While it is relatively easy to define what a hurricane or earthquake is, defining a drought is more subjective. Droughts do not have the immediate effects of floods, but sustained droughts can cause economic stress throughout an area. The word drought has various meanings, depending on a person's perspective.
For the software package, see Partition function for Interacting RNAs. Piwi-interacting RNA (piRNA) is the largest class of small non-coding RNA molecules expressed in animal cells. piRNAs form RNA-protein complexes through interactions with piwi proteins.
Quasenseâ¢ (levonorgestrel/ethinyl estradiol) is a prescription birth control pill (oral contraceptive) and is a generic version of SeasonaleÂ®. Unlike traditional birth control pills, Quasense is an extended-cycle contraceptive, allowing for menstrual periods only once every three months (four periods per year).