Researchers identify new molecular mechanism key to planarian regeneration

These flatworms are capable of regenerating any part of their bodies, even their heads.
Photo Credit: Teresa Adell.

Planaria are freshwater flatworms that have become a key model for studying regeneration and stem cells, as they can regenerate any part of the body, even the head. But how does the animal know what part of its body is missing and what kind of tissue it needs to regenerate? Researchers from the Department of Genetics, Microbiology and Statistics of the University of Barcelona and the Institute of Biomedicine of the UB (IBUB) have studied the regeneration process of these animals and have identified how the modulation of the intercellular signaling pathway Wnt modifies chromatin, the set of genetic material that cells own in the cell nucleus. A few hours after an amputation, this mechanism lets the wound stem cells know the fate of the new tissue.

The study, published in the journal Nature Communications, involves researchers from the Andalusian Centre for Developmental Biology (CABD), the Pablo de Olavide University in Seville and the University of East Anglia (Norwich, England).

Four classes of planetary systems

Artist impression of the four classes of planetary system architecture. A new architecture framework allows researchers to study an entire planetary system at the systems level. If the small planets within a system are close to the star and massive planets further away, such systems have ‘Ordered’ architecture. Conversely, if the mass of the planets in a system tends to decrease with distance to the star these systems are ‘Anti-Ordered’. If all planets in a system have similar masses, then the architecture of this system is ‘Similar’. ‘Mixed’ planetary systems are those in which the planetary masses show large variations. Research suggests that planetary systems which have the same architecture class have common formation pathways.
Illustration Credit: © NCCR PlanetS / Tobias Stierli

Astronomers have long been aware that planetary systems are not necessarily structured like our solar system. Researchers from the Universities of Bern and Geneva, as well as from the National Centre of Competence in Research PlanetS, have now shown for the first time that there are in fact four types of planetary systems. This classification will allow scientists to study planetary systems as a whole and to compare them with other systems. The results can be found in the journal Astronomy and Astrophysics.

In our solar system, everything seems to be in order: The smaller rocky planets, such as Venus, Earth or Mars, orbit relatively close to our star. The large gas and ice giants, such as Jupiter, Saturn or Neptune, on the other hand, move in wide orbits around the sun. In two studies published in the scientific journal Astronomy & Astrophysics, researchers from the Universities of Bern and Geneva and the National Centre of Competence in Research (NCCR) PlanetS show that our planetary system is quite unique in this respect. 

Lung cancer study finds new target for treatment resistance after EGFR inhibitors

Monique Nilsson, Ph.D. | John Heymach, M.D., Ph.D.
Photo Credit: Courtesy of University of Texas M. D. Anderson Cancer Center

Researchers at The University of Texas MD Anderson Cancer Center have identified CD70 as being highly expressed on drug-resistant cancer cells in EGFR-mutant non-small cell lung cancer (NSCLC), highlighting a novel therapeutic target that could be used to eliminate resistant cells remaining after treatment with commonly used EGFR tyrosine kinase inhibitors (TKIs). The study published today in Cancer Cell.

The preclinical research was led by Monique Nilsson, Ph.D., and corresponding author John Heymach, M.D., Ph.D., chair of Thoracic/Head and Neck Medical Oncology. The researchers discovered that CD70, a cell surface protein normally found on immune cells, is highly overexpressed in resistant cells as well as in the residual cancer cells immediately following TKI treatment. They demonstrated that CD70 can be effectively used to target these cells with antibody-drug conjugates (ADCs) or cell therapies in laboratory models.

“Residual cancer cells left over from TKI treatment are essentially a reservoir from which future resistant cells eventually grow,” Heymach said. “These findings set the stage for a really promising approach in which we may give initial effective therapies and immediately follow them with these CD70-targeting drugs to eliminate the remaining residual cells.”

