REU MENTORS LIST- Summer 2008

Cassandra Allsup, PhD student
Program of Ecology, Evolution and Conservation Biology (PEEC)
Montane meadows are important components to forest ecosystems. Not only do the conservation of meadows increase biodiversity but, they also render habitat and food for wildlife and provide aesthetic value. Mutualisms with Versicular-Arbuscular Mycorrhizas (VAM), an association between a plant’s roots and fungi, are prevalent in nature and are intimately associated with 80% of terrestrial plants (Smith and Read 1997).  A mycorrhizal relationship may not only contribute to nutrient exchange but, also play a major role in the structure, function, and biodiversity of communities; differentially affecting the growth of different plant species or determining their presence within the community altogether.  Thus, to understand the ecology and evolution of community composition we need to understand the interactions between mycorrhizae and their host plants.
In this study I am interested in understanding the role of mycorrhizas on plant compensatory responses (regrowth and reproduction) following herbivory, given that it is an area that has not been unexplored.  Our previous studies have shown that scarlet gilia, Ipomopsis aggregata, overcompensates (increases fitness) following ungulate herbivory.  When ungulate herbivores remove 95% or more of the aboveground biomass of this monocarpic biennial, the product of lifetime seed production, seed germination, and seedling survival averaged 3.0 times that of the uneaten controls.

Diana Anderson, Quaternary Studies and Geology

Recognizing Landuse Changes on the Navajo Nation using Aerial Photography:

Much literature describes the impact of grazing on the semiarid portions of the Navajo Nation since the turn of the century.  Comparison of narrative observations made during the Beale Expedition of 1853, photographs taken around the turn of the century, and photography taken at the same site reveals many changes to upland and riparian areas

Neil Cobb, Merriam Powell Center for Environmental Research
My research focuses on two areas of investigation; the first is conceptually based on arthropod biodiversity, examining the responsiveness of arthropod communities to habitat change (e.g., drought, fire, grazing) and I specifically target national parks as field sites.  This work is based out of  The Colorado Plateau Museum of Arthopod Biodiversity  ( http://www.bugs.nau.edu/) .  We also conduct some population-level studies on insects.  The other area is technically based and involves addressing a variety of ecological questions that can be answered using GIS and remote sensing and can include a variety of different types of plants and animals.  This work is conducted through the he Geospatial Research and Information Laboratory (http://www.grail.nau.edu/).
Cheryl Dyer, Biology-Apolipoprotein E in the ovary

Cheryl Dyer, Biology
Our research is to characterize the estrogen like activity of uranium in the reproductive system of mice and rats to determine what human health consequences may result from exposure to environmental uranium.

Matthew Gage, Chemistry
There are numerous environmental factors that have been proposed to lead to DNA
damage and subsequently to cancer formation. One such environmental factor is
uranium exposure, which has been potentially linked to DNA damage. One of the
key proteins involved in protecting the cell’s DNA is the p53 protein. p53
recognizes damaged DNA and causes increases of other proteins that are involved
in DNA repair. We are investigating the formation and function of the p53
protein. This particular project is focused on understanding how uranium affects
the function of p53. Students working on this project will work with both Dr.
Gage and with other students in the lab to learn protein purification and
protein refolding techniques, along with standard tests of p53 function. These
will be used to determine if uranium affects the function of p53, providing a
potential model for the effects of uranium within the cell.

Paul Gremillion, Civil and Environmental Engineering
Our laboratory examines human impacts on aquatic ecosystems.  Our research
emphasis this summer is to investigate linkages between mercury loading to
reservoirs and wildfires in their watersheds.  We suspect that mercury becomes
stored in plant and soil material in watersheds, is then released by wildfires,
and finally makes its way to reservoirs through storm events following
wildfires.  To search for these linkages we will analyze sediment cores from
several lakes in northern Arizona.  These cores show distinct zones of charcoal
that indicate fire events and coarse sediment bands that indicate erosive
events.  This summer we will perform a number of tests on these cores and
conduct a limited amount of field work to recover additional sediment samples.

