Tuesday 31 January 2023

Science News: Can the brain compete with advanced artificial intelligence systems?

 

Can the brain compete with advanced artificial intelligence systems?


Artificial intelligence stems from human brain dynamics, but brain learning is restricted in a number of significant aspects compared to deep learning.


By JUDY SIEGEL-ITZKOVICH, JANUARY 30, 2023
https://www.jpost.com/science/article-730071

                                   Artificial intelligence (photo credit: INGIMAGE)


Many professionals – from architects to graphic artists – are aware that artificial intelligence systems may in the near future either replace them or speed up and improve their work. Traditionally, AI stems from human brain dynamics, but brain learning is restricted in a number of significant aspects compared to deep learning (DL).

Advanced deep-learning architectures consist of tens of fully connected and convolutional hidden layers. Currently extended to hundreds, they are far from their biological counterparts.

Can the brain, with its limited realization of precise mathematical operations, compete with advanced AI systems implemented on fast and parallel computers? From our daily experience, we know that for many tasks the answer is yes. Why is this, and can we build a new type of efficient AI inspired by the brain?

A.I. Versus the Human Brain, Neuroscientist Moshe Bar



Can an AI inspired by the brain be built?

First, efficient DL wiring structures consist of many tens of feed-forward layers, while brain dynamics consist of only a few feed-forward layers. Second, DL architectures typically consist of many consecutive filter layers, which are essential to identify one of the input classes. If the input is a car, for example, the first filter identifies wheels, the second one identifies doors, the third one lights. After many additional filters, it becomes clear that the input object is, indeed, a car.

Artificial intelligence (credit: PIXABAY/WIKIMEDIA)                          Artificial intelligence (credit: PIXABAY/WIKIMEDIA)

Conversely, brain dynamics contain just a single filter located close to the retina. The last necessary component is the mathematically complex DL training procedure, which is evidently far beyond biological realization.

Yuval Meir, in an article published on Monday in the journal Scientific Reports under the title “Learning on tree architectures outperforms a convolutional feedforward network,” said researchers from Bar-Ilan University in Ramat Gan have solved this puzzle.

Lead researcher Prof. Ido Kanter, of BIU’s Physics Department and the Gonda Multidisciplinary Brain Research Center, said, “We’ve shown that efficient learning on an artificial tree architecture, in which each weight has a single route to an output unit, can achieve better classification success rates than previously achieved by DL architectures consisting of more layers and filters. This finding paves the way for efficient, biologically inspired new AI hardware and algorithms.”

Meir, a doctoral student who contributed to this work, added, “Highly pruned tree architectures represent a step toward a plausible biological realization of efficient dendritic tree learning by a single or several neurons, with reduced complexity and energy consumption, and biological realization of back-propagation mechanism, which is currently the central technique in AI.

Efficient dendritic tree learning is based on previous research by Kanter and his experimental research team and conducted by Dr. Roni Vardi. It showed evidence for sub-dendritic adaptation using neuronal cultures, together with other anisotropic properties of neurons, like different spike waveforms, refractory periods and maximal transmission rates.

The efficient implementation of highly pruned tree training requires a new type of hardware that differs from emerging graphics processing units that are better fitted to the current DL strategy. The emergence of a new hardware is required to efficiently imitate brain dynamics. 

Intel Advances in AI: Brain-Like Computing and Spiking Neural Networks Explained



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STATIONS ACROSS ANTARCTICA LOG COLDEST JANUARY TEMPERATURES EVER; UTAH ‘SINKS’ TO -62F, STATE’S COLDEST READING SINCE 2002; ASIA’S ALL-TIME LOWS; + “THE STRATOSPHERE HAS SUDDENLY BECOME VERY, VERY COLD”

JANUARY 31, 2023 CAP ALLON


STATIONS ACROSS ANTARCTICA LOG COLDEST JANUARY TEMPERATURES EVER

As discussed yesterday, for the past 7-decades –at least– Antarctica has been defying AGW Party orders and COOLING with its ice sheet EXPANDING. This trend has intensified in recent years, with the burgeoning 2023 continuing the move…

Extreme cold (for summer) is striking Antarctica this January with anomalous readings well-below -40C a regular feature.

On Saturday, Jan 28 the infamous Vostok Station, which lies at the southern Pole of Cold, posted a staggering -47.5C (-53.5F) — the station’s lowest January temperature since the -48.5C (-55.3F) of Jan 30, 1989 (solar minimum of cycle 21).

Then, on Sunday, Jan 29, Vostok sank even further, logging a low of -48.7C (-55.7F) which took out 1989’s historical January low and made it the station’s coldest-ever summer temperature since its opening back in 1957 (note: slightly lower temps were posted in 1994 and 1998 but both failed quality control).


Moreover, data for the entire month of December are also in for Vostok, and confirm that the station, with an average of -34.1C (-29.4F), endured its second-coldest final month of the year since records began (after Dec 1999).

Antarctica’s cooling is also observed across the continent, not just at Vostok.

