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Crayfish ‘trapping’ doesn’t control invasive species

Oct. 13 (UPI) — In Britain, a handful of celebrity chefs have encouraged the practice of crayfish “trapping” to control the invasion of American signal crayfish.

Unfortunately, new research — published Tuesday in the Journal of Applied Ecology — suggests the practice doesn’t work. In fact, crayfish trapping can have a host of unintended consequences.

“Trapping has been linked to a range of risks to our waterbodies, including the spread of invasive species on wet or unclean equipment, as well as the direct capture and release of invasive crayfish to seed new harvestable populations,” study co-author Eleri Pritchard told UPI in an email.

“Sadly, trapping also risks protected native wildlife, and has been responsible for the deaths of otters and water voles,” said Pritchard, a postdoctoral researcher at University College London.

American signal crayfish have led to significant declines of native crayfish in Britain and Europe. The invasive species is a carrier of what’s called crayfish plague, a disease that is lethal to the native white-clawed crayfish. American signal crayfish are also bigger and more aggressive than native species, outcompeting them for available resources.

Beyond threatening native species, American signal crayfish also burrow into stream banks, undermining natural stream structures and increasing flood risks. Researchers suggest the invasive species also poses a threat to fish, invertebrates and aquatic plants.

Taking a cue from efforts to curb the spread of invasive fish species, chefs in Britain have encouraged people to trap and eat American signal crayfish.

“Crayfish trapping involves the use of funnel traps, very similar to lobster pots,” Pritchard said. “The traps are submerged in the water and baited with something to attract the crayfish, like fresh oily fish or cat-food. This entices the crayfish through the funnel entrances of the trap and once inside, it is difficult for them to escape. The traps are then retrieved from the water with crayfish trapped inside.”

For the new study, researchers compared the effectiveness of three survey methods — baited funnel trapping, hand-searching and a novel “triple drawdown technique” — deployed to analyze local crayfish populations. The triple drawdown method involves the draining of a short section of stream in order to tally the number of crayfish present, including infants.

The triple drawdown technique proved most effective at providing scientists a comprehensive and precise picture of the size and makeup of crayfish population within a stream. The method showed crayfish population densities have likely been underestimated in many British streams.

The novel survey method also showed that only a small percentage of any given stream’s American signal crayfish is trappable. Most of the invasive crayfish are too small.

“In our research, [the triple drawdown technique] helped us understand how trapping would not be effective at controlling populations, which is really important for management and conservation,” Pritchard said.

Researchers are currently working to develop effective American signal crayfish control methods.

In the meantime, Pritchard and her colleagues suggest prevention of the spread of both crayfish and the crayfish plague is essential for the

Finding the right color to control magnets with laser pulses

Finding the right colour to control magnets with laser pulses
The spin can be seen as an elementary “needle of a compass”, typically depicted as an arrow showing the direction from North to South poles. Credit: Lancaster University

Scientists have discovered a new way to manipulate magnets with laser light pulses shorter than a trillionth of a second.

The international team of researchers, led by Lancaster and Radboud Universities, also identified the light wavelength or color which enables the most efficient manipulation. The finding is published in Physical Review Letters.

Magnets have fascinated people since ancient times, but until a hundred years ago the theoretical understanding of magnetism remained very elusive. The breakthrough in understanding occurred with the development of quantum mechanics and the discovery of the fact that each electron has an intrinsic magnetic moment or spin.

The spin can be seen as an elementary “needle of a compass,” typically depicted as an arrow showing the direction from North to South poles. In magnets all spins are aligned along the same direction by the force called exchange interaction. The exchange interaction is one of the strongest quantum effects which is responsible for the very existence of magnetic materials.

The strength of the exchange interaction can be appreciated from the fact that it generates magnetic fields 10,000 times stronger than the Earth’s magnetic field. Another manifestation of its strength is the fact that it can drive spins to rotate with a period of one trillionth of a second and even faster.

Manipulating the exchange interaction would be the most efficient and ultimately fastest way to control magnetism. To achieve this result, the researchers used the fastest and the strongest stimulus available: ultrashort laser pulse excitation.

However, in order to detect/observe the effect of light on magnetism one would need an ultrafast magnetometer—a device which would be able to trace the dynamics of spins with less that a trillionth of a second resolution. This is much faster than the temporal resolution of modern electronics.

