NMSU mosquito nutrient transport research may lead to better, safer insecticides

NMSU biology professor Immo Hansen, right, and postdoctoral researcher Hitoshi Tsujimoto work together in Hansen's mosquito laboratory on campus. (Photo by Darren Phillips)
NMSU biology professor Immo Hansen, right, and postdoctoral researcher Hitoshi Tsujimoto work together in Hansen’s mosquito laboratory on campus. (Photo by Darren Phillips)

Ever wonder why male mosquitoes don’t bite?

“They don’t have to make eggs,” explained Immo Hansen, associate professor of biology at New Mexico State University in the College of Arts and Sciences. “But, the females need nutrient proteins, so they take up our blood.”

It’s through this process that vector, or disease-causing, mosquitoes transmit malaria, dengue fever, chikungunya, yellow fever viruses and other illnesses.

Fortunately, as these mosquitoes continue to develop resistance to common insecticides, researchers in the biology department at NMSU, in collaboration with the Department of Physiology and Biophysics at Rosalind Franklin University, may have identified a new way to stop this cycle at its earliest stages.

Specifically, the team has discovered a new type of amino acid transport in the yellow fever mosquito that may lead to the development of safer and more effective insecticides that target the mosquito’s ability to produce eggs. The findings were published last month in “Nature Communications,” in a paper titled “Substrate specificity and transport mechanism of amino-acid transceptor Slimfast from Aedes aegypti.”

“In the process of producing eggs, mosquitoes convert the blood meal into nutrients and into the components of the eggs,” said Hitoshi Tsujimoto, paper co-author and postdoctoral researcher in NMSU’s Molecular Vector Physiology Lab. “Those are mostly proteins, and are digested into smaller pieces, which are amino acids.”

These amino acids, which are large and cannot cross cell membranes, are distributed throughout the body of the mosquito using specific transport proteins that allow them to pass through the cell membranes, he explained. These transport proteins allow mosquitoes to distribute the nutrients necessary for reproduction within their bodies.

“If we could inhibit the transporter,” Tsujimoto said, “the mosquito cannot develop eggs, so they can’t reproduce — that way we can stop the cycle.”

Tsujimoto and collaborators focused their study on an amino acid transporter called Slimfast, which they found to have different modes of action depending on the concentration of amino acids in the mosquito’s body during reproduction.

The first mode, they said, is the mode of action the mosquito uses when it hasn’t yet received blood meal.

“That means there are very little amino acids to go around,” said Hansen, also involved in the study. “So, in order to get the amino acids in the cell, you have to be really efficient; this is what we call the high-affinity mode of action.”

However, when Slimfast is exposed to high levels of amino acids after a blood meal, the transporter behaves very differently.

“It opens up just like a pore and lets everything through — fast,” Hansen said. “ We call this low affinity.”

“This is unprecedented,” he continued. “Nobody has ever shown an amino acid transporter that does anything like that. This explains how a mosquito can switch from high affinity transport to low affinity blood transport within seconds, without changing the complement of amino acid transporters in its membranes.”

While this discovery alone is a novel contribution to mosquito physiology research, Hansen and
Tsujimoto said inhibiting this transport system through a new insecticide could also present a relatively safe form of pest control.

“These transporters are quite mosquito specific,” Hansen said. “So, an insecticide that attacks this one will most likely have no effect on humans because we don’t have these transporters.”

The full “Nature Communications” article can be viewed at nature.com/ncomms/2015/151009/ncomms9546/full/ncomms9546.html.

For more information on the Molecular Vector Physicology Lab in NMSU’s College of Arts and Sciences, visit biology-web.nmsu.edu/~hansen/.

 

NMSU researchers work to solve infrastructure challenges, members of new Engineering Research Center

NMSU civil engineering professor Paola Bandini, right, works in her laboratory with graduate students Hend Hussien Al-Shatnawi, left, and Rachelle Mason. (Photo by Darren Phillips)
NMSU civil engineering professor Paola Bandini, right, works in her laboratory with graduate students Hend Hussien Al-Shatnawi, left, and Rachelle Mason. (Photo by Darren Phillips)

In August, New Mexico State University was announced as one of four universities in a new National Science Foundation Engineering Research Center to develop advances in geotechnical engineering that will provide solutions to some of the world’s biggest infrastructure development and environmental challenges.

NMSU’s College of Engineering joins a consortium of university, industry and government partners, led by Arizona State University. The $18.5 million NSF award establishes the Center for Bio-mediated and Bio-inspired Geotechnics (CBBG) to expand the emerging field of biogeotechnical engineering.

Paola Bandini, NMSU civil engineering associate professor, CBBG co-principal investigator and leader of the center’s work at NMSU, was honored at NMSU’s Scholarly Excellence Rally Friday, Oct. 30. She is directing the center’s work on infrastructure construction, one of four research thrusts of the program.

Engineers and scientists at NMSU, ASU, Georgia Tech and the University of California, Davis are collaborating to develop methods to use or mimic biological processes for engineering the ground in ways that reduce construction costs while mitigating natural hazards and environmental degradation.

“The Center for Bio-mediated and Bio-inspired Geotechnics will learn from nature,” Bandini said. “We will learn from biological processes. Nature has had 3.8 billion years of evolution to develop and perfect, very elegant, efficient solutions to problems.

