Researchers overcome stem cell delivery barrier, paving the way for regenerative medicine

A recent study published in Nano Letters has introduced a new method for delivering particles into stem cells, which are notoriously difficult to penetrate. The discovery will make it easier to direct and enhance the processes involved in regenerative medicine.

Regenerative medicine takes advantage of the fact that our body's stem cells can change into many other cell types that are vital for the regeneration of tissue and organs, such as heart or nerve cells.

Each type of cell has specialized properties and functions, so harnessing the potential of stem cell development means that regenerative medicine offers some of the most promising treatments for many diseases. To control the type of cell the stem cells change into, scientists need to reprogram the cells' genes by inserting genetic information into the stem cell's nucleus.

However, stem cells have robust protection to stop anything from getting in, similar to our skin, so manipulating the differentiation of stem cells has been problematic.

The researchers have been working to overcome this using rat stem cells and have created a way to bypass the cells' protective barrier.

As we age, the number of stem cells in our body decreases dramatically. So, to harness their potential to regenerate damaged cell tissue and organs, we need to implant them into the body.

But the introduced stem cells usually die within about a week once they are in the body, yet can take around four weeks to differentiate into other cell types.

So scientists  grew stem cells outside the body. Then using a new method, they can insert specific genetic information into the cells using nanoparticles to cause them to change into a particular type of cell.

Once the cells have differentiated into the target cell type, they put them into the area of the body where there is damaged tissue so that they can help to restore it.

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In a previous study, the research team identified the bottleneck in the process of delivery of nanoparticles to stem cells. They showed that the nanoparticles got trapped in bubble-like vesicles that prevented them from getting into the stem cell, but it wasn't clear why.

To understand how to overcome the difficulties posed by the stem cell barrier, the team of researchers studied ways to improve the movement of nanoparticles across the cell membranes, which could carry genetic information that would direct the transformation of a stem cell to its new cell type.

Eventually, they found that coating the nanoparticles in a type of polymer helped them to get into the stem cells.

The coated nanoparticles avoided getting trapped in vesicles, unlike the uncoated ones. In fact, they seemed to circumvent the vesicles altogether and enter the cell more directly.

It's not yet clear why the coating works, but the discovery will help to make the delivery of genetic information to stem cells more efficient so that it is easier to control which cells they become.

However, the team recognizes there is a long way to go before this method can be used clinically.

Wanchuan Ding et al, Mechanism-Driven Technology Development for Solving the Intracellular Delivery Problem of Hard-To-Transfect Cells, Nano Letters (2023). DOI: 10.1021/acs.nanolett.2c04834

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A New Way to Activate Dormant Cells in The Retina Could Restore Vision

Degenerative retinal disease is a problem for millions of people worldwide, as light-sensitive cells called photoreceptors at the back of the eye die without being replaced. Thanks to new research, a solution to the problem might not be far off.

Scientists  have come up with a way to transform dormant support neurons called Müller glial cells into tissues that work like cone photoreceptors, which are required for color perception and visual acuity. While the process has only been tested on mice cells, it could eventually be developed into a therapy that can restore vision in people.

Part of the reason the Müller glial cells were chosen for investigation is their ability to be reprogrammed in some animals. Unfortunately it's not a trick that these cells can do in humans.

What's interesting is that these Müller cells are known to reactivate and regenerate retina in fish. But in mammals, including humans, they don't normally do so, not after injury or disease. And we don't yet fully understand why.

Key to the study were the genes Ikzf1 and Ikzf4, and the proteins they produced. These proteins are known as temporal identity factors, already known to play important roles in the development of cells into various types.

The Müller glial cells were isolated and cultured before being reprogrammed using a variety of temporal identity factors, including Ikzf1 and Ikzf4. These factors didn't fully transform the glial cells into cone cells, but they did take on some of the necessary characteristics to function like the photoreceptors.

While glial cells help nourish, regulate, and organize other cells in the eye, the researchers say there's enough of a surplus to safely convert a number of the support cells into the photoreceptor-like cells – crucial for seeing light and identifying colors.

It's early days, but the process could eventually be adapted to work in humans, without the need to transplant any new cells. Further down the line, these findings could also be useful in treating diseases in the brain – being able to replace certain neurons that have been damaged by reprogramming other types of cells.

https://www.pnas.org/doi/10.1073/pnas.2122168120

Breakthrough research could bring stem cell therapy to the masses

Researchers  have made a significant breakthrough in realizing the promise of stem cell therapy: stem cells that do not trigger an immune response from an immunologically incompatible donor.

In the paper "Hypoimmune induced pluripotent stem cells survive long term in fully immunocompetent, allogeneic rhesus macaques," published in Nature Biotechnology, the researchers detail how they cloaked a line of hypoimmune pluripotent (HIP) stem cells to evade the normal rejection and destruction obstacles to therapeutic use.

In an experimental setting, hypoimmune pluripotent cells did not trigger an immune cell response. They were also impervious to cytotoxicity incited by wild-type stem cells transplanted along with them, successfully evading direct detection and effects from the enrichment of untargeted threats.

The HIP cells survived unrestricted for 16 weeks (the entire test duration) in fully immunocompetent allogeneic recipients and differentiated into several lineages, whereas wild-type cells were vigorously rejected.

In a humanized diabetic mouse model, pancreatic differentiated human HIP cells lasted four weeks and showed evidence of improving the condition. The mice were not immunosuppressed and were not a type match for the cell types used.

An additional long-term test of HIP cells found cell islets 40 weeks after implantation in rhesus macaque recipients without immunosuppression, compared to an unedited wild-type version that was destroyed within a week.

Stem cells have the potential to revolutionize medicine as they can be manipulated to differentiate into various cell types, making them a promising source of new cells for transplantation or regenerative medicine. By introducing stem cells to damaged tissue or organs, it may be possible to regenerate healthy tissue and restore proper function. This has implications for developing new therapies for various diseases, including cancer, heart disease, and neurological disorders.

Xiaomeng Hu et al, Hypoimmune induced pluripotent stem cells survive long term in fully immunocompetent, allogeneic rhesus macaques, Nature Biotechnology (2023). DOI: 10.1038/s41587-023-01784-x

Scientists discover microbes in the Alps and Arctic that can digest plastic at low temperatures

Finding, cultivating, and bioengineering organisms that can digest plastic not only aids in the removal of pollution, but is now also big business. Several microorganisms that can do this have already been found, but when their enzymes that make this possible are applied at an industrial scale, they typically only work at temperatures above 30°C.

The heating required means that industrial applications remain costly to date, and aren't carbon-neutral. But there is a possible solution to this problem: finding specialist cold-adapted microbes whose enzymes work at lower temperatures.

Scientists  knew where to look for such microorganisms: at high altitudes in the Alps, or in the polar regions. When they did that, novel microbial taxa obtained from the 'plastisphere' of alpine and arctic soils were able to break down biodegradable plastics at 15°C. Their findings are published in Frontiers in Microbiology.

How did the ability to digest plastic evolve? Since plastics have only been around since the 1950s, the ability to degrade plastic almost certainly wasn't a trait originally targeted by natural selection.

Microbes have been shown to produce a wide variety of polymer-degrading enzymes involved in the break-down of plant cell walls. In particular, plant-pathogenic fungi are often reported to biodegrade polyesters, because of their ability to produce cutinases which target plastic polymers due their resemblance to the plant polymer cutin.

Discovery of plastic-degrading microbial strains isolated from the alpine and Arctic terrestrial plastisphere, Frontiers in Microbiology (2023). DOI: 10.3389/fmicb.2023.1178474 , www.frontiersin.org/articles/1 … cb.2023.1178474/full

New method for delivering an antioxidant directly to mitochondria in the liver, mitigating oxidative stress

Mitochondria are microscopic organelles found within cells, and are by far the largest producer of the molecule adenosine triphosphate (ATP), which provides energy to many processes in living cells. The process by which mitochondria synthesize ATP generates a large amount of reactive oxygen species (ROS), chemical groups that are highly reactive.

