Scientists call for a major investigation into Congo Basin
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SUBJECT OF RESEARCH
Not applicable
Saturday, October 28, 2023
Okinawa’s ants change their seasonal rhythms amid land-cover changes
Ant communities in areas with more human development show reduced seasonal behavior.
Peer-Reviewed PublicationIMAGE:
ANTS WERE COLLECTED IN SPECIAL TRAPS AT 24 SITES ACROSS OKINAWA OVER TWO YEARS.
view moreCREDIT: OKEON, OIST
Insects have an important role in maintaining the health of ecosystems, but our understanding of how human activities affect their populations is limited. This gap in knowledge is worrying because of the decline of insect populations and the severe consequences on ecosystems and agriculture.
Researchers at the Okinawa Institute of Science and Technology (OIST), working with collaborators in Ireland, have led a project to understand how land-cover changes affect the seasonal behavior of ant communities in Okinawa.
After collecting and identifying a whopping 1.2 million ants in different environments across Okinawa Island, they found that ant communities in areas with more human development lose their natural seasonal behavior and are more unpredictable when compared to sites with greater forest cover. Their results have been published in the journal Proceedings of the Royal Society B.
“In forest areas, these natural seasonal cycles are preserved; however, in areas with more human development activities, these patterns become disrupted and degraded,” Prof. Evan Economo, head of OIST’s Biodiversity and Biocomplexity Unit, explained. “This results in a certain unpredictability regarding which species are active and a reduction in the natural cycles observed throughout the year.”
The seasonal patterns of insect communities are linked to the important roles they play in the ecosystem, including decomposition, nutrient cycling, water purification, and seed dispersal. Ants hold a key position because of their large numbers and the multiple functions they perform.
For Prof. Jamie Kass, a former OIST researcher who is now at Tohoku University, understanding how insect behavior changes over time is key. “If we only record their activities a few times a year, we risk missing important seasonal changes. Most studies do not consider this aspect, which makes our research unique. We show that human activities may be disrupting the normal seasonal behavior of insect communities, and this is an important but underexplored result of serious environmental changes worldwide.”
In natural environments, especially those with very distinct seasons, insects in general are more active in spring and summer, and less active in winter. This pattern repeats every year. However, this study shows how changes to land cover by humans can disrupt these patterns, which are linked to important ecosystem services that people depend on.
Every two weeks, worker ants were collected from traps across 24 sites in the Okinawa Environmental Observation Network (OKEON), managed by the Environmental Science and Informatics Section at OIST. Researchers identified the different ant species and counted how many of each they found. Using these data, they calculated how much ant communities were varying over time, and they modeled relationships with land cover characterized by site using remote sensing imagery. After finding that communities were changing less over time for developed areas than forested ones, they delved deeper and found that the seasonality of these communities in particular was diminished.
JOURNAL
Proceedings of the Royal Society B Biological Sciences
ARTICLE TITLE
Breakdown in seasonal dynamics of subtropical ant communities with land-cover change
Will machines soon be conscious?
IMAGE:
LEFT: A SCHEMATIC DEPICTING THE BASIC ARCHITECTURE OF A LARGE LANGUAGE MODEL, WHICH CAN HAVE
TENS OR EVEN MORE THAN A HUNDRED DECODER BLOCKS ARRANGED IN A FEED-FORWARD FASHION.
RIGHT: A HEURISTIC MAP OF THE THALAMOCORTICAL SYSTEM, WHICH GENERATES COMPLEX ACTIVITY PATTERNS THOUGHT TO UNDERLIE CONSCIOUSNESS.
CREDIT: MAC SHINE, JAAN ARU
The rise of the capabilities of artificial intelligence (AI) systems has led to the view that these systems might soon be conscious. However, we might underestimate the neurobiological mechanisms underlying human consciousness.
Modern AI systems are capable of many amazing behaviors. For instance, when one uses systems like ChatGPT, the responses are (sometimes) quite human-like and intelligent. When we, humans, are interacting with ChatGPT, we consciously perceive the text the language model generates. You are currently consciously perceiving this text here! The question is whether the language model also perceives our text when we prompt it. Or is it just a zombie, working based on clever pattern-matching algorithms? Based on the text it generates, it is easy to be swayed that the system might be conscious. However, in this new research, Jaan Aru, Matthew Larkum and Mac Shine take a neuroscientific angle to answer this question.
