58 research outputs found

    Consistency and coherence in adjudicating the ECB's unconventional monetary policy

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    Making the Case for a Rome V Regulation on the Law Applicable to Companies

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    There is significant legal variation and uncertainty in the conflict of laws rules applicable to companies in the EU. While the case law of the Court of Justice on the freedom of establishment has clarified some questions, it is evident that case law cannot provide for an adequate level of legal certainty. The main recommendation of this article is that private international company law in the EU should be harmonized. The article discusses the main challenges that a future regulation to this effect—called here ‘Rome V Regulation on the Law Applicable to Companies’—would have to overcome. Some of those are of a political nature: for instance, countries may fear that it may become easier for companies to evade domestic company law (eg, rules of employee co-determination), and there are specific considerations that concern companies established in third countries. Another challenge is that a future regulation on the law applicable to companies has to be consistent with existing EU conflict of laws rules as regards, for example, insolvency and tort law, while also complying with the freedom of establishment of the Treaty. It is the aim of this article to discuss these questions in detail, notably the general considerations for harmonisation in this field, a potential harmonization based on the ‘incorporation theory’, how it may be possible to overcome some contentious issues such as the definition of the lex societatis or the relationship between the lex societatis and other areas of law, and the prospects for future international harmonization

    Independent Recruitment of a Flavin-Dependent Monooxygenase for Safe Accumulation of Sequestered Pyrrolizidine Alkaloids in Grasshoppers and Moths

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    Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine alkaloids to their respective N-oxide, enabling the insects to avoid high concentrations of toxic pyrrolizidine alkaloids in the hemolymph. We have identified a pyrrolizidine alkaloid N-oxygenase, which is a flavin-dependent monooxygenase, of the grasshopper Zonocerus variegatus. After heterologous expression in E. coli, this enzyme shows high specificity for pyrrolizidine alkaloids of various structural types and for the tropane alkaloid atropine as substrates, a property that has been described previously for a pyrrolizidine alkaloid N-oxygenase of the arctiid moth Grammia geneura. Phylogenetic analyses of insect flavin-dependent monooxygenase sequences suggest that independent gene duplication events preceded the establishment of this specific enzyme in the lineages of the grasshoppers and of arctiid moths. Two further flavin-dependent monooxygenase sequences have been identified from Z. variegatus sharing amino acid identities of approximately 78% to the pyrrolizidine alkaloid N-oxygenase. After heterologous expression, both enzymes are also able to catalyze the N-oxygenation of pyrrolizidine alkaloids, albeit with a 400-fold lower specific activity. With respect to the high sequence identity between the three Z. variegatus sequences this ability to N-oxygenize pyrrolizidine alkaloids is interpreted as a relict of a former bifunctional ancestor gene of which one of the gene copies optimized this activity for the specific adaptation to pyrrolizidine alkaloid containing food plants

    Arbuscular Mycorrhizal Fungi and Plant Chemical Defence : Effects of Colonisation on Aboveground and Belowground Metabolomes

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    Arbuscular mycorrhizal fungal (AMF) colonisation of plant roots is one of the most ancient and widespread interactions in ecology, yet the systemic consequences for plant secondary chemistry remain unclear. We performed the first metabolomic investigation into the impact of AMF colonisation by Rhizophagus irregularis on the chemical defences, spanning above- and below-ground tissues, in its host-plant ragwort (Senecio jacobaea). We used a non-targeted metabolomics approach to profile, and where possible identify, compounds induced by AMF colonisation in both roots and shoots. Metabolomics analyses revealed that 33 compounds were significantly increased in the root tissue of AMF colonised plants, including seven blumenols, plant-derived compounds known to be associated with AMF colonisation. One of these was a novel structure conjugated with a malonyl-sugar and uronic acid moiety, hitherto an unreported combination. Such structural modifications of blumenols could be significant for their previously reported functional roles associated with the establishment and maintenance of AM colonisation. Pyrrolizidine alkaloids (PAs), key anti-herbivore defence compounds in ragwort, dominated the metabolomic profiles of root and shoot extracts. Analyses of the metabolomic profiles revealed an increase in four PAs in roots (but not shoots) of AMF colonised plants, with the potential to protect colonised plants from below-ground organisms
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