Ancient ancestors evolved to be strong and snappy, study finds

Dunkleosteus - one of the animals involved in the study.
Credit: Nobu Tamura

Researchers, led by the University of Bristol, have shown that the earliest jaws in the fossil record were caught in a trade-off between maximizing their strength and their speed.

Almost all vertebrates are jawed vertebrates, including humans, first evolving more than 400 million years ago and distinguished by their teeth-bearing jaws. Humans owe their evolutionary success to the evolution of jaws, which allowed animals to process a wider variety of foods.

Jaws evolved from the gill arches, a series of structures in fish that support their gills. A new study, published in the journal Science Advances, explores how a breathing structure came to be a biting structure. To do this, researchers based at Bristol’s School of Earth Sciences collected data on the shapes of fossil jaws during their early evolution and mathematical models to characterize them. These models allowed the team to extrapolate a wide range of theoretical jaw shapes that could have been explored by the first evolving jaws. These theoretical jaws were tested for their strength - how likely they were to break during a bite, and their speed - how efficiently they could be opened and closed. These two functions are in a trade-off – meaning that increasing strength usually means decreasing speed or vice versa.

Effectiveness of antibiotics significantly reduced when multiple bugs present

In the study, published today in The ISME Journal, researchers say that even a low level of one type of microbe in the airways can have a profound effect on the way other microbes respond to antibiotics.

The results highlight the need to consider the interaction between different species of microbe when treating infections with antibiotics - and to adjust dosage accordingly.

“People with chronic infections often have co-infection with several pathogens, but the problem is we don’t take that into account in deciding how much of a particular antibiotic to treat them with. Our results might help explain why, in these people, the antibiotics just don’t work as well as they should,” said Thomas O’Brien, who carried out the research for his PhD in the University of Cambridge’s Department of Biochemistry and is joint first author of the paper.

Chronic bacterial infections such as those in the human airways are very difficult to cure using antibiotics. Although these types of infection are often associated with a single pathogenic species, the infection site is frequently co-colonized by a number of other microbes, most of which are not usually pathogenic in their own right.

Treatment options usually revolve around targeting the pathogen, and take little account of the co-habiting species. However, these treatments often fail to resolve the infection. Until now scientists have had little insight into why this is.

To get their results the team developed a simplified model of the human airways, containing artificial sputum (phlegm) designed to chemically resemble the real phlegm coughed up during an infection, packed with bacteria.

Viagra promising as treatment for canine eating disorder

Cake, a beagle mix, who suffers from the eating disorder known as megaesophagus, sits in specialized chair known as a Bailey chair, at the WSU Veterinary Teaching Hospital. Bailey chairs allow dogs with megaesophagus to better digest their food.
Credit: Washington State University

Sildenafil, the generic version of the drug known as Viagra, could be the long-awaited remedy for a group of dogs with a rare disorder called megaesophagus.

The condition involves an enlargement of the esophagus and a loss of the organ’s ability to move food to the stomach, which leaves food bottling up in the lower esophagus. If left untreated, many animals regurgitate their food and aspirate food into their lungs, causing aspiration pneumonia.

“The literature tells us that many dogs with the disease die from aspiration pneumonia or are humanely euthanized due to poor quality of life within eight months of diagnosis,” said Dr. Jillian Haines, a veterinarian at Washington State University who co-led the study.

Liquid sildenafil was shown to relax the smooth muscle of the lower esophagus so it will open to let food pass to the stomach. Besides some rare gastrointestinal irritation, there are no side effects to dogs at the dose used in the study. While sildenafil is most known to treat erectile dysfunction, the drug is also used to treat elevated pulmonary blood pressure in dogs and humans.

Versatile ‘Nanocrystal Gel’ Could Enable Advances in Energy, Defense and Telecommunications

This graphic shows the material in its gelled state (left) and its non-gelled state (right). When the material is heated (right), the chemical bonds between the nanocrystals break and the gel breaks down. When the material is cooled (left), chemical bonds form between the nanocrystals and they organize themselves into a network (the gel). Molecular bonding(top) that controls gelation as a function of temperature is understood using supercomputer simulations (bottom).
Credit: Kang, Valenzuela, et al./UT Austin

New applications in energy, defense and telecommunications could receive a boost after a team at The University of Texas at Austin created a new type of “nanocrystal gel” — a gel composed of tiny nanocrystals each 10,000 times smaller than the width of a human hair that are linked together into an organized network.

