Research Roundup | Oct. 25

· 4 min read

Research Roundup | Oct. 25

Brian Couch
Craig Chandler | University Communication and Marketing
Brian Couch (center), associate professor of biological sciences, discusses chemical elements with students in his LIFE 120 class.

Welcome to the Research Roundup: a collection of highlights from the latest Husker research and creative activity. This latest edition looks at the spread of teaching innovations, the projected spread of an agricultural pest, and the unexpected behavior of water in nanotubes.

Innovation dissemination

Though much research has shown that interactive, student-centric approaches to teaching outperform lecturing in terms of helping students learn, the latter still dominates many STEM classrooms. In 2020, a team that included Brian Couch, associate professor of biological sciences, found that faculty who employ innovative, evidence-based teaching practices tend to share those strategies mostly among themselves — limiting their dissemination among the faculty who continue to rely on lecturing.

In a recent study published by the International Journal of STEM Education, Couch and colleagues present insights from interviews with 19 STEM faculty known for their innovative instructional practices. During those interviews, faculty reported that the colleagues they consider core members of their personal networks influence their teaching practices more than do their distant contacts. And they detailed certain factors, such as co-teaching courses and working from nearby offices, that help promote conversations with those closer colleagues. The study also revealed that the faculty talk with their peers more about student engagement and expectations than about learning outcomes.

To stimulate discussions across more faculty, the team proposed that STEM departments cultivate new teaching relationships by presenting more opportunities and incentives for faculty to share practices beyond their core networks. That’s especially important, the researchers asserted, given that many of the interviewed faculty said they seek teaching help only from peers they know to have relevant expertise. Departments that encourage faculty to share teaching approaches during meetings, and even observe their peers teaching classes, could see greater dissemination of student-focused, data-backed practices, the team said.

A pesky earworm

The Department of Entomology’s Robert Wright, Julie Peterson and Thomas Hunt contributed to a recent paper, published in Proceedings of the National Academy of Sciences, that examines the potential influences of climate change on the range of the corn earworm, an agricultural pest.

Led by a team at North Carolina State University, the researchers developed models to estimate the population and survival prospects of the corn earworm in three North American zones that are defined by their winter soil temperatures. Corn earworms can successfully overwinter in the warmer soils of the southern zone, whereas that survival is uncertain in the so-called transitional zone and impossible in the northernmost zone, or northern limits.

Maps of corn earworm ranges
PNAS / National Academy of Sciences
Overwintering ranges of the corn earworm from 1950-2021 (A), along with projected changes in those ranges from 2022-2047 (B), 2048-2073 (C), and 2074-2099 (D).

According to one of those models, the proportional area of the corn earworm’s southern range — the one suitable for surviving winters — could expand from 34% to 56% by the year 2099. The range of the inhospitable northern limits, meanwhile, could shrink from 39% to just 11%. Those trends might eventually allow the pest to overwinter in the U.S. Corn Belt, a region whose winters have historically proven too cold for the earworm. If so, populations of the pest could begin spiking earlier in the Corn Belt, the team noted. And because the species can migrate up to 600 miles, that development could also spell more earworms, and greater yield losses, in northern corn-producing regions.

Uneven flow

Carbon nanotubes — hollow, minuscule tubes of honeycomb-configured carbon atoms — have emerged as a potential option for filtering water of impurities, even salt. But maximizing the effectiveness and efficiency of those carbon nanotubes means knowing how their various properties modify the way that water molecules flow through them.

Xiao Cheng Zeng, Chancellor’s University Professor emeritus of chemistry, recently teamed with colleagues in China and the United States to study how the length of the nanotubes can influence how fast they transport water. On the macroscale, water flow typically slows as a tube lengthens. But simulations run by the team suggest that in relatively narrow carbon nanotubes — those less than a nanometer in diameter — the speed of water flow instead increases as those nanotubes lengthen from zero to 0.37 nanometers. Beyond that length, the rate of water transport either slowly decreases or slightly varies, according to the simulations.

Along with informing the design of nanotube-based filters, the findings could improve understanding of water transport among biological cells, which often feature pores roughly the same diameter as the carbon nanotubes studied by the team.

Recent News