(20,261 - 20,280 of 25,714)
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Title
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Synaptic Rearrangements and the Role of Netrin-Frazzled Signaling in Shaping the Drosophila Giant Fiber Circuit.
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Creator
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Lloyd, Brandon N., Murphey, Rodney K., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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In the developing CNS, presynaptic neurons often have exuberant overgrowth and form excess (and overlapping) postsynaptic connections. Importantly, these excess connections are refined during circuit maturation so that only the appropriate connections remain. This synaptic rearrangement phenomenon has been studied extensively in vertebrates but many of those models involve complex neuronal circuits with multiple presynaptic inputs and postsynaptic outputs. Using a simple escape circuit in...
Show moreIn the developing CNS, presynaptic neurons often have exuberant overgrowth and form excess (and overlapping) postsynaptic connections. Importantly, these excess connections are refined during circuit maturation so that only the appropriate connections remain. This synaptic rearrangement phenomenon has been studied extensively in vertebrates but many of those models involve complex neuronal circuits with multiple presynaptic inputs and postsynaptic outputs. Using a simple escape circuit in Drosophila melanogaster (the giant fiber circuit), we developed tools that enabled us to study the molecular development of this circuit; which consists of a bilaterally symmetrical pair of presynaptic interneurons and postsynaptic motorneurons. In the adult circuit, each presynaptic interneuron (giant fiber) forms a single connection with the ipsilateral, postsynaptic motorneuron (TTMn). Using new tools that we developed we labeled both giant fibers throughout their development and saw that these neurons overgrew their targets and formed overlapping connections. As the circuit matured, giant fibers pruned their terminals and refined their connectivity such that only a single postsynaptic connection remained with the ipsilateral target. Furthermore, if we ablated one of the two giant fibers during development in wildtype animals, the remaining giant fiber often retained excess connections with the contralateral target that persisted into adulthood. After demonstrating that the giant fiber circuit was suitable to study synaptic rearrangement, we investigated two proteins that might mediate this process. First, we were able to prevent giant fibers from refining their connectivity by knocking out highwire, a ubiquitin ligase that prevented pruning. Second, we investigated whether overexpressing Netrin (or Frazzled), part of a canonical axon guidance system, would affect the refinement of giant fiber connectivity. We found that overexpressing Netrin (or Frazzled) pre- & postsynaptically resulted in some giant fibers forming or retaining excess connections, while exclusively presynaptic (or postsynaptic) expression of either protein had no effect. We further showed that by simultaneously reducing (Slit-Robo) midline repulsion and elevating Netrin (or Frazzled) pre- & postsynaptically, we significantly enhanced the proportion of giant fibers that formed excess connections. Our findings suggest that Netrin-Frazzled and Slit-Robo signaling play a significant role in refining synaptic circuits and shaping giant fiber circuit connectivity.
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Date Issued
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2016
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PURL
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http://purl.flvc.org/fau/fd/FA00004758, http://purl.flvc.org/fau/fd/FA00004758
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Subject Headings
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Drosophila melanogaster--Cytogenetics., Genetic transcription., Transcription factors., Cellular signal transduction., Cellular control mechanisms., Cell receptors.
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Format
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Document (PDF)
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Title
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Synchronization and phase dynamics of oscillating foils.
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Creator
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Finkel, Cyndee L., Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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In this work, a two-dimensional model representing the vortices that animals produce, when they are flying/swimming, was constructed. A D{shaped cylinder and an oscillating airfoil were used to mimic these body{shed and wing{generated vortices, respectively. The parameters chosen are based on the Reynolds numbers similar to that which is observed in nature (104). In order to imitate the motion of ying/swimming, the entire system was suspended into a water channel from frictionless air...