“We’re going to learn from those biological processes to improve the methods and find solutions for infrastructure-related construction, maintenance and operations; to reduce the carbon footprint of our construction methods; to reduce the ecological and environmental impact of industries like mining and construction; and to make better and more sustainable use of the non-renewable resources we have,” she said.

The center’s four research thrusts include hazard mitigation, environmental protection and restoration, infrastructure construction and resource development.

The second main objective of the center is to inspire a diverse group of engineers and scientists to provide the associate workforce necessary for this new field of biogeotechnical engineering.

“In addition to the university partnership, we have education, outreach and diversity partners including community colleges, school districts and science museums that will work with us to deliver the educational materials that we will develop through the center,” Bandini said. “The CBBG also includes a strong partnership program with private industry and government agencies like state departments of transportation, cities and counties that are owners and managers of the civil infrastructure.”

The center has more than 12 companies and state government agencies confirmed as industrial partners to support the research initiatives along with 15 universities from across the globe.

A multidisciplinary team of nine NMSU researchers specialized in civil engineering, geotechnical and environmental engineering, computer science, geological sciences and biology will participate in various CBBG projects.

In the first year, NMSU research projects will include bio-inspired soil reinforcement, a study of the mechanisms of root growth and mechanical reinforcement in unsaturated soil; bio-enhanced removal of contaminants in groundwater; revegetation of degraded top soils, stripped lands or salinized and eroded soils; and development of self-motile probe for multi-sensor deployment for subsurface investigations.

In addition, NMSU’s Arrowhead Center will help implement technology transfer and pursue patents for technologies created at NMSU through CBBG’s research.

The NSF award will fund the center for five years. NSF support can be continued for an additional five years; following that period the center is expected to become self-supporting.

To learn more about the CBBG visit http://biogeotechnics.org/home.

NMSU cancer researchers collaborate for a cure

Ryan Ashley, NMSU professor, studies proteins that affect breast cancer. (NMSU photo by Angela Simental) SEP14
Ryan Ashley, NMSU professor, studies proteins that affect breast cancer. (NMSU photo by Angela Simental) SEP14

Since their arrival to New Mexico State University in 2009, Kevin and Jessica P. Houston’s investigations into cancer research have developed into a multidisciplinary partnership, coupling cancer biology with engineering for this husband and wife team.

“We are very passionate about cancer research,” said Kevin Houston, assistant professor of chemistry and biochemistry in the College of Arts and Sciences. “Cancer research is the focus of not only our collaboration, but most of our work at NMSU.”

Kevin and Jessica, an associate professor of chemical engineering, are working to design minimally invasive diagnostic measurement capabilities that can be used in clinics to monitor the effectiveness of cancer treatments.

Left to right: Biology professors Jeff Arterburn and Brad Shuster conduct cancer-related research supported by the Cowboys for Cancer Research (C4CR) Endowed Fund at the NMSU Foundation. (NMSU photo by Darren Phillips)
Left to right: Biology professors Jeff Arterburn and Brad Shuster conduct cancer-related research supported by the Cowboys for Cancer Research (C4CR) Endowed Fund at the NMSU Foundation. (NMSU photo by Darren Phillips)

“This collaboration was a natural fit due to the diversity of our research efforts,” Kevin Houston said. “Jessica builds instruments that have unique cell measurement capabilities, and my cancer cell studies benefit from the instrumentation developed in Jessica’s laboratory. We believe this research is high-risk, yet high payoff, in that it leads to the development of valuable diagnostic and therapeutic tools for cancer.”

While a number of NMSU academics are involved in cancer-related research, the Houston’s project is one of a handful supported by the Cowboys for Cancer Research (C4CR) Endowed Fund at the NMSU Foundation. C4CR is a local not-for-profit corporation raising funds in support of ongoing cancer research at NMSU and the University of New Mexico.

For the second year in a row, Cowboys for Cancer Research will raise a portion of their research funding through “NMSU Aggies are Tough Enough to Wear Pink,” a volunteer group dedicated to raising breast cancer awareness and funds on behalf of C4CR. At the Pink Aggie football game on Saturday, Oct. 24, the group will make their check presentation to C4CR.

10/16/2015: NMSU chemical engineering professor Jessica Houston, left, and NMSU biochemistry professor Kevin Houston demonstrate how they use their custom-built flow cytometer to evaluate cancer cell cultures. Jessica Houston and her research team developed the flow cytometer in her lab, which in turn is used by Kevin Houston to conduct research in his cancer cell biochemistry lab. (Photo by Darren Phillips)
NMSU chemical engineering professor Jessica Houston, left, and NMSU biochemistry professor Kevin Houston demonstrate how they use their custom-built flow cytometer to evaluate cancer cell cultures. Jessica Houston and her research team developed the flow cytometer in her lab, which in turn is used by Kevin Houston to conduct research in his cancer cell biochemistry lab. (Photo by Darren Phillips)

“Because Cowboys for Cancer Research funds are predominantly from New Mexico residents, it makes our work more intimate and provides a greater sense of responsibility to ensure we are doing the best we can to help our state and others,” said Ryan Ashley, assistant professor of animal and range sciences.

Ashley’s project investigates the role of progestins in an important signaling pathway activated in breast cancer that may lead to new targets for cancer therapy.

