How a small, unassuming fish helps reveal gene adaptations

Jesse Weber collects stickleback with a minnow trap in the Kenai Peninsula of Alaska
Credit: Matt Chotlos

At first blush, sticklebacks might seem a bit pedestrian. The finger-length, unassuming fish with a few small dorsal spines are a ubiquitous presence in oceans and coastal watersheds around the northern hemisphere. But these small creatures are also an excellent subject for investigating the complex dance of evolutionary adaptations.

A new study published in Science sheds light on the genetic basis by which stickleback populations inhabiting ecosystems near each other developed a strong immune response to tapeworm infections, and how some populations later came to tolerate the parasites.

Evolutionary biologist Jesse Weber, a professor of integrative biology at the University of Wisconsin–Madison, is one of the study’s lead authors. Sticklebacks have long been a source of fascination not only for Weber, but for biologists all over the world — so much so that the fish are among the most closely studied species.

“We arguably know more about stickleback ecology and evolution than any other vertebrate,” says Weber.

This is in part because of sticklebacks’ rich abundance in places like Western Europe, where the fish have long been involved in biological study, Weber says. But the reasons for the species’ star status go well beyond happenstance.

New Technology Can Efficiently Extract Non-Ferrous Metal from Batteries

The decomposition time of discarded nutrients can exceed 100 years.
Photo Credit: Unsplash.com / John Cameron

Scientists at Ural Federal University have developed a technology for extracting non-ferrous metals from spent zinc-manganese batteries. The zinc and manganese extracted in this way can be used in metallurgy and sent to production as raw materials. The technology is a closed cycle and can be easily implemented at existing metallurgical plants. A description of the technology and experimental results are presented in the Russian Journal of Non-Ferrous Metals.

Zinc-manganese batteries, specifically salt and alkaline batteries, are ubiquitous in everyday life, such as in remote controls, wireless computer mice, keyboards, clocks, and other devices. Recycling of such batteries is topical for obtaining zinc and especially manganese, since the latter is not produced in metallic form in Russia. The recovered zinc can be used as a reducing agent for gold in the process of its deep cleaning from impurities. Manganese can be used in steel production as an alloying element or a deoxidizer, in other words for removing dissolved oxygen from the metal.

"In Russia about 1 billion zinc-manganese batteries are accumulated as waste, and no more than 3% of them are recycled. The accumulation of batteries in landfills is dangerous because they can spontaneously ignite. Burning batteries release dioxins into the atmosphere as toxic substances that have mutagenic, immunosuppressant and carcinogenic effects. Thus, our team solves two problems: caring for the environment and people's health, as well as the possibility of useful use of metals," says Elvira Kolmachikhina, Associate Professor of the Department of Non-Ferrous Metallurgy at Ural Federal University.

New AI system predicts how to prevent wildfires

Satellite image of Borneo in 2006 covered by smoke from fires (marked by red dots).
Image Credit: Jeff Schmaltz, MODIS Rapid Response Team / NASA

A machine learning model can evaluate the effectiveness of different management strategies

Wildfires are a growing threat in a world shaped by climate change. Now, researchers at Aalto University have developed a neural network model that can accurately predict the occurrence of fires in peatlands. They used the new model to assess the effect of different strategies for managing fire risk and identified a suite of interventions that would reduce fire incidence by 50-76%.

The study focused on the Central Kalimantan province of Borneo in Indonesia, which has the highest density of peatland fires in Southeast Asia. Drainage to support agriculture or residential expansion has made peatlands increasingly vulnerable to recurring fires. In addition to threatening lives and livelihoods, peatland fires release significant amounts of carbon dioxide. However, prevention strategies have faced difficulties because of the lack of clear, quantified links between proposed interventions and fire risk.

The new model uses measurements taken before each fire season in 2002-2019 to predict the distribution of peatland fires. While the findings can be broadly applied to peatlands elsewhere, a new analysis would have to be done for other contexts. ‘Our methodology could be used for other contexts, but this specific model would have to be re-trained on the new data,’ says Alexander Horton, the postdoctoral researcher who carried out study.

Could more of Earth’s surface host life?

There are varying degrees of orbital eccentricity around a central star.
Credit: NASA/JPL-Caltech

Of all known planets, Earth is as friendly to life as any planet could possibly be — or is it? If Jupiter’s orbit changes, a new study shows Earth could be more hospitable than it is today.

