Mining's effect on fish warrants better science-based policies

Migrating sockeye salmon approach their spawning grounds on a tributary of the Copper River.
Credit: University of Alaska Fairbanks

A new paper published in Science Advances synthesizes the impact of metal and coal mines on salmon and trout in northwestern North America, and highlights the need for more complete and transparent science to inform mining policy.

It is the first comprehensive effort by an interdisciplinary group of experts that explicitly links mining policy to current understanding of watershed ecology and salmonid biology.

“Our paper is not for or against mining, but it does describe current environmental challenges and gaps in the application of science to mining governance. We believe it will provide critically needed scientific clarity for this controversial topic,” said lead author Chris Sergeant, a graduate student at the University of Alaska Fairbanks College of Fisheries and Ocean Sciences and a research scientist at the University of Montana.

For the study, experts integrated and reviewed information on hydrology, river ecology, aquatic toxicology, biology and mining policy. Their robust assessment maps more than 3,600 mines throughout Montana, Washington, British Columbia, the Yukon and Alaska. The size of the mines ranges from family-run placer sites to massive open-pit projects.

Biomedical engineering students work on transgender health project

UC College of Engineering and Applied Science students Anna King, left, and Rucha Tadwalkar use 3D printers in a biomedical engineering lab.
Photo/Michael Miller

Biomedical engineering students at the University of Cincinnati created a product to help decrease the gender dysphoria experienced by some transgender men during menstruation prior to gender-confirmation surgery.

UC College of Engineering and Applied Science students Rucha Tadwalkar and Anna King wanted to help people suffering from gender dysphoria, the condition of feeling one's emotional and psychological identity to be at variance with one's birth sex.

The students spoke to experts in adolescent and transition medicine at the Transgender Health Clinic at Cincinnati Children’s Hospital Medical Center.

“Our goal was to create a menstrual device that is inclusive of all individuals to decrease the mental health side effects of gender dysphoria, which are heightened during the menstrual cycle” Tadwalkar said.

One in 250 adults representing about 1 million people in the United States identify as transgender, according to the National Institutes of Health.

New optical device could help solar arrays focus light, even under clouds

Different stages of the graded index glass pyramid fabrication: when in optical contact with a solar cell, the pyramid at the final step (bottom right corner) absorbs and concentrates most of the incident light and appears dark.
Image credit: Nina Vaidya

Stanford engineers’ optical concentrator could help solar arrays capture more light even on a cloudy day without tracking the sun

Researchers imagined, designed, and tested an elegant lens device that can efficiently gather light from all angles and concentrate it at a fixed output position. These graded index optics also have applications in areas such as light management in solid-state lighting, laser couplers, and display technology to improve coupling and resolution.

Even with the impressive and continuous advances in solar technologies, the question remains: How can we efficiently collect energy from sunlight coming from varying angles from sunrise to sunset?

Solar panels work best when sunlight hits them directly. To capture as much energy as possible, many solar arrays actively rotate towards the sun as it moves across the sky. This makes them more efficient, but also more expensive and complicated to build and maintain than a stationary system.

Robots play with play dough

The inner child in many of us feels an overwhelming sense of joy when stumbling across a pile of the fluorescent, rubbery mixture of water, salt, and flour that put goo on the map: play dough. (Even if this happens rarely in adulthood.)

While manipulating play dough is fun and easy for 2-year-olds, the shapeless sludge is hard for robots to handle. Machines have become increasingly reliable with rigid objects, but manipulating soft, deformable objects comes with a laundry list of technical challenges, and most importantly, as with most flexible structures, if you move one part, you’re likely affecting everything else.

Scientists from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and Stanford University recently let robots take their hand at playing with the modeling compound, but not for nostalgia’s sake. Their new system learns directly from visual inputs to let a robot with a two-fingered gripper see, simulate, and shape doughy objects. “RoboCraft” could reliably plan a robot’s behavior to pinch and release play dough to make various letters, including ones it had never seen. With just 10 minutes of data, the two-finger gripper rivaled human counterparts that teleoperated the machine — performing on-par, and at times even better, on the tested tasks.