“If it were not for the Cowboys for Cancer Research support,” he said, “our lab would not have been able to perform our studies, and thus would not have discovered the differences that natural versus synthetic progestins play in breast cells.”

Brad Shuster, associate professor of biology, explained “the climate for research funding is difficult and, as a result, funding decisions by federal agencies tend to err on the cautious side.”

“Cowboys for Cancer Research funding has provided us critical seed funding to pursue an idea that would not otherwise have been funded,” he said. “We are now in a much better position to compete for federal funding as a result.”

Shuster is working to develop a new combinatorial therapeutic approach for targeting actively dividing tumor cells without the side effects associated with existing drugs.

Other NMSU researchers benefiting from C4CR are Shelley Lusetti, associate professor of biology, and Jeff Arterburn, professor of chemistry and biochemistry. Lusetti is working to increase understanding of a mechanism for DNA repair that is important for chemotherapy and cancer prevention. Arterburn has been working to unlock the potential of a unique kind of estrogen receptor (GPR 30) to diagnose and treat breast cancer.

Collaborations among researchers at NMSU are leading the way to new discoveries thanks to funding from organizations such as Cowboys for Cancer Research.

“The origin of these funds from our local community provides a direct connection to the research, and places personal context to the impacts of cancer on our families and friends that is extremely motivational for the researchers,” Arterburn said.

While the implications of these cancer research efforts extend beyond the NMSU campus, the impact of this deadly disease continues to hit close to home.

“I lost my mom to cancer,” Ashley said. “Performing research that impacts cancer biology provides a personal conviction to work wholeheartedly at all we do in the lab.”

For more information on Cowboys for Cancer Research, visit c4cr.com. For more information on NMSU Aggies are Tough Enough to Wear Pink, visit pinkaggie.com.

NMSU’s Physical Science Laboratory Flight Test Center provides testing for state, nation

10/09/15: PSL Interim Deputy Director Henry Cathey speaks at a Scholarly Excellence Rally honoring NMSU's Physical Science Laboratory for its work with the Federal Aviation Administration Center for Excellence for Unmanned Aircraft Systems Research. (Photo by Karrie Lucero)
10/09/15: PSL Interim Deputy Director Henry Cathey speaks at a Scholarly Excellence Rally honoring NMSU’s Physical Science Laboratory for its work with the Federal Aviation Administration Center for Excellence for Unmanned Aircraft Systems Research. (Photo by Karrie Lucero)

Established in 2007, the New Mexico State University Physical Science Laboratory’s Unmanned Aircraft Systems Flight Test Center is the first of its kind. In the last eight years, NMSU’s UAS FTC has become the most accomplished and most experienced Federal Aviation Administration-approved UAS test facility in the country.

NMSU’s UAS FTC provides direct access to more than 15,000 square miles of airspace, and was the first civil UAS test facility that provided direct, available access to restricted airspace – a must for testing developmental aircraft or multi-aircraft scenarios.

Henry Cathey, interim deputy director of NMSU’s Physical Science Laboratory, was honored at NMSU’s Scholarly Excellence Rally Friday, Oct. 9.

“The Flight Test Center in Las Cruces has been operating for a number of years, and it’s not only a unique resource for the state of New Mexico, but it is a unique resource for the entire country,” Cathey said. “It’s state-of-the-art, cutting-edge, and it’s very exciting that New Mexico is leading the way in this area.”

In May 2015, the FAA announced that the Alliance for System Safety of UAS through Research Excellence (ASSURE) would operate a new National Center of Excellence for UAS. NMSU is a core member-university on a team, which is comprised of 15 universities and six affiliates.

As a core university of ASSURE, NMSU is helping lead the partnership of academic and industry members that will begin a new era of commercial unmanned aircraft research, development and integration into the nation’s airspace. Dallas Brooks, NMSU UAS research and development strategic manager, is the principle investigator on the ASSURE project and co-chairs the Federal UAS Science and Research Panel, which oversees and coordinates UAS research conducted by the FAA, NASA, the Department of Defense, and the Department of Homeland Security.

The center of excellence will supply research to the FAA and UAS industry to increase the potential uses of unmanned systems with minimal changes to the current system regulating manned aircraft.

The center of excellence research areas will include: detect and avoid technology; low-altitude operations safety; control and communications; spectrum management; human factors; compatibility with air traffic control operations; and training and certification of UAS pilots and other crewmembers.

“We are supporting and trying to make the skies safer for using things like UAS or unmanned aircraft systems in the national airspace,” Cathey said. “We have been tasked to look at detect and avoid technology on how we can integrate things from small UAS up to things with a 15- to 20-foot wingspan into national airspace safely.

“The detect and avoid research area focuses on issues related to the detection of potential threats to remain well clear and avoid collisions. It explores sensors, the data produced from sensors, the management and use of that data, and the operational outcome that is considered safe and acceptable,” he said.

In this research area, NMSU is evaluating the requirements for an airborne or ground-based Detect and Avoid system compatible with small UAS (55 pounds and less) operating in limited portions of the National Air Space to comply with the regulations and not increase the risk to other aircraft or people on the ground, beyond what is currently in effect. Additionally, NMSU is accessing the requirements for software along with what are the most feasible airborne or ground-based sensors.

