COURI Symposium Abstracts, Summer 2012 Copyright (c) 2013 University of Texas at El Paso All rights reserved. http://digitalcommons.utep.edu/couri_abstracts_sum12 Recent documents in COURI Symposium Abstracts, Summer 2012 en-us Fri, 05 Apr 2013 18:04:50 PDT 3600 Novel Acceptor Materials for Solar Cells http://digitalcommons.utep.edu/couri_abstracts_sum12/97 http://digitalcommons.utep.edu/couri_abstracts_sum12/97 Fri, 27 Jul 2012 17:25:06 PDT In recent years organic photovoltaics, OPVs, have gained an increasing amount of attention for their potential use as low-cost solar energy conversion devices. The interest in solar cells using fullerenes as an acceptor component has been rapidly growing in the last years.

The research on the origin of the open circuit voltage of bulk heterojunction solar cells containing a polymer and a mono-substituted fullerene are attracting extensive academic interest. To date, a vast majority of the efficient devices reported use the regioregular poly(3-hexylthiophene) (P3HT) polymer and PCBM-C60 (Phenyl-C61-Butyric Acid Methyl Ester) respectively as electron-donor and electron acceptor material. Since the trimetallic nitride endohedral fullerenes have a higher LUMO energy level than empty fullerenes. PCBM-Sc3N@Ih-C80 (1) (figure 1) was synthesized and completely characterized in this work.

The Open Circuit Voltage (Voc), one of the critical parameters in solar cells has a linear correlation of the first reduction potential (LUMO level) of the fullerene and the observed open circuit potential.

The reduction potential of fullerene derivatives are shifted cathodically as addends are connected to the sphere due to the saturation of the fullerene double bonds. Recently, the use of bis-adduct fullerene derivatives has led to increased efficiencies of OPV devices. These reported examples are based on complex bis-adduct mixtures. Since morphology is a very important factor in the design of OPV devices, compound 2 has been synthesized to be attached to the C60 in a tether- directed remote functionalization way (scheme 1), to yield only one (or very few) bis-adduct regioisomers.

]]> Diana M. Brus et al. Synthesis of Graphene/MOF-177 composites http://digitalcommons.utep.edu/couri_abstracts_sum12/96 http://digitalcommons.utep.edu/couri_abstracts_sum12/96 Wed, 18 Jul 2012 07:23:40 PDT Metal Organic Frameworks (MOFs) are formed by the self-assembly of metallic ions and organic ligands. These compounds have shown excellent properties for gas adsorption and catalytic activity. MOF-177 has one of the highest hydrogen storage capacities reported for porous materials at ambient temperatures (surface area = 3400m2/g), reported previously by Yaghi et al. Graphene and graphene based materials have unique structural, mechanical, and electronic properties. Graphene oxide(GO) and functionalized graphene have been used as support and as a structural pieces in the construction of MOF’s in the past. Synthesis of MOF-5 on the surface of GO and benzoic acid functionalized graphene (BFG) showed bigger BET surface area and micropore volume. Here we synthesized MOF-177 on the surface of GO and BFG was synthesized using Zn(NO3)26H2O, 1,3,5 tris(tri-benzoic acid) and Diethyl formamide. GO was synthesized from graphite using Hummer’s method and BFG was synthesized by using previously reported method. We prepared MOF-177 on the surface of GO and BFG using solvothermal techniques in ratios of 3, 5 and 10 %(p/p), in order to compare their differences and similarities in terms of porosity, formation process, structural arrangement and water stability. These composites were characterized by PXRD, FT-IR, gas adsorption, TGA and SEM, yielding high porosities and crystallinities.

