When the global climate has the hiccups

This chamber has the size of a football pitch and is located deep inside the cave.
Photo Credit: University of Basel, Dominik Fleitmann

Climate changes usually happens over long periods of time, but during the last glacial period, extreme fluctuations in temperature occurred within just a few years. Researchers at the University of Basel have now been able to prove the phenomenon also occurred during the penultimate glacial period.

In recent geological history, the so-called Quaternary period, there have been repeated ice ages and warm periods. Researchers are able to determine past climate variability from the composition of climate records. In the case of the last glacial period 100,000 years ago, ice cores from Greenland in particular provide researchers with detailed data.

For example, Greenland ice cores show that there were repeated rapid increases in temperature. “We are talking about increases of 5 to 10 degrees within 30 to 40 years on average in the case of Europe. A Neanderthal would have experienced increases in the average temperature of several degrees over the course of their life,” explains Prof. Dominik Fleitmann, Professor of Quaternary Geology at the University of Basel. He calls the phenomena “climate hiccups”.

These Dansgaard-Oeschger events are well documented for the last glacial period, but the climate records from Greenland only cover the last 120,000 years. It was therefore previously unknown whether these Dansgaard-Oeschger events also occurred during the penultimate glacial period 135,000 to 190,000 years ago. Frederick Held, a PhD candidate in Fleitmann’s research group, was able to show that Dansgaard-Oeschger events also occurred during the penultimate glacial period using isotopic measurements on stalagmites. He is the lead author of the study which was published in the scientific journal Nature Communications.

Ancient air-breathing fish comes to surface

Life reconstruction of Harajicadectes zhumini, a 40 cm long lobe-finned fish that is not too distantly related to the fishes that gave rise to the earliest limbed tetrapods.
Illustration Credit: Brian Choo, Flinders University

Alice Spring’s Finke River (Larapinta), often cited as one of the oldest rivers in the world, once hosted waters teeming with bizarre animals – including a sleek predatory lobe-finned fish with large fangs and bony scales.

The newly described fossil fish has been named Harajicadectes zhumini by an international team of researchers led by Flinders University paleontologist Dr Brian Choo.

The fossil was named for the Harajica Sandstone Member where the fossils were found in Australia’s ‘Red Centre’ and the ancient Greek dēktēs (“biter”). It also pays homage to Professor Min Zhu, currently at the Chinese Academy of Sciences, Beijing, who has made some major contributions to the research of early vertebrates.

Ants Recognize Infected Wounds and Treat Them

A Matabele ant tends to the wound of a fellow ant whose legs were bitten off in a fight with termites.
 Photo Credit: Erik Frank / Universität Würzburg

The African Matabele ants are often injured in fights with termites. Their conspecifics recognize when the wounds become infected and initiate antibiotic treatment.

The Matabele ants (Megaponera analis), which are widespread south of the Sahara, have a narrow diet: They only eat termites. Their hunting expeditions are dangerous because termite soldiers defend their conspecifics – and use their powerful mandibles to do so. It is therefore common for ants to be injured while hunting.

If the wounds become infected, there is a significant survival risk. However, Matabele ants have developed a sophisticated healthcare system: they can distinguish between non-infected and infected wounds and treat the latter efficiently with antibiotics they produce themselves. This is reported by a team led by Dr Erik Frank from Julius-Maximilians-Universität (JMU) Würzburg and Professor Laurent Keller from the University of Lausanne in the journal Nature Communications.

Novel food regulations are a barrier for edible insects

Photo Credit: SatyaPrem

Edible insects could be the key to a more sustainable food system, yet Novel Food Regulations could be restricting alternative environmentally-friendly sources of protein for consumers, a new report has found.

• Edible insect companies could play a part in a more sustainable food system by providing an alternative and environmentally sustainable source of protein, relative to conventional forms of meat

• Research shows that there are still regulatory barriers for the production of edible insects that need to be addressed

• Although not a familiar part of European diets, edible insects are regularly consumed elsewhere in the world

• New report from the University of Sheffield’s Institute for Sustainable Food and the UK Edible Insect Association shows professionally farmed edible insects pose no more risks than commonly eaten foods such as chicken, pork, or shellfish

• Edible insects could be the key to a more sustainable food system, yet Novel Food Regulations could be restricting alternative environmentally-friendly sources of protein for consumers, a new report has found.

