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- Title
- SYMBOLS AND MYSTICISM IN THE NOVELS OF THOMAS BURNETT SWANN.
- Creator
- HUNT, LEIGH INA., Florida Atlantic University, Collins, Robert A.
- Abstract/Description
-
The three great classes of symbols identified by Evelyn Underhill in mystical literature are present in Swann's novels. They are the symbols of the journey, human love and marriage, and purity and perfection. An analysis of the symbols shows that their use is not random, but consistent with a pattern of spiritual development composed of several stages and called the Mystic Way. As a result, Swann's novels can be read and enjoyed as works of fantasy or of mysticism.
- Date Issued
- 1981
- PURL
- http://purl.flvc.org/fcla/dt/14088
- Subject Headings
- Swann, Thomas Burnett--Criticism and interpretation
- Format
- Document (PDF)
- Title
- Symbols of racial possibilities: Perspectives on Nella Larsen, James Weldon Johnson, and Jean Toomer.
- Creator
- Lynch, Suzanne Marie., Florida Atlantic University, King, Natalie
- Abstract/Description
-
The question of hybridity is a complex social issue that commonly addresses agendas of heart, politics, and mind. It is a question that is both deeply personal and overtly political and addresses the entire spectrum of American society. Hybridity, in my view, can be used to interrogate a society rooted in ideas of race definition. Nella Larsen's Quicksand, Jean Toomer's Cane, and James Weldon Johnson's Autobiography of an Ex-Coloured Man depict the struggles of the mixed-race characters as...
Show moreThe question of hybridity is a complex social issue that commonly addresses agendas of heart, politics, and mind. It is a question that is both deeply personal and overtly political and addresses the entire spectrum of American society. Hybridity, in my view, can be used to interrogate a society rooted in ideas of race definition. Nella Larsen's Quicksand, Jean Toomer's Cane, and James Weldon Johnson's Autobiography of an Ex-Coloured Man depict the struggles of the mixed-race characters as they seek an identity of wholeness through attempting to live up to a social prescription of sameness. These characters wander in search of a raceless society; they cross boundaries of language and live in silence in a dichotomized world of public conformity and private duality despite their efforts to unite the two.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15701
- Subject Headings
- Larsen, Nella--Quicksand, Johnson, James Weldon,--1871-1938--Autobiography of an ex-coloured man, Toomer, Jean,--1894-1967--Cane, Racism
- Format
- Document (PDF)
- Title
- SYMMETRIES IN GOPPA CODES.
- Creator
- SAYRS, BRIAN GEORGE., Florida Atlantic University, Hoffman, Frederick, Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
Properties of Goppa codes are studied. These are "good" codes in the sense that they asymptotically approach the Varshamov-Gilbert bound. E. N. Gilbert and R. R. Varshamov have shown (independently) that it is possible to construct an (n, k) linear code over GF(q) with minimum distance d if [equation] and there are long Goppa codes which achieve this bound [10]. Subclasses of Goppa codes which remain invariant under symmetries are given special attention.
- Date Issued
- 1979
- PURL
- http://purl.flvc.org/fcla/dt/13989
- Subject Headings
- Mathematics--Research
- Format
- Document (PDF)
- Title
- Symposium summary: biology and aquaculture.
- Creator
- Tucker, John W., Jr., Harbor Branch Oceanographic Institute
- Date Issued
- 1994
- PURL
- http://purl.flvc.org/FCLA/DT/3340772
- Subject Headings
- Aquaculture--Congresses, Biology--Congresses, Congresses and conventions
- Format
- Document (PDF)
- Title
- Synaptic Architecture of Cortical Columns.
- Creator
- Wilson, Daniel E., Fitzpatrick, David, Graduate College
- Abstract/Description
-
The visual cortex of higher mammals, including humans, is arranged as to achieve a continuously varying map of features such as the orientation of contours in the environment. Previous studies used intrinsic signal and two-photon imaging to examine the functional composition of these cortical maps, but lacked the functional resolution to resolve the underlying synaptic architecture. Here, we exploited recent advances in genetically encoded calcium indicators to perform in vivo two photon...
Show moreThe visual cortex of higher mammals, including humans, is arranged as to achieve a continuously varying map of features such as the orientation of contours in the environment. Previous studies used intrinsic signal and two-photon imaging to examine the functional composition of these cortical maps, but lacked the functional resolution to resolve the underlying synaptic architecture. Here, we exploited recent advances in genetically encoded calcium indicators to perform in vivo two photon imaging of dendrites and dendritic spines in an animal with a mapped visual cortex. We found sharp orientation and direction tuning when we presented drifting gratings and imaged synaptic calcium transients from large numbers of dendritic spines in single neurons, obtaining synaptic maps of orientation preference. In addition, we implemented a newly developed two-photon microscope that uses acousto-optical deflectors to rapidly steer a pulsed laser in three dimensions. This technology allowed us to image 320 single cells in an 800x800x200 micron three-dimensional volume, which yielded a three-dimensional orientation map with single-cell resolution. In the future, we will perform fast, three-dimensional imaging of a single cell and its entire dendritic tree to monitor functional properties of a cell’s inputs and its somatic spiking output. These experiments will yield important insight into synaptic integration and sensory processing in cortical maps and how such organizing principles might be disrupted in disease states.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005864
- Format
- Document (PDF)
- Title
- Synaptic Rearrangements and the Role of Netrin-Frazzled Signaling in Shaping the Drosophila Giant Fiber Circuit.
