Earth

When facing a volatile climate, nature searches for a way to survive. For plants, that often means spreading new roots deeper and wider in search of water, particularly in times of drought. While scientists have recognized the process of root emergence for decades, how intercellular communication may drive this phenomenon was previously unknown.

Now, Jung-Youn Lee, University of Delaware professor of plant molecular and cellular biology, and Ross Sager, a former graduate student and UD alumnus, have identified hormones and proteins that interact to regulate the root emergence process.

Their team's first-of-its-kind study was recently published in the journal Nature Communications.

Plant communication

Plasmodesmata function as the main communication pathways within a plant, sending messages through virtually every cell from root to shoot. Often, each cell receives the new information and this intercellular communication is critical to the plant's survival.

"Picture a brick wall and that's what the surface of a root looks like. Each brick is an individual cell. The cement binding them is the cell wall. Unlike a brick wall, however, plant cells are also linked by fine thread-like nano-tunnels called plasmodesmata, through which cells transmit various signals and messages to share. Obviously, when the channels are closed off, no signals would be transmitted, isolating the cells from getting any messages from their neighbors," said Lee.

When lateral roots, or secondary roots, need to emerge from the primary root, the cells directly above the emerging root must separate from each other to make way. To accomplish this, the plasmodesmata connecting those soon-to-split cells must be closed off so that the new root emerges at a normal speed. If the plasmodesmata remain open, the new root emerges at a faster speed which may compromise the vitality or immunity of the root and cause the plant to be vulnerable to threats from various soil pathogens.

Root emergence regulation

While studying the expression pattern of PDLP5 -- a protein associated with plasmodesmata -- in Arabidopsis seedlings, Sager noticed an unexpected pattern in the roots. Closer examination revealed that the pattern involved cells that were overlying emerging lateral roots.

"I had designed this particular experiment to study PDLP5 expression in the young seedling leaves," said Sager, "but when I noticed that pattern in the roots and showed it to Dr. Lee, we agreed it was unique for a plasmodesmal protein and warranted further research."

Pursuing this intriguing pattern led Sager and Lee to discover a critical feedback loop that seems to allow small subsets of cells to regulate their plasmodesmata connections via PDLP5, allowing them to operate independently from the rest of the plant as the lateral root develops and emerges.

When auxin, the hormone that drives the formation of the lateral root tissue, signals to the plant cells that a new root is ready to form and emerge, it also tells those cells directly overlying the newly forming root to start producing PDLP5. As this protein accumulates, Sager and Lee posit that it closes the plasmodesmata connections, ensuring that these overlying cell layers are able to operate autonomously as they separate and allow the lateral root to pass through. When the process is complete, this research suggests that PDLP5 sends a return signal that represses auxin. After the new lateral root is fully emerged, the overlying cells reopen the plasmodesmata connections, effectively reconnecting to the plant communication pathways.

"While our research suggests that plasmodesmal closure in these cells is important for lateral root emergence, we don't actually know why yet," said Sager. "Does it alter the movement of key signaling components? Prevent harmful factors in the soil from entering the cell? I look forward to other scientists using our paper as a stepping stone to answer these questions."

Opportunity because of climate change

According to Lee, this signaling mechanism and feedback loop could pave the way for groundbreaking advances in plant and crop engineering.

"Understanding the individual components that regulate lateral root emergence, both the sequence and the timing, opens up a lot of opportunity," said Lee. "When there's a drought, plants and crops die because they can't find water quickly and efficiently. One of the mechanisms they use to survive drought is to put down more roots. With this discovery of the communication loop regulating lateral roots, we may eventually be able to control when and how many additional roots a plant can form."

Crops are often adapted to the environments in which they grow. But as climate change continues to make patterns more erratic, like extending dry seasons, plant adaptability will be vital to agricultural production and ecosystem survival. Roots may need to grow at different rates or different times. Lee notes that information on engineering crops to sprout roots like this doesn't yet exist, but identifying specifically how roots emerge is an important first step.

Exploring plant communication at the molecular and cellular levels continues to be the primary focus in Lee's laboratory at the Delaware Biotechnology Institute. Following this study and previous research on cellular communication, Lee and her team are now further exploring PDLP5 and similar proteins.

"PDLP5 has been our lucky break," noted Lee. "That protein opened up so many new paths for us and also for newcomers to explore. It also became a fantastic bridge connecting us to great research collaborators, including Dr. Malcolm Bennett at the University of Nottingham, the world's leading expert on root branching."

"What's next?" Lee continued. "We are currently conducting interdisciplinary research with Dr. Li Liao in computational science and engineering at UD to discover how PDLP5 and its family members find and anchor to plasmodesmata, which is generously funded by the National Science Foundation. We are already so amazed by the path that PDLP5 is leading us."

An ecological pileup of unprecedented changes in the ocean off the West Coast beginning about 2014 led to record entanglements of humpback and other whales, putting the region's most valuable commercial fishery at risk, new research shows.

The findings reflect a new management challenge brought about by a changing climate, recovering whale populations, and fishing pressure, according to the new research published in Nature Communications. The situation calls for new measures to alert fishermen to the risk of entanglements and help managers adjust to more rapid and frequent changes in the marine environment.

"We need to put information in the hands of those who can use it, at a time when it can make a difference," said Jarrod Santora, a research scientist at NOAA Fisheries' Southwest Fisheries Science Center (SWFSC) in Santa Cruz, California, and lead author of the research. "We are seeing changes coming at us in ways they never have before."