Where Once Were Black Boxes, NIST’s New LANTERN Illuminates

How do you figure out how to alter a gene so that it makes a usefully different protein? The job might be imagined as interacting with a complex machine (at left) that sports a vast control panel filled with thousands of unlabeled switches, which all affect the device’s output somehow. A new tool called LANTERN figures out which sets of switches — rungs on the gene’s DNA ladder — have the largest effect on a given attribute of the protein. It also summarizes how the user can tweak that attribute to achieve a desired effect, essentially transmuting the many switches on our machine’s panel into another machine (at right) with just a few simple dials.
Credit: B. Hayes/NIST

Researchers at the National Institute of Standards and Technology (NIST) have developed a new statistical tool that they have used to predict protein function. Not only could it help with the difficult job of altering proteins in practically useful ways, but it also works by methods that are fully interpretable — an advantage over the conventional artificial intelligence (AI) that has aided with protein engineering in the past.

The new tool, called LANTERN, could prove useful in work ranging from producing biofuels to improving crops to developing new disease treatments. Proteins, as building blocks of biology, are a key element in all these tasks. But while it is comparatively easy to make changes to the strand of DNA that serves as the blueprint for a given protein, it remains challenging to determine which specific base pairs — rungs on the DNA ladder — are the keys to producing a desired effect. Finding these keys has been the purview of AI built of deep neural networks (DNNs), which, though effective, are notoriously opaque to human understanding.

Rensselaer Researchers Make Virus-Fighting Face Masks

Rensselaer Polytechnic Institute researchers have developed an accessible way to make N95 face masks not only effective barriers to germs, but on-contact germ killers. The antiviral, antibacterial masks can potentially be worn longer, causing less plastic waste as the masks do not need to be replaced as frequently.

Helen Zha, assistant professor of chemical and biological engineering and a member of the Center for Biotechnology and Interdisciplinary Studies at Rensselaer (CBIS), collaborated with Edmund Palermo, associate professor of materials science and engineering and a member of the Center for Materials, Devices, and Integrated systems (cMDIS) at Rensselaer, to fight infectious respiratory disease and environmental pollution with the perfect recipe to improve face masks.

“This was a multifaceted materials engineering challenge with a great, diverse team of collaborators,” Palermo said. “We think the work is a first step toward longer-lasting, self-sterilizing personal protective equipment, such as the N95 respirator. It may help reduce transmission of airborne pathogens in general.”

In research recently published in Applied ACS Materials and Interfaces, the team successfully grafted broad-spectrum antimicrobial polymers onto the polypropylene filters used in N95 face masks.

“The active filtration layers in N95 masks are very sensitive to chemical modification,” said Zha. “It can make them perform worse in terms of filtration, so they essentially no longer perform like N95s. They’re made out of polypropylene, which is difficult to chemically modify. Another challenge is that you don't want to disrupt the very fine network of fibers in these masks, which might make them more difficult to breathe through.”

Blood Pressure E-Tattoo Promises Continuous, Mobile Monitoring

Credit: University of Texas at Austin

Blood pressure is one of the most important indicators of heart health, but it’s tough to frequently and reliably measure outside of a clinical setting. For decades, cuff-based devices that constrict around the arm to give a reading have been the gold standard. But now, researchers at The University of Texas at Austin and Texas A&M University have developed an electronic tattoo that can be worn comfortably on the wrist for hours and deliver continuous blood pressure measurements at an accuracy level exceeding nearly all available options on the market today.

“Blood pressure is the most important vital sign you can measure, but the methods to do it outside of the clinic passively, without a cuff, are very limited,” said Deji Akinwande, a professor in the Department of Electrical and Computer Engineering at UT Austin and one of the co-leaders of the project, which is documented in a new paper published today in Nature Nanotechnology.

High blood pressure can lead to serious heart conditions if left untreated. It can be hard to capture with a traditional blood pressure check because that only measures a moment in time, a single data point.

“Taking infrequent blood pressure measurements has many limitations, and it does not provide insight into exactly how our body is functioning,” said Roozbeh Jafari, a professor of biomedical engineering, computer science and electrical engineering at Texas A&M and the other co-leader of the project.

The continuous monitoring of the e-tattoo allows for blood pressure measurements in all kinds of situations: at times of high stress, while sleeping, exercising, etc. It can deliver thousands of measurements, more than any device thus far.

