Humans can distinguish odors with millisecond precision, study shows

OCT. 14, 2024, by Chinese Academy of Sciences

https://medicalxpress.com/news/2024-10-humans-distinguish-odors-millisecond-precision.html

Airborne chemical compounds are drawn into the nose with each sniff we take. Our olfactory apparatus resolves their fine dynamics within each sniff, forming a temporal code that gives rise to our varying odor perceptions over time. 

Credit: Mr. Wu Yuli & Dr. Zhou Wen

When we inhale, airborne chemicals enter our nose, creating the "odor" we detect. These chemicals are then expelled when we exhale. Each breath lasts 3–5 seconds, which seems to limit how quickly we can perceive odors. Chemical changes that occur within a single breath appear to be combined into one odor. Because of this, our sense of smell, or olfaction, is often considered a slow sense.

Now, however, researchers led by Dr. Zhou Wen from the Institute of Psychology of the Chinese Academy of Sciences have challenged this view. Their study, published in Nature Human Behaviour, shows that human olfactory perception can detect fine chemical changes within the duration of a single sniff.

Dr. Zhou's team developed a unique sniff-triggered device that controls odor delivery with a precision of 18 milliseconds—about the duration of a frame on a regular LCD display (60 Hz). Using this device, the team created temporal odor mixtures, presenting two odors one after the other with precisely measured delays. They tested 229 participants across five experiments to see if they could distinguish these mixtures.

The researchers found that when two odor compounds, A and B, were presented in different orders (A before B and B before A), participants could tell the difference when the delay between the compounds was just 60 milliseconds—about a third of the time it takes to blink. For comparison, the frequency at which flickering green and red lights appear continuous is around 10–20 Hz (50–100 ms resolution).

Participants' ability to distinguish the odors improved with longer delays between the compounds and did not depend on knowing the correct order. They could distinguish "A before B" from "B before A" by smell, even if they couldn't identify the order. This ability was not influenced by factors like odor intensity, pleasantness, pungency, or the total amount of odorant molecules in a sniff.

These findings support the existence of a temporal code for odor identity. By providing precise control over odor delivery that aligns with natural sniffing dynamics, this research opens new avenues for studying the temporal aspects of olfactory perception and developing olfactory displays.

"A sniff of odors is not a long exposure shot of the chemical environment that averages out temporal variations. Rather, it incorporates a temporal sensitivity on par with that for color perception," said Dr. Zhou, the study's corresponding author.

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Study suggests that 'Jedi' rodents remotely move matter using sound to enhance their sense of smell

OCT. 14, 2024, by Bert Gambini, U. at Buffalo

https://phys.org/news/2024-10-jedi-rodents-remotely.html

Credit: CC0 Public Domain

Scientists have debated the purpose of the ultrasonic vocalizations (USVs) produced by rodents since the discovery of these sounds in the 1950s. There's a wide research consensus suggesting USVs are a form of social communication, a courtship display, which though inaudible to humans, might otherwise be compared to the calls of certain birds.

But a University at Buffalo expert in bioacoustics proposes in an article published in the journal Neuroscience & Biobehavioral Reviews that rodents aren't vocalizing to whisper sweet nothings, but rather to shake up their surroundings in ways that influence how inhaled particles enter their noses, suggesting that rodents use sound to enhance their sense of smell.

"This phenomenon has never been observed before, or I believe even suspected, in any animal," says Eduardo Mercado III, Ph.D., a professor of psychology in the UB College of Arts and Sciences. "They're creating new pathways of information by manipulating their environment and controlling the molecular interactions of particles around them."

They're not flirting; they're surveying their surroundings, he says. It's a radically different process and the findings could have far-reaching implications ranging from the development of treatments for psychological disorders; to better understanding the evolutionary drivers of many cognitive processes; to technological advancement.

"It's so far off the scale of what we know that it's like we're observing 'Jedi' rats," says Mercado. "It almost seems like magic."

But why did Mercado start looking for something that had never been assumed possible?

His background studying humpback whale song led to an invitation to a meeting on USVs. Reviewing existing research, Mercado found inconsistencies in rodents' vocal behaviors that didn't fit with the idea that USVs help males entice females.

Rodents explore their environment by stroking surfaces with their whiskers, visually scanning, and incessantly sniffing. Mercado discovered that studies on vocalizations that also monitored sniffing showed that rodents immediately sniffed after producing each USV.

"That could be a coincidence, or it might suggest the two are functionally related," he says. "I knew that techniques for using ultrasound to manipulate particles are used in the field of vibroacoustics and thought immediately that might also work for animals."

Vibroacoustics, or artificially produced ultrasonic vibrations, cause airborne particles to cluster, leading Mercado to suggest that rodents are using USVs to create odor clusters enhancing the reception of pheromones (chemical signals), thus making it easier for the vocalizer to detect and identify friends, strangers, and competitors.

Researchers use rodent vocalizations, particularly those of rats and mice, as a model for studying a variety of human disorders, especially those related to communication, social behavior, and emotional processing, including anxiety and depression, schizophrenia, Parkinson's disease, and autism. If tests confirm Mercado's hypothesis, researchers will have to reevaluate findings from these studies.

"Rodents are at the forefront of biological research," says Jessica Zhou, a student researcher at Harvard University, and the paper's co-author. "Rodents, especially rats and mice, are the unsung heroes of the scientific world."