Santora and his colleagues are developing a website that will use oceanographic data to forecast the areas where whales are most likely to be feeding off the West Coast. Crab fishermen could then use the information to help decide where--and where not--to set their traps. It may also help managers decide where and when to open--or close--fishing.

The new research teases out the ecological causes and effects that contributed to the spike in reported whale entanglements. Many involved traps set for Dungeness crab, said Nathan Mantua, a research scientist at the SWFSC and coauthor of the research. Reported entanglements have since dropped off but remain higher than before the increase.

"We had all these things that weren't part of anyone's experience come together in this remarkable three-year period," he said.

Conflict Prompts Improved Communication

The entanglements have also prompted environmental lawsuits that threaten to restrict crab fishing. At the same time, though, the focus on entanglements has led to better communication and conversation between fishermen, environmental groups, and managers. Collaborative working groups have also developed tools to better anticipate and avoid entanglement risk.

"If the working group knew then what we know now, it wouldn't have happened," said John Mellor, a crab fisherman from San Francisco, referencing the increased entanglements. "The more we understand the whole picture, the better chance we have to mitigate the impacts."

The driver behind many of the environmental changes was an unprecedented marine heatwave that took hold in 2014. It became known as "the warm Blob," because of the large expanse of unusually high temperatures that dominated waters off the West Coast. The warm temperatures attracted subtropical species rarely seen in the region. The krill that humpback whales typically feed on grew scarce.

The whales switched to feed instead on high concentrations of anchovy that the warm, less productive waters had squeezed into a narrow band near the coast.

At the same time, the higher temperatures fueled a record bloom of toxic algae. It shut down crabbing on the West Coast from November 2015 through March 2016. When toxin levels eased and the Dungeness season finally opened, fishermen set multitudes of crab traps in that same narrow band where many whales were feeding.

NOAA Fisheries' West Coast Region confirmed a then-record 53 whale entanglements in 2015 and 55 in 2016.

The scientists developed a new measure for ocean conditions called the Habitat Compression Index. It tracks the width of the productive band and how tightly species are coalescing there.

Whale Numbers Reflect Unprecedented Change

Research Biologist Karin Forney, also from the SWFSC and a coauthor of the research, lives in Moss Landing, California. She has a view of Monterey Bay and has long seen occasional humpback whales feeding just offshore. During the "the Blob" years, she would regularly see 30 to 40 whales from her front windows. Local whale watch boats made two to three trips a day to keep up with the demand.

Some 300 whales were counted at once in Monterey Bay.

"In our lifetimes living here, that was unprecedented," she said. "We knew something dramatically different was pulling these whales closer to shore."

She is also part of a NOAA team trained to free entangled whales.

"We were on call every day for weeks, with simultaneous reports of two or three entangled whales, so we could respond if they were sighted again," she said. The team disentangled a few, while others were never seen again.

The lesson of the research, Forney said, is that scientists and fishermen must share information. They can help each other understand how complex environmental connections affect marine species and fisheries. Communication may be one of their most important tools as environmental changes come ever faster.

"Things are dynamic, and things are changing," she said. "That is not going away."

PULLMAN, Wash. - A Washington State University team has developed a more efficient, safer, and cost-effective way to produce cadmium telluride (CdTe) material for solar cells or other applications, a discovery that could advance the solar industry and make it more competitive.

The researchers showed they could rapidly grow a large amount of high-purity CdTe material -- a more than kilogram-sized crystal in one day -- which would be considered lightning fast in the industry. The technique, which uses a high-pressure furnace to produce large amounts of the needed crystal feedstock material, is 45 % more cost effective than the industry standard and is scalable, which could make CdTe solar technology less expensive than natural gas. The crystal material produced also has better electrical properties than what is currently available.

Working in collaboration with the National Renewable Energy Laboratory (NREL) and industry partner Nious Technologies, Inc., the researchers report on their work in the Journal of Crystal Growth.

CdTe photovoltaics are a newer technology than popular silicon solar cells and are competitive in terms of efficiency. They also perform better in hot and humid weather. While CdTe solar cells could provide significant advantages in cost and efficiency over silicon, they currently make up less than 10 % of the solar market, mostly at the utility scale. In particular, current production methods are slow, costly, cumbersome and lack the flexibility to customize.

"Right now there is a huge kink in raw material production," said Santosh Swain, research assistant professor with the Institute of Materials Research and a co-author on the paper. "The solar industry has steadily increased device efficiency and fabricating devices, but further efficiency gains and cost reduction require improvement in CdTe material properties."

The current manufacturing process involves cooking the CdTe material in a sealed glass tube to contain the reaction. It takes a long time, the tubes are not reusable, and the silica glass is limited in how much heat, mass, and pressure it can take. Because of concerns about the material exploding, the industry is limited in the size of crystals they can grow. To make solar cells, the crystals are then evaporated onto glass substrate to make very thin films.

The new technique uses a strong graphite crucible, and the material is cooked in a high-pressure Bridgman furnace.  The high-pressure environment completely eliminates the possibility of explosions and also allows the researchers to easily add a high concentration of additional materials, called dopants, during the manufacturing process that improve the material's performance. In 2016, the WSU research team in collaboration with NREL and University of Tennessee dramatically improved CdTe technology by adding phosphorus as a dopant, overcoming a 1 Volt limit that had been pursued for six decades. For this project, the researchers added arsenic as a dopant.

Adding the highly volatile dopants during the feedstock manufacturing process also eliminates the need to dope after film deposition which can cause non uniformity issues, said Tawfeeq Al-Hamdi, a PhD student and lead author on the paper.

