When a star more massive than about 8 times the mass of the Sun goes supernova, it's extremely messy. The outer layers – most of the star's mass – are explosively ejected into the space around the star, where they form a huge, expanding cloud of dust and gas that lingers for hundreds of thousands to millions of years.

Meanwhile, the star's core, no longer supported by the outward pressure of fusion, collapses under gravity to form an ultradense object, a neutron star or a black hole, depending on the initial star's mass.

These collapsed cores don't always stay put; if the supernova explosion is lopsided, this can punt the core off into space in a natal kick. We can also sometimes trace the core's trajectory back to the cloud of material it ejected as it died, but if enough time has elapsed, the material may have dissipated. But the signs of the natal kick can remain a lot longer.

VFTS 243 is a very interesting system. It consists of a massive star that's around 7.4 million years old and around 25 times the mass of the Sun, and a black hole around 10 times the mass of the Sun.

Although we can't see the black hole directly, we can measure it based on the orbital motion of its companion star – and, of course, we can infer other things about the system. One interesting thing is the shape of the orbit. It's almost circular. This, together with the motion of the system in space, suggests that the black hole did not receive a huge kick from a supernova. The researchers who discovered the black hole back in 2022 suspected as much; now, the work of Vigna-Gómez and his colleagues have confirmed it. There has been a growing body of evidence that suggests that sometimes, massive stars can collapse directly into black holes, without passing supernova or collecting 200 space dollars. VFTS 243 represents the best evidence we have for this scenario to date.

Our results highlight VFTS 243 as the best observable case so far for the theory of stellar black holes formed through total collapse, where the supernova explosion fails and which our models have shown to be possible," says astrophysicist Irene Tamborra of the Niels Bohr Institute. "It is an important reality check for these models. And we certainly expect that the system will serve as a crucial benchmark for future research into stellar evolution and collapse."

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.191403

Part 2

Anendophasia: not having any inner speech

In recent years have scientists found that not everyone has the sense of an inner voice – and a new study sheds some light on how living without an internal monologue affects how language is processed in the brain.

This is similar to anauralia, a term researchers coined in 2021 for people who don't have an inner voice, nor can they imagine sounds, like a musical tune or siren.

Focusing on inner voices in a study, a research  team recruited 93 volunteers, half of whom said they had low levels of inner speech, while the other half reported having a very chatty internal monologue. These participants attempted a series of tasks – including one where they had to remember the order of words in a sequence, and another where rhyming words had to be paired together.

It is a task that will be difficult for everyone, but the  hypothesis of the researchers was that it might be even more difficult if people  did not have an inner voice because they have to repeat the words to themselves inside their head in order to remember them.

And this hypothesis turned out to be true.

The volunteers who reported hearing inner voices during everyday life did significantly better at the tasks than those without inner monologues: Inner speakers recalled more words correctly, and matched rhyming words faster. The researchers think this could be evidence that inner voices help people process words.

It's interesting to note that the performance differences disappeared when the volunteers spoke out loud to try and solve the problems they were given. It may be that using an audible voice is just as effective as using an inner voice in these situations.

In two other tasks, covering multitasking and distinguishing between different picture shapes, there was no difference in performance. The researchers take this as a sign that the way inner speech affects behavior depends on what we're doing.

Maybe people who don't have an inner voice have just learned to use other strategies. For example, some said that they tapped with their index finger when performing one type of task and with their middle finger when it was another type of task.

The researchers are keen to emphasize that the differences they found would not cause delays that you would notice in regular conversation. Scientists still at the very early stages in terms of figuring out how anendophasia might affect someone – and likewise anauralia.

https://journals.sagepub.com/doi/10.1177/09567976241243004

Dyson spheres: Astronomers report potential candidates for alien structures, and evidence against their existence

There are three ways to look for evidence of alien technological civilizations. One is to look out for deliberate attempts by them to communicate their existence, for example, through radio broadcasts. Another is to look for evidence of them visiting the solar system. And a third option is to look for signs of large-scale engineering projects in space.

A team of astronomers have taken the third approach by searching through recent astronomical survey data to identify seven candidates for alien megastructures, known as Dyson spheres, "deserving of further analysis." Their research is published in the journal Monthly Notices of the Royal Astronomical Society.

This is a detailed study looking for "oddballs" among stars—objects that might be alien megastructures. However, the authors are careful not to make any overblown claims. The seven objects, all located within 1,000 light-years of Earth, are "M-dwarfs"—a class of stars that are smaller and less bright than the sun.
Dyson spheres were first proposed by the physicist Freeman Dyson in 1960 as a way for an advanced civilization to harness a star's power. Consisting of floating power collectors, factories and habitats, they'd take up more and more space until they eventually surrounded almost the entire star like a sphere.

What Dyson realized is that these megastructures would have an observable signature. Dyson's signature (which the team searched for in the recent study) is a significant excess of infrared radiation. That's because megastructures would absorb visible light given off by the star, but they wouldn't be able to harness it all. Instead, they'd have to "dump" excess energy as infrared light with a much longer wavelength.
Part 1

Unfortunately, such light can also be a signature of a lot of other things, such as a disk of gas and dust, or disks of comets and other debris. But the seven promising candidates aren't obviously due to a disk, as they weren't good fits to disk models.

It is worth noting there is another signature of Dyson sphere: that visible light from the star dips as the megastructure passes in front of it. Such a signature has been found before. There was a lot of excitement about Tabby's star, or Kic 8462852, which showed many really unusual dips in its light that could be due to an alien megastructure.

It almost certainly isn't an alien megastructure. A variety of natural explanations have been proposed, such as clouds of comets passing through a dust cloud. But it is an odd observation. An obvious follow up on the seven candidates would be to look for this signature as well.
The case against Dyson spheres
Dyson spheres may well not even exist, however. I think they are unlikely to be there. That's not to say they couldn't exist, rather that any civilization capable of building them would probably not need to (unless it was some mega art project).

Dyson's reasoning for considering such megastructures assumed that advanced civilizations would have vast power requirements. Around the same time, astronomer Nikolai Kardashev proposed a scale on which to rate the advancement of civilizations, which was based almost entirely on their power consumption.

In the 1960s, this sort of made sense. Looking back over history, humanity had just kept exponentially increasing its power use as technology advanced and the number of people increased, so they just extrapolated this ever-expanding need into the future.

Part 2

However, our global energy use has started to grow much more slowly over the past 50 years, and especially over the last decade. What's more, Dyson and Kardashev never specified what these vast levels of power would be used for, they just (fairly reasonably) assumed they'd be needed to do whatever it is that advanced alien civilizations do.

But, as we now look ahead to future technologies we see efficiency, miniaturization and nanotechnologies promise vastly lower power use (the performance per watt of pretty much all technologies is constantly improving).

A quick calculation reveals that, if we wanted to collect 10% of the sun's energy at the distance the Earth is from the sun, we'd need a surface area equal to 1 billion Earths. And if we had a super-advanced technology that could make the megastructure only 10km thick, that'd mean we'd need about a million Earths worth of material to build them from.
Part3

A significant problem is that our solar system only contains about 100 Earths worth of solid material, so our advanced alien civilization would need to dismantle all the planets in 10,000 planetary systems and transport it to the star to build their Dyson sphere. To do it with the material available in a single system, each part of the megastructure could only be one meter thick.

This is assuming they use all the elements available in a planetary system. If they needed, say, lots of carbon to make their structures, then we're looking at dismantling millions of planetary systems to get hold of it. Now, I'm not saying a super-advanced alien civilization couldn't do this, but it is one hell of a job.

I'd also strongly suspect that by the time a civilization got to the point of having the ability to build a Dyson sphere, they'd have a better way of getting the power than using a star, if they really needed it (I have no idea how, but they are a super-advanced civilization).

Maybe I'm wrong, but it can't hurt to look.

Matías Suazo et al, Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae1186

https://phys.org/news/2024-05-dyson-spheres-astronomers-potential-c...

Part 4

By  Simon Goodwin

Scientists report unified framework for diverse aurorae across planets

The awe-inspiring aurorae seen on Earth, known as the Northern and Southern Lights, have been a source of fascination for centuries. Between May 10 and 12, 2024, the most powerful aurora event in 21 years reminded us of the stunning beauty of these celestial light shows.

Recently, space physicists have published a paper in Nature Astronomy that explores the fundamental laws governing the diverse aurorae observed across planets, such as Earth, Jupiter and Saturn.

This work provides new insights into the interactions between planetary magnetic fields and solar wind, updating the textbook picture of giant planetary magnetospheres. Their findings can improve space weather forecasting, guide future planetary exploration, and inspire further comparative studies of magnetospheric environments.

