Operation Safety Net is a health care outreach program operated through the Pittsburgh Mercy Hospital System and Catholic Health East. It provides medical care to homeless people living on the streets of Pittsburgh and recognized as one of nation’s first, targeted, full-time street medicine programs. Dr. Jim Withers started the program in 1992.

Nancy Jensen-Case is the founder of Dreamtime Sanctuary for animals outside Elgin, Texas. She is a graduate of the Episcopal Theological Seminary in Austin, Texas, and is a chaplain.

Keith Akers is a Christian vegetarian and environmental activist who lives in Englewood, Colo. He operates the Compassionate Spirit website, which includes articles and commentary on animal welfare from a Christian perspective.

James Serpell is a professor of humane ethics and animal welfare at the University of Pennsylvania’s school of veterinary medicine. He directs the Center for the Interaction of Animals and Society.

Andrew Isenberg is a history professor at Temple University in Philadelphia. He is an expert on the history of American environmentalism, especially in the American West. He contributed a chapter on the moral ecology of wildlife to the book Representing Animals.

David Dion DeGrazia is a philosophy professor at George Washington University in Washington, D.C. He has written about the ethics of animal research and is the author of Animal Rights: A Very Short Introduction.

Lori Gruen is an associate professor of philosophy and of women’s studies at Wesleyan University in Middletown, Conn. Among her areas of interest is injustice to animals. As a guest on a May 11, 2004, podcast of Philosophy Talk, she discussed the morality of eating animals.

Christine Gutleben is director of the animals and religion program for the Humane Society of the United States. She has an undergraduate degree in religious studies and a master’s degree from a theology school, where she studied theology and ethical food choices.

Saurabh Dalal is president of the Vegetarian Union of North America. He spoke at a panel on religious outreach at the 2009 Animal Rights Conference in Washington, D.C. He lives in Lanham, Md.