PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION

Learning about system stability from ants

Learning about system stability from ants
2021-04-19
(Press-News.org) A new type of collective behaviour in ants has been revealed by an international team of scientists, headed by biologist Professor Iain Couzin, co-director of the Cluster of Excellence "Centre for the Advanced Study of Collective Behaviour" at the University of Konstanz and director at the co-located Max Planck Institute of Animal Behavior, and Matthew Lutz, a postdoctoral researcher in Couzin's lab. Their research shows how ants use self-organized architectural structures called "scaffolds" to ensure traffic flow on sloped surfaces. Scaffold formation results from individual sensing and decision-making, yet it allows the colony as a whole to adjust dynamically to unpredictable environmental challenges.

Who does not know this situation? You are stuck in a traffic jam due to road construction, or you wanted to take the train instead of your car, but it did not show up. A problem common to many complex artificial systems, be they traffic infrastructures or other technological systems, is a lack of robustness in the face of disturbances. These systems are often rigid and inflexible, and centralized or hierarchical control structures make them vulnerable to single-point perturbations. Biological systems, on the other hand, often employ forms of distributed control and can be astonishingly robust to environmental challenges.

To learn more about the control mechanisms underlying stability and resilience in natural systems, Konstanz-based biologist Iain Couzin and his lab, together with international colleagues from Australia and the US, investigated how ants coordinate traffic during foraging. Their study, published in PNAS, describes how ants of the species Eciton burchellii organize into living architectural structures termed "scaffolds" on sloped surfaces, to avoid traffic disruption and conserve resources. The researchers propose a mechanism for scaffold formation in which each ant adjusts its behaviour based on its own experience, without a need for group-level communication. This simple but effective mechanism of proportional system control from the animal world may inspire designs for artificial systems, from autonomous vehicles to future forms of resilient infrastructure that respond to changing conditions.

Voracious predators and gifted architects For their study, the scientists travelled to Panama, where the species under investigation - the army ant Eciton burchellii - inhabits the tropical forest of Barro Colorado Island. Eciton army ants are social insects, living in large colonies with hundreds of thousands of workers. During the day, they hunt for prey in massive swarm raids that can sweep out an area of four tennis courts in a single day. Among the many evolutionary adaptations that rank these ants among the top invertebrate predators in the tropical forest is their remarkable ability to self-organize into living architecture. For the benefit of the colony, individual ants join forces to temporarily modify the environment and ensure the flow of traffic during the colony's hunts.

The PNAS study describes one type of architecture these ants construct - called "scaffolds" by the authors - for the first time in detail. Under natural conditions, scaffolds form when E. burchellii trails cross inclined surfaces, such as branches or rocks, and individual ants stop and cling to the surface, remaining fixed in place. The authors discovered that, in doing so, the ants provide additional grip for other ants, which continue along their path, marching over the immobile conspecifics.

Scaffolds were shown to be highly adaptable, growing to different shapes and sizes depending on the context - from just a few dispersed ants arranged like a climbing wall, to dense aggregations of ants forming a protruding shelf. "Scaffolds form rapidly in response to disruption, preventing ants from slipping and falling along the foraging trail. This is especially important when you are transporting valuable resources like prey through dense traffic, and your trail leads through an unpredictable rainforest environment with all kinds of slopes and obstacles," Couzin describes.

Group-level coordination without communication To experimentally investigate collective scaffolding behaviour, the authors designed an apparatus that allowed for the introduction of defined slopes into the raiding trails of wild ant colonies in the field. With repeated experiments on slopes of different angles, the researchers found the ants to reliably organize into scaffolds when crossing surfaces inclined more than 40 degrees. The steeper the slope, the more ants initially slipped or fell from the platform, and in response, the larger the scaffolds grew. Once a scaffold had formed - a few minutes after ants began crossing - the number of slipping and falling ants returned to a low level, thanks to the support structure.

In accordance with their field observations and supported by theoretical modelling, the scientists suggest a surprisingly simple mechanism for scaffold formation: When an animal slips on a sloped surface and then regains its footing, it has a certain probabilistic tendency to claw the ground and remain in place. In doing so, it either starts or joins a scaffold. The more animals show the behaviour, the less slippery the tilted surface becomes, as the scaffold grows. The structure eventually stops growing, because the trailing ants can use the existing scaffold to cross unhindered. "In a way it surprised even us how simple the mechanism is. If you observe these collective phenomena for the first time, you intuitively think that there has to be some sort of communication among the ants. However, in this particular case, there is no need for it. Each individual adjusts its behaviour based on its own experience as it crosses," Couzin explains.

