Lack of sleep affects your walk, new study finds

Good sleep can be hard to come by. But a new study finds that if you can make up for lost sleep, even for just a few weekend hours, the extra zzz's could help reduce fatigue-induced clumsiness, at least in how you walk.

There's plenty of evidence to show sleep, and how much we get of it, can affect how well we do on cognitive tasks such as solving a math problem, holding a conversation, or even reading this article. Less explored is the question of whether sleep influences the way we walk or carry out other activities that are assumed to be less mentally taxing.

The new study, by researchers at MIT and the University of São Paulo in Brazil, reports that walking—and specifically, how well we can control our stride, or gait—can indeed be affected by lack of sleep.

In experiments with student volunteers, the team found that overall, the less sleep students got, the less control they had when walking during a tread-mill test. For students who pulled an all-nighter before the test, this gait control plummeted even further.

Interestingly, for those who didn't stay up all night before the test, but who generally had less-than-ideal sleep during the week, those who slept in on weekends performed better than those who didn't.

Sleep deprivation affects gait control, Scientific Reports (2021). DOI: 10.1038/s41598-021-00705-9

https://medicalxpress.com/news/2021-10-feet-lack-affects.html?utm_s...

Underwater Drone Flies AND Swims

This device could usher in GPS-free navigation

A new era of navigation.

For over a year, the avocado-sized vacuum chamber has contained a cloud of atoms at the right conditions for precise navigational measurements. It is the first device that is small, energy-efficient and reliable enough to potentially move quantum sensors — sensors that use quantum mechanics to outperform conventional technologies — from the lab into commercial use, said Sandia National Laboratories scientist Peter Schwindt.

Sandia developed the chamber as a core technology for future navigation systems that don’t rely on GPS satellite.

Countless devices around the world use GPS for wayfinding. It’s possible because atomic clocks, which are known for extremely accurate timekeeping, hold the network of satellites perfectly in sync.

But GPS signals can be jammed or spoofed, potentially disabling navigation systems on commercial and military vehicles alike, Schwindt said.

So instead of relying on satellites,  future vehicles might keep track of their own position. They could do that with on-board devices as accurate as atomic clocks, but that measure acceleration and rotation by shining lasers into small clouds of rubidium gas like this one.

Atomic accelerometers and gyroscopes already exist, but they’re too bulky and power-hungry to use in an airplane’s navigation system. That’s because they need a large vacuum system to work, one that needs thousands of volts of electricity.

“Quantum sensors are a growing field, and there are lots of applications you can demonstrate in the lab. But when you move it into the real world there are lots of problems you have to solve. Two are making the sensor compact and rugged. The physics takes place all in a cubic centimeter (0.06 cubic inches) of volume, so anything larger than that is wasted space.”

part1

 quantum sensing can work without a high-powered vacuum system. This shrinks the package to a practical size without sacrificing reliability.

Instead of a powered vacuum pump, which whisks away molecules that leak in and wreck measurements, a pair of devices called getters use chemical reactions to bind intruders. The getters are each about the size of a pencil eraser so they can be tucked inside two narrow tubes sticking out of the titanium package. They also work without a power source.

To further keep out contaminants, Schwindt partnered with Sandia materials scientists to build the chamber out of titanium and sapphire. These materials are especially good at blocking out gasses like helium, which can squeeze through stainless steel and Pyrex glass. Funding was provided by Sandia’s Laboratory Directed Research and Development program.

Construction took sophisticated fabrication techniques that Sandia has honed to bond advanced materials for nuclear weapons components. And like a nuclear weapon, the titanium chamber must work reliably for years.

The Sandia team is continuing to monitor the device. Their goal is to keep it sealed and operational for five years, an important milestone toward showing the technology is ready to be fielded. In the meantime, they’re exploring ways to streamline manufacturing.

https://www.eurekalert.org/news-releases/932743

part2

Atoms .... see them!

Study confirms mistaken identity may explain why sharks bite humans

World-first research testing a simulated 'shark vision' model on swimming patterns of humans, seals and sea-lions, confirms theories that when great white sharks bite humans, it may be a case of mistaken identity.

Great white sharks are also called white sharks—and together with bull and tiger sharks, they account for by far the most bites on humans.

Researchers found that surfers, swimmers and pinnipeds (seals and sea-lions) on the surface of the ocean will look the same to a white shark looking up from below, because these sharks can't see fine details or colours.

Sharks use a range of sensory cues to distinguish between different objects and zero in on their food, and these differ in sensitivity between shark species. White sharks are highly visual—and juveniles are more dangerous to humans than are older, larger white sharks which have better vision.

When white sharks reach around 2.5 meters in length, their jaws begin to harden so they can take on bigger prey like seals. They need to develop a search image for these prey items and combine that with other sensory information; it's a learning process that could be prone to mistakes. Understanding why shark bites occur can help us find ways to prevent them, while keeping both humans and sharks safer.

 Laura A. Ryan et al, A shark's eye view: testing the 'mistaken identity theory' behind shark bites on humans, Journal of The Royal Society Interface (2021). DOI: 10.1098/rsif.2021.0533

https://phys.org/news/2021-10-mistaken-identity-sharks-humans.html?...

Researchers create mirror-image peptides that can neutralize SARS-CoV-2

Researchers at the University of Toronto have created chemical compounds that can neutralize SARS-CoV-2 and several of its variants.

In a recent paper published in the Journal of Medicinal Chemistry, the researchers report the creation of D-peptides that neutralize the virus and stop infection of cultured human cells.

Known as mirror-image peptides, the compounds have chemical properties that make them suitable for the development of low-cost antiviral therapeutics.

A big advantage of mirror-image peptides is their long stability and that they are relatively cheap to produce.

Peptides are similar to proteins in that they are composed of the same amino-acids building blocks. But they are smaller than protein molecules. They can be designed to bind virtually any molecular target and with a greater specificity than small-molecule drugs, reducing the risk of side effects. In this way, peptides are similar to antibodies but are at least 100 times cheaper to produce thanks to their small size. The combination of low cost and easy scaling of manufacturing makes peptides attractive, particularly for low-income countries.

But there's a caveat. In the body, peptides are rapidly degraded by the enzymes that have evolved to stamp out harmful versions produced by bacteria and other pathogens. But science has found a solution in mirror-image peptides that are resistant to degradation.

For reasons that remain unclear, all naturally occurring amino acids exist in a left-handed configuration, as defined by the direction in which they rotate. Consequently, all proteins and peptides are also left-handed—and known as L-peptides. These mirror-image molecules are manufactured from synthetic D-amino acids strung together in the same way as their left-handed counterparts.  They can be engineered to bind the same targets with undiminished specificity. The main difference is that their unusual geometry makes them resistant to enzymes in the bloodstream that break down normal L-peptides. 

