Multiphysics simulation charts the migration of harmful proteins in the brain

30 Oct 2018

The big picture: an illustration of the human brain. (Courtesy: Shutterstock/Phonlamai Photo)

Computer simulations have reproduced the spreading and accumulation of defective proteins throughout the brain – a process characteristic of several neurodegenerative diseases including Alzheimer’s, Parkinson’s and amyotrophic lateral sclerosis (ALS). Created by US and UK researchers led by Alain Goriely at the University of Oxford, the model can approximate large-scale behaviours of complex neurological processes with surprising accuracy. The team’s work could one day lead to new treatments for neurodegenerative diseases.

Brain cells communicate with each other partly through electrical signals and partly through the exchange of chemical information in the form of complex protein molecules.

Amazon rainforest sees more rain

30 Oct 2018

(Courtesy: iStock SchulteProductions)

Wet seasons in the Amazon are getting wetter, according to satellite images and observations on the ground. Rainfall increased by at least 180 mm from 1979 to 2015, but what’s driving this long-term trend?

Researchers in China and Brazil found that more than half this change could be due to warming of the tropical Atlantic. Establishing such links is crucial so scientists can better advise on how to safeguard major environmental assets. The Amazon rainforest is a significant sink of carbon dioxide and long-term changes in precipitation could compromise this.

Tumour trailing mitigates motion in MR-Linac radiotherapy

30 Oct 2018 Tami Freeman

Martin Fast from the Netherlands Cancer Institute with the Unity MR-Linac.

Stereotactic body radiation therapy (SBRT), which delivers an ablative radiation dose in a few fractions, provides a potent treatment option for patients with liver metastases. To minimize normal tissue damage, SBRT requires highly conformal dose delivery, making it essential to compensate for respiration-induced liver motion.

One option is to perform treatment planning and patient positioning based on the mid-position CT, which represents the time-averaged tumour position, and then add margins to account for uncertainties. This approach, however, relies on a stable mid-position. Any baseline drifts during radiation delivery will change this mid-position with respect to the treatment beam.

Photosynthetic sutures promote wound healing

26 Oct 2018 Héctor Capella Monsonís

Fluorescence and scanning electron microscopy images of sutures with and without microalgae loaded. (Courtesy: Acta Biomaterialia 10.1016/j.actbio.2018.09.060 ©2018)

Sutures are extensively used to close wounds. However, rather than promoting active healing of the wound, they act as a passive element that provokes scar formation. In addition, the disruption of blood vessels decreases the presence of oxygen in the wound, limiting the healing. Therefore, there is growing interest in the development of bioactive sutures that promote remodelling of the tissue.

In this context, Tomás Egaña from Pontifical Catholic University of Chile, together with researchers from other South American and European universities, have developed a suture that contains genetically modified microalgae (C.reinhardtii).

How close can cities get to 100% renewable energy?

24 Oct 2018 Dave Elliott

(Courtesy: iStock/adrian825)

Around the world, cities are beginning to think in terms of meeting their energy needs from renewable sources, to limit air pollution and climate change problems. Over 100 cities now claim to get at least 70% of their electricity from renewables, compared to 42 in 2015, and many more are aiming for high proportions, as part of a drive to “100% renewables”. With cities responsible for over 70% of global carbon emissions from energy use, that is to be welcomed, but it’s worth being a little clearer about what’s meant by “100% renewable” cities.

For rural communities, the growing appetite of cities for their resources may be perceived as a threat. Rural areas very often do not meet their own needs with locally produced energy; so how could they consider supplying other territories?CLER, Energy Cities and Réseau Action Climat

IPCC’s climate report: the future’s not looking good

17 Oct 2018 Dave Elliott

(Courtesy: Shutterstock/Eviart)

The Intergovernmental Panel on Climate Change (IPCC) SR15 special report looks at how to keep global temperature rise to 1.5 °C. Even if that was possible, impacts would be severe, but they’d be much worse at 2 °C.

