April 10, 2012    Laney 102     

Jordan Wilkerson is a senior and Claire Desrochers a junior chemistry major.  Both are synthesizing models of amino acid organic radicals in the laboratory of Dr. N. Carter of the Dept. of Chemistry.  These radicals represent molecular models of species that can form in biological systems exposed to high energy (UV, X-ray, or gamma) radiation.  Claire described work to synthesize an example of the amino acid valine, and Jordan explained his work to prepare examples of phenylalanine radicals.  A key component of both systems was the inclusion of the element selenium.  Selenium-carbon bonds in these molecules are promising targets of future UV exposure, because these bonds are easily ruptured to generate the kind of carbon-centered radicals encountered in biological settings.  Claire outlined a strategy of reverse synthesis, wherein one works backward from the final target compound to devise the best method of its synthesis from commercially available precursors.  Both students described the considerable challenges of the multiple steps involved in their synthetic procedures and the need to purify and characterize intermediates along the way to their desired final products.  They explained the use of nuclear magnetic resonance (NMR) as an important tool in this work including the use of the less common method selenium-77 NMR. 

John Lahmann is a senior physics major working under the direction of Dr. S. Addison in the Dept. of Physics and Astronomy.  John shared his experiments to characterize sound signatures from a fixed frequency Helmholz resonator, analogous to the sound emitted from a soda bottle when air is blown across the face of the bottle opening.  One application of this work is the study of acoustical signals in the ground related to seismic activity as well as anthropogenic activity like mineral mining. 

Nick Martinez is also a senior physics major working for Dr. A Walker in the Dept. of Physics and Astronomy.  Nick described the challenge of preparing extremely thin electrodes in order to measure minute action voltages in cellular systems.

March 15, 2012   Lewis Science Center 100

Venusa Phomakay and Jessica Gambill are both senior chemistry majors working with Dr. M. Kelley in the Dept. of Chemistry.  They describe their studies of the role of the Vitamin A derivatives, trans-retinoic acid (tRA) and 9-cis retinoic acid (9-cis) on adhesion and proliferation of model K652 cells cultured in Dr. Kelley’s lab.  Both tRA and 9-cis are known to influence DNA transcription leading to proteins involved in immune responses that affect cellular adhesion, differentiation, and programmed cell death.  In their work they also studied the effect of troglitazone (trog, a treatment for  inflammation and diabetes) on RA action. Their high pressure liquid chromatography analysis of cell-culture media demonstrated that Trog inhibited metabolism of RA in cells.  They also noted that trog improved cellular adhesion but reduced proliferation.  These results encourage future work in the lab to more precisely define the influence of trog on the physiological action of retinoic acid on cell function.

Skipper Thurman is a senior physics major who described a project with Dr. W. Slaton in the Dept. of Physics and Astronomy.  His goal was to develop an experiment to investigate the pressure signatures from a speaker sound source as a function of angle with respect to the source.  While he simplified his problem to a single point sound source, he noted that additional complexities would involve inclusion of a second point source (some distance from the first), leading to sound wave diffraction, or to an infinite number of sound sources like a vibrating drum surface.  He initially shared theoretical pressure wave signatures derived purely from theoretical models.  He then compared his experimentally recorded signatures to these theoretical models, with good agreement.  Skipper also noted errors inherent in his experiment and their possible effect on the experimental patterns.  In addition to providing a new experiment for acoustics instruction at UCA, Skipper’s work also has applications to investigations of acoustic signals in complex environments like cityscapes where multiple sources exist at many different angles.

Vinh Lu is a senior math/physics major working on a joint project with Drs. C. Burg (Dept. of Mathematics) and W. Slaton (Dept. of Physics and Astronomy).  Vinh developed an experimental model for the effect of drag forces on the flow of a fluid (air) past an object.  He developed a system capable of measuring the flow of air past a sphere, by comparing wind speeds about the object.  He was able to determine viscous (drag) forces from these data and noted that the forces were greatest nearest static surfaces of the air flow wall and the spherical surface.  This was related to the common experience of the flow of viscous syrup, where the liquid tends to flow slowly where it is in contact with a surface, but flows faster moving out into the bulk fluid away from the surface.  This project provided an opportunity for the comparison of detailed mathematical modeling of the phenomenon of forces acting in liquid flow and the development of an experimental system capable of testing it. 

February 21, 2012   Math Computer Science Bldg. 220

Lennon Bates is a senior biology major working under the mentorship of Dr. K. Steelman in the Dept. of Chemistry.  Her work is direct at using carbon-dating to analyze archeological samples from areas in western Australia.  Aboriginal groups there wanted these analyses to characterize the site for improved historical understanding and for preservation as they consider making the region a national park.  Lennon distinguished her work on pictographs (surface rock paintings) with petroglyphs (surface rock carvings).  She described the process of carbon-dating the over 200 samples with dates ranging as early as 5000 years before present.  The chemical challenge of the work involves careful sample pretreatment to remove non-prehistoric surface carbon accumulation followed by plasma oxidation of archeologically significant portion.  The carbon dioxide formed was carefully collected in Dr. Steelman’s lab at UCA and then subjected to high resolution mass spectrometry at Lawrence Berkeley Labs in California.  This method is equipped to eliminate complications from ubiquitous nitrogen-14 and carbon-12 impurities and obtain accurate counts of key carbon-14 and carbon-13 isotopes. 

Reese Borchers is a sophomore chemistry major and Jenna Shamburger is a junior biology major.  Both described their work in the laboratory of Dr. D. Perry in the Dept, of Chemistry investigating thin films of organic molecules deposited on carefully prepared metal surfaces.  Their specific organic system involved studies of amino acids on metal surface.  Amino acids are inherently interesting because of their relation to biological samples, but they are challenging to study because of their considerable intermolecular forces of attraction and their ability to undergo complicating acid/base reactions on the metal surfaces.  Their approach involved a combination in infrared (IR) measurements and gas chromatography mass spectrometry (GCMS).  IR measurements allowed them to characterize vibrations from specific structural features of the adsorbed amino acids, indicating the manner and strength of organic-metal and molecule-molecule interactions in the organic layers.  GCMS allowed them to follow the temperature and time-dependent desorption of the molecules from the metal surfaces.  They hoped this GCMS work would support future matrix assisted laser desorption studies to best characterize the precise form of the amino acid adhering to the metal surfaces.    