]]> Nathaly Ortiz et al. Characterization of Subthreshold Delta-Sigma DAC and Level Converters for Energy Efficient Systems http://digitalcommons.utep.edu/couri_abstracts_sum12/95 http://digitalcommons.utep.edu/couri_abstracts_sum12/95 Wed, 18 Jul 2012 03:57:35 PDT Almost every activity in modern life is becoming integrated to an electronic device. These applications require developing energy efficient, faster, and smaller devices. Lowering supply voltages has been an effective strategy to dramatically increase energy efficiency in electronics. Subthreshold circuits run at unconventionally low voltages that can deliver the minimum energy per computation, but limit the performance. During 2011 Dr. Eric MacDonald and his team in collaboration with the Naval Research Laboratories in San Diego, fabricated the UTEP DACs Test Boards v. 1.0. This board includes a MOSIS chip designed at UTEP’s ASIC lab by Dr. MacDonald’s team. The chip incorporates 8-bit ΔΣ Digital to Analog Converter (DAC), a novel UTEP proposed level converter, and a traditional level converter. These elements are to be tested using appropriate laboratory equipment, which include a BASYS2 FPGA board to drive and collect the input and output data to the Test Boards. The immediate objective of the current project is to characterize the hardware designed at UTEP, optimized for subthreshold operation, in terms of energy efficiency, performance, and voltage range. A data sheet will be developed from the analysis and further improvements will be documented for the future work. The results will further confirm the expected energy efficiency and performance of the ΔΣ DAC and the proposed level shifter, as well as a comparison between the two level shifter designs.

]]> Jorge D. Martinez-Garcia et al. Transition States of DBT Molecule at the MoS2/Co9S8 Interface: First Principles http://digitalcommons.utep.edu/couri_abstracts_sum12/94 http://digitalcommons.utep.edu/couri_abstracts_sum12/94 Wed, 18 Jul 2012 03:40:36 PDT Sulfur removal in crude oil, is one of most important application when designing catalytic material to target hydrodesulphurization reactions. This particular study comprehends the quantum computational calculations for the transitional states during the HDS reaction in the molecular model of MoS2/Co9S8, which is a theoretical molecular model to describe the synergic contact between both crystallographic structures. Results produced using the exchange correlation Perdew-Burke-Ernzerhof(PBE) functional indicate the existence of endothermic and exothermic transitions during the attachment of DBT molecules. In addition, it proves that promotion (addition of Co, Ni) provokes the electronic configuration of electron donor from Co into Mo, this allows the attachment of DBT molecules onto the MoS2 slabs efficiently.

]]> Svetlana Gelpi et al. Systems Engineering http://digitalcommons.utep.edu/couri_abstracts_sum12/93 http://digitalcommons.utep.edu/couri_abstracts_sum12/93 Wed, 18 Jul 2012 03:25:09 PDT Systems Engineering is a fast growing field in the engineering braches. It can be applied to anything that one can be described as a system. To show this, two different projects are being directed through the systems engineering department at UTEP. In the Student Busing Project, UTEP was granted funding from the Green Fund in order to pursuit the start of a busing system on campus. Research on other busing systems, as well as the effects and costs of adopting a busing system were researched. Surveys were completed, and additional research was done to see the environmental effects the buses would help reduce. From this information, DoDAF views were mapped out and created to show the internal architecture for the student busing system. These findings have been presented to the Sun Metro busing company as well as the UTEP student body. Further work is being done and the optimal result will be a functioning busing system for the UTEP campus. The second project is to go through, and correct any errors in the IBM manual for Rational Rhapsody. To do this, a class over object orientation is required. This class tackles the basic understanding and elements of systems engineering. Through these understandings it is learned how to create UML diagrams Using Visual Paradigm for UML. From this step the learning of the IBM Rational Rhapsody takes place, in order to be able to create DoDAF diagrams. Further work is needed before completion of this class.

]]> Caitlin A. Lambing et al. Smart Grid: A New Hope for Energetic Crisis http://digitalcommons.utep.edu/couri_abstracts_sum12/92 http://digitalcommons.utep.edu/couri_abstracts_sum12/92 Wed, 18 Jul 2012 02:38:19 PDT With the world changing so rapidly, new renewable energies began to develop, but a new system that integrated these energies and the Non-renewable energies has not been developed yet. A great problem grew at the same time as the renewable energies became more popular. It consisted on searching for a way to permit the control of flow of energy and the power thru the power grid. It’s a critical problem because all the energy that is lost is during the power factor phenomenon. The main factor that produces that the power factor be low (the lowest, more energy is lost) is having the power plants working when the consumers’ demand is not sufficient. Here is where the Smart Grid comes into play.

