Decoding how bacteria talk with each other

Bacillus cereus, SEM image
Credit: Mogana Das Murtey and Patchamuthu Ramasamy, CC BY-SA 3.0

Bacteria, the smallest living organisms in the world, form communities where unified bodies of individuals live together, contribute a share of the property and share common interests.

The soil around a plant’s roots contains millions of organisms interacting constantly — too many busy players to study at once, despite the importance of understanding how microbes mingle.

In a study published in the journal mBio, researchers at the University of Wisconsin–Madison learned that a drastically scaled-down model of a microbial community makes it possible to observe some of the complex interactions. In doing so, they discovered a key player in microbial communication: the presence or absence of an antibiotic compound produced by one of the community members affected the behavior of the other two members.

Little is understood about how individual microbes interact with each other in communities, but that knowledge holds incredible promise.

For example, the bacteria Bacillus cereus can protect plants by producing an antibiotic that deters the pathogen that causes “damping off,” a disease that kills seedlings and is costly to farmers. But biocontrol agents like B. cereus are not always effective. Sometimes plants treated with B. cereus flourish, sometimes they don’t — and researchers are trying to understand why.

New wearable device measures the changing size of tumors below the skin

The FAST system measures tumor size regression and is a new way to test the efficacy of cancer drugs.
  Image credit: Alex Abramson, Bao Group, Stanford University

Electronically sensitive, skin-like membrane can measure changes in tumor size to the hundredth of a millimeter. It represents a new, faster, and more accurate approach to screen cancer drugs.

Engineers at Stanford University have created a small, autonomous device with a stretchable and flexible sensor that can be adhered to the skin to measure the changing size of tumors below. The non-invasive, battery-operated device is sensitive to one-hundredth of a millimeter (10 micrometers) and can beam results to a smartphone app wirelessly in real time with the press of a button.

In practical terms, the researchers say, their device – dubbed FAST for “Flexible Autonomous Sensor measuring Tumors” – represents a wholly new, fast, inexpensive, hands-free, and accurate way to test the efficacy of cancer drugs. On a grander scale, it could lead to promising new directions in cancer treatment. FAST is detailed in a paper published Sept. 16 in Science Advances.

Each year researchers test thousands of potential cancer drugs on mice with subcutaneous tumors. Few make it to human patients, and the process for finding new therapies is slow because technologies for measuring tumor regression from drug treatment take weeks to read out a response. The inherent biological variation of tumors, the shortcomings of existing measuring approaches, and the relatively small sample sizes make drug screenings difficult and labor-intensive.

20 years of AIRS Global Carbon Dioxide (CO₂) measurements

Data visualization of global carbon dioxide (CO₂) for the period September 2002-May 2022, showcasing data products from NASA's Aqua mission 

Visualizations by Helen-Nicole Kostis

This data visualization shows the global distribution and variation of the concentration of mid-tropospheric carbon dioxide observed by the Atmospheric Infrared Sounder (AIRS) on the NASA Aqua spacecraft over a 20-year timespan. One obvious feature that we see in the data is a continual increase in carbon dioxide with time, as seen in the shift in the color of the map from light yellow towards red as time progresses. Another feature is the seasonal variation of carbon dioxide in the northern hemisphere, which is governed by the growth cycle of plants. This can be seen as a pulsing in the colors, with a shift towards lighter colors starting in April/May each year and a shift towards red as the end of each growing season passes into winter. The seasonal cycle is more pronounced in the northern hemisphere than the southern hemisphere, since the majority of the land mass is in the north.

Higher risk of serious COVID-19 complications in children with immunodeficiency

Qiang Pan Hammarström, professor at Karolinska Institutet.
Photo credit: Erik Flyg.

Children with certain immunodeficiency diseases carry mutations in genes that regulate the body’s immune system against viral infections and they have a higher mortality rate due to COVID-19. This is according to a study by researchers from Karolinska Institutet, published in the Journal of Allergy and Clinical Immunology (PDF).

Most children infected with the SARS-CoV-2 coronavirus develop a mild illness or show no symptoms at all. But for a small percentage, serious complications may develop.