For example, the South Pole Station suffered its coldest-ever coreless winter in 2021 (April-Sept), and has posted colder-than-average months ever-since: The most recent being Nov 2022’s -40.4C (-40.7F)—coldest since 1987; Dec 2022’s -29.1C (-20.4F)—coldest since 2006; Jan 2023’s (approx.) -31.3C (-24.3F)—coldest since 1995; and the Summer of 2022-23’s -30.2C (-22.4F)—coldest since 1999-2000.

Confirming the the Italian-French Concordia Station is also getting in on the act, with Monday’s (Jan 30) low of -48.5C tying the locale’s coldest-ever January reading which was set exactly a year ago, on Jan 20, 2022. its new seasonal minimum of -48.5 °C and tied the monthly low of -48.5 °C recorded only a year ago (January 30, 2022) The meteorological data of the station begins in 2005

The Italian-French Concordia Station further-confirmed the cooling on Monday, Jan 30. Its low of -48.5C (-55.3F) matched the station’s lowest-ever January temperature which was posted just last year.

A clear trend is emerging for those whose eyes are their own: Here are Concorida’s January lows in chronological order: -48C on Jan 28, 2012; -48.3C on Jan 31, 2012; -48.5C on Jan 30, 2022; and now -48.5C on Jan 30, 2023.

Nothing says “Catastrophic Sea Level Rise” like the world’s largest ice sheet, home to 90% of the planet’s surface freshwater, suffering persistent and record-breaking COLD. Nothing says “Global Warming” like the bottom of the world COOLING.

UTAH ‘SINKS’ TO -62F, STATE’S COLDEST READING SINCE 2002

Records are beginning to fall across the U.S., and indeed Canada, as this week’s Arctic Outbreak enters.

Monday was particularly-frigid in Central-Western states with Peter Sink, Utah claiming the cherry with its -62F (-52.2C) — the state’s lowest temperature since 2002.

Elsewhere, Denver’s -10F (-23.3C) on Jan 30 tied a cold record set in 1985 (solar minimum of cycle 21).

While in Dillon, Montana, a low of -27F (-32.8C) early Monday morning busted the city’s previous record from 1951.

Extreme cold also shattered benchmarks across eastern Idaho on Monday, with bone-chilling lows reported in Rexburg, Idaho Falls, Pocatello, Stanley and Challis, to name just five regions.

The above is by no means a comprehensive list of the Lower-48’s felled records.

And there is still much, much more to come…

…including another Polar Plunge currently forecast for mid-Feb:



Additionally, authorities in Nevada are blaming the state’s extortionate gas bills on two factors: 1) rising natural gas prices (questionable: gas prices have actually been tanking in recent month), and 2) an abnormally cold January.

With regards to the latter, of the 30 days so far this month, just five have reached normal highs.

ASIA’S ALL-TIME LOWS

Asia’s historic cold spell is persisting.

Concentrating on the Southeast, anomalous-lows continue to be posted, including the 2.6C at Lang Son, Vietnam; the 1.5C at Samneua, 1.6C at Viengsay, and 1.6C at Tkakhek, all Laos; and the 5.1C at Nakhon Phanom Agro, Thailand.

Also, when those parroting, obfuscating alarmists claim that “zero cold records have fallen in 2023”–as they are assured of claiming, for they claim it every year–be sure to forward them the below graphic, which logs just five of the ‘new all-time cold temperature records in Asia, by location”, including the all-time national low set in China at Mohe city on January 22:


“THE STRATOSPHERE HAS SUDDENLY BECOME VERY, VERY COLD”

Around the North Pole, “the stratosphere has suddenly become very, very cold,” writes Dr Tony Phillips.

NASA satellites are registering exceptionally-low temperatures of less than -85C which is the threshold for the formation of rare polar stratospheric clouds (PSCs).

Over the past week, PSCs, also know as nacreous clouds, have spilled outside the Arctic Circle and are seen to be intensifying and also spreading unusually-far south.

On Sunday evening into Monday morning, sky-gazers across Scotland were treated to the rare phenomenon:

PSCs cloud seen at sunset in Aberdeenshire, Scotland.

Also referred to as “mother-of-pearl”, PSCs are considered rare because of the very cold conditions needed for them to form. The fact that these clouds are forming at such low latitudes may be an indication that the ‘polar jets’ (or ‘polar vortex’) is weakening, which could in turn signal that more Arctic air is about to descend unusually-far south (as we’re already in Asia and North America).

A PSC spotted over Scotland, also known as “mother-of-pearl”.

Finishing with a brief look at sunspots, activity on the Sun has nosedived in recent days.

From the calculated 200+ sunspots of last week we’re now down into the 60s.

If a Grand Solar Minimum is indeed on the cards, as is my contention (by SC26/27), then what we just saw could be considered ‘death throes’. There may-well be additional ‘fits and starts’ and ‘violent splutterings’ to come, but I believe the current cycle (SC25) will peak sooner than forecasted and then drive into a deeper minimum than even the historically low SC24.

Time, of course, will tell on that one.