The Smart Grid Technology consists in controlling the power grid flow by having real time readings, instead of using statistics for the production of energy. It also establishes a two way communication flow between the user and the utility company. By implementing the Smart Grid we can have, three main benefits. The first advantage is the decline in CO2 in the environment. About a 40% of the CO2 in the environment comes from the production of electricity. By implementing this technology, the emission of CO2 will decrease by a 10%. The second benefit is the integration of the renewable technologies into the grid. At last, the third benefit is that having an intelligent monitoring system can help to reduce failures or detect possible problems, prevent them and/or resolve them as soon as possible.

]]> Humberto Camarena Novel Dyad-Fullerene Derivative Used as Acceptor with P3HT in Bulk Heterojunction Solar Cells http://digitalcommons.utep.edu/couri_abstracts_sum12/91 http://digitalcommons.utep.edu/couri_abstracts_sum12/91 Tue, 17 Jul 2012 16:58:50 PDT Within the world of solar cells, research is rapidly uncovering potential solutions to the alternative energy issues by utilizing bulk-heterojunction cell techniques (Figure 1a) for low-cost and quick effective manufacturing. In this scope of research, a unique concept of donor-acceptor (D-A) system pairing as an acceptor within the bulk-heterojunction cell has been brought to light; a new concept of utilizing HOMO/LUMO pairings to create effective transport systems between a combination D-A acceptor and polymer donor is being optimized for maximum Photo-Conversion Efficiency (PCE). Due to a similar band gap relationship between the commonly reported PCBM and the novel dyad fullerene derivative (Figure 1b C60-TPA) used in this bulk-heterojunction system, a reference polymer donor referred to as P3HT is the designed to accomplish the goal of achieving higher PCEs. After synthesis and characterization of the dyad and preparation of devices using this distinctive concept of a potential donor-acceptor dyad system testing of the PCE was done using a PCBM/P3HT as a reference. Research in this innovative arena of photovoltaic cells is crucial because of the alternative possibilities it offers within development of organic photovoltaic cells, vital for establishing a competitive advantage in efficiency over the inorganic counterparts in the solar cell field.

]]> Amber D. Berkobien et al. Purification and Characterization of Mycobacterium tuberculosis ESX-1 Secreted Protein ESAT-6 http://digitalcommons.utep.edu/couri_abstracts_sum12/90 http://digitalcommons.utep.edu/couri_abstracts_sum12/90 Tue, 17 Jul 2012 10:08:57 PDT Mycobacterium tuberculosis ESX-1 secreted protein ESAT-6 has been shown to contribute to the pathogenesis and virulence of M. tuberculosis. Despite many studies, little is known about how this protein interacts with the host’s membrane and evades the host’s defense mechanism. In this project, we successfully purified and characterized of ESAT-6 wild type (E6-WT) and ESAT-6 mutant with either a single (E6-S) or double (E6-D) amino acid mutation that are supposed to diminish the membrane-interacting activity of ESAT-6. The methods used in our project include: cloning in plasmid vectors, cloning in PCR products with T-Vectors, chemical transformation of E. coli, affinity chromatography, site-directed mutagenesis and DNA/protein electrophoresis. By using NuPAGE 4-12% Bis-Tris gels we were able to confirm the purity of our proteins. We would like to further extend our project by infecting mammalian cell line RAW 264 macrophages with E6-WT, E6-S and E6-D to probe cytotoxicity of the proteins of interest.

]]> Sebastian Montalvo et al. Cholesterol Degradation Pathways as Therapeutic Targets in Mycobacterium tuberculosis http://digitalcommons.utep.edu/couri_abstracts_sum12/89 http://digitalcommons.utep.edu/couri_abstracts_sum12/89 Tue, 17 Jul 2012 07:36:38 PDT Mycobacterium tuberculosis (Mtb) is an intracellular pathogen responsible for about 2 million deaths worldwide annually. During infection, Mtb faces the nutrient-deficient environment of the macrophage phagosome and switches to lipids, including cholesterol, as its main source or carbon and energy. Extensive work has been done on the cholesterol AB rings degradation, but much less is known about the degradation of the CD rings and aliphatic side-chain, which are thought to be shortened by β-oxidation reactions. In this study, we investigate the role of four fadD (fadD3, fadD17, fadD19 and fadD36) and eight fadE (fadE26-fadE33) genes, encoding for probable acyl-CoA ligases and acyl-CoA dehydrogenases, respectively. To elucidate the catalytic function and determine the essentiality/redundancy of these genes in the cholesterol degradation pathways, we will generate deletion mutant strains by homologous recombination using specialized transducing mycobacteriophages. Allelic exchange substrate (AES) at specific loci will be constructed by amplifying the flanking regions by PCR from Mtb genomic DNA, followed by their insertion into two alternative recombineering vectors (pMSG360 and pJSC407). The recombinant vectors will be converted into thermosensitive phage particles in non-pathogenic Mycobacterium smegmatis cells at the permissive temperature of 30 °C. High-titer solutions of specialized transducing mycobacteriophages will then be used to infect Mtb cells at the non-permissive temperature of 39°C, and deletion mutant clones will be obtained after 3-4 weeks of incubation at 37 °C. Progress in the construction of AES will be presented.

