Gravity-defying spike waves rewrite the rule book

The ‘spike wave’ created in the FloWave circular wave tank
Credit: University of Oxford

Researchers studying wave breaking have found that axisymmetric ‘spike waves' can far exceed limits that were previously thought to dictate the maximum height of ocean waves.

In a new study on ocean wave breaking, researchers have demonstrated that the breaking behavior of axisymmetric ‘spike waves’ is quite different to the long-established theories on the breaking of traveling waves.

Travelling waves break when waves become so steep that the crest is no longer stable. This leads to a breakdown of wave motion and energy loss. As a result, the height of the wave is limited by the breaking process.

‘Much of our understanding of wave breaking is routed in theories developed and experiments carried out in two dimensions when waves are moving in one direction,’ explained lead author Dr Mark McAllister, Department of Engineering Science, University of Oxford. ‘However, wave breaking in the ocean is a three-dimensional process.’

On the road to the super-battery

Dr. Anatoliy Senyshyn mounts a sample to analyze neutrons at the structure powder diffractometer SPODI at the Heinz Maier-Leibnitz Zentrum.
Credit: Bernhard Ludewig, FRM II /TUM

A research team led by the Technical University of Munich (TUM) has taken an in-depth look at the internal workings of batteries during charging and discharging. Their findings may help optimize charging processes.

When an electric car is being charged, the charge indicator moves quickly at first, then much more slowly at the end. "It's like putting things into a closet: In the beginning it's easy, but finding available space gets more difficult as the closet fills up," says Dr. Anatoliy Senyshyn from the Technical University of Munich's Research Neutron Source Heinz Maier-Leibnitz (FRM II).

The internal structure of a battery both before and after the charging process is already known. Led by the Heinz Maier-Leibnitz Zentrum (MLZ) at TUM, a research team has now observed for the first time a battery's lithium distribution during the entire charging and discharging process with the materials science diffractometer STRESS-SPEC. They then verified the measurements using the high-resolution powder diffractometer SPODI.

Interpreting underwater symphonies

Dr Hari Vishnu has researched on underwater soundscapes from the tropical waters of Singapore to the icy Arctic.
Credit: National University of Singapore

“The ocean is far less explored than we think. In fact, we know less about the depths of Earth’s oceans than we know about the surface of the Moon or Mars!” says Dr Hari Vishnu, Senior Research Fellow at the Acoustic Research Laboratory under the NUS Tropical Marine Science Institute, who listens to underwater sounds to discover the immense world beneath the waves.

“I study the use of sound to sense and understand underwater environments such as the ocean. Sound travels longer distances under water than light, and tells us a lot about what is happening in the ocean. I use sound-based sensing for diverse applications such as assessing Singapore’s marine biodiversity and the presence of marine mammals like dolphins and dugongs, improving capabilities of sonars used in defense applications, and deep-sea resource assessment,” shared Dr Vishnu.

With an academic background in computer engineering, as well as electrical and electronic engineering, Dr Vishnu was drawn to this area of research by his desire to make an impact on the under-explored world of the oceans: “Life originated in the oceans that cover more than 70 percent of the Earth, yet I feel it is underappreciated how crucial oceans are in determining its climate and supporting human survival. So, during my PhD, I decided to jump into this broad domain of ocean engineering. I specialized in studying how to process ocean sounds to interpret them and learn more about the ocean.”

Earth’s magnetic poles not likely to flip

Credit: ESA/ATG medialab

The emergence of a mysterious area in the South Atlantic where the geomagnetic field strength is decreasing rapidly, has led to speculation that Earth is heading towards a magnetic polarity reversal. However, a new study that pieces together evidence stretching back 9,000 years, suggests that the current changes aren’t unique, and that a reversal may not be in the cards after all. The study is published in PNAS.

The Earth’s magnetic field acts as an invisible shield against the life-threatening environment in space, and solar winds that would otherwise sweep away the atmosphere. However, the magnetic field is not stable, and at irregular intervals at an average of every 200,000 years polarity reversals happen. This means that the magnetic North and South poles swap places.

During the past 180 years, Earth’s magnetic field strength has decreased by about 10 percent. Simultaneously, an area with an unusually weak magnetic field has grown in the South Atlantic off the coast of South America. This area, where satellites have malfunctioned several times due to exposure to highly charged particles from the sun, is called the South Atlantic Anomaly. These developments have led to speculation that we may be heading for a polarity reversal. However, the new study suggests this may not be the case

Colossal collisions linked to solar system science

In this composite image of Abell 2146, Chandra X-ray data (purple) shows hot gas, and Subaru Telescope optical data shows galaxies (red and white).
Credit: Chandra X-ray / NASA

A new study shows a deep connection between some of the largest, most energetic events in the universe and much smaller, weaker ones powered by our own Sun.

The results come from a long observation with NASA’s Chandra X-ray Observatory of Abell 2146, a pair of colliding galaxy clusters located about 2.8 billion light-years from Earth. The new study was led by Helen Russell from the School of Physics and Astronomy and has been published online by The Monthly Notices of the Royal Astronomical Society

Galaxy clusters contain hundreds of galaxies and huge amounts of hot gas and dark matter and are among the largest structures in the universe. Collisions between galaxy clusters release enormous amounts of energy unlike anything witnessed since the big bang and provide scientists with physics laboratories that are unavailable here on Earth.

