Astronomers shed new light on formation of mysterious fast radio bursts

More than 15 years after the discovery of fast radio bursts (FRBs) -- millisecond-long, deep-space cosmic explosions of electromagnetic radiation -- astronomers worldwide have been combing the universe to uncover clues about how and why they form.

Nearly all FRBs identified have originated in deep space outside our Milky Way galaxy. That is until April 2020, when the first Galactic FRB, named FRB 20200428, was detected. This FRB was produced by a magnetar (SGR J1935+2154), a dense, city-sized neutron star with an incredibly powerful magnetic field.

This groundbreaking discovery led some to believe that FRBs identified at cosmological distances outside our galaxy may also be produced by magnetars. However, the smoking gun for such a scenario, a rotation period due to the spin of the magnetar, has so far escaped detection. New research into SGR J1935+2154 sheds light on this curious discrepancy.

In the July 28 issue of the journal Science Advances, an international team of scientists, including UNLV astrophysicist Bing Zhang, report on continued monitoring of SGR J1935+2154 following the April 2020 FRB, and the discovery of another cosmological phenomenon known as a radio pulsar phase five months later.

Unraveling a Cosmological Conundrum

To aid them in their quest for answers, astronomers rely in part on powerful radio telescopes like the massive Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China to track FRBs and other deep-space activity. Using FAST, astronomers observed that FRB 20200428 and the later pulsar phase originated from different regions within the scope of the magnetar, which hints towards different origins.

"FAST detected 795 pulses in 16.5 hours over 13 days from the source," said Weiwei Zhu, lead author of the paper from National Astronomical Observatory of China (NAOC). "These pulses show different observational properties from the bursts observed from the source."

This dichotomy in emission modes from the region of a magnetosphere helps astronomers understand how -- and where -- FRBs and related phenomena occur within our galaxy and perhaps also those at further cosmological distances.

Radio pulses are cosmic electromagnetic explosions, similar to FRBs, but typically emit a brightness roughly 10 orders of magnitude less than an FRB. Pulses are typically observed not in magnetars but in other rotating neutron stars known as pulsars. According to Zhang, a corresponding author on the paper and director of the Nevada Center for Astrophysics, most magnetars do not emit radio pulses most of the time, probably due to their extremely strong magnetic fields. But, as was the case with SGR J1935+2154, some of them become temporary radio pulsars after some bursting activities.

Another trait that makes bursts and pulses different are their emission "phases," i.e. the time window where radio emission is emitted in each period of emission.

"Like pulses in radio pulsars, the magnetar pulses are emitted within a narrow phase window within the period," said Zhang. "This is the well-known `lighthouse' effect, namely, the emission beam sweeps the line of sight once a period and only during a short interval in time in each period. One can then observe the pulsed radio emission."

Zhang said the April 2020 FRB, and several later, less energetic bursts were emitted in random phases not within the pulse window identified in the pulsar phase.

"This strongly suggests that pulses and bursts originate from different locations within the magnetar magnetosphere, suggesting possibly different emission mechanisms between pulses and bursts," he said.

Implications for Cosmological FRBs

Such a detailed observation of a Galactic FRB source sheds light on the mysterious FRBs prevailing at cosmological distances.

Many sources of cosmological FRBs -- those occurring outside our galaxy -- have been observed to repeat. In some instances, FAST has detected thousands of repeated bursts from a few sources. Deep searches for seconds-level periodicity have been carried out using these bursts in the past and so far no period was discovered.

According to Zhang, this casts doubt on the popular idea that repeating FRBs are powered by magnetars in the past.

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Bacteria as Blacksmiths

A hot bath is a place to relax. For scientists, it is also where molecules or tiny building blocks meet to form materials. Researchers at the Institute of Science and Technology Austria (ISTA) take it to the next level and use the energy of swimming bacteria to forge materials. A recent study in Nature Physics shows us how this works and the potential sustainability benefits that may arise from this innovative approach.

You never know when dazzling ideas will strike you. Sometimes they emerge from the most unexpected places, like a boulder gym in Vienna. Such was the case for ISTA's Daniel Grober, a graduate student in the research group of physicist Jérémie Palacci, who had been working on how to assemble materials leveraging the energy of swimming bacteria, and Mehmet Can Uçar, a postdoc in Edouard Hannezo's group. Fueled by their shared passion for science and climbing, discussions at the gym turned into a paper-pen model of Grober's experiment. Their concept captivated Ivan Palaia, a postdoc in Anđela Šarić's group, who decided to join the task force.

Together, this dynamic all-ISTA trio embarked on a collaborative effort that now reaches its pinnacle with a paper published today in Nature Physics. The study shows a novel experimental strategy to fabricate materials from small building blocks. It translates ideas from metallurgy -- the fine art of blacksmithing, where cycles of high temperature and slow cooling set a material's structure -- into soft materials, using the activity from a bath of swimming bacteria.

What are active baths?

In Jérémie Palacci's research group at the Institute of Science and Technology Austria, it is all about microscopic particles. "Our work revolves around tiny 'Lego'-like building blocks that are a hundred times smaller than a hair. We try to understand how these components come together and form larger structures," he explains. Typically, when these building blocks are suspended in water, they jiggle due to temperature, which provides the energy for the particles to hop back and forth randomly. A phenomenon first rationalized by Einstein in 1905 and known as Brownian motion.

