1. Friedel-Crafts acylations and alkylations on solid catalysts
      Keely R. Parisian, Chemistry Department
     Advisor:  Dr. Larry G. French

     Increasing interest in environmentally benign organic synthesis has placed considerable attention on alternatives to traditional Friedel-Crafts acylation and alkylation procedures.  The Friedel-Crafts acylation of aryl ethers is a fundamental reaction exemplifying the theory and mechanism of electrophilic aromatic substitution studied in organic chemistry lecture.  However, associated with the procedure commonly encountered is the use of toxic reagents including acid chlorides or anhydrides and aluminum chloride.  Our work in the area of “green chemistry” offers an undergraduate, organic chemistry laboratory incorporating the core concept of Friedel-Crafts alkylation reactions yet reducing local environmental impacts as well as working at the microscale level.
    One approach offering the practical advantage of green chemistry on an economic scale has been the procedure introduced by Ranu et al.  They demonstrated that acylation occurred only at the position para to-OMe for all of the ethers studied.  Further, they postulated that in cases where the para position was blocked the acyl group became ortho to the ether component.  The reaction time varied for each ether while the percent yield remained phenomenal.  We explored the application of this procedure to the acylation of the allyl-substituted aryl ethers, safrole and estragole which had never been successfully acylated on the aromatic ring.  We demonstrate the formation of the preferred ortho substituted acylation product for both substrates as predicted. Low yields of ring acylated materials were obtained although various conditions were modified in attempts to improve upon yield.
    Preliminary attempts were undertaken to carry out Friedel-Crafts alkylations of anisole with benzyl halides on a variety of solid supports including silver nitrate coated silica gel, acidic alumina, and plain silica gel.  Presumably due to complex reaction mixtures analyzed by GC-MS, there is no direct literature precedent for a Friedel-Crafts alkylation on solid catalysts.  Further investigation into the reactions is essential.
 

2. Investigating the Effect of “Clutter” on Distance Estimation
     Steve Diamond, Psychology Department
     Advisors: Thomas Greene & Alan Searleman

     Psychologists have long been interested in the factors that affect human judgments of distance.  One such factor is referred to as the “clutter effect.”  The clutter effect states that filled distance is sometimes perceived as longer than empty/unfilled distance of equal objective length.  Because the clutter effect has not always been observed, we decided to examine factors that may influence its occurrence by manipulating the variables of spacing, saliency, and “common region.”
    In Experiment 1, 31 participants were shown a series of 24 illustrations of lines containing varying numbers of superimposed equal sized dots.  There were seven 85 mm length lines created as test stimuli and an additional 17 illustrations of varying lengths serving as distractor stimuli.  Clutter (dots) was varied as a function of spacing, saliency (color), and membership within a common colored region.  Experimental stimuli were compared to a control condition containing no dots.  Participants made distance estimates by marking a data slip containing a 208 mm length line. Results indicated that the test stimuli containing clutter were not judged to be longer than the control stimulus containing no clutter.  These results are consistent with the findings of Herman, Norton, and Roth (1983) who showed that the clutter effect does not lengthen distance estimates if participants do not have to pay attention to the clutter. Surprisingly, the cluttered stimulus we referred to as common region was judged to be significantly shorter than the other six stimuli.
    Experiments 2 and 3 served two purposes: i) to further investigate the clutter effect by varying cognitive load and, ii) to examine convergence and divergence of the eyes as possible explanations for the unexpected common region effect.  Cognitive load was manipulated by requiring participants to add point values assigned to the dots.    Results from Experiments 2 and 3 still supported the previous finding that the original common region stimulus was estimated as smallest, but this effect does not appear attributable to convergence or divergence of the eyes.  Although employing two dot value systems presumably forced participants to pay more attention to the dots than in Experiment 1 -- and should have increased cognitive processing while viewing the line -- these manipulations did not result in greater line length estimates as predicted by the traditional interpretation of the clutter effect.
 

3. Comparing Directed Forgetting for Animal Names and Pictures
     Sunitha Reddy, Psychology Department
     Advisors: Alan Searleman & Ronald Sigmundi

     Directed forgetting, which involves the intentional forgetting of information, has been investigated almost exclusively with verbal stimuli.  Last year, as part of his senior honor’s project, Di Bella tried to extend the literature to include non-verbal stimuli as well.  He did this by comparing people’s ability to remember or forget various color names or color patches.  The results indicated that participants retrieved significantly more Remember items than Forget items during a free recall task for both the color words and color patches.  However, findings from a cued response task suggested that the participants may have recoded the color patches seen in the initial learning session into a verbal code.  Given that this may have happened, it raises doubts concerning whether or not Di Bella’s study truly demonstrated evidence for directed forgetting outside of the verbal domain.
    The present study was a new attempt to provide evidence of directed forgetting of non-verbal material.  Rather than use color names and patches, the current study used animal names and animal pictures.  The use of easily recognized animal pictures precluded the need for the training session that Di Bella employed (and thus avoids any inadvertent initial biasing toward verbal encoding).  Also, in Di Bella’s study participants had to remember fine nuances of colors, which may have further prompted use of a verbal encoding scheme.  In this new study participants were given either a list of 16 animal names or 16 animal pictures, one at a time, for 10 seconds each.  After 4 seconds each name or picture was designated as either an item to be Remembered (R) or an item to be Forgotten (F).  After completing a short-term memory distractor task, the participants were unexpectedly asked to free recall all of the R and F items.  Following this, participants were given a cued response task in which they had to pick out the original 16 animal names or animal pictures from a list of either 32 names or pictures.
    Clear evidence of directed forgetting for the animal names in both the free recall and cued response tasks was observed in the current study.  More importantly, there was evidence of directed forgetting for the animal pictures only in the free recall task.  Pictures were remembered significantly better than words in the cued task and there was no evidence that a verbal code was used at the expense of an imagery code for the pictures during the initial learning session.  Hence, the results suggest that directed forgetting with non-verbal stimuli can be achieved, but it is not as complete a process as can be demonstrated with verbal stimuli.
 

4. Wide Open Spaces: Will Technology Fill in the Gaps?
     Ed Cavallerano, Biology Department
     Advisor, Dr. Brad Baldwin

     Human activities destroy the natural ecosystem and divide complex biomes as our technology advances and our populations grow.  Throughout our history we have been expanding our own ecological niche, resulting in the destruction of many others.  Habitat fragmentation is such a process, and results in the dissection of once continuous natural ecosystems into smaller pieces of land called fragments or habitat islands.  The inhospitable environment in between habitat islands effectively separates wildlife communities and tends to favor those organisms that are adapted to the new environments that are created.  Recently a number of researchers have suggested that technology, the creator of so many environmental problems, could also be the solution. By making use of computer software and the Geographic Information System (GIS) many conservation biologists are monitoring habitat fragmentation.  They hope their work will aid in the development of land management programs that would fill in the spaces created by modernization. Is it possible to correct our past with the innovations of the future?
 

 5. The Waste Isolation Pilot Plant: The Future of Radioactive Waste Disposal
     Daniel Peppe, Biology Department
     Advisor: Dr. Brad Baldwin

     Since the discovery of radioactivity by Henri Becquerel and Marie Curie, science has been pushing to use radioactive material in more and more things, such as nuclear power and nuclear weapons; however, nuclear power has caused a tremendous problem in the form of radioactive waste.  Right now, the only real method of disposing radioactive waste is the inefficient method of storing waste in above ground or immediately underground tanks.  Yet, this is merely a short-term solution for disposal of radioactive waste.  For many years a long-term solution has been sought after, and now there appears to be a resolution to the problem of long-term disposal of radioactive waste.
    The Waste Isolation Pilot Plant, or WIPP, is the answer to this problem because it isolates radioactive waste almost a half-mile underground in salt beds in a deep geological burial repository.  The salt and gas pressure surrounding the drums of waste is then predicted to fill in the repository within decades, and the radioactive waste is then completely isolated.  The isolated radioactive waste is then left underground for hundreds of thousands of years until it has completely broken down.  This solution is much more efficient than the present ones, and there are no foreseeable problems from burying the waste deep underground in salt beds.  It is evident that the Waste Isolation Pilot Plant and other plants like it, are the wave of the future in radioactive waste disposal.
 

6. Genetic Engineering: A Technological Fix or Risk?
    Jolaine Roycewicz, Biology Department
    Advisor: Dr. Baldwin

     Genetic engineering is the manipulation of genes in an organism for practical purposes. Changing genes of crops for higher yields at a cheaper cost is one of the goals of genetic engineering. Low cost is the result of crops that produce their own nitrogen and herbicide resistant crops that are poisonous to insects. This process is even seen as the solution to famine because it will allow higher production in less space.  Genetic engineering also has the potential to be used in humans to produce organs for transplantation, to reverse effects of genetic diseases and, the ultimate, to clone people and animals.  Animal cloning can go as far as to reintroduce extinct or endangered species back into the environment.  Humans may even someday be able to choose their children’s characteristics; whether they have blond or brunette hair, blue or green eyes, whether they are smart or not, etc.  Although the outcomes of genetic engineering seem to be very beneficial, it can have many negative effects on the environment.  Transgenic crops can mix with wild crops and create “superweeds” and people can consume transgenic food that produced a protein they were allergic to. Genetic make up of humans could potentially be the same in an entire population, causing a reduction in diversity.  If everyone had a similar genetic makeup and a virus came in that couldn’t be fought off by anyone, the population would dramatically decrease. In this presentation, I will examine whether genetic engineering is a fix to our problems or the cause of more problems.
 

