Journal of Biological Research, Vol. 8 (2007)
The Cellular Basis of Growth Rates and Size Differences in Dogs. JAIMI M. BAIN, Department of Biology, Hartwick College, Oneonta, NY 13820. Domesticated dogs (Canis familiaris) exhibit the largest differences in body size of any species on Earth. This large range of body sizes, from Chihuahuas to Great Danes, suggests large differences in growth rates. The cellular basis of these differences is not understood. In this project, I used lymphocytes in vitro to compare cellular growth rates of several dog breeds, representing both very large and very small body sizes. The cells were cultured from heparinized, whole peripheral blood that was treated with a mitogen. For ease of visual counting, dividing lymphocytes were arrested at pre-metaphase using colchicine, and counts of arrested cells were performed on microscope slide preparations using computer-assisted image-analysis. In support of my hypothesis, large-breed dogs were found to have a greater percentage of dividing cells than small-breed dogs. Faculty supervisor: Dr. Stanley K. Sessions.
The effects of cooking and freezing on the antibacterial properties of spices. KYLE FOULGER, Department of Biology, Hartwick College, Oneonta, NY 13820. Using spices to flavor foods is a common practice in food preparation. For this behavior to be considered an evolved human trait, spices must: (1) show antimicrobial properties that enhance human health, (2) be used more frequently in warmer climates, (3) be used in high enough quantity to inhibit microbial growth, and (4) not be less effective after cooking. n this paper, I used a simple disc-diffusion assay to examine determine if cooking and freezing spices, both common practices, diminishes the antimicrobial properties of spices. Because certain strains of Escherichia coli are known to cause food-borne illness, I investigated the antimicrobial properties of dried garlic powder, chili powder, and parsley on this bacterium. Parsley showed no antibacterial properties before or after cooking, so it was excluded from the freezing experiment. Chili powder showed no change in its antibacterial effectiveness after cooking or freezing. Garlic powder actually showed diminished antibacterial properties after being cooked but not after being frozen. This final result from chili powder suggest that spice use is an evolved trait while the results from the garlic powder were inconsistent with this finding. Future research could look into the effects of cooking on the antimicrobial properties of more spices or the effects of fresh vs. dried spices. Faculty advisors: Dr. Peter Fauth and Dr. Mary Allen
The Beneficial Effects of Sucrose-Free Chewing Gum on Salivary pH. BRENDON L. HARRISON, Department of Biology, Hartwick College, Oneonta, NY 13820. Dental caries (cavities) result from bacteria that produce lactic acid as an end product of sugar fermentation. The lactic acid lowers the pH of saliva in the oral cavity and breaks down the protective enamel of the tooth, which eventually leads to dental caries. The physical action of chewing gum is thought to be beneficial in that it stimulates the secretion of saliva, effectively diluting acidic end products of bacterial fermentation and raising the pH of the saliva. This study investigated the effect of gum chewing on salivary pH following consumption of foods and drinks containing variable amounts of sugar. The foods were M&M's, raisins, and an apple and the drinks were Coca-Cola and Gatorade. Ten individuals from Hartwick College measured their salivary pH after eating or drinking a single beverage or food each week for 10 weeks. Each time pH was measured every 5 minutes for 30 minutes. Individuals were assigned both a gum and no gum treatment for each food or drink. The results show that after drinking Coca-Cola or Gatorade, chewing gum returns salivary pH to a significantly higher level than not chewing gum (p < .05). After eating M&Ms, raisins, and apples, chewing gum also returns salivary pH to a significantly higher level than not chewing gum (p<.05). Comparing salivary pH responses between genders showed no pattern. These results demonstrate that chewing gum maintains a neutral salivary pH and thus decreases the risk of enamel breakdown and dental caries from acidic saliva conditions. Faculty supervisor: Dr. Mary Allen
