Ärna or Uppsala Airport (ICAO: ESCM) is an airport located northwest of Uppsala, Sweden. It is a base of the Swedish Air Force and the former home of the 16th Fighter Wing (F 16). In 2009, it was announced that the Armed Forces had the intention to phase out its airport unit on July 1, 2010 and hand over the operation of the airport to a private operator. However, on 19 December 2009, it was announced by the Supreme Commander that the Armed Forces will continue with its military air operations at the airport. This is because the alternative proposals to locate the flight operations were not feasible.

Commercial flights

The company Uppsala Airport AB (formerly Uppsala Air AB), formed in 2004, has applied to the government for permission to start commercial aviation at Ärna. The company claims, based on calculations made in 2009 and 2010, that in five years' time the airport could serve up to 1.6 million passengers every year. The emphasis would primarily be on low cost flights and charter flights.

Ribonucleic acid (RNA) is a polymeric molecule implicated in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the three major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand. Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the letters G, U, A, and C to denote the nitrogenous bases guanine, uracil, adenine, and cytosine) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome.

Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression, or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis, a universal function wherein mRNA molecules direct the assembly of proteins on ribosomes. This process uses transfer RNA (tRNA) molecules to deliver amino acids to the ribosome, where ribosomal RNA (rRNA) then links amino acids together to form proteins.

Rna22 is a pattern-based algorithm for the discovery of microRNA target sites and the corresponding heteroduplexes.

The algorithm is conceptually distinct from other methods for predicting microRNA:mRNA heteroduplexes in that it does not use experimentally validated heteroduplexes for training, instead relying only on the sequences of known mature miRNAs that are found in the public databases. The key idea of rna22 is that the reverse complement of any salient sequence features that one can identify in mature microRNA sequences (using pattern discovery techniques) should allow one to identify candidate microRNA target sites in a sequence of interest: rna22 makes use of the Teiresias algorithm to discover such salient features. Once a candidate microRNA target site has been located, the targeting microRNA can be identified with the help of any of several algorithms able to compute RNA:RNA heteroduplexes. A new version (v2.0) of the algorithm is now available: v2.0-beta adds probability estimates to each prediction, gives users the ability to choose the sensitivity/specificity settings on-the-fly, is significantly faster than the original, and can be accessed through http://cm.jefferson.edu/rna22/Interactive/.