"Doping is a key strategy," said co-author Seth McPherson. "At 80 atmospheres of pressure, you can really shove the dopants into the material, and you don't have to worry about them evaporating out of the crystal or otherwise escaping the system."

White lupin is a particularly abstemious crop, requiring very little fertiliser and producing high-protein seeds of great nutritive quality. The plant has just yielded the secrets of its genome thanks to the collaboration of eleven French and foreign laboratories coordinated by Benjamin Péret, a CNRS researcher at the Biochimie et physiologie moléculaire des plantes laboratory (CNRS/Inrae/Université de Montpellier/Montpellier SupAgro). Lupin has the distinctive feature of possessing "proteoid" or cluster roots, which enable it to solubilise phosphate and extract it efficiently. However, similar to petroleum, stocks of this vital component are limited and currently being depleted. Knowing the plant's genome could accelerate programmes for lupin selection and help make this legume a major asset in future plant-based protein production. The results of this project financed by an ERC Starting Grant were published on 24 January 2020 in the journal Nature Communications.

A combination of climate change, extreme weather and pressure from local human activity is causing a collapse in global biodiversity and ecosystems across the tropics, new research shows.

The study, published today, mapped over 100 locations where tropical forests and coral reefs have been affected by climate extremes such as hurricanes, floods, heatwaves, droughts and fires. It provides an overview of how these very diverse ecosystems are being threatened by a combination of ongoing climate changes, increasingly extreme weather and damaging local human activities.

The international team of researchers argue that only international action to decrease CO2 emissions can reverse this trend.

Lead researcher Dr Filipe França from the Embrapa Amazônia Oriental in Brazil and Lancaster University said: "Tropical forests and coral reefs are very important for global biodiversity, so it is extremely worrying that they are increasingly affected by both climate disturbances and human activities".

"Many local threats to tropical forests and coral reefs, such as deforestation, overfishing, and pollution, reduce the diversity and functioning of these ecosystems. This in turn can make them less able to withstand or recover from extreme weather. Our research highlights the extent of the damage which is being done to ecosystems and wildlife in the tropics by these interacting threats."

Dr Cassandra E. Benkwitt, a marine ecologist from Lancaster University, said: "Climate change is causing more intense and frequent storms and marine heatwaves. For coral reefs, such extreme events reduce live coral cover and cause long-lasting changes to both coral and fish communities, compounding local threats from poor water quality and overfishing. Although the long-term trajectory for reefs will depend on how extreme events interact with these local stressors, even relatively pristine reefs are vulnerable to both climate change and extreme weather."

Tropical forest species are also being threatened by the increasing frequency of extreme hurricanes.

Dr Guadalupe Peralta from Canterbury University in New Zealand said: "A range of post-hurricane ecological consequences have been recorded in tropical forests: the destruction of plants by these weather extremes affects the animals, birds and insects that rely on them for food and shelter."

In some regions, such as the Caribbean Islands, extreme weather events have decimated wildlife, reducing numbers by more than half.

"We are starting to see another wave of global extinctions of tropical birds as forest fragmentation reduces populations to critical levels", explained Dr Alexander Lees, from Manchester Metropolitan University.

The combination of higher temperatures with longer and more severe dry seasons has also led to the spread of unprecedented and large-scale wildfires in tropical forests.

Dr Filipe França said that at the end of 2015, Santarém in the Brazilian state of Pará was one of the epicentres of that year's El Niño impacts. "The region experienced a severe drought and extensive forest fires, and I was very sad to see the serious consequences for forest wildlife."

The drought also affected the forests ability to recover from the fires. Dung beetles play a vital role in forest recovery by spreading seeds. The study provides novel evidence that this seed spreading activity plummeted in those forests most impacted by the dry conditions during the 2015-2016 El Niño.

Coral reefs were also critically damaged by the same El Niño, explains Professor Nick Graham from Lancaster University.

He said: "The 2015-16 coral bleaching event was the worst ever recorded, with many locations globally losing vast tracts of valuable corals. Worryingly, these global bleaching events are becoming more frequent due to the rise in ocean temperature from global warming."

The last part of the study emphasizes that urgent action and novel conservation strategies are needed to ameliorate the impacts of the multiple threats to tropical forests and coral reefs.

Dr Joice Ferreira from Embrapa Amazônia Oriental said: "To achieve successful climate-mitigation strategies, we need 'action-research' approaches that engage local people and institutions and respect the local needs and diverse socio-ecological conditions in the tropics".

The scientists caution that managing tropical ecosystems locally may not be enough if we do not tackle global climate change issues.

They stress the urgent need for all nations to act together if we really want to conserve tropical forests and coral reefs for future generations.

New research done at the University of the Witwatersrand in Johannesburg, South Africa, and Huazhang University of Science and Technology in Wuhan, China, has exciting implications for secure data transfer across optical fibre networks. The team have demonstrated that multiple quantum patterns of twisted light can be transmitted across a conventional fibre link that, paradoxically, supports only one pattern. The implication is a new approach to realising a future quantum network, harnessing multiple dimensions of entangled quantum light.

Science Advances today, published online the research by a team led by Professor Andrew Forbes from the School of Physics at Wits University in collaboration with a team lead by Professor Jian Wang at HUST. In their paper titled: Multi-dimensional entanglement transport through single mode fiber, the researchers demonstrate a new paradigm for realising a future quantum network. The team showed that multiple patterns of light are accessible after a communication link of conventional optical fibre, that paradoxically can only support a single pattern. The team achieved this quantum trick by engineering entanglement in two degrees of freedom of light, polarisation and pattern, passing the polarised photon down the fibre and accessing the many patterns with the other photon.

