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- Title
- What Controls The Nocturnal Emergence Rhythm Of Hatchling Marine Turtles?.
- Creator
- Prio, Joseph D., Salmon, Michael, Graduate College
- Abstract/Description
-
Most marine organisms partition particular activities, such as growth, migration, reproduction, and hatching, to particular seasons, times of the day or night, or phases of the lunar cycle. The result is characterized as a “rhythm”. Scientists who study these rhythms generally ask two kinds of questions: why do they occur when they do that is, what is their survival value, and how are they controlled, physiologically? Hatchling marine turtles almost always emerge from their nests at night,...
Show moreMost marine organisms partition particular activities, such as growth, migration, reproduction, and hatching, to particular seasons, times of the day or night, or phases of the lunar cycle. The result is characterized as a “rhythm”. Scientists who study these rhythms generally ask two kinds of questions: why do they occur when they do that is, what is their survival value, and how are they controlled, physiologically? Hatchling marine turtles almost always emerge from their nests at night, then crawl down the beach to the sea and migrate offshore. By doing so at night they avoid lethally warm beach sands and diurnally active predators in the shallows. But these “survival value” explanations do not account for how the turtles, digging their way upward inside the nest toward the beach surface, know that it’s dark and time to emerge. The classic explanation for how they “know” is based upon surface sand temperatures. During the day, these sands can be very warm 50° C. When hatchlings digging upward encounter these heated sands, they stop digging until the sand cools, after sunset. But these observations fail to explain why in most studies, hatchlings rarely emerge from their nests at dawn or in the early morning, when the sand is still cool. To account for those observations, we hypothesize that the turtles must also possess a time sense that inhibits emergence during inappropriate times, such as shortly before or after sunrise.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005909
- Format
- Document (PDF)
- Title
- Vegetation Community Changes in Response to Hydrology at the A.R.M. Loxahatchee National Wildlife Refuge.
- Creator
- Kepley, Janna Ellis, Hindle, Tobin, Graduate College
- Abstract/Description
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A spatial analysis of vegetation community changes over time at the Arthur R. Marshall National Loxahatchee Wildlife Refuge will be conducted in order to identify relationships with variations in water level and water quality. The analysis will use existing current and historical data in the refuge, including water gages, vegetation surveys, fire burn data, Lidar based digital elevation data and aerial photography acquired from the United States Fish and Wildlife Service, Everglades Depth...
Show moreA spatial analysis of vegetation community changes over time at the Arthur R. Marshall National Loxahatchee Wildlife Refuge will be conducted in order to identify relationships with variations in water level and water quality. The analysis will use existing current and historical data in the refuge, including water gages, vegetation surveys, fire burn data, Lidar based digital elevation data and aerial photography acquired from the United States Fish and Wildlife Service, Everglades Depth Estimation Network EDEN, South Florida Water Management District and other sources. Understanding how vegetation boundaries and dominant species shift over time in response to water level changes and other hydrological factors will allow the National Wildlife Refuge, and other scientists, to create more responsive conservation and maintenance plans for the wetland refuge.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005889
- Format
- Document (PDF)
- Title
- Utilizing Hyperspectral Reflectance to Analyze Sand Composition.
- Creator
- Smith, Molly E., Selch, Donna, Graduate College
- Abstract/Description
-
Spectral signatures quickly aid the analysis of sand composition because specific wavelengths correspond with distinct minerals. This provides objectivity to traditional microscopic methods, with the option to create a custom spectral library for Hyperspectral Remote Sensing HRS applications. Removal of salt as a precipitated solid from sea water is useful for clearer microscopic viewing of sand because certain grains are less likely to be misidentified as crystalized salt. Though removal of...
Show moreSpectral signatures quickly aid the analysis of sand composition because specific wavelengths correspond with distinct minerals. This provides objectivity to traditional microscopic methods, with the option to create a custom spectral library for Hyperspectral Remote Sensing HRS applications. Removal of salt as a precipitated solid from sea water is useful for clearer microscopic viewing of sand because certain grains are less likely to be misidentified as crystalized salt. Though removal of salts aids in qualitative visual identification, it is problematic for studies requiring spectral reflectance data to match real-life conditions. Spectroradiometric techniques were used to assess the effects of salt in spectral signatures of sand. Sand samples of mixed siliciclastic-carbonate composition were collected from 15 locations across the southeastern Florida coast. Spectral plots were generated from laboratory collected data with an ASD Spectroradiometer. Spectral data was collected before and after samples were prepared for microscopic study. Laboratory-prepared samples show negative slope at approximately 1500 nm and 2000 nm ranges on the generated plots. These wavelengths are indicative of grains having either predominately carbonate or siliciclastic compositions, which agrees with the microscopic analysis. Salts present in a sample affect the spectral signature, thus salt removal yields spectral plots not necessarily concurrent with plots generated from raw, unprepared samples. For studies utilizing airborne HRS data, the order of data collection and preparation is important. To ensure a more precise match between the spectral library and the hyperspectral imagery, spectral data must be collected before the sample is prepared for microscopic analysis.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005913
- Format
- Document (PDF)
- Title
- Using an immunohistochemical approach to identify the sex of marine turtles.
