. Scientific Frontline

Tuesday, October 31, 2023

Sets of neurons work in sync to track ‘time’ and ‘place,’ giving humans context for past, present and future

Illustration Credit: MasterTux

Two studies led by UCLA researchers offer new insights into the way neurons in the human brain represent time and space – the most basic ingredients of consciousness of human existence and the primary dimensions of experience that allow us to reconstruct the past and envision the future.

The new findings are based on recordings of the activity of single neurons in the brain, from studies led by Dr. Itzhak Fried, a neurosurgeon and researcher at the UCLA David Geffen School of Medicine, is the senior author of two articles in Cell Reports. Patients who had undergone surgical placement of special depth electrodes developed and implanted by Fried for surgical treatment of intractable epilepsy agreed to perform cognitive tasks while their brain cell activity is recorded for these studies.

Neurons that act as the brain’s GPS system – termed “place cells” and “grid cells” – were discovered initially in rodents, similar findings later described in humans by Fried and colleagues at UCLA in collaboration with Dr. Michael Kahana, professor of Psychology at the University of Pennsylvania and a co-senior author of one of the new studies. The brain’s clock cells, or “time cells,” were identified in more recent years.

New genes linked to ADHD identified potentially paving the way for new treatments

Image Credit: Braňo

Several new genes associated with conditions such as Attention-deficit hyperactivity disorder (ADHD) have been identified, unearthing a significant connection between these disorders and our immune system that could lead to new treatments. The research from the University of Surrey also confirms the role of gene ADGRL3 in conditions such as ADHD, giving scientists a greater understanding of its workings.

During this innovative study, scientists led by Dr Matt Parker from Surrey set out to understand more about ADGRL3, a gene closely linked to ADHD and other ‘externalizing’ disorders, in promoting behaviors such as substance abuse, which can be associated with the conditions. Through this work, scientists identified several new genes related to externalizing disorders, which could lead to the development of new medication to lessen the impact on individuals.

DNA organization influences the growth of deadly brain tumors in response to neuronal signals

Silvia Remeseiro
Photo Credit: Mattias Pettersson

A pioneering study at Umeå University, Sweden, has unveiled that the 3D organization of DNA can influence the progression of the aggressive brain tumor known as glioblastoma. Having identified the factors that glioblastoma uses to respond to neurons by growing and spreading, this discovery paves the way for further research into new treatments for brain tumors.

"We have now identified the most important factors behind how the tumor responds to nerve cells, thus becoming more dangerous. These findings offer hope in our long-term battle against this difficult-to-treat cancer, for which the prognosis has not improved in decades," comments Silvia Remeseiro, Wallenberg fellow at WCMM, Assistant Professor at Umeå University, and lead author of the study.

Glioblastoma is the most fatal type of brain tumor among adults and there is currently no curative treatment. Glioblastoma patients typically face a survival of roughly one-year post-diagnosis. Even following current treatment regimes, which include surgery, radiotherapy and chemotherapy, a mere four per cent of patients are still alive five years after diagnosis.

Pinpointing HIV immune response

HIV, the AIDS virus (yellow), infecting a human cell
Image Credit: National Cancer Institute

New research combining computer modeling and experiments with macaques shows the body’s immune system helps control human immunodeficiency virus (HIV) infections largely by suppressing viral production in already infected cells while also killing viral infected cells, but only within a narrow time window at the start of a cell’s infection.

“To eliminate HIV, we have to understand how the immune system attempts to control the infection,” said Ruy M. Ribeiro, a theoretical biologist at Los Alamos National Laboratory who led the development of the model underpinning the research. Ribeiro is the corresponding author of the paper about the findings, published in Nature Communications.

The research team included Los Alamos Senior Fellow Alan S. Perelson and a former Los Alamos postdoctoral researcher now at the Fred Hutchinson Cancer Research Center. Their collaborators at the University of Pittsburg managed the experiments with macaques infected with simian immunodeficiency virus (SIV) to validate the model. SIV infections in monkeys behave the same way as HIV in humans.

Giant planets cast a deadly pall

Artist's depiction of a star system that is crowded with giant planets.
Illustration Credit: NASA/Dana Berry

Giant gas planets can be agents of chaos, ensuring nothing lives on their Earth-like neighbors around other stars. New studies show, in some planetary systems, the giants tend to kick smaller planets out of orbit and wreak havoc on their climates. 

Jupiter, by far the biggest planet in our solar system, plays an important protective role. Its enormous gravitational field deflects comets and asteroids that might otherwise hit Earth, helping create a stable environment for life. However, giant planets elsewhere in the universe do not necessarily protect life on their smaller, rocky planet neighbors. 

A new Astronomical Journal paper details how the pull of massive planets in a nearby star system are likely to toss their Earth-like neighbors out of the “habitable zone.” This zone is defined as the range of distances from a star that is warm enough for liquid water to exist on a planet’s surface, making life possible.

Unlike most other known solar systems, the four giant planets in HD 141399 are farther from their star. This makes it a good model for comparison with our solar system where Jupiter and Saturn are also relatively far from the sun.  

“It’s as if they have four Jupiters acting like wrecking balls, throwing everything out of whack,” said Stephen Kane, UC Riverside astrophysicist and author of the journal paper. 

Researchers observe wolves hunting and killing sea otters and harbor seals on Alaska’s Katmai coast

Wolf with a sea otter on Alaska's Katmai coast.
Photo Credit: Kelsey Griffin

Firsthand observations of a wolf hunting and killing a harbor seal and a group of wolves hunting and consuming a sea otter on Alaska’s Katmai coast have led scientists to reconsider assumptions about wolf hunting behavior.

Wolves have previously been observed consuming sea otter carcasses, but how they obtain these and the frequency of scavenging versus hunting marine prey is largely unknown. Scientists at Oregon State University, the National Park Service and Alaska Department of Fish and Game are beginning to change that with a paper just published in Ecology.

In the paper, they describe several incidents they observed involving wolves and marine mammals in Katmai National Park that they believe haven’t been previously documented:

The importance of the Earth's atmosphere in creating the large storms that affect satellite communications

Illustration Credit: ERG Science Team

A study from an international team led by researchers from Nagoya University in Japan and the University of New Hampshire in the United States has revealed the importance of the Earth’s upper atmosphere in determining how large geomagnetic storms develop. Their findings reveal the previously underestimated importance of the Earth’s atmosphere. Understanding the factors that cause geomagnetic storms is important because they can have a direct impact on the Earth’s magnetic field such as causing unwanted currents in the power grid and disrupting radio signals and GPS. This research may help predict the storms that will have the greatest consequences. 

Scientists have long known that geomagnetic storms are associated with the activities of the Sun. Hot charged particles make up the Sun's outer layer, the one visible to us. These particles flow out of the Sun creating the ‘solar wind’, and interact with objects in space, such as the Earth. When the particles reach the magnetic field surrounding our planet, known as the magnetosphere, they interact with it. The interactions between the charged particles and magnetic fields lead to space weather, the conditions in space that can affect the Earth and technological systems such as satellites.  

Monday, October 30, 2023

Window to avoid 1.5°C of warming rapidly closing

Photo Credit: Patrick Hendry / altered by Scientific Frontline

Humanity is rapidly reaching the limit for how much additional carbon can be emitted into the atmosphere to keep global warming within 1.5 °C, according to new research.

If emissions stay at current day levels, what is known as the "remaining carbon budget" will be exhausted before the end of the decade. 

Dr Chris Smith, climate modeler and a research fellow in the School of Earth and Environment at Leeds, co-authored the study.  He said: “This study gives the most updated measure of how much more carbon dioxide humanity can continue to put into the atmosphere to give us a fifty per cent chance of staying within the 1.5 °C threshold agreed at international climate talks.  

"If we continue to emit carbon dioxide at current levels, we will exhaust that remaining 1.5°C carbon budget in just six years.   

“This is not to say that we only have ‘six years to save the planet’, because 1.5°C is not a hard boundary of when climate change will suddenly become much worse. However, damages, risks and the likelihood of exceeding physical and ecological tipping points increase sharply with continued warming.  

Study Suggests Epigenetic Age May Predict Memory Function Better Than Actual Age

The Stony Brook research team investigating epigenetic age acceleration hope to understand more about the biological and environmental factors related to it. From left: Daisy V. Zavala, Stacey Scott and Krishna Veeramah.
Photo Credit: John Griffin, Stony Brook University

A study led by researchers at Stony Brook University shows that age acceleration, when one’s so-called biological clock runs quicker than one’s actual age, is linked to poorer memory and slower rates of processing information. The team measured biological “clocks” derived from the DNA of 142 adults aged 25-65 years old and had the participants complete daily cognitive tests on smartphones. Their findings, which imply that epigenetic age acceleration could be a better indicator of how well a person remembers information and how quickly they work with information, are detailed in the Journal of Gerontology: Biological Sciences.

There are well-known chronological age differences in cognitive performance — on average, younger adults tend to remember more information and respond more quickly than older adults. One presumed explanation is biological wear-and-tear across life, but until recently, there was not a way to test biological aging to explain these differences between younger and older people.

