Heat, Livers and Herbivores: Climate change and wildlife

By Fiona Marcelino

Kurnath shows off the biology lab’s pet woodrat, Charlie.

Increasing global temperatures have the potential to alter ecosystems and the resources they provide one another.

It is estimated that 20 to 30 percent of plant and animal species will be at increased extinction if global temperature rises more than 3.6-5.4 degrees Fahrenheit.

Due to changing climate conditions, University of Utah graduate student, Patrice Kurnath, is examining the physiology of woodrats as a potential predictor of how other herbivorous mammals may react to climate change. 

“I’m investigating the relationship between ambient temperature, plant toxins and liver functions through a sacrifice free assay,” said Kurnath. “I’m interested in looking at how environmental changes affect the woodrat’s ability to metabolize plant toxins.”

Kurnath’s studies in analyzing the relationship between the woodrats’ ability to digest and metabolize plant toxins and also studying how both plants and animals adapt to environmental changes could potentially be applied to mammals and herbivores in different ecosystems as a predictor of how they might respond to climate change.

“Woodrats are great species to study because they’re not endangered and they lend themselves to numerous ecological and evolutionary questions,” said Kurnath. “They also live in the desert which is usually predicted to be affected first and most severely in climate change.”

According to the U.S. Environmental Protection Agency, rising global temperatures can affect the natural world and raise questions of how vulnerable populations will adapt to direct and indirect affects associated with climate change. Higher temperatures require higher energy expenditures, which means more energy is used to obtain food. This means that any change in temperature can cause stress and negatively affect an animal’s metabolic rate.

Findings from Scientific American connect the increase of global temperatures to increased metabolic rates in various animals. While higher metabolic rates in humans is not necessarily troubling, researches are worried about how it might affect future species, especially those living in areas where food and water are limited.

“Plants, trees and other environmental elements have been and are going to continue to change because of increasing global temperatures,” said Kurnath. “By studying the physiology of these woodrats, we can also speculate how other mammals and herbivores not living in the dessert may be affected by climate change.”

Kurnath studies the physiology of Neotoma bryanti, also known as Bryant’s woodrat.

Charlie’s cage in the biology lab.

If you can’t take the heat, get out of the ocean? Or adapt….

By Amanda Jacobson

Coral reefs, also known as the tropical rainforests of the ocean, are refuges of marine diversity. Sadly, bleached white corals have become the poster child for global warming and the effects on ocean life.

Major coral bleaching events occur due to the loss of the symbiotic nutrient-producing algae (zooxanthellae) residing within the corals. Corals themselves are clear, but receive their coloration from the algae living within their tissues.

Loss of the zooxanthellae, and subsequent coral bleaching, can be induced by a variety of factors causing stress to the algae, rising ocean temperature being one of them. Different coral species have variable susceptibility to thermal stress. It has been hypothesized that hardier, slow growing coral will replace less hardy species in the future. The increasing occurrence and magnitude of bleaching episodes have led some marine biologists to believe that corals have exhausted their capacity to adapt. 

There may be hope.  James Guest et al., in a recent article published in the journal, PLoS ONE, describe how one type of coral is adapting to the increasingly warming temperatures of the ocean.

The authors of this paper hypothesized that corals have the ability to adapt to elevated sea temperatures.  They expected to find increases in thermal tolerance on reefs that typically experience more thermally variable environments; corals in these environments would bleach less severely during episodes of elevated sea temperature. 

The study assessed the thermal tolerance of coral in South East Asia that underwent a large-scale thermally-induced bleaching event in 2010. The findings of their work suggest that coral populations that bleached during the last major warming event in 1998 have adapted to thermal stress.

The authors conclude that this study does not suggest that coral bleaching is no longer a problem. Most coral reefs are still threatened by imbalanced ecosystems from overfishing, pollution, disease and acidification.

We need to change our ways; Mother Nature is not always going to be able to bail us out. 

Corals developing resistance to bleaching (colored) thrive in warmer water temperatures relative to those corals that do not (white). Photo credit: James Guest

References:

Guest, JR et al. (2012) Contrasting Patterns of Coral Bleaching Susceptibility in 2010 Suggest an Adaptive Response to Thermal Stress. PLoS ONE 7(3):e33353. 

