Interference among photons, a fundamental phenomenon in quantum optics, serves as a cornerstone of optical quantum computing. It involves harnessing the properties of light, such as its wave-particle duality, to induce interference patterns, enabling the encoding and processing of quantum information.

In traditional multi-photon experiments, spatial encoding is commonly employed, wherein photons are manipulated in different spatial paths to induce interference. These experiments require intricate setups with numerous components, making them resource-intensive and challenging to scale. In contrast, the international team, comprising scientists from University of Vienna, Politecnico di Milano, and Université libre de Bruxells, opted for an approach based on temporal encoding. This technique manipulates the time domain of photons rather than their spatial statistics. To realize this approach, they developed an innovative architecture at the Christian Doppler Laboratory at the University of Vienna, utilizing an optical fiber loop. This design enables repeated use of the same optical components, facilitating efficient multi-photon interference with minimal physical resources.

First author Lorenzo Carosini explains: “In our experiment, we observed quantum interference among up to eight photons, surpassing the scale of most of existing experiments. Thanks to the versatility of our approach, the interference pattern can be reconfigured and the size of the experiment can be scaled, without changing the optical setup.” The results demonstrate the significant resource efficiency of the implemented architecture compared to traditional spatial-encoding approaches, paving the way for more accessible and scalable quantum technologies.

Anqa is located just across the Syrian border from Dura-Europos, in the present-day Al-Qaim district of the Anbar Governorate in Iraq. Its remains include an identifying tell mound, at the northern end of the site, a polygonal inner wall circuit, and a large outer defensive wall, or enceinte. Situated at a point where the Euphrates floodplain drastically narrows, the city would have controlled movement between the populous section of the valley upstream and the trade route downstream linking Syria, Northern Mesopotamia, and Babylonia, giving it great strategic and economic significance. However, the site was ignored entirely by archaeologists until the 1850 publication of a British Middle Euphrates expedition survey. A more thorough study of the site was performed in the late 1930s by Aurel Stein, including aerial photographs of the standing structures, but even after these forays, there was little desire to learn more than the geographical location of this twin city to Dura-Europos.

One reason for the disparity in interest between Anqa and Dura-Europos, posits article author Simon James, is the history of British and French colonial intervention in the region. In 1920, as a result of the San Remo conference, Iraq was seized for British control, and Syria for French. As James writes, the “new political, military, and administrative boundary created a barrier to research and understanding of the earlier history of the region as a whole.” Yet while Dura-Europos and some other sites in Iraq and Syria have suffered from looting, destruction, and civilian death as a consequence of conflict in the region, Anqa has remained relatively untouched. As further archaeological inquiry is performed, Anqa may continue to provide valuable insight into the history of the Middle Euphrates. And furthermore, as methods of digital scholarship bring thinkers together “despite political borders,” the practice of studying sites like it may even, in the words of Simon James, help “address the consequences of colonialism in archaeology.”

The study offers the first experimental evidence that chemicals present as additives in microplastics can leach into human sweat, and then be absorbed through the skin, into the bloodstream.

Many chemicals used as flame retardants and plasticisers have already been banned, due to evidence of adverse health effects including damage to the liver or nervous system, cancer, and risks to reproductive health. However, these chemicals are still present in the environment in older electronics, furniture, carpets, and building materials.

While the harm caused by microplastics is not fully understood, there is increasing concern over their role as conduits of human exposure to toxic chemicals.

The research team demonstrated in a study published last year, that chemicals were leached from microplastics into human sweat. The current study now shows that those chemicals can also be absorbed from sweat across the skin barrier into the body.

In their experiments, the team used innovative 3D human skin models as alternatives to laboratory animals and excised human tissues. The models were exposed over a 24-hour period to two common forms of microplastics containing polybrominated diphenyl ethers (PBDEs), a chemical group commonly used to flame retard plastics.

The results, published in Environment International, showed that as much as 8% of the chemical exposed could be taken up by the skin, with more hydrated — or ‘sweatier’ — skin absorbing higher levels of chemical. The study provides the first experimental evidence into how this process contributes to levels of toxic chemicals found in the body.