The shock wave is about 1.6 million light-years long and is most easily seen in a version of the X-ray image that has been processed to emphasize sharp features. Also labeled are the central core of hot gas in cluster #2, and the tail of gas it has left behind. A second shock wave of similar size is seen behind the collision. Called an “upstream shock,” features like this arise from the complex interplay of stripped gas from the infalling cluster and the surrounding cluster gas. The brightest and most massive galaxy in each cluster is also labeled.

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.

Locking Leukemia’s Cellular Escape Hatch

Kris Wood, PhD, associate professor of
Pharmacology and Cancer Biology

Leukemia starts in cells that would normally develop into different types of blood cells. About 61,000 people in the U.S. are diagnosed each year, and depending on the type of leukemia and the age of the patient, five-year survival rates vary between about 20-80%.

After losing a close friend to an aggressive form of leukemia, acute myeloid leukemia (AML), Kris Wood, PhD, associate professor of pharmacology and cancer biology, devoted his research to helping find better treatment options for people with leukemias and lymphomas. He and his colleagues have discovered a potential new drug therapy that is preparing to enter clinical trials.

A new class of drugs called nuclear exportin inhibitors has recently been approved for use to treat cancers. Nuclear exportins are proteins that shuttle other proteins out of the nucleus of a cell. These new drugs stop the shuttle from leaving the station.

“The idea is that if you treat cells with a drug that blocks a nuclear exportin,” Wood said, “its client proteins become trapped in the nucleus.” And while researchers don’t fully understand why this is therapeutic, it works. Wood and his team investigated the mechanisms behind it. Their results were published in Nature Cancer.

First, they treated AML cells with Selinexor, a nuclear exportin inhibitor. At the same time, they used CRISPR screens to knock out thousands of genes across the genome one at a time to identify genes that made the drug work either much better or much worse when knocked out.

Equine eye docs help horse regain sight

Willy was diagnosed with equine recurrent uveitis, a common but harmful complex autoimmune disease among horses. After treatment, Willy regained most of his vision and has a high quality of life.
Source: Provided to Cornell University

Willy, a 3-year-old quarter horse, has a goofy personality and loves to spend time with his many chicken friends at owner Mariah Kauffman’s home in Snyder County, Pennsylvania.

Soon after Willy joined their family, however, Kauffman noticed that every once in a while, his eyes would cloud over, then appear clear the next day. “He started bumping into things and getting cuts on his face,” Kauffman said. “He would run into the fence and spooked easily.”

That’s when she decided to call Willy’s veterinarian, Dr. Jacqueline Rapp of Susquehanna Valley Veterinary.

Rapp quickly referred Willy to the Cornell Equine Hospital for specialty care from Dr. Kelly Knickelbein, assistant clinical professor, alongside ophthalmology residents Dr. Irini Lamkin and Dr. Brittany Schlesener.

The Cornell team diagnosed him with equine recurrent uveitis (ERU), a common but harmful complex autoimmune disease among horses, with both genetic and environmental factors.

study finds living near trails reduces risk for heart disease

The Northeast Pioneers Greenway Is One of the Four Multi-Use Trails in Winnipeg That Was Studied in the Research Project. 
Photo Courtesy of Winnipeg Trails Association

A University of Manitoba-led study found that living close to a trail used for walking, running and cycling leads to an eight per cent reduction in the risk factors for heart disease.

“If you build it, they will come, and maybe even live longer,” said Dr. Jon McGavock, professor of pediatrics and child health at the Max Rady College of Medicine, Rady Faculty of Health Sciences.

The study looked at four multi-use trails in Winnipeg – the Yellow Ribbon Greenway, Northeast Pioneers Greenway, Transcona Trail and Southside Greenway. The trails ranged from four to seven kilometers and are in largely suburban areas.

The study, published in the International Journal of Behavioral Nutrition and Physical Activity, found that the 20 kilometers of trails attracted 5,000 cyclists every week. This added up to 1.6 million cycling trips over a five-year period.

“Since the trails were built in 2012, that adds up to 4,000 to 7,000 fewer Winnipeggers living with a risk factor for heart disease,” said McGavock, who is also an investigator with the Children’s Hospital Research Institute of Manitoba. “Importantly, this health benefit was greatest for people living along the Southside Greenway, the busiest trail.”

Common drug-resistant superbug develops fast resistance to 'last resort' antibiotic

Pseudomonas under a microscope
Credit: Sean Booth

New research has found that Pseudomonas bacterium develops resistance much faster than usual to a common ‘last-resort’ antibiotic.

A study published today in Cell Reports reveals how populations of a bacterium called Pseudomonas respond to being treated with Colistin, a 'last resort' antibiotic for patients who have developed multi-drug resistant infections.

Antibiotics play a key role in human health by helping to combat bacterial infection, but bacteria can evolve resistance to antibiotics patients rely on. Antibiotic-resistant infections now cause >1 million deaths worldwide per year.

With a small number of ‘last-resort’ antibiotics available, researchers from the University of Oxford are investigating the processes that drive the rise, and fall, of resistance in common bacterial pathogen populations, which is key to tackling the increase in antimicrobial resistance (AMR).