None of these small sunspots poses a threat for flaring. [SDO/HMI]
Note: each sunspot ‘region’ –of which there are currently 5– will often contain multiple spots.

Thank you for the ‘cornfield planting’ tips I’ve received — they’ve all been helpful.

I’ll let you know how things go (my makeshift trailer idea was an abject failure, btw).

And finally, here in Central Portugal it’s gotten so frosty that our external water pipe (leading up from our lake) has frozen, meaning, at least for today, we won’t be able to top up our water tank.

Nothing says “global warming” like… …you know how it goes…

Enjoy your Tuesday.

Spring is around the corner, believe it or not — get those vegetable beds prepped.


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Primates colonised the Arctic during a period of ancient global warming—their fate offers a lesson

JANUARY 30, 2023, by Jason Gilchrist, The Conversation

Researchers have found evidence that primates colonised northern Canada 52 million years ago.
 Credit: Kaca Skokanova/Shutterstock

Two new species of prehistoric primate were recently identified by scientists studying fossils from Canada's Ellesmere Island in the high Arctic. The primates are closely related and likely originated from a single colonization event, following which they split into two species: Ignacius dawsonae and Ignacius mckennai.

At 52 million years old, they represent the most recent known members of their genus.

The primates colonized the high latitudes during a period of historic global warming called the early Eocene climatic optimum (EECO). During this period, the high Arctic, now cold and inhospitable, had a climate similar to the cypress swamps of the southeastern U.S.. The primates shared the landscape with species that are today associated with warmer climates, including crocodilians and tapirs.

This warmer period had a major impact on biodiversity. But it also has important implications for our understanding of climate change today. Human impact on the climate is so dramatic that scientists are calling for the acknowledgement of a new geological period called the Anthropocene.
New Arctic primate fossils

The Ellesmere Ignacius species are known only from teeth and jaw fragments. But other species of Ignacius for which additional skeletal materials are available indicate a tree-living lifestyle similar to modern colugos, a gliding mammal native to southeast Asia. The new primates likely evolved from ancestral paromomyids (extinct gliding primates) from North America's southerly latitudes.

Based on tooth size, Ignacius dawsonae at 1.17 kg was twice as large as Ignacius clarkforkensis, the biggest mid-latitude member of the genus (0.47 kg). Ignacius mckennai at 1.98 kg may have been four times as large as its biggest southern cousin. The new Ignacius were roughly the size of a rabbit.

These results support Bergmann's Rule, a theory that links the climate to animal anatomy. It states that the colder the climate, the larger the animal. While the high Arctic was warmer during the EECO than it is today, its climate was still cooler than the ancestral range of Ignacius species.

As a shape gets bigger, its relative surface area to volume ratio gets smaller. This means the surface area over which heat is lost is relatively smaller for larger animals. To minimize heat loss, animals that live in colder climates tend to be bigger than similar species in warmer climates.

Penguins, for example, broadly follow Bergmann's rule. The large emperor penguin lives near the south pole, while smaller species such as the Humboldt penguin inhabit regions closer to the equator.

The Ellesmere Ignacius also exhibits large teeth and jaw muscles. The biomechanics indicate a high bite force with relatively low and serrated molars. This suggests a diet that included harder objects such as seeds and nuts that provided a food source during the long dark winters of such northerly latitudes.

The science of discovery

The fossils were excavated at multiple locations over several decades before being examined and photographed using micro-computed tomography. This is a modern technique that allows scientists to digitally map the anatomy of fossils embedded inside rocks.

The researchers then conducted phylogenetic analysis of the teeth and jaw fragments to determine identity and evolutionary relatedness to previously described species. They also compared tooth topography (a 3D landscape map of the tooth surface) with living and other fossil primates to determine the new species' likely diet.
Implications for future evolution

The EECO will have seen a turnover of animal species. As local climates warm, individual organisms have two options: move or die. At the species level, animals have a third option, to evolve over generations to adapt to changing environmental conditions.

The fact that mammals living in warmer climates colonized the changing Arctic habitat is likely because their own ancestral range was becoming too hot. This indicates the potential for migration, followed by evolutionary radiation, to fill opening ecological niches created by climate change.

But the colonization was selective. Several mammal species, including deer, antelope, horses and small herbivore groups lived in warmer regions further south but did not inhabit such northerly latitudes. A much greater variety of primitive primates also did not make Ellesmere their home during the EECO. Biodiversity in the High Arctic therefore remained lower than at more southerly latitudes.

The researchers suggest that temperature was not the main barrier to successful colonization. Instead it was probably the long winter darkness and the resultant effect on the availability of plant materials as food. Some mammal species were not capable of the transition.

History shows us that various mammals can move northwards and adapt, and that biodiversity can increase. But evolution needs two things: genetic diversity and time.

However, expanding human populations are having increasingly destructive effects on nature. Persecution and habitat loss have, for example, reduced population sizes and genetic diversity across species. Pollution also means that the climate is changing faster than ever before. It is thus harder for species to adapt.

