Search results for "Lability"
showing 10 items of 802 documents
An uptake and elimination kinetics approach to assess the bioavailability of chromium, copper, and arsenic to earthworms (Eisenia andrei) in contamin…
2019
The aim of this study was to determine the bioavailability of metals in field soils contaminated with chromated copper arsenate (CCA) mixtures. The uptake and elimination kinetics of chromium, copper, and arsenic were assessed in the earthworm Eisenia andrei exposed to soils from a gradient of CCA wood preservative contamination near Hartola, Finland. In soils contaminated with 1480–1590 mg Cr/kg dry soil, 642–791 mg Cu/kg dry soil, and 850–2810 mg Ag/kg dry soil, uptake and elimination kinetics patterns were similar for Cr and Cu. Both metals were rapidly taken up and rapidly excreted by Eisenia andrei with equilibrium reached within 1 day. The metalloid As, however, showed very slow uptak…
Impulsive control of the bilinear Schrödinger equation: propagators and attainable sets
2019
International audience; We consider a linear Schrödinger equation with an unbounded bilinear control term. The control term is the derivative of function with bounded variations (impulsive control). Well-posedness results and regularity of the associated propagators follow from classical theory from Kato. As a byproduct, one obtains a topological obstruction to exact controllability of the system in the spirit of the results of Ball, Marsden and Slemrod.
Permeability and toxicological profile estimation of organochlorine compounds by biopartitioning micellar chromatography
2008
This paper points out the usefulness of biopartitioning micellar chromatography (BMC) as a high-throughput primary screening tool providing key information about the oral absorption, skin permeability (Kp), brain–blood distribution coefficient (BB) and ecotoxicological parameters such as median lethal concentration (LC50) and bioconcentration factors of 15 organochloride compounds. The retention data of compounds in BMC conditions were interpolated in previously developed quantitative–retention activity relationships by our research group. Results show that the compounds studied readily cross the intestinal barrier (oral absorption >ercnt;) and the blood–brain barrier (log BB >p;0.4). In ad…
Comparative analysis of architectures for monitoring cloud computing infrastructures
2015
The lack of control over the cloud resources is one of the main disadvantages associated to cloud computing. The design of efficient architectures for monitoring such resources can help to overcome this problem. This contribution describes a complete set of architectures for monitoring cloud computing infrastructures, and provides a taxonomy of them. The architectures are described in detail, compared among them, and analysed in terms of performance, scalability, usage of resources, and security capabilities. The architectures have been implemented in real world settings and empirically validated against a real cloud computing infrastructure based on OpenStack. More than 1000 virtual machin…
Autonomic Brokerage Service for an End-to-End Cloud Networking Service Level Agreement
2014
8 pages; International audience; Today, cloud networking which is the ability to connect the user with his cloud services and to interconnect these services within an inter-cloud approach, is one of the recent research areas in the cloud computing research communities. The main drawback of cloud networking consists in the lack of Quality of Service (QoS) assurance and management in conformance with a corresponding Service Level Agreement (SLA). In this paper, we propose a framework for self-establishing an end-to-end service level agreement between a Cloud Service User (CSU) and multiple Cloud Service Providers (CSPs) in a cloud networking environment using brokerage service. We focus on Qo…
Role of Data Communications in Hybrid Cloud Costs
2011
Rapid adoption of cloud services in recent years has been driven by multiple factors, such as faster time-to-market and improved scalability enabled by public cloud infrastructure. Hybrid clouds, combining the in-house capacities with on-demand capacity of public clouds, achieve both the increased utilization rate of the in-house infrastructure and the limited use of more expensive public cloud, thereby lowering the total costs for the cloud user. In this paper, an analytical model of hybrid cloud costs is introduced, wherein the costs of computing and data communication are taken into account. Using this model, the costefficient division of the computing capacity between the private and th…
System times and channel availability analyses in multi-channel cognitive radio networks
2014
Channel accessibility by a secondary user (SU) in cognitive radio networks (CRNs) depends on the availability of the spectrum based on primary user and other SU activities. A new SU request may be blocked and an ongoing SU service may also be discarded if no sufficient spectrum is available. So far, little work has been done to analyze the reliability and availability aspects of CRNs from the perspective of the dependability theory. In this paper, we introduce the concept of availability for spectrum access in multi-channel CRNs, which is defined as the fraction of time that a CRN can allocate at least the minimum number of required channels for a new SU request. Through a proposed continuo…
How does the brain encode epistemic reliability? Perceptual presence, phenomenal transparency, and counterfactual richness
2014
AbstractSeth develops a convincing and detailed internalist alternative to the sensorimotor-contingency theory of perceptual phenomenology. However, there are remaining conceptual problems due to a semantic ambiguity in the notion of “presence” and the idea of “subjective veridicality.” The current model should be integrated with the earlier idea that experiential “realness” and “mind-independence” are determined by the unavailability of earlier processing stages to attention. Counterfactual richness and attentional unavailability may both be indicators of the overall processing level currently achieved, a functional property that normally correlates with epistemic reliability. Perceptual p…
Bioaccessibility and decomposition of cylindrospermopsin in vegetables matrices after the application of an in vitro digestion model.
2018
Research on the human exposure to Cylindrospermopsin (CYN) via consumption of contaminated food is of great interest for risk assessment purposes. The aim of this work is to evaluate for the first time the CYN bioaccessibility in contaminated vegetables (uncooked lettuce and spinach, and boiled spinach) after an in vitro digestion model, including the salivar, gastric and duodenal phases and, colonic fermentation under lactic acid bacteria. The results obtained showed that the digestion processes are able to diminish CYN levels, mainly in the colonic phase, especially in combination with the boiling treatment, decreasing CYN levels in a significant way. Moreover, the potential decomposition…
A grid representation for distributed virtual environments
2004
Fast Internet connections and the widespread use of high performance graphic cards are making Distributed Virtual Environments (DVE) very common nowadays. The architecture and behavior of these systems are very similar to new grid computing applications where concepts such as sharing and high scalability are extremely exploited. However, there are several key issues in these systems that should still be improved in order to design a scalable and cost-effective DVE system. One of these key issues is the partitioning problem. This problem consists of efficiently assigning clients (3-D avatars) to the arbiters (servers) in the system. As an alternative to the ad-hoc heuristic proposed in the l…