DPN

DPN may refer to:

Portsmouth Yardstick

The Portsmouth Yardstick (PY) or Portsmouth handicap scheme is a term used for a number of related systems of empirical handicapping used primarily in small sailboat racing.

The handicap is applied to the time taken to sail any course, and the handicaps can be used with widely differing types sailboats. Portsmouth Numbers are updated with data from race results, normally annually. The various schemes are not directly linked, and ratings for the same class can and often do vary in the different schemes.

The most prominent Portsmouth Yardstick systems are probably those administered in the United States by the Portsmouth Numbers Committee, in the United Kingdom by the Royal Yachting Association (RYA) and in Australia by Victoria Yachting.

History

The original UK Portsmouth Yardstick was developed by Stanley Milledge, who was in charge of handicapping racing at the Langstone Sailing Club in 1947 using the Island One design as the scratch boat (having a value 100). In 1950 he received support from the Portsmouth Harbour Racing & Sailing Association to produce the first edition of the Langstone tables for club use when they would be known as Portsmouth numbers. In 1960 he handed over the administration to the RYA and in 1976 a new YR2 format was used, with the Langstone tables being removed in 1986. The Portsmouth Yardstick was extended to multihulls in 1973 and from 1977 four forms were used, for dinghy, multihull, keel and cruiser. Due to the increasing performance of boats, particularly multihulls, the base range of the numbers has been increased twice over the years and are now roughly centred on 1,000.

Nicotinamide adenine dinucleotide

Nicotinamide adenine dinucleotide (NAD) is a coenzyme found in all living cells. The compound is a dinucleotide, because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine base and the other nicotinamide. Nicotinamide adenine dinucleotide exists in two forms, an oxidized and reduced form abbreviated as NAD⁺ and NADH respectively.

In metabolism, nicotinamide adenine dinucleotide is involved in redox reactions, carrying electrons from one reaction to another. The coenzyme is, therefore, found in two forms in cells: NAD⁺ is an oxidizing agent – it accepts electrons from other molecules and becomes reduced. This reaction forms NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. However, it is also used in other cellular processes, the most notable one being a substrate of enzymes that add or remove chemical groups from proteins, in posttranslational modifications. Because of the importance of these functions, the enzymes involved in NAD metabolism are targets for drug discovery.