3,321 research outputs found
Vernal Pool Conservation: Enhancing Existing Regulation Through the Creation of the Maine Vernal Pool Special Area Management Plan
Conservation of natural resources is challenging given the competing economic and ecological goals humans have for landscapes. Vernal pools in the northeastern US are seasonal, small wetlands that provide critical breeding habitat for amphibians and invertebrates adapted to temporary waters, and are exceptionally hard to conserve as their function is dependent on connections to other wetlands and upland forests. A team of researchers in Maine joined forces with a diverse array of governmental and private stakeholders to develop an alternative to existing top-down vernal pool regulation. Through creative adoption and revision of various resource management tools, they produced a vernal pool conservation mechanism, the Maine Vernal Pool Special Management Area Plan that meets the needs of diverse stakeholders from developers to ecologists. This voluntary mitigation tool uses fees from impacts to vernal pools in locally identified growth areas to fund conservation of âpoolscapesâ (pools plus appropriate adjacent habitat) in areas locally designated for rural use. In this case study, we identify six key features of this mechanism that illustrate the use of existing tools to balance growth and pool conservation. This case study will provide readers with key concepts that can be applied to any conservation problem: namely, how to work with diverse interests toward a common goal, how to evaluate and use existing policy tools in new ways, and how to approach solutions to sticky problems through a willingness to accept uncertainty and risk
Asymptotic Level Density of the Elastic Net Self-Organizing Feature Map
Whileas the Kohonen Self Organizing Map shows an asymptotic level density
following a power law with a magnification exponent 2/3, it would be desired to
have an exponent 1 in order to provide optimal mapping in the sense of
information theory. In this paper, we study analytically and numerically the
magnification behaviour of the Elastic Net algorithm as a model for
self-organizing feature maps. In contrast to the Kohonen map the Elastic Net
shows no power law, but for onedimensional maps nevertheless the density
follows an universal magnification law, i.e. depends on the local stimulus
density only and is independent on position and decouples from the stimulus
density at other positions.Comment: 8 pages, 10 figures. Link to publisher under
http://link.springer.de/link/service/series/0558/bibs/2415/24150939.ht
Non-analytic microscopic phase transitions and temperature oscillations in the microcanonical ensemble: An exactly solvable 1d-model for evaporation
We calculate exactly both the microcanonical and canonical thermodynamic
functions (TDFs) for a one-dimensional model system with piecewise constant
Lennard-Jones type pair interactions. In the case of an isolated -particle
system, the microcanonical TDFs exhibit (N-1) singular (non-analytic)
microscopic phase transitions of the formal order N/2, separating N
energetically different evaporation (dissociation) states. In a suitably
designed evaporation experiment, these types of phase transitions should
manifest themselves in the form of pressure and temperature oscillations,
indicating cooling by evaporation. In the presence of a heat bath (thermostat),
such oscillations are absent, but the canonical heat capacity shows a
characteristic peak, indicating the temperature-induced dissociation of the
one-dimensional chain. The distribution of complex zeros (DOZ) of the canonical
partition may be used to identify different degrees of dissociation in the
canonical ensemble.Comment: version accepted for publication in PRE, minor additions in the text,
references adde
Asymptotically Exact Solution for Superconductivity near Ferromagnetic Criticality
We analyze an asymptotically exact solution for the transition temperature of
p-wave superconductivity near ferromagnetic criticality on the basis of the
three-dimensional electron systems in which scattering processes are dominated
by exchange interactions with small momentum transfers. Taking into account all
Feynman diagrams in the gap equation, we show that vertex corrections neglected
in the conventional Eliashberg's formalism enhance the dynamical retarded
effect of the pairing interaction, and raise the superconducting transition
temperature significantly, though they just give subleading corrections to
properties of the normal state.Comment: 6 pages, 2 figures, published final versio
The dynamics of quasi-isometric foliations
If the stable, center, and unstable foliations of a partially hyperbolic
system are quasi-isometric, the system has Global Product Structure. This
result also applies to Anosov systems and to other invariant splittings.
If a partially hyperbolic system on a manifold with abelian fundamental group
has quasi-isometric stable and unstable foliations, the center foliation is
without holonomy. If, further, the system has Global Product Structure, then
all center leaves are homeomorphic.Comment: 18 pages, 1 figur
Stories of success: Cultural narratives and personal stories of elite and professional athletes
Using a narrative methodology to explore the stories Olympic and elite athletes tell about success, we identified three alternatives to the dominant conception of success as the achievement of performance outcomes. In these alternatives, success is storied as: (1) âI did the best that I couldâ â a controllable and sustainable story of effort and application; (2) âItâs the closest thing you can get to flyingâ â a story where success relates to embodied experience and discovery; (3) âPeople I made the journey withâ â which prioritises relationships and connection between people. We reflect on three key insights: (1) success is a multidimensional concept, broader than the singular conception encapsulated within the dominant performance narrative; (2) through various narrative strategies, experienced athletes resist cultural pressures towards a singular conception of success; (3) for long-term performance and well-being, it is necessary to work towards multiple forms of success over time and across contexts
Making the most of community energies:Three perspectives on grassroots innovation
Grassroots innovations for sustainability are attracting increasing policy attention. Drawing upon a wide range of empirical research into community energy in the UK, and taking recent support from national government as a case study, we apply three distinct analytical perspectives: strategic niche management; niche policy advocacy; and critical niches. Whilst the first and second perspectives appear to explain policy influence in grassroots innovation adequately, each also shuts out more transformational possibilities. We therefore argue that, if grassroots innovation is to realise its full potential, then we need to also pursue a third, critical niches perspective, and open up debate about more socially transformative pathways to sustainability
Metal-superconductor transition at zero temperature: A case of unusual scaling
An effective field theory is derived for the normal metal-to-superconductor
quantum phase transition at T=0. The critical behavior is determined exactly
for all dimensions d>2. Although the critical exponents \beta and \nu do not
exist, the usual scaling relations, properly reinterpreted, still hold. A
complete scaling description of the transition is given, and the physics
underlying the unusual critical behavior is discussed. Quenched disorder leads
to anomalously strong T_c-fluctuations which are shown to explain the
experimentally observed broadening of the transition in low-T_c thin films.Comment: 4 pp., no figs, final version as publishe
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