Capturing carbon in savannas: New research examines role of grasses for controlling climate change

Peer-Reviewed Publication

S.J. & JESSIE E. QUINNEY COLLEGE OF NATURAL RESOURCES, UTAH STATE UNIVERSITY

 

IMAGE: NEW RESEARCH SHOWS THAT IN ADDITION TO TREES, HUMBLE GRASSES PLAY AN ESSENTIAL ROLE IN CAPTURING CARBON TO FIGHT CLIMATE CHANGE IN SAVANNA ECOSYSTEMS LIKE THIS ONE IN KRUGER NATIONAL PARK, SOUTH AFRICA. view more 

CREDIT: YONG ZHOU

In recent years, the escalating impact of global warming has prompted efforts to reverse troubling trends, often by planting trees to capture and remove carbon dioxide from the atmosphere and store it. New research from a team led by Young Zhou, from the Quinney College of Natural Resources and the Ecology Center, shows that, in addition to trees, humble grasses also play an essential role in capturing carbon — more important than previously thought.

A recent initiative set its sights on capturing carbon in tropical savannas, an ecosystem characterized by shared space of trees and grasses. The project initiated a tree planting effort (afforestation) to capture carbon dioxide from the air, which resulted in stored carbon in two primary places: the woody biomass of the growing trees, and in soils. While the effectiveness of storing carbon in trees has been well-established in research, how carbon storage functions in soils was not well defined, and Zhou and his colleagues set out to determine the role grasses played in this effort.

The team, which included scientists from Yale University, Lawrence Berkeley National Laboratory, University of Cape Town, Texas A&M, Kruger National Park, Harvard University, and University of Oregon, conducted a comprehensive study investigating the contribution of grasses to carbon content in savannas soils and assessed the potential impact of increasing tree cover in tropical savannas on soil carbon storage. The study was published in the journal Nature Geoscience.

Using the case study conducted in Kruger National Park, South Africa, and data synthesized from tropical savannas worldwide, the research team demonstrated that savanna soils enriched with carbon from grasses exhibited comparatively higher concentrations of carbon. Their findings showed that grasses accounted for over half of the soil carbon content across tropical savannas, including soils directly beneath trees. This underscores the significant role that grasses play in the accumulation of carbon within tropical savannas.

Their findings showed both carbon gains and losses, as tree cover increased across tropical savannas. The most significant variation was observed in savannas receiving higher rainfall, where tree planting is more likely to thrive, as well as in areas with clay soils and savanna sites that had substantial contributions of carbon storage from grasses.

“This underscores the nuanced nature of increasing tree cover on the dynamics of carbon in savanna soils,” Zhou said. “On average, the increase in soil carbon storage resulting from the expansion of tree cover across tropical savannas is negligible.”

This finding aligns with the team's previous research published in Nature, which demonstrated that increasing tree cover due to fire suppression led to increased carbon storage in woody biomass, but did not affect soil carbon storage.

"Our findings challenge the commonly held assumption that afforestation uniformly boosts soil carbon storage," Zhou said. "However, we have yet to pinpoint the precise factors responsible for the substantial variation observed in the soil carbon storage response to increased tree cover across tropical savannas."

In general, forests primarily store their carbon in the woody trunks and aboveground leaves. In contrast, a significant portion of carbon in grassy ecosystems, such as savannas and grasslands, is stored in the soil, primarily within the extensive root systems of the grasses as well as decaying organic matter. In the context of long-term carbon storage, carbon retained in soils proves to be more reliable, particularly for a vulnerable future marked by warming and increased likelihood of drought and wildfires, he said.

“It makes even more clear that savannas play crucial roles in the global carbon cycle in their unique ways, underscoring the importance of preserving and protecting these ecosystems in an equitable manner,” he said.

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JOURNAL

Nature Geoscience

DOI

10.1038/s41561-023-01232-0 

METHOD OF RESEARCH

Case study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Soil carbon in tropical savannas mostly derived from grasses

 

Street medicine filling a major gap by providing behavioral health care for people who are homeless

While they are more at risk for mental health and substance use disorders, unhoused people in California face barriers to accessing treatment.