Niravkumar Patel is a senior physics major working with Dr. R. Mehta in the Dept. of Physics and Astronomy.  His work involved modeling the effects of zero gravity on bone density using rats as model systems from UAMS.  Such work supports the goal of understanding and treating physiological effects of long term exposure to zero gravity resulting from extended space travel and exploration.  Nirav obtained femur samples from labs at UAMS after euthanizing rats subjected to simulated zero gravity conditions.  He used elemental X-ray fluorescent (XRF) signatures collected from the bone samples using UCA’s scanning electron microscope.  His XRF results indicated a direct correlation between carbon and calcium content in the bones and a surprising indirect correlation between bone phosphorus and oxygen content.  He also subjected the bone samples to stress and strain measurements and noted a much lower modulus in zero gravity samples.  These results collectively demonstrate changes in mineral composition and reduced bone strength that must be dealt with to reverse long term physiological effects of zero gravity exposure.

November 15, 2011  Laney 102

Reshma Reddy Ginnavar is a masters student working under the direction of Dr. Sun in the Dept. of Computer Science.  Reshma’s work dealt with compressed video algorithms that would increase the rate of data bit transfer without significant loss of data integrity.  Ideally the bit transfer rate would be optimized for a particular network.  The challenge is in properly encoding the data for transfer.  Her results demonstrated that she has been able to achieve accelerated bit rates with improved quality over current methods.

Ben Ward is a junior chemistry major.  His work with Dr. Taylor in the Dept. of Chemistry involves computational modeling of postulated reaction intermediates and transition states in some of the reactions studied in their lab.  These intermediates and transition states represent key pieces of the overall mechanisms for how a particular reactant is transformed in an observed product.  Modeling such species is a challenge, because their transient nature means few isolated comparisons are known and structural features must be inferred.  Ben described the calculation of imaginary frequencies (IF) in the models as an indicator of whether the species was a marginally stable intermediate (IF = 0) or a fleeting transition state (IF = -1).  Adding to this challenge was properly dealing gold ions, computationally challenging because of the large number of electrons these ions possess and that must be modeled.  Ben’s results demonstrate early success in modeling some key intermediates that have helped the lab better understand reactions of gold ions with halocarbon molecules.

Cody Hudson is a senior computer science major working with Dr. P. Young in the Dept. of Computer Science.  Cody described his work on using an object oriented approach to improve the interoperability of health system records.  Older health record systems are plagued by poor interoperability.  He discussed the fact that medical records are a good application for his work because they possess a range of different data types that are shared among many different health care entities.  The key challenge lies in how data are represented in the record so that all stakeholders can make effective use of the information.  His particular work deals with developing more effective translations of data from one source, patient/physician input, to another (i.e. hospital) to improve the interoperability of an overall health record database.

Aaron Crawford, also a senior computer science major working with Dr. V. Sheng in the Dept. of Computer Science, is working on a data mining project involving diagnosis of fetal disorders using UAMS medical records.  The goal of the work is early prediction of disorders from a list of key indicators in medical histories obtained from fetuses in utero.  His computer-based mining project attempted to correlate patterns in such data as fetal heart rate, gestational week, and stimulus response (bright lights and loud noises) to known disorders observed in delivered infants.   The large UAMS data set proved a good test system for his work.  His system reached a best prediction rate of 77% accuracy for correlating patterns in medical data with observed disorders.  In the future, Aaron described his desire to add a decision tree to his process, where the system could be used by medical personnel to help guide their treatment of mother and fetus in prenatal periods.

October 27, 2011    LSC 100

Ashley Lawrence is a junior computer science major who worked under the mentorship of Prof. S. Kochara in the Department of Computer Science.  Her work was the result of an REU experience in this department during Summer 2011.  She explained how important it is to diagnose melanoma at its earliest stages, and her work was aimed at using computer science to tackle some of the challenges in diagnosing these lesions by visual inspection.  She worked with colored images of lesions that first were rendered as pixels in black/white/grey scale versions.  She then applied a process called modified DBSCAN to determine the edges of the lesion.  The program starts at a pixel and then samples all pixels around it, looking for interiors (dark pixels) and edges (light pixels) as the algorithm steps across the whole picture.   She found much better agreement between her computer-determined edges and the edges drawn by physicians from visual inspection.  These images were then tested for their circularity, because irregular shape is an indicator of cancerous melanomas.  Here again her program offered greater precision than physician-drawn estimates.  She hoped that such programs with artificial intelligence-driven decision making could lead to early self-diagnosis encouraging patients to see their doctors sooner for follow-up examinations.

Michael Hinds is a senior computer science major.  He described a special project under the guidance of Dr. C. Hu of the Department of Computer Science.  Michael explained that his project was motivated by his personal interest in codes and deciphering encrypted information.  He contrasted the difference between primitive ancient but highly successful encryptions during Roman times (“Caesar ciphers”) and how greater encryption awareness and modern instrumentation dictate the need for ever more sophisticated encryption algorithms.  His particular method used a tool called modular algebra.  His goal was to develop a more sophisticated version of these older ciphers using multiplication instead of simple addition on which they were originally based.

Nicholas Davis and Kyle Hurley are both new masters-level students working in the laboratory of Dr. D. Dussourd in the Department of Biology.  Both Nicholas and Kyle earned their bachelors degrees from UCA before joining Dr. Dussourd’s research group.  Their work with Dr. Dussourd is aimed at investigating the mating behavior of praying mantises.  These insects are voracious predators, important in controlling insect pest populations.  Their study began with the field observation of an unusual case of a female mantid eating the head off of its male counterpart but with apparent continuation of the mating process successfully. This had not been previously documented in the wild.  These students described the initial challenge of catching and monitoring sufficient mantids in the wild to study this behavior and how this led them to breed their examples in specially designed cages at UCA.  Both students described the considerable effort required to breed and handle these insects carefully for their work.  They developed a more cost effective way of growing the insect prey used as the food source for their mantids in captivity.  In addition, they described that successful mantid egg fertilization can be documented by dissection of egg cases even if these eggs never mature to the point of hatching.  Their methods of growing and caring for mantids in captivity can now be applied to the very careful work required to fully document and explain the purpose and extent of the unusual cannibalistic behavior of females during successful and unsuccessful mating.  

