Using data from India’s SARAS3 radio telescope, researchers led by the University of Cambridge were able to look at the very early Universe — just 200 million years after the Big Bang — and place limits on the mass and energy output of the first stars and galaxies.

Counterintuitively, the researchers were able to place these limits on the earliest galaxies by not finding the signal they had been looking for, known as the 21-centimetre hydrogen line.

This non-detection allowed the researchers to make other determinations about the cosmic dawn, placing restraints on the first galaxies, enabling them to rule out scenarios including galaxies which were inefficient heaters of cosmic gas and efficient producers of radio emissions.

While we cannot yet directly observe these early galaxies, the results, reported in the journal Nature Astronomy, represent an important step in understanding how our Universe transitioned from mostly empty to one full of stars.

Understanding the early Universe, when the first stars and galaxies formed, is one of the major goals of new observatories. The results obtained using the SARAS3 data are a proof-of-concept study that paves the way to understanding this period in the development of the Universe.

The SKA project — involving two next-generation telescopes due to be completed by the end of the decade — will likely be able to make images of the early Universe, but for current telescopes the challenge is to detect the cosmological signal of the first stars re-radiated by thick hydrogen clouds.

This signal is known as the 21-centimetre line — a radio signal produced by hydrogen atoms in the early Universe. Unlike the recently launched JWST, which will be able to directly image individual galaxies in the early Universe, studies of the 21-centimetre line, made with radio telescopes such as the Cambridge-led REACH (Radio Experiment for the Analysis of Cosmic Hydrogen), can tell us about entire populations of even earlier galaxies. The first results are expected from REACH early in 2023.

To detect the 21-centimetre line, astronomers look for a radio signal produced by hydrogen atoms in the early Universe, affected by light from the first stars and the radiation behind the hydrogen fog. Earlier this year, the same researchers developed a method which they say will allow them to see through the fog of the early universe and detect light from the first stars. Some of these techniques have been already put to practice in the current study.

In 2018, another research group operating the EDGES experiment published a result that hinted at a possible detection of this earliest light. The reported signal was unusually strong compared to what is expected in the simplest astrophysical picture of the early Universe. Recently, the SARAS3 data disputed this detection: the EDGES result is still awaiting confirmation from independent observations.

In a re-analysis of the SARAS3 data, the Cambridge-led team tested a variety of astrophysical scenarios which could potentially explain the EDGES result, but they did not find a corresponding signal. Instead, the team was able to place some limits on properties of the first stars and galaxies.

The results of the SARAS3 analysis are the first time that radio observations of the averaged 21-centimetre line have been able to provide an insight to the properties of the first galaxies in the form of limits of their main physical properties.

Working with collaborators in India, Australia and Israel, the Cambridge team used data from the SARAS3 experiment to look for signals from cosmic dawn, when the first galaxies formed. Using statistical modelling techniques, the researchers were not able to find a signal in the SARAS3 data.

“We were looking for a signal with a certain amplitude,” said Harry Bevins, a PhD student from Cambridge’s Cavendish Laboratory and the paper’s lead author. “But by not finding that signal, we can put a limit on its depth. That, in turn, begins to inform us about how bright the first galaxies were.”

“Our analysis showed that the hydrogen signal can inform us about the population of first stars and galaxies,” said co-lead author Dr Anastasia Fialkov from Cambridge’s Institute of Astronomy. “Our analysis places limits on some of the key properties of the first sources of light including the masses of the earliest galaxies and the efficiency with which these galaxies can form stars. We also address the question of how efficiently these sources emit X-ray, radio and ultraviolet radiation.”

“This is an early step for us in what we hope will be a decade of discoveries about how the Universe transitioned from darkness and emptiness to the complex realm of stars, galaxies and other celestial objects we can see from Earth today,” said Dr Eloy de Lera Acedo from Cambridge’s Cavendish Laboratory, who co-led the research.

The observational study, the first of its kind in many respects, excludes scenarios in which the earliest galaxies were both more than a thousand times as bright as present galaxies in their radio-band emission and were poor heaters of hydrogen gas.

“Our data also reveals something which has been hinted at before, which is that the first stars and galaxies could have had a measurable contribution to the background radiation that appeared as a result of the Big Bang and which has been travelling towards us ever since,” said de Lera Acedo, “We are also establishing a limit to that contribution.”

