Physical Sciences and Mathematics Commons^™

(Cyclopentadienone)Iron-Catalyzed Transfer Dehydrogenation Of Symmetrical And Unsymmetrical Diols To Lactones, Yidan Tang, Rowan I.L. Meador, Casina T. Malinchak, Emily E. Harrison, Kimberly A. Mccaskey, Melanie C. Hempel, Timothy W. Funk

Chemistry Faculty Publications

Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2- and 5-positions, [2,5-(SiMe3)2-3,4-(CH2)4(η4-C4C═O)]Fe(CO)3 (1) and [2,5-(SiMe3)2-3,4-(CH2)3(η4-C4C═O)]Fe(CO)3 (2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two …

Milky Way Morphology, Laurence A. Marschall

Physics and Astronomy Faculty Publications

From our limited perspective—living on a planet that orbits one of several hundred billion stars inside the Milky Way—the detailed structure of our home galaxy is difficult to determine. It has long been recognized by astronomers as a typical spiral galaxy, one of countless flattened pinwheels of stars seen throughout the universe. By mapping the distances to more than 2,400 stars, scientists have now created, with unprecedented precision, a three-dimensional map that shows the Milky Way has a twisted shape. [excerpt]

Gaps In Protection Of Important Ocean Areas: A Spatial Meta-Analysis Of Ten Global Mapping Initiatives, Natasha J. Gownaris, Christine M. Santora, John B. Davis, Ellen K. Pikitch

Environmental Studies Faculty Publications

To safeguard biodiversity effectively, marine protected areas (MPAs) should be sited using the best available science. There are numerous ongoing United Nations and non-governmental initiatives to map globally important marine areas. The criteria used by these initiatives vary, resulting in contradictions in the areas identified as important. Our analysis is the first to overlay these initiatives, quantify consensus, and conduct gap analyses at the global scale. We found that 55% of the ocean has been identified as important by one or more initiatives, and that individual areas have been identified by as many as seven overlapping initiatives. Using our overlay …

Changes In The Greenland Ice Sheet Of The Southeastern Maniitsoq Coast From 1994-2004 And 2009-2019, Alyssa J. Kaewwilai, Charlie E. Reisman

Student Publications

Remote sensing mechanisms through the use of technology like the Landsat 5-7 Land Manager satellites are commonly used in conjunction with multispectral methods such as unsupervised classification to record and analyze changes in snow and ice over time in areas such as the Greenland Ice Sheet (GrIS). Unsupervised classification is a method of identifying, grouping, and labeling features in an image according to their spectral values and is therefore a good method of classifying snow and ice in areas such as Greenland. The goal of unsupervised classifications is to assign pixels into potentially meaningful subsurface classes based on similarities of …

Campus-Based Agriculture: The Future Of Food At Gettysburg College, Bryn K. Werley

Student Publications

This research investigates various methods for producing food on the campus of Gettysburg College in order to improve food sustainability. The transportation of food contributes to the increased use of fossil fuels, which in turn leads to global warming and climate change. By producing a larger portion of its food on-campus, Gettysburg College could reduce the amount of food transported to the school, thereby lessening the College’s environmental impact. Urban farming techniques, hydroponics, aquaponics, and greenhouse-based agriculture are explored as viable methods for achieving this goal. Examples of the use of these techniques on college campuses are drawn from Allegheny …

Designing Women: Essentializing Femininity In Ai Linguistics, Ellianie S. Vega

Student Publications

Since the eighties, feminists have considered technology a force capable of subverting sexism because of technology’s ability to produce unbiased logic. Most famously, Donna Haraway’s “A Cyborg Manifesto” posits that the cyborg has the inherent capability to transcend gender because of its removal from social construct and lack of loyalty to the natural world. But while humanoids and artificial intelligence have been imagined as inherently subversive to gender, current artificial intelligence perpetuates gender divides in labor and language as their programmers imbue them with traits considered “feminine.” A majority of 21st century AI and humanoids are programmed to fit female …

Clearcutting In Appalachia: Impacts On Stream Water Quality In An Appalachian Watershed, Alyssa J. Kaewwilai, Hannah R. Peterson, Abigail F. Rec

Student Publications

Clearcutting forests has the potential to impact the water quality of high water headwater streams. In this study, we measured the effect of forest clearcut events on parameters of stream water quality within Michaux State Forest. The watershed of two streams included 2.1% and 11.6% of the total catchment in clearcuts, while the other 4 watersheds had no clearcuts. We measured pH, electrical conductivity, total suspended solids, and nitrate (ppm) and phosphate (ppm) concentrations from six different tributary streams. Mann-Whitney U tests maintain no statistical difference observed between pH (U= 4.00, p= 1.00), temperature (U=1.00, p=0.165), electrical conductivity (U=2.00, p=0.355), …

Secrecy In The American Revolution, Abigail N. Minzer

Student Publications

This paper analyzes how the use of various cryptographic and cryptanalytic techniques affected the American Revolution. By examining specific instances of and each country's general approaches to cryptography and cryptanalysis, it is determined that America's use of these techniques provided the rising nation with a critical advantage over Great Britain that assisted in its victory.