To introduce order amidst the chaos, adding an "active agent" to the water is beneficial. This results in what is known as an "active bath," where the agent acts like a small fire. In principle, with this extra energy, you can hope to control the assembly and properties of materials -- the way the blacksmith forges. However, until now, an approach where for instance bacteria is used to forge, had never been explored.

Bacteria -- the fire

Palacci's student, Daniel Grober, took on this challenge and started to construct such an active bath with characteristics inspired by metallurgy. Grober says, "We used E. coli bacteria as an active agent, as their swimming movement provided energy and some kind of agitation -- 'temperature' for a physicist, equivalent to 2000 °C, similar to the one needed to craft metals. But because it is made by bacteria, and it is not a real oven, it remains gentle enough to be used with gels and soft materials without burning them." The building blocks were microscopic particles in the form of sticky colloids -- round beads that stick together when in contact.

This idea proved to be successful. The swimming bacteria effectively amplified the motion of the beads, resulting in the formation of aggregations and gel-like structures.

Dance to the beat of bacteria

Moreover, the observation of these newly formed clusters showed an intriguing singularity. At all times, the aggregates were spinning clockwise, but very slowly. To shed light on this observation, Grober conducted a statistical analysis of the system's motion. He confirmed a slow and persistent rotation of the aggregates that originates in the clockwise spin (chirality) of the E. coli flagella -- the minuscule appendages that propel the bacteria in their movement. The scientist suspected that the rotational motion played a pivotal role in forming the unconventional structures he observed.

Presenting his work in a weekly lab meeting intrigued his colleague Ivan Palaia, which led to the understanding of the phenomenon. Palaia proposed a minimal computational model, to capture the chirality of the bacterial bath without simulating the swimming bacteria. The computer simulations were first validated by quantitatively reproducing the experimental results before providing a deeper understanding of the mechanism. The model confirmed the salient role of the rotation in shaping gels, by forming remarkable structures with exotic mechanical properties that cannot be achieved conventionally.

More to come in the future

This utilization of bacterial baths to assemble unconventional materials holds great promise. For instance, although the study was limited to 2D structures at the micron scale, the approach was designed for its potential in upscaling. "With this innovative approach, it could theoretically be possible to construct 3D samples, large enough to be held in the palm of my hand!" Palacci adds. This advancement could also enhance the sustainability of material production by harnessing energy from bacteria rather than relying on external energy sources.

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Researchers develop 'in vivo' RNA-based gene editing model for blood disorders

In a step forward in the development of genetic medicines, researchers at Children's Hospital of Philadelphia (CHOP) and the Perelman School of Medicine at the University of Pennsylvania have developed a proof-of-concept model for delivering gene editing tools to treat blood disorders, allowing for the modification of diseased blood cells directly within the body. If translated into the clinic, this approach could expand access and reduce the cost of gene therapies for blood disorders, many of which currently require patients receive chemotherapy and a stem cell transplant. The findings were published today in the journal Science.

"Right now, if you want to treat hematologic diseases like sickle cell disease and beta thalassemia with gene therapy, patients must receive conditioning treatments like chemotherapy to make space for the new, corrected blood cells, which is both expensive and comes with risks," said co-senior author Stefano Rivella, PhD, Kwame Ohene-Frempong Chair on Sickle Cell Anemia and Professor of Pediatrics at Children's Hospital of Philadelphia. "In our paper, we have shown that it is possible to replace diseased blood cells with corrected ones directly within the body in a 'one-and-done' therapy, eliminating the need for myeloablative conditioning treatments and streamlining the delivery of these potentially life-changing treatments. This is a big step forward in how we think about treating genetic diseases and could expand the access of gene therapies to patients who need them most."

"Targeted delivery of mRNA-encoded therapeutics to specific tissues and cell types will have an immense impact on the way diseases will be treated with nucleic acids in the future," said senior author Hamideh Parhiz, PharmD, PhD, a research assistant professor of Infectious Diseases at Penn. "In our study, we are providing a cell-specific targeted lipid nanoparticle encapsulating mRNA therapeutics/editors as a platform technology that can be used for in vivo cellular reprogramming in many diseases in need of a precisely targeted gene therapy modality. Here, we combined the targeted platform with advances in mRNA therapeutics and RNA-based genomic editing tools to provide a new way of controlling hematopoietic stem cell fate and correcting genetic defects. A targeted mRNA-encoded genomic editing methodology could lead to controlled expression, high editing efficacy, and potentially safer in vivo genomic modification compared to currently available technologies."

Hematopoietic stem cells (HSCs) reside in the bone marrow, where they divide throughout life to produce all cells within the blood and immune system. In patients with non-malignant hematopoietic disorders like sickle cell disease and immunodeficiency disorders, these blood cells don't function correctly because they carry a genetic mutation.

For these patients, there are currently two avenues for potentially curative treatments, both of which involve a bone marrow transplant: a stem cell transplant with HSCs from a healthy donor, or gene therapy in which the patient's own HSCs are modified outside of the body and transplanted back in (often referred to as ex vivo gene therapy). The former approach comes with the risk of graft versus host disease, given that the HSCs come from a donor, and both processes involve a conditioning regimen of chemotherapy or radiation to eliminate the patient's diseased HSCs and prepare them to receive the new cells. These conditioning procedures come with significant toxic side effects, underscoring the need to investigate less-toxic approaches.

