PATRICK PAYAN, ANAICK EDEYER, HÉLÈNE DE PONTUAL, GIL BORELLI, GILLES BOEUF, AND NICOLE MAYER-GOSTAN Laboratoire de Physiologie et Toxicologie Environnementales, EA 2138; Laboratoire de Physiologie Cellulaire et Moléculaire, Centre National de la Recherche Scientifique, UMR 6548; Université de Nice-Sophia Antipolis, Faculté des Sciences, 06108 Nice Cedex; and Laboratoire de Sclérochronologie des...

Unregulated river systems are organized in a hierarchy in which large-scale factors (i.e., landscape and segment scales) influence local habitats (i.e., reach, meso-, and microhabitat scales), and both differentially exert selective pressures on biota. Dams, however, create discontinua in these processes and change the hierarchical structure. We examined the relative roles of hydrology and othe...

in 2001, s. bulman-fleming et al. initiated the study of three flatness properties (weakly kernel flat, principally weakly kernel flat, translation kernel flat) of right acts $a_{s}$ over a monoid $s$ that can be described by means of when the functor $a_{s} otimes -$ preserves pullbacks. in this paper, we extend these results to$s$-posets and present equivalent descriptions of weakly kernel po...

In 2001, S. Bulman-Fleming et al. initiated the study of three flatness properties (weakly kernel flat, principally weakly kernel flat, translation kernel flat) of right acts $A_{S}$ over a monoid $S$ that can be described by means of when the functor $A_{S} otimes -$ preserves pullbacks. In this paper, we extend these results to $S$-posets and present equivalent descriptions of weakly kernel p...