Journal of Biological Research, Vol. 5 (2004)
Isolation and Identification of Atrazine-Degrading Bacteria from the Biofilms of Rocks from Streams. MONICA ALDRICH, Department of Biology, Hartwick College, Oneonta, NY, 13820.
The agriculture industry uses large quantities of pesticides for pest control. The majority of these do not reach their targets and an estimated 99.9% are left as inadvertent environmental pollutants. Streams draining agricultural lands often contain pesticides like atrazine, a widely used herbicide. Atrazine is a possible human carcinogen and an endocrine disruptor. Evidence has also shown atrazine causes DNA damage and reduces the activity of the immune system. Atrazine-degrading microorganisms could provide a solution to the cleanup of atrazine pollution. Already, atrazine-degrading microorganisms have been isolated from agricultural soils and from soils near agricultural chemical dealerships. The goal of this study was to determine if atrazine-degrading bacteria were present in biofilms on rocks in streams. To accomplish this, rocks were collected from several sites along creeks receiving agricultural run off. Biofilms were scraped from the rocks, broken apart, and then grown on basic basal medium with and without atrazine. Colonies picked from the atrazine plates were further purified using the streak plate technique. Eighteen isolates were obtained from each creek, 26 of which were frozen for later identification. The BIOLOG system was used to identify 13 isolates. A probable match was obtained for only one of the isolates, which was identified as Arthrobacter cumminsii .
Faculty supervisor: Dr. Mary Allen.
Effects of Inbreeding and Out-crossing on Measures of Fitness in an Isolated Population of Cornus florida . AMY BATEMAN, Department of Biology, Hartwick College, Oneonta, NY 13820.
Small, isolated populations may become inbred as a result of self-fertilization or breeding with genetic relatives, and this often affects measures of fitness. Out-crossing is an effective way to reduce inbreeding depression in such populations. I investigated potential benefits of out-crossing for a remnant natural population of Cornus florida at Hartwick College. The population is currently small and shows little recruitment, characteristics of inbreeding. To study the effects of out-crossing, I pollinated inflorescences with pollen from multiple donors within (1) the population (‘inbred’), (2) neighborhoods in Oneonta (‘out-crossed’), or (3) both populations (‘mixed’). I measured the effect of each treatment on measures of fitness (e.g., seed weight and germination). Inflorescences from the inbred treatment produced more fruit and had higher germination rates than inflorescences in either the out-crosssed or mixed treatments. There was no difference among treatments for fruit or seed weights, nor for growth rates of seedlings. Higher measures of fitness in the inbred treatment suggest incompatibility between the campus population and horticultural trees used for out-crossing. Inbreeding may not be occurring in the campus population; instead, the lack of recruitment may result from low levels of pollination or lack of seed dispersal. Faculty supervisor: Dr. Peter Fauth.
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The Effect of Polyphenolic Compounds From Green Tea on Human Cancer Cells. E. MICHELLE BAXTER, Department of Biology, Hartwick College, Oneonta, NY 13820.
The polyphenolic compounds of green tea (Camellia sinensis (L.) Kuntze) and soy bean have gained increasing attention as chemopreventative agents. The polyphenol compounds of green tea and soy bean have also been demonstrated to have inhibitory effects in numerous cancer cell types. We studied the effects of whole green tea polyphenols (40, 80, and 160 μg/mL) and genistein (0.5 μm, 5μm, and 50μm) on the growth and survival of A431 human epidermoid carcinoma cells. The results suggest that green tea polyphenols and genistein may induce apoptosis and inhibit the growth of these cells. The effects of green tea polyphenols and genitsein may also be cancer specific. Thesis advisors: Linda Swift and Doug HamiltonThe Effects of Ibotenate Lesions of the Hippocampus on Appetitive Learning Associations within Contextual and Trace Conditioning Paradigms. C. JASON CLARK, Department of Biology, Hartwick College, Oneonta, NY 13820.
