Fluridone

Fluridone is an aquatic herbicide often used to control invasive plants. It is sold under the names Sonar, Avast! and Whitecap and is used in the United States to control hydrilla and Eurasian watermilfoil among other species. It is a systemic herbicide that works by interfering with carotene formation which leads to chlorophyll degradation. Fluridone is sold as a liquid and as a slow release solid because the herbicide level must be maintained for several weeks.

The chemical was first reported as a possible herbicide for cotton fields in 1976. It was registered with the U.S. Environmental Protection Agency in 1986 and has low toxicity to animals with no restrictions on swimming or drinking in treated water bodies. Fluridone breaks downs in the environment over days or weeks with the major degradation product being N-methyl formamide. The half-life of fluridone in soils and sediments is nine months.

Pharmaceutical

Fluridone's main action to disrupt photosynthesis in plants is by preventing the secretion of abscisic acid. As higher Eukaryotes, such as humans, also rely on an abscisic acid pathway to create inflammation in normal physiological processes, fluridone can be used as an anti-inflammatory drug for humans.

Sonar (disambiguation)

Sonar or SONAR often refers to a technique that uses sound propagation under water.

Sonar may also refer to:

Animals

People

Geography

Art, entertainment, and media

Fictional characters

Films and literature

Music

Computing

Sonar (keelboat)

The Sonar is a 7 m (23 ft) one-design keelboat for three to five people. It is bermuda-rigged, with a large mainsail and a 100% jib. The class is recognised by the International Sailing Federation.

The Sonar showcased disabled sailing at the 1996 Paralympic where the sport was a demonstration event with just the Sonar. Sailing and the Sonar as the equipment for the three person keelboat have been in every subsequent Paralympics. When being sailed by disabled it is crewed by 3, and sailed without a spinnaker. Instead, when running downwind a whisker pole is used to hold the jib out to windward for maximum exposed sail area. The Sonar is well suited for disabled sailing because of its large open cockpit making adaptations easy.

The Sonar was designed in 1979 by Bruce Kirby, designer of the popular Laser dinghy. Since then, over 800 boats have been built. Most of the fleet is in the USA, with smaller fleets in Britain and Canada. Since its adoption as a Paralympic class the Sonar has spread to many other countries as well.

Loop (knot)

In reference to knots, loop may refer to:

References

Turn (biochemistry)

A turn is an element of secondary structure in proteins where the polypeptide chain reverses its overall direction. For beta turns go to Beta turn.

Definition

According to one definition, a turn is a structural motif where the C^α atoms of two residues separated by few (usually 1 to 5) peptide bonds are close (< 7 Å), while the residues do not form a secondary structure element such as an alpha helix or beta sheet with regularly repeating backbone dihedral angles. Although the proximity of the terminal C^α atoms usually correlates with formation of a hydrogen bond between the corresponding residues, a hydrogen bond is not a requirement in this turn definition. That said, in many cases the H-bonding and C^α-distance definitions are equivalent.

Types of turns

Turns are classified according to the separation between the two end residues:

In an α-turn the end residues are separated by four peptide bonds ().

In a β-turn (the most common form), by three bonds ().

In a γ-turn, by two bonds ().

Loopback

Loopback, or loop-back, refers to the routing of electronic signals, digital data streams, or flows of items back to their source without intentional processing or modification. This is primarily a means of testing the transmission or transportation infrastructure.

Many example applications exist. It may be a communication channel with only one communication endpoint. Any message transmitted by such a channel is immediately and only received by that same channel. In telecommunications, loopback devices perform transmission tests of access lines from the serving switching center, which usually does not require the assistance of personnel at the served terminal. Loop around is a method of testing between stations that are not necessarily adjacent, where in two lines are used, with the test being done at one station and the two lines are interconnected at the distant station. A patch cable may also function as loopback, when applied manually or automatically, remotely or locally, facilitating a loop-back test.