ASSURE will form teams between its member universities, government agencies and industry partners to address both government and commercial UAS challenges.

“Each of those universities has specific skills and abilities, and the idea is to marry all of the technical expertise to provide real research answers for flight safety in the National Air Space,” Cathey said.

For more information on the NMSU PSL UAS FTC visit http://psl.nmsu.edu or ASSURE visit www.assureuas.org.

NMSU studying optimal variety, field protocol for new mechanized chile harvester

LAS CRUCES – New Mexicans love green chile. As that love expands regionally and nationally, the New Mexico growers are faced with an increasing problem – labor.

New Mexico State University graduate student Chuck Havlik watches the mechanized chile harvester run on one of his research plots. He is testing how close chile plants can be together for optimal harvest by the machine without losing chile fruit size. (NMSU photo by Jane Moorman) SEP15
New Mexico State University graduate student Chuck Havlik watches the mechanized chile harvester run on one of his research plots. He is testing how close chile plants can be together for optimal harvest by the machine without losing chile fruit size. (NMSU photo by Jane Moorman) SEP15

Unlike red chile that is harvested mechanically, green chile benefits from the human touch, because broken fruits are undesirable.

“Green chile is a very labor-intensive crop,” said Stephanie Walker, New Mexico State University’s Extension vegetable specialist. “At harvest time, picking crews usually go in at least once, usually twice to hand-pick the fruit.”

This workforce has decreased by 5 percent since 2002, according to New Mexico Chile Association President Dino Cervantes. “We need more product; we can grow more product, but we can’t find the people to harvest it.”

During years when labor has been scarce, or when growers have not been able to get a large enough crew when the chile was at its peak, a field may go unpicked, which is a serious economic loss for the growers.

Mechanized harvests could eliminate this problem.

“As with other crops, moving to mechanization for the green chile is a challenge and something we are researching here at NMSU,” Walker said. “The question is, can we get a machine, a variety of chile and field management all coming together to give us an efficient, clean mechanical harvest of green chile?”

In previous years, researchers at NMSU have worked with the U.S. Department of Agriculture’s Ag Research Service to find the perfect machine.

“We have tested many different machines, many different picking heads, to see which one would work best on green chile harvest,” Walker said. “We think we have found it.”

The machine that has given the researchers minimal damage to the harvested fruit is a machine that is manufactured in Israel by inventor Elad Etgar.

“The machine is used in that country’s chile industry, and is now being field tested in New Mexico,” Walker said. “It is working very well on our crops.”

As a result, NMSU has purchased a one-row, small-plot machine to do experiments at its agricultural science centers to fine-tune the variety and field production protocol to come up with the best scenario for a good, clean mechanical harvest.

Walker and graduate student Chuck Havlik conducted two studies – a variety trial and plant spacing experiment – this year at NMSU’s Agricultural Science Center at Los Lunas.

“We looked at six different breeding lines and commercial cultivars that we picked with the machine to see if different plant attributes impact the efficiency of the mechanical harvest,” Walker said. “We measure many different attributes of the plants in the field prior to harvest, and then aspects of the fruit after the harvest, such as the number of fruit successfully picked and the quantity remaining on the plant and ground.”

Plant spacing may also help get a more efficient mechanical harvest.

“In red chile, which is almost all mechanical harvested, we have found that closer spacing tends to make the plant taller and brings the fruit up off the ground. These plants feed into the machine better,” Walker said. “We would like to take what we’ve learned with red chile and apply it to green chile.”

The issue is that if the plants are too close together, it can impact the size of the chile pod.

“With green chile the fruit size is critical; everyone wants a nice big, solid fruit to make their chile relleno,” Walker said. “If the plants are very close together, it may hurt the quality of the fruit.”

The researchers tested planting four, six and 12 inches apart to see the impact on the fruit and harvesting.

Another big challenge with mechanical harvesting is the destemming of the pod. When crews are hand-picking the chile, the stems are removed at the same time the fruit is harvested.

“Having a stemless fruit is important for the processing plants’ product flow,” Walker said. “If we mechanically harvest the green chile, we need a mechanism to destem the fruit.”

NMSU recently joined forces with Nag Kodali, who worked on destemming chile in his native country of India.

“He has come up with a very efficient, straightforward mechanical method of destemming,” Walker said of Kodali, who now lives in New Hampshire. “Early field testing is proving successful.”

NMSU researcher helps explore cost-effective, non-polluting enhanced geothermal systems

Tapping the natural heat of the earth may be more cost-effective and clean thanks to a research project led by researchers at Pacific Northwest National Laboratory in collaboration with New Mexico State University Assistant Professor Kenneth C. Carroll.

 New Mexico State University Assistant Professor Kenneth C. Carroll, third from left, and other researchers have created a new fracturing fluid that may increase the development of geothermal energy.
New Mexico State University Assistant Professor Kenneth C. Carroll, third from left, and other researchers have created a new fracturing fluid that may increase the development of geothermal energy.