One option that would eliminate the need for the above methods would be in vivo gene editing, in which gene editing tools are infused directly into the patient, allowing HSCs to be edited and corrected without the need for conditioning regimens.

To validate this approach, a research team led by Laura Breda, PhD, and Michael P. Triebwasser, MD, PhD at CHOP (presently at the University of Michigan), Tyler E. Papp, BS at Penn, and Drew Weissman, MD, PhD, the Roberts Family Professor in Vaccine Research, the director of the Penn Institute for RNA Innovation, and a pioneer of mRNA-vaccine research, used liquid nanoparticle (LNP) to deliver mRNA gene editing tools. LNP are highly effective at packaging and delivering mRNA to cells and became widely utilized in 2020, due to the LNP-mRNA platform for two leading COVID-19 vaccines.

However, in the case of the COVID-19 vaccines, the LNP-mRNA construct did not target specific cells or organs within the body. Given that the researchers wanted to target HSCs specifically, they decorated the surface of their experimental LNPs with antibodies that would recognize CD117, a receptor on the surface of HSCs. They then pursued three approaches to test the efficacy of their CD117/LNP formulation.

First, the researchers tested CD117/LNP encapsulating reporter mRNA to show successful in vivo mRNA expression and gene editing.

Next, the researchers investigated whether this approach could be used as a therapy for hematologic disease. They tested CD117/LNP encapsulating mRNA encoding a cas9 gene editor targeting the mutation that causes sickle cell disease. This type of gene editing converts the disease-causing hemoglobin mutation into a non-disease-causing variant. Testing their construct on cells from donors with sickle cell disease, the researchers showed that CD117/LNP facilitated efficient base editing in vitro, leading to a corresponding increase in functional hemoglobin of up to 91.7%. They also demonstrated a nearly complete absence of sickled cells, the crescent-shaped blood cells that cause the symptoms of the disease.

Finally, the researchers explored whether LNPs could be used for in vivo conditioning, which would allow bone marrow to be depleted without chemotherapy or radiation. To do so, they used CD117/LNP encapsulating mRNA for PUMA, a protein that promotes cell death. In a series of in vitro, ex vivo, and in vivo experiments, the researchers showed that in vivo targeting with CD117/LNP-PUMA effectively depleted HSC, allowing for successful infusion and uptake of new bone marrow cells, a process known as engraftment, without need of chemotherapy or radiation. The engraftment rates observed in animal models were consistent with those reported to be sufficient for the cure of severe combined immunodeficiency (SCID) using healthy donor bone marrow cells, suggesting this technique could be used for severe immunodeficiences.

"These findings may potentially transform gene therapy, not only by allowing cell-type specific gene modification in vivowith minimal risk, which could allow for previously impossibly manipulations of blood stem cell physiology but also by providing a platform that, if properly tuned, can correct many different monogenic disorders," said Dr. Breda, a research assistant professor with the Division of Hematology at Children's Hospital of Philadelphia. "Such novel delivery systems may help translate the promise of decades of concerted genetic and biomedical research to ablate a wide array of human diseases."

Read more at Science Daily

Listen to a star 'twinkle'

Many people know that stars appear to twinkle because our atmosphere bends starlight as it travels to Earth. But stars also have an innate "twinkle" -- caused by rippling waves of gas on their surfaces -- that is imperceptible to current Earth-bound telescopes.

In a new study, a Northwestern University-led team of researchers developed the first 3D simulations of energy rippling from a massive star's core to its outer surface. Using these new models, the researchers determined, for the first time, how much stars should innately twinkle.

And, in yet another first, the team also converted these rippling waves of gas into sound waves, enabling listeners to hear both what the insides of stars and the "twinkling" should sound like. And it is eerily fascinating.

The study will be published on July 27, in the journal Nature Astronomy.

"Motions in the cores of stars launch waves like those on the ocean," said Northwestern's Evan Anders, who led the study. "When the waves arrive at the star's surface, they make it twinkle in a way that astronomers may be able to observe. For the first time, we have developed computer models which allow us to determine how much a star should twinkle as a result of these waves. This work allows future space telescopes to probe the central regions where stars forge the elements we depend upon to live and breathe."

Anders is a postdoctoral fellow in Northwestern's Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). He is advised by study coauthor Daniel Lecoanet, an assistant professor of engineering sciences and applied mathematics in Northwestern's McCormick School of Engineering and member of CIERA.

Chaotic convection

All stars have a convection zone, a wild and disorderly place where gases churn to push heat outward. For massive stars (stars at least about 1.2 times the mass of our sun), this convection zone resides at their cores.

"Convection within stars is similar to the process that fuels thunderstorms," Anders said. "Cooled air drops, warms and rises again. It's a turbulent process that transports heat."

It also makes waves -- small rivulets that cause starlight to dim and brighten, producing a subtle twinkle. Because the cores of massive stars are shrouded from view, Anders and his team sought to model their hidden convection. Building upon studies that examined properties of turbulent core convection, characteristics of waves and possible observational features of those waves, the team's new simulations include all relevant physics to accurately predict how a star's brightness changes depending upon convection-generated waves.

'Soundproofing' stars

After convection generates waves, those waves bounce around inside of the simulated star. While some waves eventually emerge to the star's surface to produce a twinkling effect, other waves become trapped and continue to bounce around. To isolate the waves that launch to the surface and create twinkling, Anders and his team built a filter that describes how waves bounce around inside of the simulations.

