26 research outputs found
To buy or not to buy-evaluating commercial AI solutions in radiology (the ECLAIR guidelines).
Artificial intelligence (AI) has made impressive progress over the past few years, including many applications in medical imaging. Numerous commercial solutions based on AI techniques are now available for sale, forcing radiology practices to learn how to properly assess these tools. While several guidelines describing good practices for conducting and reporting AI-based research in medicine and radiology have been published, fewer efforts have focused on recommendations addressing the key questions to consider when critically assessing AI solutions before purchase. Commercial AI solutions are typically complicated software products, for the evaluation of which many factors are to be considered. In this work, authors from academia and industry have joined efforts to propose a practical framework that will help stakeholders evaluate commercial AI solutions in radiology (the ECLAIR guidelines) and reach an informed decision. Topics to consider in the evaluation include the relevance of the solution from the point of view of each stakeholder, issues regarding performance and validation, usability and integration, regulatory and legal aspects, and financial and support services. KEY POINTS: • Numerous commercial solutions based on artificial intelligence techniques are now available for sale, and radiology practices have to learn how to properly assess these tools. • We propose a framework focusing on practical points to consider when assessing an AI solution in medical imaging, allowing all stakeholders to conduct relevant discussions with manufacturers and reach an informed decision as to whether to purchase an AI commercial solution for imaging applications. • Topics to consider in the evaluation include the relevance of the solution from the point of view of each stakeholder, issues regarding performance and validation, usability and integration, regulatory and legal aspects, and financial and support services
Two images of Nantes as a ‘Green Model’ of Urban Planning and Governance: The ‘Collaborative City’ Versus the ‘Slow City’
This article examines how the city of Nantes, European Green Capital in 2013, came to promote plans for a new international airport at Notre-Dame-des-Landes. Deploying poststructuralist discourse theory, it analyses how the highly politicised struggle against the airport reveals the limits of the Nantes model of urban sustainability and collaboration, giving rise to a counter model, which we provisionally characterise as the ‘slow city’. While the struggle against the airport can be understood as a rural social movement, we show how its ideals and logics have been progressively displaced to Nantes itself, disclosing new images and possibilities of urban governance
How to move an amphipathic molecule across a lipid bilayer: different mechanisms for different ABC transporters?
Import of β-oxidation substrates into peroxisomes is mediated by ATP binding cassette (ABC) transporters belonging to subfamily D. In order to enter the β-oxidation pathway, fatty acids are activated by conversion to fatty acyl-CoA esters, a reaction which is catalysed by acyl-CoA synthetases (ACSs). Here, we present evidence for an unusual transport mechanism, in which fatty acyl-CoA substrates are accepted by ABC subclass D protein (ABCD) transporters, cleaved by the transporters during transit across the lipid bilayer to release CoA, and ultimately re-esterified in the peroxisome lumen by ACSs which interact with the transporter. We propose that this solves the biophysical problem of moving an amphipathic molecule across the peroxisomal membrane, since the intrinsic thioesterase activity of the transporter permits separate membrane translocation pathways for the hydrophobic fatty acid moiety and the polar CoA moiety. The cleavage/re-esterification mechanism also has the potential to control entry of disparate substrates into the β-oxidation pathway when coupled with distinct peroxisomal ACSs. A different solution to the movement of amphipathic molecules across a lipid bilayer is deployed by the bacterial lipid-linked oligosaccharide (LLO) flippase, PglK, in which the hydrophilic head group and the hydrophobic polyprenyl tail of the substrate are proposed to have distinct translocation pathways but are not chemically separated during transport. We discuss a speculative alternating access model for ABCD proteins based on the mammalian ABC transporter associated with antigen processing (TAP) and compare it to the novel mechanism suggested by the recent PglK crystal structures and biochemical data
Adherence measurements and corrosion resistance in primer/hot-dip galvanized steel systems
