Search results for "Porte"

Publication Network Analysis of an Academic Family in Information Systems

2011

The study of scientific collaboration through network analysis can give interesting conclusions about the publication habits of a scientific community. Co-authorship networks represent scientific collaboration as a graph: nodes correspond to authors, edges between nodes mark joint publications (Newman 2001a,b). Scientific publishing is decentralized. Choices of co-authors and research topics are seldomly globally coordinated. Still, the structure of co-authorship networks is far from random. Co-authorship networks are governed by principles that are similar in other complex networks such as social networks (Wasserman and Faust 1994), networks of citations between scientific papers (Egghe an…

Meeting others—supporting situation awareness on the WWW

2001

Abstract World Wide Web (WWW) techniques provide a simple interface, which is accessible almost everywhere. The WWW supports document sharing and information retrieval, but has no tools for direct user interaction, simply because the mechanisms to support user awareness are missing. The aim of this paper is twofold. First, we present general concepts of situation awareness, which concerns the user interaction on the WWW platform, and a theoretical framework, which is used in examining existing awareness support systems. Second, we provide an analysis of PeopleAwarenessEngine, which supports situation awareness and enables user communication and collaboration on the WWW.

Secure Collaborative Learning Practices and Mobile Technology

2008

During the past few years, mobile technologies have become common in everyday life. Almost everyone carry some kind of mobile technological equipment with him or her, for example a personal digital assistant (PDA), a mobile phone, a multimedia player, such as an iPod, or a laptop computer. The use of these equipments is not limited only to workplaces, schools or homes. Particularly useful information and communication technologies (ICTs) are in educational settings. Especially wireless networks and laptop computers may promote many useful practices of collaborative learning (Cutshall, Changchit, & Elwood, 2006; Jones, Holmfeld, & Lindström, 2006). On the one hand, the use of mobile …

Scripting Computer-Supported Collaborative Learning

2010

In this chapter, we will present a review of theoretical and empirical analyses of Web-based collaboration processes used during a scripted university course. The results refer to a design-based study that involved first-year teacher-education students (N = 30) studying pedagogy over a period of three months. The intervention involved structuring the subjects’ collaborative actions with three different pedagogical scripts. According to the findings, the scripts guided students’ activities by helping them find resources for knowledge construction and work together through a series of steps. However, there were variations among groups in terms of quality of collaboration, and the students mos…

Computer-Supported Collaboration Scripts

2009

Etude structure/fonction du demi-transporteur ABCD2 dans le contexte de l'Adrénoleucodystrophie liée à l'X

2013

X-linked Adrenoleukodystrophy (X-ALD) is a rare neurodegenerative disease caused by deficiency of the peroxisomal half-transporter ABCD1, implicated in very long chain fatty acids import. Two additional half-transporters are located in the peroxisomal membrane: ABCD2 and ABCD3. Over-expression of ABCD2 is known to compensate for ABCD1 deficiency, making ABCD2 a therapeutic target for X-ALD treatment. In this context, the main objective of my thesis was to investigate the function and the structure of ABCD2, and more broadly, of peroxisomal ABC transporters.Half-transporters must at least dimerize to form a functional transporter. Alternative dimerization could modulate substrate specificity…

Support effects on NiO-based catalysts for the oxidative dehydrogenation (ODH) of ethane

2019

[EN] We report on the effect of NiO-support interactions on the chemical nature of Ni species in a series of supported NiO catalysts for the ODH of ethane. SiO2, TiO2-anatase, a high surface area TiO2 and a porous clay hetero-structure (PCH) with TiO2 and SiO2 pillars were used as supports, which led to a selectivity to ethylene in the range 30-90% over supported NiO catalysts. The catalysts were characterized by means of XRD, N-2-Adsorption, H-2-TPR, XPS and in situ (under H-2 reductive atmosphere) and ex situ XAS spectroscopy. The catalytic performance of supported materials is discussed in terms of their reducibility and specific reduction kinetics, but also taking into account the speci…

Local Structure of Supported Keggin and Wells-Dawson Heteropolyacids and Its Influence on the Catalytic Activity

2019

[EN] Keggin [PW12O40]3– and Wells–Dawson [P2W18O62]6– heteropolyanions are nanosized transition-metal-oxygen clusters belonging to the heteropolyacids (HPAs) family. They are widely used as catalysts due to their high Brønsted acidity, and their dispersion on solid supports favors the accessibility to their acid sites generally increasing the catalytic activity. A series of binary materials composed of Keggin or Wells–Dawson HPAs and SiO2, TiO2, and ZrO2 have been prepared by impregnation or solvothermal methods. Remarkable differences have been found in the catalytic activities among the unsupported and supported HPAs. These differences have been correlated in the past to the structural ch…

Cutting Edge: An IL-17F-CreEYFP Reporter Mouse Allows Fate Mapping of Th17 Cells

2009

Abstract The need for reporter lines able to faithfully track Th17 cells in vivo has become an issue of exceptional importance. To address this, we generated a mouse strain in which Cre recombinase is expressed from the IL-17F promoter. Crossing the IL-17F-Cre allele to a conditional enhanced yellow fluorescent protein (EYFP) reporter mouse yielded the IL-17F-CreEYFP strain, in which IL-17F expression is twinned with EYFP in live IL-17F-expressing cells. Although we demonstrate that IL-17F expression is restricted to CD4+ T cells during experimental autoimmune encephalomyelitis, IL-17F-CreEYFP CD8 T cells robustly expressed IL-17F in response to TGF-β, IL-6, and IL-23. Fate mapping of IL-17…

Polar Localization of a Tripartite Complex of the Two-Component System DcuS/DcuR and the Transporter DctA in Escherichia coli Depends on the Sensor K…

2014

The C4-dicarboxylate responsive sensor kinase DcuS of the DcuS/DcuR two-component system of E. coli is membrane-bound and reveals a polar localization. DcuS uses the C4-dicarboxylate transporter DctA as a co-regulator forming DctA/DcuS sensor units. Here it is shown by fluorescence microscopy with fusion proteins that DcuS has a dynamic and preferential polar localization, even at very low expression levels. Single assemblies of DcuS had high mobility in fast time lapse acquisitions, and fast recovery in FRAP experiments, excluding polar accumulation due to aggregation. DctA and DcuR fused to derivatives of the YFP protein are dispersed in the membrane or in the cytosol, respectively, when …