From an evolutionary perspective, there is evidence suggesting the sense of smell used in exploration drove the evolution of more sophisticated cognitive processes, including attention and memory.

"Understanding this system might help us discover how it all started," says Mercado.

And that understanding can also lead to new technologies, just as understanding vision in nocturnal animals contributed to the development of night vision goggles.

"The fact that we were oblivious to anything like this being possible means we don't have the understanding yet for how nanoparticles might be sonically manipulated for complex uses," says Mercado. "But we might have a pretty big head start if we confirm that nature has already solved the problem for us."

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Modern mass extinction in an Ecuadorean cloud forest found to be a mirage

Oct. 15, 2024, by Harvard U.

https://phys.org/news/2024-10-modern-mass-extinction-ecuadorean-cloud.html

Aerial image of farmland for dairy cattle next to a surviving forest patch.

 Credit: Dawson White

One of the most notorious mass extinction events in modern times occurred on a hilltop in coastal Ecuador in the 1980s. Ninety species of plants known from nowhere else on Earth—many of them new to science and not yet given a name—went extinct when the last cloud forests of the Centinela range were cleared for agriculture. The cautionary tale of Centinela has long been a driving force in the fight to save the world's rainforests. But did it really happen?

In a new study published in Nature Plants, an international team of botanists reveals that, indeed, it did not happen. The researchers—who spent years of scouring natural history museums, biodiversity databases, and the slopes of Centinela—found no proof of any extinctions, but abundant evidence that Centinela's flora lives on in the scattered remaining fragments of coastal Ecuador's forests.

"It's a miracle," said lead author Dawson White, postdoctoral researcher in the Department of Organismic and Evolutionary Biology at Harvard. "Many of Centinela's plants are still on the brink of extinction, but fortunately the reports of their demise were exaggerated. There's still time to save them and turn this story around."

The study revealed that one reason earlier researchers overstated the likelihood of extinction at Centinela was due to the fact that those researchers were collecting a bounty of new and undescribed species, with limited information on which plant species grow where in the world's most diverse forests. In the decades since, those early collections have provided more than 50 new species.

As well, as botanists began to collect more widely and natural history museums digitized their specimens, plants previously thought to have gone extinct at Centinela have turned up at other sites in South America, while others were relocated in situ by the team. Of the 90 species originally presumed extinct, only one has not yet been rediscovered or confirmed to grow elsewhere.

"Understanding which plants are growing in a given Andean cloud forest is a monumental task because you will undoubtedly find new species," said White.

"What our investigation highlights is that it takes decades of work from taxonomic experts to describe new species in such forests. And only once we have names for these species that are then noted in our scientific networks can we begin to understand where else these plants grow and their risk of extinction."

The extant wildflower Gasteranthus extinctus. 

Credit: Thomas Couvreur

Ecuador, though small, is incredibly diverse, offering a good illustration of how challenging it is for scientists to monitor and protect tropical biodiversity. It contains more than 20,000 plant species, 4,000 of which occur nowhere else on Earth, hundreds of which lack names, and none of which have been fully mapped. Given these challenges, the study highlights the vital role of herbaria collections.

"Herbaria gives us the fundamental 'what' and 'where' of plant biodiversity," said co-author Juan Guevara, Universidad de Las Américas in Quito. "They are what made it possible to solve this mystery. They're the basis of everything we know about which plants are threatened with extinction."

The authors also found that Centinela's forests are more resilient than originally thought. Recent field work has pinpointed a number of fragments of original forest that were previously overlooked due to their tiny sizes and remote locations. The team found these postage-sized remnants, often less than an acre in size, to harbor many species thought to have gone extinct—including Gasteranthus extinctus, a wildflower named after its own extinction that was rediscovered by the team in 2021.

"Over the last two years we've surveyed a dozen fragments in the region," said co-author Andrea Fernández, Northwestern University and the Chicago Botanic Garden. "They're tiny islands lost in a sea of plantations, but they're still full of astonishing plants."

Not only were the researchers surprised to find much of the old Centinela flora intact, they were doubly surprised to discover a bounty of new and previously undescribed plants as well. Over the past five years, researchers have described or discovered eight new species ranging in size from miniscule wildflowers to towering canopy trees.

Dawn mist at sunrise under one of the dozen surviving forest fragments in the Centinela region of Ecuador. 

Credit: Nigel Pitman

"One of our most astonishing discoveries is a totally new species of canopy tree in the Cotton family," said Fernández.

"It's one of the tallest trees we have encountered, but it's extremely rare; there could be only 15 individuals alive in Centinela. It's now being actively targeted by local loggers, so we are rushing to describe this new tree species and get its seeds growing in botanic gardens."

Once given a wide berth because of its gloomy past, Centinela is now buzzing with scientists who see in its decimated forests abundant opportunities for research and conservation. In Ecuador, botanical gardens are establishing collections of the region's rarest, most threatened plants, while conservationists collect seeds for future reforestation efforts and look for long-term solutions to keep the remaining fragments standing.

At the global scale, the resurrection at Centinela has inspired the launch of a new conservation initiative by Earth imaging company Planet Labs, which promises to boost conservation projects with high-quality satellite imagery.