The IPCC report puts it positively, highlighting a number of climate change impacts that could be avoided by limiting global warming to 1.5 °C compared to 2 °C, or more. For instance, by 2100 global sea level rise would be 10 cm lower with global warming of 1.5 °C compared with 2 °C. The likelihood of an Arctic Ocean free of sea ice in summer would be once per century with global warming of 1.5 °C, compared with at least once per decade with 2 °C. Coral reefs would decline by 70-90% with global warming of 1.5 °C, whereas virtually all (> 99%) would be lost with 2 °C.

Amy McDowell: Improving MRI to help children with epilepsy

23 Oct 2018

Jude Dineley interviews Amy McDowell, an MRI researcher at the UCL Great Ormond Street Institute of Child Health. McDowell is one of eight physicists profiled as part of a specially commissioned article on forging a career in medical physics.

Clinical and computational: MRI specialist Amy McDowell

“It’s important for me that the projects that I take on are the sort of projects where I get a result and it gets used,” says Amy McDowell, a researcher in magnetic resonance imaging (MRI) physics at the UCL Great Ormond Street Institute of Child Health. Also a qualified clinical scientist, McDowell develops MRI techniques to solve specific clinical problems through a mix of technical and hands-on practical work.

Technical tasks include devising the sequences of radiofrequency pulses and magnetic field gradients that generate the images, and processing and analysing the images. McDowell’s computational skills have been crucial in each activity. “Programming is the basis of everything these days,” she says. McDowell also recruits patients for studies and carries out the scans. “I like the variety and the fact that every day is a challenge where I need to find out a new piece of information.”

Europe pledges €1bn for applied quantum technologies

29 Oct 2018 Margaret Harris

Statues at the entrance of the Quantum Flagship kick-off event in Vienna’s Hofburg palace.

Members of the European quantum science community gathered in Vienna today to kick off a 10-year, €1bn European Commission (EC) initiative that aims to position Europe at the forefront of the emerging quantum technologies industry.

Speaking in a glittering hall within the former palace of Austria’s Hapsburg emperors, Gustav Kalbe, head of the EC’s High Performance Computing and Quantum Computing Unit, explained that the “core idea” of the new Quantum Flagship is to take scientific results out of university labs, bring them to fruition and build an industry around them. “There are still many scientific challenges to be solved, but we are now at the point where we can begin giving the taxpayer a return on their investment,” Kalbe said. The flagship’s many industrial partners, he added, are “no longer following by the sidelines” but making active contributions.

Playing with single electrons in designer atomic structures

29 Oct 2018 Belle Dumé

AFM mechanically lifts silicon atoms

Being able to manipulate and monitor single electrons in predesigned atomically-defined structures has been a long-standing goal for condensed matter physicists. A team led by Robert Wolkow of the University of Alberta in Edmonton, Canada, has now succeeded in doing just this. As well as being useful for fundamental studies, such designer lattices could also be used to make atomic circuits in the future.

“We are now able to play with single charges (electrons) in atomically-defined structures of our own design for the first time,” explains team member Mohammad Rashidi, who is also at the Nanotechnology Research Centre and Quantum Silicon, both in Edmonton. “Previously, this had only been done on isolated atoms and molecules on insulating substrates. In our work, we can place atoms at will and compose structures of dangling bonds on a hydrogen-terminated silicon surface.

Acoustic tractor beam can grab objects from behind obstacles

29 Oct 2018

Fly ball: Gianluca Memoli and Mohd Adili Norasikin levitate a white bead using SoundBender. (Courtesy: University of Sussex)

An acoustic tractor beam that can bend sound around an obstacle to levitate an object on the other side has been created by researchers in the UK. Dubbed SoundBender, the device combines an ultrasound transducer array with an acoustic metamaterial.

