Journal of Biological Research, Vol. 7 (2006)
An Analysis of Cellular Growth in Developing Limbs. ERIC H. DIEFENBACHER, Department of Biology, Hartwick College, Oneonta, NY 13820. This study focused on the relationship between pattern formation and the topology of localized cellular growth in the developing limbs of the yellow spotted salamander, Ambystoma maculatum, using histology and anti-BrdU immuno-cytochemistry. Results show statistically significant differences in the number of dividing cells between the regions of the developing limb that correspond to the major limb axes. These "hot spots" of cellular growth varied also with developmental stage of the limb, corresponding with "hot spots" of pattern formation and morphogenesis in these limbs. These results indicate that cellular growth is a fundamental mechanism of pattern formation in developing limbs. Faculty supervisor: Dr. Stanley K. Sessions
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Field Assessment and the Relationship Between Micronutrients and Growth Stunting in Malnourished Children Ages 0-5 in the Hill Tribe Villages of Northern Thailand. JAYNE DONOVAN, Department of Biology, Hartwick College, Oneonta, NY 13820. The hill tribes of northern Thailand are transitioning from a shifting agriculture economy to a subsistence economy with a stabilized village location. This change has adversely affected household food security and the nutritional status of children ages 0-5. The prevalence of growth stunting, a physical indicator of malnutrition, was extremely high in 2002, with 55% of the hill tribe children growth stunted (Swift, 2002). Micronutrient and protein deficiencies and increased infection are suggested to be major causes of malnutrition. This study focused on evaluating the micronutrient (iron and iodine) status in children ages 0-5 in three hill tribe villages of varying economic status and food security, determining the relationship between the iron deficiency and growth stunting, and the implementation of practical solutions. Predictions included the existence of these micronutrient deficiencies and a positive correlation between growth stunting and iron deficiency. Growth stunting, quantified as Z-scores, was compared to hemoglobin levels using correlation coefficient and consumptive iodine levels were determined. No significant correlation was found between iron deficiency and growth stunting however, all three villages was demonstrated iron deficiency and insufficient iodine consumption, suggesting that the cause of growth stunting is complex and extends beyond micronutrient deficiencies. Iron cooking pots and air-tight salt containers were recommended as solutions. Faculty supervisor: Dr. Linda Swift
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Effect of Androstenetrione, Nitrix, and Creatine Supplementation on Muscle Size, Muscle Mass, Time to Fatigue, and Recovery Time in Exercised Male Mice. CHRISTOPHER EHLINGER, Department of Biology, Hartwick College, Oneonta NY, 13820. The commercial dietary supplements androstenetrione, creatine, and nitrix are three performance-enhancing substances taken by athletes to increase muscle endurance, mass, and strength, and to decrease muscle recovery time. In this study, male mice were used to measure the effects that these muscle-enhancing supplements have on the time to fatigue with endurance exercise, recovery time, muscle mass, and muscle size. The study was conducted using five groups of four mice each: a control with exercise, a control without exercise, mice intubated with androstenedione and exercised, mice intubated with nitrix and exercised, and mice intubated with creatine and exercised. This study was conducted over six weeks, with the mice being exercised on the roto rod for five days straight then given two days off. An Anova statistical analysis test showed that the percent increase in average run times for mice using creatine was significantly different from the control with exercise (P<.05). The muscle circumferences for the mice using nitrix, androstenetrione, and creatine were significantly different from the control with exercise and the control without exercise (P<.05). The average percent recovery times of the mice over the six weeks for both the nitrix and androstenetrione groups were significantly different from the control with exercise. These results showed that each supplement had an effect on muscle during endurance exercise. Facility Advisor: Dr. Allen Crooker
Population Ecology of the Caribbean Spiny Lobster (Panulirus argus) on San Salvador Island, Bahamas. SARA GOTO, Department of Biology, Hartwick College, Oneonta, NY 13820. Population bottlenecks occur at particular life stages of a species' life cycle, especially those species that use distinct habitats for each life stage. The availability of habitat at any one life stage may limit population size in subsequent life stages. Previous observations at San Salvador Island, Bahamas, suggest that the adult Caribbean spiny lobster population is small in size, but not shelter limited. To test for shelter limitation in the juvenile life stage, we measured both juvenile population and possible shelters for those lobsters. Juvenile lobster density at San Salvador Island was 0.008/m2 and shelter density 2.61 structures/m2. Compared to published densities from other locations, juvenile lobster density on San Salvador was ~49% lower than the Keys and Belize yet shelter density was similar to densities in the Keys and higher than shelter density in Belize. This indicates that shelter is not limiting to the juvenile life stage and that a bottleneck likely occurs earlier in the life cycle, such as the larval or algal stages. More studies are necessary to determine where a bottleneck actually occurs in order to understand the population ecology of spiny lobsters in this area of the Bahamas. Faculty supervisor: Dr. Mark Kuhlmann