September 20, 2011    STEM residential college

Ashley Hicks is a junior chemical physics major working in the laboratory of Dr. William Taylor in the Department of Chemistry.  Ashley summarized results for her summer work investigating the gas phase reactivity of gold(I) ions with methyl fluoride.  She explained the logic of studying the reactivity of carbon-halogen bonds as more reactive models of less reactive carbon-hydrogen bonds found in hydrocarbons.  Depending on the sputtering gas (heavy xenon or light neon) used to generate the gold(I) ions from gold metal, she was able to produce either gold(I) ions exclusively (with xenon) in their lowest energy ground state or a mixture of ground and excited state ions as was produced using neon.  Use mass spectrometer analysis of the gaseous products of these different gold ions with methyl-fluoride she was able to demonstrate unique products forming from the ground state vs the excited state.  Among these was a characteristic gold-alkene product, an interesting example of a carbon-carbon bond forming reaction that was found to form exclusively from the ground state gold(I) ions.  Being able to correlate products to specific energetic states of the metals ions enables her to discuss mechanisms for their formation and to detail fundamental atomic and molecular properties responsible for these processes.

Li Chen Chen is a junior chemistry major also working with Dr. William Taylor.  Li Chen detailed her designs of a modified electro-spray ionization (ESI) source that would enable Dr. Taylor’s group to produce gas phase metal halides (termed “ligated metal ions”) for use in reactions with other gaseous reactants.  Gas phase metal halides are implicated in many of the reactions studied in the Taylor group, but these species are secondary reactants, making it more complicated to infer their precise role in the reactions studied.  Li Chen outlined the properties of ESI sources in general, where solutions of metal halides yield droplets of solvated particles and eventually solvent-less metal halide ions as they enter the reactor assembly.  This tool should enable the group to produce metal-halide ions as initial reactants, allowing the group to study more easily direct products that result from these species.  Li Chen’s design required her to retrofit existing hardware on fittings on their primary reactor instrument with new ESI hardware.  This addition should greatly expand the range of reactions that may be studied in Dr. Taylor’s laboratory.

Wei Xia is a junior biology major doing research for Dr. B.Vohra in the Department of Biology.  Her work involves modeling neurodegenerative disorders by genetically modifying developing neural cells taken from the spine of rat embryos.  She described examples of common diseases like Parkinson’s and ALS (Lou Gehrig’s disease) as problems linked to the degeneration of the long axon portion of a neural cell.  This disrupts long range communication between the brain and muscles, resulting in diminished response to stimuli and paralysis. Her work involves the use of viruses to inject genes responsible for controlling mitochondrial fusion into the developing neural cells.  M. fusion is a key function that occurs along an axon; changes in this process along the axon can ultimately reach the main cell body and compromise the neuron’s overall health.  She develops model neural networks on a petri dish by culturing the modified cells.  Axons in this network are stressed by physically cutting axons radiating from the central starting point of the cell colony.  This model allows her to contrast the response of the neural cells when the gene for controlling mitochondrial fusion is and is not present.   She explained that such studies might allow the development of new drugs that target the mechanism of neuron degeneration.  

Nathan Hotchkiss is a masters student working under the mentorship of Dr. Victor Sheng in the Department of Computer Science.  He described a special independent study project he carried out on predictive analyses, enabling him to learn more about the technique as it applies to data mining.  Such tools could be used in protein classifications, medical record analyses, or for example to predict the weather given a broad array of input parameters.  As an example, he described a model data set where data points are characterized by many multiple labels.  A next step in this process involves parsing the multiple labeled data points to representative single label data sets, groups that retain all of the original information but in simplified form.  He further modified the data using a process called feature selection, which simplifies the data by eliminating redundancies.    At this point he tested different algorithms evaluating each for predictive accuracy against such factors as the time to achieve it.  He noted that applying feature selection had a noticeable improvement in time to achieve a certain level of accuracy.  This is an important factor when this approached is scaled to significantly larger data sets and applications.

July 22, 2011 LSC 100

Jared Evanov is a senior chemistry major working with Dr. Patrick Desrochers in the Department of Chemistry.  Jared’s work is establishing the properties of a new molecular anchor (Tp’) toward metals.  The goal is to determine the general behavior of Tp’ for metals beyond nickel commonly employed in Desrochers’ lab, because Tp’ can be anchored to solid supports allowing for recyclability of myriad metal complexes with applications ranging from protein purification to catalysis.  Jared briefly described his work with Tp’ and molybdenum and then most recently with rhodium.  He explained that rhodium possessed some similarities to molybdenum; that both metals form characteristic Tp’-metal-carbonyl complexes was used to determine the degree of electron donation from Tp’ to the bonded metal. Beyond molybdenum, Tp’-rhodium complexes are catalytically active toward the polymerization of phenylacetylene giving a distinctive red polymer.  Jared showed C-13 NMR measurements of his rhodium complexes as proof of their formation and structural geometry.  Ongoing work is preparing the same rhodium complexes on solid-Tp’ supports to test their utility as recyclable catalysts, and the red-polymer reaction is expected to provide a clear visual assay to test for successful catalytic behavior.  This work is expected to be of general interest to metal chemists worldwide who routinely employ Tp-like anchors for these and more than twenty other transition metals.

Katie Primm is a senior chemistry major working in the laboratory of Dr. Don Perry in the Department of Chemistry.  Katie has been studying the role of gold nanoparticles in the selective enhancement of infrared light absorption of organic molecules carefully layered onto the particles.  Katie explained that nanomaterials refer to particles with nanometer dimensions (on the order of one billionth of a meter), larger than single molecules, but much too small to be seen with conventional light microscopes.  She went on to emphasize that nanoparticles have applications to selective chemotherapy, pharmaceutical delivery in the body, and solar panel research, among others.  Katie described the vacuum metal-vapor deposition instrument she uses to grow her gold-nanoparticle films on infrared-transparent calcium fluoride plates.  Depending on the angle of the plate in relation to the metal-vapor source, she showed that she could control the shape of the nanoparticles, in some cases making thin films of gold atom or in other cases “forests” of gold nano-rod particles extending up from the plate surface.  She learned to image these surfaces using an atomic force microscope (AFM, UA Little Rock), and she shared distinctive AFM images of each.  These were separately studied by depositing a test molecule (p-nitrobenzoic acid) in a layer one molecule thick on each surface.  These molecule-surfaces were investigated by infrared measurements, and the nanorod surface was shown to enhance the absorption of infrared light by the test molecule through a process where gold-particle vibrations (plasmon resonances) amplify vibrations of molecules in contact with the gold-surface.  She concluded with plans to more carefully control the growth of these nanorods, toward more uniform shape and surface coverage, with the hope of seeing even greater enhancement of light absorption by adsorbed molecules.

