Tech

Ping! The popular 1990 film, The Hunt for Red October, helped introduce sonar technology on submarines to pop culture. Now, nearly 30 years later, a team of scientists at the University of Missouri is using this same sonar technology as inspiration to develop a rapid, inexpensive way to determine whether the drinking water is safe to consume. Based on their results, the scientists said they can determine changes in the physical properties of liquids.

"If the water isn't drinkable, then our method will tell you that something is wrong with the water," said Luis Polo-Parada, an associate professor of pharmacology and physiology in the MU School of Medicine and investigator at the MU Dalton Cardiovascular Research Center. "For instance, if a facility removes salt from sea water in order for water to be safe for drinking, our method can help alert the facility to potential changes such as an issue with the desalination process."

The instrument is designed to analyze the quality of liquids using the photoacoustic effect, or the generation of sound waves after light is absorbed in a material. Drops of sea water, dairy milk or ionic liquids, a class of molten salt, were used in the study. The MU scientists believe this might be the first use of this technology to analyze such small liquid samples.

"Let's use cymbals as an analogy," said Gary A. Baker, associate professor of chemistry in the MU College of Arts and Science. "Sunlight causes the cymbals to heat up and create a constant ringing sound. Here, on a much smaller scale, we create the same effect by sending flashes of laser light at our tiny homemade cymbal, which is the tape, and measure the speed of the sound that is generated."

The team is working to refine its recording methods and equipment to provide commercial industries with an inexpensive way to monitor the quality of liquids, such as the percentage of alcohol in alcoholic beverages, the amount of inferior oil in fraudulent olive oils, the quality of honey and the amount of sugar or sugar substitutes in soft drinks. They plan to publish updated results later this year.

How it works: A tattoo removal laser machine sends out a series of brief flashes of light each lasting about 10 nanoseconds. The flashes of light travel through a fiber optic cable wrapped on one end with paint-on liquid electrical tape. The cable's end, submerged in the liquid, converts the laser light into sound. The sound is recorded by a microphone and the data is analyzed in real time.

In the brain, when neurons fire off electrical signals to their neighbors, this happens through an "all-or-none" response. The signal only happens once conditions in the cell breach a certain threshold.

Now an MIT researcher has observed a similar phenomenon in a completely different system: Earth's carbon cycle.

Daniel Rothman, professor of geophysics and co-director of the Lorenz Center in MIT's Department of Earth, Atmospheric and Planetary Sciences, has found that when the rate at which carbon dioxide enters the oceans pushes past a certain threshold -- whether as the result of a sudden burst or a slow, steady influx -- the Earth may respond with a runaway cascade of chemical feedbacks, leading to extreme ocean acidification that dramatically amplifies the effects of the original trigger.

This global reflex causes huge changes in the amount of carbon contained in the Earth's oceans, and geologists can see evidence of these changes in layers of sediments preserved over hundreds of millions of years.

Rothman looked through these geologic records and observed that over the last 540 million years, the ocean's store of carbon changed abruptly, then recovered, dozens of times in a fashion similar to the abrupt nature of a neuron spike. This "excitation" of the carbon cycle occurred most dramatically near the time of four of the five great mass extinctions in Earth's history.

Scientists have attributed various triggers to these events, and they have assumed that the changes in ocean carbon that followed were proportional to the initial trigger -- for instance, the smaller the trigger, the smaller the environmental fallout.

But Rothman says that's not the case. It didn't matter what initially caused the events; for roughly half the disruptions in his database, once they were set in motion, the rate at which carbon increased was essentially the same. Their characteristic rate is likely a property of the carbon cycle itself -- not the triggers, because different triggers would operate at different rates.

What does this all have to do with our modern-day climate? Today's oceans are absorbing carbon about an order of magnitude faster than the worst case in the geologic record -- the end-Permian extinction. But humans have only been pumping carbon dioxide into the atmosphere for hundreds of years, versus the tens of thousands of years or more that it took for volcanic eruptions or other disturbances to trigger the great environmental disruptions of the past. Might the modern increase of carbon be too brief to excite a major disruption?

According to Rothman, today we are "at the precipice of excitation," and if it occurs, the resulting spike -- as evidenced through ocean acidification, species die-offs, and more -- is likely to be similar to past global catastrophes.

"Once we're over the threshold, how we got there may not matter," says Rothman, who is publishing his results this week in the Proceedings of the National Academy of Sciences. "Once you get over it, you're dealing with how the Earth works, and it goes on its own ride."

A carbon feedback

In 2017, Rothman made a dire prediction: By the end of this century, the planet is likely to reach a critical threshold, based on the rapid rate at which humans are adding carbon dioxide to the atmosphere. When we cross that threshold, we are likely to set in motion a freight train of consequences, potentially culminating in the Earth's sixth mass extinction.

Rothman has since sought to better understand this prediction, and more generally, the way in which the carbon cycle responds once it's pushed past a critical threshold. In the new paper, he has developed a simple mathematical model to represent the carbon cycle in the Earth's upper ocean and how it might behave when this threshold is crossed.

Scientists know that when carbon dioxide from the atmosphere dissolves in seawater, it not only makes the oceans more acidic, but it also decreases the concentration of carbonate ions. When the carbonate ion concentration falls below a threshold, shells made of calcium carbonate dissolve. Organisms that make them fare poorly in such harsh conditions.