- Creator
- Tezak, Boris, Wyneken, Jeanette, Graduate College
- Abstract/Description
-
Marine turtles exhibit temperature-dependent sex determination (TSD). During critical periods of embryonic development, the nest’s thermal environment directs whether an embryo will develop as a male or a female. At warmer sand temperatures the nest tends to produce female-biased sex ratios. The rapid increase of global temperature highlights the need for a clear assessment of effects on sea turtle sex ratios. However, identifying hatchling sex ratios at rookeries remain coarse estimates due...
Show moreMarine turtles exhibit temperature-dependent sex determination (TSD). During critical periods of embryonic development, the nest’s thermal environment directs whether an embryo will develop as a male or a female. At warmer sand temperatures the nest tends to produce female-biased sex ratios. The rapid increase of global temperature highlights the need for a clear assessment of effects on sea turtle sex ratios. However, identifying hatchling sex ratios at rookeries remain coarse estimates due to the lack of any external gender markers. We rely mainly upon laparoscopic procedures to verify a hatchling sex; however, in some species, morphological sex can be ambiguous even at the histological level. Recent studies using immunohistochemical techniques identified that red-eared slider (Trachemys scripta) embryos over-expressed a particular cold-induced RNA binding protein in the ovaries in comparison to the testes. This principle allows the distinction between females and males. We developed a variation of this technique and successfully identified the sexes of loggerhead sea turtle (Caretta caretta) hatchlings, as confirmed by standard histological and laparoscopic methods that reliably identifies the sex in this species. Next, we tested a more challenging species, the leatherback turtle (Dermochelys coriacea), which retains many neotenic features. The morphology of leatherback hatchling gonads remains difficult to interpret, particularly when dead-in-nest hatchlings and embryos are the source tissues. In summary, this new and more efficient technique enhances our ability to investigate and identify baseline hatchling sex ratios, a critical progression in assessing global climate change on sea turtle populations.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005915
- Format
- Document (PDF)
- Title
- Use Of Molecular Techniques To Understand The Spatial And Temporal Features Of The Oceanic Stage In Hawksbill Sea Turtles, Eretmochelys Imbricata; A Thesis Proposal.
- Creator
- Coppenrath, Christina, Salmon, Michael, Graduate College
- Abstract/Description
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For highly migratory species, it is important to understand what habitats are used and what requirements are essential for growth and development. These migrations often span different political and regulatory boundaries, complicating conservation strategies. The hatchlings and post-hatchlings of most sea turtle species migrate to oceanic habitats where they remain for several years before returning to shallow developmental habitats. For critically endangered hawksbill turtle, Eretmochelys...
Show moreFor highly migratory species, it is important to understand what habitats are used and what requirements are essential for growth and development. These migrations often span different political and regulatory boundaries, complicating conservation strategies. The hatchlings and post-hatchlings of most sea turtle species migrate to oceanic habitats where they remain for several years before returning to shallow developmental habitats. For critically endangered hawksbill turtle, Eretmochelys imbricata, most research has concentrated on nesting ecology and very little is known about the posthatchling migration. Many sea turtles then spend years in different foraging habitats before reaching sexual maturity, and such foraging grounds typically represent a mixed stock of turtles from different nesting beaches. Mitochondrial DNA analysis can be used to estimate genetic stock structure of mixedstock foraging populations for sea turtles, and the duration of the post-hatchling oceanic stage can be estimated using stable isotope analysis and satellite telemetry. Our objectives are to determine the duration of the post-hatchling oceanic stage of development, to determine if the turtles sampled in a particular foraging habitat represent a biased or unbiased assortment of matrilineages, and to infer potential migratory pathways by investigating ocean currents between nesting beaches and the foraging site. Here we discuss our methods, to determine the duration of the post-hatchling oceanic stage and stock structure for immature hawksbills at a developmental foraging ground.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005873
- Format
- Document (PDF)
- Title
- Travel-time Based Signal Performance Measures (TTSPM).
