... 2017 Spring Science Presentations Science 299 Independent Research Projects Science 299 projects are semester-long independent research projects that students pursuing an A.S. in Science are required to complete prior to graduation. Students carry out their research under the guidance of a PVCC science faculty member as mentor. Below are the abstracts of the projects completed in Spring 2017. Special thanks to the laboratory staff for facilitating or assisting with student projects: Laboratory Managers Ed Funck (Chemistry) Rosalyn Koontz (Biology) Jennifer Scott (Biology) Support from Virginia / North Carolina Alliance grant - NSF 11-543 Akauola, Tangi - Chemistry 299 Nitrates and Nitrites in Processed Meats Sodium Nitrite is commonly used as an additive in processed meats such as bacon, sausages, canned poultry etc. Its main purpose is to preserve meats, allowing them to remain in non-frozen temperatures without spoilage. However, according to the American Institute for Cancer Research, there is convincing evidence that links diets high in nitrite and colorectal cancer. Studies provided by the World Health Organization found that the consumption of large amounts of nitrite results in the formation of nitrosamine, a known carcinogen to animals. The purpose of this experiment was to measure the nitrite content in a variety of the nations most popular meat products, thus determining which processed meats contained the highest amounts of nitrate preservatives. It was hypothesized that hotdogs would yield the highest amount of nitrite due to the extensive refining process that the meat undergoes. Samples were taken from a variety of processed meat products, all of which belonged to the leading brands in terms of the highest annual sales. The products tested included: beef jerky, bacon, spam, pepperoni, bologna and hotdogs. The sodium nitrite was effectively extracted from the meat samples using ho water. The extracted nitrite was then reacted with two reagents, sulfanilamide (Sulfa) and naphthyl ethylenediamine (NEDA) in order to produce a vibrant purple dye. Because the intensity of the dyes color corresponds to the concentration of nitrite ions present in the solution, Beers law and spectrophotometry was used to estimate the relative nitrite content in the meat products. Results indicated that Beef Jerky contained the highest nitrite content with 0.0185%. Hotdogs and Spam both had similar amounts of nitrite. Hotdogs had a nitrite content of 0.0106% and Spam 0.0101%. Bacon was measured at 0.00825%, pepperoni at 0.00454% and the lowest was bologna, with a nitrite content of 0.00221%. The results indicate a strong correlation between meat products designed to remain spoil-free at warmer temperatures and having higher amounts of nitrogen based preservatives, hence why beef jerky contains a higher amount of nitrite compared to bologna. Results provided by this research encourages people to reduce the intake of processed meats, particularly the products treated to remain spoil-free in a warmer open environment. Faculty Advisor- Barbara Heyl Al Mulhim, Wadah - Biology 299 The Difference of Fungal Growth on Organic and Conventionally-Grown Apples and the Effect of Sanitation on the Amount of Growth The agricultural methods used to grow fruit and vegetables are changing rapidly to keep up with the markets demand. This includes the addition of new fungicides and pesticides to protect these crops from rotting and molding. In the past, the apple market has struggled to conserve the apples and extend shelflife. Rotting and molding caused major loss in profit for both farmers and corporations. To study the effects of fungicide/pesticide application and its effectiveness to preserve the apples, I compared the fungus growth on organic and conventionally-grown apples. I also studied the significance of sanitation by categorizing the apples into washed and unwashed groups. The samples were separated into four study groups; organic washed, organic unwashed, conventionally-grown washed, and conventionally-grown unwashed. The plates were left in the laboratory for two weeks under room temperature of 25oC. After the fourteen-day period, the fungal growth was significantly larger on the organic apple skins than the conventionally-grown samples with a p-value of 0.0001 between both unwashed and washed samples. The results match my hypothesis that organic apples, washed and unwashed, will have a larger area of fungal growth on its skin than the conventionally-grown apples. Washing did not make a difference in the fungal growth of the organic apples (p = 0.4210). However, washing did significantly reduce the fungal growth in the conventional apples (p= 0. 