Ironically, climate change may also explain why the Arctic Ignacius species went extinct. As Arctic temperatures again cooled, Ignacius likely found itself maladapted to the cold and unable to migrate south or compete with mid-latitude species that were better adapted to their environment.

Humans cheat the climate by using technology to evade environmental challenges. Air conditioning, central heating and clothes enable humans to survive in places that we would otherwise be unable to tolerate.

But we are vulnerable to climate change. If human-induced climate change continues, it is not just other animals that will experience the same fate as Ignacius. We will too.


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Tuning into brainwave rhythms speeds up learning in adults, study finds

JANUARY 31, 2023, by U. of Cambridge

The brainwaves experiment set-up in the Adaptive Brain Lab, led by Prof Zoe Kourtzi, in the University of Cambridge's Department of Psychology.
 Credit: University of Cambridge

Scientists have shown for the first time that briefly tuning into a person's individual brainwave cycle before they perform a learning task dramatically boosts the speed at which cognitive skills improve.

Calibrating rates of information delivery to match the natural tempo of our brains increases our capacity to absorb and adapt to new information, according to the team behind the study.

University of Cambridge researchers say that these techniques could help us retain "neuroplasticity" much later in life and advance lifelong learning.

"Each brain has its own natural rhythm, generated by the oscillation of neurons working together," said Prof Zoe Kourtzi, senior author of the study from Cambridge's Department of Psychology. "We simulated these fluctuations so the brain is in tune with itself—and in the best state to flourish."

"Our brain's plasticity is the ability to restructure and learn new things, continually building on previous patterns of neuronal interactions. By harnessing brainwave rhythms, it may be possible to enhance flexible learning across the lifespan, from infancy to older adulthood," Kourtzi said.

The findings, published in the journal Cerebral Cortex, will be explored as part of the Center for Lifelong Learning and Individualized Cognition: a research collaboration between Cambridge and Nanyang Technological University (NTU), Singapore.

The neuroscientists used electroencephalography—or EEG—sensors attached to the head to measure electrical activity in the brain of 80 study participants, and sample brainwave rhythms.

The team took alpha waves readings. The mid-range of the brainwave spectrum, this wave frequency tends to dominate when we are awake and relaxed.

Alpha waves oscillate between eight to twelve hertz: a full cycle every 85-125 milliseconds. However, every person has their own peak alpha frequency within that range.

An EEG cap used in the brainwaves experiment run by the Adaptive Brain Lab, led by Prof Zoe Kourtzi, in the University of Cambridge's Department of Psychology. 
Credit: University of Cambridge



Scientists used these readings to create an optical "pulse": a white square flickering on a dark background at the same tempo as each person's individual alpha wave.

Participants got a 1.5-second dose of personalized pulse to set their brain working at its natural rhythm—a technique called "entrainment"—before being presented with a tricky quick-fire cognitive task: trying to identify specific shapes within a barrage of visual clutter.

A brainwave cycle consists of a peak and trough. Some participants received pulses matching the peak of their waves, some the trough, while some got rhythms that were either random or at the wrong rate (a little faster or slower). Each participant repeated over 800 variations of the cognitive task, and the neuroscientists measured how quickly people improved.

The learning rate for those locked into the right rhythm was at least three times faster than for all the other groups. When participants returned the next day to complete another round of tasks, those who learned much faster under entrainment had maintained their higher performance level.

"It was exciting to uncover the specific conditions you need to get this impressive boost in learning," said first author Dr. Elizabeth Michael, now at Cambridge's Cognition and Brain Sciences Unit.

"The intervention itself is very simple, just a brief flicker on a screen, but when we hit the right frequency plus the right phase alignment, it seems to have a strong and lasting effect."

Importantly, entrainment pulses need to chime with the trough of a brainwave. Scientists believe this is the point in a cycle when neurons are in a state of "high receptivity".

"We feel as if we constantly attend to the world, but in fact our brains take rapid snapshots and then our neurons communicate with each other to string the information together," said co-author Prof Victoria Leong, from NTU and Cambridge's Department of Pediatrics.

"Our hypothesis is that by matching information delivery to the optimal phase of a brainwave, we maximize information capture because this is when our neurons are at the height of excitability."

The brain activity over time of a study participant, recorded at several different locations on the scalp by the EEG cap as part of the experiment. 
Credit: University of Cambridge



Previous work from Leong's Baby-LINC lab shows that brainwaves of mothers and babies will synchronize when they communicate. Leong believes the mechanism in this latest study is so effective because it mirrors the way we learn as infants.

"We are tapping into a mechanism that allows our brain to align to temporal stimuli in our environment, especially communicative cues like speech, gaze and gesture that are naturally exchanged during interactions between parents and babies," said Leong.

"When adults speak to young children they adopt child-directed speech—a slow and exaggerated form of speaking. This study suggests that child-directed speech may be a spontaneous way of rate-matching and entraining the slower brainwaves of children to support learning."

The researchers say that, while the new study tested visual perception, these mechanisms are likely to be "domain general": applying to a wide range of tasks and situations, including auditory learning.

