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- Title
- "I distinctly remember you!": an investigation of memory for faces with unusual features.
- Creator
- Keif, Autumn., Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
Many errors in recognition are made because various features of a stimulus are attended inefficiently. Those features are not bound together and can then be confused with other information. One of the most common types of these errors is conjunction errors. These happen when mismatched features of memories are combined to form a composite memory. This study tests how likely conjunction errors, along with other recognition errors, occur when participants watch videos of people both with and...
Show moreMany errors in recognition are made because various features of a stimulus are attended inefficiently. Those features are not bound together and can then be confused with other information. One of the most common types of these errors is conjunction errors. These happen when mismatched features of memories are combined to form a composite memory. This study tests how likely conjunction errors, along with other recognition errors, occur when participants watch videos of people both with and without unusual facial features performing actions after a week time lag. It was hypothesized that participants would falsely recognize actresses in the conjunction item condition over the other conditions. The likelihood of falsely recognizing a new person increased when presented with a feature, but the conjunction items overall were most often falsely recognized.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342207
- Subject Headings
- Face perception, Human face recognition, Facial expression, Physiological aspects, Recollection (Psychology)
- Format
- Document (PDF)
- Title
- “I MADE MY OWN LANE AT THE COMMUNITY COLLEGE, DROVE IT, BUT FIGURED OUT I WANTED TO CONTINUE ON FROM THERE:” A NARRATIVE STUDY ON THE HERO’S JOURNEY OF LATINO MALE TRANSFER STUDENTS.
- Creator
- Johnson, Ronald Romances, Salinas Jr., Cristóbal, Floyd, Deborah L., Florida Atlantic University, Department of Educational Leadership and Research Methodology, Charles E. Schmidt College of Science
- Abstract/Description
-
Excelencia in Education (2016) reported that 21% of traditional age college male students were Latino males, second only to White males. The report further noted that Latino males are ranked the lowest in degree attainment – of whom only 20% have earned an associate’s degree or higher (Excelencia in Education, 2016). As an insufficient number of Latino males are graduating with post-secondary degrees, more research must be conducted to explore their educational journey from the community...
Show moreExcelencia in Education (2016) reported that 21% of traditional age college male students were Latino males, second only to White males. The report further noted that Latino males are ranked the lowest in degree attainment – of whom only 20% have earned an associate’s degree or higher (Excelencia in Education, 2016). As an insufficient number of Latino males are graduating with post-secondary degrees, more research must be conducted to explore their educational journey from the community college to the university and how to best support them through their transition. Therefore, the purpose of this qualitative narrative research study was to explore the stories of Latino male students as they transfer from a community college to a university. To capture the essence of Latino male students’ stories through the community college transfer experience to university, the research questions focused on what motivated and influenced their journey through the community college to a university. The research questions that guided this study were: What motivated and influenced Latino males’ decisions to enroll in a community college? What motivated and influenced Latino males’ decisions to transfer from a community college to a university? How do Latino male transfer students describe their transition from community college to a university? In this qualitative narrative research study, 10 participants participated in in-depth, semi-structured virtual interviews and completed two journal prompts. To assist in triangulation and validity, participants reviewed the data for accuracy, and thick rich descriptions were used to provide breadth and depth to their narratives. Once the data were collected, it was organized through the qualitative research data management software MAXQDA and analyzed using in vivo, descriptive, and pattern coding. The conceptual frameworks that informed this narrative study were the hero’s journey by Joseph Campbell (2008) and transition theory by Nancy K. Schlossberg (2011).
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013922
- Subject Headings
- Transfer students, Latin American students, Education, Higher
- Format
- Document (PDF)
- Title
- “IT WOULD BE NICE TO SEE MORE STUFF ABOUT INDIAN CULTURE”: AN EXPLANATORY SEQUENTIAL MIXED METHODS STUDY OF NATIVE AMERICAN STUDENTS’ LIVED EXPERIENCES, MATRICULATION, AND RETENTION.
- Creator
- Coulson-Johnston, Katherine E., Salinas Jr., Cristóbal, Vásquez-Colina, María, Florida Atlantic University, Department of Educational Leadership and Research Methodology, Charles E. Schmidt College of Science
- Abstract/Description
-
The purpose of this explanatory sequential mixed methods study was to understand Native American students’ matriculation, retention, and lived experiences at Sunshine University (SU). Through a sequential design, academic profile, first-generation status, gender, age, campus involvement, enrollment status, and academic major were analyzed in how it predicts matriculation and retention of Native American students at SU. To provide a deeper understanding into Native American students at SU this...
