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Symmetry Breaking Of Escaping Ants
Symmetry breaking of escaping ants is a herd behaviour phenomenon observed when ants are constrained to a cell with two equidistant exits and then sprayed with an insect repellent. The ants tend to crowd one door more while trying to escape (i.e., there is a symmetry breaking in their escape behaviour), there by decreasing evacuation efficiency. Description This phenomenon arises in experiments where worker ants are enclosed into a circular cell with a glass cover in such a way that they can only move in two dimensions (i.e., ants cannot pass over one other). The cell has two exits located symmetrically relative to its center. The experiments consisted of two different set of trials. In the first set of trials, both exits were opened at the same time, letting the ants escape. After 30 repetitions, one door was used 13.666% more than the other. In the second set of trials, the configuration was identical, but a few seconds before opening the doors, a dose of 50 µL of an insect rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herd Behaviour
Herd behavior is the behavior of individuals in a group acting collectively without centralized direction. Herd behavior occurs in animals in herds, packs, bird flocks, fish schools and so on, as well as in humans. Voting, demonstrations, riots, general strikes, sporting events, religious gatherings, everyday decision-making, judgement and opinion-forming, are all forms of human-based herd behavior. Raafat, Chater and Frith proposed an integrated approach to herding, describing two key issues, the mechanisms of transmission of thoughts or behavior between individuals and the patterns of connections between them. They suggested that bringing together diverse theoretical approaches of herding behavior illuminates the applicability of the concept to many domains, ranging from cognitive neuroscience to economics. Animal behavior A group of animals fleeing from a predator shows the nature of herd behavior, for example in 1971, in the oft cited article "Geometry For The Selfish Her ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect Repellent
An insect repellent (also commonly called "bug spray") is a substance applied to skin, clothing, or other surfaces to discourage insects (and arthropods in general) from landing or climbing on that surface. Insect repellents help prevent and control the outbreak of insect-borne (and other arthropod-bourne) diseases such as malaria, Lyme disease, dengue fever, bubonic plague, river blindness, and West Nile fever. Pest animals commonly serving as vectors for disease include insects such as flea, fly, and mosquito; and ticks (arachnids). Some insect repellents are insecticides (bug killers), but most simply discourage insects and send them flying or crawling away. Nearly any would be fatal upon reaching the median lethal dose, but classification as an insecticide implies death even at lower doses. Effectiveness Synthetic repellents tend to be more effective and/or longer lasting than "natural" repellents. For protection against mosquito bites, the U.S. Centers for Diseas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetry Breaking
In physics, symmetry breaking is a phenomenon in which (infinitesimally) small fluctuations acting on a system crossing a critical point decide the system's fate, by determining which branch of a bifurcation is taken. To an outside observer unaware of the fluctuations (or "noise"), the choice will appear arbitrary. This process is called symmetry "breaking", because such transitions usually bring the system from a symmetric but disorderly state into one or more definite states. The phenomenon is part of most theories of everything. Symmetry breaking is thought to play a major role in pattern formation. In his 1972 ''Science'' paper titled "More is different" Nobel laureate P.W. Anderson used the idea of symmetry breaking to show that even if reductionism is true, its converse, constructionism, which is the idea that scientists can easily predict complex phenomena given theories describing their components, is not. Symmetry breaking can be distinguished into two types, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atta Insularis
''Atta insularis'' is a species of leafcutter ant, a New World ant of the subfamily Myrmicinae of the genus ''Atta'' endemic to Cuba. This species is from one of the two genera of advanced fungus-growing ants within the tribe Attini. This species is the largest and most notable species of ant of Cuba. ''A. insularis'' is unique to Cuba, and has great polymorphism. Its workers specialize in different activities. The warriors have remarkably large heads. They prefer to work at night, although they do by day, more if on cloudy days. The nests are huge, and may comprise one or several mounds that can be spaced several metres apart. The height of the mound can sometimes exceed a metre. These nests in natural sites can be very durable, even more than 50 years. This species is a pest of citrus, coffee, and various ''Pinus'' species. Quantitative studies in the behaviour of ''A. insularis'' has been performed both in laboratory-controlled conditions, and in the wild. Gallery Imag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Imported Fire Ant