Carroll is a member of a group that has published two papers related to a new area of geothermal energy, called enhanced geothermal systems. These systems are designed to enable power production in areas where conventional geothermal techniques don’t work.
The group, led by Carlos Fernandez, Ph.D., at PNNL, has developed a new fracturing fluid that uses an environmentally friendly polymer to create tiny cracks in bedrock deep below the surface of the earth. The cracks provide places for water to be pumped into the rock, a process called “reservoir stimulation.” There, the heat of the earth – around 150-400 degrees Celsius at depths of 900-4,000 meters – is hot enough to turn the water to steam. The steam then can be returned to the surface and used as an energy source for power plants.

Unlike typical geothermal systems, which rely on porous rock, enhanced geothermal systems have much greater potential to tap the energy of geothermal hot spots in areas of otherwise impermeable bedrock.

The potential could be especially high in the western U.S., including New Mexico.

“The U.S. Geological Survey says most of the western U.S. has heat areas close to the surface,” Carroll said. “New Mexico and most of the West has basin and range geology,” characterized by narrow mountain ranges and flat basins or valleys. This often means heat sources in the earth are closer to the surface than in other areas, making geothermal development more practical.

The new fluid addresses some of the concerns about commonly used fracturing techniques used in the development of oil and gas. Those economically costly techniques require fluids and methods that generate unacceptable environmental impacts.

Carroll is part of a collaborative research project between the Pacific Northwest National Laboratory and NMSU.

“Our new fluid can make enhanced geothermal power production more viable,” Carroll said. “And, though we designed the fluid for geothermal energy, it could also make unconventional oil and gas recovery more environmentally friendly.”

The group’s findings have been published by the Royal Society of Chemistry in the journal Green Chemistry, as well as by Elsevier in Geothermics, the International Journal of Geothermal Research and its Applications.

The project addresses some of the shortcomings of typical geothermal systems. In addition to the prospect of developing systems in areas of impermeable rock, enhanced geothermal systems also would not require that water already be present underground.

Because of the advantages, researchers see great potential for enhanced geothermal systems. Existing U.S. geothermal power plants generate up to 3.4 gigawatts of energy, making up about .4 percent of the nation’s energy supply. A 2006 Massachusetts Institute of Technology report estimates enhanced geothermal systems could boost the nation’s geothermal energy output to 100 gigawatts, enough to power 100 million American homes.

That potential has attracted the interest of the Department of Energy, which has funded five enhanced geothermal system demonstration projects in the U.S. At one project in Nevada, enhanced geothermal methods increased a conventional geothermal plant’s productivity by 38 percent. However, technical challenges and concerns over cost and the amount of water used in these systems has limited their use.

Hydraulic fracturing processes, similar to those used in oil and gas production, also have been used in enhanced geothermal systems, but those processes have drawbacks due to the amount of water required, the potential toxicity of the chemicals used and the high costs of retrieving and treating the water.

In contrast, this novel fluid is a solution of water and 1 percent polyallylamine, a chemical made of carbon and nitrogen that is similar to polymers used in medicine. After it is pumped into a well at a geothermal hot spot, pressurized carbon dioxide is injected into the well. Within 20 seconds, a chemical reaction causes a hydrogel to form, expanding the fluid up to 2.5 times its original volume, expanding existing cracks in the rock and creating new ones. The process is expected to cut in half the amount of water and time needed to open up an underground reservoir, lowering the cost of power generation.

Researchers at PNNL are testing the fluid’s performance on cylindrical samples of impermeable rock. The samples are placed inside a high-pressure, high-temperature test cell created by the researchers. Small amounts of the fluid and liquid carbon dioxide are injected into the test cell, then pressure and temperature are adjusted to match the conditions of the underground geothermal reservoirs.

The researchers found that the fluid consistently created small but effective cracks in the samples that allowed water to flow through. This led them to believe that larger scale tests might produce larger cracks.

The research team also expects that the fluid could be inexpensively recycled.

Additional studies are necessary to more thoroughly evaluate the fluid’s performance. The team is planning lab studies to measure the level at which the fluid can be recycled as well as its ability to fracture larger pieces of rock. The ultimate goal is to conduct a controlled field test.

The research was funded by the Geothermal Technologies Office within DOE’s Office of Energy Efficiency and Renewable Energy.

The team also is studying a similar fluid for unconventional oil and gas recovery.

“It would use a different polymer though the chemistry is similar to the one used in the geothermal energy extraction fluid,” Fernandez said. The fluids are stable and can withstand extreme temperatures, pressures and acidity levels, unlike some fluids used in oil and gas recovery, which degrade over time. The new non-toxic, potentially recyclable fluid also would result in more efficient use of water.

Large-scale concrete testing takes place for first time at NMSU

New Mexico State University civil engineering graduate student Andrew Giesler examines data from a large-scale test on a bridge girder build with ultra-high performance concrete that is stronger and has a longer life than regular concrete. (NMSU photo by Linda Fresques).
New Mexico State University civil engineering graduate student Andrew Giesler examines data from a large-scale test on a bridge girder build with ultra-high performance concrete that is stronger and has a longer life than regular concrete. (NMSU photo by Linda Fresques).

Andrew Giesler, a graduate student in civil engineering, and his team at New Mexico State University are testing ultra-high performance concrete bridge girders on a large scale to aid the development of bridge design procedures for the state of New Mexico that could lead to a variety of improvements to the state’s infrastructure.

The concrete possesses dramatically increased compressive strengths, a very dense microstructure, and steel fibers that greatly improve post-cracking strength. These properties allow for the design of bridges that can have much longer design lives compared to those constructed with normal strength concrete.