Alyssa Paineau is a masters student working on a collaborative project with Drs. Steve Runge and Kari Naylor in the Department of Biology.  Alyssa’s research is focused on the role of pH regulatory proteins in cancer cells.  Trafficking of these proteins on cell surfaces is controlled by structures called microtubules. These malignant cells are unique for their ability to thrive in highly acidic environments (up to 100 times more acidic than normal ~ pH 7.3) that are fatal to normal cells.  Understanding of this behavior could be exploited in more effective chemotherapies, where the acid-tolerant behavior of cancer cells be turned against them.  Alyssa described her successful preliminary development of a protocol for monitoring the pH both inside and outside cancer cells using a pH-sensitive fluorescent dye and special light microscopes.  In this calibration work she chemically “clamped” the cellular pH regulatory channels open, so that the same acidity existed inside and outside the cells covering the pH range of 5 to 8.  Her first planned experiments with cancer cells using this dye-microscopy assay will test how the cancer cells respond to the pH range of 7.25 to 6.25.  She expects to reproduce cancer cell responses observed previously by Dr. Runge, where MCF-7 breast cancer cells were observed to readily adjust to this drop in pH and resume their malignant growth.  From here she will repeat the experiment with the addition of drugs known for their ability to disrupt microtubule function.  Cells with handicapped microtubule function should not be able to resist external forces of highly-acidic environments.  She hypothesizes that such a disruption could provide progress in chemotherapeutics where uniquely acidic environments of cancer cells could be used for their targeted destruction.

Byron Burns is a masters student under the direction of Dr. Victor Sheng in the Department of Computer Science.  Byron also works in the UCA IT Department as a computer services technician.  Byron described the role of interconnectedness in social networking.  He broadly defined social networking as any data-sharing applications by interconnected computer systems.  He emphasized the importance of the degree of centrality, a quality of a site identified as a network hub.  Loss of hubs, with far-reaching connections, should be protected against because of severe disruptions this can cause throughout the network.  He described the role of peripheral connections in providing redundant feedback about the integrity of hubs and other pivotal connections.  This redundancy can ensure uninterrupted overall data-sharing should any single connection or hub be lost to viruses or hardware failure.

Amanda Bates is a masters student and Ali Mcleod is a sophomore environmental science major, both working under the direction of Dr. Sally Entrekin in the Department of Biology.  Amanda and Ali are involved in field-research studying aquatic ecosystems of Ozark mountain streams.  Their work is establishing important measurements of water quality in these headwaters of higher order waterways like the Buffalo, White, and Mississippi Rivers.  Unlike higher order rivers, these mountain streams are characterized by temporary and sometimes permanent water flow.  Amanda outlined her plans to investigate the role of crayfish (leaf shredders) vs bacterial action on the rate of leaf breakdown in heavily forested select Ozark streams.  She described her use of meshed leaf-bags with different size openings, alternatively allowing and preventing access of crayfish in the streams to the leaf-contents.  In both cases aquatic bacteria are continuously able to act on the leaves inside the mesh bags.  Decomposition of organic material is an integral component of the carbon cycle, a process that connects essential life-sustaining events of photosynthesis (P) and cellular respiration (R). Ali’s work will focus on monitoring chemical markers of the tandem processes of P and R in select temporary pools along Ozark streams.  Dissolved oxygen content will be monitored in these pools as a measure of P vs R (along with other markers) and compared to the range of biodiversity within the pools as well as the rate of organic breakdown.  Because this breakdown and the organisms involved contribute to food sources of higher order waterways, these aquatic environmental studies provide valuable descriptions of water quality throughout waterways in the central United States.

April 28, 2011 LSC 101

Caroline Davis is a senior physics major working under the direction of Dr. Will Slaton in the Department of Physics and Astronomy.  Caroline described her special project in which she produced a sound transducer, effectively a microphone that receives sound and converts it into a proportionate electrical signal.  She tested her assembly by studying the classic wave dynamics of diffraction spacings generated from a doublet slit experiment as well as the effects of reflection from a plane using sound with a frequency of 24.5 kHz.  She noted that reflection of the emitted sound by surfaces in the laboratory had an effect on her results.  An additional source of error in her work was the lag time associated with the speed of sound, a problem more common in slower sound wave experiments vs light where the speed of wave propagation is considerably faster.

Jonathan White is a senior physics major working under the direction of Dr. Will Slaton in the Department of Physics and Astronomy.  Jonathan described his special project in which he developed and tested a high altitude sensor array that could be generally employed on balloons routinely launched to monitor atmospheric conditions and weather patterns.  The goal was to make the array as light as possible and as inexpensive as possible to improve its utility and frequency of use.  The specific array he used measured pressure, temperature, carbon dioxide, and solar radiation levels as a function of altitudes up to levels as high as 87,000 feet.  As an example of the less expensive materials employed, Jonathan described his pressure calibration at ground level vs a common water manometer.  His acknowledged the advantage of making the array as durable as possible to ensure integrity of its data during recovery when it returned to ground level.

Renee Brock is a senior physics major working under the direction of Dr. Will Slaton in the Department of Physics and Astronomy.  Renee detailed her work as an example of archeoastronomy, in which astronomers today use astronomical records from ancient civilizations to correlate current star and planet positions with those of ancient times.  This can ideally provide a continuous record of shifts in the celestial sphere over two to three thousand years of astronomical observation.  She specifically mentioned the use of structures oriented with respect to the Earth’s magnetic field as well as solar observations from three archeological sites in New Mexico.  These and other sites from Egypt date to as early as 2900 B.C.E., and while some no longer are illuminated by the sun as they were when first created, their positioning provides valuable information about the respective orientation of the Earth and Sun many thousands of years ago, information otherwise lost to modern astronomers.  The New Mexico site has an ancient road oriented roughly north to south that likely originally was oriented according to the Earth’s magnetic field at the time.  Comparison of this orientation with other known changes in the Earth’s field helps description the precession of the Earth about an access that influenced observation of celestial bodies from the Earth’s both today and over the past several thousand years.  Renee’s specific work involved the development of extrapolations of current position observations to their ancient positions from the reference of Earth-bound observers.  