 7. Carbon accumulation in regenerating forests in St. Lawrence County, New York
      Michael White, Biology Department
      Advisor: Dr. Marilyn Mayer

     Burning of fossil fuels and historical clearing of forest lands world wide has released large amounts of carbon dioxide (CO₂) into the atmosphere.  Currently, net carbon (C₂)) accumulation is occurring due to forest regrowth on previously cleared areas.  Forests act to remove CO₂ from the atmosphere through photosynthesis, converting it into solid forms of C that primary producers can (e.g. cellulose and lignin).  It is believed that much of the mid to high latitude forests in the Northern Hemisphere are storing C and are thus considered C sinks.  Much of the areas which are experiencing forest regeneration are abandoned agricultural lands.  The goal of this project was to determine the C stored in local regenerating forests and how local forests compare with others around the Unites States.  Total aboveground C in living trees was estimated for three study sites located in regenerating forests in St. Lawrence County, New York.   For all three sites combined, the tree species and diameter at breast height were recorded on 2.77 acres of forest.  Total aboveground biomass was calculated using species specific biomass equations and C was estimated from the biomass values.  Sampling has been completed on two of the three sites.  Carbon density ranged from 21.9 Mg ha-¹ in a roughly 40 year old forest to 24.1 Mg ha^-1 in a roughly 50 year old forest.  These values are lower than values reported from other location in the U.S..  A shorter growing season and poorer soil quality are possible explanation for low C storage.  Tree species composition and diameter distribution of the study sites were also analyzed to examine the relationship between these two parameters and C storage.  This portion of the study is in progress.
 

8. Technology Use for Oil Spill Remediation
     Katrina Jilek, Biology Department
     Advisor: Dr. Bradley Baldwin

     Oil Spills happen so many times a year that nobody really knows how much oil is spilled.  The United States imports 100 billion gallons of oil per year.  Spills are separated into sectors, one are inland spills and on land.  Others are coastal spills.  The number of oil spills has been reduced to less then 1% of the total volume of oil handled per year but the need for prevention is seen in the fact that about half of all hazardous waste spills that are reported involve oil.  Forty days after the Exxon Valdez spill, the oil had washed up on Kodiak Island which is 350miles from the site of the spill.  This spill not only affected the environment but it affected the economy too. The main job at hand was containing the oil, reduce fish and wildlife losses and clean the beaches.  The U. S. has employed a response system that is the standard for evaluating, controlling, and cleaning oil spills.  Since spills can happen anywhere there are many federal laws that give governance over these spills such as the Clean Water Act and the Oil Pollution Act of 1999.  An Oil Spill Committee is set up and the health and safety is called in.  For spills, time is of the essence. There are many physical variables that affect the oil cleanup.  Time is a very large problem. Oil composition is also an important factor.  Chemical agents are used to make the oil adhere to the cleanup tactic. Gelling agents work well because it pickup oil particles and solidifies them. Sorbents are another type of cleaning technique that is used.  Sorbents are used to recover oil by means of absorption, adsorption, or both.  To be useful in cleaning the oil spills, sorbents must be oleophillic (oil attracting) and hydrophobic (water-repellant). Sorbents are most often used to cleanup the final traces of oil.  There are three categories of sorbents, natural organic, natural inorganic, and synthetic. Burning, while it occurs often is not a good solution to the problem because it takes a water pollution problem and turns it into an air pollution problem.  Although burning removes about 90% of oil that has been spilled, it is no better for the environment then the spill itself.  Microbes are also another method of cleaning up oil spills.  Prevention techniques seem to be the most important step in the safety of the environment from oil spills.  Alternative energy sources may be the best step for saving our environment from oil pollution in the future.
 

 9. Operating Systems
      Tim Singleton, Math Department
      Advisor:  Brian Ladd

     With the recent release of Windows 2000 and Microsoft’s anti-trust proceedings, the term “Operating System” has been thrown around a lot lately.  They have given recent cause for comparisons between operating systems such as Windows, SunOS and Novell’s operating system, and Linux.
     Most people have heard the words “Operating System” before; many could probably list some of the more important aspects of one.  The operating system is arguably the most important component of any running computer. Unfortunately, most of the people who use computers today neither have the time nor the inclination to research how it works and what goes on underneath Microsoft’s pretty graphical user interface.
     Simply put, an operating system is a program that controls the computer: it runs other programs, it communicates with the hardware, it mediates multiple applications running at the same time, all while seeming completely transparent to the user.  As described in the verse at the top of the page, the operating system acts transparently by giving the user no indication that so much is happening, it acts as seamlessly as the he or she is expecting.  Those lines simplify operating systems quite a bit, but they touch on some of the major aspects of them.
     My project explored what operating systems are and how they work.  I examined how software and hardware interact through this thing called an “operating system”.  The file system was a large portion of the project, dealing with how files are handled from the point of view of the application and the hardware.  I covered virtual memory (sometimes called “paging”) and how that works and fits in with the rest of the system.  Anything that is virtual attempts to cover over the fact that the computer is lacking resources by making the programs and user believe they really are there.  Virtual memory gives the impression that there is much more RAM, or main memory, than there actually is.  Among other things, I also covered shared resources, and how different programs and computers can use the same memory or CPU.
 

10. Computational Chemistry of Hydrogen Bonding of Substituted Amines to Clay Sheets
       Jonathan Leitch, Chemistry Department
       Advisor: Dr. Jeffery Greathouse

     The interaction between organic amine compounds and clay soils is a topic of intense environmental concern.  The amines that hydrogen bond to the clay sheet can cause adverse environmental problems.  The hydrogen bonding of amines to clay rings was studied using the Spartan molecular modeling program using semi-empirical calculations at the PM3 level.  Understanding how the amines bond to the clay surface provides insight into hazardous waste removal processes.  We found that each amine bonding to the clay attaches at only one point, and when they adsorb to the clay surface, there is a slight transfer of negative charge towards the clay ring.  Finally, we examined the behavior of clay surface clusters using PM3 geometry optimizations with no interacting amines. Each cluster composed of 1-4 hexagonal rings puckers into a U shape if bonds are left unconstrained.  This behavior of course, is completly unnatural as clay rings found in nature are very large, flat sheets.
 

11. SPECIES AND SIZE SELECTIVE PREDATION BY THE CRAYFISH,
       ORCONECTES RUSTICUS, ON DREISSENID MUSSELS
       Alexander H. Nixon, Biology Department
       Advisor: Dr. Marilyn Mayer

     A laboratory experiment was performed to determine whether a crayfish species, Orconectes rusticus, expressed species and size selective feeding behavior on two non-native freshwater bivalves, the zebra (Dreissena polymorpha) and the quagga (D. bugensis) mussel.  Previous fieldwork has shown that the quagga mussel, a more recent invader, is displacing the zebra mussel in many benthic habitats.  However, the invasion of zebra mussels has been more wide spread than the quagga mussel’s invasion.  Zebra mussels tend to have thicker shells than quagga mussels, which could make the quagga mussel shell easier to crush and more susceptible to predation.  We were interested to see whether predation by crayfish can affect mussel distribution by preferred predation.  We offered equal numbers of the two mussel species on a daily basis.  Mussels were grouped into discreet size classes based on length: 5-7 mm, 9-11 mm, 13-15 mm, 18-20 mm, and 23-26 mm.  Crayfish consumed more quagga mussels than zebra mussels (101 vs. 53, respectively).  Regardless of species, crayfish consumed more 5-7 mm mussels than 9-11 mm mussels (118 vs. 28, respectively).  Chi-square tests on these data show that mussel species difference and within species size differences had significant effects on crayfish consumption of mussels (p < 0.005).  Crayfish predation method was also observed and we found that crayfish consumed the 5-7 mm mussels of both species by crushing the shells.  However, the few larger zebras were pried open rather than crushed, whereas consumption of larger quagga was by poking a hole in the shell or by crushing.  This is a strong reflection of the role of mussel shell strength in crayfish predation.  We feel that where crayfish predation has a strong effect on benthic invertebrates, zebra mussel shell strength relative to quagga mussel shell strength will give zebras an advantage over quaggas.
 