Peer-Reviewed Publication

KECK SCHOOL OF MEDICINE OF USC

 

IMAGE: GABRIELLE JOHNSON, BRETT FELDMAN AND EDDIE MENACHO WORK AS PART OF THE STREET MEDICINE TEAM AT USC, WHICH PROVIDES MEDICAL CARE TO PEOPLE WHO ARE LIVING ON THE STREETS. view more 

CREDIT: CHRIS SHINN

Mental health and substance use disorders are prevalent among people experiencing homelessness, yet access to care for these health issues is challenging for people living on the streets. Now, a new survey conducted by a team of researchers from USC Street Medicine found that, in California, street medicine programs are helping to fill this gap, delivering critical, high-level mental health and substance use treatments to the state’s unsheltered population.

The survey, published in Community Mental Health Journal, shows that street medicine has the potential to serve as the basis for a strategy to expand access to behavioral health care for people who are unhoused.

“This survey showed that there is tremendous need for mental health and substance use services and that street medicine programs are providing more services and higher-level care out of necessity,” said Brett Feldman, director and co-founder of USC Street Medicine, assistant professor of family medicine at Keck School of Medicine of USC, and one of the authors of the study. “We found that street medicine teams have trained up to provide a higher level of behavioral health care because there’s little access to psychiatric care, especially on the street.”

The authors noted that addressing the mental health and substance use problems, common among the state’s homeless population, is one key to improving communities’ efforts to address homelessness. 

Need is great, resources are sparse

The researchers from the Keck School of Medicine surveyed 29 street medicine teams in California, 26 of which completed the survey. One was excluded because it is too new a program to have meaningful data. Street medicine organizations reported that 64% of their patients have mental health problems and 67% have substance use disorders. All but one of the street medicine programs provides some mental health and treatment for substance use disorders. 

Despite the need, most of the street medicine programs reported having difficulty successfully referring their patients to mental health and addiction treatment programs. Referring unhoused patients to specialists is often difficult, noted Feldman, since many have no address, phone number or transportation to make visits to specialists. 

Eight of the street medicine programs surveyed include a psychiatrist, but only two of them are full-time. Six of the teams have part-time psychiatrists who provide between four to 10 hours a week of care. Feldman added that there is a national shortage of psychiatrists, which has made it increasingly difficult for disadvantaged people, such as people living on the streets, to access psychiatric services. 

Street medicine programs are typically staffed with primary care providers who are trained to treat some mental health issues, but people with complex or severe mental health problems often need the type of care that only a psychiatrist can provide. 

Addressing the problem of access

The study concludes that street medicine is a promising approach to improving access to mental health and substance use care for people who are unsheltered. Feldman said 60% of the state’s programs provide very high-level care, such as medication-assisted therapy, which involves treating substance use disorders with medications, such as suboxone, in combination with counseling and behavioral therapy. 

Street medicine providers have also embraced using long-acting antipsychotics for people with severe mental illness. These drugs last up to about a month, which makes adherence simpler for people living on the street and stabilizes them for longer periods of time than daily oral medications. 

The study’s authors also suggest novel approaches to providing behavioral health services should be explored, such as using telehealth during street visits to provide patients with access to psychiatric care or treatment for addiction. They also assert that additional research should be done to understand the barriers that exist to providing medications to treat psychiatric problems and substance use disorders and find new ways to improve access. Finally, the authors conclude that the all of the strategies for providing behavioral health care through street medicine should be further studied and evaluated to allow for the development of evidence-based practices that can be tested, replicated, reimbursed and operationalized.

About this study

Additional authors of this study include Kimberly Y. Su, Corinne T. Feldman, Sonali Saluja, Alexis M. Coulourides Kogan and Michael R. Cousineau of the Keck School of Medicine of USC. 

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JOURNAL

Community Mental Health Journal

DOI

10.1007/s10597-023-01169-z 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Behavioral Health Care Delivery Through Street Medicine Programs in California

 

NIH investigates multidrug-resistant bacterium emerging in community settings

Researchers study confluence of multidrug resistance and hypervirulence among Klebsiella pneumoniae

Peer-Reviewed Publication

NIH/NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES

 

IMAGE: A HUMAN NEUTROPHIL (RED) CONTAINING INGESTED KLEBSIELLA PNEUMONIAE (PURPLE). view more 

CREDIT: NIAID

New “hypervirulent” strains of the bacterium Klebsiella pneumoniae have emerged in healthy people in community settings, prompting a National Institutes of Health research group to investigate how the human immune system defends against infection. After exposing the strains to components of the human immune system in a laboratory “test tube” setting, scientists found that some strains were more likely to survive in blood and serum than others, and that neutrophils (white blood cells) are more likely to ingest and kill some strains than others. The study, published in mBio, was led by researchers at NIH’s National Institute of Allergy and Infectious Diseases (NIAID).

