Transcranial Doppler (TCD), first described in 1982 [1], is a noninvasive ultrasound (US) study that involves the use of a low-frequency (â¤2 MHz) transducer probe to insonate the basal cerebral arteries through relatively thin bone windows.
Details. as.character and is.character are generic: you can write methods to handle specific classes of objects, see InternalMethods. Further, for as.character the default method calls as.vector, so dispatch is first on methods for as.character and then for methods for as.vector.
A single concept is called a Bliss-word, which can consist of one or more Bliss-characters. In the case of multiple character Bliss-words, the main character is called the classifier which indicates the semantic or grammatical category to which the Bliss-word belongs.