12. Scaling Properties of Light Transmission In a Simulated Cloud
      Rory Caster, Physics Department
      Advisor: Dr. Brian Watson

     The spatial distribution of liquid water in clouds has a major effect on how much light is transmitted to the earth.  Upon viewing a cloud from the ground one may think that the water drop in that cloud are just floating around in a random, independent motion.  If the water drops were evenly spaced throughout, then on an overcast day the amount of light transmitted would be low leaving us with a much darker daytime.  In actuality the drops exhibit a clumping property that permits light to be transmitted through the less dense regions of the cloud.  I am continuing a project that was attempted last year where we simulate a cloud in a 1 m³  box using small polystyrene beads that will represent water drops.  A leaf blower is used to blow around the beads, which recreates the random, turbulent motion present in real clouds.  A laser beam is then sent through the simulated cloud and gets detected by a sensor.  The transmission of light will fluctuate a great deal as the beads are sent across the path of the laser.  By studying these fluctuations we hope to discover what the scaling properties of the system might be.  Preliminary analysis of the power spectrum (Fourier transform) of the light transmission shows a frequency dependence of f^-1.75 over one order of magnitude in f .  Results on how the scaling depends on transmission distance will be presented.
 

13. The Advantages and Disadvantages of Fuel Cell Power Plants
       George Williams, Biology Department
       Advisor: Dr. Brad S. Baldwin

     The poser presentation that I would like to present will explore fuel cell power plants. I will include in the presentation a short history of fuel cells and explain how the fuel cell and the fuel cell power plant work. The presentation will explore one power plant in particular, the Santa Clara Power Plant in California. The presentation will also provide both the advantages and disadvantages of fuel cell power plants.
 

14. Atherosclerosis and Lipoprotenis
       Kasia Poczwardowska, Biology Department
       Advisor: Dr. T. Budd

     This poster presentation will summarize a review of the most recent literature on the role of lipoproteins in atherosclerosis. Atherosclerosis is a vascular disease that progresses slowly over decades and is characterized by thickening, hardening and remodeling of the arterial wall. During the disease process the accumulation of plaque components occurs in blood vessel walls that can lead to serious complications such as aneurysms, stroke, gangrene of the extremities, coronary occlusion, and even cause death.  The pathogenesis of atherosclerosis depends on smooth muscle proliferation, presence of lipids in the arterial lesions and the role of a number of important risk factors.  These risk factors are: the concentration level of low density lipoprotein (LDL), high density lipoprotein (HDL), and irritation of tobacco smoke. Plasma concentration of LDL-cholesterol particles and HDL-cholesterol particles are crucial for the progress or regress of atherogenesis. When LDL cholesterol level increase and HDL decrease, the progression in atherogenesis is observed. Also, a precise control of LDL cholesterol level conducted for a period of several years led to its decrease and increase of HDL.  HDL is responsible for reverse transport of cholesterol to the liver where its excretion proceeds. There are several factors that can decrease the reverse transport of cholesterol by HDL and include oxidation of HDL and cigarette smoke exposure. The higher the total cholesterol level, the higher the rate of atherosclerosis. The worst total level of cholesterol has been specified at the level  between 225-260 mg/dL when accompanied with the low HDL cholesterol level.  The ratio of the total cholesterol level to HDL cholesterol level is used when predicting atherosclerosis. This ratio-based indicator works more accurately than taking under consideration total cholesterol level to LDL level or triglyceride level. Additionally, as people age their arteries are clogged  more by atherosclerotic plaque. Results of the research projects reviewed significantly shaped therapeutic approach of physicians.  The most recent approaches in clinical treatment of atherosclerosis are based on lowering LDL levels through the use of appropriate diet, exercise and drug therapy.  These approaches allow for direct elimination of the most atherogenic particles.
 

15. Alternatives to insecticides?
       Amanda Drefus, Biology
       Advisor: Dr. Brad Baldwin

     Today large commercial farms look for the ultimate chemical insecticide to rid themselves of pests.  It may not be that simple. Insecticides in mass use today create all sorts of problems.  They damage crops, the environment and its numerous species, create genetic resistance and are hazardous to human health.  Pest damage in the last few years has slightly increased while pesticide use has gone up radically.  This fact alone shows that we will not be able to rely on pesticides forever and that there is need for alternatives.  An alternative system of integrated pest management, or IPM, uses natural, biological, and agrotechnical strategies to control pests. In natural strategies, predator populations are manipulated to help control pests.  There are three forms of biological control through biopesticides that are called microbial, plant, and biochemical pesticides. Microbial pesticides use fungus, bacterium, protozoan, or algae as control agents.  Plant pesticides are substances that plants already make in defense against pests. Biochemical pesticides are natural substances to control pests instead of conventional pesticides that are synthetic.  Agrotechnical approaches are mainly cultural steps that involve more labor to reduce pest numbers.  Two examples are rotating crops or trap crops.  IPM takes technical know-how of the specific environment combined with the techniques best suited for the area in order to achieve an environmentally and ecologically safe way to deal with pests.
 

16. Medicinal Plants of El Salvador: The Effectiveness of Traditional Healing
       Michael B. McDonnell, Regina V. Alvarez1, and Carlos R. Ramírez-Sosa
       Department of Biology, St. Lawrence University, Canton, NY 13617
       1 Central Park Conservancy, New York, NY 10021

Abstract:  Traditional medicine is an integral part of rural health care in many areas of Central America, including El Salvador.  Midwives and healers use local plants to effectively treat ailments, ranging from abrasions and fevers to infections and breaks.  Four species, Hamelia patens (Rubiaceae), Calea urticifolia (Compositae), Calea ternifolia (Compositae), and Tagetes lucida (Compositae), were selected to be tested for their antimicrobial activity.  These plants were suggested by a local midwife in San Francisco Menéndez, Ahuachapán, El Salvador.  This type of medicinal plant knowledge is transmitted through oral tradition.  Ethanol (80%) extractions were used to assess the relative antimicrobial properties of the plants against 12 species of bacteria and one fungus.  Although none of the plants tested were found to inhibit the growth of all the bacteria used, all the plants had an affect on the growth of at least one culture.  The fact that traditional practitioners often use a concoction of several plants together may indicate that they work synergistically to form a more potent compound.  The overall effectiveness of plant treatments is considered quite good by local people in San Francisco Menéndez, including both the provider and the patients.  Our results partially support the use of these plants for the treatment of infections.  However, more detailed studies are necessary to confidently define their medicinal properties.

This project has been partially funded by the Merck/AAAS Funds for Summer Research 1999 and the International and Intercultural Studies Program at SLU.  We thank Mrs. Marina Estela Velázquez (midwife), San Francisco Menéndez, El Salvador for her assistant.
 

17. Substrate Response versus Water Depth in the Weakly Electric Elephantnose Fish,
      Gnathonemus petersii (Mormyridae)
      Westley Nolin, Psychology Department
      Advisor: Dr. Peter Cain

     Previous research has shown that the weakly electric elephantnose fish, Gnathonemus petersii,  utilize electrolocation to orient themselves in a novel environment, but cease to attend to electrolocation cues in a familiar environment.  One of the goals of this experiment was to determine if the weakly electric fish relied on hydrostatic pressure cues or electrolocation of the bottom, also called the substrate response, to maintain their depth orientation in a familiar environment.  The fish were trained, for one week, to locate a circular aperture located in the divider wall that separated a 200-litre aquarium into two equal compartments.  The circular aperture was placed @17.7 cm above the bottom of the aquarium. We hypothesized that their depth orientation would be maintained by hydrostatic cues rather than substrate cues.  We recorded three dependent variables: (1) the time it took the fish to locate the aperture, (2) the number of times the fish crossed through the aperture, and (3) the height the fish made contact with the divider.  The second week, a false bottom was placed 10 cm above the bottom of the aquarium.  The hydrostatic pressure cues remained the same, but the substrate cue was changed.  The fish’s task was to locate the aperture under the new conditions for four days.  On the fifth day, the fish were placed in the tank with no false bottom, but after 10 minutes the false bottom was slipped into place and the dependent variables were recorded for 5 minutes.  We hypothesize that the inclusion of the false bottom will cause (1) an increase in the number of crossings, (2) an initial increase in the time it takes to locate the aperture as well as (3) an increase in the height the fish made contact with the divider.
 

18. Identification of North Country Freshwater Mussels:  A Comparison of
       Morphological And Molecular Characters
       Heidi Moore and Amy Soden, Biology Department
       Advisor: Dr. Michael Temkin

     Species and subspecies of freshwater mussels are not easily identified using morphological characters.  Recently published studies have identified North American freshwater mussels using partial sequences of two mitochondrial genes: the cytochrome C oxidase subunit I gene (CO I) (Graf and O'Foighil, 1999)  and the 16s rRNA gene (Lydeard et al., 1996).  The goals of this research project were 1) to develop molecular protocols to obtain the partial sequences of CO I and 16s rRNA genes from North Country freshwater mussels and 2) use these sequences to determine the molecular identity of six specimens previously identified by Dr. Mark Erickson using morphological characters: Lampsilis radiata from two sites, Lampsilis ovata, Lampsilis sp., Eliptio complinata and an unidentified specimen.  Mitochondrial  DNA was isolated from each specimen using the Easy DNA kit (Invitrogen, Carlsbad, CA). This DNA was used for a nested PCR protocol to amplify a 400 bp segment of the CO I gene and a 362 bp segment of the 16s rRNA gene.  PCR products were cloned using the Prime PCR Cloner Cloning kit (Eppendorf 5 Prime, Boulder, CO) and sequenced using the T7 Sequenase DNA Sequencing Kit (USB, Cleveland, OH).  After the DNA sequences were obtained, the sequences for each gene were aligned with MACAW and compared against the known sequences for Lampsilis, Eliptio and other known local genera.  PHYLIP was used to generate phylogenetic trees comparing the relationships of the species in our study with other freshwater mussels.  Phylogenetic analyses were made using important characters from the CO I gene, the 16s rRNA gene, and a joint data set from both genes.  The data from this study is the first step in examining the biodiversity of North Country freshwater mussels at the molecular level.  Molecular characterization of native freshwater mussels may be important in assessing the impact of introduced species, such as Dreissena polymorpha (zebra mussels) and Dreissena bugensis (quagga mussels), on local populations.
 