“This important study is among the first to investigate interaction of these emergent Klebsiella pneumoniae strains with components of human host defense,” Acting NIAID Director Hugh Auchincloss, M.D., said. “The work reflects the strength of NIAID’s Intramural Research Program. Having stable research teams with established collaborations allows investigators to draw on prior work and quickly inform peers about new, highly relevant public health topics.”

More than a century ago scientists identified K. pneumoniae as a cause of serious, often fatal, human infections, mostly in people already ill or with weakened immune systems and especially people in hospitals. Over a span of many decades, some strains developed resistance to multiple antibiotics, and became difficult to treat. This bacterium, often called classical Klebsiella pneumoniae (cKp), ranks as the third most common pathogen isolated from hospital bloodstream infections. Certain other Klebsiella pneumoniae strains cause severe infections in healthy people in community settings (outside of hospitals) even though they are not multidrug-resistant. They are known as hypervirulent Klebsiella pneumoniae, or hvKp. More recently, strains with both multidrug resistance and hypervirulence characteristics, so-called MDR hvKp, have emerged in both settings.

NIAID scientists have studied this general phenomenon before. In the early 2000s they observed—and actively investigated—virulent strains of methicillin-resistant Staphylococcus aureus (MRSA) bacteria that had emerged in U.S. community settings and caused widespread infections in otherwise healthy people.

Now, the same NIAID research group at Rocky Mountain Laboratories in Hamilton, Montana, is investigating similar questions about the new Klebsiella strains, such as whether the microbes can evade human immune system defenses. Their findings were unexpected: the hvKp strains were more likely to survive in blood and serum than MDR hvKp strains. And neutrophils had ingested less than 5% of the hvKp strains, but more than 67% of the MDR hvKp strains—most of which were killed.

The researchers also developed an antibody serum specifically designed to help neutrophils ingest and kill two selected hvKp and two selected MDR hvKp strains. The antiserum worked, though not uniformly in the hvKp strains. These findings suggest that a vaccine approach for prevention/treatment of infections is feasible.

Based on the findings, the researchers suggest that the potential severity of infection caused by MDR hvKp likely falls in between the classical and hypervirulent forms. The work also suggests that the widely used classification of K. pneumoniae into cKp or hvKp should be reconsidered. 

The researchers also are exploring why MDR hvKp are more susceptible to human immune defenses than hvKp: Is this due to a change in surface structure caused by genetic mutation? Or perhaps because combining components of hypervirulence and antibiotic resistance reduces the bacterium's ability to replicate and survive in a competitive environment. 

As a next step, the research team will determine the factors involved in MDR hvKp susceptibility to the body’s immune defenses using mouse infection models. Ultimately, this knowledge could inform treatment strategies to prevent or decrease disease severity.  

Reference:  F DeLeo et al. Interaction of multidrug-resistant hypervirulent Klebsiella pneumoniae with components of human innate host defense. mBio DOI: 10.1128/mbio.01949-23 (2023).

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NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website. 

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit https://www.nih.gov/. 

NIH...Turning Discovery Into Health®

 

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JOURNAL

mBio

DOI

10.1128/mbio.01949-23 

Psychedelic rock gecko among dozens of species in need of further conservation protection in Vietnam

Peer-Reviewed Publication

PENSOFT PUBLISHERS

 

VIDEO: ONE OF THE MOST ENDANGERED TURTLE SPECIES IN VIETNAM AND IN THE WORLD, WHICH IS NOT KNOWN FROM ANY PROTECTED AREA. ALTHOUGH LIKELY BEING EXTINCT IN THE WILD, EX SITU CONSERVATION PROGRAMS HAVE BEEN IMPLEMENTED IN TIME WITH A HIGH NUMBER OF INDIVIDUALS BEING KEPT AND BRED IN ZOOS AND STATIONS AND NOW READY FOR RESTOCKING ACTIONS. view more 

CREDIT: VIDEO BY PROF. DR. THOMAS ZIEGLER. EDITED BY ANNA RAUHAUS.

Further conservation measures are required to protect Vietnamese reptiles, such as the psychedelic rock gecko (Cnemaspis psychedelica), from habitat loss and overharvesting, concludes a new report, published in the open-access scientific journal Nature Conservation.