The crux of the team’s discovery is that this new material is easily tunable. That is, it can be switched between two different states by changing the temperature. This means the material can work as an optical filter, absorbing different frequencies of light depending on whether it’s in a gelled state. So, it could be used, for example, on the outside of buildings to control heating or cooling dynamically. This type of optical filter also has applications for defense, particularly for thermal camouflage.

Bacteria upcycle carbon waste into valuable chemicals

Credit: Justin Muir

Bacteria are known for breaking down lactose to make yogurt and sugar to make beer. Now researchers led by Northwestern University and LanzaTech have harnessed bacteria to break down waste carbon dioxide (CO2) to make valuable industrial chemicals.

In a new pilot study, the researchers selected, engineered and optimized a bacteria strain and then successfully demonstrated its ability to convert CO2 into acetone and isopropanol (IPA).

Not only does this new gas fermentation process remove greenhouse gases from the atmosphere, it also avoids using fossil fuels, which are typically needed to generate acetone and IPA. After performing life-cycle analysis, the team found the carbon-negative platform could reduce greenhouse gas emissions by 160% as compared to conventional processes, if widely adopted.

The study was published in the journal Nature Biotechnology.

“The accelerating climate crisis, combined with rapid population growth, pose some of the most urgent challenges to humankind, all linked to the unabated release and accumulation of CO2 across the entire biosphere,” said Northwestern’s Michael Jewett, co-senior author of the study. “By harnessing our capacity to partner with biology to make what is needed, where and when it is needed, on a sustainable and renewable basis, we can begin to take advantage of the available CO2 to transform the bioeconomy.”

Jewett is the Walter P. Murphy Professor of Chemical and Biological Engineering at Northwestern’s McCormick School of Engineering and director of the Center for Synthetic Biology. He co-led the study with Michael Koepke and Ching Leang, both researchers at LanzaTech.

Molecule snapshot by explosion

Scientists use X-rays to trigger a violent explosion of single molecules. From the fragmentation pattern they infer detailed information on the molecule and its fragmentation.
Credit: illustratoren.de/TobiasWuestefeld in cooperation with European XFEL

 An international team of scientists at the European XFEL has taken a snapshot of a cyclic molecule using a novel imaging method. Researchers from the European XFEL, DESY, Universität Hamburg and the Goethe University Frankfurt and other partners used the world's largest X-ray laser to explode the molecule iodopyridine in order to construct an image of the intact molecule from the resulting fragments.

Exploding a photo subject in order to take its picture? An international research team at the European XFEL, the world's largest X-ray laser, applied this “extreme" method to take pictures of complex molecules. The scientists used the ultra-bright X-ray flashes generated by the facility to take snapshots of gas-phase iodopyridine molecules at atomic resolution. The X-ray laser caused the molecules to explode, and the image was reconstructed from the pieces. “Thanks to the European XFEL's extremely intense and particularly short X-ray pulses, we were able to produce an image of unprecedented clarity for this method and the size of the molecule," reports Rebecca Boll from the European XFEL, principal investigator of the experiment and one of the two first authors of the publication in the scientific journal Nature Physics in which the team describes their results. Such clear images of complex molecules have not been possible using this experimental technique until now.

A “hot Jupiter’s” dark side is revealed in detail for first time

An artists’s impression of WASP-121 b.
Credit: Mikal Evans

MIT astronomers have obtained the clearest view yet of the perpetual dark side of an exoplanet that is “tidally locked” to its star. Their observations, combined with measurements of the planet’s permanent day side, provide the first detailed view of an exoplanet’s global atmosphere.

“We’re now moving beyond taking isolated snapshots of specific regions of exoplanet atmospheres, to study them as the 3D systems they truly are,” says Thomas Mikal-Evans, who led the study as a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research.