Pedro A. Valiente et al, Computational Design of Potent D-Peptide Inhibitors of SARS-CoV-2, Journal of Medicinal Chemistry (2021). DOI: 10.1021/acs.jmedchem.1c00655

https://phys.org/news/2021-10-mirror-image-peptides-neutralize-sars...

**

The Pupil in Your Eye Can Perceive Numerical Information, Not Just Light

You might know that the size of the pupils in our eyes changes depending on how well lit our environment is, but there's more to the story: Scientists have now discovered that the pupil also shifts in size depending on how many objects we're observing.

The more objects in a scene, the bigger the pupil grows, as if to better accommodate everything that it has to look at. This "perceived numerosity" is a simple and automatic reflex, the new research shows.

In a new study, researchers observed the pupil sizes of 16 participants while they looked at pictures of dots. In some of the pictures, the dots were linked together in dumbbell shapes – creating the illusion that there were fewer objects – and pupil size then shrank. This result shows that numerical information is intrinsically related to perception.

As for where this reaction comes from, it's likely to be linked to the need for survival – most species are thought to have a dedicated 'number sense' that enables them to spot enemies in the wild, find food, get back home, and more besides.

When it comes to humans, being able to weigh up numbers is something that seems to appear as soon as a few hours after birth – even if you're terrible at math, you have a built-in aptitude for judging numerosity, and it appears the dilation of our pupils is part of a response to that. When we look around, we spontaneously perceive the form, size, movement and color of a scene. Equally spontaneously, we perceive the number of items before us. This ability, shared with most other animals, is an evolutionary fundamental: it reveals immediately important quantities, such as how many apples there are on the tree, or how many enemies are attacking.

And there's lots more to explore here as well. Our eyes seem to be more sensitive to the number of items we're looking at rather than how they're spaced or arranged, which is another reaction that can be analyzed in future studies.

https://www.nature.com/articles/s41467-021-26261-4

https://www.sciencealert.com/pupil-size-changes-depending-on-how-ma...

Technology to produce unbreakable screens

Cracked phone screens could become a thing of the past thanks to breakthrough research.

A team of researchers  have unlocked the technology to produce next-generation composite glass for lighting LEDs and smartphone, television and computer screens.

The findings will enable the manufacture of glass screens that are not only unbreakable but also deliver crystal clear image quality.

The discovery was a huge step forward in perovskite nanocrystal technology as previously, researchers were only able to produce this technology in the bone-dry atmosphere of a laboratory setting. The emitting materials are made from nanocrystals, called lead-halide perovskites.

They can harvest sunlight and concert it into renewable electricity—playing a vital role in low-cost and high-efficiency new generation solar cells and many promising applications like lighting. Unfortunately, these nanocrystals are extremely sensitive to light, heat, air and water—even water vapor in our air would kill the current devices in a matter of minutes. But this team of chemical engineers and material scientists has developed a process to wrap or bind the nanocrystals in porous glass. This process is key to stabilizing the materials, enhancing its efficiency and inhibits the toxic lead ions from leaching out from the materials.

At present QLED or quantum dot light-emitting diode screens are considered the top performer for image display and performance. This research will enable us to improve on this nanocrystal technology by offering stunning picture quality and strength.

Jingwei Hou et al, Liquid-phase sintering of lead halide perovskites and metal-organic framework glasses, Science (2021). DOI: 10.1126/science.abf4460

https://phys.org/news/2021-10-technology-unbreakable-screens.html?u...

10 UNESCO forests emit more CO2 than they soak up

Sites containing some of the world's most treasured forests, including the Yosemite National Park and Indonesia's Sumatra rainforest, have been emitting more heat-trapping carbon dioxide than they have absorbed in recent years, a U.N.-backed report said.

According to the report released Thursday, factors like logging, wildfires and clearance of land for agriculture are to blame. The excess carbon turns up from just 10 of 257 forests classified among UNESCO World Heritage sites.

The 10 sites that were net sources of carbon from 2001 to 2020 were the Tropical Rainforest in Sumatra; the Río Platano Biosphere Reserve in Honduras; Grand Canyon National Park and Yosemite National Park in the United States: Waterton Glacier International Peace Park in Canada and the U.S.; the Barberton Makhonjwa Mountains in South Africa; Kinabalu Park in Malaysia; the Uvs Nuur Basin in Russia and Mongolia; the Greater Blue Mountains area of Australia; and Morne Trois Pitons National Park in Dominica.

The Switzerland-based International Union for Conservation of Nature and UNESCO, the U.N.'s cultural and educational agency, said their report provides the first-ever assessment of greenhouse gases produced and absorbed in UNESCO-listed forests. The study was based on information collected through on-site monitoring and from satellites.

The study adds to growing signs that human activities and the fallout from climate change —which scientists say has made weather extremes like drought and wildfires more likely—have transformed some natural carbon sinks that suck up CO₂ from the air into net sources of it over the last two decades.

The report's finding that even some of the most iconic and best protected forests, such as those found in World Heritage sites, can actually contribute to climate change is alarming.

This is because of cutting trees and clearing forests , which produce CO2 and  also largely due to a bout of devastating wildfires in these areas in recent years.

https://phys.org/news/2021-10-unesco-forests-emit-co2.html?utm_sour...

Study finds California condors can have 'virgin births'

 Condors can have "'virgin births," according to a study released recently. 

Researchers with the San Diego Zoo Wildlife Alliance said genetic testing confirmed that two male chicks hatched in 2001 and 2009 from unfertilized eggs were related to their mothers. Neither was related to a male.

The study was published Thursday in the the Journal of Heredity. It's the first report of asexual reproduction in California condors, although parthenogenesis can occur in other species ranging from sharks to honey bees to Komodo dragons.

But in birds, it usually only occurs when females don't have access to males. In this case, each mother condor had previously bred with males, producing 34 chicks, and each was housed with a fertile male at the time they produced the eggs through parthenogenesis.

The researchers said they believe it is the first case of asexual reproduction in any avian species where the female had access to a mate.

These findings now raise questions about whether this might occur undetected in other species too. 

OUP accepted manuscript, Journal Of Heredity (2021). DOI: 10.1093/jhered/esab052

https://phys.org/news/2021-10-california-condors-virgin-births.html...

Study finds the SARS-CoV-2 virus can infect the inner ear

Many COVID-19 patients have reported symptoms affecting the ears, including hearing loss and tinnitus. Dizziness and balance problems can also occur, suggesting that the SARS-CoV-2 virus may be able to infect the inner ear.

A new study from MIT and Massachusetts Eye and Ear provides evidence that the virus can indeed infect cells of the inner ear, including hair cells, which are critical for both hearing and balance. The researchers also found that the pattern of infection seen in human inner ear tissue is consistent with the symptoms seen in a study of 10 COVID-19 patients who reported a variety of ear-related symptoms.

