Chrysalis, the lost moon that gave Saturn its rings

Artistic rendering of the moon Chrysalis disintegrating in Saturn’s intense gravity field. The chunks of icy rock eventually collided and shattered into smaller pieces that became distributed in the thin ring we see today.
Image credit B. Militzer and NASA

Rings appear to be common around planets in the solar system, but the dramatic rings of Saturn have long puzzled astronomers, as has the steep tilt of the rings and the planet’s rotation axis relative to its orbit around the sun.

Scientists now show that the rings and the tilt are intimately linked, and that the key is a former moon of Saturn that was torn apart some 160 million years ago to form the rings. The researchers dubbed the lost moon Chrysalis because it blossomed into the rings much as a chrysalis transforms into a butterfly.

The new proposal for how Saturn became “Lord of the Rings” in our solar system and how Saturn got its axial tilt will be published this week in the journal Science. The lead author is Jack Wisdom, a professor of planetary science at the Massachusetts Institute of Technology (MIT), with key contributions from Burkhard Militzer at the University of California, Berkeley.

Militzer, UC Berkeley professor of earth and planetary science, was part of a team that in 2019 concluded that the rings of Saturn are relatively recent, having formed a mere 100 million years ago and perhaps even more recently. The planet itself is as old as the solar system, about 4.5 billion years. The rings could be debris left over from the tidal destruction of a former icy moon of Saturn or the remains of a comet that strayed too close to the planet.

Strawberries were smaller when bees ingested pesticides

Photo credit: Trollinho on Unsplash

Solitary bees that ingested the pesticide clothianidin when foraging from rapeseed flowers became slower. In addition, the strawberries pollinated by these bees were smaller. This is shown by a new study from Lund University in Sweden.

Strawberries are known to become bigger if bees have visited their flowers, but how strawberry growth is affected if the bees have been exposed to neonicotinoid insecticides has so far been unclear. In a new study published in PLOS ONE, a Swedish research team has made two discoveries.

“We studied bees that ingested clothianidin, a pesticide that was previously used in rapeseed to control flea beetles. Our study indicates that the substance made the bees slower and impaired their ability to pollinate the strawberry flowers”, says Lina Herbertsson, biology researcher at Lund University.

The researchers used twelve outdoor cages where solitary bees could forage from rapeseed and strawberry flowers. In half of the cages, the rapeseed had been treated with clothianidin. The bees that were exposed to the treated rapeseed needed more time than other bees to visit the same number of rapeseed flowers. When the researchers later weighed the strawberries, they made another discovery. It turned out that the strawberries were smaller if they had been pollinated by bees that foraged from clothianidin-treated rapeseed.

No-till management may reduce nitrous oxide gas releases, fight climate change

Mara Cloutier, shown here as a doctoral degree student in soil science and biogeochemistry, talking about the study at a field day, is now a project manager at the Soil Health Institute, based in Raleigh, North Carolina.
Credit: Pennsylvania State University

Scientists have long known that no-till farming reduces erosion and lessens water and nutrient runoff from crop fields, but now a new study by a team of Penn State researchers suggests that limiting soil disturbance may also diminish releases of nitrous oxide.

A greenhouse gas that contributes to climate change, nitrous oxide is 300 times more potent than carbon dioxide. To learn how no-till affects soil microbes that both produce and break down nitrous oxide, the researchers focused their study on a 40-year tillage experiment that has been maintained at Penn State’s Russell E. Larson Agricultural Research Center.

“We aimed to see whether the level of tillage in the long-term experiment affected the soil microbes responsible for net nitrous oxide emissions,” said team leader and study co-author Mary Ann Bruns, professor of soil microbiology and biogeochemistry in the College of Agricultural Sciences. “This is a particularly challenging objective because many diverse bacteria produce nitrous oxide, yet many others can convert it to an inert nitrogen gas that does not contribute to the greenhouse effect.”

The study, led by Mara Cloutier, a doctoral degree student in soil science and biogeochemistry when the research was conducted, collected and evaluated soil samples taken from plots that have been managed as no-till, chisel-disked or moldboard-plowed — three tillage practices that represent low-, intermediate- and high-intensity levels of physical disturbance, respectively — for four decades.

