Negative cross-diiusion has been identiied as a factor increasing the possibility of spatio-temporal instabilities in Lotka-Volterra equations. But such terms have been considered as quite rare in ecological modeling, since imply deceitful prey-predator relationships. We show that negative cross-diiusion appears naturally in reaction diiusion equations obtained using a simple mean eld decouplin...

The series connection of sarcomeres in a muscle raises the possibility of instabilities due to some sarcomeres being capable of greater isometric tension than others, due to non-uniform activation, cross-sectional area or sarcomere length. Such instabilities are heavily damped by the force-velocity curve and stabilized by passive tension. The variation of active tension with sarcomere length ma...

Dorsiflexion, palmar flexion, ulnar translocation, and dorsal carpal subluxation are four, not uncommon, post-traumatic carpal ligamentous instabilities. Palmar carpal subluxation is a theoretical possibility. Dorsiflexion and palmar flexion instabilities are named for the way the distal lunate articular surface dorsally and palmarly, respectively. Ulnar translocation, and dorsal and ventral ca...