Loya, Y et al. (2001) Coral bleaching: the winners and the losers. Ecol Lett 4: 122–131.

Hughes TP et al. (2003) Climate change, human impacts, and the resilience of coral reefs. Science 301: 929–933. 

Carbon dioxide model could aid in reducing Utah pollution

By Javan Rivera

Salt Lake City, Utah is facing a very serious problem concerning air pollution.

It’s no secret that Utah winters often cause severe inversions that trap large amounts of dirty air in the Salt Lake Valley. However, what’s less widely known is the cause of the problem and what exactly is being done to rectify the situation.

Enter Carolyn Stwertka, a graduate research assistant at the University of Utah who, along with her advisor, are currently developing a model for measuring carbon dioxide movement in the Salt Lake Valley.

Stwertka’s work, which is funded by a GK-12 National Science Foundation grant http://www.gk12.org/ called Think Globally, Learn Locally http://tgll.utah.edu/home.html, is vital to understanding exactly how carbon dioxide circulates through the greater Salt Lake City area and how exactly carbon dioxide emissions can be accurately measured for future Utah policy and legislation.

According to Stwertka, the main cause of Utah’s inversion problem is that the Salt Lake Valley acts as a natural bowl for collecting dirty air. With the Oquirrh and Wasatch mountain ranges hedging in the valley’s south and east sides, the Great Salt Lake trapping air from the west, and the high elevation of the valley’s north end, very little air is able to escape the valley without the aid of significant weather changes such as storms.

“Studying carbon dioxide in an urban environment is of interest to a lot of people because humans are creating a new ‘urban environment’ and this [modeling] provides a way to verify if emissions are decreasing due to [potential future] policy change,” she said.

Salt Lake City provides a very unique testing ground for this research not only because of its natural, inversion-causing barriers, but also because it is home to “the longest standing, consistently running set of [carbon dioxide measuring] stations in a city in the world,” said Stwertka.

The set of stations, mostly owned and operated by University of Utah professor Jim Ehleringer, is the primary source from which Stwertka drew her carbon dioxide measurements of Salt Lake City’s surface layer of air for her case study of the winter of 2010-2011.

Using carbon dioxide measurements along with a set of data points that account for wind forces, biogenic flux as a result of plant life in the valley, man-made emissions, and entrainment http://en.wikipedia.org/wiki/Entrainment_%28meteorology%29, are all input into Stwertka’s model in an attempt to accurately measure carbon dioxide movement through the valley.

“We have our model data and we can see how well it compares to the carbon dioxide observations around the valley [as measured by Ehleringer’s stations],” Stwertka said.

The real core of Stwertka’s work comes into play when it comes to finding an accurate measurement of not only how carbon dioxide circulates through the valley, but more importantly how those emissions eventually make their way out of the city air, and into the higher parts of the troposphere. Ultimately, what effect that has on the global mean of greenhouse gases.

Based on her observations from her own unpublished research, she’s discovered that in urban environments such as Salt Lake City, carbon dioxide tends to form a concentrated dome over the city similar to the “urban heat island effect.”

“In cities you produce a lot of carbon dioxide because it is concentrated,” Stwertka explained. “This essentially means that cities create a lot of carbon dioxide that stays isolated around the city and doesn’t extend into the surrounding rural environment. The question is, how do you relate the surface measurements to the global mean average?”

If Stwertka’s model can successfully measure carbon dioxide emission dispersal into the greater atmosphere, her model could be vital to creating future Utah policy changes regarding carbon dioxide emission regulation.

Salt Lake City is currently in violation of the Environmental Protection Agency’s National Ambient Air Quality Standards, thanks in part, to the valley’s severe inversion problem. With Salt Lake City currently attempting to create a State Implementation Plan (SIP), in order to regulate emissions, Stwertka’s work presents an opportunity to gain accurate carbon dioxide dissemination measurements for the plan.

Not only does Stwertka’s model hold promise for measuring carbon dioxide levels, but it also holds the possibility of measuring additional air pollutants such as PM 2.5 and PM 10 http://en.wikipedia.org/wiki/Particulates.

