L'historien et l'algorithme

Les relations houleuses qu’histoire et informatique entretiennent ne sont pas nouvelles et la révolution des sciences historiques annoncée depuis plusieurs décennies continue de se faire attendre. Dans ce chapitre, nous aimerions néanmoins tenter de montrer qu’une évolution inédite est aujourd’hui à l’oeuvre dans les sciences historiques et que cette transformation est différente de celle qui a caractérisé, il y a quelques décennies l’arrivée de la « cliométrie » et des méthodes quantitatives. Notre hypothèse est que nous assistons par les effets de deux processus complémentaires à une généralisation des algorithmes comme objets médiateurs de la connaissance historique

Knowing What the Peer Knows: The Differential Effect of Knowledge Awareness on Collaborative Learning Performance of Asymmetric Pairs

In an empirical study, we provided (or not) pairs of students working in a remote collaborative learning situation with a knowledge awareness tool that provided learner A with learner B’s level of knowledge measured through a pre-test. We analyzed the effect of the knowledge awareness tool on asymmetric pairs with regards to the prior-knowledge. Post-hoc analysis on the pairs’ knowledge level showed that the knowledge awareness tool mainly affects the learning performances of asymmetric pairs. Further analysis on the learners’ level showed that the knowledge awareness tool mainly affects the collaborative learning gain of the more-knowledgeable peers of asymmetric pairs. The results are discussed in light of socio-cognitive processes such as audience design and perspective taking

Dual Eye-Tracking: Lessons Learnt

Dual eye-tracking (DUET) is at the confluents of cognitive (and social) psychology and computer science. DUET is a novel methodology to explore the socio-cognitive processes underlying collaboration. The basic aims of DUET are to better understand, through gaze indicators, a socially distributed cognitive system and to support collaboration by real time gaze display of collaborators. We are interested in finding whether and how patterns of eye-movements can reflect the cognition underlying collaboration. This paper concentrates on the major motivations, methodological challenges and the future aspects of DUET

Encoding metaknowledge for historical databases

Historical knowledge is fundamentally uncertain. A given account of an historical event is typically based on a series of sources and on sequences of interpretation and reasoning based on these sources. Generally, the product of this historical research takes the form of a synthesis, like a narrative or a map, but does not give a precise account of the intellectual process that led to this result. Our project consists of developing a methodology, based on semantic web technologies, to encode historical knowledge, while documenting, in detail, the intellectual sequences linking the historical sources with a given encoding, also know as paradata. More generally, the aim of this methodology is to build systems capable of representing multiple historical realities, as they are used to document the underlying processes in the construction of possible knowledge spaces

Crystal structure of amylose complexes with small ligands

International audienc

CT-diagnosed mesenteric alterations in patients with non-Hodgkin's lymphoma: a population-based study

BACKGROUND: Mesenteric alterations are associated with non-Hodgkin's lymphoma (NHL), but the frequency and prognostic value of mesenteric alterations are unknown in patients with NHL. PATIENTS AND METHODS: We retrospectively screened 120 patients that were treated for NHL between January 1996 and December 2001 for the presence of mesenteric alterations, defined on computed tomography (CT) scans as nodular or diffuse infiltration of the abdominal mesentery with increased density of mesenteric fat. RESULTS: 21 patients (17.5%) had radiological findings of mesenteric alterations at the time of the initial NHL diagnosis. Mesenteric alterations were significantly associated with mesenteric lymphadenopathy (p = 0.01). In about 50% of the patients, mesenteric alterations could not be explained by direct mesenteric tumour invasion or overt lymphatic obstruction. Patients with initial findings of mesenteric alterations tended to have a better 4-year survival as compared to patients without such findings (79 vs. 43%, p = 0.11). The International Prognostic Index (IPI) score was the only independent predictor of survival in the multivariate analysis. CONCLUSION: This retrospective screening study found a moderate prevalence of mesenteric alterations in patients with various subtypes of NHL. The diagnostic and prognostic value of mesenteric alterations should be further assessed in prospective studies

Experimental validation of the food disgust scale using olfactory stimuli

Individual disgust reactions can be elicited through different types of sensory stimuli. Most well-known scales measuring disgust are text-based, thus more cognitive stimuli. This study aimed to validate the food disgust scale using olfactory stimuli related to food. For this, 150 participants were invited to our lab to rate different odours for the level of disgust evoked. Exploratory factor analysis (principal axis factoring) revealed two factors. The seven more disgusting items loaded on a first factor, whereas the two less disgusting items loaded on a second factor. The seven items loading on Factor 1 had acceptable reliability (Cronbach's α = 0.73, McDonald's Ω = 0.72). Further, Factor Score 1 was significantly correlated with the FDS short, a food disgust sensitivity questionnaire (r = 0.40, p <.001). We conclude that food disgust sensitivity can help predict individuals’ odour perception and our data support the incremental validity of the FDS short. Our study is the first to validate the FDS short using olfactory stimuli. Finally, our study indicates that there is significant potential for the creation of a food disgust odour scale.ISSN:0950-3293ISSN:1873-634

Perspectives of Starch in Food Science

Starch is amongst the most abundant plant products and is a mixture of two polymers, amylose and amylopectin. During food processing starch is transformed by hydrothermal treatments. The structural features of starch in food cover a size range of more than six orders of magnitude and encompass the macromolecules, crystalline domains, phase separated amylose and amylopectin structures, starch granules and extensive starch networks. The structure of starch is also influenced by specific and non-specific interactions with other food constituents and ingredients. Starch, particularly amylose, is able to specifically interact with small ligands and form helical inclusion complexes that influence the colloidal properties of aqueous food systems. Furthermore, the nutritional properties of starch, for instance the amount of resistant starch, which is not digested in the upper human gastrointestinal tract, but fermented by the colonic microflora, are determined by food composition and processing conditions. An in-depth understanding of the relationships between processing and structure of starch taking into account the different structural levels will allow the prediction and control of bulk properties of food including textural, sensory and nutritional properties