Shells, in addition to protecting marine life, provide a "ballast effect," weighing organisms down and enabling them to sink to the ocean floor along with detrital organic carbon, effectively removing carbon dioxide from the upper ocean. But in a world of increasing carbon dioxide, fewer calcifying organisms should mean less carbon dioxide is removed.

"It's a positive feedback," Rothman says. "More carbon dioxide leads to more carbon dioxide. The question from a mathematical point of view is, is such a feedback enough to render the system unstable?"

"An inexorable rise"

Rothman captured this positive feedback in his new model, which comprises two differential equations that describe interactions between the various chemical constituents in the upper ocean. He then observed how the model responded as he pumped additional carbon dioxide into the system, at different rates and amounts.

He found that no matter the rate at which he added carbon dioxide to an already stable system, the carbon cycle in the upper ocean remained stable. In response to modest perturbations, the carbon cycle would go temporarily out of whack and experience a brief period of mild ocean acidification, but it would always return to its original state rather than oscillating into a new equilibrium.

When he introduced carbon dioxide at greater rates, he found that once the levels crossed a critical threshold, the carbon cycle reacted with a cascade of positive feedbacks that magnified the original trigger, causing the entire system to spike, in the form of severe ocean acidification. The system did, eventually, return to equilibrium, after tens of thousands of years in today's oceans -- an indication that, despite a violent reaction, the carbon cycle will resume its steady state.

This pattern matches the geological record, Rothman found. The characteristic rate exhibited by half his database results from excitations above, but near, the threshold. Environmental disruptions associated with mass extinction are outliers -- they represent excitations well beyond the threshold. At least three of those cases may be related to sustained massive volcanism.

"When you go past a threshold, you get a free kick from the system responding by itself," Rothman explains. "The system is on an inexorable rise. This is what excitability is, and how a neuron works too."

Although carbon is entering the oceans today at an unprecedented rate, it is doing so over a geologically brief time. Rothman's model predicts that the two effects cancel: Faster rates bring us closer to the threshold, but shorter durations move us away. Insofar as the threshold is concerned, the modern world is in roughly the same place it was during longer periods of massive volcanism.

In other words, if today's human-induced emissions cross the threshold and continue beyond it, as Rothman predicts they soon will, the consequences may be just as severe as what the Earth experienced during its previous mass extinctions.

"It's difficult to know how things will end up given what's happening today," Rothman says. "But we're probably close to a critical threshold. Any spike would reach its maximum after about 10,000 years. Hopefully that would give us time to find a solution."

Potential precursors to life on Earth form from a variety of complex mixtures, according to a team of scientists who say this could point to the development of building blocks crucial to forming genetic molecules for the origins of life on Earth.

Genetic molecules provide the ability to store and replicate information and may have been critical for the origin of life, but it is unclear how they arose from complex chemical environments that existed on early Earth. New findings, published this week in the journal Scientific Reports, suggest the answer may start with nitrogen heterocycles, ringed molecules believed to be common on young Earth and elsewhere in the solar system. Several types of heterocycles serve as nucleobases, or subunits, of DNA and RNA, the genetic molecules used by life as we know it.

"One of the challenges of studying the origin of life is deciphering what reactions were key steps," said Christopher House, professor of geosciences at Penn State. "Our work here identified the most likely next steps these molecules could and would take."

A team of researchers found that nitrogen heterocycles may have served as building blocks toward life in a series of tests that generated complex chemical mixtures like those possibly created by lightning strikes passing through early Earth's atmosphere. Dozens of different heterocycles produced similar primitive genetic precursors even when the atmospheric composition was varied in the study.

"The real surprises were that so many different such ringed molecules were found to be reactive and that they formed the same next step regardless of what simulated atmosphere we used," said House, who also serves as director of the Penn State Astrobiology Research Center and the NASA Pennsylvania Space Grant Consortium.

The results support a hypothesis that simpler genetic structures could predate the formation of DNA and RNA and suggest that similar prebiotic reactions could happen elsewhere in the solar system.

Unlike previous studies, which have explored similar reactions in isolated conditions, the team used organically complex mixtures that better simulate early Earth chemistry not knowing whether the reactions would represent a constructive step toward life or a dead end.

In the study, the heterocycles reacted in the complex mixture to form chemically reactive side chains, structures that link heterocycles together and facilitate the formation of more complex molecules, the researchers said.

These modified heterocycles could serve as the subunit of peptide nucleic acids (PNAs), a proposed precursor to RNA. That they formed so readily in different atmospheric conditions supports the theory that PNAs could have formed on prebiotic Earth.

"Our findings hint at the possibility of PNA on the early Earth since we observed many robust synthetic pathways for some of its components," said Mike Callahan, assistant professor of chemistry at Boise State University.

The findings also have implications for similar genetic precursors on other worlds.

"The organics reacting with the heterocycles and forming these side chains have also been identified in the interstellar medium, comets, and even Titan's atmosphere," said Laura Rodriguez, who led the research as a doctoral student studying geosciences at Penn State. "And since the reactions were robust in complex mixtures under a broad range of conditions, our results may have implications for the formation of PNAs beyond Earth."

New research from Northwestern University's Kellogg School of Management could upend the approach to sales forecasting for industries from cell phones to cars.

