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.
FROM THEORY TO PRACTICE. Character analysis represents one of the most common assignments given in language arts classes. A successful character analysis demands that students infer abstract traits and values from literal details contained in a text. This lesson plan not only asks students to infer those traits but also to show that knowledge by applying the traits as they create their own list from the character's perspective.