The researchers used novel cellular models of the human inner ear that they developed, as well as hard-to-obtain adult human inner ear tissue, for their studies. The limited availability of such tissue has hindered previous studies of COVID-19 and other viruses that can cause hearing loss.

Direct SARS-CoV-2 infection of the human inner ear may underlie COVID-19-associated audiovestibular dysfunction, Communications Medicine, DOI: 10.1038/s43856-021-00044-w

https://medicalxpress.com/news/2021-10-sars-cov-virus-infect-ear.ht...

Researchers invent chemical reaction that could accelerate drug discovery

Medicines come from chemical reactions, and better chemical reactions lead to better medicines.

Yet, the most popular reaction used in drug discovery, called the amide coupling, makes an inherently unstable amide bond. Because the body excels at metabolizing medication, one of the most important and difficult goals of drug research is to invent metabolically stable molecules, so we can take one pill a day instead of every 15 minutes.

To that end, researchers at the University of Michigan College of Pharmacy hacked the popular amide coupling to produce a carbon-carbon bond instead of an amide. The carbon-carbon bond is the most prevalent bond arrangement in nature and in synthetic drugs, and it's also typically more stable than the amide bond, the study appears online in the Angewandte Chemie International Edition.

The discovery of the carbon-carbon bond-forming reaction opens the door to more stable medicines, and is particularly applicable to biological probes and new medical imaging agents.

The common amide bond is formed by coupling an amine and a carboxylic acid. To form a carbon-carbon bond, researchers identified a catalyst that deaminates the amine and decarboxylates the carboxylic acid, forming a carbon-carbon bond in the process.

Joining an amine and a  carboxylic acid to make a carbon-carbon bond is also advantageous because these reagents are available in the highest diversity, and are typically less expensive than other raw ingredients that could be used to make a carbon-carbon bond.

Timothy Cernak et al, The Formal Cross‐Coupling of Amines and Carboxylic Acids to Form sp3–sp3 Carbon–Carbon Bonds, Angewandte Chemie International Edition (2021). DOI: 10.1002/anie.202112454

https://phys.org/news/2021-10-chemical-reaction-drug-discovery.html...

What is net-zero?

The search for people who never get COVID

Scientists have launched a global hunt for people who are genetically resistant to infection with SARS-CoV-2. They hope that identifying the genes protecting these individuals could lead to the development of virus-blocking drugs that not only protect people from COVID-19, but also prevent them from passing on the infection.

Vascular disease in COVID-19 is not caused by viral infection of blood vessels

The SARS-CoV-2 virus does not infect blood vessels, despite the high risk of blood clots to COVID-19 patients, researchers have found.

The researchers found that the cardiovascular complications of COVID-19 are triggered by inflammation caused by infected airway cells. At least 40 per cent of patients that are hospitalised with COVID-19 are at high risk of blood clots, and anti-coagulation therapies are now being routinely used.

There have been many studies attempting to prove whether the virus is infecting cells of the inner blood vessel wall or not.

By conducting the experiments using real, infectious virus rather than fragments of the virus’s spike protein,researchers now can definitively say it is not.

The researchers used UQ’s sophisticated microscopy facilities to track where the virus travelled in the cells and visualise how blood vessels respond to the live virus.
The body’s inflammatory response had a big effect on the cardiovascular system because they work together to fight infection – the blood delivers the immune cells to the site of infection and makes blood clots if the blood vessel is damaged.

When our immune system works well, it clears the virus from our bodies. But sometimes it goes into overdrive and we get an overblown inflammatory response causing complications –in the case of COVID-19, this is often blood clots, when there shouldn’t be any.

Knowing that it is inflammation causing these cardiovascular complications arising from COVID-19 rather than the virus itself will help us develop the right treatments, and a better understanding of how and why these complications arise.

https://onlinelibrary.wiley.com/doi/10.1002/cti2.1350

https://www.uq.edu.au/news/article/2021/10/vascular-disease-covid-1...

https://researchnews.cc/news/9726/Vascular-disease-in-COVID-19-is-n...

Experts name new species of human ancestor

An international team of researchers, led by University of Winnipeg palaeoanthropologist Dr. Mirjana Roksandic, has announced the naming of a new species of human ancestor, Homo bodoensis. This species lived in Africa during the Middle Pleistocene, around half a million years ago, and was the direct ancestor of modern humans.

The Middle Pleistocene (now renamed Chibanian and dated to 774,000–129,000 years ago) is important because it saw the rise of our own species (Homo sapiens) in Africa, our closest relatives, and the Neanderthals (Homo neanderthalensis) in Europe.

However, human evolution during this age is poorly understood, a problem which paleoanthropologists call "the muddle in the middle." The announcement of Homo bodoensis hopes to bring some clarity to this puzzling, but important chapter in human evolution.

 Resolving the "muddle in the middle": The case for Homo bodoensis sp. nov, Evolutionary Anthropology Issues News and Reviews, DOI: 10.1002/EVAN.21929

https://phys.org/news/2021-10-experts-species-human-ancestor.html?u...

Using immunotherapeutics to tackle the threat of superbugs

Recognizing familiar faces relies on a neural code shared across brains

The ability to recognize familiar faces is fundamental to social interaction. This process provides visual information and activates social and personal knowledge about a person who is familiar. But how the brain processes this information across participants has long been a question. Distinct information about familiar faces is encoded in a neural code that is shared across brains, according to a new study published in the Proceedings of the National Academy of Sciences.

Within visual processing areas, researchers found that information about personally familiar and visually familiar faces is shared across the brains of people who have the same friends and acquaintances. The surprising part of these findings was that the shared information about personally familiar faces also extends to areas that are non-visual and important for social processing, suggesting that there is shared social information across brains.

In decoding personally familiar identities, the findings demonstrated that there was much more shared information across the brains of the participants. There was high decoding accuracy in four other areas outside of the visual system: the dorsal medial prefrontal cortex, which is known to be involved in social processing (processing other people's intentions and traits); the precuneus, an area which has been shown to be more active when processing personally familiar faces; the insula, which is known to be involved in emotional processing; and the temporal parietal junction, which plays an important role in social cognition and in representing the mental states of others (also known as the "theory of the mind").

This shared conceptual space for the personal knowledge of others allows us to communicate with people that we know in common.

Shared neural codes for visual and semantic information about familiar faces in a common representational space, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2110474118.

Part 1

For the study, the research team applied a method called hyperalignment, which creates a common representational space for understanding how brain activity is similar between participants. The team used data obtained from three fMRI tasks with 14 graduate students who had known each other for at least two years. In two of the tasks, participants were presented with images of four other personally familiar graduate students and four other visually familiar persons, who were previously unknown. In the third task, participants watched parts of The Grand Budapest Hotel. The movie data, which is publicly available, was used to apply hyperalignment and align participants' brain responses into a common representational space. This allowed the researchers to use machine learning classifiers to predict what stimuli a participant was looking at based on the brain activity of the other participants.

