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Pheromones In Animals

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  Pheromones Pheromones are invisible chemical signals between members of the same species. This is probably the most common mode of communication in the animal kingdom. The discovery of pheromones We meet references to the existence of pheromones from very ancient times. The ancient Greeks were familiar with the invisible signals that dogs emit during estrus and that males feel. They knew that if the female's secretions were placed on a towel, the male would follow the towel. It's not the sound the females made, it's the smell. The problem is that the number of pheromones is very small, and most people are not able to smell such signals between animals. Only in the 1950s, after twenty years of work by a group of chemists led by Adolf Butenandt, who received the Nobel Prize for his work on human molecules - steroids, was a paper published with the chemical definition of the first pheromone. It was bombykol, the female sex pheromone of the silkworm.      How Pheromone...
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Types of pheromones

Classification of pheromones According to their effects, pheromones are divided into two main types: releasers and primers. Releasers  ( eng.  releaser ) encourage the individual to take some immediate action; are used to attract mates, signal danger, and prompt other immediate action. Primers ( eng.  primer ) are used to form certain behavior and influence the development of other individuals: for example, a special pheromone secreted by the queen bee and suppresses the sexual development of other female bees, thus turning them into worker bees. As separate names for some types of pheromones, the following can be given: epagons - sexual attractants ; odmihnions - path marks indicating the way to a hole or to found prey, marks on the boundaries of an individual territory; toribones - pheromones of fear and anxiety ; gonophyons - pheromones that induce sex change ; gamophions - pheromones of puberty; etofion - pheromones of behavior; Lichneumons are pheromones that disguis...
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Spatiotemporal signal propagation in complex networks

Spatiotemporal signal propagation in complex networks A major achievement in the study of complex networks is the realization that diverse systems, from sub-cellular biology to social networks, exhibit universal topological characteristics. Yet, such universality does not naturally translate to the dynamics of these systems, as dynamic behavior cannot be uniquely predicted from topology alone. Rather, it depends on the interplay of the network’s topology with the dynamic mechanisms of interaction between the nodes. Hence, systems with similar structure may exhibit profoundly different dynamic behavior. We therefore seek a general theoretical framework to help us systematically translate topological elements into their predicted dynamic outcome. Here, we offer such a translation in the context of signal propagation, linking the topology of a network to the observed spatiotemporal spread of perturbative signals across it, thus capturing the network’s role in propagating local information...
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