In recent years, researchers have used transducer arrays to build sonic tractor beams that can create complex acoustic holograms to manipulate objects in mid-air. Acoustic metamaterials are engineered materials with structural properties that do not usually occur naturally. They have been used to produce acoustic holograms, bend beams of sound and create static acoustic levitation devices. But the team behind the SoundBender, based at the University of Sussex, say that these technologies have key limitations.

Α WAVE OF DISCOVERY

Α WAVE OF DISCOVERY

29 Oct 2018

Taken from the October 2018 issue of Physics World, which celebrates 30 years of the world’s best physics magazine. Members of the Institute of Physics can enjoy the full issue via the Physics World app.

James Hough outlines the last 30 years of gravitational-wave astronomy, from building prototype detectors to making a revolutionary discovery

“Gravitational waves, yet to be convincingly detected, promise to open a new astronomical window.” Those are the words I wrote for Physics World in early 1989. Today, with six detections of gravitational waves confirmed over the past three years, I am delighted to see how many of the predictions I made in that article have come to fruition.

ΦΥΣΙΚΗ Β ΓΥΜΝΑΣΙΟΥ "ΘΕΡΜΟΤΗΤΑ - ΘΕΡΜΙΚΗ ΑΛΛΗΛΕΠΙΔΡΑΣΗ" ΦΥΣΙΚΗ Β ΛΥΚΕΙΟΥ ΠΡΟΣΑΝΑΤΟΛΙΣΜΟΥ ΘΕΤΙΚΩΝ ΣΠΟΥΔΩΝ "ΘΕΡΜΟΔΥΝΑΜΙΚΗ"

ΦΥΣΙΚΗ Β ΓΥΜΝΑΣΙΟΥ "ΘΕΡΜΟΤΗΤΑ - ΘΕΡΜΙΚΗ ΑΛΛΗΛΕΠΙΔΡΑΣΗ" ΦΥΣΙΚΗ Β ΛΥΚΕΙΟΥ ΠΡΟΣΑΝΑΤΟΛΙΣΜΟΥ ΘΕΤΙΚΩΝ ΣΠΟΥΔΩΝ "ΘΕΡΜΟΔΥΝΑΜΙΚΗ"

How does the interplay effect impact paediatric proton therapy?

29 Oct 2018

(A) Dose distribution of intensity-modulated photon therapy for an example patient; (B) proton therapy dose distribution for the same patient; (C) simulated interplay effect for proton therapy without motion management, red and blue represent overdose and underdose, respectively. (Courtesy: Chia-ho Hua)

The effectiveness of proton therapy using pencil-beam scanning technology can be offset by the interplay effect, in which relative motion between the tumour and the scanning proton beam causes deviation of the delivered dose distribution from the original treatment plan.

The interplay effect has been widely investigated in adult patients but minimally in children. Now, researchers at St. Jude Children’s Research Hospital have investigated the effect of interplay between respiration-induced tumour motion and spot-scanning proton beams on internal target volume (ITV) coverage in paediatric patients. They performed simulations for a sample of patients, aged from two to 19 years, who had previously received radiotherapy for abdominal tumours (Int. J. Particle Ther. 10.14338/IJPT-17-00030.1).

Egypt looks likely to fail on wheat self-sufficiency

29 Oct 2018

(Courtesy: iStock/jiangill)

A plan by the Egyptian government to make the country self-sufficient in wheat will likely fail by the 2040s, according to a study by researchers in Egypt and the US.

The plan involves intensifying farming methods and the near-doubling of irrigated land for wheat production by 2035, from 3.9 to 7.7 million hectares. According to the study, however, even a modest growth in population will swiftly consume the extra yield from this expansion.

“As about 30% of wheat is irrigated globally, the challenges Egypt is facing are similar to other countries trying to increase agricultural production,” says Senthold Asseng of the University of Florida, US. “What we learn from our study in Egypt will also apply to other parts of the world.”