Does Curcumin Feeding Alter the Vascular Physiology of Rats with Diet Induced Insulin Resistance? LAKEISHA JACKSON. Biology Hartwick College Oneonta NY 13820. The polyphenol, curcumin, is found in the Indian spice turmeric and is known for antioxidant and anti-inflammatory properties. Curcumin has been shown to decrease insulin resistance. Because insulin resistance increases the risk of atherosclerosis, we asked if curcumin could alter the effects of insulin resistance on blood vessels. We fed twenty four rats a high fat/low protein diet (32.5 % protein, 46.4% fat and 13.3 of carbohydrates) for five weeks. Twelve rats we also fed curcumin (0.75 g/25g) for the last two weeks of the protocol. Animals were anesthetized to a surgical level using pentobarbital sodium (80 mg /kg) with heparin (1.6u/gm) added as an anticoagulant, and sacrificed. The aortas were extracted, maintained at 37 degrees C in modified Krebs Henseleit buffer bubbled with 95% oxygen and 5% CO2, and mounted on a vascular myograph. Vessels were stretched to a preload of 2 grams and exposed to chemical or mechanical stimuli. We measured the contraction response to Phenylephrine (PE) ( 10-9 to 10 -4 M) and Potassium Chloride (KCL) (10 to 80 mM), a relaxation response curve to Acetylcholine (ACH) ( 10-9 to 10 -4 M), and the passive force developed in the response to 2.25mm of stretch. Our study confirmed that a high fat/ high sugar /low protein diet induces insulin resistance and this may be reversed by curcumin. There were no differences between control and curcumin treated rats in dose response to PE and the passive elasticity test. KCL and ACH is still under analysis. However the curcumin demonstrated significantly lower maximum contractile response to PE. I conclude that arteries for curcumin treated rats are no less sensitive to PE and no more elastic but they do have less contractile ability. Therefore the curcumin treated rats would be less likely to develop high blood pressure or atherosclerosis. Faculty Advisor Dr. Laura Malloy
The Effects of Atrazine on Tail Regeneration in Salamanders. CARLENA JOHNSON, Department of Biology, Hartwick College, Oneonta, NY 13820. Atrazine, a widely used herbicide, is thought to be contributing to amphibian declines. Atrazine has been shown to have negative effects on amphibians, including sex differentiation, the immune system, and overall growth and development. In order to test the idea that atrazine is acting on mitotic cell division, I studied the effects of atrazine on dividing cells in regenerating salamander tails using three concentrations of atrazine: 1 ppb, 10 ppb, and 100 ppb, and standard histological techniques. It was found that there was a significant difference between the percentages of dividing cells in the experimental salamanders. Specifically, the tissues appear to show a dose-dependent effect in which an increase in cellular growth was seen only at the lowest concentration. This result is consistent with atrazine acting as an endocrine disruptor. Dead cells were also observed in most of the regenerating tails but not quantified in this study. Further research should be conducted into the effects of atrazine on both cellular growth and cell death during amphibian growth and development, including the immune system and sex differentiation. Faculty supervisor: Dr. Stan Sessions
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The Biomechanics of the Discus Throw: the Application and Importance of Stretching. JENNIFER MCDONNELL, Department of Biology, Hartwick College, Oneonta, NY. Throwing is a category of field events in the sport of Track & Field / Athletics, and is found in historical record as early as 776 BCE. However there is very little research on how stretching might improve throwing performance. Existing research is not based on biomechanical analysis although popular books contain descriptions of stretches that could be effective for some sports. Of the four throws in the field events (shot put, discus, hammer and javelin) the discus throw appears have the simplest mechanics. A scrupulous biomechanical analysis of the discus throw could lead to a stretching regimen that will promote the best storage of elastic energy and the greatest ability to increase to maximum release velocity. I have used books, scholarly periodicals and credible websites to break down the discus throw into five mechanical phases: 0-start, 1-kick start, 2-kick through, 3-drop, 4-block, and 5- release. Using these five phases I determined the major muscle/tendon groups involved in each phase and how to apply stretch to these groups for the purposes of a) elongating muscle fibers to their optimum length for force development, b) stressing connective tissues to where they reach a length for optimum elastic recoil, and c) developing elastic tissues for greatest resiliency. This led me to identify specific stretches relevant to the mechanical demand of each phase of the throw. Faculty advisor: Dr. Laura Malloy