Study links length of REM sleep to body temperature

Credit: Lancet Neurology

Warm-blooded animal groups with higher body temperatures have lower amounts of rapid eye movement (REM) sleep, while those with lower body temperatures have more REM sleep, according to new research from UCLA professor Jerome Siegel, who said his study suggests that REM sleep acts like a “thermostatically controlled brain heater.”

The study in Lancet Neurology suggests a previously unobserved relationship between body temperature and REM sleep, a period of sleep when the brain is highly active, said Siegel, who directs the Center for Sleep Research at the Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA.

Birds have the highest body temperature of any warm-blooded, or homeotherm, animal group at 41 degrees while getting the least REM sleep at 0.7 hours per day. That’s followed by humans and other placental mammals (37 degrees, 2 hours of REM sleep), marsupials (35 degrees, 4.4 hours of REM sleep), and monotremes (31 degrees, 7.5 hours of REM sleep).

Physicists generate new nanoscale spin waves

Illustration of the experiment
Photo: Dreyer et al, Nature Communications (CC-BY-SA 4.0)

Strong alternating magnetic fields can be used to generate a new type of spin wave that was previously just theoretically predicted. This was achieved for the first time by a team of physicists from Martin Luther University Halle-Wittenberg (MLU). They report on their work in the scientific journal "Nature Communications" and provide the first microscopic images of these spin waves.

The basic idea of spintronics is to use a special property of electrons - spin - for various electronic applications such as data and information technology. Spin is the intrinsic angular momentum of electrons that produces a magnetic moment. Coupling these magnetic moments creates the magnetism that could ultimately be used in information processing. When these coupled magnetic moments are locally excited by a magnetic field pulse, this dynamic can spread like waves throughout the material. These are referred to as spin waves or magnons.

A special type of those waves is at the heart of the work of the physicists from Halle. Normally, the non-linear excitation of magnons produces integers of the output frequency - 1,000 megahertz becomes 2,000 or 3,000, for example. "So far, it was only theoretically predicted that non-linear processes can generate spin waves at higher half-integer multiples of the excitation frequency," explains Professor Georg Woltersdorf from the Institute of Physics at MLU. The team has now been able to show experimentally which conditions are needed in order to generate these waves and to control their phase. Phase is the state of the oscillation of a wave at a certain point and time. "We are the first to confirm these excitations in experiments and have even been able to map them," says Woltersdorf.

Airway antibodies protect against omicron infection

Charlotte Thålin, assistant chief physician and associate professor at Department of Clinical Sciences, Danderyds Hospital, Karolinska Institutet, led the study.
Credit: Ludvig Costyal

High levels of antibodies in the airways reduce the risk of being infected by omicron, but many do not receive measurable antibody levels in the airways desperate three doses of SARS-Cov-2 vaccine. It shows a new study published in The New England Journal of Medicine by researchers at Karolinska Institutet and Danderyds Hospital.

The COMMUNITY study started in the spring of 2020 with a provincial collection of 2,149 employees at Danderyds Hospital. The study participants and their immune response to the coronavirus sars-cov-2 have since followed up every four months. At the beginning of 2022, a study was conducted in which 338 employees who received three doses of vaccine were regularly screened for SARS-Cov-2 infection. Of those who were not infected at the start of the study, sixth participants (57 people) were infected with omics during the course of the study. This allowed the research team to investigate what protects against infection and what the immune response after omicron infection looks like.

Researchers Discover First Pair of Mated Blue Crabs in Great Bay

UNH doctoral student Kelsey Meyer with large male blue crab in Great Bay Estuary.
Courtesy photo University of New Hampshire

Researchers at the University of New Hampshire have documented the first discovery of a pair of recently mated blue crabs in Great Bay Estuary (GBE), a finding that is expected to have serious impacts on the estuary’s ecosystem, particularly its fragile oyster population. Blue crabs have been captured in GBE since 2012 but this is the first-time researchers have found compelling evidence that the crabs are actually mating.

“The arrival of blue crabs capable of creating a sustained population poses a new threat to oysters and other native GBE species,” said Bonnie Brown, professor, and chair of the department of biological sciences.