The results showed that the identity of visually familiar and personally familiar faces was decoded with accuracy across the brain in areas that are mostly involved in visual processing of faces. Outside of the visual areas however, there was not a lot of decoding. For visually familiar identities, participants only knew what the stimuli looked like; they did not know who these people were or have any other information about them.

https://medicalxpress.com/news/2021-11-familiar-neural-code-brains....

Part 2

 Ocean plastics could be converted to ship fuel

A team of researchers think that the plastic amassing in floating islands in the oceans could be used to power the ships that are sent to clean them up. In their paper published in Proceedings of the National Academy of Sciences, the group describes how ocean plastics could be converted to ship fuel.

Prior research has shown that millions of tons of plastics enter the ocean each year—some of it is ground into fragments and disperses, and some of it winds up in colossal garbage patches floating in remote parts of the ocean. Because of the danger that such plastics present to ocean life, some environmentalists have begun cleanup operations. Such operations typically involve sending a ship to a garbage patch, collecting as much as the ship will hold and then bringing it back to port for processing. In this new effort, the researchers suggest it would be far more efficient and greener to turn the plastic into fuel for both a processing machine and for uninterrupted operation of the ships.

The researchers note that the plastic in a garbage dump could be converted to a type of oil via hydrothermal liquefaction (HTL). In this process, the plastic is heated to 300–550 degrees Celsius at pressures 250 to 300 times that of sea-level conditions. The researchers have calculated that a ship carrying an HTL converter would be capable of producing enough oil to run the HTL converter and the ship's engine. Under their scenario, plastic collection booms would be permanently stationed at multiple sites around a large garbage patch, able to load the plastic it collects onto ships.

--

The researchers acknowledge that burning the oil produced would release carbon into the atmosphere, but note that the amount emitted would still be less than that emitted by a ship burning conventional oil making trips back and forth to ports. They also note that HTL does produce a small amount of solid waste, which would have to be taken back to port, likely every few months—excess fuel produced by the HTL could be used for these trips.

 Elizabeth R. Belden et al, Thermodynamic feasibility of shipboard conversion of marine plastics to blue diesel for self-powered ocean cleanup, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2107250118

https://techxplore.com/news/2021-11-ocean-plastic-power-cleanup-shi...

Change in the Arctic and how it affects the whole world

Researchers discover new type of nerve cell in the retina

Scientists have discovered a new type of nerve cell, or neuron, in the retina.

In the central nervous system, a complex circuitry of neurons communicate with each other to relay sensory and motor information; so-called interneurons serve as intermediaries in the chain of communication. Publishing in the Proceedings of the National Academy of Sciences of the United States of America, a research team  identifies a previously unknown type of interneuron in the mammalian retina.

The discovery marks a notable development for the field as scientists work toward a better understanding of the central nervous system by identifying all classes of neurons and their connections.

Based on its morphology, physiology, and genetic properties, this cell doesn't fit into the five classes of retinal neurons first identified more than 100 years ago. Researchers, therefore, propose they might belong to a new retinal neuron class by themselves.

The research team named their discovery the Campana cell after its shape, which resembles a hand bell. Campana cells relay visual signals from both types of light-sensing rod and cone photoreceptors in the retina, but their precise purpose is the subject of ongoing research. Experiments showed Campana cells remain activated for an unusually long time—as long as 30 seconds—in response to a 10 millisecond light flash stimulation.

In the brain, persistent firing cells are believed to be involved in memory and learning. Since Campana cells have a similar behavior, we theorize they could play a role in prompting a temporal 'memory' of a recent stimulation.

Brent K. Young, Charu Ramakrishnan, Tushar Ganjawala, Ping Wang, Karl Deisseroth, Ning Tian. An uncommon neuronal class conveys visual signals from rods and cones to retinal ganglion cells. Proceedings of the National Academy of Sciences, 2021; 118 (44): e2104884118 DOI: 10.1073/pnas.2104884118

https://researchnews.cc/news/9777/Researchers-discover-new-type-of-...

COVID-19 virus test sensitivity follows the body’s circadian rhythm

Ecosystems worldwide are disrupted by lack of large wild herbivores—except in Africa

Biological research has repeatedly demonstrated that the relationship between the producer and the consumer is governed by a scaling law. An international research team has now looked into whether this law of nature can be reproduced in the relationship between the production of plants in an area and the number of large herbivores that graze on them. The study reveals that Africa is the only continent where the scaling law holds true.

June 2021 saw the start of the United Nations Decade on Ecosystem Restoration. A total of 115 countries have committed themselves to restoring up to a billion hectares of nature worldwide.

According to a group of researchers from Aarhus University and the University of Sussex, one of biggest challenges will be restoring the historical and prehistoric grazing of large mammals. What level of restoration should we aim for? How many large herbivores will we need? And how are we going to co-exist with these large animals?

The researchers examined the current low densities of large herbivores in a scientific article in the Journal of Applied Ecology. In the article, they calculated a baseline for large animals based on the ratio between producer and consumer, i.e. plants and herbivores, in nature reserves in Africa.

They stress that this relationship between producers and consumers applies across ecosystems and biomes implying a close correlation between the biomass produced and the biomass of dependent consumers.

However, after investigating the density of large herbivores in  nature reserves throughout the world, the researchers were only able to find such a close correlation on one continent: Africa. On the other continents, they found strong indications of impoverished fauna, even in protected natural areas.

African ecosystems have species-rich mammal fauna and a large biomass of big herbivores that are significantly linked to plant productivity. But we can't find this pattern on other continents, and in general the large herbivore biomass is much lower than we would expect considering the level of productivity.

In the article, the researchers argue that large herbivores are still being displaced, hunted and eradicated, and that there is a widespread perception, even among game managers, that there are plenty of herbivores in the wild, perhaps even too many. This perception is not supported by the new study.

On the contrary, efforts to decrease populations of large herbivores can reflect a shifting baseline.

Bringing back big animals is crucial to restoring self-sustaining ecosystems and conserving biodiversity, but it is not going to be easy. Large animals are troublesome, because they damage crops, disrupt traffic and generally just get in the way. It will require political commitment and careful physical planning, including fenced reserves.

Camilla Fløjgaard et al, Exploring a natural baseline for large‐herbivore biomass in ecological restoration, Journal of Applied Ecology (2021). DOI: 10.1111/1365-2664.14047

https://phys.org/news/2021-11-ecosystems-worldwide-disrupted-lack-l...

Using microbes to make carbon-neutral fuel

Researchers  have discovered a new way to train microbes to make a readily usable biofuel.

A team of biologists and engineers modified a microbe called Rhodopseudomonas palustris TIE-1 (TIE-1) so that it can produce a biofuel using only three renewable and naturally abundant source ingredients: carbon dioxide, solar panel-generated electricity and light.