New model offers potential solutions for next-generation battery challenges

A new mathematical model has brought together the physics and chemistry of highly promising lithium-metal batteries, providing researchers with plausible, fresh solutions to a problem known to cause degradation and failure.

A new study by Stanford University researchers lights a path forward for building better, safer lithium-metal batteries.

Close cousins of the rechargeable lithium-ion cells widely used in portable electronics and electric cars; lithium-metal batteries hold tremendous promise as next-generation energy storage devices. Compared to lithium-ion devices, lithium-metal batteries hold more energy, charge up faster, and weigh considerably less.

To date, though, the commercial use of rechargeable lithium-metal batteries has been limited. A chief reason is the formation of “dendrites” – thin, metallic, tree-like structures that grow as lithium metal accumulates on electrodes inside the battery. These dendrites degrade battery performance and ultimately lead to failure which, in some instances, can even dangerously ignite fires.

The new study approached this dendrite problem from a theoretical perspective. As described in the paper, published in the Journal of The Electrochemical Society, Stanford researchers developed a mathematical model that brings together the physics and chemistry involved in dendrite formation.

This model offered the insight that swapping in new electrolytes – the medium through which lithium ions travel between the two electrodes inside a battery – with certain properties could slow or even outright stop dendrite growth.

Going Platinum: A Non-Toxic Catalyst for Clean, Re-Usable Water

Harmful aldehydes (found in treated wastewater can be transformed to carboxylic acids by using the existing oxygen found in water and platinum as a catalyst to speed up the reaction. note: The reaction scheme shown appears not to be balanced. The illustration is used to simplify the presentation of the multiple reactions occurring and which are balanced. details are available in the material cited.
Image Credit: Daniel McCurry.

Platinum has set a new “gold standard” in jewelry, and now it’s about to upscale the quality of your water.

As wastewater treatment for potable – drinkable – reuse becomes a more viable and popular option to address water shortages, the question of what harmful byproducts might form in treatment and how to address them looms large. One group of these chemicals, aldehydes, are known to stubbornly persist through treatment. Toxic to humans, aldehydes will be at the top of the list of regulated byproducts in forthcoming reuse regulations, USC researchers believe, and require sustainable methodology to be removed from our drinking water.

In research published in Environmental Science & Technology, USC Viterbi School of Engineering researchers introduced platinum to help clean even the most stubborn toxins from wastewater. Platinum, the same metal used in catalytic converters to clean up air pollutants in car exhaust, can serve as a catalyst, said Dan McCurry, assistant professor in civil and environmental engineering, speeding up oxidation to transform once-toxic aldehydes into harmless carboxylic acids.

Stanford engineers develop tiny robots to bring health care closer to precisely targeted drug delivery

The origami millirobot integrates capabilities of spinning-enabled multimodal locomotion, cargo transportation, and targeted drug delivery.
Credit: Zhao Lab

A Stanford mechanical engineer creates multifunctional wireless robots to maximize health outcomes and minimize invasiveness of procedures.

If you’ve ever swallowed the same round tablet in hopes of curing everything from stomach cramps to headaches, you already know that medicines aren’t always designed to treat precise pain points. While over-the-counter pills have cured many ailments for decades, biomedical researchers have only recently begun exploring ways to improve targeted drug delivery when treating more complicated medical conditions, like cardiovascular disease or cancer.

A promising innovation within this burgeoning area of biomedicine is the millirobot. These fingertip-sized robots are poised to become medicine’s future lifesavers – to crawl, spin, and swim to enter narrow spaces on their mission to investigate inner workings or dispense medicines.

Researchers solve mystery surrounding dielectric properties of unique metal oxide

University of Minnesota Associate Professor Bharat Jalan and his students discovered that the true dielectric constant of their strontium titanate films exceeds 25,000—the highest ever measured for this material.
Credit: Jalan Group, University of Minnesota

A University of Minnesota Twin Cities-led research team has solved a longstanding mystery surrounding strontium titanate, an unusual metal oxide that can be an insulator, a semiconductor, or a metal. The research provides insight for future applications of this material to electronic devices and data storage.