While the new study corrects the record on one mass extinction event, it does not cast doubt on the biodiversity crisis underway around the world. According to the IUCN Red List, more than 45,000 species on Earth are currently threatened with extinction, including nearly half of all amphibians, a third of all corals, and a quarter of all mammals. Scientists at Kew Botanical Gardens curated a list of the more than 800 plant species presumed to have gone extinct to date.

"Plants in coastal Ecuador and a lot of other hard-hit places in the tropics are finding a way to hang on in the last nooks and crannies," said co-author Nigel Pitman, the Field Museum of Natural History. "They won't survive for long under those conditions, but we've still got time to act before they're gone forever."

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Archaeology News: ‘Lady of the house’: Governor daughter’s grave uncovered in Egypt during archaeological cleaning

‘Lady of the house’: Governor daughter’s grave uncovered in Egypt during archaeological cleaning

An Egyptian-German team discovered the burial chamber of Eddie, daughter of Governor Jfay-Habi, revealing insights into ancient Egyptian life and funerary practices.

By Jerusalem Post Staff, October 7, 2024

https://www.jpost.com/archaeology/article-823480

                               Eddie's coffin. (photo credit: Screenshot/Facebook )

An Egyptian-German archaeological mission uncovered the burial chamber of Eddie, daughter of Assiut Region's governor Jfay-Habi, during archeological cleaning work at the governor’s cemetery in the Western Mount of Assiut, the Egyptian Tourism and Antiquities Ministry posted on Facebook on Wednesday.

The archaeological mission, a collaboration between Sohag and Berlin Universities, has discovered the burial chamber of a lady Eddie, the only daughter of the governor Jfay-Habi during the reign of King Snosert I.

This site where her grave was discovered is part of the largest non-royal cemetery in Egypt from that era, the Egyptian ministry noted in their post, indicating Jfay-Habi's status as an important ruler of ancient Egyptian territories.

Following the discovery, the Tourism and Archeological Minister, Sharif Fathi, emphasized the importance of it, and promised the ministry’s full support, contributing to the efforts to reveal the secrets of ancient Egypt and its people’s rites of passage.

Mohamed Ismail Khaled, Secretary General of the Supreme Council of Antiquities, reported that the burial chamber was found approximately 15 meters deep on the north side of Jfay-Habi's grave.

Coffin's hieroglyphs found where Eddie was entombed. (credit: Screenshot/Facebook )

Inside the chamber were two nested coffins, intricately engraved with texts depicting the journey to the afterlife. The smaller coffin measures 2.3 meters in length, while the larger coffin measures 2.62 meters. Additional artifacts found include a small coffin lid, a canopy vessel box, and wooden statues.

Evidence of theft

"Finding two intact Middle Kingdom coffins is extraordinary," Live Science cited Kathlyn Cooney, a professor of ancient Egyptian art and architecture at UCLA. While not being part of the excavation team, Cooney stated these coffins "not only seem well preserved but [are] covered with intricate coffin texts that helped the deceased find their way in the realm of the Underworld.”

Preliminary investigation revealed evidence of ancient theft, as Eddie’s mummy had been removed and her canopy vessels damaged, the Egyptian Tourism and Antiquities Ministry noted in their post. Initial examinations of the skeletal remains, which were returned after the grave was robbed, indicate that Eddie died at a young age, likely before 40, and exhibited a congenital foot defect.

The ministry’s post noted that cleanup efforts and scientific studies of the bones will continue to uncover further insights into the lives of Eddie and her father, as well as the historical period in which they lived.

Wolfram Grajetzki, an Egyptologist and honorary senior research fellow at University College London who wasn’t part of the research, told Live Science that the coffin's hieroglyphs refer to Eddie as the "lady of the house."

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Study links children's bedtimes to gut health, finds early sleepers have greater microbial diversity in gut flora

OCT. 13, 2024 **REPORT**, by J Jackson , Medical Xpress

https://medicalxpress.com/news/2024-10-links-children-bedtimes-gut-health.html

Credit: Unsplash/CC0 Public Domain



Researchers from the Department of Child Rehabilitation, China, have found significant differences in the gut microbiota of children who go to bed early compared to those who stay up late. The study revealed that children with earlier bedtimes had greater microbial diversity in their gut flora.

Beneficial bacteria like Akkermansia muciniphila were more abundant in the early sleepers. These bacteria are associated with maintaining gut health and have been linked to healthy cognitive functions.

Previous studies have shown that adequate sleep improves academic performance, physical growth and is associated with healthier BMI levels. The current study investigated the relationship between children's sleep patterns and their gut microbiota. In a paper, "Characteristics of gut flora in children who go to bed early versus late," published in Scientific Reports, researchers analyzed the genomics of fecal samples from 88 healthy children aged 2 to 14 years.

The children were split into two groups based on their bedtimes: those who slept before 9:30 p.m. and those who slept after. Over two weeks, sleep diaries recorded factors such as time at falling asleep, night awakenings, sleep efficiency, and sleep quality.

Genomic analysis found that children who went to bed early had a higher abundance of certain beneficial gut bacteria. Specifically, Akkermansia muciniphila was significantly more prevalent in the early bedtime group.

Other elevated bacteria among early sleepers included Holdemania filiformis, Firmicutes bacterium CAG-95, Streptococcus sp. A12, Weissella confusa, Clostridium sp. CAG-253, Alistipes finegoldii, and Eubacterium siraeum. Additionally, levels of CAG-83 fungi were higher in the early bedtime group.