The resulting biofuel, n-butanol, is an authentically carbon-neutral fuel alternative that can be used in blends with diesel or gasoline. The results are reported Nov. 3 in the journal Communications Biology.

 n-Butanol production by Rhodopseudomonas palustris TIE-1, Communications Biology (2021). DOI: 10.1038/s42003-021-02781-z

https://techxplore.com/news/2021-11-microbes-carbon-neutral-fuel.ht...

The Twisted Paths of Perception

These patterned pavements make pedestrians watch their step

The King Pedro IV Square in Lisbon, Portugal, better known as the Rossio, regales visitors with a delightful exemplar of the traditional pavement called calçada portuguesa. Originally cobbled in 1848, the dizzying light and dark undulations symbolize the sea voyages of Portuguese navigators and predate 20th-century designs by Op Art creators such as Victor Vasarely and Bridget Riley, while inducing similar perceptions of flowing motion. But does the vibrant pattern stand in the way of safety?

A recent study from the University of Bristol in England asked participants how walking on floors patterned with visual illusions affected their discomfort levels and feeling of instability. Neuropsychologist Ute Leonards, who led the study, first considered the potential negative impact of such illusory patterns on walking during a visit to the iconic street of La Rambla in Barcelona, Spain. “I had noticed the 3-D effect of the floor patterns and wanted to add them to my collection,” she recalls. As Leonards photographed the waves in the paving design, an older gentleman approached her. “He said that he didn’t like the floor at all, as he wasn’t sure when his feet would actually hit the ground and how high he should lift his feet not to trip . . . he walked [as if] afraid that there might be black ice.”

Part1 

Back in the laboratory, Leonards and her collaborators investigated the effects of four illusory patterns on people’s walking experience. Two of the designs, consisting of black-and-white alternating “furrows and ridges” modeled after the undulating pattern in Rossio Square, looked three-dimensional despite being printed on flat surfaces. More than half of the walkers found such designs aversive or uncomfortable to tread on, affecting their stability and even occasionally inducing fear of falling. The discomfort may lie in the mismatch between the sensory and physical characteristics of the walking environment. In nature, surfaces that look bumpy are generally bumpy, but this was not the case for the floor patterns examined in the study—a concern that may extend to a number of human-built environments.

The clue to avoiding the clash of art and accessibility, Leonards says, is to bring people into the planning process directly from the start and think of the project in a human-centered way. “I don’t think that this comes at the cost of aesthetics,” she explains, “but rather allows a far bigger group of people to enjoy beautiful places safely.”

This article was originally published with the title "The Twisted Paths of Perception" in SA Mind 32, 6, 33-34 (November 2021)

doi:10.1038/scientificamericanmind1121-33

https://www.scientificamerican.com/article/the-twisted-paths-of-per...

Part 2

Vascular disease in COVID-19 is not caused by viral infection of blood vessels

Researchers identify bird and reptile 'microchromosomes' once thought to be dust specks on a microscope slide

 Scientists have discovered that tiny 'microchromosomes' in birds and reptiles, initially thought to be specks of dust on the microscope slide, are linked to a spineless animal ancestor that lived 684 million years ago. They prove to be the building blocks of all animal genomes, but underwent "dizzying rearrangement" in mammals, including humans.

A team of researchers made the discovery by lining up the DNA sequence of microchromosomes that huddle together in the cells of birds and reptiles.

When these little microchromosomes were first seen under the microscope, scientists thought they were just specks of dust among the larger bird chromosomes, but they are actually proper chromosomes.

Using advanced DNA sequencing technology, scientists can at last sequence microchromosomes end-to-end.

Researchers lined up these sequences from birds, turtles, snakes and lizards, platypus and humans and compared them. Astonishingly, the microchromosomes were the same across all bird and reptile species. Even more astonishingly, they were the same as the tiny chromosomes of Amphioxus—a little fish-like animal with no backbone that last shared a common ancestor with vertebrates 684 million years ago.

 In marsupial and placental mammals these ancient genetic remnants are split up into little patches on our big, supposedly normal, chromosomes. The exception is the platypus genome, in which the microchomosomes have all fused together into a few large blocks that reflect our oldest mammal ancestor.  the findings highlight the need to rethink how we view the human genome.

Microchromosomes form a compartment in the cell that might help the genes work together.

Rather than being 'normal,' chromosomes of humans and other mammals were puffed up with lots of 'junk DNA' and scrambled in many different ways. The new knowledge helps explain why there is such a large range of mammals with vastly different genomes inhabiting every corner of our planet. 

https://researchnews.cc/news/9809/Researchers-identify-bird-and-rep...

https://theconversation.com/specks-of-dust-on-the-microscope-slide-...

Part1

https://www.karger.com/Article/Abstract/63018

https://www.pnas.org/content/118/45/e2112494118

https://www.pnas.org/content/118/45/e2112494118

part2

Antibiotic resistance outwitted by supercomputers

 Scientists may have made a giant leap in fighting the biggest threat to human health by using supercomputing to keep pace with the impressive ability of diseases to evolve.

A new study by an international team tackled the problem of antibiotic resistance by redesigning existing antibiotics to overcome bacterial resistance mechanisms.

About 700,000 people are estimated to die every year because of antibiotic resistant bacteria, and that number is expected to rise to millions.

Without effective antibiotics, life expectancy is predicted to drop by 20 years.

The race has been on for many years to develop new antibiotics to fight disease faster than a disease can evolve.

Computers have been used in drug design for decades, but this is the first study to use a multi-pronged computer-guided strategy to make a new antibiotic from an existing one which bacteria have outwitted.

The research was published in PNAS.

Antibiotics are one of the pillars of modern medicine and antibiotic resistance is one of the biggest threats to human health. There's an urgent need to develop new ways of fighting ever-evolving bacteria. It's only a matter of time until bacteria develop counterstrategies against our counterstrategies and become resistant to the new antibiotic, so we will have to keep on studying bacterial resistance mechanisms and develop new derivatives accordingly.

The hope of this new work lies in showing that the resistance mechanisms of bacteria can be addressed in a systematic way, allowing science to continually fight back with a computational evolution of new antibiotics.

Researchers developed a strategy to simulate many aspects of a redesigned antibiotic at the same time, including how soluble it is, how effective it is at entering into the bacteria, and how efficient it is at blocking their protein production.

The computational work outlined in the research was done in a matter of weeks on one of the top supercomputers in Europe, but it took the international team several years to verify experimentally that their approach was indeed correct.

Using a computational approach makes the development of new antibiotic derivatives faster and cheaper, and predicting whether a chemical compound is going to be active before it is synthesized also avoids chemical waste. This is an extremely empowering technology.

https://www.port.ac.uk/news-events-and-blogs/news/antibiotic-resist...

https://researchnews.cc/news/9807/Antibiotic-resistance-outwitted-b...

