I was so sad to hear the news of David’s passing.  I worked with David on various projects over the last year at Zoetis, he was always so willing to help & chat through your thoughts on things.  He was incredibly knowledgeable and had a very good way of explaining things that weren’t necessarily straightforward, in a straightforward way.  I learned a lot from David over the last year and I am grateful that I was able to know him.  He was such a kind and patient man.  My thoughts are with his friends, family and colleagues who will all miss him dearly.