000407). The difference between organic and conventional samples were not exclusively limited to the fungal growth, but other observations were reordered during the laboratory work. Conventionally-grown apples required additional effort to cut the samples. In contrast, organic samples were easier to cut. Also, the organic samples changed color from yellow to brown faster than conventionally-grown apples. It is reasonable to conclude that organic apples contain less pesticides and thus it is less likely to shield itself from fungal growth than the conventional apples. The use of pesticide and fungicide to conserve the apples and extend the shelf-life has both positives and negatives, including the positives of extended shelf life, but also potential negative effects of pesticides/fungicides on human health. Due to limited resources and time restriction, I could not test which option is healthier, but additional experiments can be helpful to test this hypothesis. Faculty Advisor: Joanna Vondrasek Butts, Sarah Biology 299 Enrichment of fluoroquinolone-resistant E. coli mutants under conditions similar to the subsurface environment. Antibiotic resistance has existed since the very discovery of antibiotics. It has become more of a problem lately however, due to its frequent misuse. In the agricultural setting, antibiotics are used very effectively to prevent diseases. However, a study done in by the department of Medical Biochemistry and Microbiology at the Uppsala University in Sweden, showed that low doses of antibiotics as found in soil, could select for resistance. They used three groups of antibiotics that are relevant to both human and veterinary use, tetracyclines, fluoroquinolones and aminoglycosides. The antibiotic used in this experiment is of the fluoroquinolone family and is commonly used in the agricultural setting. Runoff from unmetabolized or wasted antibiotics can enter the soil and will be present there in low doses, allowing for resident microbial populations to be exposed and potentially develop resistance mechanisms. Based on this, an experiment was generated to test if a lab strain of Escherichia coli could evolve resistance to low doses of danofloxacin under conditions similar to the subsurface environment. Equal amounts of autoclaved soil samples were placed into tubes that were inoculated with a standard laboratory strain of Escherichia coli. Two minimum inhibitory concentration tests were performed at the end of a four-day and seven-day trial. The first MIC was done on the fifth day with nine different danofloxacin dilutions. The results showed that the bacteria grew at a level it was originally susceptible to which was 0.01g/ml. The procedure was continued for another three days upon which another MIC was performed. The results showed the same data as the previous test. According to these data the bacteria exposed to lower concentrations than their original minimal inhibitory dose, grew resistant to a slightly higher dose. This data is significant as it shows that even a strain of bacteria that is commonly used in the laboratory, can potentially evolve resistance in a short amount of time. Resistance is known to evolve at high doses and/or inconsistent doses, it is however less common, to understand that low doses can maintain and enrich resistance in bacteria. Faculty Advisor: Melinda Clark Conner, Caleb Chemistry 299 Determining Concentration and Purity of Lactate Dehydrogenase Extracted From Caprine Heart Lactate dehydrogenase (LDH) is an enzyme that is found in the cytosol of most living cells including animal, plant, and prokaryote cells. LDH has a responsibility of catalyzing the last step of anaerobic glycolysis, which creates pyruvate into lactate and the other way, lactate into pyruvate. During anaerobic glycolysis, lactic acid fermentation serves as a back-up to allow glycolysis to continue producing ATP when the electron transport chain is shut down during aerobic glycolysis. Another important use of LDH is its relevance in medicine. LDH can be located in body tissues, like heat muscle and blood cells. Due to its release in tissue damage, an LDH test can show the levels of LDH in heart failure, hypothyroidism, anemia, meningitis, HIV, and cancers. For further understanding, research was conducted to perform an extraction of LDH enzyme using ammonium sulfate precipitation, purification by desalting procedure and using an affinity column; an LDH assay and Bradford Protein Assay was used to determine LDH activity and its concentration. In the crude homogenate, 40% ammonium sulfate supernatant, 65% ammonium sulfate pellet, and Cibacron blue column chromatography samples, the protein concentration (mg/mL) was found to be 11.1, 6.3, 7.5, 0.8, respectively. Although the concentration of protein declined, an increase of fold purification happened each step of the purification process; 1, 1.7, 8.1, 15.4. Fold purification a measure of how much purer the protein is after the purification step in comparison to the crude sample. Electrophoresis will be used to show to purity of the end sample by showing how farther the sample traveled compared to a standard solution. Size of the protein will also be determined. Lactate dehydrogenase is an ideal enzyme to study because of the abundant information about this enzyme. It can be found in a variety of sources and purification procedures have been replicated many times. This allowed for a vast amount of learning and comprehension of enzyme purification and biochemistry procedures. Faculty Advisor: Barbara Heyl Davis, Skyler Biology 299 Essential Oils as Antimicrobial Agents Against E. coli Bacterial resistance to antimicrobials is an increasing problem in our society due to the overexposure of bacteria to medications and disinfectants. Researchers are now evaluating essential oils (EOs oils extracted from plants) in the hopes of identifying new antimicrobial compounds. Aromatic EOs have been shown to have