A fungus that uses chemicals to trick male flies into mating with infected dead females

A combined team of researchers from the University of Copenhagen and the Swedish University of Agricultural Sciences reports that a certain fungus uses chemicals to trick male flies into mating with infected dead females. They have written a paper describing their findings and have posted it on the bioXiv preprint server.

Prior research has shown that some types of fungus can give insect victims what has become known as summit disease, in which a victim's nervous system is infected and the unwilling creature begins climbing to the highest vantage point possible. Once there, the wings are spread wide and the victim begins spewing spores. In this new effort, the researchers have found a fungus that takes summit disease one step further by having its female victims also emit chemicals that sexually attract males.

In studying the fungus Entomophthora muscae, the researchers found that it was capable of infecting other insects, primarily house flies, with summit disease. Airborne spores land on a female victim and penetrate her skin. Soon, they invade her entire body, including her nervous system and brain. Chemicals produced by the spores incite the female to begin climbing until she reaches the highest possible point, such as a leaf on a tree. Then, she opens her wings and dies. Meanwhile, the fungus covers her body with little spore-filled cannons. At some point, a male happens by, and when he touches her body, the cannons fire, filling the air with spores, ready to infect others in the vicinity.

Part 1

In their lab, the researchers captured a host of infected and non-infected flies. Males were given a choice of mating with either an infected or non-infected female, and more often than not, chose the one that was infected. This suggested that the fungus was doing something to make the infected female more attractive to the male even though she was dead. In studying the dead females, the researchers found instances of unusual volatile compounds, including some chemicals called sesquiterpenes, which are not normally associated with house flies but have been found to sexually attract many types of insects, including house flies.

---

The vast little library inside your cells

The human genome can be thought of as a massive library, containing over 20,000 different "instruction manuals": your genes. For example, there are genes which contain information to build a brain cell, a skin cell, a white blood cell, and so on. There are even genes that contain information about regulating the genome itself—like books that explain how to organize a library. The ability to regulate gene expression—in other words, the cell's ability to turn various constellations of genes on or off—is the basis of why different cells (such as a muscle cell or a brain cell) have different forms and functions.
In a cellular nucleus, there is over six feet of genetic material packed into a space 50 times smaller than the width of a human hair. How is the "library" in the nucleus organized? When a cell needs to regulate certain genes, how does the cellular machinery find the right ones amongst 20,000 others?
A new study uses a powerful new tool that can peer into the world of the cell's genetic material (DNA and RNA) in order to find answers to these questions.

Part1

A research  team found that molecules of non-coding RNA are responsible for establishing "compartments" within the nucleus and shepherding in key molecules to precise regions in the genome. Noncoding RNA are molecules that do not encode for proteins, and instead have an array of functions that are often still mysterious to biologists. In the library analogy, non-coding RNA molecules act as the "shelves" that organize different groups of genes and the machinery that interacts with them.

Understanding how genetic material is organized spatially is a crucial part of understanding the basic workings of life. Dysfunction within the nucleus is a hallmark of many diseases, including cancer, neurodegenerative disorders, and others.

The research was made possible by a powerful tool developed in the Guttman laboratory that enables detailed views of the RNA world, called RD-SPRITE (RNA and DNA Split-Pool Recognition of Interactions by Tag Extension). In essence, RD-SPRITE works by tagging molecules of RNA and DNA with miniscule unique barcodes based on their locations; analyzing the barcodes can then tell you which molecules were at which positions within the cell.

 Sofia A. Quinodoz et al, RNA promotes the formation of spatial compartments in the nucleus, Cell (2021). DOI: 10.1016/j.cell.2021.10.014

https://phys.org/news/2021-11-vast-library-cells.html?utm_source=nw...

Part2

Lightning Strikes Carve a Deadly Signature Deep Inside The Bones, Scientists Discover

When a body is struck by lightning, a lot of different things happen. For those who do not survive the ordeal, a range of physical evidence is left on their bodies that can identify the cause of death: damage to the skin, including sometimes burn marks, as well as trauma to various organs.

But what if all the tissue decomposes? From the standpoint of forensic scientists who may only have bones to work with, does lightning leave any discernible trace behind on a skeleton?

According to a new study, yes it does.

In previous experiments, Bacci and fellow researchers identified these unique markers in animal bones, noting "extensive micro-fracturing and fragmentation of the bone matrix" in pig bones subjected to high impulse current, simulating the electrical jolt of a lightning bolt.

In that study, the same kind of micro-fracturing was also seen in the bones of a wild giraffe that was killed by a lightning strike, but it remained unclear whether human skeletons exposed to lightning-levels of current would reveal the same gruesome signature.

With the aid of cadavers donated to science, we now have our answer, with the researchers observing similar patterns of micro-fracturing in human bone subjected to the current application, and of a kind that's distinct from purely thermally induced changes to bone (such as bones burnt in a fire).

"[The lightning damage] takes the form of cracks which radiate out from the center of bone cells, or which jump irregularly between clusters of cells. The pattern of trauma is identical even though the micro-structure of human bone is different from animal bone.

Part 1

Another expected differentiator affecting micro-fracture propagation in human skeletons is bone density, which decreases with age after people reach about 40 years of age, and which might be susceptible to greater amounts of lightning-induced fracturing due to bones being more brittle.

According to the researchers, a two-fold mechanism explains why the micro-fractures in bones form the way they do.

"Firstly, the current itself produces a high-pressure shock wave when traveling through the bone," members of the research team explain in an article written for The Conversation.

"Lightning specialists term this barotrauma: the passage of electrical energy literally blows bone cells apart."

The second mechanism is an example of the piezoelectric effect, affecting how bone behaves when it's in an electric field.

"Collagen, the organic part of bone, is arranged as fibers or fibrils," the researchers explain.

"These fibrils rearrange themselves when a current is applied, causing stress to build up in the mineralized and crystallized component of bone, in turn leading to deformation and cracking."

For forensic pathologists, the discovery of the micro-fracture patterns could indeed be a "smoking gun", indicating the probable cause of death in mysterious fatalities where no other evidence remains.

For the rest of us, if we want to avoid sustaining these microscopic ruptures ourselves, it's best to stay inside whenever the weather looks like it could turn deadly.

After all, even if lightning (almost) never strikes twice, it often only needs once.

The findings are reported in Forensic Science International: Synergy.

https://www.sciencealert.com/lightning-strikes-carve-a-deadly-signa...

part 2

**

How bacteria can clean up oil spills too 

Bacteria are often painted as our adversaries, but when it comes to oil spills, toxic chemicals, and radioactive waste, they could be what save us from ourselves.