19. Safer Alternatives to Burning Trash
      Lynita Brandon, Biology Department
      Advisors: Dr. Brad Baldwin

Abstract: The use of incinerators as a solution to waste disposal is a danger to both human health and the environment. Incinerators emit hazardous toxins and gases into the air of wich we breathe. Currently, there aren't any alternative methods that could be used that would not cause any danger to humans or our surrounding environment. But, there are possible alternatives that could mitigate the dangers of incineration. My poster will display both general information about incinerators and some possilbe alternatives to their use.
 

20. Periodicity of El Nino Events through Geologic Time
      Tasha Brown, Geology Department
      Advisor: Dr. Jim Willemin

     This poster will be based on research that I have conducted for my senior thesis.  My goal is to study documented cases of global climatic changes and see if they can be attributed to El Nino activity.  I would ultimately like to explore the possibility that other events found in the rock record result from El Nino activity in the Earth’s past.
     “Evidence of El Nino conditions has appeared in written records for more than 400 years,” (UNEP/GEMS Environment Library No. 8), but it is possible that the phenomenon is much older than written records can attest to.  Our modern knowledge of its global effects is relatively recent, as is our full understanding of what changes signal the onset of an event.  Much focus is placed on predicting the occurrence of an event based on changes in weather patterns and ocean currents in the Pacific.  Studies have been conducted to help determine predictors, but much is still unknown about their exact cause.
     Finding evidence of El Nino events in the rock record may help us gain a better understanding of when and where the most devastating conditions strike.  We may find evidence of a pattern of temperature extremes, floods and droughts, and overall irregular and extreme weather. It may even be possible to isolate such happenings to particular places around the globe.  The prediction of onsets and severity will undoubtedly aid in the prevention of major social and economic impacts caused by El Nino.
 

21. The Relationship Between Inclusion in the Athlete-Coach Relationship and
       Athlete Satisfaction
       Edward Kupiec, Psychology Department
       Advisor: Dr. Artur Poczwardowski

     Athlete-coach interactions have a significant influence on the athlete-coach relationship, and these interactions have frequently been studied in the sport psychology (Carron & Chelladurai, 1978).  In athlete-coach relations, inclusion behavior is found to be the predominant contributor to incompatibility between the athlete and coach (Carron & Bennett, 1977).  Inclusion, in addition to being a significant component of athlete-coach relationships, is also found to be a major influence on athletic satisfaction. In this study, the relationship between inclusion in the athlete-coach relationship and athlete satisfaction was explored.  The Fundamental Interpersonal Relations Orientation-B (FIRO-B) was used to obtain inclusion scores and the Scale of Athlete Satisfaction was used to measure athlete satisfaction. Both measures have been shown in the literature to be valid and reliable.  A sample of about 100 varsity athletes and 4 head coaches from 5 St. Lawrence University individual, winter season teams participated in the study. The data was subjected to statistical analysis to determine the degree to which a relationship exists between levels of inclusion and the level of athlete satisfaction.  It was hypothesized that low inclusion scores would be associated with decreased athlete satisfaction scores.  It was also expected that low discrepancy scores between the inclusion behavior that athletes desire and the inclusion behavior their coaches express would be associated with higher reports of athlete satisfaction.  No statistically significant correlation coefficients supporting the study hypotheses were found.  Future studies should first identify athlete-coach dyads in which those athletes are meaningfully engaged with their coach.  All surveyed athletes had at least two coaches.  Some of these athletes may not have perceived the relationship with their head coach, from whom the inclusion scores were obtained, as meaningful as the relationship with one of the assistant coaches.  It is also possible that older and more experienced athletes, such as the investigated population, may not consider a highly inclusive relationship with their coaches as an important component in their athletic experience.  Finally, the FIRO-B is a general measure and was adapted to an athletic environment in this study.  In future studies, the measure of inclusion may need to be specific to an athletic setting.
 

22. The Application of Hydrogen Fuel Cells: The Next Step in Transportation
       John Labbe, Biology Department
       Advisor, Dr.Brad Baldwin

     Hydrogen is the fuel of the 21st century. Fuel cell vehicles that operate on hydrogen fuel travel further on a gallon of fuel than internal combustion engine vehicles and emit only water vapor as exhaust. This technology offers the chance to eliminate the use of fossil fuels in transportation. Every major automaker has already developed their own hydrogen fuel cell vehicles with which they plan to mass-produce in 2004 to meet California’s zero emission policy. Two factors are holding back this technology, the cost of the materials used to construct these vehicles as well as the lack of a hydrogen-refueling infrastructure. While technological advancements can be used to reduce the cost of the car it is up to the consumer to decide if the billions of dollars needed to create a refueling infrastructure is worth a clean atmosphere.
 

23. Predicting Hurricanes
      Eric O’Neil, Biology
      Advisor: Dr. Brad Baldwin

     Hurricanes have always been a part of the natural world that humans live in, and humans have attempted to alter and even stop the intense power of a hurricane. However by using new technology and the natural world, we can now predict hurricanes up to a year in advance. Using natural oscillation patterns, pressure systems, rainfall over land, ocean surface temperature, and El Nino/La Nina, we can take these natural phenomena to predict the occurrence and strength of hurricanes for the following season. Implementing this prediction method will allow residents of hurricane threatened areas ample evacuation time, which will save many lives. Property and land damages will also decrease and destruction of the natural environment could also be prevented or decreased.
 

24. The Algorithmic Manipulation of MIDI Files Through Perl
       Aileen Ang, Math Department
       Advisor:  Brian Ladd

     Since 1982, Musical Instrument Digital Interface (MIDI) has been a standard for communication and storage between electronic musical instruments.  MIDI is stored information that can take and interpreted though a medium, which allows for sound output.  This differs from most music files that are saved in wave formats in which “real sound,” or audio such as voices can be heard.  Most modern computers can interpret the sequence of sound events in a MIDI file and play back the music.
     Many graphical composition packages have been developed using MIDI. They provide a broad range of manipulation tools.  Often, so many of these make it difficult to find any particular transformation in the mix. Approaching the problem from the other direction, I have designed a series of seven simple, algorithmic music transformations in Perl, which support simple MIDI composition.  The transformations are interfaced through the World Wide Web, permitting users to manipulate MIDI files through their Web browser.  The transformations include transposing, offset, ostinato, mirroring, adding major and minor chords, changing the instrument, and joining two files.  The MIDI files can then be played or used as the basis for additional composition.
     Using a Perl (Practical Extraction Report Language) package, MIDI::Simple,  and learning the structure of the MIDI file used by the package, some of the transformations, such as transposition, offset, mirroring  were created by manipulating a midi file to change the value of a note or duration.  Other manipulations such as changing the instrument, ostinato (taking a sequence of notes and repeating them several times, usually use as a base to a music piece), and adding chords requires notes or information to be added to the structure with some changes to the properties of the new notes.
     In this project I have combined concepts that are being taught in both the Computer Science and Music curriculums.  By using simple algorithms in programs to transform a musical idea, variations of the musical idea can be expanded.  As composers have done through out history, these variations can be used to expand and create compositions.
 

25. Estimating home range size in eastern gray squirrels, Sciurus carolinensis
       Karin E. Roux, Biology Department
       Advisor: Dr. Erika Barthelmess

     This research project had two objectives.  The first objective focused on the effects of sex and reproductive status on the home range size of the gray squirrels, Sciurus carolinensis, of the St. Lawrence University campus.  I tested two hypotheses.  I predicted males would have larger home ranges than females, and reproductive males would have larger home ranges than nonreproductive males.  The second objective focused on the methodology used to calculate home range size.  I predicted the function Minimum Convex Polygon (MCP) would generate a smaller home range size than the Kernel Home Range (KHR) function, but that KHR would provide more information on space use and probability of time concentration.
     Squirrels were live trapped, their sex and reproductive status recorded, given numbered ear tags and unique freeze brand patterns for identification from a distance.  Range location points were noted by a combination of repeated live trapping and sightings on predetermined walking routes.  Squirrel location points were plotted on a map of St. Lawrence University in a Geographical Information System (GIS) using ArcView software.
     Three different methods were used to analyze the home range sizes.  MCP and KHR were incorporated in to the GIS as animal movement analysis functions.  These two functions are widely used as home range quantifying techniques, but are sensitive to sample size.  The third method used for analysis was Mean Squared Distance (MSD) which is not as sensitive to sample size.  Because my sample size for each squirrel tended to be small, the MSD function was used to calculate a standard result by which to compare the home range sizes calculated by the MCP and KHR methods.
     My results showed neither sex nor reproductive status influenced home range size in gray squirrels.  The results generated by the KHR function did provide more information about space use than MCP function.  However, small sample sizes per individual squirrel made it difficult to assess home range size with accuracy.  The implications of using different methods of measuring home range size will be discussed in light of the data I obtained for S. carolinensis.
 

