Instabilit\'{e} des cocycles d'\'{e}volution fortement mesurables dans   des espaces de Banach
  The aim of the paper is to present various asymptotic behaviors of skew-evolution semiflows in Banach spaces, as exponential decay, instability, exponential in- stability and integral instability. Relations between these asymptotic properties are also given. As main results, two Datko type theorems are proved. A unified nonuniform approach is provided. 
Codru\c{t}a Stoica (IMB)