Data analysis published today, July 8, in Nature Human Behavior shows that products that are considered to be substitutive in nature have a very different growth trajectory from predictions by traditional models, where product growth is considered similar to epidemics or the spread of viruses.

Corresponding author Dashun Wang defines substitutive products as products that are typically owned and purchased one at a time, with the new purchase replacing the old version. Examples include cell phones, cars and houses. The term also applies to less tangible concepts such as the adoption of new scientific ideas because it requires the idea holders to change or replace their existing understanding of how something works.

"Much research has looked at rates of adoption - how quickly new products or ideas spread," said Wang, associate professor of management and organizations at Kellogg. "But substitution appears to be fundamentally different because it is influenced not only by awareness and desire for the new product, but also by attachment to the old product."

Traditional models for adoption of new products predict exponential growth caused by a ripple effect of awareness as consumers see others using the new product. In contrast, researchers found that growth for substitutive items tends to follow power law growths, which is relatively slower than exponential after an initial flash of excitement surrounding the product release.

"This type of progression really isn't something we have ever seen or predicted in business or even in social adoption behavior," said study first author Ching Jin.

"We now have a new predictive model for growth that business leaders can use to create growth forecasts for substitutive products ranging from cell phones to electric cars," said Jin, who also is a post-doctoral fellow at Kellogg and the Northwestern Institute on Complex Systems.

The researchers' analysis was fed by several years' worth of sales data for top cell phone brands and automobiles. They also studied less traditional product fields, including smartphone app downloads and the spread of scientific ideas.

The wide variety of fields and customer demographics involved in the study lead researchers to believe their model may be accurate for a broad array of growth predictions including the adoption of green energy systems, health behavior or social beliefs.

"We have already seen how this model works for both consumer products and the adoption of new scientific studies - two very different things," Wang said. "That gives us confidence that the model may apply in ways we haven't studied yet."

WEST LAFAYETTE, Ind. - A gene called MYC has become one of the hottest targets for cancer researchers around the world. MYC is known to drive tumor growth in nearly all cancer types - but successfully targeting the gene has proven to be a challenge. One that has been baffling researchers for more than three decades.

Now, researchers at Purdue University have discovered a novel set of MYC promoter G-quadruplex stabilizers that have demonstrated anticancer activity in human cancer cell cultures. The discovery is published in the July 8 edition of the Journal of the American Chemical Society.

"We are striving to discover effective anticancer agents," said Mark Cushman, a distinguished professor of medicinal chemistry in Purdue's College of Pharmacy, who helps lead the research team. "The ability to incorporate MYC promoter G-quadruplex stabilizing activity into existing topoisomerase I inhibitors has shown promise in making them more potent as anticancer agents and in making cancer cells less likely to become resistant to them."

The Purdue team discovered potential anticancer agents that target the MYC promoter G-quadruplex and downregulate the expression of the MYC oncogene, which is overexpressed in cancer and is associated with almost all aspects of cancer development. The work has been supported by the National Cancer Institute and the National Institutes of Health.

Cushman, whose cancer research work contributed to his election as a fellow of the National Academy of Inventors, said they discovered a novel class of indenoisoquinoline MYC promoter G-quadruplex stabilizers in collaboration with Danzhou Yang. Some of them also inhibit topoisomerase I, an enzyme that facilitates DNA replication and is produced in greater amounts in cancer cells.

"Targeting promoter G-quadruplexes offers a relatively new and exciting strategy to inhibit the critical oncogene expression in cancer cells," said Yang, the Martha and Fred Borch Chair of Cancer Therapeutics in Purdue's College of Pharmacy, who led the research with Cushman. "We hope to combine the potency of the DNA-targeted drugs and selectivity of molecular-targeted approaches for new cancer therapeutics."

Yang and Cushman, both members of the Purdue University Center for Cancer Research, said the agents they discovered could be used in helping to treat nearly every type of cancer. Some of the technology from their work has been licensed to Gibson Oncology LLC through the Purdue Research Foundation Office of Technology Commercialization.

Some of the work Cushman and his team previously developed led to three anticancer agents that are in clinical trials. The MYC innovation will greatly enhance interest in these anticancer agents within the scientific community and will also contribute to the understanding of how they work.

Many different countries have a tea culture, and Japanese Matcha tea is growing in popularity around the world. In Japan, Matcha has a long history of being used for various medicinal purposes. It has been suspected to have various beneficial effects to health, but relatively little scientific evidence supported that claim. Now, a group of Japanese researchers from Kumamoto University has shown that anxious behavior in mice is reduced after consuming Matcha powder or Matcha extract. Its calming effects appear to be due to mechanisms that activate dopamine D1 receptors and serotonin 5-HT1A receptors, both of which are closely related to anxious behavior.

Matcha is the finely ground powder of new leaves from shade-grown (90% shade) Camellia sinensis green tea bushes. The tea (and food flavoring) is enjoyed around the world. In Japan, historical medicinal uses for Matcha included helping people relax, preventing obesity, and treatment of skin conditions. The researchers, therefore, sought to determine its various beneficial effects.