"We first put a damping layer around the star -- like the padded walls you would have in a recording studio -- so we could measure exactly how the core convection makes waves," Anders explained.

Anders compares it to a music studio, which leverages soundproof padded walls to minimize the acoustics of an environment so musicians can extract the "pure sound" of the music. Musicians then apply filters and engineer those recordings to produce the song how they want.

Similarly, Anders and his collaborators applied their filter to the pure waves they measured coming out of the convective core. They then followed waves bouncing around in a model star, ultimately finding that their filter accurately described how the star changed the waves coming from the core. The researchers then developed a different filter for how waves should bounce around inside of a real star. With this filter applied, the resulting simulation shows how astronomers expect waves to appear if viewed through a powerful telescope.

"Stars get a little brighter or a little dimmer depending on various things happening dynamically inside the star," Anders said. "The twinkling that these waves cause is extremely subtle, and our eyes are not sensitive enough to see it. But powerful future telescopes may be able to detect it."

Music in the stars

Taking the recording studio analogy one step further, Anders and his collaborators next used their simulations to generate sound. Because these waves are outside the range of human hearing, the researchers uniformly increased the frequencies of the waves to make them audible.

Depending on how large or bright a massive star is, the convection produces waves corresponding to different sounds. Waves emerging from the core of a large star, for example, make sounds like a warped ray gun, blasting through an alien landscape. But the star alters these sounds as the waves reach the star's surface. For a large star, the ray gun-like pulses shift into a low echo reverberating through an empty room. Waves at the surface of a medium-sized star, on the other hand, conjure images of a persistent hum through a windswept terrain. And surface waves on a small star sound like a plaintive alert from a weather siren.

Next, Anders and his team passed songs through different stars to listen to how the stars change the songs. They passed a short audio clip from "Jupiter"(a movement from "The Planets" orchestral suite by composer Gustav Holst) and from "Twinkle, Twinkle, Little Star" through three sizes (large, medium and small) of massive stars. When propagated through stars, all songs sound distant and haunting -- like something from "Alice in Wonderland."

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Scientists caught Hofstadter's butterfly in one of the most ancient materials on Earth

Researchers in the National Graphene Institute (NGI) at The University of Manchester have revisited one of the most ancient materials on Earth -- graphite, and discovered new physics that has eluded the field for decades.

Despite being made entirely of layers of carbon atoms arranged in a honeycomb pattern, natural graphite is not as simple as one may think. The manner in which these atomic layers stack on top of one another can result in different types of graphite, characterised by different stacking order of consecutive atomic planes. The majority of naturally appearing graphite has hexagonal stacking, making it one of the most "ordinary" materials on Earth. The structure of graphite crystal is a repetitive pattern. This pattern gets disrupted at the surface of the crystal and leads to what's called 'surface states', which are like waves that slowly fade away as you go deeper into the crystal. But how surface states can be tuned in graphite, was not well understood yet.

Van der Waals technology and twistronics (stacking two 2D crystals at a twist angle to tune the properties of the resulting structure to a great extent, because of moiré pattern formed at their interface) are the two leading fields in 2D materials research. Now, the team of NGI researchers, led by Prof. Artem Mishchenko, employs moiré pattern to tune the surface states of graphite, reminiscent of a kaleidoscope with everchanging pictures as one rotates the lens, revealing the extraordinary new physics behind graphite.

In particular, Prof. Mishchenko expanded twistronics technique to three-dimensional graphite and found that moiré potential does not just modify the surface states of graphite, but also affects the electronic spectrum of the entire bulk of graphite crystal. Much like the well-known story of The Princess and The Pea, the princess felt the pea right through the twenty mattresses and the twenty eider-down beds. In the case of graphite, the moiré potential at an aligned interface could penetrate through more than 40 atomic graphitic layers.

This research, published in the latest issue of Nature, studied the effects of moiré patterns in bulk hexagonal graphite generated by crystallographic alignment with hexagonal boron nitride. The most fascinating result is the observation of a 2.5-dimensional mixing of the surface and bulk states in graphite, which manifests itself in a new type of fractal quantum Hall effect -- a 2.5D Hofstadter's butterfly.

Prof. Artem Mishchenko at The University of Manchester, who has already discovered the 2.5-dimensional quantum Hall effect in graphite said: "Graphite gave rise to the celebrated graphene, but people normally are not interested in this 'old' material. And now, even with our accumulated knowledge on graphite of different stacking and alignment orders in the past years, we still found graphite a very attractive system -- so much yet to be explored." Ciaran Mullan, one of the leading authors of the paper, added: "Our work opens up new possibilities for controlling electronic properties by twistronics not only in 2D but also in 3D materials."

Prof. Vladimir Fal'ko, Director of the National Graphene Institute and theoretical physicist at the Department of Physics and Astronomy, added: "The unusual 2.5D quantum Hall effect in graphite arises as the interplay between two quantum physics textbook phenomena -- Landau quantisation in strong magnetic fields and quantum confinement, leading to yet another new type of quantum effect."

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Scientists discover secret of virgin birth, and switch on the ability in female flies

Scientists have pinpointed a genetic cause for virgin birth for the first time, and once switched on the ability is passed down through generations of females.

For the first time, scientists have managed to induce virgin birth in an animal that usually reproduces sexually: the fruit fly Drosophila melanogaster.

Once induced in this fruit fly, this ability is passed on through the generations: the offspring can reproduce either sexually if there are males around, or by virgin birth if there aren't.