When a planet has a perfectly circular orbit around its star, the distance between the star and the planet never changes. Most planets, however, have "eccentric" orbits around their stars, meaning the orbit is oval-shaped. When the planet gets closer to its star, it receives more heat, affecting the climate.

Using detailed models based on data from the solar system as it is known today, UC Riverside researchers created an alternative solar system. In this theoretical system, they found that if gigantic Jupiter’s orbit were to become more eccentric, it would in turn induce big changes in the shape of Earth’s orbit.

“If Jupiter’s position remained the same, but the shape of its orbit changed, it could actually increase this planet’s habitability,” said Pam Vervoort, UCR Earth and planetary scientist and lead study author.

Between zero and 100 degrees Celsius, the Earth’s surface is habitable for multiple known life forms. If Jupiter pushed Earth’s orbit to become more eccentric, parts of the Earth would sometimes get closer to the sun. Parts of the Earth’s surface that are now sub-freezing would get warmer, increasing temperatures in the habitable range.

Smart birds think smart and economical

Birds need significantly less energy for their brains than mammals.
Credit: RUB, Marquard

Bird brain cells only need about a third of the energy mammals have to use to supply their brains. "This partly explains how birds manage to be so smart, even though their brains are so much smaller than that of mammals," says Prof. Dr. Onur Güntürkun, head of the biopsychology unit at the Ruhr University Bochum. Together with colleagues from Cologne, Jülich and Düsseldorf, his research team examined the energy consumption of the brains of pigeons using imaging methods. The researchers report in the Current Biology journal dated 8. September 2022.

Why it can take in a crow with a chimpanzee

Our brain only makes up about two percent of our body weight, but consumes about 20 to 25 percent of body energy. "The brain is by far the most energetically expensive organ in our body, and we could only afford it in the course of evolution by successfully learning to supply a lot of energy," explains Güntürkun. The brains of birds are much smaller in comparison. Nevertheless, birds are just as smart as many mammals: crows and parrots, for example, whose brains only weigh about 10 to 20 grams, can cognitively absorb a chimpanzee whose brain weighs 400 grams.

How can that be? A study in 2016 brought light into the dark: It showed that birds per volume of brain mass have two to three times as many nerve cells as mammals. So, your brains are packed much denser. In addition, their cranial nerve cells are smaller. “But the question still arises: How can such a small animal afford so many nerve cells??“Says Onur Güntürkun.

Study unearths ancient reef structure high and dry on the Nullarbor Plain

A satellite image of the ring-shaped structure on the Nullarbor Plain.
Source: Curtin University

Curtin researchers and international collaborators using advanced satellite imagery have discovered an ancient reef-like landform ‘hidden’ in plain view on the Nullarbor Plain, which has been preserved for millions of years since it first formed when the Plain was underwater.

Research author Dr Milo Barham, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences said the finding further challenged the understanding that the Nullarbor Plain, which emerged from the ocean about 14 million years ago, was essentially flat and featureless.

“Unlike many parts of the world, large areas of the Nullarbor Plain have remained largely unchanged by weathering and erosion processes over millions of years, making it a unique geological canvas recording ancient history in remarkable ways,” Dr Barham said.

“Through high-resolution satellite imagery and fieldwork, we have identified the clear remnant of an original sea-bed structure preserved for millions of years, which is the first of this kind of landform discovered on the Nullarbor Plain.

Risk of multiple climate tipping points escalates above 1.5°C global warming

 The location of climate tipping elements in the cryosphere (blue), biosphere (green) and ocean/atmosphere (orange), and global warming levels their tipping points will likely be triggered at. Pins are colored according to our central global warming threshold estimate being below 2°C, i.e. within the Paris Agreement range (red, circles); between 2 and 4°C, i.e. accessible with current policies (pink, diamonds); and 4°C and above (purple, triangles).
Credit: Designed by Globaia for the Earth Commission, PIK, SRC and Exeter University

Multiple climate tipping points could be triggered if global temperature rises beyond 1.5°C above pre-industrial levels, according to a major new analysis published in the journal Science. Even at current levels of global heating the world is already at risk of passing five dangerous climate tipping points, and risks increase with each tenth of a degree of further warming.

An international research team synthesized evidence for tipping points, their temperature thresholds, timescales, and impacts from a comprehensive review of over 200 papers published since 2008, when climate tipping points were first rigorously defined. They have increased the list of potential tipping points from nine to sixteen.