The "elevated plus maze" test is an elevated, plus-shaped, narrow platform with two walled arms that provide safety for the test subject, typically a mouse. It is used as an anxiety test for rodents with the idea that animals experiencing higher anxiety will spend more time in the safer walled-off areas. Using this test, researchers found that mouse anxiety was reduced after consuming Matcha powder or Matcha extract. In addition, when the anxiolytic activity of different Matcha extracts were evaluated, a stronger effect was found with the extract derived using 80% ethanol in comparison to the extract derived from only hot water. In other words, a poorly water-soluble Matcha component has stronger anxiolytic effects than a component that is easily soluble in water. A behavioral pharmacological analysis further revealed that Matcha and Matcha extracts reduce anxiety by activating dopamine D1 and serotonin 5-HT1A receptors.

"Although further epidemiological research is necessary, the results of our study show that Matcha, which has been used as medicinal agent for many years, may be quite beneficial to the human body," said study leader, Dr. Yuki Kurauchi. "We hope that our research into Matcha can lead to health benefits worldwide."

With the maturing of the perovskite solar cells (PSCs) technology, it is highly desirable to develop colorful solar cells to satisfy the requirements of aesthetic purposes in applications including building integrated photovoltaics and wearable electronics. The broad optical absorption and the large absorption coefficient of perovskites normally lead to high-efficiency cells with dark-brown colors. Till now, two representative approaches have been used to achieve colorful PSCs: (1) bandgap engineering and (2) structural colors. The former approach usually leads to considerably reduced power conversion efficiency (PCE) values (typically less than 13%) owing to diminished optical absorption associated with the enlarged bandgap. The latter approach takes advantage of engineered optical properties arising from patterned structures, enabling the generation of structural colors that are bright and dazzling. Despite the great efforts devoted to the colorful PSCs with respectable efficiencies, it remains a challenge to realize high-efficiency, colorful PSCs through deliberate structural design.

2D patterned nanobowl arrays with a remarkable photonic structure have been previously employed an electron transport layer (ETL) to fabricate efficient PSCs, but the obtained PSCs showed only dark or dark-brown colors, which could be related to the full filling of the nanobowls by the perovskite overlayer. Recently, Limin Qi's research group in Peking University have developed a novel strategy to prepare colorful PSCs by delicate deposition of a uniform perovskite thin layer into arrayed NBs acting as a structured ETL without jeopardizing their photonic properties. They succeeded in using TiO2 NB arrays as a photonic ETL to integrate with a uniform thin overlayer of CH3NH3PbI3, achieving high-efficiency colorful perovskite solar cells. A new crystalline precursor film based on lead acetate was prepared through a Lewis acid base adduct approach, which allowed for uniform deposition of the precursor thin film onto the inner walls of the TiO2 NBs and subsequent formation of a uniform overlayer of high-quality perovskite crystals.

The perovskite solar cells fabricated using the nanobowl arrays inherited the photonic properties of the periodic structures, showing angle-dependent vivid colors under light illumination (Figure 1). These colorful PSCs exhibited a remarkable photovoltaic performance with a champion efficiency up to 16.94% and an average efficiency of 15.47%, which are higher than those for all the colorful PSCs reported so far. It is expected that the performance of the colorful PSCs based on the nanobowl arrays could be further improved by delicately manipulating the patterned nanoarray structure and optimizing the deposition processes of the perovskite films. This work may open a new avenue toward high-efficiency colorful perovskite solar cells with promising applications including building integrated photovoltaics.

The Researchers from HSE University (The Higher School of Economics) have used machine learning to discover that the two most widespread DNA structures - stem-loops and quadruplexes - cause genome mutations that lead to cancer. The results of the study were published in BMC Cancer.

In the early 2000s, researchers invented a new method to obtain the nucleotide sequence of DNA and RNA - Next-Generation Sequencing, NGS. This technology allows reading simultaneously several million genome regions, which had been impossible with earlier sequencing methods. Now, the human genome (genetic information) can be recorded in a text file weighing about 3.2 Gb.

'Cancer is a genome disease,' explains Maria Poptsova, Head of the HSE Laboratory of Bioinformatics and one of the study's authors, 'When we sequence the genome in a tumour tissue, we see a spectrum of different mutations. There may be point or large-scale mutations. For example, in point mutations, one nucleotide disappears and is replaced by another. We looked at large-scale mutations where parts of the genome (from several to millions of nucleotides) were deleted, reversed, copied, and inserted in a different place. As a result of these rearrangements, genome breakpoints appear.

HSE University researchers investigated the influence of two types of DNA secondary structures - stem-loops and quadruplexes - on genome breakpoints, with the use of machine learning. The authors analysed half a million breakpoints in over 2,000 genomes of ten types of cancer. Researchers looked for genomic hotspots, considering breakpoint hotspots to be the regions with frequent and recurrent rearrangements - in other words, risk zones. It appeared that the stem-loop-based model best explains blood, brain, liver, and prostate cancer breakpoint hotspot profiles, while quadruplex-based model has higher performance for bone, breast, ovary, pancreatic, and skin cancer.

The appearance of breakpoints cannot be explained exclusively by the impact of DNA secondary structures, but their contribution is at least 20-30%. The analysis demonstrates that the impact of stem-loops and quadruplexes on breakpoint evolution depends on the type of tissue, which is determined by epigenetic factors.

'These are the kind of markers that distinguish different kinds of tissues over the genome,' said Maria Poptsova. 'We are actively studying the correlation between secondary DNA structures and epigenetic marks. English researchers have already looked at the impact of DNA secondary structures and epigenetic marks on point mutations. We focused on breakpoint hotspots and are the first to determine the contribution of the two most widespread genome structures - stem-loops and quadruplexes.'

