Supercomputing study Sayan Roychowdhury of Duke University presents his team’s work on simulating cancer cell transport through the body. (Courtesy: Kevin Jackson) The SC23 conference, held earlier this month, broke previous audience records with over 14,000 attendees heading to Denver, CO, to find out about the latest achievements in high-performance computing (HPC). Like every other year, the conference hosted a variety of lectures that allowed scientists to discuss how supercomputing positively impacted their fields. With HPC invaluable to just about every scientific domain, biological stud ..read more

This episode of the Physics World Weekly podcast features two pioneers in their fields. Margaret Gardel is a biophysicist who is setting up a new National Science Foundation Physics Frontier Center at the University of Chicago. The Center for Living Systems will focus on the physics of adaptation, a new field that looks at how living matter stores, retrieves, and processes information as it adapts to change. Gardel explains how physics-inspired theory and experiments are providing fresh insights into biological systems. Our second pioneer is Susannah Glickman who has just completed what is pro ..read more

Researchers at the University of the Basque Country (UPV/EHU), Spain have shed fresh light on the viscoelastic behaviour of human tears, demonstrating that real tears are much more complex than the artificial tears and eye drops used to replace them. The work could help clinicians better understand conditions such as dry eye syndrome and may aid the development of customized treatments. In the study, the researchers monitored the Brownian motion of micron-sized particles in healthy human tears. To track this movement, they examined how the light reflects off the particles, a technique known as ..read more

Vital cell tracking in a breast tumour explant (a) Yellow lines show the tracks of cell nuclei movement over 150 min; an unjammed region of cell motion is seen in the lower middle of the sample, surrounded by jammed cells. (b) Cell nuclei colour-coded for aspect ratio (AR), with red indicating elongated (high AR) cells and green showing rounder (low AR) cells. The region of motile cells exhibits more elongated nuclei than the surrounding cells. (Courtesy: CC BY 4.0/P Gottheil et al Phys. Rev. X 10.1103/PhysRevX.13.031003) The physical concept of jamming – originally developed to understand the ..read more

Spaceflight – both short-duration space shuttle missions and longer periods living on the International Space Station (ISS) – alters the human body, including widespread changes in the brain. By studying brain scans of astronauts before and after space travel, a multi-institutional research team has found that ventricles – fluid-filled cavities in the brain – expand significantly in longer spaceflight missions, and that inter-mission intervals of less than three years may not be long enough for them to fully recover. Time spent in space induces displacement of intracranial fluid and an upward ..read more

How does the human brain work? It depends on who you ask. At school, you were likely taught that our brains contain billions of neurons that process inputs and help us form thoughts, emotions and movements. Ask imaging specialists, and you’ll learn about how we can see the brain in different ways using a variety of imaging techniques and about what we can learn from each image. Neuroscientists also will tell you about the interactions between neurons and related chemicals, such as dopamine and serotonin. If you ask a subgroup of neuroscientists who focus on mathematical frameworks for how the ..read more

Reactivating damaged motoneurons Thomas Herrmannsdörfer (left) and Richard Funk are investigating the therapeutic effect of magnetic fields on impaired motoneurons. (Courtesy: HZDR/Amac Garbe) Amyotrophic lateral sclerosis (ALS) is a severe incurable disorder in which motoneurons – nerve cells in the brain and spinal cord that send signals to muscles to control movement – are damaged. Without functioning motoneurons, the muscles do not receive instructions and no longer work, leading to progressive paralysis, muscle atrophy and, eventually, failure of the respiratory system. Currently, there i ..read more

Since the inception of quantum mechanics, physicists have sought to understand its repercussions for our universe. One of the theory’s stranger consequences is entanglement: the phenomenon whereby a pair or group of particles becomes connected in such a manner that the state of any one particle cannot be described independently. Instead, its state is intrinsically correlated with the state of the other(s), even if the particles are separated by large distances. As a result, a measurement performed on a particle in an isolated location can affect the state of its entangled twin far away. Resear ..read more

Rhodopsin, the protein that enables humans and other vertebrates to sense light, belongs to the family of light-sensitive G protein-coupled receptors (GPCRs). It comes first in the signal transduction pathway for vision to begin. Once it absorbs a photon, an immediate (within 200 fs) conformational change occurs in the retinal, a chromophore located inside rhodopsin. This early structural change initiates the cellular signal transduction processes that set early stages of vision. However, details of the real-time intramolecular events through which the photoactivated retinal induces the a ..read more

Researchers in Israel have uncovered the unique optical nanostructure that gives an ocean-going scavenger its brilliant white colouring. Using a range of imaging techniques, a team led by Benjamin Palmer at Ben-Gurion University of the Negev, Israel, showed that spherical particles in Pacific cleaner shrimp scatter incoming light in all directions, while avoiding any overlap in the scattering patterns they produce. The discovery could lead to new bio-inspired white pigments. Many organisms have evolved the ability to manipulate light in unique and fascinating ways. Mimicking these mechanisms h ..read more