Reverse transcriptase is characteristic of retroviruses, including HIV (human immunodeficiency virus), the virus responsible for AIDS (acquired immunodeficiency syndrome). All retroviruses encode a polymerase enzyme in their pol gene that is both necessary and sufficient for the replication of their RNA genomes.
PDO positive phase global pattern. The Pacific Decadal Oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin.
The temperature in the Pacific Northwest is governed by the Pacific Decadal Oscillation (PDO)  a natural cycle. The following figure shows the annual mean temperature anomalies for the two 5x5 degree grids covering the Pacific Northwest coast of the U.S. -- western Oregon and Washington from 1900 to 2007.