In a healthy cell, the ROS are controlled by the mitochondria; however, when this balance is lost, the excess ROS damages the mitochondria and subsequently cells and tissues. This phenomenon, known as oxidative stress, can cause premature aging and disease. The ROS that cause oxidative stress can be controlled by antioxidants.

A research team has developed a system to deliver antioxidants to mitochondria to mitigate the effects of excess ROS. Their findings have been published in Scientific Reports.

They  developed a drug delivery system which they named CoQ₁₀-MITO-Porter. This system consists of the antioxidant molecule Coenzyme Q₁₀ (CoQ₁₀)—which is also required by mitochondria for ATP production—encapsulated by a lipid nanoparticle that would target mitochondria. 

Variations of the formula for the synthesis of CoQ₁₀-MITO-Porter were tested, and their structures were examined with electron microscopy. CoQ₁₀-MITO-Porter was administered to mice models with acetaminophen-induced liver damage. Acetaminophen overdoses cause excess ROS in mitochondria, which in turn damages cells in the liver. CoQ₁₀-MITO-Porter was transported primarily to the liver and measurably reduced the damage caused by ROS. A further discovery was that downsized CoQ₁₀-MITO-Porter particles with more efficient packaging of CoQ₁₀ were more effective at treating liver damage than the original formulation.

Mitsue Hibino et al, A System that Delivers an Antioxidant to Mitochondria for the treatment of Drug-Induced Liver Injury, Scientific Reports (2023). DOI: 10.1038/s41598-023-33893-7. www.nature.com/articles/s41598-023-33893-7

A New Urine Test Could Be a Simple Way to Check For Cancer

Diagnosing cancer early makes a significant difference to the chances of a patient's successful recovery, which is why cheap, non-invasive screening tests are so important.

A new diagnostic tool development by researchers 

needs little more than a sample of urine, making it possible for some types of cancer to be screened at home much like a pregnancy test. No need for a trip to the doctor or to hospital, and no need for expensive scanning procedures or bothersome blood tests.

While the test might be simple, the technology behind it is rather sophisticated, relying on the presence of enzymes that are specific to the emergence of different cancers.

Researchers developed a new type of nanoparticle with a coating of proteins tagged with an array of DNA sequences. When cancer-related enzymes encounter a nanoparticle in the blood, they snip off a protein specific to that enzyme. Excreted out of the body through the urine, the sequences connected to the protein can then be read like a barcode, identifying the presence of cancer.

Tested on mice via an injection, the same nanoparticles could eventually be developed to be taken orally, through an inhaler, or as a local treatment such as a cream, according to the researchers.

Not only do the nanoparticle's various DNA barcodes have the potential to identify whether or not a tumor is present, they could also be able to distinguish between types of tumors, and spot if a tumor has metastasized (spread to other parts of the body). All of this is vital information for developing and targeting treatments.

The nanoparticle sensors were shown to detect five different enzymes produced by tumors. Up to 46 different DNA barcodes can potentially be expressed in a single sample, once the technology has been scaled up further.

https://www.nature.com/articles/s41565-023-01372-9

Cold Water Therapy Might Do More Harm Than Good. 

Immersion in cold water is definitely an activity that divides people – some love it, others hate it. But many now practice it weekly or even daily in the belief that it's good for their mental and physical health.

Cold water therapy, as it has come to be known, can take the form of outdoor swimming – in lakes, rivers or the ocean – cold showers, or even ice baths. It has been used for a while by sportspeople as a way to reduce muscle soreness and speed up recovery time – with people typically spending about ten minutes after exercise in cold water that's about 10 to 15 °C (50 to 59 °F).

Cold water has also been used to help treat symptoms of depression, pain, and migraine. Indeed, there are many accounts of how cold water therapy has changed lives, cured broken hearts, and helped people during difficult times.

While many studies have shown benefits linked to ice baths and post-exercise recovery, research from 2014 found there could be a placebo effect going on here.

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New Synthetic Blood Clotting System Could Help Stop Internal Bleeding

Blood clots are one of the body's most important natural defense systems, a mechanism for plugging internal and external gaps to keep us alive. However, in cases where the body is losing a lot of blood, the clotting process can't keep up. This is where a new synthetic replacement could come in.

Researchers have developed a two-component system that targets internal injuries without causing any unwanted damage of its own. The two components match the body's platelets (cell fragments that trigger clotting) and fibrinogen (a protein that helps clots to form). So far, the synthetic process has only been tested on mice, but it effectively triggered the blood clotting part of the natural hemostasis reaction to wounds and proved significantly better at stopping bleeding than previous approaches.

The idea of using two components allows selective gelation of the hemostatic system as the concentration is enhanced in the wound, mimicking the end effect of the natural clotting cascade.

The first part of the system is a biocompatible polymer nanoparticle called PEG-PLGA that is engineered to bind to whatever platelets the body can provide while injured. Platelets are drawn to the site of an injury, which in turn carries in these bound nanoparticles.

The second part of the system is a polymer that takes the place of fibrinogen and starts creating clumps through a reaction with the nanoparticles. The team describes this second component as a crosslinker, essentially getting the particles that have formed around a wound to join together.

Crucially, the researchers designed the particles in a form where they wouldn't accumulate in places where they shouldn't (in the wrong spots, blood clots can also be dangerous to our health) by having them only crosslink at a high enough concentration.

In a tiny initial mouse trial, not only did the synthetic system prove highly effective, but also it lasted longer than normal blood clots would. Moreover, the system didn't trigger any unwanted immune system reactions in the animals.

https://onlinelibrary.wiley.com/doi/full/10.1002/adhm.202202756

Growing crops under solar panels provide food and energy at the same time

 Imagine growing greens in your back yard under a solar panel, and then juicing them in a blender powered by the same energy. A new  project is working to make that a reality. By growing spinach under different solar panels,  researchers are measuring how the process affects both plant growth and the electrical output of the panels. Known as agrivoltaics, the fairly new sustainable practice integrates solar panels with crops, making simultaneous use of land for both food and energy production. Agrivoltaics has the potential to address several pressing issues around sustainability.

https://www.ualberta.ca/folio/2023/05/could-growing-crops-under-sol....

Using reflections to see the world from new points of view

As a car travels along a narrow city street, reflections off the glossy paint or side mirrors of parked vehicles can help the driver glimpse things that would otherwise be hidden from view, like a child playing on the sidewalk behind the parked cars.

Drawing on this idea, researchers have created a computer vision technique that leverages reflections to image the world. Their method uses reflections to turn glossy objects into “cameras,” enabling a user to see the world as if they were looking through the “lenses” of everyday objects like a ceramic coffee mug or a metallic paper weight.

Using images of an object taken from different angles, the technique converts the surface of that object into a virtual sensor which captures reflections. The AI system maps these reflections in a way that enables it to estimate depth in the scene and capture novel views that would only be visible from the object’s perspective. One could use this technique to see around corners or beyond objects that block the observer’s view.

This method could be especially useful in autonomous vehicles. For instance, it could enable a self-driving car to use reflections from objects it passes, like lamp posts or buildings, to see around a parked truck.

The researchers  have shown that any surface can be converted into a sensor with this formulation that converts objects into virtual pixels and virtual sensors. This can be applied in many different areas.

In real life, exploiting these reflections is not as easy as just pushing an enhance button. Getting useful information out of these reflections is pretty hard because reflections give us a distorted view of the world.

Part 1

This distortion depends on the shape of the object and the world that object is reflecting, both of which researchers may have incomplete information about. In addition, the glossy object may have its own color and texture that mixes with reflections. Plus, reflections are two-dimensional projections of a three-dimensional world, which makes it hard to judge depth in reflected scenes.

