Microtubule configurations and nuclear DNA synthesis during initiation of suspensor-bearing embryos from Brassica napus cv. Topas microspores

In the new Brassica napus microspore culture system, wherein embryos with suspensors are formed, ab initio mimics zygotic embryogenesis. The system provides a powerful in vitro tool for studying the diverse developmental processes that take place during early stages of plant embryogenesis. Here, we studied in this new culture system both the temporal and spatial distribution of nuclear DNA synthesis places and the organization of the microtubular (MT) cytoskeleton, which were visualized with a refined whole mount immunolocalization technology and 3D confocal laser scanning microscopy. A ‘mild’ heat stress induced microspores to elongate, to rearrange their MT cytoskeleton and to re-enter the cell cycle and perform a predictable sequence of divisions. These events led to the formation of a filamentous suspensor-like structure, of which the distal tip cell gave rise to the embryo proper. Cells of the developing pro-embryo characterized endoplasmic (EMTs) and cortical microtubules (CMTs) in various configurations in the successive stages of the cell cycle. However, the most prominent changes in MT configurations and nuclear DNA replication concerned the first sporophytic division occurring within microspores and the apical cell of the pro-embryo. Microspore embryogenesis was preceded by pre-prophase band formation and DNA synthesis. The apical cell of the pro-embryo exhibited a random organization of CMTs and, in relation to this, isotropic expansion occurred, mimicking the development of the apical cell of the zygotic situation. Moreover, the apical cell entered the S phase shortly before it divided transversally at the stage that the suspensor was 3–8 celled

How do supranational regulators keep companies in line?: An analysis of the enforcement styles of EU agencies

National governments have increasingly transferred enforcement powers to EU agencies that monitor and penalize non-compliance by private actors. How do EU agencies apply enforcement competences in practice? Based on the Eurolegalism thesis, pressures for deeper integration have led to the emergence of a more adversarial enforcement style in Europe. Consequently, supranational regulators are expected to employ formal and coercive enforcement instruments. Conversely, studies of EU enforcement suggest that EU agencies may be reluctant to antagonize national governments by prosecuting private actors. In this study, we analyze the enforcement practices of supranational agencies with direct enforcement powers: the EU Aviation Safety Agency (EASA), European Securities and Markets Authority (ESMA) and European Medicines Agency (EMA). We find that EU agencies apply a legalistic approach, but they vary in coerciveness of enforcement. Whereas EU agencies tend to apply more coercive measures against non-conform products, they are generally not adversarial toward non-compliant organizations

CO2 reductie in nieuwbouwlocaties. Een inventarisatie en drie case studies naar de voorgenomen opties voor CO2 reductie in VINEX-locaties

Abstract niet beschikbaarA great deal of energy is used in urban areas for heating and electricity use in dwellings and buildings and for traffic. Many options are available to reduce CO2 emissions in the development of new urban areas, like district heating, smal-scale combined heat and power, several forms of solar energy, insulation, construction of public transport, mixing of functions and parking policies. Although a number of measures are being applied, there are still barriers to the large-scale diffusion of options for far-reaching CO2 reduction. This report presents the results of a study into the adoption of options for CO2 reduction in large building locations in the Netherlands. It consists of a survey of options adopted in the 26 largest VINEX locations and three case studies. In these case studies (the Kop van Zuid, Nieuwland and Meerhoven) the planning process was analysed to answer the question: what factors can explain the diffusion or otherwise of options for CO2 reduction. By analysing documents and holding interviews we followed the process of strategic planning from the design of the urban area through to implementation in individual building projects. Conclusions are drawn about the motives of the different actors involved, the organisation of the planning process, the role of knowledge, the policy instruments used and the role of external factors.SG-NO