The paper is published in the prestigious Proceedings of the National Academy of Sciences of the United States of America (PNAS), a peer-reviewed, multidisciplinary, scientific journal.

When an insulator like strontium titanateis placed between oppositely charged metal plates, the electric field between the plates causes the negatively charged electrons and the positive nuclei to line up in the direction of the field. This orderly lining up of electrons and nuclei is resisted by thermal vibrations, and the degree of order is measured by a fundamental quantity called the dielectric constant. At low temperature, where the thermal vibrations are weak, the dielectric constant is larger.

In semiconductors, the dielectric constant plays an important role by providing effective “screening,” or protection, of the conducting electrons from other charged defects in the material. For applications in electronic devices, it is critical to have a large dielectric constant.

New delivery method allows slow-release of broader array of peptide drugs in the body

Schwendeman Lab.
Image credit: Michigan Photography

A new study from the University of Michigan describes one of the first entirely new drug delivery microencapsulation approaches in decades.

Microencapsulation in biodegradable polymers allows drugs such as peptide therapeutics to be released over time in the body.

Peptides are molecules in the body that are composed of short chains of amino acids, and include messengers, growth factors and well-known hormones such as insulin. Because of their larger size and structure, peptide drugs are rarely given by mouth and must be injected. Microencapsulation is one way to decrease the time needed between injections.

One slow-release delivery method for peptide drugs is to encapsulate them within the type of resorbable polymers often used as dissolving sutures, said study co-author Steven Schwendeman, professor of pharmaceutical sciences and biomedical engineering.

However, development of polymer dosage forms for delivery of certain peptide drugs has been difficult because the currently available methods to microencapsulate the peptide molecules in the polymer require organic solvents and complex manufacturing.

Making Robotic Assistive Walking More Natural

 

A team of graduate students in Caltech's Advanced Mechanical Bipedal Experimental Robotics Lab (AMBER), led by Professor Aaron Ames, Bren Professor of Mechanical and Civil Engineering and Control and Dynamical Systems, is developing a new method of generating gaits for robotic assistive devices, which aims to guarantee stability and achieve more natural locomotion for different users.

A paper published in IEEE Robotics and Automation Letters outlines the AMBER team's method and represents the first instance of combining hybrid zero dynamics (HZD)—a mathematical framework for generating stable locomotion—with a musculoskeletal model to control a robotic assistive device for walking. The musculoskeletal model is a computational tool to noninvasively measure the relationship between muscle force and joint contact force. HZD is currently used to create stable walking gaits for bipedal robots, and the muscle model represents how much a muscle stretches or contracts with a given joint configuration.

The team demonstrates its approach on a battery-operated, motorized prosthetic leg. The battery powers the motors, which turn the joints. The motor movement is dictated by the mathematical algorithm developed by the researchers.

To create this mathematical algorithm, the AMBER research team recorded the muscle activity of a person walking with a prosthesis that followed the desired motion generated with HZD alone. This was done using electromyography (EMG), in which one electrode is placed on the skin above a specific muscle. Then the team analyzed the EMG activity of a person walking with a prosthesis that followed the desired motion generated by HZD combined with the muscle models. The latter more closely resembles how a human walks without a prosthesis.

Lab Earthquakes Show How Grains at Fault Boundaries Lead to Major Quakes

A three-dimensional visualization shows how rock gouge can arrest a rupture (in red) but, with a combination of dynamic stressing and dynamic weakening, will ultimately re-nucleate the rupture shortly thereafter (in blue).
Credit: Vito Rubino / California Institute of Technology

By simulating earthquakes in a lab, Caltech engineers have provided strong experimental support for a form of earthquake propagation now thought responsible for the magnitude-9.0 earthquake that devastated the coast of Japan in 2011.

Along some fault lines, which are the boundaries of tectonic plates, a fine-grained gravel is formed as the plates grind against one another. The influence of this gravel on earthquakes has long been the subject of scientific speculation. In a new paper appearing in the journal Nature the Caltech researchers show that the fine gravel, known as rock gouge, first halts earthquake propagation, but then triggers the rebirth of earthquakes to generate powerful ruptures.