All three being neuroscientists, these authors argue that although the responses of systems like ChatGPT seem conscious, they are most likely not. First, the inputs to language models lack the embodied, embedded information content characteristic of our sensory contact with the world around us. Secondly, the architectures of present-day AI algorithms are missing key features of the thalamocortical system that have been linked to conscious awareness in mammals. Finally, the evolutionary and developmental trajectories that led to the emergence of living conscious organisms arguably have no parallels in artificial systems as envisioned today. The existence of living organisms depends on their actions and their survival is intricately linked to multi-level cellular, inter-cellular, and organismal processes culminating in agency and consciousness.
Thus, while it is tempting to assume that ChatGPT and similar systems might be conscious, this would severely underestimate the complexity of the neural mechanisms that generate consciousness in our brains. Researchers do not have a consensus on how consciousness rises in our brains. What we know, and what this new paper points out, is that the mechanisms are likely way more complex than the mechanisms underlying current language models. For instance, as pointed out in this work, real neurons are not akin neurons in artificial neural networks. Biological neurons are real physical entities, which can grow and change shape, whereas neurons in large language models are just meaningless pieces of code. We still have a long way to understand consciousness and, hence, a long way to conscious machines.
JOURNAL
Trends in Neurosciences
METHOD OF RESEARCH
Literature review
SUBJECT OF RESEARCH
Not applicable
Overview of an EU project’s wild pollinator conservation efforts: Safeguard’s open-access collection
The EU Horizon 2020 project Safeguard has opened an outcomes collection in the Research Ideas and Outcomes (RIO) journal.
IMAGE:
SAFEGUARD OPEN-ACCESS COLLECTION IN RIO JOURNAL
view moreCREDIT: PROJECT SAFEGUARD
For the past decade, the European Union has been actively investing in innovative projects, addressing major social concerns, such as climate change, renewable energy, and biodiversity loss. Although these projects give valuable results, some of the outcomes remain unseen and undiscovered by many. To avoid this knowledge oblivion, Safeguard has recently released an open-access collection in the Research Ideas and Outcomes (RIO) journal.
Safeguarding European wild pollinators (Safeguard) is a four-year EU Horizon 2020 funded project (2021-2025) that brings together world-leading researchers, NGOs, and industry and policy experts to substantially contribute to Europe’s capacity to reverse the losses of wild pollinators. Safeguard aims to significantly expand current assessments of the status and trends of European wild pollinators including bees, butterflies, flies, and other pollinating insects.
The open-access collection of the project in the RIO journal will not only increase the discoverability, visibility, and recognition of the research outcomes, but also set a comfortable digital environment for knowledge exchange, collaboration, sharing, and re-use of research. The collection in RIO will ensure that Safeguard outputs remain findable, accessible, interoperable, and reusable beyond the project’s lifetime.
Currently, the collection hosts 14 project papers, published in different journals and linked through their metadata. The collection will further expand to a one-stop knowledge hub, hosting a range of outputs, reports, protocols, methodologies, and research papers.
Access the Safeguard RIO collection here.
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This project receives funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 101003476.
Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the EU nor the EC can be held responsible for them.
FOREVER CHEMICALS
Tracking down environmental toxins
Detection of per- and polyfluoroalkyl substances (PFAS) by interrupted energy transfer
Peer-Reviewed PublicationPFAS, a family of highly fluorinated substances, represent a danger for humans and the environment. Particularly problematic members of this family, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) appear to cause organ damage and cancer, as well as disrupting the endocrine system. In the journal Angewandte Chemie, researchers have now introduced a new method for an economical, easy-to-use fluorescence sensor for sensitive on-site testing for PFAS in water samples.
The term per- and polyfluoroalkyl substances (PFAS) refers to a group of organic compounds in which most or all the hydrogen atoms bound to the carbon atoms have been replaced with fluorine atoms. They are used to provide water-, oil-, and dirt-resistance to a variety of products, such as nonstick pans, outdoor clothing, and packaging. They may also be found in fire-suppressing foam, paint, and car polish. These compounds are highly useful—and highly dangerous when they find their way into the environment: they do not break down and thus become concentrated in plants, animals, and people.
Limits of 100 ng/l for individual specific PFAS substances and 500 ng/l for the total of all PFAS were set for drinking water in the EU. In Germany, water providers must begin testing drinking water for PFAS in 2026. The US Environmental Protection Agency has set stricter limits: for the most widespread PFAS (PFOS and PFOA), the upper limit is set at 4nm/l for each substance.