"In essence, the research introduces the concept of communicating across legacy fibre networks with multi-dimensional entangled states, bringing together the benefits of existing quantum communication with polarised photons with that of high-dimension communication using patterns of light," says Forbes.

A new twist, a new paradigm

Present communication systems are very fast, but not fundamentally secure. To make them secure researchers use the laws of Nature for encoding by exploiting the quirky properties of the quantum world, such as in the case of the use of Quantum Key Distribution (QKD) for secure communication.

"Quantum" here refers to the spooky action at a distance so abhorred by Einstein: quantum entanglement. In the last few decades, quantum entanglement has been extensively explored for a variety of quantum information protocols, notably making communication more secure through QKD. Using so-called "qubits" (2D quantum states) the information capacity is limited but it is easy to get such states across fibre links using polarisation as a degree of freedom for the encoding. The spatial pattern of light, its pattern, is another degree of freedom that has the benefit of high-dimensional encoding. There are many patterns to use, but unfortunately this requires custom fibre optical cable and so unsuitable to already existing networks. In the present work, the team have found a new way to balance these two extremes, by combining polarisation qubits with high-dimensional spatial modes to create multi-dimensional hybrid quantum states.

"The trick was to twist the one photon in polarisation and twist the other in pattern, forming "spirally light" that is entangled in two degrees of freedom," says Forbes. "Since the polarisation entangled photon has only one pattern it could be sent down the long-distance single-mode fibre (SMF), while the twisted light photon could be measured without the fibre, accessing multi-dimensional twisted patterns in the free-space. These twists carry orbital angular momentum (OAM), a promising candidate for encoding information."

Overcoming the present challenges

Quantum communication with high-dimensional spatial modes (for example OAM modes) is promising but only possible in specially designed multi-mode fibre, which however, is greatly limited by mode (pattern) coupling noise. Single-mode fibre is free of this "pattern coupling" (which degrades entanglement) but can only be used for two-dimensional polarisation entanglement.

"The novelty in the published work is the demonstration of multi-dimensional entanglement transport in conventional single-mode fibre. The light is twisted in two degrees of freedom: the polarisation is twisted to form spirally light, and so is the pattern. This is referred to as spin-orbit coupling, here exploited for quantum communication," says Forbes. "Each transmission is still only a qubit (2D) but there are an infinite number of them because of the infinite number of twisted patterns we could entangle in the other photon."

The team demonstrated transfer of multi-dimensional entanglement states over 250 m of single-mode fibre, showing that an infinite number of two-dimensional subspaces could be realised. Each subspace could be used for sending information, or multiplexing information to multiple receivers.

"A consequence of this new approach is that the entire high-dimensional OAM Hilbert space can be accessed, but two dimensions at a time. In some sense it is a compromise between simple 2D approaches and true high-dimensional approaches," says Forbes. Importantly, high-dimensional states are unsuitable for transmission over conventional fibre networks, whereas this new approach allows legacy networks to be used.

CINCINNATI -- A new study suggests that significant early childhood exposure to traffic-related air pollution (TRAP) is associated with structural changes in the brain at the age of 12.

The Cincinnati Children's Hospital Medical Center study found that children with higher levels of TRAP exposure at birth had reductions at age 12 in gray matter volume and cortical thickness as compared to children with lower levels of exposure.

"The results of this study, though exploratory, suggest that where you live and the air you breathe can affect how your brain develops, says Travis Beckwith, PhD, a research fellow at Cincinnati Children's and lead author of the study. "While the percentage of loss is far less than what might be seen in a degenerative disease state, this loss may be enough to influence the development of various physical and mental processes."

Gray matter includes regions of the brain involved in motor control as well as sensory perception, such as seeing and hearing. Cortical thickness reflects the outer gray matter depth. The study found that specific regions in the frontal and parietal lobes and the cerebellum were affected with decreases on the order of 3 to 4 percent.

"If early life TRAP exposure irreversibly harms brain development, structural consequences could persist regardless of the time point for a subsequent examination," says Dr. Beckwith.

The researchers on the study, which is published online in PLOS One, used magnetic resonance imaging to obtain anatomical brain images from 147 12 year olds. These children are a subset of the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), which recruited volunteers prior to the age of six months to examine early childhood exposure to TRAP and health outcomes.

The volunteers in the CCAAPS had either high or low levels of TRAP exposure during their first year of life. The researchers estimated exposure using an air sampling network of 27 sites in the Cincinnati area, and 24/7 sampling was conducted simultaneously at four or five sites over different seasons. Participating children and their caregivers completed clinic visits at ages 1, 2, 3, 4, 7 and 12.

Previous studies of TRAP suggest that it contributes to neurodegenerative diseases and neurodevelopmental disorders. This work supports that TRAP changes brain structure early in life.

When we cut our skin, groups of cells rush en masse to the site to heal the wound.

But the complicated mechanics of this collective cell movement -- which are facilitated by rearrangements between each cell and its neighbors -- have made it challenging for researchers to decipher what's actually driving it.

"If we can understand the key factors causing cell migration, then we could perhaps develop new treatments to speed up wound healing," says Jacob Notbohm, an assistant professor of engineering physics at the University of Wisconsin-Madison.

Notbohm and doctoral student Aashrith Saraswathibhatla recently made a surprising discovery that sheds new light on how this collective cell migration happens. They detailed their findings today in the journal Physical Review X.

Through experiments, they found that the force each cell applies to the surface beneath it -- in other words, traction -- is the dominant physical factor that controls cell shape and motion as cells travel as a group.