A number of studies have demonstrated that the hippocampus is required for context conditioning and trace conditioning tasks within aversive paradigms. In the current study two conditioning experiments were conducted to determine whether deficits observed in aversive context conditioning and trace conditioning can be generalized to appetitive conditioning paradigms. Since context cues are capable of predicting the arrival of a unconditioned stimulus (US) and consequently eliciting conditioned responses (CR) (i.e., appetitive behavior), the first study sought to examine whether the hippocampus was necessary for the acquisition and extinction of context-food associations. A second study examined the role of the hippocampus within a trace-conditioning paradigm that provided the opportunity for the conditioned stimulus (CS) to acquire concurrent inhibitory and excitatory associations between the US and the CS. Both hippocampal lesioned (HL) and control (C) rats failed to show differences in context acquisition or extinction. Furthermore, both HL and C rats failed to acquire trace-conditioning acquisition during a 15-s CS and a 30-s trace interval. Therefore, a subsequent trace-conditioning task was examined using a 5-s CS and a 10-s trace interval. Both HL and C rats acquired the task despite small differences in average CR rates. These results suggest that the hippocampus may not be required for appetitive context and trace conditioning paradigms. Thesis Advisor: Dr. Allen Crooker
The Effects of Chlorhexidine on the Viability of Dental Plaque Biofilms Supplemented with Fructose. MARK COLITE, Department of Biology, Hartwick College, Oneonta, New York, 13820.
Chlorhexidine has antibacterial properties that have led to its usage for the treatment of dental caries (tooth decay) and periodontitis (gum disease). These diseases are caused by bacteria that form biofilms in the mouth. The aims of this study were to test the anti-microbial effects of chlorhexidine on dental plaque biofilms. The biofilms were grown on four-chambered slides from whole saliva supplemented with a mucin solution and were incubated at 37˚ C˚ for 24 hours. A 10% fructose solution was added to the saliva/mucin solution at the beginning of the incubation period to simulate dietary patterns. After 24 hours of growth, each dental biofilm was treated with one of three different concentrations of chlorhexidine, 0.02%, 0.2%, or 2.0%, for 120 seconds. The controls were treated with sterilized water. After treatment biofilms were stained with LIVE/DEAD BacLight flourescent stain (Molecular Probes) and the density of live and dead cells was determined. A 0.2% concentration of chlorhexidine showed a significant effect (p =.003) on the percentage of dead cells in the biofilms in comparison to the control. A .02% concentration of chlorhexidine also showed a smaller, but significant effect (p= .023) on the percentage of dead cells in the biofilm in comparison to the control. A 2.0% concentration of chlorhexidine had not significant effect (p=.127). The time that saliva was donated for use as the inoculum for the biofilm also significantly effected the percentage of dead cells composing the biofilm (p=.037). This suggests that oral hygiene and dietary habits may nullify the positive effects of chlorhexidine treatment. Thesis Advisor: Dr. Mary Allen
The Effects of Black Cohosh on Surgically Castrated Female Rats. AMANDA J. DANIELS, Department of Biology, Hartwick College, Oneonta, NY 13820.
Menopause is a natural event that occurs late in life when estrogen production decreases to a level that is too low to create the luteinizing hormone surge; ovulation becomes irregular and then stops. Herbal therapies have become popular in reducing physiological side effects of conditions and could potentially do so for menopause without the side effects of the synthetic hormones, but there is great controversy over their use and effects on women. Laboratory rats had their ovaries removed under isofluorine and were divided into four groups: one group received regular estrogen replacement therapy, a second treatment received Black Cohosh and the third received no other treatment but had their ovaries removed and the fourth group was the control: no surgery no treatment. The bone density, cholesterol, glucose levels and uterine horn weights were monitored to determine if Black Cohosh has estrogenic effects. Black Cohosh exhibited estrogen like effects because it increased the uterine weight, and maintained the cholesterol levels to that of the control. There was no statistical significance from the one-way ANOVA on the bone density or glucose levels. Faculty Advisor: Dr. Linda Swift
Stunted Bone Growth and Fluctuating Asymmetry in Mice (mus musculus) In Relationship To Protein Intake. COLLEEN M. DIDAS, Department of Biology, Hartwick College, Oneonta, NY 13820.
