Search results for "Concentration."
showing 10 items of 1849 documents
The reconstitution of human C1, the first complement component Binding of C1r and C1s to C1q influences the C1q conformation
1981
Pb(II) adsorption by a novel activated carbon - alginate composite material. A kinetic and equilibrium study.
2016
The adsorption capacity of an activated carbon – calcium alginate composite material (ACAA-Ca) has been tested with the aim of developing a new and more efficient adsorbent material to remove Pb(II) ion from aqueous solution. The study was carried out at pH = 5, in NaCl medium and in the ionic strength range 0.1–0.75 mol L−1. Differential Pulse Anodic Stripping Voltammetry (DP-ASV) technique was used to check the amount of Pb(II) ion removed during kinetic and equilibrium experiments. Different kinetic (pseudo first order, pseudo second order and Vermuelen) and equilibrium (Langmuir and Freundlich) models were used to fit experimental data, and were statistically compared. Calcium alginate …
Differentiation of DctA and DcuS function in the DctA/DcuS sensor complex ofEscherichia coli: function of DctA as an activity switch and of DcuS as t…
2014
Summary The C4-dicarboxylate responsiveness of the sensor kinase DcuS is only provided in concert with C4-dicarboxylate transporters DctA or DcuB. The individual roles of DctA and DcuS for the function of the DctA/DcuS sensor complex were analysed. (i) Variant DctA(S380D) in the C4-dicarboxylate site of DctA conferred C4-dicarboxylate sensitivity to DcuS in the DctA/DcuS complex, but was deficient for transport and for growth on C4-dicarboxylates. Consequently transport activity of DctA is not required for its function in the sensor complex. (ii) Effectors like fumarate induced expression of DctA/DcuS-dependent reporter genes (dcuB–lacZ) and served as substrates of DctA, whereas citrate ser…
Recovering coronavirus from large volumes of water
2021
The need for monitoring tools to better control the ongoing coronavirus disease (COVID-19) pandemic is extremely urgent and the contamination of water resources by excreted viral particles poses alarming questions to be answered. As a first step to overcome technical limitations in monitoring SARS-CoV-2 along the water cycle, we assessed the analytical performance of a dead end hollow fiber ultrafiltration coupled to different options for secondary concentrations to concentrate viral particles from large volume of spiked tap water, seawater and surface water together with two quantitative RT-qPCR detection kits. Spiking the porcine epidemic diarrhea virus (PEDV), an enveloped virus surrogat…
Comment renforcer la règlementation sur l'indépendance des auditeurs ? Quelques leçons tirées du marché français
2010
This paper draws on the growing academic literature, over the last decade, to assess the effects of the French regulation aimed at promoting external auditor independence. For listed companies, the joint-audit requirement results in a less concentrated audit market: Big 4 auditors have a weaker market share as compared with other markets. But audit fees are not lower, however. This could be explained by (1) coordination costs between joint-auditors that outweigh the benefits of a more “open” market, and/or (2) the impossibility to switch auditor during a six-year legal engagement. Elsewhere, the a priori stronger independence associated with that specific regulation does not result in less …
La réglementation de l'audit est-elle dans l'intérêt public : quelques enseignements du modèle français
2010
This paper draws on the growing academic literature, over the last decade, to assess the effects of the French regulation aimed at promoting external auditor independence. For listed companies, the joint-audit requirement results in a less concentrated audit market: Big 4 auditors have a weaker market share as compared with other markets. But audit fees are not lower, however. This could be explained by (1) coordination costs between joint-auditors that outweigh the benefits of a more “open” market, and/or (2) the impossibility to switch auditor during a six-year legal engagement. Elsewhere, the a priori stronger independence associated with that specific regulation does not result in less …
Local Interactions and the Global City Metropolization in Warsaw
2002
A number of the world's large cities are taking on increasing economic importance in the international arenas because they concentrate high-order activities This metropolization process is a result of the changes occurring in the emerging post-industrial economy, i.e. the rise of services and information. It is based on the combination of proximity interactions and global interactions and it is characterized both by a specific internal spatial pattern and by a large outside area of influence. Since the transition period, services, and particularly high-order services, have grown more rapidly in Poland than in EU countries, as if a catching-up process has been underway. A large part of these…
Services supérieurs et recomposition urbaine
2000
Since the 1980s, we have observed an increasing tendency o f specialized services like producer services to leave their « natural habitat » in the center o f large met ropolitan areas in order to re loc at e in suburban zones. This phenomenon is particularly apparen t in North American citi es and seems to be occurring around certain French cities too. This paperinvestigates the forms taken by this new trend, and the reasons behind it. Taking economic geography and economics of cities as our theoretical basis, we first describe the main forces deter mining the agglomeration o f producer services and their preference for certain big cities. Agglomeration factors are to be looked for not only…
Sample Preparation to Determine Pharmaceutical and Personal Care Products in an All-Water Matrix: Solid Phase Extraction
2020
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L'ambivalence des concentrations d'entreprises au sein de l'industrie pharmaceutique
2006
Collection des travaux du Credimi