Show moreIn this work, a two-dimensional model representing the vortices that animals produce, when they are flying/swimming, was constructed. A D{shaped cylinder and an oscillating airfoil were used to mimic these body{shed and wing{generated vortices, respectively. The parameters chosen are based on the Reynolds numbers similar to that which is observed in nature (104). In order to imitate the motion of ying/swimming, the entire system was suspended into a water channel from frictionless air{bearings. The position of the apparatus in the channel was regulated with a linear, closed loop PI controller. Thrust/drag forces were measured with strain gauges and particle image velocimetry (PIV) was used to examine the wake structure that develops. The Strouhal number of the oscillating airfoil was compared to the values observed in nature as the system transitions between the accelerated and steady states... As suggested by previous work, this self-regulation is a result of a limit cycle process that stems from nonlinear periodic oscillations. The limit cycles were used to examine the synchronous conditions due to the coupling of the foil and wake vortices. Noise is a factor that can mask details of the synchronization. In order to control its effect, we study the locking conditions using an analytic technique that only considers the phases.. The results suggest that Strouhal number selection in steady forward natural swimming and flying is the result of a limit cycle process and not actively controlled by an organism. An implication of this is that only relatively simple sensory and control hardware may be necessary to control the steady forward motion of man-made biomimetically propelled vehicles.
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Date Issued
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2013
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PURL
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http://purl.flvc.org/fcla/dt/3362333
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Subject Headings
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Mathematical physics, Fluid dynamics, Unsteady flow (Fluid dynamics), Aerofoils, Aerodynamics
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Format
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Document (PDF)
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Title
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Synchronization in digital wireless radio receivers.
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Creator
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Nezami, Mohamed Khalid., Florida Atlantic University, Sudhakar, Raghavan, Helmken, Henry, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
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Abstract/Description
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Time Division Multiple Access (TDMA) architecture is an established technology for digital cellular, personal and satellite communications, as it supports variable data rate transmission and simplified receiver design. Due to transmission bandwidth restrictions, increasing user demands and the necessity to operate at lower signal-to-noise ratio (SNR), the TDMA systems employ high order modulation schemes such as M-ary Quadrature Amplitude Modulation (M-QAM) and burst transmission. Use of such...
Show moreTime Division Multiple Access (TDMA) architecture is an established technology for digital cellular, personal and satellite communications, as it supports variable data rate transmission and simplified receiver design. Due to transmission bandwidth restrictions, increasing user demands and the necessity to operate at lower signal-to-noise ratio (SNR), the TDMA systems employ high order modulation schemes such as M-ary Quadrature Amplitude Modulation (M-QAM) and burst transmission. Use of such techniques in low SNR fading channels causes degradations of carrier frequency error, phase rotation error, and symbol timing jitter. To compensate for the severe degradation due to additive white Gaussian noise (AWGN) and channel impairments, precise and robust synchronization algorithms are required. This dissertation deals with the synchronization techniques for TDMA receivers using short burst mode transmission with emphasis on preamble-less feedforward synchronization schemes. The objective is to develop new algorithms for symbol timing, carrier frequency offset acquisition, and carrier phase tracking using preamble-less synchronization techniques. To this end, the currently existing synchronization algorithms are surveyed and analyzed. The performance evaluation of the developed algorithms is conducted through Monte-Carlo simulations and theoretical analyses. The statistical properties of the proposed algorithms in AWGN and fading channels are evaluated in terms of the mean and variance of the estimated synchronization errors and their Cramer-Rao lower bounds. Based on the investigation of currently employed feedforward symbol timing algorithms, two new symbol timing recovery schemes are proposed for 16-QAM land mobile signals operating in fading channels. Both schemes achieve better performance in fading channels compared to their existing counterparts without increasing the complexity of the receiver implementation. Further, based on the analysis of currently employed carrier offset and carrier phase recovery algorithms, two new algorithms are proposed for carrier acquisition and carrier tracking of mobile satellite systems utilizing short TDMA bursts with large frequency offsets. The proposed algorithms overcome some of the conventional problems associated with currently employed carrier recovery schemes in terms of capture range, speed of convergence, and stability.
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Date Issued
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2001
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PURL
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http://purl.flvc.org/fcla/dt/11947
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Subject Headings
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Radio--Receivers and reception, Digital communications, Time division multiple access
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Format
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Document (PDF)
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Title
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Synchronization of coupled semiconductor lasers.
