Category: Research

In Print: Jill Olin

Congratulations to Jill Olin and her postdoctoral fellow, Jim Junker, who recently published a paper titled “Can biodiversity of preexisting and created salt marshes match across scales? An assessment from microbes to predators” in the Ecosphere Journal. You can learn more about the research on the LSU website.

Jill Olin
Jill Olin
Jim Junker

Abstract: Coastal wetlands are rapidly disappearing worldwide due to a variety of processes, including climate change and flood control. The rate of loss in the Mississippi River Delta is among the highest in the world and billions of dollars have been allocated to build and restore coastal wetlands. A key question guiding assessment is whether created coastal salt marshes have similar biodiversity to preexisting, reference marshes. However, the numerous biodiversity metrics used to make these determinations are typically scale dependent and often conflicting. Here, we applied ecological theory to compare the diversity of different assemblages (surface and below-surface soil microbes, plants, macroinfauna, spiders, and on-marsh and off-marsh nekton) between two created marshes (4–6 years old) and four reference marshes. We also quantified the scale-dependent effects of species abundance distribution, aggregation, and density on richness differences and explored differences in species composition. Total, between-sample, and within-sample diversity (γ, β, and α, respectively) were not consistently lower at created marshes. Richness decomposition varied greatly among assemblages and marshes (e.g., soil microbes showed high equitability and α diversity, but plant diversity was restricted to a few dominant species with high aggregation). However, species abundance distribution, aggregation, and density patterns were not directly associated with differences between created and reference marshes. One exception was considerably lower density for macroinfauna at one of the created marshes, which was drier because of being at a higher elevation and having coarser substrate compared with the other marshes. The community compositions of created marshes were more dissimilar than reference marshes for microbe and macroinfauna assemblages. However, differences were small, particularly for microbes. Together, our results suggest generally similar taxonomic diversity and composition between created and reference marshes. This provides support for the creation of marsh habitat as tools for the maintenance and restoration of coastal biodiversity. However, caution is needed when creating marshes because specific building and restoration plans may lead to different colonization patterns.

Amy Marcarelli Receives NSF Grant to Explore How Microbes Process Organic Matter in Streams

Professor Amy Marcarelli and a multi-disciplinary team have received a two-year, $300,000 NSF grant. The grant from the National Science Foundation is to study the relationships between organic matter and micro-organisms in streams. 

Marcarelli and colleague in stream with five gallon bucket collecting a water sample
Marcarelli and colleague collecting water samples

An ecosystems ecologist, Marcarelli is leading a team of Michigan Tech ecosystem scientists, microbiologists, environmental chemists, and data scientists. The researchers are conducting detailed laboratory experiments to gather data on how microbial communities work together to process complex mixtures of dissolved organic matter in streams.  Steve Techtmann, associate professor of Biological Sciences and an environmental microbiologist, is doing all the microbial work on the project in his lab at Michigan Tech. 

Dissolved organic matter comprises many different kinds of molecules that come from terrestrial and aquatic plants and microbes.  The researchers expect different microbes that live in streams to be specialized to break down these different molecules. 

“We expect the relationships to be extremely complicated,” Marcarelli says. 

They are looking at rates of respiration, carbon breakdown, and energy release. They hope to discover how the characteristics of dissolved organic matter and stream microbes can explain rates of carbon dioxide emission from streams. 

The researchers will use the data to develop machine-learning models. “The relationships between the organic matter and micro-organisms might not be evident in simpler analysis methods,” Marcarelli explains. 

The current work is the start of a much larger project. “We hope to build on the results of this project with a much bigger proposal for a large field project,” she says. 

And why is this work important?  “Although we, as a field, have studied carbon dioxide production and emission across many different streams, we can only predict a small amount of the variation we see based on environmental characteristics like temperature,” Marcarelli explains. “We think there is an important role of both microbes and organic matter structure that contributes to this variability, and understanding that is important for predicting these emissions in the future and response to global changes like climate and land use change.”

