988 resultados para internal representations
Resumo:
Regulatory agencies such as Europol, Frontex, Eurojust, CEPOL as well as bodies such as OLAF, have over the past decade become increasingly active within the institutional architecture constituting the EU’s Area of Freedom, Security and Justice and are now placed at the forefront of implementing and developing the EU’s internal security model. A prominent feature of agency activity is the large-scale proliferation of ‘knowledge’ on security threats via the production of policy tools such as threat assessments, risk analyses, periodic and situation reports. These instruments now play a critical role in providing the evidence-base that supports EU policymaking, with agency-generated ‘knowledge’ feeding political priority setting and decision-making within the EU’s new Internal Security Strategy (ISS). This paper examines the nature and purpose of knowledge generated by EU Home Affairs agencies. It asks where does this knowledge originate? How does it measure against criteria of objectivity, scientific rigour, reliability and accuracy? And how is it processed in order to frame threats, justify actions and set priorities under the ISS?
Resumo:
We describe a remote sensing method for measuring the internal interface height field in a rotating, two-layer annulus laboratory experiment. The method is non-invasive, avoiding the possibility of an interaction between the flow and the measurement device. The height fields retrieved are accurate and highly resolved in both space and time. The technique is based on a flow visualization method developed by previous workers, and relies upon the optical rotation properties of the working liquids. The previous methods returned only qualitative interface maps, however. In the present study, a technique is developed for deriving quantitative maps by calibrating height against the colour fields registered by a camera which views the flow from above. We use a layer-wise torque balance analysis to determine the equilibrium interface height field analytically, in order to derive the calibration curves. With the current system, viewing an annulus of outer radius 125 mm and depth 250 mm from a distance of 2 m, the inferred height fields have horizontal, vertical and temporal resolutions of up to 0.2 mm, 1 mm and 0.04 s, respectively.
Resumo:
When considering contaminated site ecology and ecological risk assessment a key question is whether organisms that appear unaffected by accumulation of contaminants are tolerant or resistant to those contaminants. A population of Dendrodrilus rubidus Savigny earthworms from the Coniston Copper Mines, an area of former Cu mining, exhibit increased tolerance and accumulation of Cu relative to a nearby non-Cu exposed population. Distribution of total Cu between different body parts (posterior, anterior, body wall) of the two populations was determined after a 14 day exposure to 250 mg Cu kg(-1) in Cu-amended soil. Cu concentrations were greater in Coniston earthworms but relative proportions of Cu in different body parts were the same between populations. Cu speciation was determined using extended X-ray absorption fine structure spectroscopy (EXAFS). Cu was coordinated to 0 atoms in the exposure soil but to S atoms in the earthworms. There was no difference in this speciation between the different earthworm populations. In another experiment earthworms were exposed to a range of Cu concentrations (200-700 mg Cu kg(-1)). Subcellular partitioning of accumulated Cu was determined. Coniston earthworms accumulated more Cu but relative proportions of Cu in the different fractions (cytosol > granular > tissue fragments, cell membranes, and intact cells) were the same between populations. Results suggest that Coniston D. rubidus are able to survive in the Cu-rich Coniston Copper Mines soil through enlargement of the same Cu storage reservoirs that exist in a nearby non-Cu exposed population.