"Our novel experimental approach has enabled us to look into the earthquake process up close, and to uncover key features of rupture propagation and friction evolution in rock gouge," says Vito Rubino, research scientist and lead author of the Nature paper. "One of the main findings of our study is that fault sections previously thought to act as barriers against dynamic rupture may in fact host earthquakes, as a result of the activation of co-seismic friction weakening mechanisms."

Bumps could smooth quantum investigations

Stamping or growing 2D materials onto a patterned surface could create models for 1D systems suitable for the exploration of quantum effects, according to a new theory by Rice University engineers. The “bumps” would manipulate the flow of electrons into bands that mimic 1D semiconductors.
Credit: Yakobson Research Group/Rice University

Atoms do weird things when forced out of their comfort zones. Rice University engineers have thought up a new way to give them a nudge.

Materials theorist Boris Yakobson and his team at Rice’s George R. Brown School of Engineering have a theory that changing the contour of a layer of 2D material, thus changing the relationships between its atoms, might be simpler to do than previously thought.

While others twist 2D bilayers -- two layers stacked together -- of graphene and the like to change their topology, the Rice researchers suggest through computational models that growing or stamping single-layer 2D materials on a carefully designed undulating surface would achieve “an unprecedented level of control” over their magnetic and electronic properties.

They say the discovery opens a path to explore many-body effects, the interactions between multiple microscopic particles, including quantum systems.

The paper by Yakobson and two alumni, co-lead author Sunny Gupta and Henry Yu, of his lab appears in Nature Communications.

An edible QR code takes a shot at fake whiskey

The days of fake whiskey could be numbered, thanks to a team of biomedical engineers from Purdue University and South Korea. The team, led by Young Kim, associate head for research and an associate professor in Purdue’s Weldon School of Biomedical Engineering, has developed an QR code on an edible silk tag that manufacturers can place in bottles of whiskey. Consumers can use a smartphone app to confirm the whiskey’s authenticity. 
Credit: Purdue University photo/John Underwood

In the future, when you order a shot of whiskey, you might ask the bartender to hold an edible fluorescent silk tag that could be found floating inside – even though it is safe to consume.

This little silk tag with a QR code is a security measure that could reveal if the whiskey you’re wanting to buy is fake. Simply using a smartphone to scan the tag, which was developed by biomedical engineers from Purdue University and the National Institute of Agricultural Sciences in South Korea, could confirm the drink’s authenticity.

There are, of course, no tags currently placed in bottles of whiskey. But this new anticounterfeiting technology, published in the journal ACS Central Science, could be a step toward not only finding a solution for the alcohol industry but also addressing fake medications.

“Some liquid medicines contain alcohol. We wanted to test this first in whiskey because of whiskey’s higher alcohol content,” said Young Kim, associate head for research and an associate professor in Purdue’s Weldon School of Biomedical Engineering. “Researchers apply alcohol to silk proteins to make them more durable. Because they tolerate alcohol, the shape of the tag can be maintained for a long time.”

Textile Filter Testing Shows Promise for Carbon Capture

A new design for a filter could help remove carbon dioxide from flue gas emissions and air.
Credit: Sonja Salmon.

North Carolina State University researchers found they could filter carbon dioxide from air and gas mixtures at promising rates using a proposed new textile-based filter that combines cotton fabric and an enzyme called carbonic anhydrase – one of nature’s tools for speeding chemical reactions.

The findings from initial laboratory testing represent a step forward in the development of a possible new carbon capture technology that could reduce carbon dioxide emissions from biomass, coal or natural gas power plants. And while the filter would need to be scaled up in size significantly, the researchers think their design would make that step easier compared with other proposed solutions.

“With this technology, we want to stop carbon dioxide emissions at the source, and power plants are the main source of carbon dioxide emissions right now,” said the study’s lead author Jialong Shen, postdoctoral research scholar at NC State. “We think the main advantage of our method compared to similarly targeted research is that our method could be easily scaled up using traditional textile manufacturing facilities.”

The centerpiece of the research team’s design for a proposed textile-based chemical filter is the naturally occurring enzyme carbonic anhydrase, which can speed a reaction in which carbon dioxide and water will turn into bicarbonate, a compound in baking soda. The enzyme plays an important role in the human body; it helps transport carbon dioxide so it can be exhaled.