26. Nuclear Power: The Solution?
      Scott Edkin, Biology Department
      Advisor: Dr. Baldwin

      Nuclear power may be the answer to many of our energy needs in the future and deserves a closer look and further research.  Today much of the energy we use comes from the burning of fossil fuels, which not only pollute our air and water but are also a nonrenewable resource.  Therefore other ways of producing electricity need to be explored and at the current time nuclear power may be one of the best ways to do this. Many other methods are either too new and unreliable or just not capable of producing the quantity of energy required.  Nuclear power has its problems with waste disposal and suffers from many public misconceptions but the current technology is old and could possibly benefit from further research and further development.  If these misconceptions can be addressed and some safety and disposal problems can be solved nuclear power may be the answer to some of our future problems.
 

27.The Effects of Tactile and Vestibular Stimulation on Maternally Separated Mouse Pups
       Jessica Martin, Psychology Department
       Advisor: Dr. Loraina Ghiraldi

     This study was designed to assess the effects of tactile and vestibular stimulation on growth and motor performance of maternally separated mouse pups.  Separation of rodent young from the mother has been shown to produce physiological stress in the offspring.  Detrimental effects include changes in circulating hormones, heart rate, inhibition of cellular growth, and reduced locomotor activity (Matthews et al., 1996; Schanberg & Field, 1987).  In cases of extreme or prolonged maternal separation, severe growth retardation and developmental delays can occur in the offspring (Schanberg & Field, 1987).  Research has shown that supplemental stimulation given to maternally separated pups can counter the harmful physical and behavioral effects of separation (Thoman & Korner, 1971; Pauk et al., 1986).  More specifically, studies have examined the beneficial influence of tactile, kinesthetic and vestibular stimulation.
     In the present study, male Swiss-Webster albino mouse pups (3 days of age) were randomly assigned to one of four groups: control, separated, separated with tactile stimulation or separated with vestibular stimulation (n=12 per group).  The control pups remained with their mothers at all times.  The pups in the experimental groups were separated from the mother for a total of 2 hours per day for 10 consecutive days, starting on postnatal day 3.  The separated pups remained alone for 2 hours.  The tactile stimulation group received stroking from a damp camelhair brush for 30 seconds every 5 minutes over the 2 hour time period (modified from Pauk et al., 1986).  Vestibular stimulation was administered by placing pups in a device with a motor-driven rotating table (6 rev/min along the horizontal axis).  The pups were rotated on the apparatus for 15 seconds every 5 minutes over the 2-hour period (modified from Thoman & Korner, 1971).  After the 2-hour cycle was completed, the pups were returned to the mother in the home cage.  On day 14,  all pups were weighed and tested for screen climbing ability and activity.  For the screen-climbing test, pups were individually placed at the bottom of an inclined screen.  If a pup fell off, it was placed back at the starting point.  The distance traveled and number of falls were measured during a 180-second test.  For the activity measure, pups were individually placed in the center of a plexiglass covered checkerboard of one-inch squares.  The number of lines crossed by the pup during 180 seconds was recorded (Joseph et al., 1983).  The order in which pups performed each test was counterbalanced.  Preliminary results suggest that pups given vestibular stimulation gain more weight, are more active and have better motor ability than separated pups.
     This study is currently being partially replicated using Jimpy mice.  This strain has a genetic mutation that results in little or no mylenation of the axons in the central nervous system of some male offspring.  Affected males develop severe motor tremors at 8-12 days of age and die prematurely at approximately 30 days of age (Knapp & Skoff, 1993; Chen et al., 1993).
 

28.  Using Environmental Data and Computer Software to Teach Statistical Concepts
       Sarah E. Auer, Math Department
       Advisor:  Dr. Robin Lock

     As an independent project for the spring semester I choose to explore how Fathom, a statistic software program could be used to teach statistical concepts within the context of a high school statistics course. In addition, the data used are focused on environmental issues. My intention for doing this project rather than taking a traditional math course within the department was driven by a desire to incorporate an interest in environmental education, a minor in education, and a future career as a high school math teacher into the final requirements for my mathematics major. I felt that such a project would be the most beneficial and educational approach to take as a way of enhancing my knowledge in the field that I am choosing to pursue.
     The project has involved creating a series of activities to be used to guide students through various components of the software program while at the same time introducing them to statistical concepts. Information regarding topics that would be appropriate to cover at the high school level was obtained from the curriculum of the Advanced Placement Statistics course provided by the College Board and the following textbook: Moore, David S. The Basic Practice of Statistics. W.H. Freeman and Company: New York, 1995.
     Since Fathom cannot be utilized to aid in the instruction of every statistical concept within a curriculum, I chose topics where I felt Fathom could most effectively be used as an instructional tool. The first group of activities leads students through an exploration of bivariate data. This includes concepts such as analyzing patterns in scatterplots, linearity, least squares regression line, residual plots, outliers, influential points, correlation and transformation. The second section focuses on statistical inference using confidence intervals and tests of significance.
     My presentation for the Festival of Science will demonstrate the capabilities of Fathom to teach statistical concepts with an environmental focus. I could use an oral session format whereby I would give a brief introduction to my project followed by a demonstration of how students would carry out one of the activities. Otherwise, I could present my project in poster format by visually displaying the capabilities of Fathom and also allow interested participants to try one of the activities for themselves. In this case I would need access to a computer.
 

29.  Landmark Use and Spatial Learning in the Weakly Electric Fish Gnathonemus petersii
      Sapna Malwal, Psychology Department
      Advisor: Dr. Peter Cain

     This study examined how weakly electric fish use landmarks to form an internal representation of their environment.  It was hypothesized that weakly electric fish would learn their environment faster with a landmark present than without, rely on water depth cues over landmark cues, and change their navigation path when landmark size was altered.  Eight Gnathonemus petersii were subjected to 10 training trials where they had to locate an aperture with either a landmark present or no landmark present.  Following the training trials, landmark size and water depth cues were manipulated.  Results indicated that fish provided with landmarks learned to locate the aperture more quickly than fish without landmarks, they relied on water depth cues over landmark cues, and their navigation path was not significantly altered with a change in landmark size.
 

30.  Hybrid Vehicles: Cleaner and more fuel-efficient than gas combustion vehicles
      Dustin Brecher, Biology Department
      Advisor: Dr. Baldwin

Abstract: The world's population is exponentially growing resulting in an increased number of vehicles being driven on our small planet. The vehicles being sold today are powerful and cheap but have poor mileage and high emissions of CO2. On the average, one car can release as much as 11,000 pounds of dangerous pollutants each year. Our small planet cannot withstand these poor emissions practices much longer. The hybrid vehicle is a short-term solution to our
problems. This vehicle combines a small electric motor with a small gas combustion engine to extend a car's mileage to 80 miles per gallon and its emissions to 1/10 of cars today. Hybrid vehicles are also beings developed with such technologies as flywheels, ultra capacitors, gas turbines, and turbo diesel engines to farther extend these cars mileage and efficiency. The idea involved is simple and holds great advantages for the future of our people and the planet.
 

31.  Solid Waste and Our Environment: Are Today’s Technologies of Waste Disposal
       Environmentally Sound?
       Nic Long, Biology Department
       Advisor: Dr. Baldwin

     The waste production of the United States is inevitable.  Piles of contaminated garbage and trash keeps accumulating as the population keeps rising and businesses keep producing more outputs to increase their profits.  Waste is creating many environmental problems that not only puts human health at risk but also the environment and its wildlife.   Waste management is a serious crisis and more action must be taken before our environment is destroyed.  By creating new technology and more efficient resource recovery facilities, we could cut the amount of waste going to landfills.  If landfill waste could be cut to a minimum and the handling of landfills could keep rodents away and stop contaminants from leaking into the ground water, our waste pollution problem could be solved.  The advancement of landfills, resource recovery facilities, and recycling will settle the problem of waste management and reduce the pollutants that waste products produce.
 