Luke Irvin recently earned his bachelors degree in computer science and worked for Dr. Chenyi Hu in the Department of Computer science.  Luke’s experience in computer science has led him to become an independent computer application entrepreneur.  He emphasized the importance of using online communication as a powerful tool of listening for potential customers, persistent problems searching for technical solutions, and possible venture capital for novel ideas.  He shared his own experience with Twitter, and how it can be a valuable means of listening to the persistent current of ideas in the public square.  According to Luke, the brief but frequent tweets more accurately reflect current market opportunities, trends, and needs than other networking vehicles.  Luke shared specific examples of how other successful self-employed entrepreneurs have used such tools to identify business ideas, to market their solutions, and to keep customers apprised of emerging trends for new products resulting from their new businesses.  He shared this as an untapped resource for intellectual property development in areas of applied science that could emerge from science and math research interests at UCA.

March 8, 2011 MCS 220

Marcus Truscello is a senior computer science major working with Dr. Yu Sun in the Department of Computer Science.  Marcus’ research is in the development of more effective computer programs for rendering 3-D video images.  He described some of the newest optical tools available like polarized light to alternately illuminate images that are recombined by the brain as a 3-D image.  Such techniques, he noted, are not cost effective for example in home use, because of the need of costly glasses with active shutters necessary to render the mixed views as a single composite image.  His own work instead is trying to create the 3-D image computationally, where the observer is rapidly presented with tilted images yielding simulated depth information that is recombined in the brain as the desired 3-D image.  He identified challenges in his work, trying to parse image information with variable spacings and different spacing morphologies (parsed as lines or as circles).  He did note that through his work he hopes to achieve an improved tilt viewing angle, a persistent problem in 3-D imaging related to the maximum angle at which a viewer can still perceive a 3-D image when viewed from an extreme of one side or the other.

Brian Besel gave a summary of work with mentors Drs. Patrick Desrochers and Richard Tarkka in the Department of Chemistry.  Brian is a senior chemistry major.  He described recent success attaching a class of molecular anchors call “scorpionates” to solid supports.  Scorpionates are used by chemists worldwide with every metal on the periodic table in applications as varied as small molecule sensors, molecular magnets, active catalysts, and metalloprotein models.  Brian’s breakthrough work established a unique covalently attached scorpionate (one of only 3 examples to date) to solid supports, confirmed spectroscopically using C-13 NMR and by chemical test involving nickel.  Brian shared confirmatory C-13 results recorded for his anchored scorpionate that required more than an hour of careful sample preparation and more than 12 hours of automated data collection.  Importantly, he further used this anchored system to bind nickel (bead-nickel) and then demonstrated that bead-nickel showed the same selective binding of cysteine as was originally identified for solution phase nickel-scorpionates in Desrochers’ lab some ten years earlier.  This system is to be investigated for its effectiveness in protein purification using histidine-tagged proteins, a common commercial purification tool employed by biochemists.  

Abhinav Atla and Rahul Tada shared data mining research they are conducting as part of their masters work under the direction of Dr. Sheng in the Department of Computer Science.  They identified many challenges in their work, including the need to be able to filter noise from useful information and the need to use effective learning algorithms so that the data mining procedure can act autonomously when necessary.  The current model employs a mix of 70% of its information to train their learning algorithm and 30% of its information to test the predictive ability of the machine learning process.  Following their progress with this experiment, they will return to the model and inject varying amounts of noise and note the effect on their learning program’s performance.

Zuzanna Sisperova is a senior physics major doing research on synthetic organic chemistry in the laboratory of Dr. N. Carter in the Department of Chemistry.  Zuzanna’s research involves the preparation of models of amino acid radicals of the type that could results in living systems under UV irradiation.  This work can shed light both on the development of cancer as a result of such exposure as well as the potential for such irradiation methods to be used to treat such diseases.  Her research involves the develop of selenium-containing phenylalanine radical precursors.  Selenium-carbon bonds are readily cleaved by UV irradiation resulting in the formation of targeted carbon-radicals.  She emphasized that the specific compounds prepared in her work could more selective in their behavior as therapeutics than other common radicals, like hydroxyl radicals, for example.  She specifically described the challenges of maintaining stereoselectivity (important subtle structural features with profound effects on biological activity) in her synthetic procedures and detailed key progress using esterification to make protecting groups for reactive groups in her compounds.  

February 15, 2011 Laney 103

Ben Nordin is a masters student working under the direction of Dr. Chenyi Hu in the Department of Computer Science.  Ben described his work on a method of rapid screening for large data sets, enabling summary predictions to be made about the information they contain.  The test system he employs for this work was a DNA sequence obtained from the Protein Data Bank.  This DNA model was the right size to provide a meaningful test for his method, while it also represented an important real-world system.  Computer-aided rapid screening of DNA sequences for structural information predicted by these sequences would be a valuable tool for biochemists.  Ben’s method involved parsing the large data set into intervals each with a defined upper and lower bound.  He then employed a K-means test to average his clusters of data.  The real test of his method involved its ability to take a random primary DNA sequence (the ordered pattern of base pairs along a DNA strand) and from this alone deduce the most likely folded-three-dimensional structure predicted to result from this base pattern.  He described the daunting challenge of modeling such a large data set (up to 180 dimensional space) as well some early success with his method and its promise for structural predictability. 

November 16, 2010 LSC 100

Philip Cook is a senior chemistry major and Tristan Phillips is an environmental science major working under the direction of Dr. Rick Tarkka in the Department of Chemistry.  Philip and Tristan have been working for over a year to establish a clean and efficient synthetic method for anchoring so-called “scorpionate” ligands to solid supports (scorpionate ligands are pincer-like molecular anchors for metal ions).  They described very promising preliminary results using a microwave synthesizer to prepare samples of scorpionates in a fraction of the time traditionally required and in higher yields than had been previously reported.  Their methods have never before been reported for this widely used ligand class.  The utility of their approach should significantly impact the preparation of many existing and new scorpionates, and among these should be ligands well-suited for attachment to solid supports.

Christopher Kline is a senior computer science major working with Dr. Yu Sun in the Department of Computer Science. Christopher described his work to develop an improved rate control algorithm for video compression. He explained the importance and the challenge of developing effective rate control algorithms for the newest video compression standard - H.264/SVC.   His work with Dr. Sun involved the proposed use of an adaptive initial encoding parameter selection for H.264/SVC rate control.   He described their research progress that has produced considerable performance improvement in bit-rate regulation and video coding quality when compared with the rate control algorithm adopted by H.264/SVC compression standard.

