While seen as a pest on farmland — for example, when competing with livestock for resources — they usually aren’t widely seen as a pest in conservation areas.

But a new collaborative study led by UNSW Sydney found that conservation reserves are showing signs of kangaroo overgrazing — that is, intensive grazing that negatively impacts the health and biodiversity of the land.

Surprisingly, the kangaroos’ grazing impacts appeared to be more damaging to the land than rabbits, an introduced species.

“The kangaroos had severe impacts on soils and vegetation that were symptomatic of overgrazing,” says Professor Michael Letnic, senior author of the paper and professor in conservation biology and ecosystem restoration at UNSW Science.

“Not only did the areas grazed by overabundant kangaroos have fewer species of plants, but the soils were depleted in nutrients and were compacted — which means that less water can be absorbed by the soil when it rains.”

The findings, published late last year in Global Ecology and Conservation, are based on fieldwork conducted in conservation areas during the drought in 2018. The researchers made observations across four conservation reserves in semi-arid parts of the country.

While kangaroos and rabbits can roam freely in these areas, each reserve has several small ‘exclosures’ — fenced sections designed to keep unwanted animals out — to help native vegetation regenerate. These areas excluded either rabbits, kangaroos, or both.

The team compared the health of the soil and vegetation inside the exclosures with the areas outside. They looked for signs of land degradation specific to each species and monitored animal populations in the area.

Kangaroos were the most populous herbivore across all reserves.

“We tend to think of kangaroo grazing as a natural process because they’re a native species, but there are now too many kangaroos in conservation reserves,” says Prof. Letnic. “Their grazing can be detrimental for biodiversity conservation.

“We need to start thinking about developing strategies to restore the balance and reduce the adverse impacts of overgrazing — particularly during times of drought.”

Dr Graeme Finlayson, SA Arid Rangeland ecologist for Bush Heritage, says overgrazing had dire implications for other native species who rely on vegetation cover and associated food resources to survive. Bush Heritage owns and manages Boolcoomatta Reserve, one of the conservation sites included in this study.

“One of the key species that is likely to be impacted by overgrazing is the critically endangered Plains Wanderer (Pedionomus torquatus), of which there are less than 1000 left in the wild,” he says. “Despite sighting three birds at Boolcoomatta in May 2019, monitoring on the reserve has failed to detect any birds since then.

“Overgrazing and then a two-year drought which have greatly reduced cover and food resources are likely to be key drivers behind this.”

A dry and delicate ecosystem

Ecosystems are fragile and can be thrown off-balance by an overabundance of one species.

For example, kangaroo overgrazing leads to a lower plant diversity — and fewer plants means less food and shelter for other animals.

Dr Charlotte Mills, lead author of the study and visiting fellow at UNSW Science, hopes that this study paves the way for future research into how threatened species might be affected by kangaroo overgrazing.

“There isn’t a lot of research about how kangaroos differentially affect different parts of the ecosystem,” she says. “A lot of past research has focused on rabbits.”

The team found that rabbits still had negative impacts on the land — for example, there were more woody plants in exclosures that rabbits couldn’t get to — but not to the same degree as kangaroos.

“Rabbits and other introduced herbivores like goats are often considered the main contributor to overgrazing in Australia,” says Dr Mills.

“But we found kangaroos had a greater impact on the land — and on the grass in particular.”

Human intervention is a key contributing factor to the growth of kangaroo populations.

“Humans have been culling dingoes — kangaroos natural predators,” says Prof. Letnic.

“We’ve been making it easier for kangaroos to thrive.”

Rethinking conservation practices

Conservation reserves help protect native vegetation from threats like grazing from livestock or introduced species like rabbits or goats.

The findings suggest native species might need to be kept in check, too.

“If we aren’t managing threats that have been exacerbated by human activities — such as overabundant kangaroo populations — then we’re not using conservation areas in the best way that we can,” says Dr Mills.

Prof. Letnic says that while kangaroo populations on farms have been managed for 100 years, they have generally been unmanaged on conservation reserves.

“This research changes thinking by suggesting it’s time to ask some questions,” he says. “We need to ask whether there are too many kangaroos and if they’re having unacceptable impacts on our conservation reserves.”

Dr Finlayson says it’s a difficult balance to get right, but a humane and science-led approach is best for the entire ecosystem.

“Reducing total grazing pressure clearly has great conservation benefit but can be a challenging issue when this requires the management of native species, such as kangaroos,” he says.

“We need to make sure we have a landscape-wide strategy, working across government, conservation and agriculture, to ensure we tackle this problem together, and in the most humane way possible.”

Clive Randall, director of Penn State’s Materials Research Institute (MRI), developed the material and device in partnership with researchers from QorTek, a State College, Pennsylvania-based company specializing in smart material devices and high-density power electronics.