Fluctuating asymmetry is the ‘random stress-induced deviations from perfect symmetry,’ and has a negative correlation with an individual’s health and fitness. Environmental stresses include parasites, pathogens, and nutritional factors (Swift 2002). Children in northern Thailand hill tribes are experiencing chronic malnutrition at 55%, most likely a result of types of foods consumed, such as protein-poor food. For this experiment three groups of mice were raised with differences in diet; the first group had a normal diet and mice were periodically euthanized to create a growth curve. The second and third groups were both weaned at 15 days old to a diet of no protein. The second group was euthanized at 24 and 34 days. The third group had protein reintroduced at 24 days old and were then euthanized at 34 days. The lengths of the left and right humorous and femur were measured for average length, rate of growth, and fluctuating asymmetry and compared against the growth curve. The findings of fluctuating asymmetry and stunted growth as a result of poor-protein diet will indicate the necessity of protein in relation to growth. The reintroduction of protein would indicate if it was possible to have catch-up growth. Faculty supervisor: Dr. L. Swift.
A Comparison of Stream Water Quality in the Upper Tract of Pine Lake. MELEIA EGGER, Department of Biology, Hartwick College, Oneonta, NY 13820.
Hartwick’s Pine Lake Environmental Campus is 364 hectares of land located 12.8 km from the main campus outside of Oneonta NY. Shelly Brook runs through the upper tract of Pine Lake (a forest preserve since 1971) and down into the nearby West Davenport area. It is intersected about half way down the hill by a small tributary that originates in the adjacent property. The private property surrounding the tributary was logged 15 years ago. This study compared water quality of upper Shelly Brook (an undisturbed watershed) with lower Shelly Brook (as defined by the intersecting stream) and the water quality of the adjacent tributary itself (a logged watershed). Three sampling sites were selected along each stream branch, and water collections were taken from all nine sites. Sampling occurred on three dates throughout the year, and temperature and dissolved oxygen were measured in the field. In the lab, samples were tested for chemical indicators of water quality, including pH, total nitrogen (nitrite + nitrate), phosphates, and suspended solids. Macroinvertebrate samples were also collected in conjunction with the last water sampling but have yet to be analyzed for the presence of bioindicator species. Preliminary analyses of water chemistry indicate that there are statistically significant differences between the three stream branches (as averaged over the course of three sampling dates) in terms of both phosphate and total nitrogen. All other variables showed no significant differences. My results suggest that there is no currently detectable differences in water quality between these three branches, despite the past disturbance. However, bioindicators (macroinvertebrate sampling) have yet to be analyzed. Faculty supervisor: Dr. Mark L. Kuhlmann
Glutamine and Its Enhancement Effects on Puncture Wounds in Mice. VINCENT FERRARA, Department of Biology, Hartwick College, Oneonta, NY 13820.
Although traumatic injuries from athletic activities, automobile accidents and animal bites often create puncture wounds, puncture wound healing specifically has not been as widely studied. The amino acid glutamine has been frequently evaluated as an aid to recovery from athletic injuries (Wilmore, 2001). Glutamine provides carbon for energy, is a precursor for the neurotransmitter glutamate, a nitrogen carrier, an essential component of structural proteins and a signal and/or regulator of metabolic demands (Lobley, 2000). However, the mechanism by which it acts to aid in wound healing and its role in puncture wounds have not been evaluated. In this study, the recovery rates from puncture wounds were evaluated in sixteen mice. We hypothesized that supplementation with a glutamine-based diet, would lead to a better recovery rate at higher concentrations. Three groups of four mice received a puncture wound to the right gastocnemius. Two of these groups received glutamine supplementation at either a high (4%) or low (3%) concentration. Muscle recovery was evaluated by swim testing on days 5, 7, 9, 11, 13, 15, and 17, post surgery. Data was analyzed using a univariate ANOVA test. None of the comparisons between groups were statistically significant. This suggests that our experimental model for injury was flawed since there was no difference found between the untreated surgical controls versus the no surgery group, (p<.935). Thus the hypothesis cannot be supported or rejected. Low sample size and a very high degree of variability in swimming endurance from mouse to mouse may explain this lack of significance. The averages that resulted from the measurements fell into a very predictable pattern. Thus, I conclude that there may be some merit in working to improve the injury model and continuing to evaluate this hypothesis. Faculty supervisor: Laura Malloy
Sex and Age Determination of Thrushes Using Feather Morphology and Ptilochronolgy. NOELLA GIRARD, Department of Biology, Hartwick College, Oneonta, NY 13820.
