They are present in approximately 60 to 80 percent of people diagnosed with RA. Studies have found that, for many people, the antibodies precede the development of clinical symptoms by 5 to 10 years. If you have symptoms consistent with RA and a positive test for the antibody, an RA diagnosis is almost a certainty.Previously, seropositivity was defined in terms of an antibody called rheumatoid factor (RF).f you have symptoms consistent with RA and a positive test for the antibody, an RA diagnosis is almost a certainty. Previously, seropositivity was defined in terms of an antibody called rheumatoid factor (RF).
Clark Leonard Hull (May 24, 1884 â May 10, 1952) was an influential American psychologist who sought to explain learning and motivation by scientific laws of behavior.Hull is known for his debates with Edward C. Tolman.He is also known for his work in drive theory.Hull spent the mature part of his career at Yale University, where he was recruited by the president and former-psychologist, James Rowland Angell.lark Hull found inspiration for his own theory of learning after learning about Ivan Pavlov âs idea of conditional reflexes, and Watson âs system of behaviorism.
Clark Hull did his undergraduate work at University of Michigan (1913) and later earned his Ph.D. from the University of Wisconsin in 1918. He spent most of his professional career at the Institute of Psychology at Yale University (1929 until his death in 1952).ajor influences on Hull's thinking included the work of Pavlov, Darwin, Thorndike and Tolman. His theory was an attempt to create a synthesis of the theories of these researchers plus Newtonian physics.