The red imported fire ant (''Solenopsis invicta''), also known as the fire ant or RIFA, is a species of ant native to South America. A member of the genus ''Fire ant, Solenopsis'' in the subfamily Myrmicinae, it was Species description, described by Swiss entomologist Felix Santschi as a variant of ''Solenopsis saevissima, S. saevissima'' in 1916. Its current species, specific name ''invicta'' was given to the ant in 1972 as a separate species. However, the variant and species were the same ant, and the name was preserved due to its wide use. Though South American in origin, the red imported fire ant has been accidentally introduced in Australia, New Zealand, several Asian and Caribbean countries, and the United States. The red imported fire ant is Polymorphism (biology), polymorphic, as workers appear in different shapes and sizes. The ant's colours are red and somewhat yellowish with a brown or black Gaster (insect anatomy), gaster, but males are completely black. Red imported ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herd Behavior
Herd behavior is the behavior of individuals in a group acting collectively without centralized direction. Herd behavior occurs in animals in herds, packs, bird flocks, fish schools and so on, as well as in humans. Voting, demonstrations, riots, general strikes, sporting events, religious gatherings, everyday decision-making, judgement and opinion-forming, are all forms of human-based herd behavior. Raafat, Chater and Frith proposed an integrated approach to herding, describing two key issues, the mechanisms of transmission of thoughts or behavior between individuals and the patterns of connections between them. They suggested that bringing together diverse theoretical approaches of herding behavior illuminates the applicability of the concept to many domains, ranging from cognitive neuroscience to economics. Animal behavior A group of animals fleeing from a predator shows the nature of herd behavior, for example in 1971, in the oft cited article "Geometry For The Selfish H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicsek's Rule
Self-propelled particles (SPP), also referred to as self-driven particles, are terms used by physicists to describe autonomous agents, which convert energy from the environment into directed or persistent motion. Natural systems which have inspired the study and design of these particles include walking, swimming or flying animals. Other biological systems include bacteria, cells, algae and other micro-organisms. Generally, self-propelled particles often refer to artificial systems such as robots or specifically designed particles such as swimming Janus colloids, bimetallic nanorods, nanomotors and walking grains. In the case of directed propulsion, which is driven by a chemical gradient, this is referred to as chemotaxis, observed in biological systems, e.g. bacteria quorum sensing and ant pheromone detection, and in synthetic systems, e.g. enzyme molecule chemotaxis and enzyme powered hard and soft particles. Overview Self-propelled particles interact with each other, which c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are ''alarm signal, alarm pheromones'', ''food trail pheromones'', ''sex pheromones'', and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology. Background The portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω ''pheroo'' ('I carry') and ὁρμων ''hormon'' ('stimulating'). P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ants
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been classified. They are easily identified by their geniculate (elbowed) antennae and the distinctive node-like structure that forms their slender waists. Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies that may occupy large territories and consist of millions of individuals. Larger colonies consist of various castes of sterile, wingless females, most of which are workers (ergates), as well as soldiers (dinergates) and other specialised groups. Nearly all ant colonies also have some fertile males called "drones" and one or more fertile females called "queens" (gynes). The colonies are described as superorganisms because the ants appea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biophysics
Biophysics is an interdisciplinary science that applies approaches and methods traditionally used in physics to study biological phenomena. Biophysics covers all scales of biological organization, from molecular to organismic and populations. Biophysical research shares significant overlap with biochemistry, molecular biology, physical chemistry, physiology, nanotechnology, bioengineering, computational biology, biomechanics, developmental biology and systems biology. The term ''biophysics'' was originally introduced by Karl Pearson in 1892.Roland Glaser. Biophysics: An Introduction'. Springer; 23 April 2012. . The term ''biophysics'' is also regularly used in academia to indicate the study of the physical quantities (e.g. electric current, temperature, stress, entropy) in biological systems. Other biological sciences also perform research on the biophysical properties of living organisms including molecular biology, cell biology, chemical biology, and biochemistry. Overview ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistical Mechanics
In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. It does not assume or postulate any natural laws, but explains the macroscopic behavior of nature from the behavior of such ensembles. Statistical mechanics arose out of the development of classical thermodynamics, a field for which it was successful in explaining macroscopic physical properties—such as temperature, pressure, and heat capacity—in terms of microscopic parameters that fluctuate about average values and are characterized by probability distributions. This established the fields of statistical thermodynamics and statistical physics. The founding of the field of statistical mechanics is generally credited to three physicists: *Ludwig Boltzmann, who developed the fundamental interpretation of entropy in terms of a collection of microstates *James Clerk Maxwell, who developed models of probability distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