A carbon-lite atmosphere could be a sign of water and life on other terrestrial planets

In the search for extraterrestrial life, MIT scientists say a planet’s carbon-lite atmosphere, relative to its neighbors, could be a sure and detectable signal of habitability.
Image Credit: Scientific Frontline stock image.

Scientists at MIT, the University of Birmingham, and elsewhere say that astronomers’ best chance of finding liquid water, and even life on other planets, is to look for the absence, rather than the presence, of a chemical feature in their atmospheres.

The researchers propose that if a terrestrial planet has substantially less carbon dioxide in its atmosphere compared to other planets in the same system, it could be a sign of liquid water — and possibly life — on that planet’s surface.

What’s more, this new signature is within the sights of NASA’s James Webb Space Telescope (JWST). While scientists have proposed other signs of habitability, those features are challenging if not impossible to measure with current technologies. The team says this new signature, of relatively depleted carbon dioxide, is the only sign of habitability that is detectable now.

“The Holy Grail in exoplanet science is to look for habitable worlds, and the presence of life, but all the features that have been talked about so far have been beyond the reach of the newest observatories,” says Julien de Wit, assistant professor of planetary sciences at MIT. “Now we have a way to find out if there’s liquid water on another planet. And it’s something we can get to in the next few years.”

The team’s findings appear today in Nature Astronomy. De Wit co-led the study with Amaury Triaud of the University of Birmingham in the UK. Their MIT co-authors include Benjamin Rackham, Prajwal Niraula, Ana Glidden Oliver Jagoutz, Matej Peč, Janusz Petkowski, and Sara Seager, along with Frieder Klein at the Woods Hole Oceanographic Institution (WHOI), Martin Turbet of Ècole Polytechnique in France, and Franck Selsis of the Laboratoire d’astrophysique de Bordeaux.

Electronic “soil” enhances crop growth

Alexandra Sandéhn, PhD student, one of the lead authors, and Eleni Stavrinidou, Associate Professor, and supervisor of the study, connect the eSoil to a low power source for stimulating plant growth.
Photo Credit: Thor Balkhed

Barley seedlings grow on average 50% more when their root system is stimulated electrically through a new cultivation substrate. In a study published in the journal PNAS, researchers from Linköping University have developed an electrically conductive “soil” for soilless cultivation, known as hydroponics.

Alexandra Sandéhn, PhD student, one of the lead authors, and Eleni Stavrinidou, Associate Professor, and supervisor of the study, connect the eSoil to a low power source for stimulating plant growth. Thor Balkhed

“The world population is increasing, and we also have climate change. So, it’s clear that we won’t be able to cover the food demands of the planet with only the already existing agricultural methods. But with hydroponics we can grow food also in urban environments in very controlled settings,” says Eleni Stavrinidou, associate professor at the Laboratory of Organic Electronics at Linköping University, and leader of the Electronic Plants group.

Her research group has now developed an electrically conductive cultivation substrate tailored to hydroponic cultivation which they call eSoil. The Linköping University researchers have shown that barley seedlings grown in the conductive “soil” grew up to 50% more in 15 days when their roots were stimulated electrically.

Brain cell discovery sparks hope for fertility treatments

Photo Credit: Yoshihisa Uenoyama, Graduate School of Bioagricultural Sciences, Nagoya University

Researchers at Nagoya University’s Graduate School of Bioagricultural Sciences and the National Institute of Physiological Sciences in Japan have demonstrated how a specific type of neuron in the brain affects the release of hormones that control ovarian function, such as follicular development and ovulation in females. These findings, published in the journal Scientific Reports, could help researchers understand and treat reproductive disorders in both animals and humans.  

Kisspeptin neurons in the brain regulate the release of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary follicle-stimulating hormone/luteinizing hormone (LH). This process is important for reproduction, as pituitary hormones stimulate the ovaries to perform their reproductive functions. Examples include follicular development and ovulation in all mammals, including humans.   