7 Facts About Coffee You Probably Didn’t Know

         



7 Facts About Coffee You Probably Didn’t Know



28/10/2018

Tuneable superconductivity appears in topological insulator

27 Oct 2018 Belle Dumé

A superconductor and a topological insulator

Researchers at the Massachusetts Institute of Technology have discovered that monolayer tungsten ditelluride (WTe2) is superconducting at ultralow temperatures despite its very low charge carrier density. And that the state of the material can be electrically tuned from being a superconductor to an insulator. More importantly still, it could be used to engineer Majorana zero modes – a key step towards making a topological quantum computer.

“We recently confirmed in experiments that the insulating phase of monolayer WTe2 is a topological insulator,” explains team leader Pablo Jarillo-Herrero. “This means that it is the first material that can be electrically tuned over a wide range – all the way from being a topological insulator to a superconductor. This makes it an excellent candidate for engineering Majorana modes according to the famous Fu-Kane proposal.”

ΦΥΣΙΚΗ Β ΓΥΜΝΑΣΙΟΥ ΚΑΙ ΦΥΣΙΚΗ Β ΛΥΚΕΙΟΥ ΠΡΟΣΑΝΑΤΟΛΙΣΜΟΥ ΘΕΤΙΚΩΝ ΣΠΟΥΔΩΝ "Η ΘΕΡΜΟΤΗΤΑ - Η ΘΕΡΜΙΚΗ ΙΣΟΡΡΟΠΙΑ"

ΦΥΣΙΚΗ Β ΓΥΜΝΑΣΙΟΥ ΚΑΙ ΦΥΣΙΚΗ Β ΛΥΚΕΙΟΥ ΠΡΟΣΑΝΑΤΟΛΙΣΜΟΥ ΘΕΤΙΚΩΝ ΣΠΟΥΔΩΝ "Η ΘΕΡΜΟΤΗΤΑ - Η ΘΕΡΜΙΚΗ ΙΣΟΡΡΟΠΙΑ"

Panel calls for more research into carbon-capture technologies

26 Oct 2018

Hot air: artist's impression of a carbon-dioxide extraction system (Courtesy: Carbon Engineering)

Avoiding global temperature rises of just a few degrees in the coming decades will require the use of technologies that directly remove greenhouse gases from the atmosphere. That is according to a new report released on 24 October by the US National Academies of Sciences, Engineering and Medicine, which warns that even having a carbon-neutral energy sector would not be enough to reverse potentially catastrophic alterations to the Earth’s climate.

The report – Negative Emissions Technologies and Reliable Sequestration: A Research Agenda – states that to meet the Paris Accord goal of limiting anthropogenic warming to 1.5-2.0 °C, greenhouse-gas emissions will have to fall from 50 gigatonnes of equivalent carbon dioxide (GtCO2e) today to less than 20 GtCO2e by 2050 and zero by 2100.

Ancient enzyme resurrected for commercial biocatalysis

26 Oct 2018 Belle Dumé

Elizabeth Gillam

By “resurrecting” the genetic sequence of an ancestral form of the technologically important P450 enzymes, researchers at the University of Queensland in Brisbane, Australia, have succeeded in significantly improving its thermal stability. The enzyme can now be made to be robust to temperatures as high as 66°C and better resist solvents compared to the non-stabilised form. The new technique might be applied to a whole range of other enzymes and proteins and could revolutionize commercial biocatalysis. The stabilised enzymes will also be ideal for studying the fundamental function and structure of proteins to better understand how they work.

Enzymes will play a crucial role as catalysts in the emerging bioeconomy of the 21st century, says Elizabeth Gillam of the School of Chemistry and Molecular Biosciences at the University of Queensland, who led this research effort. The problem is that naturally occurring enzymes are often not very stable at the elevated temperatures and over the long time periods routinely employed in industrial processes. “It is difficult to design an enzyme so that it is thermostable because proteins are very complex and we simply don’t know enough about how they work to design them from scratch, despite much intensive and costly wet-lab research over the past decades.

