A Reply to the Comment by A. Rivera et al.

in Physical Review Letters (2005), 94

On the Income Dependence of Equivalence Scales

in Journal of Public Economics (2005), 89(5-6), 967-996

Household consumption exhibits economies of scale as the number of household members increases. We collect survey data from two countries, Germany and France, in order to obtain direct subjective ... [more ▼]

Household consumption exhibits economies of scale as the number of household members increases. We collect survey data from two countries, Germany and France, in order to obtain direct subjective estimates of household consumption economies of scale, and, in particular, to examine an additional dimension: whether household consumption economies of scale change as living standards go up. Our data from both countries indicate strongly that household economies of scale increase as the living standard goes up. We discuss the robustness of our survey method and compare our results to these of alternative estimation methods in the literature. [less ▲]

Nucleation in suspensions of anisotropic colloids

in Computer Physics Communications (2005), 169(1-3), 117-121

We report Monte Carlo studies of liquid crystal nucleation in two types of anisotropic colloidal systems: hard rods and hard ellipsoids. In both cases we find that nucleation pathways differ strongly from ... [more ▼]

We report Monte Carlo studies of liquid crystal nucleation in two types of anisotropic colloidal systems: hard rods and hard ellipsoids. In both cases we find that nucleation pathways differ strongly from the pathways in systems of spherical particles. Short hard rods show an effect of self-poisoning. This part of the article is based on a previous publication [T. Schilling, D. Frenkel, Self-poisoning of crystal nuclei in hard-rod liquids, Phys. Rev. Lett. 92 (2004) 085505]. When a crystallite forms, its surfaces are covered preferentially by rods which align perpendicular to the surface. Therefore subsequent growth is stunted. Hard, almost spherical ellipsoids can be compressed to very high densities without crystallization—in contrast to hard spheres, which crystallize easily. When forced to crystallize, ellipsoids form very loosely aggregated nuclei. In both cases nucleation pathways are complex and it is therefore difficult to define an appropriate reaction coordinate. The common strategies of investigation of nucleation problems (i.e. definition of a coordinate and then sampling barrier crossing with well-known techniques) fail in these systems. [less ▲]

An approach to qualify the intensity of mixing on a forward acting grate.

in Chemical Engineering Science (2005), (60/6), 1649-1659

A bioinformatics perspective on proteomics: Data storage, analysis, and integration

in Bioscience Reports (2005), 25(1-2), 95-106

The field of proteomics is advancing rapidly as a result of powerful new technologies and proteomics experiments yield a vast and increasing amount of information. Data regarding protein occurrence ... [more ▼]

The field of proteomics is advancing rapidly as a result of powerful new technologies and proteomics experiments yield a vast and increasing amount of information. Data regarding protein occurrence, abundance, identity, sequence, structure, properties, and interactions need to be stored. Currently, a common standard has not yet been established and open access to results is needed for further development of robust analysis algorithms. Databases for proteomics will evolve from pure storage into knowledge resources, providing a repository for information (meta-data) which is mainly not stored in simple flat files. This review will shed light on recent steps towards the generation of a common standard in proteomics data storage and integration, but is not meant to be a comprehensive overview of all available databases and tools in the proteomics community. [less ▲]

Uncertainty of absolute gravity measurements

in Journal of Geophysical Research (2005), 110(B05406), 1-9

Muster-Freundschaft: Gerhart Hauptmann und Walther Rathenau

in Hahn, Hans-Joachim (Ed.) Gerhart Hauptmann und die Juden. Konstellationen und Konstruktionen in Leben und Werk (2005)

A new functional role of the fibrinogen RGD motif as the molecular switch that selectively triggers integrin alphaIIbbeta3-dependent RhoA activation during cell spreading

in Journal of Biological Chemistry (2005), 280(39), 33610-33619

A number of RGD-type integrins rely on a synergistic site in addition to the canonical RGD site for ligand binding and signaling, although it is still unclear whether these two recognition sites function ... [more ▼]

