4,134 research outputs found

    Risiken im Lebenszyklus: Theorie und Evidenz

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    Der einzelne Mensch ist im Lebensverlauf erheblichen biometrischen, ökonomischen, familiären und politischen Risiken ausgesetzt. Viele meinen, diese wären in den letzten Jahren größer geworden. Haben wir die richtigen Institutionen, um diese Risiken effizient abzudecken? Unter Institutionen verstehen wir individuelles Sparen, familiäre Hilfe, private Versicherungen und schließlich den Staat mit seinen Sozialversicherungen. Wo und wann funktionieren diese Institutionen? Wo und wann nicht? Was muss man tun, um sie zu verbessern? Wie sieht modernes "Social Risk Management" aus? Der erste Teil dieses Übersichtsbeitrags skizziert die wirtschaftstheoretischen Grundlagen des Sparverhaltens, der Portefeuillewahl und der Versicherungsnachfrage. Im Hauptteil werden die empirischen Befunde gesammelt, um im dritten Teil wirtschaftspolitische Schlussfolgerungen zu ziehen

    EFFECT OF LIVING MULCH ON PEST/BENEFICIAL INTERACTION

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    The aim of this study was to evaluate the effect of cover crops on pest/beneficial dynamics and to test the potential of living mulch on enhancing biological control against insect pests. The research, carried out in the frame of the InterVeg (Core Organic II) project, involved four European countries: Germany, Slovenia, Denmark and Italy. Three crops were tested: cauliflower, leek and artichoke. The preliminary results obtained in Italy on cauliflower, indicated that the living mulch did not affect the infestation of the cabbage butterfly, Pieris brassicae, showing no detrimental effect of this technique on pest dynamics. A very high level of parasitization against cabbage butterfly was detected either in the living mulch crop (88%) and in the sole one (63%). Living mulch showed to increase the spider and rove beetle activity density, while the carabid activity density was slightly higher in the sole crop

    Cluster Performance reconsidered: Structure, Linkages and Paths in the German Biotechnology Industry, 1996-2003

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    This paper addresses the evolution of biotechnology clusters in Germany between 1996 and 2003, paying particular attention to their respective composition in terms of venture capital, basic science institutions and biotechnology firms. Drawing upon the significance of co-location of "money and ideas", the literature stressing the importance of a cluster's openness and external linkages, and the path dependency debate, the paper aims to analyse how certain cluster characteristics correspond with its overall performance. After identifying different cluster types, we investigate their internal and external interconnectivity in comparative manner and draw on changes in cluster composition. Our results indicate that the structure, i.e. to which group the cluster belongs, and the openness towards external knowledge flows deliver merely unsystematic indications with regard to a cluster's overall success. Its ability to change composition towards a more balanced ratio of science and capital over time, on the other hand, turns out as a key explanatory factor. Hence, the dynamic perspective proves effective illuminating cluster growth and performance, where our explorative findings provide a promising avenue for further evolutionary research

    A manganese photosensitive tricarbonyl molecule [Mn(CO)3(tpa-κ(3)N)]Br enhances antibiotic efficacy in a multi-drug-resistant Escherichia coli

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    Carbon monoxide-releasing molecules (CORMs) are a promising class of new antimicrobials, with multiple modes of action that are distinct from those of standard antibiotics. The relentless increase in antimicrobial resistance, exacerbated by a lack of new antibiotics, necessitates a better understanding of how such novel agents act and might be used synergistically with established antibiotics. This work aimed to understand the mechanism(s) underlying synergy between a manganese-based photoactivated carbon monoxide-releasing molecule (PhotoCORM), [Mn(CO)3(tpa-κ(3)N)]Br [tpa=tris(2-pyridylmethyl)amine], and various classes of antibiotics in their activities towards Escherichia coli EC958, a multi-drug-resistant uropathogen. The title compound acts synergistically with polymyxins [polymyxin B and colistin (polymyxin E)] by damaging the bacterial cytoplasmic membrane. [Mn(CO)3(tpa-κ(3)N)]Br also potentiates the action of doxycycline, resulting in reduced expression of tetA, which encodes a tetracycline efflux pump. We show that, like tetracyclines, the breakdown products of [Mn(CO)3(tpa-κ(3)N)]Br activation chelate iron and trigger an iron starvation response, which we propose to be a further basis for the synergies observed. Conversely, media supplemented with excess iron abrogated the inhibition of growth by doxycycline and the title compound. In conclusion, multiple factors contribute to the ability of this PhotoCORM to increase the efficacy of antibiotics in the polymyxin and tetracycline families. We propose that light-activated carbon monoxide release is not the sole basis of the antimicrobial activities of [Mn(CO)3(tpa-κ(3)N)]Br