Show moreThe purpose of this explanatory sequential mixed methods study was to understand Native American students’ matriculation, retention, and lived experiences at Sunshine University (SU). Through a sequential design, academic profile, first-generation status, gender, age, campus involvement, enrollment status, and academic major were analyzed in how it predicts matriculation and retention of Native American students at SU. To provide a deeper understanding into Native American students at SU this study centered Native American students’ voices as it relates to their lived experiences in matriculating and persisting at SU. This study used an explanatory sequential mixed methods design. Mixed methods research combines both qualitative and quantitative data collection and analyses (Creswell & Plano Clark, 2007; Ivankova et al., 2006; Merriam & Tisdell, 2016; Teddlie & Tashakkori, 2009). A sequential mixed methods design is conducted through sequences, in this study, phases, beginning with quantitative data collection and analyses and followed by qualitative data collection and analysis (Creswell & Plano Clark, 2007; Ivankova et al., 2006; Merriam & Tisdell, 2016; Teddlie & Tashakkori, 2009). This study was conducted in a three-phrase process: 1) quantitative data collection and analyses; 2) qualitative data collection and analysis; and 3) meta-inference and integration of the phases.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013824
- Subject Headings
- Indians of North America, Students
- Format
- Document (PDF)
- Title
- 1/f structure of temporal fluctuation in rhythm performance and rhythmic coordination.
- Creator
- Rankin, Summer K., Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences
- Abstract/Description
-
This dissertation investigated the nature of pulse in the tempo fluctuation of music performance and how people entrain with these performed musical rhythms. In Experiment 1, one skilled pianist performed four compositions with natural tempo fluctuation. The changes in tempo showed long-range correlation and fractal (1/f) scaling for all four performances. To determine whether the finding of 1/f structure would generalize to other pianists, musical styles, and performance practices, fractal...
Show moreThis dissertation investigated the nature of pulse in the tempo fluctuation of music performance and how people entrain with these performed musical rhythms. In Experiment 1, one skilled pianist performed four compositions with natural tempo fluctuation. The changes in tempo showed long-range correlation and fractal (1/f) scaling for all four performances. To determine whether the finding of 1/f structure would generalize to other pianists, musical styles, and performance practices, fractal analyses were conducted on a large database of piano performances in Experiment 3. Analyses revealed signicant long-range serial correlations in 96% of the performances. Analysis showed that the degree of fractal structure depended on piece, suggesting that there is something in the composition's musical structure which causes pianists' tempo fluctuations to have a similar degree of fractal structure. Thus, musical tempo fluctuations exhibit long-range correlations and fractal scaling. To examine how people entrain to these temporal fluctuations, a series of behavioral experiments were conducted where subjects were asked to tap the pulse (beat) to temporally fluctuating stimuli. The stimuli for Experiment 2 were musical performances from Experiment 1, with mechanical versions serving as controls. Subjects entrained to all stimuli at two metrical levels, and predicted the tempo fluctuations observed in Experiment 1. Fractal analyses showed that the fractal structure of the stimuli was reected in the inter-tap intervals, suggesting a possible relationship between fractal tempo scaling, pulse perception, and entrainment. Experiments 4-7 investigated the extent to which people use long-range correlation and fractal scaling to predict tempo fluctuations in fluctuating rhythmic sequences., Both natural and synthetic long-range correlations enabled prediction, as well as shuffled versions which contained no long-term fluctuations. Fractal structure of the stimuli was again in the inter-tap intervals, with persistence for the fractal stimuli, and antipersistence for the shuffled stimuli. 1/f temporal structure is suficient though not necessary for prediction of fluctuations in a stimulus with large temporal fluctuations.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2705083
- Subject Headings
- Music, Psychological aspects, Emotions in music, Perceptual-motor learning, Computational neuroscience, Synchronization, Musical perception
- Format
- Document (PDF)
- Title
- 2D AND 3D SHAPE VARIATION AMONG ELASMOBRANCH OLFACTORY ROSETTES.
- Creator
- Clark, Aubrey E., Porter, Marianne E., Meredith, Tricia L., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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The functional impacts of olfactory rosette variation in elasmobranchs is unresolved. Our goal was to quantify rosette morphology and shape from 14 species using dissections, phylogenetic comparisons, and microCT imaging. We hypothesized that lamellar count and rosette shape (fineness ratio) would not scale with animal size, but internal rosette size variables must scale positively. We found that fineness ratio and lamellar counts varied significantly among species, and were positively...