Behavioral and demographic studies of avian populations often require information about specific age and sex classes. I investigated the usefulness of quantitative measurements of rectrix (tail feather) morphology, body weight, and wing length for aging and sexing Veeries (Catharus fuscescens) and Wood Thrushes (Hylocichla mustelina). Although both species are easily sexed by breeding characteristics (e.g., brood patches on females) during summer, sexing at other times is difficult. Birds were assigned to known sex classes based on observations of breeding characteristics, and assigned to probable age classes using a published technique involving overall feather shape. Body length and weight were measured in the field. I used
computer-imaging software to measure angles and distances on retrices taken from individuals during the breeding season. I quantified the ptilochronology of each retrix by measuring the distance between visible ‘bands’ produced during feather growth. I used discriminant analysis function to determine which of the measurements are useful in classifying birds into age or sex classes, and to calculate the probability of correct classification into age or sex classes based on the morphological measurements. The results of the discriminant analysis function and its practical implications for aging and sexing thrushes will be discussed.
Faculty advisor: Dr. Peter Fauth
The Comparative Efficacies of Three Soft Contact Lens No-Rub Disinfecting Solutions Against Pseudomonas aeruginosa Biofilms in Contact Lens Cases. GAYLE GREGORY, Department of Biology, Hartwick College, Oneonta, NY 13820.
One of the most common microorganisms associated with infections in contact lens wearers is Pseudomonas aeruginosa. This bacterium gains access to the eye either from contaminated contact lenses or contaminated disinfecting or storage solutions, but most frequently from contaminated contact lens storage cases where P. aeruginosa routinely adhere and form biofilms. The purpose of this study was to compare the effectiveness of three multi-purpose no-rub disinfecting solutions against P. aeruginosa biofilms inside contact lens cases. Opti-Free No-Rub, ReNu No-Rub and Equate No-Rub disinfecting solutions were tested. These solutions differ from other multi-purpose contact lens disinfecting solutions, in that the manufactures claim that no physical cleaning (rubbing) of the lens is necessary before disinfection in the lens case to remove daily build up, proteins and contaminants. For this study, P. aeruginosa were grown inside contact lens cases for 48 hours, at 37°C, to encourage biofilm growth. After 48 hours, the planktonic cells and the growth media were removed and replaced with one of the disinfecting solutions or saline solution, which served as the control. The solutions were left in the cases for one of two time periods: 4 hours, the minimum disinfecting time recommended by the manufactures, or 8 hours. After 4 or 8 hours the solutions were removed and the lens cases were scrapped to remove the remaining biofilms. The biofilms were homogenized and plated on tryptic soy agar (TSA). After a 24-hour incubation at 37ºC, the number of viable cells was determined by counting colony-forming units (CFUs) on the plates. The Opti-Free No-Rub disinfectant was significantly more effective than the saline control (p<.001), ReNu No-Rub (p<.001) and Equate No-Rub (p<.001) disinfectants at reducing the number of live bacteria from the biofilms. ReNu No-Rub and Equate No-Rub were significantly more effective then the saline control (p=.004 and p=.015, respectively), but significantly less effective than Opti-Free No-Rub (p>.05). There was no significant difference between the effects of ReNu No-Rub and Equate No-Rub solutions (p>.05). For all the solutions, except Opti-Free No-Rub, the number of viable cells remaining after 8 hours of disinfection was significantly greater (p=.006) than after 4 hours. This suggests that these solutions lose their effectiveness sometime after 4 hours. Opti-Free No-Rub was equally effective at 4 and 8 hours. Thesis Advisor: Dr. Mary Allen
The Relationship of Fluctuating Asymmetry and Malnutrition in Children Age 0-5 Years in Hill Tribe Villages of Northern Thailand. KRISTIN HARDMAN, Department of Biology, Hartwick College, Oneonta, NY 13820.