Targeting Native Amphibian Lymphocytes Using an Anti-CD8 Xenopus Antibody. PATRICK HANLEY, Department of Biology, Hartwick College, Oneonta, NY 13820.The association between amphibian decline and a compromised immune system has been proposed in literature, but due to the relative difficulty in obtaining antibodies against amphibian lymphocytes for native species, the kinds of feasible immunological assays have been limited. Antibodies are available against cell surface receptors of lymphocytes of the African Clawed Frog, Xenopus laevis. Of particular interest are T-lymphocytes which are required for the production of mature anti-body secreting plasma cells (B-lymphocytes). The purpose of my study is to determine the cross-reactivity of a monoclonal antibody that recognizes the T-cell specific CD8 cell surface receptor in Xenopus. My goal is to use this antibody to quantify the immune response in native species of frogs. Faculty Supervisor: Dr. Stanley Sessions
Malaria Vaccines: The Current Situation and Prospects for the Future. MEGAN IRLAND, Department of Biology, Hartwick College, Oneonta, NY 13820. Malaria is a common, life-threatening disease caused by the protozoan parasite Plasmodium, and transmitted by species of Anopheles mosquitoes. Malaria infects an estimated 300-500 million people a year, and causes 1.5-3 million deaths annually (World Health Organization, 2002). Increasing parasite resistance to effective and affordable medications, as well as the instability of malaria endemic areas, make controlling malaria with a vaccine is the only lasting solution. However, no such vaccine currently exists. Here we review the possible subunit vaccines under development which target the pre-erythrocytic stage, the merozoite or asexual-blood stage, or the sexual stage (transmission blocking vaccines) of the parasite, and why none of these vaccines have been successful yet. Finally, we review alternative approaches which are most likely to lead to vaccine development in the future, such as combining antigens from different life stages, and creating vaccines which mimic response to the whole organism, instead of subunits. Faculty supervisor: Dr. Linda Swift.
Taking the Human Body to the Extreme. MOLLY KELTNER, Department of Biology, Hartwick College, Oneonta, NY 13820. Athletes and doctors alike have figured out ways to artificially induce production of red blood cells from bone marrow, so in respiratory diseases and athletics it can be used to enhance oxygen transport. However, appropriate use of these techniques can be turned into physiologically dangerous abuse in the absence of understanding the link between red blood cells and oxygen transport. There are a variety of mechanisms used by educators to teach human biology including respiratory physiology. Educational literature suggests that students' understanding is enhanced through a constructivist or "hands-on approach" to education. The purpose of this study is to evaluate the effectiveness of a hands-on approach to learning with respect to human respiratory physiology. To accomplish this I first completed a literature review to gain a master's level knowledge of respiratory physiology during exercise and its link to the circulatory system with respect to gas exchange. I then identified 6 critical concepts in respiration to teach in a secondary level biology class. From an overall curriculum outline, I designed, as a control, one lesson plan that uses a traditional lecture method with PowerPoint slides and a second lesson plan using a case study as the constructivist approach to learning. The case study has students looking at both the pros and cons to blood packing, blood doping, high altitude training, and pure oxygen supplementation as man takes on training for the Ironman. Students have to place a bet on the method they believe will most benefit the athlete by considering both ethical and physiological issues. These lessons were implemented in a college anatomy and physiology classroom and assessed using videotape of classroom participation, written concept tables, quizzes, and validation papers. Students' abilities to identify pertinent facts, organize information in a concept table, recognize and apply underlying physiological mechanisms, evaluate choice based on fact, and collaborate to build a consensus will all be part of the assessment rubric. I expect to find through my evaluation methods that those who engaged in the case study exercise were more fully engaged in the classroom experience, retains used information more effectively, drew more thoughtful and accurate conclusions, and enjoyed class more. Both qualitative and quantitative data will address the hypothesis that a hands-on approach to teaching will help students retain and use information about respiratory physiology more effectively. Faculty Supervisor: Dr. Laura G. Malloy
Effects of Protein C Deficiencies, Obesity and the Continued Use of Oral Contraceptives on Venous Thrombosis. HOLLY LAFOUNTAIN, Department of Biology, Hartwick College, Oneonta, NY 13820. Venous thrombosis is the formation of a clot or thrombus inside a blood vessel, obstructing the flow of blood. Protein C deficiencies, obesity, and the use of oral contraceptives have, in one way or another, been linked to venous thrombosis. The purposes of this review paper are to obtain a better understanding of venous thrombosis and some of its causes along with understanding the relationship of oral contraceptives, protein C deficiency and obesity to venous thrombosis. This paper demonstrates that protein C deficiencies and the use of oral contraceptives are directly linked to venous thrombosis while obesity has not been found to be a direct cause of venous thrombosis. However, obesity may increase a person's probability of developing venous thrombosis, though this has not yet been supported by research. Faculty supervisor: Dr. Allen Crooker.