Show moreThe functional impacts of olfactory rosette variation in elasmobranchs is unresolved. Our goal was to quantify rosette morphology and shape from 14 species using dissections, phylogenetic comparisons, and microCT imaging. We hypothesized that lamellar count and rosette shape (fineness ratio) would not scale with animal size, but internal rosette size variables must scale positively. We found that fineness ratio and lamellar counts varied significantly among species, and were positively correlated. The first two principal components of the pPCA explained 82% of the variation, with fineness ratio and lamellar count contributing the most. There were no significant differences between rosette structure or volume when comparing dissected values to in situ values obtained using diceCT. Based on our results, we hypothesize that variations in rosette shape and morphology will impact hydrodynamics and optimize odorant detection, and these data can be used to create 3D models for future hydrodynamic studies.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013591
- Subject Headings
- Elasmobranchs, Olfactory sensors, Morphology
- Format
- Document (PDF)
- Title
- 9,11-secogorgosterol biosynthesis in gorgonians.
- Creator
- Kellman, Jaelle, Florida Atlantic University, Kerr, Russell G., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
9,11-secogorgosterol is a secondary metabolite from the gorgonian Pseudopterogorgia americana which acts as a chemical defense. The soft coral lives in a symbiotic association with unicellular algae known as zooxanthellae. A biosynthetic investigation, using in vivo and in vitro methods, has resulted in the identification of the metabolic precursor of 9,11-secogorgosterol as gorgosterol. This finding is significant as it indicates that the conversion of gorgosterol to 9,11-secogorgosterol is...
Show more9,11-secogorgosterol is a secondary metabolite from the gorgonian Pseudopterogorgia americana which acts as a chemical defense. The soft coral lives in a symbiotic association with unicellular algae known as zooxanthellae. A biosynthetic investigation, using in vivo and in vitro methods, has resulted in the identification of the metabolic precursor of 9,11-secogorgosterol as gorgosterol. This finding is significant as it indicates that the conversion of gorgosterol to 9,11-secogorgosterol is due to gorgonian metabolism. Since gorgosterol is known to be a product of zooxanthellae metabolism, this would be the first example of a defensive secondary metabolite being produced by two organisms living in symbiosis. A viable acetone powder has been generated from the crude cell-free extract and has demonstrated the efficient transformation of gorgosterol to 9, 11-secogorgosterol. This indicates possible future value as a synthetic tool for secosterol production.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15180
- Subject Headings
- Sterols--Synthesis, Alcyonacea
- Format
- Document (PDF)
- Title
- A biological mechanism for enhanced wading bird foraging patches in seasonally-pulsed wetlands.
- Creator
- Faughnan, Thomas J., Gawlik, Dale E., Florida Atlantic University, Charles E. Schmidt College of Science, Center for Environmental Studies
- Abstract/Description
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In tropical wetlands, breeding wading birds rely on concentrations of aquatic fauna during the dry season to meet increased energetic demands. Wetland microtopography increases aquatic fauna concentration levels. Crocodilians modify the landscape creating deep-water refugia but their role as a mechanism for aquatic fauna concentration is unknown. I sampled alligator (Alligator mississippiensis) abundance and slough microtopography to examine correlation between the two measures. Despite...
Show moreIn tropical wetlands, breeding wading birds rely on concentrations of aquatic fauna during the dry season to meet increased energetic demands. Wetland microtopography increases aquatic fauna concentration levels. Crocodilians modify the landscape creating deep-water refugia but their role as a mechanism for aquatic fauna concentration is unknown. I sampled alligator (Alligator mississippiensis) abundance and slough microtopography to examine correlation between the two measures. Despite increased microtopography in high alligator use sloughs, the differences were not significant. Using an in situ experimental approach, I quantified the magnitude, timing, and spatial extent of aquatic fauna concentrations within simulated alligator depressions and the surrounding marsh. Aquatic fauna density and biomass were greater within simulated depressions, thus enhancing wading bird foraging habitat. Further understanding the mechanisms creating microtopography, thus enhancing wading bird habitat, is critical to facilitate restoration and prevent declines of wading bird populations in seasonally pulsed wetlands worldwide.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013060
- Subject Headings
- Wading birds., Wetland ecology., American alligator.
- Format
- Document (PDF)
- Title
- A CASE STUDY OF THE COLLEGE CHOICE PROCESS FOR CONTINUING-GENERATION COLLEGE STUDENTS AT MIAMI DADE COLLEGE DURING THE COVID-19 PANDEMIC.
- Creator
- Perez, Georgette T., Floyd, Deborah L., Maslin-Ostrowski, Patricia, Florida Atlantic University, Department of Educational Leadership and Research Methodology, Charles E. Schmidt College of Science
- Abstract/Description
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A review of the literature revealed the need to further explore continuing-generation college students attending community colleges. This case study sought to understand the choice process of continuing-generation, direct-entry college students who enrolled in Miami Dade College (MDC), a baccalaureate community college. This research was planned prior to the COVID-19 pandemic, yet was conducted during the pandemic, creating a unique context for the study. A total of 25 participants were...