Real-time, accurate virus detection method could help fight the next pandemic

Scanning electron microscopy image showing carbon nanotubes (purple) effectively trapping Influenza viruses (light purple round objects). These trapped viruses are then analyzed by Raman spectroscopy and machine learning and they can be identified with accuracies >95%.
Credit: Elizabeth Floresgomez and Yin-Ting Yeh.

A method of highly accurate and sensitive virus identification using Raman spectroscopy, a portable virus capture device and machine learning could enable real-time virus detection and identification to help battle future pandemics, according to a team of researchers led by Penn State.

“This virus detection method is label-free and not aimed at any specific virus, thus enabling us to identify potential new strains of viruses,” said Shengxi Huang, assistant professor of electrical engineering and biomedical engineering and co-author of the study that appeared today (June 2) in the Proceedings of the National Academy of Sciences. “It is also rapid, so suitable for fast screening in crowded public spaces. In addition, the rich Raman features together with machine learning analysis enable a deeper understanding of the virus structures.”

Raman spectroscopy detects unique vibrations in molecules by picking up shifts when a laser light beam induces these vibrations. To capture the viruses, a tool known as a microfluidic device would be used to trap viruses between forests of aligned carbon nanotubes.

Microfluidic devices use very small amounts of body fluids on a microchip to do medical and laboratory tests. Such a device could use virus cultures, saliva, nasal washes, or even exhaled breath, including samples gathered on-site during an outbreak. The carbon nanotubes forests would filter out any foreign substance or background molecules from the host or surrounding air that could make it more difficult to get an accurate reading.

New Artificial Enzyme Breaks Down Tough, Woody Lignin

Researchers Xiao Zhang (L) and Chun-long Chen (R) examine the products of lignin digestion by their novel biomimetic peptoid catalyst.
Photo by Andrea Starr | Pacific Northwest National Laboratory

A new artificial enzyme has shown it can chew through lignin, the tough polymer that helps woody plants hold their shape. Lignin also stores tremendous potential for renewable energy and materials.

Reporting in the journal Nature Communications, a team of researchers from Washington State University and the Department of Energy’s Pacific Northwest National Laboratory showed that their artificial enzyme succeeded in digesting lignin, which has stubbornly resisted previous attempts to develop it into an economically useful energy source.

Lignin, which is the second most abundant renewable carbon source on Earth, mostly goes to waste as a fuel source. When wood is burned for cooking, lignin byproducts help impart that smoky flavor to foods. But burning releases all that carbon to the atmosphere instead of capturing it for other uses.

“Our bio-mimicking enzyme showed promise in degrading real lignin, which is considered to be a breakthrough,” said Xiao Zhang, a corresponding author on the paper and associate professor in WSU’s Gene and Linda Voiland School of Chemical Engineering and Bioengineering. Zhang also holds a joint appointment at PNNL. “We think there is an opportunity to develop a new class of catalysts and to really address the limitations of biological and chemical catalysts.”

Scientists discover new clues to liver cancer progression

A team of researchers from the College of Design and Engineering, the N.1 Institute for Health and the Cancer Science Institute of Singapore at the National University of Singapore has recently engineered in vitro tumor models to better understand the crosstalk between liver cancer cells and their microenvironment. Using lab-grown mini liver tumors co-cultured with endothelial cells – these are cells that form the lining of blood vessels – to conduct their study, the research team investigated the role of endothelial cells in liver cancer progression.

“The conventional understanding is that endothelial cells are structural cells that form blood vessels. Our latest findings suggest that these cells also give ‘instructions’ to liver cancer cells to increase the production of a protein called CXCL1, which is associated with poor survival outcome in liver cancer patients,” explained Assistant Professor Eliza Fong, who led the research study.

CXCL1 is a type of chemokine, which signals proteins secreted by cells to regulate the infiltration of different immune cells into tumors. Hence, these molecules affect tumor immunity and may influence therapeutic outcomes in patients.

“Our results pave the way for new therapeutic targets to control tumor development, and further our team’s understanding of the mechanisms behind the progression of liver cancer,” Dr. Toh Tan Boon added, who is also a key member of the research team.