Distribution of relevant sleep indicators in the early and late sleep groups. 

Credit: Scientific Reports (2024). DOI: 10.1038/s41598-024-75006-y

At the phylum and genus levels, Verrucomicrobia, Akkermansia, Holdemania and unclassified Firmicutes showed greater abundance in the early sleep group.

Correlation analysis between sleep metrics and microbial species revealed that Akkermansia muciniphila and Alistipes finegoldii were positively correlated with the time it took to fall asleep. Clostridium sp. CAG-253 was negatively correlated with sleep onset latency.

Alistipes finegoldii was positively correlated with total sleep duration but negatively correlated with dream frequency and sleep efficiency. Negative correlations were observed between Alistipes finegoldii, Akkermansia muciniphila and Holdemania filiformis in relation to sleep quality.

Metabolic analysis showed increased activity in amino acid metabolism and neurotransmitter regulation among early sleepers. These pathways are crucial for brain function and development, hinting at a possible relationship with gut health and cognition.

"These differences in species diversity and metabolic pathways suggest that sleep patterns significantly influence gut microbiota," the research paper states. "Our findings may lead to new pharmacological interventions targeting sleep disorders in children."

Correlation without causation

The finding could be correlating sleep patterns to microbiome outcomes or the inverse, where the microbiome influences sleep patterns. While the study focused on the first scenario, the children's sleep schedules were their own regular, habitual bedtimes without any intervention from the researchers.

These correlations have great potential to be followed up in multiple directions to determine the causal mechanisms behind the sleep-gut-cognitive connection.

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Ancient Fires and Fossils Unveil Early Human Secrets in Southeast Asia

BY FLINDERS U., OCT. 13, 2024

https://scitechdaily.com/ancient-fires-and-fossils-unveil-early-human-secrets-in-southeast-asia/

Local archaeologists excavating in the Tam Pà Ling cave, Laos. 

Credit: Vito Hernandez, Flinders University

New archaeological studies at Tam Pà Ling cave in Laos provide insights into the lives of early Homo sapiens, showing how shifts in climate influenced their presence and the deposition of fossils over thousands of years.

A team of Flinders University archaeologists and their international colleagues has uncovered new insights into some of the earliest evidence of Homo sapiens in mainland Southeast Asia by analyzing microscopic layers of dirt from the Tam Pà Ling cave site in northeastern Laos.

For the past 14 years, the site has been studied by a team of Laotian, French, American, and Australian scientists, yielding some of the earliest fossil evidence of our direct ancestors in Southeast Asia.

Excavation in Tam Pà Ling. Credit: Vito Hernandez, Flinders University

New Insights through Microstratigraphy

In a new study, led by PhD candidate Vito Hernandez and Associate Professor Mike Morley from the College of Humanities, Arts and Social Sciences, the team reconstructed the ground conditions in the cave between 52,000 and 10,000 years ago.

“Using a technique known as microstratigraphy at the Flinders Microarchaeology Laboratory, we were able to reconstruct the cave conditions in the past and identify traces of human activities in and around Tam Pà Ling,” says Hernandez.

“This also helped us to determine the precise circumstances by which some of the earliest modern human fossils found in Southeast Asia were deposited deep inside.”

Author Associate Professor Mike Morley. 

Credit: Flinders University



Discoveries and Environmental Analysis

Microstratigraphy allows scientists to study dirt in its smallest detail, enabling them to observe structures and features that preserve information about past environments and even traces of human and animal activity that may have been overlooked during the excavation process due to their minuscule size.

The human fossils discovered at Tam Pà Ling were deposited in the cave between 86,000 and 30,000 years ago but until now, researchers had not conducted a detailed analysis of the sediments surrounding these fossils to gain an understanding of how they were deposited in the cave or the environmental conditions at the time.

Lead author Vito Hernandez, PhD Candidate, Flinders University. 

Credit: Flinders University



Climate Influence and Human Activity

Published in Quaternary Science Reviews, the findings reveal conditions in the cave fluctuated dramatically, going from a temperate climate with frequent wet ground conditions to becoming seasonally dry.

“This change in environment influenced the cave’s interior topography and would have impacted how sediments, including human fossils, were deposited within the cave,” says Associate Professor Morley.

“How early Homo sapiens came to be buried deep within the cave has long been debated, but our sediment analysis indicates that the fossils were washed into the cave as loose sediments and debris accumulating over time, likely carried by water from surrounding hillsides during periods of heavy rainfall.”

The team also identified preserved micro-traces of charcoal and ash in the cave sediments, suggesting that either forest fires occurred in the region during the drier periods, or that humans visiting the cave may have used fire, either in the cave or near the entrance.
Conclusion on Ancestral Dynamics in Southeast Asia

“This research has allowed our team to develop unprecedented insights into the dynamics of our ancestors as they dispersed through the ever-changing forest covers of Southeast Asia, and during periods of variable regional climate instability,” says study co-author Assistant Professor Fabrice Demeter, palaeoanthropologist from the University of Copenhagen, who has been leading the team of international researchers studying Tam Pàn Ling since 2009.