Having identified areas of high reptile diversity and large numbers of endangered species, the study provides a list of the 50 most threatened species as a guide for further research and conservation action in Vietnam. 

The study, based on the bachelor thesis of Lilli Stenger (University of Cologne, Germany), recommends IUCN CPSG’s One Plan Approach to Conservation measures, which, next to improved habitat conservation, also involves increasing the number of threatened species in breeding stations and zoos to maintain populations suitable for restocking. 

Co-authors of the report are Anke Große Hovest (University of Cologne, Germany), Truong Quang Nguyen (Vietnam Academy of Science and Technology), Cuong The Pham, (Vietnam Academy of Science and Technology), Anna Rauhaus (Cologne Zoo, Germany), Minh Duc Le (Vietnam National University), Dennis Rödder (Leibniz Institute for the Analysis of Biodiversity Change, Germany) and Thomas Ziegler (University of Cologne and Cologne Zoo, Germany).

“Modern zoos, as well as local facilities, can play a crucial role in not only conducting or financially supporting in situ conservation projects, that is to say in nature, but also by protecting species from extinction through maintaining ex situ assurance colonies to reinforce in situ conservation programs,” said Prof. Dr. Thomas Ziegler, Vietnam conservation team member and coordinator from Cologne Zoo, Germany.

The scientists identified 484 reptile species known to Vietnam, aiming to provide a baseline to authorities, conservationists, rescue centers, and zoos, so they can follow up with appropriate conservation measures for endangered species. They note that the number is likely to go up, as the country is regarded as a top biodiversity hotspot, and the rate of new reptile species discoveries remains high.

According to the IUCN Red List, 74 of the identified species are considered threatened with extinction, including 34 endemic species. For more than half of Vietnam’s endemic reptiles (85 of 159), the IUCN Red List status is either missing or outdated, and further research is imperative for these species, the researchers say.

Vietnam has a high level of reptile diversity and an outstanding number of endemic species. The species richness maps in the study revealed the Central Annamites in central Vietnam to harbor the highest endemic species diversity (32 species), which highlights it as a site of particular importance for reptile conservation. Alarmingly, a protected area analysis showed that 53 of the 159 endemic species (33.2%) including 17 threatened species, have been recorded exclusively from unprotected areas, such as the Psychedelic Rock Gecko.

In General, Vietnam is considered a country with high conservation priority due to habitat loss and overharvesting for trade, traditional medicine and food.

Globally, reptiles are considered a group of special conservation con­cern, as they play an important role in almost all ecosystems and often have relatively small distri­bution ranges, making them especially vulnerable to human threats.

Endangered psychedelic rock gecko (Cnemaspis psychedelica)

Endangered psychedelic rock gecko (Cnemaspis psychedelica).

Endangered Truong Son pit viper or Quang Binh pit viper (Trimeresurus truongsonensis).

CREDIT

Thomas Ziegler

Original source:

Stenger L, Große Hovest A, Nguyen TQ, Pham CT, Rauhaus A, Le MD, Rödder D, Ziegler T (2023) Assessment of the threat status of reptile species from Vietnam - Implementation of the One Plan Approach to Conservation. Nature Conservation 53: 183-221. https://doi.org/10.3897/natureconservation.53.106923

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JOURNAL

Nature Conservation

DOI

10.3897/natureconservation.53.106923 

ARTICLE TITLE

Assessment of the threat status of reptile species from Vietnam - Implementation of the One Plan Approach to Conservation

ARTICLE PUBLICATION DATE

5-Sep-2023

 

Recent advances in melon and gourd research

Peer-Reviewed Publication

AMERICAN CHEMICAL SOCIETY

As summer draws to a close, the long vines and tendrils of most melons and gourds in the Cucurbitaceae family snake their way along the ground. And they’re dotted with fruits, such as cucumbers or pumpkins. Below are some recent papers published in ACS journals that report insights into melons’ potential health impacts, pathogens and contaminants. Reporters can request free access to these papers by emailing newsroom@acs.org.

“Nanoparticles Loaded with a Carotenoid-Rich Extract from Cantaloupe Melon Improved Hepatic Retinol Levels in a Diet-Induced Obesity Preclinical Model”
ACS Omega
July 26, 2023
Cantaloupe melons are rich in beta-carotene and other carotenoids, which break down into vitamin A, also called retinol, in the human body. However, people with obesity tend to consume less of this micronutrient than those of average weight. So, these scientists created carotenoid nanocapsules by extracting the molecules from cantaloupes and coating them with gelatin. When obese rats ingested the capsules, they ate less food, and their livers contained more retinol. The team says that the technique should be evaluated as a treatment for diseases associated with vitamin A deficiency and obesity.