antimicrobial, antiviral, and antifungal properties, and some researchers speculate that the oils might not select for resistance in bacteria due to their complex chemical makeup. In this study, I evaluated the antibacterial effects of four EOs (tea tree, lavender, oregano, and red thyme) against Escherichia coli. My hypothesis was that all four would inhibit bacterial growth. This hypothesis was supported, with oregano and red thyme having the largest zones of inhibition of average diameter 4.54 cm and 3.80 cm, respectively. To evaluate the claims that EOs do not create resistant bacteria, I chose and grew colonies from the edges of the initial tests on the red thyme and oregano plates. The expectation was that the EOs would produce smaller zones of inhibition when grown with colonies of these selected E. coli. This expectation was not supported, however, as the new average diameters were not significantly different for red thyme and oregano (5.80 cm, p= 0.0639, t=2.0829, df=10, and 4.88 cm, p=0.1733, t= 1.4790, df=9) respectively. To determine if plant oils in general have an antimicrobial effect, a separate test was done using red thyme and oregano EOs diluted with corn oil ( and dilutions). The results showed that the oregano and red thyme EOs specifically inhibited growth, and not just plant oils in general (p=0.0002 t=5.7637 df=10 and p= 0.0001 t=6.2811 df=10). All four essential oils were effective at inhibiting the growth of E. coli, and their effectiveness was ultimately concentration dependent. There was some suggestion that a few small colonies developed resistance to the EO they were previously exposed to, but more tests would need to be done in order to make any solid conclusions. Faculty Advisor: Joanna Vondrasek Duckworth, Cameron Chemistry 299 Water Quality Index Test on the Rockfish River Currently, Dominion Transmission, Inc. and Atlantic coast Pipeline, LLC are proposing the construction of a 600-mile natural gas pipeline connecting West Virginia and North Carolina. The pipeline is expected to provide approximately 1.44 billion cubic feet per day of natural gas to electric generation, distribution, and end-use markets in the Mid-Atlantic region (FERC). However, the projected route crosses the Allegheny and Blue Ridge Mountains and jeopardizes the health of important ecological systems, such as the Rockfish River Valley in Nelson County, Virginia. In 1970, the National Sanitation Foundation devised a standard index for measuring water quality on a scale from 0-100, known as the Water Quality Index (WQI). The objective of this experiment is to rate the quality of the Rockfish River at the Rockfish River Trail site by conducting a WQI test. The purpose of this research is to provide an initial condition of this water source prior to the Atlantic Coast Pipeline construction to serve as a reference study for comparison with post-construction water quality data. Temperature, pH, turbidity, total solids, dissolved oxygen, biochemical oxygen demand, ortho-phosphates, nitrates, and fecal coliform were all tested using Vernier equipment and scored using the WQI rating system. My research indicates that even after a heavy rain the water quality of the South Fork Rockfish River is within the excellent range, however, nitrates and fecal coliform levels were significantly higher near agricultural areas. Accordingly, my research illustrates that the South Fork Rockfish River is a clean water source safe enough to drink from and is at risk of pollution from installation of the ACP. Faculty advisor: Barbara Heyl Graham, Kyle Chemistry 299 Caffeine Levels in Coffee: Are Brewing Methods Significant? The purpose of this experiment was to determine if there is a significant difference in caffeine levels in coffee through different brewing methods. Three different brewing methods were used in this experiment: a French press, cold brew, and a drip machine. A particular brand of coffee known as Death Wish Coffee was used due to its higher caffeine content. This was done to ensure a measurable yield could be extracted. The extraction of the caffeine involved dichloromethane as a solvent. The extraction was done in a separatory funnel. Once isolated, the dichloromethane was distilled, leaving only caffeine behind. Seven different trials for each brewing method were conducted to obtain an adequate sample size. An ANOVA (analysis of variance) test was then used to determine if there was a significant difference in caffeine levels. The ANOVA test produced a p-value of 5.014 x 10-5 and the null hypothesis was then rejected. The average caffeine content was much higher in the French press than any other brewing method. Faculty Advisor: Frances Rees Homan, Sarah Chemistry 299 Molecular Weight Determination of Isolation of Casein Using Electrophoresis Casein is a well-known slow digestive protein used in the production of dairy products and is often found in various types of milk. The goal of this experiment was to test five different types of milk including organic whole, fat free, 2%, raw cow and goats milk for the five different strands of casein using an isolation process. The molecular weights of the five strands of casein include Alpha s1 between 22-23 kDa, Alpha s2 at 25 kDa, Beta at 24 kDa, Kappa at 19 kDa, and Gamma between 75-100 kDa. The weights of each strand