Earth, Saturn and Jupiter all generate their own dipole-like magnetic field, resulting in funnel-canopy-shaped magnetic geometry that leads the space's energetic electrons to precipitate into polar regions and cause polar auroral emissions.

Yet the three planets differ in many aspects, including their magnetic strength, rotating speed, solar wind condition, moon activities, etc. It is unclear how these different conditions are related to the different auroral structures that have been observed on those planets for decades.

Using three-dimensional magnetohydrodynamics calculations, which model the coupled dynamics of electrically conducting fluids and electromagnetic fields, the research team assessed the relative importance of these conditions in controlling the main auroral morphology of a planet.

Combining solar wind conditions and planetary rotation, they defined a new parameter that controls the main auroral structure, which for the first time, nicely explains the different auroral structures observed at Earth, Saturn and Jupiter.

The aurorae at Earth and Jupiter are different. Yet, it is a big surprise that they can be explained by a unified framework.

By advancing our fundamental understanding of how planetary magnetic fields interact with the solar wind to drive auroral displays, this research has important practical applications for monitoring, predicting, and exploring the magnetic environments of the solar system.

This study also represents a significant milestone in understanding auroral patterns across planets that deepen our knowledge of diverse planetary space environments, paving the way for future research into the mesmerizing celestial light shows that continue to capture our imagination.

B. Zhang et al, A unified framework for global auroral morphologies of different planets, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02270-3

Part 2

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Debunking Fake Banana Hack Viral Videos

Debunking YouTube video myths and dis- and misinformation using bananas

Light therapy increases brain connectivity following injury, study finds

Low-level light therapy appears to affect healing in the brains of people who suffered significant brain injuries, according to a study published in Radiology.

Lights of different wavelengths have been studied for years for their wound-healing properties. Researchers at Massachusetts General Hospital (MGH) conducted low-level light therapy on 38 patients who had suffered moderate traumatic brain injury, an injury to the head serious enough to alter cognition and/or be visible on a brain scan. Patients received light therapy within 72 hours of their injuries through a helmet that emits near-infrared light.

The skull is quite transparent to near-infrared light. Once you put the helmet on, your whole brain is bathing in this light. 

The researchers used an imaging technique called functional MRI to gauge the effects of the light therapy. They focused on the brain's resting-state functional connectivity, the communication between brain regions that occurs when a person is at rest and not engaged in a specific task. The researchers compared MRI results during three recovery phases: the acute phase of within one week after injury, the subacute phase of two to three weeks post-injury and the late-subacute phase of three months after injury.

Of the 38 patients in the trial, 21 did not receive light therapy while wearing the helmet. This was done to serve as a control to minimize bias due to patient characteristics and to avoid potential placebo effects.

Patients who received low-level light therapy showed a greater change in resting-state connectivity in seven brain region pairs during the acute-to-subacute recovery phase compared to the control participants.

There was increased connectivity in those receiving light treatment, primarily within the first two weeks. Researchers were unable to detect differences in connectivity between the two treatment groups long term, so although the treatment appears to increase the brain connectivity initially, its long-term effects are still to be determined. 

The precise mechanism of the light therapy's effects on the brain is also still to be determined. Previous research points to the alteration of an enzyme in the cell's mitochondria (often referred to as the "powerhouse" of a cell). 

This leads to more production of adenosine triphosphate, a molecule that stores and transfers energy in the cells. Light therapy has also been linked with blood vessel dilation and anti-inflammatory effects.

"There is still a lot of work to be done to understand the exact physiological mechanism behind these effects, though.

While connectivity increased for the light therapy-treated patients during the acute to subacute phases, there was no evidence of a difference in clinical outcomes between the treated and control participants. Additional studies with larger cohorts of patients and correlative imaging beyond three months may help determine the therapeutic role of light in traumatic brain injury. 

Effects of Low-Level Light Therapy on Resting-State Connectivity Following Moderate Traumatic Brain Injury: Secondary Analyses of a Double-blinded, Placebo-controlled Study, Radiology (2024).

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Study demonstrates how cytokines produce long lasting humoral immunity following vaccination

A new study has shed new light on how cytokines, in particular interleukin 21(IL-21), shape long lasting humoral immunity following vaccination.

Published in Nature Communications, the study  elucidates how various immune responses impact the recruitment and maintenance of memory plasma cells in the bone marrow. These cells are crucial for secreting protective antibodies and sustaining humoral immunity throughout a lifetime.

Researchers revealed the heterogeneity of human bone marrow plasma cells (BMPCs) and their origins from various immune reactions.

By analyzing single-cell transcriptomes from individuals vaccinated against SARS-CoV-2 and the triple vaccine against diphtheria, tetanus, and pertussis (DTaP), the team uncovered distinct pathways through which plasma cells are recruited to the bone marrow.

The study categorizes BMPCs into different "clans" based on their transcriptional profiles, presuming that these cells reflect the specific signals they received during their activation in the tissue.

Understanding the mechanisms behind the recruitment and maintenance of plasma cells in the bone marrow is crucial for improving vaccine strategies and developing therapies for immune-related diseases, including chronic inflammatory diseases such as systemic lupus erythematosus.

Part 1

IL-21 plays a crucial role in the formation of bone marrow plasma cells. Cells formed in IL-21-dependent follicular germinal centers have low CD19 expression, while those from IL-21-independent extrafollicular reactions have high CD19 levels.

Primary immune responses produce both CD19low and CD19high BMPCs, but secondary responses mainly create CD19high cells from reactivated memory B cells in extrafollicular sites. This finding is important for understanding how long-term immunity is maintained and how previous immune responses can impact the effectiveness of future vaccinations.

The rapid extrafollicular immune responses in tissues, like the bone marrow itself, are especially crucial for responding to emerging variants quickly. This research could help optimize vaccination strategies for better long-term protection.

Marta Ferreira-Gomes et al, Recruitment of plasma cells from IL-21-dependent and IL-21-independent immune reactions to the bone marrow, Nature Communications (2024). DOI: 10.1038/s41467-024-48570-0

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Part 2

Green chemistry: Producing gold nano-particles (and hydrogen) in water without the need for toxic chemicals

In a surprise discovery, Flinders University nanotechnology researchers have produced a range of different types of gold nanoparticles by adjusting water flow in the novel vortex fluidic device—without the need for toxic chemicals. The article, "Nanogold Foundry Involving High-Shear-Mediated Photocontact Electri...," has been published in Small Science.

The green chemistry lab work on nano gold formation also led to the discovery of a contact electrification reaction in water in the device—which resulted in the generation of hydrogen and hydrogen peroxide.

In their study scientists collaborated on the developing size and form of gold nanoparticles from various VFD processing parameters and concentrations of gold chloride solution.

Through this research, they have discovered a new phenomenon in the vortex fluidic device. The photo-contact electrification process at the solid-liquid interface which could be used in other chemical and biological reactions.

They also have achieved synthesis of pure, pristine gold nanoparticles in water in the VFD, without the use of chemicals commonly used—and thus minimizing waste.

This method is significant for the formation of nanomaterials in general because it is a green process, quick, scalable and yields nanoparticles with new properties.

Gold nanoparticles' size and shape are critical for a range of applications—from drug delivery to catalysis, sensing and electronics—due to their physical, chemical and optical properties.

The vortex fluidic device, devised a decade ago is a rapidly rotating tube open at one end with liquids delivered through jet feeds. Different rotational speeds and external application of light in the device can be used to synthesize particles to specification.

Researchers around the world are now finding the continuous flow, thin film fluidic device useful in exploring and optimizing more sustainable nano-scale processing techniques.

In this latest experiment, the researchers hypothesize that the high shear regimes of the VFD led to the quantum mechanical effect known as contact electrification, which is another exciting development.

Badriah M. Alotaibi et al, Nanogold Foundry Involving High‐Shear‐Mediated Photocontact Electrification in Water, Small Science (2024). DOI: 10.1002/smsc.202300312

Biologists find nanoplastics in developing chicken heart

Nanoplastics can accumulate in developing hearts, according to a study published in Environment International by biologists. Research on chicken embryos sheds new light on how these tiny plastic particles pose a threat to our health.

Disposable cups, plastic bags and packaging material: Plastics exposed to the elements become brittle over time, and start shedding small particles from their surface into nature. These particles can be as tiny as only a few nanometers in size.

You can find these nanoplastics everywhere now: in the sea, in the soil, in the food chain… and in our blood.   They have even been found in human placentas.