Notbohm says this unexpected finding provides a new interpretation of recent theoretical models.

Researchers have known that cell shape plays an important role in how they rearrange and collectively migrate. For example, circular cells packed together within a single layer can't easily exchange positions with neighboring cells; think of being stuck shoulder-to-shoulder in a large crowd where it's impossible to move.

On the other hand, cells that have more elongated shapes can easily slide past their neighbors.

"These long and skinny cells can be packed in infinite configurations, so it's very easy for them to rearrange. That facilitates the motion of the collective," Notbohm says.

Since elongated cells have greater perimeters, most computer models have predicted the forces at the periphery of each cell are the most important for dictating its shape.

Notbohm and Saraswathibhatla set out to test that theory in the lab.

Their experiments used fluorescent imaging to assess forces at the periphery of each cell in a single layer of epithelial cells, a type of cells that line surfaces in the body like skin and blood vessels. They also placed the cells on a soft gel surface and analyzed how the gel deformed as cells migrated across it. The gel test allowed them to quantify traction, or how strongly the cells tugged on the surface.

In addition, they used chemicals to decrease or increase forces produced by each cell and studied the effects of those changes.

In the end, Notbohm says their experiments showed that, in fact, the force a cell applies to the surface beneath it primarily controls its shape.

"This was quite surprising because the key factors affecting a cell's perimeter are underneath the cell. They are nowhere near the periphery of the cell," he says.

And now, they can focus on what's important. Looking at the cell-substrate interface, Notbohm hopes to enable further advances in this area.

"The good news is the general phenomena of the models is still correct. This discovery just changes our understanding about the theory," he says. "That's really important, because to eventually develop a new intervention to accelerate wound healing you need to understand the key factors in the cell that are affecting its shape and motion."

The entire set of our emotions is topographically represented in a small region of the brain, a 3 centimeters area of the cortex, report scientists in a study conducted at the IMT School for Advanced Studies Lucca, Italy. The discovery of this "map" of emotions comes from a work conducted by the Molecular Mind Laboratory (MoMiLab) directed by Professor Pietro Pietrini, and recently published in Nature Communications.

To investigate how the brain processes the distinct basic component of emotional states, the IMT School researchers asked a group of 15 volunteers enrolled in the study to express, define and rate their emotions while watching the iconic 1994 American movie Forrest Gump. For the entire length of the film, in fact, the 15 volunteers reported scene by scene their feelings and their respective strength on a scale from 1 to 100. Their answers were then compared to those of 15 other persons who had watched the same movie during a functional magnetic resonance imaging (fMRI) study conducted in Germany. The imaging data were obtained through "open science", a platform where scientists from different laboratories can share their data, so that anyone can replicate their findings or use the data for novel experiments, as in this case.

To unveil cortical regions involved in emotion processing, the "emotional ratings" were used by scientists for predicting the fMRI response of the brain. The correspondence between functional characteristics and the relative spatial arrangement of distinct patches of cortex was then used to test the topography of affective states. As researchers found out, the activation of temporo-parietal brain regions was associated to the affective states we feel in an exact moment, providing us with the map of our emotional experience.

The analysis of the data by Giada Lettieri, first author of the study along with Giacomo Handjaras, both PhD students at the IMT School, and their collaborators shows that the polarity, complexity and intensity of emotional experiences are represented by smooth transitions in right temporo-parietal territories. The spatial arrangement allows the brain to map a variety of affective states within a single patch of cortex.

To summarize, the right temporo-parietal junction can topographically represent the variety of the affective states that we experience: which emotions we feel in a specific moment, and how much we perceive them. The process resembles the way senses, like sight or hearing, are represented in the brain. For this reason, the researchers proposed the definition emotionotopy as a principle of emotion coding.

Historically, emotions have often been considered a "separate" human faculty, well distinct from cognition. As a matter of fact, this point of view has been recently challenged by various studies showing how much affective responses can influence cognitive processes, such as decision-making and memory. The IMT School study adds new details to this more recent view that the principles responsible for the representation of sensory stimuli are also responsible for the mapping of emotions.

"This study is also an interesting example of open science and sharing data initiatives in neuroscience", said Luca Cecchetti, senior author of the paper and Assistant Professor at the IMT School. "The fMRI data were collected by Michael Hanke and colleagues at Otto von Guericke University Magdeburg and publicly released at studyforrest.org. This allowed us to exploit high-quality neuroimaging data, at the same time saving resources and time. Following the same principle, we released data and code at https://osf.io/tzpdf/".

"Dissecting the brain correlates of elementary factors that modulate intensity and quality of our emotions has major implications to understand what happens when emotions get sick, as in case of depression and phobia. These studies are getting psychiatry closer to other fields of medicine in finding objective biological correlates of feelings, which are subjective states", commented Professor Pietro Pietrini, psychiatrist and co-author of the research, director of MoMiLab at the IMT School.

Biomedical data scientists at the Stanford University School of Medicine have shown that the number of genes a cell uses to make RNA is a reliable indicator of how developed the cell is, a finding that could make it easier to target cancer-causing genes.

Cells that initiate cancer are thought to be stem cells, which are hard-to-find cells that can reproduce themselves and develop, or differentiate, into more specialized tissue, such as skin or muscle -- or, when they go bad, into cancer.

"Right now, targeted therapies are focused on specific genes or molecules, the vast majority of which may not be specific to cancer stem cells," said Aaron Newman, PhD, assistant professor of biomedical data science and a member of the Institute for Stem Cell Biology and Regenerative Medicine. "Usually these therapies don't work for very long. But if you can identify the least-differentiated cells and then look for markers specific to them, it's no longer a guessing game to find the genes to target."