were then compared to the isolation results of the milk samples to determine casein concentration. For the isolation process, each milk was first heated to 40 C, then acetic acid was added and run through a cheese cloth to collect the precipitate which was then washed with ethanol and run through vacuum filtration to collect the casein. The amount isolated from fat free milk was 0.269 g, organic whole milk was 1.426 g, raw milk was 1.751 g, 2% was 0.507 g and raw goats milk at 2.106 g. Once the isolation process was complete, the samples were tested using a process called electrophoresis to ensure that the casein was isolated effectively. Electrophoresis is the movement of charged particles in a fluid or gel under the influence of an electric field. Once run to completion, bands appear which can then be compared to the standards and calculated for the unknown molecular weights. In my study, it was hypothesized that the raw milk would produce the most casein due to the fact that it is uncultured and the proteins havent been denatured in the pasteurization process. Through electrophoresis, the bands allowed for identification as to what types of casein were present in each sample and just how heavily. Faculty Advisor: Barbara Heyl Johnson, Miranda - Biology - 299 Analysis and Manipulation of pGLO Plasmid This research study was conducted to analyze and manipulate a commonly used plasmid called pGlo. Plasmids are small circular pieces of DNA that can be introduced into bacteria for a range of bioengineering purposes. pGlo is a plasmid approximately 5,400 bases around that contains an inducible gene that codes for GFP, a protein that luminesces under ultraviolet light. Several PVCC lab courses use this plasmid, but the supplier, BioRad, has not previously made the plasmid DNA sequence available. This lack of information reduced our ability to interpret experiments, limiting its use in the lab. BioRad recently made the pGlo plasmid sequence available in early 2017, allowing me to compare their sequence to another pGlo sequence that was publicly available in the NCBI nucleotide sequence database. I used a free sequence analysis tool by GenomeCompiler to generate a multiple sequence alignment. This alignment revealed a single nucleotide difference located in a non-coding region of the plasmid. Restriction digests were used to confirm the plasmid sequence. An attempt to engineer an alternate version of the plasmid lacking a functional GFP gene failed, likely at the ligation step. Future studies could include different ligation methods. This work confirms the identity of the pGlo plasmid sequence and will allow us to move forward with related studies. Faculty Advisor: Anne Allison Kilmer, Julia Biology 299 Disinfectants versus Klebsiella pneumoniae The purpose of this experiment was to test the effects of certain disinfectants against bacteria in a planktonic (individual cells in liquid) state as well as in a biofilm. A biofilm is a film of bacteria that adhere to a surface by forming a thick and slimy polysaccharide complex. The bacteria that make up a biofilm are able to change their phenotype in order to adhere to surfaces and each other. This change in phenotype makes it harder to treat because the cells are slightly different from the planktonic cells. The biofilm can also be very hard to treat with disinfectants and antibiotics because of the thickness and adherence. The thicker the biofilm, the hard it is to kill. Disinfectants and antibiotics may only be able to penetrate the biofilm to a certain point before the treatment becomes ineffective. The cells on the bottom will reproduce and grown another biofilm if the treatment does not penetrate the bottom layer. Biofilm formation in places such as hospitals and ambulances can prevent proper disinfection and sterilization of surfaces, which leaves the patients more susceptible to nosocomial (hospital-acquired) infections. Lysol and Virex were chosen to test against Klebsiella pneumoniea in a biofilm and planktonic state for their recommended ten minutes of treatment. Disinfectant effectiveness is directly dependent to the state of bacterial growth. Planktonic growth and biofilm growth are the two different states I wanted to test. Klebsiella pneumoniea was chosen because it is commonly found as the source of hospital-acquired pneumonia. The effectiveness was tested by submerging the bacteria cells in the disinfectants. This project was designed to analyze how the disinfectants worked against K. pneumoniae in the different growth states. These disinfectants work against the bacteria by dehydration of the cell and also disrupting its membrane which ultimately kills the cell. In a biofilm, there are cells that are able to use pumps that take the drugs and such out making them useless. They are also hard to kill because the biofilm contains cells that may be able to lay dormant while treatment is present and reactivate when treatment stops to produce more cells to regrow the biofilm. A control group was used to assure the procedure did not kill the cells. The viability was tested using a protein assay and colony forming units on nutrient agar plates. The results provided data similar to what was expected. The control groups used produced the highest numbers because they were not treated with disinfectants, only