Marcarelli is the director of the Ecosystem Science Center at Michigan Tech.

This blog post initially appeared in the Fall 2022 Biological Sciences Newsletter. Read this article and others like it today.

Saving the Brook Trout by Restoring their Spawning Habitat

Professor Casey Huckins has been studying the ecology of coaster brook trout for nearly 20 years. He started out investigating these migratory fish’s population ecology and life history. His research now focuses on analyzing the movement patterns of coaster brook trout due to human impact on the watershed. He is also focusing on ways to restore them and the habitat they need to spawn. Recently, with funding from the Michigan Departments of Environment, Great Lakes and Energy (EGLE) and the Department of Natural Resources, his lab has been actively restoring its critical habitat. “Human actions have turned these iconic heritage species of Lake Superior into a conservation concern by overharvesting them and disturbing their habitat,” Huckins explains.

Casey using a tool in a stream
Casey Huckins working in the field

His team is actively studying the two coaster brook trout populations still known to exist along the south-central shore of Lake Superior.

These migratory coaster brook trout live in Lake Superior. However, they return to their rivers of origin to breed in the same spots where they were spawned. Due to disturbances in the watersheds, like logging and road use, the spawning habitat of these creatures has been buried. This has altered the critical dynamic of erosion and sedimentation, leading to a buildup of fine sand. The sand present here is responsible for covering larger sediment particles like cobbles and pebbles. Cobbles are small rocks that have been rounded by water flow. These pebbles serve as the spawning habitat and also as the home for the brook trout’s food and aquatic insects.

With his recent state funding, Huckins says his goal is to restore the critical spawning habitat. He will do this by removing excess sand and studying the impacts on the habitat and the brook trout population. His team has installed in-stream sand collectors that passively collect sand as it flows over them. The researchers then routinely operate pumps to move the sand out of the floodplain.

Huckins’ team is now investigating whether the community of stream insects that are key food items for the brook trout also increases in abundance, diversity, and community structure. He hopes to see a site with natural, free-flowing cobble-based cold-water habitat. Huckins found this at the site when he started studying it with his graduate students nearly two decades ago.

Brook trout
Brook Trout

His next goal is to acquire additional funding to automate the sand collectors to operate independently. Huckins’ goal is to eliminate the need for researchers to manually pump sand at the site, saving them time and fuel expenses. The team is currently expanding their efforts to implement this system in various streams and rivers. Their equipment is being utilized to rehabilitate other waterways that have suffered from erosion due to flooding, land use, or other factors that cause sand to flow downstream. As our climate changes, we expect to see more extreme events that will have outcomes we need to address to restore and maintain these critical aquatic ecosystems.

This blog post initially appeared in the Fall 2022 Biological Sciences Newsletter. Read this article and others like it today.

2022 Provost’s Award Winner Plans to Practice Rural Medicine

Christian Johnson won the 2022 Provost’s Award for Academics. He is pursuing a double major in Human Biology and English.  

Johnson’s goal is to attend medical school and become a primary care physician in a rural area. 

A native of Detroit, he chose Michigan Tech because the small size of the university and community appealed to him. He found the faculty in the College of Arts and Sciences so helpful.  He visited Tech many times and participated in a Summer Youth Program. “I could see myself being part of the Michigan Tech community,” he says.

Christian Johnson
Christian Johnson

He worked with Greg Miodonski, a graduate student in Qinghui Chen’s lab. They studied the effect of exercise training on cardiovascular function in animals.  Chen is a professor of Kinesiology and Integrative Physiology and an affiliated professor of Biological Sciences and Biomedical Engineering. 

The research investigated how exercise impacts the function of small conductance calcium-activated potassium (SK) channels in the paraventricular nucleus of the hypothalamus (PVN) of rodents. It aimed to assess whether exercise could augment SK channel function in normotensive and hypertensive rats and, consequently, sympathetic nerve activity and blood pressure.  