The planet at the center of the new study, which appears in Nature Astronomy, is WASP-121b, a massive gas giant nearly twice the size of Jupiter. The planet is an ultrahot Jupiter and was discovered in 2015 orbiting a star about 850 light years from Earth. WASP-121b has one of the shortest orbits detected to date, circling its star in just 30 hours. It is also tidally locked, such that its star-facing “day” side is permanently roasting, while its “night” side is turned forever toward space.  

“Hot Jupiters are famous for having very bright day sides, but the night side is a different beast. WASP-121b's night side is about 10 times fainter than its day side,” says Tansu Daylan, a TESS postdoc at MIT who co-authored the study.

Scientists engineer bacteria to cope in challenging environments

Green fluorescent protein (shown in the middle) is used by engineered bacteria as a reserve of amino acids. When nutrients become scarce, the protein can be broken down to provide essential amino acids needed for survival.
Credit: Klara Szydlo and Thomas Gorochowski

Researchers from the Universities of Bristol and Hamburg have engineered bacteria with internal nutrient reserves that can be accessed when needed to survive extreme environmental conditions. The findings, published in ACS Synthetic Biology, pave the way for more robust biotechnologies based on engineered microbes.

Synthetic Biology allows scientists to redesign organisms, harnessing their capabilities to lead to innovative solutions spanning the sustainable production of biomaterials to advanced sensing of pathogens and disease.

Dr Thomas Gorochowski, joint senior author and a Royal Society University Research Fellow in the School of Biological Sciences at Bristol, said: “Many of the engineered biological systems we have created to date are fragile and break easily when removed from the carefully controlled conditions of the lab. This makes their deployment and scale-up difficult.”

To tackle this problem, the team focused on the idea of building up reserves of protein within cells when times are good, and then breaking these down when conditions are difficult and additional nutrients are needed.

Pollination by birds can be advantageous

Photo by Philippe Donn from Pexels

Why have some plant species changed pollinators in their evolution? An international team of researchers from the Universities of Bonn and Xi'an Jiaotong-Liverpool University Suzhou (China) studied the reproductive systems of three sister species pairs, where one species is pollinated by insects and the other by hummingbirds. Mechanisms were discovered that explain the switch from insect to bird pollination. The study has now appeared in the journal Ecology and Evolution.

Different strategies have evolved in the pollination of flowering plants. The frequency and efficiency of the flower visitor plays a role. Here, there are major differences between the various animal groups. Worldwide, insects, especially bees, are the most common pollinators. Bees usually have quite a small activity range while other pollinator groups such as hummingbirds fly much longer distances. "It was previously assumed that plants switch their pollinator group from bees to hummingbirds when the activity and thus the pollination efficiency of bees is too low or too unpredictable, for example in the high mountains," says Dr. Stefan Abrahamczyk of the Nees Institute for Plant Biodiversity at the University of Bonn. For example, in cloud forests of tropical high mountains, it is often too humid or too cold for many bees.

Self-healing materials for robotics made from ‘jelly’ and salt

The low-cost jelly-like materials, developed by researchers at the University of Cambridge, can sense strain, temperature and humidity. And unlike earlier self-healing robots, they can also partially repair themselves at room temperature.

The results are reported in the journal NPG Asia Materials.

Soft sensing technologies could transform robotics, tactile interfaces and wearable devices, among other applications. However, most soft sensing technologies aren’t durable and consume high amounts of energy.

“Incorporating soft sensors into robotics allows us to get a lot more information from them, like how strain on our muscles allows our brains to get information about the state of our bodies,” said David Hardman from Cambridge’s Department of Engineering, the paper’s first author.

As part of the EU-funded SHERO project, Hardman and his colleagues have been working to develop soft sensing, self-healing materials for robotic hands and arms. These materials can detect when they are damaged, take the necessary steps to temporarily heal themselves and then resume work – all without the need for human interaction.

“We’ve been working with self-healing materials for several years, but now we’re looking into faster and cheaper ways to make self-healing robots,” said co-author Dr Thomas George-Thuruthel, also from the Department of Engineering.