Photosynthesis, Key to Life on Earth, Starts with a Single Photon

A cutting-edge experiment has revealed the quantum dynamics of one of nature’s most crucial processes
Illustration Credit: Jenny Nuss/Berkeley Lab

Using a complex cast of metal-studded pigments, proteins, enzymes, and co-enzymes, photosynthetic organisms can convert the energy in light into the chemical energy for life. And now, thanks to a study published today in Nature, we know that this organic chemical reaction is sensitive to the smallest quantity of light possible – a single photon.

The discovery solidifies our current understanding of photosynthesis and will help answer questions about how life works on the smallest of scales, where quantum physics and biology meet.

“A huge amount of work, theoretically and experimentally, has been done around the world trying to understand what happens after a photon is absorbed. But we realized that nobody was talking about the first step. That was still a question that needed to be answered in detail,” said co-lead author Graham Fleming, a senior faculty scientist in the Biosciences Area at Lawrence Berkeley National Laboratory (Berkeley Lab) and professor of chemistry at UC Berkeley.

In their study, Fleming, co-lead author Birgitta Whaley, a senior faculty scientist in the Energy Sciences Area at Berkeley Lab, and their research groups showed that a single photon can indeed initiate the first step of photosynthesis in photosynthetic purple bacteria. Because all photosynthetic organisms use similar processes and share an evolutionary ancestor, the team is confident that photosynthesis in plants and algae works the same way. “Nature invented a very clever trick,” Fleming said.

Plate tectonics not required for the emergence of life

Plate tectonics involves the horizontal movement and interaction of large plates on Earth’s surface. New research indicates that mobile plate tectonics—thought to be necessary for the creation of a habitable planet—was not occurring on Earth 3.9 billion years ago.
Illustration Credit: Michael Osadciw / University of Rochester

The finding contradicts previous assumptions about the role of mobile plate tectonics in the development of life on Earth.

Scientists have taken a journey back in time to unlock the mysteries of Earth’s early history, using tiny mineral crystals called zircons to study plate tectonics billions of years ago. The research sheds light on the conditions that existed in early Earth, revealing a complex interplay between Earth’s crust, core, and the emergence of life.

Plate tectonics allows heat from Earth’s interior to escape to the surface, forming continents and other geological features necessary for life to emerge. Accordingly, “there has been the assumption that plate tectonics is necessary for life,” says John Tarduno, who teaches in the Department of Earth and Environmental Sciences at the University of Rochester. But new research casts doubt on that assumption.

New Clues About Origin of Complex Life Trace Roots to Common Ancestor

According to this latest study, all complex life forms (a.k.a. eukaryotes) trace their roots back to a common ancestor among a group of microbes called the Asgard archaea.
Illustration Credit: The University of Texas at Austin.

Thor, the legendary Norse god from the mythological city of Asgard, is not alone. According to groundbreaking research published in the journal Nature, we humans — along with eagles, starfish, daisies and every complex organism on Earth — are, in a sense, Asgardians.

Analyzing the genomes of hundreds of different microbes called archaea, researchers at The University of Texas at Austin and other institutions have discovered that eukaryotes — complex life forms with nuclei in their cells, including all the world’s plants, animals, insects and fungi — trace their roots to a common Asgard archaean ancestor. That means eukaryotes are, in the parlance of evolutionary biologists, a “well-nested clade” within Asgard archaea, similar to how birds are one of several groups within a larger group called dinosaurs, sharing a common ancestor. The team has found that all eukaryotes share a common ancestor among the Asgards.

No fossils of eukaryotes have been found from farther back than about 2 billion years ago, suggesting that before that, only various types of microbes existed.

“So, what events led microbes to evolve into eukaryotes?” said Brett Baker, UT Austin associate professor of integrative biology and marine science. “That’s a big question. Having this common ancestor is a big step in understanding that.”

New Insights into the Liquid Core of Mars

The RISE instrument on the InSight lander (artist’s concept).
Image Credit: NASA/JPL-Caltech.

New results from the radio-science instrument of the NASA InSight mission on Mars are published today in the scientific journal Nature. With the data accumulated during the first two and a half years of the mission, a team of planetary scientists mainly from the Royal Observatory of Belgium has precisely measured the rotation of Mars. They detected a signature that can only be explained by the presence of a liquid core. These variations in rotation provide important information about the deep interior of Mars.

