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.
San Andreas Fault boundary. A transform boundary is a type of strike-slip fault that occurs between crustal plates. The San Andreas Fault is the most famous transform fault. It starts in the south at the East Pacific Rise. The East Pacific Rise is a spreading center in the Pacific Ocean.