Extending group actions on metric spaces

We address the following natural extension problem for group actions: Given a group $G$, a subgroup $H\le G$, and an action of $H$ on a metric space, when is it possible to extend it to an action of the whole group $G$ on a (possibly different) metric space? When does such an extension preserve interesting properties of the original action of $H$? We begin by formalizing this problem and present a construction of an induced action which behaves well when $H$ is hyperbolically embedded in $G$. Moreover, we show that induced actions can be used to characterize hyperbolically embedded subgroups. We also obtain some results for elementary amenable groups

The me in memory:the role of the self in autobiographical memory development

This paper tests the hypothesis that self development plays a role in the offset of childhood amnesia; assessing the importance of both the capacity to anchor a memory to the self-concept, and the strength of the self-concept as an anchor. We demonstrate for the first time that the volume of 3- to 6-year-old’s specific autobiographical memories is predicted by both the volume of their self-knowledge, and their capacity for self-source monitoring within self-referencing paradigms (N =186). Moreover, there is a bidirectional relationship between self and memory, such that autobiographical memory mediates the link between self-source monitoring and self-knowledge. These predictive relationships suggests that the self memory system is active in early childhood

Short-Term Climate Changes and Coastal Erosion, Barrow, Alaska

Records of shoreline and bluff positions in the vicinity of Barrow, Alaska, have been obtained from aerial photographs and taped measurements for intervals between 1948 and 1969. Although the source material in the bluffs is frozen and masses of pure ice are present, temperature and rainfall data fail to show any marked correlation with the retreat of the bluff face or with the retreat of the fronting or downdrift beaches. Removal of beach material for construction and frequency of storms from the west do show a relationship. Recorded retreats of the bluffs up to 3 m per year and of the beaches up to 4 m per year have resulted where there has been excessive beach borrow or where a series of severe storms have attacked the coast

Disposition of precipitation: Supply and Demand for Water Use by New Tree Plantations

As the greatest rainwater users among all vegetative land covers, tree plantations have been employed strategically to mitigate salinity and water-logging problems. However, large-scale commercial tree plantations in high rainfall areas reduce fresh water inflows to river systems supporting downstream communities, agricultural industries and wetland environmental assets. A bio-economic model was used to estimate economic demand for water by future upstream plantations in a sub-catchment (the 2.8 million ha Macquarie valley in NSW) of the Murray-Darling Basin, Australia. Given four tree-product values, impacts were simulated under two settings: without and with the requirement that permanent water entitlements be purchased from downstream entitlement holders before establishing a tree plantation. Without this requirement, gains in economic surplus from expanding tree plantations exceeded economic losses by downstream irrigators, and stock and domestic water users, but resulted in reductions of up to 154 GL (gigalitres) in annual flows to wetland environments. With this requirement, smaller gains in upstream economic surplus, added to downstream gains, could total $330 million while preserving environmental flows. Extending downstream water markets to new upstream tree plantations, to equilibrate marginal values across water uses, helps ensure water entitlements are not diminished without compensation. Outcomes include better economic-efficiency, social-equity and environmental-sustainability.Environmental Economics and Policy, forest, environmental services, catchment, water sources, interception, entitlement, supply, demand, market, economic surplus, evapo-transpiration, urban water, irrigation, wetlands.,