“NASA’s need was how to power electronics in remote locations where batteries are difficult to access for changing,” Randall said. “They also wanted self-powering sensors that monitor systems such as engine stabilities and have these devices work during rocket launches and other high-temperature situations where current piezoelectrics fail due to the heat.”

Piezoelectric materials generate an electric charge when rapidly compressed by a mechanical force during vibrations or motion, such as from machinery or an engine. This can serve as a sensor to measure changes in pressure, temperature, strain or acceleration. Potentially, piezoelectrics could power a range of devices from personal electronics like wristband devices to bridge stability sensors.

The team integrated the material into a version of a piezoelectric energy harvester technology called a bimorph that enables the device to act either as a sensor, an energy harvester or an actuator. A bimorph has two piezoelectric layers shaped and assembled to maximize efficient energy harvesting. Sensors and energy harvesters, while bending the bimorph structure, generate an electrical signal for measurement or act as a power source.

Unfortunately, these functions work less-effectively in high-temperature environments. Current state-of-the-art piezoelectric energy harvesters are normally limited to a maximum effective operating temperature range of 176 degrees Fahrenheit (80 degrees Celsius) to 248 degrees Fahrenheit (120 degrees C).

“A fundamental problem with piezoelectric materials is their performance starts to drop pretty significantly at temperatures above 120 C, to the point where above 200 C (392 F) their performance is negligible,” Gareth Knowles, chief technical officer of QorTek, said. “Our research demonstrates a possible solution for that for NASA.”

The new piezoelectric material composition developed by the researchers showed a near-constant efficient performance at temperatures up to 482 F (250 C). In addition, while there was a gradual drop-off in performance above 482 F (250°C), the material remained effective as an energy harvester or sensor at temperatures to well-above 572 F the researchers reported in the Journal of Applied Physics.

“The compositions performing just as well at these high temperatures as they do at room temperature is a first, as no one has ever managed piezoelectric materials that effectively operate at such high temperatures,” Knowles said.

Another benefit of the material was an unexpectedly high level of electricity production. While at present, piezoelectric energy harvesters are not at the level of more efficient power producers such as solar cells, the new material’s performance was strong enough to open possibilities for other applications, according to Randall.

“The energy production part of this was very impressive, the material shows record performance efficiencies as a piezoelectric energy harvester,” Randall said. “This would potentially enable a continuous, battery-free power supply in dark or concealed environments such as inside an automotive system or even the human body.”

Both Randall and Knowles noted that the partnership between Penn State and QorTek, which goes back over 20 years, enabled development of the new, improved piezoelectric material by complementing each other’s resources.

“In general, a big benefit of a partnership like this is you can tap into the large knowledge reservoir in the field that MRI and Penn State has and that small companies like ours sometimes do not,” Knowles said. “Another benefit is often universities have physical resources such as equipment that again, you won’t ordinarily find inside a small company.”

Randall noted that since QorTek has many employees who are Penn State alumni, there is a familiarity with both the research subject and the people involved.

“One of my post-doctoral researchers and first author on the paper, Wei-Ting Chen, was hired by QorTek so there was a transfer of expertise in that case,” Randall said. “Also, the skillsets offered by QorTek such as mechanical engineering, device design and measurement expertise pushed development at a much faster rate than would be possible given the budget we were given. So the partnership enabled a really fruitful amplification of the project.”

The National Aeronautics and Space Administration’s Small Business Technology Transfer Program and the National Science Foundation funded this research.

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Materials provided by Penn State. Original written by Jamie Oberdick. Note: Content may be edited for style and length.

“Students who participated in the study were twice as likely to meet the state standards in their mathematics achievement,” said Neuharth-Pritchett. “School becomes more challenging as one progresses through the grades, and so if in middle school, students are still twice as likely to meet the state standards, it’s clear that something that happened early on was influencing their trajectory.”

The study found that, in fourth through seventh grades, the odds of a pre-K participant in the study meeting Georgia’s state academic standards on the statewide standardized test were 1.67-2.10 times greater than the odds for a nonparticipant, providing evidence of sustained benefits of state-funded pre-K programs.

“Pre-K is a critical space where children experience success, and it sets them on a trajectory for being successful as they make the transition to kindergarten,” she said. “The hope is that when children are successful early in school, they are more likely to be engaged as they progress and more likely to complete high school.”

Although quality learning experiences during the early years of development have been shown to provide the skills and knowledge for later mathematics achievement, access and entry to high-quality preschool programs remain unequal across the nation.

“Our study looked at a high-needs school district that enrolled children from vulnerable situations in terms of economics and access to early learning experiences,” said Neuharth-Pritchett. “A number of the children in the study had not had any other formative experiences before they went to kindergarten.”