Taking inspiration from nature As human technological and social systems increase in complexity, it is crucial to find and implement mechanisms that robustly and rapidly correct for errors, increasing stability. The example of scaffolding in Eciton army ants offers one such mechanism. Due to its simplicity - only requiring information about the state of individual elements instead of complex group-level communication - this may serve as a blueprint for robust yet flexible engineered systems with similar distributed forms of control. Lutz, an architect whose fascination with self-organized patterns in biology led to his PhD and postdoctoral research on collective behaviour and self-assembly in Couzin's lab, concludes: "Because the mechanism is quite simple in terms of sensing and communication, it may be useful for applications at many scales, across disciplines. These range from swarm robotics, where restrictions on sensing and communication can be limiting factors, to the design of self-healing materials, bio-fabrication techniques, and new models of responsive infrastructure."

INFORMATION:

The study received funding from the National Science Foundation (NSF, US), the Office of Naval Research (ONR, US), the Deutsche Forschungsgemeinschaft (DFG, Germany) under Germany's Excellence Strategy (EXC 2117; "Centre for the Advanced Study of Collective Behaviour"), the Max Planck Society (MPG, Germany), the Australian Research Council (ARC, Australia), the Santa Fe Institute (US), and Princeton University's Department of Ecology and Evolutionary Biology (US).

Key facts: * The embargo on the paper will lift on the 19th of April at 3:00 PM U.S. Eastern time! * Original study: Matthew J. Lutz, Chris R. Reid, Christopher J. Lustri, Albert B. Kao, Simon Garnier, and Iain D. Couzin (2021) "Individual error correction drives responsive self-assembly of army ant scaffolds", PNAS * Ants of the species Eciton burchellii self-organize into temporary support structures termed "scaffolds" to avoid traffic disruption and the loss of prey resources when crossing sloped surfaces. * Data suggest that the collective behaviour is controlled by the action of individual animals without a need for complex group-level communication. * The proposed mechanism may serve as a blueprint for robust yet flexible engineered systems using similar forms of distributed control. * Funding: National Science Foundation (NSF; US), Office of Naval Research (ONR, US), Deutsche Forschungsgemeinschaft (DFG, Germany) under Germany's Excellence Strategy (EXC 2117; "Centre for the Advanced Study of Collective Behaviour"), Max Planck Society (MPG, Germany), Australian Research Council (ARC, Australia), Santa Fe Institute (US), and Princeton University (US).

Note to editors: You can download the photos and a video here:

Photo 1: https://cms.uni-konstanz.de/fileadmin/pi/fileserver/2021_EXTRA/learning_about_system_stability_from_ants_image_james_herndon.JPG Caption: The army ant Eciton burchellii. Copyright: James Herndon

Photo 2: https://cms.uni-konstanz.de/fileadmin/pi/fileserver/2021_EXTRA/learning_about_system_stability_from_ants_image_matthew_lutz.jpg Caption: Eciton army ants self-organize into architectural structures called "scaffolds" to ensure traffic flow on sloped surfaces. Copyright: Matthew Lutz

Video: https://cms.uni-konstanz.de/fileadmin/pi/fileserver/2021_EXTRA/learning_about_system_stability_from_ants_image_matthew_lutz_video_matthew_lutz_chris_reid_simon_garnier_and_iain_couzin.mp4 Caption: Timelapse of scaffold formation at two different slope angles (top: 50°, bottom: 90°). Copyright: Matthew Lutz, Chris Reid, Simon Garnier, and Iain Couzin

Contact: University of Konstanz
Communications and Marketing
Phone: + 49 7531 88-3603
Email: kum@uni-konstanz.de


[Attachments] See images for this press release:
Learning about system stability from ants

ELSE PRESS RELEASES FROM THIS DATE:

POT1 gene mutation predisposes to glioma and affects survival in a sex-specific manner

2021-04-19
Researchers at Baylor College of Medicine and collaborators at other institutions have discovered that POT1, a gene known to be associated with risk of glioma, the most common type of malignant brain tumor, mediates its effects in a sex-specific manner. Researchers found that female mice with glioma that lacked the gene survived less than males. This led them to investigate human glioma cells, where they found that low POT1 expression correlated with reduced survival in females. Published in the journal Cancer Research, the study also shows that, compared to males', female tumors had reduced expression of immune signatures and increased expression of cell replication markers, suggesting that the immune response and tumor cell proliferation seemed to be ...