sterile saline. This was important in proving the effectiveness of the disinfectants in different bacterial growth states. Faculty Advisor: Melinda Clark Little, Fulton Biology 299 The Effectiveness of Antimicrobials in Toothpaste and Mouthwash against S. mutans and S. aureus The research that has been conducted has tested the resistance of two bacteria, Streptococcus mutants and Staphylococcus aureus against four antimicrobial agents. The antimicrobials are found in dental care products as the aim of this research is to see which agents is best suited to fight bacteria in a clinical and home setting. The four agents are; sodium fluoride found in Colgate toothpaste, sodium monofluorophosphate found in Toms of Maine toothpaste, cetylpyridinium found in Colgate mouthwash, and benzoic acid found in Toms of Maine mouthwash. To test the effectiveness of these antimicrobials, the Kirby-Bauer test was used where paper disk containing the antimicrobial were placed on an inoculated agar plate and left to diffuse into the agar. Zones of inhibition were then measured after incubation to see the effectiveness of each. The results indicate that sodium fluoride was the most effective against both strains of bacteria. Based on the gathered results sodium fluoride is the most effective at fighting S. mutans, a common bacteria in the mouth and leading cause of dental carries. Against S. aureus, a bacteria found in the nasal pathway and sometimes the mouth, it was the most effective as well. But with the resistance shown by the one culture, it is possible that over time the S. aureus bacteria inside the host could become completely resistant. Further research could test the sodium fluoride antimicrobial to see if resistance is acquired. This could be viable research because during testing, one plate of S. aureus showed growth within the zone of inhibition. Faculty Advisor: Marlena Yost Maynard, Jamy Biology 299 Horizontal Gene Transfer between Escherichia coli and Staphylococcus saprophyticus mediated through biofilm creation Bacteria can evolve at a much faster rate than most organisms. They are constantly mutating or acquiring genes that allow for additional functions, including antimicrobial resistance. Exchange of genes can occur easily within a biofilm which is a thicker, protective state the bacteria take on. When bacteria grow into a biofilm they become harder to treat due to a typically thick polysaccharide that surrounds the microbes. Staphylococcus saprophyticus and Escherichia coli are the two leading causes of urinary tract infections, which occur due to biofilm formation on devices such as catheters. The close proximity of the cells in a biofilm allows for the transfer of genes to occur easily. I attempted to prove this by growing S. saprophyticus and E. coli, which contains a plasmid encoding for ampicillin resistance, in a biofilm together. A small amount of the antibiotic was added to the nutrient broth the biofilm was grown in to provide pressure for horizontal gene transfer to take place. Biofilm biomass was collected, plated, and Gram stained to differentiate between E. coli and S. saprophyticus. The presence of S. saprophyticus growing on this plate indicates that the E. coli shared its resistant gene with the S. saprophyticus. Faculty Advisor: Melinda Clark McCracken, Jared Biology 299 Difference in Zooplankton Species Population Densities and Organism Size during Seasonal Temperature Changes in a Freshwater Pond Ecosystem Freshwater zooplankton are small free floating crustaceans that are found in wetland areas such as ponds, lakes, streams, and rivers. Along with all plankton communities, zooplankton are vital to the freshwater food web complex. Other studies have shown that the fluctuations of zooplankton population have an effect on the food web efficiency. Many factors can affect the populations of these organisms but temperature from seasonal changes was the main issue that was observed and tested in this experiment. The hypothesis for this experiment is that as the temperature increases from winter to spring, the population densities and the organism size of the zooplankton species will increase. Only two species of zooplankton were able to be identified accurately. A rotifer species; Keratella cochlearis, and a copepod species; Nauplius larva, which is the basic larva stage all copepods go through. The hypothesis was supported throughout the entirety of the experiment. The samples that were collected from the freshwater pond were taken over a span of a few months. The three sampling dates were February 6th, March 8th, and March 29th. On each date, a higher water temperature was recorded each time. This temperature increase correlated to the ongoing increase of population density and organism size of these two distinct zooplankton species. All plankton thrive under a certain water temperature range. I was unable to find the point where the populations would begin to decrease due to warmer water temperatures. More testing would have to be performed with more samples in order to calculate the precise range of temperature. Faculty Advisor: John Walsh McQueen, Lucas Biology 299 The Effect of Seasonal Temperature Change on Invertebrate Biomass in Leaf Litter The purpose of this study was to evaluate the role sun exposure and the increasing