orbicule


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orbicule

[′ȯr·bə‚kyül]
(geology)
A nearly spherical body, up to 2 centimeters (0.8 inch) or more in diameter, in which the components are arranged in concentric layers.
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The orbicule surface ornamentation often resembles that of the pollen sexine (Rowley et al.
Ubisch and Kosmath are considered as pioneers in orbicule research, but they were most likely inspired by preceding papers by Chatin (1870; angiosperms), Mascre (1922; Boraginaceae), Schnarf (1923; Lilium), and Krjatchenko (1925; Lilium).
LEUVEN, Belgium and BOSTON -- Orbicule, developers of innovative Mac OS X software, today announced the integration of Wi-Fi Positioning software from Skyhook Wireless into Undercover.
Laptop theft is a serious threat to Mac owners," said Peter Schols, president of Orbicule.
Six orbicule types can be described in Rubiaceae (Huysmans et al.
Orbicules are tiny sporopollenin particles up to 3-4 [micro]m in
2000) found that the tribes Coffeeae, Octotropideae, Ixoreae, and Pavetteae are characterized by specific orbicule types.
Another problem that needs to be addressed is the relationship among tapetum type, sexine ornamentation, and orbicule type.
From the early days of orbicule research two other lists of taxa with presence/absence of orbicules were published.
It has been reported that [11] orbicules originate in the cytoplasm of the tapetal cells as lipoidal pro-orbicular bodies that accumulate below the membrane and eventually extrude to the cell surface (facing the locule) where they provide sporopollenin precursors for exine formation.
The circular patterns in this piece of ijolite are called orbicules --circular or ovoid structures that grow in concentric shells around a central core.
It also produces exine precursors, orbicules, and sporophytic recognition proteins and lipids which form the pollen coat (or pollenkitt or tryphine) (Echlin, 1971; Pacini et al.