“Christian was an invaluable assistant, and his Cool Hand Luke demeanor will be missed,” said Miodonski. “Working with rodents is challenging and can be intimidating, but Christian took to the rodents immediately. Unlike exercising humans, exercising rodents poses several challenges. Mainly, rodents are poor listeners and don’t follow instructions too well. This means that exercising them requires diligence, focus, and lots of patience. Christian exhibited all of these qualities. Some undergraduate assistants require a lot of mentoring and instruction before gaining autonomy, but not Christian. A quick study, he handled obstacles exactly how I would have and impressed me at every turn. Christian also aided me with recording blood pressures in conscious rodents. This is challenging and requires constant attention for many hours. Here again, Christian exceeded expectations.”

In addition to research, Johnson immersed himself in many activities at Michigan Tech, including the Blue Key National Honor Society, Alpha Epsilon Delta—the National Health Pre-Professional Honor Society, the Pavlis Honors College, the Pre-Health Association, and Sexual Assault and Violence Education. He also worked as a writing coach in the Michigan Tech Writing Center, served as a resident assistant, and worked in various other mentoring roles. Christian found time to serve as an active volunteer for Dial Help. He also recently had a piece of his creative writing published.

This summer, he studied at the University of Stirling in Scotland, where he took courses to fulfill major requirements for his English degree.

“When I heard that I received the Provost’s Award, I was shocked,” Johnson says. “Hearing all of the work I have been putting in and my accomplishments being read aloud; picking up the plaque; and shaking Dean Kampe’s, Dean Southerland’s, and President Koubek’s hands is a moment I will never forget.”

Johnson is currently applying to medical schools. Being from Detroit and living in Houghton, he has had the opportunity to see medical care in both urban and rural settings. Working with Dial Help particularly opened his eyes to the struggles that rural area residents face in accessing resources and being able to see a physician. “That experience made me want to serve rural areas and help with the primary care physician shortages in those areas,” he says.  

This blog post initially appeared in the Fall 2022 Biological Sciences Newsletter. Read this article and others like it today.

NIH Grant Helps Dr. M. Tang Explore Cancer Mechanisms and Novel Treatments

Mark Tang
Mark Tang

Xiaohu (Mark) Tang’s Laboratory of Cancer Metabolism and Functional Genomics is using a three-year $413,090 grant from the National Institutes of Health to find ways to optimize the efficacy of targeted cysteine therapy and broaden its application for the treatment of different subtypes of breast cancer. Tang is an assistant professor of Biological Sciences. He earned his Ph.D. at The Weizmann Institute of Science. Haiying Liu, Professor of Chemistry, is a co-investigator on this project.

“Targeted cancer therapy is an emerging trend in precision cancer medicine,” Tang explains. “It uses the specific genetic makeup of a patient’s tumor to select the safest and most effective personalized treatment, instead of the traditional symptom-driven practice of medicine. Identifying and targeting metabolic vulnerabilities in cancer is a promising therapeutic strategy.”

The NIH grant will also provide research-based training for undergraduates and graduate students in Biological Sciences and the Biochemistry and Molecular Biology programs. “The work will enable students to understand the complexity of cancer and motivate them to seek novel strategies to improve health issues,” says Tang.

Tang’s lab works to characterize the deregulation of cancer metabolism and the role of nutrients during cancer initiation and progression. He is working to understand the underlying mechanisms of cancer to pursue workable alternative treatments for patients. He also hopes that a better understanding of diet-cancer interactions could establish a strategy for long-term cancer prevention.

This blog post initially appeared in the Fall 2022 Biological Sciences Newsletter. Read this article and others like it today.

Erika Hersch-Green Receives NSF CAREER Award

Erika Hersch-Green, plant evolutionary ecologist and associate professor of Biological Sciences, received a National Science Foundation CAREER Award. She will investigate how specific attributes of plants, such as their genome size, influence community biodiversity responses to increased nitrogen and phosphorus availability. Hersch-Green’s approach combines molecular, cytological, physiological, and phylogenetic techniques.  