 32.  Ventilatory Effects of DEPC Perfusion in the Nucleus Tractus Solitarius (NTS).
       Vikram Narayan and Aaron Cook, Biology Department
       Advisor:  Dr. Joseph Erlichman

     Carbon dioxide, the by-product of oxidative metabolism forms carbonic acid in aqueous solution.  This by-product represents a source of continous acidification.  Most biological systems can only operate within an narrow pH range, therefore acid-base balance is tightly regulated by the body.  Both renal and respiratory systems are important in systemic pH regulation. The ventilatory effects of CO₂ are mediated by CO₂-sensitive neurons located throughout the medulla. Although the precise stimulus to these cells is unknown, many hypotheses include an important role of pH in the chemotransduction process. The cellular targets affected pH are also unknown, but may include proton tranporters, ion channels, muscarinic and purinergic receptors.  A common motif in the sequence of all of these proteins are the abundance of the amino acid histidine. The pKa of histidine is close to physiological pH, consequently alteration in physiological pH results in a change in the fractional ionization of histidine. Presumably, this change in charge of the histidine by protons can impart an alteration in the stoichiometry of the protein.  Importantly, this change in conformation may then lead to change in function of the protein. Diethyl pyrocarbonate, (DEPC) avidly binds to the imidazole group of histidine preventing changes in protonation.  A previous study utilizing intrsisternal perfusion of DEPC in conscious rabbits has shown that exposure of the ventral medulla to DEPC diminishes ventilatory responses to increased levels of CO₂.  The effects on ventilatory control in the intact rat in the nucleus tractus solitarius of the medulla are still unclear.
     The goal of this study was to examine the effects of focal application of DEPC in a dorsal chemosensitive site, the nucleus tractus solitarius, (NTS).  To this end, we instrumented rats with chronic indwelling cannulas.  This allowed us to perfuse the NTS of the unencumbered conscious animal while monitoring the ventilatory response to the hypercapnia.  The design of the present study differs significantly from previous work in two ways. First, the application of DEPC in the proposed study is restricted to a single nucleus rather than exposure to a large region of the medulla. Second, it allows for comparison of  the dorsal and ventral chemosensitive sites responsible for pH regulation. This work was supported through the generosity of the Merck Foundation.
 

33.  The Effects of Hypoxia on Intracellular pH Regulation in the Pons and Rostral Ventral
       Lateral Medulla
       Monique Nichols and Daniel Hoy, Biology Department

     The evolution of respiratory organs in terrestrial animals is related both to the need for oxygen to fuel aerobic metabolism and the necessity of eliminating carbon dioxide. The predominant site involved in oxygen sensing are the carotid bodies located at the bifurcation of the common carotid arteries. These oxygen sensors send afferent information regarding blood oxygen levels to neurons involved in respiratory control located in the rostral medulla and pons. Activation of these neurons results in a vigorous increase in ventilation in an attempt to correct the hypoxemia. Recent studies have shown that there is a central component of this response arising from a separate group of neurons that inhibits further increases in ventilation stemming from carotid body stimulation. This phenomena has been called ‘hypoxic depression’ and may involve central oxygen sensors residing in either the pons or the rostral ventral lateral medulla (RVLM). A previous study has shown that lesions in the pons eliminates the central depression of ventilation associated with hypoxia. In addition, one study in vitro has identified neurons in the RVLM that increase their firing rate in response to graded hypoxia. Anatomical tracing of neurons in this region have shown extensive projections to areas of the brainstem involved in respiratory control. Although the unique stimulus to the RVLM cells is not known, we hypothesize that changes in intracellular pH resulting from hypoxia-induced lactic acidosis may be important in altering the neuronal output.
     Using rat brain slices loaded with the pH sensitive dye, BCECF, we hypothesized that some neurons in the RVLM and pons would show a sustained acidification during exposure to hypoxia implicating these cells in the hypoxic depression response. We found that decreasing the oxygen concentration from 95% to 21% in artificial cerebral spinal fluid (pH 7.48) had no effect on intracellular pH in any off the cells in the pons tested. In contrast, we observed a slight and sustained acidification during hypoxia in many of the cells located in the RVLM. We conclude that although the pons appears to have the circuitry necessary for hypoxic depression the primary sensors may be located in the RVLM. In future studies we wish to examine: 1) the compliment of proton transporters present in cells located in the RVLM and 2) the relationship between neuronal activity and intracellular pH  [This work was supported through the generosity of the Merck Foundation Grant].
 

34.  Intracellular pH Regulation of Glia in the Medullary Chemosensitive Site,
       the Retrotrapezoid Nucleus
       Melissa Babbie, Biology Department

     Ventilatory effects of CO₂ arise from chemosensitive neurons widely distributed throughout the medulla oblongata.  One such site, the retrotrapezoid nucleus (RTN) plays an important role in sensing tissue levels of carbon dioxide, a by-product of oxidative metabolism.  Carbon dioxide results in the subsequent formation of carbonic acid thereby acidifying tissues. Given that most biological systems utilize proteins and enzymatic pathways that operate within a narrow pH range, it is crucial that there is tight regulation of tissue acid/base balance.  Intracellular pH (pH_i) is regulated by membrane bound transporters that exchange acid/base equivalents across the cell membrane.   Neurons in the RTN increase their activity with increased levels of carbon dioxide.  Recent evidence has shown that glial impairment with the selective glial toxin fluorocitrate in the RTN of the anesthetized rat leads to a decrease in extracellular pH (pH_o) and an increase in phrenic nerve activity.  This suggests that pH_o and hence neural activity of chemosensitive cells may be influenced in part by glia.  An initial step in understanding how glia may regulate pHo in this region of the brain is to identify the specie(s) of proton transporters present in this cell type.
     In this study, transverse brain slices were prepared from juvenile rats and treated with the neurotoxin kainic acid to generate a slice devoid of neurons.  Using the pH sensitive, fluorescent dye BCECF we monitored pH regulation in in single cells in response to an acid load generated using the ammonia-prepulse technique.  The kinetics of pHi recovery in RTN cells was  monitored in both the presence and absence of pharmacological agents known to inhibit specific proton transporters.  Cells were exposed to 4,4-diisothiocyanatostilbenesulphonic (DIDS) to evaluate the presence of HCO₃- dependent transporters and to amiloride to evaluate the presence of Na⁺/H⁺ transport (NHE).  This study revealed that there are two discrete populations of cells. One population of cells recovered from acidification utilizing an amiloride sensitive proton transporter. Based on previous studies it is likely this transporter is NHE. In contrast, a second population of cells recovered from acidification  using a DIDS sensitive proton transport mechanism. These data implicate HCO₃- dependent transport mechanisms. In addition, the presence of Na⁺/HCO₃- co-transport in some cells is supported by our observation that pHi in media containing CO₂ was  more alkaline than pHi in CO₂-free media. In conclusion, the glia in the RTN appear to rely on a single proton transport system . Depending on the cell, this may be either NHE, HCO₃- dependent transport, or Na⁺/HCO₃- co-transport. This work is supported through the generosity of the Merck Foundation.
 

35.  Was there ever rainfall on Mars?
        Shannon Brooks, Geology Department

     This semester I have been looking at Mars Global Surveyor and Mars Explorer images to see if I could answer this question.  The Martian channels that I have observed have been predominantly single channels, although there are a small amount of dendritic networks. Much of the planet has been severely cratered and wind blown, which may have lead to the disappearance of some channels.  Most of the channels seem to be outflow channels, instead of water flowing down from the surrounding land, it appears to have been flowing upward from underground. The dendritic channel patterns are small scale compared with the ones on Earth.  Plus, the channel networks have shorter tributaries then the ones we are used to seeing, which also brings up the lack of any other fluvial characteristics, including drainage basins.  With these problems, it may conclude that there may not have ever been rain on Mars in its past geologic history.
 

36.  Risky Behaviors In Children
       Anya Burke, Psychology Department
       Advisor: Dr. James Wallace

     Risky behaviors can allow youngsters to explore their identity, develop new  friendships, and progress through stages of maturity by determining what they are and aren't capable or willing to do (Maggs and Almeida, 1995).  Positive risks are those activities that we would encourage children to try, such as a new sport or volunteering to answer a question in class. Negative risks are those activities that are more harmful or dangerous such as jumping off a high cliff or drinking alcohol.  Developing a healthy distinction of what is a positive risk and what is a negative risk is a part of growing up and experimenting.  The present study is designed to determine the elements that children take into consideration when deciding whether or not to engage in a risk, and to explore the occurrence and determining factors of both the positive and negative risks that children choose to take.  The participants in the study are 72 fourth, sixth and eighth graders from Canton Middle School.  All children were tested in small groups.  Each child completed a questionnaire composed of 18 risks and a series of follow up questions intended to investigate factors that they consider when contemplating the risk.  Multiple regression analyses will help us to determine the relative importance of potential predictors for each risky behavior.
 