Scientists identify protein that could serve as a therapeutic target in lung cancer

2021-04-19
Scientists at VCU Massey Cancer Center have identified a protein that operates in tandem with a specific genetic mutation to spur lung cancer growth and could serve as a therapeutic target to treat the disease. Mutations in the p53 gene are found in more than half of all cancers, but it remains difficult to effectively target the gene with drugs even decades after its discovery. Though previous research has shown that p53 acts as a tumor suppressor and initiates cancer cell death in its natural state, a new study led by Sumitra Deb, Ph.D., suggests that gain-of-function (GOF) mutations -- a type of mutation where the changed gene has an added function ...

New AI tool tracks evolution of COVID-19 conspiracy theories on social media

New AI tool tracks evolution of COVID-19 conspiracy theories on social media
2021-04-19
LOS ALAMOS, N.M., April 19, 2021--A new machine-learning program accurately identifies COVID-19-related conspiracy theories on social media and models how they evolved over time--a tool that could someday help public health officials combat misinformation online. "A lot of machine-learning studies related to misinformation on social media focus on identifying different kinds of conspiracy theories," said Courtney Shelley, a postdoctoral researcher in the Information Systems and Modeling Group at Los Alamos National Laboratory and co-author of the study that was published last week in the Journal of ...

Penn study finds reassuring data on common heart valve procedure, MitraClip

2021-04-19
PHILADELPHIA-- A retrospective study led by researchers from Penn Medicine found that with MitraClip for treatment of secondary mitral regurgitation (MR), a heart disease associated with problems in the left ventricle, there was no negative effect of having a slightly smaller mitral valve opening as long as there was good reduction of the mitral regurgitation. The study is published today in JACC: Cardiovascular Interventions. "This data is very reassuring for physicians who place MitraClips in patients with secondary mitral regurgitation. It demonstrates that the benefits of MR reduction in patients with heart failure were maintained even when mild-to-moderate mitral stenosis, which can be caused by a narrowing of the ...

Addressing and integrating social determinants of health effective in reducing blood pressure in pat

Addressing and integrating social determinants of health effective in reducing blood pressure in pat
2021-04-19
While cardiovascular disease (CVD) remains the leading cause of death globally, new research led by NYU Grossman School of Medicine and Moi University School of Medicine (Kenya) found that addressing and incorporating social determinants of health (such as poverty and social isolation) in the clinical management of blood pressure in Kenya can improve outcomes for patients with diabetes or hypertension. The study -- recently published online in The Journal of the American College of Cardiology - found that after one year, patients who received a multi-component intervention that combined community microfinance groups with group medical visits (where patients with similar medical conditions met together with a clinician and community health worker) ...

Research inside hill slopes could help wildfire and drought prediction

2021-04-19
A first-of-its-kind study led by The University of Texas at Austin has found that rock weathering and water storage appear to follow a similar pattern across undulating landscapes where hills rise and fall for miles. The findings are important because they suggest that these patterns could improve predictions of wildfire and landslide risk and how droughts will affect the landscape, since weathering and water storage influence how water and nutrients flow throughout landscapes. "There's a lot of momentum to do this work right now," said study co-author Daniella Rempe, an assistant professor at the UT Jackson School of Geosciences Department of Geological Sciences. "This kind of data, across large scales, is what is needed to inform next-generation models of land-surface processes." The ...

New algorithm uses online learning for massive cell data sets

2021-04-19
The fact that the human body is made up of cells is a basic, well-understood concept. Yet amazingly, scientists are still trying to determine the various types of cells that make up our organs and contribute to our health. A relatively recent technique called single-cell sequencing is enabling researchers to recognize and categorize cell types by characteristics such as which genes they express. But this type of research generates enormous amounts of data, with datasets of hundreds of thousands to millions of cells. A new algorithm developed by Joshua Welch, Ph.D., of the Department of Computational Medicine and Bioinformatics, Ph.D. candidate Chao Gao and their team uses online learning, greatly speeding up this process and providing a way for researchers ...