]]> Veronica Escalante et al. Do Roads Affect Genetic Diversity of Lizard Populations in Southern New Mexico? http://digitalcommons.utep.edu/couri_abstracts_sum12/88 http://digitalcommons.utep.edu/couri_abstracts_sum12/88 Tue, 17 Jul 2012 07:00:16 PDT Roads can increase mortality rates, potentially decreasing population sizes. This could increase inbreeding, which will decrease genetic diversity. Decreased genetic diversity can negatively affect long-term viability of populations. We investigated how genetic population structure of the Western Whiptail lizard (Aspidocelis marmorata) is affected by an interstate highway (I-10) in Southern New Mexico. We hypothesize that animals near the road will have lower genetic diversity then individuals farther from the road. We used microsatellites to investigate patterns of genetic diversity (allelic richness and observed heterozygosity) near and away from I-10. Microsatellites are highly variable genetic markers widely used for studying the genetic structure of wildlife populations, including potential disease vectors. Tissue samples were collected from lizards trapped at different distances from the road on both sides of I-10. DNA was extracted, and PCR was used to amplify eight microsatellite loci. Genotypes were obtained for 42 individuals, 28 from arrays near the road and 14 from arrays 125 m from the road. Average number of alleles per locus were similar at both distances from the road (near road: 7.625±3.306, far from road: 5.875±2.216), as was average observed heterozygosity (near road: 0.512 ±0.160, far from road: 0.455 ±0.158). Initial results show little difference in genetic diversity between populations near to and far from the road. Large population sizes have been observed near I-10, allowing animals more opportunity to mate with unrelated individuals, lowering the possibility of inbreeding. However, if roads are barriers to movement, isolated populations can become genetically differentiated. Later analyses will investigate this possibility.

]]> Raul F. Marin et al. Validation of Interaction Between the GlyT2 and the NSF http://digitalcommons.utep.edu/couri_abstracts_sum12/87 http://digitalcommons.utep.edu/couri_abstracts_sum12/87 Mon, 16 Jul 2012 15:31:20 PDT The Glycine Transporter 2 (GlyT2) is a presynaptic membrane transporter in charge of re-uptake of glycine from the synaptic cleft back into the presynaptic neuron. GlyT2 is present only in vertebrate neurons and possesses a 200 amino- acid long N-terminal tail of unknown function. We hypothesize that such domain serve as a docking site for a network of presynaptic proteins, such as NSF that plays a pivotal role during vesicle transport. Therefore, our goal in this project is to analyze protein-protein interaction between GlyT2 and NSF. We have used co-immunoprecipitation experiments from rat brainstem with GlyT2 and NSF antibodies as bait, and heterologous expression of both genes in porcine aortha epithelial (PAE) cells. Preliminary results showed that both antibodies are capable of precipitating the corresponding protein from rat brain; at the same time, blotting of a GlyT2 immunoprecipitate with NSF antibodies readily detected a protein at the predicted molecular weight for NSF (about 110 kDa for GlyT2, and 82kDa for NSF). These results suggest that NSF is a potential GlyT2 interacting protein. To study this interaction in vitro, we tagged NSF gene with the green fluorescent protein at the N-terminus and the final construct was expressed in PA cells. We immunoprecipitated GFP-NSF from transfected cells with NSF or GFP antibodies and after separation in SDS-PAGE and western blot analysis with NSF antibodies, we identified an reactive band of ~110 kDa corresponding to the fusion protein. Future experiments to analyze the interaction will include the additional expression of GlyT2 and studies of localization and interaction by fluorescence microscopy.

