Journal of Biological Research, Vol. 2 (2001)

Mud Lake Forest Community: Historical Patterns and Projections of Future Change
Aarianne L. Chandler
Faculty Supervisor: Dr. Mark Kuhlmann

Succession is the gradual changing of a community following a disturbance or the creation of a new substrate. It is a difficult process to study because a tree’s life spans decades or centuries and therefore change in a community occurs over an even larger period of time. Chronosequences are sites that contain a chronological sequence of communities demonstrative of the successional changes that would occur at a single site over a longer period of time. Such sites are valuable because they make it possible to study succession on a shorter time scale. It was hypothesized that the tree community surrounding Mud Lake, a sphagnum bog in central New York, would yield such a sequence because as the bog fills in it forms a new substrate. This new substrate is then colonized as the existing community surrounding it changes. Tree species, size, and location were recorded and selected cores were taken along 8 transects radiating out from the perimeter of the bog. The data enabled zones of vegetation to be determined and the relationship between variables to be described.

Population Ecology of the Mottled Sculpin (Cottus bairdi): Population Genetics and Distribution, with Comparison to Native and Introduced Crayfish
Peter Hazelton
Faculty Spervisor: Dr. Mark Kuhlmann

Cottus bairdi is a benthic fish native to the upper Susquehanna River Basin. Sculpins share habitat (rock shelters) with the native (Cambaris bartonii, Orconectes propinquus, and Orconectes obscurus) and introduced (Orconectes rusticus) crayfish of the region. O. rusticus was introduced from the Ohio River system and has become quite dominant in the upper Susquehanna R. During the summers of 1999 and 2000, the Susquehanna River and six of its uppermost tributaries were surveyed for these five species. Sculpin density is independent of crayfish densities. However, C. bairdi density was correlated with several abiotic factors (i.e. substrate). Cambaris bartonii also was associated with larger substrate, and was found primarily in the uppermost locations of each stream. O. obscurus and O. propinquus densities were negatively correlated to one another, and thus are not often found in the same location. O. rusticus was the most abundant species sampled throughout the system; its densities were correlated to substrate and current. O. rusticus density also showed a negative relationship to the density of O. propinquus, O. obscurus and C. bartonii, thus suggesting that the rusty crayfish is invasive in this drainage and could be considered a threat to the populations of native fauna. An attempt to assess the genetic distance and gene flow between populations of the mottled sculpin was also begun using Random Amplified Polymorphic DNA (RAPDs). The results from this study are as yet inconclusive.

The Lowering Effects of Chinese Green Tea on Serum Cholesterol in Mice Compared to Two Known Treatments
Jessica M. Joy
Faculty Supervisor: Dr. Linda Swift

The search is on to find treatments that will decrease the risk of developing hyperlipidaemia and arteriosclerosis by lowering serum cholesterol levels with minimal side effects or precautions. Chinese Green Tea may be just what the doctor ordered. In this experiment serum blood samples were taken from mice fed a high lipid diet with thiouracil, to inhibit the natural response to the high lipid diet. The serum cholesterol levels were measured with a standard kit and the atherogenic index was calculated. The one way analysis of variance calculations showed that the Green Tea lowered the total serum cholesterol significantly in comparison to a control and to a prescribed drug. Further studies along this line could greatly benefit individuals with high cholesterol.

The Effects of PM-10 and PM-2.5 on Alveolar Macrophage Number and Morphology in Vivo
Wendy L. Magnuson
Faculty Supervisor: Dr. Allen Crooker

The effects of PM-10 (particulate matter less than 10 um in diameter) and PM-2.5 (particulate matter less than 2.5 um in diameter) on phagocytic alveolar macrophage cell numbers and morphology were tested in vivo using mice. Four groups of two mice each were established and exposed to high PM dosages of 15 mg PM-10, 15 mg PM-2.5, 6.5 mg PM-2.5, and 0 mg PM (control) in a 1 m3 makeshift full-body inhalation exposure chamber. Mice were anesthetized following a 72 hr exposure and lungs were removed, embedded in paraffin, and stained with hematoxylin & eosin. Macrophages were counted in the alveoli and their morphology was observed. The percentage of alveoli containing macrophages and the total number of macrophages were higher in the control group than in all treated groups, though not significantly. All treated groups showed similar total macrophage numbers and similar percentages of alveoli containing macrophages. The ratio of deformed to normal macrophage cells was significantly higher in the 15 mg PM-2.5 group than in the control group.

