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Adaptive radiation is not a strictly vertebrate phenomenon, and examples are also known from among plants. The most famous example of adaptive radiation in plants is quite possibly the Hawaiian silverswords , named for alpine desert-dwelling Argyroxiphium species with long, silvery leaves that live for up to 20 years before growing a single ...
The cosmic microwave background radiation observed today is the most perfect blackbody radiation ever observed in nature, with a temperature of about 2.7 K. [51] It is a "snapshot" of the radiation at the time of decoupling between matter and radiation in the early universe. Prior to this time, most matter in the universe was in the form of an ...
An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, [1] that may or may not be associated with an increase in morphological disparity. [2] A significantly large and diverse radiation within a relatively short geologic time scale (e.g. a period or epoch) is often referred to as an ...
Phenotypic plasticity refers to some of the changes in an organism's behavior, morphology and physiology in response to a unique environment. [1] [2] Fundamental to the way in which organisms cope with environmental variation, phenotypic plasticity encompasses all types of environmentally induced changes (e.g. morphological, physiological, behavioural, phenological) that may or may not be ...
Pathogen-associated molecular patterns (PAMPs) are small molecular motifs conserved within a class of microbes, but not present in the host. [1] They are recognized by toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) in both plants and animals. [2]
Radiation hardening is the strengthening of the material in question by the introduction of defect clusters, impurity-defect cluster complexes, dislocation loops, dislocation lines, voids, bubbles and precipitates. For pressure vessels, the loss in ductility that occurs as a result of the increase in hardness is a particular concern.
A dose of 100 to 200 rad delivered to the entire body in less than a day may cause acute radiation syndrome (ARS), but is usually not fatal. Doses of 200 to 1,000 rad delivered in a few hours will cause serious illness, with poor prognosis at the upper end of the range. Whole body doses of more than 1,000 rad are almost invariably fatal. [3]
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