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Fluoroscopy was discontinued in shoe-fitting because the radiation exposure risk outweighed the trivial benefit. Only important applications such as health care , bodily safety, food safety , nondestructive testing , and scientific research meet the risk-benefit threshold for use.
A simplified Jablonski diagram illustrating the change of energy levels.. The principle behind fluorescence is that the fluorescent moiety contains electrons which can absorb a photon and briefly enter an excited state before either dispersing the energy non-radiatively or emitting it as a photon, but with a lower energy, i.e., at a longer wavelength (wavelength and energy are inversely ...
The eye of a bird is larger compared to the size of the animal than for any other group of animals, although much of it is concealed in its skull. The ostrich has the largest eye of any land vertebrate, with an axial length of 50 mm (2.0 in), twice that of the human eye. [1] Bird eye size is broadly related to body mass.
Some animals, such as chameleons and anoles, have a highly developed background adaptation response capable of generating a number of different colours very rapidly. [33] They have adapted the capability to change colour in response to temperature, mood, stress levels, and social cues, rather than to simply mimic their environment.
Many scientists have found the evolution of the eye attractive to study because the eye distinctively exemplifies an analogous organ found in many animal forms. Simple light detection is found in bacteria, single-celled organisms, plants and animals. Complex, image-forming eyes have evolved independently several times. [1]
Some reptiles, such as the sand lizard of Europe, have eyespots; in the sand lizard's case, there is a row of spots along the back, and a row on each side. [12]Many species of cat, including Geoffroy's cats, jungle cats, pampas cats, and servals, have white markings, whether spots or bars, on the backs of their ears; it is possible that these signal "follow me" to the young of the species.
A Delaware woman who was reported missing last week after she didn't show up to work for several days was found dismembered in a car over the weekend, police said.
This is a red pigment seen at the back of the eye in animals that have a white background to their eye called Tapetum lucidum. The pigment is not noticeable under photopic and mesopic conditions. The principle that the wavelength sensitivity does not change during scotopic vision led to the ability to detect two functional cone classes in ...