This made scientists think: What happens when those nanoplastics end up in the blood of the embryo?

During an earlier study, investigators discovered that a high concentration of nanoplastics can cause malformations in the heart, eyes, and nervous systems of chicken embryos. But for a more complete understanding of the toxicity of nanoplastics, they first need more information about how they spread from the blood throughout the rest of the body.

That knowledge will also be informative in nanomedicine, where scientists aim to use nanoplastics (and other nanoparticles) as vehicles for drug-delivery.

Researchers administered polystyrene nanoparticles directly into the bloodstream of chicken embryos. Chicken embryos are a widely used model for research on growth and development. In mammals, it's much more challenging to administer substances or take measurements because their embryos develop inside the mother's womb.

Part 1

Because nanoparticles are so small, it's impossible to see them using conventional microscopes. Therefore, the researchers tagged the nanoparticles with either fluorescence or europium, a rare metal that is not naturally present in the human body.

They  found that the nanoplastics can cross blood vessel walls, and that they accumulated to relatively high levels in the heart, liver and kidneys. Some nanoplastics were excreted by the kidneys.

Interestingly, the researchers also found nanoplastics in the avascular heart cushions: a type of heart tissue without blood vessels. They think the nanoplastics might enter the heart through the fenestrate. These are small openings within the developing heart tissue that play a role in the formation and remodeling of the heart's structure during development. These fenestrations are temporary structures that typically close as the heart matures.

Now we know how these nanoplastics spread, we can start investigating the health risks.

There is already research linking nanoparticles to a higher risk of heart attacks and strokes. Especially during the developmental stage, nanoparticles could potentially be quite dangerous.

We now understand that we shouldn't administer nanomedicines to pregnant women indiscriminately, as there is a risk that nanoparticles could reach and affect the developing organs of their babies.

Meiru Wang et al, The biodistribution of polystyrene nanoparticles administered intravenously in the chicken embryo, Environment International (2024). DOI: 10.1016/j.envint.2024.108723

Part 2

Study suggests 'biodegradable' teabags don't readily deteriorate in the environment

Some teabags manufactured using plastic alternatives do not degrade in soil and have the potential to harm terrestrial species, a new study has shown.

The research looked at commonly available teabags made using three different compositions of polylactic acid (PLA), which is derived from sources such as corn starch or sugar cane.

The teabags were buried in soil for seven months, and a range of techniques were then used to assess whether—and to what extent—they had deteriorated.

The results showed that teabags made solely from PLA remained completely intact. However, the two types of teabags made from a combination of cellulose and PLA broke down into smaller pieces, losing between 60% and 80% of their overall mass and with the PLA component remaining.

The study also examined the impacts of the disks cut from the teabags on a species of earthworm, Eisenia fetida, which has a critical role in soil nutrient turnover as it consumes organic matter.

Researchers found that being exposed to three different concentrations of teabag disks—equivalent to the mass of half, one and two teabags—resulted in up to 15% greater mortality, while some concentrations of PLA had a detrimental effect on earthworm reproduction.

Writing in the journal Science of the Total Environment, the study's authors highlight the need for accurate disposal information to be clearly displayed on product packaging.

Only one of the manufacturers whose products were chosen for the study indicated on the packaging that the teabags were not home compostable.

This could lead to them ending up in soil, while there is also high potential for consumer confusion about the meaning of terms such as plant-based or biodegradable, emphasizing the need for clear guidance on appropriate disposal.

W. Courtene-Jones et al, Deterioration of bio-based polylactic acid plastic teabags under environmental conditions and their associated effects on earthworms, Science of The Total Environment (2024). DOI: 10.1016/j.scitotenv.2024.172806

What causes landslides? 

Landslides happen when the pull from gravity exceeds the strength of the geomaterial forming the slope of a hill or mountain. Geomaterials can be as varied as rocks, sand, silt and clays.

Then, part of this slope starts sliding downhill. Depending on where the slope fails, the material sliding down can be just a few cubic meters or a few million cubic meters in volume.

Why do slopes fail? Most natural landslides are triggered by earthquakes or rainfall, or a combination of both.

Earthquakes shake the ground, stress it and weaken it over time. Rainwater can seep through the ground and soak it—the ground is often porous like a sponge—and add weight to the slope. This is why PNG is so prone to landslides, as it sits on an active fault and is subjected to heavy rainfalls.

Another adverse effect of water is erosion: the constant action of waves undercuts coastal slopes, causing them to fail. Groundwater can also dissolve rocks within slopes.

Humans can (and do) cause landslides in several ways, too. For example, deforestation has a negative impact on slope stability, as tree roots naturally reinforce the ground and drain water out. Also, mine blasts produce small earthquake-like ground vibrations that shake slopes nearby.

It's very difficult to predict and mitigate landslide risk effectively.

Part 1

So what would it take to warn people of a coming landslide? You would need a prediction for earthquakes and rainfall, in addition to a perfect knowledge of the slope-forming geomaterial.

Under our feet, geomaterials may include multiple, entangled layers of various kinds of rocks and particulate materials, such as sand, silt and clays. Their strength varies from a factor of one to 1,000, and their spatial distribution dictates where the slope is likely to fail.

To accurately assess the stability of the slope, a three-dimensional mapping of these materials and their strengths is needed. No sensor can provide this information, so geologists and geotechnical engineers must deal with partial information obtained at a few selected locations and extrapolate this data to the rest of the slope.

The weakest link of the chain—such as an existing fracture in a rock mass—is easily missed. This is an inevitable source of uncertainty when trying to predict how much material might slip. We do know that the larger the volume of a landslide, the farther its runout distance. But it's hard to gauge the exact size of a landslide, making predictions of runout distances and safe zones uncertain. The question of "when will a landslide will occur" is also uncertain. Mechanical analysis enables us to estimate the vulnerability of a slope in a particular scenario, including earthquake magnitude and distribution of groundwater. But predicting if and when these triggers will happen is as "easy" as predicting the weather and seismic activity—a difficult task. Unfortunately, all the money in the world can't buy accurate landslide predictions—especially in remote parts of the world.

https://theconversation.com/what-causes-landslides-can-we-predict-t...

Part 2

The death of Vulcan: Study reveals planet is actually an astronomical illusion caused by stellar activity

A planet thought to orbit the star 40 Eridani A—host to Mr. Spock's fictional home planet, Vulcan, in the "Star Trek" universe—is really a kind of astronomical illusion caused by the pulses and jitters of the star itself, a new study shows.

A science team led by astronomer Abigail Burrows of Dartmouth College, and previously of NASA's Jet Propulsion Laboratory, has published a paper describing the new result, titled "The death of Vulcan: NEID reveals the planet candidate orbiting HD 26965 is stellar activity," in The Astronomical Journal. (Note: HD 26965 is an alternate designation for the star 40 Eridani A.)

The possible detection of a planet orbiting a star that Star Trek made famous drew excitement and plenty of attention when it was announced in 2018. Only five years later, the planet appeared to be on shaky ground when other researchers questioned whether it was there at all.

Now, precision measurements using a NASA-NSF instrument, installed a few years ago atop Kitt Peak in Arizona, seem to have returned the planet Vulcan even more definitively to the realm of science fiction.

Two methods for detecting exoplanets—planets orbiting other stars—dominate all others in the continuing search for strange new worlds. The transit method, watching for the tiny dip in starlight as a planet crosses the face of its star, is responsible for the vast majority of detections. But the "radial velocity" method also has racked up a healthy share of exoplanet discoveries.

This method is especially important for systems with planets that don't, from Earth's point of view, cross the faces of their stars. By tracking subtle shifts in starlight, scientists can measure "wobbles" in the star itself, as the gravity of an orbiting planet tugs it one way, then another. For very large planets, the radial velocity signal mostly leads to unambiguous planet detections. But not-so-large planets can be problematic.

Part 1

Even the scientists who made the original, possible detection of planet HD 26965 b—almost immediately compared to the fictional Vulcan—cautioned that it could turn out to be messy stellar jitters masquerading as a planet. They reported evidence of a "super-Earth"—larger than Earth, smaller than Neptune—in a 42-day orbit around a sun-like star about 16 light-years away. The new analysis, using high-precision radial velocity measurements not yet available in 2018, confirms that caution about the possible discovery was justified.

The bad news for "Star Trek" fans comes from an instrument known as NEID, a recent addition to the complex of telescopes at Kitt Peak National Observatory. NEID, like other radial velocity instruments, relies on the Doppler effect: shifts in the light spectrum of a star that reveal its wobbling motions. In this case, parsing out the supposed planet signal at various wavelengths of light, emitted from different levels of the star's outer shell (photosphere), revealed significant differences between individual wavelength measurements—their Doppler shifts—and the total signal when they were all combined.