Analysis of Bone Catch-up Growth in Relation to Protein Consumption in Mice (Mus musculus) HEIDI MARIANI, Department of Biology, Hartwick College, Oneonta, NY 13820. Protein restricted diets have shown to cause long bone growth stunting. Reintroduced protein consumption can cause catch-up growth. For this experiment seven timed pregnant mice were used. The first litter was euthanized on day zero of experiment, and the next group after weaning at 15 days of age, and the third litter after a weaning and a 5 day protein restricted diet. The next three litters were euthanized every 7 days, all consuming a normal diet of protein after a five day protein restriction. The femur lengths were measured using a stain method and measuring by image analysis (Photo Shop) for the first litter and using a caliper for the rest of the older groups. The control groups were compared to a non-restricted diet growth curve found by (Didas, 2004). Data for the control and experimental groups was plotted using the average femur length.The results indicated that femur growth was stunted during the 5 day protein restriction, but caught up to the control group by day 41. Growth increased once protein was available by allowing cellular activity in the growth plate regions to increase, allowing accelerated growth, which allowed the stunted groups catch-up to normal growth rates. Faculty supervisor: Dr. Linda Swift
Determination of the Nutrient Intake and the Relationship Between Nutrients and Growth Stunting in Children 0-5 Years of Age in Thapo Village, Northern Thailand. ANN MICKA, Department of Biology, Hartwick College, Oneonta, NY 13820. Previous studies conducted in the village of Thapo suggested that a major factor in growth stunting, which affected over half of their children under five years of age, was due to low protein intake by the children. In order to gain a more accurate representation the children's actual nutrient consumption, the diets of five children were observed for seven full days in January, 2005. Anthropometric data was collected for each child in order to calculate height for weight Z-scores, and the weighed record method was used for assessing each child's dietary intake. The relationship between a child's average daily nutrient consumption and their z-score for height-for-age was determined using a correlation coefficient. No strong relationship existed between growth stunting and any macronutrients, but growth stunting was the most correlated with the micronutrient calcium (Pearson correlation=.453). A comparison of the average actual intake versus the recommended daily intake of calcium for each child indicated that none of the sampled children were consuming adequate amounts of calcium. The development of culturally relevant nutrition education materials would benefit villages in Thailand to help explain and reinforce important nutrition information. Faculty supervisor: Dr. Linda Swift
Reduction in Phantom Limb Sensation: Treatment Options for Preventing Cortical Reorganization. KATHRYN NILSEN, Biology Department, Hartwick College, Oneonta, NY. Phantom limb sensation is a feeling of pressure, tingling, warmth, coldness, or pain in a body part that has been amputated. This phenomenon plagues the vast majority of amputees and is a reason for major concern. It is caused by cortical reorganization in the brain as a result of the brain's natural plasticity. When one area of the brain is no longer receiving signals from its neural pathways, neurons from surrounding areas expand their receptive fields into that area. This creates a way for damaged areas of the brain to receive signals even when their neural pathways have been severed. Currently, there are several treatment options for phantom limb sensation, such as drugs administered prior to surgery and specialized prostheses, although some are not entirely effective. This review explores the evidence and causes of cortical reorganization after amputation as well as current treatments being used and/or tested and which show the most promise in relieving phantom limb sensations. Research has found that neither psychological treatments nor epidural analgesics administered before amputation are effective in reducing phantom pain; however, hormone inhibiting drugs and the use of a myoelectric prosthesis show promise. Faculty Supervisor: Dr. Allen Crooker