]]> David Quispe Escudero et al. Poly(3,4-ethylenedioxy-thiophene)：Poly（styrenesulfonate）（PEDOT:PSS） as a Hole-transporting/electron-blocking Interfacial Layer to Increase the Efficiency of Polymer Bulk-heterojunction Solar Cells http://digitalcommons.utep.edu/couri_abstracts_sum12/86 http://digitalcommons.utep.edu/couri_abstracts_sum12/86 Mon, 16 Jul 2012 15:09:30 PDT Solar energy is playing a critical role in today’s renewable energy resources. Polymer bulk-heterojunction solar cells have the possibility to be cost-effective and highly efficient. However, the technology is fairly new and has not yet been perfected. Therefore, In order to enhance the efficiency of polymer bulk-heterojunction solar cells, thin layers of Poly(3,4-ethylenedioxy-thiophene)：poly（styrenesulfonate）（PEDOT:PSS） are inserted between the active organic layer, poly(3-hexylthiophene)(P3HT)+[6,6]-phenyl-C61 butyric acid methyl ester(PCBM), and the ITO(tin-doped indium oxide) anode of bulk-heterojunction ITO/P3HT:PCBM/LiF /Al solar cells. Both the interfacial layer, which is PEDOT: PSS, and the active layer are deposited by spin-coating. So far, I have been able to produce this variant of bulk-heterojunction solar cells that have power conversion efficiencies of up to 3.8% and enhance the fill factor to 59% , as well as an open-circuit voltage (Voc) of 600mv versus an ITO/P3HT: PCBM/LiF/Al control device. The results show that such hole-transporting/electron-blocking interfacial layers are a great alternative to current existing photovoltaic materials.

]]> Yanyu Wu et al. Silica supported silver Nanoparticles Catalyst Systems for Oxidation of DBT in Crude Oil. http://digitalcommons.utep.edu/couri_abstracts_sum12/84 http://digitalcommons.utep.edu/couri_abstracts_sum12/84 Mon, 16 Jul 2012 15:09:13 PDT Metal nanoparticles (NP’s) have become a subject of intense interest in various fields of chemistry and physics primarily because of its catalytic activity at their specific surfaces. Their catalytic activity depending solely of their factes, it is recomendable to achieve six-fold symmetry along with edge sites, ideal places for the attachment of molecules. The aim of this project is to achieve the synthesis of NP-Ag and their functionalizatiin using supported on silica to later perform an oxidation model reaction of diobenzothiophene (DBT) to diobenzenethiophene-sulfone. The DBT oxidation reaction was performed in a reflux system using DBT and silica solved in decalin heated at 140°C with vigorous stirring for two hours. All reaction products were identified by using Fourier Transmitted Infrared, FTIR; X-Ray Diffraction, XRD; and Scanning Electron Microscope techniques. Results indicate a catalytic activity when using this particular systems.

]]> Ashlie Santaliz et al. The regulation of the Glycine Transporter 1 by phosphorylation http://digitalcommons.utep.edu/couri_abstracts_sum12/83 http://digitalcommons.utep.edu/couri_abstracts_sum12/83 Mon, 16 Jul 2012 14:53:35 PDT The plasma membrane glycine transporters 1 (GlyT1) is the carrier molecule responsible for the fast removal of the inhibitory neurotransmitter glycine from the synaptic cleft back into the presynaptic terminals of glycinergic neurons by an electrogenic, Na+-Cl- transport couple mechanism maintained by the Na+,K+-ATPase. GlyTs belong to SLC6 family that includes other neurotransmitter transporters, such as the dopamine, norepinephrine, serotonin, and GABA transporters. In order to determine the role of PKC-dependent phosphorylation on GlyT1, we have analyzed the effect of PKC activation by phorbol ester (PMA) on the activity, post-translational modifications and the levels of cell surface transporter in mutants where several replacements of Ser/Thr to Ala were made. We found that, similar to other transporters like DAT, NET and SERT, activation of protein kinase C by phorbol ester led to increased phosphorylation and ubiquitination of GlyT1. These modifications were accompanied by a reduction in transport capacity and enhanced transporter endocytosis. Interestingly, replacement of serine/threonine residues to alanine at both tails abolished PKC-dependent phosphorylation but dramatically enhanced ubiquitination and degradation. These results suggest that transporter modifications represent a mechanism of GlyT1 regulation. This work was supported by a grant from NIMH 5SC1MH 086070-04 to MM, AA is a recipient from the bridges program, grant NIH 5R25GM049011-13

