1. To shoot. 3. To give a final sales talk in a projected swindle. 3. To smoke marijuana. "Get out the old gage (marijuana) and let's blast."

- american underworld dictionary - 1950

Exclamation used to convey frustration, annoyance, and/or things just not going to plan. Usually reserved for arch-nemesis and super-villain types.

blargh = B = blat

blast 1. v.,n.

Synonym for BLT, used esp. for large data sends over a network or comm line. Opposite of snarf. Usage: uncommon. The variant `blat' has been reported. 2. vt. [HP/Apollo] Synonymous with nuke (sense 3). Sometimes the message Unable to kill all processes. Blast them (y/n)? would appear in the command window upon logout.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.

While Blast (the one Xia referred to) is certainly not for everyone, "bad" is probably not a good way to put it. During the time that Blast performed at the London Apollo Theater, it was advertised as a standing ovation every night, and they weren't lying. More than one person (quite a few, I've heard) have returned to see the performance several times.

Blast is fairly unique so far. While it does bear resemblances to a high school marching band, it's more closely evolved from drum and bugle corps. Nearly every one of Blast's ~70 performers is a former member of a corps, forced out by DCI rules prohibiting performers over 21.

Really, though, Blast is beyond the drum corps level (and, therefore, light-years past high school marching band). Their show runs from traditional jazz/blues, to ballet score, Broadway musical, awe-inspiring percussion breaks, and trumpet solos with enough emotion to bring tears to the eyes of audience members -- All while executing drill that would make your high school marching band director drool in awe. I recommend it both as someone who's well on his way to wearing the tape out, and as someone who's already horded tickets for the St. Louis performance.

"Blast - And a truer word was never spoken. A terrific good time -- explosive entertainment. It is indeed a blast." -Chicago Tribune

BLAST, or basic local alignment search tool, is an approach to rapid sequence comparison introduced in 1990 by bioinformaticist Stephen Altschul. It is often used to compare two large sets of sequences with one another, quickly uncovering long and significant similarities between a member of one set and a member of another.

BLAST is a fundamental tool in the field of bioinformatics, an aspect of which revolves around the comparison of huge amounts of genetic sequence data in order to find similarities, called homologs. BLAST enables this to be done over a large number of sequences quite quickly.

The BLAST algorithm is quite clever, and its speediness makes it possible to locate matches to sequences of reasonable size (1,000 to 10,000 characters in length) to sets of sequences much, much larger (all of GenBank, for instance), and do it in reasonable time.

In a nutshell, the BLAST algorithm is a heuristic search method that seeks words of length W that score at least T when aligned with the query and scored with a substitution matrix. Pairs that score T or better are extended in both directions in an attempt to fina a locally optimal ungapped alignment or HSP (high scoring pair) with a score of at least S or an E value lower than the specified thresholds. HSPs that meet these criteria will be returned by BLAST, provided they do not exceed the cutoff value specified for number of descriptions and/or alignments to report.

Lost yet? Let's explain what's going on in more detail. Let's start off by saying that BLAST takes several inputs, and understanding each of these inputs in turn leads to a greater understanding of how the BLAST algorithm works.

The first important element is the database of sequences that we will be searching through. There are various ways to prepare these for searching; the most common method is to divide them up into small pieces and record the location of the pieces, then assemble them using some known string searching algorithm, such as a suffix tree.

The second important element is the substitution matrices. A substitution matrix is a table which indicates the likelihood that one small piece of information can replace another without any significant problems. In terms of genetics, the question usually revolves around whether or not the change of one base pair or one amino acid can alter the resulting protein, and if it does, whether or not the alteration is significant enough to change the resulting protein. The impact of each of these changes is given a score, with a higher score indicating that not much change is evident, and a lower score meaning that a major unacceptable change is evident. Obviously, a perfect match has the highest possible score.

There are various methods for indexing the scoring matrices against the database. One method is that for each possible piece, a small list of sequences is assembled in order of substitution score from the matrix. This means that when a sequence is received, it can be broken up and compared to its list, then the elements in this list can be searched using a standard speedy exact-match string algorithm, like a suffix tree.

Obviously, the third element of importance is the search sequence or sequences. Without something to compare against the database, there would be no purpose in having a database, would there?