“Mortality is much higher among children with primary immunodeficiency diseases infected with SARS-CoV-2. Our results indicate that basic immunological examination and genetic analysis should be conducted in children with severe COVID-19 or multi-inflammatory syndrome (MIS-C). The clinicians will then be able to help these children with more precise therapies based on their genetic changes,” says Qiang Pan-Hammarström, professor at the Department of Biosciences and Nutrition, Karolinska Institutet, who led the study.

How the infection affects patients with primary immunodeficiency diseases, i.e. hereditary and congenital diseases of the immune system, is controversial. Even among these patients, some suffer from severe COVID-19 while others experience mild or no symptoms.

Improved Mineralized Material Can Restore Tooth Enamel

Scientists tested the effectiveness of the new enamel coating on real healthy teeth.
Photo credit: Danil Ilyukhin

Scientists have perfected hydroxyapatite, a material for mineralizing bones and teeth. By adding a complex of amino acids to hydroxyapatite, they were able to form a dental coating that replicates the composition and microstructure of natural enamel. Improved composition of the material repeats the features of the surface of the tooth at the molecular and structural level, and in terms of strength surpasses the natural tissue. The new method of dental restoration can be used to reduce the sensitivity of teeth in case of abrasion of enamel or to restore it after erosion or improper diet. The study and experimental results are published in Results in Engineering.

"Tooth enamel has a protective function, but unfortunately, its integrity can be destroyed by, for example, abrasion, erosion or microfractures. If the surface of the tissue is not repaired in time, the enamel lesion will affect the dentin and then the pulp of the tooth. Therefore, it is necessary to restore the enamel surface to a healthy level or build up additional layers on the surface if it has become very thin. We have created a biomimetic (i.e., mimicking natural) mineralized layer whose nanocrystals replicate the ordering of apatite nanocrystals of tooth enamel. We also found out that the designed layer of hydroxyapatite has increased nanohardness that exceeds that of native enamel," says Pavel Seredin, Leading Specialist of Research and Education Center "Nanomaterials and Nanotechnologies", Ural Federal University, Head of the Department of Solid State Physics and Nanostructures at Voronezh State University.

Mexican mangroves have been capturing carbon for 5,000 years

Unusual forests on stilts mitigate climate change
Credit: Ramiro Arcos Aguilar/UCSD

Researchers have identified a new reason to protect mangrove forests: they’ve been quietly keeping carbon out of Earth’s atmosphere for the past 5,000 years.

Mangroves thrive in conditions most plants cannot tolerate, like salty coastal waters. Some species have air-conducting, vertical roots that act like snorkels when tides are high, giving the appearance of trees floating on stilts.

A UC Riverside and UC San Diego-led research team set out to understand how marine mangroves off the coast of La Paz, Mexico, absorb and release elements like nitrogen and carbon, processes called biogeochemical cycling.

As these processes are largely driven by microbes, the team also wanted to learn which bacteria and fungi are thriving there.

The team expected that carbon would be found in the layer of peat beneath the forest, but they did not expect that carbon to be 5,000 years old. This result, along with a description of the microbes they identified, is now published in the journal Marine Ecology Progress Series.

Hitting the bullseye

Flexible: Electronic circuits on a film of polyimide from the Empa laboratory form synaptic transistors.
 Image: Empa

In the FOXIP project, researchers from Empa, EPFL and the Paul Scherrer Institute attempted to print thin-film transistors with metal oxides onto heat-sensitive materials such as paper or PET. The goal was ultimately not achieved, but those involved consider the project a success – because of a new printing ink and a transistor with "memory effect".

The bar was undoubtedly set high: In the research project Functional Oxides Printed on Polymers and Paper – FOXIP for short – the goal was to succeed in printing thin-film transistors on paper substrates or PET films. Electronic circuits with such elements play an important role in the growing Internet of Things (IoT), for example as sensors on documents, bottles, packaging ... – a global market worth billions.

If it were feasible to manufacture such transistors with inorganic metal oxides, this would open up a plethora of new possibilities. Compared with organic materials such as the semiconducting polymer polythiophene, explains project leader Yaroslav Romanyuk from Empa's Laboratory for Thin Films and Photovoltaics, the electrons in these materials are much more mobile. They could therefore significantly increase the performance of such elements and would not need to be protected against air and moisture with expensive encapsulation.