A number of RGD-type integrins rely on a synergistic site in addition to the canonical RGD site for ligand binding and signaling, although it is still unclear whether these two recognition sites function independently, synergistically, or competitively. Experimental evidence has suggested that fibrinogen binding to the RGD-type integrin alphaIIbbeta3 occurs exclusively through the synergistic gamma(400-411) sequence, thus questioning the functional role of the RGD recognition site. Here we have investigated the respective role of the fibrinogen gamma(400-411) sequence and the RGD motif in the molecular events leading to ligand-induced alphaIIbbeta3-dependent Chinese hamster ovary (CHO) cell or platelet spreading, by using intact fibrinogen and well characterized plasmin-generated fibrinogen fragments containing either the RGD motif (fragment C) or the gamma(400-411) sequence (fragment D), and CHO cells expressing resting wild type (alphaIIbbeta3wt), constitutively active (alphaIIbbeta3T562N), or non-functional (alphaIIbbeta3D119Y) receptors. Our data provide evidence that the gamma(400-411) site by itself is able to initiate alphaIIbbeta3 clustering and recruitment of intracellular proteins to early focal complexes, mediating cell attachment, FAK phosphorylation, and Rac1 activation, while the RGD motif subsequently acts as a molecular switch on the beta3 subunit to trigger cell spreading. More importantly, we show that the premier functional role of the RGD site is not to reinforce cell attachment but, rather, to imprint a conformational change on the beta3 subunit leading to maximal RhoA activation and actin cytoskeleton organization in CHO cells as well as in platelets. Finally, alphaIIbbeta3-dependent RhoA stimulation and cell spreading, but not cell attachment, are Src-dependent and phosphoinositide 3-kinase-independent and are inhibited by the Src antagonist PP2. [less ▲]

Tauschprozesse Kulturwissenschaftliche Verhandlungen des Ökonomischen

Book published by Transcript (2005)

Transition école - vie active : une typologie des mesures pour les jeunes sans qualification

in Actes de l'Université européenne d'été de la FREREF (2005)

Comme dans tous les pays européens, un grand nombre de mesures à destination des jeunes sortis du système scolaire sans qualification ont été mises en place au Luxembourg. Une étude systématique par ... [more ▼]

Comme dans tous les pays européens, un grand nombre de mesures à destination des jeunes sortis du système scolaire sans qualification ont été mises en place au Luxembourg. Une étude systématique par interview semi-dirigée a été réalisée auprès des responsables formation de l'ensemble des 32 dispositifs répertoriés au Luxembourg, en distinguant les mesures spécifiquement destinées aux jeunes et celles destinées pour tout âge, jeunes compris. L'enquête visait surtout à déterminer les caractéristiques des pratiques pédagogiques mises en oeuvre avec les publics concernés. A partir du dépouillement du matériel recueilli, une typologie en trois catégories a été élaborée. Celle-ci est construite sur 10 indicateurs importants : pré-requis, statut de l'apprenant, profil de l'apprenant, activités de remotivation, description de la formation (contenus et méthodes), suivi, stages, formateurs, qualification/certification, débouchés. Elle distingue les formations par le travail (formation "sur le tas" permettant d'apprendre des tâches professionnelles spécifiques ainsi que des compétences sociales de base), les formations d'insertion socio-professionnelle (formations se basant sur un programme de formation défini et donnent droit à une attestation en fonction d'une évaluation) et les formations qualifiantes (formations permettant d'obtenir un diplôme ou un certificat officiel du ministère et donnant droit à un barème salarial légal). Chacun de ces dispositifs a une logique de fonctionnement propre, une certaine cohérence en fonction du profil du groupe cible, des objectifs visés et de la démarche socio-pédagogique adoptée. Chacun de ces dispositifs correspond à des possibilités de travail avec une certaine partie du groupe cible. Situées à des distances spécifiques sur l'axe de transition entre la formation initiale et la vie active, ces types de mesures combinent de façon variable des caractéristiques spécifiques du champ scolaire et du champ professionnel. [less ▲]