Educational experiences are seen as foundational to later school success with some studies documenting other beneficial outcomes for students who attend pre-K, including a higher chance to complete high school, less mental health concerns, less reliance on the welfare system and more. However, students from low-income families often have more limited opportunities to learn at home as well as in pre-K programs.

While some families are knowledgeable about providing their children with basic mathematical concepts and other foundational skills for a smooth home to school entry, other families might not be aware of the expectations for having mastered a number of these foundational skills before entering kindergarten.

“Equal access to pre-K education has a long history that goes all the way back to the war on poverty. Part of the thinking during the 1960s was that such early learning opportunities would provide the high-quality preschool education that could level the educational playing field between those with economic resources and those without,” she said. “Our study indicated sustained benefits for children’s early learning experiences that persist into the elementary and middle school years.”

Some implications of the study for policymakers to consider include ensuring more equitable access to pre-K programs and hiring highly skilled teachers to promote children’s learning and development. More than half of the pre-K teachers involved in the study held either a master’s or specialist degree, indicating the importance and influence of high-quality, experienced instructors on children’s academic success.

Because of a change in program support for the Georgia Prekindergarten Program during Gov. Nathan Deal’s term, a high proportion of pre-K teachers are now very early in their teaching careers.

Along with Jisu Han, an assistant professor at Kyung Hee University and co-author of the study, Neuharth-Pritchett plans to continue following the study’s participants as they progress through high school.

“The state of Georgia invests substantial resources into this program, so it’s good that these outcomes can be cited for its efficacy,” said Neuharth-Pritchett. “The data from this study gives a much more longitudinal view of success and suggests these programs contribute to children’s education and success. Our results ultimately contribute to evidence supporting early learning and factors influencing long-term academic success for Georgia’s children.”

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Materials provided by University of Georgia. Note: Content may be edited for style and length.

A team comprising researchers from UTEP and the historically Black research university in Washington, D.C., discovered valuable data in comparing the fundamental mechanisms of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and SARS-CoV-2 — also known as COVID-19 — to better understand how these viruses attack the human body. Their findings are published in an article titled “Spike Proteins of SARS-CoV and SARS-CoV-2 Utilize Different Mechanisms to Bind with Human ACE2” that recently appeared in the scientific journal Frontiers in Molecular Biosciences.

“We are very excited and interested in the timely work that Dr. Li and his collaborators have reported,” said Robert Kirken, Ph.D., dean of UTEP’s College of Science. “As the SARS-COV2 continues to evolve through its passage by infected humans, the rapid identification and assessment of these mutants using the research and testing approaches they have established will be critically important for the development of new vaccines and therapeutics.”

In comparing the viruses, researchers found that both are very similar in sequence and almost identical in structure. Using computational approaches, they were also able to identify mutations of SARS-CoV that make SARS-CoV-2 significantly more contagious and prone to cause serious infections.

“We found that because of mutations, the binding from SARS-CoV-2 to the human cell is much stronger compared with SARS-CoV,” Li said. “This might be one of the reasons why SARS-CoV-2 is spreading much faster and is difficult to control. SARS-CoV-2 also uses a much smarter strategy to attack the human cell than SARS-CoV. For example, when SARS-CoV infects or binds to the human cell, it uses several key residues or amino acids to do so, while SARS-CoV-2 uses more residues, making it more robust and easier to completely hijack the human cell.

“We identified the most important residues for SARS-CoV-2 to bind to the human cell. This type of data is key for drug development to cure or treat infections caused by these types of viruses. These fundamental rules and features can also be used for future disease control when perhaps 10 years from now, there’s a SARS-CoV-3 or 4.”

Researchers from both universities focused on examining one of the virus’ four main proteins, known as the spike protein, that initiates infection to the human body. They discovered that from SARS-CoV to SARS-CoV-2 there is an interesting change in mechanism of the binding domain of the spike protein.

“The binding domain needs to flip out so that it can bind to the human cell, but we found some strange mutations that happened. Like the hinge of a door, the binding domain may affect the flip mechanism of SARS-CoV-2. It may be more flexible, making it easier to bind to the human cell,” Li said.

The team included an interdisciplinary mix of undergraduate and graduate students, postdoctoral researchers and faculty from both UTEP and Howard University. Yixin Xie, a UTEP graduate student and research assistant, served as the paper’s first author, and led the calculation and analysis portions of the project while working closely with other UTEP and Howard University students remotely due to the pandemic.

In the future, the goal of the team is to expand their research to study the mechanisms of all four proteins to better understand the inner workings of these viruses even more to help combat COVID-19 and related viruses.

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Materials provided by University of Texas at El Paso. Note: Content may be edited for style and length.