According to the study's authors, in the future, quadruplexes may be used as therapeutic targets. If drug therapy makes them more stable, the telomerase enzyme won't be able to work in cancer cells, and they will become vulnerable.

Scientists have developed a new method for detecting traces of primordial life in ancient rock formations using potassium.

The method relies on searching for high concentrations of potassium in ancient sedimentary rocks, rather than traditional methods that look for carbon, sulfur, or nitrogen--which can appear in ancient rocks through processes unrelated to ancient life.

"Our findings show that microbial biofilms trapped potassium from ancient seawater and facilitated its accumulation into clay minerals that were buried on the seafloor," explainedKurt Konhauser, professor in the University of Alberta's Department of Earth and Atmospheric Sciences and co-author on the study. "This is critical because there is no abiotic mechanism that can be used to explain the potassium enrichment aside from life itself."

The study examined clay particles from the Francevillian Formation located in Gabon, on the west coast of central Africa. This 2.1 billion-year-old formation hosts well-preserved microfossils in clay.

2.1 billion year old sediment from Gabon with ancient microbial mat features and biologically-induced potassium enrichment.

"In our quest to find evidence of early life on Earth, we have been limited to looking for a number of signatures that have all proven ambiguous, because, unfortunately, the signatures can be explained by both bacterial and abiotic processes," explained Konhauser. "Our results indicate that a different signature--potassium--is potentially a more unique tracer, as it could only have been created through the metabolism of living bacteria."

Researchers have demonstrated a technique that allows them to track microscopic changes in metals or other materials in real time even when the materials are exposed to extreme heat and loads for an extended period of time -- a phenomenon known as "creep." The technique will expedite efforts to develop and characterize materials for use in extreme environments, such as nuclear reactors.

"Until now, you could look at a material's structure before exposing it to heat or load, then apply heat and load until it broke, followed by a microstructural observation. That means you'd only know what it looked like before and after loading and heating," says Afsaneh Rabiei, corresponding author of a paper on the work and a professor of mechanical and aerospace engineering at North Carolina State University.

"Our technique, which is called 'in situ scanning electron microscopy (SEM) heating and loading,' allows us to see the microscopic changes taking place throughout the process. You can see how cracks form and grow, or how microstructure transforms during the failure process. This is extremely valuable for understanding a material's characteristics and its behavior under different conditions of loading and heating."

Rabiei developed the in situ SEM technique for high temperatures and load (tension) as a means of conducting high throughput assessments of the behavior of advanced materials. The goal was to be able to predict how a material responds under a variety of heating and loading conditions. The project was supported by the Department of Energy. The instrument can capture SEM images at temperatures as high as 1,000 degrees Celsius (C), and at stresses as high as two gigapascal - which is equivalent to 290,075 pounds per square inch.

For their recent demonstration of the technique's potential, researchers conducted "creep-fatigue" testing on a stainless steel alloy called alloy 709, which is being considered for use in nuclear reactors.

"Creep-fatigue testing involves exposing materials to high heat and repeated, extended loads, which helps us understand how structures will perform when placed under loads in extreme environments," Rabiei says. "That is clearly important for applications such as nuclear reactors, which are designed to operate for decades."

To that end, Rabiei and her collaborators tested samples of alloy 709 at temperatures of 750 degrees C, which experienced repeated load cycles ranging from holding the load for one second to holding the load for one hour repeatedly until they failed. In one iteration, where the sample was repeatedly exposed to a load for one hour, with seven-second intervals between loads, the experiment lasted for more than 600 hours. And the in situ SEM captured it all.

"In situ SEM allowed us to track the microscopic development of cracks in the material and the evolution of the microstructure during the creep-fatigue testing," Rabiei says. "We were then able to use these data to model what alloy 709's behavior would be over years of use in a nuclear reactor. And alloy 709 outperformed 316 stainless steel, which is what's currently used in many reactors.

"That's good news, but what is most exciting here is the methodology we used. For example, our in situ SEM technique allowed us to witness the role that micro-structural details called twin boundaries play in controlling crack growth in alloy 709. Our observations showed that when a crack reaches such twin boundaries in alloy 709, it redirects itself and takes a detour. This detouring effect delays crack growth, improving the material's strength. Without our in situ SEM heating and loading technology, such observations could not be possible. Moreover, using this technique, we only need small specimens and can generate data that normally take years to generate. As such we are saving both time and the amount of material used to evaluate the material's properties and analyze its failure process.

"The ability to capture insights like these is a significant advance for research into any number of new, high-performance materials, particularly those that are designed to perform in extreme environments," Rabiei says.

The paper, "Performance of alloy 709 under creep-fatigue at various dwell times," is published in the journal Materials Science and Engineering: A. First author of the paper is Amrita Lall, a Ph.D. student at NC State. The paper was co-authored by Siddhartha Sarkar, a Ph.D. student at NC State; and by Rengen Ding and Paul Bowen of the University of Birmingham.

The work was done with support from the U.S. Department of Energy's Nuclear Energy University Program under award number 2015-1877/DE-NE0008451; and from the Research Councils UK (now UK Research and Innovation) under award number EP/N016351/1.

