Life Sciences Commons^™

Nutrient Availability And Species Evenness Influence Productivity During Early Stages Of A Tropical Forest Restoration, Emma Rosenfield, Lauren Bizzari, Julia Rogers

CLAS: Colby Liberal Arts Symposium

Forest restorations aim to maximize the number of species and the productivity at the community level. In a tropical rainforest restoration, often limited number of species are available from local growers; so manipulating the number of individuals of each species (the evenness) might best achieve the goals of restoration. Planting equal numbers of individuals of each species may allow for the most complementary use of soil nutrients; however fertilizer may change this dynamic. Moreover, in a community where there is one dominant species, the productivity of the community may depend upon the identity of that dominant species. We asked whether …

Concussions In Varsity Athletes, Lily Cabour

CLAS: Colby Liberal Arts Symposium

This research project will analyze the HIT App (Hit Injury Tracker) data from the 2013-14 school year. The HIT App is an ongoing research project for the Colby-based nonprofit, Maine Concussion Management Initiative (MCMI). MCMI is dedicated to improving the safety of Maines youth by increasing awareness and education on concussion management. MCMI is a pioneer in concussion research and education outreach in the state of Maine, and is beginning to expand its impact across New England. Through the HIT App data, we hope to reveal trends in concussion injury for student athletes (high school and college level) based on …

Avian Species Of The Chacabuco Valley, Walker Nordin, Sydney Morison

CLAS: Colby Liberal Arts Symposium

The focus of this poster is the avian ecology of the Chacabuco Valley in the Aysen Region of Chilean Patagonia. Information on various bird species and habitat types was obtained via structured bird surveys near lakes throughout the valley, with the aim of correlating certain bird species and behaviors with specific habitat types. The results showed the most common bird species of woodland, shrubland, and lake habitats, as well as associated behaviors. Some bird behaviors were analyzed in greater depth, in order to speculate on certain species habitat requirements. The findings of this project will provide baseline reference information for …

Identification Of Water Kefir Microbial Composition And Rapidly Growing Yeast, Wei Ma

CLAS: Colby Liberal Arts Symposium

Products of microbial fermentation such as probiotic yogurt have been found to confer health benefits, such as inhibiting fungal and bacterial growth, prevention of oral, mammary neoplasia and multidrug-resistant myeloid leukemia. Water kefir, or tibicos, is a type of symbiotic culture of yeast and bacteria that shows potential to be used as preventative and chemotherapeutic agent against cancer. Here, we study water kefir in terms of its microbial composition to determine the species of microorganism responsible for producing the proposed antineoplastic extracellular polymeric substance, using both culture-dependent and independent techniques. Selective and non-selective media were used to promote the growth …

Genetic Diversity And Gene Flow Among Populations Of Witheringia Solanacea, Crystiana Tsujiura

CLAS: Colby Liberal Arts Symposium

To evaluate fitness consequences of population structure in the Costa Rican plant Witheringia solanacea, we have genotyped individuals from different populations of Witheringia solanacea to examine inbreeding within populations and gene flow between populations at different altitudes. We predict that plants at high elevations will have a higher frequency of inbreeding because high elevation populations tend to consist of fewer plants and there tend to be fewer pollinators at higher altitudes.

Psychrobacter Arcticus Cold Shock Protein Expression In Escherichia Coli Increases Cold Resistance, Daniel Sunderland

CLAS: Colby Liberal Arts Symposium

Psychrophilic (cold-loving) microorganisms live in some of the most inhospitable environments in the world. The newly-sequenced genome of the psychrophile Psychrobacter arcticus presents the opportunity to study the molecular mechanisms by which it is possible for this organism to thrive in extremely cold environments such as the permafrost of Antarctica. The cold presents challenges such as decreased membrane fluidity, slower reaction rates, and conformational changes in proteins and nucleic acids. Putative genes for cold-shock proteins (csps) were identified within the sequenced genome that could play an important role in facilitating the psychrophilic lifestyle. This study sought to analyze the function …

Does Fertilization Influence Herbivory During Tropical Forest Restoration?, Emma Rosenfield, Arianna Porter, Julia Rogers, Lauren Bizzari

CLAS: Colby Liberal Arts Symposium

Tropical deforestation is occurring at an alarming rate throughout our world today. It is critical that we actively try to restore these landscapes because rainforests provide us with important resources and services. However, it can be difficult to set appropriate goals for restoration. Under which conditions is a landscape the healthiest? For example, fertilizer is often used to increase growth and survivorship of tree seedlings; however, adding fertilizer may alter other aspects of the community, such as herbivory. In the context of a tropical forest restoration experiment, we asked 1) does fertilization influence herbivory; 2) does fertilization alter leaf tissue …