That means, in all likelihood, that the planet signal is really the flickering of something on the star's surface that coincides with a 42-day rotation—perhaps the roiling of hotter and cooler layers beneath the star's surface, called convection, combined with stellar surface features such as spots and "plages," which are bright, active regions. Both can alter a star's radial velocity signals.

The demonstration of such finely tuned radial velocity measurements holds out the promise of making sharper observational distinctions between actual planets and the shakes and rattles on surfaces of distant stars.

Abigail Burrows et al, The Death of Vulcan: NEID Reveals That the Planet Candidate Orbiting HD 26965 Is Stellar Activity*, The Astronomical Journal (2024). DOI: 10.3847/1538-3881/ad34d5

Part 2

The digital touchscreens of the future could let you 'feel' items through your phone

New molecule found to suppress bacterial antibiotic resistance evolution

Researchers have developed a new small molecule that can suppress the evolution of antibiotic resistance in bacteria and make resistant bacteria more susceptible to antibiotics. The paper, "Development of an inhibitor of the mutagenic SOS response that suppresses the evolution of quinolone antibiotic resistance," has been published in the journal Chemical Science.

The global rise in antibiotic-resistant bacteria is one of the top global public health and development threats, with many common infections becoming increasingly difficult to treat. It is estimated that drug-resistant bacteria are already directly responsible for around 1.27 million global deaths each year and contribute to a further 4.95 million deaths. Without the rapid development of new antibiotics and antimicrobials, this figure is set to rise significantly.

A new study led by researchers at the Ineos Oxford Institute for antimicrobial research (IOI) and the Department of Pharmacology at Oxford University offers hope in the discovery of a small molecule that works alongside antibiotics to suppress the evolution of drug-resistance in bacteria.

One of the ways that bacteria become resistant to antibiotics is due to new mutations in their genetic code. Some antibiotics (such as fluoroquinolones) work by damaging bacterial DNA, causing the cells to die. However, this DNA damage can trigger a process known as the "SOS response" in the affected bacteria.

The SOS response repairs the damaged DNA in bacteria and increases the rate of genetic mutations, which can accelerate the development of resistance to the antibiotics. In the new study, the Oxford scientists identified a molecule capable of suppressing the SOS response, ultimately increasing the effectiveness of antibiotics against these bacteria.

The researchers studied a series of molecules previously reported to increase the sensitivity of methicillin-resistant Staphylococcus aureus (MRSA) to antibiotics, and to prevent the MRSA SOS response. MRSA is a type of bacteria that usually lives harmlessly on the skin. But if it gets inside the body, it can cause a serious infection that needs immediate treatment with antibiotics. MRSA is resistant to all beta-lactam antibiotics such as penicillins and cephalosporins.

Researchers modified the structure of different parts of the molecule and tested their action against MRSA when given with ciprofloxacin, a fluoroquinolone antibiotic. This identified the most potent SOS inhibitor molecule reported to-date, called OXF-077. When combined with a range of antibiotics from different classes, OXF-077 made these more effective in preventing the visible growth of MRSA bacteria.

Part 1

In a key result, the team then tested the susceptibility of bacteria treated with ciprofloxacin over a series of days to determine how quickly resistance to the antibiotic was developing, either with or without OXF-077. They found that the emergence of resistance to ciprofloxacin was significantly suppressed in bacteria treated with OXF-077, compared to those not treated with OXF-077.

This is the first study to demonstrate that an inhibitor of the SOS response can suppress the evolution of antibiotic resistance in bacteria. Moreover, when resistant bacteria previously exposed to ciprofloxacin were treated with OXF-077, it restored their sensitivity to the antibiotic to the same level as bacteria that had not developed resistance.

 Jacob D. Bradbury et al, Development of an inhibitor of the mutagenic SOS response that suppresses the evolution of quinolone antibiotic resistance, Chemical Science (2024). DOI: 10.1039/D4SC00995A

Part 2

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Debunking "Healthy" TikTok DESSERTS

This (Edible) Mushroom Could Kill You

Chocolate's tasty flavors might pose a health risk in other desserts

What makes chocolate taste and smell so delicious? Chemistry, of course. A variety of molecules work together to create that unmistakable aroma, but those same molecules might carry some unwanted health effects if there are too many around. According to research published in Journal of Agricultural and Food Chemistry, while many of the compounds appeared in chocolate in low enough concentrations to be safe, higher amounts were found in some baked sweet treats.

When making chocolate, cocoa beans are roasted to help their chocolatey flavors shine. During this process, new molecules like α,β-unsaturated carbonyls are formed when they react with other ingredients under high temperatures. This class of carbonyls is highly reactive and potentially genotoxic, or able to cause damage to DNA when consumed.

Though naturally found in many foods, these carbonyls are also used as flavoring additives, and some have been banned in some countries, including the buttery-tasting furan-2(5H)-one. To better understand how these molecules form naturally in foods, and whether or not they are present in levels that could pose a health concern, researchers tested chocolates and other sweet treats for 10 different α,β-unsaturated carbonyls—some of which have been confirmed as safe by the European Food Safety Authority, while others are still under evaluation.

The team created its own chocolates and found that α,β-unsaturated carbonyls formed during roasting and after the addition of cocoa butter; however, their concentrations remained too low to pose any health concerns from consuming the chocolates.

Next, researchers screened 22 commercially available desserts, including crepes, waffles, cakes and biscuits, either with or without chocolate. In these packaged treats, they found even lower concentrations of nine of the 10 carbonyls compared to the chocolates.

The remaining carbonyl—genotoxic furan-2(5H)-one—appeared in much higher concentrations in the crepe and cake samples, reaching up to 4.3 milligrams per kilogram. Considering that the recommended threshold for genotoxic substances is only 0.15 micrograms per person per day, consuming these desserts could exceed that limit, though additional studies are needed to accurately assess the potential health risk.

Researchers concluded that the furan-2(5H)-one molecule likely formed during the baking process and did not seem to correlate with the amount of chocolate present in the packaged desserts. The team says that this work helps to better understand where these carbonyls come from in chocolate and highlights the importance of monitoring flavorings in food to keep consumers informed and safe.

Occurrence and Synthesis Pathways of (Suspected) Genotoxic α,β-Unsaturated Carbonyls in Chocolate and Other Commercial Sweet Snacks, Journal of Agricultural and Food Chemistry (2024). DOI: 10.1021/acs.jafc.4c01043 , pubs.acs.org/doi/abs/10.1021/acs.jafc.4c01043

More rogue planets discovered
The Euclid space telescope has discovered seven more rogue planets, shining a light on the dark and lonely worlds floating freely through the universe untethered to any star.

The Euclid study also offered clues to how rogue planets are created: Some could be formed in the outer part of a solar system before getting detached from their star and floating away.

But the study indicates that many rogue planets may be created as a "natural byproduct" of the star-formation process. This suggests a "really close connection between stars and planets and how they form".

Without being bound to a star, as the Earth is to the sun, there are no days or years on these planets, which languish in perpetual night. Yet scientists think there is a chance they could be able to host life—and estimate there may be trillions dotted throughout the Milky Way.

Last week the European Space Agency released the Euclid telescope's first scientific results since the mission launched in July.

Among the discoveries were seven new free-floating planets, gas giants at least four times the mass of Jupiter.

They were spotted in the Orion Nebula, the nearest star-forming region to Earth, roughly 1,500 light years away.

Euclid also confirmed the existence of dozens of other previously detected rogue planets. This is likely to be just the tip of the iceberg.

Because they do not reflect the light of a star, spotting rogue planets is like "finding a needle in a haystack".

Younger planets, such as those discovered by Euclid, are hotter, making them a little easier to see.

Some research has suggested there are around 20 rogue planets for every star, which could put their number in the trillions in our home galaxy alone.

Given there are thought to be hundreds of billions of galaxies across the universe, the potential number of free-floating worlds becomes difficult to fathom.

When NASA's Roman space telescope launches in 2027 it is expected to find many more rogue planets, possibly offering clarity about how many could be out there.

But not all rogue planets wander alone. Four of the more than 20 confirmed by Euclid are believed to be binaries—two planets orbiting each other in a single system.

If rogue planets are habitable, they could be a key target in humanity's search for extraterrestrial life.

Lacking heat from a nearby star, free-floating planets are believed to be cold, with frozen surfaces.