They argue that potential applications for brainwave entrainment may sound like the stuff of science fiction, but are increasingly achievable. "While our study used complex EEG machines, there are now simple headband systems that allow you to gauge brain frequencies quite easily," said Kourtzi.

"Children now do so much of their learning in front of screens. One can imagine using brainwave rhythms to enhance aspects of learning for children who struggle in regular classrooms, perhaps due to attentional deficits."

Other early applications of brainwave entrainment to boost learning could involve training in professions where fast learning and quick decision-making is vital, such as pilots or surgeons. "Virtual reality simulations are now an effective part of training in many professions," said Kourtzi.

"Implementing pulses that sync with brainwaves in these virtual environments could give new learners an edge, or help those retraining later in life."


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Monday 30 January 2023

Intriguing Meteorite From Mars Reveals 'Huge Organic Diversity', Scientists Say

30 January 2023, ByLAURENCE TOGNETTI, UNIVERSE TODAY

Martian meteorite Tissint. (Ludovic Ferriere/Natural History Museum Vienna)

In a recent study published in Sciences Advances, an international team of scientists led by the Technical University of Munich examined the Martian meteorite Tissint, which fell near the village of Tissint, Morocco, on 18 July 2011, with pieces of the meteorite found as far as approximately 50 kilometers (30 miles) from the village.

What makes Tissint intriguing is the presence of a "huge organic diversity", as noted in the study, which could help scientists better understand if life ever existed on Mars, and even the geologic history of Earth, as well.

"Mars and Earth share many aspects of their evolution," Dr. Philippe Schmitt-Kopplin, who is the director of the research unit Analytical Biochemistry at the Technical University of Munich, and lead author of the study, said in a statement.

"And while life arose and thrived on our home planet, the question of whether it ever existed on Mars is a very hot research topic that requires deeper knowledge of our neighboring planet's water, organic molecules, and reactive surfaces."



ALH 84001 meteorite. (NASA/Johnson Space Center)



Organic molecules are molecules comprised of carbon atoms that are bonded to hydrogen atoms, but can also contain oxygen, nitrogen, and other elements, as well. The four primary classes of organic molecules include carbohydrates, proteins, nucleic acids, and lipids.

As seen on Earth, organic molecules are analogous to life, but the study notes that abiotic organic chemistry, non-biological processes, have been observed "in other Martian meteorites."

"Understanding the processes and sequence of events that shaped this rich organic bounty will reveal new details about Mars' habitability and potentially about the reactions that could lead to the formation of life," Dr. Andrew Steele, who is a staff scientist at Carnegie Science, a member of the Mars Sample Return Campaign Science Group for NASA's Perseverance rover, and a co-author on the study, said in a statement.

Dr. Steele has also conducted extensive research pertaining to organic material found in Martian meteorites, to include Tissint.

For the study, the researchers examined the entirety of Tissint's organic composition, and identified a "diverse chemistry and abundance in complex molecules ", as noted in the study, while also helping to unlock the past geologic processes within the crust and mantle of the red planet.

The researchers also identified a plethora of organic magnesium compounds never before observed on Mars, which could bring new evidence about the geochemical processes that shaped Mars' deep interior while possibly making a link between the red planet's mineral evolution and carbon cycle.

NASA's upcoming Mars Sample Return mission could provide even greater insights into both the organic and mineral composition of the red planet. Dr. Schmitt-Kopplin recently told Universe Today that such a mission could be just as successful as Japan's Hayabusa2 asteroid sample return mission since they "were able to show that meteorites reflect nicely the chemistry found in the return mission, we probably will be able to do the same."

Tissint has a total weight of 7 kilograms (15 pounds), and is currently the fifth meteorite classified as being of Martian origin, with a 2012 study estimating it was ejected from Mars approximately 700,000 years ago from some type of violent event.

Microscopic structures within ALH 84001 fragments that were initially interpreted to be microfossils, but those findings have since been rendered inconclusive. (NASA)



Tissint draws some parallels with one of the most famous meteorites of Martian origin found on Earth, ALH 84001, which was the subject of much scrutiny in the late 1990s when it was initially believed to contain microfossils, findings that since been rendered inconclusive.

"ALH 84001 was one of the most studied Mars meteorites because it was found in Antarctica and thus was 'conserved' in the ice with low contamination," Dr. Schmitt-Kopplin recently told Universe Today.

"That time looking at molecules of life in the diverse chemistry of that meteorite and seeing in addition biological-like features in microscopy led to a too rapid conclusion of having found life on Mars."

What new secrets of Mars will Tissint, future meteorites, and the future samples returned from Mars teach us about the red planet? Only time will tell, and this is why we science!


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Our Body Temps Have Been Dropping For 160 Years. Gut Microbes May Be Playing a Role

30 January 2023, By DAVID NIELD

(image_jungle/iStock/Getty Images Plus)

The average temperature of the human body has been steadily declining since the middle of the 19th century, and scientists aren't sure why. A new study suggests one key factor that might play a role in this: gut microbes.

