Scientists Have Found Neurons that Control Some Symptoms of Sickness

During an infection, inflammatory signals activate immune-sensitive neurons (genetically labeled in red) in the ventral medial preoptic area (VMPO) leading to the induction of fever and other sickness behaviors. All cells are labeled with a nuclear stain (blue).
Credit: Courtesy of Dulac Lab/HHMI at Harvard University

Feeling ill is about both the body and the brain. Now scientists have identified a group of neurons in mice that has ultimate control over symptoms such as fever and behaviors like seeking out warmth.

Fevers, chills, an appetite that vanishes – we can tell when we’re getting sick. Many people chalk these symptoms of illness up to the immune system fighting off infection. But there’s another player involved when we feel woefully under the weather.

“All of this is orchestrated by the brain,” says neurobiologist Catherine Dulac, who is a Howard Hughes Medical Institute Investigator at Harvard University. Now research from Dulac’s team, published in Nature, pins this broad response on a previously uncharacterized population of neurons in the brain.

How exactly the brain serves as an infection ringleader has been unclear. Earlier research had identified receptors in the brain that were required for animals to develop a fever. But fever is only part of the story. One of the bigger mysteries is: Where does ultimate control for the symptoms and behaviors associated with sickness lie?

Dulac, her postdoctoral fellow, Jessica A. Osterhout, and colleagues injected mice with molecules that mimic bacterial or viral infections to investigate that question. As the mice’s immune systems reacted to these inflammatory molecules, the researchers homed in on which neurons jumped into action. The team watched neurons’ gene expression through single-cell RNA sequencing and mapped the whereabouts of those neurons using a visualization technique called MERFISH, which was developed in the lab of HHMI Investigator Xiaowei Zhuang at Harvard, a collaborator in this work.

Carbon Dioxide Glaciers Are Moving at Mars’ South Pole

Perspective view of the South Polar Cap of Mars using Viking imagery draped over topography from the Mars Orbiter Laser Altimeter. White ice is a residual carbon dioxide cap that resides on top of and protects the much thicker CO2 glaciers. The surrounding terrain is composed of red dust that overlies the mountains in the background and the 4-kilometer-thick H2O ice cap that supports the CO2 glaciers.
  Credit: NASA data visualized using JMARS.

Glaciers of carbon dioxide are moving, creating deposits kilometers thick today across the south polar region of Mars, something that could have been going on more than 600,000 years, a paper by Planetary Science Institute Research Scientist Isaac Smith says.

“The CO2 deposits that were first identified in 2011 turn out to be flowing today, just like glaciers on Earth,” said Smith, lead author of “Carbon Dioxide Ice Glaciers at the South Pole of Mars” that appears in the Journal for Geophysical Research - Planets.

“Approximately 600,000 years ago CO2 ice started forming at the Martian south pole. Due to climate cycles, the ice has increased in volume and mass several times, interrupted by periods of mass loss through sublimation,” Smith said. “If the ice had never flowed, then it would mostly be where it was originally deposited, and the thickest ice would only be about 45 meters thick. Instead, because it flowed downhill into basins and spiral troughs – curvilinear basins – where it ponded, it was able to form deposits reaching one kilometer thick.

The Earth moves far under our feet: New study shows Earth’s inner core oscillates

The Earth’s inner core — a hot, dense ball of solid iron the size of Pluto — has been shown to move and/or change over decades.
Credit: USC Graphic/Edward Sotelo

USC scientists have found evidence that the Earth’s inner core oscillates, contradicting previously accepted models that suggested it consistently rotates at a faster rate than the planet’s surface.

Their study, published in Science Advances, shows that the inner core changed direction in the six-year period from 1969-74, according to the analysis of seismic data. The scientists say their model of inner core movement also explains the variation in the length of day, which has been shown to oscillate persistently for the past several decades.

“From our findings, we can see the Earth’s surface shifts compared to its inner core, as people have asserted for 20 years,” said John Vidale, co-author of the study and Dean’s Professor of Earth Sciences at USC Dornsife College of Letters, Arts and Sciences. “However, our latest observations show that the inner core spun slightly slower from 1969-71 and then moved in the other direction from 1971-74. We also note that the length of the day grew and shrank as would be predicted.

“The coincidence of those two observations makes oscillation the likely interpretation.”

