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Stability and resilience of plant-pollinator networks in an Andean montane community in Southern Ecuador.
No full text30 pages, illustrations.Includes bibliographical references (leaves 27-29).Mutualistic interactions sustain biodiversity and influence community stability. If there are only a few interactions within a community, or multiple interactions that are weak, the community is more likely to collapse. This research investigated the stability of a plant-pollinator community in the Ecuadorian Andes to understand how vulnerable these interactions are to environmental stressors such as climate change and habitat degradation. To do this, we used two species interaction networks based on foraging fidelity (i.e., consistent returns to a particular plant species) and floral association data from both native and non-native pollinators. We used the network metrics connectance, specialization, and weighted network nestedness to determine the strength of these interactions, and therefore, the resiliency of this montane community. Based on these metrics, we found that our visitation network is relatively robust to ecosystem stressors, however, our larger-scale survey, which may be a more accurate depiction of the community due to sample size and increased diversity, showed a lack of resilience to stressors. Honey bees (Apis mellifera) were much more abundant than native bees in both networks, and may be providing many of the pollination services previously provided by native bees. Honey bees were generalists at the species level, but individuals were faithful to particular plant species. This research can help inform future conservation and non-native species management efforts, and can be used to further understand the nuanced relationships between plants and pollinators, which are essential to agricultural production and ecosystem maintenance on a global scale.
A Comparison of Prokaryotic Thermophile Community Structure and Coastal Infrastructure Development
No full text12 pages; color illustrations
Wheaton Magazine
No full textSpring 2020 issue of the Wheaton MagazineWheaton College (MA)Between the lines: Thank you for your patience and understanding, pg.2@DHANNO: A change of plans, pg.3Around the Dimple: Growing voter turnout, pg.4Around the Dimple: Commencement preview, pg.5Around the Dimple: Wheaton partners to serve first-generation students, pg.6Around the Dimple: Summer spark, pg.7Around the Dimple: Helping women take the lead, pg.8Around the Dimple: Playing with language, pg.9Around the Dimple: Unpacking lessons from Tanzania, pg.10Around the Dimple: Instrumental education, pg.11Conversation: Lessons from Bhutan, pg.12Publications, Honors and Creative Works, pg.13Lyons pride: Bravo, 2019 Yowell Hall of Fame inductees, pg.14Lyons pride: Senior day, pg.15Lyons pride: Bowling along, pg.15Campus scene: Academic growth, pg.16Campus scene: Senior scoop, pg.16Campus scene: Activities fair, pg.17Campus scene: MLK legacy celebration, pg.17Campus scene: A path for all, pg.18Campus scene: A powerful partnership, pg.22Campus scene: Ride of her life, pg.28Alumni association network: Announcing our 2020 Alumni Achievement Award winners, pg.32Alumni association network: Teaching teachers, pg.33Alumni association network: A Fulbright to Serbia, pg.34Alumni association network: Global insights from Japan, pg.35Class Notes, pg.36Class Notes: Lifting up others, pg.38Class Notes: Strong advice, pg.39Class Notes: In her nature, pg.40Class Notes: Focusing on homelessness, pg.41Class Notes: Wheaton in the Himalayas, pg.42Class Notes: Career insight, pg.43Class Notes (removed), pg.44In Memoriam, pg.62Perspective: Thinking big, pg.6
Sub-diffraction-limited microscopy with fluorescent nanoparticles.
No full text73 pages; illustrationsIncludes bibliographical references (leaves 65-67).Due to the properties of light, optical microscopes cannot resolve images of
objects that are smaller than a few hundred nanometers wide. This is known as the diffraction limit. There are several techniques that researchers have used to overcome the diffraction limit. Techniques such as STED, NSOM, STORM, and PALM use fluorescence in clever ways to mark and isolate objects of interest so that images of these objects on the nanoscale can be resolved and studied in greater detail. This thesis provides an exploration into using fluorescent nanoparticles to perform sub-diffraction limit imaging. This method is designed to be both low-tech and cost-effective so that it can be easily implemented at Wheaton College. A microscope was constructed consisting of a camera, a sample stage, optical filters, and a laser used to excite the nanoparticles. Exciting the nanoparticles with a laser causes them to fluoresce and the fluorescence can be imaged with the camera. Images of the nanoparticles at various concentrations both in and out of solution were taken and analyzed. The nanoparticles were blurred out in the images because of their small size but individual particles could be located by fitting a Gaussian model to the pixel values. The locations of the nanoparticles were able to be narrowed down in the sample to regions between 11.2 nm and 64.8 nm wide. This constituted a considerable improvement in resolution from a traditional optical microscope, but results were mixed because individual particles were hard to discern in many of the images. There are improvements to be made but, overall, this research opens the door for nanoscale imaging at Wheaton College
Investigations of cell types that are ciliated in regenerating Zebrafish (Danio rerio) hearts.
No full text80 leaves : illustrations.Human heart disease is one of the leading causes of death in the United States. Myocardial infarction (heart attack) is a possible result of human heart disease, which leads to scar tissue formation at the injury site. The scar tissue is inelastic and does not allow for efficient heart contractions thus reducing overall cardiac function. Zebrafish can regenerate injured heart tissue within 30 days after injury. The regeneration of the zebrafish heart tissue is accomplished through immediate clotting of the injury site, activation of the three cardiac tissue types (epicardium, myocardium, and endocardium), neovascularization, redifferentiation, cardiomyocyte proliferation, ultimately fully replacing the scar tissue. Primary cilia are sensory organelles found on the surface of many eukaryotic cells, and cilia play many essential roles. Cilia have been observed on regenerating cardiac tissue of zebrafish, however, the exact tissue types that cilia are present on are unknown. Determining where cilia are present is important as it will provide insight into how cilia facilitate regeneration involving the three cardiac tissue types. We hypothesize that cilia are found preferably on epicardial tissue along with a detectable presence in endocardial and myocardial cells during cardiac regeneration. Also, we hypothesize that cilia are present longer than 7 days post amputation (dpa), as the entire regeneration process takes a month. The hypotheses were tested using injured transgenic zebrafish hearts, which identifies each tissue type along with uninjured EK zebrafish (wild type) hearts at various dpas. This was to be followed by immunofluorescence staining to identify the cilia and quantification to determine cilia quantity and location, however, this was not possible due to the spring 2020 coronavirus pandemic. Regardless, understanding the possible roles of cilia in the three cardiac tissues may lead to advancements in diagnostic procedures and treatments for individuals suffering from heart disease