VARANASI, Sept. 17 -- A host of dignitaries, including defence minister Rajnath Singh, Uttar Pradesh chief minister Yogi Adityanath, his Andhra Pradesh counterpart N Chandrababu Naidu and several senior Bharatiya Janata Party (BJP) leaders, will participate in Prime Minister Narendra Modi's birthday celebrations in his parliamentary constituency Varanasi on Thursday, people familiar with the matter said on Wednesday. The celebrations will mark the launch of the BJP's month-long "Seva Sankalp Abhiyan" to commemorate Modi's 25 years in public service, first as Gujarat chief minister and then as PM. Rajnath Singh and Adityanath will flag off the "Seva Sankalp Bike Yatra" from Varanasi's Rudraksh International Convention Centre on September 17 ...