The research, published in advance of a major conference “Tipping Points: from climate crisis to positive transformation” at the University of Exeter (12-14th September), concludes human emissions have already pushed Earth into the tipping points danger zone. Five of the sixteen may be triggered at today’s temperatures: the Greenland and West Antarctic ice sheets, widespread abrupt permafrost thaw, collapse of convection in the Labrador Sea, and massive die-off of tropical coral reefs. Four of these move from possible events to likely at 1.5°C global warming, with five more becoming possible around this level of heating.

Chlamydia’s Stealthy Cloaking Device Identified

Left: Chlamydia (green) surrounded by the GarD protein (red) that cloaks it from detection. Right: Chlamydia with GarD knocked out (green) enveloped by antimicrobial ubiquitin proteins (yellow) and RNF213 (magenta).
Credit: Stephen C. Walsh, Duke University

Chlamydia, the leading cause of sexually transmitted bacterial infections, evades detection and elimination inside human cells by use of a cloaking device. But Duke University researchers have grasped the hem of that invisibility cloak and now hope they can pull it apart.

To enter the cell and peacefully reproduce, many pathogenic bacteria, including Chlamydia, cloak themselves in a piece of the cell’s membrane, forming an intracellular free-floating bubble called a vacuole or, in the case of Chlamydia, an inclusion. Chlamydia's cloak appears to be especially effective at evading the cell’s built-in immunity, allowing the infection to last for months.

A Duke team led by graduate student Stephen Walsh and Jörn Coers, PhD, an associate professor of molecular genetics and microbiology in the Duke School of Medicine, wanted to know how the cloaking worked.

“We knew there was the potential to kill Chlamydia, but when we did experiments with the human-adapted form, Chlamydia trachomatis, it was very good at growing in human cell cultures,” Coers said. Even after the scientists used an immune stimulant to alert the cell’s defense systems of the presence of Chlamydia, nothing happened. “We said, there’s the pathogen. Our defense system should see it. Why does it not see it?”

New study finds subtle structural brain alterations in youth with suicidal behaviors

ENGIMA-STB aims to identify neurobiological variations associated with suicidal ideations and behaviors, to ultimately leverage information from brain structure, function, along with clinical and demographic factors, to predict the likelihood of a future suicidal attempt.
Image credit: USC Stevens INI

The ENIGMA Suicidal Thoughts and Behaviors (ENIGMA-STB) consortium gathered and analyzed neuroimaging data from 18 different studies worldwide to examine associations between brain structure and suicide attempt in young people with major depressive disorder.

Suicide is the second leading cause of death in the United States for young people from the age of 10 up to 33. Tragically, the number of suicide attempts among children and adolescents has continued to increase despite national and international prevention efforts. Collaborative research where specialists all over the world work together is needed to advance our understanding of the complex nature of suicidal thoughts and behaviors, and ultimately, to develop better interventions and preventions.

A new study by a global team of researchers including Neda Jahanshad, PhD, of the Keck School of Medicine of USC’s Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI), has revealed subtle alterations in the size of the brain’s prefrontal region in young people with mood disorders and suicidal thoughts and behaviors. The study was recently published in Molecular Psychiatry.

New Advances in Stem-Cell Derived Mouse Embryo Model

A day 8 stem cell-derived mouse embryo with developing brain and heart regions
Credit: Kasey Lau for the Zernicka-Goetz laboratory

Just two weeks after announcing the development of a mouse embryo model, complete with beating hearts and the foundations for a brain and other organs, from mouse stem cells, researchers in the laboratory of Magdalena Zernicka-Goetz, Bren Professor of Biology and Biological Engineering, have published new findings about another mouse embryo model reaching similar developmental stages, but created out of only mouse embryonic stem cells. This modification has simplified the protocol and makes the embryo model easier to be adopted in other laboratories.

The new study appears in the journal Cell Stem Cell on September 8. The research was led by graduate students Kasey Lau and Hernan Rubinstein of the University of Cambridge and the Weizmann Institute of Science, respectively.

"This discovery opens up new avenues for understanding why the great majority of human pregnancies are lost and to create knowledge that will prevent this from happening," says Zernicka-Goetz, who is also a professor of mammalian development and stem cell biology at Cambridge University in the Department of Physiology, Development and Neuroscience. "This knowledge will also let us, with time, repair tissues and organs much more effectively than we can do now."