A Numerical Model of Crossed Andreev Reflection and Charge Imbalance

We present a numerical model of local and nonlocal transport properties in a lateral spin valve structure consisting of two magnetic electrodes in contact with a third perpendicular superconducting electrode. By considering the transport paths for a single electron incident at the local F/S interface - in terms of probabilities of crossed or local Andreev reflection, elastic cotunneling or quasiparticle transport - we show that this leads to nonlocal charge imbalance. We compare this model with experimental data from an aluminum-permalloy (Al/Py) lateral spin valve geometry device and demonstrate the effectiveness of this simple approach in replicating experimental behavior.Comment: 9 pages, 14 figure

Marine organisms as sources of C4-weed-specific herbicides

Imagine that you are a plant propagule looking for a home. You find a nice warm sunny place where the nutrients wash over you and think that you have arrived in paradise. And, what is more, there are few other plants with which to compete. However there are many animals close by in the form of corals and sponges and a variety of animals which make up the Great Barrier Reef. If you were on land, where plants occupy much of the available surface area over which animals wander, you would seem less out of place. Yet on healthy and pristine coral reefs found on the outer shelf of the Great Barrier Reef off the north east coast of Australia, only 20–28% of the available surface area comprises plants, i.e. algae (Sweatman et al., 1998) (Figure 1). Sea grass and kelp beds are more reminiscent of the terrestrial situation. Why is this so? Maybe coral reefs are, in fact, not a good place for plants to grow. But if this were the case, why then would the space be dominated by animals reliant for much of their nutrition upon symbiotic relationships with plants such as are found in corals and their symbiotic unicellular plants, zooxanthellae. What then, keeps the number of freegrowing plants low on coral reefs relative to the land? Does chemical warfare by the animals play some role? And if so, can these chemicals be developed for use as herbicide in the terrestrial environment

Political strategies of external support for democratization

Political strategies of external support to democratization are contrasted and critically examined in respect of the United States and European Union. The analysis begins by defining its terms of reference and addresses the question of what it means to have a strategy. The account briefly notes the goals lying behind democratization support and their relationship with the wider foreign policy process, before considering what a successful strategy would look like and how that relates to the selection of candidates. The literature's attempts to identify strategy and its recommendations for better strategies are compared and assessed. Overall, the article argues that the question of political strategies of external support for democratization raises several distinct but related issues including the who?, what?, why?, and how? On one level, strategic choices can be expected to echo the comparative advantage of the "supporter." On a different level, the strategies cannot be divorced from the larger foreign policy framework. While it is correct to say that any sound strategy for support should be grounded in a theoretical understanding of democratization, the literature on strategies reveals something even more fundamental: divergent views about the nature of politics itself. The recommendations there certainly pinpoint weaknesses in the actual strategies of the United States and Europe but they have their own limitations too. In particular, in a world of increasing multi-level governance strategies for supporting democratization should go beyond preoccupation with just an "outside-in" approach

Maintaining Indiana\u27s Urban Green Spaces: A Report from the Indiana Climate Change Impacts Assessment

Cities use green infrastructure, including forests, community gardens, lawns and prairies, to improve the quality of life for residents, promote sustainability and mitigate the effects of climate change. These and other kinds of green spaces can decrease energy consumption, increase carbon storage and improve water quality, among other benefits. More than 70 percent of Hoosiers reside in urban settings, and green infrastructure can provide significant economic advantages. In Indianapolis, for example, urban forests provide a $10 million annual benefit through stormwater control, carbon sequestration, energy reduction and air pollution filtration. However, just like human-built infrastructure, urban green infrastructure will be subject to the impacts of a changing climate, and its management must be considered as Indiana gets warmer and precipitation patterns change. This report from the Indiana Climate Change Impacts Assessment (IN CCIA) applies climate projections for the state to explore the potential threats to urban green infrastructure, and considers potential management implications and opportunities

Implications of climate change for managing urban green infrastructure in Indiana

Urban areas around the world are increasingly investing in networks of urban forests, gardens, and other forms of green infrastructure for its many benefits, including enhanced livability, sustainability, and climate change mitigation and adaptation. Proactive planning for climate change requires anticipating potential climate change impacts to green infrastructure and adjusting management strategies accordingly. We apply climate change projections for Indiana to assess the possible impacts of climate change on common forms of urban green infrastructure, and identify management implications. Projected changes in Indiana’s temperature and precipitation could pose numerous management challenges for managing urban green infrastructure, including water stress; pests, weeds, disease and invasive species; flooding; frost risk; and timing of maintenance. Meeting these challenges will involve managing for key characteristics of resilient systems (e.g. biodiversity, redundancy) as well as more specific strategies addressing particular climate changes (e.g. shifting species compositions, building soil water holding capacity). Climate change also presents opportunities to promote urban green infrastructure. Unlike human built infrastructure, green infrastructure is conducive to grassroots stewardship and governance, relieving climate change-related strains on municipal budgets. Many online resources for adapting urban green infrastructure to climate change are already available, and emerging research will enhance understanding of best management practices