But the authors have found a solution to this problem, as lead researcher Dr. Rostislav Mikhaylovskiy from Lancaster University explains: “The spins oscillate at Terahertz frequencies almost a trillion times faster than the standard power line frequency of 50 Hz. Thanks to such high frequencies of oscillations, the spins act as efficient antennas emitting electromagnetic radiation. By analyzing the properties of the emitted radiation we can extract information about the ultrafast magnetization dynamics triggered by the optical steering of the exchange forces.”

By systematically varying the color of the excitation laser pulses from red to blue, the scientists were able to identify the light wavelength for which the effect of light on magnetism is the strongest.

Dr. Mikhaylovskiy said: “It was very important to see that the effect of light on the exchange interaction really exists. By tuning the wavelength or color of light we started to understand how to enhance this effect.”

This exciting discovery opens a new research line at Lancaster University led by Dr. Mikhaylovskiy. The next step is to perform systematic studies

Fuels, not fire weather, control carbon emissions in boreal forest

Fuels, not fire weather, control carbon emissions in boreal forest
Rockets represent carbon stored in wood, trees, and soil in four main boreal forest regions. Though fire weather helps “ignite” the rockets, the amount of emissions each forest can produce is determined by fuel load (soil layers) and flammability (soil moisture). Credit: Victor Leshyk, Center for Ecosystem Science and Society

As climate warming stokes longer fire seasons and more severe fires in the North American boreal forest, being able to calculate how much carbon each fire burns grows more urgent. New research led by Northern Arizona University and published this week in Nature Climate Change suggests that how much carbon burns depends more on available fuels than on fire weather such as drought conditions, temperature, or rain. In a large retrospective study that stretched across Canada and Alaska, the international team of researchers found that the carbon stored belowground in soil organic matter was the most important predictor of how much carbon a fire will release.

The team surveyed the vast Western Boreal’s diverse forest conditions by analyzing field data collected from 417 burn sites in six ecoregions in Canada and Alaska between 2004-2015. They found that the amount of carbon stored in soils was the biggest predictor of how much carbon would combust, and that soil moisture was also significant in predicting carbon release.

“In these northern forests, soil, not trees, can account for up to 90 percent of carbon emissions, so we expected that these organic soils would be a significant driver,” said lead author Xanthe Walker of the Center for Ecosystem Science and Society at Northern Arizona University. “But we were surprised that fire weather and the time of year a fire starts proved to be poor indicators of carbon combustion. It’s really about the fuels that are there when a fire starts.”

That’s a pivotal finding, since fire weather, as measured by a Fire Weather Index, is one of the main tools scientists and fire managers currently use to model carbon emissions in these boreal forests. This study suggests fuels should be a bigger component of those models. “When we think of climate change and wildfires, we often instinctively think of extreme weather conditions,” said Marc-André Parisien, a research scientist with the Canadian Forest Service and co-author of the study. “But our study shows that vegetation also matters—a lot! Predicting future vegetation is a tough nut to crack, but this study emphasizes the need to keep chipping away at it.”

The vegetation patterns they uncovered were complex—soil moisture, tree species composition, and stand age at the time of fire all interacted to predict combustion amounts. For instance, highly flammable black spruce was generally a predictor of carbon combustion, and the presence of this species increased with site moisture and stand age at the time of fire. But such interactions are likely to change with the climate. For example, as the climate warms and fire intervals shorten, black spruce stands are being replaced by deciduous trees and jack pine, which grow in shallower soils that release less

GOP could lose control of University of Colorado Board of Regents for the first time in 4 decades

The University of Colorado Board of Regents is due for some new blood in 2020 with three positions up for election.

One contentious race has the potential to flip the board majority from Republican to Democrat for the first time since the 1970s. Regardless of party, the nine-member board hasn’t had three newcomers at once since 2008.

“Three new regents on a board of nine is a good challenge in terms of how they become part of the team, who they see as their constituents and dealing with all of the important issues moving forward,” said Glen Gallegos, R-Grand Junction, who serves as board chair.

The regents serve staggered six-year terms. One is elected from each of Colorado’s seven congressional districts and two are elected from the state at large. The board is responsible for governing the four-campus, multibillion-dollar university system, making decisions about how CU spends money and who should be selected as university president when the time comes.