The study's finding is also significant because identifying stem cells of various tissue types is an important step toward regenerating damaged or malfunctioning tissues.

What the scientists showed is that as stem cells become more differentiated and more like adult cells, they express fewer and fewer genes. Previously, other researchers had noticed this correlation and thought it might be an interesting coincidence. But Newman and his colleagues were the first to sort through thousands of single-cell genetic tests in public databases and prove this pattern was consistent and reliable.

Newman and MD-PhD student Gunsagar Gulati combined the measurement of the number of genes expressed in a cell with the measurement of the number of RNA copies created per gene as the basis for a computer algorithm, CytoTRACE, designed to determine how developmentally advanced cells are.

A paper describing the research is being published online Jan. 24 in Science. Newman is the senior author. Gulati and Shaheen Sikandar, PhD, an instructor at the institute, share lead authorship.

Tumor cells are diverse

Cancerous tumors can contain many millions of cells, each of which may have thousands of gene mutations. The cells in a tumor are diverse. Most will be differentiated cells that die out naturally on their own, while relatively few are the more dangerous cancer stem cells, or tumor-initiating cells. These cells are hard to find and therefore hard to characterize using current methods, but far easier to find with CytoTRACE.

"As a cancer researcher, what I find most exciting is that this tool helps us find the tumor-initiating cells that have long been known to be responsible for resistance to treatment, metastasis and relapse after treatment," Sikandar said.

Michael Clarke, MD, one of the authors of the paper, was the first researcher to identify cancer stem cells in a solid tumor. A professor of medicine at Stanford, Clarke said that CytoTRACE, which analyzes data on all the RNA created in a single cell, can quickly recapitulate research that takes years using traditional methods. "The way that we currently find cell markers for cancer stem cells is to make educated guesses about which markers will likely be important, then sort those cells and look for stem cell activity," said Clarke, the Karel H. and Avice N. Beekhuis Professor in Cancer Biology and associate director of the Institute for Stem Cell Biology and Regenerative Medicine.

Researchers can look at relatively few markers at a time, so it takes a lot of sorting and analysis, and in the end, they will likely be only partially successful in finding good markers of the stem cells they are looking for, he said. "What CytoTRACE allows us to do is first find the stem or progenitor cells, then look at what unique markers they have on them."

In the paper, the researchers describe using CytoTRACE to query single-cell RNA data for triple-negative breast cancer, a type of tumor that is rarer but more dangerous because tumor growth doesn't rely on the biochemical pathways that physicians usually target to treat breast cancer. Not only did CytoTRACE identify known markers of cancer stem cells, it also spotted a marker that had not been previously been thought to be important. "This one gene looks like it has amazing potential as a therapeutic," Clarke said.

Potential tool for hunting other disease-linked stem cells

CytoTRACE also has the potential to transform how researchers hunt for stem cells associated with other diseases, Newman said. "This tool could also be useful in finding treatments for disorders such as Alzheimer's or other degenerative diseases where loss of stem cell function might be part of the disease process," he said.

Regenerative medicine, in which diseased or damaged tissue is repaired through the activity of stem cells, requires the ability to isolate purified populations of stem cells specific to a given tissue. To regrow bone, the heart or the eyes, for example, researchers must first find the stem cells responsible for regrowing those organs. Finding the markers that are specific to these normal stem cells has been much like the process for finding cancer stem cell markers, the researchers say -- that is, the product of educated guesses, luck and a lot of work in the lab. CytoTRACE could significantly shorten that process.

"One of the main motivations behind developing CytoTRACE was to create a tool for rapid and accurate identification of stem cells in humans," Gulati said. "But another important question we hope to answer is how the inner workings of a cell change as the cell transforms from one state to another. This research opens up a whole new avenue of research to study how global changes in gene expression and DNA structure influence a cell's state."

Overall, Newman said, the study shows the power and promise of using big data to advance biology and medicine through computer research that complements discoveries made in the lab.

"It wouldn't have been possible to gather all this data in our lab, but by using public databases and asking the right questions, it's more and more possible to make fundamental discoveries in biology and medicine," he said.

The impact of the tobacco display ban on young people's attitudes to smoking has been analysed by University of Stirling experts.

The five-year public health study also looked at the effect of the ban on young people's exposure to point-of-sale tobacco promotions and the likelihood of them taking up smoking - as well as the potential for e-cigarettes to influence smoking initiation.

Professor Sally Haw, of Stirling's Faculty of Health Sciences and Sport, and colleagues found the ban on point-of-sale tobacco displays "had been a great success", with retailer compliance high at 98%. This has led to reduction in exposure to tobacco products, however the message that tobacco is still available and still for sale remains very prominent.

She added: "Our research demonstrated that legislation banning tobacco displays at point-of-sale was appropriate and has had a positive impact on young people's attitudes towards smoking and their susceptibility to becoming smokers in the future.

"We believe that the research will inform not only future policy developments in this country but also in other countries, where policymakers may be considering introducing similar legislation."

Professor Haw's team recommend:

Limiting tobacco retail outlet density.

Reducing the visible presence of gantries and other smoking-related products by regulating the size, design and position of storage units and the use of generic signage to indicate tobacco availability.

Focusing policy on reducing parental smoking, particularly in front of children, and encouraging parents to keep products out of sight.

Targeting schoolchildren with 'good news' messages about the decline in youth smoking prevalence.

Enforcing existing regulations to prevent the use of retailer incentives and rewards by tobacco company representatives.

