Breakthrough in Tin-Vacancy Centers for Quantum Network Applications

Tin-vacancy (Sn-V) centers in diamond have the potential to function as quantum nodes in quantum networks to transmit information. However, they pose limitations while showing optical properties to generate quantum entanglement. Tokyo Tech researchers have now overcome this challenge by generating stable Sn-V centers that can produce photons with nearly identical frequencies and linewidths, paving the way for the advancement of Sn-V centers as a quantum-light matter interface.

Quantum entanglement refers to a phenomenon in quantum mechanics in which two or more particles become linked such that the state of each particle cannot be described independently of the others, even when they are separated by a large distance. The principle, referred to by Albert Einstein as "spooky action at a distance", is now utilized in quantum networks to transfer information. The building blocks of these networks—quantum nodes—can generate and measure quantum states.

Among the candidates that can function as quantum nodes, the Sn-V center in diamond (a defect where a tin (Sn) atom replaces a carbon atom, resulting in an interstitial Sn atom between two carbon vacancies) has been shown to have suitable properties for quantum network applications. The Sn-V center is expected to exhibit a long spin coherence time in the millisecond range at Kelvin temperatures, allowing it to maintain its quantum state for a relatively long period of time. However, these centers have yet to produce photons with similar characteristics, which is a necessary criterion for creating remote entangled quantum states between quantum network nodes.

Zombie forests

As the climate changes, plants often struggle to keep up. In many areas, the vegetation that stands today may not be well adapted for the climate it is now living in. After a major disturbance, such as a wildfire, the plant community likely will not return.

Video Credit: Lindsay Filgas, Madison Pobis & Rob Jordan

The researchers created maps showing where warmer weather has left trees in conditions that don’t suit them, making them more prone to being replaced by other species. The findings could help inform long-term wildfire and ecosystem management in these “zombie forests.”

Like an old man suddenly aware the world has moved on without him, the conifer tree native to lower elevations of California’s Sierra Nevada mountain range finds itself in an unrecognizable climate. A new Stanford-led study reveals that about a fifth of all Sierra Nevada conifer forests – emblems of Western wilderness – are a “mismatch” for their regions’ warming weather. The paper, published Feb. 28 in PNAS Nexus, highlights how such “zombie forests” are temporarily cheating death, likely to be replaced with tree species better adapted to the climate after one of California’s increasingly frequent catastrophic wildfires.

“Forest and fire managers need to know where their limited resources can have the most impact,” said study lead author Avery Hill, a graduate student in biology at Stanford’s School of Humanities & Sciences at the time of the research. “This study provides a strong foundation for understanding where forest transitions are likely to occur, and how that will affect future ecosystem processes like wildfire regimes.” Hill led a related study this past November showing how wildfires have accelerated the shifting of Western trees’ ranges.

Could Space Dust Help Protect the Earth from Climate Change?

Illustration Credit: Ben Bromley/University of Utah

On a cold winter day, the warmth of the Sun is welcome. Yet as humanity emits more greenhouse gases, the Earth's atmosphere traps more and more of the Sun's energy, which steadily increases the Earth's temperature. One strategy for reversing this trend is to intercept a fraction of sunlight before it reaches our planet.

For decades, scientists have considered using screens or other objects to block just enough of the Sun’s radiation — between 1 or 2 percent — to mitigate the effects of global warming. Now, a new study led by scientists at the Center for Astrophysics | Harvard & Smithsonian and the University of Utah explores the potential of using dust to shield sunlight.

The paper, published today in the journal PLOS Climate, describes different properties of dust particles, quantities of dust and the orbits that would be best suited for shading Earth. The team found that launching dust from Earth to a way station at the "Lagrange Point" between Earth and the Sun would be most effective but would require an astronomical cost and effort.

The team proposes moondust as an alternative, arguing that lunar dust launched from the Moon could be a low-cost and effective way to shade the Earth.

A motion freezer for particles

Illustration Credit: Jakob Hüpfl / TU Wien

Tailor-made laser light fields can be used to slow down the movement of several particles and thus cool them down to extremely low temperatures - as shown by a team from TU Wien.

Using lasers to slow down atoms is a technique that has been used for a long time already: If one wants to achieve low-temperature world records in the range of absolute temperature zero, one resorts to laser cooling, in which energy is extracted from the atoms with a suitable laser beam.