The researchers found a way to overcome these challenges. Their technique, known as ORCa (which stands for Objects as Radiance-Field Cameras), works in three steps. First, they take pictures of an object from many vantage points, capturing multiple reflections on the glossy object.

Then, for each image from the real camera, ORCa uses machine learning to convert the surface of the object into a virtual sensor that captures light and reflections that strike each virtual pixel on the object’s surface. Finally, the system uses virtual pixels on the object’s surface to model the 3D environment from the point of view of the object.

Imaging the object from many angles enables ORCa to capture multiview reflections, which the system uses to estimate depth between the glossy object and other objects in the scene, in addition to estimating the shape of the glossy object. ORCa models the scene as a 5D radiance field, which captures additional information about the intensity and direction of light rays that emanate from and strike each point in the scene.

The additional information contained in this 5D radiance field also helps ORCa accurately estimate depth. And because the scene is represented as a 5D radiance field, rather than a 2D image, the user can see hidden features that would otherwise be blocked by corners or obstructions.

In fact, once ORCa has captured this 5D radiance field, the user can put a virtual camera anywhere in the scene and synthesize what that camera would see, Dave explains. The user could also insert virtual objects into the environment or change the appearance of an object, such as from ceramic to metallic.

It 's especially challenging to go from a 2D image to a 5D environment. You have to make sure that mapping works and is physically accurate, so it is based on how light travels in space and how light interacts with the environment. 

The researchers evaluated their technique by comparing it with other methods that model reflections, which is a slightly different task than ORCa performs. Their method performed well at separating out the true color of an object from the reflections, and it outperformed the baselines by extracting more accurate object geometry and textures.

They compared the system’s depth estimations with simulated ground truth data on the actual distance between objects in the scene and found ORCa’s predictions to be reliable.

Consistently, with ORCa, it not only estimates the environment accurately as a 5D image, but to achieve that, in the intermediate steps, it also does a good job estimating the shape of the object and separating the reflections from the object texture.

https://news.mit.edu/2023/using-reflections-shiny-objects-camera-0510

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What happens when fish encounter their robotic counterparts?

Study observes the interactions between live fish and fish-like robots

In recent decades, engineers have created a wide range of robotic systems inspired by animals, including four legged robots, as well as systems inspired by snakes, insects, squid and fish. Studies exploring the interactions between these robots and their biological counterparts, however, as still relatively rare.

So recently researchers set out to explore what happens when live fish are placed in the same environment as a robotic fish. Their findings, published in Bioinspiration & Biomimetics, could both inform the development of fish-inspired robots and shed some new light on the behavior of real fish.

During their field experiments, the researchers observed an exciting phenomenon where live fish were observed following the swimming robotic fish. They  are eager to further explore the underlying principles behind this phenomenon and gain a deeper understanding of this 'fish following' behaviour.

 The robotic fish used in their experiments was carefully designed to replicate the appearance, body shape, and movements of koi fish, large and colorful freshwater fish originating from Eastern Asia.

In their experiments, the researchers placed one or two prototypes of their koi fish-like robot in the same tank with one or more live fishes. They then observed how the fish behaved in the presence of this robot and assessed whether their behavior varied based on how many other live fish were present in the tank with them.

Through extensive experimentation, they discovered that live fish exhibit significantly lower proactivity when alone, and the most proactive case is one where a robotic fish is interacting with two real fish. In addition, their experiments on parameter variation indicated that live fish may respond more proactively to robotic fish that swim with high frequency and low amplitude, but they may also move together with the robotic fish at high frequency and high amplitude.

The researchers' observations shed an interesting new light on the collective behavior of fish, which could potentially guide the design of additional fish-like robots. 

Ziye Zhou et al, Proactivity of fish and leadership of self-propelled robotic fish during interaction, Bioinspiration & Biomimetics (2023). DOI: 10.1088/1748-3190/acce87

This video is not related to this research work. I just posted it here to get an idea of robotic fish swimming along with real fish in the ocean

Fearful memories of pain stored in the prefrontal cortex could shape the experience of pain later in life

While pain and fear are very different experiences, past studies showed that they can sometimes be closely related to one another. For instance, when many animals and humans are in dangerous or life-threatening situations, acute fear can suppress their perception of pain, allowing them to fully focus their attention on what is happening to them.

Conversely, research showed that when humans experience high levels of pain, they can create long-term and associative fear memories that make them fearful of situations that they associate with the pain they felt. These memories can in turn increase their sensitivity to pain or lead to the development of unhelpful behavioral patterns aimed at avoiding pain.

The increase in the intensity with which animals or humans perceive pain after very painful past experiences could be liked to their fearful anticipation of pain. The exact neural underpinnings of this process, however, are still poorly understood.

Researchers have recently carried out a study aimed at better understanding which regions of the mice brain stores very painful experiences and how these stored memories can affect future experiences of pain. Their findings, published in Nature Neuroscience, suggest that these memories are stored in the prefrontal cortex, the area covering the front part of the mammalian brain.

The researchers conducted a series of experiments on adult mice using a neural tagging method and optogenetic techniques. During these experiments, the mice received small electric shocks on their feet and were conditioned to become fearful of receiving these shocks again. The team also used optogenetic techniques to either activate or suppress different neural circuits in the mice's brain, to determine how this would affect their sensitivity to pain.

They found that in mice that long-term associative fear memory stored in neuronal engrams in the prefrontal cortex determines whether a painful episode shapes pain experience later in life.

Furthermore, under conditions of inflammatory and neuropathic pain, prefrontal fear engrams expand to encompass neurons representing nociception and tactile sensation, leading to pronounced changes in prefrontal connectivity to fear-relevant brain areas. Conversely, silencing prefrontal fear engrams reverses chronically established hyperalgesia and allodynia.

These results reveal that a discrete subset of prefrontal cortex neurons can account for the debilitating comorbidity of fear and chronic pain and show that attenuating the fear memory of pain can alleviate chronic pain itself.

Alina Stegemann et al, Prefrontal engrams of long-term fear memory perpetuate pain perception, Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01291-x

New study puts a definitive age on Saturn's rings

A new study has delivered the strongest evidence yet that Saturn's rings are remarkably young—potentially answering a question that has boggled scientists for well over a century.

The research, published May 12 in the journal Science Advances, pegs the age of Saturn's rings at no more than 400 million years old. That makes the rings much younger than Saturn itself, which is about 4.5 billion years old.

The researchers arrived at that closure by studying what might seem like an unusual subject: dust.

Tiny grains of rocky material wash through Earth's solar system on an almost constant basis. In some cases, this flux can leave behind a thin layer of dust on planetary bodies, including on the ice that makes up Saturn's rings.

In the new study, researchers set out to put a date on Saturn's rings by studying how rapidly this layer of dust builds up.

Think about the rings like the carpet in your house. If you have a clean carpet laid out, you just have to wait. Dust will settle on your carpet. The same is true for the rings.

It was an arduous process: From 2004 to 2017, the research team used an instrument called the Cosmic Dust Analyzer aboard NASA's late Cassini spacecraft to analyze specks of dust flying around Saturn. Over those 13 years, the researchers collected just 163 grains that had originated from beyond the planet's close neighborhood. But it was enough. Based on their calculations, Saturn's rings have likely been gathering dust for only a few hundred million years.

The planet's rings, in other words, are new phenomena, arising (and potentially even disappearing) in what amounts to a blink of an eye in cosmic terms.

Sascha Kempf, Micrometeoroid infall onto Saturn's rings constrains their age to no more than a few hundred million years, Science Advances (2023). DOI: 10.1126/sciadv.adf8537. www.science.org/doi/10.1126/sciadv.adf8537

Scientists identify mutated gene behind mirror movement disorder

Mirror movement disorder is an inherited neurological condition first manifested by involuntary movements, primarily in the arms and hands, at an early age. In those affected, the right hand involuntarily reproduces the movements of the left hand and vice versa, hence the term "mirror movement."

