The protein sequences exhibit a quasi-symmetrical pattern of complementary charges that can form extended ladders of salt bridges.
A huge Canadian flag hung between the extended ladders of two fire trucks parked on a bridge over the road.
"Instead of extending the ladder that helped her climb to the top, she pulled it up behind her," Mr. Castro said.
Without space on firm ground to erect a 100ft hydraulic ladder, firefighters here still rely on old-fashioned extending wooden ladders, which usually reach low levels only; the amount of equipment that can be transported on their fire boats is limited; and when high tides swell, the canals boats often have difficulty passing under many of the bridges.
Driver crawls across ladder in US floods Jump to media player Firefighters in Texas extend a ladder to a stranded driver as the floodwaters wreak havoc below.
A fireman got out, extended his ladder and climbed up to cut the string.
He extended a ladder to the room and firefighters began making their way through the smoke and pitch darkness with flashlights, looking for children.
Around the same time, the police extended a ladder up to a second-floor bedroom window and brought out Mia Camby, who had locked herself in the room.
As people go about their daily lives, they are invited to undertake "tiny acts" of political participation (liking, sharing, tweeting, retweeting, following, uploading, viewing, signing, and so on) which extend the ladder of participation at the lower end.