]]> Alejandro A. Acuna et al. The Fly Way http://digitalcommons.utep.edu/couri_abstracts_sum12/82 http://digitalcommons.utep.edu/couri_abstracts_sum12/82 Mon, 16 Jul 2012 10:26:18 PDT This project is related to the way a common house fly’s eye works. Dr. Moya has received a patent that helps mimic the way the ommatidia(compound eye of the fly) processes and “pinpoints” the location of a given image / object. It is on the basis of this patent that his graduate students Ruben Hernandez and Amauri Perez have improved the programming of the algorithm that shows that an object can be effectively be detected by a camera interfaced with these programs. Potential applications include but are not limited to security (both public and private), robotic assisted surgical procedures/treatments, gaming…etc.

Although it’s not entirely refined, the possibilities are open for interpretation. My primary goal for this summer has been to be able to write a program equivalent to the initial code to lay a solid foundation so that my contributions go beyond the summer.

]]> Daniel Moran et al. Selection of Critical Design Parameters for MMOD Protection in Interplanetary Missions http://digitalcommons.utep.edu/couri_abstracts_sum12/81 http://digitalcommons.utep.edu/couri_abstracts_sum12/81 Mon, 16 Jul 2012 10:26:06 PDT This research presents a methodology for the selection of critical design-parameters for the design of Micro Meteoroid and Orbital Debris (MMOD) spacecraft protection based on a modified implementation of the concept of the Probability of No Impact (PNI). The PNI methodology, based on Poisson’s discrete statistics, has been widely used to determine critical particle sizes for the design of protection systems. However, it does not provide guidelines for the selection of the design impact speed, especially when the impact speed has a very wide statistical distribution like that encountered in interplanetary missions. The modifications to the PNI methodology presented here allows for the selection of both, a design particle size and impact speed, based on the same discrete probability theory. This methodology is applied to determine critical design parameters for the Solar Probe Plus (SPP) spacecraft; a mission currently under study funded by the NASA’s Office of Space Science – Sun-Earth Connection theme. Results are presented for the Solar Array in the SPP spacecraft in the form of design particle size and impact speed for various PNI levels.

]]> Lisa M. Haisan et al. Seismic Tomography and Smoothing Filters http://digitalcommons.utep.edu/couri_abstracts_sum12/80 http://digitalcommons.utep.edu/couri_abstracts_sum12/80 Mon, 16 Jul 2012 10:26:02 PDT Seismic Tomography and Smoothing Filters Seismic Tomography is a technique used by geologists to map the Earth's crust. Seismic Tomography is an iterative process that develops a model based on travel times of waves from explosion sites to sensors. First, travel times are gathered by using shot points and sensors. Then an optimization process begins with an initial simple model (velocity increasing monotonically with depth), is used to predict the travel times. These predictions are compared to the observed travel times, and the model is refined so that it can better match the observed data until a satisfactory solution is found. A key component in tomography that takes a great amount of time is the smoothing process. Smoothing is when velocity perturbations are calculated and are spread throughout the model so the difference between the calculated model and observed data is decreased. Recent research has proposed an efficient smoothing algorithm called the Box Filter, or formally the Mean Filter. However, the downside is the simplicity results in need for more smoothing iterations. Our research focuses on developing an alternative and faster overall filter algorithm, the Tent Filter, which will give efficiency just as the mean filter but improve the quality output. An importance of using a Tent Filter is that it will give more weight to what is believed to have more importance, unlike the Box Filter, resulting in a reduced number of smoothing iterations. With the improvement of smoothing algorithms, models will be computed faster and with greater accuracy.