Many children living in the hill tribe villages of Northern Thailand suffer from malnutrition as a result of economic crisis and poor sanitary practices. Growth stunting is caused by chronic malnutrition related to inadequate food intake. Fluctuating asymmetry is random stress-induced deviation from prefect symmetry which occurs when a developing organism is under environmental stress caused by nutrition or disease. Both of these factors are predictors of life expectancy and health. The aim of this study was to determine if a correlation exists between growth stunting and asymmetry in children suffering from chronic malnutrition. Anthropometric measurements of age, height, and digit length were taken from 72 children in three villages. There was no significant correlation between growth stunting and fluctuating asymmetry. Results indicated, however that 49% of the children (village range 22%-68%) were growth stunted and 57% (village range 37%-77%) demonstrated fluctuating asymmetry. These data indicate that the children display developmental instability, as well as malnutrition. Thesis Advisor: Dr. Linda Swift
Analysis Of Cutaneous Bacteria In the Lungless Salamander, Plethadon cinereus (Family Plethodontidae). KELLY HONSINGER, Department of Biology, Hartwick College, Oneonta, NY 13820.
The purpose of this study was to analyze the bacterial community on the skin of the plethodontid salamander, Plethodon cinereus, and to answer the following questions: 1) What sorts of bacteria are found on the skin of P. cinereus ? 2) Does the bacterial community of P. cinereus differ from that associated with the soil and leaf litter? 3) Are the cutaneous bacteria of P. cinereus able to inhibit the growth of other microbes? 4) Do any resident skin bacteria inhibit fungal growth? A total of ten different bacteria were isolated from the skin of the salamanders sampled. Salamanders (n=10) were collected along with soil samples from each collection site in the fall. Each salamander and its respective soil sample were kept isolated in sterile petri dishes at 16°C for a one-week period. After a week, a sample was taken from each salamander’s dorsal side using sterile cotton swabs. Soil samples were mixed in a centrifuge tube with sterile water. Each soil sample was then diluted (1:100) with sterile water. All samples were cultured on sterile tryptic soy agar using standard microbiological techniques (streak plate and spread plate). They were then Gram-stained, and their colonial morphology was recorded. Many different bacteria and fungi were found in the soil, but five were found to be common among all soil samples. These were used along with the cutaneous bacteria for the antibiotic tests, which were used to test the cutaneous microbes for antibiotic activity. Each kind of cutaneous isolate was streaked vertically down the center of individual plates. The soil bacteria or fungi were then streaked perpendicular to these cutaneous bacteria. Trials were replicated four times. No lateral growth of the soil bacteria towards the middle streak was considered inhibition. The results indicate that the cutaneous bacterial community of P. cinereus includes microbes not found in the surrounding soil, and that some of these cutaneous bacteria show antimicrobial and antifungal activity.
Thesis advisor: Dr. Stanley Sessions
Comparative Effects of Antibiotic and Bacteriophage Treatment on Wound Healing in Mice. MELISSA HUIZINGA, Department of Biology, Hartwick College, Oneonta, NY 13820.
Staphylococcus aureus is a major pathogen that causes numerous infections, including infections of the skin. Antibiotic treatment of this pathogen may result in bacterial resistance to antibiotics. Increased bacterial resistance to antibiotics has spurred an interest in alternative methods of treating infections. This study looked at the effectiveness of bacteriophage treatment as an alternative to antibiotic therapy. Bacteriophage therapy was evaluated in vivo by creating cutaneous S. aureus infections in 18 mice, then treating the infections. Six mice were treated with bacteriophage, six with the topical antibiotic silver sulfadiazine, and six with a water control. Progression of the wound healing was evaluated by observing wound appearance and by quantification of the wound area. No significant difference was seen between the wound areas for the three treatments. Faculty Supervisor: Dr. Allen R. Crooker.
Impact of Agricultural and Waste Water Treatment Facility Runoff on the Incidence of Antibiotic Resistant Bacteria in Streams. ANDREA M. JONES, Department of Biology, Hartwick College, Oneonta, NY 13820.