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Creator
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London, Michael S., Charles E. Schmidt College of Science, Department of Physics
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Abstract/Description
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The synchronization of coupled semiconductor lasers with delay is investigated by numerical simulations of the nonlinear dynamic models complemented by a stability analysis of the linearized system. The equations used in the dissertation are based on the well known "Lang-Kobayashi" model modified to include unidirectional and bidirectional coupling. Stability diagrams are calculated and supplemented by numerically integrated time series. Synchronization is determined and quantified by...
Show moreThe synchronization of coupled semiconductor lasers with delay is investigated by numerical simulations of the nonlinear dynamic models complemented by a stability analysis of the linearized system. The equations used in the dissertation are based on the well known "Lang-Kobayashi" model modified to include unidirectional and bidirectional coupling. Stability diagrams are calculated and supplemented by numerically integrated time series. Synchronization is determined and quantified by computing the cross-correlation function. It is found that synchronized states are achievable for a wide range of coupling constants and delay times. These findings have implications for experiment and technological applications, notably in cryptography.
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Date Issued
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2011
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PURL
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http://purl.flvc.org/FAU/3318673
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Subject Headings
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Semiconductor lasers, Optical bistability, Nonlinear theories, Diodes, Semiconductor, Mathematical models
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Format
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Document (PDF)
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Title
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Synchronous spatial array processing for underwater vehicle tracking.
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Creator
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Normand, Olivier., Florida Atlantic University, Schock, Steven G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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Navigation of Unmanned Underwater Vehicles (UUVs) is commonly assisted in confined areas by acoustic positioning systems. The Department of Ocean Engineenng at Florida Atlantic University is developing an altemative system based on submerged modems. This thesis describes an optimal target location estimation technique using a multi-channel spatial receiver array (Millscross) used as a development tool combined with a synchronous modem and transponder network mounted on buoys and UUVs. The...
Show moreNavigation of Unmanned Underwater Vehicles (UUVs) is commonly assisted in confined areas by acoustic positioning systems. The Department of Ocean Engineenng at Florida Atlantic University is developing an altemative system based on submerged modems. This thesis describes an optimal target location estimation technique using a multi-channel spatial receiver array (Millscross) used as a development tool combined with a synchronous modem and transponder network mounted on buoys and UUVs. The Millscross provides a reference to evaluate the performance of the navigation estimator. Spatial array principles are used to develop decoding and beamforming techniques to process modem messages, enabling the end user (the UUV) to estimate in real-time its own position and navigate in space. A simulation was used to compare actual results with theory and determine the processing and decoding algorithms. These algorithms were then applied to real data to estimate the target position (direction of arrival and geodetic coordinates).
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Date Issued
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2002
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PURL
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http://purl.flvc.org/fcla/dt/12917
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Subject Headings
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Underwater navigation, Underwater acoustics, Signal processing--Digital techniques
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Format
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Document (PDF)
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Title
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Synchrony andsociality: breeding strategies in constant and variable environments.
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Creator
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Young, Craig M., Harbor Branch Oceanographic Institute
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Date Issued
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1999
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PURL
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http://purl.flvc.org/fau/fd/FA00007271
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Subject Headings
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Breeding, Reproduction, Benthos, Aquatic ecology
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Format
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Document (PDF)
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Title
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Synchrony in adult male Atlantic Spotted Dolphins (Stenella frontalis) during aggression.
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Creator
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Myers, Alyson J., Bjorklund, David F., Herzing, Denise L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
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Abstract/Description
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Synchrony between Atlantic spotted dolphins (Stenella frontalis) is crucial for successfully fending off bottlenose dolphins (Tursiops truncatus) during interspecies aggression. The present study examined synchrony in adult Atlantic spotted dolphins during aggressive encounters with bottlenose dolphins. Across group size, aggressive behavioral events increased preceding synchrony, peaked during synchrony, and decreased dramatically after synchrony. Although smaller groups ( 10 dolphins),...
