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Title: Influence of small conductance calcium-activated potassium channels (SK,Kca2) on long-term memory: global and local analysis across time- and task- dependent measures.
Creator: Vick, Kyle A., Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Small conductance calcium-activated potassium (SK) channels are found ubiquitously throughout the brain and modulate the encoding of learning and memory. Systemic injection of 1-ethyl-2-benzimidalzolinoe (EBIO), a SK channel activator, impairs the encoding of novel object memory and locomotion but spares fear memory encoding in C57BL/6NHsd mice. The memory impairments discovered were not due to non-cognitive performance confounds such as ataxia, anxiety, attention or analgesia. Further...
Show moreSmall conductance calcium-activated potassium (SK) channels are found ubiquitously throughout the brain and modulate the encoding of learning and memory. Systemic injection of 1-ethyl-2-benzimidalzolinoe (EBIO), a SK channel activator, impairs the encoding of novel object memory and locomotion but spares fear memory encoding in C57BL/6NHsd mice. The memory impairments discovered were not due to non-cognitive performance confounds such as ataxia, anxiety, attention or analgesia. Further investigation with intra-hippocampal application of EBIO revealed SK channels in dorsal CA1 contribute to the encoding deficits seen systemically, but do not account for the full extent of the impairment. Concentrated activation of dorsal CA1 SK channels do not influence fear memory encoding or locomotor impairments. Taken together, these data indicate SK channels, especially in the dorsal hippocampus, have a modulatory role on novel object memory encoding, but not retrieval; however, pharmacological activation of hippocampal SK channels does not appear to influence fear memory encoding.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/192991
Subject Headings: Mice as laboratory animals, Cellular signal transduction, Memory, Research, Biological transport, Research, Potassium channels, Physiological effect
Format: Document (PDF)

Title: Morphologic Evolution and Alongshore Variability of Two Nourishment Projects in Southeast FL, USA.
Creator: Shahan, Thomas A., Roberts Briggs, Tiffany, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Geosciences
Abstract/Description: For the last several decades, beach nourishment has been a widely implemented erosion mitigation strategy along many developed coastlines. Measuring subsequent patterns of erosion and accretion can help elucidate local sediment transport trends, improve time scale predictions of profile equilibration, decrease renourishment intervals, and adjust future engineering design of nourishments. This study evaluates the morphologic evolution of two beach nourishment projects (e.g., characterized as a...
Show moreFor the last several decades, beach nourishment has been a widely implemented erosion mitigation strategy along many developed coastlines. Measuring subsequent patterns of erosion and accretion can help elucidate local sediment transport trends, improve time scale predictions of profile equilibration, decrease renourishment intervals, and adjust future engineering design of nourishments. This study evaluates the morphologic evolution of two beach nourishment projects (e.g., characterized as a full and partial nourishment) at the same location in Boca Raton, Florida using time series beach profiles, surface sediment samples, and wave data. More than 85% of sediment volume was retained within the full nourishment six months after project completion, compared to 50% retained eight months after completion of the partial nourishment. Wave energy largely influenced immediate post nourishment change. Profile equilibration was controlled by high-energy events (i.e., hurricanes) for both nourishments.
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Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00005973
Subject Headings: Beach nourishment, Florida--Boca Raton, Erosion--Florida, Sediment transport
Format: Document (PDF)

Title: Phosphate-associated phenotype plasticity as a driver of cattail invasion in the sawgass-dominated Everglades.
Creator: Webb, James., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: In plants, phenotypic plasticity, the ability to morphologically adapt to new or broad environmental conditions, is a consequence of long-term evolutionary genetic processes. Thus, plants adapted to low phosphate (P) environments exhibit only limited plasticity to take advantage of nutrient enrichment, a global phenomenon in terrestrial and aquatic environments. In the face of anthropogenic P-enrichment, low nutrient adapted resident plant species are frequently displaced by species with high...
Show moreIn plants, phenotypic plasticity, the ability to morphologically adapt to new or broad environmental conditions, is a consequence of long-term evolutionary genetic processes. Thus, plants adapted to low phosphate (P) environments exhibit only limited plasticity to take advantage of nutrient enrichment, a global phenomenon in terrestrial and aquatic environments. In the face of anthropogenic P-enrichment, low nutrient adapted resident plant species are frequently displaced by species with high morphological and genetic plasticity. However, it remains unclear whether plasticity is systemically expressed across molecular, biochemical, physiological, and morphological processes that ultimately contribute to the root and shoot phenotypes of plants. In this study, we demonstrated high plasticity in root-borne traits of sawgrass (Cladium jamaicense), the dominant plant species of the P-impoverished Everglades, and counter the idea of inflexibility in low P adapted species. However, sawgras s expressed inflexibility in processes contributing to shoot phenotypes, in contrast to cattail, which was highly plastic in shoot characteristics vii in response to P enrichment. In fact, plasticity in cattail shoots is likely a function of its growth response to P that was globally regulated by P-availability at the level of transcription. Plasticity and inflexibility in the growth of both species also diverged in their allocation of P to the chloroplast for growth in cattail versus the vacuole for P storage in sawgrass. In the Everglades, anthropogenic P-enrichment has changed the environment from a P-limited condition, where plasticity in root-borne traits of sawgrass was advantageous, to one of light-competition, where plasticity in shoot-borne traits drives competitive dominance by cattail., We hypothesize that these shifts in plasticity competitive advantage from root to shoots has been a major driver of cattail expansion in the Everglades ecosystem. Further, this understanding of how natural plant species adapt and shift in response to nutrient availability could also be used a model system to optimize agricultural systems to increase efficiencies in food production and protect low nutrient adapted natural systems from cultural eutrophication.
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Date Issued: 2010, 2010
PURL: http://purl.flvc.org/FAU/2979377
Subject Headings: Ecosystem management, Vegatation dynamics, Phosphorous, Physiological transport, Biogeochemical cycles
Format: Document (PDF)