Now things begin to get interesting. For simplicity and terminology sake, let's say that we are only going to BLAST one sequence against a large database of sequences. The BLAST algorithm works by breaking this sequence down into small words of length W (the fourth element, which is passed as an option much like the search sequence is). These words are then compared to the database itself, already broken down into words of length W. These comparisons are usually through some sort of intermediary data structure based on a substitution matrix based sort.

The fifth element is a quality threshold level T. When the search occurs, each word in the search sequence is matched to words in the database that pass the basic quality threshold test; these are noted. Once all of these matches are found, then the sequence is slowly stretched out, extending beyond the word size both earlier and later in the search sequence, and is compared to the matches. If the stretching continues to maintain an acceptable average threshold (the sixth element) and the exact matching of the sequence is above another threshold (the seventh element), then it is considered a good match and BLAST will report the match. Otherwise, BLAST discards it.

It is important to note that with any reasonable level of cutoff settings, BLAST discards virtually every match that it finds. You can search a large set of sequences against a huge database and still get only a small number of matches using BLAST. That, in itself, is part of why BLAST is so efficient; it discards unacceptable matches very quickly and gets on to the next one.

BLAST is a clever tool that fills a need in an emerging scientific field. It enables the geneticist and the bioinformaticist to quickly conduct large scale searches against databases with results that actually have biological meaning, thanks to the substitution matrices. This alone is revolutionizing the field of genetics.

Blast (?), n. [AS. blst a puff of wind, a blowing; akin to Icel. blastr, OHG. blast, and fr. a verb akin to Icel. blasa to blow, OHG. blasan, Goth. blsan (in comp.); all prob. from the same root as E. blow. See Blow to eject air.]


A violent gust of wind.

And see where surly Winter passes off, Far to the north, and calls his ruffian blasts; His blasts obey, and quit the howling hill. Thomson.


A forcible stream of air from an orifice, as from a bellows, the mouth, etc. Hence: The continuous blowing to which one charge of ore or metal is subjected in a furnace; as, to melt so many tons of iron at a blast.

⇒ The terms hot blast and cold blast are employed to designate whether the current is heated or not heated before entering the furnace. A blast furnace is said to be in blast while it is in operation, and out of blast when not in use.


The exhaust steam from and engine, driving a column of air out of a boiler chimney, and thus creating an intense draught through the fire; also, any draught produced by the blast.


The sound made by blowing a wind instrument; strictly, the sound produces at one breath.

One blast upon his bugle horn Were worth a thousand men. Sir W. Scott.

The blast of triumph o'er thy grave. Bryant.


A sudden, pernicious effect, as if by a noxious wind, especially on animals and plants; a blight.

By the blast of God they perish. Job iv. 9.

Virtue preserved from fell destruction's blast. Shak.


The act of rending, or attempting to rend, heavy masses of rock, earth, etc., by the explosion of gunpowder, dynamite, etc.; also, the charge used for this purpose.

"Large blasts are often used."



A flatulent disease of sheep.

Blast furnace, a furnace, usually a shaft furnace for smelting ores, into which air is forced by pressure. -- Blast hole, a hole in the bottom of a pump stock through which water enters. -- Blast nozzle, a fixed or variable orifice in the delivery end of a blast pipe; -- called also blast orifice. -- In full blast, in complete operation; in a state of great activity. See Blast, n., 2. [Colloq.]


© Webster 1913.

Blast, v. t. [imp. & p. p. Blasted; p. pr. & vb. n. Blasting.]


To injure, as by a noxious wind; to cause to wither; to stop or check the growth of, and prevent from fruit-bearing, by some pernicious influence; to blight; to shrivel.

Seven thin ears, and blasted with the east wind. Gen. xii. 6.


Hence, to affect with some sudden violence, plague, calamity, or blighting influence, which destroys or causes to fail; to visit with a curse; to curse; to ruin; as, to blast pride, hopes, or character.

I'll cross it, though it blast me. Shak.

Blasted with excess of light. T. Gray.


To confound by a loud blast or din.

Trumpeters, With brazen din blast you the city's ear. Shak.


To rend open by any explosive agent, as gunpowder, dynamite, etc.; to shatter; as, to blast rocks.


© Webster 1913.

Blast, v. i.


To be blighted or withered; as, the bud blasted in the blossom.


To blow; to blow on a trumpet.


Toke his blake trumpe faste And gan to puffen and to blaste. Chaucer.


© Webster 1913.

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