The usual method used to detect such trace amounts involves chromatography and mass spectrometry, is time-consuming and expensive, and requires complex equipment and experienced personnel. Timothy M. Swager and Alberto Concellón at the Massachusetts Institute of Technology (MIT) in Cambridge, USA, have now introduced a technique for making a portable, inexpensive test that uses fluorescence measurements to easily and selectively detect PFAS in water samples.
The test is based on a polymer—in the form of a thin film or nanoparticles—with fluorinated sidechains that have fluorinated dye molecules (squaraine derivatives) embedded in them. The special polymer backbone (poly-phenylene ethynylene) absorbs violet light and transfers the light energy to the dye by an electron exchange (Dexter mechanism). The dye then fluoresces red. If PFAS are present in the sample, they enter the polymer and displace the dye molecules by a fraction of a nanometer. This is enough to stop the electron exchange and thus the energy transfer. The dye’s red fluorescence is “switched off”, while the blue fluorescence of the polymer is “switched on”. The degree of fluorescence change is proportional to the concentration of PFAS.
This new technique, which has a detection limit in the µg/l range for PFOA and PFOS is suitable for on-site detection in highly contaminated regions. Detection of trace amounts of these contaminants in drinking water can be achieved with sufficient precision after pre-concentration of the samples by solid-phase extraction.
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About the Author
Dr. Timothy M. Swager is a Professor of Chemistry at the Massachusetts Institute of Technology. His research is at the chemistry/materials interface and he has pioneered the use of novel materials in the creation of chemical sensors with ultra-trace detection capabilities. Dr. Alberto Concellón was a postdoctoral researcher at MIT, and is presently at Ramón y Cajal Researcher at the University of Zaragoza, Spain working on functional self-assembled materials.
JOURNAL
Angewandte Chemie International Edition
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Detection of Per- and Polyfluoroalkyl Substances (PFAS) by Interrupted Energy Transfer
ARTICLE PUBLICATION DATE
5-Oct-2023
COI STATEMENT
A provisional patent has been filed.
New discovery concerning receptors used by coronaviruses to enter human cells
IMAGE:
SARS-COV-2 BINDS TO ACE2 PROTEIN. THE PROTEASE TMPRSS2 THEN CLEAVES THE SPIKE TO ENABLE VIRAL FUSION AND ENTRY INTO THE TARGET CELL. HKU1 BINDS DIRECTLY TO TMPRSS2 IN ORDER TO ENTER THE CELL WITHOUT USING ACE2.
view moreCREDIT: © INSTITUT PASTEUR
The SARS-CoV-2 virus responsible for COVID-19 can cause severe acute respiratory syndrome, contrasting with other coronaviruses that were known to cause mild seasonal colds prior to its emergence in 2019. This raises the question of why one coronavirus affects humans more severely than another. Scientists at the Institut Pasteur, Université Paris Cité and the VRI have now provided part of the answer by identifying a gateway used by the seasonal coronavirus HKU1 to enter human cells. HKU1 binds to a different receptor than SARS-CoV-2, which may partly explain the difference in severity between these two coronaviruses. Receptors provide a useful means of elucidating coronavirus transmissibility and pathology as part of surveillance work on viral evolution. These results are published in the October 25, 2023 issue of Nature.
Seven coronaviruses are known for their ability to infect humans. Four of these are generally mild: HKU1, 229E, NL63 and OC43, while the other three are more pathogenic: SARS-CoV-1, Mers-CoV and SARS-CoV-2.
The HKU1 virus was first identified in an elderly patient with severe pneumonia in Hong Kong in 2005. Like SARS-CoV-2, HKU1 mainly infects upper respiratory tract cells. However, it rarely affects the bronchi and alveoli in the lungs. The HKU1 virus causes colds and other mild respiratory symptoms. Complications may also occur, including severe respiratory tract infections, particularly in young children, the elderly and immunocompromised individuals. It is estimated that 70% of children are infected before the age of 6. In total, 75 to 95% of the global population has been exposed to HKU1, which is comparable to other seasonal human coronaviruses.
At cellular level, coronavirus spike proteins are cleaved, or split in two, after binding to their receptors. This cleavage phenomenon is vital for viral fusion, entry and multiplication. Some coronaviruses (SARS-CoV-2 and NL63) use the ACE2 receptor as a gateway for entering cells. Until now, HKU1 and OC43 were the only coronaviruses with unknown receptors.