Title: Mutant huntingtin reduces palmitoylation of GAD65 and impairs its vesicular trafficking.
Creator: Rush, Daniel., Charles E. Schmidt College of Medicine, Department of Biomedical Science
Abstract/Description: Huntington's disease (HD) is caused by an expanded plyglutamine repeat in the huntingtin protein. In this study, I focused on the effect of the mutant huntingtin protein (mhtt) on the subcellular localization of glutamic acid decarboxylase (GAD), the enzyme responsible for synthesizing gama-aminobutyric acid (GABA). Subcellular distribution of GAD65 is significantly altered in two neuronal cell lines that express either the N-terminus or full length mhtt. GAD65 is predominantly associated...
Show moreHuntington's disease (HD) is caused by an expanded plyglutamine repeat in the huntingtin protein. In this study, I focused on the effect of the mutant huntingtin protein (mhtt) on the subcellular localization of glutamic acid decarboxylase (GAD), the enzyme responsible for synthesizing gama-aminobutyric acid (GABA). Subcellular distribution of GAD65 is significantly altered in two neuronal cell lines that express either the N-terminus or full length mhtt. GAD65 is predominantly associated with the Golgi membrane in cells expressing normal huntingtin (Htt). However, it diffuses in the cytosol of cells expressing mhtt. Palmitoylation of GAD65 is required for GAD65 trafficking, and I demonstrated the palmitoylation of GAD65 is reduced in the HD model. Overexpression of huntingtin-interacting protein 14 (HIP14), the enzyme that palmitoylates GAD65, rescues GAD65 palmitoylation and vesicle-associated trafficking. This data suggests that impairment of GAD65 palmitoylation by mhtt may alter its localization and lead to altered inhibitory neurotransmission in HD.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3352831
Subject Headings: Glutamic acids, Antagonists, Cellular signal transduction, Proteolytic enzymes, Research, Proteins, Physiological transport, Huntington's chorea, Research
Format: Document (PDF)

Title: New insights into the neuromodulatory role and potential action site of taurine in retinal neurons.
Creator: Bulley, Simon, Charles E. Schmidt College of Science, Department of Biomedical Science
Abstract/Description: Taurine is the second most abundant amino acid in the CNS after glutamate and its functions have been found largely related to intracellular calcium ([Ca2+]i) modulation, osmoregulation, membrane stabilization, reproduction and immunity. The action of taurine has also been implicated in neurotransmission and neuromodulation though its specific sites of action are not fully understood. Isolated retinal neurons from the larval tiger salamanders (Ambystoma tigrinum) were used as a model to study...
Show moreTaurine is the second most abundant amino acid in the CNS after glutamate and its functions have been found largely related to intracellular calcium ([Ca2+]i) modulation, osmoregulation, membrane stabilization, reproduction and immunity. The action of taurine has also been implicated in neurotransmission and neuromodulation though its specific sites of action are not fully understood. Isolated retinal neurons from the larval tiger salamanders (Ambystoma tigrinum) were used as a model to study the neuromodulatory role of taurine in the CNS and to gain insights into its potential sites of action. A combination of techniques was used, including whole-cell patch clamp recording to study taurine's regulation of voltage-gated potassium (K+) and Ca2+ channels and Fluo-4AM Ca2+-imaging to study taurine's regulation of glutamate-induced [Ca2+] I,. Taurine was shown to suppress of glutamate-induced [Ca2+] l, in a dose dependent manner. This suppression was mostly sensitive to the glycine rece ptor antagonist Strychnine but insensitive to any GABA receptor antagonist. The remaining strychnine-insensitive effect was inhibited with the protein kinase A (PKA) inhibitor, PKI, suggesting that there was an additional metabotropic pathway. Moreover, using the protein kinase C (PKC) inhibitor, GF109203X, there was an enhancement in strychnine-insensitive taurine's regulation. Taurine inhibits voltage-gated Ca2+ channels in the retinal neurons and has a dual effect on voltage-gated K+ channels. Taurine causes an increase in K+ current amplitude which is further enhanced with PKI and blocked with GF109203X, suggesting that it is through a PKC-dependent pathway negatively controlled by PKA-dependent pathway., There is a suppression of K+ current by taurine with intracellular application of GF109203X, suggesting that the reduction is through a PKA-dependent pathway. With both PKC and PKA inhibitors there is no longer an enhancement in maximum amplitude but a shift of volt dependence on a hyperpolarizing direction. Taurine's enhancement of K+ current is blocked by the Kv1.3 subtype antagonist Margatoxin, with Kv1.3 accounting for the majority of delayed-rectifier sustained current in bipolar and amacrine cells, as well as 50% of ganglion cells. Interestingly, the enhancement of K+ current by taurine is blocked by 5HT2A antagonist MDL11939, suggesting that activation of PKC is through this metabotropic serotonin receptor subtype. The suppression of voltage-gated Ca2+ channels is reversed with a combination of MDL11939 and the 5HT1A antagonist NAN-190. These results provide the evidence that the natural effect of taurine in the retinal neurons might be dependent on the activation of both 5HT1A and 5HT2A receptors. The high apparent activity of taurine on 5HT receptors could have important implication for the actions of taurine in central brain in which taurine has been known to be beneficial for improving mental health, as well as learning and memory processes.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2953206
Subject Headings: Biological transport, Eye, Physiology, Taurine, Physiological effect, Taurine, Therapeutic use, Central nervous system, Physiology
Format: Document (PDF)