That means any life-supporting energy would have to come from inside the planet.

And geothermal vents allow animals to survive on Earth that have never seen the sun's rays.

But even under the best conditions, this extreme isolation would likely be able to support only bacterial and microbial life.

Advantages of being a rogue planet: Rogue planets could be thought of as traversing a lonely path through the cosmos.

But "being around a star has its downsides".

Once the sun becomes a red giant—in an estimated 7.6 billion years—it will greatly expand, swallowing the Earth.

Rogue planets do not have to worry about eventually being destroyed by a star. "These things will last forever". ( Maybe if they don't go near any other star or planet or anybody that can influence its path and structure).

"If you don't mind the cold temperatures you could survive on these planets for eternity."

The study published ‘s on arXiv.org e-Print archive Friday.

https://arxiv.org/abs/2405.13497

Is a train's risk of derailment affected by its length?

Longer freight trains are more likely to derail compared with shorter trains, according to new research published in Risk Analysis. The increased risk held even after accounting for the need for fewer trains if more cars were on each train.

For the study, investigators assessed information on US freight train accidents between 2013–2022 from Federal Railroad Administration databases. The team found that running 100-car trains would lead to an 11% higher risk of derailment compared with running 50-car trains, even when accounting for the fact that only half as many 100-car trains would need to run. For 200-car trains, the risk was 24% higher than for 50-car trains.

he Relationship between Freight Train Length and the Risk of Derailment, Risk Analysis (2024). DOI: 10.1111/risa.14312

The eye is one of a few sites in the body with something called immune privilege. That special status makes the eye an ideal environment for researching certain therapies for treating vision loss.

The body’s immune system—made up of organs, tissues and cells—works to protect us from infection and disease. When a virus or other foreign substance is detected, the immune system kicks in. It makes molecules called antibodies to attack these invading substances known as antigens. This natural defense system is called an inflammatory response, and results in swelling of tissue and a higher-than-normal temperature.

While an inflammatory response can help fight off infection or disease, it can also cause problems. For example, if someone has a donated organ transplanted in their body, their immune system may recognize the organ as foreign tissue and mount an inflammatory response. This can cause the transplant to fail.

Interestingly, certain areas of the body have something called immune privilege. This means that the body’s normal inflammatory immune response is limited here. Scientists think the purpose of immune privilege is to protect these important areas from damage that may occur with swelling and higher temperatures from the immune response. The eye is one of a few areas of the body with immune privilege. The eye limits its inflammatory immune response so that vision isn’t harmed by swelling and other tissue changes. Other sites with immune privilege include the brain, testes, placenta and fetus.

Because of this immune privilege, the eye offers an excellent location for certain kinds of research and therapy. For example, scientists can implant types of cells called stem cells in the eye to study their role in regrowing or repairing damaged tissue. Cells implanted in the immune-privileged eye are less likely to be rejected than they might be in other parts of the body. Studies of stem cell use in the eye have shown promise in treating vision loss.

Another reason the eye is a good place for researching new therapies? It is relatively easy to reach and see inside of the structure. That makes implanting cells in the eye much easier than other areas of the body.

Source: https://www.aao.org/eye-health/tips-prevention/eye-immune-privilege

The ocular immune system protects the eye from infection and regulates healing processes following injuries. The interior of the eye lacks lymph vessels but is highly vascularized, and many immune cells reside in the uvea, including mostly macrophages, dendritic cells, and mast cells.[1] These cells fight off intraocular infections, and intraocular inflammation can manifest as uveitis (including iritis) or retinitis. The cornea of the eye is immunologically a very special tissue. Its constant exposure to the exterior world means that it is vulnerable to a wide range of microorganisms while its moist mucosal surface makes the cornea particularly susceptible to attack. At the same time, its lack of vasculature and relative immune separation from the rest of the body makes immune defense difficult. Lastly, the cornea is a multifunctional tissue. It provides a large part of the eye's refractive power, meaning it has to maintain remarkable transparency, but must also serve as a barrier to keep pathogens from reaching the rest of the eye, similar to function of the dermis and epidermis in keeping underlying tissues protected. Immune reactions within the cornea come from surrounding vascularized tissues as well as innate immune responsive cells that reside within the cornea.

https://en.wikipedia.org/wiki/Ocular_immune_system

Astronomers find most distant galaxy using James Webb Space Telescope

An international team of astronomers recently announced the discovery of the two earliest and most distant galaxies ever seen, dating back to only 300 million years after the Big Bang. These results, using NASA's James Webb Space Telescope (JWST), mark a major milestone in the study of the early universe.

The discoveries were made by the JWST Advanced Deep Extragalactic Survey (JADES) team. 

Because of the expansion of the universe, the light from distant galaxies stretches to longer wavelengths as it travels. This effect is so extreme for these two galaxies that their ultraviolet light is shifted to infrared wavelengths where only JWST can see it. Because light takes time to travel, more distant galaxies are also seen as they were earlier in time.

The two record-breaking galaxies are called JADES-GS-z14-0 and JADES-GS-z14-1, the former being the more distant of the two. In addition to being the new distance record holder, JADES-GS-z14-0 is remarkable for how big and bright it is.

The size of the galaxy clearly proves that most of the light is being produced by large numbers of young stars, rather than material falling onto a supermassive blackhole in the galaxy's center, which would appear much smaller.

The combination of the extreme brightness and the fact that young stars are fueling this high luminosity makes JADES-GS-z14-0 the most striking evidence yet found for the rapid formation of large, massive galaxies in the early universe. It is stunning that the universe can make such a galaxy in only 300 million years.

The galaxy is located in a field where the JWST Mid-Infrared Instrument had conducted an ultra-deep observation. Its brightness at intermediate infrared wavelengths is a sign of emission from hydrogen and even oxygen atoms in the early universe. Despite being so young, the galaxy is already hard at work creating the elements familiar to us on Earth.

This amazing object shows that galaxy formation in the early universe is very rapid and intense.

A shining cosmic dawn: spectroscopic confirmation of two luminous galaxies at z∼14, arXiv:2405.18485 [astro-ph.GA] arxiv.org/abs/2405.18485

JWST/MIRI photometric detection at 7.7 μm of the stellar continuum and nebular emission in a galaxy at z>14, arXiv:2405.18462 [astro-ph.GA] arxiv.org/abs/2405.18462

Brant Robertson et al, Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic Star-Formation Rate Density 300 Myr after the Big Bang, arXiv (2023). DOI: 10.48550/arxiv.2312.10033

Study results indicate that pitavastatin inhibits interleukin-33 to suppress skin and pancreatic cancers

A new study led by investigators from Mass General Cancer Center reveals that statins—commonly used cholesterol-lowering drugs—may block a particular pathway involved in the development of cancer that results from chronic inflammation. The findings are published in Nature Communications.

Chronic inflammation is a major cause of cancer worldwide.

Researchers investigated the mechanism by which environmental toxins drive the initiation of cancer-prone chronic inflammation in the skin and pancreas.

They also examined safe and effective therapies to block this pathway in order to suppress chronic inflammation and its cancer aftermath.

The researchers study relied on cell lines, animal models, human tissue samples and epidemiological data. The group's cell-based experiments demonstrated that environmental toxins (such as exposure to allergens and chemical irritants) activate two connected signaling pathways called the TLR3/4 and TBK1-IRF3 pathways. This activation leads to the production of the interleukin-33 (IL-33) protein, which stimulates inflammation in the skin and pancreas that can contribute to the development of cancer.

When they screened a library of U.S. Food and Drug Administration–approved drugs, the researchers found that a statin, pitavastatin, effectively suppresses IL-33 expression by blocking the activation of the TBK1-IRF3 signaling pathway. In mice, pitavastatin suppressed environmentally-induced inflammation in the skin and the pancreas and prevented the development of inflammation-related pancreatic cancers.

In human pancreas tissue samples, IL-33 was over-expressed in samples from patients with chronic pancreatitis (inflammation) and pancreatic cancer compared with normal pancreatic tissue. Also, in analyses of electronic health records data on more than 200 million people across North America and Europe, use of pitavastatin was linked to a significantly reduced risk of chronic pancreatitis and pancreatic cancer.

The findings demonstrate that blocking IL-33 production with pitavastatin may be a safe and effective preventive strategy to suppress chronic inflammation and the subsequent development of certain cancers.

Park JH et al. Statin prevents cancer development in chronic inflammation by blocking interleukin 33 expression, Nature Communications (2024). DOI: 10.1038/s41467-024-48441-8

Antibiotic pollution disrupts the gut microbiome and blocks memory in aquatic snails, study finds

Antibiotics prevent snails from forming new memories by disrupting their gut microbiome—the community of beneficial bacteria found in their guts.

