spicule

Definitions

  • WordNet 3.6
    • n spicule small pointed structure serving as a skeletal element in various marine and freshwater invertebrates e.g. sponges and corals
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Webster's Revised Unabridged Dictionary
    • Spicule A minute, slender granule, or point.
    • Spicule (Zoöl) Any small calcareous or siliceous body found in the tissues of various invertebrate animals, especially in sponges and in most Alcyonaria. "Description of the Illustration :""a Acerate; b Tricurvate, or Bowshaped; c d Hamate; e Broomshaped; f Scepterellate; g Spinispirulate; h Inequi-anchorate; i Sexradiate; j A Trichite Sheaf; k Six-rayed Capitate; l Rosette of Esperia ; m Equi-anchorate."
    • Spicule (Bot) Same as Spicula.
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Century Dictionary and Cyclopedia
    • n spicule A fine-pointed body resembling a needle: as, ice -spicules.
    • n spicule In botany:
    • n spicule A spikelet.
    • n spicule One of the small projections or points on the basidia of hymenomycetous fungi which bear the spores. There are usually four to each basidium. See sterigma.
    • n spicule In zoology, a hard, sharp body like a little spike, straight or curved, rod-like, or branched, or diversiform; a spiculum; a sclere: variously applied, without special reference to size or Shape. Specifically— One of the skeletal elements, scleres, or spicula of the protozoans, as radiolarians, either calcareous or silicious, coherent or detached. See cuts under Radiolaria and Sphærozoum.
    • n spicule In botany, the empty frustule of a diatom.
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Chambers's Twentieth Century Dictionary
    • n Spicule (bot.) a little spike—also Spic′ūla: a minute, slender granule or point
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Etymology

Webster's Revised Unabridged Dictionary
L. spiculum, a little point, a dart
Chambers's Twentieth Century Dictionary
L. spica, an ear of corn.

Usage

In literature:

Other theorists have explained the aurora as due to the accumulation of electricity on clouds or on spicules of ice in the upper air.
"A History of Science, Volume 3(of 5)" by Henry Smith Williams
Neve and ice surfaces were covered with sharp spicules, and the sides and bridges of crevasses were unmistakably thawed.
"The Home of the Blizzard" by Douglas Mawson
The skeleton of calcareous sponges consists of a number of spicules composed of carbonate of lime.
"Scientific American Supplement, No. 601, July 9, 1887" by Various
Sometimes instead of crystal plates the fall is of minute agglomerate spicules like tiny sea-urchins.
"The Worst Journey in the World, Volumes 1 and 2" by Apsley Cherry-Garrard
The contents may be clear yellow serum or watery pus; sometimes a small spicule of bone is discharged.
"Manual of Surgery" by Alexis Thomson and Alexander Miles
The morning of the 29th of March, 1909, a heavy and dense fog of frost spicules overhung the camp.
"A Negro Explorer at the North Pole" by Matthew A. Henson
More commonly, however, the fragments, if of any size, appear torn, and if small, are mere spicules.
"Surgical Experiences in South Africa, 1899-1900" by George Henry Makins
Spiculum: a small spicule or thin, pointed process.
"Explanation of Terms Used in Entomology" by John. B. Smith
The long, dark cells are brown cystidia, termed spicules by some to distinguish them from the colorless cystidia.
"Studies of American Fungi. Mushrooms, Edible, Poisonous, etc." by George Francis Atkinson
Spicules elongated into threads.
"The Mushroom, Edible and Otherwise" by M. E. Hard
Sometimes these tubes, or spicules, send out one or two lateral branches, each terminated by a spore.
"Fungi: Their Nature and Uses" by Mordecai Cubitt Cooke
Sponges are represented by spicules and anchor ropes.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 3" by Various
The mouth is terminal and anterior and surrounded by a ring of spicules or a half-ring of hooks.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 7" by Various
The latter contains the proximal moieties of the zooids and numerous but separate spicules.
"Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 2" by Various
Notice the arrangement, shape, and length of the spicules and of the fibers.
"A Guide for the Study of Animals" by Worrallo Whitney
At the same time the thecal plates degenerated into spicules.
"Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 10" by Various
A=Gemmule-spicules; B=flesh-spicules (from type specimen), x 240.
"Freshwater Sponges, Hydroids & Polyzoa" by Nelson Annandale
The tangentially disposed spicules are seen arranged in masses on the surface.
"Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2" by Various
Sea urchins were also abundant, and sponges contributed their spicules to form nodules of flint.
"The Elements of Geology" by William Harmon Norton
Have these spicules a regular arrangement?
"Elementary Zoology, Second Edition" by Vernon L. Kellogg
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In science:

De Pontieu et al. (2011) type II spicules observed in coronal holes (see the online movies).
Can coronal hole spicules reach coronal temperatures?
They are comprised of numerous high velocity thin long spicules (termed type II spicules) which evolve simultaneously.
Can coronal hole spicules reach coronal temperatures?
In Fig. 1 we show the three spicules which represent ‘bushes’ of many thin spicules which rise simultaneously forming a large spicule (see the online movies).
Can coronal hole spicules reach coronal temperatures?
The proper motion of the spicules was estimated by following individual spicules in as many images as possible.
Can coronal hole spicules reach coronal temperatures?
The spicules are clearly present in the chromospheric lines.
Can coronal hole spicules reach coronal temperatures?
In these lines as well as in transition region lines, the spicules appear as the so-called ‘macrospicules’, i.e. larger size with respect to the Ca ii H spicules.
Can coronal hole spicules reach coronal temperatures?
Koza, Rutten, and Vourlidas (2009) measured the dynamics of several Lyα spicules and found many similarities to the Hα dynamic fibrils despite the short VAULT time series.
The Structure and Dynamics of the Upper Chromosphere and Lower Transition Region as Revealed by the Subarcsecond VAULT Observations
For the moment, the above discussion suggests that spicules/fibrils may provide the mass heated to coronal temperatures (e.g., de Pontieu et al., 2007a).
The Structure and Dynamics of the Upper Chromosphere and Lower Transition Region as Revealed by the Subarcsecond VAULT Observations
In addition, the VAULT observation of spicules show that they extend higher and have larger widths but otherwise similar dynamics (Koza, Rutten, and Vourlidas, 2009) with their Hα counterparts.
The Structure and Dynamics of the Upper Chromosphere and Lower Transition Region as Revealed by the Subarcsecond VAULT Observations
I spicules and macro-spicules may need longer time series due to their longer lifetimes (Xia et al., 2005).
The Structure and Dynamics of the Upper Chromosphere and Lower Transition Region as Revealed by the Subarcsecond VAULT Observations
Evershed (often supersonic) flows and moving magnetic features in sunspots, convective collapse of flux tubes, supersonic horizontal flows in granules, moving spicules and other features in the chromosphere, high-frequency prominence oscillations, and magnetic reconnection are some examples.
Size matters
Abstract In the present work we derive a Differential Emission Measure (DEM) distribution from a region dominated by spicules.
Off-limb (spicule) DEM distribution from SoHO/SUMER observations
Rouppe van der Voort et al. (2009) correlated the off-limb type II spicules to ondisk Rapid Blueshifted Excursions (RBEs) and established that these features occur ubiquitously on the Sun.
Off-limb (spicule) DEM distribution from SoHO/SUMER observations
The authors suggested, therefore, that the recent observations of spicules by De Pontieu et al. (2011) in AIA/SDO 171 ˚A and 211 ˚A channels may come from the existence of transition region emission in these passbands.
Off-limb (spicule) DEM distribution from SoHO/SUMER observations
We, therefore, emphasise that future studies related to off-limb features, especially spicules, should adopt the use of the off-limb DEM.
Off-limb (spicule) DEM distribution from SoHO/SUMER observations
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