Dr. Kamal Ranadive’s 104th BirthdayToday’s (google's) Doodle celebrates Indian cell biologist Dr. Kamal Ranadive, who is best known for her groundbreaking cancer research and devotion to creating a more equitable society through science and education.

Why Arthritis Keeps Flaring Up in The Same Joints

According to new research conducted on mice, this could be because our immune system keeps a record of these past afflictions, creating a personalized disease pattern in each individual. Understanding more about how and why this happens could open up new opportunities for treating the disorder.

This latest study zooms in on the T cells in mice's bodies, white blood cells that are key to the immune system. In particular, the T cells in the synovium – the tissue lining the inside of the capsule around each joint – appear to hold a memory of previous RA problems.

Overwhelmingly, flares occur in a previously involved joint. The study shows that  these T cells anchor themselves in the joints and stick around indefinitely after the flare is over, waiting for another trigger. If you delete these cells, arthritis flares stop.

This was demonstrated through two mouse models using chemical triggers to cause joint inflammation and one mouse model using a genetic trigger to generate the same effect: The researchers removed a protein that blocked the pro-inflammatory cytokine IL-1.

These triggers caused T cells to rally other cells to the immunity cause, leading to arthritis flare-ups in specific joints in the mice. When these T cells were taken out, additional inflammation was prevented. These T cells don't move between joints and take up "long-term residency" where they are, the researchers say, ready to be reactivated again.

The approach taken here was actually inspired by skin studies. T cells with a form of memory are known to reside in the skin, leading to repeating patterns in skin problems such as psoriasis. It also happens with reactions to nickel in jewelry or wristwatches.

The research team thinks that other types of autoimmune arthritis could work in the same way, which could lead to better treatments and approaches to these issues. The next step is to confirm that the same process happens in humans and find out ways to target it.

https://www.cell.com/cell-reports/fulltext/S2211-1247(21)01372-3

https://www.sciencealert.com/immune-system-memory-might-explain-why...

Why teapots always drip

The "teapot effect" has been threatening spotless white tablecloths for ages: if a liquid is poured out of a teapot too slowly, then the flow of liquid sometimes does not detach itself from the teapot, finding its way into the cup, but dribbles down at the outside of the teapot.

This phenomenon has been studied scientifically for decades—now a research team  has succeeded in describing the "teapot effect" completely and in detail with an elaborate theoretical analysis and numerous experiments: An interplay of different forces keeps a tiny amount of liquid directly at the edge, and this is sufficient to redirect the flow of liquid under certain conditions.

The "teapot effect" was first described by Markus Reiner in 1956.

So rheology is the science of flow behavior. Again and again, scientists have tried to explain this effect precisely. Although this is a very common and seemingly simple effect, it is remarkably difficult to explain it exactly within the framework of fluid mechanics. 

The sharp edge on the underside of the teapot beak plays the most important role: a drop forms, the area directly below the edge always remains wet. The size of this drop depends on the speed at which the liquid flows out of the teapot. If the speed is lower than a critical threshold, this drop can direct the entire flow around the edge and dribbles down on the outside wall of the teapot.

Researchers  have now succeeded for the first time in providing a complete theoretical explanation of why this drop forms and why the underside of the edge always remains wetted. 

 The mathematics behind it is complicated—it is an interplay of inertia, viscous and capillary forces. The inertial force ensures that the fluid tends to maintain its original direction, while the capillary forces slow the fluid down right at the beak. The interaction of these forces is the basis of the teapot effect. However, the capillary forces ensure that the effect only starts at a very specific contact angle between the wall and the liquid surface. The smaller this angle is or the more hydrophilic (i.e. wettable) the material of the teapot is, the more the detachment of the liquid from the teapot is slowed down.

Interestingly, the strength of gravity in relation to the other forces that occur does not play a decisive role. Gravity merely determines the direction in which the jet is directed, but its strength is not decisive for the teapot effect. The teapot effect would therefore also be observed when drinking tea on a moon base, but not on a space station with no gravity at all.

B. Scheichl et al, Developed liquid film passing a smoothed and wedge-shaped trailing edge: small-scale analysis and the 'teapot effect' at large Reynolds numbers, Journal of Fluid Mechanics (2021). DOI: 10.1017/jfm.2021.612

https://phys.org/news/2021-11-teapots.html?utm_source=nwletter&...

We don’t ‘believe in’ Newton’s laws. We trust them and accepted them because there is genuine evidence that they work.

Newton's laws of motion are three laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows (1):

Law 1. A body continues in its state of rest, or in uniform motion in a straight line, unless acted upon by a force.

Law 2. A body acted upon by a force moves in such a manner that the time rate of change of momentum equals the force.

Law 3. If two bodies exert forces on each other, these forces are equal in magnitude and opposite in direction.

Newton's laws were verified by experiment and observation for over 200 years, and they are excellent approximations at the scales and speeds of everyday life. 

1. https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion

How are epilepsy and autism linked?

Epilepsy and autism spectrum disorders, or ASD, show a remarkable degree of comorbidity and may share pathological mechanisms. Questions that have bogged down scientists about these disorders include: Does autism lead to an increase in epilepsy? Or does epilepsy alter the brain circuit, which then leads to autism?

One hypothesis is that during brain development, inhibitory neurons,  which regulate brain rhythms, develop in an abnormal manner. If this is true, then how the brain circuit gets set up is abnormal, which may lead to both autism and epilepsy. 

unlike excitatory neurons that lead to a forward propagation of information, inhibitory neurons work like a brake by suppressing and sculpting the activity of downstream neurons.

The researchers generated mice with a global mutation in all cells that prevented the inhibitory neurons from migrating to their normal location in mature brain circuits. Not surprisingly, they found a reduction in inhibitory currents in the hippocampus, a region of the brain known for memory function. Notably, the mutant mice showed behavioral traits associated with ASD and were more prone to seizures.

Results of the study suggest that a common underlying defect in circuit formation could contribute to both ASD and epilepsy.

Carol Eisenberg et al, Reduced hippocampal inhibition and enhanced autism-epilepsy comorbidity in mice lacking neuropilin 2, Translational Psychiatry (2021). DOI: 10.1038/s41398-021-01655-6

https://medicalxpress.com/news/2021-11-epilepsy-autism-linked.html?...

Modified silk cloth keeps skin cooler than cotton

A team of researchers has developed a modified textile that can keep skin cooler than materials made of cotton. In their paper published in the journal Nature Nanotechnology, the group describes their approach to developing garments that are cooler when worn in outdoor conditions.

The researchers noted that silk does a good job of reflecting sunlight in the mid-infrared range, which suggests it could be suitable as a cooling garment material. But because it is made by spiders, it contains a protein component that tends to absorb ultraviolet radiation, making the material and its wearer grow hotter under direct sunlight.