Show moreA review of the literature revealed the need to further explore continuing-generation college students attending community colleges. This case study sought to understand the choice process of continuing-generation, direct-entry college students who enrolled in Miami Dade College (MDC), a baccalaureate community college. This research was planned prior to the COVID-19 pandemic, yet was conducted during the pandemic, creating a unique context for the study. A total of 25 participants were interviewed, including continuing-generation students, parents/family members, and high school personnel. This study used Hossler and Gallagher’s (1987) choice model as the conceptual framework to address how and why continuing-generation college students decided to pursue higher education in a community college rather than a traditional four-year college or university. The study derived five findings: financial considerations, addressing affordability and cost in the choice process; family influence and support, describing the role family play in the college selection process; proximity and accessibility, addressing how MDC is a good choice for being “close to home” and being accessible to students who may not have otherwise accessed higher education; institutional reputation, and its importance in the selection process as related to students’ knowledge of MDC, transferability options, faculty and opportunities; and college preparedness, addressing the choice process in terms of student exposure, academic readiness, and college transfer preparedness.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013923
- Subject Headings
- College students, College choice, COVID-19 Pandemic, 2020-, Miami Dade College
- Format
- Document (PDF)
- Title
- A CELL BIOLOGICAL AND ELECTROPHYSIOLOGICAL STUDY OF MOUSE RETINA.
- Creator
- Sullivan, James P., Shen, Wen, Prentice, Howard, Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Both proliferative diabetic retinopathy and exudative age-related macular degeneration are major causes of blindness which are caused by growth of defective, leaky and tortuous blood vessels in the retina. Hypoxia is implicated in triggering both of these diseases and results in induction of HIF-1alpha transcription factor in addition to the angiogenic factor VEGF. Müller cells are the major glial cell in the retina and they contribute to neovascularization in hypoxic regions of the retina...
Show moreBoth proliferative diabetic retinopathy and exudative age-related macular degeneration are major causes of blindness which are caused by growth of defective, leaky and tortuous blood vessels in the retina. Hypoxia is implicated in triggering both of these diseases and results in induction of HIF-1alpha transcription factor in addition to the angiogenic factor VEGF. Müller cells are the major glial cell in the retina and they contribute to neovascularization in hypoxic regions of the retina through eliciting secretion of growth factors, cytokines and angiogenic factors. As Müller cells span the breadth of the retina they can secrete angiostatic factors as well as neuroprotective trophic factors, the Müller cell is a valuable cell type for targeting by potential new gene therapies. The current investigation tests the hypoxia responsiveness of an AAV vector containing a hybrid hypoxia response element together with a GFAP promoter, and this vector encodes the angiostatic protein decorin, a well characterized multi-receptor tyrosine kinase inhibitor. Decorin may have advantages over other key angiostatic factors such as endostatin or angiostatin by virtue of its multiple anti-angiogenic signaling modalities. We employed Q-RT-PCR to evaluate the cell specificity and hypoxia responsiveness of an AAV-Vector termed AAV-REG-Decorin containing a hybrid HRE and GFAP promoter driving expression of the decorin transgene. The vector also contains a silencer element between the HRE and the GFAP domains to enable low basal expression in normoxia as well as high level inducibility in hypoxia. AAV-REGDecorin was found to elicit high level expression of decorin mRNA in hypoxia with greater than 9 – fold induction of the transgene in hypoxic conditions in astrocytes by comparison to normoxic astrocytes. AAV-REG-Decorin showed low levels of transgene expression by comparison to the positive control vector AAV-CMV -decorin containing the ubiquitously active CMV-promoter. The expression levels of decorin mRNA from AAV-REG-Decorin and from AAV-GFAP-Decorin were low in the PC12 neuronal cell model and in the ARPE19 line of retinal pigment epithelial cells with respect to those of AAV-CMV-decorin and no induction of Decorin mRNA was found with AAV-REGDecorin in these two control cell lines. Our novel gene therapy vector will serve as a platform for testing efficacy in rodent disease models (OIR and laser induced choroidal neovascularization) for assessment of the benefits of tightly regulated antiangiogenic gene therapy eliciting decorin transgene expression, both in terms of timing and the cellular source of production, during the progression of the retinal pathophysiology.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013725
- Subject Headings
- Macular Degeneration, Retina, Gene therapy, Decorin
- Format
- Document (PDF)
- Title
- A Comparative Analysis of Monte Carlo and Collapsed Cone Dose Calculation Algorithms for Monaco 3D Treatment Plans.