Doctoral student Alyssa Stasse and technician Emily Williams were checking traps set out by doctoral student Kelsey Meyer, who is monitoring the estuary’s invasive green crab population, when they found the two blue crabs and the mating proof: the female, which had recently molted, had distended turgid seminal receptacles with large sperm plugs, clear evidence of crustacean copulation.

First light at the most powerful laser in the US

The laser that will be the most powerful in the United States is preparing to send its first pulses into an experimental target at the University of Michigan.

Funded by the National Science Foundation, it will be a destination for researchers studying extreme plasmas around the U.S. and internationally.

Called ZEUS, the Zetawatt-Equivalent Ultrashort pulse laser System, it will explore the physics of the quantum universe as well as outer space, and it is expected to contribute to new technologies in medicine, electronics and national security.

“ZEUS will be the highest peak power laser in the U.S. and among the most powerful laser systems in the world. We’re looking forward to growing the research community and bringing in people with new ideas for experiments and applications,” said Karl Krushelnick, director of the Center for Ultrafast Optical Science, which houses ZEUS, and the Henry J. Gomberg Collegiate Professor of Engineering.

The first target area to get up and running is the high-repetition target area, which runs experiments with more frequent but lower power laser pulses. Michigan alum Franklin Dollar, an associate professor of physics and astronomy at the University of California Irvine, is the first user, and his team is exploring a new kind of X-ray imaging.

They will use ZEUS to send infrared laser pulses into a gas target of helium, turning it into plasma. That plasma accelerates electrons to high energies, and those electron beams then wiggle to produce very compact X-ray pulses.

New Evidence of Baby Planet in the Making

Artist's illustration of a small Saturn-like planet discovered in the system LkCa 15. The planet resides within dense rings of dust and gas that surround a bright yellow star. Material accumulates in a clump and arc-shape, about 60 degrees away from the planet. Note: This illustration is not to scale.
Credit: M.Weiss/Center for Astrophysics | Harvard & Smithsonian

Astronomers agree that planets are born in protoplanetary disks — rings of dust and gas that surround young, newborn stars. While hundreds of these disks have been spotted throughout the universe, observations of actual planetary birth and formation have proved difficult within these environments.

Now, astronomers at the Center for Astrophysics | Harvard & Smithsonian have developed a new way to detect these elusive newborn planets — and with it, "smoking gun" evidence of a small Neptune or Saturn-like planet lurking in a disk. The results are described today in The Astrophysical Journal Letters.

"Directly detecting young planets is very challenging and has so far only been successful in one or two cases," says Feng Long, a postdoctoral fellow at the Center for Astrophysics who led the new study. "The planets are always too faint for us to see because they’re embedded in thick layers of gas and dust."

Scientists instead must hunt for clues to infer a planet is developing beneath the dust.

Pioneering research using bacteria brings scientists a step closer to creating artificial cells with lifelike functionality

Amoeba-shaped bacteriogenic protocell: membrane (red boundary); nucleus (blue); cytoskeleton (red filaments); vacuole (red circle); ATP production (green). Scale bar, 5 μm.
Credit: Professor Stephen Mann and Dr Can Xu

Scientists have harnessed the potential of bacteria to help build advanced synthetic cells which mimic real life functionality.

The research, led by the University of Bristol and published today in Nature, makes important progress in deploying synthetic cells, known as protocells, to more accurately represent the complex compositions, structure, and function of living cells.

Establishing true-to-life functionality in protocells is a global grand challenge spanning multiple fields, ranging from bottom-up synthetic biology and bioengineering to origin of life research. Previous attempts to model protocells using microcapsules have fallen short, so the team of researchers turned to bacteria to build complex synthetic cells using a living material assembly process.

Professor Stephen Mann from the University of Bristol’s School of Chemistry, and the Max Planck Bristol Centre for Minimal Biologytogether with colleagues Drs Can Xu, Nicolas Martin (currently at the University of Bordeaux) and Mei Li in the Bristol Centre for Protolife Research have demonstrated an approach to the construction of highly complex protocells using viscous micro-droplets filled with living bacteria as a microscopic building site.