For most animals, reproduction is sexual -- it involves a female's egg being fertilised by a male's sperm. Virgin birth, or 'parthenogenesis', is the process by which an egg develops into an embryo without fertilisation by sperm -- a male is not needed.

The offspring of a virgin birth are not exact clones of their mother but are genetically very similar, and are always female.

"We're the first to show that you can engineer virgin births to happen in an animal -- it was very exciting to see a virgin fly produce an embryo able to develop to adulthood, and then repeat the process," said Dr Alexis Sperling, a researcher at the University of Cambridge and first author of the paper.

She added: "In our genetically manipulated flies, the females waited to find a male for half their lives -- about 40 days -- but then gave up and proceeded to have a virgin birth."

In the experiments, only 1-2% of the second generation of female flies with the ability for virgin birth produced offspring, and this occurred only when there were no male flies around. When males were available, the females mated and reproduced in the normal way.

Switching to a virgin birth can be a survival strategy: a one-off generation of virgin births can help to keep the species going.

The study is published today in the journal Current Biology.

To achieve their results, researchers first sequenced the genomes of two strains of another species of fruit fly, called Drosophila mercatorum. One strain needs males to reproduce, the other reproduces only through virgin birth. They identified the genes that were switched on, or switched off, when the flies were reproducing without fathers.

With the candidate genes for virgin birth ability identified in Drosophila mercatorum, the researchers altered what they thought were the corresponding genes in the model fruit fly, Drosophila melanogaster. It worked: Drosophila melanogaster suddenly acquired the ability for virgin birth.

The research involved over 220,000 virgin fruit flies and took six years to complete.

Key to the discovery was the fact that this work was done in Drosophila melanogaster -- the researchers say it would have been incredibly difficult in any other animal. This fly has been the 'model organism' for research in genetics for over 100 years and its genes are very well understood.

Sperling, who carried out this work in the Department of Genetics, has recently moved to Cambridge Crop Science Centre to work on crop pests and hopes to eventually investigate why virgin birth in insects may be becoming more common, particularly in pest species.

"If there's continued selection pressure for virgin births in insect pests, which there seems to be, it will eventually lead to them reproducing only in this way. It could become a real problem for agriculture because females produce only females, so their ability to spread doubles," said Sperling.

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Genome analysis of 46,000-year-old roundworm from Siberian permafrost reveals novel species

Some organisms, such as tardigrades, rotifers, and nematodes, can survive harsh conditions by entering a dormant state known as "cryptobiosis." In 2018, researchers from the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia found two roundworms (nematode) species in the Siberian Permafrost. Radiocarbon dating indicated that the nematode individuals have remained in cryptobiosis since the late Pleistocene, about 46,000 years ago. Researchers from the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, the Center for Systems Biology Dresden (CSBD), and the Institute of Zoology at the University of Cologne, all located in Germany, used genome sequencing, assembly, and phylogenetic analysis and found that the permafrost nematode belongs to a previously undescribed species, Panagrolaimus kolymaensis. They showed that the biochemical mechanisms employed by Panagrolaimus kolymaensis to survive desiccation and freezing under laboratory conditions are similar to those of a life-cycle stage in the important biological model Caenorhabditis elegans.

When Anastasia Shatilovich at the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia revived two frozen individual nematodes from a fossilized burrow in silt deposits in the Siberian permafrost, she and her colleagues were beyond excited. After thawing the worms in the lab, a radiocarbon analysis of plant material from the burrow revealed that these frozen deposits, 40 meters below the surface, had not thawed since the late Pleistocene, between 45,839 and 47,769 years ago. At the same time, the research group of Teymuras Kurzchalia at the MPI-CBG (Teymuras Kurzchalia is now retired) was already addressing the question of how larval stages of the nematode Caenorhabditis elegans survive extreme conditions. When the team heard about the permafrost nematodes, they immediately reached out for a collaboration with Anastasia Shatilovich.

Vamshidhar Gade, a doctoral student at that time in the research group of Teymuras Kurzchalia, started to work with the permafrost nematodes. "What molecular and metabolic pathways these cryptobiotic organisms use and how long they would be able to suspend life are not fully understood," he says. Vamshidhar is now working at the ETH in Zurich, Switzerland.

The researchers in Dresden conducted a high-quality genome assembly of one of the permafrost nematodes in collaboration with Eugene Myers, Director Emeritus and research group leader at the MPI-CBG, the DRESDEN-concept Genome Center, and the research group of Michael Hiller, research group leader at that time at the MPI-CBG and now Professor of Comparative Genomics at the LOEWE-TBG and the Senckenberg Society for Nature Research. Despite having DNA barcoding sequences and microscopic pictures, it was difficult to determine whether the permafrost worm was a new species or not. Philipp Schiffer, research group leader at the Institute of Zoology, co-lead of the incipient Biodiversity Genomics Center Cologne (BioC2) at the University of Cologne, and expert in biodiversity genomics research, joined forces with the Dresden researchers to determine the species and analyze its genome with his team. Using phylogenomic analysis, he and his team were able to define the roundworm as a novel species, and the team decided to call it "Panagrolaimus kolymaensis." In recognition of the Kolyma River region from which it originated, the nematode was given the Latin name Kolymaensis.

