Important additional driver of insect decline identified

The grape wood borer (Chlorophorus varius) is one of over 33,000 insect species in Germany. The development of the insect biomass depends significantly on weather conditions, as a study published in "Nature" in 2023 shows.
Photo Credit: Didier Descouens
(CC BY-SA 3.0)

Combinations of unfavorable weather conditions over several years can cause a decline in insect biomass. This is shown by a study published in "Nature" with TUD being involved.

Insects react sensitively when temperature and precipitation deviate from the long-term average. In an unusually dry and warm winter, their survival probabilities are reduced; in a wet and cold spring, hatching success is impaired. A cool, wet summer hampers bumblebees and other flying insects from reproducing and foraging.

If several such weather anomalies occur in combination and over several years, this can lead to a decline in insect biomass on a large scale and in the long term. This is shown in a new report in the journal Nature.

According to the report, weather conditions and accumulations of unfavorable weather anomalies in the course of climate change can be important drivers of global insect decline. Only insect populations with a large number of individuals, as found in sufficiently large and high-quality habitats, appear to be able to survive under such adverse conditions.

Saturated fat may interfere with creating memories in aged brain

The study in cell cultures found the omega-3 fatty acid DHA, found in fish and a common supplement, may help protect the brain from an unhealthy diet’s effects by curbing fat-induced inflammation at the cellular source.
Photo Credit: Leohoho

New research hints at a few ways fatty foods affect cells in the brain, a finding that could help explain the link between a high-fat diet and impaired memory – especially as we age.

The Ohio State University study in cell cultures found the omega-3 fatty acid DHA may help protect the brain from an unhealthy diet’s effects by curbing fat-induced inflammation at the cellular source. 

Separate experiments using brain tissue from aging mice showed a high-fat diet may lead specific brain cells to overdo cell-signaling management in a way that interferes with the creation of new memories. 

The same lab found in an earlier study in aging rats that a diet of highly processed ingredients led to a strong inflammatory response in the brain that was accompanied by behavioral signs of memory loss – and that DHA supplementation prevented those problems. 

“The cool thing about this paper is that for the first time, we’re really starting to tease these things apart by cell type,” said senior author Ruth Barrientos, an investigator in Ohio State’s Institute for Behavioral Medicine Research and associate professor of psychiatry and behavioral health and neuroscience in the College of Medicine. 

Tree rings reveal a new kind of earthquake threat to the Pacific Northwest

Price Lake, in the eastern Olympic Mountains, formed when the Saddle Mountain fault impounded a stream and flooded the forest. Lead author Bryan Black and his team of divers collected the samples using an underwater hydraulic chainsaw.
Photo Credit: Bryan Black

In February, a 7.8-magnitude earthquake shook the Turkey-Syria border, followed by one nearly as large nine hours later. Shallow faults less than 18 miles beneath the surface buckled and ruptured, causing violent focused quakes that leveled thousands of buildings and killed tens of thousands.

Similar shallow faults ruptured about 1,000 years ago in the Puget Lowlands in western Washington, according to new University of Arizona-led research. Tree rings helped pinpoint that the seismic event occurred in late A.D. 923 or early 924. Their findings mean that a repeat event has the potential to again shake the region that is now home to over 4 million people, including Seattle, Tacoma and Olympia. The results were published in the journal Science Advances.

The ancient quake was either the result of all the shallow faults in the region rupturing together to produce an estimated 7.8-magnitude earthquake or – like in Turkey and Syria – twin quakes that occurred back-to-back with estimated magnitudes of 7.5 and 7.3, researchers found. Shallow faults typically result in more violent and focused shaking than earthquakes generated from other geological configurations.