The disorder can cause pain in the arms during prolonged activities as well as difficulties in performing tasks requiring left-right coordination.

Mirror movement disorder has a daily impact on the life of those affected.

In fact, the simple act of buttoning one's shirt or tying one's shoelaces can be challenging, as well as practicing certain sports or music instruments such as the piano.

Over the last 30 years, scientists have identified a group of genes called the Netrin signaling pathway that work together to attract neurons connecting the left and right sides of the brain to each other and to the spinal cord. This mechanism of neuronal guidance during embryonic development is essential for motor development.

A 

new study sheds light on a new genetic mutation that causes mirror movement disorder and incites its mechanism of action at the molecular level. Using a preclinical model, the researchers found that the mutation in a gene newly involved in the Netrin pathway results in abnormal movements, similar to those observed in the disorder.

The Canadian study is based on studying the genetics of a family whose members have carried the disease for more than four generations. The advance is good news for people with the condition who, until now, did not know which mutated gene was the cause, the scientists say.

Identifying the genes involved is an important first step towards rapid and effective diagnosis; understanding the mechanisms causing mirror movements is also essential in the search for innovative treatments, and could also help target other conditions caused by developmental defects of the nervous system.

 Sabrina Schlienger et al, Genetics of mirror movements identifies a multifunctional complex required for Netrin-1 guidance and lateralization of motor control, Science Advances (2023). DOI: 10.1126/sciadv.add5501

Accretion disk around black holes recreated in the lab

Researchers have created a spinning disk of plasma in a lab, mimicking disks found around black holes and forming stars.

The experiment more accurately models what happens in these plasma disks, which could help researchers discover how black holes grow and how collapsing matter forms stars. As matter approaches black holes it heats up, becoming plasma—a fourth state of matter consisting of charged ions and free electrons. It also begins to rotate, in a structure called an accretion disk. The rotation causes a centrifugal force pushing the plasma outwards, which is balanced by the gravity of the black hole pulling it in.

These glowing rings of orbiting plasma pose a problem—how does a black hole grow if the material is stuck in orbit rather than falling into the hole? The leading theory is that instabilities in magnetic fields in the plasma cause friction, causing it to lose energy and fall into the black hole.

The primary way of testing this has been using liquid metals that can be spun, and seeing what happens when magnetic fields are applied. However, as the metals must be contained within pipes, they are not a true representation of free-flowing plasma.

Now, researchers have used their Mega Ampere Generator for Plasma Implosion Experiments machine (MAGPIE) to spin plasma in a more accurate representation of accretion disks. Details of the experiment are published May 12 in the journal Physical Review Letters.

V. Valenzuela-Villaseca et al, Characterization of Quasi-Keplerian, Differentially Rotating, Free-Boundary Laboratory Plasmas, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.195101

Black holes might be defects in spacetime

A team of theoretical physicists have discovered a strange structure in space-time that to an outside observer would look exactly like a black hole, but upon closer inspection would be anything but: they would be defects in the very fabric of the universe.

Einstein's general theory of relativity predicts the existence of black holes, formed when giant stars collapse. But that same theory predicts that their centers are singularities, which are points of infinite density. Since we know that infinite densities cannot actually happen in the universe, we take this as a sign that Einstein's theory is incomplete. But after nearly a century of searching for extensions, we have not yet confirmed a better theory of gravity.

But we do have candidates, including string theory. In string theory all the particles of the universe are actually microscopic vibrating loops of string. In order to support the wide variety of particles and forces that we observe in the universe, these strings can't just vibrate in our three spatial dimensions. Instead, there have to be extra spatial dimensions that are curled up on themselves into manifolds so small that they escape everyday notice and experimentation. That exotic structure in spacetime gave a team of researchers the tools they needed to identify a new class of object, something that they call a topological soliton. In their analysis they found that these topological solitons are stable defects in space-time itself. They require no matter or other forces to exist—they are as natural to the fabric of space-time as cracks in ice. The research is published in the journal Physical Review D.

Part 1

The researchers studied these solitons by examining the behavior of light that would pass near them. Because they are objects of extreme space-time, they bend space and time around them, which affects the path of light. To a distant observer, these solitons would appear exactly as we predict black holes to appear. They would have shadows, rings of light, the works. Images derived from the Event Horizon Telescope and detected gravitational wave signatures would all behave the same.

It's only once you got close would you realize that you are not looking at a black hole. One of the key features of a black hole is its event horizon , an imaginary surface that if you were to cross it you would find yourself unable to escape. Topological solitons, since they are not singularities, do not feature event horizons.

These topological solitons are incredibly hypothetical objects, based on our understanding of string theory, which has not yet been proven to be a viable update to our understanding of physics. However, these exotic objects serve as important test studies. If the researchers can discover an important observational difference between topological solitons and traditional black holes, this might pave the way to finding a way to test string theory itself.

Pierre Heidmann et al, Imaging topological solitons: The microstructure behind the shadow, Physical Review D (2023). DOI: 10.1103/PhysRevD.107.084042

Part 2

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Study reveals 'developmental window' for thinking styles

While people change and learn throughout life, experts recognize that certain formative periods, known as developmental windows, are crucial for acquiring particular skills. For example, using vocalizations and words to interact with people in the first few years of life is critical for children's language learning.

The researchers found that following the collapse of Romania's authoritarian communist regime in 1989, the rapid increase in education and technology use and the transition from a single, government-controlled source of information to diverse sources had a strong effect on the way people, particularly younger generations, thought about and determined truthfulness, a process known as "epistemic thinking."

Epistemic thinking runs the gamut from absolutist thinking, the belief that only one claim can be right, to multiplist thinking, the belief that more than one claim could be right—it's just a matter of opinion. Finally, evaluativist thinking posits that assertions can be evaluated in terms of both logic and evidence.

Amalia Ionescu et al, The effects of sociocultural changes on epistemic thinking across three generations in Romania, PLOS ONE (2023). DOI: 10.1371/journal.pone.0281785

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Mouse Study Reveals Unlikely Connection Between Menthol And Alzheimer's

A new study reports something strange: When mice with Alzheimer's disease inhale menthol, their cognitive abilities improve. It seems the chemical compound can stop some of the damage done to the brain that's usually associated with the disease.

In particular, researchers noticed a reduction in the interleukin-1-beta (IL-1β) protein, which helps to regulate the body's inflammatory response – a response that can offer natural protection but one that leads to harm when it's not controlled properly.

The team behind the study says it shows the potential for particular smells to be used as therapies for Alzheimer's. If we can figure out which odors cause which brain and immune system responses, we can harness them to improve health.

Researchers  have focussed on the olfactory system's role in the immune and central nervous systems, and they have confirmed that menthol is an immunostimulatory odour in animal models.

They observed that short exposures to this substance for six months prevented cognitive decline in the mice with Alzheimer's and, what is most interesting, also improved the cognitive ability of healthy young mice.

https://www.frontiersin.org/articles/10.3389/fimmu.2023.1130044/full

Unique insights into differences between primary and metastatic cancer by large-scale DNA data analyses

Cancer is caused by DNA changes that cause a cell to gradually change from benign to malignant. This can lead to metastases in other parts of the body. By analyzing the DNA data of more than 7,000 patients, the researchers show that there are major differences between primary and metastatic cancer and that there are also tumor types in which the primary tumor and the metastasis hardly differ from one another. By studying the types of DNA changes and the consequences of the changes, important insights into the underlying biological processes were obtained.

Researchers have mapped the DNA changes of the 23 most common tumor types. They have studied the differences in genetic characteristics between the source of the cancer, the primary tumor, and metastatic tumors.