Physically bound to a specific location, plants have to devise special ways to secure their supply of vital nutrients. Most plants have developed a root system to the nutrients they need in order to survive out of the soil. But what if nutrient-poor soils fail to provide the necessities of life? Carnivorous plants such as the Venus flytrap have found a way out of this dilemma.

The Venus flytrap is native to the wetlands of North and South Carolina on the East Coast of the USA. Instead of taking in nutrients through its roots alone, the carnivorous plant traps prey within its leaves that can snap shut within a fraction of a second. The plant is capable of sensing prey through delicate trigger hairs on the inside of its flat leaves. Since prey insects come in different sizes and the Venus flytrap cannot afford to be fussy, the plant grows traps across a variety of sizes.

Now researchers from the universities of Würzburg and Cambridge have discovered that the tactile sensors in these traps already respond to minute pressure stimuli, converting them to electrical signals that cause the trap to close. They have published their results in the current issue of Nature Plants.

Trigger hair converts touch into electricity

"Each trap lobe features three to four multicellular hairs which are torsion-resistant except for a notch at the base. When an insect, lured by the smell, colour or nectar of the trap, touches the trigger hair, the hair will yield in the area of the non-reinforced base. This causes the sensory cells in this area to be stretched on one side and compressed on the other side," says Professor Rainer Hedrich, explaining the operating principle of the Venus flytrap. The biophysicist and plant researcher, who holds the Chair of Botany I at the University of Würzburg, has been studying the carnivorous plant species for some time.

When the sensory cells are deformed in this way, the tactile sensors respond by converting mechanical energy into electrical signals, triggering an action potential, which rapidly propagates from the base of the trigger hair throughout the entire trap. When a trigger hair is touched a second time within a short time period, the process is restarted - and only then does the trap close.

But how much does an insect deflect the trigger hair? What is the minimum size and weight that an insect must have in order to be detected by the Venus flytrap? Professor Hedrich had these questions in mind when conducting his latest study. "It was clear from the beginning that we would not easily get the answers using flying insects," Professor Hedrich explains. So when looking for a suitable insect prey to use in their experiments, Professor Hedrich and his team opted for ants. Professor Walter Federle, a biomechanics expert and ant specialist at the University of Cambridge, provided the necessary expertise and support for the experiments of the Würzburg plant scientists.

Minimal deflection triggers electrical stimulation

How can ants be made to touch a trigger hair on command? To solve this problem, ant specialist Federle chose leaf-cutting ants. This ant species regularly commutes between the foraging site and the nest. For the experiment, Federle mounted single-trap lobes within the foraging trail of a leaf-cutting ant colony. He then monitored the ant traffic on the flytrap trail using a high-speed camera that recorded all contacts. The result: Federle's analysis yielded a minimum and maximum trigger hair deflection of 3.5 and 7.5 degrees, respectively.

Now in order to determine the angle and force necessary to trigger an action potential in the Venus flytrap, the scientists replaced the ants with computer-controlled micro-manipulators equipped with special force transducers. After the micro-manipulators had been deposited on the trigger hairs, the deflection angle was varied progressively. "We were surprised to find that our voltage detectors already recorded an action potential at a deflection of around 2.9 degrees," says Dr Sönke Scherzer, lead author of the study and a scientist in Professor Hedrich's department. This means that the Venus flytrap already detects the weakest contact with a leaf-cutting ant.

A trap for each fly size

An ant or housefly creates a force when walking which is approximately equivalent to its body weight. So a fly weighing ten milligrams is capable of generating 100 micronewtons, a force that is easily sufficient to excite a large trap. However, if a mosquito weighing just three milligrams ends up in such a large trap, the trigger hairs will not be deflected.

But since a mosquito, too, can be an important source of nutrients, the Venus flytrap has also developed smaller traps during the course of evolution. These mini-traps also respond to the smaller forces generated by the lightweight mosquito. "This trap-size-based sensitivity of the trigger hairs is crucial for the economic efficiency of the traps," Professor Hedrich explains. After all, it costs the plant much more energy to reopen a large trap than a small one. "If underweight, low-nutrient prey insects were able to trigger large traps, the cost-benefit ratio would turn out negative and the Venus flytrap would slowly starve in the worst case," Professor Hedrich explains.

When trigger hairs get weary

Once the trap has closed, the insect prey usually does not just accept its fate. Instead it struggles and tries to escape. In its panic, it constantly touches the tactile hairs, triggering up to 100 action potentials in two hours. According to Professor Hedrich, the Venus flytrap takes into account these electrical signals and initiates a corresponding response that ranges from the production and excretion of digestive enzymes to taking up the nutrients from the decomposed prey.

The scientists conducted another experiment to determine how often a single trigger hair can be stimulated within one hour. The result: "From a frequency of a tenth of a hertz, that is one stimulation every ten seconds, the trigger hair starts to exhibit signs of fatigue," says Sönke Scherzer. At higher frequencies, an action potential was no longer triggered each time a tactile hair is stimulated and eventually the electrical events did not take place at all. When the scientists interrupted the repeated stimulation sequence for a minute, the hair fully regained its mechano-electrical properties.

Sensory cells under the microscope

To build on this research, the researchers aim to find out how the flytrap counts and why the tactile hair stops responding when stimulated at high frequency. For this purpose, they will isolate the trigger hairs and sensory cells and determine a number of properties such as the fatigue and recovery of the ion channels that convert the tactile stimulus to an electrical event.