Through collaboration between scientists at eight Institut Pasteur units, it was possible to identify the TMPRSS2 enzyme as the receptor to which HKU1 binds to enter cells. Once binding has occurred, TMPRSS2 triggers fusion of HKU1 with the cell, leading to viral infection. Through a combination of techniques performed in vitro and in cell culture, the scientists demonstrated that the TMPRSS2 receptor has high affinity with the HKU1 spike, which is not the case for SARS-CoV-2.
"Once a receptor has been identified for a virus, it is possible to characterize target cells more accurately, while also gaining insights on viral entry and multiplication mechanisms and infection pathophysiology," comments, Olivier Schwartz, co-last author of the study and Head of the Institut Pasteur's Virus and Immunity unit.
"Our findings also shed light on the various evolution strategies employed by coronaviruses, which use TMPRSS2 either to bind to target cells or trigger fusion and viral entry," adds Julian Buchrieser, co-last author of the study and scientist in the Institut Pasteur's Virus and Immunity unit.
These human-pathogenic viruses' use of different receptors probably affects their degree of severity. Receptor levels vary among respiratory tract cells, thus influencing the sensitivity of cells to infection and viral spread. Once the route of viral entry into cells is known, it should also be possible to fight infection more effectively by developing targeted therapies and assess the risk of virulence posed by any future emerging coronaviruses.
In parallel with this work, Institut Pasteur teams led by Pierre Lafaye and Felix Rey have developed and characterized nano-antibodies (very small antibodies) that inhibit HKU1 infection by binding to the TMPRSS2 receptor. These reagents have been patented for potential therapeutic activities.
This work was funded by the above-mentioned research bodies with additional support from the French Foundation for Medical Research (FRM), ANRS-Emerging Infectious Diseases, Vaccine Research Institute, the European HERA DURABLE project, the Labex IBEID and the ANR/FRM Flash Covid project.
Human respiratory tissue with ciliated cells stained green (anti-TMPRSS2 antibodies), nuclei in dark blue and cell membranes in light blue.
CREDIT
© Vincent Michel, Institut Pasteur
JOURNAL
Nature
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Cells
ARTICLE TITLE
TMPRSS2 is a functional receptor for human coronavirus HKU1
ARTICLE PUBLICATION DATE
25-Oct-2023
The race of water droplets
A team of researchers has delved into the mechanisms governing the speed at which a water droplet slides along one or several fibers.
Peer-Reviewed PublicationVIDEO:
HOW FAST DOES A DROPLET FLOW ALONG A FIBRE? IT DEPENDS ON THE DIAMETER OF THE FIBRE... AND ALSO ON ITS SUBSTRUCTURE! THESE ARE THE FINDINGS OF A STUDY CONDUCTED BY RESEARCHERS FROM THE GRASP MABPRATORY OF THE UNIVERSITY OF LIÈGE WHO ARE INTERESTED IN MICROFLUIDICS, ESPECIALLY WATER HARVESTING IN ARID/SEMI-ARID REGIONS OF OUR PLANET.
view moreCREDIT: @UNIVERSITY OF LIÈGE / GRASP / M.LEONARD
How fast does a droplet flow along a fiber? It depends on the diameter of the fiber... and also on its substructure! These are the findings of a study conducted by researchers from the University of Liège who are interested in microfluidics, especially water harvesting in arid/semi-arid regions of our planet. These results are the subject of a publication highlighted by the editors in the journal Physical Review Fluids.
Similar to moisture farms imagined in science-fiction worlds like that of "Star Wars," many plant species from arid or semi-arid regions of Earth have developed ingenious strategies to capture water from the air, ensuring their survival. Recently, researchers have focused on understanding the fundamental mechanisms of water transport, intending to reproduce and improve them, especially for facilitating the collection of atmospheric moisture in deserts. A recent study led by the GRASP at the University of Liège (ULiège) has sought to better grasp the factors influencing these precious droplets' movement. To do this, scientists have tracked in real-time the characteristics and dynamics of these droplets as they slid along individual fibres or bundles of fibres.