- Creator
- Petrovska, Natasha, Stevanovic, Aleksandar, Graduate College
- Abstract/Description
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Vehicle travel time on arterial roads with signalized intersections is an essential parameter for traffic management. There is an increasing interest in signal performance measurement for signalized intersections in the United States. Reducing the journey times and increasing the capacity are some of the fundamental aims with potential benefits in environmental pollution, and energy utilization. The Travel-time Based Signal Performance Measures application is a tool for estimating signal...
Show moreVehicle travel time on arterial roads with signalized intersections is an essential parameter for traffic management. There is an increasing interest in signal performance measurement for signalized intersections in the United States. Reducing the journey times and increasing the capacity are some of the fundamental aims with potential benefits in environmental pollution, and energy utilization. The Travel-time Based Signal Performance Measures application is a tool for estimating signal performance measures based on upstream-link travel times. The application utilizes well known concept of Volume- Delay Functions to convert measured travel times into signal performance measures. Based on this functionality, it can estimate the performance measures for 7 signalized intersections on Glades Road, Boca Raton, Florida. Available performance measures for the major through movements are: volumeto- capacity ratio, Level of Service LOS, and the number of cycles to wait. The derived measures can be graphically visualized on Google Maps. The travel time data acquisition is performed using BlueTOAD devices. The goal is to introduce automated assessment tool, visualization and evaluation of the intersections’ performance measures simultaneously at multiple intersections. The main objective of this web application is to help traffic operators/engineers to evaluate performance of the signalized corridors exploiting the archived measured travel times.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005907
- Format
- Document (PDF)
- Title
- TLR agonists differentially induce maturation of nicotine-exposed dendritic cell.
- Creator
- Tamjidi, Saba, Nourishirazi, Erika, Graduate College, Bible, Brittany, Zeng, Menghua, Nouri-Shirazi, Mahyar
- Abstract/Description
-
Background: Vaccines aid in saving lives from infections and biological warfare attacks. They should be effective in all target populations otherwise the likelihood that an unprotected person will transmit disease to a vulnerable individual is greatly increased. There is compelling evidence that smokers are less responsive to vaccination. We have reported that both therapeutic and prophylactic vaccines fail to protect and cure animals from disease due to negative effects of nicotine in...
Show moreBackground: Vaccines aid in saving lives from infections and biological warfare attacks. They should be effective in all target populations otherwise the likelihood that an unprotected person will transmit disease to a vulnerable individual is greatly increased. There is compelling evidence that smokers are less responsive to vaccination. We have reported that both therapeutic and prophylactic vaccines fail to protect and cure animals from disease due to negative effects of nicotine in biological activities of DCs. Using in vitro mouse culture system we have identified an appropriate TLR agonist capable of correcting the defects in DCs exposed to nicotine. Hypothesis: In order to translate these studies to human, we tested the hypothesis that appropriate TLR agonists will also correct the degrading effects of nicotine on human DCs and consequently DC-NK cross talk and T cell polarization. Methods: Monocyte-derived DCs were generated in culture media containing growth factors GM-CSF and IL-4 with or without nicotine treatment. DCs were activated with indicated TLR agonists and their phenotypes and cytokine profiles were analyzed by flow cytometry and ELISA, respectively. Results: Among the TLR agonists tested, we found that nicotine has less effect on human DC maturation in response to TLR4 plus TLR7/8 agonists as evidenced by expression levels of their costimulatory CD80/83/86/40 and antigen-presenting HLA-DR molecules as well as inflammatory cytokines IL-12, IL-10,TNF-α and IL-1β production. Conclusion: We are currently investigating whether these TLR agonists also augment human DC-NK bidirectional signals essential for T cell differentiation in a nicotinic environment.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005169
- Format
- Document (PDF)
- Title
- Tissue-specific requirement of the autophagy gene atg-18 in controlling C. elegans dauer morphogenesis, fat metabolism and adult longevity.
- Creator
- Minnerly, Justin, Zhang, Jiuli, Graduate College, Jia, Kailiang
- Abstract/Description
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The conserved insulin growth factor IGF signaling pathway is one of the major regulators of lifespan in many species including C. elegans. In C. elegans the insulin/IGF-like receptor is encoded by the daf-2 gene, mutations in which result in lifespan extension, fat accumulation and dauer formation. The daf-2 activity in the nervous system controls these phenotypes cell non-autonomously. Interestingly, the longevity phenotype of daf-2 mutant worms is dependent on macroautophagy hereafter...