Recently, such techniques have also been applied to small particles in the nano- and micro-meter range. This already works quite well for individual particles – but if you want to cool several particles at once, the problem turns out to be much more difficult. Prof. Stefan Rotter and his team at the Institute of Theoretical Physics at TU Wien have now presented a method with which extremely effective cooling can also be achieved in this case.

Steel Was Already Used in Europe 2900 Years Ago

Using geochemical analyses, the researchers were able to prove that stone stelae on the Iberian peninsula that date back to the Final Bronze Age feature complex engravings that could only have been done using tempered steel. This was backed up by metallographic analyses of an iron chisel from the same period and region that showed the necessary carbon content to be proper steel.
Photo Credits: Rafael Ferreiro Mählmann (A), Bastian Asmus (B), Ralph Araque Gonzalez (C-E)

A study by an international and interdisciplinary team headed by Freiburg archaeologist Dr. Ralph Araque Gonzalez from the Faculty of Humanities has proven that steel tools were already in use in Europe around 2900 years ago. Using geochemical analyses, the researchers were able to prove that stone stelae on the Iberian Peninsula that date back to the Final Bronze Age feature complex engravings that could only have been done using tempered steel. This was backed up by metallographic analyses of an iron chisel from the same period and region (Rocha do Vigio, Portugal, ca. 900 BCE) that showed the necessary carbon content to be proper steel. The result was also confirmed experimentally by undertaking trials with chisels made of various materials: only the chisel made of tempered steel was suitably capable of engraving the stone. 

Until recently it was assumed that it was not possible to produce suitable quality steel in the Early Iron Age and certainly not in the Final Bronze Age, and that it only came to be widespread in Europe under the Roman Empire. “The chisel from Rocha do Vigio and the context where it was found show that iron metallurgy including the production and tempering of steel were probably indigenous developments of decentralized small communities in Iberia, and not due to the influence of later colonization processes. This also has consequences for the archaeological assessment of iron metallurgy and quartzite sculptures in other regions of the world,” explains Araque Gonzalez. The study ‘Stone-working and the earliest steel in Iberia: Scientific analyses and experimental replications of final bronze age stelae and tools’ has been published in the Journal of Archaeological Science.

Child obesity linked to increased risk of several types of diabetes as an adult

Yuxia Wei, doctoral student at Institute of Environmental Medicine and the study's first author.
Photo Credit: Jingwei Zhao

Child obesity is linked to an increased risk of suffering from diabetes in adulthood and the risk increase concerns both autoimmune forms of diabetes and various forms of type 2 diabetes, according to a new study published in Diabetologia. For example, the risk of suffering from the most insulin-resistant form of diabetes is three times as high for obese children.

Diabetes affects about seven percent of the adult population and is one of the world's fastest growing diseases. Diabetes has traditionally been divided into two subgroups, type 1 and type 2 diabetes, but research suggests that this is a gross simplification.

In 2018, a Swedish study identified five subgroups of adult-duty diabetes. These are characterized by autoimmunity, severe insulin deficiency, severe insulin resistance, obesity and high age, respectively.

Diabetes affects about seven percent of the adult population and is one of the world's fastest growing diseases. Diabetes has traditionally been divided into two subgroups, type 1 and type 2 diabetes, but research suggests that this is a gross simplification.

Blood test for brain cancer may be on horizon, new research finds

Researchers at Penn State College of Medicine have identified a biomarker that can be used in blood tests to diagnose glioblastoma, the most common and deadliest type of brain cancer, and track its progression and guide treatment.
Photo Credit: National Cancer Institute

Glioblastoma (GBM) is the most common and deadliest type of brain cancer with a five-year survival rate of only 5%. Researchers at Penn State College of Medicine have identified a biomarker that can be used in blood tests to diagnose GBM, track its progression and guide treatment. The researchers said that such a non-invasive liquid biopsy for GBM could help patients get the care they need more quickly.

“Patients normally receive imaging, such as MRI or CT scans, to diagnose and track the progression of brain tumors, but it can be difficult for physicians to tell from those scans if the patient is getting better or worse because they don’t provide detail at the cellular or molecular level,” said Vladimir Khristov, graduate and medical student, Penn State. “That is why we need a supplemental diagnostic test to help physicians determine if the tumors are responding to therapy and regressing, or if they are getting worse and need additional treatment.”