“Degradation of α-Subunits, Doa1 and Doa4, are Critical for Growth, Development, Programmed Cell Death Events, Stress Responses, and Pathogenicity in the Watermelon Fusarium Wilt Fungus Fusarium oxysporum f. sp. niveum"
Journal of Agricultural and Food Chemistry
July 24, 2023
To find better ways to combat watermelon fusarium wilt, researchers focused on two genes in the fungus that causes the disease. They infected young watermelon roots with spores from a wild-type fungal strain and from mutant ones with either the FonDoa1 or FonDoa2 gene removed. After three weeks, the mutant fungal strains grew less, caused less severe disease and killed fewer plants. The team suggests targeting these genes with future fungicides.

“Highly Efficient and Simultaneous Analysis of Three Common Fluorotelomer Alcohols in Vegetables and Soils”
Journal of Agricultural and Food Chemistry
July 21, 2023
As a step toward routine analyses of fluorinated compounds in foods, researchers have optimized a method to measure levels of three fluorotelomer alcohols. The team developed their technique using fruits and vegetables, including cucumbers. Then they measured the contaminants in calabash gourd, bitter gourd, towel gourd, pumpkins and 16 other edible vegetables grown near a fluorochemical facility. Many samples had detectable levels of one or more of the contaminants.

“Pumpkin and Pumpkin Byproducts: Phytochemical Constitutes, Food Application and Health Benefits”
ACS Omega
June 23, 2023
Pumpkin pulp is a tasty addition to autumnal pies, soups and drinks. But what are its health benefits? In this review, the authors assessed the edible parts of pumpkin and pumpkin waste byproducts for their nutritional qualities. They report that the flesh, seeds, leaves and skin of pumpkins contain important trace elements, vitamins and nutrients. Phytochemicals, in particular, can provide antidiabetic, antioxidant and antidepressant effects. And the waste products of pumpkins can serve as functional ingredients for baked goods, drinks, and meat and dairy products.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohi

 

New method enables efficient isolation of raccoon-borne food poisoning pathogen

Peer-Reviewed Publication

OSAKA METROPOLITAN UNIVERSITY

 

IMAGE: THE NOVEL CULTURE MEDIUM BOOSTS THE ISOLATION RATE OF E. ALBERTII FROM RACCOON FECAL SAMPLES view more 

CREDIT: SHINJI YAMASAKI, OSAKA METROPOLITAN UNIVERSITY

Osaka, Japan – As cute as raccoons may look, their behaviors are troublesome, and so are their droppings. Known to contain Escherichia albertii—a harmful enteropathogen—raccoon feces challenge zoonotic researchers who grapple to isolate this bacterium for further study. Fortunately, Osaka Metropolitan University scientists have come up with a novel culture medium for efficient isolation of E. albertii, making progress toward alleviating this particular raccoon-conveyed threat.

Due to global warming, wildlife habitats are overlapping with human residential areas, raising concerns about the transmission and spread of zoonotic diseases. In recent years, an emerging zoonotic pathogen called E. albertii—transmitted by wild animals such as raccoons—has garnered attention due to its remarkable similarities to several strains of Escherichia coli (E. coli), including O157, and its potential for causing severe illness, particularly in children. However, characteristics of this bacterium, including its infection routes and antibiotic resistance status, remain unclear.

To identify the route of infection, it is essential to isolate and then investigate E. albertii from specimens of wild animals acting as vectors. However, the quantity of E. albertii in samples sourced from raccoons is often minuscule, making its extraction an ongoing challenge.

Addressing this issue, a research group led by Professor Shinji Yamasaki of the Graduate School of Veterinary Science at Osaka Metropolitan University has developed a novel culture medium that selectively promotes the growth of E. albertii from raccoon fecal samples. They succeeded in isolating E. albertii at a rate as high as 48%, even from samples with very low quantities of this bacterium.

Professor Yamasaki explained, “The selective enrichment medium developed in this study is expected to provide better insights into the epidemiology of E. albertii, facilitating improved control of food poisoning.”

Their findings were published in the Journal of Applied Microbiology.

