Graduate Mentor Research Projects - 2009
For the 2009-2010 year we have 8 mentors who will be working with undergraduate fellows.
Amanda Bosch, Psychology
Kristine Callis, Biology
Samantha Hilber, Biology
Lan Hoang-Minh, Biomedical Engineering
Babak Mahmoudi, Biomedical Engineering
Clare Rittschof, Biology
Christine Stracey, Biology
Monique Udell, Psychology, Animal Behavior
Links to previous projects: 2007, 2008
PhD Student – Psychology
Project Areas: Autism in children; training verbal behavior in dogs
Common Autism Treatments- In this study, we will be evaluating the effectiveness of social stories and weighted vests, two interventions commonly-used with autistic children. We will begin by conducting a functional analysis (a standard assessment to determine why behavior is occurring). Then, we will compare a social story developed to target the participant’s problem behavior (or weighted vest) with a behavioral treatment based on the results of the functional analysis. If social stories or weighted vests are effective at decreasing problem behavior, we will attempt to figure out why. We will be working with children who engage in problematic behavior and who have receptive and expressive language necessary for listening to a story and answering questions about the story. Research will be conducted during weekdays at a school in the Gainesville area.
Evaluation of Repetitive Behavior- The purpose of this study is to determine situations that make repetitive behavior (e.g. nail biting, hair twirling, skin picking, stereotypy, or self-injurious behavior) more likely. If repetitive behavior occurs more in one condition of a functional analysis, we will evaluate ways to decrease repetitive behavior. This study will be conducted with both children and undergraduates. Research with children will be conducted during weekdays at a school in the Gainesville area. The research with undergraduates will be conducted at the university throughout the week, and possibly on weekends and evenings.
Training verbal behavior in dogs- The purpose of the study is to evaluate if dogs are capable of requesting certain preferred items by bringing stimuli associated with the items to a human. The study consists of training dogs to associate certain frisbees with different treats and then training them to bring the frisbees to request a treat. Participants are privately owned dogs, and sessions will be conducted in the dog’s homes.
Undergraduate research assistants will be involved in every step of each research study. They will conduct sessions and collect data. In addition, they will be taught to analyze and graph data. Undergraduate research assistants will also learn to calculate agreement scores between observers.
PhD Student – Biology
Project Area: Is silica a defense strategy in cucumber? A study of plant-animal interactions.
Herbivory induced silica in cucumber:
Previous research suggests that plants may be able to regulate silica accumulation in response to herbivory -- insects and animals eating the plants. Understanding how plants defend themselves against herbivory can help scientists better understand the balance between plant and animal populations, as well as potentially develop natural insecticides. I will guide an undergraduate in designing an experiment to test the hypothesis that plants start to uptake silica when they experience herbivory. We will gather baseline data that will then be used in a field study for “real world” data. We will use cucurbitaceae (cucumber) as our model plant since it grows in both warm and cool climates and is both of ecological importance, as a vine in the forest, and has horticultural importance as a crop. Undergraduates who work on this project will learn to design an experiment to answer an original question. They will also gain experience in greenhouse, lab and field techniques, such as learning how to tent plants to keep insects in or out of plants, isolating and quantifying silica in leaves, and designing and running large scale studies in field settings. Depending on the results of the experiment, there may be an opportunity for traveling to other field sites in Panama and the northern USA.
Physical mechanisms to trigger silica accumulation:
What is the physical mechanism that induces silica uptake? Previous research suggests that plants sequester silica to defend against herbivory –picture an insect taking a juicy bite of plant leaf, only to get a mouthful of glass. This defense strategy has been shown to be inducible, which means that plants only start to accumulate silica after they have experienced herbivory. However, it is not well understood what the physical mechanisms are that trigger silica accumulation. In order to determine the cause of silica uptake under the influence of herbivory, we will design an experiment to test various mechanisms of damage (such as tearing or cutting of the leaf, scratching the leaf surface…) and how they affect silica accumulation in cucumber plants. Undergraduates who work on this project will learn how to design an experiment to test an original hypothesis and how to use various leaf damaging techniques, such as pinhole testing for leaf toughness. Since this is an important piece of the puzzle in plant silica research, upon completion of the study, the undergraduate will have the opportunity to write up results for possible publication.
Advantages of working with plants and silica: the timing of work hours is very flexible, since cucumber grows quickly, with high success rates and without much help. This means it does not usually take long hours to set up experiments, nor do you need to babysit the experiment while it runs. Silica, once accumulated, is very stable. Therefore silica testing can be done when convent. Research in this topic also allows for the possibility of working in the greenhouse, the lab and the field, so that you never get stuck in one place for too long.
