Germanité et amitié : trois modèles d’entraide

L’entraide recouvre d’innombrables activités mais implique aussi de la confiance et suscite des aspirations. Les instituts statistiques qui comptabilisent les échanges gratuits entre foyers observent les biens offerts ou reçus et des services rendus. De fait, une partie de la production domestique – fruits ou légumes récoltés dans son jardin, transport de personnes dans son véhicule, cuisine et ménage, garde d’enfant ou soins aux malades, bricolage, conseil pour financer l’acquisition d’un lo..

Optimization of the Culture Medium Composition to Improve the Production of Hyoscyamine in Elicited Datura stramonium L. Hairy Roots Using the Response Surface Methodology (RSM)

Traditionally, optimization in biological analyses has been carried out by monitoring the influence of one factor at a time; this technique is called one-variable-at-a-time. The disadvantage of this technique is that it does not include any interactive effects among the variables studied and requires a large number of experiments. Therefore, in recent years, the Response Surface Methodology (RSM) has become the most popular optimization method. It is an effective mathematical and statistical technique which has been widely used in optimization studies with minimal experimental trials where interactive factors may be involved. This present study follows on from our previous work, where RSM was used to optimize the B5 medium composition in [NO3−], [Ca2+] and sucrose to attain the best production of hyoscyamine (HS) from the hairy roots (HRs) of Datura stramonium elicited by Jasmonic Acid (JA). The present paper focuses on the use of the RSM in biological studies, such as plant material, to establish a predictive model with the planning of experiments, analysis of the model, diagnostics and adjustment for the accuracy of the model. With the RSM, only 20 experiments were necessary to determine optimal concentrations. The model could be employed to carry out interpolations and predict the response to elicitation. Applying this model, the optimization of the HS level was 212.7% for the elicited HRs of Datura stramonium, cultured in B5-OP medium (optimized), in comparison with elicited HRs cultured in B5 medium (control). The optimal concentrations, under experimental conditions, were determined to be: 79.1 mM [NO3−], 11.4 mM [Ca2+] and 42.9 mg/L of sucrose

Integrating environmental assessment in the assembly line design process

This study focuses on including the environmental assessment of a process in its design. Two improvement targets can be considered to optimize the environmental efficiency of a production phase: a cleaner process, and the optimization of the assembly of the different product parts. This work makes it possible to apply life cycle assessment to product industrialization, and specifically to assembly lines. The reduction of the environmental impacts (EI) of the production phase can be achieved by modeling the assembly line and/or optimizing equipment choices and organization. To accomplish this, we developed a tool. In this tool,equipment EI are calculated using two databases: i) an equipment database, listing Equipment characteristics: lifetime, EI for individual functional units and use parameters; and ii) a consumption database, listing the consumables and energy EI. A comparison of the equipment EI is carried out for the same function, use conditions and functional unit. Equipment is then selected according to its EI. Finally, the tool determines the EI of the optimized assembly lin

Proving the existence of macropsychological phenomena? The Katona-Tobin controversy over the predictive value of attitudinal data

URL des Documents de travail : http://centredeconomiesorbonne.univ-paris1.fr/documents-de-travail/Documents de travail du Centre d'Economie de la Sorbonne 2015.11 - ISSN : 1955-611XThis paper analyzes the controversy between George Katona and James Tobin that happened at the end of the nineteen fifties. The central problem of the paper concerns the nature of psychological phenomena. While Tobin defends that economic behavior stems from the individual, Katona tries to develop a macropsychological approach in which the individual plays a secondary role. The controversy thus reveals the arguments that initiated the developments of microeconomic theories and the construction of microeconomic data during the nineteen fifties

Conceptualizing the formation and role of expectations before 1950: George Katona's thought

URL des Documents de travail : http://centredeconomiesorbonne.univ-paris1.fr/documents-de-travail/Documents de travail du Centre d'Economie de la Sorbonne 2015.10 - ISSN : 1955-611XThis article analyzes Katona's theory of expectations and compares it to that of Keynes and Hicks. It discusses the implicit and explicit debates on the introduction of psychology in economic theory. The aim of this paper is twofold: define Katona's thought and examine the impact of this work on the debate on expectations in macroeconomics. This paper shows that Katona is the only author, to our knowledge, who develops both an empirical and theoretical research program on expectations that borrows from the epistemology of Keynes. While rediscovering Katona's work, this paper contributes to highlight the forgotten methodology that initiated the construction of confidence (or sentiment) indexes. It also discusses the implicit and explicit debates on the introduction of psychology in economic theory.Cet article étudie la théorie des anticipations de Katona et la compare à celle de Keynes et de Hicks. Il poursuit deux objectifs : définir la pensée de Katona et examiner son impact dans le débat sur les anticipations en macroéconomie. Ce papier met en évidence que Katona est le seul auteur, à notre connaissance, à développer un programme à la fois empirique et théorique sur les anticipations qui empreinte à l'épistémologie de Keynes. En s'intéressant aux travaux peu étudiés de Katona, cet article remet en avant la méthodologie à l'origine de la construction des indicateurs de confiance. Il discute aussi les débats implicites et explicites sur l'introduction de la psychologie en théorie économique