The brain is 'programmed' for learning from people we like

Image Credit: Gemini Advance AI

Our brains are "programmed" to learn more from people we like – and less from those we dislike. This has been shown by researchers in cognitive neuroscience in a series of experiments.

Memory serves a vital function, enabling us to learn from new experiences and update existing knowledge. We learn both from individual experiences and from connecting them to draw new conclusions about the world. This way, we can make inferences about things that we don't necessarily have direct experience of. This is called memory integration and makes learning quick and flexible.

Inês Bramão, associate professor of psychology at Lund University, provides an example of memory integration: Say you're walking in a park. You see a man with a dog. A few hours later, you see the dog in the city with a woman. Your brain quickly makes the connection that the man and woman are a couple even though you have never seen them together. 

“Making such inferences is adaptive and helpful. But of course, there's a risk that our brain draws incorrect conclusions or remembers selectively”, says Inês Bramão.

Electrons screen against conductivity-killer in organic semiconductors

Muhamed Duhandžić, doctoral candidate and study author, writes the equations he and Zlatan Akšamija (left) derived to describe the physics happening inside the doped polymer.
Photo Credit: Harriet Richardson/University of Utah

California’s Silicon Valley and Utah’s Silicon Slopes are named for the element most associated with semiconductors, the backbone of the computer revolution. Anything computerized or electronic depends on semiconductors, a substance with properties that conduct electrical current under certain conditions. Traditional semiconductors are made from inorganic materials—like silicon—that require vast amounts of water and energy to produce.

For years, scientists have tried to make environmentally friendly alternatives using organic materials, such as polymers. Polymers are formed by linking small molecules together to make long chains. The polymerization process avoids many of the energy-intensive steps required in traditional semiconductor manufacturing and uses far less water and fewer gasses and chemicals. They’re also cheap to make and would enable flexible electronics, wearable sensors and biocompatible devices that could be introduced inside the body. The problem is that their conductivity, while good, is not as high as their inorganic counterparts.

All electronic materials require doping, a method of infusing molecules into semiconductors to boost conductivity. Scientists use molecules, called dopants, to define the conductive parts of electrical circuits. Doping in organic materials has vexed scientists because of a lack of consistency—sometimes dopants improve conductivity while other times they make it worse.  In a new study, researchers from the University of Utah and University of Massachusetts Amherst have uncovered the physics that drive dopant and polymer interactions that explain the inconsistent conductivity issue.

The ties that bind

The soils in many iconic Australian landscapes, like the outback and deserts, are colored red by an abundant mineral known as goethite. This mineral tends to lock away trace metals over time, according to research from Washington University in St. Louis
Photo Credit: Nathan March

Trace metals are nutrient elements, like zinc, that animals and plants need in small amounts to function properly. Animals generally get trace metals in their diets or through environmental exposures, while plants take their trace minerals up from soil. If we get too little, we may experience a deficiency, but the opposite can also be true: too much of a trace metal can be toxic.

Scientists believe that up to 50% of the trace metals in soils and urban environments may be bound to the surfaces of mineral grains — rendering the trace metals essentially unavailable for consumption or exposure. Researchers at Washington University in St. Louis wondered what holds them in place.

“When minerals bind trace metals, we often assume that they act like a sponge,” said Jeffrey G. Catalano, a professor of earth, environmental and planetary sciences and the director of environmental studies in Arts & Sciences. “But sometimes, they bind trace metals and won’t let them go. That is great when they are contaminants, but bad when they are serving as micronutrients.”

In a study published in the journal Environmental Science & Technology, Catalano and Greg Ledingham, a PhD candidate in his laboratory, discovered that a common mineral called goethite — an iron-rich mineral that is abundant in soils that cover the Earth — tends to incorporate trace metals into its structure over time, binding the metals in such a way that it locks them out of circulation.

SwRI scientists find evidence of geothermal activity within icy dwarf planets

Eris and Makemake
Image Credit: Courtesy of Southwest Research Institute

A team co-led by Southwest Research Institute found evidence for hydrothermal or metamorphic activity within the icy dwarf planets Eris and Makemake, located in the Kuiper Belt. Methane detected on their surfaces has the tell-tale signs of warm or even hot geochemistry in their rocky cores, which is markedly different than the signature of methane from a comet.

“We see some interesting signs of hot times in cool places,” said SwRI’s Dr. Christopher Glein, an expert in planetary geochemistry and lead author of a paper about this discovery. “I came into this project thinking that large Kuiper Belt objects (KBOs) should have ancient surfaces populated by materials inherited from the primordial solar nebula, as their cold surfaces can preserve volatiles like methane. Instead, the James Webb Space Telescope (JWST) gave us a surprise! We found evidence pointing to thermal processes producing methane from within Eris and Makemake.”

The Kuiper Belt is a vast donut-shaped region of icy bodies beyond the orbit of Neptune at the edge of the solar system. Eris and Makemake are comparable in size to Pluto and its moon Charon. These bodies likely formed early in the history of our solar system, about 4.5 billion years ago. Far from the heat of our Sun, KBOs were believed to be cold, dead objects. Newly published work from JWST studies made the first observations of isotopic molecules on the surfaces of Eris and Makemake. These so-called isotopologues are molecules that contain atoms having a different number of neutrons. They provide data that is useful in understanding planetary evolution.

Scientists are unraveling the secrets of red and grey squirrel competition

Image Credit: Gemini Advance AI

In a first of its kind study, researchers have identified significant differences between the diversity of gut bacteria in grey squirrels compared to red squirrels which could hold the key to further understanding the ability of grey squirrels to outcompete red squirrels in the UK. 