The new research highlights the damaging effects that human pollution could be having on aquatic wildlife.

In the study published in The ISME Journal, pond snails were given a favorite food—carrot juice—but had to quickly learn and remember that it was no longer safe to eat.

Snails in clean water did well, avoiding feeding on the carrot juice when it had been paired with a chemical they dislike. However, snails that had been exposed to high concentrations of antibiotics in the water failed to learn and form a memory, and continued to show normal feeding behavior even after training.

It's well known that a healthy gut microbiome is important to human health, and this  study is the first to show this is also the case in snails and other animals.

The researchers found the antibiotics altered the gut microbiome substantially and changed the abundance of bacteria that have been found to relate to healthy memory formation in other animals, including humans. This relationship between the bacteria found in the gut and brain function is called the microbiome-gut-brain axis. Chemicals produced by good gut bacteria when breaking down food can improve brain health and cognitive function.

Reducing the abundance of these healthy bacteria in the gut blocks the gut microbiome's otherwise beneficial effects on the brain.

Previous studies on the link between the gut microbiome and brain function have focused on terrestrial species. However, aquatic wildlife is more likely to be directly affected by antibiotic exposure in the environment.

Antibiotics are not removed effectively by waste treatment, and so they enter the freshwater environment. The antibiotic concentrations snails were exposed to in this new experiment were detected at similar levels in freshwater in the UK, Europe and globally.

Gabrielle Davidson et al, Antibiotic-altered gut microbiota explain host memory plasticity and disrupt pace-of-life trait covariation for an aquatic snail, The ISME Journal (2024). DOI: 10.1093/ismejo/wrae078

Reduced sulfur content in shipping fuel associated with increased maritime atmospheric warming

An 80% reduction in sulfur dioxide shipping emissions observed in early 2020 could be associated with substantial atmospheric warming over some ocean regions, according to a modeling study published in Communications Earth & Environment. The sudden decline in emissions was a result of the introduction of the International Maritime Organization's 2020 regulation (IMO 2020), which reduced the maximum sulfur content allowed in shipping fuel from 3.5% to 0.5% to help reduce air pollution.

Fuel oil used for large ships has a significantly higher percentage content of sulfur than fuels used in other vehicles. Burning this fuel produces sulfur dioxide, which reacts with water vapor in the atmosphere to produce sulfate aerosols. These aerosols cool the Earth's surface in two ways: by directly reflecting sunlight back to space; and by affecting cloud cover.

Increasing the number of aerosols increases the number of water droplets that form while reducing their size, both increasing the cloud coverage and forming brighter clouds which reflect more sunlight back to space. Marine cloud brightening is a form of geoengineering where marine clouds are deliberately seeded with aerosols to achieve this effect.

Researchers  calculated the effect of IMO 2020 on the atmospheric levels of sulfate aerosols over the ocean and how this affected cloud composition. They found substantial reductions in both the levels of atmospheric aerosols and the cloud droplet number density.

The greatest modeled aerosol reductions were in the North Atlantic, the Caribbean Sea, and the South China Sea—the regions with the busiest shipping lanes. The authors then estimated the effect of IMO 2020 on Earth's energy budget (the difference between the energy received from the sun and the energy radiated from the Earth) since 2020. They calculated that the estimated effect is equivalent to 80% of the observed increase in the heat energy retained on Earth over that period.

The authors suggest that the substantial modeled effect of IMO 2020 on Earth's energy budget demonstrates the potential effectiveness of marine cloud brightening as a strategy to temporarily cool the climate. However, they also warn that the intended reduction in sulfur dioxide emissions due to IMO 2020 potentially causing an inadvertent increase in marine atmospheric temperature is an example of a geoengineering termination shock, which could affect regional weather patterns.

Tianle Yuan, Abrupt reduction in shipping emission as an inadvertent geoengineering termination shock produces substantial radiative warming, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01442-3. www.nature.com/articles/s43247-024-01442-3

How does the word 'not' affect what we understand? Scientists find negation mitigates our interpretation of phrases

When we're told "This coffee is hot" upon being served a familiar caffeinated beverage at our local diner or cafe, the message is clear. But what about when we're told "This coffee is not hot"? Does that mean we think it's cold? Or room temperature? Or just warm?

A team of scientists has now identified how our brains work to process phrases that include negation (i.e., "not"), revealing that it mitigates rather than inverts meaning—in other words, in our minds, negation merely reduces the temperature of our coffee and does not make it "cold."

We now have a firmer sense of how negation operates as we try to make sense of the phrases we process.

In identifying that negation serves as a mitigator of adjectives—bad or good, sad or happy, and cold or hot—we also have a better understanding of how the brain functions to interpret subtle changes in meaning.

In an array of communications, ranging from advertising to legal filings, negation is often used intentionally to mask a clear understanding of a phrase. In addition, large language models in AI tools have difficulty interpreting passages containing negation. The researchers say that their results show how humans process such phrases while also potentially pointing to ways to understand and improve AI functionality.

This research spotlights the complexity that goes into language comprehension, showing that this cognitive process goes above and beyond the sum of the processing of individual word meanings.

Find the full details of the experimental work here: Zuanazzi A, Ripollés P, Lin WM, Gwilliams L, King J-R, Poeppel D, Negation mitigates rather than inverts the neural representations of adjectives. PLoS Biology (2024). DOI: 10.1371/journal.pbio.3002622

Scientists create the thinnest lens on Earth, enabled by excitons

Lenses are used to bend and focus light. Normal lenses rely on their curved shape to achieve this effect, but physicists have made a flat lens of only three atoms thick that relies on quantum effects. This type of lens could be used in future augmented reality glasses.

Curved-glass lenses work because light is refracted (bent) when it enters the glass, and again when it exits, making things appear larger or closer than they actually are.

Using a single layer of a unique material called tungsten disulfide (WS₂ for short), researchers constructed a flat lens that is half a millimeter wide, but just 0.0000006 millimeters, or 0.6 nanometers, thick. This makes it the thinnest lens on Earth.

Rather than relying on a curved shape, the lens is made of concentric rings of WS₂ with gaps in between. This is called a "Fresnel lens" or "zone plate lens," and it focuses light using diffraction rather than refraction. The size of, and distance between the rings (compared to the wavelength of the light hitting it) determines the lens's focal length. The design used here focuses red light 1 mm from the lens.

A unique feature of this lens is that its focusing efficiency relies on quantum effects within WS2. These effects allow the material to efficiently absorb and re-emit light at specific wavelengths, giving the lens the built-in ability to work better for these wavelengths.
This quantum enhancement works as follows. First, WS2 absorbs light by sending an electron to a higher energy level. Due to the ultra-thin structure of the material, the negatively charged electron and the positively charged "hole" it leaves behind in the atomic lattice stay bound together by the electrostatic attraction between them, forming what is known as an "exciton."
These excitons quickly disappear again by the electron and hole merging together and sending out light. This re-emitted light contributes to the lens's efficiency.
The scientists detected a clear peak in lens efficiency for the specific wavelengths of light sent out by the excitons. While the effect is already observed at room temperature, the lenses are even more efficient when cooled down. This is because excitons do their work better at lower temperatures.

Ludovica Guarneri et al, Temperature-Dependent Excitonic Light Manipulation with Atomically Thin Optical Elements, Nano Letters (2024). DOI: 10.1021/acs.nanolett.4c00694

New method advances cancer detection by counting tiny blood-circulating particles

Researcher are reporting a new method to detect cancer which could make cancer detection as simple as taking a blood test. With a 98.7% accuracy rate, the method—which combines PANORAMA imaging with fluorescent imaging—has the potential to detect cancer at the earliest stage and improve treatment efficacy.

The remarkably precise method allows researchers to peer into nanometer-sized membrane sacs, called extracellular vesicles or EVs, that can carry different types of cargos, like proteins, nucleic acids and metabolites, in the bloodstream.

The researchers  observed differences in small EV numbers and cargo in samples taken from healthy people versus people with cancer and are able to differentiate these two populations based on their analysis of the small EVs. The findings came from combining two imaging methods—their previously developed method PANORAMA and imaging of fluorescence emitted by small EVs—to visualize and count small EVs, determine their size and analyze their cargo.

For this research it was a matter of counting the number of small EVs to detect cancer.

Using a cutoff of 70 normalized small EV counts, all cancer samples from 205 patients were above this threshold except for one sample, and for healthy samples, from 106 healthy individuals, all but three were above this cutoff, giving a cancer detection sensitivity of 99.5% and specificity of 97.3%.