Prohibiting e-cigarette advertising in the external environment, on billboards, and at bus stops.

Holding a debate as to whether e-cigarette promotions should be banned at point-of-sale.

In the UK, a ban on the open display of tobacco products at the point-of-sale was phased in between 2012 and 2015. In 2012, large stores and supermarkets in England, Wales and Northern Ireland had to put tobacco products out of sight, before Scotland followed suit in 2013. Across the UK, smaller stores had until 2015 to adapt their displays to cover tobacco products.

The University of Stirling led the DISPLAY study - funded by the National Institute for Health Research and published in the Public Health Research journal - and worked alongside the Universities of Edinburgh and St Andrews and ScotCen Social Research.

E-cigarettes emerged as an issue in some focus group discussions with young people in 2013 and, therefore, became an area of interest for the research team. They found that:

The percentage of young people who had used an e-cigarette increased from 14.3% in 2014 to 33.7% in 2017. In 2017, this compared with only 21.1% who had tried cigarettes.

Regular e-cigarette use in secondary school pupils is less common, especially among those who have never smoked.

Study participants' recall of e-cigarette advertisements was a significant predictor of future e-cigarette use.

Young people who have never smoked but had tried an e-cigarette, were more likely than those who had never tried an e-cigarette to go on to take up smoking at both one-year and two-year follow-up.

The DISPLAY study was conducted between 2013 and 2017 in four communities: two urban, two small town; and two medium/low deprivation and two high deprivation. The team conducted: annual mapping of tobacco retail outlets; annual marketing audits of retail premises that sold tobacco; semi-structured interviews with small retailers from matched communities; annual surveys of schoolchildren, resulting in 14,344 completed questionnaires from 6,612 pupils over five years; and a total of 80 focus groups with S2 and S4 pupils.

Sheila Duffy, Chief Executive of Ash Scotland, said: "I welcome the important research published today by the University of Stirling, which underlines the world-leading measures being taken in Scotland to close down the visibility of tobacco and protect young people from a predatory industry.

"The research demonstrates that the legislation has been effective in reducing risk of young people taking up smoking.

"Very interestingly, during this research, the team uncovered an unexpected emerging awareness of e-cigarettes amongst schoolchildren and identified a link between study participants' recall of e-cigarette advertisements and future e-cigarette use. This confirms the findings of international evidence reviews and should help inform the Scottish Government's drive to close down the visibility of e-cigarettes in Scotland in order to protect future generations."

When a plant is lacking important nutrients, it cannot simply move to another location where it can get the nutrients it needs. Instead, it has to adapt to the situation by adjusting its metabolism. It does this by activating certain programmes incorporated in its genome.

Iron is one of those nutrients that is essential for plants' growth and survival. It plays a role in photosynthesis and water regulation. Plants absorb iron through their roots, but the iron must be present in sufficient quantities and in a form that can be processed by the plant.

Past research has identified more than 1,000 genes in plant roots that can be active in regulatory processes responding to iron deficiency. 'Cis-regulatory elements' (CREs) coordinate the specific genetic response. A team of researchers working under Prof. Dr. Petra Bauer from the HHU Institute of Botany and Prof. Dr. Shin-Han Shiu from the Department of Plant Biology at MSU has developed a method for predicting candidates for these specific CREs. The team used an artificial intelligence method known as the machine learning approach.

The approach helped the researchers to identify roughly 100 CRE candidates in the model plant Arabidopsis thaliana (thale cress). They used this knowledge to determine transcription factors - specific CRE-binding proteins that trigger the response to iron deficiency and activate it in the root cells.

For optimised plant cultivation, it is important to know how the plant responds in situations of scarcity and whether any targeted cultivation measures can be taken to produce particularly robust plants. "Growers can use the CREs identified to increase iron uptake in new plant varieties in a targeted manner", emphasises Prof. Bauer. Her staff member and first author of the study, Dr. Birte Schwarz, adds: "In this way, a better supply of iron can be ensured along with better adaptation of the plants to poor soil."

Physicists at Ludwig-Maximilians-Universitaet (LMU) in Munich, together with colleagues at Saarland University, have successfully demonstrated the transport of an entangled state between an atom and a photon via an optic fiber over a distance of up to 20 km - thus setting a new record.

'Entanglement' describes a very particular type of quantum state which is not attributed to a single particle alone, but which is shared between two different particles. It irrevocably links their subsequent fates together - no matter how far apart they are - which famously led Albert Einstein to call the phenomenon as "spooky action at a distance". Entanglement has become a cornerstone of new technologies based on effects at the quantum level and is distribution over long distances a central goal in quantum communication. Now LMU researchers led by physicist Harald Weinfurter, in collaboration with a team at the University of the Saarland in Saarbrücken, have shown that the entangled state of an atom and a photon can be transmitted via an optic fiber (like those used in telecommunications networks) over a distance of up to 20 km. The previous record was 700 meters. "The experiment represents a milestone, insofar as the distance covered confirms that quantum information can be distributed on a large scale with little loss," says Weinfurter. "Our work therefore constitutes a crucial step toward the future realization of quantum networks."

Quantum networks essentially consist of quantum memories (made up of one or more atoms, for example) that act as nodes, and communication channels in which photons (light quanta) can propagate to link the nodes together. In their experiment, the researchers entangled a rubidium atom with a photon, and were able to detect the entangled state - which now shares the quantum properties of both particles - after its passage through a 20-km coil of optic fiber.