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DNA Reveals a Surprise Twist About Christopher Columbus

14 Oct. 2024, By M. MCRAE

https://www.sciencealert.com/dna-reveals-a-surprise-twist-about-christopher-columbus

Portrait of Christopher Columbus. (Sebastiano del Piombo/Wikimedia Commons/PD)

On 22 February 1498, a well-weathered mid-40s Christopher Columbus ordained in writing that his estate in the Italian port city of Genoa would be maintained for his family "because from it I came and in it I was born".

Though most historians regard the document to be a cut-and-dried record of the famed explorer's birthplace, some have questioned its authenticity and wondered if there's more to the story.

A decades-long investigation led by forensics scientist José Antonio Lorente from the University of Granada in Spain has now come out in support of claims that Columbus may not be of Italian heritage after all, but was actually born somewhere in Spain to parents of Jewish ancestry.

The revelation was announced as part of a special program broadcast in Spain to celebrate Columbus's arrival in the New World on 12 October 1492.

It's important to keep in mind that science by media ought to be viewed with caution, especially when there isn't a peer-reviewed publication to critically examine.

"Unfortunately, from a scientific point of view, we can't really evaluate what was in the documentary because they offered no data from the analysis whatsoever," former director of Spain's National Institute of Toxicology and Forensic Sciences, Antonio Alonso, told Manuel Ansede and Nuño Domínguez at the Spanish news service, El País.

"My conclusion is that the documentary never shows Columbus's DNA and, as scientists, we don't know what analysis was undertaken."

Nonetheless, historical documents are increasingly being challenged – and bolstered – by forensic analyses of biological records, raising the possibility that Columbus's own DNA could potentially reveal insights into his family history.

Based on interpretations of records written when he was an adult, the man known throughout much of the western world by the anglicized name Christopher Columbus was born Cristoforo Columbo sometime between late August and late October in 1451 in Genoa, the bustling capital of the northwestern Italian region of Liguria.

It was only later in life as a young man in his twenties that he traveled west to Lisbon, Portugal, in search of affluent patrons who might fund his audacious attempt to take a 'short cut' to the east by heading in completely the other direction.

Though most historians accept the court documents placing his birthplace in Genoa as the real-deal, speculation of an alternative heritage has been floated for decades.

One persistent rumor maintains Columbus was covertly Jewish, born in Spain at a time of intense religious persecution and ethnic cleansing. Supporters of the claim cite curious abnormalities in his will and interpretations of the syntax in his letters.

Now, it appears his own genes may provide a new line of evidence.

Lorente and his team of researchers claimed in the televised special that their analysis of Y chromosome and mitochondrial DNA taken from the remains of Columbus's son Ferdinand and brother Diego is compatible with a Spanish or Sephardim Jewish heritage.

This doesn't categorically rule out Genoa, of course, nor does it pin down any one place in Europe as a place of birth for the explorer. Indeed, Jews exiled from Spain at the end of the 15th century just as Columbus was making his landmark voyage flooded into the Italian city seeking asylum, albeit with few succeeding.

But any merit to Lorente's findings would make Columbus's Italian origin a little harder to support, raising questions of how somebody of Sephardim Jew heritage would come to be born in Genoa in the 1450s.

For the findings to become widely adopted, the results would need to be carefully scrutinized, if not convincingly replicated in detail.

Even then, there's more to an individual's story than genetics – leaving open the case of how an individual from a persecuted minority truly came to represent the spearhead of Spanish expansion.

For now, the story of Columbus remains one of an Italian sailor who caught the eye of Spanish royalty, who came to be both celebrated and scorned for the mark he inadvertently made on history far from that "noble and powerful city by the sea", his home of Genoa.

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Study proposes a new bias: The tendency to assume one has adequate information to make a decision

OCT. 9, 2024, by Public Library of Science

https://phys.org/news/2024-10-bias-tendency-assume-adequate-decision.html

The authors suggest that the ability to navigate other perspectives might be improved by encouraging people to consider whether they may be lacking key information.

 Credit: geralt, Pixabay, CC0 (creativecommons.org/publicdomain/zero/1.0/)

New experimental data support the idea that people tend to assume the information they have is adequate to comprehend a given situation, without considering that they might be lacking key information. Hunter Gehlbach of Johns Hopkins University and colleagues present these findings in the open-access journal PLOS ONE on October 9, 2024.

When navigating alternative perspectives, people may demonstrate psychological biases that influence their ability to understand others' viewpoints. For instance, in the bias of naive realism, people presume their own subjective perspective is objective truth.

Gehlbach and colleagues now propose the existence of a related bias, which they call the illusion of information adequacy: the failure to consider the possibility that one might be missing key information. For instance, one driver might honk at a car stopped in front of them, only to then see a pedestrian crossing the road—a possibility they hadn't considered.

To demonstrate the illusion of information adequacy, the researchers presented 1,261 study participants with a hypothetical scenario in which they had to recommend whether two schools should be merged or not, as well as answer questions about their perceptions. Some participants received information about the benefits of merging, some about the benefits of staying separate, and some about both.

In line with the illusion of information adequacy, participants who—unbeknownst to them—lacked either the pro-merge or the pro-separate information tended to assume that the information they had was just as adequate as others' information, that they were just as well equipped to make a thoughtful recommendation, and that most others would make a similar decision. Indeed, people lacking pro-merge information tended to recommend the schools remain separate, and vice versa.

