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Fruit fly ‘Fox’ neurons show how brains assign value to food

Why do we sometimes keep eating even when we’re full and other times turn down food completely? Why do we crave salty things at certain times, and sweets at other times? The answers, according to new neuroscience research at the University of Delaware, may lie in a tiny brain in an organism you might not expect.

Lisha Shao, assistant professor in the Department of Biological Sciences in the College of Arts and Sciences, has uncovered a neural network in the brains of fruit flies that represents a very early step in how the brain decides—minute by minute—whether a specific food is worth eating. The work was published in the journal Current Biology.

“Our goal is to understand how the brain assigns value—why sometimes eating something is rewarding and other times it’s not,” Shao said.

Refractive-index microscope measures a sample’s optical properties with pinpoint accuracy

In this way, and almost by chance, researchers at TU Wien developed a novel microscopy technique that allows the refractive index of biological samples to be measured at a resolution far below what conventional light microscopy theory would seem to allow. Their paper is published in the journal ACS Nano.

The trick behind resolution beyond the wavelength of light

What happens if you try to image two molecules whose separation is smaller than the wavelength of light? You will not see two distinct points, but a single blurred spot of light—the images of the two molecules overlap, no matter how precise the microscope is.

New Study Reveals How Nanoplastics Make Bacteria More Dangerous

Nanoplastics already raise fears because people can ingest them directly. Now scientists say these tiny particles can create a different kind of danger when they end up in water: they can help bacteria become tougher and harder to remove.

A study in Water Research led by Virginia Tech’s Jingqiu Liao, working with international collaborators, found that nanoplastics can influence how environmental microbes behave in ways that may indirectly affect human health. The concern is not just what the particles might do in the body, but what they might encourage in the water systems people rely on every day.

“It is very important to better understand the adverse effects of the nanoplastics on human health, and not just in humans but also in the environment, which indirectly influences human health,” said Liao, assistant professor of civil and environmental engineering. “The nanoplastics can make the antimicrobial-resistant pathogens better survive, which could be harmful to the environment and would have public health implications.”

Native postsynaptic density is a functional condensate formed via phase separation

To obtain direct evidence supporting the theory that the postsynaptic density (PSD) in neuronal synapses is formed via phase separation, Chen et al. purified and characterized the native PSD from the mouse brain. Their results demonstrate that the native PSD has characteristic features of biological condensates formed via phase separation.

Procrastination in adulthood linked to brain development during adolescence

Procrastination, the tendency to unnecessarily delay or put off tasks even if this will have negative consequences, is a common behavior for many people. While occasionally delaying or putting off bothersome tasks is not necessarily problematic, severe and prolonged procrastination is closely tied to some neuropsychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD) and anxiety disorders.

Unveiling patterns in the brain’s structure and genetic factors linked to procrastination could help to reliably uncover this tendency to postpone tasks in affected individuals. This could in turn inform the development of preventative strategies or interventions that tackle procrastination early, before it exacerbates other underlying mental health disorders.

Researchers at the Chinese Academy of Sciences and other institutes in China recently carried out a study aimed at shedding new light on the biological and genetic roots of procrastination. Their paper, published in Molecular Psychiatry, outlines specific patterns in the brain’s structure during adolescence that are linked to procrastination in adulthood.

Novel ‘XFELO’ laser system produces razor-sharp X-ray light

A team of engineers and scientists has shown for the first time that a hard-X-ray cavity can provide net X-ray gain, with X-ray pulses being circulated between crystal mirrors and amplified in the process, much like happens with an optical laser. The result of the proof-of-concept at European XFEL is a particularly coherent, laser-like light of a quality that is unprecedented in the hard X-ray spectrum.

Lasing inside a cavity had been challenging to achieve with short-wavelength X-rays for a variety of reasons, including—on a basic level—that the nature of the light makes it difficult to reflect the beam at large angles. The “XFELO” (short for: X-Ray Free-Electron Laser Oscillator) technique opens new perspectives for scientific investigations, from ultrafast chemical reactions to detailed analyses of the smallest biological structures. The research is published in the journal Nature.

As puzzling as a platypus: The JWST finds some hard to categorize objects

The platypus is one of evolution’s lovable, oddball animals. The creature seems to defy well-understood rules of biology by combining physical traits in a bizarre way. They’re egg-laying mammals with duck bills and beaver-like tails, and the males have venomous spurs on their hind feet. In that regard, it’s only fitting that astronomers describe some newly discovered oddball objects as “Astronomy’s Platypus.”

The discovery consists of nine galaxies that also have unusual properties and seem to defy categorization. The findings were recently presented at the 247th meeting of the American Astronomical Society in Phoenix. The results are also in new research titled “A New Population of Point-like, Narrow-line Objects Revealed by the James Webb Space Telescope,” posted to the arXiv preprint server. The lead author is Haojing Yan from the University of Missouri-Columbia.

“We report a new population of objects discovered using the data from the James Webb Space Telescope, which are characterized by their point-like morphology and narrow permitted emission lines,” the authors write in their research. “Due to the limitation of the current data, the exact nature of this new population is still uncertain.”

Raman sensors with push-pull alkyne tags amplify weak signals to track cell chemistry

Seeing chemistry unfold inside living cells is one of the biggest challenges of modern bioimaging. Raman microscopy offers a powerful way to meet this challenge by reading the unique vibrational signatures of molecules. However, cells are extraordinarily complex environments filled with thousands of biomolecules.

To make specific molecules stand out, researchers often attach small chemical probes, such as alkyne tags, that produce signals in a so-called cell-silent spectral window where native cellular components do not scatter light. This allows Raman microscopes to selectively detect the tagged molecules against an otherwise crowded molecular background. Despite this advantage, the widespread adoption of Raman microscopy in biology has been limited by one fundamental problem: Raman signals are extremely weak.

Watching atoms roam before they decay

Together with an international team, researchers from the Molecular Physics Department at the Fritz Haber Institute have revealed how atoms rearrange themselves before releasing low-energy electrons in a decay process initiated by X-ray irradiation. For the first time, they have gained detailed insights into the timing of the process—shedding light on related radiation damage mechanisms. Their research is published in the Journal of the American Chemical Society.

High-energy radiation, for example in the X-ray range, can cause damage to our cells. This is because energetic radiation can excite atoms and molecules, which then often decay—meaning that biomolecules are destroyed and larger biological units can lose their function. There is a wide variety of such decay processes, and studying them is of great interest in order to better understand and avert radiation damage.

In the study, researchers from the Molecular Physics Department, together with international partners, investigated a radiation-induced decay process that plays a key role in radiation chemistry and biological damage processes: electron-transfer-mediated decay (ETMD). In this process, one atom is excited by irradiation. Afterward, this atom relaxes by stealing an electron from a neighbor, while the released energy ionizes yet another nearby atom.

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