Indeed, added Brad Zacharia, associate professor of neurosurgery and of otolaryngology, Penn State, a liquid biopsy for glioblastoma could be of tremendous value to patients suffering from this devastating tumor.

In the end, it's the individual advantage that counts

The three phases of exceptional dynamics: (1) Predation on the unprotected bacteria by predators, (2) toxin formation as cooperative defense and recovery of the bacterial population, (3) filament formation as individual defense through evolution and stabilization of densities.
Photo Credit: David Kneis/TU Dresden

Bacteria rely on cooperation and evolution in order to defend themselves against predatory protists

Eating and being eaten is a normal process in nature. These predator-prey dynamics help to stabilize ecosystems. It ensures that individual species do not become too abundant, controls their populations, and prevents damage caused by overpopulation (e.g., browsing by deer in the forest or damage to crops by caterpillars). But how is it that the predators do not simply eat away all the prey, thus breaking down the system? A research team from the Helmholtz Centre for Environmental Research (UFZ) together with scientists from the Technical University (TU) of Dresden and the University of Potsdam has investigated this using bacteria and protists that live in bodies of water and discovered something astonishing. According to an article recently published in ISME Journal, bacteria defend themselves against predatory protists with cooperative behavior and evolution.

In a lake or river, between one and 10 million bacteria live in just 1 ml of water. Such a high density is necessary because bacteria permanently break down organic compounds and pollutants and thus purify the water. However, if there are too many bacteria, this can lead to the spread of pathogens. Preventing this requires predators: microscopic protists of which there are usually between a few hundred and a few thousand individuals in 1 ml of water. They constantly eat bacteria and thus ensure that the bacteria fulfil their cleaning function but do not become too abundant. Using the bacterium Pseudomonas putida and the bacterivorous protist Poteriospumella lacustris, the research team investigated the role of the various defense strategies of the bacteria and how the formation of feeding resistance is related to the dynamics of ecological systems.

Breathing is going to get tougher

Dust rising at Noordoewer, Namibia. Research shows dust will be a major contributor to poor air quality as the climate changes.
Photo Credit: Matthieu Joannon

Not all pollution comes from people. When global temperatures increase by 4 degrees Celsius, harmful plant emissions and dust will also increase by as much as 14 percent, according to new UC Riverside research.

The research does not account for a simultaneous increase in human-made sources of air pollution, which has already been predicted by other studies. 

“We are not looking at human emissions of air pollution, because we can change what we emit,” said James Gomez, UCR doctoral student and lead author of the study. “We can switch to electric cars. But that may not change air pollution from plants or dust.”

Details of the degradation in future air quality from these natural sources have now been published in the journal Communications Earth & Environment. About two-thirds of the future pollution is predicted to come from plants.

All plants produce chemicals called biogenic volatile organic compounds, or BVOCs. “The smell of a just-mowed lawn, or the sweetness of a ripe strawberry, those are BVOCs. Plants are constantly emitting them,” Gomez said.

First patient receives milestone stem cell-based transplant for Parkinson’s Disease

On 13th of February, a transplant of stem cell-derived nerve cells was administered to a person with Parkinson’s at Skåne University Hospital, Sweden. The product has been developed by Lund University and it is now being tested in patients for the first time. The transplantation product is generated from embryonic stem cells and functions to replace the dopamine nerve cells which are lost in the parkinsonian brain. This patient was the first of eight with Parkinson’s disease who will receive the transplant.

“This is an important milestone on the road towards a cell therapy that can be used to treat patients with Parkinson’s disease. The transplantation has been completed as planned, and the correct location of the cell implant has been confirmed by magnetic resonance imaging. Any potential effects of the STEM PD-product may take several years. The patient has been discharged from the hospital and evaluations will be conducted according to the study protocol,” says Gesine Paul-Visse, principal investigator for the STEM-PD clinical trial, consultant neurologist at Skåne University Hospital and adjunct professor at Lund University in Sweden.

There are around eight million people living with Parkinson’s disease globally; a disease which involves loss of dopamine nerve cells deep in the brain, leading to problems in controlling movement. The standard treatment for Parkinson’s disease is medications that replace the lost dopamine, but over time these medications often become less effective and cause side effects. As of today, there are no treatments that can repair the damaged structures within the brain or that can replace the nerve cells that are lost.