Unique collections of whole genome sequencing data from tumors were used. This enabled the researchers to study in great detail which changes in the tumor had occurred during and after the tumor had developed. The researchers have harmonized and systematically compared the world's largest publicly available data sets of primary tumors (from the international PCAWG consortium with information from ~2,800 patients) and metastatic tumors (Hartwig Medical Database, ~4,400 patients). The results of this research were published May 10 in the journals Nature and Nature Genetics.

Part 1

The paper published in Nature describes the overall genomic differences found when comparing primary and metastatic tumors and highlights the fact that the differences are highly dependent on the type of cancer studied, as well as the tumor's exposure to previous anti-tumor treatments.

One could state that this work confirms many observations that were previously done in cancer type-specific studies. However, the pan-cancer nature of the current study demonstrates which processes and mechanisms are shared between tumor types and also quantifies their prevalence per tumor type. Such a systematic analysis and comparison from a genome-wide perspective has never been performed before.

The second study, published in parallel in the journal Nature Genetics, presents an analysis of the genomic alterations that allow tumors to escape the immune system, as well as a comparison of their prevalence in primary and metastatic tumors.

The researchers found that the prevalence of genetic immune escape is highly variable between tumor types and that in certain tumor types only a single mechanism is present, while in others various processes were affected. Furthermore, they showed that there are not many differences between primary and metastatic tumors, indicating that immune evasion is a characteristic that is acquired relatively early in tumor development.

This is the first time a complete tumor genome-wide sequencing dataset has been generated for primary and metastatic tumors of this magnitude. These data are public and available for research, providing a new global resource for further research into the biology and evolution of cancer, as well as the development of new therapies to combat the disease.

Part 2

Metastatic spread involves the detachment of tumor cells from a primary tumor, colonization of secondary tissue and growth in a hostile environment. Advanced metastatic tumors are often able to withstand aggressive treatment regimens and represent the leading cause of cancer-associated death.

 The researchers found that the differences are highly dependent on the type of tumor. In some types of tumors, such as pancreatic cancer, the genomic differences between primary and metastatic tumors are subtle. While in others, such as prostate, thyroid and some subtypes of breast cancer, there are very important genomic differences.

In addition, the exhaustive analysis has allowed the researchers to identify recurrent genomic patterns in metastatic tumors such as the presence of high genomic instability, greater enrichment of structural genomic alterations versus point mutations, and the presence of genomic alterations associated with the acquisition of resistance to treatment. However, hardly any driver alterations exclusively associated with the metastatic process could be identified.

Francisco Martínez-Jiménez et al, Pan-cancer whole-genome comparison of primary and metastatic solid tumours, Nature (2023). DOI: 10.1038/s41586-023-06054-z

Francisco Martínez-Jiménez et al, Genetic immune escape landscape in primary and metastatic cancer, Nature Genetics (2023). DOI: 10.1038/s41588-023-01367-1

Part 3

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Viruses in the guts of centenarians may help them resist pathogens

New research suggests that centenarians—people who live to be at least 100—have a diverse collection of viruses in their gut that could help protect them from infectious diseases. The findings, published May 15 in Nature Microbiology, shed light on some of the biological pathways that may help centenarians live long, healthy lives.

In the study, researchers analyzed the viromes—or viral genomes—from 195 individuals from Japan and Sardinia. They found that centenarians  had a greater diversity of bacteria and viruses in their guts.

They also found that viruses found in centenarians increased the ability of the healthy gut bacteria to break down sulfate, which could help preserve the gut's ability to fight bacterial infections.

The study adds to a growing body of evidence showing that the interactions between bacteria, viruses, and fungi in the gut play an important role in preventing age-related conditions.

This snapshot of how the virome interacts with gut microbiomes could tell us about how microbial and viral ecology evolves over the lifetime of a person. This offers an important starting point for uncovering the mechanisms behind how the gut ecosystem maintains health.

Part 1

Earlier  it was found that intestinal bacteria in centenarians produced unique bile acids that could help keep infections at bay. Other researchers have found that bacteriophages—or viruses that infect bacteria—had an effect on cognition and memory in mice.

 Now the researchers compared the viromes of young adults over 18, older adults over 60, and centenarians aged 100 and over. 

 In centenarians, the team found not only more diverse bacteria and viruses, but also more viruses in the lytic life cycle, during which viruses are active and burst and kill the bacteria they infect—a phase that is more common in infants than adults. At least a quarter of the viruses found in centenarians encoded genes that support key stages of sulfate metabolism. The researchers think this could help sustain the integrity of the mucosal barrier, a highly selective collection of tightly-bound cells that allows the body to absorb nutrients in the gut while keeping bacteria and toxins at bay.

Joachim Johansen et al, Centenarians have a diverse gut virome with the potential to modulate metabolism and promote healthy lifespan, Nature Microbiology (2023). DOI: 10.1038/s41564-023-01370-6

Part 2

This is made of plants. Why do we call it “meat”?

Deficiency causes rare tropical plant to develop appetite for meat

Under certain circumstances, a rare tropical plant develops into a carnivore. A research team  has now deciphered the mechanism responsible for this.

Triphyophyllum peltatum is a unique plant. Native to the tropics of West Africa, the liana species is of great interest for medical and pharmaceutical research due to its constituents: In the laboratory, these show promising medically useful activities against pancreatic cancer and leukemia cells, among others, as well as against the pathogens that cause malaria and other diseases.

However, the plant species is also interesting from a botanical perspective: Triphyophyllum peltatum is the only known plant in the world that can become a carnivore under certain circumstances. Its menu then includes small insects, which it captures with the help of adhesive traps in the form of secretion drops and digests with lytic enzymes synthesized.

A high flexibility can be observed in the leaves of the plant, which develop three different types depending on the stage of development. While in the juvenile phase simple leaves are initially formed, later so-called "trap leaves" can be formed, which carry a large number of adhesive traps. When these trap leaves have served their purpose, the plant either forms normal leaves again or—if the plant has entered the liana stage—leaves with two hooks at the tip as a climbing support.

As far as the expression of leaf identity is concerned, Triphyophyllum peltatum shows a high degree of flexibility: the developmental stages can vary in length, and the carnivorous stage can be omitted completely or made up for at a later stage. Thus, the plant seems to adapt to the prevailing conditions of its habitat.

The trigger that turns the plant into a carnivore was previously unknown. One reason for this was the fact that Triphyophyllum peltatum was considered very difficult to cultivate and therefore the formation of trap leaves was difficult to study experimentally. This problem has now been solved by scientists now.

But what is even more significant is that with the help of these plants, the research team was able to identify the factor that triggers the transformation to the carnivore lifestyle. The team has now published the results of this research in the current issue of the journal New Phytologist.

Researchers exposed the plant to different stress factors, including deficiencies of various nutrients, and studied how it responded to each. Only in one case were we able to observe the formation of traps: in the case of a lack of phosphorus. In fact, a greatly reduced supply of phosphorus is already sufficient to trigger the development into a carnivorous plant, according to the scientists.

Part 1

In its original habitat in African tropical forests on nutrient-poor soils, Triphyophyllum peltatum can thus avoid the threat of malnutrition by forming traps and accessing the important nutritional element through digestion of its insect prey. "These new findings are a breakthrough because they allow future molecular analyses that will help understand the origins of carnivory," the scientists say.

Traud Winkelmann et al, Carnivory on demand: phosphorus deficiency induces glandular leaves in the African liana Triphyophyllum peltatum, New Phytologist (2023). DOI: 10.1111/nph.18960

How superbug A. baumannii survives metal stress and resists antibiotics

The deadly hospital pathogen Acinetobacter baumannii can live for a year on a hospital wall without food and water. Then, when it infects a vulnerable patient, it resists antibiotics as well as the body's built-in infection-fighting response. The World Health Organization (WHO) recognizes it as one of the three top pathogens in critical need of new antibiotic therapies.