37.  The College Years: The Effect of Self-Esteem Level on Alcohol Related Risk
       Taking Behavior
       Christine McAuliffe, Psychology Department
       Advisor: Dr. Sarah Dakin

     This study extends previous self-esteem research performed by Rosenberg (1956) and others. It attempts to identify self-esteem level as a predictor of how risky one will be in his/her consumption of alcohol and other alcohol related behaviors. The study utilizes a self-esteem scale manufactured by Rosenberg as well as four researcher produced "Choose-Your-Own-Adventure" stories in order to correlate risk taking behavior with self-esteem level. The "Choose-Your-Own- Adventure" stories cover alcohol behavior, sexual behavior, academic risk taking, and health behavior and were produced using data from a pilot study conducted by the researcher. The stories allow the subject to actively choose what decisions they would make in specific situations, with each decision effecting the overall outcome of the story. The self-esteem scale and "Choose-Your-Own-Adventures" will be distributed to the subject pool in mass testing sessions, with the subjects coming from the Psychology department pool. Once data has been collected from approximately 100 PSychology students (both upper and lower level students), the scores on the self-esteem scale will be correlated with the scores on the individual alcohol related "Choose-Your-Own -Adventure." The scores from the other three "Choose-Your-Own-Adventures" will not be correlated with the self-esteem scores as they were used primarily as distractors for the study. The correlation between the self-esteem scores and the alcohol story scores is predicted to show a curvilinear relationship between the two variables (i.e. both high and low self-esteem scores will correlate with low alcohol risk taking while mid-range self esteem scores will correlate with high alcohol risk taking).
 

38.  Has Technology Helped or Hindered the Population Crisis?
      David Bentley, Biology Department
      Advisor: Dr. Brad Baldwin

     Possibly the biggest threat to the future survival of the human race, and all other species for that matter, is the overexertion of the earth’s resources.  The continual growth of our population is constantly eating away at the world’s finite resources, hence exceeding the carrying capacity of the planet.  It may not seem like a big problem now, but eventually, we will not be able to feed the entire population and not just human will suffer, but all other organisms as well.  To ensure that this day never comes we must start to activate greener technologies and to get a handle on our over consumption and over population.
 

39.  The Use of Expert Testimony in Cases of Domestic Violence
      Marianne Rugari, Psychology Department
      Advisor: Dr. Cathy Crosby-Currie

     In order to help people understand the dynamics of domestic violence and the situation many battered women are in, the use of expert testimony in the courtroom has been introduced to support claims of self-defense by a battered woman who is on trial for killing her abuser.  The traditional form of expert testimony is battered women syndrome testimony, which explains the actions of the battered woman as stemming from the cycle of violence in a battering relationship and a result of learned helplessness.  This testimony has been criticized because it pathologizes the battered woman who defends herself against her abuser, suggesting her actions are the result of a mental disorder or illness.
     Due to this criticism, an alternative form of expert testimony, called social agency testimony, has been suggested which emphasizes the social reality of the situation the battered woman is in, such as the inadequacy of the police response, instead of the pathological reactions.  Research has shown that both types of testimony significantly increase the likelihood of not guilty by self-defense verdicts than when no expert testimony is provided at all; however, research has found no difference in the effect of the two types of testimony on verdicts.  The present study focuses on the mechanism through which these types of testimony are successful in achieving not guilty by self-defense verdicts.  It is hypothesized that whereas battered women syndrome tendency leads to a pathologizing and subsequent excusing of the woman, the alternative testimony leads to not guilty verdicts by changing the jurors’ misconceptions of domestic violence.
     One hundred and forty-five Introductory Psychology students participated in the study.  Participants first completed a survey of beliefs questionnaire during a group testing session.  Three weeks later, the participants were exposed to an audiotaped re-enactment of an actual trial which contained either social agency testimony, battered women syndrome testimony, or no expert testimony at all.  Then, participants rendered an individual verdict and completed a questionnaire regarding the case and the defendant and the survey of beliefs again.
Although all of the data have been collected, we are still in the process of data collection which will be complete by the time of the presentation.  Of the total sample of participants, 2.8% voted for first degree murder, 9.7% voted for second degree murder, 39.3% voted voluntary manslaughter, and 48.3% voted not guilty by self-defense.  The guilty verdicts were collapsed, and a dichotomous, guilty-not guilty outcome variable was created.  Surprisingly, in light of previous research which has consistently found a significant effect for the presence of expert testimony, a chi-square on the outcome variable by testimony condition was not significant, ² (2,145) = .965, n.s.  Before the hypotheses can be further explored, explanations for this finding must be investigated.  Preliminary analyses on memory checks suggest that participants were committing many errors, in particular in their memory for the judge’s instructions regarding the verdict categories.  These errors may explain the surprising finding as well as having significant implications for jury research in general.
 

40.  The Relationship between the Loss of Perceptual Intensity and Water Solubility in
       Subjects  with Colds
       Landry, A.L.,¹ Hornung, D.E.,^1,2 and Kurtz, D.B ²
       1. Biology Department, St. Lawrence University, Canton, NY, 13617
       2. Department of Neuroscience and Physiology, SUNY Health Science Center,
           Syracuse, NY, 13210

     This study examined the hypothesis that the magnitude of the decrease in olfactory ability that is usually seen during a cold (Chojnacki et al., Chemical Senses 19(5): 453, 1994) is related, in part, to an odorant’s water solubility (Hornung et al., Chemical Senses 20(6): 710, 1995).  After subjects with upper respiratory infections were confirmed to be hyposomic by scoring between 20 and 30 on the University of Pennsylvania Smell Identification Test (UPSIT), sixteen subjects rated the perceptual intensity of 18 odorant stimuli using the Green Scale (Chemical Senses 18:683-702, 1993).  The test series was composed of nine odorants chosen based upon their water solubilities (Propionic Acid, Butyric Acid, Isopropanol – highly water soluble; Octanol, Hexanoic Acid, Pentanol – moderately water soluble; Hexanol, Trans-cinnamaldehyde, Heptanoic Acid- water insoluble).  Each odorant was presented at two concentrations resulting in perceptual intensities of about 40 and 20 as judged by normosmic control subjects.  Subjects with colds also used the Green Scale to rate the brightness of a series of lights.  After the cold had resolved, subjects repeated the odorant and light intensity ratings.  The perceptual intensity of the highly water soluble odorants was reduced by 36% in subjects with colds, whereas the intensity was reduced by 24% for the moderately water soluble odorants and only 12% for the water soluble odorants.  The cold did not affect the light intensity ratings.  We hypothesize that during a cold there is a direct relationship between an odorant’s water solubility and the percent of incoming molecules that are sorbed by the narrowed passageways.  As a result, water-soluble odorants have comparatively fewer odorant molecules that reach the headspace above the olfactory receptors and so the perceptual intensity for these odorants is more dramatically reduced during a cold.
 

41.  The effect of the drag force on model rocket flight
       Stacey Benson, Physics Department
       Advisor: Dr. Catherine Jahncke

     In our previous studies of the height achieved by model rockets, we have found that our simple model used to predict the height is inadequate; the drag force must be taken into account.  We present the results of a study of the thrust of Estes* model rocket engines and the drag coefficient of model rockets.  In order to accomplish this we have divided the study into two components.  In the first part we determined the thrust and impulse of Estes model rocket engines.  In the second part we determined the drag coefficient of the rocket and the thrust of the engine.  Two types of rocket engines were tested: 1/2A-6 and A8-3.  For A8-3 engines the average thrust was measured to be 3.00 +/- 0.39 N, and for the 1/2A-6 the average thrust was measured to be 4.32 +/- 0.38 N.  These are well below the Estes' reported averages. However the measured impulses are in excellent agreement with Estes' published data.  The measured A8-3 impulse is 2.36 +/- 0.07 as compared with Estes' data of 2.5 +/-.25 Ns and the 1/2 A-6 has a measured impulse of 1.24 +/- 0.3 Ns as compared with Estes' prediction of 1.25 +/- .125 Ns.  The next step in the research process was to determine how the drag coefficient influences rocket flight.  To accomplish this we digitized a video-tape of the rocket trajectories for of both types of engines.  We developed a model describing the height of the rocket as a function of time that included the drag force of the air.  We fit the model to the data in order to determine the drag coefficient of the rocket and the average thrust of the model rocket engine.
*Estes is the leading manufacturer of model rocket engines.
 

42.  Beowulf Clusters
       Caleb Crane, Math Department
       Advisor: Brian C. Ladd

Assume for a moment that the physics department at St. Lawrence University needs to crunch an incredible number of astronomical related numbers. The person in charge of the project could attempt to complete the project with a typical lab PC, and fifty years later they
would get the results. Given the current computer technology, if they wanted to complete their project in a reasonable amount of time they would have to purchase a parallel computer.

 A parallel computer is capable of executing multiple instructions in parallel, while a classical sequential computer, a lab PC, is only capable of executing a single instruction at a time.

 Now our physics department technician has two choices for purchasing a parallel computer. They could contact Silicon Graphics and buy a Cray supercomputer for several million dollars. The other alternative is to build a Beowulf cluster. In order to build a Beowulf the technician would need to log onto the Internet and order fifty modestly priced PCs and a high-speed network switch to connect them. Total cost for a Beowulf, around fifty thousand dollars.

My senior project used donated PCs and the Linux operating system to build a small Beowulf cluster. A program to take advantage of the parallel architecture of the Beowulf was written in order to demonstrate the benefits of parallel computing. This program solved a one-dimensional equation, which calculates the diffusion of heat through a substrate. Running time of this model on one, two, three and four processors is presented.
 