Show moreThe conserved insulin growth factor IGF signaling pathway is one of the major regulators of lifespan in many species including C. elegans. In C. elegans the insulin/IGF-like receptor is encoded by the daf-2 gene, mutations in which result in lifespan extension, fat accumulation and dauer formation. The daf-2 activity in the nervous system controls these phenotypes cell non-autonomously. Interestingly, the longevity phenotype of daf-2 mutant worms is dependent on macroautophagy hereafter autophagy. Autophagy is a highly conserved lysosomal degradation pathway involved in the removal of long-lived proteins and cytoplasmic organelles. During autophagy, cellular components are sequestered into the double-membrane autophagosomes and delivered to lysosomes for degradation. Increasing evidence has emerged that the autophagy process is a central regulator of lifespan that is required for the effects of DAF-2 signaling, dietary restriction and some mitochondrial mutations on C. elegans longevity. It is unknown however whether autophagy activity in every tissue or in a single tissue mediates the influence of these longevity signals. To address this question, we examined the tissue requirement of autophagy gene atg-18 for the lifespan of wild type animals and the daf-2 mutant. We discovered that neurons and intestinal cells are two key tissues where atg-18 mediates the effect of DAF-2 insulin-like signaling on lifespan, fat accumulation and dauer morphogenesis, suggesting autophagy acts cell non-autonomously in controlling C. elegans dauer formation, fat metabolism and adult longevity.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005160
- Format
- Document (PDF)
- Title
- The Role of the Nurse Navigator: Reducing 30-Day Readmissions?.
- Creator
- Leavitt, Mary Ann M., Graduate College
- Abstract/Description
-
The aim of this study is to compare readmission rates for patients who transition home from the hospital under the care of the Heart Failure Nurse Navigator (HFNN) with patients who receive usual home health care. Heart failure (HF) accounts for 20% of all hospital admissions and is the most common diagnosis associated with a 30-day readmission of Medicare patients. Nationally, 24.7% of patients with HF are readmitted within 30 days. The AHA and ACCF recognize a critical need for evidence...
Show moreThe aim of this study is to compare readmission rates for patients who transition home from the hospital under the care of the Heart Failure Nurse Navigator (HFNN) with patients who receive usual home health care. Heart failure (HF) accounts for 20% of all hospital admissions and is the most common diagnosis associated with a 30-day readmission of Medicare patients. Nationally, 24.7% of patients with HF are readmitted within 30 days. The AHA and ACCF recognize a critical need for evidence identifying best processes of care in transition from hospital to home. The comprehensive NN role not only teaches the patient to adapt to the prescribed medical protocol, but also provides connectedness and relationship. Home health nurses taught to perform the role of a HFNN may improve coordination of post-hospital care and patient outcomes. The research design will be sequential mixedmethod. Phase I will be a quantitative, quasi-experimental randomized study of the effect of HFNN on 30-day readmissions. Pre- and post-testing for HF self-care knowledge and quality-of-life will be analyzed by repeated ANOVA. Independent T-tests will compare readmission rates between groups. Phase II will be a qualitative study of transitioning home under the care of the HFNN. Intervention patients will be invited to focus groups, and their responses to semi-structured questions will be coded using conventional content analysis. It is hoped that the quantitative portion of the study will demonstrate that the HFNN intervention will keep more patients out of the hospital for at least 30 days and improve the HF self-care knowledge and quality of life. The qualitative portion may uncover unknown elements of the HFNN/patient dynamic, as well as themes helpful in formulating further questions about care of the patient with HF.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005894
- Format
- Document (PDF)
- Title
- The Nurse Practitioner Holistic Caring Instrument: A Pilot Study.
- Creator
- Kinchen, Elizabeth V., Graduate College
- Abstract/Description
-
Holistic care has long been a defining attribute of nursing practice. From the earliest years of its
formal history, nursing has favored a holistic approach in the care of patients, an approach that is grounded in relationship and considers the interconnectedness of mind, body, and spirit. With passage of the Patient Protection and Affordable Care Act PPACA and the publication of the Institute of Medicine’s report on the future of nursing, nurses are slated to take on an expanded role in...
Show moreHolistic care has long been a defining attribute of nursing practice. From the earliest years of its
formal history, nursing has favored a holistic approach in the care of patients, an approach that is grounded in relationship and considers the interconnectedness of mind, body, and spirit. With passage of the Patient Protection and Affordable Care Act PPACA and the publication of the Institute of Medicine’s report on the future of nursing, nurses are slated to take on an expanded role in healthcare delivery in the near future. Nurse practitioners, in particular, will be instrumental in filling the gap in primary care availability engendered by the increasing specialization of physician practice and increased access to healthcare made possible by the provisions of the PPACA.