Under the direction of Brad Weldon, assistant professor of civil engineering, Giesler conducted three large-scale flexural tests on 16-foot-long, prestressed UHPC bridge girders to evaluate their flexural strength. Graduate student Mark Manning assisted Giesler with the testing and will be conducting similar tests on a full-scale UHPC girder after Giesler graduates in fall 2014.

UHPC was designed to be stronger and more durable than average concrete. The mixture proportions used to create the UHPC Giesler tested was a modified mixture originally developed by a former NMSU graduate student, under the supervision of Craig Newtson, civil engineering professor. The idea was to use primarily local products to produce UHPC, which would drive down the ultimate cost of the final product. With the new UHPC mixture design, Giesler faced the challenges of integrating UHPC production into an industrial setting.

To familiarize local producers with this material, the prestressed UHPC beams were mixed, cast, and cured at Coreslab Structures in Albuquerque, a company that donated a portion of the materials as well as their equipment and labor. The unique mixture design and consistency of this UHPC required careful observation as it went through the batching process. This particular UHPC, made primarily from New Mexico materials, had never been produced on a large scale prior to the casting of these beams.

“We needed to make sure that Coreslab’s facility would be able to accommodate this new concrete. Some of the procedures were new to them, however the entire process went very smoothly and according to plan,” Giesler said.

UHPC has a longer lifespan than average concrete. Whereas normal strength concrete bridges are designed to last approximately 50 years, UHPC bridges have been estimated to have design lives of up to 150 years.

Alongside Ph.D. candidate Jorge Marquez, Giesler designed and erected a structural testing frame that was needed in order to perform the large-scale testing. The testing frame is anchored to the floor and is designed to withstand the resistance created by the beam testing. Parts of the frame were made from recycled bridge girders donated by the U.S. Department of Transportation. Weldon acquired other materials used to build the frame, as well as the actuators used to load the UHPC girders. In addition, monetary assistance was donated by the Associated Contractors of New Mexico for the fabrication and construction of the frame.

Michael McGinnis, a civil engineering associate professor at the University of Texas at Tyler, traveled to NMSU to assist Giesler with a unique form of structural monitoring. McGinnis specializes in digital image correlation. Using the DIC equipment, pictures were taken of a grid drawn on the surface of the beam used to track the formation and propagation of cracks throughout the testing. DIC is capable of covering a large area and can track small changes in the concrete, aiding the equipment used by Giesler. Giesler’s measurement equipment tracked certain areas of the beams in regions prone to cracking as the beams were loaded. DIC served to validate Giesler’s measurements, as well as capture shear behavior closer to the end of the beams near the supports.

The testing was to study the flexural behavior of the UHPC at a large-scale level to evaluate design procedures that can aid in the future development of standardized design codes. Previously, tests had been done on only small-scale rectangular beams. Large-scale tests provide a more realistic representation of how full-scale UHPC beams will behave in a structure such as a bridge.

“Large-scale testing provides much more accurate data. Hopefully, these tests will help to prove that UHPC can be designed both accurately, and efficiently, using simplified methods,” Giesler said.

UHPC is significantly stronger in compression than normal strength concrete, and has strengths exceeding 22,000 pounds per square inch. The compressive strength of average concrete ranges from 4,000 to 6,000 psi. Currently no bridge design specifications for concrete of this strength exist in the United States. The unique material properties, along with the steel fibers that are included in the mixture, are not accounted for in the common design standards. Giesler hopes that through these large-scale tests, he will be able to present data that will aid in the development of new specifications for the design of UHPC bridges.

Jobe Materials donated a high-strength concrete that Giesler and his team used for a cast-in-place bridge deck on one of his three beams. In a real-life scenario, this deck serves as the surface that vehicles drive on. If the beams are designed correctly, the deck and the bridge beam lock together to make the girder stronger.

“We wanted to investigate how a composite lower-strength concrete deck would influence the flexural behavior of a UHPC girder. We wanted to see if it would serve any practical purpose from a structural performance standpoint,” Giesler said.

Right now, the specific UHPC Giesler tested is not being used in any bridges. Giesler said there are commercially available UHPC’s that are being used in a few bridges in the United States, but the UHPC he tested would need to meet specific specifications before it can be used.

“The uniqueness of this UHPC is that it is local to New Mexico,” Giesler said. “If it does make it to a bridge, it will be the first bridge in New Mexico constructed with UHPC. We need to make sure we are confident in our design procedures before UHPC is implemented into a real bridge.”

Giesler received the Daniel P. Jenny Research Fellowship from the Precast/Prestressed Concrete Institute to help fund his graduate work on UHPC. A variety of equipment and materials were also donated to the UHPC project by the NMDOT, BASF, Dayton Superior, El Paso Machine and Steel, Voss Engineering and Bekaert. The NMSU MTECH Lab also provided assistance and equipment for Giesler to fabricate customized testing equipment. Giesler is currently working on his master’s thesis and hopes to defend it in September. After Giesler completes his master’s degree, he plans on working for an engineering firm in the Southwest, where he can design unique and exciting structures and put his knowledge of structural engineering to use.

Watch this video on YouTube at https://www.youtube.com/watch?v=g0posvemFM8&feature=youtu.be.

