New View on the Brain: It’s All in the Connections

Source: Radboud University Nijmegen

It’s not the individual brain regions but rather their connections that matter: neuroscientists propose a new model of how the brain works. This new view enables us to understand better why and how our brains vary between individuals. The researchers published it in a special issue of Science on November 4th.

Our right hemisphere is for creativity, and the left is for rational thinking. It’s an urban myth that stems from a classical view of how our brain works, namely that we have several brain regions that all have a specific function. Even though this ‘modular’ view of the brain is superseded, it can still be found in many textbooks.

However, we should look at brain function differently, according to neuroscientists Stephanie Forkel at Radboud University and Michel Thiebaut de Schotten at the University of Bordeaux. Brain functions are not localized in individual brain regions but rather emerge from the exchange between these regions.

Platypus Populations Impacted by Large River Dams Are More Vulnerable to Threats

Photo Credit: David Clode

The platypus is possibly the most irreplaceable mammal existing today. They have a unique combination of characteristics, including egg-laying despite being mammals, venomous spurs in males, electroreception for locating prey, biofluorescent fur, multiple sex chromosomes, and the longest evolutionary history in mammals.

Platypuses are a threatened species in some Australian states and their conservation is of concern more broadly, due to known decline in their populations.

A new study published in Communications Biology examined the genetic makeup of platypuses in free-flowing and nearby rivers with large dams in New South Wales. These included the free-flowing Ovens River, along with the dammed Mitta Mitta River, and the free-flowing Tenterfield Creek, along with the nearby Severn River regulated by a large dam.

The study found that large dams are significant barriers to platypus movements. This was reflected in greater genetic differentiation between platypuses above and below large dams compared to rivers without dams. Importantly, this genetic differentiation increased over time since the dam was built, reflecting the long-term impacts of the dam.

Tonga volcano had highest plume ever recorded, new study confirms

The Hunga Tonga–Hunga Haʻapai eruption as seen by Japan's Himawari-8 satellite on 15 January 2022. Top image: Eruption at 4:20 UTC (about 15 minutes into the eruption); Middle image: Eruption at 4:50 UTC (45 minutes into the eruption); Bottom image: Eruption at 5:40 UTC (1 hour 35 minutes into the eruption).
Resized Image using AI by SFLORG
Image credit: Simon Proud / STFC RAL Space / NCEO / JMA.

A new analysis led by Oxford University researchers has shown the devastating Hunga Tonga–Hunga Haʻapai eruption in January 2022 created the tallest volcanic plume ever recorded. The research has been published in the journal Science.

At 57km high (35 miles), the ash cloud generated by the eruption is also the first to have been observed in the mesosphere, a layer of the atmosphere more commonly associated with shooting stars. The previous record-holder, the 1991 eruption of Mount Pinatubo in the Philippines, caused a plume was recorded as 40km high, although accurate satellite images, such as those taken over Tonga, were not available at the time.

The Tonga eruption took place under the sea, around 65km from the country’s main island, causing tsunamis felt as far away as Russia, the United States, and Chile. The waves claimed six lives, including two people in Peru, 10,000km away.

‘It’s the first time we’ve ever recorded a volcanic plume reaching the mesosphere. Krakatau in the 1800s might have done as well, but we didn’t see that in enough detail to confirm,’ said Dr Simon Proud, a National Centre for Earth Observation senior scientist at the University of Oxford and the Science and Technology Facilities Council’s RAL Space facility.

A new weapon against antibiotic-resistant bacteria

This inoculated MacConkey agar culture plate cultivated colonial growth of Gram-negative, small rod-shaped and facultatively anaerobic Klebsiella pneumoniae bacteria. K. pneumoniae bacteria are commonly found in the human gastrointestinal tract, and are often the cause of hospital acquired, or nosocomial infections involving the urinary and pulmonary systems.
Credit: CDC

The unreasonable use of antibiotics has pushed bacteria to develop resistance mechanisms to this type of treatment. This phenomenon, known as antibiotic resistance, is now considered by the WHO as one of the greatest threats to health. The lack of treatment against multi-resistant bacteria could bring us back to a time when millions of people died of pneumonia or salmonella. The bacterium Klebsiella pneumoniae, which is very common in hospitals and particularly virulent, is one of the pathogens against which our weapons are becoming blunt. A team from the University of Geneva (UNIGE) has discovered that edoxudine, an anti-herpes molecule discovered in the 60s, weakens the protective surface of Klebsiella bacteria and makes them easier to eliminate for immune cells. These results can be read in the journal PLOS One.