To further test the performance of the detection threshold of 70 normalized small EV counts in plasma, the team analyzed two independent sets of samples from stage I-IV or recurrent leiomyosarcoma/gastrointestinal stromal tumors and early-and-late-stage cholangiocarcinoma that were anonymously labeled and mixed in with healthy samples and achieved 100% accuracy.

Nareg Ohannesian et al, Plasmonic nano-aperture label-free imaging of single small extracellular vesicles for cancer detection, Communications Medicine (2024). DOI: 10.1038/s43856-024-00514-x

‘Smart’ antibiotic can kill deadly bacteria while sparing the microbiome

We need our microbiome. But if we take antibiotics, they will disrupt it. 

Scientists have developed an antibiotic that kills pathogenic Gram-negative bacteria — even those resistant to many other drugs — without impairing the gut microbiome. So far, it has been studied only in mice, but if the compound works in humans, “it could help us dramatically".
However, there is a caveat: the compound’s usefulness “depends on whether bacteria will develop resistance to it in the long run”.
To find a way around the bacteria’s defences, the study’s authors started with compounds that don’t kill the bacteria but are known to inhibit the ‘Lol system’, a group of proteins that is exclusive to Gram-negative bacteria. Tinkering with those compounds produced one that the researchers called lolamicin, which “selectively kills pathogenic bacteria over non-pathogenic bacteria based on differences in Lol proteins between these bacteria.
Lolamicin had anti-microbial effects against more than 130 multidrug-resistant strains of bacteria growing in laboratory dishes.
Mice that developed blood stream infections after exposure to antibiotic-resistant bacteria all survived after being given lolamicin, whereas 87% of those that didn’t receive the compound died within three days.

https://www.nature.com/articles/d41586-024-01566-8?utm_source=Live+...

This tiny fern has the largest genome of any organism on Earth

In a new study published in the journal iScience, researchers  presented a new record-holder for the largest amount of DNA stored in the nucleus of any living organism on the planet.

Coming in at more than 100 meters of unraveled DNA, the New Caledonian fork fern species Tmesipteris oblanceolata was found to contain more than 50 times more DNA than humans and has dethroned the Japanese flowering plant species Paris japonica, which has held this record since 2010.

In addition, the plant has achieved three Guinness World Records titles for Largest plant genome, Largest Genome, and Largest fern genome for the amount of DNA in the nucleus.

T. oblanceolata is a rare species of fern found on the island nation of New Caledonia, an overseas French territory situated in the Southwest Pacific, about 750 miles east of Australia, and some of the neighboring islands such as Vanuatu. The genus Tmesipteris is an understudied group of plants consisting of about 15 species, most of which occur across a range of Pacific Islands and Oceania.

Until now, scientists have only estimated the size of the genomes for two species of Tmesipteris—T. tannensis and T. obliqua—both of which were found to contain gigantic genomes, at 73.19 and 147.29 gigabase pairs (Gbp) respectively.

The analysis revealed the species T. oblanceolata to have a record-breaking genome size of 160.45 Gbp, which is about 7% larger than that of P. japonica (148.89 Gbp).

Tmesipteris is a unique and fascinating small genus of ferns, whose ancestors evolved about 350 million years ago—well before dinosaurs set foot on Earth—and it is distinguished by its mainly epiphytic habit [it grows mainly on the trunks and branches of trees] and restricted distribution in Oceania and several Pacific Islands.

 Oriane Hidalgo and Jaume Pellicer et al, A 160 Gbp fork fern genome shatters size record for eukaryotes. iScience (2024). DOI: 10.1016/j.isci.2024.109889

Dark matter could make our galaxy's innermost stars immortal

Stars near the center of our galaxy are acting kind of weird. Dark matter may be the explanation.

A team of scientists have discovered a potential new class of stars that could exist within a light-year of the Milky Way's center that could be operating according to an unusual mechanism: dark matter annihilation. This process would produce an outward pressure on the stars other than hydrogen fusion, keeping them from gravitationally collapsing—and making them essentially immortal, their youth being refreshed constantly. The findings are published  on the arXiv preprint server.

Collectively, the dark matter–powered stars would inhabit a new region of a long-established diagram that classifies stars by their temperature and luminosity, placing them away from the so-called main sequence where the vast majority of stars exist.

Observing our Galactic Center, around which the galaxy's stars rotate, is quite difficult, as the region is extremely bright. A supermassive black hole, Sagittarius A*, sits at the center, with a mass four million times that of the sun. It is a bright source of radio waves, and was imaged in 2022. Stars near Sgr A* orbit it at speeds of several thousands of kilometers per second (compared to the sun's orbital speed of 240 km/s).
These close inner stars, called S-cluster stars, are very puzzling, with properties unlike any others in the Milky Way. Their provenance is unknown, since the environment within about three light-years of the center is considered hostile to star formation. They appear to be much younger than would be expected if they had moved inward from someplace else. Most mysterious of all, they look unusually young, with fewer older stars in the neighborhood than expected, and also unexpectedly, there seem to be many heavy stars.
Part 1

Stars are nuclear ovens, generating heat burning hydrogen via nuclear fusion. The thermal radiation from this reaction, as well as thermodynamic convection of the stellar plasma, exerts an outward force on a star's constituents—mostly hydrogen and helium. That force is balanced by the inward force of self-gravity.

The Hertzsprung–Russell (HR) diagram classifies stars by plotting their luminosity against the effective temperature of their surface. Excluding white dwarfs and red giants, the "main sequence" of this diagram curves from its upper left to lower right, and most stars fall on this curve. (The sun falls near the middle, as their luminosities are plotted as their ratio with the sun's). Stars in different locations on the sequence correspond to stars of different masses and ages.

However, dark matter also exists in the galaxy. Its presence has been inferred by observations that find insufficient ordinary matter to account for the higher-than-expected rotational speeds of stars around the Galactic Center.

Dark matter's density is highest near the center and falls off with the distance from it. It's reasonable to expect it would be incorporated within stars near the center, where dark matter is densest. If so, dark matter annihilation—dark matter particles and antiparticles that collide and produce photons, electrons, etc.—would exert an additional outward pressure within a star and could even dominate over nuclear fusion.
A research team has found that incorporating dark matter power into the dynamics of the innermost stars—those within about a third of a light-year of the center (equivalent to about 8% of the distance to the sun's nearest star)—solves many of the known paradoxes.
To incorporate dark matter annihilation, the group used relatively standard star formation parameters over the evolutionary course of the Milky Way, and dark matter particles just slightly more massive than the proton. Using a stellar evolution computer model, they assumed that stars migrate on the main sequence towards the Galactic Center, then they began to inject dark matter energy into a star's composition. The star then evolved until it reached the red giant branch on the HR diagram, or until it reached an age of 10 billion years, the lifetime of the Milky Way.
Part 2

They calculated stellar populations without and with the presence of dark matter. With dark matter, more massive stars experienced a lower dark matter density, and hydrogen in their core fused more slowly and their evolution was slowed down. But stars in a higher dark matter density region were changed significantly—they maintained equilibrium through dark matter burning with less fusion or no fusion, which led to a new stellar population in an HR region above the main sequence.
The scientists' simulations show that stars can survive on dark matter as a fuel alone and because there is an extremely large amount of dark matter near the Galactic Center, these stars become immortal staying forever young, occupying a new, distinct, observable region of the HR diagram.
Their dark matter model may be able to explain more of the known mysteries. For lighter stars, scientists saw in their simulations that they become very puffy and might even lose parts of their outer layers something similar to this might be observed at the Galactic Center: the so-called G-objects, which might be star-like, but with a gas cloud around them.
There are a limited number of individual stars known to exist so close to the Galactic Center, as the region is extremely bright. Upcoming 30-meter telescopes will be able to see much better into the region, which will allow scientists to better understand the population of its stars and verify or rule out the dark main sequence.

Isabelle John et al, Dark Branches of Immortal Stars at the Galactic Center, arXiv (2024). DOI: 10.48550/arxiv.2405.12267

Part 3

**

Most powerful anti-fungal chemistries cause fungal pathogens to self-destruct

Scientists have discovered that the most widely-used class of antifungals in the world causes pathogens to self-destruct. The  research could help improve ways to protect food security and human lives.

Fungal diseases account for the loss of up to a quarter of the world's crops. They also pose a risk to humans and can be fatal for those with weakened immune systems.