Lorentz And Cpt Tests Using Penning Traps, Yunhua Ding

Physics and Astronomy Faculty Publications

The theoretical prospects for quantum electrodynamics with Lorentz-violating operators of mass dimensions up to six are revisited in this work. The dominant effects due to Lorentz and CPT violation are studied in measurements of magnetic moments of particles confined in Penning traps. Using recently reported experimental results, new coefficients for Lorentz violation are constrained and existing bounds of various coefficients are improved.

Building A Green Dorm: How Colleges And Universities Across America Have Embraced Sustainable Communal Living, Theresa M. Blickenstaff

Student Publications

Building a dorm is hard work. Building a green, sustainable dorm is doubly so. With their extensive lighting, appliances, heating and cooling needs, fans, and laundry machines, traditional college residence halls are notorious for their large energy footprints. Particularly for colleges such as Gettysburg where dorm living is mandatory for some or all four years, the environmental impact of residence halls is particularly large. As leaders with long histories of inspiring change, colleges and universities in the United States have an obligation to promote sustainable practices. Gettysburg College has announced that in the next few years, it is planning to …

Earth: "Un-Human Me", Hakim Mohandas Amani Williams

Peace and Justice Studies Faculty Publications

He took a rib from your side and made others.

So you considered Others your children, forever.

He told you to go forth and produce and multiply so you made capitalism.

He told you to go forth and conquer and pillage and mark your name and plant your flag where-ever you wanted.

So now the moon is yours. Jupiter, beware! [excerpt]

Ai Education Matters: Data Science And Machine Learning With Magic: The Gathering, Todd W. Neller

Computer Science Faculty Publications

In this column, we briefly describe a rich dataset with many opportunities for interesting data science and machine learning assignments and research projects, we take up a simple question, and we offer code illustrating use of the dataset in pursuit of answers to the question.

The Traits That Predict The Magnitude And Spatial Scale Of Forest Bird Responses To Urbanization Intensity, Grant D. Paton, Alexandra V. Shoffner, Andrew M. Wilson, Sara A. Gagné

Environmental Studies Faculty Publications

As humans continue moving to urban areas, there is a growing need to understand the effects of urban intensification on native wildlife populations. Forest species in remnant habitat are particularly vulnerable to urban intensification, but the mechanisms behind these effects are poorly understood. An understanding of how species traits, as proxies for mechanisms, mediate the effects of urban intensification on forest species can help fill this knowledge gap. Using a large point count dataset from the Second Pennsylvania Breeding Bird Atlas, we tested for the effects of species traits on the magnitude and spatial scale of the responses of 58 …

Analysis Of Flood Patterns In Adams County, Pennsylvania Utilizing Drone Technology And Computer Simulations, Alyssa J. Kaewwilai

Student Publications

Drone imagery and photogrammetry models of the Gettysburg College campus and the terrain at Boyer Nurseries and Orchards were utilized to study flood patterns in Adams County, Pennsylvania. Gettysburg College has lower-sloped land and moderately built infrastructure while Boyer Orchards has drastically sloped land with many patches of abundant vegetation. The two locations were selected due to the fact that they have starkly different surface features, while the bedrock geology of the areas are very similar. The terrain of the models was isolated before a 3D carver and 3D printer were used to construct physical models to further analyze potential …

Applying Science To Pressing Conservation Needs For Penguins, P. D. Boersma, P. García Borboroglu, Natasha J. Gownaris, C. A. Bost, A. Chiaradia, S. Ellis, T. Schneider, P. J. Seddon, A. Simeone, P. N. Trathan, L. J. Waller, B. Wienecke

Environmental Studies Faculty Publications

More than half of the world's 18 penguin species are declining. We, the Steering Committee of the International Union for Conservation of Nature Species Survival Commission Penguin Specialist Group, determined that the penguin species in most critical need of conservation action are African penguin (Spheniscus demersus) , Galápagos penguin (Spheniscus mendiculus) , and Yellow‐eyed penguin (Megadyptes antipodes) . Due to small or rapidly declining populations, these species require immediate scientific collaboration and policy intervention. We also used a pairwise‐ranking approach to prioritize research and conservation needs for all penguins. Among the 12 cross‐taxa research areas we identified, we ranked quantifying …