Urban birds prefer native trees

Urban great tits prefer native trees for breeding
Photo Credit: Sandra Alekseeva

Small passerine birds, such as blue and great tits, avoid breeding in urban areas where there are many non-native trees. Chicks also weigh less the more non-native trees there are in the vicinity of the nest. This is shown in a long-term study from Lund University in Sweden.

City trees contribute to several important ecosystem services such as lowering local temperature and purifying air but are also homes to birds and insects. Vegetation, especially trees, is the primary managed biological component of a city’s ecosystem. It is therefore important to understand the consequences of our planning of parks and green spaces. To find out how different types of trees affect birdlife, a research team, led by Lund University, monitored 400 nest boxes in five parks in the Swedish city Malmö over a seven-year period.

The results, now published in the scientific journal, Oecologia, show that native trees – defined in the study as species that have been in the ecosystem for at least 700 years – provide more resources and are preferred by urban birds.

Researchers solve a 150-year-old mystery

A reconstruction - of the aetosaur assemblage in its habitat.
Illustration Credits: © J. Kowalski (drawing) and P. Janecki (coloring)

The Aetosaurs had a small head and a crocodile-like body. The land dwellers were up to six meters long and widely distributed geographically. They died out about 204 million years ago, at the end of the Triassic. In Kaltental near Stuttgart, Germany, an assemblage of 24 Aetosaurus ferratus individuals, only between 20 and 82 centimeters long, was discovered in 1877. Since then, scientists have been puzzling over whether they were juveniles or small adults. A team led by Elżbieta M. Teschner from the University of Bonn has now solved the mystery: Bone examination of two specimens shows that they are juveniles. The results have now been published in the Journal of Vertebrate Paleontology.

Reptiles of the genus Aetosaurus ferratus were discovered in a quarry near Kaltental, now a district of Stuttgart, and were first described nearly 150 years ago. The assemblage of about 24 individuals was dated to be about 215 million years old. "What was striking was that the total body length was only between 20 and 82 centimeters," says Elżbieta M. Teschner, who is pursuing a doctorate in paleontology at the University of Bonn while also conducting research at the University of Opole (Poland). "Interestingly, they were also the only fossils found in the area," she adds.

A sense of purpose may have significant impact on teens' emotional well-being

Educational psychology professor Kaylin Ratner found in a study of more than 200 adolescents that feeling a sense of purpose had a significant impact on their emotional well-being. Those who scored high on purposefulness were more satisfied with their lives and experienced more positive emotions in general. 
Photo Credit: Fred Zwicky

Adolescents who feel a greater sense of purpose may be happier and more satisfied with life than peers who feel less purposeful, suggests a recent study of more than 200 teens.

Studies with adults have suggested that a sense of purpose in life is an integral component of well-being that fuels hope and optimism and has a variety of positive effects on individuals’ physical and mental health.

However, less is known about the effects of purposefulness in adolescents, who, while characteristically hopeful, are in the throes of developing their identities, making choices that reflect who they are and aspire to be, according to the study.

Educational psychology professor Kaylin Ratner of the University of Illinois Urbana-Champaign led the current study, which examined how youths’ feelings of purposefulness related to their daily levels of life satisfaction and subjective well-being.

‘Magic’ solvent creates stronger thin films

This micrograph image shows an initiated chemical vapor deposition coating made by doctoral student Pengyu Chen in the lab of Rong Yang, assistant professor in the Smith School of Chemical and Biomolecular Engineering in Cornell Engineering.
Image Credit: Courtesy of the researchers 

A new all-dry polymerization technique uses reactive vapors to create thin films with enhanced properties, such as mechanical strength, kinetics and morphology. The synthesis process is gentler on the environment than traditional high-temperature or solution-based manufacturing and could lead to improved polymer coatings for microelectronics, advanced batteries and therapeutics.

“This scalable technique of initiated chemical vapor deposition polymerization allows us to make new materials, without redesigning or revamping the whole chemistry. We just simply add an ‘active’ solvent,” said Rong Yang, assistant professor in the Smith School of Chemical and Biomolecular Engineering in Cornell Engineering. “It’s a little bit like a Lego. You team up with a new connecting piece. There’s a ton you can build now that you couldn’t do before.”