]]> Mathew Guevara et al. Characterization and Localization of Glycinergic Neurons from the Mouse Brain Stem http://digitalcommons.utep.edu/couri_abstracts_sum12/79 http://digitalcommons.utep.edu/couri_abstracts_sum12/79 Mon, 16 Jul 2012 10:16:27 PDT The neurotransmitter glycine functions as the major inhibitory neurotransmitter in the brain stem, cerebellum and spinal cord, where is contained in synaptic vesicles within glycinergic neurons. However the location of cell bodies, neuronal projections and connections are undefined to date. While the presence of glycine, the glycine transporters GlyT1, GlyT2 and the vesicular glycine transporter VIAAT may define a glycinergic neuron, little efforts have been made to investigate these neurons. To better identify and characterize these glycinergic neurons, we prepared primary cultures from the brain stem and the retina, using a transgenic mouse that expresses the green fluorescent protein (GFP) under control of the GlyT2 promoter. After several 5-15 days in culture, we subject these cells to immunostaining with GlyT1 and GlyT2 antibodies followed by identification of glycinergic neurons by fluorescence microscopy. The results suggest the identification of three populations of GFP-positive neurons: those positive for GlyT1, other population containing GlyT2 and the third class devoid of either glycine transporter. Given that GFP expression is controlled by the GlyT2 promoter and to explain the absence of the glycine transporter, experiments are underway to characterize these GFP-positive neurons. This work was supported by a grant from NIMH 5SC1MH 086070-04 to MM and a stipend from grant R25DA033613 to AR.

]]> Astrid M. Rodriguez et al. Aversive Visual Conditioning in Drosophila melanogaster http://digitalcommons.utep.edu/couri_abstracts_sum12/78 http://digitalcommons.utep.edu/couri_abstracts_sum12/78 Mon, 16 Jul 2012 09:00:31 PDT Visual cues in our environment revive past experiences that have impacted our life in a positive or negative manner. Furthermore, such behavior may not only require a prompt response, but it may also scale to a permanent effect on the individual. Dopamine regulates motivation and reward, along with learning and memory. Via classical olfactory conditioning knowledge has been attained that dopamine, a major monoamine in Drosophila melanogaster, is essential for learning and memory. Flies learn and remember odor associated with either sugar or electrical shock and dopamine plays a crucial role in both appetitive and aversive olfactory memory formation. Nonetheless, dopamine’s significance in visual memory formation continues to be poorly understood. The purpose of this research is to elucidate the role of dopamine in visual conditioning in Drosophila. A visual conditioning paradigm has been designed in which flies are exposed to blue or green color light paired with an electric shock. If test subjects learn to associate the colored light with electric shock, they will avoid the shock-associated light color. Along with the wild-type Canton-S, we investigated the flies with deficiency in dopamine D1 receptors, dDA1 (dumb) and dopamine D2 receptors, dDR2 (dd2R) for the ongoing study. It is hypothesized that the mutants deficient in D1 or D2 receptors will exhibit reduced capacity to learn and memory in visual conditioning in comparison to wild-type flies. This ongoing study will enable us to understand how visual learning and memory formation is acquired in Drosophila and possibly humans.

]]> Raudel Melchor et al. Generating Minimal t-wise Covering Test Suites using Constraints http://digitalcommons.utep.edu/couri_abstracts_sum12/77 http://digitalcommons.utep.edu/couri_abstracts_sum12/77 Mon, 16 Jul 2012 09:00:25 PDT Software testing is an essential part of software development that seeks quality assurance, reliability, and robustness. Unfortunately, exhaustive testing can be a very expensive, time consuming, and tedious process. With large sets of inputs, exhaustive testing can result in unpractical test suites, of size that grows exponentially with the number of input parameters.

As a way to address this growth, t-wise testing consists in focusing on test suites that only cover the interactions of the t-tuples of input parameters of the system at hand. Adding constraints further restricts the size of the test suite by limiting the possible values of the input parameters.

In this work, we propose and present a deterministic approach to generating minimal t-wise covering test suites with constraints that consistently produces minimum-size test suites while guaranteeing full coverage of t-wise combinations of values of input parameters. This new approach evaluates each test case and populates it with values that cover the most unused t-tuples. It significantly reduces the time and cost of testing software or even of machinery and circuits.

]]> Carlos A. Nieto et al.