The Effect of Calcium Deficiency and Water Sanitation on Growth Stunting on Malnourished Children Ages 0-5 in the Hill Tribes of Northern Thailand. CHRISTOPHER SAJ, Department of Biology, Hartwick College, Oneonta, NY 13820. The hill tribes of Northern Thailand are shifting from a swidden agriculture lifestyle to a subsistence economy and stable village locations. This change has been detrimental to the health of the villagers, especially the children. The prevalence of growth stunting in 2002 was quite high among the hill tribes for children age 0-5. Growth stunting has been found to be a good indicator of malnutrition (Swift, 2002). Malnutrition is the inadequate intake of micronutrients and frequent disease (WHO, 2003). This study focuses on calcium and its relationship to growth stunting in children age 0-5 in villages of differing economic status and food security. Blood calcium levels were used to compare the Hartwick nutrition program with the government nutrition program. Height/age Z-scores were calculated and -2 standard deviations as a cut off for growth stunting. The Z-scores were then compared to the serum calcium levels (mg/dL). No significant correlation was found between the height/age z-scores and serum calcium levels, demonstrating that malnutrition and growth stunting is a complex syndrome of various factors. However, all children in the Hartwick nutrition program and government program had low serum calcium levels, therefore while it is not a major factor in growth stunting it still is a contributor. Suggestions were made to add pulverized egg shells to the diet and add more green leafy vegetables to increase the calcium intake. Faulty Supervisor: Dr. Linda Swift
Serum Albumin Level Correlation with Growth-Stunted Children in the Hill Tribe Villages of Northern Thailand. KRISTA WADSWORTH, Department of Biology, Hartwick College Oneonta, NY 13820. Hill Tribes in Northern Thailand have had to change from a slash and burn, migratory economy to a stabilized village, subsistence economy the past few decades. Presently the villagers have little land with poor soil to support their family. Children ages 0-5 are the most affected by the lack of quality food, as they are growing and developing rapidly. These children are malnourished and are consequently growth stunted. To determine the severity of the growth stunting, a Z-score was computed and compared to an international growth curve. Serum albumin levels were tested using a Bioassay Albumin Assay Kit to determine the protein levels. A Pearson correlation coefficient, was calculated to determine if there was a significant correlation between Z-scores and serum albumin levels. The results showed no significant correlation (P > 0.05) between growth stunting scores and serum albumin levels. This indicates that malnutrition causing growth stunting is a complex problem caused by inadequate consumption of macro and micronutrients. Serum albumin levels in the children in the Hartwick Nutrition Program and children in a government lunch program were compared. T-tests showed that there was no significant difference (P >0.05) in serum albumin levels between the two nutrition plans. Therefore, the consumption of soybeans and peanuts for protein are as effective in maintaining serum albumin levels as meat in the diet. With this information, the cost effective Hartwick Nutrition Program can be expanded and promoted in other villages. Advisor: Linda Swift
Effects of Extended Hypergravity on the Development of Embryonic Quail Eggs. SARA B. CALDWELL, Department of Biology, Hartwick College, Oneonta, NY 13820. Prior studies of life in the universe have suggested that high-protein foodstuffs can be derived from living organisms, such as fowl, that stay aboard spacecraft. These studies often use gravity as a topic of experimentation, however these studies are few and have dealt primarily with adults or organisms that have been conceived and born in terrestrial gravity. This study was undertaken to determine general morphological and cellular changes that occur in the Japanese Courtnix quail (Coturnix coturnix japonica) when exposed to a 3 G (hypergravity) environment during embryonic development. An incubation chamber at 37ºC contained two groups with each group comprised of a centrifuge, which spun four experimental eggs, and a plastic carton, which held four control eggs. The trial ran for ten days (d4 - d14), with all eggs manually turned three times daily. Ten additional eggs were placed in the incubator as additional controls. Only two experimental and seven control embryos grew sufficiently, with both experimental embryos exhibiting morphological abnormalities. Experimental vertebrae were significantly shorter than that of the control (P= 0.015; One-Way ANOVA) and the intestines were located outside of both bodies. Unidentified white masses along the flanks of both experimental embryos were also noted. No cellular changes were seen. The mass of the organism, head diameter, heart mass, and eye mass were not significantly different between the experimental and control groups. Faculty supervisor: Dr. Allen Crooker