The Research and Teaching of Polymorphisms in the Human Genome
Jonathan Palma
Faculty Supervisor: Dr. Hamiliton

DNA from various individuals is more alike than different, but many regions of human chromosomes exhibit a great deal of diversity. Such variable sequences are termed “polymorphic” (meaning many forms), and these sequences are located in the estimate 95% of the human genome that does not encode proteins. I investigated the VNTR (variance number of tandem repeats) pMCT118 locus on a population of students who have access to Miller Science Building (thus simulating the size of a biology class). I hypothesized that the region that the pMCT118 locus codes for contains a significant genetic variability, which can be utilized in biology experiments for teaching and laboratory purposes. I further hypothesized that the alleles of the tested individuals would correlate with their ancestral nationalities. My hypothesis that the pMCT118 locus contains a significant genetic variability was supported because all seventeen individuals tested yielded different allelic combinations at this locus. However, I was unable to see any correlation of a particular allele for any of the nationalities. This may be due to a small sample size, or my inability to link allele combinations to specific nationalities. The ability of this experiment to identify specific alleles for nationalities as well as an individual of a population could be improved by amplifying other VNTR regions in addition to the pMCT118 locus.   

An In Vivo and In Vitro Study of the Abortifacient and Labor Inducing Properties of Plumbago indica
Kathryn A. Rickershauser
Faculty Supervisor: Dr. Linda Swift

Plumbago indica is a plant in the family Plumbaginaceae which is used in traditional Akha medicine to cause an abortion or aid in delivery. The abortive and labor inducing properties of Plumbago indica were compared to those of oxytocin, a clinically used labor inducing drug. Four treatment groups of three timed pregnant mice received either a dose of 32mg/kg of P. indica orally, 64mg/kg of P. indica orally , 0.1IU of oxytocin IP, or the control of physiological saline IP. The mice were treated on days 15-17 of their pregnancy and monitored for signs of labor and abortion. The weights were monitored daily, the length of pregnancy was recorded, and the number and crown to rump length of the young were measured. One way ANOVA for four populations showed that there were no significant differences between the length of pregnancy, number of births per mouse, and the crown to rump lengths between the experimental and the control groups. However the low dose group did undergo one abortion, and two maternal deaths showing that perhaps the abortifacient property of P. indica comes from its ability to poison the fetus, and in some cases the mother as well, and not from affecting the contractions of the uterus as expected. The uterus of a female rat was also removed and the effect of P. indica on the force and rate of spontaneous contractions was measured in an organ bath. Linear regression analysis showed that 89% of the variance in the rate of the contractions was due to P. indica (as the dose increased the rate decreased). There was no correlation found between the drug and the force of the contractions.  

Relationship Between Localized Cellular Growth and Patterning in Salamander Limbs
[Full text - .pdf format]
Matthew Sander
Faculty Supervisor: Dr. Stan Sessions

Considerable research has been done examining the genetic basis of pattern formation in the tetrapod limb. Sonic Hedgehog has been shown to have expression restricted to the zone of polarizing activity in the limb bud. Fibroblast growth factors (FGFs) have been shown to be present in various regions of the limb bud mesenchyme and epidermis. Homeobox (Hox) genes have been shown to have inter-nesting expression patterns in the tip of the limb bud. Pattern formation in vertebrate limbs is epimorphic, and so dependent on cell division, and the effects of these patterning genes should be reflected in the pattern of the dividing cells. However, the actual patterns of dividing cells in developing or regenerating limbs have not been examined. Salamanders provide ideal material for such a study because of their large cell sizes and the fact that they regenerate their limbs. I used bromodeoxyuridine (BrdU) immunocytochemistry to analyze the patterns of dividing cells in the regenerating limbs of salamanders.   