“Understanding the broad pattern [of carbon dioxide emissions] can help you understand the traveling of other pollutants,” Stwertka said. “We would like to further develop the model to track other pollutants as well so that our model can be used for the SIP.”

http://www.youtube.com/watch?feature=player_embedded&v=3dxx_RNsbLs

An inversion creeps across the city as Carolyn Stwertka hikes up the Grandeur Trail to gather carbon dioxide density measurements of Salt Lake City’s surface air.

Throughout the hike, the inversion managed to spread all the way to the base of Grandeur Peak, and even enveloped part of the mountain.

Carolyn Stwertka hiked ¾ of the way up the Grandeur Trail during the winter of 2010, carrying a backpack full of electronic equipment designed to take measurements of carbon dioxide emissions throughout the trek.

What Do Women Really Think?

Profiles of Female Scientists at the University of Utah

By Kirstin Roundy

In the science, technology, engineering and mathematical (STEM) fields, career progression is similar to the steps of a ladder; you have to climb the lower steps if you want to advance to the top. However, according to statistics from the National Science Foundation (NSF), most female scientists don’t make it to the top of the academic ladder. Although women represent 41 percent of awarded STEM doctoral degrees, female scientists occupy only 28 percent of full-time professor positions.

In an academic setting, the basic steps of the ladder are undergraduate student, graduate student, post-doctoral fellow, assistant professor and professor. This series of articles profiles female scientists, at various points in their careers, striving to climb the ladder in the Department of Pathology at the University of Utah.

Betsy Ott – Post-Doctoral Fellow

Betsy Ott

Science is cool. 

At least that’s the message that Elizabeth (Betsy) Ott wants to share. Ott is a post-doctoral fellow at the University of Utah, researching how bacteria that cause urinary tract infections are able to infiltrate host cells.

Her interest in science has been a life-long pursuit.

“Probably the earliest memory I have of really loving science is in the fifth grade,” said Ott. “We had to do our first research project. I did marine biology. I was infatuated with Jacques Cousteau and oceanography…I remember bioluminescence was amazing to me and just knowing that it’s a chemical reaction done by these cells in the skin of these animals was so exciting to me. I couldn’t wait to learn more about it, all aspects.”

This desire to learn about every aspect of what she studies has led Ott through a very diverse research career.  From pumping fish stomachs to document dietary choices in stocked versus unstocked lakes to analyzing urine samples in infants for defects in metabolic pathways, Ott dabbled in several arenas during her undergraduate career.

It was the repetitiveness of analyzing urine samples every day that led Ott to apply to graduate school.

“The idea (analyzing urine samples) was cool, but actually you just did the same thing over and over again,” she said. “I guess that was the biggest motivation for me to go to graduate school. So it was a very good experience for me because it wasn’t research and it was very clear to me that I wanted to be in research.”

Ott’s graduate research focused on following the degradation and movement of cellular membrane proteins in yeast. During her research, she discovered that the degradation pathway also regulated the multivesicular body (MVB) pathway during the starvation response. The interesting thing to Ott was “that these proteins that do the sorting of the MVB pathway are hijacked by HIV in human cells to get out.”

The combination of knowledge gained during graduate school and a desire to apply that knowledge to infectious disease is what led Ott to her current position studying uropathogenic bacteria. “Now I can still apply all my trafficking knowledge to a new problem that’s much closer to infectious diseases,” she said.

Ott talked about her transition from graduate student to post-doctoral fellow by stating, “the expectations are different, which is gratifying. I’m expected to, if I don’t know something, go figure it out, which is great. It’s kind of freeing to have somebody have that confidence in me.”

Ott hasn’t witnessed blatant displays of gender discrimination in regards to the NSF statistics stated previously.

“In college, our class essentially was more women than men. Also, the NIH (National Institutes of Health) does not discriminate [between] male or female post-docs. So I feel like that is equalizing. There’s no bonus for a PI (Principal Investigator) to hire more males than females,” she said.