Klebsiella pneumoniae causes many respiratory, intestinal and urinary tract infections. Due to its resistance to most common antibiotics and its high virulence, some of its strains can be fatal for 40% to 50% of infected people. There is an urgent need to develop new therapeutic molecules to counter it. “Since the 1930s, medicine has relied on antibiotics to get rid of pathogenic bacteria,” explains Pierre Cosson, professor in the Department of Cell Physiology and Metabolism at the UNIGE Faculty of Medicine, who led this research. “But other approaches are possible, among which trying to weaken the bacteria’s defense system so that they can no longer escape the immune system. This avenue seems all the more promising as the virulence of Klebsiella pneumoniae stems largely from its ability to evade attacks from immune cells.”

Polarized X-Rays Reveal Shape, Orientation of Extremely Hot Matter Around Black Hole

An artist’s impression of the Cygnus X-1 system, with the black hole appearing in the center and its companion star on the left. New measurements from Cygnus X-1, reported Nov. 3 in the journal Science, represent the first observations of a mass-accreting black hole from the Imaging X-Ray Polarimetry Explorer (IXPE) mission, an international collaboration between NASA and the Italian Space Agency.
Illustration Credit: John Paice

Researchers’ recent observations of a stellar-mass black hole called Cygnus X-1 reveal new details about the configuration of extremely hot matter in the region immediately surrounding the black hole.

Matter is heated to millions of degrees as it is pulled toward a black hole. This hot matter glows in X-rays. Researchers are using measurements of the polarization of these X-rays to test and refine models that describe how black holes swallow matter, becoming some of the most luminous sources of light — including X-rays — in the universe.

The new measurements from Cygnus X-1, reported Nov. 3 in the journal Science, represent the first observations of a mass-accreting black hole from the Imaging X-Ray Polarimetry Explorer (IXPE) mission, an international collaboration between NASA and the Italian Space Agency (ASI). Cygnus X-1 is one of the brightest X-ray sources in our galaxy, consisting of a 21 solar mass black hole in orbit with a 41 solar mass companion star.

Carnivore Gut Microbes Offer Insight into Health of Wild Ecosystems

wild American marten
Photo Credit: Cunigunde 

A new study finds the microbial ecosystem in the guts of wild marten (Martes americana) that live in relatively pristine natural habitat is distinct from the gut microbiome of wild marten that live in areas that are more heavily impacted by human activity. The finding highlights an emerging tool that will allow researchers and wildlife managers to assess the health of wild ecosystems.

“Specifically, we found that wild marten in relatively undisturbed environments have more carnivorous diets than martens in human-affected areas,” says Erin McKenney, co-lead author of a paper on the work and an assistant professor of applied ecology at North Carolina State University. Marten are small mammals, related to weasels, ferrets and mink.

“In conjunction with our other work on carnivore microbiomes, this finding tells us the microbial ecosystems in carnivore guts can vary significantly, reflecting a carnivore’s environment,” McKenney says. “Among other things, this means we can tell how much humans are impacting an area by assessing the gut microbiomes of carnivores that live in that area – which can be done by testing wild animal feces. In practical terms, this work reveals a valuable tool for assessing the health of wild ecosystems.”

“Our goal here was to determine how, if at all, human disturbance of a landscape affects the gut microbiome of American marten that live in that landscape,” says Diana Lafferty, co-lead author of the paper and an assistant professor of biology at Northern Michigan University. “And the answers here were pretty clear.”

How magnetism could help explain Earth’s formation

Artist's impression of massive impact with proto-Earth.
Image Credit NASA/JPL.

A peculiar property of the Earth’s magnetic field could help us to work out how our planet was created 4.5 billion years ago, according to a new scientific assessment.

There are several theories about how the Earth and the Moon were formed, most involving a giant impact. They vary from a model where the impacting object strikes the newly formed Earth a glancing blow and then escapes, through to one where the collision is so energetic that both the impactor and the Earth are vaporized.

Our theoretical understanding of the Earth’s magnetic field today can actually tell us something about the very formation of the Earth-Moon system.