Factors Affecting Dominance and Aggressive Interactions Among Castrated Male Domestic Horses (Equus caballus)
[Full text - .pdf format]
Janine Van Doren
Faculty Supervisor: Dr. Mark Kuhlmann

Dominance hierarchies and aggression in feral horse (Equus caballus) populations have been well studied. Though research has extended somewhat into the organization of domestic horse populations, no studies have been done on aggression and dominance in bands consisting almost entirely of castrated males. In this study, I investigated the effects of rank, height, weight, age, age at castration and group size on rates of aggression in a population of seventeen castrated male domestic horses organized into six groups. I found that weight was the most significant predictor of rank as well as rate of aggression, but that rank was not significantly correlated with rate of aggression. Height, age, age at castration and group size all had negligible effects on rank and rate of aggression.

The Effects of Garlic Supplementation on Spontaneously Hypertensive Rats
Lindsay Ward
Faculty Supervisor: Dr. Allen Crooker

Nitric Oxide (NO) is a potent vasodilator that imparts a continuous dilator tone in the maintenance of systemic blood pressure. Garlic has been found to activate nitric oxide synthase, which increases the levels of nitric oxide in the arterial cells. To assess the effect garlic has on already existing hypertension the effect of garlic supplementation on spontaneously hypertensive rats was studied. Ten spontaneously hypertensive rats were randomly assigned to two groups of five rats each. Their blood pressure was determined using the tail cuff method, and readings were taken every six days. After thirty days of garlic supplementation (100mg/ kg body weight) the differences in systolic blood pressure were analyzed. No statistical differences in their systolic blood pressure were found in the rats that were given the garlic supplementation. The NO2- and NO3- were measured in the urine samples as an index of NO production. The urine samples were incubated with E. coli nitrate reductase in phosphate ammonium buffer (pH 7.3) and the nitrate levels were measured using the Griess reagent. No reliable results were obtained from the urinalysis. Therefore further study is needed to determine if garlic activates NO in the blood leading to its antihypertensive properties.

Where Biology and Economics Meet - Valuations of Environmental Resources and Biodiversity
[Full text - .pdf format]
Meghan Zysik
Faculty Supervisors:  Dr. Stan Sessions and Dr. Carlena Cochi-Ficano

Biodiversity loss has become a global crisis, with some experts figuring losses of 27,000 species a year.  Environmental degradation is a leading cause of biodiversity loss, therefore correct assessment of the value of environmental resources is essential to making appropriate decisions concerning land management.  This research looks at the methods of valuation of environmental resources and biodiversity, from both biological and economic perspectives.  The Pine Lake environmental campus in West Davenport was used as a case study of current techniques.   The Shannon diversity index was determined for Pine Lake utilizing past senior research projects, faculty research, and other studies.  This index was then compared with national park data to put perspective on Pine Lake in a large-scale sense.  This data was also used to determine a rough monetary value of the biodiversity.  The value of Pine Lake from a student perspective was ascertained through conjoint analysis surveys.  This enabled the students’ “willingness to pay” and “willingness to accept” values for the Pine Lake environmental campus to be calculated.   

Morphological Responses of Bacteria in Response to Grazing Pressure by the Protozoan Colpoda and Mosquito Larvae
Devin A. Zysling
Faculty Supervisor: Dr. Mary Allen

Grazing is a major force that shapes bacterial community structure and morphology. Predator-prey interactions between bacteria and protozoans are known to affect bacterial size structure through the development of bacteria that are too large to be ingested by protists. Previous studies have demonstrated that protozoan grazing induces shifts in morphology resulting in grazing-resistant filamentous bacteria. In this study, I examined the effects of predatory grazing by the protozoan Colpodaand mosquito larvae on the morphology of the bacteria Klebsiela pneumoniae, Chromobacterium violacium, Rhodococcus rhodochrous, and Micrococcus luteus. It was found that the introduction of Colpoda caused an increase in filament formation for all four species of bacteria observed, but the abundance of grazing-resistant filamentous bacteria varied between species. The introduction of mosquito larvae did not cause any substantial increase in filament formation, suggesting that the degree of filament formation is dependent on predator size.