“It’s amazing to be able to look so far back in time — to just 200 million years after the Big Bang- and be able to learn about the early Universe,” said Bevins.

The research was supported in part by the Science and Technology Facilities Council (STFC), part of UK Research & Innovation (UKRI), and the Royal Society. The Cambridge authors are all members of the Kavli Institute for Cosmology in Cambridge.

Animals also have personalities

Red knots of all ages and sexes show behavioural traits. These remain mostly unchanged over time but differ across individuals. Some individuals are more adventurous and show more exploratory behaviours a in new environment than others. Other individuals take less risks and hardly dare to move around in a new environment. These ‘personalities’ have ecological and evolutionary consequences, but to what extent is largely unknown, because few studies have investigated this in the field.

During her PhD research Selin Ersoy has developed a new way of identifying the variation in personality between individual red knots. She wanted to know if the behaviour in experimental settings could be extrapolated to a larger and more complex natural setting, and how individual differences develop.

“With our new method that allowed studying animal personality in the wild, we found that red knots develop their personality probably through the experience that they get when growing up ,” says Ersoy. “After growing up, adults stick with exploratory behaviours. They seem to be like character types in humans.”

Explorers eat higher quality food

It was even possible for Ersoy and her colleagues to predict a suit of other behaviours in the wild. For instance, variation in explorative personality type (i.e., slow vs. fast explorer) predicts foraging tactics and dietary choice in the wild. Fast explorers use more visual foraging and eat soft prey such as shrimp or worms, while slow explorers use tactile foraging and feed on hard-shelled prey such as cockles. This is a new explanation for variation in foraging niche specialisation between individuals in the same population.

Exploratory behaviour also relates to variation in movement across the landscape and over time. Ersoy: “We were amazed to see that slow and fast explorers have clearly different movement patterns during the night, while at day they moved more or less the same way. These different individuals even have different arrival times from migration. Fast explorers arrive to the Wadden Sea later than the slower explorers.” Ersoy and her colleagues want to study next where they stay in the meantime. Maybe these red knots take more time to care for their youngs in the Arctic.

The whole group benefits

“We found striking differences in feeding and movement patterns between slow and fast exploring red knots. This suggests that fast explorers might provide foraging information and new foraging opportunities for entire populations,” says Ersoy. “Such new opportunities are important because red knots face pressures from human impact on their coastal wintering habitats, directly related to availability of food. Fast explorers can help the entire population to cope with environmental change.”

Gap closed between controlled experiments and real Wadden Sea

The goal of determining behaviour in experimental setups is to understand the mechanisms behind the behaviour in the wild. Selin Ersoy’s study fills a critical gap between experimental research on wild animals in controlled environments and observed behaviour in the wild.

“It’s a first step. We need to do similar personality research on other animals and on other natural habitats,” says Ersoy. “We want to know if personalities work the same in other species and situations.”

Tracking movements of guillemots with tiny transmitters

Researchers like Selin Ersoy track birds using ultra-small radio transmitters placed on their backs during the summer months. Birds are not bothered by them. Those transmitters send out unique signals. These are received by antennas scattered throughout the Wadden Sea.

Reverse GPS

WATLAS is a new system that makes use of so-called ‘reverse-GPS’. The tiny transmitters that are temporarily attached to birds transmit a signal of their own. That signal is received by fixed receiving stations in and around the Wadden Sea. Due to the tiny differences in the time of arrival of the signal between different receivers, the position of the animal-with-transmitter is calculated to the accuracy of a few meters, from second to second.

Thanks to WATLAS, researchers can watch a migratory bird such as the red knot move back and forth with low and high tide very precisely in search of food. Because many birds can be fitted with the relatively inexpensive transmitters at the same time, researchers can now see interactions between different animals happening from the comfort of their office chairs.

A team led by ETH Zurich Professor Paola Picotti could now help to close this gap. In a study just published in the journal Nature Structural and Molecular Biology, the researchers present 76 proteins that might serve as biomarkers for the detection of Parkinson’s disease.

