In this Focus article, the authors ask a seemingly simple question: Are harmful algal blooms (HABs) becoming the greatest inland water quality threat to public health and aquatic ecosystems? When HAB events require restrictions on fisheries, recreation, and drinking water uses of inland water bodies significant economic consequences result. Unfortunately, the magnitude, frequency, and duration ...

surface has been altered by human action (Vitousek et al. 1997), resulting in an unprecedented loss of biodiversity. As a result, some 10 to 30 percent of all mammal, bird, and amphibian species are threatened with extinction (Levin and Levin 2004, Kiesecker et al. 2004). Looking forward, such impacts could increase dramatically: the global economy is expected to double by 2030 (World Bank 2007...

Motivations I “Flat” RL : difficult to learn complex behaviours (eg, sequence of subgoals) ⇒ Humans abstract from low-level actions I Hierarchical RL : decompose large problems into smaller ones by imposing constraints on value function or policy I Possible implementation: options [Sutton et al., 1999] I Empirical observations: introducing options in an MDP can speed up learning but can also be...

This Special Issue publishes papers on ocean stresses, impacts and solutions that underpinned the findings of workshops hosted by The International Programme on the State of the Ocean (IPSO; http://www.stateoftheocean.org) in partnership with the International Union for the Conservation of Nature (IUCN: http://http:// www.iucn.org/). IPSO was founded to investigate anthropogenic stressors and i...

INTRODUCTION: As of 2001, it was estimated that approximately 50,000 nonindigenous species had been introduced into the United States (Pimentel et al. 2000). Some are beneficial, including food crops (e.g. corn, wheat), livestock (e.g. cattle, sheep), landscape enhancement (e.g. crape myrtles, boxwoods), or biological pest controls (e.g. host-specific biological control insects and pathogens). ...

Introduction S the 2007 Conference of the Parties to the United Nations Framework Convention on Climate Change in Bali, there has been heightened international interest in policy approaches and incentives for REDD. Broadly, such schemes involve the provision of funds to developing countries to reduce emissions from deforestation and degradation, below those that occurred during a certain refere...

© The Ecological Society of America www.frontiersinecology.org B invasions complicate the conservation of biodiversity and ecosystem integrity worldwide. Invasive species can threaten biological diversity in various ways, from reducing genetic variation and eroding gene pools, through the extinction of endemic species, and by altering habitat and ecosystem functioning (Hulme 2007; Table 1). Bio...

The occurrence of harmful algal blooms (HABs), caused by toxic phytoplankton, has detrimental environmental, economic and human health effects within many aquatic habitats (Horner et al., 1997). Understanding the environmental conditions that control the development and decline of HABs has consequently become an important element of ecosystem management within heavily affected environments. Pot...

Diabetes mellitus type-2 (DM-2) is a global epidemic that is associated with a large economic burden, an increased risk of cardiovascular disease, poor outcomes as a result of vascular occlusion, and premature mortality. The clinical hallmark of DM-2 is hyperglycemia – with an etiology which involves genetic, environmental, and behavioral elements. Vascular endothelial function is impaired in D...