Show moreSynchrony between Atlantic spotted dolphins (Stenella frontalis) is crucial for successfully fending off bottlenose dolphins (Tursiops truncatus) during interspecies aggression. The present study examined synchrony in adult Atlantic spotted dolphins during aggressive encounters with bottlenose dolphins. Across group size, aggressive behavioral events increased preceding synchrony, peaked during synchrony, and decreased dramatically after synchrony. Although smaller groups (< 10 dolphins) became synchronous more frequently than larger groups (> 10 dolphins), larger groups remained synchronous longer; however, smaller groups exhibited more frequent aggressive behavioral events during synchrony, suggesting that additional aggressive behaviors may be necessary to compensate for the small group size, whereas larger groups may be able to rely on synchrony alone. Disorganized squawk bouts synchronized as physical synchrony began, but only if coupled with escalating aggressive behaviors. The synchrony during aggressive episodes observed in adult Atlantic spotted dolphins can be used as a baseline to determine the process of the development of this critical skill in juveniles.
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Date Issued
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2015
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PURL
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http://purl.flvc.org/fau/fd/FA00004454
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Subject Headings
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Atlantic spotted dolphin, Atlantic spotted dolphin -- Behavior -- Research, Bottle nose dolphin, Bottle nose dolphin -- Behavior -- Research, Dolphins, Social behavior in animals
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Format
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Document (PDF)
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Title
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Synergistic effects of invasive species (Melaleuca quinquenervia) and management practices on native plant community resilience in the Florida Everglades.
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Creator
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Lange, James J., Graduate College
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Date Issued
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2012-03-30
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PURL
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http://purl.flvc.org/fcla/dt/3342389
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Format
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Document (PDF)
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Title
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SYNESTHESIA AND THIN BOUNDARIES OF THE MIND.
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Creator
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Mayernik, Samantha M., Lanning, Kevin, Florida Atlantic University, Harriet L. Wilkes Honors College
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Abstract/Description
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Synesthesia is a phenomenon in which the lines between senses are blurred, suggesting permeable boundaries in the mind. This notion of boundary permeability is inherently linked with Openness to Experience, one of the Big Five personality traits. Conversely, some people are characterized by heavy boundaries and thus a lack of Openness. Since the 1930s, the relationship between Openness and boundaries has been important in political psychology, as previous research has established that...
Show moreSynesthesia is a phenomenon in which the lines between senses are blurred, suggesting permeable boundaries in the mind. This notion of boundary permeability is inherently linked with Openness to Experience, one of the Big Five personality traits. Conversely, some people are characterized by heavy boundaries and thus a lack of Openness. Since the 1930s, the relationship between Openness and boundaries has been important in political psychology, as previous research has established that conservatives tend to be low in Openness, while the opposite is true for liberals. Authoritarianism can be seen as the embodiment of a mind with thick boundaries, while the most pure example of a thin-bounded mind would be synesthesia. I perform a text analysis of Reddit comments made by 117 self-reported synesthetes and compare their responses to the Openness category of the Linguistic Inquiry and Word Count (LIWC), to examine whether synesthesia correlates with Openness.
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Date Issued
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2020
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PURL
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http://purl.flvc.org/fau/fd/FA00013662
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Format
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Document (PDF)
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Title
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SynGAP1 Haploinsufficiency affects neuronal structure and development in mouse models.
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Creator
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McGuire, Megan, Dragojlovic, Veljko, Harriet L. Wilkes Honors College
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Abstract/Description
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Intellectual Disability (ID) is an increasingly common neurological disorder that causes intellectual deficients in cognition and behavior and is scientifically diagnosed by an intelligence score (IQ) under 70 along with the presence of two or more associated behaviors. A recent study showed that sporadic ID in humans was correlated with autosomal dominant de novo mutations in SynGap1.
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Date Issued
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2013
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PURL
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http://purl.flvc.org/fau/fd/FA00003525
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Format
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Document (PDF)
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Title
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Synopsis of researcher meeting: Bottlenose dolphin health & risk assessment project.
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Creator
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Fair, Patricia A., Bossart, Gregory D.
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Date Issued
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2005
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PURL
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http://purl.flvc.org/fcla/dt/3359274
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Subject Headings
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Bottlenose dolphin, Bottlenose dolphin--Atlantic Coast (U.S.), Dolphins--Research
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Format
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Document (PDF)
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Title
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Synoptic Octaves.