Due to increased usage of antibiotic drugs over the past few decades, researchers are finding increasing proportions of bacteria in the environment that are resistant to antibiotics. Areas that are especially affected include streams that receive runoff from farms utilizing antibiotic drugs in their animal feed and from waste water treatment facilities. The goal of this study was to determine if these types of pollution are causing an increase in populations of antibiotic resistant bacteria in streams. Water was collected from three points along a stream receiving runoff from agricultural areas and from points above, at, and below the outflow pipe of a waste water treatment facility. Water was also collected from a location geographically removed from these pollution sources. Bacteria filtered from the water samples were plated on media selective for the growth of coliforms or media selective for the growth of Acinetobacter. Colonies picked from these plates were grown on media containing ampicillin, chloramphenicol, norfloxacin, streptomycin, or tetracycline, or no antibiotic. Susceptibility or resistance to antibiotics was determined by comparing the percentage of colonies that grew on media with and without antibiotic. The number of coliform bacteria resistant to ampicillin was significantly higher at the waste water treatment facility outflow pipe than upstream of the outflow. Greater numbers of coliforms and Acinetobacter resistant to chloramphenicol, streptomycin, and tetracycline were also found at and below the outflow compared to upstream. Agricultural runoff seems to contribute to an increase in the number of coliform bacteria resistant to ampicillin, streptomycin, and tetracycline, and to the number of Acinetobacter resistant to tetracycline. These results appear to indicate that the use of antibiotics in both agriculture and in humans is increasing the incidence of antibiotic resistant bacteria in lotic environments. Faculty supervisor: Dr. Mary E. Allen
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In Vitro Heterochronic Transplantations and Cellular Growth in Neuronal Cells. Derrek Krasnicki, Department of Biology, Hartwick College, Oneonta, NY 13820.
Neural and stem cell transplantation is emerging as a potential treatment for neurodegenerative diseases. Recent studies and clinical trials have shown that, though implantation of fetal brain cells can reduce Parkinsonism in a patient, little is known about what is going at the cellular level. One idea is that transplants of younger cells induce cellular growth in older host cells. In order to test this idea, I transplanted fetal neuronal cells of a mouse embryo early in development into older established in vitro culture of sub-adult age mouse cells. Bromodeoxyuridine and immunocytochemistry were used to label actively dividing cells in culture to compare cellular growth rates. The results show that there were significant differences between the growth rates of mixed heterochronic culture cells, as opposed to the young and old culture cells alone. Advisor: Stanley K. Sessions
Stage-dependent Birth Defects Induced by Retinoic Acid in Mice. ELIZABETH MCDONALD, Department of Biology, Hartwick College, Oneonta, NY 13820.
Teratogens are biochemicals that can cause abnormal development of an organism. Retinoic acid (RA), a known teratogen commonly used as an active ingredient in wrinkle creams and acne treatments, induces birth defects in a stage and dose dependent fashion. It is known that RA mimics steroid hormones and can interfere with a wide variety of cellular activity including the expression of many genes. Examples of some affected genes are sonic hedgehog and Hox genes. RA can also disrupt cell mitosis and cell migration, which are two cellular behaviors that are essential for normal morphogenesis. In this experiment, three pregnant mice were treated by intraperitoneal injection with a 12 mg/kg dose of all-trans RA at developmental age 8 days post coital (p.c.). This age corresponds to Theiler stages 12 and 13, when embryonic turning occurs and the first somites are visible. The embryos were collected at day 18 of gestation. Microscopic examination of whole mounts showed that 50% of embryos with this treatment exhibited exencephaly, eye and craniofacial abnormalities. The same treatment of two pregnant mice at day 10 p.c., Theiler stages 16 and 17 when limb buds become prominent, yielded no observable teratogenic effects by gross anatomical examination or the technique of clearing and staining. These results indicate that day 8 p.c. is critical for craniofacial morphogenesis and also demonstrate that treatment during later stages of development is less disruptive overall. This study is consistent with previous studies that have investigated the effects of RA during developmental stages earlier than day 8 p.c. and have documented strong stage-dependent effects. Faculty Supervisors: Dr. Allen Crooker and Dr. Stanley Sessions
Localization of Zm13 Expression by In-Frame Ligation to the Green Fluorescent Protein. PAULINA MELECHKINA, Department of Biology, Hartwick College, Oneonta NY 13820.