Title: The effect of small conductance calcium-activated potassium channels on emotional learning and memory.
Creator: Sanguinetti, Shannon, Stackman, Robert W., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
Abstract/Description: Small conductance Ca2+-activated K+ (SK) channels have been shown to alter the encoding of spatial and non-spatial memory in the hippocampus by shaping glutamatergic postsynaptic potentials and modulating NMDA receptor-dependent synaptic plasticity. When activated, dendritic SK channels reduce hippocampal neuronal excitability and LTP. Similar SK channel properties have been demonstrated in lateral amygdala (LA) pyramidal neurons. Additionally, induction of synaptic plasticity and beta...
Show moreSmall conductance Ca2+-activated K+ (SK) channels have been shown to alter the encoding of spatial and non-spatial memory in the hippocampus by shaping glutamatergic postsynaptic potentials and modulating NMDA receptor-dependent synaptic plasticity. When activated, dendritic SK channels reduce hippocampal neuronal excitability and LTP. Similar SK channel properties have been demonstrated in lateral amygdala (LA) pyramidal neurons. Additionally, induction of synaptic plasticity and beta-adrenoreceptor activation in LA pyramidal neurons causes PKA-mediated internalization of SK channels from the postsynaptic density. Chronic activation of the amygdala through repetitive stressful stimuli can lead to excitatory synaptic strengthening that may create permanent hyper-excitability in its circuitry. This mechanism may contribute to a number of mood and anxiety disorders. The selective influence of SK channels in the LA on anxiety and fear conditioning are not known. The thesis project outlined herein examined whether SK channel blockade by bee venom peptide, apamin, during a repetitive acute fear conditioning paradigm was sufficient to alter fear memory encoding and the resulting behavioral outcome. Following the final fear memory test session, mice were tested in the open field immediately after the second fear conditioning test session. The findings indicate that intracranial LA microinfusions of apamin did not affect memory encoding or subsequent anxiety.
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Date Issued: 2015
PURL: http://purl.flvc.org/fau/fd/FA00004543, http://purl.flvc.org/fau/fd/FA00004543
Subject Headings: Biological transport -- Research, Cellular signal transduction, Memory -- Research, Mice as laboratory animals, Potassium channels -- Physiological effect
Format: Document (PDF)