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Creator
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McIntyre, Constance, Dorothy F. Schmidt College of Arts and Letters, Brooks, Clarence, Madden, Kristine, Department of Theatre and Dance
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Abstract/Description
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The Dances We Dance Performance Showcase is a capstone experience for students enrolled in all levels of the Department of Theatre and Dance performance course offerings.
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Date Issued
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2012
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PURL
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http://purl.flvc.org/fau/fd/FAdwd12syno
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Subject Headings
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Dance performance
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Format
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Set of related objects
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Title
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A SYNTACTIC APPROACH TO HAND PRINTED CHARACTER RECOGNITION.
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Creator
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KING, ALLAN KAI-CHUNG, Florida Atlantic University, Hadlock, Frank O., Charles E. Schmidt College of Science, Department of Mathematical Sciences
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Abstract/Description
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A study was made on the feasibility of the syntactic approach to the problem of hand printed character recognition. The characters are represented as postfix expressions in Picture Description Language. By comparing them with the prototype expressions, each character is classified as the prototype that is closest to it. Programs written in the Pascal language, which generate the postfix expressions for the characters, and recognize the characters, are presented.
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Date Issued
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1983
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PURL
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http://purl.flvc.org/fcla/dt/14168
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Subject Headings
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Pattern recognition systems, Character sets (Data processing)
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Format
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Document (PDF)
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Title
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Synthesis and Bioactivity Investigation of Bridged Bicyclic Compounds and a Mechanistic Investigation of a Propargyl Hydrazine Cycloaddition Catalyzed by an Ammonium Salt.
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Creator
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St.Germain, Elijah, Lepore, Salvatore D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
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Abstract/Description
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We report the development of a general route to the synthesis of [4.3.1], [3.3.1], an especially [3.2.1] bicyclic compounds structurally related to vitisinol D, a natural product. This allows for diastereoselective synthesis of bicyclic compounds with five adjacent chiral centers. This route was employed in a preliminary SAR investigation into the neuroprotectant effect of small molecules in an in vivo experiment measuring the degree of restorative effect of synaptic transmission in the...
Show moreWe report the development of a general route to the synthesis of [4.3.1], [3.3.1], an especially [3.2.1] bicyclic compounds structurally related to vitisinol D, a natural product. This allows for diastereoselective synthesis of bicyclic compounds with five adjacent chiral centers. This route was employed in a preliminary SAR investigation into the neuroprotectant effect of small molecules in an in vivo experiment measuring the degree of restorative effect of synaptic transmission in the neuromuscular junction of Drosophila melanogaster larvae under acute oxidative stress. One of the compounds exhibited intriguing potential as a neuroprotectant and outperformed resveratrol in restoring synaptic function under oxidative stress. The hypothesis that bridged bicyclic compounds may hold promise as drug scaffolds due to their conformational rigidity and ability to orient functional appendages in unique orientations is developed. The second focus is a mechanistic investigation into a tetrabutylammoniumcatalyzed cycloaddition as evidence of a novel ammonium-alkyne interaction. A carbamate nitrogen adds to a non-conjugated carbon–carbon triple bond under the action of an ammonium catalyst leading to a cyclic product. Studies in homogeneous systems suggest that the ammonium agent facilitates cyclitive nitrogen–carbon bond formation through a cation–π interaction with the alkyne unit. Using Raman spectroscopy, this cation–π interaction is directly observed for the first time. DFT modeling elucidated the mechanistic factors in this cycloaddition. A teaching experiment was developed based on this mechanistic investigation. Control experiments were employed to demonstrate the testing of two alternative mechanistic hypotheses. Cyclization reactions were performed with a soluble base (sodium phenoxide) with and without tetrabutylammonium bromide under homogeneous conditions. Students observed that ammonium salt accelerates the reaction. They were encouraged to develop a testable hypothesis for the role of the ammonium salt in the cyclization mechanism: typical phase transfer or other. IR spectroscopy was used to directly observe a dose dependent shift of the alkyne stretching mode due to a cation−π interaction. Undergraduates were able to employ the scientific method on a contemporary system and see how data are generated and interpreted to adjudicate between rival hypotheses in a way that emulates authentic and current research in a lab setting.