Notably, a subgroup of participants who later received the information they initially lacked tended to stick with their original decisions. However, this subgroup's combined final recommendations did mirror the recommendations of the subgroup that initially received all the information.

The authors suggest that the ability to navigate other perspectives might be improved by encouraging people to consider whether they may be lacking key information. Meanwhile, additional research could deepen understanding of this type of bias.

The authors add, "A major source of misunderstanding and conflict in our daily lives arises from this paradox: We know that, in theory, there are plenty of things that we don't know we don't know. Yet, in practice, we almost always behave as though we have adequate information to voice our opinions, make good decisions, and pass judgment on others. A little more intellectual humility about what we do and don't know would serve us well."

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Ancient climate analysis reveals unknown global processes

OCT. 12, 2024, by A. Hadhazy, Stanford U.

https://phys.org/news/2024-10-ancient-climate-analysis-reveals-unknown.html

A review of research of over a hundred geographical sites worldwide, outlining every continental landmass, has revealed a globally extensive gap in the geologic record. 

Credit: Bernd Dittrich/Unsplash

According to highly cited conventional models, cooling and a major drop in sea levels about 34 million years ago should have led to widespread continental erosion and deposited gargantuan amounts of sandy material onto the ocean floor. This was, after all, one of the most drastic climate transitions on Earth since the demise of the dinosaurs.

Yet a new Stanford review of hundreds of studies going back decades contrastingly reports that across the margins of all seven continents, little to no sediment has ever been found dating back to this transition. The discovery of this globally extensive gap in the geologic record was published this week in Earth-Science Reviews.

"The results have left us wondering, 'where did all the sediment go?'" said study senior author Stephan Graham, the Welton Joseph and Maud L'Anphere Crook Professor in the Stanford Doerr School of Sustainability. "Answering that question will help us get a better fundamental understanding about the functioning of sedimentary systems and how climatic changes imprint on the deep marine sedimentary record."

The geological gap offers fresh insights into sediment deposition and erosion processes, as well as the broader environmental signals from dramatic climate change, which could help researchers better grasp the global enormity of today's changing climate.

"For the first time, we've taken a global look at an understudied response of the planet's largest sediment mass-movement systems during the extreme transition of the Eocene-Oligocene," said study lead author Zack Burton, Ph.D. '20, who is now an assistant professor of Earth sciences at Montana State University.

Tim McHargue, an adjunct professor of Earth and planetary sciences at Stanford, is also a co-author on the study.

From hothouse to icehouse

During the Eocene-Oligocene period, Earth underwent profound planetary cooling. Giant ice sheets appeared in Antarctica, which was previously ice-free, global sea level plunged, and land and marine life suffered severe die-offs.

Prior to that, in the early part of the Eocene that lasted from about 56 million to 34 million years ago, Earth had the warmest temperatures and highest sea levels since dinosaurs walked the Earth more than 66 million years ago, according to climate-proxy records.

Burton and colleagues initially focused on exploring the effects of early Eocene conditions on deep-sea depositional systems. The resulting study—published in Scientific Reports in 2023—found abundant sand-rich deposits in the ocean basins along Earth's continental margins.

The research team attributed this deposition increase mainly to intensified climatic and weather conditions boosting erosion from land. Their curiosity piqued, Burton and colleagues then extended the investigation to the late Eocene and early Oligocene, when Earth suddenly went from "hothouse" and "greenhouse" climates to the opposite, an "icehouse" climate.

For the new study, the researchers painstakingly pored over scientific and technical literature documenting ancient sediment up to several kilometers beneath the sea floor, surveying studies published in the past decade to over a century ago. The literature included offshore oil and gas drilling studies, onshore rock outcrop studies, and even interpretations of seismic data to infer Eocene-Oligocene sediment characteristics. In total, just over a hundred geographical sites worldwide were included, outlining every continental landmass.

While the study's method of literature analysis is not new on its own, the scale of such an approach made possible by vast online databases could prove highly illuminating, Graham said. "There could be other similar events in the geologic past that would bear a closer investigation," said Graham, "and the way to start that is by doing exactly what we did—a really thorough canvassing of the global geologic literature for certain suspect periods in time."

"The actual process of reappraising, reinvestigating, and reanalyzing literature that has in some cases been out for decades is challenging, but can be very fruitful," Burton said. "The method can lead to exciting and unexpected findings, like we were able to make here."
Wholly unanticipated

As Burton and his colleagues made their way through the compiled data inventory, they grew increasingly perplexed by the apparent sedimentary no-show.

"We didn't see abundant sand-rich deposition, as in our study of warm climates of the early Eocene," said Burton. "Instead, we saw that prominent, widespread erosional unconformities—in other words, gaps in the rock record—had developed during the extreme climatic cooling and oceanographic change of the Eocene-Oligocene."

The researchers offer a few theories about why this lack of deposition occurred. Vigorous ocean bottom currents, driven by temperature and salinity of the waters, may have been triggered or magnified by the major climate shift, potentially eroding the ocean floor and sweeping away sediment that flowed off the continents.

Meanwhile, mechanisms from continental shelves exposed by sea-level fall could have allowed sediments to entirely bypass the closer-in sedimentary basins, sending deposits much farther out onto the abyssal plain of the ocean floor. More regionally restricted processes, like glacial erosion around Antarctica, likely played a part, too.