This paper focuses on the adherence during ageing of a primer (made of polyester resins crosslinked with melamine) applied onto hot-dip galvanized (HDG) steel for coil coating application and its influence on corrosion protection. A chromium-free surface treatment, composed of fluorotitanic acid, phosphoric acid, manganese phosphate, and vinylphenol was applied on the HDG steel to obtain high corrosion resistance and high adherence of a polyester and melamine primer. The influence of the manganese phosphate on the corrosion and adherence was investigated. To measure the adherence between the metal and the primer, a three-point flexure test was set up. The adherence was then linked with corrosion resistance during ageing, using electrochemical impedance spectroscopy
Vers une évaluation de la valeur économique totale de la nappe phréatique d'Alsace
Le but de ce travail a consisté à poser les bases d'une estimation de la valeur économique totale de la nappe phréatique d'Alsace. Cet article s'articule autour de trois points : (i) la typologie des services d'usage et de non-usage de la nappe (ii) la quantification des prélèvements à travers la constitution d'une base de données (iii) la mise en parallèle des bénéfices et des méthodes d'évaluation monétaire. Le recensement exhaustif des prélèvements effectués dans la nappe établit un volume prélevé annuellement compris entre 624 et 717 millions de m3, tous usages confondus. Le second résultat marquant est le poids de l'activité industrielle (plus de 70 % des prélèvements). Finalement ces résultats ne constituent que la première étape d'un travail plus ambitieux portant sur l'estimation de la valeur patrimoniale de la nappe d'Alsace. / The objective of this article was to raise the basis of the total value estimation for the Alsatian aquifer. This work is constructed around three principal points: (i) the use and non use values identification; (ii) an exhaustive quantifying of all the effective charges through a data base building; (iii) a parallel of the use and non use benefits with the monetary valuation methods. An exhaustive account of all the effective charges in the aquifer has established a charged volume between 624 et 717 millions of m3 per year. The second result is based on the industrial activity weight in the total charged volume of the aquifer (more than 70%). These results represent only the first step of a more ambitious work: the total value estimation for the aquifer, knowing that the choice of all the relevant monetary indicators have to discussed before
Rubber-toughened epoxy loaded with carbon nanotubes: structure-property relationships
The paper reports on the preparation, structure and properties of ternary
thermosetting blends, based on DGEBA epoxy, cured with 3,3′-DDS and modified by
the addition of CTBN reactive liquid rubber and/or 0.3wt% of commercial multi-
walled carbon nanotubes. The toughening effect of the phase-separated rubber
particles is enhanced by the presence of the nanotubes, through a change in the
morphology. In the absence of the rubber, the nanotubes alone produce a minimal
effect upon the thermo-mechanical characteristics of the resin. However, the
electrical conductivity of the cured resin samples is found to increase by five
orders of magnitude, up to 3.6×10-3 S/m in the ternary bl
Synthesis And Preliminary Dna-Interaction Studies Of A New Cationic Porphyrin
A new water-soluble porphyrin containing benzyl-trimethylammonium groups was synthesized in a two-step sequence from tetraphenylporphyrin and preliminary studies show that it binds strongly to DNA in an outside manner and gives fairly stable complexes with nucleotides and nucleosides. A new water-soluble porphyrin containing benzyl-trimethylammonium groups was synthesized in a two-step sequence and preliminary studies show that it binds strongly to DNA in an outside manner
Light-independent phospholipid scramblase activity of bacteriorhodopsin from Halobacterium salinarum.
The retinylidene protein bacteriorhodopsin (BR) is a heptahelical light-dependent proton pump found in the purple membrane of the archaeon Halobacterium salinarum. We now show that when reconstituted into large unilamellar vesicles, purified BR trimers exhibit light-independent lipid scramblase activity, thereby facilitating transbilayer exchange of phospholipids between the leaflets of the vesicle membrane at a rate >10,000 per trimer per second. This activity is comparable to that of recently described scramblases including bovine rhodopsin and fungal TMEM16 proteins. Specificity tests reveal that BR scrambles fluorescent analogues of common phospholipids but does not transport a glycosylated diphosphate isoprenoid lipid. In silico analyses suggest that membrane-exposed polar residues in transmembrane helices 1 and 2 of BR may provide the molecular basis for lipid translocation by coordinating the polar head-groups of transiting phospholipids. Consistent with this possibility, extensive coarse-grained molecular dynamics simulations of a BR trimer in an explicit phospholipid membrane revealed water penetration along transmembrane helix 1 with the cooperation of a polar residue (Y147 in transmembrane helix 5) in the adjacent protomer. These results suggest that the lipid translocation pathway may lie at or near the interface of the protomers of a BR trimer