Title: A role for polynucleotide phosphorylase in protecting cells and controlling RNA quality under oxidative stress.
Creator: Wu, Jinhua., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: RNA damage occurring under oxidative stress has been shown to cause RNA dysfunction and must be detrimental to cells and organisms. We propose that damaged RNA can be removed by specific RNA surveillance activities. In this work, we investigated the role of polynucleotide phosphorylase (PNPase), a 3'->5' exoribonuclease, in protecting the cells against oxidative stress and eliminating oxidatively-damaged RNA. Previously, it was reported that E. coli PNPase has a higher affinity to poly(8-oxoG...
Show moreRNA damage occurring under oxidative stress has been shown to cause RNA dysfunction and must be detrimental to cells and organisms. We propose that damaged RNA can be removed by specific RNA surveillance activities. In this work, we investigated the role of polynucleotide phosphorylase (PNPase), a 3'->5' exoribonuclease, in protecting the cells against oxidative stress and eliminating oxidatively-damaged RNA. Previously, it was reported that E. coli PNPase has a higher affinity to poly(8-oxoG:A). We further confirmed that E. coli PNPase can specifically bind to an oxidized RNA with a high affinity. An E. coli strain deficient in PNPase (pnp) is hypersensitive to hydrogen peroxide (H2O2). Importantly, the level of H2O2-induced RNA damage, measured by the content of 8-hydroxyguanosine, increases significantly in the pnp mutant cells. Consistent with the notion that PNPase plays a direct role in these processes, introduction of the pnp gene encoding E. coli PNPase can restore the viability and RNA oxidation level of the pnp mutant cells in response to H2O2 treatment. Interestingly, degradosome-association is not required for PNPase to protect cell against oxidative stress. PNPase is evolutionary conserved in most of organisms of all domains of life. The human polynucleotide phosphorylase (hPNPase) localizes mainly in mitochondria and plays pleiotropic roles in cell differentiation and has been previously shown to bind 8- oxoG-RNA with a high affinity. Here we show that similar to E. coli PNPase, hPNPase plays an indispensable role in protecting HeLa cells against oxidative stress. The viability in HeLa cell and 8-oxoG levels in RNA are inversely correlated in response to H2O2- treatment. After removal of oxidative challenge, the elevated level of 8-oxoG in RNA decreases, suggesting the existence of surveillance mechanism(s) for cleaning up oxidized RNA., We have shown that hPNPase may be responsible for the surveillance of oxidized RNA in mammalian cells.Overexpresion of hPNPase reduces RNA oxidation and increases HeLa cell viability against H2O2 insult. Conversely, hPNPase knockdown decreases the viability and increases 8-oxoG level in HeLa cells exposed to H2O2. Taken together, our results suggest that RNA oxidation is a challenging problem for living organisms, and PNPase may play an important role in protecting both prokaryotic and eukaryotic cells by limiting damage to RNA under oxidative stress.
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Date Issued: 2008
PURL: http://purl.flvc.org/FAU/186302
Subject Headings: RNA, Metabolism, Biopolymers, Physiological transport, Bacterial genetics, Proteins, Synthesis, Cellular signal transduction
Format: Document (PDF)

Title: Transit signal priority for emergency evacuation: mitigating disaster.
Creator: Parr, Scott A., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: The goal of this research is to answer a single question. During an urban evacuation, is it advisable for regional planners to allow transit units signal priority in cases where police assisted traffic controls are not an option? Standard practice for emergency evacuation is to place police officers at intersection throughout the evacuation area. However, this is not always an option where environmental factors such as the presence of fire, chemical plume, radioactive fallout (nuclear...
Show moreThe goal of this research is to answer a single question. During an urban evacuation, is it advisable for regional planners to allow transit units signal priority in cases where police assisted traffic controls are not an option? Standard practice for emergency evacuation is to place police officers at intersection throughout the evacuation area. However, this is not always an option where environmental factors such as the presence of fire, chemical plume, radioactive fallout (nuclear contaminated wind and dust) do not permit police presence. Results from a case study conducted on Washington D.C. show that it would take four non-prioritized transit units to accomplish the same task as three prioritized vehicles. Furthermore, allowing transit signal priority during an urban evacuation has little to no effect on evacuation clearance time or evacuee travel time. Moreover, when transit signal priority is restricted to operate only on evacuation routes, evacuee travel and delay time decreases.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1930488
Subject Headings: Emergency transportation, Government policy, Emergency management, Evacuation of civilians, Electronic traffic controls
Format: Document (PDF)

Title: Intelligent Supervisory Switching Control of Unmanned Surface Vehicles.
Creator: Bertaska, Ivan Rodrigues, von Ellenrieder, Karl, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: novel approach to extend the decision-making capabilities of unmanned surface vehicles (USVs) is presented in this work. A multi-objective framework is described where separate controllers command different behaviors according to a desired trajectory. Three behaviors are examined – transiting, station-keeping and reversing. Given the desired trajectory, the vehicle is able to autonomously recognize which behavior best suits a portion of the trajectory. The USV uses a combination of a...
Show morenovel approach to extend the decision-making capabilities of unmanned surface vehicles (USVs) is presented in this work. A multi-objective framework is described where separate controllers command different behaviors according to a desired trajectory. Three behaviors are examined – transiting, station-keeping and reversing. Given the desired trajectory, the vehicle is able to autonomously recognize which behavior best suits a portion of the trajectory. The USV uses a combination of a supervisory switching control structure and a reinforcement learning algorithm to create a hybrid deliberative and reactive approach to switch between controllers and actions. Reinforcement learning provides a deliberative method to create a controller switching policy, while supervisory switching control acts reactively to instantaneous changes in the environment. Each action is restricted to one controller. Due to the nonlinear effects in these behaviors, two underactuated backstepping controllers and a fully-actuated backstepping controller are proposed for each transiting, reversing and station-keeping behavior, respectively, restricted to three degrees of freedom. Field experiments are presented to validate this system on the water with a physical USV platform under Sea State 1 conditions. Main outcomes of this work are that the proposed system provides better performance than a comparable gain-scheduled nonlinear controller in terms of an Integral of Absolute Error metric. Additionally, the deliberative component allows the system to identify dynamically infeasible trajectories and properly accommodate them.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004671, http://purl.flvc.org/fau/fd/FA00004671
Subject Headings: Adaptive control systems, Artificial intelligence, Engineering mathematics, Intelligent control systems, Mechatronics, Nonlinear control theory, Transportation engineering
Format: Document (PDF)