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Date Issued
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2018
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PURL
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http://purl.flvc.org/fau/fd/FA00013100
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Subject Headings
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Bicyclic compounds., Ammonium salts., Cycloaddition Reaction.
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Format
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Document (PDF)
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Title
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Synthesis and biological evaluation of 10, 11-Dihydrodictyostatin, a potent analogue of the marine anticancer agent dictyostatin.
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Creator
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Paterson, Ian, Gardner, Nicola M., Poullennec, Karine G., Wright, Amy E.
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Date Issued
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2008
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PURL
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http://purl.flvc.org/FCLA/DT/3333013
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Subject Headings
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Macrolides, Antineoplastic agents, Biological evaluation, Synthesis, Antimitotic agents
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Format
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Document (PDF)
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Title
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Synthesis and biological evaluation of novel analogues of dictyostatin.
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Creator
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Paterson, Ian, Gardner, Nicola M., Poullennec, Karine G., Wright, Amy E.
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Date Issued
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2007
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PURL
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http://purl.flvc.org/FCLA/DT/2763290
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Subject Headings
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Microtubules --Research--Methodology, Microtubules
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Format
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Document (PDF)
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Title
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Synthesis and Biological Evaluation of β-hairpin Peptides as Covalent Inhibitors of the PD-1/PD-L1 Immune Checkpoint.
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Creator
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Naylon, Sarah, Roche, Stephane, Florida Atlantic University, Department of Chemistry and Biochemistry, Charles E. Schmidt College of Science
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Abstract/Description
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Protein─protein interactions (PPIs) are essential for cell─cell interactions and cellular signal transduction, which play a crucial role in various human diseases. PPIs involved in cancer immunology pathways, known as immune checkpoints, have been intensely studied, leading to a new approach to cancer therapy. The PD1:PDL1 interaction is one of the most essential immune checkpoints. Studies on PD1:PDL1 showed over ten clinical monoclonal antibodies (mAb) used to treat cancer patients....
Show moreProtein─protein interactions (PPIs) are essential for cell─cell interactions and cellular signal transduction, which play a crucial role in various human diseases. PPIs involved in cancer immunology pathways, known as immune checkpoints, have been intensely studied, leading to a new approach to cancer therapy. The PD1:PDL1 interaction is one of the most essential immune checkpoints. Studies on PD1:PDL1 showed over ten clinical monoclonal antibodies (mAb) used to treat cancer patients. Unfortunately, antibodies do not penetrate the tumor microenvironment well, and clearance from the body is slow, leading to unwanted side effects. There is a significant gap in the drug market between the typical Rule of 5 (Ro5) small-molecule drugs (MW<0.5 kDa, SASA ~150 Å) and large antibodies with molecular weights greater than 40 kDa (SASA >2,000 Å). PPIs remain challenging to modulate by small molecules due to their large, shallow, often dynamic, and water-exposed surfaces lacking well-defined binding pockets. Thus, our lab was drawn to work on large β-hairpin peptides (2-3 kDa) that can potentially mimic the CDR-H3 loops of some of the most potent and clinical anti-PD1 antibodies. Exploration of these β-hairpin peptides provided valuable insights into their folding stability, conformational flexibility, passive membrane permeability, and protein-protein interaction (PPI) blocking activities. Additionally, the rational design of TCIs against PD1, specifically targeting a lysine residue, emerged as a strategy to irreversibly obstruct the PD1:PDL1 protein-protein interaction enhancing potency of the non-covalent inhibitors by taking advantage of their specificity. Meticulous structural analysis, peptide synthesis, and biological evaluations are presented contributing comprehensions into covalent inhibitor development of drugs fbRo5.
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Date Issued
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2023
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PURL
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http://purl.flvc.org/fau/fd/FA00014353
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Subject Headings
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Cancer--Immunological aspects, Protein-protein interactions, Antibodies, Monoclonal
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Format
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Document (PDF)
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Title
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Synthesis and characterization of aluminum phenylphosphonate.
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Creator
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Brady, Jennifer Beth., Florida Atlantic University, Haky, Jerome E.