Now scientists at the University of Leeds and the University of Chicago have analyzed the dynamics of electrically conducting fluids and concluded that the Earth must have been magnetized either before the impact or as a result of it.

They claim this could help to narrow down the theories of the Earth-Moon formation and inform future research into what really happened.

Ocean microbes get their diet through a surprising mix of sources, study finds

Long thought to rely solely on photosynthesis, the microbe Prochlorococcus may get as much as one-third of its carbon through a second strategy: consuming the dissolved remains of other dead microbes. Illustration Credit: Jose-Luis Olivares, MIT

One of the smallest and mightiest organisms on the planet is a plant-like bacterium known to marine biologists as Prochlorococcus. The green-tinted microbe measures less than a micron across, and its populations suffuse through the upper layers of the ocean, where a single teaspoon of seawater can hold millions of the tiny organisms.

Prochlorococcus grows through photosynthesis, using sunlight to convert the atmosphere’s carbon dioxide into organic carbon molecules. The microbe is responsible for 5 percent of the world’s photosynthesizing activity, and scientists have assumed that photosynthesis is the microbe’s go-to strategy for acquiring the carbon it needs to grow.

But a new MIT study in Nature Microbiology today has found that Prochlorococcus relies on another carbon-feeding strategy, more than previously thought.

Organisms that use a mix of strategies to provide carbon are known as mixotrophs. Most marine plankton are mixotrophs. And while Prochlorococcus is known to occasionally dabble in mixotrophy, scientists have assumed the microbe primarily lives a phototrophic lifestyle.

The new MIT study shows that in fact, Prochlorococcus may be more of a mixotroph than it lets on. The microbe may get as much as one-third of its carbon through a second strategy: consuming the dissolved remains of other dead microbes.

The importance of light for grassland plant diversity

Light experiment at the Global Change Experimental Facility (GCEF) of the UFZ research station in Bad Lauchstädt.
Photo Credit: Anu Eskelinen / University of Oulu

Plants need light to grow. However, due to excess nutrients and/or the absence of herbivores less light can reach lower vegetation layers in grasslands. Consequently, few fast-growing species dominate and plant diversity declines. So far, this relationship has been established indirectly through experiments, but never directly by means of experimentally adding light in the field. Now, an international team of researchers including scientists from the Helmholtz Centre for Environmental Research (UFZ), the Martin Luther University Halle-Wittenberg (MLU) and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, was able to experimentally prove the dominant role of light competition for the first time. The results have been published in Nature.

The team of researchers led by Prof. Dr. Anu Eskelinen from the University of Oulu (Finland) used the Global Change Experimental Facility (GCEF) at the UFZ research station in Bad Lauchstädt for their experiments. Scientists from UFZ, iDiv and various universities use the GCEF platform to study the influence of different climate models and land use intensities on plant community structure - specifically food webs and interactions between species.

Bacterial armor plating has implications for antibiotics

Magnified view of the E. coli outer membrane showing hexagonal clustering of proteins (red/green), alongside body armor for comparison. The black background represents lipids that are shared between neighboring proteins.
Image Credit: Dheeraj Prakaash and Syma Khalid Department of Biochemistry, University of Oxford

A new study published in the journal Science Advances sheds light on how Gram-negative bacteria like E. coli construct their outer membrane to resemble body armor, which has far-reaching implications for the development of antibiotics.

Professor Colin Kleanthous in the Department of Biochemistry at the University of Oxford led the interdisciplinary study, with contributions from colleagues in Oxford and University College London. They undertook a microscopic examination of the outer membrane of E. coli to understand the molecular basis for the protection it affords against many classes of antibiotics. E. coli causes infections such as pneumonia, UTIs and sepsis that are notoriously difficult to treat due to multidrug resistance.

The outer membrane is composed of two types of lipids that stack on top of each other, an unusual arrangement which, it was thought, is solely responsible for making the membrane resistant to antibiotics. As well as lipids, the outer membrane contains numerous proteins which the bacterium relies on to acquire nutrients and excrete waste products. Textbooks classically show these proteins dotted randomly in the membrane, contributing little to its stability or structure.

The discovery of Professor Kleanthous and colleagues came from them asking a simple question: do protein interactions play any role in the structural integrity of the outer membrane?