Doubled raw materials use is climate risk

26 Oct 2018

Photo by Dominik Vanyi on Unsplash

Just when you might think the world has heard an unmistakable warning of the need to curb climate change drastically and fast, along comes another warning, about humans’ voracious appetite for the raw materials we use so profligately.

Its message is simple: one of the main causes of the Earth’s growing warmth is likely to be twice as severe 40 years from now as it is today.

This latest warning, from the club of the world’s richest countries, the Organisation for Economic Co-operation and Development (OECD), says consumption of raw materials is on course to nearly double by 2060 as the global economy expands and living standards rise.

Large family of quantum spin liquids revealed

20 Oct 2018 Anna Demming

The general crystal structure of rare-earth chalcogenides. Credit Chinese Physics Letters

“Quantum spin liquids are the exception,” says Gang Chen, Professor of Physics at Fudan University in China. He is describing the theory Soviet theoretical physicist Lev Landau developed to characterize the ferromagnetic or antiferromagnetic ordering adopted by spins in a magnet when they get too cold to keep fluctuating thermally. Quantum spin liquids shirk this theory. “The spins in quantum spin liquids do not order even down to absolute zero temperature. It is a very exotic quantum phase of matter and cannot be understood in the framework by Landau.”

Nanoparticle-coated membrane improves dental implants

25 Oct 2018 Tami Freeman

SEM images of uncoated (top) and nanoparticle-coated (bottom) collagen membrane. Confocal imaging shows that cells seeded on either membrane are morphologically comparable.

Dental implants are commonly used to replace missing teeth. The success of such an implant relies on solid anchorage into the alveolar bone that contains the tooth sockets. But many patients do not have sufficient bone volume to secure the implant and require bone reconstruction before tooth implantation.

The reconstruction procedure involves infilling a bone substitute into the alveolar socket to initiate bone formation. Infection, however, remains a major concern in dental surgery. A barrier membrane can help prevent infection, while also blocking soft-tissue ingrowth as the new bone forms.

Electrical pulses speed up nerve regeneration in rats

24 Oct 2018 Lizzie Norris

The wireless device is absorbed naturally into the body at a rate which can be tailored to the patient's needs. Credit: John Rogers

Pain, tingling and numbness in the hands, legs and arms are common symptoms of peripheral nerve injuries. Typically caused by trauma or acute compression, they are considered a significant problem for public health, making up 2-5% of all trauma cases.

Researchers at Washington University School of Medicine in St Louis and Northwestern University have developed an implantable device that can deliver scheduled electrical stimulation to targeted peripheral nerves after surgery has been completed. Their research, published in Nature Medicine, has shown that these electrical pulses help with the nerve regrowth and enhanced muscle recovery in rats.

Dandelion seeds create vortexes to remain aloft

22 Oct 2018

Long haul flight: micro CT image of a dandelion seed with yellow false colour. (Courtesy: Madeleine Seale and Alice Macente)

A brush-shaped structure called a pappus creates vortex rings that help keep dandelion seeds aloft, according to a comprehensive study by researchers at the University of Edinburgh in the UK. The team was also able to created artificial structures that mimicked the seeds.

Dandelions are yellow wildflowers that grow in temperate regions. Widespread and prolific, the plant is often considered a weed but is also edible and has a number of culinary uses.

The dandelion flower – actually a collection of multiple flowers – matures into white blowball full of single-seed fruits attached to a bundle of bristle filaments called a “pappus” (see figure). Resembling a chimney brush, the pappus helps the windblown seed to stay aloft over incredible distances. Although most dandelion seeds travel less than 2 m from their flowers, seeds can easily travel over 100 km in warm, dry air.

Neutrinos shine new light on fusion reactions in the Sun

25 Oct 2018

Nuclear power: the Sun as seen by NASA's Solar Dynamics Observatory. (Courtesy: NASA/SDO)

Neutrino fluxes generated by nuclear reactions inside the Sun have been measured more precisely than ever before. Using a detector housed under the Gran Sasso mountain in central Italy, the Borexino collaboration has captured neutrinos from four different reactions involved in the creation of helium-4 from hydrogen. The results confirm the nuclear origin of solar power and could help to pin down the abundance of elements heavier than helium inside the Sun.