Aging researchers currently have significant interest in examining epigenetic patterns that change how the DNA in our cells fold and how genes behave. Unlike our DNA genome, which stays the same throughout our lifetime in every cell of our body, our epigenome can change through time and can be influenced by our behavior and environment. These epigenetic changes can thus indicate a person’s biological age, which may differ from chronological age.

To advance space colonization, WVU research explores 3D printing in microgravity

WVU engineering students and Microgravity Research Team members Renee Garneau, Trenton Morris and Ronan Butts test a 3D printer the MRT lab has designed to operate in weightless environments like a spaceship, the moon or Mars.
Photo Credit: Brian Persinger / West Virginia University

Research from West Virginia University students and faculty into how 3D printing works in a weightless environment aims to support long-term exploration and habitation on spaceships, the moon or Mars.

Extended missions in outer space require the manufacture of crucial materials and equipment onsite, rather than transporting those items from Earth. Members of the Microgravity Research Team said they believe 3D printing is the way to make that happen.

The team’s recent experiments focused on how a weightless microgravity environment affects 3D printing using titania foam, a material with potential applications ranging from UV blocking to water purification. ACS Applied Materials and Interfaces published their findings.

“A spacecraft can’t carry infinite resources, so you have to maintain and recycle what you have and 3D printing enables that,” said lead author Jacob Cordonier, a doctoral student in mechanical and aerospace engineering at the WVU Benjamin M. Statler College of Engineering and Mineral Resources. “You can print only what you need, reducing waste. Our study looked at whether a 3D-printed titanium dioxide foam could protect against ultraviolet radiation in outer space and purify water. 

New Frequency Comb Can Identify Molecules in 20-Nanosecond Snapshots

A new frequency comb setup can capture the moment-by-moment details of carbon dioxide gas escaping from a nozzle at supersonic speeds in an air-filled chamber, followed by rapid oscillations of gas due to complex aerodynamics within the chamber. The data plot shows the absorbance of light (vertical) over time (horizontal left to right) across a range of frequencies (horizontal forward to back).
Illustration Credit: G. Mathews/University of Colorado Boulder

From monitoring concentrations of greenhouse gases to detecting COVID in the breath, laser systems known as frequency combs can identify specific molecules as simple as carbon dioxide and as complex as monoclonal antibodies with unprecedented accuracy and sensitivity. Amazing as they are, however, frequency combs have been limited in how fast they can capture a high-speed process such as hypersonic propulsion or the folding of proteins into their final three-dimensional shapes.

Now, researchers at the National Institute of Standards and Technology (NIST), Toptica Photonics AG and the University of Colorado Boulder have developed a frequency comb system that can detect the presence of specific molecules in a sample every 20 nanoseconds, or billionths of a second. With this new capability, researchers can potentially use frequency combs to better understand the split-second intermediate steps in fast-moving processes ranging from the workings of hypersonic jet engines to the chemical reactions between enzymes that regulate cell growth. The research team announced its results in a paper published in Nature Photonics.

Bowel cancer: aspirin activates protective genes

Photo Credit: günter

Colorectal cancer (bowel cancer) is the third most common form of cancer worldwide, with around 1.9 million newly diagnosed cases and 900,000 deaths every year. Therefore, preventive substances represent an urgent clinical need. Aspirin/acetylsalicylic acid has proven to be one of the most promising candidates for the prevention of colorectal cancer. Among other findings, studies have shown that when patients with cardiovascular diseases took low doses of aspirin over several years, it reduced their risk of colorectal cancer. Furthermore, aspirin can inhibit the progression of colorectal cancer. Now a team led by Heiko Hermeking, Professor of Experimental and Molecular Pathology at LMU, has investigated which molecular mechanisms mediate these effects.

As the researchers report in the journal Cell Death and Disease, aspirin induces the production of two tumor-suppressive microRNA molecules (miRNAs) called miR-34a and miR-34b/c. To do this, aspirin binds to and activates the enzyme AMPK, which in turn alters the transcription factor NRF2 such that it migrates into the cell nucleus and activates the expression of the miR-34 genes. For this activation to succeed, aspirin additionally suppresses the oncogene product c-MYC, which otherwise inhibits NRF2.

New strategies needed to help banana farmers recover from climate shocks

Photo Credit: Jonas Von Werne

Extreme weather events and the globalized nature of food production puts smallholder farmers at risk of ‘double exposure’ of production and market loss, according to a new study.

Researchers including from the University of Exeter, University of Oxford and ETH Zurich, examined the Global Food Value Chain (GFVC) – an international network of stakeholders involved in food production, processing, distribution, retailing and consumption – of bananas grown in the Dominican Republic, the UK’s most important supplier of organic bananas.