 43.  The Effect of Water Depth and Trim Angle on Efficiency in Marathon Racing Canoes.
        Brendan Hogan, Physics Department
        Advisor Dr. Brian Watson

      In the world of marathon canoe racing, technology is increasingly being used to ensure that competitors have the greatest chance for success.  Typical races are up to fifteen miles and two hours in length and for that reason even small improvements in efficiency will have a significant effect on performance.  One proposed improvement is to shift the center of gravity of the boat forwards when the boat is in shallow water.  The idea is that having the canoe trimmed bow down (the front end lower then the back end) is more efficient when traveling through shallow water.
      The purpose of my project is to access the validity of that claim.  I will be using a one-sixth scale model of a racing canoe and simulating the effect of paddling through still water by holding the model in place while a current of water flows past it.  By measuring the drag of the model while it sits at a range of different trim angles, I can determine how the weight should be positioned in the canoe for a given depth.  By repeating that procedure at a range of different depths I will be able to determine whether moving the weight forward in a canoe does have the desired improvement in efficiency when traveling in shallow water.  The results may then be extrapolated to life-sized canoes by using scaling laws.
      My results to date indicate that there is a surprisingly significant change in efficiency of the canoe for even small changes of the trim angle.  For example, in the deep water regime, a change of only one degree in trim angle changes the drag by a factor of four.
 

44.  FOSSIL ORIBATID MITES (ARTHROPODA: ACARI) AS PROXIES FOR
       PALEO-HABITAT INTERPRETATION, HISCOCK SITE (LATE PLEISTOCENE),
       BYRON, NEW YORK.
      Booth Platt, Geology Department
      Advisor: Dr. J. Mark Erickson

      This project compares oribatid fossil assemblages with living faunas in order to make inferences about paleo-microhabitat.  Fossil mites can be used as proxies for paleo-vegetation and paleo-climate conditions.
       Five stratigraphic samples from 4 units were washed, stored in ethanol, picked under a dissecting microscope and the fossils mounted in Hoyers medium.  Identifications of the specimens were made to the generic level and subsequently verified by Dr. Valerie Behan-Pelletier (Agriculture Canada) and Dr. Roy Norton (SUNY-ESF) who included species identifications where possible.
      Data here commence with the stratigraphically oldest unit, the cobble layer, which contains little organic material and no mites.  Above that lies the fibrous gravelly clay layer, which includes chopped conifer twigs, but contained no oribatids.  The lower portion of the overlying woody layer contained a sparse oribatid fauna including the genera: Podoribates(1), Galumna(2) and Anachipteria(1).  The upper woody layer, has a wide range of genera including Heterozetes(14), Naiazetes(2), Zetomimus(1), Ceratozetes(1), Hydrozetes(1), Pergalumna(1), Podoribates(2), Trimalaconothrus(1), Tectocepheus(3), and Tegeocranellus(2).  Achipteria(1), Peloptulus(1), Carabodes(1), and Suctobelbella(1) were reported previously by Jennings (1993).  Laub (1988)  demonstrated that a disconformity occurs within the woody layer between our samples.  Lastly, a fine peat unit, the dark earth layer, produced the greatest generic diversity. Heterozetes(13), Naiazetes(1), Pelopsis(1), Suctobelbella(2), Allosuctobelba(1), Oripoda(2), Scheloribates(4), Rostrozetes (1), Podoribates(3), Phauloppia(2), Protoribates(1), Ommatocepheus(1), Trimalaconothrus(2), Tegoribates(2), Anachipteria(1), Tectocepheus(2), Tegeocranellus(1), Cultrobates(1) were discovered.  Ceratozetes(1), Zetomimus(2) and Oppiella(1) were reported by Jennings in 1993.
 Some oribatids are eurytopic and are unlikely to represent specific micro-habitats when found in fossil deposits thus rendering them poor proxies.  An example at the Hiscock site is Tectocepheus velatus, which is a cosmopolitan species ranging from temperate to arctic habitats all across the globe (Behan-Pelletier, 1978).  Hiscock stenotopic taxa include Hydrozetes, Trimalaconothrus, Heterozetes and Zetomimus, which require standing water; Naiazetes and Tegeocranellus from wet grasses on bog margins; Podoribates is a dry grassland taxon; Oripoda, Scheloribates are arboricolous taxa whereas Ommatocepheus is found on lichens covering dead tree limbs and bark.  Phauloppia lives on the bark of elm trees, and Cultrobates dwells in hardwood litter.   These habitat preferences suggest that the site was open, grassy and not very wet when woody layer deposition began, but that it became quite wet in the upper part dominated by the several aquatic and semi-aquatic taxa.  The diverse fauna from the peat-rich dark earth layer suggests that the site remained wet, but dry areas existed in the nearby surroundings, indicating that the climate might have been more temperate but dryer again.
 

45.  An Overview of the Steiner Problem
       Allen Zoracki, Math Department
       Advisor:  Dr. Patti Lock

      The Steiner Problem is a topic in Graph Theory in mathematics that explores the question: what is the shortest network of edges interconnecting an arbitrary set of points?  This question has been answered for very few cases.  In particular, the first that was considered was the case of three vertices, for which the shortest network is a set of three edges meeting at a junction point in such a way that the edges form 120^o angles with one another.  However, for larger sets of vertices, the Steiner Problem cannot be solved in a reasonable amount of time.
      The Steiner Problem is NP-complete, meaning that it is in the class of the hardest of all problems without a solution in polynomial time.  The difficulty of the problem arrives from the large number of possible solutions that must be checked in order to find out which has the shortest length.  For example, for sets of ten points, the number of possible solutions is in the millions, and for sets of twenty points, the number of possible solutions is in the billions.
     The few cases for which the Steiner Problem has been solved are sets of three points, sets of four points, ladder graphs, square lattice graphs, vertices of a regular n-gon, vertices on a zig-zag line, and vertices of a splitting tree.  I have done an in depth study on the first four of these categories.  These few topics alone cover a majority of what is known about the Steiner Problem.
The most interesting property of the Steiner Problem is that it is easy to understand, but extremely hard to solve.  Thus, making conjectures about the solution to a certain problem is easy with basic knowledge about the properties of Steiner trees and using the method of trial and error.  I have studied the case of a 5 x 6 lattice and made a conjecture as to what the shortest network is for this graph, and I have shown that this conjecture is a good answer to the problem, without proving it to be the best solution.  While good solutions can be attained in most situations, a complete solution to the problem will probably never be found.
 

46.  The Kinetics and Temperature Dependence of F sex factor Mediated Conjugation in
       Escherichia coli
       Njogu J. Njuguna, Biology Department
       Advisor: Dr. Allen Rogerson

     Bacterial conjugation is a plasmid mediated deoxyribonucleic acid (DNA) transfer mechanism in which DNA is transferred from a donor to a recipient cell across the cell wall and membranes of both cells when the cells are in contact. The best-known self-transmissible plasmid is the F-plasmid, which contains the F sex factor responsible for mediating conjugation between F⁺ and F- bacteria. The mechanism for DNA transfer mediated by the F sex factor has not been not been determined, but it is known to involve the F pilus, which initiates cell-cell contact between the donor the recipient cells. Harrington and Rogerson (1990) demonstrated that the F-pilus could serve as a conduit for DNA during conjugation, in the absence of direct cell to cell contact.
     This research project is focused on determining the kinetics of high frequency recombination (Hfr)-mediated DNA transfer, as well as the effects of temperature of this mechanism. This has been achieved 6 micron thick polycarbonate filters (Nucleopore) with up to 10^-9 pores (diameter: 50 nanometers) to separate mating pairs comprising bacteria which area assayed for transconjugant formation. Cells of an E. coli Hfr strain, KL226, were plated on nutrient agar transfer plates and separated from a multiple auxotroph lacking genes for six different nutritional markers, AB1157, which were plated on Davis and Mingioli (DM) minimal agar plates with different combinations of amino acids.
     The results found thus far have show that the expected order of transfer of nutritional markers relative to the oriT (proline, leucine, threonine, thiamine, arginine, histidine) of HfrC is reversed. What has been seen so far is that leucine transfers and recombines fastest, followed by threonine and proline. Triple recombinant transconjugants (proline, leucine and threonine) that have to receive all three genes from the donor before they can grow on selective minimal agar plates have also been seen to form faster than proline transconjugants. Further experiments have yielded the following: proline transconjugant formation at 0.5 and 1 hour is significantly slower than triple transconjugant formation. The rate of formation (i.e. receipt of DNA from the donor cell via conjugation and its recombination into the chromosome) of both proline transconjugants and triple recombinant recipient cells is not significantly different at 2 hours.
Interrupted mating experiments using recipient cells transformed with an ampicillin resistance gene are currently being run to determine the order of transfer, and hence the possible identity of the Hfr strain responsible for the transfer of genes from the donor strain KL226. Further experiments will also be run to determine how the temperature at which the transfer assays are performed will affect the rate of marker transfer, and an analysis of transfer at 37^oC, 42^oC, and 20^oC will be made relative to F-plasmid mediated transfer.
 
 

Created by: Peg Barkley
4/18/2000