Erika Hersch-Green
Erika Hersh-Green

Hersch-Green is conducting her research on three fronts. First, she is currently gathering fresh data and merging it with information from experimental grassland sites around the world. These sites have plots with different nutrient treatments, allowing her to examine how response patterns vary depending on climate conditions. Second, she is conducting controlled greenhouse studies to better understand mechanisms that focus on two common grassland plants: fireweed and goldenrod, both of which she has studied before. Lastly, she developed a new research site at Churning Rapids, north of Hancock and south of McClain State Park. There she is extending her research to look at how disturbance patterns affect levels of biodiversity. 

She is also exploring ways to improve students’ scientific literacy and engagement in research.  To accomplish this, she is incorporating students in grades 6 through 12 and undergraduates in research, enhancing research involvement in the classroom, facilitating effective scientific communication skills of graduate students, and promoting collaboration among undergraduate students and faculty in the Departments of Biological Sciences and Humanities. These students will produce video content that will be used to enhance education and public understanding of biological science and ecology.

To summarize, Hersch-Green aims to provide a system-level understanding of how nutrient eutrophication—the increasingly dense growth of particular plants at the expense of other species—and landscape disturbances affect individual organisms and multi-species communities by looking at their interactions.

Although she is passionate about her research, Hersch-Green is also deeply committed to the educational component of her CAREER award. Her educational goals are to increase both scientific literacy and engagement of high school and university students on critical topics related to nutrient eutrophication, biodiversity, evolutionary adaptation, and awareness of related STEM (science, technology, engineering, and math) career pathways. 

This blog post initially appeared in the Fall 2022 Biological Sciences Newsletter. Read this article and others like it today.

Paul Goetsch Receives NIH Grant to Study Cell Cycle Regulation

Dr. Goetsch assisting a graduate student in the lab

Assistant Professor Paul Goetsch received a $423,381 grant from the National Institutes of Health. Dr. Goetsch will study how the DREAM transcriptional repressor complex regulates the cell cycle of cellular progression and cellular quiescence.

Cellular division is extremely important as an organism grows to maturity, but just as important are the mechanisms that stop cells from dividing. Dysfunction in cellular quiescence generally leads to the development of cancer cells, Goetsch explains.

Working in the model system Caenorhabditis elegans, a 1 mm-long transparent nematode, the Goetsch lab is using CRISPR/Cas9-mediated genome editing to disrupt how the DREAM complex forms and test how that affects its function. “By exploiting advances in genomic editing and genetic tools in a tractable model system, we will gain new insights into how the DREAM complex protects cellular and organismal health,” says Goetsch.

Another part of the grant supports bringing research directly into the classroom for Biological Sciences students in the second-year genetics lab. Goetsch and his colleagues are implementing Course-based Undergraduate Research Experiences (CUREs). These are used to provide students a glimpse into research opportunities within the department.

In Spring 2021, Goetsch and his student Emily Washeleski developed a unique experiment combining C. elegans genetics with environmental microbiology. “We are continuing to expand upon our CURE approach to provide students equitable access to research experience as a cornerstone of their professional development within the department,” Goetsch says.

This blog post initially appeared in the Fall 2022 Biological Sciences Newsletter. Read this article and others like it today.

In the News

Ebenezer Tumban portriat
Ebenezer Tumban

Ebenezer Tumban (BioSci) was quoted in the story “MTU virologist discusses virus differences,” in the Daily Mining Gazette:

MTU virologist discusses virus differences

Joshua Vissers, Associate Editor, Daily Mining Gazette, March 27, 2020

HOUGHTON — Influenza and coronaviruses both travel between the infected wrapped in a stolen bit of the previous host cell’s outer, lipid-based layer called an envelope. That layer protects the viruses from harsh environments, and works as a kind of disguise to help them inject themselves into the next cell. The difference that makes an outbreak of coronavirus so much more dangerous is the difference in that envelope.