 

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About OMU 

Osaka Metropolitan University is a new public university established in April 2022, formed by merger between Osaka City University and Osaka Prefecture University. For more research news, visit https://www.omu.ac.jp/en/ or follow @OsakaMetUniv_en and #OMUScience.

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JOURNAL

Journal of Applied Microbiology

DOI

10.1093/jambio/lxad123 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Cefixime–tellurite-deoxycholate tryptic soy broth (CTD-TSB), a selective enrichment medium, for enhancing isolation of Escherichia albertii from wild raccoon fecal samples

 

The discovery of a new kind of cell shakes up neuroscience

Peer-Reviewed Publication

UNIVERSITY OF LAUSANNE

Neuroscience is in great upheaval. The two major families of cells that make up the brain, neurons and glial cells, secretly hid a hybrid cell, halfway between these two categories. For as long as Neuroscience has existed, it has been recognized that the brain works primarily thanks to the neurons and their ability to rapidly elaborate and transmit information through their networks. To support them in this task, glial cells perform a series of structural, energetic and immune functions, as well as stabilize physiological constants. Some of these glial cells, known as astrocytes, intimately surround synapses, the points of contact where neurotransmitters are released to transmit information between neurons. This is why neuroscientists have long suggested that astrocytes may have an active role in synaptic transmission and participate in information processing. However, the studies conducted to date to demonstrate this have suffered from conflicting results and have not reached a definitive scientific consensus yet. By identifying a new cell type with the characteristics of an astrocyte and expressing the molecular machinery necessary for synaptic transmission, neuroscientists from the Department of Basic Neurosciences of the Faculty of Biology and Medicine of the University of Lausanne (UNIL) and the Wyss Center for Bio and Neuroengineering in Geneva put an end to years of controversy.

The Key to the Puzzle

To confirm or refute the hypothesis that astrocytes, like neurons, are able to release neurotransmitters, researchers first scrutinized the molecular content of astrocytes using modern molecular biology approaches. Their goal was to find traces of the machinery necessary for the rapid secretion of glutamate, the main neurotransmitter used by neurons. "The precision allowed by single-cell transcriptomics approaches enabled us to demonstrate the presence in cells with astrocytic profile of transcripts of the vesicular proteins, VGLUT, in charge of filling neuronal vesicles specific for glutamate release. These transcripts were found in cells from mice, and are apparently preserved in human cells. We also identified other specialized proteins in these cells, which are essential for the function of glutamatergic vesicles and their capacity to communicate rapidly with other cells," says Ludovic Telley, Assistant professor at UNIL, co-director of the study.

New Functional Cells

Next, neuroscientists tried to find out if these hybrid cells were functional, that is, able to actually release glutamate with a speed comparable to that of synaptic transmission. To do this, the research team used an advanced imaging technique that could visualize glutamate released by vesicles in brain tissues and in living mice. "We have identified a subgroup of astrocytes responding to selective stimulations with rapid glutamate release, which occurred in spatially delimited areas of these cells reminiscent of synapses," says Andrea Volterra, honorary professor at UNIL and visiting faculty at the Wyss Center, co-director of the study.

In addition, this glutamate release exerts an influence on synaptic transmission and regulates neuronal circuits. The research team was able to demonstrate this by suppressing the expression of VGLUT by the hybrid cells. "They are cells that modulate neuronal activity, they control the level of communication and excitation of the neurons," says Roberta de Ceglia, first author of the study and senior researcher at UNIL. And without this functional machinery, the study shows that long-term potentiation, a neural process involved in the mechanisms of memorization, is impaired and that the memory of mice is impacted.

Links With Brain Pathologies

The implications of this discovery extend to brain disorders. By specifically disrupting glutamatergic astrocytes, the research team demonstrated effects on memory consolidation, but also observed links with pathologies such as epilepsy, whose seizures were exacerbated. Finally, the study shows that glutamatergic astrocytes also have a role in the regulation of brain circuits involved in movement control and could offer therapeutic targets for Parkinson's disease.

"In between neurons and astrocytes, we now have a new kind of cell at hand. Its discovery  opens up immense research prospects. Our next studies will explore the potential protective role of this type of cell against memory impairment in Alzheimer's disease, as well as its role in other regions and pathologies than those explored here," projects Andrea Volterra.