The biggest problem the experimenters faced start with the properties of the rubidium atom. Following targeted excitation, these atoms emit photons with a wavelength of 780 nanometers, in the near-infrared region of the spectrum. "In an optic fiber made of glass, light at this wavelength is rapidly absorbed," Weinfurter explains. Conventional telecommunications networks therefore make use of wavelengths around 1550 nanometers, which markedly reduces losses in transit.

Obviously, this wavelength would also improve the experimenters' chances of success. So Matthias Bock, a member of the group in Saarbrücken, built what is called a quantum frequency converter that was specifically designed to increase the wavelength of the emitted photons from 780 to 1520 nanometers. This task itself posed a number of extremely demanding technical challenges. For it was imperative to ensure that conversion from only a single photon to only one other photon happens and that none of the other properties of the entangled state, especially the polarization of the photon, were altered during the conversion process. Otherwise, the entangled state would be lost. "Thanks to the use of this highly efficient converter, we were able to maintain the entangled state over a much longer range at telecommunications wavelengths, and therefore to transport the quantum information that it carries over long distances," says Weinfurter.

In the next step, the researchers plan to frequency convert the light emitted by a second atom, which should enable them to generate entanglement between the two atoms over long telecommunications fibers. The properties of glass-fiber cables vary depending on factors such as the temperature and strain to which they are exposed. For this reason, the team intends to first carry out this experiment under controlled conditions in the laboratory. In the event of success, field experiments will be undertaken also adding new nodes to a growing network. After all, even long journeys can be successfully completely by taking one step at a time.

The three proteins Teneurin, Latrophilin and FLRT hold together and bring neighboring neurons into close contact, enabling the formation of synapses and the exchange of information between the cells. In the early phase of brain development, however, the interaction of the same proteins leads to the repulsion of migrating nerve cells, as researchers from the Max Planck Institute of Neurobiology and the University of Oxford have now shown. The detailed insight into the molecular guidance mechanisms of brain cells was possible due to the structural analyses of the protein complex.

Well anchored, the proteins Teneurin and FLRT are located on the surface of nerve cells. They are on the lookout for their partner protein, Latrophilin, on other neurons. When the three proteins come into contact, they interconnect and hold the membranes together. They then trigger still largely unknown signaling cascades and thus promote the formation of a synapse at this site.

Teneurin and its partner proteins are known to establish these important cell contacts in the brain. Teneurin is also an evolutionary very old protein, with related proteins found in diverse organisms ranging from bacteria to worms, fruit flies and vertebrates. However, the role of these proteins during brain development, when neurons are not yet forming synapses, remained unknown.

Studying the function of the protein complex

An international team of researchers now investigated in detail the structure of the Teneurin-Latrophilin protein complex. Using high-resolution X-ray crystallography, they were finally able to find out more about its function in early brain development.

The structural analyses and the subsequent simulation of FLRT-binding enabled the researchers to identify the binding sites, where the three proteins interconnect. By introducing minimal changes, the scientists could interrupt these binding sites. As a result, the migration behavior of the embryonic neurons changed in the brains of mice.

During brain development, embryonic neurons migrate to "their" brain area. As the investigations have now shown, the three proteins help to guide the cells to their destination. "Surprisingly, this happens not by attraction, as in synapse formation, but by repulsion of the cells," explains Rüdiger Klein from the Max Planck Institute of Neurobiology. "This function was completely new and unexpected," adds Elena Seiradake from Oxford University.

Different reactions

Embryonic neurons often have only a cell body and short protrusions, called neurites. When Teneurin and FLRT on these structures bind to Latrophilin, the cells repel each other. As a result, the migrating cells partially lose their hold and progress more slowly. Thus guided, the cells reach their target brain area at the right time, where they mature and form a long axon.

However, when on the surface of such an axon, Teneurin and FLRT no longer trigger a repulsive reaction upon the encounter with Latrophilin. Here and now, the proteins pull the cells together, induce the formation of synapses and ultimately lead to the assembly of networks of communicating neurons. "The same proteins thus lead to completely different reactions - depending on their location on the cell," summarizes Elena Seiradake the results.

"We now have ideal conditions to investigate further interactions of the proteins during brain development," explains Rüdiger Klein. In their previous studies, the researchers were able to show that FLRT influences both the migration behavior of young nerve cells and the formation of folds on the brain surface via interactions with its own binding partners. "It will be exciting to see whether and how Teneurin and Latrophilin are involved in these interactions," says Klein.

Brain region-specific organoids have allowed researchers to peer inside the complex programming of human forebrain development, a process once inaccessible to molecular study. The results bring new insight into the gene-regulatory dynamics of human forebrain development during previously inaccessible stages and reveal transcriptional signatures of neuropsychiatric disorders. The development of the human forebrain - the region of the brain that houses many of our most uniquely human traits and cognitive abilities - is a complex process. Through a lengthy series of precisely orchestrated cellular and molecular events, cells differentiate and organize into the circuits that store memories, allow conscious thought and create our emotions. Epigenetic gene regulation is known to play a crucial role in guiding the forebrain development. Environmental or genetic disruptions to the highly synchronized process can cause severe neurodevelopmental diseases. However, due to the challenges of working with developing human brain tissues, much of what is known stems mainly from animal models. As a result, our understanding of the molecular programs that underpin the precise and dynamic processes in the human brain is limited, particularly during critical developmental periods. To address this, Alexandro Trevino and colleagues developed 3D organoid models of human forebrain development to study chromatin accessibility and gene expression in specific cells over several critical developmental stages. The in vitro approach allowed Trevino et al. to identify transcription factors that regulate cortical development. Furthermore, the authors were able to map genetic risk for neurodevelopmental disease to specific cell types during development.