There are two main areas of the brain involved in the process: the arcuate nucleus (ARC), in which kisspeptin neurons maintain the regular rhythmic (pulsatile) secretion of GnRH/LH that maintains normal follicular development and sex steroid production; and the anteroventral periventricular nucleus (AVPV), in which kisspeptin neurons trigger a surge of GnRH/LH that leads to ovulation.  

Human-driven extinction of birds much greater than previously known

The dodo was endemic to the island of Mauritius. It could not fly and was exterminated by man during the 17th century.
Image Credit: German Rojas

On many of the world's islands, bird species began to become extinct with the arrival of humans. In a new study involving researchers from the University of Gothenburg and Uppsala University, it is estimated that humans have contributed to the extinction of around 1,400 bird species – twice as high as previously thought.

Because the lightweight bones of birds break down quickly, few fossils are formed. In the past, when scientists had to rely on observations and fossils, it was estimated that 640 species of birds had become extinct during the lifetime of modern humans, 90 percent of them on islands inhabited by humans. Classic examples are the dodo on Mauritius and the great auk in the North Atlantic, which, like penguins, could not fly.

However, by using statistical modeling, scientists now dare to estimate that around 1,400 bird species have become extinct.

“This is twice as many species as those that have left fossils as evidence of their existence. “Virtually all of these species were wiped out directly or indirectly due to human activity,” says Søren Faurby, a researcher in Zoology at the University of Gothenburg and co-author of the study published in Nature Communications.

The Evolutionary Timeline of Diminished Boric Acid and Urea Transportation in Aquaporin 10

Aquaporin (Aqp) 10 water channels in humans allow the free passage of water, glycerol, urea, and boric acid across cells. However, Aqp10.2b in pufferfishes allows only the passage of water and glycerol and not urea and boric acid. Researchers from the Tokyo Institute of Technology sought to understand the evolutionary timeline that resulted in the variable substrate selection mechanisms among Aqp10s. Their results indicate that Aqp10.2 in ray-finned fishes may have reduced or lost urea and boric acid permeabilities through evolution.

Aquaporins (Aqps) are proteins that form water channels in the membranes of living cells, including those of bacteria, fungi, animals, and plants. These channels facilitate water transportation across cells more rapidly than diffusion through the membrane phospholipid bilayer.

Aqp10 belongs to the aquaglyceroporin subfamily of water channels. These proteins facilitate many of our body's physiological processes, including gut function, liver and fat cell metabolism, and skin elasticity. Water and solutes, such as glycerol, urea, and boric acid, get transported through human Aqp10 depending on concentration gradients across the membrane.

Sarcopterygians, which include coelacanths, lungfish, and tetrapods (such as amphibians, reptiles, birds, and mammals), are known to have a single gene that codes for Aqp10. In contrast, actinopterygians, such as ray-finned fishes, have paralogs, or near-identical copies, of the aqp10 gene, such as aqp10.1 and aqp10.2. Interestingly, the ray-finned Japanese pufferfish has paralog called aqp10.2b that shows permeability to water and glycerol but not to urea and boric acid.

Western Cascades landscapes in Oregon historically burned more often than previously thought

Students, tribal members and others visit the study site.
Photo Credit: Sarah Altemus Pope of the Southern Willamette Forest Collaborative.

Forests on the west slope of Oregon’s Cascade Range experienced fire much more often between 1500 and 1895 than had been previously thought, according to new research by scientists at Oregon State University.

The findings provide important insight, the authors say, into how landscapes might adapt to climate change and future fire regimes.

James Johnston of the OSU College of Forestry led the study, which was published in Ecosphere.

“Wildland fire is a fundamental forest ecosystem process,” he said. “With temperatures rising and more and more area burning, we need to know as much as we can about the long-term variability in fire.”

Johnson and collaborators at Oregon State, the University of Oregon and the U.S. Forest Service gathered tree ring data at 16 sites in the southern part of the Willamette National Forest, in the general vicinity of Oakridge.

Trees form scars after cambial cells are killed by wildfire heat, he said. These scars are partially or completely covered by new tissue as a tree grows, and tree rings tell the story of when the fire exposure occurred.