Complex sentence: Buckley was first to apply concepts from General Systems Theory (GST) based on the work of Bertalanffy to sociology; but was not specifically aligned to either the cybernetics or the general systems movements.
Split into simpler sentences: Buckley was first to apply concepts from General Systems Theory (GST) based on the work of Bertalanffy to sociology. However, the sociologist was not specifically aligned to either the cybernetics or the general systems movements.