Before revision:  Furthermore, the nature of the swimmer is  found to be affected by the confinement: the swimmer can behave  as a pusher at low confinement, and becomes a puller at higher confinement , or vice versa; this shows that the swimmernature is not an intrinsic property.
After revision:  Furthermore, the nature of the swimmer is found to be affected by the confinement: the swimmer can behave as a pusher at low confinement, and becomes a puller at higher confinement . The swimmer's nature is thus not an intrinsic property.