In November 2018, the NASA InSight mission successfully touched down in the region of Elysium Planitia on the surface of Mars. As suggested by its acronym (Interior exploration using Seismic Investigations, Geodesy, and Heat Transport), this mission was the first of its kind, dedicated to the exploration of the deep interior of Mars. InSight was equipped with a seismometer and a radio-science transponder named RISE (Rotation and Interior Structure Experiment). The mission concluded in December 2022.

The RISE experiment was specifically designed to measure the nutations of Mars. Nutations are the periodic oscillations, also called wobbles, of the spin axis in space. Sébastien Le Maistre, the lead author explains: “The RISE transponder has the ability to establish communication with gigantic (up to 70 m dish) radio-telescopes on Earth and of measuring the tiniest variations of the distance between a lander on Mars and Earth, caused by the orbital and rotational movements of the two planets. For the first time, we detected at such a large distance, hundreds of millions of km, the 40 cm oscillations due to the presence of the Martian liquid core. These oscillations are affected by a resonant behavior that only occurs when the core is liquid.”

Scientists Discover Small RNA That Regulates Bacterial Infection

Pseudomonas aeruginosa clumps grown in synthetic cystic fibrosis sputum.
Image Credit: Courtesy of Georgia Institute of Technology

People with weakened immune systems are at constant risk of infection. Pseudomonas aeruginosa, a common environmental bacterium, can colonize different body parts, such as the lungs, leading to persistent, chronic infections that can last a lifetime – a common occurrence in people with cystic fibrosis.

But the bacteria can sometimes change their behavior and enter the bloodstream, causing chronic localized infections to become acute and potentially fatal. Despite decades of studying the transition in lab environments, how and why the switch happens in humans has remained unknown.

However, researchers at the Georgia Institute of Technology have identified the major mechanism behind the transition between chronic and acute P. aeruginosa infections. Marvin Whiteley – professor in the School of Biological Sciences and Bennie H. and Nelson D. Abell Chair in Molecular and Cellular Biology – and Pengbo Cao, a postdoctoral researcher in Whiteley’s lab, discovered a gene that drives the switch. By measuring bacterial gene expression in human tissue samples, the researchers identified a biomarker for the transition.

Their research findings, published in Nature, can inform the development of future treatments for life-threatening acute infections.

A New Magnetizable Shape Memory Alloy with Low Energy Loss, Even at Low Temperatures

Image Credit: Scientific Frontline

Shape memory alloys (SMA) remember their original shape and return to it after being heated. Similar to how a liquid transforms into a gas when boiled, SMAs undergo a phase transformation when heated or cooled. The phase transformation occurs with the movement of atoms, which is invisible to the naked eye.

SMAs are utilized in a diverse array of applications, including as actuators and sensors. However, the need to cool or heat SMAs means there is a delay in their phase transformation.

As a recently invented type of SMA, metamagnetic shape memory alloys (MMSMA) negate this limited response rate thanks to their ability to undergo phase transformation when exposed to an external magnetic field. Yet to date, MMSMAs have failed to solve another common problem with most SMAs: the fact that they lose a large amount of energy when phase transforming - something that worsens substantially in low temperatures.

Alcohol harm reduction can also reduce other substance use

Photo Credit: cottonbro studio

Quitting alcohol or drugs was not a top priority for people experiencing homelessness in a harm reduction treatment study, yet participants still reduced their use of both.

A different approach than traditional abstinence-based programs, harm reduction treatment for alcohol use disorder, also called HaRT-A, has patients set their own goals. In a study of 308 people experiencing homelessness, the participants receiving harm reduction treatment set goals of meeting basic needs and improving quality of life well above quitting alcohol and other substances.

Yet harm reduction treatment still led to more reduced use compared to a control group who received regular services. The findings are detailed in the Journal of Addiction Medicine.

“It’s a good reminder that all people have the same basic goals: we all want to be safer, healthier and happier, and when we help people experiencing homelessness achieve those goals, they might end up doing the things that treatment providers want them to do anyway,” said Susan Collins, a Washington State University psychology professor and the study’s senior author. “They might end up cutting down their use; they might end up quitting, but it’s on their own terms and their own timeline, so it’s more sustainable.”

