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.
Moral character or character is an evaluation of a particular individual's stable moral qualities. The concept of character can imply a variety of attributes including the existence or lack of virtues such as empathy, courage, fortitude, honesty, and loyalty, or of good behaviors or habits.