One in 500 men carry extra sex chromosome, putting them at higher risk of several common diseases

In a study published in Genetics in Medicine, researchers analyzed genetic data collected on over 200,000 UK men aged 40-70 from UK Biobank, a biomedical database and research resource containing anonymized genetic, lifestyle and health information from half a million UK participants. They found 356 men who carried either an extra X chromosome or an extra Y chromosome.

Sex chromosomes determine our biological sex. Men typically have one X and one Y chromosome, while women have two Xs. However, some men also have an extra X or Y chromosome – XXY or XYY.

Without a genetic test, it may not be immediately obvious. Men with extra X chromosomes are sometimes identified during investigations of delayed puberty and infertility; however, most are unaware that they have this condition. Men with an extra Y chromosome tend to be taller as boys and adults, but otherwise they have no distinctive physical features.

In today’s study, the researchers identified 213 men with an extra X chromosome and 143 men with an extra Y chromosome. As the participants in UK Biobank tend to be ‘healthier’ than the general population, this suggests that around one in 500 men may carry an extra X or Y chromosome.

Only a small minority of these men had a diagnosis of sex chromosome abnormality on their medical records or by self-report: fewer than one in four (23%) men with XXY and only one of the 143 XYY men (0.7%) had a known diagnosis.

By linking genetic data to routine health records, the team found that men with XXY have much higher chances of reproductive problems, including a three-fold higher risk of delayed puberty and a four-fold higher risk of being childless. These men also had significantly lower blood concentrations of testosterone, the natural male hormone. Men with XYY appeared to have a normal reproductive function.

Perpetual motion is possible

Researchers cooled a helium-3 superfluid down to one ten-thousandth of a degree from absolute zero and proceeded to create two time-crystals inside the liquid.
Credit: Mikko Raskinen / Aalto University.

Professor and Nobel laureate in Physics Frank Wilczek, who also recently visited Aalto University to speak at a colloquium of Finland’s foremost quantum community InstituteQ, theorised the existence of time-crystals in 2012. They were experimentally confirmed to exist in 2016.

Now researchers have succeeded in creating and observing the interaction of two time-crystals in an experiment at Aalto University’s Low Temperature Lab.

The study was recently published in Nature Communications.

In an ordinary crystal the atoms or molecules comprising it have organized themselves into a regular crystal structure. Conversely, a time-crystal is a grouping of particles that moves without external energy, always returning to the same state in certain intervals. That means its regularity is expressed in time rather than in space.

‘Everyone knows perpetual motion machines are impossible. However, in quantum physics perpetual motion itself is possible as long as it’s not observed. By weakly connecting the particles to their environment, we were able to create up to two time-crystals and make them interact,’ says Samuli Autti, researcher at Lancaster University who carried out the experiment at Aalto.

Seeking COVID’s Kryptonite

Photos of the setup. Left: A closeup of the interior of the box containing the laser-to-fiber-optic coupling system. Center: The laser system in the hallway outside the door to BSL-3. Right: A closeup of the experimental setup inside BSL-3, including the chamber the housed the samples of SARS-CoV-2.
 Credit: NIST

To disinfect a surface, you can illuminate it with a blast of ultraviolet (UV) light, which is bluer than the human eye can see. But to specifically inactivate SARS-CoV-2, the virus that causes COVID-19, which wavelengths are best? And how much radiation is enough?

Answering those questions requires scientists to overcome two main obstacles. First, they need to separate the virus completely from extraneous substances in the environment. Second, they need to illuminate the virus with a single wavelength of UV light at a time, with minimal changes to the experimental setup between tests.

A recent collaboration between the National Institute of Standards and Technology (NIST) and the National Biodefense Analysis and Countermeasures Center (NBACC), a U.S. Department of Homeland Security Science and Technology Directorate laboratory, overcame both these obstacles and completed what may be the most thorough test ever conducted of how several different UV and visible wavelengths affect SARS-CoV-2.

In a new paper published this week in Applied Optics, the collaborators describe their novel system for projecting a single wavelength of light at a time onto a sample of COVID-19 virus in a secure laboratory. Classified as Biosafety Level 3 (BSL-3), the lab is designed for studying microbes that are potentially lethal when inhaled. Their experiment tested more wavelengths of UV and visible light than any other study with the virus that causes COVID-19 to date.

