abstract identification & supervision of fluctuations in physical ecosystems have a special place in optimum using of natural resources. urmia lake is the largest interior natural lake of iran which its potentials and ecosystem & environmental characteristics attracted researchers and environmental planners attention. fluctuations in area and perimeter of the lake attracted many attentions in r...

Studies on environmental changes provide important insights into modes of speciation, into the (adaptive) reoccupation of ecological niches and into species turnover. Against this background, we here examine the history of the gastropod genus Lanistes in the African Rift Lake Malawi, guided by four general evolutionary scenarios, and compare it with patterns reported from other endemic Malawian...

The SharedPlans formalization of collaboration (Grosz and Kraus 1999) stipulates that collaborating agents must commit to certain decision-making processes, but it does not specify those processes. This paper presents a mechanism for group decision making that may be applied to the decisions that agents involved in a SharedPlan need to make: adopting the initial commitment, selecting a recipe, ...

The Mighan playa/lake is characterized as a closed catchment. In the recent years, the rapid industrialization and urbanization has resulted in a pollution area in the city of Arak. In this work, we focus on six regions around the playa/lake to study the distribution of heavy metals in the waters and their contamination risk. A total of 32 water samples are analyzed to determine the conta...