Swarm intelligence

A new study of animal swarms uncovers some new features of their collective behavior when overcrowding sets in

2013-03-15

(Press-News.org) Swarming is the spontaneous organised motion of a large number of individuals. It is observed at all scales, from bacterial colonies, slime moulds and groups of insects to shoals of fish, flocks of birds and animal herds. Now physicists Maksym Romenskyy and Vladimir Lobaskin from University College Dublin, Ireland, have uncovered new collective properties of swarm dynamics in a study just published in EPJ B. Ultimately, this could be used to control swarms of animals, robots, or human crowds by applying signals capable of emulating the underlying interaction of individuals within the swarm, which could lead to predicted motion patterns elucidated through modelling.

The authors were inspired by condensed matter models, used for example in the study of magnetism, which were subsequently adapted to be biologically relevant to animal swarms. In their model, in addition to the ability to align with its neighbours, each model animal is endowed with two new features: one for collision avoidance and another preventing direction change at every step to ensure persistence of motion. The team performed computer simulations of up to 100,000 self-propelled particles, each mimicking an individual animal and moving at a constant speed on a plane surface.

They found that when the swarm becomes overcrowded, the globally ordered motion breaks down. At high density and when the nearest neighbours are within one step of each other, each animal can no longer decide on the safe direction of motion. Instead, it is busy correcting its motion to avoid collisions.

They also described, for the first time, a power law that quantifies the average degree of alignment in the direction of motion for animals within the swarm. The law describes how the alignment decays from the centre of the swarm, where animals can best judge the swarm motion due to their maximum number of neighbours, to the periphery.

### Reference M. Romenskyy and V. Lobaskin (2013), Statistical properties of swarms of self-propelled particles with repulsions across the order-disorder transition, European Physical Journal B, DOI 10.1140/epjb/e2013-30821-1

For more information, please visit http://www.epj.org

The full-text article is available to journalists on request.

ELSE PRESS RELEASES FROM THIS DATE:

Mobile LIDAR technology expanding rapidly

2013-03-15

CORVALLIS, Ore. – Imagine driving down a road a few times and obtaining in an hour more data about the surrounding landscape than a crew of surveyors could obtain in months. Such is the potential of mobile LIDAR, a powerful technology that's only a few years old and promises to change the way we see, study and record the world around us. It will be applied in transportation, hydrology, forestry, virtual tourism and construction – and almost no one knows anything about it. That may change with a new report on the uses and current technology of mobile LIDAR, which has ...

Dinosaur-era climate change study suggests reasons for turtle disappearance

2013-03-15

The dry, barren prairie around Alberta's Drumheller area was once a lush and subtropical forest on the shores of a large inland sea, with loads of wetlands inhabited by dinosaurs, turtles, crocodiles and small mammals. But that changed about 71-million-years ago, according to a new study by researchers Annie Quinney and Darla Zelenitsky in paleontology at the University of Calgary. The researchers' calculations show that drastic climate change occurred during a five-million-year period in Alberta's badlands. At this time, the wetlands dried up and the warm humid climate ...

Penn research shows that suppressing the brain's 'filter' can improve performance in creative tasks

2013-03-15

The brain's prefrontal cortex is thought to be the seat of cognitive control, working as a kind of filter that keeps irrelevant thoughts, perceptions and memories from interfering with a task at hand. Now, researchers at the University of Pennsylvania have shown that inhibiting this filter can boost performance for tasks in which unfiltered, creative thoughts present an advantage. The research was conducted by Sharon Thompson-Schill, the Christopher H. Browne Distinguished Professor of Psychology and director of the Center for Cognitive Neuroscience, and Evangelia ...

UCLA, Harvard experts propose new structure to guide governance of geoengineering research

2013-03-15

Geoengineering, the use of human technologies to alter the Earth's climate system — such as injecting reflective particles into the upper atmosphere to scatter incoming sunlight back to space — has emerged as a potentially promising way to mitigate the impacts of climate change. But such efforts could present unforeseen new risks. That inherent tension, argue two professors from UCLA and Harvard, has thwarted both scientific advances and the development of an international framework for regulating and guiding geoengineering research. In an article to be published March ...

Know thyself: How mindfulness can improve self-knowledge

2013-03-15

Mindfulness — paying attention to one's current experience in a non-judgmental way — might help us to learn more about our own personalities, according to a new article published in the March 2013 issue of Perspectives on Psychological Science, a journal of the Association for Psychological Science. Recent research has highlighted the fact that we have many blind spots when it comes to understanding our patterns of thinking, feeling, and behaving. Despite our intuition that we know ourselves the best, other people have a more accurate view of some traits (e.g., intellect) ...

Study shows how vitamin E can help prevent cancer

2013-03-15

COLUMBUS, Ohio – Researchers have identified an elusive anti-cancer property of vitamin E that has long been presumed to exist, but difficult to find. Many animal studies have suggested that vitamin E could prevent cancer, but human clinical trials following up on those findings have not shown the same benefits. In this new work, researchers showed in prostate cancer cells that one form of vitamin E inhibits the activation of an enzyme that is essential for cancer cell survival. The loss of the enzyme, called Akt, led to tumor cell death. The vitamin had no negative ...

No sons linked to lower contraception use in Nepal

2013-03-15

While poverty and under-education continue to dampen contraception use in Nepal, exacerbating the country's efforts to reduce maternal and child mortality rates, researchers say another, more surprising factor may be more intractable: Deeply held cultural preferences for sons over daughters. Writing in the March 7, 2013 online International Journal of Gynecology and Obstetrics, scientists from the University of California, San Diego School of Medicine found that geography (urban versus rural), age and levels of education, wealth and social status all predictably influenced ...

One gene, many mutations

2013-03-15

For deer mice living in the Nebraska Sandhills, color can literally be the difference between life and death. When they first colonized the region, the dark-coated mice stood out starkly against the light-colored, sandy soil, making them easy prey for predators. Over the next 8,000 years, however, the mice evolved a new system of camouflage – lighter coats, changes in the stripe on their tails and changes in the extent of pigment across their body – that allowed them to blend into their new habitat. Now Harvard researchers are using their example to answer one of ...

Water signature in distant planet shows clues to its formation, Lawrence Livermore research finds

2013-03-15

TORONTO, ON (date) – A team of international scientists including a Lawrence Livermore National Laboratory astrophysicist has made the most detailed examination yet of the atmosphere of a Jupiter-size like planet beyond our solar system. The finding provides astrophysicists with additional insight into how planets are formed. "This is the sharpest spectrum ever obtained of an extrasolar planet," said co-author Bruce Macintosh, an astronomer at Lawrence Livermore National Laboratory. "This shows the power of directly imaging a planetary system - the exquisite resolution ...

'Hot spots' ride a merry-go-round on Jupiter

2013-03-15

In the swirling canopy of Jupiter's atmosphere, cloudless patches are so exceptional that the big ones get the special name "hot spots." Exactly how these clearings form and why they're only found near the planet's equator have long been mysteries. Now, using images from NASA's Cassini spacecraft, scientists have found new evidence that hot spots in Jupiter's atmosphere are created by a Rossby wave, a pattern also seen in Earth's atmosphere and oceans. The team found the wave responsible for the hot spots glides up and down through layers of the atmosphere like a carousel ...

Researchers from MARE ULisboa discover that the European catfish, an invasive species in Portugal, has a prolonged breeding season, enhancing its invasive potential

Swarm intelligence

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: