Security Issues in a SOA-based Provenance System

Recent work has begun exploring the characterization and utilization of provenance in systems based on the Service Oriented Architecture (such as Web Services and Grid based environments). One of the salient issues related to provenance use within any given system is its security. Provenance presents some unique security requirements of its own, which are additionally dependent on the architectural and environmental context that a provenance system operates in. We discuss the security considerations pertaining to a Service Oriented Architecture based provenance system. Concurrently, we outline possible approaches to address them

Effect of various crop and pasture species on the growth of a subsequent wheat crop

83WH29: The effect of various crop and pasture species on the growth of a subsequent wheat crop. Aim: To characterise the effect of various crop and pasture species on the growth and yield components of a subsequent wheat crop with special emphasis on the nitrogen nutrition of that crop. To provide validation data for modelling wheat growth and nitrogen uptake. Measurements: Factors to be monitored through time were; Soil moisture profiles; Mineral nitrogen profiles; Root growth profiles; Top growth and nitrogen uptake; Development score; Incidence of disease and pests. Seasonal notes, trial design, weed diseases and pests. Results: The results are presented in the following tables. As yet they have not been subject to statistical analysis and conclusions drawn from them should be treated with caution. Table 1. Records the rainfall at WHRS in 1984. Table 2. 1983 production and estimates of nitrogen balance. Table 3. Summer dry matter balance. Table 4. Mineral nitrogen levels. Table 5. Anthesis cuts and yield components. Table 6. Dry matter production through time. Table 7. Soil nitrogen profiles. Table 8. Root lengths. Table 9. ZADOK development scores. Table 10. Water use to 2 metres depth. Table 11. Pre anthesis water use by depth. Table 12. Post anthesis water use by depth

Little angels: The mediation of parenting

This Article does not have an abstract

Phenology is the dominant control of methane emissions in a tropical non-forested wetland

Tropical wetlands are a significant source of atmospheric methane (CH4), but their importance to the global CH4 budget is uncertain due to a paucity of direct observations. Net wetland emissions result from complex interactions and co-variation between microbial production and oxidation in the soil, and transport to the atmosphere. Here we show that phenology is the overarching control of net CH4 emissions to the atmosphere from a permanent, vegetated tropical swamp in the Okavango Delta, Botswana, and we find that vegetative processes modulate net CH4 emissions at sub-daily to inter-annual timescales. Without considering the role played by papyrus on regulating the efflux of CH4 to the atmosphere, the annual budget for the entire Okavango Delta, would be under- or over-estimated by a factor of two. Our measurements demonstrate the importance of including vegetative processes such as phenological cycles into wetlands emission budgets of CH4