PhD Student – Biology
Project Area: Parental care in Neotropical fishes
Website: http://www.zoology.ufl.edu/sahilber/
Broadly, I am interested in the behavioral and evolutionary ecology of reproductive biology. Currently, my research focuses on the dynamics of parental investment in fishes; i.e., how and why parents care for their offspring. The study of parental investment is essential for understanding mating systems in animals; because many of the most remarkable differences in the reproductive biology of males and females are associated with their involvement in offspring care. For example, parental investment can, in part, determine the intensity of competition between individual within a sex and conflict between the sexes.
My study species is the biparental convict cichlid fish, in which both parents take extensive care of offspring for several weeks after hatching. Thus, in this species, parental investment can be investigated at two levels: gamete investment and (post-gamete) care of offspring. The specific questions students working with me might address include: (1) does a parent who cares for offspring alone take longer to re-mate; (2) do offspring preferentially associate with one parent versus the other parent; or (3) is filial cannibalism (i.e., parents eating their offspring) a significant source of offspring mortality? By investigating these questions, we can gain insight into the costs and benefits of providing care to offspring, and thus better understand the cooperation (and conflict) between males and females during biparental care.
I will involve students in my research by working with them to develop individual projects within the area of my research. This will allow students who work with me to participate in all aspects of the scientific process: formulating questions, experimental design, data collection, data analysis, and presentation of results. Depending on the particulars of a project, a student will also learn at least one of the following: to quantify behavior from visual observations, or to quantify reproductive investment from egg clutches. In addition to their individual projects, students will also learn how to care for and handle laboratory fishes, and the basic experimental procedures used when working with fishes. [Please note that the fish require daily care and typically students will be expected to be in the lab daily.]
My expectation is that a student, with guidance, will generate novel findings, co-author a manuscript to be submitted to a scientific journal, and present their research at a scientific meeting. I am particularly interested in students wishing to design and conduct carefully controlled innovative experiments to reveal insights into parental behavior of these fascinating fishes.
PhD Student – Biomedical Engineering
Project Area: Circadian control of neurogenesis
Website: http://stemcell.bme.ufl.edu
The overall goal of my project is to investigate the mechanisms behind the circadian control of cell production in the adult brain. Several studies have shown that more new neurons are produced in the hippocampus of adult rats and mice during the dark (active) rather than the light (inactive) phase of the light:dark cycle. I will also be investigating whether circadian shifts in cell production are observable in other areas of the brain, such as the substantia nigra and the cerebral peduncles.
Undergraduate research assistants will be valued members of our lab, who will be properly trained and guided to conduct smaller individual projects within the framework of my graduate research project. These smaller projects will include rodent brain sectioning, histological staining and analysis using a light microscope. Students will learn how to collect, input, and analyze data. They will be encouraged to think critically about their projects, keep detailed records of their experiments and results, and find information from primary resources in the scientific literature. Students will also be supervised in the analysis, writing, and presentation of their projects for the UF Undergraduate Research Symposium and a national scientific conference. In addition, our research team will work together to develop a collaborative manuscript that will be submitted to a scientific peer-reviewed journal. Students will attend weekly lab group meetings where graduate and undergraduate students discuss their research projects, as well as discoveries in the neuroscience and stem cell biology field, with the group and our faculty research advisor.
These experiences will be especially useful to students wishing to pursue a career in research in the future. Applicants are encouraged to contact me at hoang@ufl.edu if they have questions about research in the Ormerod Laboratory, or wish to discuss their interest in working in our lab.
PhD Student – Biomedical Engineering
Project Area: Brain-Machine Interface for motor neuro-prosthetics
Website: http://nrg.mbi.ufl.edu
My research is on designing a Brain-Machine Interface (BMI) for direct control of a prosthetic device using brain activity. This technology is to enable patients with severe motor deficiency (spinal cord injury) to bypass their injury and control their prosthetic devices directly with their thoughts. In order to interface the prosthetic device with brain, we conduct neurophysiologic studies in behaving animals by recording the firing activity of ensembles of neurons in rats using electrophysiology techniques. The data are then analyzed to determine aspects of the “neural code” to understand the neural response of the brain during goal-directed behavior. Ultimately, a decoder would be designed to convert neural response to actions.