This pilot study used a Content Validity Index CVI, with a convenience sample of experts n8 in Nurse Practitioner care and Holistic Nursing practice, to evaluate the Nurse Practitioner Holistic Caring Instrument NPHCI, a new, investigator-developed measure of the holistic attributes of Nurse Practitioner care. Analysis of CVI responses revealed that the majority of participants were in perfect agreement 1.00 in rating the scale as a whole as ‘content relevant’. In addition, 14 out of 19 instrument items were accorded a perfect score of 1.00. Free-text responses were also solicited in evaluating validity of the instrument. Results from this pilot study indicate that the NPHCI has sufficient validity to render it eligible for use in a larger study, surveying patients on holistic attributes of Nurse Practitioner care.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005152
- Format
- Document (PDF)
- Title
- The Evolution of Brand Strategy.
- Creator
- Cherniavsky, Vanessa, Jolly, Ishraaj, Graduate College, Smith, Allen E.
- Abstract/Description
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This paper is an exploration of how the definition of an experience has changed over time and the impact this change has had on experiential marketing and branding. In the literature, there are numerous implications as to what this morphing definition means to businesses and how businesses should react in order to stay competitive in a society that is hyper stimulated. Research into what defines an experience and the impact this definition has on business is vital because in order for...
Show moreThis paper is an exploration of how the definition of an experience has changed over time and the impact this change has had on experiential marketing and branding. In the literature, there are numerous implications as to what this morphing definition means to businesses and how businesses should react in order to stay competitive in a society that is hyper stimulated. Research into what defines an experience and the impact this definition has on business is vital because in order for businesses to offer innovative experiences they need to understand what an experience is and the role it plays in the success of their organization. Furthermore, a deep understanding of what comprises an experience and how to manipulate those elements to create a unique and targeted experience are tools a company could use to reinvent itself, change its brand meaning, and rewrite its marketing strategy.
The evolution of marketing and branding has taken an exponential leap since technology changed the way society functions. A wide breadth of literature is dedicated to virtual experiences and internet based branding and marketing advances. In addition to virtual experiences, this paper will also explore the success of experience based brands such as Disney and Lexus. The implications of this success have gone beyond name brands and into niche markets. Finally, the paper will explore the implications these findings have for managers. Our hypothesis is that marketing and delivering a complete experience is more vital in the modern business world than it used to be.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005142
- Format
- Document (PDF)
- Title
- The effect of parasite infection on reproductive potential of bony fish.
- Creator
- Young, Joy M., Whittington, Jim, Graduate College, Hughes, Colin
- Abstract/Description
-
Accurate predictions of population growth, including reproduction, are vital for the effective management of fisheries. However, factors effecting reproductive potential in boney fishes are not entirely understood. In several species of fish, parasite infection has been associated with decreased fecundity including fewer and smaller eggs, shortened spawning season, and decreased larval survival. We examined the effect of parasite infection and life history parameters on egg quality of 40...
Show moreAccurate predictions of population growth, including reproduction, are vital for the effective management of fisheries. However, factors effecting reproductive potential in boney fishes are not entirely understood. In several species of fish, parasite infection has been associated with decreased fecundity including fewer and smaller eggs, shortened spawning season, and decreased larval survival. We examined the effect of parasite infection and life history parameters on egg quality of 40 spawning capable female common snook, Centropomus undecimalis, collected from 3 inlets on the Atlantic coast of Florida in the summer of 2013. Egg quality was measured as fatty acid DHA, PI, and EPA composition of eggs. Six major taxons of parasites were identified: Cestoda 1 adult, 68 trypanorhyncha larvae, Copepoda 1 Lernae sp., 62 Lernanthropus sp., Digenea 1 adult, Monogenea 1 adult, Nematoda 861 Contracecum sp., and Pentastomida 36 Sebekia sp.. In addition, dead parasites of unknown taxa 262 total were counted. Parasite infracommunities were described as total number of live parasites per individual, total number of dead parasites per individual, the Shannon Wiener Index H as a measure of diversity, and the Berger-Parker Index BPI as a measure of numerical dominance. Total number of dead parasites and BPI had a significant, negative effect on percent composition of DHA of eggs. Individuals with higher amounts of dead parasites 20 were predicted to drop below a 13 DHA composition threshold needed for hatching and larval success.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005174
- Format
- Document (PDF)
- Title
- The Effect of Flexibility and Aspect Ratios on Ribbon-Fin-Propulsion.
- Creator
- Liu, Hanlin, Taylor, Bevan, Lashaw, Evan, Graduate College, Curet, Oscar M.
- Abstract/Description
-
Ribbon-fin-based propulsion has the potential to improve the maneuverability of underwater vehicles in complex environments. In this type of propulsion a series of rays are used to send traveling waves along an elongated fin, which is referred to as ribbon fin. In this work, in order to know the effect of flexural rigidities and aspect ratios on undulating ribbon fin propulsion; we built a robotic ribbon fin, and tested the physical model in a water flume. In a series of experiments we...