temperature of the season change from winter to spring plays on the presence of macroinvertebrates in leaf litter. Findings to this end would allow for a greater understanding of a world that, though macroscopic in nature, is rarely seen. The initial hypothesis was that locations with higher sun exposure would yield a greater number of macroinvertebrates, especially as the temperature increased with the coming of spring. Thirty collections of leaf litter placed into a Berlese funnel under light exposure for a period of four hours were conducted to assess this relationship, with a Forest Densiometer used to calculate relative sun exposure percentage. Collected invertebrates were evaluated not just on total number, but also on dried biomass. With only twelve of the thirty collections returning any samples, the initial hypothesis is rejected, and there is no way to make a definitive statement regarding the role sun exposure and temperature change play in the seasonal activity of leaf litter macroinvertebrates in the context of this experiment. The sun exposure also remained constant throughout the collection period between twenty-five and thirty percent and therefore was not considered in the final results. Experimental refinement and future research could potentially yield more substantial results and give rise to a statistically-significant statement. This lack of consistency regarding invertebrate presence through the seasonal change could potentially be explained by a somewhat unusual March that was a degree colder than February on average and included several days above fifteen degrees Celsius and some approaching zero degrees Celsius. This could explain the finding of sixteen organisms in a warm February compared to twelve in a very inconsistent March. This unusual short-term weather could relate to larger-scale climate change concerns, but further research is needed to make such a statement. Faculty Advisor: John Walsh Nelson, Audun Chemistry 299 Optical Purity of Advil vs Generic Ibuprofen When ibuprofen is synthesized, two substances are formed; both are ibuprofen. They look the same, have identical physical properties, and react at the same speed with the same reagents. Ibuprofen is what is called a chiral compound, meaning it has a chiral center. A chiral center is a quirk of geometry found in atoms with four bonds to four different substituents. This allows for multiple arrangements of the substituents around the central atom. Different arrangements are called enantiomers, and in most respects, they are identical. Ibuprofen is special because only one of its enantiomers acts as an antiinflammatory. The purpose of this experiment was to determine the difference in enantiomeric excess (the ratio of enantiomers) between brand name ibuprofen (Advil) and two types of generic ibuprofen. To achieve this, prescription (pure active enantiomer), brand, and generic ibuprofen was separated from solid tablets by crushing the medication, dissolving it in hot hexane, filtering, and air drying to recover pure product. The product was tested for purity by melting point then tested for enantiomeric excess with polarimetry. The Advil was found to have an excess of 7.7 %, the CVS Dye Free was 13 %, and Food Lion was 8.8 %. The data would suggest no difference in purity between the three varieties, but although the measurements were fairly consistent, they were all within the 0.3 margin of error specified by the polarimeter. In other words, all three types of ibuprofen appeared to be racemic mixtures (equal quantities of two enantiomers), but the accuracy of the polarimeter makes a solid conclusion impossible. Faculty Advisor: Frances Rees Pandagade, Catherine Biology 299 The Symbiotic Association of Mycorrhizae and Plants in Relation to Plant Growth and Reproduction Plants and mycorrhizae have a symbiotic relationship where the fungi colonize the root system of the host plant, providing increased water and nutrient absorption. In turn, the plant provides the fungi with carbohydrates formed from photosynthesis. Mycorrhizae also provide the plants with increased protection from pathogens. My project investigates whether the presence of mycorrhizae influences growth and reproductive rates of the Wisconsin Fast Plant, Brassica rapa. I hypothesize the presence of mycorrhizae will increase plant growth and reproduction. My experimental set-up included three groups: 1) regular soil, which could contain a variety of microbial life, 2) sterilized soil that should be free of all microbes, and 3) soil with added mycorrhizae. Plants grown in regular soil had a lower average biomass and a higher average seed mass. These findings indicate that poor growth correlates with more seed production. One possibility is that Fast Plants undergo more seed production as a survival strategy for when growing conditions are poor. Faculty Advisor: Anne Allison Perch, Miah Biology 299 Detecting a Cell Surface Molecule Important for Multicellularity in a Colonial Group of Protists Closely Related to Land Plant forms of Green Algae Understanding the cell and molecular processes that give rise to more complex life helps us better understand ourselves and the world around us. Organisms one would recognize as multicellular include plants, animals and fungi. These groups, along with a fourth group called