Complex Adaptive System Modelling of River Murray Salinity Policy Options

This paper reports on complex adaptive system (CAS) simulation of the River Murray Basin in Australia to compare capacity of institutional options to maintain functioning of key river system within a "bandwidth" that limits irreversible system state changes and highly adverse consequences. The modelling framework characterise diverse irrigation agents who profit from water diversion and cause external salinity impacts, water and salt process that form the link between irrigator actions and agricultural profits and external costs, and a river manager who sets institutional rules. Emphasis is on the CAS nature of the system and on institutional rules to accommodate choosing actions differently based on con dition of the system has been referred to as state contingent management (Wills, 2003) or threshold based management (Roe and Van Eeten, 2001). Key findings are that policy focus on the source of salinity by reducing drainage are much more cost effective than strategies to mitigate salinity once it occurs and that state contingent dilution provision when it has high benefit and low opportunity cost is also a cost effective way to manage salinity.Resource /Energy Economics and Policy,

L2L^2 estimates for the ∂ˉ\bar \partial operator

This is a survey article about $L^2$ estimates for the $\bar \partial$ operator. After a review of the basic approach that has come to be called the "Bochner-Kodaira Technique", the focus is on twisted techniques and their applications to estimates for $\bar \partial$, to $L^2$ extension theorems, and to other problems in complex analysis and geometry, including invariant metric estimates and the $\bar \partial$-Neumann Problem.Comment: To appear in Bulletin of Mathematical Science

Analytic inversion of adjunction: L^2 extension theorems with gain

We establish new results on weighted $L^2$ extension of holomorphic top forms with values in a holomorphic line bundle, from a smooth hypersurface cut out by a holomorphic function. The weights we use are determined by certain functions that we call denominators. We give a collection of examples of these denominators related to the divisor defined by the submanifold.Comment: To Appear in Ann. Inst. Fourie

Hydrogen in Type Ic Supernovae?

By definition, a Type Ic supernova (SN Ic) does not have conspicuous lines of hydrogen or helium in its optical spectrum. SNe Ic usually are modelled in terms of the gravitational collapse of bare carbon-oxygen cores. We consider the possibility that the spectra of ordinary (SN 1994I-like) SNe Ic have been misinterpreted, and that SNe Ic eject hydrogen. An absorption feature usually attributed to a blend of Si II 6355 and C II 6580 may be produced by H-alpha. If SN 1994I-like SNe Ic eject hydrogen, the possibility that hypernova (SN 1998bw-like) SNe Ic, some of which are associated with gamma-ray bursts, also eject hydrogen should be considered. The implications of hydrogen for SN Ic progenitors and explosion models are briefly discussed.Comment: Accepted by PASP. Several significant changes including one additional figur