By comparing the genome of Panagrolaimus kolymaensis with that of the model nematode Caenorhabditis elegans, the researchers in Cologne identified genes that both species have in common and that are involved in cryptobiosis. To their surprise, most of the genes necessary for entering cryptobiosis in Caenorhabditis elegans so-called Dauer larvae were also present in Panagrolaimus kolymaensis. The research team next evaluated Panagrolaimus kolymaensis's ability to survive and discovered that mild dehydration exposure before freezing helped the worms prepare for cryptobiosis and increased survival at -80 degrees Celsius. At a biochemical level, both species produced a sugar called trehalose when mildly dehydrated in the lab, possibly enabling them to endure freezing and intense dehydration. Caenorhabditis elegans larvae also benefited from this treatment, surviving for 480 days at -80 degrees Celsius without suffering any declines in viability or reproduction following thawing.

According to Vamshidhar Gade and Temo Kurzhchalia, "Our experimental findings also show that Caenorhabditis elegans can remain viable for longer periods in a suspended state than previously documented. Overall, our research demonstrates that nematodes have developed mechanisms that allow them to preserve life for geological time periods."

Read more at Science Daily

Webb snaps highly detailed infrared image of actively forming stars

Young stars are rambunctious!

NASA's James Webb Space Telescope has captured the "antics" of a pair of actively forming young stars, known as Herbig-Haro 46/47, in high-resolution near-infrared light. To find them, trace the bright pink and red diffraction spikes until you hit the center: The stars are within the orange-white splotch. They are buried deeply in a disk of gas and dust that feeds their growth as they continue to gain mass. The disk is not visible, but its shadow can be seen in the two dark, conical regions surrounding the central stars.

The most striking details are the two-sided lobes that fan out from the actively forming central stars, represented in fiery orange. Much of this material was shot out from those stars as they repeatedly ingest and eject the gas and dust that immediately surround them over thousands of years.

When material from more recent ejections runs into older material, it changes the shape of these lobes. This activity is like a large fountain being turned on and off in rapid, but random succession, leading to billowing patterns in the pool below it. Some jets send out more material and others launch at faster speeds. Why? It's likely related to how much material fell onto the stars at a particular point in time.

The stars' more recent ejections appear in a thread-like blue. They run just below the red horizontal diffraction spike at 2 o'clock. Along the right side, these ejections make clearer wavy patterns. They are disconnected at points, and end in a remarkable uneven light purple circle in the thickest orange area. Lighter blue, curly lines also emerge on the left, near the central stars, but are sometimes overshadowed by the bright red diffraction spike.

All of these jets are crucial to star formation itself. Ejections regulate how much mass the stars ultimately gather. (The disk of gas and dust feeding the stars is small. Imagine a band tightly tied around the stars.)

Now, turn your eye to the second most prominent feature: the effervescent blue cloud. This is a region of dense dust and gas, known both as a nebula and more formally as a Bok globule. When viewed mainly in visible light, it appears almost completely black -- only a few background stars peek through. In Webb's crisp near-infrared image, we can see into and through the gauzy layers of this cloud, bringing a lot more of Herbig-Haro 46/47 into focus, while also revealing a deep range of stars and galaxies that lie well beyond it. The nebula's edges appear in a soft orange outline, like a backward L along the right and bottom.

This nebula is significant -- its presence influences the shapes of the jets shot out by the central stars. As ejected material rams into the nebula on the lower left, there is more opportunity for the jets to interact with molecules within the nebula, causing them both to light up.

There are two other areas to look at to compare the asymmetry of the two lobes. Glance toward the upper right to pick out a blobby, almost sponge-shaped ejecta that appears separate from the larger lobe. Only a few threads of semi-transparent wisps of material point toward the larger lobe. Almost transparent, tentacle-like shapes also appear to be drifting behind it, like streamers in a cosmic wind. In contrast, at lower left, look beyond the hefty lobe to find an arc. Both are made up of material that was pushed the farthest and possibly by earlier ejections. The arcs appear to be pointed in different directions, and may have originated from different outflows.

Take another long look at this image. Although it appears Webb has snapped Herbig-Haro 46/47 edge-on, one side is angled slightly closer to Earth. Counterintuitively, it's the smaller right half. Though the left side is larger and brighter, it is pointing away from us.

Over millions of years, the stars in Herbig-Haro 46/47 will fully form -- clearing the scene of these fantastic, multihued ejections, allowing the binary stars to take center stage against a galaxy-filled background.

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New planetary formation findings

Rochester Institute of Technology's Joel Kastner, a professor in the Chester F. Carlson Center for Imaging Science and School of Physics and Astronomy, and a team of researchers with the European Southern Observatory (ESO) have discovered new evidence of how planets as massive as Jupiter can form, using images from the ESO's Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA).

The combination of VLT and ALMA imaging have yielded detections of dusty clumps close to the young star V960 Mon that could collapse to create giant planets. The work is based on an infrared image obtained with the Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument on ESO's VLT and a radio-wavelength image with ALMA that together reveal, in fascinating detail, the material around the star.

This young star attracted astronomers' attention when it suddenly increased its brightness more than 20 times in 2014. SPHERE observations taken shortly after the onset of this brightness "outburst" revealed that the material orbiting V960 Mon is assembling together in a series of intricate spiral arms extending over distances bigger than the entire solar system.

Kastner worked on the SPHERE imaging project with former RIT student David Principe '14 Ph.D. (astrophysical sciences and technology), who is now at the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology.