For reaching and grasping tasks, we are interested in the perception-action cycle; therefore, neural activity is recorded from the forelimb motor area (M1) and a reward center of brain called Nucleus Accumbens (NAcc) that represents goal information. We have designed a framework in which the BMI integrates goal information and motor commands extracted from brain to generate goal-directed trajectories. This project spans three main areas; operant conditioning and behavioral experiment design, neural recording and data analysis and finally running closed-loop experiments where the animal uses brain controlled robotic arm to complete a reaching task. Within my project, there are three sub-projects that mentees would be involved in:
- Stereotaxic neurosurgery to obtain chronic microwire array electrophysiology from the brain
In this project mentees would learn stereotaxic neurosergery to implant microwire electrode arrays chronically into M1 and NAcc areas of rat’s brain. During a lever press task, neural activity of motor neurons in M1 and reward neurons in NAcc would be recorded simultaneously. The aim of this project is to detect a pattern in the neural activity of M1 and NAcc neurons that signals motor intent and the reception of reward.
- Investigating the coordination between motor states and reward expectation in the brain during goal-directed behavior
In this study, students will conduct operant conditioning behavioral experiments. Rats would be trained in two paradigms. In the first paradigm they would press a set of levers in their cage to earn water reward. In the second paradigm, pressing the cage levers would activate a robotic arm to press a set of distal levers for earning reward. During the behavior, neural activity of M1 and NAcc would be recorded. The aim of this study is to analyze and compare the relationship between motor states and reward expectation in the brain during manual and robot assisted execution of reaching task.
- Running control BMI experiment
Students will learn how to design a closed-loop BMI system that acquires signals from the brain and translates them into prosthetic arm control. This area of study involves learning real-time data acquisition, computing, and biomechanics of robotics. As mentioned above, my project is on developing a new framework for BMI design in which goal information is integrated with motor commands to generate goal-directed trajectories. The aim of this project is to benchmark our BMI design against trajectory based BMIs that do not incorporate goal information.
Students can work on each of these projects but are not limited to one. Getting involved in each of these projects, students would be exposed to a broad range of scientific experiences. Mentees would gain experience on how to collect experimental data and analyze the collected data to test their hypothesis in a problem driven project. During this experience they would learn electrophysiology techniques and data analysis methods for investigating neural data. Students are expected to participate in our weekly lab meetings where a specific topic is discussed. In addition to achieving technical experience, I hope students learn to think critically and take initiative at research in order to generate new ideas and experiment their ideas in a scientific way.
PhD Student – Biology
Project Area: The evolution of mating tactics in the banana spider
Variation in reproductive success among individuals within a species is the cornerstone of evolution by natural selection. Individuals who have the greatest reproductive success have the greatest genetic contribution to subsequent generations. Understanding the tactics animals employ to achieve reproduction is fundamental to our knowledge of species evolution. My general interests are twofold; first, to illuminate the selection pressures individuals face when making reproductive decisions, and second, to understand the variety of ways in which these selection pressures have shaped the evolution of reproductive behavior.
Broadly, my research foci are centered on the evolution of mating tactics in the banana spider, Nephila clavipes. N. clavipes has a partial sex-role-reversed mating system: there is male-male competition as well as male mate choice. Such mating systems are complex and poorly explained by current sexual selection theory. One major focus of my research is to understand how male mating tactics accommodate both the costs of mate search and male-male competition and the benefits of mate choice. My second research goal is to explore whether male N. clavipes account for partner mortality risk when making mating decisions. In species with sperm storage like N. clavipes, reproductive pay-off for males is delayed; they risk losing their investment if their mate dies before she lays eggs. In general, if females in a population differ both in their quality as a mate (as measured as proportion of brood sired by the male in N. clavipes) and their probability of surviving a breeding cycle, a female’s profitability and mortality represent two conflicting mate choice criteria for males. For N. clavipes, this trade-off is particularly important because males are sperm limited. Partner mortality risk as a component of mate choice could be widespread in the animal kingdom, and N. clavipes presents a unique opportunity to explore this feature of male mate choice.
Undergraduate assistants have the opportunity to assist on projects directly related to my research goals. In particular, this summer I am interested in developing a mate choice bioassay for males in order to test the criteria used in male choice. This will involve monitoring male behavior both in real time and with video recordings in a semi-natural enclosure where males are presented with two potential female mates. A second project involves quantifying female mortality risk. This project will involve monitoring females in the field over time in order to estimate mortality at different life stages. A third project is centered on understanding how body size affects male-male communication and competition. This project involves pairing male competitors on a female web and measuring rates of male signaling and the probability that an encounter will escalate to a fight. I am interested in motivated students who will work with me as a team to gain experience developing and carrying out a research project. Students should not be afraid to provide creative input on experimental design and project goals. This is a great opportunity for students that enjoy working outside, and want to gain expertise in field techniques, sexual selection theory, and evolutionary biology.