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Abstract/Description
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A new aluminum phenylphosphonate compound, AlH(C6H5P03)2 was obtained by refluxing a mixture of aluminum nitrate and excess phenylphosphonic acid in water. The compound was characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, x-ray powder diffraction and nuclear magnetic resonance spectroscopy. The data indicates that an intercalation compound formed, with an interlayer spacing of 15 angstroms. The compound contains both tetrahedrally and octahedrally...
Show moreA new aluminum phenylphosphonate compound, AlH(C6H5P03)2 was obtained by refluxing a mixture of aluminum nitrate and excess phenylphosphonic acid in water. The compound was characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, x-ray powder diffraction and nuclear magnetic resonance spectroscopy. The data indicates that an intercalation compound formed, with an interlayer spacing of 15 angstroms. The compound contains both tetrahedrally and octahedrally coordinated aluminum atoms, suggesting the presence of two or more crystalline phases or a complex unit cell structure. The compound also possesses some unique ion-exchange properties.
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Date Issued
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1996
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PURL
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http://purl.flvc.org/fcla/dt/15314
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Subject Headings
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Aluminum compounds, Phosphonates
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Format
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Document (PDF)
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Title
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Synthesis and characterization of group IVB metallocene materials derived from hematoporphyrin IX.
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Creator
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Rivalta, Alberto Enrico., Florida Atlantic University, Carraher, Charles E., Haky, Jerome E.
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Abstract/Description
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New organometallic containing materials were synthesized by the reaction of Group IVB metallocene dichlorides of the form Cp2MCl2 where M = Ti, Ar, and Hf with Hematoporphyrin IX using the interfacial condensation polymerization technique. The structural characterization was accomplished using infrared and mass spectroscopy and elemental analysis. The results obtained from these techniques showed the presence of the metal ester and ether bonding as evidence that the reaction occurred. The...
Show moreNew organometallic containing materials were synthesized by the reaction of Group IVB metallocene dichlorides of the form Cp2MCl2 where M = Ti, Ar, and Hf with Hematoporphyrin IX using the interfacial condensation polymerization technique. The structural characterization was accomplished using infrared and mass spectroscopy and elemental analysis. The results obtained from these techniques showed the presence of the metal ester and ether bonding as evidence that the reaction occurred. The product derived from titanocene dichloride, 12-A, exhibited growth inhibition characteristics towards the Candid albicans and Staphylococcus aureus microorganisms. From the preliminary metal adsorption studies it was shown that this product also bound nickel ions.
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Date Issued
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1993
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PURL
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http://purl.flvc.org/fcla/dt/14940
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Subject Headings
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Organometallic chemistry, Porphyrins, Hematoporphyrin, Metallocenes
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Format
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Document (PDF)
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Title
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Synthesis and characterization of organostannane modified poly(ethylene-co-vinyl alcohol) copolymers.
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Creator
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Pandya, Bhoomin Mahendra., Florida Atlantic University, Carraher, Charles E.
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Abstract/Description
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Ethylene/vinyl alcohol (EVOH) copolymers are widely used. These copolymers have been reacted with metallic and organometallic groups for various applications. In the present work, organostannane modified EVOH copolymers are synthesized and characterized and their structure-property relationships, especially with respect to their applications as antibacterials and fungicides as well as their film forming ability, are studied. The modified copolymers exhibit "ionomer-like" thermal properties....
Show moreEthylene/vinyl alcohol (EVOH) copolymers are widely used. These copolymers have been reacted with metallic and organometallic groups for various applications. In the present work, organostannane modified EVOH copolymers are synthesized and characterized and their structure-property relationships, especially with respect to their applications as antibacterials and fungicides as well as their film forming ability, are studied. The modified copolymers exhibit "ionomer-like" thermal properties. Some of the properties of the modified EVOH products are also compared to analogous modified polyvinyl alcohol products.
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Date Issued
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1993
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PURL
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http://purl.flvc.org/fcla/dt/14939
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Subject Headings
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Organotin compounds, Ionomers, Ethylene compounds
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Format
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Document (PDF)
Pages