"Following a droplet as it descends along a vertical fibre under the influence of gravity presents a complex experimental challenge: how to track a droplet over several meters of thread? Explains Matteo Léonard, a researcher at GRASP and the study's lead author. To address this problem, researchers devised a clever device in their laboratory. "Instead of following the fall of a droplet, we set the fibre in motion so that its speed is exactly equal and opposite to that of the droplet. This way, the droplet remains 'stationary' in front of the camera." With this challenge overcome, they first used fibres of different diameters. They observed that droplets had a lower speed at a given volume when the fibres were thicker, as predicted by theory. Subsequently, researchers created bundles of fibres by tying the ends of two or more fibres together and applying slight torsion to ensure contact between all the fibres. "This configuration created a bundle of fibres with grooves, similar to the braiding of strands in a rope, which resulted in grooves appearing on the cord," explains Matteo Leonard. In this configuration, researchers observed the same behaviours as with single fibres: as the number of fibres in the bundle increased, the overall diameter of the bundle increased, resulting in lower speed at a given volume. This predictable behaviour, however, concealed a more complex phenomenon...
Indeed, what about the behaviour of the droplet in the case where both configurations (single and bundle) have the same diameter (i.e., a fibre with a diameter of 0.28mm versus two fibres with a diameter of 0.14mm)? Since the hindrance of the phenomenon is dissipation (i.e., friction within the liquid and between the liquid and the fibre), one might expect that both cases would yield identical results because the contact surface between the liquid and the fibre is the same. "Not at all. We observed that over the same distance travelled, the droplet on the bundle of fibres was faster. It also lost the most volume." Researchers believe that in this configuration, the droplet loses volume because it tends to "fill" the grooves with its own volume, thereby creating a liquid rail on which it slides more efficiently and thus faster.
The results of this study make a significant contribution to the field of designing structures for atmospheric water collection. Notably, it can potentially improve the efficiency of cloud nets, which consist of a network of fibres, at a low cost. Furthermore, this research highlights the growing importance of substructures regularly observed on organisms living in desert environments. These substructures, such as micro-grooves or micro-hairs, demonstrate nature's ingenuity in capturing and transporting water, inspiring future technological innovations.
How fast does a TIONdroplet flow along a fibre? It depends on the diameter of the fibre... and also on its substructure!
CREDIT
@University of Liège/GRASP/M.Leonard
*A moisture farm is an area of land devoted to the production of water by extracting moisture from dry air.
JOURNAL
Physical Review Fluids
ARTICLE TITLE
Droplets sliding on single and multiple vertical fibers
ARTICLE PUBLICATION DATE
23-Oct-2023
Protein root discovery seals future of climate proof plants
Researchers have discovered a protein that seals plant roots to regulate the uptake of nutrients and water from the soil, the discovery could help develop climate proof crops that require less water and chemical fertilizers.
Researchers from the University of Nottingham identified new components of the lignin barrier in plant roots and the specific function of dirigent proteins (DPs), located in the root endodermis that control water and nutrient uptake. Their findings have been published today in Science Direct.
Plant roots function by absorbing mineral nutrients and water from the soil and also controlling their proper balance in the plant. This control is exerted by a specialised layer of root tissue called the endodermis.
The endodermis contains a barrier to the movement of solutes and water that is made of lignin, the same material present in wood. This impermeable barrier blocks the uncontrolled movement of material into the root, by forming a tight seal between cells. This seal ensures the only pathway for nutrients and water to be taken up by roots is through the cells of the endodermis. This allows full cellular control over what enters and leaves the plant via the roots.
This research has identified new components of the lignin deposition machinery that focus on the function of dirigent proteins (DPs), located in the root endodermis. These proteins act in coordination with other described root regulatory components to direct and organize the correct deposition of lignin in the endodermis allowing the plant to ensure it receives the optimum balance of nutrients from the soil.
Dr Gabriel Castrillo from the University of Nottingham’s School of Biosciences one of the leaders of the research, said: “With record temperatures being reached in parts of the world this year and erratic rainfall it is ever more important to understand the mechanisms of plants so we can future proof them to secure future food supplies. This research shows how plant roots regulate their uptake of water and nutrients through the deposition of lignin, which is regulated by DPs. Without these proteins, proper root sealing is not completed and the nutrient balance in the plant is compromised. We can use this knowledge to engineer plants to be able to grow with less water and chemical fertilizers.”
JOURNAL
Science
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
A dirigent protein complex directs lignin polymerization and assembly of the root diffusion barrier
ARTICLE PUBLICATION DATE
26-Oct-2023