Answer to Question 1
Manchester is used in Ethernet and other LANs, whereas Differential Manchester is used in token ring LANs. With Manchester, the direction of the transition in mid-interval, negative to positive or positive to negative, indicates the binary bit value. For a 1 bit, the transition is always from negative to positive; for a 0 bit, it is from positive to negative. This mid-bit transition serves not only to represent data, but also provides clocking. With Differential Manchester, the presence or absence of a transition at the beginning of a bit interval indicates the bit value. The transition in mid-interval is used only for self-clocking, not to provide data, which is an advantage.
Answer to Question 2
Digital signaling uses only two values: 0 and 1. These values are represented electronically. Because digital signals are one value or the other, with no variance in between, they are a discrete representation. This discrete representation means that digital signals have only a given, specific value. Digital signaling is usually less expensive than analog signaling because it requires less complex circuitry. Noise interference is less of a problem in digital signaling, making error detection and correction easier. A disadvantage is that digital signals are more susceptible to attenuation. This weakening of the signal is caused by friction. The longer the distance that a signal needs to travel though a circuit the more probable attenuation becomes. Different media, however, will suffer from attenuation at varying distances. Digital signals can be carried over copper or fiber-optic cables.
Common sites of colorectal cancer.
Common phlebotomy issues.
Diagonal pliers are another common tool that has many names.
Common Prefixes
Common restriction enzymes, with their recognition sequence, DNA cutting patterns, and sources
Manhattan plots resulting from a genome-wide association study of seven common human disease