- Creator
- Pereira, Shakeel, Kyriacou, Andreas, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
The Monaco treatment planning system offers three different dose calculation algorithms for use in calculating 3D treatment plans. These include Monte Carlo (MC), Collapsed Cone (CC) and the pencil beam algorithms. The aim of this study is an in-depth analysis of Monte Carlo and Collapsed Cone dose calculation methods to find the optimal parameters for clinical use for both algorithms. An end-to-end phantom with inhomogeneities was scanned and the DICOM images were imported into Monaco for...
Show moreThe Monaco treatment planning system offers three different dose calculation algorithms for use in calculating 3D treatment plans. These include Monte Carlo (MC), Collapsed Cone (CC) and the pencil beam algorithms. The aim of this study is an in-depth analysis of Monte Carlo and Collapsed Cone dose calculation methods to find the optimal parameters for clinical use for both algorithms. An end-to-end phantom with inhomogeneities was scanned and the DICOM images were imported into Monaco for contouring and planning. Treatment plans were then created in Monaco for both MC and CC using different permutations of variables for approximately 400 plans. These variables include CT Slice thickness, grid size, statistical uncertainty, and beam energy. Following planning the end-to-end phantom was then irradiated on an Elekta Linac and plans for each beam energy were created. Clinical beam data was then compared to the computed plans for each dose calculation method.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014019
- Subject Headings
- Radiotherapy, Radiotherapy Dosage, Radiation dosimetry
- Format
- Document (PDF)
- Title
- A Comparative Study on the Tensile Properties of Shark Skin.
- Creator
- Creager, Shelby, Porter, Marianne C., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Our goal was to assess regional differences in denticle density and skin tensile properties in four coastal species of shark. We hypothesized that the denticle density, tensile strength (MPa), stiffness (MPa), and toughness of skin (MJ·m^-3) would vary regionally along the body of an individual and among species. An hourglass-shaped punch was used to extract the skin samples at 10 anatomical landmarks and denticle density was quantified. Denticle density varied significantly among both...
Show moreOur goal was to assess regional differences in denticle density and skin tensile properties in four coastal species of shark. We hypothesized that the denticle density, tensile strength (MPa), stiffness (MPa), and toughness of skin (MJ·m^-3) would vary regionally along the body of an individual and among species. An hourglass-shaped punch was used to extract the skin samples at 10 anatomical landmarks and denticle density was quantified. Denticle density varied significantly among both regions and species, and showed a significant species by region interaction. Skin samples were tested in tension at a strain rate of 2 mm-s until failure. We found significant species and region effects for all tensile and denticle density properties. Also, denticle density increases with skin stiffness but decreases with toughness. Shark skin toughness is similar to that of mammalian tendons. These data show shark skin functions as an exotendon, able to conserve energy during swimming.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004761, http://purl.flvc.org/fau/fd/FA00004761
- Subject Headings
- Sharks--Anatomy., Sharks--Locomotion., Surfaces (Physics), Biophysics.
- Format
- Document (PDF)
- Title
- A comparison of body proportions in juvenile sea turtles: how shape may optimize survival in a vulnerable life stage.
- Creator
- Pate, Jessica Hope, Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Marine turtles produce many offspring which offsets the high mortality experienced by turtles during early development. Juvenile mortality might be reduced by evolving effective behavioral as well as morphological anti-predator defenses. Body proportions of three species (Caretta caretta, Chelonia mydas, Dermochelys coriacea) of turtles were measured in the first fourteen weeks of development to examine how growth may mitigate predation by gape-limited predators. Growth was categorized as...
Show moreMarine turtles produce many offspring which offsets the high mortality experienced by turtles during early development. Juvenile mortality might be reduced by evolving effective behavioral as well as morphological anti-predator defenses. Body proportions of three species (Caretta caretta, Chelonia mydas, Dermochelys coriacea) of turtles were measured in the first fourteen weeks of development to examine how growth may mitigate predation by gape-limited predators. Growth was categorized as isometric if shape did not change during development or allometric if body shape did change. All three species showed allometric growth in carapace width; however it was less pronounced in the larger D. coriacea turtles. Allometric growth in carapace width decreased as all three species grew in size. When high predation occurs in early development, many species will favor rapid growth into a size refuge. Juvenile sea turtles may optimize their survival by growing allometrically when predation risk is the greatest.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004223, http://purl.flvc.org/fau/fd/FA00004223
- Subject Headings
- Predation (Biology), Sea turtles -- Growth, Sea turtles -- Mortality, Sea turtles -- Population viability analysis
- Format
- Document (PDF)
- Title
- A COMPARISON OF TASK RELEVANT NODE IDENTIFICATION TECHNIQUES AND THEIR IMPACT ON NETWORK INFERENCES: GROUP-AGGREGATED, SUBJECT-SPECIFIC, AND VOXEL WISE APPROACHES.