Democrat Callie Rennison, Republican Dick Murphy and Libertarian Christian Vernaza will be facing off in the Democratic stronghold of District 2 to replace incumbent Linda Shoemaker.

Democrat Nolbert Chavez is running unopposed for outgoing Democrat Irene Griego’s seat in District 7.

The District 6 race — covering a wide swath of the north, east and south Denver area — is garnering the most attention, with Republican Richard Murray, Democrat Ilana Spiegel and Unity candidates Christopher Otwell and Robert Worthey competing to replace outgoing John Carson, R-Highlands Ranch.

“The big issue is will the political control of the board flip from Republican to Democrat?” said Ken McConnellogue, CU system spokesman.

CU is one of just a handful of universities in the nation whose governing boards are chosen through partisan political elections. The board has long been criticized for its partisan nature, most recently after voting 5-4 along party lines to name controversial finalist Mark Kennedy the new president last year.

Gallegos said the board usually unanimously agrees on matters, including keeping tuition low, but there are a few issues that wind up with political division.

“There are some things that it pays to be in the majority,” Gallegos said. “It matters a lot, and it matters to a lot of our Democratic colleagues who believe that the board over the years should have been more balanced. It’s the elephant in the room. There are issues that people feel like the majority is always going to win.”

Outgoing board member Griego said a few of those partisan issues revolve around diversity and social justice.

“It’s really been a struggle for us to move some of our agendas forward because we just don’t have the votes,” Griego said. “It’s been 41 years since we’ve had Democrats in the majority, and I believe these last nine years we have avoided really tough conversations because of political agendas.”

During a virtual candidate forum  held by CU Staff Council, CU Faculty Council and CU Anschutz Faculty Assembly last week, Murray and Spiegel shared their ideas about

Quality control mechanism closes the protein production ‘on-ramps’ in cells

Quality control mechanism closes the protein production 'on-ramps'
An illustration of stalled ribosomes as stalled cars on a freeway. New work shows that factors GIGYF2 and 4EHP prevent translation from being initiated on problematic messenger RNA fragments. This is akin to closing an on-ramp to prevent additional traffic backups after an incident. Credit: Kamena Kostova and Navid Marvi.

Recent work led by Carnegie’s Kamena Kostova revealed a new quality control system in the protein production assembly line with possible implications for understanding neurogenerative disease.

The DNA that comprises the chromosomes housed in each cell’s nucleus encodes the recipes for how to make proteins, which are responsible for the majority of the physiological actions that sustain life. Individual recipes are transcribed using messenger RNA, which carries this piece of code to a piece of cellular machinery called the ribosome. The ribosome translates the message into amino acids—the building blocks of proteins.

But sometimes messages get garbled. The resulting incomplete protein products can be toxic to cells. So how do cells clean up in the aftermath of a botched translation?

Some quality assurance mechanisms were already known—including systems that degrade the half-finished protein product and the messenger RNA that led to its creation. But Kostova led a team that identified a new tool in the cell’s kit for preventing damage when protein assembly goes awry. Their work was published by Molecular Cell.

Using CRISPR-Cas9-based genetic screening, the researchers discovered a separate, and much needed, device by which the cell prevents that particular faulty message from being translated again. They found two factors, called GIGYF2 and 4EHP, which prevent translation from being initiated on problematic messenger RNA fragments.

“Imagine that the protein assembly process is a highway and the ribosomes are cars traveling on it,” Kostova explained. “If there’s a bad message producing incomplete protein products, it’s like having a stalled car or two on the road, clogging traffic. Think of GIGYF2 and 4EHP as closing the on-ramp, so that there is time to clear everything away and additional cars don’t get stalled, exacerbating the problem.”

Loss of GIGYF2 has previously been associated with neurodegenerative and neurodevelopmental problems. It is possible that these issues are caused by the buildup of defective proteins that occurs without the ability to prevent translation on faulty messenger RNAs.

Mechanism discovered how the coronavirus hijacks the cell

More information:
Kelsey L. Hickey et al, GIGYF2 and 4EHP Inhibit Translation Initiation of Defective Messenger RNAs to Assist Ribosome-Associated Quality Control, Molecular Cell (2020). DOI: 10.1016/j.molcel.2020.07.007
Provided by
Carnegie Institution for Science

Quality control mechanism closes the protein production ‘on-ramps’ in cells (2020, October 8)
retrieved 8 October 2020

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