Dr Ovokeroye Abafe, now at Brunel University, carried out the research while at the University of Birmingham. He said: “Microplastics are everywhere in the environment and yet we still know relatively little about the health problems that they can cause. Our research shows that they play a role as ‘carriers’ of harmful chemicals, which can get into our bloodstream through the skin. These chemicals are persistent, so with continuous or regular exposure to them, there will be a gradual accumulation to the point where they start to cause harm.”

Dr Mohamed Abdallah, Associate Professor of Environmental Sciences at the University of Birmingham, and principal investigator for the project, said: “These findings provide important evidence for regulators and policymakers to improve legislation around microplastics and safeguard public health against harmful exposure.”

Professor Stuart Harrad, co-author of the paper, added “the study provides an important step forward in understanding the risks of exposure to microplastics on our health. Building on our results, more research is required to fully understand the different pathways of human exposure to microplastics and how to mitigate the risk from such exposure.”

In future research, the team plan to investigate other routes through which microplastics could be responsible for toxic chemicals entering the body, including inhalation and ingestion. The work is funded by a Marie Curie Research Fellowship, within the European Union’s Horizon 2020 Research and Innovation Programme.

A new study published in the journal Nature Geoscience led by scientists at University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, and the National Oceanic and Atmospheric Administration’s Atlantic Oceanographic and Meteorological Laboratory, found that human-induced environmental changes around Antarctica are contributing to sea level rise in the North Atlantic.

The research team analyzed two decades of deep sea oceanographic data collected by observational mooring programs to show that a critical piece of Earth’s global system of ocean currents in the North Atlantic has weakened by about 12 percent over the past two decades.

“Although these regions are tens of thousands of miles away from each other and abyssal areas are a few miles below the ocean surface, our results reinforce the notion that even the most remote areas of the world’s oceans are not untouched by human activity,” said the study’s lead author Tiago Biló, an assistant scientist at the Rosenstiel School’s NOAA Cooperative Institute for Marine and Atmospheric Studies.

As part of the NOAA-funded project DeepT (Innovative analysis of deep and abyssal temperatures from bottom-moored instrument), the scientists analyzed data from several observational programs to study changes over time in a cold, dense, and deep water mass located at depths greater than 4,000 meters (2.5 miles) below the ocean surface that flow from the Southern Ocean northward and eventually upwells to shallower depths in other parts of the global ocean such as the North Atlantic.

This shrinking deep-ocean branch — that scientists call the abyssal limb — is part of the Atlantic Meridional Overturning Circulation (AMOC), a three-dimensional system of ocean currents that act as a “conveyer belt” to distribute heat, nutrients, and carbon dioxide across the world’s oceans.

This near-bottom branch is comprised of Antarctic bottom water, which forms from the cooling of seawater in the Southern Ocean around Antarctica during winter months. Among the different formation mechanisms of this bottom water, perhaps the most important is the so-called brine rejection, a process that occurs when salty water freezes. As sea ice forms, it releases salt into the surrounding water, increasing its density. This dense water sinks to the ocean floor, creating a cold, dense water layer that spreads northward to fill all three ocean basins — the Indian, Pacific, and Atlantic oceans. During the 21^st century, the researchers observed that the flow of this Antarctic layer across 16°N latitude in the Atlantic had slowed down, reducing the inflow of cold waters to higher latitudes, and leading to warming of waters in the deep ocean.

“The areas affected by this warming spans thousands of miles in the north-south and east-west directions between 4,000- and 6,000-meters of depth,” said William Johns, a co-author and professor of ocean sciences at the Rosenstiel School. “As a result, there is a significant increase in the abyssal ocean heat content, contributing to local sea level rise due to the thermal expansion of the water.”

“Our observational analysis matches what the numerical models have predicted — human activity could potentially impose circulation changes on the entire ocean,” said Biló. “This analysis was only possible because of the decades of collective planning and efforts by multiple oceanographic institutions worldwide.”