    EFFECT OF LIVING MULCH ON PEST/BENEFICIAL INTERACTION

    Get PDF
    The aim of this study was to evaluate the effect of cover crops on pest/beneficial dynamics and to test the potential of living mulch on enhancing biological control against insect pests. The research, carried out in the frame of the InterVeg (Core Organic II) project, involved four European countries: Germany, Slovenia, Denmark and Italy. Three crops were tested: cauliflower, leek and artichoke. The preliminary results obtained in Italy on cauliflower, indicated that the living mulch did not affect the infestation of the cabbage butterfly, Pieris brassicae, showing no detrimental effect of this technique on pest dynamics. A very high level of parasitization against cabbage butterfly was detected either in the living mulch crop (88%) and in the sole one (63%). Living mulch showed to increase the spider and rove beetle activity density, while the carabid activity density was slightly higher in the sole crop

    The role of universities in regional development: conceptual models and policy institutions in the UK, Sweden and Austria

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    The literature on universities’ contributions to regional development is broad and diverse. A precise understanding of how regions may draw advantages from various university activities and the role of public policy institutions in promoting such activities is still missing. The aim of this paper is to provide a framework for analysing universities’ contributions to regional economic and societal development in differing national contexts and the policy institutions that underpin them. To do this, we review four conceptual models: the entrepreneurial university model, the regional innovation system (RIS) model, the mode 2 university model and the engaged university model. The paper demonstrates that these four models emphasize very different activities and outputs by which universities are seen to benefit regional economy and society. It is also shown that these models differ markedly with respect to the policy implications and practice. Analysing some of the public policy imperatives and incentives in the UK, Austria and Sweden, the paper highlights that in the UK, policies encourage all four university models. In contrast, in Sweden and Austria, policy institutions tend to privilege the RIS university model, whilst at the same time, there is some evidence for increasing support of the entrepreneurial university model

    Adaptive plasticity of killifish (Fundulus heteroclitus) embryos: dehydration-stimulated development and differential aquaporin-3 expression

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    13 pages, 7 figures, 3 tablesEmbryos of the marine killifish Fundulus heteroclitus are adapted to survive aerially. However, it is unknown if they are able to control development under dehydration conditions. Here, we show that air-exposed blastula embryos under saturated relative humidity were able to stimulate development, and hence the time of hatching was advanced with respect to embryos continuously immersed in seawater. Embryos exposed to air at later developmental stages did not hatch until water was added, while development was not arrested. Air-exposed embryos avoided dehydration probably because of their thickened egg envelope, although it suffered significant evaporative water loss. The potential role of aquaporins as part of the embryo response to dehydration was investigated by cloning the aquaporin-0 (FhAqp0), -1a (FhAqp1a), and -3 (FhAqp3) cDNAs. Functional expression in Xenopus laevis oocytes showed that FhaAqp1a was a water-selective channel, whereas FhAqp3 was permeable to water, glycerol, and urea. Expression of fhaqp0 and fhaqp1a was prominent during organogenesis, and their mRNA levels were similar between water- and air-incubated embryos. However, fhaqp3 transcripts were highly and transiently accumulated during gastrulation, and the protein product was localized in the basolateral membrane of the enveloping epithelial cell layer and in the membrane of ingressing and migrating blastomers. Interestingly, both fhaqp3 transcripts and FhAqp3 polypeptides were downregulated in air-exposed embryos. These data demonstrate that killifish embryos respond adaptively to environmental desiccation by accelerating development and that embryos are able to transduce dehydration conditions into molecular responses. The reduced synthesis of FhAqp3 may be one of these mechanisms to regulate water and/or solute transport in the embryo.This study was supported by the European Commission New and Emerging Science and Technologies (NEST) program (contract no. 012674-2 Sleeping Beauty) and by a grant from the Spanish Ministry of Education and Science (MEC; AGL2004-00316/ACU) to J. Cerda`. Participation of C. Zapater and F. Chauvigne´ was financed by a predoctoral fellowship from MEC (Spain) and by the European Commission [Marie Curie Research Training Network Aqua (glycero)porins, MRTN-CT-2006-035995], respectively.Peer reviewe
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