Title: Structure-function relationships in eukaryotic and prokaryotic family 6 glycosyltransferases.
Creator: Tumbale, Percy., Charles E. Schmidt College of Medicine, Department of Biomedical Science
Abstract/Description: Carbohydrate Active Enzyme family 6 (CA6) glycosyltransferases (GTs) are type II transmembrane proteins localized in the Golgi apparatus. CA6 GTs have a GT-A fold, a type of structure that resembles the Rossman fold and catalyze the transfer either galactose (Gal) or N-acetylgalactosamine (GalNAc) from the UDP nucleotide sugar to an non-reducing terminal Gal or GalNAc on an acceptor via an a-1,3 linkage. In this reaction, the anomeric configuration of the sugar moiety of the donor is retained...
Show moreCarbohydrate Active Enzyme family 6 (CA6) glycosyltransferases (GTs) are type II transmembrane proteins localized in the Golgi apparatus. CA6 GTs have a GT-A fold, a type of structure that resembles the Rossman fold and catalyze the transfer either galactose (Gal) or N-acetylgalactosamine (GalNAc) from the UDP nucleotide sugar to an non-reducing terminal Gal or GalNAc on an acceptor via an a-1,3 linkage. In this reaction, the anomeric configuration of the sugar moiety of the donor is retained in the product. CA6 GTs includes the histo-blood group A and B GTs, a-galactosyltransferase (a3GT), Forssman glycolipid synthase (FS), isogloboside 3 synthase (iGb3) in mammals. a3GT and its products (a-Gal epitode) are present in most mammals but are absent in humans and old world primates because of inactivating mutations. The absence of a3GT and its products results in the production of anti-a-Gal epitope natural antibodies in these species., Up to date, the catalytic mechanisms of the CA6 GTs are not well understood. Based on previous structural and mutagenesis studies of bovine aB3GT, we investigated active site residues (His315, Asp316, Ser318, His319, and Lys359) that are highly conserved among CA6 GTs. We have also investigated the role of the C-terminal region by progressive C-terminal truncations. Findings from these studies clarify the functional roles of these residues in structure, catalysis, and specificity in these enzymes and have implications for their catalytic mechanisms. GTs are useful tools in synthesis of glycans for various applications in science and medicine. Methods for the large scale production of pure glycans are continuously being developed. We created a limited randomized combinatorial library based on knowledge of structural information and sequence analysis of the enzyme and its mammalian homologues., Two GalNAc-specific variants were identified from the library and one Glc-specific variant was identified by site-direct mutagenesis. The glycosyltransferase activities of these variants are expected to be improved by further screens of libraries which are designed using the variants as templates. The mammalian CA6 GTs that have been characterized to date are metal-independent and require the divalent cation, Mn2+ for activity. In some recently-discovered bacterial CA6 GTs, the DXD sequence that is present in eukaryotic GTs is replaced by NXN. We cloned and expressed one of these proteins from Bacteroides ovatus, a bacterium that has been linked with inflammatory bowel disease. Functional characterization shows it is a metal-independent monomeric GT that efficiently catalyzes the synthesis of oligosaccharides similar to human blood group A glycan., Mutational studies indicated that despite the lack of a metal cofactor there are similarities in structure-function relationships between the bacterial and vertebrate family 6 GTs.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/186686
Subject Headings: Molecular biology, Mathematical models, Glycotransferase genes, Biological transport, Proteins, Synthesis, Evolutionary genetics
Format: Document (PDF)

Title: Studies of specific gene expression of phosphate transporters in sawgrass (Cladium jamaicense crantz) and cattail (Typha domingensis pers.).
Creator: Lin, Li, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: In the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass...
Show moreIn the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass roots, not cattail, at low phosphate concentrations in lab and field samples by trypan blue staining. AM fungi could increase sawgrass growth and had little effect on cattail growth. Four phosphate transporters were identified in sawgrass. CjPT1, CjPT2 and CjPT3 were expressed in roots and shoots independent of AM fungi and phosphate availability, while CjPT4 appeared to be an AM regulated phosphate transporter gene and its expression was induced by AM fungi.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1930493
Subject Headings: Phosphorus, Physiological transport, Soil stabilization, Vegetation dynamics, Ecosystem management, Soil mineralogy, Plant physiology
Format: Document (PDF)