Zm13 is a pollen specific gene that is expressed during the late stages of pollen development. While the timing of its expression is known, little is known about its function. Analogs of Zm13 , such as the tomato LAT52 , have been found to be involved in pollen hydration and pollen tube development, and may be receptor kinases. The goal of the current research was to determine the specific function of Zm13 by localizing the sub-cellular destination of its protein product. To do this the intact Zm13 gene was to be ligated into a plasmid, in-frame to the green fluorescent protein (GFP) marker gene. The resulting Zm13-GFP protein product should be detectable through fluorescent microscopy in transformed Arabidopsis pollen grains. An appropriate fragment of the Zm13 DNA was created via PCR, but ligation into a binary plasmid containing GFP proved problematic, so no results concerning Zm13 function were obtained. Faculty advisor: Dr. Douglas Hamilton
Effects of an Invasive Plant Species on Pine Lake, Delaware County, NY. ANTHONY F. PRISCIANDARO, Department of Biology, Hartwick College, Oneonta, NY 13820.
Since the introduction of Eurasian watermilfoil (Myriophyllum spicatum ) in the mid 1980s Pine Lake (Delaware County, NY) has seen an increase in vegetative cover but a decrease in plant diversity. Milfoil is known to affect aquatic plant communities by out-competing native species, but it should also have effects on fish by altering food and habitat types. To examine the impact of the invasion I compared the current plant and fish communities to earlier surveys of the lake. I sampled the plant community using 1m x 25m belt transects. Fish population and community structure was measured from a single electroshocking sample and repeated trap netting. Milfoil has increased from being absent in 1976 to being present in every transect in 2003, and overall plant diversity in the lake has decreased. The overall diversity of the fish community has decreased since 1985. Bluegills have increased from only 33% of the community in 1985 to over 57% in 2003. Chain pickerel and largemouth bass have also increased in abundance perhaps because of the increase in food, juvenile bluegills. All other fish species found in 1985 have decreased in abundance. Faculty Supervisor: Dr. Mark L. Kuhlmann
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Testing the FCC Microwave Emission Limit for Cell Phones Utilizing Rejuvenation in Planaria. RYAN REGRUTTO, Department of Biology, Hartwick College, Oneonta, NY 13820.
Cell phones are in common use; however, the potential risks that accompany the microwave radiation they emit have received little study. In the current study, the effects of microwave radiation were examined in a model system that utilized the rapidly dividing cells of rejuvenating planaria. Microwave radiation was provided by a microwave oven that emitted the equivalent energy output of a heavily used cell phone at the FCC legal limit; rapidly dividing cells were produced in planaria by cutting the organisms in half transversely. Planaria were exposed to microwave radiation at times varying from 0 to 14 days before and after cutting. Following treatment, planaria were weighed and later examined by clearing, then staining with Erhlich’s hematoxylin to view internal structures. Data indicate a weight loss in planaria with seven days microwave exposure; no effects were seen with the other treatments. Clearing and staining techniques were unable to demonstrate treatment-related changes in internal organs. Thesis Advisor: Dr. Allen Crooker
Evaluation of Agrobacterium Mediated Transformation by Floral-Dip Method of Arabidopsis thaliana and Brassica rapa.. LAUREN SCOTT, Department of Biology, Hartwick College, Oneonta, New York.