- Creator
- Falco, Dimitri, Bressler, Steven L., Florida Atlantic University, Center for Complex Systems and Brain Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The dissertation discusses various node identification techniques as well as their downstream effects on network characteristics using task-activated fMRI data from two working memory paradigms: a verbal n-back task and a visual n-back task. The three node identification techniques examined within this work include: a group-aggregated approach, a subject-specific approach, and a voxel wise approach. The first chapters highlight crucial differences between group-aggregated and subject-specific...
Show moreThe dissertation discusses various node identification techniques as well as their downstream effects on network characteristics using task-activated fMRI data from two working memory paradigms: a verbal n-back task and a visual n-back task. The three node identification techniques examined within this work include: a group-aggregated approach, a subject-specific approach, and a voxel wise approach. The first chapters highlight crucial differences between group-aggregated and subject-specific methods of isolating nodes prior to undirected functional connectivity analysis. Results show that the two techniques yield significantly different network interactions and local network characteristics, despite having their network nodes restricted to the same anatomical regions. Prior to the introduction of the third technique, a chapter is dedicated to explaining the differences between a priori approaches (like the previously introduced group-aggregated and subject-specific techniques) and no a priori approaches (like the voxel wise approach). The chapter also discusses two ways to aggregate signal for node representation within a network: using the signal from a single voxel or aggregating signal across a group of neighboring voxels. Subsequently, a chapter is dedicated to introducing a novel processing pipeline which uses a data driven voxel wise approach to identify network nodes. The novel pipeline defines nodes using spatial temporal features generated by a deep learning algorithm and is validated by an analysis showing that the isolated nodes are condition and subject specific. The dissertation concludes by summarizing the main takeaways from each of the three analyses as well as highlighting the advantages and disadvantages of each of the three node identification techniques.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013553
- Subject Headings
- Functional magnetic resonance imaging, Brain mapping, Working memory, Neural networks (Neurobiology), Neuroimaging--methods
- Format
- Document (PDF)
- Title
- A Computational Study on Different Penalty Approaches for Constrained Optimization in Radiation Therapy Treatment Planning with a Simulated Annealing Algorithm.
- Creator
- Mohammadi Khoroushadi, Mohammad Sadegh, Kalantzis, Georgios, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Intensity modulated radiation therapy (IMRT) is a cancer treatment method in which the intensities of the radiation beams are modulated; therefore these beams have non-uniform radiation intensities. The overall result is the delivery of the prescribed dose in the target volume. The dose distribution is conformal to the shape of the target and minimizes the dose to the nearby critical organs. An inverse planning algorithm is used to obtain those non-uniform beam intensities. In inverse...
Show moreIntensity modulated radiation therapy (IMRT) is a cancer treatment method in which the intensities of the radiation beams are modulated; therefore these beams have non-uniform radiation intensities. The overall result is the delivery of the prescribed dose in the target volume. The dose distribution is conformal to the shape of the target and minimizes the dose to the nearby critical organs. An inverse planning algorithm is used to obtain those non-uniform beam intensities. In inverse treatment planning, the treatment plan is achieved by using an optimization process. The optimized plan results to a high-quality dose distribution in the planning target volume (PTV), which receives the prescribed dose while the dose that is received by the organs at risk (OARs) is reduced. Accordingly, an objective function has to be defined for the PTV, while some constraints have to be considered to handle the dose limitations for the OARs.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004765
- Subject Headings
- Image-guided radiation therapy., Radiation--Dosage., Mathematical optimization., Evolutionary programming (Computer science), Medical physics., Medical radiology--Data processing.
- Format
- Document (PDF)
- Title
- A Constructive Theory of Ordered Sets and their Completions.
- Creator
- Joseph, Jean S., Richman, Fred, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
The context for the development of this work is constructive mathematics without the axiom of countable choice. By constructive mathematics, we mean mathematics done without the law of excluded middle. Our original goal was to give a list of axioms for the real numbers R by only considering the order on R. We instead develop a theory of ordered sets and their completions and a theory of ordered abelian groups.
- Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013007
- Subject Headings
- Constructive mathematics, Ordered sets, Abelian groups
- Format
- Document (PDF)
- Title
- A CORRELATIONAL ANALYSIS OF TEACHER JOB SATISFACTION AND JOB STRESS IN BROWARD COUNTY SCHOOLS.
- Creator
- Rodney-Hillaire, Renee, Shockley, Robert, Bogotch, Ira, Florida Atlantic University, Department of Educational Leadership and Research Methodology, Charles E. Schmidt College of Science
- Abstract/Description
-
This study aimed to analyze factors that predict job satisfaction and stress among Broward County teachers. A modified version of the WeBS survey was used to collect data on teachers' demographics, attitudes, and experiences related to job satisfaction. The sample used in this study was delimited to include only full-time teachers in Broward County Schools. Six research questions provided the foundation of the study, which was operationalized by Astin's (1993) input environment outcome model ...