They found that smallholder farmers hit by hurricane-induced flooding faced not only the loss of production but also a loss of market access for their undamaged produce, and called for new strategies to tackle the aftermath of climate shocks.

The researchers integrated satellite, household survey and trade data to investigate the impacts of two consecutive hurricanes (Hurricanes Irma and Maria in 2017) and subsequent flooding on smallholder banana farmers in Dominican Republic and what factors determined their recovery from such events.

Weekly insulin injections have the potential to be as effective

Photo Credit: Peter Stanic

Insulin icodec, a once-weekly basal injection to treat type 1 diabetes, has the potential to be as effective in managing the condition as daily basal insulin treatments, according to research from the University of Surrey. The results of the year-long phase 3 clinical trial could revolutionize the future of diabetes care and help millions of people better manage their condition. 

During this pioneering study, scientists across 12 countries at 99 sites, led by Professor David Russell-Jones from Surrey, tested the efficacy and safety of a weekly basal injection of icodec (a long-lasting type of insulin) and compared it to a daily basal injection of insulin degludec in adults with type 1 diabetes. Short acting insulin to cover meals was used in both groups. 

Professor David Russell-Jones, Professor of Diabetes and Endocrinology at the University of Surrey and a Consultant at the Royal Surrey Foundation Trust, said: 

"Many people find managing a long-term condition such as diabetes very difficult and report missing vital insulin injections. Missed injections can affect glycaemic control, and a lack of consistency in the treatment has been linked to increased rates of diabetic ketoacidosis, a serious complication of the condition that can be life-threatening. Reducing insulin injection frequency could lessen the burden of treatment for some people with the condition and improve their glycaemic control." 

Type 1 diabetes occurs when the body cannot produce enough of the hormone insulin, causing the level of glucose (sugar) in the blood to become too high, leading to an increased risk of developing heart, eye, and kidney disease. 

To learn more about the efficacy of icodec, scientists recruited 582 participants with type 1 diabetes. Participants were split into two groups; the first received once-weekly injections of icodec (700U/ml), and the second received daily injections of degludec (100 U/ml), both in combination with aspart, a short-acting insulin at mealtimes. 

After 26 weeks, scientists identified HbA1C (a protein within red blood cells with glucose attached to it and the universal marker for overall diabetes control) levels in those who had taken icodec had decreased from a mean of 7.59 percent at baseline to an estimated mean of 7.15 percent, and for degludec, the mean had decreased from 7.63 percent to 7.10 percent. The estimated treatment difference between them being 0.05 percent, confirming the non-inferiority of icodec to degludec, but with a significantly reduced injection frequency for patients to manage. 

 Scientists did also identify higher rates of hypoglycemic episodes (abnormally low levels of glucose in the blood) in the icodec group compared to degludec. However, despite the higher levels in the icodec group, scientists noted that incidences were low in both groups, with most episodes only requiring oral carbohydrate administration. For icodec, time below 3.0 mmol/L was at the threshold of the internationally recommended targets during weeks 22-26 and below recommended targets during weeks 48-52.  

 Professor Russell-Jones added: 

 "What we have found is that once-weekly icodec injections showed non inferiority to once-daily injections of degludec in reducing HbA1C after 26 weeks. Although there is a slightly higher rate of hypoglycaemia under this regime, we found this could be easily managed. We’ve concluded this new insulin may have a role in reducing the burden of daily basal injections for patients managing type 1 diabetes. 

 "Our findings are very promising, but further analysis of continuous glucose monitoring data and real-world studies are needed." 

Funding: Provided by Novo Nordisk. 

Published in journalThe Lancet

Source/CreditUniversity of Surrey

Reference Number: phar103023_01

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Humans have substantially altered the relationship between wolves and deer

A breeding female wolf traveling on a logging road carrying a deer fawn back to her pups in June 2023.
 Photo Credit: Voyageurs Wolf Project

New research from the University of Minnesota’s Voyageurs Wolf Project found that human activities in northern Minnesota — logging, road and trail creation, and infrastructure development — have profoundly impacted where wolves hunt and kill deer fawns. By altering forest ecosystems, humans have created an environment that possibly favors predators. 

This research, recently published in Ecological Applications, is a collaboration between the University of Minnesota, Northern Michigan University, the University of Manitoba, Voyageurs National Park, and the Voyageurs Wolf Project. The Voyageurs Wolf Project is funded, in part, by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR). 

“The premise is really quite simple: human activities change where deer are on the landscape, and wolves go where the deer are,” said co-lead author Thomas Gable, a postdoctoral researcher at the University of Minnesota and project lead for the Voyageurs Wolf Project. 

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