Purification Of Gst::Taabf1 Fusion Protein In Order To Assess Its Phosphorylation By Endosperm Proteins, Jessica Moore

CLAS: Colby Liberal Arts Symposium

Transcription factor TaABF1, a member of the ABA response element binding factor family, has been shown to have an important role in the signaling pathways of gibberellin (GA) and abscisic acid (ABA) in cereal grains. TaABF1 has also been found phosphorylated in vivo in aleurone cells and is possibly regulated by phosphatases. In order to investigate whether TaABF1 can be phosphorylated by proteins in wheat grains and which regions of the protein are phosphorylated, the GST::TaABF1 fusion protein was purified by a glutathione affinity column and a phosphorylation assay with wheat endosperm proteins was performed. Then, the possibly phosphorylated GST::TaABF1 …

Mamb And Mamm: Genes Involved In Magnetotaxis, Rachel Bolender

CLAS: Colby Liberal Arts Symposium

Magnetotactic bacteria (MTB) are a group of bacteria that synthesize magnetosomes, magnetic crystals of magnetite (Fe304) or greigite (FeS4), which allow MTB to travel along the earths geomagnetic fields. In addition, MTB have been shown to be promising agents for bioremediation through their ability to absorb heavy metals, such as gold. Little is known of the genetic elements that allow for the biosynthesis of magnetic particles in MTB. In this study, genes MamB and MamM, genes known to be involved in magnetosome formation but whose functions are not known, were studied using the magnetotactic bacteria Magnetospirillum magneticum. Genomic DNA was …

Listeriosis: A Case Study, Tara Tischio

CLAS: Colby Liberal Arts Symposium

In large animal veterinary medicine, a minor infection in one animal can easily cripple the success of a farm. Listeria, a bacterial infection caused by the ingestion of contaminated silage, can spread rapidly throughout a farm inflicting serious damage to the central nervous system and killing the infected animals within weeks or even days. By following the case study of a pregnant, listeria-positive cow, this study aims to provide an overview of this disease in order to further educate the public on the human implications.

Identifying The Role Of Bacterio-Opsin Associated Protein Gene In Bacteriorhodopsin Production In The Halophilic Archaeon Halobacterium Salinarum, Tarini S. Hardikar

CLAS: Colby Liberal Arts Symposium

The halophilic archaeon Halobacterium salinarum survives in low-oxygen conditions by producing a light-driven proton pump, bacteriorhodopsin (BR). BR is formed by a retinal cofactor covalently bound to the protein bacterioopsin (BO). In reduced oxygen conditions, H. salinarum synthesizes BR, which requires production of both BO and the retinal cofactor. The gene that encodes for BO is called bacterio-opsin protein gene (bop). In several organisms, it has been observed that another gene, bacterio-opsin associated protein gene (bap) is located next to the bop gene. However, the function of bap is unknown. To identify whether the bap gene has any role in …

Optimization Of A Chemical Genetic Screen To Identify Druggable Targets In U138 Cells Treated With Laromustine, Kathryn Coe

Honors Theses

Laromustine is an experimental sulfonylhydrazine prodrug used in late-stage clinical studies against acute myeloid leukemia (AML) and glioblastoma multiforme (GBM). Despite initial promise for both indications, clinical trials for GBM have not been as successful as those for AML. To investigate methods for improving the effectiveness of laromustine in GBM and to learn more about the mechanism of action of laromustine, a chemical genetic screen will be conducted to identify agents that sensitize GBM cells to the anti-proliferative effects of laromustine. The library, which will include approximately 450 FDA-approved drugs, will be screened using a newly optimized high throughput assay …

Variations In Intra- And Interspecific Response To Mobbing Calls By The Black-Capped Chickadee (Poecile Atricapillus), Katerina M. Faust

Honors Theses

Mobbing calls are produced by a variety of bird species in response to predator sightings. These mobbing calls often function in intraspecific recruitment, but have recently been shown to have an interspecific response component as well. The mobbing calls produced by the Black-capped Chickadee (Poecile atricapillus) are distinct and encode information about the threat level of the predator. Conservation biologists often use playbacks of chickadee mobbing calls to detect species of birds and numbers of individuals in an area with higher accuracy than counts conducted without the use of playbacks. In this study, the factors that could potentially …