Yang collaborated on the project with Jingjie Yeo, assistant professor in the Sibley School of Mechanical and Aerospace Engineering, and Shefford Baker, associate professor of materials science and engineering.

VISTA X-62 Advancing Autonomy and Changing the Face of Air Power

The X-62A VISTA Aircraft flying above Edwards Air Force Base, California.
Photo Credit: Kyle Brasier, U.S. Air Force

The Lockheed Martin VISTA X-62A, a one-of-a-kind training aircraft, was flown by an artificial intelligence agent for more than 17 hours recently, representing the first time AI engaged on a tactical aircraft.

VISTA, short for Variable In-flight Simulation Test Aircraft, is changing the face of air power at the U.S. Air Force Test Pilot School (USAF TPS) at Edwards Air Force Base in California.

VISTA is a one-of-a-kind training airplane developed by Lockheed Martin Skunk Works® in collaboration with Calspan Corporation for the USAF TPS. Built on open systems architecture, VISTA is fitted with software that allows it to mimic the performance characteristics of other aircraft.

"VISTA will allow us to parallelize the development and test of cutting-edge artificial intelligence techniques with new uncrewed vehicle designs," said Dr. M. Christopher Cotting, U.S. Air Force Test Pilot School director of research. "This approach, combined with focused testing on new vehicle systems as they are produced, will rapidly mature autonomy for uncrewed platforms and allow us to deliver tactically relevant capability to our warfighter."

Ingestible sensor could help doctors pinpoint GI difficulties

MIT engineers have shown that they can use magnetic fields to track the location of this ingestible sensor within the GI tract.
Photo Credit: Courtesy of the researchers / Massachusetts Institute of Technology

Engineers at MIT and Caltech have demonstrated an ingestible sensor whose location can be monitored as it moves through the digestive tract, an advance that could help doctors more easily diagnose gastrointestinal motility disorders such as constipation, gastroesophageal reflux disease, and gastroparesis.

The tiny sensor works by detecting a magnetic field produced by an electromagnetic coil located outside the body. The strength of the field varies with distance from the coil, so the sensor’s position can be calculated based on its measurement of the magnetic field.

In the new study, the researchers showed that they could use this technology to track the sensor as it moved through the digestive tract of large animals. Such a device could offer an alternative to more invasive procedures, such as endoscopy, that are currently used to diagnose motility disorders.

“Many people around the world suffer from GI dysmotility or poor motility, and having the ability to monitor GI motility without having to go into a hospital is important to really understand what is happening to a patient,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women’s Hospital.

Efficient technique improves machine-learning models’ reliability

Researchers from MIT and the MIT-IBM Watson AI Lab have developed a new technique that can enable a machine-learning model to quantify how confident it is in its predictions, but does not require vast troves of new data and is much less computationally intensive than other techniques.
Image Credit: MIT News, iStock
Creative Commons Attribution Non-Commercial No Derivatives license

Powerful machine-learning models are being used to help people tackle tough problems such as identifying disease in medical images or detecting road obstacles for autonomous vehicles. But machine-learning models can make mistakes, so in high-stakes settings it’s critical that humans know when to trust a model’s predictions.

Uncertainty quantification is one tool that improves a model’s reliability; the model produces a score along with the prediction that expresses a confidence level that the prediction is correct. While uncertainty quantification can be useful, existing methods typically require retraining the entire model to give it that ability. Training involves showing a model millions of examples so it can learn a task. Retraining then requires millions of new data inputs, which can be expensive and difficult to obtain, and also uses huge amounts of computing resources.

Researchers at MIT and the MIT-IBM Watson AI Lab have now developed a technique that enables a model to perform more effective uncertainty quantification, while using far fewer computing resources than other methods, and no additional data. Their technique, which does not require a user to retrain or modify a model, is flexible enough for many applications.