Examining data from patients hospitalized with sepsis – where the body reacts in a dangerously extreme way to infection – as well as from tests on mice, the researchers behind the study looked at the relationship between gut bacteria, changes in temperature, and health outcomes.

That choice of sepsis patients is deliberate because the condition can lead to a variety of temperature fluctuations in the body that are often related to the chances of someone pulling through and recovering.

"We know that temperature response is important in sepsis because it strongly predicts who lives and who dies," says microbiologist and immunologist Robert Dickson from the University of Michigan.

"But we don't know what drives this variation and whether it can be modified to help patients."

The team studied gut bacteria samples taken from 116 people with sepsis, discovering that there were wide variations in the microbiota – and that the variations correlated with changes in the temperature trajectories of the patients.

Bacteria from the Firmicutes phylum were most closely associated with having a higher fever. These bacteria produce important substances for body growth and health and influence the body's immune response and metabolism.

While it's not enough to show that gut bacteria are why our insides have been getting cooler over the last 150 years, it's an interesting hypothesis – and it shows how our gut microbiome is linked to body temperature.

"Arguably, our patients have more variation in their microbiota than they do in their own genetics," says internist Kale Bongers, also from the University of Michigan. "Any two patients are more than 99 percent identical in their own genomes, while they may have literally 0 percent overlap in their gut bacteria."

In further tests on healthy mice with and without a bacteria microbiome, lower base body temperatures were observed in the animals without the bacteria – while treatment with antibiotics also reduced body temperature in the mice.

What's more, across both the humans and the mice, the same family of bacteria seemed to be associated with fluctuations in temperature. The next step is to look at more samples from a broader range of people and to work out what biological mechanisms are underpinning this relationship.

With more research, it's possible that we might be able to develop ways of modifying the gut microbiome specifically to affect body temperature – and that, in turn, could improve the outlook for people with conditions such as sepsis.

"There's a reason that temperature is a vital sign," says Bongers. "It's both easily measured and tells us important information about the body's inflammatory and metabolic state."


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Sunday 29 January 2023

We've just discovered a new part of the brain's waste disposal system

5 January 2023, By Clare Wilson

A cross-section of the skull (top) and the outer layer of the brain, showing the subarachnoid lymphatic-like membrane in green

University of Copenhagen

A new anatomical structure has been discovered that is part of the brain’s waste disposal system.

The tissue is a thin membrane encasing the brain that keeps newly made cerebrospinal fluid – which circulates inside the brain – separate from “dirty” fluid containing cells’ waste products.

It was already known that there are three membranes between the skull and the brain. The new structure is a fourth membrane, lying on top of the innermost membrane, called the subarachnoid lymphatic-like membrane (SLYM). It is extremely thin, with a width of just a few cells or, in places, even one cell.

The SLYM hadn’t been noticed before, partly because the membrane disintegrates when the brain is removed from the skull in post-mortems, says Maiken Nedergaard at the University of Rochester Medical Center in New York, who helped discover the structure. It is also too thin to be seen in living people via brain-scanning machines.

The tissue was first discovered in mice, after Nedergaard’s team used a genetic labelling technique that made the SLYM’s cells glow fluorescent green. It was then also observed covering human brains by dissolving away the skull in bodies donated for research.

In 2012, Nedergaard also helped to discover a network of thin tubes that collect waste fluid from brain cells, known as the glymphatic system. These tubes may drain into the outgoing cerebrospinal fluid, says Nedergaard.

The waste products of brain cells include proteins called beta-amyloid and tau that are thought to be involved in Alzheimer’s disease when they build up in excessive amounts.

In both mice and people, the SLYM also contains immune cells, so it may allow them to detect signs of infection present in the cerebrospinal fluid, says Nedergaard. “It is loaded with immune cells.”

“This is a fascinating discovery that will have significant implications for our understanding of the glymphatic system,” says Marios Politis at the University of Exeter, UK.


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Archaeology News: Egyptian mummy covered in golden foliage could be the oldest ever discovered

 

Egyptian mummy covered in golden foliage could be the oldest ever discovered


The mummy, found with three others, is thought to be one of the best-preserved and oldest discovered in Egypt.



By JERUSALEM POST STAFF, JANUARY 29, 2023
https://www.jpost.com/archaeology/article-729935

 'Golden boy’ mummy (credit: CAIRO EGYPTIAN MUSEUM VIA FRONTIERS)

One of the oldest and best-preserved mummies to ever be found was recently discovered in Saqqara, Egypt. His name was Hekashepes.

Dr. Zahi Hawass, lead archaeologist and former antiquities minister, dated the finds from roughly the 25th-22nd century BCE. Dr. Hawass said on Facebook, "This mummy may be the oldest and most complete mummy found in Egypt to date."

The mummy was found, covered in gold leaf, down a 50ft shaft with three other tombs. It is believed that the sarcophagi have not been opened for around 4,300 years.

Egypt: 'Possibly the oldest, most complete' 4,300-year-old mummy found


The other finds

The other mummies found are thought to be an ancient Egyptian priest named Khnumdjedef, a senior palace official named Meri and a judge and writer named Fetek.