Show moreThis study aimed to analyze factors that predict job satisfaction and stress among Broward County teachers. A modified version of the WeBS survey was used to collect data on teachers' demographics, attitudes, and experiences related to job satisfaction. The sample used in this study was delimited to include only full-time teachers in Broward County Schools. Six research questions provided the foundation of the study, which was operationalized by Astin's (1993) input environment outcome model (IEO). A descriptive analysis described the sample's individual and institutional characteristics and demographics. Correlational analyses were conducted to determine the strength of the relationship between variables. Finally, the data were analyzed using hierarchical, multiple regression. The regression model explored factors predicting job satisfaction and job stress among teachers. This study reported statistically significant results for each regression model. Statistically significant at p < .001, the factors that explained 55% of the variance in the final job satisfaction model included: How do background characteristics (e.g., sex, ethnic origin, and age), behavioral factors (e.g., openness, intrinsic motivation), and institutional variables (autonomy, student behavior, leadership, and school climate and culture) predict teacher job stress in Broward County? Implications for policy, practice and future research regarding job satisfaction and stress are included.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013959
- Subject Headings
- Teachers--Job satisfaction, Broward County (Fla.), Teachers--Job stress
- Format
- Document (PDF)
- Title
- A DISINHIBITORY MICROCIRCUIT FOR GATED CEREBELLAR LEARNING.
- Creator
- Zhang, Ke, Christie, Jason, Dawson-Scully, Ken, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Performance motor errors trigger animals’ adaptive learning behaviors to improve the accuracy and efficiency of the movement. The cerebellum is one of the key brain centers for encoding motor performance and motor learning. Climbing fibers relay information related to motor errors to the cerebellar cortex, evoking elevation of intracellular Ca2+ signals at Purkinje cell dendrites and inducing plasticity at coactive parallel fiber synapses, ultimately recalibrating sensorimotor associations to...
Show morePerformance motor errors trigger animals’ adaptive learning behaviors to improve the accuracy and efficiency of the movement. The cerebellum is one of the key brain centers for encoding motor performance and motor learning. Climbing fibers relay information related to motor errors to the cerebellar cortex, evoking elevation of intracellular Ca2+ signals at Purkinje cell dendrites and inducing plasticity at coactive parallel fiber synapses, ultimately recalibrating sensorimotor associations to alter behavior. Molecular layer interneurons (MLIs) inhibit Purkinje cells to modulate dendritic excitability and action potential output. How MLIs contribute to the regulation and encoding of climbing fiber-evoked adaptive movements remains poorly understood. In this dissertation, I used genetic tools to manipulate the activity of MLIs while monitoring Purkinje cell dendritic activity during a cerebellum-dependent motor learning task with different contexts to evaluate how MLIs are involved in this process. The results show that by suppressing dendritic Ca2+ signals in Purkinje cells, MLI activity coincident with climbing fiber-mediated excitation prevents the occurrence of learning when adaptation is not necessary. On the other hand, with error signals present, disinhibition onto Purkinje cells, mediated by MLI-MLI microcircuit, unlocked the ability of climbing fibers to induce plasticity and motor learning.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013526
- Subject Headings
- Cerebellum, Interneurons, Purkinje cells, Dendrites, Sensorimotor integration, Neuroplasticity
- Format
- Document (PDF)
- Title
- A Dosimetric Comparison of 3D-CRT, IMRT, and SAVI HDR via NTCP/TCP and DVH Analysis of Critical Organs for Breast Cancer.
- Creator
- Wisnoskie, Sarah, Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
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Accelerated Partial Breast Irradiation (APBI) is a common treatment of breast cancer with many modalities including 3D Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), and High Dose Rate Brachytherapy (HDR). In this research, a retrospective analysis of patient’s data was performed to analyze the NTCP/TCP (Normal Tissue Complication Probability/Tumor Control Probability) and Dose Volume Histogram (DVH) parameters for HDR with SAVI, 3D, and IMRT and compare...
