This paper describes the Electronic Schoolbag, a digital workspace developed at the University of Savoie (France) and analyses its usages. This online environment is dedicated to the educational world: it offers pupils, students, teachers, school staff, or parents, personal and group workspaces in which individual or collaborative activities can take place. The flexibility of this software, allowing synchronous or asynchronous activities, lies in the “participation model”. This model allows groups themselves to describe and organise their activities. The architecture that permits (...) its implementation in the Electronic Schoolbag workspace is described. The study of the practices of the workspace is then presented. This requires different observation methods, according to the different procedures chosen: real practices provided by quantitative methods (analysis of the logs of the actions and questionnaires) and imagined practices provided by qualitative methods (semi-directive interviews). The results obtained from the university users allow us to assess the evolution of the usages for different periods and on different university sites. The observatory also lets us list the main uses of the Electronic Schoolbag for educative communication (collaborative vs. individual, informative vs. communicative). (shrink)

The state-of-art research in the field of life’s organization confronts the need to investigate a number of interacting components, their properties and conditions of sustainable behaviour within a natural system. In biology, ecology and life sciences, the performance of such stable system is usually related to homeostasis, a property of the system to actively regulate its state within a certain allowable limits. In our previous work, we proposed a deterministic model for systems’ homeostasis. The model was based on dynamical system’s (...) theory and pairwise relationships of competition, amensalism and antagonism taken from theoretical biology and ecology. However, the present paper proposes a different dimension to our previous results based on the same model. In this paper, we introduce the influence of inter-component relationships in a system, wherein the impact is characterized by direction (neutral, positive, or negative) as well as its (absolute) value, or strength. This makes the model stochastic which, in our opinion, is more consistent with real-world elements affected by various random factors. The case study includes two examples from areas of hydrobiology and medicine. The models acquired for these cases enabled us to propose a convincing explanation for corresponding phenomena identified by different types of natural systems. (shrink)

A geometric formulation of the gravitation theory in the spacetime R × S 3 is given. A linear connection is introduced on the tangent bundle T(R × S 3 ) and then the connection coefficients and the Riemann curvature tensor are calculated. It is shown that their expressions differ from those of Carmeli and Malin [Found. Phys.17, 407 (1987)] by supplementary terms due to the noncommutativity of derivatives used on the spacetime R × S 3 . The Einstein field equations (...) are written as usually and a comparison with other results is given. Finally, some observations about a possible gauge theory of gravitation in the spacetime R × S 3 are made. (shrink)

Mathematical modeling is a convenient way for characterization of complex ecosystems. This approach was applied to study the dynamics of zooplankton in Lake Sevan (Armenia) at different stages of anthropogenic eutrophication with the use of a novel method called discrete modeling of dynamical systems with feedback (DMDS). Simulation demonstrated that the application of this method helps in characterization of inter- and intra-component relationships in a natural ecosystem. This method describes all possible pairwise inter-component relationships like “plus–plus,” “minus–minus,” “plus–minus,” “plus–zero,” “minus–zero,” (...) and “zero–zero” that occur in most ecosystems. Based on the results, a working hypothesis was formulated. It was found that the sensitivity to weak external influence in zooplanktons was the greatest during the mid period of eutrophication in Lake Sevan, whereas in the final stages of eutrophication, an outbreak in the biomass production of cyanobacteria was evident. To support this approach, a weak external disturbance in the form of magnetic storm was used to see its effect on species Daphnia longispina sevanica. A statistically significant correlation between the frequency of magnetic storms and the number of this species was revealed and an increase in the number of toxic cyanobacteria species as a consequence of eutrophication. This paper, for the first time, suggests a DMDS method, to diagnose impact of anthropogenic eutrophication on environment. (shrink)

Keine ausführliche Beschreibung für "Über das Wesen der Naturgesetze" verfügbar.

A lyrical variation on vv. 27–30, the present passage is, at the same time, a new version of Hec. 631–7. A comparison is instructive in various respects, but Hel. 27 f. will not be quoted in justification of what L gives in vv. 236 f. This wording raises the following objections: the last word, , is outside the metre and not easily attached to the following colon, the beginning of which naturally coincides with the new sentence and new idea If, (...) then, is obelized—and this seems unavoidable—the words. (shrink)

A directory of archives and manuscript repositories, with links to web pages for the repositories and to online finding aids. Searchable by: collection name; city; state; National Inventory of Documentary Sources (NIDS) number; and National Union Catalog of Manuscript Collections (NUCMC) number.

There are methodological problems with the new techniques reviewed by Posner & Raichle. Some brain mechanisms are not detected by the temporal and spatial resolution. Questions are also raised by the stimulation paradigms.