Meri’s official duties would have included performing religious rituals and acting as a “secret keeper.”

Archaeologists also found a number of precious amulets, a false door, pottery and some of the largest statues to have ever been found.

A little over 10 meters below the original find, the team discovered a collection of wooden statues and an altar for ritualistic offerings.

The teenage mummy digitally unwrapped in four stages. Pic: SN Saleem, SA Seddik, M el-Halwagy


The significance of the mummies

Mummies of non-royal descent are rarely found. Even rarer they are found in as well-preserved condition as the mummies found during this discovery.

In describing the importance of the discovery, Archeologist Abu Deshish is reported to have said, “This discovery is so important as it connects the kings with the people living around them." 


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Camera-trap study provides photographic evidence of pumas' ecological impact

JANUARY 24, 2023, by Diana Yates, U. of Illinois at Urbana-Champaign

A new study adds to the evidence that apex predators like pumas play a unique role in ecosystems that is not fulfilled by smaller carnivores. 
Credit: Camera-trap photo courtesy Alex Avrin

A camera-trap study of two ecosystems—one with pumas and one without—adds to scientists' understanding of the many ways apex predators influence the abundance, diversity and habits of other animals, including smaller carnivores.

Reported in the journal Ecosphere, the study followed multiple members of the order Carnivora, looking at how the largest carnivore in each locale influenced the behavior and presence of other animals in the same vicinity.

"Nobody's really looked at how the whole carnivore community changes when you lose that top predator," said Alex Avrin, who led the research as an M.S. student at the University of Illinois Urbana-Champaign with Max Allen, a research scientist at the Illinois Natural History Survey and professor of natural resources and environmental sciences at the U. of I. Avrin is now a scientist with the California Fish and Wildlife Service.

Previous studies have shown that pumas tend to suppress populations of medium-sized carnivores like coyotes, which do their best to avoid pumas, Avrin said. Reduced coyote populations allow other medium-sized carnivores to flourish. This has a cascading effect on many other species.

Pumas also leave behind a lot of carrion, allowing a host of scavengers—from microbes to birds and other animals—to feast on the remains that the pumas don't consume, Avrin said. Coyotes tend to target smaller species and eat most of what they kill, leaving less behind for other creatures.

When pumas disappear, other carnivores, like this coyote, function as the top predator. But their influence on other carnivore species is distinctly different than that of pumas, a study finds. 
Credit: Camera-trap photo courtesy Max Allen

The researchers wanted to compare the dynamics of ecosystems with and without pumas.

"We specifically wanted to look at whether, in the absence of pumas, coyotes step up and fill that role of the apex predator," she said.

Over several weeks-long or months-long sessions between 2011 and 2019, the researchers deployed grids of motion-activated cameras in various locales in the southern Santa Cruz Mountains of California and across the vast military installation of Fort Hood, Texas. The Santa Cruz site has a healthy population of pumas as well as bobcats, gray foxes, raccoons, striped skunks and coyotes. Fort Hood has those same carnivorous mammals except pumas. It also hosts the eastern spotted skunk and the ringtail, a member of the raccoon family. All of these species were included in the new analysis.

"We used the photos to get an idea of which species were at each site, what areas they were using and how frequently we detected them," Avrin said. "And we used a couple of different measures to look at how the smaller carnivores behaved around both the pumas and coyotes."


Striped skunks were more likely to use areas frequented by pumas, but not those used by coyotes.
 Credit: Michael Jeffords and Susan Post



The two locales were similar enough to make these comparisons, "but of course climate, human land use and other variables differed between the sites," she said.

As expected, the analysis revealed that wherever pumas were present, coyotes were rarely seen. While other carnivores also appeared to avoid pumas, they were much more likely to be detected by the same camera traps as pumas—just at different times. Even bobcats and gray foxes used areas frequented by pumas more often than the researchers expected.

In Fort Hood, where pumas were absent, coyotes had a different effect on the other carnivores.

If coyotes were filling that same apex role that pumas do, we would expect them to suppress bobcats—their next largest competitor—releasing the smaller carnivores," Avrin said. "And what we found is that they really just suppressed everything—bobcats and the other carnivores."


The study also evaluated other carnivores, including gray foxes.
 Credit: Camera-trap photo courtesy Alex Avrin



The coyotes appeared to exert less of a suppressive effect on the other carnivores than the pumas had on coyotes, she said.

"This is a correlational study, so we can't say definitively that the absence of pumas caused these other effects," she said. But the study strongly suggests that coyotes do not replace the apex predator in an ecosystem that lacks pumas.

"So yes, when you lose an apex predator, pretty much your whole ecosystem is going to change," Avrin said.

"In the absence of pumas, you'll likely have more intensive grazing by deer, especially in areas near water, which can affect stream flows and other species," she said. "Coyotes, because they can't control those bigger prey populations the same way, don't have the same effect. They likely end up suppressing smaller prey populations, which then changes things in a different way."

