51.  There are also ambitious efforts to develop measurements for interactive media that advertisers and agencies would use in the same manner as television and radio ratings.

52.  This change will end an ambitious effort, begun almost two decades ago, to shelter all who knocked at the municipal door.

53.  Two months later, Ms. Davis is leading the most ambitious effort to date by a television network to deliver news in cyberspace.

54.  While Indianapolis is pursuing the most ambitious effort to turn city departments into businesses, scores of mayors around the country are fine-tuning services in ways that save money.

55.  Pinning their hopes on the use of radiation to sterilize male tsetse flies, African governments have launched an ambitious effort to eradicate sleeping sickness.

56.  But more ambitious efforts turned into fiascos that were colorful enough for, say, a Hollywood movie.

57.  In an ambitious effort to seduce wary Russians into putting their savings somewhere other than under their mattresses, Russia is creating its first Western-style mutual funds.

58.  On Wednesday, they will witness the beginning of the most ambitious effort yet to find justice and reconciliation.

59.  Spain has promised an ambitious effort to pursue negotiations for EU expansion into Eastern Europe during its presidency.

60.  The outcome could determine whether ambitious efforts to tackle climate change will stall or become re-energized.