Title: Real Time Traffic Monitoring System from a UAV Platform.
Creator: Biswas, Debojit, Su, Hongbo, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: Today transportation systems are facing big transitions all over the world. We created fly overs, roads under the ground, bridges over the river and ocean to get efficient access and to increase the road connectivity. Our transportation system is more intelligent than ever. Our traffic signaling system became adaptive. Our vehicles equipped with new gadgets and we developed new tools for more efficient analysis of traffic. Our research relies on existing traffic infrastructure to generate...
Show moreToday transportation systems are facing big transitions all over the world. We created fly overs, roads under the ground, bridges over the river and ocean to get efficient access and to increase the road connectivity. Our transportation system is more intelligent than ever. Our traffic signaling system became adaptive. Our vehicles equipped with new gadgets and we developed new tools for more efficient analysis of traffic. Our research relies on existing traffic infrastructure to generate better understanding of traffic. More specifically, this research focused on traffic and UAV cameras to extract information about the traffic. Our first goal was to create an automatic system to count the cars using traffic cameras. To achieve this goal, we implemented Background Subtraction Method (BSM) and OverFeat Framework. BSM compares consecutive frames to detect the moving objects. Because BSM only works for ideal lab conditions, therefor we implemented a Convolutional Neural Network (CNN) based classification algorithm called OverFeat Framework. We created different segments on the road in various lanes to tabulate the number of passing cars. We achieved 96.55% accuracy for car counting irrespective of different visibility conditions of the day and night. Our second goal was to find out traffic density. We implemented two CNN based algorithms: Single Shot Detection (SSD) and MobileNet-SSD for vehicle detection. These algorithms are object detection algorithms. We used traffic cameras to detect vehicles on the roads. We utilized road markers and light pole distances to determine distances on the road. Using the distance and count information we calculated density. SSD is a more resource intense algorithm and it achieved 92.97% accuracy. MobileNet-SSD is a lighter algorithm and it achieved 79.30% accuracy. Finally, from a moving platform we estimated the velocity of multiple vehicles. There are a lot of roads where traffic cameras are not available, also traffic monitoring is necessary for special events. We implemented Faster R-CNN as a detection algorithm and Discriminative Correlation Filter (with Channel and Spatial Reliability Tracking) for tracking. We calculated the speed information from the tracking information in our study. Our framework achieved 96.80% speed accuracy compared to manual observation of speeds.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013188
Subject Headings: Traffic monitoring, Intelligent transportation systems, Neural networks (Computer science), Vehicle detectors, Unmanned aerial vehicles
Format: Document (PDF)

Title: Real-time traffic incidents prediction in vehicular networks using big data analytics.
Creator: Al-Najada, Hamzah, Mahgoub, Imad, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: The United States has been going through a road accident crisis for many years. The National Safety Council estimates 40,000 people were killed and 4.57 million injured on U.S. roads in 2017. Direct and indirect loss from tra c congestion only is more than $140 billion every year. Vehicular Ad-hoc Networks (VANETs) are envisioned as the future of Intelligent Transportation Systems (ITSs). They have a great potential to enable all kinds of applications that will enhance road safety and...
Show moreThe United States has been going through a road accident crisis for many years. The National Safety Council estimates 40,000 people were killed and 4.57 million injured on U.S. roads in 2017. Direct and indirect loss from tra c congestion only is more than $140 billion every year. Vehicular Ad-hoc Networks (VANETs) are envisioned as the future of Intelligent Transportation Systems (ITSs). They have a great potential to enable all kinds of applications that will enhance road safety and transportation efficiency. In this dissertation, we have aggregated seven years of real-life tra c and incidents data, obtained from the Florida Department of Transportation District 4. We have studied and investigated the causes of road incidents by applying machine learning approaches to this aggregated big dataset. A scalable, reliable, and automatic system for predicting road incidents is an integral part of any e ective ITS. For this purpose, we propose a cloud-based system for VANET that aims at preventing or at least decreasing tra c congestions as well as crashes in real-time. We have created, tested, and validated a VANET traffic dataset by applying the connected vehicle behavioral changes to our aggregated dataset. To achieve the scalability, speed, and fault-tolerance in our developed system, we built our system in a lambda architecture fashion using Apache Spark and Spark Streaming with Kafka. We used our system in creating optimal and safe trajectories for autonomous vehicles based on the user preferences. We extended the use of our developed system in predicting the clearance time on the highway in real-time, as an important component of the traffic incident management system. We implemented the time series analysis and forecasting in our real-time system as a component for predicting traffic flow. Our system can be applied to use dedicated short communication (DSRC), cellular, or hybrid communication schema to receive streaming data and send back the safety messages. The performance of the proposed system has been extensively tested on the FAUs High Performance Computing Cluster (HPCC), as well as on a single node virtual machine. Results and findings confirm the applicability of the proposed system in predicting traffic incidents with low processing latency.
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Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013114
Subject Headings: Vehicular ad hoc networks (Computer networks), Big data, Intelligent transportation systems, Prediction, traffic incidents
Format: Document (PDF)