Some 99% of the Sun’s energy is generated through reactions that begin with the fusion of two protons. This “proton-proton chain” proceeds via a number of different routes. The most common route involves the fusion of two helium-3 nuclei, while others feature the temporary production of beryllium-7 and one the creation of boron-8.

Fluorescent peptide probe tracks lung infections

24 Oct 2018 Belle Dumé

Identifying Gram-negative bacteria in the lung

A new fluorescent imaging probe that can image Gram-negative bacteria in the human lung in real time could be used to find out whether a patient is suffering from a bacterial infection. The device, which has been tested in a small clinical study, opens up a whole new field in medicine and could make for a new diagnostic platform for pneumonia and other infections, say the researchers at the University of Edinburgh who developed it.

Patients with respiratory disease can contract Gram-negative pulmonary infections such as pneumonia in hospital. The problem is unfortunately even worse for patients who are on mechanical ventilators in intensive care units.

Quantum Reality: Space, Time, and Entanglement

   



Quantum Reality: Space, Time, and Entanglement



25/10/2018

Sean Carroll: The Paradoxes of Time Travel

             



Sean Carroll: The Paradoxes of Time Travel



25/10/2018

Do We Live In An Infinite Universe? Featuring Paul Sutter

   



Do We Live In An Infinite Universe? Featuring Paul Sutter



25/10/2018

ΦΥΣΙΚΗ Β ΓΥΜΝΑΣΙΟΥ "Η ΘΕΡΜΟΤΗΤΑ" ΚΑΙ ΦΥΣΙΚΗ Β ΛΥΚΕΙΟΥ ΠΡΟΣΑΝΑΤΟΛΙΣΜΟΥ ΘΕΤΙΚΩΝ ΣΠΟΥΔΩΝ " ΟΙ ΜΕΤΑΒΟΛΕΣ ΤΩΝ ΦΑΣΕΩΝ"

ΦΥΣΙΚΗ Β ΓΥΜΝΑΣΙΟΥ "Η ΘΕΡΜΟΤΗΤΑ" ΚΑΙ ΦΥΣΙΚΗ Β ΛΥΚΕΙΟΥ ΠΡΟΣΑΝΑΤΟΛΙΣΜΟΥ ΘΕΤΙΚΩΝ ΣΠΟΥΔΩΝ " ΟΙ ΜΕΤΑΒΟΛΕΣ ΤΩΝ ΦΑΣΕΩΝ"

3D cell printing enables investigations into cervical tumour metastasis

24 Oct 2018 Luciana Stanica

The study authors (from left to right): Zhenzhen Zhou, Jianyu He, Yuan Pang and Shuangshuang Mao.

The epithelial–mesenchymal transition (EMT) is a process by which polarized epithelial cells undergo multiple biochemical changes enabling their transfer into a mesenchymal cell phenotype, which is characterized by an enhanced migratory capacity, invasiveness and elevated resistance to cell death. Although it is known that EMT plays an important role in tumour metastasis, the regulation mechanism is still to be elucidated.

Three-dimensional bioprinting has emerged as a useful tool for the study of cancer mechanisms, because it can mimic the in vivo microenvironment of tumour cells by the precise control of cells and biomaterials.

Computer model picks which roofs to make green

23 Oct 2018 Liz Kalaugher

Pilot green roof project at Chicago City Hall in 2008. By Conservation Design Forum [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

The installation of green roofs in cities to reduce the “urban heat island” effect should take into account which areas are hottest, which people are most vulnerable and where air-conditioning usage is highest, say researchers in the US. The effect describes the heightened air temperatures of cities relative to the surrounding countryside.

Using computer models to include all these factors, the researchers found that in the US city of Chicago, areas to the south and west, as well as certain other isolated areas, would benefit most from green roof installation.