Show moreRibbon-fin-based propulsion has the potential to improve the maneuverability of underwater vehicles in complex environments. In this type of propulsion a series of rays are used to send traveling waves along an elongated fin, which is referred to as ribbon fin. In this work, in order to know the effect of flexural rigidities and aspect ratios on undulating ribbon fin propulsion; we built a robotic ribbon fin, and tested the physical model in a water flume. In a series of experiments we measured the propulsive force, power consumption and the free-swimming speed of the robotic fin as a function of wave frequency for fins with different ray stiffness and aspect ratios. The propulsive performance of the robotic ribbon fin was based on the propulsive force generated and power consumption. A series of kinematic experiments were performed using a high-speed camera. Based on the fin kinematics, the natural frequencies of the ribbon fin with different stiffness were determined. We found that the flexible rays would improve or worsen the propulsive performance compared to a rigid counterpart depending on the actuation parameters. For the aspect ratios considered, the propulsive efficiency improves with increase in the fin height. Our data suggest that, the ribbon fin can yield best propulsive behavior close to its natural frequency.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005881
- Format
- Document (PDF)
- Title
- Task Decoding using Recurrent Quantification Analysis of Eye Movements.
- Creator
- LaCombe, Daniel C. Jr., Barenholtz, Elan, Graduate College
- Abstract/Description
-
In recent years, there has been a surge of interest in the possibility of using machine-learning techniques to decode generating properties of eye-movement data. Here we explore a relatively new approach to eye movement quantification, Recurrence Quantification Analysis RQA— which allows analysis of spatio-temporal fixation patterns — and assess its diagnostic power with respect to task decoding. Fifty participants completed both aesthetic-judgment and visual-search tasks over natural images...
Show moreIn recent years, there has been a surge of interest in the possibility of using machine-learning techniques to decode generating properties of eye-movement data. Here we explore a relatively new approach to eye movement quantification, Recurrence Quantification Analysis RQA— which allows analysis of spatio-temporal fixation patterns — and assess its diagnostic power with respect to task decoding. Fifty participants completed both aesthetic-judgment and visual-search tasks over natural images of indoor scenes. Six different sets of features were extracted from the eye movement data, including aggregate, fixation-map, and RQA measures. These feature vectors were then used to train six separate support vector machines using an n-fold cross validation procedure in order to classify a scanpath as being generated under either an aesthetic-judgment or visual- search task. Analyses indicated that all classifiers decoded task significantly better than chance. Pairwise comparisons revealed that all RQA feature sets afforded significantly greater decoding accuracy than the aggregate features. The superior performance of RQA features compared to the others may be that they are relatively invariant to changes in observer or stimulus; although RQA features significantly decoded observer- and stimulus-identity, analyses indicated that spatial distribution of fixations were most informative about stimulus-identity whereas aggregate measures were most informative about observer-identity. Therefore, changes in RQA values could be more confidently attributed to changes in task, rather than observer or stimulus, relative to the other feature sets. The findings of this research have significant implications for the application of RQA in studying eye-movement dynamics in topdown attention.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005892
- Format
- Document (PDF)
- Title
- Swimming Upstream: Summary of Findings from The Writing Hour Micro-autoethnography.
- Creator
- Kamin, Fran, Felsher, Rivka A., Brittain, Kristin, Graduate College, Swann, Elizabeth G., Bryan, Valerie
- Abstract/Description
-
This qualitative, micro-autoethnographic study explored the perceptions of four female doctoral students at FAU that made up the founding and consistent membership of a self-created, self-directed, and self-sustaining blendedlearning cohort focused on doctoral dissertation completion. The participants also served as co-researchers of this study that investigated their motivation to persist through their doctoral programs in educational leadership with a focus on the dissertation phase. This...
Show moreThis qualitative, micro-autoethnographic study explored the perceptions of four female doctoral students at FAU that made up the founding and consistent membership of a self-created, self-directed, and self-sustaining blendedlearning cohort focused on doctoral dissertation completion. The participants also served as co-researchers of this study that investigated their motivation to persist through their doctoral programs in educational leadership with a focus on the dissertation phase. This study utilized group and individual interviews, spontaneous drawing, document review, and the SDLRS instrument to collect and analyze data on the group’s formation, development, challenges, culture, sustaining factors, and outcomes. Findings show that while this group of doctoral students faced substantial challenges and distractions, their self-created cohort evolved through the stages of group development into a viable and supportive community of practice based on their learner motivation orientations achievement and affiliation, personal strengths, and strategies that included dependence on technology; meeting structure, time management techniques, rules, sharing, critiquing, accountability, artificial deadlines, and emotional support. This study fills a major void in the literature. While research exists that examine doctoral cohorts, graduate student retention factors, and graduate student peer mentoring, literature is sparse regarding the outcomes of self-created and self-sustaining graduate student cohorts. Given the high rate of attrition among doctoral students across disciplines in the U.S., the implications of this study include improvement of graduate student advising, suggestions for supportive restructuring of graduate study programs toward increased retention, and the creation of an empowering model for student cohort formation to be validated through further research.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005886
- Format
- Document (PDF)
- Title
- Swimming Kinematics of Juvenile Sphyrna Lewini.