The Role Of Underutilized Fish In New England's Seafood System, Taylor Witkin

Honors Theses

The global fisheries crisis has led to an increasing recognition for the need to relieve pressure on overfished, popular food fish stocks. Opportunities exist to shift consumer demand toward more sustainable choices, including fish that may be locally abundant. Attempts have been made to market underused fish (sometimes termed “trash fish”) that represent more sustainable alternatives; however, it is unclear whether consumers will choose to purchase these more sustainable options, particularly if underused fish are also unfamiliar. Chapter 1 reviews existing research and current issues surrounding sustainable seafood and the recent shift toward local, abundant, undervalued species in New England’s …

The Impact Of Dams On Nitrogen Cycling In The Messalonskee Stream, Rebecca K. Forgrave

Honors Theses

The Messalonskee Stream in central Maine has five hydroelectric dams on 16.6km. Each dam drastically changes the flow regime of the stream, dividing it into segments with different patterns of sediment settling and organic matter retention. I investigated how these disruptions impact nitrogen cycling, specifically nitrification rates above and below each dam. I expected higher nitrification rates above the dams, where levels of organic matter are higher, and lower rates below the dam where scouring removes organic matter and fine sediment from the streambed. I measured sediment nitrification rates with a nitrapyrin-inhibition assay and potential drivers of nitrification including sediment …

Tracking The Forest People: In The Rainforests Of Borneo, Erin Vogel '95 Studies A Group Of Orangutans In Hopes Of Protecting This Dwindling Species, Adriana Nordin Manan

Colby Magazine

Erin Vogel ’95 studies orangutans up close in the rainforest of Borneo. An anthropologist at UC Santa Cruz, Vogel wants to know what these orangutans eat and why, in hopes that the knowledge will help protect this dwindling species.

The Perfect Fit

Colby Magazine

From the classrooms and laboratories of Mayflower Hill, they found their niche in science. Microbiologist Carrie Harwood ’73, transplant surgeon Patrick Wood ’75, and marine biologist Paul Wade ’80 have passion for their professions.

Farm Hands: With A Fresh Perspective, Colbians Join Farming's Next Generation, Molly Pindell

Colby Magazine

As the nation’s farmers grow older, fewer young people are turning to agriculture as a career. Meet Colby farmers who are bucking the trend with everything from organic vegetables to rodeo calves.

The Search For The Ivory-Billed Woodpecker: Sara Barker And A Team Of Researchers Find Conclusive Evidence That Brings The Ivory-Billed Woodpecker Back From 'Extinction', Gerry Boyle

Colby Magazine

An extinct ivory-billed woodpecker in an Arkansas swamp? Sara Barker '94 coordinated the team that quietly searched the swamp to see if the "grail bird" lives.

The Great Mudpuppy Escape (Sort Of), Stephen Collins

Colby Magazine

The origin of unusual salamanders that inhabit parts of the Belgrade Lakes? We confess, a Colby professor was the culprit.

Campus Life: In Perkins Arboretum There Are Birds Of All Feathers, Trees That Tell A Story, And Even Romance (Especially If You're A Frog), Gerry Boyle

Colby Magazine

To the uninitiated, Perkins Arboretum is the edge of campus. For those familiar with its flora and fauna, the arboretum is a wondrous classroom and refuge.

Investigating The Effects Of Bag3 Knockdown On The Cytotoxicity Of The Anticancer Drug Laromustine, Kayla Gross

Honors Theses

Laromustine is a sulfonylhydrazine anticancer prodrug whose cytotoxicity results from the formation of interstrand cross-links caused by the synergistic action of co- generated 2-chloroethylating and carbamoylating species. The cytotoxic activities of Laromustine involve the induction of apoptosis. Described herein is an investigation into this drug’s effects on apoptotic gene expression in HL-60 cells using qRT-PCR. Significant changes in the expression levels of 13 genes were observed, most dramatically in the upregulation of the bcl2-associated athanogene 3 (BAG3) gene. Given the pro-survival role of BAG3 in the cell, this investigation sought to decrease BAG3 mRNA levels in HL-60 cells using transient …

Prenatal Choline Supplementation And Mk-801 Toxicity: Protecting Memory And Preventing Neurodegeneration, Chelsea Nickerson

Honors Theses

Choline is essential to the development and function of the central nervous system. Supplemental choline is neuroprotective against a variety of insults, including neurotoxins like dizocilpine (MK-801). MK-801 is an NMDA receptor antagonist that is frequently used in rodent models of psychological disorders. At low doses, it causes cognitive impairments, and at higher doses it induces motor deficits, anhedonia, and neuronal degeneration. The primary goals of the present study were to investigate whether prenatal choline supplementation protects against the cognitive impairments, motor deficits, and neuropathologies that are precipitated by MK-801 administration in adulthood. Adult male Sprague Dawley rats were fed …