Researchers at SLAC use purified liquid xenon to search for mysterious dark matter particles

 Xenon purification system at SLAC. The two central columns are each filled with almost half a ton of charcoal, which is used to produce ultra-clean xenon for the LUX-ZEPLIN (LZ) dark matter experiment.
Resized Image using AI by SFLORG
Credit: Jacqueline Ramseyer Orrell/SLAC National Accelerator Laboratory

Sitting a mile below ground in an abandoned gold mine in South Dakota is a gigantic cylinder holding 10 tons of purified liquid xenon closely watched by more than 250 scientists around the world. That tank of xenon is the heart of the LUX-ZEPLIN (LZ) experiment, an effort to detect dark matter – the mysterious invisible substance that makes up 85% of the matter in the universe.

“People have been searching for dark matter for over 30 years, and no one has had a convincing detection yet,” said Dan Akerib, professor of particle physics and astrophysics at the Department of Energy’s (DOE) SLAC National Accelerator Laboratory. But with the help of scientists, engineers, and researchers around the globe, Akerib and his colleagues have made the LZ experiment one of the most sensitive particle detectors on the planet.

To reach that point, SLAC researchers built on their expertise in working with liquid nobles – the liquid forms of noble gases such as xenon – including advancing the technologies used to purify liquid nobles themselves and the systems for detecting rare dark matter interactions within those liquids. And, Akerib said, what researchers have learned will aid not only the search for dark matter, but also other experiments searching for rare particle physics processes.

“These are really profound mysteries of nature, and this confluence of understanding the very large and very small at the same time is very exciting,” Akerib said. “It’s possible we could learn something completely new about nature.”

Lockheed Martin Delivers Its Highest-Powered Laser to Date to U.S. Department of Defense

U.S. Army’s Indirect Fires Protection Capability-High Energy Laser (IFPC-HEL) Demonstrator laser weapon system.
Image credit: Lockheed Martin.

Lockheed Martin delivered to the Office of the Under Secretary of Defense for Research & Engineering OUSD (R&E) a new benchmark: a tactically-relevant electric 300 kW-class laser, the most powerful laser that Lockheed Martin has produced to date. This 300 kW-class laser is ready to integrate with the DOD demonstration efforts including the U.S. Army’s Indirect Fires Protection Capability-High Energy Laser (IFPC-HEL) Demonstrator laser weapon system.

The OUSD (R&E) selected Lockheed Martin in 2019 to scale its spectral beam combined high energy laser architecture to the 300 kW-class level as part of the High Energy Laser Scaling Initiative (HELSI), and the team recently achieved that milestone ahead of schedule.

“Lockheed Martin increased the power and efficiency and reduced the weight and volume of continuous-wave high energy lasers which reduces risk for future fielding efforts of high-power laser weapon systems,” said Rick Cordaro, vice president, Lockheed Martin Advanced Product Solutions.

The HELSI laser will support demonstration efforts with the Army’s IFPC-HEL, which is scheduled for laboratory and field testing this year.

Cells from miniature pigs are paving the way for improved stem cell therapies.

A breed of pigs called Wisconsin Miniature Swine — created by a team of UW–Madison scientists — will help researchers better model and understand human diseases.
Credit: Jeff Miller

A team led by University of Wisconsin–Madison Stem Cell & Regenerative Medicine Center researcher Wan-Ju Li offers an improved way to create a particularly valuable type of stem cell in pigs – a cell that could speed the way to treatments that restore damaged tissues for conditions from osteoarthritis to heart disease in human patients.

In a study published in Scientific Reports, Li’s team also provides insights into the reprogramming process that turns cells from one part of the body into pluripotent stem cells, a type of building block cell that can transform into any type of tissue. These new insights will help researchers study treatments for a wide range of diseases.

The researchers turned to pigs, a well-established animal model for potential human treatments, because translating research to improve human health is deeply important to Li, a professor of Orthopedics and Rehabilitation and Biomedical Engineering. He has spent much of his career studying cartilage and bone regeneration to develop innovative therapies to help people.

Li and members of his Musculoskeletal Biology and Regenerative Medicine Laboratory obtained skin cells from the ears of three different breeds of miniature pigs — Wisconsin miniature swine, Yucatan miniature swine and Göttingen minipigs.