Bobcats were more likely to be present at sites also used by pumas, but appeared to avoid coyotes, researchers found. 
Credit: Camera-trap photo courtesy Alex Avrin

"This study gives us a fuller picture of the changes that occur when an apex predator goes missing," Allen said. "While many people think that smaller carnivores can move into the apex role, we see that mesocarnivores like coyotes don't provide the same effects as a true apex predator. This highlights how important it is to keep each species in place for an intact ecological community."


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Study: Modern arms technologies help autocratic rulers stay in power

JANUARY 26, 2023, by U. of Copenhagen

Effectiveness and Price of Infantry Firearms. 
Notes: (a) The geometric mean of the range (in meters) and the rate of fire (in shots/minute) for infantry firearms.
 Data on range and rate of fire are for arms used by the Prussian/German army. 
(b) Prices are for guns procured by the US government.
 Credit: The Economic Journal (2022). DOI: 10.1093/ej/ueac073

Autocrats and dictators quickly acquire new arms technologies from abroad and often use them against their own citizens. Now a study of multiple nations during the period 1820–2010 shows that the spread of military technologies inhibits democratic reform. This raises serious questions regarding the future.

The findings are published in The Economic Journal.

Back in the early 19th century, a skilled soldier could fire a flintlock musket 2-3 times a minute if subjects rebelled against the king, and at best, hit the mark at a distance of 75 meters. During the Arab Spring, the Syrian regime used combat helicopters against protestors, and tanks rolled through the streets of Cairo.

When autocratic rulers have access to modern arms that are both fast and accurate at long ranges, it allows them to suppress protests and riots more effectively and at a lower cost. Now a large study confirms that access to modern military technology substantially reduces the probability of democratization of authoritarian regimes.

The study details the spread of 29 groundbreaking military technologies in all independent states from 1820–2010 as well as the forms of government in these states. Based on statistical analysis of the data, the study establishes connections among states' access to specific weapons, their economies, and their forms of government.

According to the researchers, it makes sense that modern weapons play a key role in suppressing democratic movements.

"In short, the more protesters a regime can kill using as few resources as possible, the stronger it will be. But this is the first scientific study to show that regimes' access to weapons [does] have a systematic, measurable effect on democratization," says Associate Professor Asger Mose Wingender from the University of Copenhagen's Department of Economics, who conducted the study with Professor Jacob Gerner Hariri from the Department of Political Science.

Less chance of democratization

Incumbent rulers often use violence, or the mere threat thereof, to suppress popular uprisings. Although such uprisings contributed to two of three successful democratizations in the period 1820–2010, many more were nipped in the bud.

The study shows that the success of pro-democracy movements crucially depends on the incumbent rulers' (in)ability to inflict violence on protesters, and that this ability depends on arms technology. Overall, the study concludes that the chance of a democratic transition today is about 1.3 percentage points lower per year in the autocracies with the most advanced arms compared with the autocracies having access to the least advanced weaponry.

A difference of 1.3 percentage points may seem small, but over many years, it becomes significant. Because modern arms technologies have become far more effective, the resources available to present-day autocratic regimes are radically different from those of their predecessors. The poorest countries in the world have access to potent arms technologies that are merely a few decades old, despite that these countries, by some measures, are less economically developed than Western Europe was two centuries ago.

This is an entirely new situation, Wingender explains: "Historically, the development in military technology has run parallel to economic and other technological developments. It propelled the democratization of the Western world, because in order to wage war, the state collected taxes from its citizens, who in turn would often demand and be granted the right to vote," he says.

"Today, there is less pressure on autocratic regimes. Weapons are more cost-efficient, and technologies have spread to poor countries, giving authoritarian rulers access to extremely strong means of repression. Consequently, an imbalance has emerged between military-technological development and economic development that inhibits democratization."

Democratization does not occur automatically

This imbalance between prosperity and democratic reform may be the most thought-provoking result of the study. Many Western economists and political scientists have suggested that a country's level of economic development is a deciding factor in democratic reform: When the wealth of the state and its citizens increases, many countries will move towards democratization.

The new study confirms that economic modernization is indeed a key factor in democratization, but it refutes the idea that it happens automatically as authoritarian regimes' increased access to highly effective arms yields economic progress and prosperity.

"Our conclusion is in fact rather pessimistic," says Asger Mose Wingender.

"We have this idea in the West that the economic development of countries such as China and Russia will lead to democracy when the growing middle classes begin to demand a say. And it is true that the economic development has made people in general want democracy, but at the same time, the states have access to better means of repression. This makes revolutionary waves like the ones we saw in Europe, in e.g. 1848-1849 and after the fall of the Berlin Wall, less likely to succeed today, particularly in parts of the world that are less developed than Europe."

A change in the balance of power

Evidently, access to modern weapons does not entirely protect regimes against democratic reform. Nevertheless, Wingender believes it is important to acknowledge that many countries have seen a change in the balance of power between state and citizens to the advantage of the state.

This may affect the way the Western world relates to autocratic regimes.

"Our study suggests that we in the Western world may have been naïve when it comes to modern dictatorships, and that we cannot simply apply Western European experiences with democratization to the rest of the world."





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