Researchers find ten-billion-year-old “ghost stars” from swallowed galaxy

Two galaxies merging 
Illustration: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva

Astronomers at Lund University in Sweden have found a group of stars in the Milky Way disk, that are most likely remnants from an unknown baby galaxy that was swallowed by the Milky Way over 10 billion years ago. Nothing like it has been discovered in the galaxy disk before.

After the Big Bang 13.8 billion years ago, space was a veritable Wild West. Stars formed inside huge gas clouds that collided and fused into larger and larger clouds. However, after a few billion years of space chaos, galaxy embryos became more stable, eventually evolving into well-ordered spiral galaxies, such as the Milky Way. In a new study on the origins of the Milky Way, published in Astrophysical Journal, a research team has made a surprising discovery.

“We have found traces of a smaller galaxy that was swallowed by the Milky Way. This intergalactic relic was indirectly discovered through a population of ten-billion-year-old stars in the Milky Way's disk. This is the first time such old stars have been found in the disk that show signs of coming from another galaxy”, says Diane Feuillet, astronomer at Lund University who led the study.

Clouds played an important role in climate history

Clouds have a strong influence on ice ages in earth's history. The simulation shows a snapshot of the cloud cover in the lowest layer of the atmosphere (up to approx. three kilometers above the surface of the earth) in an assumed water belt climate. The color scale ranges from "no cloud cover" (dark blue) to "fully covered" (white)
Credit Graphic: IMK-TRO

Were the world's oceans in cryogenium - around 700 million years ago - completely covered with ice or an ice-free water belt stretched around the equator, in which sponges and other life forms could survive? A research team from the Karlsruhe Institute of Technology (KIT) and the University of Vienna has now been able to show in global climate models that a climate condition with a water belt is rather unlikely and therefore not a reliable explanation for the persistence of life in the cryogenium. The reason for this is the uncertain influence of clouds on the climate at that time. The team presents the results of the study in the journal Nature geoscience.

From space, Earth might have looked like a big snowball during the global ice ages in the Cryogenium. Geoscience therefore describes this assumption of a closed sea ice sheet established in research as a snowball earth theory. It is still particularly unclear how sponges - of which fossil finds testify - could have survived in the very cold snowball earth climate. Therefore, some researchers have proposed an ice-free water belt around the equator as an alternative theory.

Genetic analysis of tree confirms what Indigenous people of Borneo knew

The pingan tree’s fruit (left) is distinct from the lumok tree’s (right), but Western scientists misclassified the two trees as one species for almost two centuries.
Credit: left, Elias Ednie; right, Elliot Gardner

A study led by Northwestern University plant biologists has determined that a species of fruit-bearing tree found in Borneo and the Philippines, long considered by Western botanists to be a single species, is actually two genetically distinct species.

The findings confirm what the Iban people, who are indigenous to Borneo, already knew from experience: The tree has two different varieties, which they call lumok and pingan, distinguished by their fruit size and shape.

The researchers conducted a genetic analysis of Artocarpus odoratissimus, a single species in current Linnaean taxonomy, first described to western science by a Spanish botanist close to 200 years ago. Throughout the scientific process, the team engaged with Indigenous people to combine their knowledge with DNA data.

The study, which includes Malaysian scientists and Iban field botanists as authors, was published this week in the journal Current Biology.

Native Americans Name Asteroid 'Ayló'chaxnim or 'Venus Girl'

Members of the Pauma band pose inside the dome of the 200-inch Hale Telescope.
Credit: Palomar Observatory/Caltech

On June 7, at Caltech's Palomar Observatory in the forested mountain outside San Diego, members of the Pauma band of indigenous peoples gathered to celebrate the naming of the first known asteroid to circle entirely within the orbit of Venus. The asteroid was originally discovered in 2020 by the Zwicky Transient Facility, or ZTF, which operates at the Palomar Observatory. Sometime after its discovery, the ZTF team decided to ask the Pauma band, whose ancestral lands include the mountainous region where the observatory is located, if they would like to bestow the new cosmic find with a name of their choosing.

Ultimately, the indigenous group chose to name the asteroid 'Ayló'chaxnim, which means "Venus girl" in their native language of Luiseño.

The Palomar naming ceremony included blessings, traditional Pauma songs, and a reading of a poem titled Luiseño Songs of the Seasons, which describes how "it will soon be time for the acorns to fall from the trees" when "Venus is rising."