The methodology can and should be applied to other places that suffer from the urban heat island effect, the researchers say.

What teaching physics Kenya taught me about inspiring students to study maths and science

23 Oct 2018

Potential energy: Artur Donaldson speaks to students about the physics of the pendulum. (Courtesy: Artur Donaldson)

We met Mr Odhiambo at the base of the hill which rises above Maseno University in Western Kenya. I am grateful he has invited me and two Kenyan mathematicians visit the school where he teaches. My mathematician colleagues, Lazarus Kioko and John Maina, are members of the African Maths Initiative (AMI) — an organization whose mission is to strengthen the culture of mathematics across Africa.

I am a physics undergraduate at Imperial College London and I was in Kenya recently with two objectives: to encourage more Kenyan students to study physics and to see how technology can be used in teaching physics.

Trimodal imaging platform tracks implanted pancreatic islets

23 Oct 2018

Representative bioluminescence (left), fluorescence (centre) and axial MR images (right) of 3000 and 1000 pancreatic islets transplanted into scaffolds, on days 4 and 14. (Courtesy: A. Gálisová et al. Mol. Imaging Biol. 10.1007/s11307-018-1270-3; CC BY 4.0)

Type I diabetes sufferers use insulin injections to control their blood sugar; but in unstable diabetes, blood sugar levels swing sharply and unpredictably, causing frequent episodes of hypo- or hyper-glycaemia. The transplantation of functioning pancreatic islet cells into the liver is a possible treatment for unstable diabetes, but current grafts are partially or fully rejected over time.

Artificial scaffolds show promising transplantation efficiency, but to better understand and therefore improve islet engraftment, more precise methods of non-invasively monitoring grafts are required. A number of imaging modalities have been used to track islet engraftments, each with its own limitations. Therefore, scientists are looking to combine imaging modalities to monitor islet distribution, number and viability.

PETRUS hybrid device acquires multimodal images in vivo

19 Oct 2018

Inserm researchers (left to right): head of the group Bertrand Tavitian, research engineer Thomas Viel, PhD student Thulaciga Yoganathan and postdoctoral researcher Mailyn Pérez-Liva.

A research team in France has evaluated the PETRUS hybrid imaging instrument both in vitroand in vivo in small animals. The researchers demonstrated the capability of the device, which simultaneously performs PET/CT and ultrafast ultrasound, to acquire multimodal images in vivo without significant degradation of image quality (Phys. Med. Biol. 63 19NT01).

The researchers — based at Inserm, the Université Paris Descartes and ESPCI Paris — explored the effect of using a PETRUS system on image quality, finding deviations of below 10% between images acquired with and without ultrasound probes.

Graphene twists again

22 Oct 2018 Belle Dumé

Graphene moiré superlattice

Umklapp electron-electron scattering in so-called moiré superlattices made from aligned layers of 2D materials such as graphene and hexagonal boron nitride could degrade the high-temperature mobility of graphene’s charge carriers. This is the new result from researchers in the UK, US and Japan who say the effect would limit the potential applications of these technologically important materials in room-temperature high-mobility devices. The problem could be overcome, however, by misaligning, or twisting, the 2D layers with respect to each other.

Stephen Hawking’s ‘final paper’ on hairy black holes hits the headlines

11 Oct 2018 Hamish Johnston

Information storage: do soft hairs exist on black holes? (Courtesy: Shutterstock/oorka)

A few days after Stephen Hawking died in March, you might recall us covering what we said was the great cosmologist’s “last” paper. Now, however, it seems that the article wasn’t actually his last: the Guardian is running two stories about what it dubs Hawking’s “final” scientific paper. And in what seems a carefully planned publicity exercise, Hawking’s “final book” is scheduled for publication next week too.

Uploaded to the arXiv preprint server last week and updated on Tuesday, Hawking’s “final” paper is called “Black hole entropy and soft hair”. It contains calculations that aim to help solve the “information paradox” that arises when stuff is sucked into a black hole.