Now a team of international researchers have discovered how the superbug can survive harsh environments and then rebound, causing deadly infections. They have found a single protein that acts as a master regulator. When the protein is damaged, the bug loses its superpowers allowing it to be controlled, in a lab setting. The research is published in Nucleic Acids Research.

During infection our cells fight back by either flooding or starving bacteria of essential metals such as copper and zinc. A. baumannii has strong drug pumps that push antibiotics, metals and other threats out of the cell.

By studying how this bug deals with infection stresses,  researchers have found an important uncharacterized regulatory protein (DksA). When scientists disrupted this protein, it lead to changes in about 20 percent of the bug's genome and breaks its pumping system.

Ram P Maharjan et al, DksA is a conserved master regulator of stress response in Acinetobacter baumannii, Nucleic Acids Research (2023). DOI: 10.1093/nar/gkad341

Why wavy wounds heal faster than straight wounds

Wavy wounds heal faster than straight wounds because shapes influence cell movements, a team of researchers has found.

Scientists observed the motion of cells and found that those near wavy shaped wounds moved in a swirling manner while cells near straight wounds moved in straight lines, traveling parallel to the edges.

The team concluded that the swirling or vortex-like movement is crucial to gap bridging, in which cells build bridges to heal damaged tissues, and which accelerates the wound healing process in wavy wounds.

This is the first time that the relationship between gap bridging, and the speed of wound healing has been determined. The scientists said their findings open the door to the development of more effective strategies to speed up wound healing, for better wound management, tissue repair, and plastic surgery.

An essential component of wound healing is re-epithelialization, a process in which the epithelial cell—a type of cell found on the skin—moves to form a bridge between the wound and the skin, closing its gap.

While previous studies have found that zig zag wounds healed faster than straight wounds, little is known about how different wound curvatures (shape) and wound sizes influence healing efficiency, nor about the mechanism of re-epithelialization.

To investigate, the NTU scientists prepared synthetic wounds with a range of widths (30 micrometers to 100 micrometers) and curvatures (radius of curvature: 30 micrometers, 75 micrometers, 150 micrometers and straight line) to learn how cells moved to close wound gaps in different circumstances.

Using particle image velocimetry—an optical measurement technique for fluid flow—researchers found that wavy wounds induced more complex collective cell movements, such as a swirly, vortex-like motion. By contrast in a straight wound, cells moved parallel to the wound front, moving in straight lines like a marching band.

Wavy wounds heal nearly five times faster

The  team also observed the healing progress of the synthetic wounds over a period of 64 hours and found that the healing efficiency of wavy gaps—measured by the percentage area covered by the cells over time—is nearly five times faster than straight gaps.

 Hongmei Xu et al, Geometry-mediated bridging drives nonadhesive stripe wound healing, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2221040120

How bending implantable medical devices can lead to bacterial growth

A study by researchers  shows that mechanical deformation of medically implantable materials—such as bending or twisting—can have a big impact on the formation of potentially harmful biofilms.

The study, described in a paper published in Scientific Reports, shows that even slight bending of elastomeric materials such as polydimethylsiloxane (PDMS)—also known as silicone—opens up microscopic cracks that are perfect environments for colonizing bacteria.

These kinds of materials are used in all kinds of biomedical applications, from catheters to tracheal tubes and prosthetic breast implants.

The formation of microbial biofilms on these materials is common, but scientists were surprised by the degree to which bending silicone, and other rubber materials, causes these cracks to reversibly open and close—and how big a difference they make in terms of biofilm formation.

Biofilms are complex communities of organisms that grow on surfaces. While individual microbial cells are susceptible both to antibiotics and the body's natural defensive systems, the biofilm environment can shield them from these interventions, which can lead to persistent infections.

Infections associated with medical-device biofilms, which sometimes develop after surgery, can be serious health risks—lengthening hospital stays or causing patients who have been discharged to be readmitted.

They have combined not only   microbiology and materials science, but also mechanical engineering, because they're talking about mechanical stress, strain and deformation. This bending effect is something that had not been noticed before.

Part 1

The team tested various samples of silicone, including some they synthesized themselves as well as commercial-grade medical tubing used for urinary catheters. They then subjected these samples to mechanical forces to create surface damage. Their experiments showed that the microcracks can be formed very easily.

Even  wiping with lab tissue was enough to create surface damage. To the unaided  eye it still looks fine, but under the microscope, scientists could already see microcracks of the size that bacteria could get into. Bacteria are only a few micrometers big, so it doesn't take much. They saw that the bacteria very clearly preferred to attach in these microscopic cracks.

In the bent samples, there were four to five times as many bacteria on the side that was in tension versus the side that was in compression. These cells have full choice about where to grow, but they clearly love the side where all these microcracks are opened up.

Now scientists are researching methods to reduce surface damage, or modifying the silicone surface to reduce the formation of such cracks.

Desmond van den Berg et al, Mechanical deformation of elastomer medical devices can enable microbial surface colonization, Scientific Reports (2023). DOI: 10.1038/s41598-023-34217-5

Part 2

Heat wave in Asia made 30 times more likely because of climate change, scientists say

A searing heat wave in parts of southern Asia in April this year was made at least 30 times more likely by climate change, according to a rapid study by international scientists released recently.

Sizzling temperatures of up to 45 degrees Celsius (113 degrees Fahrenheit) were recorded in monitoring stations in parts of India, Bangladesh, Thailand and Laos last month—which was unusually high for the time of year.

The climate-change-fueled heat caused deaths, widespread hospitalizations, damaged roads, sparked fires and led to school closures in the region.

The World Weather Attribution group uses established models to quickly determine whether climate change played a part in extreme weather events. While the studies themselves are not yet peer-reviewed, which is the gold standard for science, they are often later published in peer-reviewed journals.

The southern Asian region is considered among the most vulnerable to climate change in the world, according to various global climate studies. But India, the largest country in the region and the most populous in the world is also currently the third highest emitter of planet-warming gases.

Scientists say that drastic measures to reduce carbon dioxide emissions immediately is the only solution.

Heat waves will become more common, temperatures will rise even more and the number of hot days will increase and become more frequent if we continue to pump greenhouse gases into the atmosphere, according to them.

www.worldweatherattribution.or … e-event-attribution/

Source: AP

https://phys.org/news/2023-05-asia-climate-scientists.html?utm_sour...

Our Earth is becoming unlivable. Can we still turn the tide?

We have crossed six of the nine boundaries within which human life on Earth will still be possible for future generations. That is not good news. Can the tide still be turned?

The planetary boundaries were discussed on May 9 as part of the Leiden University Green Office's Sustainability Day. They include climate change, biodiversity loss and ocean acidification. Six of the nine boundaries have already been crossed (see figure above). Crossing planetary boundaries increases the risk of large-scale abrupt or irreversible environmental changes.

Drastic changes are needed to ensure that the Earth remains habitable. Systemic changes are needed in food, energy and how we live and consume. In fact, all planetary boundaries are interconnected.

For example, once the nitrogen limit is exceeded, it affects biodiversity and climate. Besides planetary boundaries, experts also stress the importance of social boundaries, which include education, social equality and health care. Planetary boundaries and social  boundaries affect each other, and if we are to preserve a livable Earth, they must be addressed in an integrated way—which is possible.