Fluctuating Asymmetry: A Case Study of Three Thailand Villages' Children. JENNIFER PALAZZARI, Department of Biology, Hartwick College, Oneonta, NY 13820. When random stress-induced deviations from perfect symmetry occur from a developing organism is under stress, it is called fluctuating asymmetry. In Thailand these events of fluctuating asymmetry are prevalent. It is thought that this is due to the lack of protein within the diet of prenatal nutrient. While much work has been done on fluctuating asymmetry, not many have looked at fluctuating asymmetry overtime. Over a two year period (2004-2006) anthropometric measures of a group of children was taken, in three separate Thailand villages, to measure fluctuating asymmetry. A change in fluctuating asymmetry values was observed over time in the children. Faculty supervisor: Dr. Linda Swift
Effects of Dogwood Anthracnose (Discula destructiva) on Fitness in an Isolated Population of Flowering Dogwood (Cornus florida). JENNIFER RYAN, Department of Biology, Hartwick College, Oneonta, NY, 13820. The flowering dogwood (Cornus florida) population at Hartwick College is small and isolated, which can make it vulnerable to extinction for many reasons including the exposure to introduced diseases. One such disease is dogwood anthracnose, caused by the fungus (Disculadestructiva). D. destructiva is suspected to be present in the dogwood population on campus. I sampled leaves to score the severity of infection of D. destructiva on 40 dogwood trees growing on campus. I also collected fruit to evaluate the effects of the disease on measures of fitness. I found no significant relationship between my disease score and any measure of fitness (e.g., number of fruit produced, seed weight and germination time). Although a similar study conducted in Virginia found a negative association between levels of D. destructiva and fruit production in dogwoods, the trees on campus in 2005 were only mildly infected by the disease because of an unusually dry growing season that inhibited D. destructiva growth. In order to verify the results of this study, I suggest a further examination of the effects of D. destructiva on the flowers and fruits during more a typical rainfall year. Faculty supervisor: Dr. Peter Fauth.
The Effects of Prenatal Malnutrition on Fluctuating Asymmetry in Mus Musculus. JULIE L. SCARANO, Department of Biology, Hartwick College, Oneonta, NY 13820. Fluctuating asymmetry (FA) is defined as the random, stress-induced deviations from perfect bilateral symmetry that arise during the development of symmetrical traits. It is often seen as a result of stress experienced by individuals during development including infection with parasites or pathogens, nutritional or energetic stresses, prenatal stresses that affect the fetus's developmental stability, and inbreeding (Kowner, 2001). This experiment was designed in an attempt to correlate FA in the long bones of Mus musculus pups with lower than normal percentages of protein present in the diet of their mothers to identify protein deficiencies as a prominent cause of the chronic malnutrition in Thailand or a more minor cause indicating a need to focus on other possibilities. It was found that although the mean FAs in the width, length of epiphyseal plate and overall length of the femurs and humeri of the pups coming from a mother on a 12.5% protein diet were more than those coming from a mother on a 22% protein diet, a nested ANOVA indicated that these FAs were primarily significant in femur and humerus width possibly demonstrating the body's priority for maintaining symmetry in longitudinal skeletal growth. Faculty Supervisor: Dr. Linda A. Swift
The Effect of Hippocampal Lesion on Trace Conditioning; Role of Stimulus Modality. ELIZABETH SELL, Department of Biology, Hartwick College, Oneonta, NY 13820. Hippocampal damage is associated with impaired performance in spatial maze and context recognition tasks. Other studies utilizing hippocampal lesion techniques have found this structure to play a role in aversive trace conditioning tasks involving the nictitating membrane response in rabbits and rats. However, relatively little is known about the role of the hippocampus in appetitive trace conditioning. This experiment was a continuation of research using appetitive trace conditioning to explore the role of hippocampus in relation to learning. Hippocampally lesioned rats were found to be impaired in learning both appetitive trace conditioning and long delay tasks when the conditioned stimulus was a tone. When the conditioned stimulus was a light, however, hippocampally lesioned rats showed evidence of learning both tasks. These results suggest that hippocampal learning may be stimulus dependant. Thesis advisors: Dr. Laura Malloy and Dr. KinHo Chan
