We prove separator theorems in which the size of the separator is minimized with respect to non-negative vertex costs. We show that for any planar graph G there exists a vertex separator of total vertex cost at most c q P v2V (G) (cost(v)) 2 and that this bound is optimal within a constant factor. Moreover such a separator can be found in linear time. This theorem implies a variety of other sep...

We address the problem of nding a minimal separator in a di rected acyclic graph DAG namely nding a set Z of nodes that d separates a given pair of nodes such that no proper subset of Z d separates that pair We analyze several versions of this problem and o er polynomial algorithms for each These include nding a minimal separator from a restricted set of nodes nding a minimum cost separator and...

Cyclone is an actively developed, type-safe, C-like programming language. Historically, language designers have either leaned toward safety or toward explicit memory management. Cyclone aims to provide the safety of a language like Java, while providing the control over data representation and memory management of low-level languages like C. Cyclone features a garbage-collected heap. However, g...

Cyclone Yasi, one of the most severe tropical storms on record, crossed the central Great Barrier Reef (GBR) in February 2011, bringing wind speeds of up to 285 km hr⁻¹ and wave heights of at least 10 m, and causing massive destruction to exposed reefs in the Palm Island Group. Following the cyclone, mean (± S.E.) hard coral cover ranged from just 2.1 (0.2) % to 5.3 (0.4) % on exposed reefs and...

Ecological degradation within areas of remnant forest may be amplified if the effects of fragmentation interact with the effects of other environmental disturbances such as wind storms. We used before-after comparisons to assess the effects of Tropical Cyclone Larry on remnant and continuous rainforest in the Wet Tropics uplands of north-eastern Australia. Vegetation structure was measured thre...

If changes in the structural characteristics of rainforest at edges are caused by wind, then physical damage from a tropical cyclone might be greatest at edges or in small fragments that have a high proportion of edge. We tested whether this was true of a fragmented rainforest landscape impacted by a category 4 severe tropical cyclone in March 2006. Six structural variables (canopy cover, canop...