One approach that can help keep the Earth livable is to let communities come up with their own local solutions. You see that communities often achieve more than their original goal. There is hope if we give communities responsibility for themselves.

source: https://www.universiteitleiden.nl/en

CRISPR zeroes in on death cap antidote

The CRISPR–Cas9 gene-editing tool might have cracked the mystery of how death cap mushrooms (Amanita phalloides) kill — and it led researchers to a potential antidote. Using the gene-editing technology, researchers created a pool of human cells — each with different genetic mutations — and exposed them to the mushrooms’ toxin. The toxin could not enter cells that lacked a functional version of an enzyme called STT3B, and cell survival increased. The researchers then sifted through thousands of chemical compounds to find one that would block the action of STT3B. They uncovered indocyanine green, a dye developed by the photography company Kodak in the 1950s and used in medical imaging. Indocyanine green has not yet been tested as an antidote in humans, but it reduced deaths when given to mice.

https://www.nature.com/articles/s41467-023-37714-3.epdf?sharing_tok...

WHO warns against artificial sweeteners

Sweeteners don’t help people to lose weight in the long run and could increase the risk of type 2 diabetes and cardiovascular diseases if consumed continuously, the World Health Organization (WHO) advises. The guideline includes both artificial and natural sweeteners, such as aspartame and stevia. But it’s conditional, in keeping with life’s complexities — the WHO isn’t warning against sweetened toothpaste, for example, or recommending a change for people with pre-existing diabetes. The announcement contradicts some findings that sweeteners are harmless, even if they don’t offer any health benefits.

https://www.who.int/publications/i/item/9789240073616?utm_source=Na...

Human DNA is everywhere. That's a boon for science, and an ethical quagmire

In the water, on the land, in the air. In most cases the quality of DNA is almost equivalent to if you took a sample from a person.

We  cough, spit, shed and flush our DNA into all of these places and countless more. Signs of human life can be found nearly everywhere, short of isolated islands and remote mountaintops, according to a new  study.

That ubiquity is both a scientific boon and an ethical dilemma, say the UF researchers who sequenced this widespread DNA. The DNA was of such high quality that the scientists could identify mutations associated with disease and determine the genetic ancestry of nearby populations. They could even match genetic information to individual participants who had volunteered to have their errant DNA recovered.

Ethically handled environmental DNA samples could benefit fields from medicine and environmental science to archaeology and criminal forensics. For example, researchers could track cancer mutations from wastewater or spot undiscovered archaeological sites by checking for hidden human DNA. Or detectives could identify suspects from the DNA floating in the air of a crime scene.

But this level of personal information must be handled extremely carefully. Now, scientists and regulators must grapple with the ethical dilemmas inherent in accidentally—or intentionally—sweeping up human genetic information, not from blood samples but from a scoop of sand, a vial of water or a person's breath.

Published May 15 in Nature Ecology and Evolution, a paper by researchers outlines the relative ease of collecting human DNA nearly everywhere they looked.

Because of the ability to potentially identify individuals, the researchers say that ethical guardrails are necessary for this kind of research. The study was conducted with approval from the institutional review board of UF, which ensures that ethical guidelines are adhered to during research studies.

1. Liam Whitmore, Mark McCauley, Jessica A. Farrell, Maximilian R. Stammnitz, Samantha A. Koda, Narges Mashkour, Victoria Summers, Todd Osborne, Jenny Whilde, David J. Duffy. Inadvertent human genomic bycatch and intentional capture raise beneficial applications and ethical concerns with environmental DNA. Nature Ecology & Evolution, 2023; DOI: 10.1038/s41559-023-02056-2

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Cosmic Cycles: Earth, Our Home

Humans were making fires at least 250,000 years ago in Europe, research finds

Early humans in Europe were making and controlling fire at least 50,000 years earlier than previously thought, researchers have found.

In a paper published in the journal, Scientific Reports, the scientists set out evidence that our ancestors in Europe were using fires for activities like cooking, heating and defense at least 250,000 years ago. Previous evidence had suggested humans were managing fire in Europe much later than this, around 200,000 years ago.

Using forensic chemical methods to identify molecules of incomplete burning, the research team detected fire at Valdocarros II, an archaeological site near Madrid in Spain.

Researchers have found definitive evidence of things being burnt and those remains are organized into a pattern, suggesting it's humans who are making and controlling the fire. Either they were using the fire to cook or to defend themselves. The spatial patterning in the fire tells us that they were encircling something, like a home or sleeping area, a living room or kitchen, or an enclosure for animals.

The chemical profiles of the charred remains also suggest our human ancestors chose certain types of firewood for its burning properties, such as heat and lack of smoke.

The findings are "very exciting" and close a gap in our understanding of human-controlled fire and human development.

This is important because our species is defined by our use of fire. Being able to cook food to feed our big brains is one of the things that made us so successful in an evolutionary sense. Fire also brings protection and fosters communication and family connection. And scientists now have definitive, incontrovertible evidence that humans were starting and stopping fires in Europe about 50,000 years earlier than researchers suspected.

Clayton Magill et al, Organic geochemical evidence of human‑controlled fires at Acheulean site of Valdocarros II (Spain, 245 kya), Scientific Reports (2023). DOI: 10.1038/s41598-023-32673-7

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Researchers transform our understanding of crystals

When most people think of crystals, they picture suncatchers that act as rainbow prisms or the semi-transparent stones that some believe hold healing powers. However, to scientists and engineers, crystals are a form of materials in which their constituents—atoms, molecules, or nanoparticles—are arranged regularly in space. In other words, crystals are defined by the regular arrangement of their constituents. Common examples are diamonds, table salt, or sugar cubes.

However, in research just published in Soft Matter, a team  of researchers discovered that crystal structures are not necessarily always regularly arranged. The discovery advances the field of materials science and has unrealized implications for the materials used for semiconductors, solar panels, and electric vehicle technologies.

One of the most common and important classes of crystal structures is the close-packed structures of regular spheres constructed by stacking layers of spheres in a honeycomb arrangement. There are many ways to stack the layers to construct close-packed structures, and how nature selects specific stacking is an important question in materials and physics research. In the close-packing construction, there is a very unusual structure with irregularly spaced constituents known as the random stacking of two-dimensional hexagonal layers (RHCP). This structure was first observed from cobalt metal in 1942, but it has been regarded as a transitional and energetically unpreferred state.

Researchers now  collected X-ray scattering data from soft model nanoparticles made of polymers and realized that the scattering data contains important results about RHCP but is very complicated.

What they found 's that the RHCP structure is, very likely, a stable structure, and this is the reason that RHCP has been widely observed in many materials and naturally occurring crystal systems. This finding challenges the classical definition of crystals. 

The study provides insights into the phenomenon known as polytypism, which enables the formation of RHCP and other close-packed structures. A representative material with polytypism is silicon carbide, widely used for high-voltage electronics in electric vehicles and as hard materials for body armor. These new  findings indicate that those polytypic materials may have continuous structural transitions, including the non-classical random arrangements with new useful properties.

 Juhong Ahn et al, Continuous transition of colloidal crystals through stable random orders, Soft Matter (2023). DOI: 10.1039/D3SM00199G

Half of the world's largest lakes are losing water

More than 50% of the largest lakes in the world are losing water, according to a new assessment published recently in Science . The key culprits are not surprising: warming climate and unsustainable human consumption.

Researchers combined three decades of observations from an array of satellites with models to quantify and attribute trends in lake storage globally.

For the new paper, the team used 250,000 lake-area snapshots captured by satellites between 1992–2020 to survey the area of 1,972 of Earth's biggest lakes. They collected water levels from nine satellite altimeters and used long-term water levels to reduce any uncertainty. For lakes without a long-term level record, they used recent water measurements made by newer instruments on satellites. Combining recent level measurements with longer-term area measurements allowed scientists to reconstruct the volume of lakes dating back decades.

The results were staggering: 53% of lakes globally experienced a decline in water storage. 

Lakes in both dry and wet areas of the world are losing volume. The losses in humid tropical lakes and Arctic lakes indicate more widespread drying trends than previously understood.

Researchers also assessed storage trends in reservoirs. They found that nearly two-thirds of Earth's large reservoirs experienced significant water losses.