- Creator
- Hoffmann, Sarah, Sanders, R., Porter, M. E., Graduate College
- Abstract/Description
-
The head of Sphyrnid sharks is an exaggerated dorso-ventrally compressed cephalofoil, which likely influences their swimming kinematics. Previous researchers hypothesized that the cephalophoil may act as a stabilizer during turning to maintain the shark’s position parallel to the substrate. Sphyrnid sharks have also been shown to be highly maneuverable and more flexible when compared to other shark species. Here, we explore swimming performance variable of Sphyrna lewini scalloped hammerhead...
Show moreThe head of Sphyrnid sharks is an exaggerated dorso-ventrally compressed cephalofoil, which likely influences their swimming kinematics. Previous researchers hypothesized that the cephalophoil may act as a stabilizer during turning to maintain the shark’s position parallel to the substrate. Sphyrnid sharks have also been shown to be highly maneuverable and more flexible when compared to other shark species. Here, we explore swimming performance variable of Sphyrna lewini scalloped hammerhead during swimming. We obtained video of juvenile Sphyrna lewini swimming from dorsal and lateral views. We assigned 15 anatomical landmarks on the shark and tracked the movement of each during swimming. Anatomical landmarks included points on the cephalofoil, pectoral fins, caudal fin, and along the body midline. The movements of these points were correlated with swimming performance variables such as velocity, tail beat frequency, and tail beat amplitude. We also examined variables such as head yaw and body curvature along the length of the body.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005884
- Format
- Document (PDF)
- Title
- Summary of Findings from a Case Study of Policy Entrepreneurship in Higher Education: A Descriptive Portrait.
- Creator
- Felsher, Rivka A., Graduate College
- Abstract/Description
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The call for higher education reform in the U.S. intensifies as the gap between the haves and have-nots widens. Policy actors from across the political spectrum advocate for various policy solutions creating a policy environment that is complex and often contentious. In such environments, policy entrepreneurs— those individuals who advocate for policy innovation from within and without government—try to break through the barriers of incremental politics to create reform. As important as this...
Show moreThe call for higher education reform in the U.S. intensifies as the gap between the haves and have-nots widens. Policy actors from across the political spectrum advocate for various policy solutions creating a policy environment that is complex and often contentious. In such environments, policy entrepreneurs— those individuals who advocate for policy innovation from within and without government—try to break through the barriers of incremental politics to create reform. As important as this role is in structuring higher education policy, it has not yet been explored. This study fills a gap in the extant literature by cataloging the traits, values, motivation, skills, and strategies that enable higher education policy entrepreneurs at state and national levels to accomplish sustainable and innovative higher education reform. This study employed a descriptive, revelatory, singlecase study research design interpreted from the postpositivist paradigm. Data drawn from interviews with 23 policy entrepreneurs from across the U.S. were triangulated with document reviews and a multi-level coding strategy. Data were then juxtaposed against nine propositions extracted from the extant literature to derive the findings. Policy entrepreneurs in this study are creative political leaders with a passion for improving educational opportunity. They are pragmatic, resourceful, perseverant, strategic, and influential actors who don’t work in isolation; rather, they are network dependent and value collaboration, compromise, and listening. They reach across the aisle, work hard to build credibility and trust, recognize windows of opportunity, create opportunities to advocate for policy innovation, take calculated risks, and make sacrifices for their cause.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005877
- Format
- Document (PDF)
- Title
- Sparse Representation Classification of Dolphin Whistles Using Gabor Wavelets.
- Creator
- Esfahanian, Mahdi, Zhuang, Hanqi, Graduate College, Erdol, Nurgun
- Abstract/Description
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This research presents a novel approach to categorize dolphin whistles into various types. Most accurate methods to identify dolphin whistles are tedious and not robust, especially in the presence of ocean noise. One of the biggest challenges of dolphin whistle extraction is the coexistence of short-time duration wide-band echo clicks with the whistles. In this research, a subspace of select orientation parameters of the 2D Gabor wavelet frames is utilized to enhance or suppress signals by...