Different protein structure

What makes this study special is that while the potential biomarker proteins are found in both healthy and diseased individuals, their molecules are present in different shapes (or structures) in each of the two groups. It is not the presence of certain proteins that indicates the disease, but rather the shape they have assumed. This is the first time that scientists have shown that an analysis of the structures of all proteins in a body fluid can identify potential biomarkers for disease.

The next step will be to thoroughly test the markers found and verify them using larger groups of patients. That means these candidates are not yet available for clinical diagnoses. “But from what we’ve seen so far, they’re actually a very strong indicator for the disease. So I’m confident that this idea of structural biomarkers will bear out,” says Natalie de Souza, senior scientist in Paola Picotti’s group and one of the study’s co-authors.

Measuring structural changes

In their study, the ETH Zurich researchers examined the cerebrospinal fluid of 50 healthy individuals and 50 Parkinson’s patients. The sample material was provided to them by Dutch clinicians.

To search for biomarkers, the scientists used a specific method for measuring the proteome (i.e. the totality of all proteins in a sample), called LiP-MS, which can measure structural changes in proteins and reveal where exactly the changes are located. Conventional proteome measurements tend to record only the different types of protein and their amounts, but not structural changes.

Since the structure of proteins is closely linked to their functions (or, indeed, dysfunctions), the researchers hypothesised that people with Parkinson’s and healthy individuals will exhibit different shapes of some proteins.

The present study marks the first time that the researchers have successfully applied the method to a disease.

Sharpening analysis further

In subsequent steps, the researchers want to further improve the LiP-MS method to amplify the biomarker signal and thus increase the sensitivity with which the disease can be detected. Moreover, the scientists would like to test the new biomarkers to assess how specifically they detect Parkinson’s disease or whether there might be overlap with other neurodegenerative diseases such as Alzheimer’s disease. In future, the researchers also want to use their method to determine subtypes of Parkinson’s disease and make more accurate predictions about the course of the disease.

Exactly what clinically useful diagnostics this might lead to is still uncertain. De Souza estimates that a future testing strategy could be based on antibodies that would distinguish between healthy and diseased protein structures. Making regular use of mass spectrometers in a clinical setting is in principle possible, she says, but would be a big challenge.

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Materials provided by ETH Zurich. Original written by Peter Rueegg. Note: Content may be edited for style and length.

A new study led by researchers at Imperial College London finds that the most unique birds on the planet are also the most threatened. Losing these species and the unique roles they play in the environment, such as seed dispersal, pollination and predation, could have severe consequences to the functioning of ecosystems.

The study analysed the extinction risk and physical attributes (such as beak shape and wing length) of 99% of all living bird species, making it the most comprehensive study of its kind to date.

The researchers found that in simulated scenarios in which all threatened and near-threatened bird species became extinct, there would be a significantly greater reduction in the physical (or morphological) diversity among birds than in scenarios where extinctions were random.

Bird species that are both morphologically unique and threatened include the Christmas Frigatebird (Fregata andrewsi), which nests only on Christmas Island, and the Bristle-thighed Curlew (Numenius tahitiensis), which migrates from its breeding grounds in Alaska to South Pacific islands every year.

Jarome Ali, a PhD candidate at Princeton University who completed the research at Imperial College London and was the lead author of the research, said: “Our study shows that extinctions will most likely prune a large proportion of unique species from the avian tree. Losing these unique species will mean a loss of the specialised roles that they play in ecosystems.

“If we do not take action to protect threatened species and avert extinctions, the functioning of ecosystems will be dramatically disrupted.”

In the study, the authors used a dataset of measurements collected from living birds and museum specimens, totalling 9943 bird species. The measurements included physical traits like beak size and shape, and the length of wings, tails and legs.

The authors combined the morphological data with extinction risk, based on each species’ current threat status on the IUCN Red List. They then ran simulations on what would happen if the most threatened birds were to go extinct.

Although the dataset used in the study was able to show that the most unique birds were also classified as threatened on the Red List, it was unable to show what links uniqueness in birds to extinction risk.

Jarome Ali said: “One possibility is that highly specialised organisms are less able to adapt to a changing environment, in which case human impacts may directly threaten species with the most unusual ecological roles. More research is needed to delve deeper into the connection between unique traits and extinction risk.”

