37 research outputs found

    Reciprocity as a foundation of financial economics

    Get PDF
    This paper argues that the subsistence of the fundamental theorem of contemporary financial mathematics is the ethical concept ‘reciprocity’. The argument is based on identifying an equivalence between the contemporary, and ostensibly ‘value neutral’, Fundamental Theory of Asset Pricing with theories of mathematical probability that emerged in the seventeenth century in the context of the ethical assessment of commercial contracts in a framework of Aristotelian ethics. This observation, the main claim of the paper, is justified on the basis of results from the Ultimatum Game and is analysed within a framework of Pragmatic philosophy. The analysis leads to the explanatory hypothesis that markets are centres of communicative action with reciprocity as a rule of discourse. The purpose of the paper is to reorientate financial economics to emphasise the objectives of cooperation and social cohesion and to this end, we offer specific policy advice

    Modification of cell surface properties of Pseudomonas alcaligenes S22 during hydrocarbon biodegradation

    Get PDF
    Biodegradation of water insoluble hydrocarbons can be significantly increased by the addition of natural surfactants one. Very promising option is the use of saponins. The obtained results indicated that in this system, after 21 days, 92% biodegradation of diesel oil could be achieved using Pseudomonas alcaligenes. No positive effect on the biodegradation process was observed using synthetic surfactant Triton X-100. The kind of carbon source influences the cell surface properties of microorganisms. Modification of the surface cell could be observed by control of the sedimentation profile. This analytical method is a new approach in microbiological analysis

    Rhamnolipids: diversity of structures, microbial origins and roles

    Get PDF
    Rhamnolipids are glycolipidic biosurfactants produced by various bacterial species. They were initially found as exoproducts of the opportunistic pathogen Pseudomonas aeruginosa and described as a mixture of four congeners: α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-Rha-C10-C10), α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoate (Rha-Rha-C10), as well as their mono-rhamnolipid congeners Rha-C10-C10 and Rha-C10. The development of more sensitive analytical techniques has lead to the further discovery of a wide diversity of rhamnolipid congeners and homologues (about 60) that are produced at different concentrations by various Pseudomonas species and by bacteria belonging to other families, classes, or even phyla. For example, various Burkholderia species have been shown to produce rhamnolipids that have longer alkyl chains than those produced by P. aeruginosa. In P. aeruginosa, three genes, carried on two distinct operons, code for the enzymes responsible for the final steps of rhamnolipid synthesis: one operon carries the rhlAB genes and the other rhlC. Genes highly similar to rhlA, rhlB, and rhlC have also been found in various Burkholderia species but grouped within one putative operon, and they have been shown to be required for rhamnolipid production as well. The exact physiological function of these secondary metabolites is still unclear. Most identified activities are derived from the surface activity, wetting ability, detergency, and other amphipathic-related properties of these molecules. Indeed, rhamnolipids promote the uptake and biodegradation of poorly soluble substrates, act as immune modulators and virulence factors, have antimicrobial activities, and are involved in surface motility and in bacterial biofilm development

    Working passionately does not always pay off : the negative moderating role of passion on the relationship between deliberate practice and venture performance

    Get PDF
    Deliberate practice, an iterative process that leads to expertise, is found to be positively associated with superior performance in domains such as sports, education, and entrepreneurship. At the same time, deliberate practice is also seen as being less than enjoyable and difficult to pursue consistently. As such, passion is considered to be a vital motivator of engagement in and maintenance of deliberate practice. Despite the evident importance of passion, the relationship between passion and deliberate practice in entrepreneurship has not been subject to sufficient empirical evaluation. Therefore, in this study, we consider the way in which passion moderates the relationship between deliberate practice and venture performance. We hypothesize that deliberate practice is positively related to venture performance and that passion positively moderates this relationship. We find support for our first hypothesis, in line with previous studies. However, contrary to our second hypothesis, we find that entrepreneurial passion negatively moderates the deliberate practice-venture performance relationship. In response to this finding, we provide possible explanations as to why this negative moderation effect was observed by drawing on Kolb’s experiential learning cycle

    A taxonomic bibliography of the South American snakes of the Crotalus durissus complex (Serpentes, Viperidae)

    Full text link
    corecore