“Normally, envelope viruses are not stable in the environment,” Ebenezer Tumban said.

Tumban is a molecular virologist and vaccinologist at Michigan Technological University. He’s been studying viruses in an effort to learn how to vaccinate against them.

Envelopes dry out and deteriorate fairly quickly outside the body, and the virus inside is rendered helpless to infect another cell, he said.

This image shows the lipid envelope of coronavirus, taken from an infected cell, and the crown-like proteins added by the virus that are its namesake.
Provided image This image shows the lipid envelope of coronavirus, taken from an infected cell, and the crown-like proteins added by the virus that are its namesake.

However, coronaviruses have hollow proteins embedded in their envelope. Scientists thought this structure looked like a crown, and so called it corona (Latin for crown).

“The crown basically makes them more stable compared to the regular flu,” Tumban said.

This extra stability allows it to last longer in the air and on surfaces compared to influenza viruses. So a coronavirus-infected person coughing in an area can infect people passing though that area for much longer than someone with influenza.

Despite having symptoms quite similar to a flu, fighting a coronavirus is more difficult for the body than fighting a flu virus for a few reasons. 

“There’s a lot of things, some of it has to do with the virus and some of it has to do with us,” Tumban said.

A more stable envelope means the virus can exist in more parts of the human body. The flu virus is typically destroyed by fluid in the gastrointestinal tract, but COVID-19’s corona protects them from that, according to Tumban.

The virus also seems to be able to suppress immune system response in some people.

“People that were infected with coronavirus had a low level of lymphocytes,” he said.

This suggests that the coronavirus is also infecting those types of cells, which are part of the body’s defense system. The influenza virus doesn’t do that. 

Tumban said there’s also evidence that the virus can trigger a reaction in the body similar to an allergic reaction.

“My body might overreact and produce a lot of cytokines,” he said.

These cytokines can trigger sepsis and organ failure in severe cases.

And medical professionals have fewer tools to fight coronavirus, too.

“We don’t have a vaccine for corona, we have a vaccine for influenza,” Tumban said.

Influenza vaccines have been in use for a long time, training our immune systems in how to make antibodies that fight that particular virus and creating a group immunity that protects even those without the vaccine. While the flu virus does mutate regularly, it’s rarely enough to render a vaccine entirely ineffective.

“Vaccinations from the past might help to make the disease less severe compared to coronavirus which is new,” Tumban said. “You don’t have a single antibody against it in your body.”

People hospitalized with the flu can receive certain treatments like Tamiflu, but Tumban said with coronavirus, doctors right now mostly give “supportive care” – using tools like ventilators to support the patient’s body while it fights or endures the infection on its own.

These factors together create a much more deadly virus than the flu.

“The mortality rate is about 10 times that of influenza,” Tumban said on Tuesday.

Tumban’s calculations, based on numbers from the Centers for Disease Control, show that a high estimate of influenza’s mortality this year is about 0.1% in the United States, but coronavirus is showing to be about 1.27%. 

Worldwide, the mortality rate for coronavirus is about 4.3% according to Tumban.

The increased mortality and lack of treatment and defense are what is leading countries and organizations around the world to implement social distancing and quarantine measures as healthcare providers ramp up capacity and researches search for vaccines.

However, while coronavirus can be far more infectious and harmful than the influenza virus, many of the same precautions work to prevent infection. The No. 1 recommendation, hand washing and sanitizing, destroys the all-important envelope protecting the virus, rendering it virtually harmless.

“There’s no way they can cause the disease,” Tumban said.

Editor’s Note: This story has been changed to more accurately portray Dr. Tumban’s work. While he has worked directly with Zika, dengue, HPV and other viruses, he has not worked directly with coronaviruses.