Sedimentation dominated the global storage decline in existing reservoirs. In long-established reservoirs—those that filled before 1992—sedimentation was more important than droughts and heavy rainfall years.

 Fangfang Yao, Satellites reveal widespread decline in global lake water storage, Science (2023). DOI: 10.1126/science.abo2812. www.science.org/doi/10.1126/science.abo2812

Human evolution has no single birthplace

Humans did not emerge from a single region of Africa, but from several populations that moved around the continent one millio... and intermingled for millennia. The widely held idea of a single origin of Homo sapiens is based in part on fossil records. Computer modelling and genome data from modern African and European populations revealed that “our roots lie in a very diverse overall population made up of fragmented local populations”, says evolutionary archaeologist Eleanor Scerri. This means human evolution looks more like a tangled vine than a ‘tree of life.’

https://www.nature.com/articles/s41586-023-06055-y.epdf?sharing_tok...

Human-evolution story rewritten by fresh data and more computing power

A global effort to identify critical illness in some COVID-19 patients highlights genetic risk, potential treatments

Researchers  have led a study in collaboration with scientists worldwide, looking into cases of critical illness in COVID-19 patients.

Critical illness in COVID-19 is an extreme and clinically consistent disease phenotype the team has found presenting in patients with shared genetic attributes. These shared genetics hint at a shared mechanism for the critical illness not seen in other patients and potential therapies to address the condition.

Patients with confirmed COVID-19 and requiring continuous cardiorespiratory monitoring or organ support (a generalizable definition for critical illness) were recruited in 2020–2022.

Researchers analyzed 24,202 cases of COVID-19 with critical illness with a combination of microarray genotyping and whole-genome sequencing data from the international GenOMICC study (11,440 cases) and other studies recruiting hospitalized patients with severe and critical illness, including the COVID-19 Human Genetics Initiative, the International Severe Acute Respiratory and Emerging Infection Consortium, the Spanish Coalition to Unlock Research on Host Genetics consortium and 23andMe.

The team found 49 genome-wide significant associations, of which 16 have not been reported previously and 196 significantly associated genes in a gene-level analysis. Although the implicated variants are not directly causing illness in the patients, they can highlight molecular mechanisms that make some COVID-19 infections much more severe. The findings are published in the journal Nature.

Part 1

Many genes implicated in critical COVID-19 are highly expressed in the monocyte-macrophage system, which has poor coverage in existing expression quantitative trait loci datasets. Macrophages synthesize many substances involved in host defense and inflammation and play a pivotal role in immune system reactions.

Additionally, the investigation found variation in circulating protein levels with 15 unique proteins linked to critical illness and some with well-studied biomarkers that make them good candidates for drug targeting.

The research has identified several potential druggable targets in multiple systems, including inflammatory signaling, monocyte-macrophage activation and endothelial permeability. Some of the targets found have already seen positive results with therapeutic signals in multiple drug trials, providing a good proof-of-concept for drug target identification using comparative genetics.

 Erola Pairo-Castineira et al, GWAS and meta-analysis identifies 49 genetic variants underlying critical COVID-19, Nature (2023). DOI: 10.1038/s41586-023-06034-3

Part2

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Scientists urge crackdown on methane emissions with only 13% regulated

New research  shows that only around 13% of global methane emissions are regulated, despite methane emissions causing at least 25% of current global warming.

The global review, published on May 19 in One Earth, also found that little is known about the effectiveness of the policies that exist, with potentially unrepresentative methane emission estimations used rather than actual measurements. Inaccurate estimations can also mean the issue is taken less seriously by decision-makers by masking its severity.

The researchers argue that the lack of regulation and clarity into their impact must urgently be addressed if we are to meet our global climate targets. The review suggests a consistent approach worldwide with robust quantification and reporting could unlock new opportunities to drastically reduce global warming levels.

To meet the Paris Agreement 1.5°C objective, man-made methane emissions should be reduced by at least 40%–45% by 2030, compared to the 2020 levels. Methane mitigation is not only a cost-effective strategy to reduce global warming but could also improve the air quality. Today methane emissions are increasing faster than at any time since the 1980s.

A global review of methane policies reveals only 13% of emissions are covered with unclear effectiveness, One Earth (2023). DOI: 10.1016/j.oneear.2023.04.009

Plastic pervasive in food supply, says new study

Micro and nanoplastics are pervasive in our food supply and may be affecting food safety and security on a global scale, a new study led by CSIRO has found.

The study is one of the first to analyze the academic literature on microplastics from a food safety and food security risk viewpoint, building on past studies which primarily tracked plastics in fish.

It shows that plastics and their additives are present at a range of concentrations not only in fish but in many products including meat, chicken, rice, water, take-away food and drink, and even fresh produce.

These plastics enter the human food chain through numerous pathways, such as ingestion as shown in the fish studies, but one of the main ways is through food processing and packaging. The research is published in the journal TrAC Trends in Analytical Chemistry.

Fresh food for example can be plastic free when it's picked or caught but contain plastics by the time it's been handled, packaged and makes its way to us. Machinery, cutting boards, plastic wrapping can all deposit micro and nanoplastics onto our food that we then consume. This study highlights the need to understand what plastic could end up in food to manage food safety and security.

Another important pathway for these contaminants to enter our agriculture system is through biosolids sourced from wastewater treatment.

Biosolids are a rich fertilizer for agricultural land, but they can contain plastic particles from many sources, such as from the washing of synthetic clothing.

These particles could build up in the soil and change the soil structure over time, which may affect crop production, food security and ecosystem resilience. For example, plastic materials can "trick" the good bacteria in the soil into thinking they are the roots of plants, meaning the plants end up with less of the nutrients they need.

The study also discussed how additives in plastics that help make plastic work in our modern world can leach into our environment, potentially contaminating our food supply. Additives that make plastic flexible or resistant to UV radiation, for example, can include flame retardants, heavy metals, phthalates, hardeners or other chemical compounds.

We can no longer ignore this problem, according to scientists.

Joost L.D. Nelis et al, The measurement of food safety and security risks associated with micro- and nanoplastic pollution, TrAC Trends in Analytical Chemistry (2023). DOI: 10.1016/j.trac.2023.116993

Fatty acids might exist in space

A team of physicists have discovered that the environment of a molecular cloud in interstellar space can support the existence of fatty acids, a key component of life on Earth.

Astronomers have made great strides over the past few years in identifying a variety of organic and prebiotic molecules in interstellar gas clouds. These molecules, rich in carbon and oxygen, form the basic building blocks of the chemistry used by life. For example, astronomers have recently discovered some amino acids, which are the fundamental components of all proteins used by life on Earth.

As astronomers continue to discover ever more complex organic molecules, it's natural to wonder what else could be out there. But space is an exceptionally harsh environment for life, not just because of its low temperatures, but also because of the intense radiation constantly flooding through any region of interstellar space.

Despite these challenges, a team of physicists ran a series of computer simulations of the typical interstellar environment and discovered that fatty acids can form and stabilize there. Fatty acids are chains of carbon and hydrogen atoms that form the building blocks of every kind of fat that we consume and maintain in our bodies.

The researchers discovered that carbon and hydrogen can naturally link together in spite of the low temperature and low pressure environments of interstellar gas clouds. These chains then form stable bonds that can persist for long timescales. Their research is available on the arXiv pre-print server.

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Fatty acids also combine with amino acids to form much more complex protein structures, and so the discovery of fatty acids in nebulae would confirm that the ingredients for life are abundant throughout the cosmos.

To find these fatty acids the astronomers discovered that we can use existing techniques. One such technique is called microwave rotational spectra. The fatty acids can rotate in certain ways which release particular frequencies of microwave radiation that we can detect. Further observations will be necessary to discover if these essential ingredients truly exist in the depths of space.