CHAMPAIGN, Ill. -- Human waste might be an unpleasant public health burden, but scientists at the University of Illinois see sanitation as a valuable facet of global ecosystems and an overlooked source of nutrients, organic material and water.

Their research, directed by civil and environmental engineering professor Jeremy Guest, is reported in the journal Nature Sustainability.

Human beings derive benefits from the ecosystems around them - services that often go undervalued in traditional economic systems, the researchers said. These ecosystem benefits include things like forests providing wood as a building material and natural hydrological processes that improve water quality.

"In previous research, we have shown that human waste can provide a potentially valuable source of nutrients and water to enhance agriculture," said lead author John Trimmer, a civil and environmental engineering graduate student. "In the new study, we expand this concept and set out to find connections between ecosystem services and the recovery of nutrients, water and organic matter from sanitation systems - then define and analyze the viability of pathways through which those recovered resources might further enhance ecosystem services."

The researchers found that between 2000 and 2018, there were over 56,000 published studies that discussed sanitation and resource recovery and approximately 36,000 on ecosystem services; of these, 155 discussed the linkages between the two fields.

The team identified six key resource recovery and sanitation topics covered in the published studies: wastewater treatment, wastewater reuse, natural or constructed wetlands, nutrient and carbon recovery, stormwater reuse and regulation, and energy recovery.

"We next identified the pathways in which the recovered resources and ecosystem services may lead to something of direct societal value," Trimmer said. "For example, nutrients recovered from a wastewater facility can be applied to farmland to increase food production."

The study describes 17 potential ecosystem services made available from the nutrients, water and organic material recovered from sanitation systems serving human populations. These include water purification, nutrient cycling, food provisioning and climate regulation, for example.

"The practical feasibility of the potential linkages is difficult to define at this conceptual stage, but they will be highly dependent on local circumstances such soil conditions, climate, fertilizer and energy markets, water resources and socio-cultural norms," Trimmer said. "However, we began to examine some critical issues related to the location of recoverable resources and ecosystems, sanitation and recovery technology and financing mechanisms."

"Environmental issues like biodiversity loss and climate change are increasingly prominent in the public eye and people now want to know what we, as a society, are going to do about them," said Daniel Miller, a natural resources and environmental sciences professor and study co-author. "Our research points to the unexplored aspect of sanitation and how it might contribute to addressing such problems. We typically think of sanitation as degrading the environment, but we find ways it could actually help improve it while bringing benefits for people."

Fish die-offs in Wisconsin lakes are expected to double by mid-century and quadruple by 2100 due to warmer summer temperatures, according to a study published today in the journal Nature Climate Change.

To better understand how fish die-offs are changing, researchers from Reed College and the University of California, Davis, analyzed a database of freshwater fish die-offs in Wisconsin combined with lake temperature data and simulations. They found that more than 100 of 500 fish die-offs recorded between 2004 and 2014 in the state were strongly linked with heat waves and warmer average surface water temperatures.

"This research takes a substantial step forward in connecting the dots between the occurrence of rare ecological catastrophes and climate warming," said lead author Samuel Fey, a mass mortality specialist and assistant professor at Reed College in Portland, Oregon. "Historically, the causes of animal die-offs have been difficult to study because these events tend to be rare and unpredictable."

Summertime die-off events occurred in lakes that were warmer than lakes without die-offs, and during years of particularly high water temperatures.

'WHAT CLIMATE CHANGE WILL LOOK LIKE'

The scientists used climate projections to forecast fish die-offs driven by warming summer temperatures over the coming decades. Their results indicate a sobering future for common species such as bluegill, walleye, largemouth bass and northern pike that inhabit these lakes. In the modeling, significant numbers of fish die-offs occurred with an increase of just 2 degrees Celsius, which the globe is on track to surpass by 2100.

"This study is unveiling another reality of what climate change will look like for north-temperate lakes across the world," said co-author Andrew Rypel, an associate professor at UC Davis and the Peter B. Moyle and California Trout Chair in Coldwater Fish Ecology. "Analyses provide an up-close view of how fish populations will die, and how species will die due to climate change. It's particularly problematic for freshwater fishes in landlocked lakes, as they don't have the ability to adapt to changing climates by migrating. Effects have to be dealt with by managers right where they are."

ADAPTATION OPPORTUNITIES

The study shows most future fish kills are expected to occur in the southern portion of the state, which is the warmest and most populated part of Wisconsin. Urban, agricultural and industrial activities combine to impact lakes in the area.

Rypel says this presents a problem for fish but also opportunities for their management, adaptation and resilience. Cities, communities and resource managers could take measures to improve lake conditions through heightened efforts to manage phosphorous loads and restore forests around riparian areas to act as a sponge for contaminants that could otherwise enter the lake.

TAMPA, Fla.\ - Uveal melanoma is a very aggressive type of melanoma that affects the eye. It is a rare disorder, affecting an estimated 2,500 people in the United States each year. However, nearly half of uveal melanoma patients will develop metastatic disease that migrates to other part of the body, primarily the liver. The prognosis for patients with metastatic uveal melanoma is very poor, with median survival of only 17 to 20 months. Researchers in Moffitt Cancer Center's Donald A. Adam Melanoma and Skin Cancer Center of Excellence are working to change that. They have identified a new drug combination that is effective against metastatic uveal melanoma cells in preclinical studies. Their findings were published in Clinical Cancer Research.