"The two of us put SPHERE observing proposals together to look at these outbursting objects," said Kastner. "We were hoping to see structure around them that is lit up by the outbursts, but we really weren't sure what kind of structure we might see. We thought we might be able to see the dusty material around the star that is feeding the star and maybe forming planets, and this was a great case where both appear to have been detected."

Astronomers believe that giant planets form either by "core accretion,"' when dust grains slowly coagulate to form a massive core that sweeps up gas, or by "gravitational instability," when large fragments of the material around a star quickly contract and collapse. While researchers have previously found evidence for the first of these scenarios, support for the latter has been scant. The images from VLT now show a real observation of gravitational instability happening at planetary scales.

"It's a confirmation that one of the basic ideas of how planets form works," said Kastner. "It's a pretty good demonstration of what has been shown in very detailed simulations of discs around young stars to determine if they are making planets."

The research team presented its findings in the July 25 issue of The Astrophysical Journal Letters. Authors span across the globe while the VLT and ALMA are located in Chile's Atacama Desert.

The ESO enables scientists worldwide to discover the secrets of the universe for the benefit of all. Established as an intergovernmental organization in 1962, today ESO is supported by 16 member states (Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland, and the United Kingdom), along with the host state of Chile and with Australia as a strategic partner.

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Automated analysis of microplastic concentrations

How high are concentrations of microplastics in the environment, in our drinking water or in foods? Researchers at the Technical University of Munich (TUM) have developed an automated analysis method for the identification and quantification of particles.

Microplastics are everywhere in the environment. The tiny particles, with diameters of less than 5 millimeters, can also absorb and transport contaminants and toxins. “We urgently need analytical techniques to learn about the size, concentration and composition of these particles,” says Dr. Natalia Ivleva at the Chair of Analytical Chemistry and Water Chemistry at TUM. Together with her team, the scientist has developed a new process.

To be able to detect microplastic particles, the researchers had several hurdles to overcome: The first was the problem of low concentrations. River water, for example, contains massive amounts of suspended solids and fine sand, with plastic accounting for less than 1 percent of the particles. These particles must first be isolated before their concentrations and ultimately their chemical composition are determined. Previous methods have relied on the analysis of the residues that are released when the samples are heated. With that approach, however, it is not possible to determine the number, size and shape of the plastic particles.

Plastics can be identified through light scattering

“Our approach is fundamentally different,” says Dr. Ivleva: “It is particle-based. That means that instead of destroying the particles, we analyze them directly.” To do this, the researchers use a method known as Raman microspectroscopy. It works by shining a monochromatic laser source onto a sample and detecting the light scattered by the molecules. Comparing the scattered light against the laser source provides information on the substance under investigation. To analyze plastic particles with a diameter greater than 1 µm (micrometer), they must first be filtered out of the aqueous solution, detected under the microscope and then illuminated with laser light. Because plastics such as polyethylene, polystyrene and polyvinyl chloride scatter the photons in characteristic ways, they each generate signals as unique as a fingerprint.

Automation instead of manual measurements

It took years to develop the tracing process: “When we started, we still had to make manual measurements,” recalls the chemist. “It took us months to investigate a few thousand particles.” In the meantime the team has succeeded in automating the detection of microplastics. A single analysis no longer takes weeks, but only a matter of hours. Although the tiny particles still have to be filtered out of the aqueous solution, followed by placement of the filter under the Raman microspectroscope, all remaining steps are carried out by the software developed by the team. The plastic particles are first localized with a light microscope, photographed and measured, and the particles are distinguished from fibers. The software uses these data to compute the number of particles and fibers and to select the image sections needed for a statistically significant result in the subsequent Raman spectroscopy.

In the next step, the laser is directed onto the sample and the scattering is detected and analyzed. This allows quick and reliable analysis of the number, size, shape and composition of the microplastics. The open-source TUM-Particle Typer 2 software is now available to researchers around the world.

Nanoplastics require special detection processes

To investigate nanoparticles with diameters of less than 1 µm, however, Dr. Ivleva’s team is already working on a modified process. “Nanoparticles like these are difficult or even impossible to discern under a light microscope. To detect them, we first have to carry out size fractionation and then identify them,” explains the researcher.

For this purpose, a field flow fractionation (FFF) system is used. This creates a water flow that captures the particles – depending on their size – and separates them by transporting them at varying speeds. A specially developed device, combined with Raman spectroscopy, permits the chemical characterization of different types of nanoplastics.

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Family trees from the European Neolithic

The Neolithic burial site of Gurgy 'les Noisats' in France revealed two unprecedentedly large family trees which allowed a Franco-German team to explore the social organization of the 6,700-year-old community. Based on multiple lines of evidence, the team describes a close kin group which practiced monogamy and female exogamy, and experienced generally stable times.

The Neolithic lifestyle, based on farming instead of hunting and gathering, emerged in the Near East around 12,000 years ago and contributed profoundly to the modern way of life. The ability to produce and store extra food led Neolithic people to develop new social customs built on wealth, and therefore form social hierarchies. After an early phase of diffusion and having reached regions in western Europe, settled societies became more complex, which is sometimes reflected in the funerary world as well. The Paris Basin region in northern modern-day France is known for its monumental funerary sites, understood as being built for the society's "elite." In this context, the site of Gurgy 'Les Noisats', one of the biggest Neolithic funerary sites without monument in the region, begs the question who these people buried with different practices were.

