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The Anchor, Volume 130.15: February 1, 2017
Get PDFThe Anchor began in 1887 and was first issued weekly in 1914. Covering national and campus news alike, Hope College’s student-run newspaper has grown over the years to encompass over two-dozen editors, reporters, and staff. For much of The Anchor\u27s history, the latest issue was distributed across campus each Wednesday throughout the academic school year (with few exceptions). In recent years The Anchor moved to monthly print issues and a more frequently updated website. The Anchor is now published in print twice per academic semester. Occasionally, the volume and/or issue numbering is irregular
The Anchor, Volume 131.08: November 1, 2017
Get PDFThe Anchor began in 1887 and was first issued weekly in 1914. Covering national and campus news alike, Hope College’s student-run newspaper has grown over the years to encompass over two-dozen editors, reporters, and staff. For much of The Anchor\u27s history, the latest issue was distributed across campus each Wednesday throughout the academic school year (with few exceptions). In recent years The Anchor moved to monthly print issues and a more frequently updated website. The Anchor is now published in print twice per academic semester. Occasionally, the volume and/or issue numbering is irregular
From Beyond the Stars: Innovation and Inspiration in Meiji Japanese Art, 1868-1912
Get PDFDesign by Tom Wagner. Photography by the Kruizenga Art Museum, Tom Wagner, and Curatorial Assistance/WorldBridge Art, Inc. Produced by Storming the Castle Pictures (StCP) for the Kruizenga Art Museum as a catalogue for the exhibition, From Beyond the Stars, August 29 - December 16, 2017.https://digitalcommons.hope.edu/kam_catalogs/1001/thumbnail.jp
Specific Lipid Requirements and Localized Lipid Composition Changes Associated with Flock House Virus RNA Replication in Drosophila Cells
No full textPositive-strand RNA [(+)RNA] viruses are significant human pathogens. A universal feature of (+)RNA viruses is that they replicate their genomes in association with host intracellular membranes. This association may be a target for broad spectrum antivirals against (+)RNA viruses. The (+)RNA virus used in our studies is the alphanodavirus Flock House virus (FHV). FHV is a simple (+)RNA virus with a 4.5 kb bipartite genome that replicates in insect cells. FHV replicates its RNA genome at the outer mitochondrial membrane of infected cells where it forms 50-70 nm in diameter invaginations that are membrane-bound RNA replication complexes. Previous work by others has shown an increase in the amount of phosphatidylcholine in FHV infected cells. Additionally, decreasing the amount of phosphatidylcholine in Drosophila cells thru targeted down regulation of biosynthetic genes decreased FHV replication. We hypothesized that increased levels of phosphatidylcholine were required for the formation and maintenance of the membrane-bound replication complexes located at mitochondria. To test this hypothesis, we synthesized the choline analog, propargylcholine, which is incorporated into phosphatidylcholine and can be “tagged” using copper(I) catalyzed cycloaddition chemistry. FHV infected cells were incubated with propargylcholine, tagged with a fluorescent dye, and visualized with confocal fluorescence microscopy. Our results suggest that there is an enrichment of phosphatidylcholine at the sites of FHV RNA genome replication. Additionally, we determined that two other major classes of cellular lipids, phosphatidylethanolamine and phosphatidylserine, were not enriched at FHV genome replication sites. Ongoing work includes a quantitative analysis of the mitochondrial lipid composition of FHV infected cells. Our work provides support for the importance of specific lipids in (+)RNA virus genome replication and the possibility that lipid biosynthetic pathways may be good antiviral targets
Genomic Analyses of the Novel Mycobacteriophage Opia
No full textEighteen new mycobacteriophages were isolated from soil samples collected around the state of Michigan and parts of the United States. All phages were capable of infecting Mycobacterium smegmatis and were isolated through either enrichment or direct plating at 32°C or 37°C. A variety of plaque morphologies were produced based on size, shape, and clarity; both lytic and temperate phages appear represented in this collection. The mycobacteriophage, Opia, was chosen as one of three phages for complete genome sequencing and comparative genomic analyses. The predominant plaque produced by Opia at 37°C was circular and approximately 1 mm in diameter. The complete genome sequence for Opia revealed relationships to members of the Cluster B2, which contains 22 sequenced members to date. The genome of Opia is 67.4 Kb, 68.9% GC, and contains 93 genes. Phages in Cluster B2 share very high sequence identity throughout the genomes lengths. Opia maintains this pattern, being nearly identical to phages Glass, Rosebush, and Hedgerow despite isolation of the phages in different years (15 year span) and in different geographical locations. A detailed analysis of the complete genome sequences and comparison with sequenced mycobacteriophages is the subject of the second semester of this yearlong course and is presented
Genomic and Physiological Characteristics of Novel Escherichia Strains Isolated from Freshwater Sources
