Activator
Activator may refer to:
Enzyme activator
Enzyme activators are molecules that bind to enzymes and increase their activity. They are the opposite of enzyme inhibitors. These molecules are often involved in the allosteric regulation of enzymes in the control of metabolism. An example of an enzyme activator working in this way is fructose 2,6-bisphosphate, which activates phosphofructokinase 1 and increases the rate of glycolysis in response to the hormone insulin.
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Activator (genetics)
A transcriptional activator is a protein (transcription factor) that increases gene transcription of a gene or set of genes. Most activators are DNA-binding proteins that bind to enhancers or promoter-proximal elements.
Most activators function by binding sequence-specifically to a DNA site located in or near a promoter and making protein-protein interactions with the general transcription machinery (RNA polymerase and general transcription factors), thereby facilitating the binding of the general transcription machinery to the promoter. The DNA site bound by the activator is referred to as an "activator site." The part of the activator that makes protein-protein interactions with the general transcription machinery is referred to as an "activating region." The part of the general transcription machinery that makes protein-protein interactions with the activator is referred to as an "activation target."
Example
The catabolite activator protein (CAP; also known as cAMP receptor protein, CRP) activates transcription at the lac operon of the bacterium Escherichia coli.Cyclic adenosine monophosphate (cAMP) is produced during glucose starvation, binds to CAP, causes a conformational change that allows CAP to bind to a DNA site located adjacent to the lac promoter. CAP then makes a direct protein-protein interaction with RNA polymerase that recruits RNA polymerase to the lac promoter.
Quicksand
Quicksand is a colloid hydrogel consisting of fine granular material (such as sand or silt), clay, and water.
Quicksand forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that loses strength and cannot support weight. Quicksand can form in standing water or in upwards flowing water (as from an artesian spring). In the case of upwards flowing water, seepage forces oppose the force of gravity and suspend the soil particles.
The saturated sediment may appear quite solid until a sudden change in pressure or shock initiates liquefaction. This causes the sand to form a suspension and lose strength. The cushioning of water gives quicksand, and other liquefied sediments, a spongy, fluidlike texture. Objects in liquefied sand sink to the level at which the weight of the object is equal to the weight of the displaced soil/water mix and the submerged object floats due to its buoyancy.
Liquefaction is a special case of quicksand. In this case, sudden earthquake forces immediately increase the pore pressure of shallow groundwater. The saturated liquefied soil loses strength, causing buildings or other objects on that surface to sink or fall.
Finger Eleven
Finger Eleven is a Canadian rock band from Burlington, Ontario, formed in 1990. They have released seven total studio albums (six as Finger Eleven and one as Rainbow Butt Monkeys), with their album The Greyest of Blue Skies bringing them into the mainstream. The 2003 self-titled album achieved Gold status in the United States and Platinum in Canada, largely from the success of the single "One Thing", which marked the band's first placing on the US Hot 100 Chart at number 16. Their 2007 album, Them vs. You vs. Me, launched the single "Paralyzer", which went on to top numerous charts including the Canadian Hot 100 and both US rock charts, as well as reaching No. 6 on the US Hot 100 and No. 12 on the Australian Singles Chart. They won the Juno Award for Rock Album of the Year in 2008. It was later certified gold status in the US and multi platinum in Canada. They released their sixth studio album, Life Turns Electric, on October 5, 2010; it was nominated for a Juno Award for Best Rock Album of the Year. They released their first single, "Living in a Dream", adding a little bit of more of funk rock and dance rock, just like their hit song "Paralyzer". Five Crooked Lines, their 7th studio album, was released July 31, 2015, with "Wolves and Doors" as the lead single.
Quicksand (board game)
Quicksand is a board game published in 1989 by Parker Brothers.
Each player controls one of six explorers racing to discover an ancient temple. The object of the game is to be the first player to get your adventurer around the board from START to the finish line back at CAMP.
The player pawns represent a mustachioed archetypical British explorer, and they're in parts. To represent your sinking into the quicksand, you remove his feet, then his waist, and so on until only the pith helmet remains.
You actually start already partially mired (by an initial die roll); every turn you move forward a number of spaces given by your height, plus an optional movement die. You can never sink more than hat-deep (so you cannot be eliminated).
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