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PLANT DIVINATION. "Future changes in resource availability are also predicted and acted upon. It has been known for some years that light reflected from green vegetation has an enhanced far red/red (FR/R) ratio and contains more blue light than normal sunshine. Many plants perceive these parts of the light spectrum and thus model the possibility of future, not current, shading from competitors and thus future reductions of available light energy." http://link.springer.com/article/10.1007/s00114-005-0014-9 View in LinkedIn

COMPETING GRADIENTS. “Mound repair, therefore, is a race between numerous initiation sites to be the one that transitions to self-sustaining σ-building first. In the damaged mound, this is usually assured by a small bias toward more intense τ-building near the site of damage. This produces a denser concentration of initiation sites there, making the progress to spongy build slightly faster there.” https://link.springer.com/article/10.1007/s12304-016-9256-5 View in LinkedIn

STATISTICAL MOVEMENTS. “These initiation sites (“hypotheses”) are widespread throughout the damaged mound, and as repair progresses, these compete with one another for workers to “sustain” the hypothesis. In the end, the “winning” hypothesis will be the sites that can recruit enough workers to drive repair building most rapidly to the formation of a plug that blocks the passage. “Correctly” interpreting the distorted AC perturbation field in the damaged mound turns, therefore, on ensuring that plug formation takes place at the focal point of the distorted AC perturbation field.” https://link.springer.com/article/10.1007/s12304-016-9256-5 View in LinkedIn

THE HYPOTHESIS GRADIENT. “The statistical character of the transient perturbation field means that doing so is not a simple matter of swarms of termites migrating “up the gradient” to the site of injury. Rather, there is a complex swarm decision-making process at work, where different groups of termites each generate a multiplicity of “hypotheses” for where the site of damage is. A “hypothesis” is “posed” when a termite is exposed to a transient perturbation of some threshold intensity, which prompts the termite to deposit a dollop of wet clay.” https://link.springer.com/article/10.1007/s12304-016-9256-5 View in LinkedIn

INJURY TEST. “A breach in the mound also alters the shape of the mound’s AC perturbation field. Whereas the undisturbed mound has a field that is distributed roughly uniformly with respect to the mound surface, the field in a damaged mound now has a focus at the site of injury, where wind-induced transient perturbations will be most intense. Once an unexpected AC perturbation has drawn a termite swarm from the nest into the mound, the distorted AC field must be interpreted so that repair efforts are ultimately focused at the site of injury.” https://link.springer.com/article/10.1007/s12304-016-9256-5 View in LinkedIn

THE PARAMETERS. “Termites can interpret this field because they act essentially as mobile φ-transducers. In the steady regime of the nest, (low- to null φ), termites will carry out their activities unperturbed. A threshold change of φ, however, elicits a marked shift of the swarm’s behavior. In response to a pulse of CO2, for example, termites immediately stop what they are doing and begin to move about vigorously. They do not move about randomly, however. Some termites will rush toward the source of the perturbation. Others, called tocsins (“bell-ringers”) run away from the source and agitate other termites that may not have experienced the pulse directly. Eventually, a large wave of termites runs toward the perturbation source, consisting of termites that have experienced the perturbation directly as well as those…

ASSUMPTIONS. “In a DC field of, say, oxygen partial pressure (PO2), one can predict with some reliability, r(PO2), what the actual PO2 at a particular location in the mound might be, irrespective of time. Indeed, that is the very nature of a DC field: it contains within it no dimension of time. What is mapped in an AC perturbation field, in contrast, is the likelihood of a particular time-dependent change of PO2, that is dPO2/dt. For sake of brevity, let us call this φ (= dP/dt). Any location within a transient perturbation field is characterized by some probability distribution, r(φ). Within the mound, r(φ) is broad at the periphery, and tends toward peaked and skewed to low frequency in the center.” https://link.springer.com/article/10.1007/s12304-016-9256-5 View in LinkedIn