protists, comprise the eukaryotic domain of life. Interestingly, there are many separate origins of multicellularity in eukaryotes. By looking at these separate instances, biologists find certain themes such as proteins that help bind one cell to another. Lectins are a family of proteins located on the surface of cells, and they perform diverse functions such as mediating cell adhesion. Lectins bind carbohydrates, including the commonly used laboratory reagent wheat germ agglutinin (WGA). Previous studies have used a fluorescently tagged version of WGA to detect lectin-like proteins on single-celled protists closely related to animals. Nicole Kings laboratory at UC Berkeley demonstrated that such lectin-like proteins are only seen at the surface of choanoflagellates when they are in a group formation called a colony. I hypothesized that protists in the green algae, a group closely related to land plants, will bind WGA when in colonial but not free swimming form. I used three green algae: Eudorina elegans, Volvox carteri, and Chlamydomonas reinhardtii. I observed WGA binding only among colonial Eudorina. This finding suggests Eudorina express a lectin-like protein at the cell surface only when the cells are part of a multi celled unit. This matches similar findings carried out in relatives of animals, and this is the first time this has been shown in relatives of the land plants. These findings add to our understanding of the origins of multicellularity among eukarya. Faculty Advisor: Anne Allison Perkins, Cody Chemistry 299 Fluoride Concentrations of Drinking Water The fluoridation of drinking water has been a growing topic of controversy. The water quality report in 2016 for Charlottesville Virginia stated that the Rivana Water and Sewer Authority operate two water treatment plants in which chemical and physical treatment are applied to the water before distribution. Details describing water treatment read: Fluoride is added at all treatment plants to promote dental health. This sparks concern due to the numerous health hazards overexposure to fluoride can cause. Examples of reported health issues linked with fluoride overexposure are: increased cancer rate, diabetes, endocrine disruption, male infertility, and thyroid disease. In addition, the most prevalent and concerning health issue related to this topic is that of skeletal fluorosis. This disease is known to cause pain and damage to bones and joints within the body, and is believed to be the reason why millions of people in China and India suffer from crippling bone diseases. The purpose of this experiment was to find the source of drinking water with the lowest fluoride concentration in order to determine which source would be the best option to avoid fluoride exposure via water. This was completed by reacting drinking water samples with the SPADNS-2 reagent dye that detects fluoride in water from a range of 0.02 mg/L-2.00 mg/L, and then testing the absorbance with light absorption spectroscopy at 580nm to find relative fluoride concentrations using Beers law. The water samples being tested were tap water provided by the City of Charlottesville, well water from Greene County Virginia, and name brand water bottling companies (Aquafina, Fiji, and Culligan). The calculated fluoride concentrations in each sample were as follows: city water- 0.740 mg/L, well water- 0.142 mg/L, Aquafina- 0.064 mg/L, Fiji- 0.268 mg/L, Culligan- 0.054 mg/L. In conclusion, the fluoride concentration in city water significantly was the highest, while the bottled waters, with the exception of Fiji water, had miniscule amounts; making the m the best choice of drinking water if one desires to avoid fluoride exposure via water consumption. Faculty Advisor: Frances Rees Tisdelle, Matthew- Biology 299 Testing the SODIS Method Water is the most essential compound for human survival, however many developing countries do not have access to clean and potable water sources. In 2015 the World Health Organization estimated some 1.8 billion people worldwide lacked access to properly treated water sources (World Health Organization, 2016). The main concern with these improperly sanitized sources lies in the pathogenic organisms, such as Salmonella typhi, Vibrio cholera, and Escherichia coli, that thrive in those conditionsall of which are associated to serious health complications (World Health Organization, 2016). According to the Environmental Protection Agency, the three most effective methods to eliminate pathogenic organisms from water sources are to boil the water, treat the water chemically, or to implement a passive disinfectant system (United States Environmental Protection Agency, 2017). Given the economic constraints imposed upon these developing nations, and the expenses associated to the boiling and chemical treatment of water, the need for an inexpensive, effective, and easy to perform disinfectant system becomes evident. This experiment was implemented to determine the bactericidal effectiveness of such a system; the solar disinfection system (SODIS). 250 mL clear polyethylene terephthalate (PET) bottles containing 2.5 mL of Escherichia coli and Pseudomonas aeruginosa respectively and 247.5 mL of sterile H2O, were sequestered into three experimental environments: a dark box to act as a control, an ultraviolet light box to test the UVA component, and outside to test the SODIS method directly. 