Kendall Fancher is a sophomore biology/chemistry major who has been working with Dr. Taylor for about a year in the Department of Chemistry.  Kendall’s work involves a series of experiments conducted on gas-phase ions and molecules in which he is investigating the energy associated with the reaction of gaseous nickel ions (Ni⁺) with halogenated methane molecules.  Kendall described his use of a technique call electronic state chromatography that allows him to separate his Ni⁺ into ground state (lower) and excited state (higher energy) groupings.  This separation allows him to select one state over the other and see which of these two states reacts with various halogenated molecules.  He is able to identify the products of these reactions by their specific masses (using mass spectrometry and isotope patterns).  By correlating the known energies of the two states of Ni⁺ with the energies required to produce specific product, Kendall’s work should describe some of the specific aspects of the mechanism of Ni⁺ with these molecules.  Such results help describe fundamental reactive properties of these molecules which can be useful in condensed-phase catalytic processes as well as atmospheric reactions.

Luke Irvin is a senior computer science major. He has worked as a software developer at Clarovista, LLC, a new media agency in Conway, Arkansas. Luke described how he applied his knowledge learned in Computer Science at UCA on developing IPhone Apps and IPaD.  He demonstrated some of the basic routines common to traditional Apps.  He outlined the logic necessary to assemble these routines into a simple App, providing a simple but effective example of the organization involved in these tools so common to modern hand-held electronics

October 28, 2010  MCS 220

Tsung Yen Chen is a junior chemistry major working in the laboratory of Dr. Don Perry in the Department of Chemistry.  Tsung Yen described his studies of the interaction of halobenzoic acid molecules with silver nanoparticle surfaces.  The silver surfaces enhance the infrared absorption by these molecules, enabling the layers they form to be probed experimentally.  Tsung Yen prepared layers of two different molecules (iodo- and fluorobenzoic acid), deposited from solutions of carbon tetrachloride and heptane onto the silver surfaces.  Infrared measurements showed that the benzoic acid molecules were dissociated into their ionic form when in direct contact with the silver surface.  These measurements characterized layers of molecules deposited onto the silver and found that successive layers incorporated solvent molecules through halogen-solvent attractive forces.  These measurements are among the first to provide evidence for the halogen-halogen interaction in such samples.

Ryan Parker is a senior chemistry major currently work with Dr. Cameron Dorey in the Chemistry Department, and he discussed his work over the summer at NCTR in collaboration with Dr. Dorey.  Ryan worked to develop a faster open air method of mass spec analysis of molecules, with the goal of using the method to rapidly screen samples for specific bacteria by detecting molecular markers emitted by the bacteria.  The method Ryan helped develop (DICI, direct impact chemical ionization) used a stream of heated helium atoms, some of which became ionized, to vaporize and ionize marker molecules from bacterial samples inserted into the hot helium stream.   He noted that this first design overheated and scorched the bacterial samples.  Subsequent modifications added a protective glass sheath around the bacterial samples (reducing ambient oxygen interference and scorching) and a modified helium heating/ionization source.   

Natasha Skiver is a senior biology major working with Dr. J. D. Swanson in the Department of Biology.  Natasha pointed out that her work was a promising new outgrowth of Dr. Swanson’s research that traditionally involves genetic origins of cell differentiation leading to prickle development in the genus rubis (blackberries, raspberries).  She explained that a compound called gallic acid is common to these plants and that this compound was a potential anticancer therapeutic.  To investigate this possibility, she worked during the summer at NCTR screening variable doses of gallic acid with different cancer cell lines.

September 28, 2010    STEM residential college

Jared Evanov is a senior chemistry major working in the laboratory of Dr. Patrick Desrochers and in collaboration with Dr. Rick Tarkka all from the Department of Chemistry.  Jared described his work to make complexes of molybdenum using both an  established ligand and a new ligand (Tp′) developed in the laboratory.  Jared described ligands as molecular tweezers that bind and control metals. His current work involves the metal molybdenum, a departure from the normal nickel work of the Desrochers and Tarkka labs, because molybdenum forms complexes with Tp′ and carbon monoxide that enabled the new ligands properties to be studied--its symmetry/structure and its electronic behavior towards metals.  This was an advantage over nickel that could not form these same complexes.  Jared described carbon-13 NMR and infrared measurements on these new molybdenum complexes. Tp′ is particularly noteworthy because it has been attached to plastic resin in the lab, allowing molybdenum and nickel to be immobilized with potential uses as catalysts and biomolecule sensors. 

Jabin Miller is a senior chemistry major working in the laboratory of Dr. Lance Bridges and in collaboration with Dr. Melissa Kelley all from the Department of Chemistry.  Jabin described his work studying the effect of 9-cis retinoic acid, a Vitamin A derivative, on the adhesion of white blood cells to cell walls.  Adhesion of these cell types is carefully controlled to prevent both infection and disease, and Jabin's work is shedding light on how 9-cis-RA may be a key factor in regulating immune cell adhesion. Certain types of leukemias are treated with retinoic acid, but unfortunately this therapy results in an adverse side-effect known as retinoic acid syndrome that is largely due to augmented immune cell adhesion.  Jabin's work revealed that 9-cis-RA can specifically induce immune cell adhesion and this is attenuated by regimens administered to individuals exhibiting retinoic acid syndrome.  His future work will be identifying which protein receptor is responsible for the cell adhesion and if this may be the underlining cause of retinoic acid syndrome.

Andrea Kirkpatrick is a senior chemistry major working in the laboratory of Dr. Melissa Kelley and also part of the collaboration with Dr. Lance Bridges.  Andrea’s work focuses on the affects of vitamin A derivatives, 9-cis and all-trans retinoic acids (RA) on immunity.  Vitamin A derivatives work by helping to control immune cell adhesion and proliferation.  Andrea tested four different human immune cell lines.  Two of these cell lines showed adhesion and proliferation responses to retinoic acid and two did not.  She analyzed the media in which the cells were grown, looking for retinoic acid byproducts using extraction techniques and HPLC (high pressure liquid chromatography).  None were detected in these cell lines.  Andrea’s data revealed that retinoic acid is the sole compound that is responsible for increasing cellular adhesion and decreasing cellular proliferation.  Her work demonstrates the important role this common compound has in controlling cellular adhesion and proliferation in immune cells. 