Life Without The Beach: Projected Sea Level Rise And Its Impact On Barrier Islands Along The East Coast, Usa, Cara Johnson, Gabrielle N. Kase, Samantha B. Pfeffer

Student Publications

As climate change is becoming a global issue, the impact of sea level rise is increasingly becoming a threat to humans, wildlife, infrastructure, and ecosystems. To evaluate the effects of sea level rise on barrier islands and coastal regions, we studied future projections of sea level rise at Ocean City and Assateague Island, Maryland. We hypothesize that the sea levels at Assateague and Ocean City will have different beach profiles, and will show different levels of flooding through the Representative Concentration Pathways (RCP) simulations. We measured beach profiles at four locations, two at Ocean City and two at Assateague Island, …

Wolves Are Wild: A Collection Of Narratives About Rescued Wolves And Wolfdogs, Molly G. Vorhaus

Student Publications

Breeders across the country are creating wolfdogs by breeding dogs (Canis lupus familiaris) with wolves (Canis lupus) for a large profit. This project is a response to the growing exotic pet trade of wolves and wolfdogs. Through this project, I hope to bring awareness to the issues associated with these animals being raised in captivity. Recent research has shown that raising a wolf or wolfdog in captivity can lead to various negative psychological and physical effects on the animal, and can cause potential problems for humans as well. This practice is embedded in the concept of humans wanting to own …

Disappearing Act(Ions): College Perceptions Of Climate Change And Its Impacts On Tourism, Natalie A. Kisak, Brianna M. Costira

Student Publications

Various locations around the world are considered to be ‘disappearing’ due to the impacts of climate change on their natural attributes. This disappearance raises the question of how travel to those destinations will change in the future, and whether or not awareness of climate change might limit tourism. This study examines the presence of the last-chance tourism theory in college students, and hypothesizes that willingness to travel or engage in environmentally responsible behaviors will not change with increased awareness because of a desire to visit places before they disappear. A survey is used to gauge awareness and concern, as well …

Blue Sky Olympics: Satellite Observations Of Air Quality During The 2008 Beijing Olympics, Lincoln M. Butcher

Student Publications

China has imposed short-term emission control regulations on industry and transportation to quickly improve air quality during certain events, including the 2008 Summer Olympic Games. Previous research noted reductions in NO2 vertical column density, CO emissions, CO2 emissions, and Aerosol Optical Depth (AOD). NO2 and SO2 decreased in neighboring provinces, during this time period. Using MODIS level-2 atmospheric aerosol product (MYD04_L2) data, processed by the dark target algorithm, this study observes trends in regional AOD and temporal change in AOD during the Olympic emissions reduction program. 2008 observations are referenced against AOD observations from 2003 to 2013, within 9-day intervals …

The Disparity Between Scientific Consensus And American Public Opinion Of Genetically Modified Organisms And Genetic Engineering, Matthew A. Cherubino

Student Publications

Genetically modified organisms (GMOs) and genetic engineering (GE) are accepted as safe and useful by the consensus of the scientific community. Their diverse utility has shown promise in addressing major challenges of the 21st century, including world hunger, global warming, and the prevalence of diet-related diseases (e.g. heart disease, cancer, diabetes, etc.). A 2014 Pew Research Center survey revealed that while 88% of scientists agreed that GM foods were safe to eat, only 37% of American consumers agreed. Furthermore, only 35% of U.S. adults trusted scientists to accurately inform the public about GMOs. To explain this disparity, I synthesize information …

Three-Dimensional Time-Resolved Trajectories From Laboratory Insect Swarms, Michael Sinhuber, Kasper Van Der Vaart, Rui Ni, James G. Puckett, Douglas H. Kelley, Nicholas T. Ouellette

Physics and Astronomy Faculty Publications

Aggregations of animals display complex and dynamic behaviour, both at the individual level and on the level of the group as a whole. Often, this behaviour is collective, so that the group exhibits properties that are distinct from those of the individuals. In insect swarms, the motion of individuals is typically convoluted, and swarms display neither net polarization nor correlation. The swarms themselves, however, remain nearly stationary and maintain their cohesion even in noisy natural environments. This behaviour stands in contrast with other forms of collective animal behaviour, such as flocking, schooling, or herding, where the motion of individuals is …

