Not able to create connections to http://dmoz.org/Health/Medicine/Medical_Specialties/Hematology/Bone_Marrow_Transplantation/ from your server.
The reason might be a firewall, proxy, or http://dmoz.org/Health/Medicine/Medical_Specialties/Hematology/Bone_Marrow_Transplantation/ or your web hosting company might be blocking outside connections.
Another possibility is a timeout because of slowdown in internet itself.