings) often fail to survive. To compensate, sea turtles nest several times/season and produce large clutches of eggs. The hawksbill produces the largest clutches (150 eggs) and the smallest hatchlings of any marine turtle. My study, done at Jumby Bay in Antigua, West Indies, was designed to determine whether they did so to compensate for loss in the nest, hatchling loss in the water, or both factors. I found that most of the eggs (79 %) survived to become hatchlings that left the nest and entered the sea. However, 88 % of the hatchlings swimming offshore were taken by predators within minutes after they began their migration. These results suggest that at Jumby Bay, large clutch size is favored in hawksbills because of predation pressures on the hatchlings.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004049
- Subject Headings
- Animal migration -- Antigua -- Jumbo Bay, Animal orientation -- Antigua -- Jumbo Bay, Hawksbill turtle -- Research -- Antigua -- Jumbo Bay, Predation (Biology), Sea turtles -- Research -- Antigua -- Jumbo Bay, Wildlife conservation -- Antigua -- Jumbo Bay
- Format
- Document (PDF)
- Title
- Simulation study on option pricing under jump diffusion models.
- Creator
- Rodrigues, Justin, Long, Hongwei, Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
The main objective of this thesis is to simulate, evaluate and discuss several methods for pricing European-style options. The Black-Scholes model has long been considered the standard method for pricing options. One of the downfalls of the Black-Scholes model is that it is strictly continuous and does not incorporate discrete jumps. This thesis will consider two alternate Levy models that include discretized jumps; The Merton Jump Diffusion and Kou's Double Exponential Jump Diffusion. We...
Show moreThe main objective of this thesis is to simulate, evaluate and discuss several methods for pricing European-style options. The Black-Scholes model has long been considered the standard method for pricing options. One of the downfalls of the Black-Scholes model is that it is strictly continuous and does not incorporate discrete jumps. This thesis will consider two alternate Levy models that include discretized jumps; The Merton Jump Diffusion and Kou's Double Exponential Jump Diffusion. We will use each of the three models to price real world stock data through software simulations and explore the results.Keywords: Levy Processes, Brownian motion, Option pricing, Simulation, Black-Scholes, Merton Jump Diffusion, Kou, Kou's Double Exponential Jump Diffusion.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004051
- Subject Headings
- Finance -- Mathematical models, Levy processes, Prices -- Econometric models, Statistical physics, Stochastic processes, Valuation -- Econometric models
- Format
- Document (PDF)
- Title
- Functional aspects of behavior and morphology in the decorator crab Microphrys Bicornutus (Latreille, 1825) (Crustacea: Brachyura: Mithracidae).
- Creator
- Salazar, Monique Alexandra, Brooks, W. Randy, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Masking or decorator crabs, conceal themselves partially through camouflage, by selecting or indiscriminately attaching materials from their environment to their exoskeleton. Functional aspects of decorating behavior and morphology in this group have not been documented. Using Microphrys bicornutus as a model species, this dissertation demonstrates clearly that decorating is an advantageous phenotype that has evolved to serve several functions. Decorating is a complex behavior that begins...
Show moreMasking or decorator crabs, conceal themselves partially through camouflage, by selecting or indiscriminately attaching materials from their environment to their exoskeleton. Functional aspects of decorating behavior and morphology in this group have not been documented. Using Microphrys bicornutus as a model species, this dissertation demonstrates clearly that decorating is an advantageous phenotype that has evolved to serve several functions. Decorating is a complex behavior that begins when a crab approaches an algal substrate and results in the attachment of algae to hooked setae on the exoskeleton. Once decorated, crabs remain motionless on the substrate until disturbed or until another behavior is initiated. This was confirmed for M. bicornutus, as crabs spent a significant amount of time feeding, remaining motionless, picking, and walking when compared to decorating. Crabs displayed agonistic behaviors during encounters with conspecifics conspecifics. These included both active aggressive behavior and display behavior. Crabs showed a decrease in motility during these encounters, helping maintain dispersed distributions, thereby decreasing intrsapecific encounters in the field. Trials were done to determine the effect of conspecifics, predators and feeding preferences on algal utilization. M. bicornutus showed a significant decrease in the amount of algae used for decoration in the highest density trials (i.e., 4 and 8 crabs). Agonistic displays and aggressive behavior between these crabs likely affected the time available for decorating. Decorated crabs isolated from an algal substrate were more likely to survive in the presence of either of two sympatric fish predators. Thus, being protected by the algal decoration on their exoskeletons. Trials also showed a parallel between algal consumption and algal materials used for decoration. In addition to its protective function, algae used by M. bicornutus for decoration simultaneously serve as short term food supplies for the crabs. Eleven morphologically complex structures were identified and mapped on the exoskeleton. Hooked setae were the primary structures used to attach algae to the crab’s body. Ten additional setal structures were present, including two novel types of setae. On the basis of location and morphological variation exhibited among these latter structures, a primary sensory function may be inferred.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004056
- Subject Headings
- Animal behavior, Camouflage (Biology), Crabs -- Behavior, Marine ecology, Predation (Biology)
- Format
- Document (PDF)
- Title
- Personality and perceptions of situations from the thematic apperception test: quantifying alpha and beta press.
- Creator
- Serfass, David G., Sherman, Ryne A., Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
Theoretical models posit that the perception of situations consists of two components: an objective component attributable to the situation being perceived and a subjective component attributable to the person doing the perceiving (Murray, 1938; Rauthmann, 2012; Sherman, Nave & Funder, 2013; Wagerman & Funder, 2009). In this study participants (N = 186) viewed three pictures from the Thematic Apperception Test (TAT; Murray, 1938) and rated the situations contained therein using a new measure...