The Limited Reign Of Saturn's Rings, Laurence A. Marschall

Physics and Astronomy Faculty Publications

Saturn’s rings—stretching tens of thousands of miles above its equator but no more than a few hundred yards thick—mark an ancient debris field of orbiting ice shards, the remains of a moon-sized object that strayed too close and was torn to pieces by Saturn’s intense gravitation. Astronomers have debated when the rings formed and how long they will stay in orbit. Recent observations from large, land-based telescopes and orbiting spacecraft reveal that Saturn’s rings are remarkably young and are dissipating at a rapid rate. [excerpt]

Budget Magic: The Gathering For Beginners, Todd W. Neller

Computer Science Faculty Publications

In this talk, Neller overviewed budget-friendly entry points to playing Magic: The Gathering (M:TG) after its first quarter-century of success. Noting the ways in which M:TG players have applied head-designer Mark Rosewater’s “restrictions breed creativity” lesson, he celebrated their creative formats that push back against expensive “pay to win” dynamics.

Comparison Of Periglacial Block Fields And Talus Slopes In South-Central Pennsylvania And Northern Maryland, Ilana B. Sobel, Abigail F. Rec, Sarah M. Principato

Environmental Studies Faculty Publications

Relict periglacial boulder fields, or block fields, are scattered across south-central Pennsylvania and northern Maryland (e.g. Potter and Moss, 1968; Denn et al 2018). This pilot study uses a combination of digital analyses using Google Earth Pro and fieldwork to investigate block fields at different scales. Fieldwork focused on two block fields, which were compared with fieldwork conducted on two talus slopes. The block fields studied were Raven Rock Hollow in Maryland and River of Rocks at Hawk Mountain in Pennsylvania, and the talus slopes were located at Catoctin Mountain, Maryland and Waggoner’s Gap, Pennsylvania. The importance of geomorphic processes …

Kaggle And Click-Through Rate Prediction, Todd W. Neller

Computer Science Faculty Publications

Neller presented a look at Kaggle.com, an online Data Science and Machine Learning learning community, as a place to seek rapid, experiential peer education for most any Data Science topic. Using the specific challenge of Click-Through Rate Prediction (CTRP), he focused on lessons learned from relevant Kaggle competitions on how to perform CTRP.

Getting Things Done For The Glory Of God, Todd W. Neller

Computer Science Faculty Publications

The seminar covered a fusion of David Allen’s Getting Things Done; Covey, Merrill and Merrill’s First Things First; and Matt Perman’s What’s Best Next books on time management, with a view to being a good steward of time and effort for the glory of God. More information is available at http://cs.gettysburg.edu/~tneller/resources/gtd/index.html

After The Fall: Legacy Effects Of Biogenic Structure On Wind-Generated Ecosystem Processes Following Mussel Bed Collapse, John A. Commito, Brittany R. Jones, Mitchell A. Jones, Sondra E. Winders, Serena Como

Environmental Studies Faculty Publications

Blue mussels (Mytilus edulis) are ecosystem engineers with strong effects on species diversity and abundances. Mussel beds appear to be declining in the Gulf of Maine, apparently due to climate change and predation by the invasive green crab, Carcinus maenas. As mussels die, they create a legacy of large expanses of shell biogenic structure. In Maine, USA, we used bottom traps to examine effects of four bottom cover types (i.e., live mussels, whole shells, fragmented shells, bare sediment) and wind condition (i.e., days with high, intermediate, and low values) on flow-related ecosystem processes. Significant differences in transport of sediment, meiofauna, …

Sex‐Biased Survival Contributes To Population Decline In A Long‐Lived Seabird, The Magellanic Penguin, Natasha J. Gownaris, P. D. Boersma

Environmental Studies Faculty Publications

We developed a Hidden Markov mark–recapture model (R package marked) to examine sex‐specific demography in Magellanic Penguins (Spheniscus magellanicus ). Our model was based on 33 yr of resightings at Punta Tombo, Argentina, where we banded ~44,000 chicks from 1983 to 2010. Because we sexed only 57% of individuals over their lifetime, we treated sex as an uncertain state in our model. Our goals were to provide insight into the population dynamics of this declining colony, to inform conservation of this species, and to highlight the importance of considering sex‐specific vital rates in demographic seabird studies. Like many other …

Programming Safety Tips: Why You Should Use Immutable Objects Or How To Create Programs With Bugs That Can Never Be Found Or Fixed., Charles W. Kann

Programming Tips and Tricks

Program safety deals with how to make programs as error free as possible. The hardest errors in a program for a programmer to find are often errors in using memory. There are two reasons for this. The first is that errors in accessing memory almost never show problems in the proximate area of the program where the error is made. The error has no apparent impact when it is made, but often causes catastrophic results to occur much later in the program, in areas of the program unrelated to memory error that caused it.

The second reason memory errors are …