Whatever mechanisms may have been in play, they collectively created similar scenes of erosion in oceanic basins around every continent. That ubiquity points to what the researchers referred to as global controls—meaning that profound climatic change was felt everywhere, from the tallest landmasses down into the deepest waters.

In this way, the abrupt climatic event at the Eocene-Oligocene boundary and its newly observed, substantial effects along continental margins could help researchers better grasp the global enormity of today's unfolding climate change. Although the human-caused climate change of the past couple centuries is currently much smaller in overall magnitude compared to the Eocene-Oligocene transition, it is happening at an alarmingly faster pace, the Stanford researchers said.

"Our findings can help inform us of the kinds of radical changes that can happen on the Earth's surface in the face of rapid climate change," said Graham. "The geologic past informs the present, and particularly the future."

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Magnetogenetics Breakthrough Offers New Hope for Treating Parkinson’s, Depression, Obesity, and Chronic Pain

BY WEILL CORNELL MEDICINE, OCT. 12, 2024

https://scitechdaily.com/magnetogenetics-breakthrough-offers-new-hope-for-treating-parkinsons-depression-obesity-and-chronic-pain/

Magnetogenetics offers a new approach to brain science, enabling the manipulation of neurons via magnetic fields, potentially revolutionizing treatments for neurological and psychiatric conditions. 

Credit: SciTechDaily.com

Researchers have developed a revolutionary magnetogenetics technology that can control brain circuits non-invasively using magnetic fields.

This new method, which has been successfully tested in mice, offers promise for treating neurological and psychiatric disorders by allowing precise activation or inhibition of neurons without the need for invasive procedures.

Magnetogenetics and Brain Control

A new non-invasive technology enables the control of specific brain circuits using magnetic fields, according to a preclinical study from researchers at Weill Cornell Medicine, The Rockefeller University, and the Icahn School of Medicine at Mount Sinai. This technology shows great potential as a tool for brain research and as a foundation for future treatments of diverse neurological and psychiatric conditions, including Parkinson’s disease, depression, obesity, and complex pain.

The new gene therapy technology is described in a paper published on October 9 in the journal Science Advances. The researchers performed experiments in mice showing that it can switch on or off selected populations of neurons, with clear effects on the animals’ movements. In one experiment, they used it to reduce abnormal movements in a mouse model of Parkinson’s disease.

A gene therapy allows precise magnetic field control of specific brain circuits without implanted devices. The image shows restricted mRNA expression of the genetically encoded magnetic sensor (red) in dopaminergic neurons type 2 (green) in the mouse striatum that regulate the initiation of movement. Dopaminergic neurons type 1 (cyan) and cell nuclei shown with dapi staining (blue). 

Credit: Dr. Santiago Unda

“We envision that magnetogenetics technology may someday be used to benefit patients in a wide range of clinical settings,” said study senior author Dr. Michael Kaplitt, professor and executive vice-chairman of neurological surgery at Weill Cornell Medicine and director of Movement Disorders Surgery at NewYork-Presbyterian/Weill Cornell Medical Center.

The study was a collaboration between Dr. Kaplitt’s laboratory and the laboratories of Dr. Jeffrey Friedman, the Marilyn M. Simpson Professor in the Laboratory of Molecular Genetics at The Rockefeller University; and Dr. Sarah Stanley, an assistant professor in the Department of Medicine at the Icahn School of Medicine at Mt. Sinai.

The study’s first author was Dr. Santiago Unda, a postdoctoral researcher in Dr. Kaplitt’s laboratory.
Non-Invasive Techniques for Neural Modulation

Controlling brain circuits in real-time, in a way that allows animals—or humans—to move around normally, has been a major goal for neuroscientists, but a very challenging one. In the laboratory, optogenetics technology, for example, can make selected neurons switch on or off immediately with light pulses, but requires an invasive apparatus for delivering those light pulses to the brain. In the clinic, deep brain stimulation permits modulation of brain regions, but this also requires a permanently implanted device and greater precision also remains a goal.

After doing early work on magnetogenetic technology as an alternative to other approaches, Dr. Friedman and Dr. Stanley joined forces with Dr. Kaplitt, a pioneer of brain-targeted gene therapies, to develop a method of this type with the potential for clinical applications.

Proof of Concept and Future Prospects

The resulting approach uses gene therapy techniques to deliver an engineered ion-channel protein to a desired type of neuron. The ion channel protein essentially works as a switch to turn affected neurons on or off, and is sensitive to a magnetic field because it includes an antibody-like protein that sticks to a natural iron-trapping protein called ferritin. While the gene therapy is delivered to precise brain regions through a minimally invasive surgery, a sufficiently strong magnetic field can then exert enough force on the ferritin-trapped iron atoms to open or close the channel—activating the neuron or inhibiting it, depending on the design, without the need for an implanted device or drug.

In one proof of concept, the team injected the gene therapy for the magnetically sensitive channels into specific neurons within a movement-controlling region called the striatum in mice; they then used the magnetic field from a magnetic resonance imaging machine to activate the neurons and markedly slow, even freeze, the mice’s movements. In another experiment, they reduced neuronal activity in a brain region called the subthalamic nucleus to ameliorate movement abnormalities in a Parkinsonism mouse model.