The MAPK protein signaling pathway is commonly deregulated in melanoma of the skin and uveal melanoma. Drugs that target a protein called MEK, which is involved in the MAPK signaling pathway, have significantly improved the outcomes of patients with melanoma of the skin. However, a recent phase 3 clinical trial in uveal melanoma revealed that patients treated with a MEK inhibitor plus chemotherapy had no improvement in survival over those patients treated with chemotherapy alone.

Many patients with uveal melanoma quickly develop resistance to MEK inhibitors. Moffitt researchers, in collaboration with scientists from the UF Health Cancer Center and Sylvester Comprehensive Cancer Center, wanted to determine how this resistance develops and identify additional drugs that could be used in combination with MEK inhibitors to target uveal melanoma cells for destruction.

The researcher team performed laboratory experiments with uveal melanoma cell lines and discovered that MEK inhibitors blocked their growth; however, this inhibition was short-lived and eventually the cell lines developed resistance and continued to grow. The researchers used proteomics analysis to determine which signaling pathways were activated during MEK inhibitor resistance.

"We identified a number of putative escape pathways that were upregulated following MEK inhibition, including the PI3K/AKT pathway, ROR1/2 and IGF-1R signaling," explained Keiran Smalley, PhD, director of Moffitt's Donald A. Adam Melanoma and Skin Cancer Center of Excellence. They also discovered that signaling through the YAP protein contributed to MEK inhibitor resistance.

Since there are no known drugs that are able to target both AKT and YAP signaling, the researchers performed a drug screen of 289 compounds to identify those that could limit escape from MEK inhibition. The drug type with the biggest impact across four different uveal melanoma cell lines were histone deacetylase (HDAC) inhibitors. HDACs regulate the expression level of many genes involved in cancer development, and several HDAC inhibitors are currently approved to treat different types of cancer. The researchers discovered that, of the HDAC inhibitors investigated, panobinostat was the most effective at blocking the development of resistance through YAP and AKT and enhancing the effects of MEK inhibitors in uveal melanoma cell lines. Additionally, combination treatment with panobinostat and the MEK inhibitor trametinib was more effective at reducing uveal melanoma tumor growth in mice than either agent alone.

They hope that the preclinical findings will lead to the initiation of clinical trials in uveal melanoma patients. "Our finding that a clinically approved pan-HDAC inhibitor was effective at simultaneously limiting YAP and AKT signaling in uveal melanoma cells suggests this could be a good candidate for future clinical development," explained Smalley.

Physical activity is important for physical and mental wellbeing and keeping socially connected. This themed review, Moving Matters, brings together more than 50 published and ongoing studies funded by the National Institute for Health Research (NIHR) on ways to increase physical activity in everyday life. This review considers the changing needs and opportunities of different age groups from infancy onwards, as well as considering interventions in the workplace and in the built and natural environments.

"The NIHR physical activity evidence review will be an invaluable tool to anyone working in practice or policy. Evidence should be one of the key building blocks for any decisions. It helps decision makers determine what works and what doesn't, what should be commissioned and prioritised, and (equally important) what should be stopped." Sarah Ruane, Strategic Lead for Health, Sport England.

"The importance of physical activity to many aspects of physical and mental health and wellbeing is well understood. This report shows the depth and breadth of that understanding, and encourages us to consider how we can work with people and places to achieve the best possible impact.

"Walking and cycling are among the best ways for many people to incorporate physical activity into their lives. Ongoing work should emphasise the connection between helping people to travel locally by foot and by cycle with supporting social connectedness, reducing isolation, improving local amenity, and supporting access to jobs and services." Dr Andy Cope, Director of Insight at Sustrans.

This review highlights that there is no single solution and that what is effective to help us become and stay active depends on who we are, the environment we live in, and our wider social and cultural context. But we do know something about what works from this evidence, which focuses on high quality research. In the past we have often depended on smaller studies with people reporting their own activity rather than using objective measures of change. This review highlights an important and growing evidence base to support decision-makers.

Findings in the NIHR review include:

Community organisations and decision makers should consider the whole range of ways people can be active and the diversity of factors that shape people's habits and behaviours, and avoid seeing physical activity solely in terms of sport and exercise.

The largest and most sustainable benefits, particularly for people who are least active now, are likely to come from increasing activity as an incidental part of everyday routines. Promising interventions include improving opportunities for public and active transport, enhancing access to green spaces and leisure facilities, and changing school and workplace routines to reduce time spent sitting.

Programmes tailored to particular individuals and groups can also be effective, such as a weight loss programme run through football clubs and an education programme to help people at risk of diabetes to walk more. Some features shared by many successful programmes are: encouraging people to use a diary or pedometer to monitor how active they are, increasing activity a little at a time, setting goals, and making the activity enjoyable and sociable.

Beyond direct physical benefits, interventions to help people become more active can bring many co-benefits such as improved wellbeing and social connectedness, reduced traffic with safer streets and lower emissions, and more pleasant open spaces.

More research is needed into adapting interventions to support particular groups that are likely to be less active whether because of social and cultural norms, difficulty or expense accessing opportunities to be active, or a change in their life circumstances.