Recent Submissions

  • Reuleaux undergraduate research magazine: third edition backmatter

    The backmatter includes a request for future authors, a meet the editors section, and a dedication.
  • What secrets do biological vesicles hold? Separation and size characterization of outer membrane vesicles with asymmetrical flow field-flow fractionation and light scattering

    Betz, Elizabeth; Plavchak, Christine; Hansen, Riley; Williams, Kim R.
    Extracellular vesicles (EVs) are nano-vesicles (50-500 nm) that are released by cells and play an important role in cell-to-cell communication. EVs have applications ranging from disease treatment and detection to developing more efficient biofuels. Outer membrane vesicles (OMVs) are a specific type of EV released by gram-negative bacteria. Specifically, OMVs from the soil bacteria Pseudomonas putida, contain enzymes with the ability to break down lignin, a complex plant polymer that is a plentiful resource for biofuels. Studying the relationship of size and content of OMVs within a cultivation of vesicles aids in the understanding of how these OMVs efficiently break down lignin. To investigate P. putida OMVs, we hypothesized that asymmetrical flow field-flow fractionation (AF4), dynamic light scattering (DLS), and multi-angle light scattering (MALS) could be used to efficiently separate and determine the size distributions of OMVs. Liposome standards were utilized in initial experiments to analyze retention times according to size due to their similar structure to OMVs. AF4-DLS-MALS fractionations of P. putida OMVs showed two different sized populations when grown on lignin. Separating these OMV populations will help correlate differences in protein and lipid content between small (50-150 nm) and large (200-500 nm) vesicles.
  • Experimental platform for thermal conductivity measurements

    Allen, Portia; Blagg, Kirsten; Singh, Meenakshi
    Thermal conductivity measurement techniques are extremely well established at room temperature, but become more challenging at cryogenic temperatures. The development of a dedicated thin film measurement platform for sub-Kelvin temperatures is explored here. Delicately suspended Si-N platforms ensure thermal isolation of the sample, while lithographically patterned Joule heaters provide a controllable temperature gradient across the platforms. A carbon-platinum (C-Pt) composite, fabricated using focused ion beam (FIB) assisted deposition, was patterned on the platforms as a local, resistive thermometer. These C-Pt thermometers are highly sensitive below 1K, and comparable to commercially available cryogenic thermometers. While suspended platforms have been used for thermal conductivity measurements before, the integration of highly sensitive, locally deposited cryogenic thermometers allows for more precise measurements over a wider temperature range.
  • Optimizing genetic algorithm parameters for atmospheric carbon monoxide modeling

    Duggal, Meera; Hammerling, Dorit
    Climate indices can measure the variability in the climate such as changes in sea surface temperature and wind. With this knowledge a predictive CO model was developed (Buchholz et al., 2018). This model uses climate indices to predict future CO emissions which are directly linked to large burn events that will occur in the southern hemisphere. We use four different climate indices in our model: the El Nino Southern Oscillation in the central tropical Pacific region 3.4, Indian Ocean Dipole/Dipole Mode Index (IOD/DMI), Tropical South Atlantic Index (TSA), and the Antartic [sic] Oscillation Index (AAO).
  • Reuleaux writing grant publications

    Articles on pages 18-50 received Reuleaux Writing Grants. Those articles are: Characterizing mixed culture beer, Self-regulated learning: using educational psychology to enhance the learning experience for undergraduate students, What secrets do biological vesicles hold?, Experimental platform for thermal conductivity measurements, and Optimizing genetic algorithm parameters for atmospheric carbon monoxide.
  • Self-regulated learning: using educational psychology to enhance the learning experience for undergraduate students

    Palmer, Allison; Strong, Scott
    Students, like all humans, carry within them more than just their intellectual capacities and technical abilities. In order to reach students' minds, help them learn, and help them develop as people, education systems must strive to view learners in a more holistic manner.
  • Laboratory spotlight: welcome to the Payne Institute

    Reid, Juliana
    If you've ever wondered how governments, businesses, and investors learn more about the technological issues shaping our world, then you might be surprised to learn that there is an entire subset of researchers and writers who focus on bridging that gap. At the Payne Institute for Public Policy, rather than performing lab experiments or taking soil samples, we focus on the interaction between pure academic research -- what the other talented professors and laboratories do on campus -- and the laws, opportunities, and practices that help keep our society progressing and evolving.
  • Investigation of reservoir rock properties measurement methods for conventional sandstone and unconventional Bakken shale

    Cheng Siew, Chiang; Teklu, Tadesse
    The ability to accurately measure rock properties is important to oil and gas field development since the implementation of resources, production forecasts, and the economics of the reservoir are derived from this foundation. This study measured the porosity and permeability of 118 sandstone and 10 Bakken shale samples using a variety of non-destructive methods that are used in industry and can provide a basis for more complex techniques. Measuring these properties can be difficult depending on the composition of the reservoir rock, especially for unconventional shale due to their tight and complex structure. Many of the oil and gas reservoirs are sandstone and carbonates, but significant quantities of oil and gas are produced from low-permeability unconventional shale reservoirs that have been developed in recent years around the world.
  • Characterizing mixed culture beer

    Peel, Henry
    The increasing demand for novel and unique flavors in the craft beer industry has led to a rise in the use of Mixed Culture Fermentation (MCF). These cultures house complex microbial biomes that exhibit extraordinary metabolic diversity. Because of this, MCFs can produce beverages with unique profiles likely as a result of the biochemistry associated with their high heterogeneity. Using high-throughput DNA sequencing and bioinformatics it is possible to quantify the diverse conglomerate of microorganisms found in these cultures. There is potential to couple this information with metabolomics and transcriptomics to better understand, control and build cultures with desired characteristics. Such characteristics may include metabolites with pleasant aromas or flavors, pH adjustment, tolerance to environmental changes or fermentation speed. We analyzed 6 mixed cultures by using high-throughput 16S rRNA gene sequencing and the DADA2 (Divisive Amplicon Denoising Algorithm 2) open source bioinformatic software package to identify unique sequences of genetic code to elucidate the makeup of the microbial communities. Our study revealed 122 different genera of Bacteria, 3 genera of Eucarya, and one genus of Archaea across the analyzed beer cultures. Lactobacillus acetotolerans was found to be the dominating strain of Bacteria, while the dominant eukaryotes were Brettanomyces custersianus and Brettanomyces bruxellensis yeasts. Only one genus of Archaea, Methanobrevibacter sp., was found.
  • Reuleaux undergraduate research magazine: third edition frontmatter

    Wade, Kacey
    The frontmatter includes the cover page, a description of the Creative Commons licenses used in the publication, a letter from the editor, Kacey Wade, the table of contents, and a description of the peer reviewed articles.
  • Quantum fluids: space curves on vortex rings

    Rudge, Kaleigh; Strong, Scott
    Vortex filaments are a fundamental structure in fluid dynamics for transferring energy and are crucial in the understanding of how quantum turbulent structures settle. Building these geometric vortex lines can be performed by using Jacobi elliptic functions to piece together hoops on an elliptical curve in space. In this article we will discuss the geometry of these space curves. We will start with the static elliptical track with the hoop, and introduce the use of the Jacobi elliptic functions in the parameterized planes. Then we will observe the curve in space to discuss the curvature and torsion features of the curve. Finally, we will look at the vortex line in a unit parameterization case to further discuss our results.