2,964 research outputs found
Nitrogen removal during summer and winter in a primary facultative WSP pond: preliminary findings from 15N-labelled ammonium tracking techniques
Nitrogen removal mechanisms and pathways within WSP have been the focus of much research over the last 30 years. Debates and theories postulated continue to refine our knowledge regarding the cycling and removal pathways for this important nutrient, but a succinct answer has yet to be provided for holistic nitrogen removal. In this study, two experimental runs using labelled 15N as a stable isotope tracking technique were conducted on a pilot-scale primary facultative WSP in the UK; one in the summer of 2006, and the other in the winter of 2007. An ammonium chloride (15NH4Cl) spike was prepared as the slug for each experimental run, which also contained rhodamine WT to act as a dye tracer enabling the hydraulic characteristics of the pond to be mapped. Initial results from the study are reported here, and findings are compared and contrasted. Preliminary findings reveal that a greater proportion of 15N is incorporated into the algal biomass by assimilation and subsequent release as soluble organic nitrogen in summer than in winter. 15N ammonium passes out of the system much sooner and in a much higher proportion in the winter than in summer
Similar biodiversity of ectomycorrhizal fungi in set-aside plantations and ancient old-growth broadleaved forests
Setting aside overmature planted forests is currently seen as an option for preserving species associated with old-growth forests, such as those with dispersal limitation. Few data exist, however, on the utility of set-aside plantations for this purpose, or the value of this habitat type for biodiversity relative to old-growth semi-natural ecosystems. Here, we evaluate the contribution of forest type relative to habitat characteristics in determining species richness and composition in seven forest blocks, each containing an ancient old-growth stand (> 1000 yrs) paired with a set-aside even-aged planted stand (ca. 180 yrs). We investigated the functionally important yet relatively neglected ectomycorrhizal fungi (EMF), a group for which the importance of forest age has not been assessed in broadleaved forests. We found that forest type was not an important determinant of EMF species richness or composition, demonstrating that set-aside can be an effective option for conserving ancient EMF communities. Species richness of above-ground EMF fruiting bodies was principally related to the basal area of the stand (a correlate of canopy cover) and tree species diversity, whilst richness of below-ground ectomycorrhizae was driven only by tree diversity. Our results suggest that overmature planted forest stands, particularly those that are mixed-woods with high basal area, are an effective means to connect and expand ecological networks of ancient old-growth forests in historically deforested and fragmented landscapes for ectomycorrhizal fungi
SPIRIT: A Microservice-Based Framework for Interactive Cloud Infrastructure Planning
The IaaS model provides elastic infrastructure that enables
the migration of legacy applications to cloud environments. Many cloud
computing vendors such as Amazon Web Services, Microsoft Azure, and
Google Cloud Platform offer a pay-per-use policy that allows for a sustainable
reduction in costs compared to on-premise hosting, as well as
enable users to choose various geographically distributed data centers.
Using state-of-the-art planning algorithms can help application owners to
estimate the size and characteristics of the underlying cloud inveterate.
However, it’s not always clear which is the optimal solution especially
in multi-cloud environments with complex application requirements and
QoS constraints. In this paper, we propose an open framework named
SPIRIT, which allows a user to include cloud infrastructure planning
algorithms and to evaluate and compare their solutions. SPIRIT achieves
this by allowing users to interactively study infrastructure planning algorithms
by adjusting parameters via a graphical user interface, which
visualizes the results of these algorithms. In the current prototype, we
have included from the IaaS Partial Critical Path algorithm. By taking
advantage of SPIRIT’s microservice-based architecture and its generic
interfaces a user can add to the framework, new planning algorithms.
SPIRIT can transform an abstract workflow described using the CWL
to a concrete infrastructure described using the TOSCA specification.
This way the infrastructure descriptions can be ranked on various key
performance indicators
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