Title: Optimization of bus system characteristics in urban areas under normal and emergency conditions.
Creator: Psarros, Ionannis, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: Catastrophic events in the past revealed the need for more research in the field of emergency evacuation. During such a procedure, different problems such as congestion at the related traffic networks because of the large number of the evacuating vehicles can occur. Current best practices, in order to deal with such problems, suggest the further involvement of buses in evacuation operations. On the first part of this study after the accurate development of the related simulation model, the...
Show moreCatastrophic events in the past revealed the need for more research in the field of emergency evacuation. During such a procedure, different problems such as congestion at the related traffic networks because of the large number of the evacuating vehicles can occur. Current best practices, in order to deal with such problems, suggest the further involvement of buses in evacuation operations. On the first part of this study after the accurate development of the related simulation model, the optimization of a selected bus system characteristics focusing on the vehicle routing parameter will follow through the development and the application of a non-linear cost minimization problem. On the second part, the potential use of the regular-everyday bus routes in a no-notice emergency evacuation in order to save time comparing to the time needed so as to assign the actual evacuation routes to the evacuation bus vehicles will be analyzed.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3352285
Subject Headings: Transportation planning, Mathematical models, Local transit, Analysis, Emergency management, Evacuation of civilians
Format: Document (PDF)

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

Title: Hydrodynamics of mangrove root-type models.
Creator: Kazemi, Amirkhosro, Curet, Oscar M., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Mangrove trees play a prominent role in coastal tropic and subtropical regions, providing habitat for many organisms and protecting shorelines against storm surges, high winds, erosion, and tsunamis. The motivation of this proposal is to understand the complex interaction of mangrove roots during tidal flow conditions using simplified physical models. In this dissertation, the mangrove roots were modeled with a circular array of cylinders with different porosities and spacing ratios. In...
Show moreMangrove trees play a prominent role in coastal tropic and subtropical regions, providing habitat for many organisms and protecting shorelines against storm surges, high winds, erosion, and tsunamis. The motivation of this proposal is to understand the complex interaction of mangrove roots during tidal flow conditions using simplified physical models. In this dissertation, the mangrove roots were modeled with a circular array of cylinders with different porosities and spacing ratios. In addition, we modeled the flexibility of the roots by attaching rigid cylinders to hinge connectors. The models were tested in a water tunnel for a range of Reynolds number from 2200 to 11000. Additionally, we performed 2D flow visualization for different root models in a flowing soap film setup. We measured drag force and the instantanous streamwise velocity downstream of the models. Furthermore, we investigated the fluid dynamics downstream of the models using a 2-D time-resolved particle image velocimetry (PIV), and flow visualization. The result was analyzed to present time-averaged and time-resolved flow parameters including the velocity distribution, vorticity, streamline, Reynolds shear stress and turbulent kinetic energy. We found that the frequency of the vortex shedding increases as the diameter of the small cylinders decreases while the patch diameter is constant, therefore increasing the Strouhal number, St=fD/U By comparing the change of Strouhal numbers with a single solid cylinder, we introduced a new length scale, the “effective diameter”. In addition, the effective diameter of the patch decreases as the porosity increases. In addition, patch drag decreases linearly as the spacing ratio increases. For flexible cylinders, we found that a decrease in stiffness increases both patch drag and the wake deficit behind the patch in a similar fashion as increasing the blockage of the patch. The average drag coefficient decreased with increasing Reynolds number and with increasing porosity. We found that the Reynolds stress (−u′v′) peak is not only shifted in the vortex structure because of shear layer interference, but also the intensity was weakened by increasing the porosity, which causes a weakening of the buckling of vorticity layers leading to a decline in vortex strength as well as increase in wake elongation.
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Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004948, http://purl.flvc.org/fau/fd/FA00004948
Subject Headings: Fluid mechanics., Atmospheric models., Ocean currents--Mathematical models., Sediment transport., Estuarine oceanography.
Format: Document (PDF)

Title: Artificial neural network prediction of alluvial river geometry.
Creator: Hoffman, David Carl., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D.
Abstract/Description: An artificial neural network is used to predict the stable geometry of alluvial rivers. This knowledge is useful for the design of new channels or modification of natural rivers. Given inputs of river discharge, slope and mean particle size, an artificial neural network is trained to predict the corresponding stable channel width and depth. The network is trained using data from several alluvial canals and rivers. Various factors including training set size and composition, number of hidden...
Show moreAn artificial neural network is used to predict the stable geometry of alluvial rivers. This knowledge is useful for the design of new channels or modification of natural rivers. Given inputs of river discharge, slope and mean particle size, an artificial neural network is trained to predict the corresponding stable channel width and depth. The network is trained using data from several alluvial canals and rivers. Various factors including training set size and composition, number of hidden layer nodes, activation function type, and data scaling method are analyzed as variables affecting network performance. These factors are studied to determine impacts on network accuracy and generalizing ability.
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Date Issued: 1995
PURL: http://purl.flvc.org/fcla/dt/15179
Subject Headings: Alluvial streams, Neural networks (Computer science), Back propagation (Artificial intelligence), Sediment transport--Computer programs
Format: Document (PDF)