How the Heart Starts Beating

Researchers were surprised to discover that heart cells in developing zebrafish abruptly start beating all at once, and quickly become regular. Here, heart cells are labeled with green fluorescent protein, which becomes brighter when calcium levels spike during each heartbeat.
Image Credit: Bill Jia

Becoming a full-fledged organism out of a handful of cells, complete with functioning tissues and organs, is a messy yet highly synchronized process that requires cells to organize themselves in a precise manner and begin working together.

This process is especially dramatic in the heart, where static cells must start beating in perfect unison.

Now, a cross-school collaboration led by researchers at Harvard Medical School and Harvard University has provided a glimpse into exactly how cells in the heart start beating.

In a study conducted in zebrafish, the team discovered that heart cells start beating suddenly and all at once as calcium levels and electrical signals increase. Moreover, each heart cell has the ability to beat on its own, without a pacemaker, and the heartbeat can start in different places, the researchers discovered. The findings are published Sep. 27 in Nature.

Extreme Weight Loss: Star Sheds Unexpected Amounts of Mass Just Before Going Supernova

Artist's conception of pre-explosion mass loss by the progenitor star of SN 2023ixf. In the year prior to going supernova the red supergiant star now known as SN 2023ixf shed an unexpected amount of mass equivalent to the mass of the Sun. This artist's conception illustrates what the final stages of mass loss might have looked like before the star exploded. 
Illustration Credit: Melissa Weiss/CfA

A newly discovered nearby supernova whose star ejected up to a full solar mass of material in the year prior to its explosion is challenging the standard theory of stellar evolution. The new observations are giving astronomers insight into what happens in the final year prior to a star’s death and explosion.

SN 2023ixf is a new Type II supernova discovered in May 2023 by amateur astronomer Kōichi Itagaki of Yamagata, Japan shortly after its progenitor, or origin star, exploded. Located about 20 million light-years away in the Pinwheel Galaxy, SN 2023ixf's proximity to Earth, the supernova's extreme brightness, and its young age make it a treasure trove of observable data for scientists studying the death of massive stars in supernova explosions.

Type II or core-collapse supernovae occur when red supergiant stars at least eight times, and up to about 25 times the mass of the Sun, collapse under their own weight and explode. While SN 2023ixf fits the Type II description, follow-up multi-wavelength observations led by astronomers at the Center for Astrophysics | Harvard & Smithsonian (CfA), and using a wide range of CfA's telescopes, have revealed new and unexpected behavior.

Tiny CRISPR tool could help shred viruses

Model of a minimal CRISPR-Cas13bt3 molecule generated with a cryo-electron microscope. The RNA to be recognized and cleaved is colored in light blue, while the scissor is formed by the magenta and cyan colored domains. The two loops for controlling the CRISPR-Cas13bt3 are shown in green and red.
 Illustration Credit: Courtesy of the Yang Gao lab/Rice University

Small and precise: These are the ideal characteristics for CRISPR systems, the Nobel-prize winning technology used to edit nucleic acids like RNA and DNA.

Rice University scientists have described in detail the three-dimensional structure of one of the smallest known CRISPR-Cas13 systems used to shred or modify RNA and employed their findings to further engineer the tool to improve its precision. According to a study published in Nature Communications, the molecule works differently than other proteins in the same family.

“There are different types of CRISPR systems, and the one our research was focused on for this study is called CRISPR-Cas13bt3,” said Yang Gao, an assistant professor of biosciences and Cancer Prevention and Research Institute of Texas Scholar who helped lead the study. “The unique thing about it is that it is very small. Usually, these types of molecules contain roughly 1200 amino acids, while this one only has about 700, so that’s already an advantage.”

Atlantic walrus more vulnerable than ever to Artic warming

Photo Credit: Rod Long

Past cycles of climate change, along with human exploitation, have led to only small and isolated stocks of Atlantic walrus remaining. The current population is at high risk of the same issues affecting them severely, according to a new study led by Lund University in Sweden.