However, in looking to the future, Ott does have one issue when it comes to gender equity. What happens when she wants to have children?  Ott has a right to be concerned. According to the NSF, women who were single and without children showed the greatest gains in terms of obtaining full professorships than did women who were married and had children.

“Thinking about kids, I’m very nervous about that because I do want a family,” Ott said. “I do know that that will sacrifice my salary, it will sacrifice my position…it could very well sacrifice some of the respect that I think I deserve.  I’m nervous about walking that delicate line.”

Regardless of the complications, Ott plans to stay in research. “I think I’d have to spend my time searching for the right job in order to be happy. I might have to look around a few times in order to find it and I’m willing to do that.” 

Until that time, Ott continues with her own research and strives to find opportunities to share her love of science with others.

“I like judging science fairs because it’s just so fun to see kids get involved in science. They do these projects where their eyes just pop open and they’re like, ‘This is so cool!’ and I say, ‘I know! Just wait, you don’t even know,’” she said.

U of U student researches more efficient methods for testing drugs

By Fiona Marcelino

 Gaukler  researchs on wild mice in her lab at the University of Utah

Few people realize that prescription drugs have become the leading cause of death, disease and disability in the United States. The Food and Drug Administration (FDA) reported in 2010 more than 1,742 drug recalls. This surge has raised questions about the quality of drug manufacturing in the United States.

In order to assess the safety of pharmaceutical drugs, University of Utah graduate student Shannon Gaukler, is investigating a new method of testing pharmaceutical drugs.

Before pharmaceutical drugs can be made available to the public they must first undergo several forms of testing which the FDA review in order to assess their safety.

This is where Gaukler’s research comes in. She explains that while many pharmaceutical drugs have been approved for clinical use, they later have been found to cause detrimental health problems. Additionally, current methods used to evaluate health affects of pharmaceuticals are organ or organ-system specific and overlook the interactions between physiological systems. 

Since drugs undergo animal pharmacology and toxicology studies in order to assess the safety for initial testing in humans, Gaukler is exploring a unique method of testing pharmaceutical drugs.

Gaukler uses wild mice in a semi-natural environment and compares organismal performances between a controlled group of mice and a drug-exposed group. By measuring the mice’s performance, Gaukler observes their survivorship, territoriality and reproductive success in order to predict how pending drugs could potentially affect humans.

“The organismal performance assay (OPA) has previously and successfully demonstrated health consequences from a variety of different treatments,” said Gaukler. “We thought that if we utilized the OPA to assess pharmaceutical safety, we could prevent harmful drugs from reaching the market.”

Gaukler notes the importance in her research is the social interaction between mice that is not usually present in low-population density testing labs, such as cages. Mice competing in this environment require high performance from most physiological systems to be successful individuals and establish social dominance.

“Wild mice are an appropriate model because they live in close association with humans so man-made environments are natural for them,” said Gaukler.

Her alternate form of research is capable of detecting fitness declines on a smaller scale as opposed to other approaches of safety testing in which they assess mortality and/or gross birth defects.

“Our research has the potential to suggest safer levels of exposure of these treatments,” she said.

With instances stretching from the Thalidomide controversy in the 1960s to Johnson & Johnson recalling their products eight times in 2010, consumers are growing wary of the safety of pharmaceuticals.

“Our research is important because this is a unique way of assessing health consequences from pharmaceuticals, environmental pollutants, nutritional supplements and many other treatments that have the potential to degrade health,” said Gaukler.

Mice in controlled environment at U

Mice in controlled environment at U

Mice in controlled environment at U

Parasites represent new opportunity for University of Utah Biologist 

By Javan Rivera

Peromyscus maniculatus, more commonly known as the Deer Mouse

Parasites are beautiful. They are amazing and interesting.

Those are not the words that the average person associates with the worms and parasitic creatures that reside within the intestines of various mammals. However, graduate student Craig Gritzen of the University Of Utah Department Of Biology is not the average person.

For Gritzen, the various parasites that reside within the intestines of the local deer mouse and their possible connections to the Sin Nombre Virus (SNV) represent the sum of his entire graduate career and research.