Title: Assay development for lysyl hydroxylase.
Creator: Patel, Deepak A., Florida Atlantic University, Fields, Gregg B.
Abstract/Description: Hydroxylysine is produced as a posttranslational modification mainly in collagens, the most abundant protein in mammals. Lysyl hydroxylase (LH) is the enzyme that catalyzes the formation of hydroxylysyl residues in collagen by hydroxylation of -X-Lys-Gly- sequences, for which it requires Fe 2+, 2-oxoglutarate, O2 and ascorbate. In order to study the hydroxylation reaction catalysed by LH, we have synthesized 4 different peptides [for example, GFP*GLP*GAKGE (P*=hydroxyproline) and the...
Show moreHydroxylysine is produced as a posttranslational modification mainly in collagens, the most abundant protein in mammals. Lysyl hydroxylase (LH) is the enzyme that catalyzes the formation of hydroxylysyl residues in collagen by hydroxylation of -X-Lys-Gly- sequences, for which it requires Fe 2+, 2-oxoglutarate, O2 and ascorbate. In order to study the hydroxylation reaction catalysed by LH, we have synthesized 4 different peptides [for example, GFP*GLP*GAKGE (P*=hydroxyproline) and the corresponding hydroxylated (hydroxylysine-containing) peptide] using Fmoc solid-phase methodology. Peptides have been characterized by HPLC, MALDI-TOF mass spectrometry and CD spectroscopy. A new method for efficient separation of lysine- from hydroxylysine-containing peptides by HPLC has been developed in both organic phase (1-anthroylnitrile as derivatizating reagent) and aqueous phase (dansyl chloride as derivatizating reagent). These reagents have been used to derivatize peptides prior to HPLC analysis. The products (di- and tetra-substituted lysine- and hydroxylysine-containing peptides) have been fully separated by HPLC and their structure confirmed by MALDI-TOF MS analysis. Efficient separation of derivatized peptides will allow for the convenient and rapid measurement of LH activity by HPLC methods.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13384
Subject Headings: Biological transport, Proteins--Metabolism, Peptides--Analysis, Coenzymes, Bioorganic chemistry
Format: Document (PDF)

Title: Data Envelopment Analysis Model for Assessment of Safety and Security of Intermodal Transportation Facilities.
Creator: Gundersen, Elisabeth, Kaisar, Evangelos I., Florida Atlantic University
Abstract/Description: Following September 11, 2001, numerous security policies have been created which have caused a number of unique challenges in planning for the transportation networks. In particular, there is a need to enhance security by improving collaboration between various transportation modes. The transportation modes are disconnected and have unequal levels of security and efficiency. Tools need to be refined for collaboration and consensus building to serve as catalysts for efficient transportation...
Show moreFollowing September 11, 2001, numerous security policies have been created which have caused a number of unique challenges in planning for the transportation networks. In particular, there is a need to enhance security by improving collaboration between various transportation modes. The transportation modes are disconnected and have unequal levels of security and efficiency. Tools need to be refined for collaboration and consensus building to serve as catalysts for efficient transportation solutions. In this study, we developed and investigated a mathematical model using Data Envelopment Analysis (DEA) to assess the safety and security of intermodal transportation facilities. The model identifies the best and worst performers by assessing several safety and security-related variables. The DEA model can assess the efficiency level of safety and security of intermodal facilities and identify potential solutions for improvement.
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Date Issued: 2008
PURL: http://purl.flvc.org/fau/fd/FA00012524
Subject Headings: Data envelopment analysis, Benchmarking (Management), Transportation and state--United States, Performance--Measurement
Format: Document (PDF)

Title: A PROFILE OF THE LEADERSHIP OF TEXAS MOTOR TRANSPORTATION ASSOCIATION, INC.
Creator: TOWNSEND, TERRY., Florida Atlantic University, Preston, Paul
Abstract/Description: This thesis is a study of the profiles of chief executives of motor truck and bus companies and allied industry companies who are members of their state association, the Texas Motor Transportation Association, Inc. The profiles were obtained from questionnaires received from 250 responding member chief executives out of the total membership of 921. From what was learned in a review of the questionnaires, characteristics were determined for each discipline of operation and for the entire...
Show moreThis thesis is a study of the profiles of chief executives of motor truck and bus companies and allied industry companies who are members of their state association, the Texas Motor Transportation Association, Inc. The profiles were obtained from questionnaires received from 250 responding member chief executives out of the total membership of 921. From what was learned in a review of the questionnaires, characteristics were determined for each discipline of operation and for the entire association leadership. These indicated the makeup of the leadership, their interest areas in the association, and what they perceived to be the future needs of the industry. The conclusion emerged that such a profile can be an appropriate management tool for both the association and the individual members of the association.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13763
Subject Headings: Texas Motor Transportation Association--History, Trucking--Texas--Societies, etc
Format: Document (PDF)

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