what is the major advantage of blast over smith-waterman
BLAST The main idea of BLAST is that there are often High-scoring Segment Pairs (HSP) contained in a statistically significant alignment. BLAST searches for high scoring sequence alignments between the query sequence and the existing sequences in the database using a heuristic approach that approximates the Smith-Waterman algorithm. However, the exhaustive Smith-Waterman approach is too slow for searching large genomic databases such as GenBank. Therefore, the BLAST algorithm uses a heuristic approach that is less accurate than the Smith-Waterman algorithm but over 50 times faster. [8] The speed and relatively good accuracy of BLAST are among the key technical innovations of the BLAST programs.
For Whom the Bell Tolls The enemy, apprised of the coming offensive, has prepared to ambush it in force and it seems unlikely that the blown bridge will do much to prevent a rout. Regardless of this, Jordan understands that he must still demolish the bridge unless he receives explicit orders not to. Lacking the detonation equipment stolen by Pablo, Jordan plans an alternative method to explode the dynamite by using hand grenades with wires attached so that their pins can be pulled from a distance. This improvised plan is considerably more dangerous because the men must be nearer to the explosion. While Pilar, Pablo, and other guerrilla members attack the posts at the two ends of the bridge, Jordan and Anselmo plant and detonate the dynamite, costing Anselmo his life when he is hit by a piece of shrapnel. While escaping, Jordan is maimed when a tank shoots his horse out from under him. Knowing that his wound is severe enough that he is highly unlikely to survive, and that he would slow the others down, he bids goodbye to María and ensures that she escapes to safety with the surviving guerrillas. He refuses an offer from Agustín to shoot him and lies in agony, hoping to kill an enemy officer and delay their pursuit of his comrades before dying. The narrative ends right before Jordan launches his ambush.