Using new methods for obtaining and analysing ancient DNA data, and by sampling nearly every individual from the flat cemetery, researchers from the PACEA laboratory in Bordeaux, France, and from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, reveal two massive family trees which open a window into the lives of the people of this prehistoric community.

Massive family trees

In their study, the scientists analysed genome-wide ancient DNA data from 94 individuals buried at Gurgy, combined with strontium isotope ratio values, mitochondrial DNA (maternal lineages) and Y-chromosome (paternal lineages) data, age-at-death, and genetic sex. Two family trees could be reconstructed, the first connecting 64 individuals over seven generations is the largest pedigree reconstructed from ancient DNA to date, while the second connects twelve individuals over five generations.

"Since the beginning of the excavation, we found evidence of a complete control of the funerary space and only very few overlapping burials, which felt like the site was managed by a group of closely related individuals, or at least by people who knew who was buried where," says Stéphane Rottier from the University of Bordeaux, the archaeo-anthropologist who excavated the site between 2004 and 2007. Indeed, a positive correlation between spatial and genetic distances showed that the deceased were likely to be buried close to a relative.

Insights into the social structure of Gurgy

Exploring the pedigrees revealed a strong patrilineal pattern, where each generation is almost exclusively linked to the previous generation through the biological father, which connects the entire group of Gurgy through the paternal line. At the same time, combined evidence from mitochondrial lineages and strontium stable isotope revealing a non-local origin of most women suggested the practice of patrilocality, meaning that the sons stayed where they were born, and had children with females from outside of Gurgy. Settling in with the male partner's home community is known as virilocality. By contrast, most of the lineage adult daughters are missing, in line with female exogamy, potentially indicating a reciprocal exchange system. Interestingly, these "new incoming" female individuals were only very distantly related to each other, meaning that they must have come from a network of nearby communities, instead of just one nearby group. This lends support to the existence of a relatively wide and potentially fluid exchange network comprising many (including smaller) groups.

Looking at the family trees, Maïté Rivollat, first author of the study, is amazed: "We observe a large number of full siblings who have reached reproductive age. Combined with the expected equal number of females and significant number of deceased infants, this indicates large family sizes, a high fertility rate and generally stable conditions of health and nutrition, which is quite striking for such ancient times." Another notably unique feature at Gurgy is a lack of half-siblings, suggesting neither polygamous nor serial monogamous reproductive partnerships (or the exclusion of offspring from these unions from the main cemetery), when compared to the so far only other example of union practices from Neolithic megaliths.

A founding ancestor

In the frame of this patrilocal system, one male individual from which everyone in the largest family tree was descended could be identified as the "founding father" of the cemetery. His burial is unique at the site, as his skeletal remains were buried as a secondary deposit inside the grave pit of a woman, for whom, unfortunately, no genomic data could be obtained. Therefore, his bones must have been brought from wherever he had originally died to be reburied at Gurgy. "He must have represented a person of great significance for the founders of the Gurgy site to be brought there after a primary burial somewhere else," explains Marie-France Deguilloux from the University of Bordeaux, co-senior author of the study.

Although the main pedigree spans seven generations, the demographic profile suggests that a large family group spanning several generations arrived at the site. With almost no subadults buried at the site during the first few generations, and by contrast no adult burials in the last generations, only a short use of the site is expected. The group must have left a previous site, leaving behind any previously deceased children but still brought the lineage father. Only a few generations later the same happened: the adult of the last generations left Gurgy for another place, leaving behind their own children. Hence, Gurgy was probably only used for three to four generations, or approximately one century.

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Ancient DNA reveals diverse community in 'Lost City of the Incas'

Who lived at Machu Picchu at its height? A new study, published today in Science Advances, used ancient DNA to find out for the first time where workers buried more than 500 years ago came from within the lost Inca Empire.

Researchers, including Jason Nesbitt, associate professor of archaeology at Tulane University School of Liberal Arts, performed genetic testing on individuals buried at Machu Picchu in order to learn more about the people who lived and worked there.

Machu Picchu is a UNESCO World Heritage Site located in the Cusco region of Peru. It is one of the most well-known archaeological sites in the world and attracts hundreds of thousands of visitors every year. It was once part of a royal estate of the Inca Empire.

Like other royal estates, Machu Picchu was home not only to royalty and other elite members of Inca society, but also to attendants and workers, many of whom lived in the estate year-round. These residents did not necessarily come from the local area, though it is only in this study that researchers have been able to confirm, with DNA evidence, the diversity of their backgrounds. "It's telling us, not about elites and royalty, but lower status people," Nesbitt said. "These were burials of the retainer population."

This DNA analysis works in much the same way that modern genetic ancestry kits work. The researchers compared the DNA of 34 individuals buried at Machu Picchu to that of individuals from other places around the Inca Empire as well as some modern genomes from South America to see how closely related they might be.

The results of the DNA analysis showed that the individuals had come from throughout the Inca Empire, some as far away as Amazonia. Few of them had shared DNA with each other, showing that they had been brought to Machu Picchu as individuals rather than as part of a family or community group.

"Now, of course, genetics doesn't translate into ethnicity or anything like that," said Nesbitt of the results, "but that shows that they have distinct origins within different parts of the Inca Empire."

"The study does really reinforce a lot of other types of research that have been done at Machu Picchu and other Inca sites," Nesbitt said. The DNA analysis supports historical documentation and archaeological studies of the artifacts found associated with the burials.

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