Newborn Mouse Neuronal Activity, Muscle Strength, and Endurance in Response to Prenatal Psychotropic (Sertraline) Medication Exposure. ALISON GARCIA, Department of Biology, Hartwick College, Oneonta, NY 13820. Selective serotonin reuptake inhibitors (SSRIs) act by inhibiting serotonin reuptake at the presynaptic junction, leading to increased concentrations and serotonergic neurotransmissions thereby improving symptoms of depression. In this study we assess the SSRI sertraline HCl (Zoloft) for the purpose of determining whether or not prenatal exposure to the inhibitor negatively affects a newborn's endurance, muscle strength, or mental capabilities. Four of the eight mice used in this experiment were exposed to 0.05mg/kg of sertraline daily during their gestational period. Weight was assessed throughout the study and experimental mice were intubated with a solution of the drug dose until the end of the gestational period. Endurance, muscle strength, and object recognition tasks were performed by newborns to assess developmental levels between groups. A steady increase in time was seen for both groups throughout the nine days reflecting a significant effect of time in the muscle strength test. No significant differences were found between experimental and control mice in the endurance or object recognition tasks. Faculty Supervisor: Dr. Allen Crooker.
The Cardioprotective Effects of Curcuminoids on Ischemic Isolated Perfused Hearts from Insulin Resistant Rats. CHRISTOPHER HOLL, Department of Biology, Hartwick College, Oneonta, NY 13820. An increased risk of a myocardial infarction has been associated with insulin resistance and curcuminoids (polyphenols found in the Indian spice turmeric) have been shown to attenuate insulin resistance. Thus, it is possible that curcuminoids have cardioprotective effects in insulin resistant rats. In this study, I will test this hypothesis in ischemic isolated perfused hearts from insulin resistant rats. A high fat, high sugar, low protein diet was used (32.5% fat, 46.4% carbohydrates, 13.3% protein/100 grams feed) to induce insulin resistance. Twenty-four rats were fed the high fat diet for five weeks, and twelve of these received a curcuminoid supplement (3 grams curcuminoids/100 grams feed) to the high fat diet for the final two weeks. A glucose tolerance test was administered on three occasions: before the high fat diet, after three weeks of high fat diet, and after two weeks of eating the high fat diet alone or with the curcuminoids. Rats were then anesthetized to a surgical level with 80 mg/kg pentobarbital sodium and heparin was administered (1.6 units/gram) as an anticoagulant. Hearts were extracted and placed on the Langendorff apparatus perfused at 37°C with Krebs-Henseleit buffer bubbled with 95% O2/5% CO2. A balloon was inserted into the left ventricle and coronary flow, heart rate, and left ventricular developed pressure (LVDP) were recorded before and after thirteen minutes of globally induced ischemia. Glucose tolerance tests confirmed that a high fat, high sugar diet increases insulin resistance and that curcuminoids attenuate the level of insulin resistance in most rats. Curcuminoid-treated rats demonstrated higher coronary flow and lower heart rate. Both groups performed similarly when comparing the left ventricular developed pressure. I conclude that although curcuminoids decrease cardiac contraction and increase coronary flow, they do not appear to increase cardiac performance. Faculty Supervisor: Dr. Laura Malloy
The History and Physiological Effects of Anabolic Steroid Use in Athletes. MIKE JECKO, Department of Biology, Hartwick College, Oneonta, NY 13820. The first anabolic steroid to be synthetically produced was testosterone in the 1930s. Anabolic steroids eventually made their way into athletics in the 1950s, and became prevalent in the 1970s and 1980s. Many athletes began taking anabolic steroids to gain a competitive edge; however, the negative effects associated with the use of anabolic steroids tend to outweigh the benefits of using these substances. Positive effects include an increase in muscle mass, a decrease in fat mass, increased strength, decreased recovery time, and increased athletic performance. The negative effects can include negative shifts in cholesterol levels, damage to liver and kidney tissues, and thickening of the left ventricle, which can lead to heart failure. The increased use of anabolic steroids by competitors has lead professional, as well as amateur organizations, to tighten their substance abuse policies and establish more severe punishments for athletes who test positive for anabolic steroids. Faculty supervisor: Dr. Allen Crooker.