New research, published in the Journal of Medical Microbiology, looked to understand more about the mechanisms by which grey squirrels are able to gain an advantage over red squirrels. Chris Nichols, Conservation Evidence Manager at the Woodland Trust, and co-author of the study, said:

“The more we know about grey squirrels, the more equipped we’re going to be in the future to tackle the threats they pose to red squirrels and our native trees, which is one of the biggest problems for forest conservation in the UK.”

Grey squirrels are an invasive, non-native species introduced from North America to sites in Great Britain and Ireland between 1876 to 1929. They out-compete the native red squirrels and multiply thanks to various traits including their ability to access a broader range of food sources including the bark of UK broadleaved trees. This causes significant damage to the trees, and is a behavior that, prior to this research, was not completely understood. 

Asexual Propagation of Crop Plants Gets Closer

Two varieties of the model plant thale cress: on the left a significantly larger hybrid variety, on the right the standard variety for laboratory research.
Photo Credit: Nicholas Desnoyer, UZH

When the female gametes in plants become fertilized, a signal from the sperm activates cell division, leading to the formation of new plant seeds. This activation can also be deliberately triggered without fertilization, as UZH researchers have shown. Their findings open up new avenues for the asexual propagation of crop plants.

Seeds are the end product of plant reproduction. Whether directly as food, or indirectly as animal feed, they provide around 80 percent of human calorie consumption. In the millennia since humans first settled, we have bred countless plant varieties with advantageous characteristics, such as increased yields, improved quality, resistance to pests or hardiness. Where possible, farmers use hybrid varieties, which are created by crossing two inbred lines and are more resistant and higher-yielding than normal varieties. The problem is that these desired properties are lost during propagation and, therefore, hybrid seeds have to be recreated every year.

Targeting inflammation to tackle long covid

Illustration Credit: Gerd Altmann

Overactivation of the immune system leading to circulation of inflammatory proteins around the body contributes to the development of long covid, and could be targeted to provide treatments for patients, finds new research.

Cardiff University research has uncovered biological markers that could be targeted by repurposing medication to treat long covid.

The research conducted extensive analysis of plasma samples obtained from a large cohort of healthy post-covid individuals and non-hospitalized patients with long covid. They found that the complement system – a system that plays a crucial part of the immune system, consisting of a group of proteins that work together to enhance the function of antibodies and immune cells – was commonly overactivated in those with long covid.

“The covid-19 pandemic has left a global legacy of ill health, with long covid estimated to affect up to 1.9 million people in the UK. Long covid can last for months or years after the triggering infection and is associated with diverse symptoms including brain fog, chest pain, breathlessness, fatigue, and sensory problems. The causes of this disease remain largely unknown, emerging evidence suggests an important role for chronic inflammation."
Professor Paul Morgan 'Professor of complement biology, Division of Infection and Immunity

The life of a Stone Age man has been mapped

Illustration Credit: Niels Bach
CC-BY 4.0

Researchers have mapped the life of a Stone Age man in detail. New scientific methods have revolutionized archaeology and the Swedish-Danish team of researchers at the University of Gothenburg are now able to state that “Vittrup Man”, a Stone Age man found in a bog in Denmark, travelled across a wide geographical area during his lifetime.

Vittrup Man was first discovered in 1915. His skull had been split by at least eight blows from a club and his body placed in a wetland in north Jutland. Until recently, this was all we knew about him. Researchers now know that he had travelled a long way before his death in about 3200 BCE. He must have led an interesting life.

“He comes from the north, from a relatively cold area, and it must have been a coastal area because the food he ate as a child came from the sea,” says archaeologist Karl-Göran Sjögren, a member of the research team.

Scientists help discover new treatment for many cancers

UniSA/CCB Professor Greg Goodall, part of the team that made the landmark discovery.
Photo Credit: Courtesy of University of South Australia 

Australian scientists have made a major discovery that could underpin the next generation of RNA-based therapeutics, and lead to more potent and longer-lasting RNA-based drugs with an even wider array of potential uses.

In a paper published in the journal Nature, Peter MacCallum Cancer Centre scientists Vi Wickramasinghe and Linh Ngo and collaborator Greg Goodall at the University of South Australia and SA Pathology’s Centre for Cancer Biology, have described a new pathway that could help to overcome a major drawback of RNA-based therapeutics to date.

Currently these breakthrough therapeutics utilize mRNA – injectable genetic material that produces a desired therapeutic or vaccine effect, but they can also break down quickly once absorbed into the human body.

“It’s the linear shape of mRNA that makes it relatively unstable and lack durability inside the body and this has been a limiting factor in the potential application of RNA-based therapeutics for diseases such as cancer,” explains Dr Wickramasinghe, senior author on the paper.

New Algorithm Disentangles Intrinsic Brain Patterns from Sensory Inputs

Image Credit: Omid Sani, Using Generative Ai

Maryam Shanechi, Dean’s Professor of Electrical and Computer Engineering and founding director of the USC Center for Neurotechnology, and her team have developed a new machine learning method that reveals surprisingly consistent intrinsic brain patterns across different subjects by disentangling these patterns from the effect of visual inputs.

The work has been published in the Proceedings of the National Academy of Sciences (PNAS).

When performing various everyday movement behaviors, such as reaching for a book, our brain has to take in information, often in the form of visual input — for example, seeing where the book is. Our brain then has to process this information internally to coordinate the activity of our muscles and perform the movement. But how do millions of neurons in our brain perform such a task? Answering this question requires studying the neurons’ collective activity patterns, but doing so while disentangling the effect of input from the neurons’ intrinsic (aka internal) processes, whether movement-relevant or not.

That’s what Shanechi, her PhD student Parsa Vahidi, and a research associate in her lab, Omid Sani, did by developing a new machine-learning method that models neural activity while considering both movement behavior and sensory input.