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Materials provided by British Ecological Society. Note: Content may be edited for style and length.

How our genes are expressed is a process that is fundamental to the functionality of cells in all living organisms. Simply put, the genetic code in DNA is transcribed to the molecule messenger RNA (mRNA), which tells the cell’s factory which protein to produce and in which quantities.

Researchers have put a lot of effort into trying to control gene expression because it can, among other things, contribute to the development of protein-based drugs. A recent example is the mRNA vaccine against Covid-19, which instructed the body’s cells to produce the same protein found on the surface of the coronavirus. The body’s immune system could then learn to form antibodies against the virus. Likewise, it is possible to teach the body’s immune system to defeat cancer cells or other complex diseases if one understands the genetic code behind the production of specific proteins.

Most of today’s new drugs are protein-based, but the techniques for producing them are both expensive and slow, because it is difficult to control how the DNA is expressed. Last year, a research group at Chalmers, led by Aleksej Zelezniak, Associate Professor of Systems Biology, took an important step in understanding and controlling how much of a protein is made from a certain DNA sequence.

“First it was about being able to fully ‘read’ the DNA molecule’s instructions. Now we have succeeded in designing our own DNA that contains the exact instructions to control the quantity of a specific protein,” says Aleksej Zelezniak about the research group’s latest important breakthrough.

DNA molecules made-to-order

The principle behind the new method is similar to when an AI generates faces that look like real people. By learning what a large selection of faces looks like, the AI can then create completely new but natural-looking faces. It is then easy to modify a face by, for example, saying that it should look older, or have a different hairstyle. On the other hand, programming a believable face from scratch, without the use of AI, would have been much more difficult and time-consuming. Similarly, the researchers’ AI has been taught the structure and regulatory code of DNA. The AI then designs synthetic DNA, where it is easy to modify its regulatory information in the desired direction of gene expression. Simply put, the AI is told how much of a gene is desired and then ‘prints’ the appropriate DNA sequence.

“DNA is an incredibly long and complex molecule. It is thus experimentally extremely challenging to make changes to it by iteratively reading and changing it, then reading and changing it again. This way it takes years of research to find something that works. Instead, it is much more effective to let an AI learn the principles of navigating DNA. What otherwise takes years is now shortened to weeks or days,” says first author Jan Zrimec, a research associate at the National Institute of Biology in Slovenia and past postdoc in Aleksej Zelezniak’s group.

The researchers have developed their method in the yeast Saccharomyces cerevisiae, whose cells resemble mammalian cells. The next step is to use human cells. The researchers have hopes that their progress will have an impact on the development of new as well as existing drugs.

“Protein-based drugs for complex diseases or alternative sustainable food proteins can take many years and can be extremely expensive to develop. Some are so expensive that it is impossible to obtain a return on investment, making them economically nonviable. With our technology, it is possible to develop and manufacture proteins much more efficiently so that they can be marketed,” says Aleksej Zelezniak.

The authors of the study are Jan Zrimec, Xiaozhi Fu, Azam Sheikh Muhammad, Christos Skrekas, Vykintas Jauniskis, Nora K. Speicher, Christoph S. Börlin, Vilhelm Verendel, Morteza Haghir Chehreghani, Devdatt Dubhashi, Verena Siewers, Florian David, Jens Nielsen and Aleksej Zelezniak.

The researcher are active at Chalmers University of Technology, Sverige; National Institute of Biology, Slovenia; Biomatter Designs, Lithuania; Institute of Biotechnology, Lithuania; BioInnovation Institute, Denmark; King’s College London, UK.

A study published in Science — led by Nicholas Strausfeld,a Regents Professor in the University of Arizona Department of Neuroscience, and Frank Hirth, a reader of evolutionary neuroscience at King’s College London — provides the first detailed description of Cardiodictyon catenulum, a wormlike animal preserved in rocks in China’s southern Yunnan province. Measuring barely half an inch (less than 1.5 centimeters) long and initially discovered in 1984, the fossil had hidden a crucial secret until now: a delicately preserved nervous system, including a brain.

“To our knowledge, this is the oldest fossilized brain we know of, so far,” Strausfeld said.

