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Disappointment alters brain chemistry and behavior

From work meetings to first dates, it’s essential to adjust our behavior for success. In certain situations, it can even be a matter of life or death. So how do we switch our behavior when situations change? Published in Nature Communications, neuroscientists describe the neural basis of behavioral flexibility in mice, with insights which may help us understand a wide variety of diseases and disorders, from addiction to obsessive compulsive disorder (OCD) to Parkinson’s disease.

“The brain mechanisms behind changing behaviors have remained elusive, because adapting to a given scenario is very neurologically complex. It requires interconnected activity across multiple areas of the brain,” explains a co-author. “Previous work has indicated that cholinergic interneurons—brain cells that release a neurotransmitter called acetylcholine—are involved in enabling behavioral flexibility. Here, we were able to use advanced imaging techniques to see neurotransmitter release in real time and delve into the fundamental mechanisms behind behavioral flexibility”

In their investigations, the researchers trained mice in a virtual maze, teaching them the correct route to receive a reward. They then switched the route, leading to an unexpected loss of reward for the mice, and observed the effects of this disappointing change using two-photon microscopy.

Modified tau thwarts aggregation in neurodegenerative disease—while retaining its biological function

A designer version of the tau protein, developed by a team led by UT Southwestern Medical Center researchers, maintains its biological function while resisting aggregation, a pathological trait linked to neurodegenerative diseases called tauopathies.

These findings, reported in Structure, could lead to new treatments for conditions including Alzheimer’s disease, frontotemporal dementia, chronic traumatic encephalopathy (CTE), and progressive supranuclear palsy.

“This is the first step toward creating a molecule that could, in principle, replace a protein that’s pathogenic (disease-causing) while still retaining its normal function,” said study leader Lukasz Joachimiak, Ph.D., Associate Professor in the Center for Alzheimer’s and Neurodegenerative Diseases and of Biochemistry and Biophysics at UT Southwestern.

Peering inside perovskite: 3D imaging reveals how passivation boosts solar cell efficiency

Perovskite solar cells have garnered widespread attention as a low-cost, high-efficiency alternative to conventional silicon photovoltaics. However, defects in perovskite films impede charge transport, resulting in energy loss and compromised operational stability.

One solution to this problem is “passivation treatment”—a process that adds chemicals such as simple salts or organic molecules to the film. These small molecules or ions latch onto defects in the perovskite material, preventing the defects from interfering with electrical flow. Unfortunately, verifying the internal efficacy of various passivation treatments remains challenging since most characterization techniques only probe the surface or provide averaged macroscopic information.

Now, however, researchers at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences (CAS) have made an important breakthrough by developing a three-dimensional (3D) electrical imaging technique that directly reveals how defect passivation treatments work in perovskite films. The study was published in Newton on December 31.

On-demand hydrogen fuel production goes dark-mode

Hydrogen, the lightest element on the periodic table, is a master of escaping almost any container it’s stored in. Its extremely small size allows it to squeeze through atomic-scale gaps in the storage materials, which is one of the major issues hindering hydrogen energy from becoming mainstream.

A team of Chinese researchers has solved the issue of containment with on-demand hydrogen production. They developed a simple chemical system containing commercial ammonium metatungstate (W12) and graphitic carbon nitride (g-C3N4) in a liquid suspension. This system captures solar energy and, rather than converting it into electricity, uses it to produce hydrogen fuel on demand—even in darkness.

The new system provided twofold benefits: it made solar energy available even when the sun isn’t shining, and it eliminated the need to transport hydrogen in dangerous, high-pressure tanks.

Melanoma cancer cells secrete extracellular vesicles to paralyze immune cells

A new international study led by Prof. Carmit Levy of the Department of Human Genetics and Biochemistry at the Gray Faculty of Medical & Health Sciences at Tel Aviv University finds that melanoma cancer cells paralyze immune cells by secreting extracellular vesicles (EVs), which are tiny, bubble-shaped containers secreted from a given cell. The research team believes that this discovery has far-reaching implications for possible treatments for the deadliest form of skin cancer.

The work is published in the journal Cell.

Melanoma is the deadliest type of skin tumor. In the first stage of the disease, melanocytic cells divide uncontrollably in the skin’s outer layer, the epidermis. In the second stage, the cancer cells invade the inner dermis layer and metastasize through the lymphatic and blood systems.

Currents 072: Ben Goertzel on Viable Paths to True AGI

https://www.jimruttshow.com/currents-ben-goertzel-2/

Jim talks with Ben Goertzel about the ideas in his recent essay “Three Viable Paths to True AGI.” They discuss the meaning of artificial general intelligence, Steve Wozniak’s basic AGI test, whether common tasks actually require AGI, a conversation with Joscha Bach, why deep neural nets are unsuited for human-level AGI, the challenge of extrapolating world-models, why imaginative improvisation might not be interesting to corporations, the 3 approaches that might have merit (cognition-level, brain-level, and chemistry-level), the OpenCog system Ben is working on, whether it’s a case of “good old-fashioned AI,” where evolution fits into the approach, why deep neural nets aren’t brain simulations & attempts to make them more realistic, a hypothesis about how to improve generalization, neural nets for music & the psychological landscape of AGI research, algorithmic chemistry & the origins of life problem, why AGI deserves more resources than it’s getting, why we may need better parallel architectures, how & how much society should invest in new approaches, the possibility of a cultural shift toward AGI viability, and much more.