Show moreAccelerated Partial Breast Irradiation (APBI) is a common treatment of breast cancer with many modalities including 3D Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), and High Dose Rate Brachytherapy (HDR). In this research, a retrospective analysis of patient’s data was performed to analyze the NTCP/TCP (Normal Tissue Complication Probability/Tumor Control Probability) and Dose Volume Histogram (DVH) parameters for HDR with SAVI, 3D, and IMRT and compare them focusing on critical organs such as the heart, ipsilateral lung, chest wall, ribs, and skin. TCP was 90.275%, 55.948%, and 53.369% for HDR, 3D, and IMRT respectively. The ribs were the most sensitive critical organ for all 3 modalities with a mean NTCP of 8%, 15%, and 8% for HDR, 3D, and IMRT respectively. DVH analysis showed HDR spares critical organs more than EBRT except for 2 patients receiving high doses to the ribs and chest wall.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013281
- Subject Headings
- Radiation dosimetry--Evaluation, Breast--Cancer--Treatment, Organs, Tissues--Effect of radiation on
- Format
- Document (PDF)
- Title
- A dosimetric study of a heterogeneous phantom for lung stereotactic body radiation therapy comparing Monte Carlo and pencil beam calculations to dose distributions measured with a 2-d diode array.
- Creator
- Curley, Casey Michael, Ouhib, Zoubir, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
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Monte Carlo (MC) and Pencil Beam (PB) calculations are compared to their measured planar dose distributions using a 2-D diode array for lung Stereotactic Body Radiation Therapy (SBRT). The planar dose distributions were studied for two different phantom types: an in-house heterogeneous phantom and a homogeneous phantom. The motivation is to mimic the human anatomy during a lung SBRT treatment and incorporate heterogeneities into the pre-treatment Quality Assurance process, where measured and...
Show moreMonte Carlo (MC) and Pencil Beam (PB) calculations are compared to their measured planar dose distributions using a 2-D diode array for lung Stereotactic Body Radiation Therapy (SBRT). The planar dose distributions were studied for two different phantom types: an in-house heterogeneous phantom and a homogeneous phantom. The motivation is to mimic the human anatomy during a lung SBRT treatment and incorporate heterogeneities into the pre-treatment Quality Assurance process, where measured and calculated planar dose distributions are compared before the radiation treatment. Individual and combined field dosimetry has been performed for both fixed gantry angle (anterior to posterior) and planned gantry angle delivery. A gamma analysis has been performed for all beam arrangements. The measurements were obtained using the 2-D diode array MapCHECK 2™.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004360
- Subject Headings
- Cancer -- Radiotherapy, Drug development -- Computer simulation, Image guided radiation therapy, Ion bombardment, Lung cancer -- Treatment, Medical physics, Monte Carlo method, Proton beams
- Format
- Document (PDF)
- Title
- A Framework for Understanding Power Supply and Demand in Presynaptic Nerve Terminals.
- Creator
- Justs, Karlis Anthony, Macleod, Gregory T., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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The molecular mechanisms of synaptic function and development have been studied extensively, but little is known about the energy requirements of synapses, or the mechanisms that coordinate their energy production with their metabolic demands. These are oversights, as synapses with high energy demands are more susceptible to degeneration and degrade in the early stages of diseases such as amyotrophic lateral sclerosis, spinal muscle atrophy and Parkinson’s disease. Here, in a structure...
Show moreThe molecular mechanisms of synaptic function and development have been studied extensively, but little is known about the energy requirements of synapses, or the mechanisms that coordinate their energy production with their metabolic demands. These are oversights, as synapses with high energy demands are more susceptible to degeneration and degrade in the early stages of diseases such as amyotrophic lateral sclerosis, spinal muscle atrophy and Parkinson’s disease. Here, in a structure-function study at Drosophila motor neuron terminals, a neurophysiological model was generated to investigate how power (ATP/s) supply is integrated to satisfy the power demand of presynaptic terminals. Power demands were estimated from six nerve terminals through direct measurements of neurotransmitter release and Ca2+ entry, as well as theoretical estimation of Na+ entry and power demands at rest (cost of housekeeping). The data was leveraged with a computational model that simulated the power demands of the terminals during their physiological activity, revealing high volatility in which power demands can increase 15-fold within milliseconds as neurons transition from rest to activity. Another computational model was generated that simulated ATP production scenarios regarding feedback to the power supply machinery (Oxphos and glycolysis) through changes in nucleotide concentrations, showing that feedback from nucleotides alone fail to stimulate power supply to match the power demands of each terminal. Failure of feedback models invokes the need for feed forward mechanisms (such as Ca2+) to stimulate power supply machinery to match power demands. We also quantified mitochondrial volume, density, number and size in each nerve terminal, revealing all four features positively correlate with the terminals power demands. This suggests the terminals enhance their oxidative capacity by increasing mitochondrial content to satisfy their power demands. And lastly, we demonstrate that abolishing an ATP buffering system (the phosphagen system) does not impair neurotransmission in the nerve terminals, suggesting motor nerve terminals are capable of satisfying their power demands without the ATP buffering system.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013323
- Subject Headings
- Presynaptic Terminals, Adenosine triphosphate, Synapses--metabolism, Bioenergetics
- Format
- Document (PDF)