The durable structures of housing and housing institutions are often subject to long-term processes of incremental change. Nevertheless, housing studies have largely focused either on static snapshots of policies or, more recently, on the inertia of institutional path dependence, while processes of incremental change have been almost entirely neglected. Political scientists (Streeck/Thelen/Mahoney) have proposed a typology of patterns of incremental institutional change, and this paper explores the applicability of this typology to housing structures and housing institutions. We draw on empirical illustrations from the housing literature to show how five types of change – layering, conversion, displacement, drift, exhaustion – apply to housing structures and institutions. We conclude with some general observations on how the typology can be used in further studies of developments in national housing regimes.
Necessary and sufficient conditions have been found to force all solutions of the equation \[ (r(t)y^{\prime }(t))^{(n-1)} + a(t)h(y(g(t))) = f(t), \] to behave in peculiar ways. These results are then extended to the elliptic equation \[ |x|^{p-1} \Delta y(|x|) + a(|x|)h(y(g(|x|))) = f(|x|) \] where $ \Delta $ is the Laplace operator and $p \ge 3$ is an integer.
The ultrastructure and histochemistry of the tegument and penetration glands of adult Amphilina foliacea from the body cavity and the tissues of the internal organs of Acipenser ruthenus and A. stellatus were studied. New data on the localization in the tissue, development and in encapsulation of the adult A. foliacea mostly in the liver of A. ruthenus were obtained. The well developed penetration glands are necessary for penetration into the tissue and for migration of A. foliacea into the body cavity of the hosts. The tegument of the adult A. foliacea is a syncytium with cytons deeply embedded into the parenchyma. The secretory activity of the tegument of worms has a protective function against the immune system of the host. Our results give further information about the phylogeny of Amphilinidea and confirm the view of the close phylogenetic relationship of Amphilinidea and Cestoidea.