Light up your mind: A novel light-based treatment for neurodegenerative diseases

Light up your mind: A novel light-based treatment for neurodegenerative diseases
2021-04-19
A lot about the human brain and its intricacies continue to remain a mystery. With the advancement of neurobiology, the pathogenesis of several neurodegenerative diseases (ND) has been uncovered to a certain extent along with molecular targets around which current therapies revolve. However, while the current treatments offer temporary symptomatic relief and slow down the course of the disease, they do not completely cure the condition and are often accompanied by a myriad of side effects that can impair normal daily functions of the patient. Light stimulation has been proposed as a promising therapeutic alternative for treating various ND like ...

The auditory system tracks moving sounds

The auditory system tracks moving sounds
2021-04-19
The brain's auditory system tracks the speed and location of moving sounds in the same way the visual system tracks moving objects. The study recently published in eNeuro lays the groundwork for more detailed research on how humans hear in dynamic environments. People who use hearing aids have trouble discriminating sounds in busy environments. Understanding if and how the auditory system tracks moving sounds is vital to improving hearing aid technology. Prior research utilizing eye movements to gauge whether the brain is following the trajectory of a moving sound indicates it cannot. A new study from García-Uceda Calvo et al. instead used head movements, a more accurate measure of sound tracking. The team analyzed head movements of hearing ...

Novel drug regenerates erectile nerves damaged by prostate surgery

Novel drug regenerates erectile nerves damaged by prostate surgery
2021-04-19
April 19, 2021--(BRONX, NY)--Researchers at Albert Einstein College of Medicine have developed a topical drug that regenerates and restores the function of erectile nerves damaged by radical prostatectomy, the most common treatment for localized prostate cancer. The drug was tested in rats, and the findings were published online today in JCI Insight. "Erectile dysfunction (ED) after radical prostatectomy has a major impact on the lives of many patients and their partners," said study co-leader David J. Sharp, Ph.D., professor of physiology & biophysics and of ophthalmology and visual sciences and professor in the Dominick P. Purpura Department of Neuroscience at Einstein. "Since rats are reliable animal models in urologic research, our drug offers real hope of normal sexual ...

LAST 30 PRESS RELEASES:

Scientists model 'true prevalence' of COVID-19 throughout pandemic

New breakthrough to help immune systems in the fight against cancer

Through the thin-film glass, researchers spot a new liquid phase

Administering opioids to pregnant mice alters behavior and gene expression in offspring

Brain's 'memory center' needed to recognize image sequences but not single sights

Safety of second dose of mRNA COVID-19 vaccines after first-dose allergic reactions

Changes in disparities in access to care, health after Medicare eligibility

Use of high-risk medications among lonely older adults

65+ and lonely? Don't talk to your doctor about another prescription

Exosome formulation developed to deliver antibodies for choroidal neovascularization therapy

Second COVID-19 mRNA vaccine dose found safe following allergic reactions to first dose

Plant root-associated bacteria preferentially colonize their native host-plant roots

Rare inherited variants in previously unsuspected genes may confer significant risk for autism

International experts call for a unified public health response to NAFLD and NASH epidemic

International collaboration of scientists rewrite the rulebook of flowering plant genetics

Improving air quality reduces dementia risk, multiple studies suggest

Misplaced trust: When trust in science fosters pseudoscience

Two types of blood pressure meds prevent heart events equally, but side effects differ

New statement provides path to include ethnicity, ancestry, race in genomic research

Among effective antihypertensive drugs, less popular choice is slightly safer

Juicy past of favorite Okinawan fruit revealed

Anticipate a resurgence of respiratory viruses in young children

Anxiety, depression, burnout rising as college students prepare to return to campus

Goal-setting and positive parent-child relationships reduce risk of youth vaping

New research identifies cancer types with little survival improvements in adolescents and young adul

Oncotarget: Replication-stress sensitivity in breast cancer cells

Oncotarget: TERT and its binding protein: overexpression of GABPA/B in gliomas

Development of a novel technology to check body temperature with smartphone camera

The mechanics of puncture finally explained

Extreme heat, dry summers main cause of tree death in Colorado's subalpine forests

[Press-News.org] Learning about system stability from ants