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.
If you are not getting the results you want in life, the first place to look is at how you are interacting with the world. Positive character traits can be developed in ourselves. There is a simple, three step process to integrate a new positive trait into your life. 1. Notice what you want to change.