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JOURNAL

Nature

DOI

10.1038/s41586-023-06502-w 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

Specialized astrocytes mediate glutamatergic gliotransmission in the CNS

ARTICLE PUBLICATION DATE

6-Sep-2023

 

The limestone spheroids of ‘Ubeidiya: Intentional imposition of symmetric geometry by early hominins?

Peer-Reviewed Publication

THE HEBREW UNIVERSITY OF JERUSALEM

 

IMAGE: SPHEROIDS view more 

CREDIT: AUTHORS OF THE PAPER

Limestone spheroids, enigmatic lithic artifacts from the ancient past, have perplexed archaeologists for years. While they span from the Oldowan to the Middle Palaeolithic, the purpose behind their creation remains a subject of intense debate. Now, a study conducted by a team from the Computational Archaeology Laboratory of the Hebrew University of Jerusalem, in collaboration with researchers from Tel Hai College and Rovira i Virgili University seeks to shed light on these mysterious objects, offering insights into the intentions and skills of early hominins.

Spheroids are among the most enduring yet least understood archaeological artifacts, often considered as by-products of percussive tasks. However, the team’s research challenges this conventional wisdom. The central question at the heart of this study is whether these spheroids were unintentional by-products or intentionally crafted tools designed for specific purposes.

To answer this question, cutting-edge 3D analysis methods, including spherical harmonics and surface curvature, were applied to a collection of 150 limestone spheroids from the 'Ubeidiya archaeological site, dating back to approximately 1.4 million years ago. These methods were developed at the Computational Archaeology Laboratory of the Hebrew University, directed by Professor Leore Grosman. 'Ubeidiya is presently recognized as the earliest known Acheulean occurrence outside of Africa, making it a crucial location for investigating the evolution of early hominin technology.

The research team meticulously reconstructed the spheroid reduction sequence based on the trends observed in scar facets and geometry. Their findings revealed a remarkable pattern: the spheroids at 'Ubeidiya were crafted with a premeditated reduction strategy. Contrary to the notion that they were accidental by-products, the spheroids did not become smoother during their manufacture; instead, they became markedly more spherical. This transformation towards an ideal sphere required exceptional knapping skills and a clear preconceived goal.

This discovery challenges existing beliefs about the capabilities of early hominins and their relationship with technology. While Acheulean bifaces are traditionally thought to represent the earliest evidence of hominins imposing intentional, symmetrical shapes on stone, the intentional production of sphere-like objects at 'Ubeidiya similarly suggests that these early hominins had a desire for and achieved intentional geometry and symmetry in stone. Slightly older spheroids exist at sites in Africa. If this same intentionality can be demonstrated there, this would represent the oldest evidence of hominins desiring and achieving symmetrical shapes in stone.

The team’s research opens new avenues for understanding the cognitive abilities and technological achievements of our distant ancestors. It also raises questions about the purpose and significance of these spheroids in the daily lives of early hominins.

 

Research Team: Antoine Muller-1, Deborah Barsky-2,3, Robert Sala-Ramos-2,3, Gonen Sharon-4, Stefania Titton-3, Josep-Maria Vergès-2,3 and Leore Grosman-1

Institutions:
1-Computational Archaeology Laboratory, Institute of Archaeology, Hebrew University of Jerusalem

2- Institut Català de Paleoecologia Humana i Evolució Social (IPHES-CERCA), Zona Educacional Campus Sescelades URV (Edifici W3), 43007 Tarragona, Spain

3-Departament d’Història i Història de l’Art, Universitat Rovira i Virgili, Avinguda de Catalunya, Spain

4-Multidisciplinary Studies, East Campus, Tel-Hai College, Israel

The Hebrew University of Jerusalem is Israel’s premier academic and research institution. With over 25,000 students from 90 countries, it is a hub for advancing scientific knowledge and holds a significant role in Israel’s civilian scientific research output, accounting for nearly 40% of it and has registered over 11,000 patents. The university’s faculty and alumni have earned eight Nobel Prizes and a Fields Medal, underscoring their contributions to ground-breaking discoveries. In the global arena, the Hebrew University ranks 86th according to the Shanghai Ranking. To learn more about the university’s academic programs, research initiatives, and achievements, visit the official website at http://new.huji.ac.il/en

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JOURNAL

Royal Society Open Science

DOI

10.1098/rsos.230671 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The limestone spheroids of ‘Ubeidiya: intentional imposition of symmetric geometry by early hominins?

ARTICLE PUBLICATION DATE

6-Sep-2023