Our strongest weapons against fungal plant diseases are azole fungicides. These chemical products account for up to a quarter of the world agricultural fungicide market, worth more than $3.8 billion per year. Antifungal azoles are also widely used as a treatment against pathogenic fungi which can be fatal to humans, which adds to their importance in our attempt to control fungal disease.

Azoles target enzymes in the pathogen cell that produce cholesterol-like molecules, named ergosterol. Ergosterol is an important component of cellular bio-membranes. Azoles deplete ergosterol, which results in killing of the pathogen cell. However, despite the importance of azoles, scientists know little about the actual cause of pathogen death.

In a new study published in Nature Communications,  scientists have uncovered the cellular mechanism by which azoles kill pathogenic fungi. The paper is titled "Azoles activate type I and type II programmed cell death pathways in crop pathogenic fungi." 

Part 1

The team of researchers combined live-cell imaging approaches and molecular genetics to understand why the inhibition of ergosterol synthesis results in cell death in the crop pathogenic fungus Zymoseptoria tritic (Z. tritici). This fungus causes septoria leaf blotch in wheat, a serious disease in temperate climates.
The team observed living Z. tritici cells, treated them with agricultural azoles and analyzed the cellular response. They showed that the previously-accepted idea that azoles kill the pathogen cell by causing perforation of the outer cell membrane does not apply. Instead, they found that azole-induced reduction of ergosterol increases the activity of cellular mitochondria, the "powerhouse" of the cell, required to produce the cellular fuel that drives all metabolic processes in the pathogen cell.
While producing more "fuel" is not harmful in itself, the process leads to the formation of more toxic by-products. These by-products initiate a "suicide" program in the pathogen cell, named apoptosis. In addition, reduced ergosterol levels also trigger a second "self-destruct" pathway, which causes the cell to eat its own nuclei and other vital organelles—a process known as macroautophagy. The authors show that both cell death pathways underpin the lethal activity of azoles. They conclude that azoles drive the fungal pathogen into "suicide" by initiating self-destruction.

The authors found the same mechanism azoles killing pathogen cells in the rice-blast fungus Magnaporthe oryzae

Azoles activate type I and type II programmed cell death pathways in crop pathogenic fungi, Nature Communications (2024). www.nature.com/articles/s41467-024-48157-9

Part 2

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A new way of healing wounds in diabetics fast

Wounds that are superficial for some can be life-threatening for others. With diabetic wounds, healing can be slow, particularly in the feet, increasing the tissue's susceptibility to infection. Foot ulcers and other diabetic foot complications have similar mortality rates to some cancers, yet progress toward improved treatments has plateaued. Now, researchers may have found a better way to kickstart the healing process.

B ioengineers have developed a multistep strategy that applies different nanomaterials to wounds at different times to support both early- and late-stage healing. In a study published in the journal Biomaterials, the authors' method outperformed a common wound dressing in a diabetic mouse model, closing wounds faster and producing more robust skin tissue.

Clinically, the standard practice for wounds is to keep them clean and use a dressing to protect them while they heal. This approach gets the job done for most injuries but falls short for patients with conditions that interfere with the healing process, such as diabetes. In addition to causing poor circulation and neuropathy, diabetes can disrupt wound healing by impairing the function of various immune cells.

The researchers' analysis also suggests that their approach unexpectedly activated an immune cell population not normally seen in wounds that can resolve inflammation, which highlights a new potential avenue to accelerate healing.

The researchers devised a strategy to treat wounds like these and compared it to a commonly used dressing in a diabetic mouse model.

For the first step, the team fabricated a silk nanomaterial dressing embedded with gold nanorods. Because gold nanoparticles readily convert light to heat, the team was able to direct a laser at dressings placed over fresh wounds in mice, producing heat that quickly sealed them in place and provided a high level of protection.

The strategy, which the authors previously found success with, creates something akin to an instantaneous scab.

This time around, the authors added histamine to the mix, a natural biochemical produced by the immune system that plays important roles in inflammation, blood vessel development, and allergic reactions.

Inflammation dominates the body's initial response to injuries, but eventually subsides to allow the body to rebuild. However, diabetic wounds can get stuck in first gear, maintaining persistent, low-grade inflammation, which can inhibit the healing process.

Since the wound is stalled, the researchers wanted to co-deliver histamine with the dressing, to give a push and bring the inflammation stage to a resolution.

Part 1

The authors monitored the wounded mice for 11 days and found that animals treated with a combination of the nanomaterial dressing and histamine healed at the fastest rate compared to those treated with the standard dressing with histamine or the nanomaterial dressing alone.

The researchers mechanically tested the healed skin as well, finding that the tissue treated with both the nanomaterial and histamine was strongest and most similar to unwounded skin.
For a better understanding, the team analyzed tissue samples by assessing gene expression and examining cells under the microscope.

They found that a specific immune cell type, N2 neutrophils, were highly prevalent in treated wounds up to seven days post-injury. As the first responders of the immune system, these cells usually clear out within a day or two, making their presence in the wound after a week highly unusual. But since they are known to produce histamine and other reparative molecules, it is also possible that these immune cells are the linchpin of the treatment.
The team injected the nanoparticles at various time points into the nanomaterial-dressed wound bed, finding that delivery on day six had the best outcomes with regards to wound closure and tissue strength. This time point corresponds to a transitionary phase in which cells begin proliferating and remodeling tissue.
With promising results in mice behind them, the authors are now testing their strategy in larger animal models more relevant to human health, such as pigs.

Deepanjan Ghosh et al, Bioactive nanomaterials kickstart early repair processes and potentiate temporally modulated healing of healthy and diabetic wounds, Biomaterials (2024). DOI: 10.1016/j.biomaterials.2024.122496

Part 2

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An outlandish molecule may be lurking inside Uranus and Neptune, affecting their magnetic fields

Scientists  have determined the conditions that enable the existence of a very peculiar ion. Dubbed aquodiium, it can be conceptualized as an ordinary neutral molecule of water with two additional protons stuck to it, resulting in a net double positive charge.

They  suggest that the ion could be stable in the interior of the ice giants Uranus and Neptune, and if so, it must play a part in the mechanism that gives rise to these planets' unusual magnetic fields. The study is published in Physical Review B

The magnetic fields of Uranus and Neptune are not understood quite as well as those of Jupiter and Saturn—or our own planet, for that matter.

In the Earth's interior, circulation of the electronically conductive liquid iron-nickel alloy produces magnetism. Deep inside Jupiter and Saturn, hydrogen is thought to be pressed into a metallic state and give rise to magnetic fields in much the same way.

By contrast, the magnetic fields of Uranus and Neptune are hypothesized to stem from the circulation of ionically conductive media, where the constituent ions are themselves charge carriers, rather than merely a support structure enabling the flow of electrons.

If planetary scientists knew exactly what ions and in which proportions are involved, perhaps they could figure out why the ice giants' magnetospheres are so quirky: misaligned with the direction of the planets' rotation and offset from their physical centers.

They explain how ionic and electronic conductivity are different and where the newly predicted ion fits into this: The hydrogen surrounding Jupiter's rocky core at those conditions is a liquid metal: It can flow, the way molten iron in the Earth's interior flows, and its electrical conductivity is due to the free electrons shared by all the hydrogen atoms pressed together.

In Uranus, they think that hydrogen ions themselves—i.e., protons—are the free charge carriers. Not necessarily as standalone H⁺ ions, but perhaps in the form of hydronium H₃O⁺, ammonium NH₄⁺, and a series of other ions. This new study adds one more possibility, the H₄O²⁺ ion, which is extremely interesting from the chemical viewpoint."

Part 1

In chemistry, there's the notion of sp3 hybridization, which refers to the way electron orbitals combine with each other and amounts to something like a natural template for making plausible molecules and ions. Under sp3 hybridization, the nucleus of an atom—e.g., carbon, nitrogen, or oxygen—occupies the center point of an imaginary tetrahedron.

Each of the four vertices hosts either a valence electron or two paired electrons that are not available for making bonds with other atoms. The simplest example would be a carbon atom with four unpaired electrons at the four vertices—add four hydrogen atoms and you get a methane molecule: CH4.

For an oxygen atom, which has two electron pairs of its own in the outermost shell, along with two valence electrons, sp3 hybridization would mean only two of the vertices could host a covalent bond with hydrogen, with the remaining two occupied by electron pairs, which yields H2O, water.

If you attach a hydrogen ion (a proton) to one of the electron pairs, you get a hydronium ion H3O+, and this is actually what you get in an acid solution, because acids donate protons H+ into the solution and lone protons are immediately drawn to electron pairs.
Part 2