Agrobacterium mediated transformation of plants has long required tissue culture and experienced practitioners in order to obtain transformants. In recent years, the use of the floral dip method of Agrobacterium mediated transformation of Arabidopsis thaliana , Brassica campestris subsp. Chinensis and Medicago truncatula has resulted in successful transformants without tissue culture (Bent and Clough, 1998, Bent et al., 2000). In the current study, the floral dip method was evaluated for Arabidopsis thaliana and Brassica rapa (Wisconsin fast plant). While Arabidopsis and Brassica rapa are both readily available research plants, Brassica rapa has larger flowers than Arabidopsis and transformation would be beneficial to individuals studying plant development. Both were grown to flowering stage where bolts are 2-10 cm tall then dipped in a simplified inoculation medium (5% sucrose, 0.05 % Silwet L-77, and Agrobacterium tumefaciens containing the binary vector pCAMBIA1305) as outlined by Bent and Clough (1998). The plants were allowed to continue to grow until seeds were ready to be harvested. The seeds were then germinated on selection medium containing hygromycin to identify successful transformants. Several putative Arabidopsis thaliana transformants were produced. Faculty advisor: Dr. Douglas Hamilton
The Effectiveness of Oral Rinses on the Viability of Streptococcus mutans Grown as a Bbiofilm. NATASHA TEIXEIRA, Department of Biology, Hartwick College, Oneonta, NY 13820.
Microbial biofilms were utilized as a model system in which to evaluate the effectiveness of oral rinses on bacterial viability. Biofilms of Streptococcus mutans were established in slide chambers by seeding the chamber with saliva and a mucin solution. Mature biofilms became established after 48 hours and were then treated with 3, 30 and 60 second rinses of water (control), a common oral rinse (Listerine) and an oral rinse used by dental professionals (CloSys II). Microbial viability was evaluated by fluorescent light microscopy using the Live/Dead Baclight Bacterial Viability Kit (Molecular Probes, Eugene, Oregon). After eight trials, data indicated that the effect of Listerine on bacterial viability was similar to that of water and that CloSys II was significantly more effective at killing Streptococcus mutans than was Listerine. Thesis Advisor: Dr. Allen Crooker
The Effects of the Chemical Pollutant, Atrazine, on the Immune Systems of the Amphibian, Rana pipiens. TARA WILKES, Department of Biology, Hartwick College, Oneonta, NY 13820.
Deformities in frogs have become a major environmental issue in recent years. One of the most important questions surrounding the issue is why has there been an increase in deformities of natural population of frogs now? Many culprits have been suggested, including global climate change, habitat destruction, acid precipitation, toxins, predation from introduced species, and diseases, among others. The pesticide atrazine is a suspected endocrine disruptor. Previous research involving atrazine shows significant sexual abnormalities at just 0.1 parts per billion (ppb), which is 30 times lower than levels allowed by the Environmental Protection Agency (EPA) for drinking water and 120 times lower than the 12 ppb EPA guideline for the protection of aquatic life. Here I examine the effects of different concentrations of atrazine on the immune systems of frogs. Specifically, I wanted to test whether atrazine can cause acquired immune deficiency in frogs, making them more susceptible to parasites and other diseases. My results indicate that atrazine does in fact have a negative impact on the immune system of Rana pipiens . Thesis Supervisor: Dr. Stan Sessions
The Effect of Chronic and Acute Alcohol Administration on the Developing Fetal Mouse. KERRY WRIGHT, Department of Biology, Hartwick College, Oneonta, NY 13820.
The effects of alcohol on human and animal tissues are widely documented. The current study was conducted to evaluate how the mode of administration, dosage and duration of alcohol exposure affected alcohol-induced damage in the fetal mouse. Ten time-mated pregnant mice were exposed chronically to 5% ethanol for the duration of gestation beginning on day 6 of pregnancy. Five time-mated mice were intubated on day 7 of gestation with the equivalent of 5g/kg of ethanol for acute exposure. All mice were sacrificed on gestational day 18 (equivalent to the third trimester in humans), and four offspring from each litter were measured, weighed, fixed, dehydrated, and embedded. Fetal mice exposed to ethanol were smaller and weighed less than controls. Mice exposed chronically were on average 13% smaller and weighed 29% less than control mice; mice given acute exposure were 24% shorter and weighed 31% less than controls. The chronically exposed fetal mice demonstrated the most alcohol-induced liver damage. Damage included inflammation and fatty liver cells. There was no significant change in brain tissue in either treatment. Faculty supervisor: Dr. Allen Crooker.