A method and apparatus for efficiently transmitting large multimedia data over a wireless network are provided. During a rotation of an encoder rotor having rotary slits formed at the same intervals on the encoder rotor and continuous contrast patterns formed between the respective rotary slits, analog sensor signals \u03b8a to \u03b8d detected in proportion to the contrast patterns are compared with a switching-onoff command signal controlled by a digital-to-analog converter. A sensing circuit senses the load current, to thereby generate a sense signal in accordance with the load current. Thus changing the width of the thin film heaters andor the amount of the supply current thereto enables the permanent control of the effective refractive index independently in the transverse electric polarization mode and the transverse magnetic polarization mode. Specifically, isolated nucleic acids, polypeptides, host cells, and methods and materials for producing 3-HP and other organic compounds are disclosed.