For more information on this, and other NMSU stories, visit the NMSU News Center.

NIH grant supports NMSU research aimed at improving education for deaf students

 

Linda Spencer, center, director of the Communication Disorders Program in New Mexico State University’s College of Education, talks to her students Shelbie Claycomb, left, and Ruthie Montes who are working in her lab analyzing data for a research project. (NMSU Photo by Darren Phillips)
Linda Spencer, center, director of the Communication Disorders Program in New Mexico State University’s College of Education, talks to her students Shelbie Claycomb, left, and Ruthie Montes who are working in her lab analyzing data for a research project. (NMSU Photo by Darren Phillips)

New Mexico State University’s Communication Disorders Program is partnering on a $2.3 million research project to pinpoint the types of teaching and services that will help deaf students in their educational pursuits.

Linda Spencer, program director of the Communication Disorders Program in NMSU’s College of Education, along with her students are analyzing data for the project that is funded by the National Institute of Deafness and Other Communication Disorders, part of the National Institutes of Health.

The four-year research project is a partnership with the Rochester Institute of Technology and the National Technical Institute of the Deaf’s Center for Research Partnerships. Data for the project that started in 2012 is being collected in Rochester, N.Y., and sent to Spencer for analysis in her Phonology, Hearing, Articulation, Language and Literacy Lab, where her students are learning to analyze speech production by doing sound by sound level transcription.

Spencer said it is a great opportunity for undergraduate volunteers who have had transcription coursework and for graduate students to increase their experience.

“Their skills are being honed to listen and learn what is going on with the speech. Who knows what idea we are going to spark in a student?” she said. 

Junior Annie Wood said she is learning a lot by getting to participate in the project. 

“I’m very interested in the way hearing and speech connect with each other and how they rely on each other to work,” Wood said. “It is really exciting to work in the lab as an undergraduate.”

Wood said the experience she is gaining will help with graduate school applications and perhaps provide an opportunity to present at state and national meetings, but she said it has not been easy.

“It is really difficult to transcribe speech you are not used to hearing, but it is interesting to see how deaf individuals speak,” Wood said.

The study is looking at three groups of college students – deaf students who wear cochlear implants, deaf students who do not use cochlear implants and students who have hearing. Cochlear implants are devices that provide direct electrical stimulation to the auditory or hearing nerve in the inner ear. The cochlear implant does not result in “restored” or “cured” hearing. It does, however, allow for the perception of the sensation of sound. 

Spencer said they are exploring how spoken language and sign language skills relate to and influence each other. They also are measuring verbal and nonverbal cognitive abilities and comparing how students learn from reading and from lectures that are spoken and/or signed. 

“We’re hoping that by looking at the relationship between language and thinking in individuals who are deaf, we will get a better idea of how to teach those individuals,” she said. “We’re hoping what we learn can be instituted in their curriculum to achieve the highest level possible for these individuals.”

The research participants in Rochester come from all walks of life and are for perhaps the first time surrounded by other deaf individuals. Spencer said they will look at how mixing these types of students has impacted them.

“We want to discover how their background influences how they think,” she said. “We want to get a better idea of how thinking and memory and language combine.”

Watch this video on YouTube at http://youtu.be/WUn3PtBhmGk.

For more information on this, and other NMSU stories, visit the NMSU News Center.

NMSU researchers estimate density, abundance of black bears in New Mexico

 

A black bear’s curiosity gets the best of him when he discovers a lure set by NMSU researchers. (NMSU photo by Matt Gould)
A black bear’s curiosity gets the best of him when he discovers a lure set by NMSU researchers. (NMSU photo by Matt Gould)

Using noninvasive genetic sampling, researchers from the Department of Biology and the Department of Fish, Wildlife and Conservation Ecology at New Mexico State University are leading the way in estimating the density and abundance of black bears in the state of New Mexico.

Funded by the New Mexico Department of Game and Fish, the research, in its third year, will conclude its data collection this summer in the Sangre de Cristo Mountains in northern New Mexico and the Sacramento Mountains in south-central New Mexico. 

“The goal is to provide accurate estimates of bear abundance that will contribute to the establishment of harvest objectives for the state,” said James Cain, assistant unit leader in the New Mexico Cooperative Fish and Wildlife Research Unit. The research unit consists of three NMSU faculty members, who support graduate students and post-doctoral associates through research topics ranging from native fish conservation to mammal resource selection and population ecology. 

The project includes Gary Roemer from FWCE and William Gould of the Applied Statistics Program at NMSU.

Ph.D. biology student Matthew Gould works closely with the research unit to gain in-field experience while applying statistical research to determine the necessary data on the bears. 

The management of the black bear populations will benefit from the research because the estimates of abundance are an integral part of establishing sustainable hunting quotas. 

Researchers use two methods to collect the necessary samples: bear rubs and hair traps. 

A hair trap is a single strand of barbed wire, which is stretched around 3-6 trees in a corral fashion at knee height. The barbed wire snags hair, allowing researchers to extract DNA from the root.

Bear rubs are different because they use the bear’s natural behavior to obtain samples. 

“They like to rub up against structures, which is a natural behavior,” Matthew Gould said. “We attach short strips of wire from knee height to head height and when they rub on these structures, the barbs collect hair.”