Jani Ingram, Chemsitry
The Ingram group is investigating interfacial chemistries of biosurfactants and mineral oxide.  These studies are focused on understanding the role of biosurfactants in the fate and transport of metals in the environment.

Tom Kolb, Forestry
Tom Kolb's research group is studying the impact of forest management thinning and wildfire on exchange of a key greenhouse gas, carbon dioxide, and energy, and water between ponderosa pine forests and the atmosphere.  They also are working on understanding interactions between forest fires and mortality caused by bark beetles, and the decline of high-elevation forests.

Jeff Leid, Biology
Biofilms are structured communities of microorganisms that are attached to
either an inanimate substrate, such as a rock in an alpine stream or a catheter
in a human, or an animate substrate, such as a human heart valve, that are
enclosed in a self-produced or host-derived matrix. In medicine, they are an
important problem with implanted medical devices as well as in the establishment
of chronic infections. Biofilms are notoriously less susceptible to antibiotics
then their single cell, non-community orientated bacteria and are also less
susceptible to attack and killing from the human immune system. The overall
focus of our research is to determine what makes biofilms less susceptible to
attack and killing from the host’s defenses and to determine how we can take
advantage of these gaps in protection to make the human immune system better
defend itself against biofilm-related infections. One of the recent findings,
lead by a team of undergraduate students in the lab, has been the discovery that
certain genes in the opportunistic pathogen Pseudomonas aeruginosa regulate
biofilm susceptibility to human white blood cell killing. We are actively
pursing these leads and will continue to work on elucidating what mechanisms
biofilms utilize to escape from killing in the host and how we can positively
regulate the host response so that humans are better protected against biofilm
infections. 

Mansel Nelson, Institute for Tribal Environmental Professionals
There are many possibilities, depending on interests of students. GLOBE has
atmospheric protocols, hydrology protocols, soil protocols, and biometry
protocols. An REU student could use the GLOBE protocols (www.globe.gov) to
collect data on surface water resources in the Flagstaff area. They could work
with High School students, teach them the protocols, then have the high school
students help with the field work, collecting data on the water sources. The
summer group (REU student and High School students) could also review existing
data on the GLOBE server to compare their data to other data in the region.
Potential hydrology protocols include: Water Transparency, Water Temperature,
Dissolved Oxygen, Electrical Conductivity, Salinity, pH, Alkalinity, Nitrate,
Freshwater Macroinvertebrates. The students could also report the results of
their investigations on the GLOBE server.

Catherine Propper, Biology
Dr. Cathy Propper uses amphibians as model systems to understand how environmental contaminants impact development, reproduction and behavior. Specifically, work in her lab tests hypotheses regarding whether individual compounds and complexes mixes impact physiological function.

Diane M. Stearns, Chemistry
The Stearns lab looks at how uranium and chromium interact with DNA to cause mutations that may lead to cancer.  We expose isolated DNA or cultured cells to metal complexes and investigate the resulting DNA lesions, for example, strand breaks, crosslinks, and metal-DNA adducts.
 

Thomas Whitham-Biology
Catherine Gehring-Biology
Amy Whipple- Biology
Drought Effects in Pinyon Pine Communities
This research area involves ongoing ecological studies in the piñon-juniper
woodland surrounding Flagstaff, AZ. For two decades we have examined
environmental controls on interactions among plants, fungi, bacteria,
arthropods, and vertebrates through monitoring efforts and long-term experiments
that allow us to address the importance of genetically-based resistance traits
in piñon pines on community and ecosystem processes. With recent acquisition of
new tools for genetic and molecular analysis, we are now able to examine how the
presence or absence of individual genes translates to higher levels of
organization, including population genetics, microbial and plant community
composition, and ecosystem function. Similarly, we can probe the influence of
environmental perturbations, such as the recent drought in the Southwest, on the
genetic structure and distribution of pinyon pine trees and dependent
communities.