4, 6, 24, and 48 hour increments were implemented to track the bacterial reproductive rate in each environment using spectrophotometry, as well as a series of serial dilutions to obtain a bacterial colony count and evaluate bacterial viability. Preliminary results suggest ultraviolet light alone will not reduce bacterial reproductive rates and will not inhibit bacterial viability. However, exposure to four or more hours of direct sunlight will inhibit the bacterial growth, and viability of all tested bacterial species, with a correlation value of 99.94%. Further testing would be necessary to determine whether ultraviolet or infrared light plays a larger role in the bactericidal effectiveness of the SODIS system, however within these experimental parameters this method definitively eradicates the bacterial species E. coli and P. aeruginosa completely. Faculty Advisor: Marlena Yost Willis, Brian Biology 299 Survey of Amphibian Species Diversity at Piedmont Virginia Community College As part of one of the most diverse regions for amphibian life on the continent, Albemarle County suffers from a lack of ecological data regarding frogs, toads, and salamanders. Maintaining updated species lists in this area will allow for the monitoring of the ecological health of the region and provide background knowledge for deeper investigation. This study was a survey of the amphibian biodiversity present at Piedmont Virginia Community College (PVCC). A 2016 survey of Ragged Mountain Natural Area (RMNA) was used to directly compare PVCC to a nearby protected wildland. My hypothesis was that there would be fewer species found at PVCC than RMNA. A total of five species, three salamanders and two frogs, were found and verified at the survey site (Notophthalmus viridescens, Desmognathus fuscus, Plethodon cinerus, Acris crepitans, and Pseudacris crucifer); three more frog species were suspected to be present. The 2016 RMNA survey catalogued thirteen species including eight frogs, two toads, and three salamanders. Of note are two salamander species that are present at PVCC (Notophthalmus viridescens and Plethodon cinerus) which were not found at RMNA. The data appears to support my hypothesis of lower species diversity though because of the short period of the survey at PVCC there are likely to be species left unidentified. More surveys are needed at other times of the year to truly assess the full amphibian biodiversity here on campus. Faculty Advisor: Joanna Vondrasek Yates, Jennifer Geology 299 Sauropod Fossil Excavation and Identification The Morrison Formation is a sequence of Jurassic (155-148 MYA) sedimentary rock in the western United States composed of mudstone, sandstone, siltstone, and limestone. It is the most fertile source of dinosaur fossils in North America. According to the rock record, the environment around the area was dry and arid, lacking of grasses, flowering plants, and trees. The most common dinosaurs found in the formation are the Camarasaurus, Diplodocus, Apatosaurus, Stegosaurus, and Allosaurus. The saurischian or lizard-hipped dinosaurs are quadrupedal (four-legged) with a simple body plan. They differ throughout the group, however, some similarities are very long necks and tails, nostrils located up high on the skull, and limbs resembling that of elephants. They are nicknamed lizard-hipped because the pubis points downward and forward at an angle to ischium (the pelvis is composed of the pubis, ischium, and pubis). Sauropods are found on every continent except Antarctica and are one of the most long-lived groups of dinosaurs existing from the lower Jurassic to the upper Cretaceous. The process of extracting a fossil from rock is very tedious work. The air scribe, basically a micro-jack, was used most the time to take rock off layer by layer. The saw was used to cut down the plaster jacket that is placed around the fossil in the field. The Chicago Pneumatic is also a micro jack with a little more power behind it than the air scribe. I used this in Martinsville towards the end of my project. I also used the Air Abrader there which uses air and sodium bicarbonate to remove the matrix (rock present on the fossil). As the fossil began to appear little by little, I noticed how intact the middle of the bone was. I was not able to finish prepping the fossil due to only being able to go to Lynchburg once a week, however, with the prep work that has been done so far I have been able to identify the fossil. The fossil is 21 centimeters long, 5.5 centimeters wide in the center, 8 centimeters wide on the smaller end, and an estimated 10 centimeters on the larger end. The larger end was damaged somewhere in the history of the fossil and appears to have lost a significant amount of bone. That end also appears to be extremely concave, which was odd to the professors and me. I have also been able to tell that the actual thickness of the bone is quite the oppositeit is surprisingly thin. This also helped me to deduce that it is in fact, a hand bone. I believe that the fossil is a metacarpal from a Diplodocus. I came to this conclusion because the Diplodocus is one of the smaller Sauropods and the fossil panned out to be smaller than most Sauropod metacarpals. Faculty Advisor: Larry Tiezzi ...