PhD Candidate – Biology
Project Area: Effects of urbanization on bird communities
Project website: http://www.flmnh.ufl.edu/ordwaylab/stracey/
I am investigating the effects of urbanization on bird communities for my dissertation. One characteristic of urban bird communities is an increased abundance of certain species. How is it that some species are able to survive, and even flourish, in urban areas? To answer this I am testing two hypotheses that could explain why Northern Mockingbirds are more abundant in urban habitats than in non-urban habitats: an increase in food resources and a decrease in nest predation rates in urban habitats. To test these hypotheses I am comparing reproductive parameters of mockingbirds in parking lots, residential areas, pastures, and wildlife preserves. Understanding the mechanisms that underlie patterns of community structure in urban environments is critical for predicting how species will respond to urbanization and for providing recommendations to urban planners.
Project 1: How does light pollution affect mockingbird behavior?
With the exception of a few studies on amphibians, sea turtles, and migrating birds, scientists know very little about how light pollution influences populations of wild animals. Because mockingbirds are mostly insectivorous during the breeding season an increase in light may allow them to forage for longer periods of time. For this project we will be investigating how mockingbirds that live under different levels of light pollution vary their daily time budgets and their feeding rates of nestlings. This would be the first study to investigate the effects of urban light pollution on breeding parameters of a bird species.
Project 2: Do mockingbirds adjust their songs in response to urban noise?
Recent research has demonstrated that some birds living in noisy urban environments sing at a higher pitch to overcome background noise. Because mockingbirds mimic other bird species in their environment as well as other noises, e.g. car alarms, they are likely to demonstrate marked differences in song properties between urban and non-urban populations. There is also an opportunity to compare which sounds are mimicked in the two environments and to see if mimicked versions of the same sounds differ between habitats. For this project we will collect recordings of mockingbirds singing in urban and non-urban habitats, along with recordings of ambient noise.
Both of these projects will require a significant field component in the summer followed by data processing in the fall and writing in the spring. I will work with my students during each step of the process and train them in the field techniques they will be using. Once they are comfortable with the techniques, I expect my students to take the lead in data collection and processing and take ownership of their projects. By taking on their own projects, students will gain valuable experience in the process of science, from the development of ideas and methods to the production of a final product in the form of a poster/presentation at a national meeting and a co-authored manuscript that will be submitted to a peer-reviewed journal.
PhD Student – Psychology, Animal Behavior
Project Area: Human-canine interactions: The domestic dogs’ responsiveness to human gestures.
My research is in the area of canine social behavior and cognition, specifically social interactions between domestic dogs (Canis familiaris) and humans. Our lab works with dogs from a variety of niches (pets in human homes, working dogs, pound dogs, ect.) to identify aspects of environment and experience that predict a dog’s responsiveness to human gestures on a number of behavioral tests. Although previous research had suggested that the unique social interactions that characterize the human-dog symbiosis were mainly the result of genetic domestication, our lab has recently demonstrated that this is only a piece of the puzzle. Not only can non-domesticated canids, such as wolves, use human gestures to solve behavioral tasks if they are intensely socialized, but domestic dogs in impoverished environments (e.g. the pound) generally do not.
Since domestication alone does not explain the origin or maintenance of the domestic dogs’ sensitivity to human behavioral cues, I am currently asking two related questions: (1) What variables better predict a canid’s ability to utilize human social stimuli (e.g. gestures) to enhance success in their environment, (2) What are the stimulus properties of human social stimuli that domestic dogs are attending to during choice tasks, and can this knowledge be used to improve the performance of underperforming subjects (e.g. dogs in the pound)? The goal is to identify variables that predict successful or unsuccessful human canine interactions, based on a dog’s ability to utilize simple human gestures to obtain access to available reinforcers- such as hidden toys or food. These findings will contribute to a more refined understanding of how millions of dogs adapt to and succeed in a variety of human environments and identify factors that promote or hinder this aspect of canine social development.
More information about this research can be found on our website www.caninecognition.com
Overview of Undergraduate Involvement
Undergraduate members of this research team will also be valued members of our lab. Each student will first learn about the methods we use by acting as an assistant in one or more on-going studies. Based on their interests, they will then have the opportunity to carry out an independent project related to one of the two broad questions outlined above. Students will learn how to collect, input, and analyze data, become familiar with the current scientific literature in this field, attend weekly lab meetings, and present his/her findings at a national conference. In addition, our team will work together to develop a collaborative manuscript to be submitted to a scientific peer-reviewed journal. These experiences will be especially useful to students wishing to pursue a career in research or graduate school in the future.
Applicant Considerations
This research will involve working directly with domestic dogs on a regular basis. Applicants should be comfortable handling dogs and working in a variety of environments where dogs are housed. Applicants are encouraged to contact me if they have questions about this research, or to discuss their interest in working with our lab.