Show moreTheoretical models posit that the perception of situations consists of two components: an objective component attributable to the situation being perceived and a subjective component attributable to the person doing the perceiving (Murray, 1938; Rauthmann, 2012; Sherman, Nave & Funder, 2013; Wagerman & Funder, 2009). In this study participants (N = 186) viewed three pictures from the Thematic Apperception Test (TAT; Murray, 1938) and rated the situations contained therein using a new measure of situations, the Riverside Situational Q-Sort (RSQ; Wagerman & Funder, 2009). The RSQ was used to calculate the overall agreement among ratings of situations and to examine the objective and subjective properties of the pictures. These results support a twocomponent theory of situation perception. Both the objective situation and the person perceiving that situation contributed to overall perception. Further, distinctive perceptions of situations were consistent across pictures and were associated with the Big Five personality traits in a theoretically meaningful manner. For instance, individuals high in Openness indicated that these pictures contained comparatively more humor (r = .26), intellectual stimuli (r = .20), and raised moral or ethical issues (r = .19) than individuals low on this trait.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004059
- Subject Headings
- Discourse analysis, Narrative, Ethnopsychology, Personality assessment, Statistical hypothesis testing
- Format
- Document (PDF)
- Title
- Ecological correlates of the abundance of juvenile green sea turtles (Chelonia Mydas) on nearshore reefs in southeast Florida.
- Creator
- Stadler, Melanie, Salmon, Michael, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Juvenile green turtle (Chelonia mydas) abundance differs among nearshore reefs, but why some sites are preferred over others is unknown. My study had two objectives: to quantify differences in abundance over time (one year) and to determine what ecological factors were correlated with those differences. I conducted quarterly surveys on reefs in Palm Beach and Broward Counties and compared reef sites with respect to (i) water depth, (ii) algal abundance and composition, and (iii) changes in...
Show moreJuvenile green turtle (Chelonia mydas) abundance differs among nearshore reefs, but why some sites are preferred over others is unknown. My study had two objectives: to quantify differences in abundance over time (one year) and to determine what ecological factors were correlated with those differences. I conducted quarterly surveys on reefs in Palm Beach and Broward Counties and compared reef sites with respect to (i) water depth, (ii) algal abundance and composition, and (iii) changes in reef area (caused by sand covering) through time (11 years). Turtles were most abundant on shallow reefs exposed to high light levels that remained stable (uncovered by sand) for long periods of time. These reefs had the highest diversity of algal species, in part because cropping by the turtles prevented any one species from becoming dominant. My results suggest that both physical and biological factors make some reefs more attractive to turtles than others
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004064
- Subject Headings
- Conservation biology -- Florida, Ecology -- Statistical methods, Sea turtles -- Ecology -- Florida, Wildlife conservation -- Florida
- Format
- Document (PDF)
- Title
- Binary neutron star mergeres: simulations with arbitrarily spinning stars.
- Creator
- Tsatsin, Petr, Marronetti, Pedro, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
The starting point of any general relativistic numerical simulation is a solution of the Hamiltonian and momentum constraints that (ideally) represents an astrophysically realistic scenario. This dissertation presents a new method to produce initial data sets for binary neutron stars with arbitrary spins and orbital eccentricities. The method only provides approximate solutions to the constraints. However, it was shown that the corresponding constraint violations subside after a few orbits,...
Show moreThe starting point of any general relativistic numerical simulation is a solution of the Hamiltonian and momentum constraints that (ideally) represents an astrophysically realistic scenario. This dissertation presents a new method to produce initial data sets for binary neutron stars with arbitrary spins and orbital eccentricities. The method only provides approximate solutions to the constraints. However, it was shown that the corresponding constraint violations subside after a few orbits, becoming comparable to those found in evolutions of standard conformally flat, helically symmetric binary initial data. This dissertation presents the first spinning neutron star binary simulations in circular orbits with a orbital eccentricity less then 0.01. The initial data sets corresponding to binaries with spins aligned, zero and anti-aligned with the orbital angular momentum were evolved in time. These simulations show the orbital “hang-up” effect previously seen in binary black holes. Additionally, they show orbital eccentricities that can be up to one order of magnitude smaller than those found in helically symmetric initial sets evolutions.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004067
- Subject Headings
- Astrophysics, Black holes (Astronomy), General relativity (Physics), Gravitational waves, Neutron stars, Particles (Nuclear physics)
- Format
- Document (PDF)
- Title
- Fire ants on sea turtle nesting beaches in South Florida, USA, and ST. Croix, USVI.
- Creator
- Romais, Danielle K., Wetterer, James K., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The red imported fire ant, Solenopsis invicta, is a South American native introduced in Alabama in the early 20th century. This predatory species has rapidly spread throughout the southeastern US and parts of the West Indies, inflicting great ecological and economic damage. For example, Solenopsis invicta is known to attack the eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests attacking hatchlings and diminishing their chance for survival. My thesis...
Show moreThe red imported fire ant, Solenopsis invicta, is a South American native introduced in Alabama in the early 20th century. This predatory species has rapidly spread throughout the southeastern US and parts of the West Indies, inflicting great ecological and economic damage. For example, Solenopsis invicta is known to attack the eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests attacking hatchlings and diminishing their chance for survival. My thesis research aimed to survey the distribution of ants on sea turtle nesting beaches in South Florida and St. Croix, USVI, and to evaluate the possible threat of Solenopsis invicta and other predatory ants to sea turtle hatchlings.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004052
- Subject Headings
- Biological invasions, Fire ants -- Venom -- Physiological effect, Predation (Biology), Sea turtles -- Florida -- Mortality, Sea turtles -- St. Croix -- Mortality, Wildlife conservation -- Florida, Wildlife conservation -- St. Croix
- Format
- Document (PDF)