Today, the last remaining stocks of Atlantic walrus are more at danger than ever, due to a combination of Arctic warming and a long history of devastating human exploitation. Rising global temperatures are significantly impacting Arctic marine ecosystems and their inhabitants. However, little is known about exactly how this combination of stress factors will impact Arctic species.

Now, researchers have examined how walrus coped with past cycles of climate change. Using breakthroughs in ancient genomics, the team was able to extract, sequence and interpret ancient genetic information contained in teeth and bone that survive well in the Arctic’s frozen archaeological sites. These DNA results were integrated with modern genetic samples, enabling them to reconstruct how the genetic diversity of Atlantic walrus had changed under earlier cycles of global warming.

Understanding bacterial motors may lead to more efficient nanomachine motors

The FliG protein in the "bacterial motor"
Illustration Credit: Atsushi Hijikata, Yohei Miyanoiri, Osaka University

A research group led by Professor Emeritus Michio Homma (he, him) and Professor Seiji Kojima (he, him) of the Graduate School of Science at Nagoya University, in collaboration with Osaka University and Nagahama Institute of Bio-Science and Technology, have made new insights into how locomotion occurs in bacteria. The group identified the FliG molecule in the flagellar layer, the ‘motor’ of bacteria, and revealed its role in the organism. These findings suggest ways in which future engineers could build nanomachines with full control over their movements. They published the study in iScience. 

As nanomachines become smaller, researchers are taking inspiration from microscopic organisms for ways to make them move and operate. In particular, the flagellar motor can rotate clockwise and counterclockwise at a speed of 20,000 rpm. If scaled up, it would be comparable to a Formula One engine with an energy conversion efficiency of almost 100% and the capacity to change its rotation direction instantly at high speeds. Should engineers be able to develop a device like a flagellar motor, it would radically increase the maneuverability and efficiency of nanomachines. 

Curtin study suggests rare echidna noises could be the ‘language of love’

Echidnas, sometimes known as spiny anteaters, are quill-covered monotremes (egg-laying mammals) belonging to the family Tachyglossidae
Photo Credit: Emmanuel Higgins

Curtin University researchers have captured rare recordings of echidnas cooing, grunting and making a range of other sounds, but only during the breeding season.

Lead author Dr Christine Cooper, from Curtin’s School of Molecular and Life Sciences, said there had been ongoing scientific debate around the ability of echidnas to vocalize as a way of communicating or if the sounds they make are simply sniffing noises related to breathing.

“We observed wild short-beaked echidnas at Dryandra National Park, near Narrogin, Western Australia, making cooing and grunting sounds, in addition to the wheezing and exhalation noises that the animals are known to make,” Dr Cooper said.

“Our team managed to capture some of these sounds with hand-held microphones as well as a camera and microphone left unattended at the entrance to a cave popular with echidnas.

Could RNA folding play a role in the origin of life?

New research in membaneless compartments that model protocells reveals that naturally occurring chemical modifications to RNA molecules help them fold better into functional structures. Image of the structures of tRNA molecules from protocells determined by high-throughput sequencing using tRNA structure-seq are overlaid on and image of the membraneless compartments made through liquid-liquid phase separation.
(CC BY-NC-ND 4.0)
Image Credit: Bevilacqua and Keating Labs / Penn State.

New research in model protocells reveals naturally occurring chemical modifications to RNA molecules help them properly fold into functional structures

To investigate potential early steps taken by the first life to develop on Earth, researchers have been studying a model of pre-life protocells comprising membraneless compartments. Now, a team of Penn State scientists have found that RNA molecules within these compartments fold better when they have naturally occurring chemical modifications. These modifications that allow for better folding in RNAs may offer a hint into how the molecules evolved from arbitrary chemical compounds to the dynamic, organized building blocks of life. The new study, published by a team of Penn State scientists in the journal Science Advances, used high-throughput genetic sequencing to determine the structure of the RNAs, which also has implications for the design of delivery methods for RNA-based therapeutics that rely on properly folded RNAs to function.