Show moreThis research presents a novel approach to categorize dolphin whistles into various types. Most accurate methods to identify dolphin whistles are tedious and not robust, especially in the presence of ocean noise. One of the biggest challenges of dolphin whistle extraction is the coexistence of short-time duration wide-band echo clicks with the whistles. In this research, a subspace of select orientation parameters of the 2D Gabor wavelet frames is utilized to enhance or suppress signals by their orientation. The result is a Gabor image that contains a noise free grayscale representation of the fundamental dolphin whistle which is resampled and fed into the Sparse Representation Classifier. The classifier uses the l1 norm to select a match. Experimental studies conducted demonstrate: a a robust technique based on the Gabor wavelet filters in extracting reliable call patterns, and b the superior performance of Sparse Representation Classifier for identifying dolphin whistles by their call type.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005146
- Format
- Document (PDF)
- Title
- Should we use RapidArc (VMAT) for breast radiotherapy? A Dosimetric comparison of IMRT versus VMAT optimization.
- Creator
- Moshiri Sedeh, Nader, Pella, Silvia, Leventouri, Theodora, Graduate College
- Abstract/Description
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Purpose: The purpose of this study is to compare the dose-volumetric results of intensity modulated radiation therapy (IMRT) with RapidArc (RA Varian Medical Systems, Palo Alto, CA) for whole breast irradiation. Methods: 25 patients previously treated for whole left breast (either RapidArc plan or IMRT) were the subjects of this planning study. Eclipse v 11.0.47 was used to make all retrospective plans using the same contours, energy, machine and normalization. Prescription dose to the...
Show morePurpose: The purpose of this study is to compare the dose-volumetric results of intensity modulated radiation therapy (IMRT) with RapidArc (RA Varian Medical Systems, Palo Alto, CA) for whole breast irradiation. Methods: 25 patients previously treated for whole left breast (either RapidArc plan or IMRT) were the subjects of this planning study. Eclipse v 11.0.47 was used to make all retrospective plans using the same contours, energy, machine and normalization. Prescription dose to the planning target volume was 5000 Gy in 25 fractions. All plans were normalized such that 100% covered 95% of planning target volume (PTV). Results: V10, V20 and Dmean Gy of left lung significantly differed between the two plans (p-value <0.0001, =0.0473 and <0.0001 respectively), but V30 Gy did not (p-value 0.463). V25, D33 and Dmean Gy of heart significantly differed between the two plans (p-value =0.034, <0.0001 and 0.01 respectively), but V10 Gy did not (p-value 0.058). V5 of both right breast and right lung significantly differed between the two plans (p-value <0.0007 and =0.0112, respectively). Also Dmean of both right breast and right lung significantly differed between the two plans (p-value <0.0001 for both). The mean conformity index did not significantly differ, p-value 0.142. There was a significant difference between the mean MUs of the two plans as well, p-value <0.0001.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005901
- Format
- Document (PDF)
- Title
- Sea Level Rise Misconceptions in Broward County, FL.
- Creator
- Bolter, Keren P., Hindle, Tobin, Graduate College
- Abstract/Description
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Global climate change stressors downscale to specific local vulnerabilities, thus requiring tailored adaptation strategies. Southeast Florida is uniquely vulnerable in terms of exposure to sea level rise due to low-lying porous limestone geology, high-valued coastal properties, treasured ecosystems, and dense populations at risk. Coastal populations are particularly at risk due to erosion, inundation and storm surge, but interior populations are also susceptible to rising water tables and...
Show moreGlobal climate change stressors downscale to specific local vulnerabilities, thus requiring tailored adaptation strategies. Southeast Florida is uniquely vulnerable in terms of exposure to sea level rise due to low-lying porous limestone geology, high-valued coastal properties, treasured ecosystems, and dense populations at risk. Coastal populations are particularly at risk due to erosion, inundation and storm surge, but interior populations are also susceptible to rising water tables and extended periods of inundation amplified by SLR. Robust SLR adaptation options require significant economic costs that people may not be willing to pay for if they do not understand their real risk. If perceived risk does not adequately line up with actual risk, the necessary strategies may not be implemented.
This study aims to compare perceived risk to actual risk to sea level rise in Broward County, FL. Perceived risk of residents, measured via an online survey, was layered over actual risk in terms of flooding, storm surge, and loss of property. Using GIS, a coastal vulnerability index was constructed for the actual risk, and principal component analysis identified the key factors influencing perceived risk. Results show where risk is underestimated, realistic, or overestimated, quantified both spatially and demographically. The concerns of residents are misaligned with the true vulnerability on many impacts, while others were very accurately understood. There are many opportunities for resilience that require preparation and adaptation. The first step to solving a problem is acknowledging that it exists. Where should outreach be targeted for increasing awareness?
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005139
- Format
- Document (PDF)