Cardiodictyon belonged to an extinct group of animals known as armored lobopodians, which were abundant early during a period known as the Cambrian, when virtually all major animal lineages appeared over an extremely short time between 540 million and 500 million years ago. Lobopodians likely moved about on the sea floor using multiple pairs of soft, stubby legs that lacked the joints of their descendants, the euarthropods — Greek for “real jointed foot.” Today’s closest living relatives of lobopodians are velvet worms that live mainly in Australia, New Zealand and South America.

A debate going back to the 1800s

Fossils of Cardiodictyon reveal an animal with a segmented trunk in which there are repeating arrangements of neural structures known as ganglia. This contrasts starkly with its head and brain, both of which lack any evidence of segmentation.

“This anatomy was completely unexpected because the heads and brains of modern arthropods, and some of their fossilized ancestors, have for over a hundred years been considered as segmented,” Strausfeld said.

According to the authors, the finding resolves a long and heated debate about the origin and composition of the head in arthropods, the world’s most species-rich group in the animal kingdom. Arthropods include insects, crustaceans, spiders and other arachnids, plus some other lineages such as millipedes and centipedes.

“From the 1880s, biologists noted the clearly segmented appearance of the trunk typical for arthropods, and basically extrapolated that to the head,” Hirth said. “That is how the field arrived at supposing the head is an anterior extension of a segmented trunk.”

“But Cardiodictyon shows that the early head wasn’t segmented, nor was its brain, which suggests the brain and the trunk nervous system likely evolved separately,” Strausfeld said.

Brains do fossilize

Cardiodictyon was part of the Chengjiang fauna, a famous deposit of fossils in the Yunnan Province discovered by paleontologist Xianguang Hou. The soft, delicate bodies of lobopodians have preserved well in the fossil record, but other than Cardiodictyon none have been scrutinized for their head and brain, possibly because lobopodians are generally small. The most prominent parts of Cardiodictyon were a series of triangular, saddle-shaped structures that defined each segment and served as attachment points for pairs of legs. Those had been found in even older rocks dating back to the advent of the Cambrian.

“That tells us that armored lobopodians might have been the earliest arthropods,” Strausfeld said, predating even trilobites, an iconic and diverse group of marine arthropods that went extinct around 250 million years ago.

“Until very recently, the common understanding was ‘brains don’t fossilize,'” Hirth said. “So you would not expect to find a fossil with a preserved brain in the first place. And, second, this animal is so small you would not even dare to look at it in hopes of finding a brain.”

However, work over the last 10 years, much of it done by Strausfeld, has identified several cases of preserved brains in a variety of fossilized arthropods.

A common genetic ground plan for making a brain

In their new study, the authors not only identified the brain of Cardiodictyon but also compared it with those of known fossils and of living arthropods, including spiders and centipedes. Combining detailed anatomical studies of the lobopodian fossils with analyses of gene expression patterns in their living descendants, they conclude that a shared blueprint of brain organization has been maintained from the Cambrian until today.

“By comparing known gene expression patterns in living species,” Hirth said, “we identified a common signature of all brains and how they are formed.”

In Cardiodictyon, three brain domains are each associated with a characteristic pair of head appendages and with one of the three parts of the anterior digestive system.

“We realized that each brain domain and its corresponding features are specified by the same combination genes, irrespective of the species we looked at,” added Hirth. “This suggested a common genetic ground plan for making a brain.”

Lessons for vertebrate brain evolution

Hirth and Strausfeld say the principles described in their study probably apply to other creatures outside of arthropods and their immediate relatives. This has important implications when comparing the nervous system of arthropods with those of vertebrates, which show a similar distinct architecture in which the forebrain and midbrain are genetically and developmentally distinct from the spinal cord, they said.

Strausfeld said their findings also offer a message of continuity at a time when the planet is changing dramatically under the influence of climatic shifts.

“At a time when major geological and climatic events were reshaping the planet, simple marine animals such as Cardiodictyon gave rise to the world’s most diverse group of organisms — the euarthropods — that eventually spread to every emergent habitat on Earth, but which are now being threatened by our own ephemeral species.”

Funding for this work was provided by the National Science Foundation, the University of Arizona Regents Fund, and the UK Biotechnology and Biological Sciences Research Council.