Investigating The Role Of Epibiotic Bacteria In Defense Against Chytridiomycosis In The Green Frog, Lithobates Clamitans, Sarah Nalven

Honors Theses

Amphibian populations have been declining for several decades, in part due to the emerging fungal skin disease, chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Chytridiomycosis has caused extinctions and extirpations in many parts of the world, but its influence varies across species, populations, and individuals. The Green Frog (Lithobates clamitans), which inhabits the eastern half of the United States, seems capable of sustaining Bd infections without experiencing die-offs. It is possible that the Green Frog's epibiotic bacteria are contributing to its defense against Bd as the epibiotic bacteria of several amphibian species are known to play …

Relationship Of Cross-Linking Potential To Mechanism Of Cell Death, Adam N. Spierer

Honors Theses

Mechlorethamine (HN2), a nitrogen derivative of mustard gas, was the first synthetic anti-tumor chemotherapeutic because it forms covalent cross-links between strands of duplex DNA. HN2 represents a class of bifunctional alkylating agents that are both chemotherapeutic and carcinogenic: diepoxybutane (DEB), the active form of the pro-drug treosulfan, and epichlorohydrin (ECH), a structural hybrid of HN2 and DEB, also form covalent cross-links between DNA. While HN2 and DEB are clinically used as anti-tumor chemotherapeutics, ECH is a structural hybrid of these two compounds not used in a clinical setting. Accordingly, we aimed to understand the relationship between the cross-linking potential of …

The Kennebec River: A Historic Maine Resource, Elise Begin

Historical Ecology Atlas of New England

The Kennebec River has been considered one of Maine’s most important resources for at least the past 6-8 thousand years; its basin is located in west central Maine and drains 5,893 square miles, an area that is approximately one-fifth the area of the state. The river originates at Moosehead lake and runs 170 miles to the Atlantic Ocean. The river can be divided into two basins: the upper basin, which spans from Moosehead Lake to Waterville; and the lower basin, which spans from Waterville to the ocean.

Before the arrival of Europeans in 1606, the Abenaki Indians controlled the entirety …

Maine Learns To Love Dairying, Erin Love

Historical Ecology Atlas of New England

The transition from subsistence to commercial farming is a defining trend in Maine dairying that continues today. Technological advances that often caused large landscape scale changes were catalysts in the division between small and large farmers. The industry developed in a relatively short time period—the last thirty years of the 19th century—but the characteristic divide between large and small farmers has continued to be exacerbated.

Bath, Maine: A City Of Ships, Taylor Witkin

Historical Ecology Atlas of New England

Known as Maine’s city of ships, Bath sits on the shores of the Kennebec River, about 15 miles from the Gulf of Maine and 40 miles up the coast from Portland. Though small in population, Bath’s impact on Maine, the rest of United States, and even on the world has been anything but small. Today Bath is known mostly for the Bath Iron Works, which supplies the US Navy with a large portion of its fleets, however, in Bath’s early days it built large, wooden yachts and schooners mostly for trade, not war. The next few pages will explore Bath’s …

The Happy Valley, Cassie Raker

Historical Ecology Atlas of New England

On the Connecticut River in Western Massachusetts, there exists the Happy Valley. Surrounded by the humble Holyoke Range, today you will find a bustling New England settlement dominated by local colleges and universities. But it was not always so. The picturesque Mount Holyoke and its accompanying hotel, known as the Summit House, have overlooked the area for hundreds of years, watching it change from forest to farmland to industry to the modern landscape it is today.

Changing Water Quality In Great Pond: The Roles Of Lake Sediments, Invasive Macrophytes, And The Watershed, Colby Environmental Assessment Team, Colby College, Problems In Environmental Science Course (Biology 493), Colby College

Colby College Watershed Study: Great Pond (2012, 2010, 1998)

Eutrophication as a result of human activity is a threat to lake water quality globally and within the state of Maine. Great Pond, in the Belgrade Lakes region of Maine, has traditionally been an oligotrophic lake that is experiencing early signs of eutrophication and is currently classified as a mesotrophic lake. In the fall of 2012, the Colby Environmental Assessment Team (CEAT) measured the primary sources of nutrient loading to Great Pond including the catchment and the lake sediment, current water quality in Great Pond, and the potential impact of the variable milfoil invasion on the lake’s water quality. An …