Mickelene Hackman is a senior chemistry major who works in in the laboratory of Dr. Richard Tarkka during the academic year.  The work she shared was a result of a summer research internship at the National Center for Toxicological Research in Jefferson, AR.  Mickelene was charged with testing the ability of a computer model to predict the relative binding affinity (RBA) of 45 test molecules for estrogen receptors.  Her test molecules had RBA ranging from 100 times weaker to as much as 10,000 times stronger binding over estrogen itself to the receptor of interest.  Her model used a hybrid of properties extracted from carbon-13 NMR spectra of these molecules and structural properties of the molecules including distance between specific atoms in the molecules.  Importantly, such properties can be determined easily for molecules, without elaborate clinical or molecular biological studies.  If successful, therefore, the model would allow rapid screening of many compounds for possible toxicological side effects such as estrogen binding inhibition.   Mickelene described considerable success with the model she tested.  It successfully predicted known RBA of selected test molecules in her group to a 90% level of certainty, a considerable improvement over the previous work in this group that had shown only a 60 – 70% level of prediction success.

July 16, 2010, LSC 100

Ashley Bonde and Taylor Razer are junior biology majors working in the laboratory of Dr. Don Perry in the Department of Chemistry.  These students described their use of two techniques called surface enhanced infrared analysis (SEIRA) and surface enhanced Raman spectroscopy (SERS) to characterize the interaction of small organic molecules with silver nanonparticles.  The two surface techniques use silver particles to enhance the infrared light absorption of halogen-substituted benzoic acid molecules that are deposited in small numbers on the silver surfaces.  In the absence of these silver particles, such a small number of organic molecules on a surface would be effectively undetectable using infrared light.  However, the silver particles enhance the light absorption of these molecules by a factor of as much as 1000 times, greatly increasing the sensitivity of these techniques to detect low concentrations of absorbed molecules.  Ashley and Taylor’s research has demonstrated that the benzoic molecules show varying degrees of proton loss, due to interaction with surface silver oxide particles, as well as solvent-dependent intermolecular forces termed “halogen bonds.”  Their work represents significant experimental evidence for this halogen-bonding force.  Ultimately, their work will be extended to the interaction of silver particles to more interesting biomolecules like amino acids and proteins in the hope of characterizing some of the reported medical benefits for materials like colloidal silver.   

Skipper Thurman is a junior/senior physics major who has been working for over a year under the mentorship of Dr. Azida Walker in the Department of Physics and Astronomy.  His work with Dr. Walker involves the development of an automated apparatus for testing pain thresholds and responses in rats serving as animal models for nerve damage and tingling in extremities common in humans suffering from Type I diabetes.  Skipper described his project as one of applied physics and engineering with a primary benefit being marked improvement in precision associated with measurements of a fairly subjective observable, pain response in animals.   The apparatus he described with a sketch encompasses a computer controlled magnetically driven fine-stepping motor that drives the up and down movement of a thin metal rod.  This metal rod is pushed slowly up into the paw of a rat standing in a cage above the apparatus.  The computer control monitors the amount of and duration of force applied and observes rapid changes in force associated with the rat removing its paw from the probe, a presumptive pain-threshold response.  Skipper described that the probe/contact model is one commonly applied to such pain threshold studies, but that his automated apparatus should reduce some of the subjectivity associated with other hand-held instruments.  He also described that his assembly would allow a more precise definition of the force as a function of probe configuration, a result that could be correlated to the nerve density per unit area of the animal tested. 

LaRhonda Apata is a biology major working on mitochondrial structure during cell division in the laboratory of Dr. Kari Naylor in the Department of Biology.  She described the importance of mitochondrial division as occurring via two pathways (fission and fusion) and how extreme examples of either of these can lead to disease conditions in humans.  Her particular cellular model (dictyostelium) is at the biological interface of primitive single-celled organisms that lack structured mitochondria (prokaryotes) and higher-order cells that comprise plants and animals, possessing highly structure mitochondria (eukaryotes).  LaRhonda’s cells contain a protein called FtsZ that has a role in prokaryotic cell division in which mitochondrial division is an important step.  A protein with a similar amino acid sequence to FtsZ, dynamin, is also found in dictyostelium, but its specific role there is not completely known.  Dynamin, is responsible for mitochondrial division in most higher cells.  LaRhonda plans to tag dynamin in dictyostelium with a fluorescent marker and use this to monitor whether or not dynamin localizes at the site of mitochondrial fission and fusion in these cells.

Brian Besel presented his third chalk-talk summary of work with mentors Drs. Patrick Desrochers and Richard Tarkka in the Department of Chemistry.  Brian is a senior chemistry major.  Brian described the experimental evolution of a solid molecular support designed to immobilize nickel ions while still allowing these ions to interact selectively with specific amino acids in solution.  The earliest incarnation of this solid support, involving a carbon-based molecule, was efficiently synthesized, but it did not enable nickel’s selective reaction with amino acids cysteine and histidine, nor was it very effective at immobilizing these metals ions.   For the past year, his work has been refocused to prepare a boron-based molecule anchored to solid supports, presenting considerable synthetic challenges over the carbon-based analogue, but with the benefit of negative charge (introduced by replacing boron for carbon).  This negative charge has been shown to improve nickel ion binding.  Brian described the preparation of the new boron-based molecule, beginning from a surprising synthetic experiment last August, through a logical stepwise preparation of the new supported molecule, to its eventual superior binding of nickel ions demonstrated by his measurements.  While Brian’s new boron-based support shows excellent nickel ion immobilization compared to commercial nickel-based tools for protein purification (abbrev. IMAC), the selectivity of supported-nickel toward cysteine and histidine still must be improved.  Histidine is the primary amino acid used by biochemists to tag recombinant proteins to ease their IMAC purification.

April 13, 2010, Laney 102

Anthony Hightower is a senior chemistry working in the laboratory of Dr. Kyle Felling in the Department of Chemistry.  He described a novel approach to purifying dendrimer polymers (PAMAM), large organic molecules with extensive branching and containing polar appendages made of nitrogen (amides) and oxygen (carboxylic acid groups).  The purification method separates target polymers from impurities by encouraging the molecules to migrate through a gel under the influence of an electric charge and with variable pH.  This method appears to yield these polymers in higher purity than has been obtained before.  PAMAM polymers are useful in coatings, membranes, and in the delivery of some pharmaceuticals in humans.