Spotlight falls on radiomics at French radiology congress

22 Oct 2018

© AuntMinnieEurope.com

Being both data-driven and a vital element of discovery research, radiomics is poised to be a pivotal process for the development of new diagnostic imaging strategies and therapies, delegates learned at the French national radiology congress JFR 2018, held in Paris from 12 to 15 October.

Rapid progress is being made, but as those in the field of radiomics seek to stratify which imaging parameters are useful for answering certain questions, they are facing a number of challenges, according to Laure Fournier, professor of radiology at Hôpital Européen Georges Pompidou in Paris.

Gluons account for much more pion momentum than previously thought

19 Oct 2018

Pion exchange: the team used data from the HERA accelerator, which ran at DESY in Hamburg. (Courtesy: DESY)

Gluons contribute around 30% to the total momentum of energetic pions, which is about three times more than previously estimated. The research was done by a team led by Chueng-Ryong Ji at North Carolina State University in the US. They deduced the fraction by combining data gathered by two previous studies that took different approaches to exploring the interior structures the particles.

Pions are the lightest members of the meson family. An individual pion comprises a quark and an antiquark, one of which has up flavour and the other down flavour. Yet this description is overly simplistic because the quark-antiquark pairs are embedded in a sea of “virtual” quarks and antiquarks which appear and disappear instantaneously. The quarks and antiquarks also interact with each other through the strong force by continuously exchanging gluons. However, calculating the precise internal properties of pions and other hadrons is extremely difficult and so physicists have not had a good understanding of the contributions of gluons to pion momenta.

In the 1980s, researchers first explored the interiors of pions by observing how pairs of leptons are created when the mesons are scattered by atomic nuclei at high energies. These studies suggested that gluons contributed around 10% to total pion momenta, but the lack of available data for low-momentum pions meant this value was highly uncertain.

Optical innovations deliver research results

22 Oct 2018

(Courtesy: iStock/Terraxplorer)

Commercial systems that harness the power of light are allowing researchers to probe everything from novel materials to fundamental physical systems. These recent highlights show how light-based tools can be applied to carbon nanomaterials, biomolecular structures, and the quantum and atomic worlds.

Raman measurements extended to “challenging” inorganic materials

Raman spectroscopy has become a powerful tool for probing the structure and properties of graphene, carbon nanotubes and other thin-film structures.

NASA must revamp search for life beyond Earth, experts warn

12 Oct 2018

Faraway worlds: artist's impression of the seven Earth-size planets of TRAPPIST-1. (Courtesy: NASA/JPL-Caltech)

NASA must revamp its astrobiology strategy if it to make progress tackling the question of whether life exists beyond Earth. That is according to a report issued on 10 October by the National Academies of Sciences, Engineering, and Medicine (NASEM), which recommends that the space agency increase collaboration with other scientific disciplines as well as with organizations inside and outside the government.

The report – An Astrobiology Strategy for the Search for Life in the Universe – says that recent advances in astrobiology have been helped by rapid advances in detecting exoplanets in the so-called habitable zone that could support liquid water on their surfaces.

Gluons account for much more pion momentum than previously thought

19 Oct 2018

Pion exchange: the team used data from the HERA accelerator, which ran at DESY in Hamburg. (Courtesy: DESY)

Gluons contribute around 30% to the total momentum of energetic pions, which is about three times more than previously estimated. The research was done by a team led by Chueng-Ryong Ji at North Carolina State University in the US. They deduced the fraction by combining data gathered by two previous studies that took different approaches to exploring the interior structures the particles.

Pions are the lightest members of the meson family. An individual pion comprises a quark and an antiquark, one of which has up flavour and the other down flavour. Yet this description is overly simplistic because the quark-antiquark pairs are embedded in a sea of “virtual” quarks and antiquarks which appear and disappear instantaneously. The quarks and antiquarks also interact with each other through the strong force by continuously exchanging gluons.