To make the silk material UV reflective, the researchers dipped a standard piece of silk fabric into a liquid solution containing highly refractive inorganic oxide nanoparticles. These adhered to the silk fabric, allowing it to become evenly saturated throughout the material. They allowed the fabric to dry and then tested it to see if the addition of the nanoparticles made the material more UV reflective. They found that under peak sunlight conditions, the temperature under the material was approximately 3.5 degrees Celsius cooler than the ambient air temperature. Next, they placed the material on a patch of simulated skin and found the skin temperature was approximately 8 degrees Celsius cooler than the same type of simulated skin without the material covering. They also found that it kept the artificial skin approximately 12.5 degrees Celsius cooler than standard cotton material. Further testing showed that the material was able to reflect approximately 95% of sunlight, preventing it from passing through to the skin underneath.

Bin Zhu et al, Subambient daytime radiative cooling textile based on nanoprocessed silk, Nature Nanotechnology (2021). DOI: 10.1038/s41565-021-00987-0

https://phys.org/news/2021-11-silk-skin-cooler-cotton.html?utm_sour...

White-tailed deer found to be huge reservoir of coronavirus infection

New research from the US has shown that white-tailed deer are being infected with SARS-CoV-2, the virus that causes COVID-19 in humans. Antibodies were found in 40% of deer that were tested from January to March 2021 across Michigan, Pennsylvania, Illinois and New York state. A second unpublished study has detected the virus in 80% of deer sampled in Iowa between November 2020 and January 2021.

Such high levels of infection led the researchers to conclude that deer are actively transmitting the virus to one another. The scientists also identified different SARS-CoV-2 variants, suggesting there have been many human-to-deer infections.

The large numbers of white-tailed deer in North America and the fact that they often live close to people provide several opportunities for the disease to move between the two species. This can include wildlife management operations, field research, recreation, tourism and hunting. In fact, hunters are likely to be one of the most obvious sources of potential reinfection as they regularly handle dead animals. It has also been suggested that water sources contaminated with SARS-CoV-2 might provide a pathway for transmission, although this has yet to be proved.

Human-to-deer and deer-to-deer transmission are believed to be driving the rapid spread of the disease within white-tailed deer populations across the US. This is particularly apparent during the early months of 2021 when COVID infections were spiking in the human population. Previous studies have shown that SARS-CoV-2 can be passed from humans to domestic and captive animals including cats, dogs, zoo animals and, most notably, farmed mink. But, until now, the disease had not been shown to spread in wildlife species.

There is the possibility that viral mutation in a reservoir host, such as white-tailed deer, could lead to new variants of the disease. These variants may lead to greater infection rates, increased virulence (severity of symptoms) and prove more effective at evading the human immune system. Likewise, any reinfection from wildlife reservoirs could also complicate our long-term efforts to fight and suppress the disease.

https://www.pnas.org/content/118/47/e2114828118

https://www.biorxiv.org/content/10.1101/2021.10.31.466677v1

https://theconversation.com/white-tailed-deer-found-to-be-huge-rese...

Humans are guilty of breaking an oceanic law of nature: study

A new international study has examined the distribution of biomass across all life in the oceans, from bacteria to whales. Their quantification of human impact reveals a fundamental alteration to one of life's largest scale patterns.

Scientists have used advances in ocean observation and large meta-analyses to show that human impacts have already had major consequences for the larger oceanic species, and have dramatically changed one of life's largest scale patterns—a pattern encompassing the entire ocean's biodiversity, from bacteria to whales.

Early samples of marine plankton biomass from 50 years ago led researchers to hypothesize that roughly equal amounts of biomass occur at all sizes. For example, although bacteria are 23 orders of magnitude smaller than a blue whale, they are also 23 orders of magnitude more abundant. This size-spectrum hypothesis has since remained unchallenged, even though it was never verified globally from bacteria to whales. The authors of the study, published in the journal Science Advances, sought to test this hypothesis on a global scale for the first time. They used historical reconstructions and marine ecosystem models to estimate biomass before industrial scale fishing got underway (pre-1850) and compared this data to the present-day.

One of the biggest challenges to comparing organisms spanning bacteria to whales is the enormous differences in scale.

The ratio of their masses is equivalent to that between a human being and the entire Earth. Researchers estimated organisms at the small end of the scale from more than 200,000 water samples collected globally, but larger marine life required completely different methods.

Their approach focused on 12 major groups of aquatic life over roughly 33,000 grid points of the ocean. Evaluating the pre-industrial ocean conditions (pre-1850) largely confirmed the original hypothesis: There is a remarkably constant biomass across size classes.

Researchers were amazed to see that each order of magnitude size class contains approximately 1 gigaton of biomass globally.

While bacteria are over-represented in the cold, dark regions of the ocean, the largest whales are relatively rare, thus highlighting exceptions from the original hypothesis.

In contrast with an even biomass spectrum in the pre-1850 ocean, an investigation of the spectrum at present revealed human impacts on ocean biomass through a new lens. While fishing and whaling only account for less than 3 percent of human food consumption, their effect on the biomass spectrum is devastating: large fish and marine mammals such as dolphins have experienced a biomass loss of 2 Gt (60% reduction), with the largest whales suffering an unsettling almost 90% decimation. The authors estimate that these losses already outpace potentialbiomass losses even under extreme climate change scenarios.

Humans have impacted the ocean in a more dramatic fashion than merely capturing fish. It seems that we have broken the size spectrum—one of the largest power law distributions known in nature.  These results provide a new quantitative perspective on the extent to which anthropogenic activities have altered life at the global scale. 

Ian A. Hatton et al, The global ocean size spectrum from bacteria to whales, Science Advances (2021). DOI: 10.1126/sciadv.abh3732

https://phys.org/news/2021-11-humans-guilty-oceanic-law-nature.html

Nuclear radiation used to transmit digital data wirelessly

Engineers have successfully transferred digitally encoded information wirelessly using nuclear radiation instead of conventional technology.

Radio waves and mobile phone signals relies on electromagnetic radiation for communication but in a new development, engineers from Lancaster University in the UK, working with the Jožef Stefan Institute in Slovenia, transferred digitally encoded information using "fast neutrons" instead.

The researchers measured the spontaneous emission of fast neutrons from californium-252, a radioactive isotope produced in nuclear reactors.

Modulated emissions were measured using a detector and recorded on a laptop.

Several examples of information, i.e., a word, the alphabet and a random number selected blindly, were encoded serially into the modulation of the neutron field and the output decoded on a laptop which recovered the encoded information on screen.

A double-blind test was performed in which a number derived from a random number generator was encoded without prior knowledge of those uploading it, and then transmitted and decoded. 

All transmission tests attempted proved to be 100% successful.

Malcolm J. Joyce et al, Wireless information transfer with fast neutrons, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2021). DOI: 10.1016/j.nima.2021.165946

https://phys.org/news/2021-11-nuclear-transmit-digital-wirelessly.html