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Bacterial Counts in the Muskegon Area Watershed
Get PDFThe goal of this experiment was to identify non-sulfur bacteria counts in the Muskegon Watershed area. We did so by cultivating bacteria in twelve different Winogradsky columns to determine if non-sulfur bacteria life is viable in the four different waterways that were sampled: Gilligan Lake, Lake Macatawa, Lake Michigan, and the Kalamazoo River. Bacteria grown in shade had highest colony counts in Lake Macatawa and the forest area of Lake Michigan. Bacteria grown in sunlight had highest colony counts in the forest area of Lake Michigan. Extended research could identify the non-sulfur bacteria types and allow us to discern how each affects the biome in which it lives. This research lays the groundwork for future studies involving sulfur-bacterial growth
Opus: Fall 2016
Get PDFAn issue of Opus from fall 2016.https://digitalcommons.hope.edu/opus_2010s/1008/thumbnail.jp
Physical and electrochemical area determination of electrodeposited Ni, Co, and NiCo thin films
Get PDFThe surface area of electrodeposited thin films of Ni, Co, and NiCo was evaluated using electrochemical double-layer capacitance, electrochemical area measurements using the [Ru(NH3)6]3+/[Ru(NH3)6]2+ redox couple, and topographic atomic force microscopy (AFM) imaging. These three methods were compared to each other for each composition separately and for the entire set of samples regardless of composition. Double-layer capacitance measurements were found to be positively correlated to the roughness factors determined by AFM topography. Electrochemical area measurements were found to be less correlated with measured roughness factors as well as applicable only to two of the three compositions studied. The results indicate that in situ double-layer capacitance measurements are a practical, versatile technique for estimating the accessible surface area of a metal sample
Decarbonylative Cross Coupling of Phthalimides with Diorganozinc Reagents—Efforts Toward Catalysis
Get PDFThe decarbonylative coupling of phthalimides with diorganozinc reagents to form o-substituted benzamides has been previously demonstrated as a viable process, but only with stoichiometric nickel(0). Investigations into a number of reaction variables, including solvent, ligand, and substrate substitution, have yielded multiple sets of conditions capable of achieving up to 10 catalyst turnovers, most successfully with the use of electron withdrawing nitrogen substituents on the phthalimide. In addition, these investigations have provided insight into the intermediates within the catalytic cycle and have revealed new approaches to the development of a general catalytic methodology
From Woods to Water: Reviving a G-W Invader
Get PDFFrom Woods to Water: Reviving a G-W Invader is an article concerning the full restoration of a 1972 G-W Invader 10.3\u27 Rally fiberglass boat by high school students Peter Reynolds, Gurjinder Sandhu, and instructor Geoffrey Reynolds, during May and June 2016
In Their Own Language: Toward a Receptive Ecumenism in Christian Higher Education
No full textThe purpose of this essay is to encourage those who inhabit Christian colleges to think about the notion of ecumenism, what it means—or could mean—to be an ecumenical Christian college, and how this concept might shape their thinking, their common life together, and the degree of trust they have for each other, both within and among their campuses
Aggregation of A(12-28) in the Presence of Ru3O clusters
No full textAlzheimer’s disease (AD) is a neurodegenerative disease that affects more than 5 million Americans, and is currently the 6th leading cause of death in the United States. The A(1-42) protein is implicated in memory loss and degeneration of the brain in AD patients. The misfolding of the fragment A(12-28) is often studied to give insight into misfolding of the parent sequence, A (1-42). This fragment contains the hydrophobic KLVFFA section and the His residues, both of which are implicated in aggregation. A growing body of work shows that metal complexes with hydrophobic ligands are able to influence aggregation of A(1-42). We have prepared a library of hydrophobic Ru3O(OAc)6(L3)+/0 complexes where L = 4-phenlpyridine, pyridine, 4-dimethylaminopyridine, and isoquinoline. We are using label-free assays as well as fluorescent thioflavin T aggregation assays to investigate the effects of these Ru3O complexes on aggregation of A(12-28)
Activity Preferences and Cognitive Development in Children: Effects of Children’s Preference for Active Outdoor Activities Versus Sedentary Indoor Activities on Cognitive and Literacy Scores
No full textThis study assesses children’s preferences for active outdoor and sedentary indoor play based on an outdoor science enrichment intervention for preschool children. Researchers analyzed the relationship between the children’s activity preferences and their cognitive and literacy scores. A previous systematic review was conducted about the relationship between sedentary behavior and cognitive development in early childhood. Included in this comprehensive review were 37 studies (either experimental studies or observational studies) that discussed how “optimal cognitive development” in early childhood is related to many different domains, including physical activity (Carson et al., 2015). A large majority of children engage in excessive sedentary behavior, which results in detrimental effects to cognitive development (2015). For the current study, participants were recruited from local preschools through partnership with the Outdoor Discovery Center Macatawa Greenway (ODCMG) in Holland, Michigan and the Kellogg Foundation. Participants were both male and female preschool students (ages 3-5). Preferences for active outdoor or sedentary indoor activities were examined using two items from a self-report interview measure designed for use with preschoolers. We expect that preference toward active outdoor play will positively correlate with higher cognitive and literacy scores. The Teaching Strategies GOLDTM instrument observes the overall development and capabilities of children prior to first grade. With this holistic approach, GOLDTM is used as a tool to identify and assess school success predictors in order for teachers and administrators to have an accurate account of each child’s readiness for school. The current study used the GOLDTM results to indicate cognitive and literacy capabilities among participants. Results of this study should encourage parents and teachers towards active outdoor play for their children and will guide recommendations for future research and planning
A Designed Multi-Sensor System for SLAM on Multiple Robots
No full textA research group at Hope College is designing a multi-ultrasonic-sensor system for the open source robot Kobuki Turtlebot. The operating system used in this research project, Robot Operating System (ROS), is also an open source project initially released in 2007. This system has higher accuracy, reduced response time and lower cost compared to traditional laser sensors. It consists of 8 HY-SRF05 rangers that can work sequentially on an embedded system such as a Raspberry Pi. The communication between the embedded system and the robot is achieved with a Python package designed to communicate locally via Transmission Control Protocol/Internet Protocol (TCP/IP). By making the HY-SRF05 rangers work successively, the response time needs to be reduced as much as possible to minimize the errors in the localization process. This structure can also be applied to our multi-agent system, composed of 3 robots of the same model. By implementing this improved design on a multi-agent system, the Simultaneous Localization and Mapping (SLAM) process can be conducted more efficiently and accurately. However, the development of ROS for multi-agent systems is still in a very early stage, which is a challenge for our project