Collins and first author Nicki Mostofi analyzed data from an earlier clinical study focused on harm reduction and alcohol use. That study involved people with alcohol use disorder from three Seattle homeless shelters who were divided into different groups: one received harm reduction treatment alone, another treatment with naltrexone which reduces alcohol cravings, and a third group had the treatment and a placebo. A fourth control group received traditional services.

Towards the New-Space Era with Foldable Phased-Array Transmitters for Small Satellites

A foldable phased-array transmitter for LEO satellites By varying the number of liquid crystal polymer layers, the proposed design incorporates foldable creases, contributing to a smaller form factor and lower weight.
Photo Credit: Courtesy of Tokyo Institute of Technology

A new design for a foldable phased-array transmitter can help make satellites lightweight, smaller, and cost-efficient to launch, report scientists at Tokyo Tech. The transmitter is made of stacked layers of liquid crystal polymer and incorporates flexible creases, which provide flexibility and deployability. The new design could make research and implementation of space technologies more accessible to private companies and startups.

By varying the number of liquid crystal polymer layers, the proposed design incorporates foldable creases, contributing to a smaller form factor and lower weight.

There has been a recent shift in the space industry towards what is now called the "new-space era." The term refers to how space is no longer dominated exclusively by government agencies such as NASA but has instead become a playground for many private companies and startups interested in exploring and deploying space technologies. While this opens up a vast ocean of possibilities for space research, exploration, and telecommunications, launching satellites remains an expensive endeavor.

In general, low earth orbit (LEO) satellites are both low cost and low latency. However, modern antenna designs for LEO satellites are heavy, leading to a trade-off between making satellites compact and achieving a large antenna aperture for better performance. Such issues increase launch costs significantly and are regarded as major hurdles to overcome in the new-space era.

A marine mystery: finding the link between climate change and sea sponge loss

The latest findings suggest that thermal stress disturbs sponge-microbes symbiosis, which likely causes the sponge to die.
Photo Credit: Heidi Luter.

Microbes could hold the key to explaining how climate change affects sea sponges, warn scientists from UNSW Sydney. 

Sea sponges are essential to marine ecosystems. They play critical roles in the ocean, as they provide shelter and food to a plethora of marine creatures, recycle nutrients by filtering thousands of liters of sea water daily, and are hosts to microbes that may be the key to some of the most pressing medical challenges we face today. 

Now, scientists from UNSW have discovered that when a tropical sea sponge is exposed to warmer temperatures, it loses an important microbe, which could explain why the sponge tissue dies.  

The latest study, published in ISME Communications, has revealed that by exposing sea sponges to a temperature increase of 3°C, one essential microbe abandons the sponge, potentially causing tissue poisoning.   

The collaboration between researchers from UNSW, Heidi Luter from the Australian Institute of Marine Science and James Bell from the Victoria University of Wellington, has added an important piece to the puzzle on the impact of climate change on sponge populations around the world. 

Paleontologists Discovered Unique Remains of Paleogene Reptiles in the Urals

Rare remains have been found in the Sverdlovsk and Kurgan Regions
Photo Credit: Courtesy of Ural Federal University

At the river Miass (Kurgan Region) paleontologists of the Ural Branch of the Institute of Ecology of Animals and Plants of the Russian Academy of Sciences and the Ural Federal University discovered rare for the Urals and Siberia finds - vertebrae of a sea snake and a piece of a turtle shell. Approximate dating of bones - 45-35 million years, but the exact figures have not yet been established. The findings were sent to the Paleontological Institute of the Russian Academy of Sciences in Moscow for further research.

"This is the second such unique find, and we were lucky to study both of them. The fact is that fossil remains of Paleogene snakes from the territory of Western and Eastern Europe, the Caucasus, and Central Asia are quite well described, but such finds are not known in the Urals and Western Siberia. Last year we managed to find a vertebra of a sea snake on the Dernei River in the Sverdlovsk Region. This year, our friend and paleontology enthusiast Alexey Sofrygin showed us a snake vertebra from a new spot - the Miass River. Unfortunately, we did not find any other vertebrae when we conducted a complete study of the Miass River sediments. However, we did find a piece of a turtle shell. This is also an extremely rare find," says Dmitry Gimranov, Head of Research, Senior Researcher at the Laboratory of Natural Science Methods in Humanities of the Ural Federal University.