The researchers showed that their method can work even when using a much smaller and less expensive “transcranial magnetic stimulation” device, which is often used currently in the clinic to treat patients with depression, migraine, and other conditions.

The experiments uncovered no safety issues, and the researchers noted that normal ambient magnetic fields would be far too weak to trigger magnetogenetic switches inadvertently.

The team now intends to explore potential clinical applications including treatments for psychiatric disorders and even chronic pain in peripheral nerves. They also will continue to explore and optimize the magnetogenetics technology itself.

“Being able now to do directional manipulations of brain activity with this relatively simple system is going to be very important in helping us better understand the underlying principles to help further advance this new technology,” Dr. Unda said.

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Industry payments common for physician peer reviewers of top journals

OCT. 11, 2024, by L. Solomon

https://medicalxpress.com/news/2024-10-industry-payments-common-physician-peer.html

More than half of U.S. physician peer reviewers for the most influential medical journals receive industry payments, according to a research letter published online Oct. 10 in the Journal of the American Medical Association.

David-Dan Nguyen, M.P.H., from the University of Toronto, and colleagues characterized payments by drug and medical device manufacturers to U.S. peer reviewers of major medical journals. The analysis included 1,962 U.S.-based physician peer reviewers (2020 to 2022) for The BMJ, JAMA, The Lancet, and the New England Journal of Medicine.

The researchers found that 58.9 percent of identified peer reviewers received at least one industry payment, including general payments (54.0 percent) and research payments (31.8 percent). Overall, reviewers received $1.06 billion in industry payments during the study period, including $1.00 billion (94.0 percent) to individuals or their institutions and $64.18 million (6.0 percent) in general payments. Consulting fees accounted for $34.31 million, and speaking compensation unrelated to continuing medical education programs accounted for $11.80 million. Among reviewers receiving such payments, the median general payment was $7,614 and the median research payment was $153,173. There were significant payment differences seen by sex and specialty.

"Additional research and transparency regarding industry payments in the peer review process are needed," the authors write.

One author disclosed ties to the biopharmaceutical industry.

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Gazing at your dog can connect your brains, research suggests

OCT. 11, 2024, by J. Boyd, The Conversation

https://phys.org/news/2024-10-dog-brains.html

Credit: Chris Packham, Creative Commons license CC-0

It might sound far-fetched, but recent research suggests that dogs' and humans' brains synchronize when they look at each other.

This research, conducted by researchers in China, is the first time that "neural coupling" between different species has been witnessed.

Neural coupling is when the brain activity of two or more individuals aligns during an interaction. For humans, this is often in response to a conversation or story.

Neural coupling has been observed when members of the same species interact, including mice, bats, humans and other primates. This linking of brains is probably important in shaping responses during social encounters and might result in complex behavior that would not be seen in isolation, such as enhancing teamwork or learning.

When social species interact, their brains "connect". But this case of it happening between different species raises interesting considerations about the subtleties of the human-dog relationship and might help us understand each other a little better.

What's new puppy dog?

The dog was one of the first animals humans domesticated. And they have a long history of sharing time and space with us. Dogs are not only companions for us, they also have key roles in our society, including therapeutic support, detecting diseases and protecting and herding livestock.

As a result, dogs have developed some impressive skills, including the ability to recognize and respond to our emotional state.

In the recent study, the researchers studied neural coupling using brain-activity recording equipment called non-invasive electroencephalography (EEG). This uses headgear containing electrodes that detect neural signals—in this case, from the beagles and humans involved in the study.

Researchers examined what happened to these neural signals when dogs and people were isolated from each other, and in the presence of each other, but without looking at each other. Dogs and humans were then allowed to interact with each other.

Look into my eyes

When dogs and humans gazed at each other and the dogs were stroked, their brain signals synchronized. The brain patterns in key areas of the brain associated with attention, matched in both dog and person.

Dogs and people who became more familiar with each other over the five days of the study had increased synchronization of neural signals. Previous studies of human-human interactions have found increased familiarity between people also resulted in more closely matching brain patterns. So the depth of relationship between people and dogs may make neural coupling stronger.

The ability of dogs to form strong attachments with people is well known. A 2022 study found the presence of familiar humans could reduce stress responses in young wolves, the dog's close relative. Forming neural connections with people might be one of the ways by which the dog-human relationship develops.

The researchers also studied the potential effect of differences in the brain on neural coupling. They did this by including dogs with a mutation in a gene called Shank3, which can lead to impaired neural connectivity in brain areas linked with attention. This gene is responsible for making a protein that helps promote communication between cells, and is especially abundant in the brain. Mutations in Shank3 have also been associated with autism spectrum disorder in humans.

Study dogs with the Shank3 mutation did not show the same level of matching brain signals with people as those without the mutation. This was potentially because of impaired neural signaling and processing.

However, when researchers gave the study dogs with the Shank3 mutation a single dose of LSD (a hallucinogenic drug), they showed increased levels of attention and restored neural coupling with humans.

LSD is known to promote social behavior in mice and humans, although clearly there are ethical concerns about such treatment.

The researchers were clear that there remains much to be learned about neural coupling between dogs and humans.

It might well be the case that looking into your dog's eyes means that your respective brain signals will synchronize and enhance your connection. The more familiar you are with each other, the stronger it becomes, it seems.

So the next time a dog gazes at you with their puppy dog eyes, remember you could be enhancing your relationship.

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