Chris Rhodes is a senior computer science major working under the direction of Dr. Sun in the Department of Computer Science.  Chris is working on the problem of data compression during transfers of large volumes of data such as in streaming video.  He explained the common experience of halting video playback or grainy low resolution videos one commonly finds on YouTube and the need to improve on this problem.  His work involves creative parsing of digital information within a data stream, segmenting the large volume into manageable pieces that can be read individually or combined later to give a higher quality composite.  This could, for example, allow higher resolution information, like full length animations, to be transferred and utilized more efficiently even when broadband connections are limited.

Kevin McElhanon is a senior biology working with Dr. Steve Runge in the Department of Biology.  Kevin’s work focuses on trying to identify the role of cellular machinery in regulating acidification in cancer cells.  Such cells are characterized by the ability to thrive in highly acidic environments induced by their own unchecked growth.  Kevin is specifically focusing on a protein termed NHE-3, a membrane bound protein that exchanges hydrogen ions for sodium ions from outside the cell.  Although a less common hydrogen exchange protein, NHE-3 may prove to be an important and efficient regulator of cancer cell pH levels.  Kevin will measure the expression of this protein throughout the cell while the cells are held under highly acidic and oxygen-starved conditions—a simulated tumor environment.  This work may explain the role NHE-3 plays in enabling cancerous cells to proliferate under conditions that cause rapid death in normal cells, at the expense of healthy tissue.

Elizabeth Schiefer is a senior chemistry major working in collaboration with Dr. Donald Perry in the Department of Chemistry.  Liz explained that her work uses infrared light to probe the arrangement and chemical behavior of layers of molecules on silver nanoparticle surfaces.  Specifically she studies halogen-substituted benzoic acid molecules.  The silver nanoparticle surfaces serve the special purpose of increasing the sensitivity of these benzoic acid molecules to incident infrared light, allowing them to be studied even when the layers are only a single molecule thick, when very few molecules are present.  Through these experiments she has shown that the acids’ behaviors vary depending on whether they were deposited from solutions with solvents of high or low polarity.  She hypothesizes varying degrees of acid dissociation and unique halogen-bonding interactions to account for her observed measurements.

Feb 18, 2010, LSC 101

Cody Hudson and Aaron Crawford are both junior computer science majors working under the direction of Prof. Lev Igolnikov.  Aaron and Cody developed a basic computer using a breadboard system, rudimentary chips and simple computer constructs.  While the system operated very slowly (at 1 Hz), this very basic computer enabled them to study the effects of machine-level programming on computer hardware operation.  These students emphasized that studying this basic computer should improve their ability to program software in machine-level code.

Brian Besel is a junior chemistry major who has been working in the laboratory of Prof. Patrick Desrochers for nearly two and a half years.  Brian summarized progress on a new anchor for nickel(II) that he developed as an unexpected positive result from a control experiment last August.  The goal of this work is to be able to anchor nickel(II) ions securely to a solid support and then use these bound-nickel ions as sensors for specific amino acids and for protein purification.  The new anchor developed by Brian and a coworker in the lab exhibits interesting cis/trans isomerism when bound to nickel(II).

Nov 12, 2009

Justin Allen is a senior biology major working in the lab of Prof. Kari Naylor, UCA Biology.  Justin described his work to identify features of proteins  responsible for the segmentation of mitochondria during cellular division.  His work has narrowed the features down to three different protein domains.  He describe the preparation of proteins containing different combinations of these three different domains.  His preliminary results indicated two of the three domains were critical for mitochondrial structural changes. 

Dean Turbeville is a senior biology preprofessional major also working in the lab of Prof. Kari Naylor.  Dean is working to determine the optimum conditions for obtaining real-time images of cellular phases and specific mitochondria structure.  He stained mitochondria of cultured live yeast cells that were then imaged at different stages of their life cycle.  The goal was to correlate what stage of cellular culturing would be optimum for observing desired stages of variable mitochondria structure.

Alec Watson is a junior physics major working with Prof. Rahul Mehta of the UCA Physics & Astronomy.  Alec is using X-ray fluorescence to determine the composition of bones of rats subjected to simulated zero-gravity.  Alec’s work is expected to help define the long-term effects of zero-gravity on bone composition, structure, and integrity and contribute to successful long-term human space exploration including deep space missions to Mars.  Alec described reproducible differences in calcium phosphate composition of leg bones of zero-gravity rats vs control rats living under normal conditions.

Ben Magie is a senior biochemistry major working with Prof. J. D. Swanson, UCA Biology.   Ben is working to identify the genetic markers that signal the develop of prickles in bramble plants like raspberries and blackberries.  He described a staining procedure that allowed him to image cellular contents in a sample of plant tissue.  What was uncertain in this procedure was whether the stain adhered to genes of interest, those responsible for prickle development, or to some other gene in the cell.  Ben’s developed a positive-control model for RNA/stain binding involving the protein cellulose-synthase (CS).  He outlined his use of web-based nucleotide databases to select a CS-specific gene sequence, the use of PCR to produce quantities of this gene, and his incorporation of the gene into bacterial cells, that were subsequently tested using a similar staining procedure as for his desired prickle-gene system.

Sep 24, 2009

Nikki Knox is a new masters student in the lab of Prof. JD Swanson, UCA Biology.  Nikki outlined the rationale for her new thesis work.  She is focusing on genetic differences between two types of raspberry plants, one with thorny prickles and one without.  Through DNA analysis of these plants, she hopes to identify genetic markers causing this difference.

Adam Corken is a senior biology major, and he discussed his work from a research summer spent at Oklahoma State University.  At OSU he worked on purifying a portion of a large protein called midline-1.  This protein is responsible for development of features positioned along the midline of the human body.  Adam learned to use techniques of genetic engineering and affinity chromatography in his work.  Interestingly, one of the affinity chromatography techniques he used at OSU is related to his research on nickel at UCA in the department of chemistry.

Luke Irvin from computer science shared his work with Prof. Sheng.  Luke described his efforts to develop more efficient algorithms for data mining from internet sources.  The process he outlined involved a ranking system whereby a weighting scheme is applied to answers provided from a specific query sent through common search engines like Google, Yahoo, Ask, and Bing.  One advantage of this method is by making use of existing search engine results, this could make their process faster to use, because it did not require the storage of vast amounts of information independently drawn the internet.