Bear rubs can be placed on anything, such as telephone poles, trees, posts and large buildings. 

Researchers will deploy hair traps every 5 km across the Sacramento Mountains. They will visit and check about 160 hair traps over six sampling occasions. The team will conduct the research throughout May to August. During travel days, researchers hike to the areas and camp at night. 

Black bears are generally active from mid April to mid November.

Looking at the bears’ genetic health allows the researchers to check if they are connected to any other populations and see any landscape factors that may influence movement between populations. 

“In the Southwest, these populations don’t exist as one contiguous population. They’re often separated, almost like islands,” Gould said. 

Researchers look at factors that may cause habitat loss and fragmentation and what the potential effects are on black bear populations. Factors could include transportation corridors, city developments, agriculture, or natural and human-influenced climate change. 

“As fragmentation and habitat loss occurs, the distance between populations may become greater, which may isolate these populations from each other,” Gould said. “If you have isolation, then over time these populations can become smaller, which may result in inbreeding. As inbreeding increases it can cause problems with health, reproduction and survival.”

This research and data collected from the study prove useful in many ways. 

“It provides a really good opportunity for training graduate students who are looking into fish and wildlife research as a career,” Cain said. 

Game and Fish funded the research to use the data in establishing sustainable harvest limits for black bear populations throughout the state, helping keep the bears on the landscape while still providing hunting opportunities. 

“NMSU is dedicated to conducting research that benefits all New Mexicans,” Gould said.

Watch this video on YouTube at https://www.youtube.com/watch?v=qw3HQqY6rQQ.

For more information on this, and other NMSU stories, visit the NMSU News Center.

NMSU physics department to acquire new instrumentation through DOD funding

 

NMSU physics professor Stefan Zollner speaks at a research rally event on campus. (Photo by Darren Phillips)
NMSU physics professor Stefan Zollner speaks at a research rally event on campus. (Photo by Darren Phillips)

A team of faculty led by Professor Stefan Zollner of New Mexico State University has received a grant of about $300,000 for the acquisition of a high-resolution, high-intensity X-ray diffractometer and reflectometer.

The grant was awarded through the Army Research Office from the Department of Defense Research and Education Program. The new instrument will be housed in Gardiner Hall and will replace an older diffractometer with lower resolution and intensity. 

“We can perform thickness measurements with this instrument; we can measure very thin structures,” Zollner said. “Crystals are made out of atoms which have regular arrangements. There are bonds between the atoms and these bonds have certain lengths and the atoms are certain distances apart. This device can measure distances between atoms, bond angles, lengths of crystal structures and film thickness, and can be applied to a broad range of materials – semiconductors, metals and oxides.” 

Zollner, head of the physics department in the College of Arts and Sciences, gave a presentation of his work at a Research Rally held Friday, May 2, at NMSU. 

The device will aid scientists pursuing a variety of research areas at NMSU, including Zollner’s colleagues Heinz Nakotte and Edwin Fohtung of the physics department and Shuguang Deng and Hongmei Luo of the chemical engineering department. 

“This acquisition is truly an interdisciplinary collaboration of two departments in two different colleges,” Zollner said.

“I commend Dr. Zollner for his efforts to secure this award,” said Vice President for Research Vimal Chaitanya. “Once operational, this XRD will fill a gap that our researchers presently have in order to become more competitive in pursuing research endeavors in materials science and engineering.” 

Zollner, an expert in the areas of semiconductor process integration, complementary metal-oxide semiconductors, device engineering, semiconductor metrology and process control, and optical properties of materials, said he is especially interested in preparing students in the operation of these instruments.

“My goal is training students so they can be successful and get jobs,” he said. “It would be a misconception to think that only faculty perform the research on campus. I would rather compare a faculty member to the director of our marching band, who supports and directs the band from the sideline; but the music is produced by the students on the field. It is the same with research. 

“I’m confident we’ve only seen the tip of the iceberg in semiconductor technologies and many innovations and energy applications are still ahead of us.”

A self-described basic scientist, Zollner explained that many consumer technologies (smart phones, for example, which contain semiconductor chips) would not exist without basic research at the university level.

Physics graduate student Dennis Trujillo from Espanola will be in charge of maintaining the XRD and will train others on the operation of the instrument. He will be assisted by Luis Barrera from Las Cruces, a double major in mechanical engineering and engineering physics. 

Although there is no semiconductor industry in Las Cruces, there is a plant in Albuquerque, as well as state-of-the-art semiconductor plants in Austin and Phoenix.

During the rally, Luo gave a brief presentation of the research she is conducting, researching chemical solutions to creating metal oxide films. 

The Department of Defense has awarded more than $1.7 million in grants and contracts to the NMSU Department of Physics. These funds are used to train undergraduate and graduate students and acquire equipment. 

“You look at this project and you see research, teaching and outreach all coming together,” said Greg Fant, associate vice president and deputy provost. “That’s what we’re all about. Bringing in the industry from Dr. Zollner’s background (he previously worked at Motorola and IBM) and showing that to our students and making things grow, we’re much appreciative. These competitive grants are hard to get. We’re proud of the work he’s doing.”

The XRD is expected to be installed this fall.

Watch this video on YouTube at http://youtu.be/8yTugULAQEE.

For more information on this, and other NMSU stories, visit the NMSU News Center.