Evolution of long scalp hair in humans

Hair is a signature mammalian characteristic with versatile functions, including thermoregulation, protection from ultraviolet radiation, physical and chemical insults, sensation of pain, vibration and touch, and defence from predators.1–3 Human hair patterns, which feature prominently reduced body hair length combined with extremely long scalp hair,4–8 are an outlier among mammals. The likely original function of long scalp hair was to shield the sun-exposed head of upright-standing human ancestors. Long scalp hair probably reduced the amount of sweat secretion required to counter the total thermal load experienced by individuals from incoming solar radiation in equatorial Africa, and from endogenous muscle-generated heat during exercise.9 Tightly curled scalp hair is more efficacious at reducing heat gains compared with other hair shapes, and such hair probably represents the ancestral scalp hair form (Figure 1).9 Variability in hair shapes increased over time. These variations are thought to be associated with the dispersal of anatomically modern humans (AMHs) and accompanying effects of populational bottlenecks, admixture with Neanderthals and Denisovans, and adaptations to diverse environments at new geographic locations (Figure 1a).10 Extreme scalp hair length was probably universal across all African AMH populations and available for diverse functions, other than thermoregulation. In this sense, long scalp hair is an excellent example of exaptation, a form of evolutionary co-option,11 whereby it acquired secondary essential functions in communicating social cues.12 Under these conditions, unwanted hair loss triggered significant psychological stress in affected individuals.

Despite variations, both across different species and different body regions, hair typically has a finite length. A fully grown hair fibre commonly remains attached within its hair follicle (HF) until a new round of growth replaces it. In a typical adult human, approximately 90% of scalp HFs are in active growth (anagen) at any given time, which lasts for 5–7 years.13,14 This is in contrast to small (vellus) body HFs, which have short-lasting anagen, such as 22–28 days on the upper arm.15 When large (terminal) scalp HFs reduce in size, start growing vellus-like hairs, and/or stop growing for an extended period, they are considered to be entering a pathological state.

Elucidation of long scalp hair roles in human prehistory requires further investigation of its thermoregulatory benefit vs. the physical burden it may have caused by hindering vision and locomotion. Continuous hair growth is also metabolically expensive, requiring synthesis of large quantities of keratins and keratin-associated proteins.1,2,16,17 Conversely, highly visible long scalp hair effectively communicates a good state of fitness, whereas compromised hair growth implies poor nutrition and disease.17,18 Indeed, kwashiorkor, a disease caused by severe dietary protein deficit, features dramatic hair thinning and depigmentation.19 The ornamental potential of long hair enables the use of distinct hairstyles to signify a person’s social position, creativity and manual skills.20 Therefore, in prehistory, hair styling likely became an essential part of social communication, which probably further promoted long-hair trait selection.

New ultrathin ferroelectric capacitors show promise for compact memory devices

An ultrathin ferroelectric capacitor, designed by researchers from Japan, demonstrates strong electric polarization despite being just 30 nm thick including top and bottom electrodes—making it suitable for high-density electronics. Using a scandium-doped aluminum nitride film as the ferroelectric layer, the team achieved high remanent polarization even at reduced thicknesses. This breakthrough demonstrates good compatibility with semiconductor devices combining logic circuits and memory, paving the way for compact and efficient on-chip memory for future technologies.

Modern electronic technology is rapidly advancing towards miniaturization, creating devices that are increasingly compact yet high-performing. As the devices continue to shrink in size, there is an increasing demand for ultra-small memory materials that can efficiently store data, even in smaller dimensions. Ferroelectric memory devices are promising options for future mobile and compact electronics, as they store information using switchable electric polarization, allowing data retention even without power. However, very few initiatives have reported progress in downscaling of these ferroelectric devices.

Bridging this gap, a research team led by Professor Hiroshi Funakubo from the School of Materials and Chemical Technology, Institute of Science Tokyo (Science Tokyo), Japan, in collaboration with Canon ANELVA Corporation (Canon ANELVA), successfully downscaled a total ferroelectric memory capacitor stack using scandium-substituted aluminum nitride ((Al, Sc)N) thin films with platinum electrodes, reducing the total thickness to just 30 nm including top and bottom electrodes.

Ants may hold solution to human superbug, researchers discover

Has a crucial component to the development of human medicine been hiding under our feet? Auburn University Assistant Professor of Entomology Clint Penick and a team of graduate students may have found that ants are far ahead of humans in antibiotic innovation. “In our study, we tested how ants use antibiotic compounds to fight off pathogens and asked why their chemical defenses remain effective over evolutionary time,” Penick said.

“Humans have relied on antibiotics for less than a century, yet many pathogens have already evolved resistance, giving rise to ‘superbugs.’ Ants, by contrast, have been using antibiotics for tens of millions of years, and they might hold the key to using these powerful drugs more wisely.”

Ants as a source of antibiotics The team looked at just six ant species, all found easily in the Southeastern United States.

Simple wipe test reveals hidden PFAS contamination on firefighter protective gear

The flames die down. The sirens fade. Firefighters peel off their gear, thinking the danger has passed. But in the quiet aftermath, another enemy lingers, an invisible film of “forever chemicals” clinging to jackets, pants and masks.

Researchers at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, have developed a way to see what the eye cannot.

A simple wipe test detected invisible cancer-linked “forever chemicals” on every set of firefighter gear examined, including breathing masks, according to new research from Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine. The non-destructive method offers fire departments a practical way to identify and reduce exposure to per-and polyfluoroalkyl substances (PFAS), chemicals tied to increased cancer risk that can linger on gear long after a fire is out.

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