Implications of Administration of Ginkgo biloba: Is Its Questionable Efficacy Resolved by Published Results? KRYSTLE GRANT, Department of Biology, Hartwick College, Oneonta, NY 13820. Ginkgo biloba has often been touted as a naturalistic cure for several ailments, including memory loss. An analysis of published experimental data on G. biloba would help in determining its overall efficacy in memory enhancement. To analyze overall efficacy and to understand the biological mechanism, experimental data analyzed includes experiments on the genetic, cellular, and organism level. Chicks, rats, transgenic rats, and humans were all used within the organism level experimental data analysis with relation to determining efficacy on different levels of cognitive learning behavior observed. From the experiments related to memory enhancement, G. biloba has also been related to delay of the onset of type II diabetes and a decrease in the build up of plaque, which prevents cardiovascular disease. Before G. biloba or EGb 761 can become a widely used medicine to prevent dementia, type II diabetes, or cardiovascular disease, more experiments must be completed to determine effectiveness over long term use and any side effects that may occur.
Ecological Correlates of Genome Size in Plants. ANNE E. ROBERTS, Department of Biology, Hartwick College, Oneonta, NY 13820. A wide range in genome size (the nuclear amount of DNA) is found within and between families of plants. Large genome sizes appear to impose physiological constraints on plants which could potentially limit their evolution, distribution, life-cycle, and geographic range. However, little is known about how genome size affects the composition of a single plant community. I compared the genome sizes of over forty species of vascular plants with population metrics from a long term (48 year) study of old field succession. The results of this study suggest that genome size may play a role in the succession of a single biotic community. Faculty advisor: Dr. Stanley K. Sessions.
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Point-Count Survey of the Birds of Pine Lake. REBECCA SCHWARTZ, Department of Biology, Hartwick College, Oneonta, NY. Over the past several years, many ornithologists have suggested a decline in songbird populations. I tested to determine the species present in the Upper Tract of Pine Lake and if the Upper Tract demonstrated the same decline as other bird populations. JR Miller observed bird densities in the Upper Tract from 1972 to 1976 using spot-mapping in two locations: the Upper Dry Chestnut Oak Forest and Mud Lake. I used those two locations and six more locations in different forest types. I tested in three seasons, Winter, Fall, and Breeding, conducting ten-minute, unlimited radius point-counts. The program SURVIV was used to calculate detectability and density of the birds observed. The trends in my densities when compared to JR Miller's densities were compared to the trends of the USGS's Breeding Bird Survey to determine if there was an actual discrepancy in density between the 1970's and 2006-2007. These species did not follow the Breeding Bird Survey trends exactly, showing that the bird population has changed since the 1970's, albeit slightly. Thesis Supervisor: Dr. Peter Fauth