- Creator
- Lloyd, Brandon N., Murphey, Rodney K., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
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.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004758, http://purl.flvc.org/fau/fd/FA00004758
- Subject Headings
- Drosophila melanogaster--Cytogenetics., Genetic transcription., Transcription factors., Cellular signal transduction., Cellular control mechanisms., Cell receptors.
- Format
- Document (PDF)
- Title
- Synchronization and phase dynamics of oscillating foils.
- Creator
- Finkel, Cyndee L., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
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.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362333
- Subject Headings
- Mathematical physics, Fluid dynamics, Unsteady flow (Fluid dynamics), Aerofoils, Aerodynamics
- Format
- Document (PDF)
- Title
- Synchronization in digital wireless radio receivers.
- Creator
- 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
- Abstract/Description
-
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.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/11947
- Subject Headings
- Radio--Receivers and reception, Digital communications, Time division multiple access
- Format
- Document (PDF)
- Title
- Synchronization of coupled semiconductor lasers.
- Creator
- London, Michael S., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
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.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3318673
- Subject Headings
- Semiconductor lasers, Optical bistability, Nonlinear theories, Diodes, Semiconductor, Mathematical models
- Format
- Document (PDF)
- Title
- Synchronous spatial array processing for underwater vehicle tracking.
- Creator
- Normand, Olivier., Florida Atlantic University, Schock, Steven G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
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).
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12917
- Subject Headings
- Underwater navigation, Underwater acoustics, Signal processing--Digital techniques
- Format
- Document (PDF)
- Title
- Synchrony andsociality: breeding strategies in constant and variable environments.
- Creator
- Young, Craig M., Harbor Branch Oceanographic Institute
- Date Issued
- 1999
- PURL
- http://purl.flvc.org/fau/fd/FA00007271
- Subject Headings
- Breeding, Reproduction, Benthos, Aquatic ecology
- Format
- Document (PDF)
- Title
- Synchrony in adult male Atlantic Spotted Dolphins (Stenella frontalis) during aggression.
- Creator
- Myers, Alyson J., Bjorklund, David F., Herzing, Denise L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
-
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.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004454
- Subject Headings
- Atlantic spotted dolphin, Atlantic spotted dolphin -- Behavior -- Research, Bottle nose dolphin, Bottle nose dolphin -- Behavior -- Research, Dolphins, Social behavior in animals
- Format
- Document (PDF)
- Title
- Synergistic effects of invasive species (Melaleuca quinquenervia) and management practices on native plant community resilience in the Florida Everglades.
- Creator
- Lange, James J., Graduate College
- Date Issued
- 2012-03-30
- PURL
- http://purl.flvc.org/fcla/dt/3342389
- Format
- Document (PDF)
- Title
- SYNESTHESIA AND THIN BOUNDARIES OF THE MIND.
- Creator
- Mayernik, Samantha M., Lanning, Kevin, Florida Atlantic University, Harriet L. Wilkes Honors College
- Abstract/Description
-
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.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013662
- Format
- Document (PDF)
- Title
- SynGAP1 Haploinsufficiency affects neuronal structure and development in mouse models.
- Creator
- McGuire, Megan, Dragojlovic, Veljko, Harriet L. Wilkes Honors College
- Abstract/Description
-
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.
- Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA00003525
- Format
- Document (PDF)
- Title
- Synopsis of researcher meeting: Bottlenose dolphin health & risk assessment project.
- Creator
- Fair, Patricia A., Bossart, Gregory D.
- Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/3359274
- Subject Headings
- Bottlenose dolphin, Bottlenose dolphin--Atlantic Coast (U.S.), Dolphins--Research
- Format
- Document (PDF)
- Title
- Synoptic Octaves.
- Creator
- McIntyre, Constance, Dorothy F. Schmidt College of Arts and Letters, Brooks, Clarence, Madden, Kristine, Department of Theatre and Dance
- Abstract/Description
-
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.
- Date Issued
- 2012
- PURL
- http://purl.flvc.org/fau/fd/FAdwd12syno
- Subject Headings
- Dance performance
- Format
- Set of related objects
- Title
- A SYNTACTIC APPROACH TO HAND PRINTED CHARACTER RECOGNITION.
- Creator
- KING, ALLAN KAI-CHUNG, Florida Atlantic University, Hadlock, Frank O., Charles E. Schmidt College of Science, Department of Mathematical Sciences
- Abstract/Description
-
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.
- Date Issued
- 1983
- PURL
- http://purl.flvc.org/fcla/dt/14168
- Subject Headings
- Pattern recognition systems, Character sets (Data processing)
- Format
- Document (PDF)
- Title
- Synthesis and Bioactivity Investigation of Bridged Bicyclic Compounds and a Mechanistic Investigation of a Propargyl Hydrazine Cycloaddition Catalyzed by an Ammonium Salt.
- Creator
- St.Germain, Elijah, Lepore, Salvatore D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
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.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013100
- Subject Headings
- Bicyclic compounds., Ammonium salts., Cycloaddition Reaction.
- Format
- Document (PDF)
- Title
- Synthesis and biological evaluation of 10, 11-Dihydrodictyostatin, a potent analogue of the marine anticancer agent dictyostatin.
- Creator
- Paterson, Ian, Gardner, Nicola M., Poullennec, Karine G., Wright, Amy E.
- Date Issued
- 2008
- PURL
- http://purl.flvc.org/FCLA/DT/3333013
- Subject Headings
- Macrolides, Antineoplastic agents, Biological evaluation, Synthesis, Antimitotic agents
- Format
- Document (PDF)