“It is cool and important because these parasites are [possibly] important, immunologically, to these mice,” said Gritzen. “It’s a very complex field of immunology.”

While Gritzen feels confident that there is a link between the parasites and the immune system of the mice, he stressed the fact that no link has yet been identified or proven.

Gritzen is currently pursuing a Master of Science in biology at the U, but his interest in mice and the parasites that infect them began during his undergraduate career at Penn State University.

As an undergraduate, Gritzen chose to focus his studies on infectious diseases. He said that for the most part he was interested in the diseases that could infect humans, but that through those studies he became interested in diseases that could jump from animals to humans.

“Those core classes sparked my interest in studying diseases in wildlife,” Gritzen said of his time at Penn State.

He first began studying parasites that infected the white-footed mouse in Pennsylvania during his junior year. During that year, he began working with Professor Peter Hudson doing fieldwork, including setting the traps for the mice and collecting samples for the research.

It was through this work that he secured a spot in Hudson’s lab studying the complex lifecycle of the parasites that infected the white-footed mice. His work mostly consisted of studying crickets that acted as a secondary host for the parasites that infected the mice.

“My tasks there consisted mostly of field work,” Gritzen said. “We’d collect the crickets and dissect them to verify that they had the parasites in them.”

His work with the labs at Penn State went on for two years before he finally graduated with a Bachelor of Science and applied for graduate school at the University of Utah.

According to Gritzen, he was drawn to the parasite studies that were going on at the U. It provided him an opportunity to continue to apply his knowledge from his undergraduate career into his graduate work.

“The research experience [at Penn State] prepared me to conduct the research I’m doing today,” Gritzen said.

Gritzen currently works in the Dearing Lab at the U. The goal of his research is to see if a connection exists between the various intestinal parasites that infect the deer mice of Utah and the deadly virus the mice carry.

Sin Nombre Virus, Spanish for the “No Name” virus, first came into public awareness when a deadly outbreak of the virus killed a number of people in the four corners region in the early 90s. The virus, which is a type of Hantavirus, is spread to humans through the inhalation of airborne fecal particles, when people attempt to clean up deer mice droppings that they find.

“Understanding what parasites are infecting these mice and identifying the effects of these parasites on the mice, will allow researchers to understand whether the parasites will increase or decrease the likelihood of the mice becoming infected by the virus, which in turn can determine the likelihood of humans getting infected due to close proximity to the mice,” Gritzen said.

Gritzen believes that discovering a connection between the parasites and SNV could allow future researchers to predict SNV outbreaks in mice populations in the future, thereby, increase preventative care taken by humans who live in close proximity to the mice.

In his time researching at the Dearing Lab, Gritzen has found eight species of intestinal parasites that infect the deer mice he is studying, and has been able to conduct various tests ranging from dissection of infected mice to fecal floats that allow him to search for parasite eggs in deer mice droppings.

For Gritzen, however, the work not only represents an opportunity to further scientific knowledge of the subject for human protection, but also an opportunity for him to continue to pursue his love of science.

“Becoming a researcher here at the U has been a really enjoyable experience because I really love science,” Gritzen said. “Going in and asking a question and then trying to discover an answer through science feels really good. It helps me to apply my experience. It’s amazing.”

Gritzen will be defending his thesis for his masters in May, and with his schooling coming to an end, he is looking forward to a future where he can continue to apply his scientific knowledge to beneficial causes. For him, those opportunities lie in the Utah Division of Wildlife Resources.

“As a scientist I’d like to continue studying wildlife,” Gritzen said. “I’d be interested in looking at and researching parasites of other mammal species.”

He also hopes that his work can act as a catalyst for future study in the field of parasites.

“I really hope that the work I’m doing can inspire other scientists to look into these parasites,” Gritzen said, “It’s sad that we discovered some of these [deer mice] parasites over 100 years ago and we still don’t know what they do [to the mice].”

Protospirura numidica is just one of the many parasites that can infect the digestive tract of Deer Mice.

Craig Gritzen doing fieldwork in the Great Basin Desert, in Juab County Utah, 2009. Working with the "Sin Nombre Virus" requires the use of specialized headgear to prevent human infection.