No full textEscherichia coli is primarily viewed as a commensal of the mammalian gut, but this view is changing with the recognition of “naturalized” populations of Escherichia found in non-host associated, secondary environments. The majority of Escherichia genome sequences comes from studies of host-associated isolates. While these strains are important to health and agriculture, they do not adequately address the potential diversity of strains found in secondary environments (e.g., freshwater streams and lakes, beach sands, soils). These sources may serve as reservoirs in which diverse strains of Escherichia exchange genetic information. We produced genome sequences of Escherichia isolates from freshwater sources as part of a longitudinal survey of microbial communities in Lake Macatawa Watershed. Relationships of isolates with publicly available sequenced Escherichia strains were determined using core genome phylogenetic inference. Approximately 98% of watershed strains are related to traditional E. coli; 2% of strains are related to non-traditional environmental clades. Members of Phylogroup B1, often isolated from freshwater environments in previous studies, make up 46% of the strains within the E. coli lineage. We used in silico methods to screen watershed strains for antibiotic resistance genes and virulence factors. Most watershed strains contain ≤30 antibiotic resistance genes, consistent with strains isolated from host sources, but more than the number of genes found within the non-traditional environmental clades. We conducted comparisons to determine protein families that distinguish among watershed isolates and reference Escherichia strains within established phylogroups. While there are protein families that clearly distinguish between different phylogroups, few differences were observed between watershed and related reference E. coli strains. Physiological experiments testing metabolic activity of watershed strains at 2-11°C revealed that many metabolize glucose at 8°C. These data expand our knowledge of potentially naturalized E. coli strains, allowing better water quality monitoring techniques that quantify E. coli as fecal indicator bacteria
Long Wavelength Azo Dye Monomers for Photomechanical Applications
No full textAzo dyes have long been incorporated into photomechanical systems with promise as wireless actuators (White, T.J.; Broer, D.J. Nat. Mater. 2015, 14, 1087-1098). Most azo dyes photoisomerize in the ultraviolet to blue-green region of the electromagnetic spectrum. However, these high energy wavelengths are prone to competitive absorption by other components of photomechanical devices, and are correlated to high levels of photodegradation of the material. These wavelengths also limit any biomedical applications, as they are incompatible with human tissue. Recently, Aprahamian and coworkers published a series of BF2-coordinated azo dyes which photoisomerize in the red-orange (Yang, Y.; Hughes, P.; Aprahamian, I. J. Am. Chem. Soc. 2012, 134, 15221-15224) to near-infrared (Yang, Y.; Hughes, P.; Aprahamian, I. J. Am. Chem. Soc. 2014, 136, 13190-13193) region of the spectrum. At these wavelengths, competitive absorption and photodegradation are minimal, as is absorption by mammalian tissue. In the Gillmore organic photochemistry research group, we are preparing analogs of Aprahamian’s dyes with polymerizable “handles” which may be incorporated into photomechanical polymers. These polymers will be prepared and studied in collaboration with the materials science / mechanical engineering research group of Professor Matt Smith in the Hope College Engineering Department. Synthetic efforts to date and future plans for this nascent research collaboration are described in this poster
Modeling Surface Electrical Stimulation
No full textSurface electrical stimulation is a non-invasive method for interfacing with the nervous system. However, variations in electrode placement, limb position and an individual’s anatomy make the results difficult to replicate, even in the same person. This project developed and validated a model to allow systematic varying of these key parameters to assess their contribution to nerve activation. The objective of this research in the future is to use the model to develop a surface electrical stimulation system that allows for precise nerve activation. A three-dimensional finite element model of the elbow was created, using two illustrated cross sections of the arm swept together and extruded in both directions. Three versions of the median nerve were modeled with 10 fascicles in random arrangements and 250 axons per fascicle. The fascicle diameters and distribution of axon diameters were based on measurements of a human median nerve at the elbow. Parameters were adjusted to reflect the differences in channel properties between motor and sensory axons; fifteen percent of the axons had motor properties and the remaining axons had sensory properties. Simulations were run, applying a voltage across two electrodes placed on the skin. The threshold voltages predicted by the model were consistent with experimental results from human subjects. In addition, the model predicted 20% activation of sensory axons before any motor axons, in the same way that sensory perception occurred before muscle movement experimentally. Using an ANOVA analysis, it was found that voltage, axon diameter, axon type, and fascicle location were all significant predictors of percent activation. The model has been validated with experimental results from human subjects. Next, the model will be used to analyze differences in nerve activation for different electrode arrangements and an algorithm will be developed to adjust and optimize nerve activation for various individuals
Incorporating Exogenous Variables in Disease Incidence
No full textDengue Fever, Dengue Hemorrhagic Fever. Chikungunya and Zika are four viral diseases which share a common vector, the Aedes mosquito, which is found in tropical and sub-tropical regions of the world. Environmental factors play a role in the survival of the Aedes mosquito. Thus, modeling disease incidence trends using environmental data, as well as information about the diseases themselves, would be a viable approach. Various models (both frequentist and Bayesian) for predicting disease incidence using exogenous variables are suggested and compared; with one of the comparison metrics being prediction accuracy
The Effect of Stepsize on Prediction Accuracy in Time Series Models
No full textPrediction accuracy of the response variable at future time points in a time series is a function of many factors, one of which is the number of available observations. We look at how adversely larger stepsizes (which are related to the number of available observations) affect prediction accuracy. We also consider the effect of using information from additional predictor variables on prediction accuracy as a function of stepsize