Limb Regeneration: To Suture or Not to Suture (that is the question). CHRISTOPHER SHEPHARD. Department of Biology, Hartwick College, Oneonta, NY 13820. A major goal of regenerative medicine is to understand why salamanders can completely regenerate their limbs, but humans cannot. One possible explanation for this difference is that salamanders have undifferentiated connective tissue stem cells ("masterblasts") that can be mobilized to replace missing body parts. If this hypothesis is true, then preventing the mobilization of masterblasts by suturing the wound should inhibit regeneration by physically restraining their travel to the wound site by covering the wound with flaps of mature dermis. To test this idea, I amputated the hind limbs of axolotls and compared regenerative ability in those that were sutured and those that were not. My results showed that sutured limbs either did not regenerate or the regeneration was retarded as compared to the limbs that were not sutured. The implications of these results are discussed especially in regard to regenerative medicine in humans. Thesis Adviser: S. K. Sessions
Bacteria Associated with Periodontal Disease are a Risk Factor for Systemic Diseases. STEPHANIE SONNER, Department of Biology, Hartwick College, Oneonta, NY 13820. Chronic periodontal disease is caused by a variety of microorganisms including: Porphyromonas gingivalis, Bacteroides forsythus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, and Treponemadenticola. Numerous studies have focused on a possible link between these periodontal bacteria and certain systemic diseases including cardiovascular disease, stroke, diabetes type 2, preterm and low weight births, and cancer. This paper reviews current research on this topic to determine whether a casual relationship exists between periodontal bacteria and the progression of non-oral disease. In this presentation I will discuss a possible link between periodontal disease and cardiovascular disease. Many studies focus on the coronary or brachial artery to determine if there is a risk of developing atherosclerosis. Important research findings include finding periodontal pathogens within arterial plaques, increase of carotid artery plaque with increased tooth loss, bacterial invasion of coronary endothelial and epithelial cells, reduced brachial artery flow in periodontal patients, and increase of intima-media wall thickness in individuals with periodontal disease. It remains questionable whether a definite cause-effect relationship exists. Future research should focus on controlling alternative risk factors (i.e. smoking), the presence of specific periodontal bacteria within the coronary and brachial arteries, identifying the exact pathogenic mechanisms of the bacteria, and establishing if periodontal treatment will decrease the progression and incidence of cardiovascular disease. Faculty supervisor: Dr. Mary Allen
The Role of Histamine H3 Receptors in Myocardial Function and Infarct Size Following Cardiac Ischemic Preconditioning. LINDSAY YORNS, Department of Biology, Hartwick College, Oneonta, NY 13820. During a period of low or no blood flow in the heart, mast cells release histamine which causes an inflammatory response in the myocardial tissue. Histamine H3 receptors are thought to aid in the protection of the heart following the reduced blood flow. However, little is known about the role these receptors might play following ischemic preconditioning. Because ischemic preconditioning, like H3 receptor stimulation, attenuates myocardial damage after ischemia reperfusion injury, we hypothesized that some of the protective effects of preconditioning may be mediated via H3 receptors. Thus, this experiment was performed to test the hypothesis that H3 receptor stimulation is one of the mechanisms responsible for the positive effects of ischemic preconditioning. A modified Langendorff apparatus was used to perfuse hearts in two experimental groups and one control group (n=5 rats) using Krebs Henseleit buffer. The experimental groups tested the effects of R-a-methyl histamine (RHA, 1µM), an H3 agonist, and Thioperamide (Thiop, 1µM), an H3 antagonist administered prior to ischemic preconditioning. The control group had no supplemental chemicals in the perfusate. Four indicators of cardiac function coronary flow, heart rate, force of cardiac contraction, and speed of contraction were measured in 1-5 minute intervals during preconditioning (3min), recovery (10 min), ischemia (7 min) and reperfusion (60 min). Mean treatment effects for each indicator were compared over the length of the experiment using one way ANOVA with repeated measures and LSD (least significant difference pair-wise multiple comparison) as post hoc test. We found significant differences (p=0.034) in force of contraction between Thioperamide treated hearts and controls. This is consistent with our hypothesis that H3 receptors may aid in the protective effects of preconditioning. However, results for the RHA treated rats were ambiguous and require further analysis and interpretation. Faculty Supervisor: Dr. Laura G. Malloy
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