56 research outputs found
Verwilderungen in den Gewächshäusern des Botanischen Gartens Braunschweig / Jens Nitzsche & Dietmar Brandes
No full textIn Ergänzung zu unserer Studie über die Verwilderungen von kultivierten Arten im Freiland des Botanischen Gartens Braunschweig (BRANDES & NITZSCHE 2013) haben wir auch die Verwilderungen innerhalb der Gewächshäuser untersucht. Wenn auch die meisten der dort subspontan angetroffenen Arten in Mitteleuropa (unter den derzeitigen Klimabedingungen) wohl nicht im Freien überleben können und deswegen natürlich nicht zu seiner Flora gerechnet werden können, gibt es doch einige wenige Arten, die an Sonderstandorten in wintermilden Gebieten Mitteleuropas bereits als unbeständige Neophyten gefunden wurden. Da Anfangsstadien der Ausbreitung von gebietsfremden Pflanzenarten nur in Sonderfällen beobachtet werden können und konnten, erscheint uns eine Dokumentation des Ist-Zustandes sinnvoll. Sie lässt zugleich gewisse Rückschlüsse auf das „Verwilderungspotenzial“ einzelner Zierpflanzen unter warm-temperierten Bedingungen zu.
Seit November 2010 wird vom Erstautor eine Inventur und Revision des gesamten kultivierten, verwilderten und spontanen Artenbestandes im Botanischen Garten Braunschweig durchgeführt. Dabei wurde der Garten auch als Sonderhabitat im Kontext der Erforschung urbaner Lebensräume untersucht. Wenn auch die Fläche der Gewächshäuser ebenso wie diejenige der Freiflächen vergleichsweise klein ist, so ist der erreichte Vollständigkeitsgrad doch sehr hoch anzusetzen.grounds of the Botanical Garden of Braunschweig (BRANDES & NITZSCHE 2013), we examined the naturalization of plants inside the greenhouses. Most of the found subspontaneous species could not survive outdoors in central Europe (due to the current climatic conditions) and are therefore of course not included in its flora. But among these are a few species that have been found to be transient neophytes in special habitats of winter-mild areas in central Europe. Since the first stages of expansion of non-indigenous plant species can only be observed under special circumstances, it appeared appropriate to document the current situation. It also allows certain conclusions to be drawn on the “naturalization potential” of several ornamental plants under warm-temperate conditions.
The first author performs since November 2010 an inventory and revision of the entire stock of cultivated, naturalized and spontaneous species of the Botanical Garden of Braunschweig. While doing so, the garden was also examined as a special habitat in context of the research on urban biotopes. Even so the area of the greenhouses, as well as those of the exterior planting grounds, is relatively small, the attained grade of completion has to be valued highly
Paladin is a phosphoinositide phosphatase regulating endosomal VEGFR2 signalling and angiogenesis
No full textCell signalling governs cellular behaviour and is therefore subject to tight spatiotemporal regulation. Signalling output is modulated by specialized cell membranes and vesicles which contain unique combinations of lipids and proteins. The phosphatidylinositol 4,5-bisphosphate (PI(4,5)P-2), an important component of the plasma membrane as well as other subcellular membranes, is involved in multiple processes, including signalling. However, which enzymes control the turnover of non-plasma membrane PI(4,5)P-2, and their impact on cell signalling and function at the organismal level are unknown. Here, we identify Paladin as a vascular PI(4,5)P-2 phosphatase regulating VEGFR2 endosomal signalling and angiogenesis. Paladin is localized to endosomal and Golgi compartments and interacts with vascular endothelial growth factor receptor 2 (VEGFR2) in vitro and in vivo. Loss of Paladin results in increased internalization of VEGFR2, over-activation of extracellular regulated kinase 1/2, and hypersprouting of endothelial cells in the developing retina of mice. These findings suggest that inhibition of Paladin, or other endosomal PI(4,5)P-2 phosphatases, could be exploited to modulate VEGFR2 signalling and angiogenesis, when direct and full inhibition of the receptor is undesirable.Shared first authorship: Anja Nitzsche, Riikka Pietilä and Dominic T Love</p
Verliererinnen der Erneuerung? Die Situation von Frauen im ländlichen Vietnam
No full textSince the mid-1980s Vietnam has been undergoing a far-reaching transformation process. Up till now it is the economic indicators in particular that point to success of the reforms. Thus it is often overseen that the so called Doi Moi (the "Vietnamese version" of Perestroika) has led to severe social discrepancies. Close examination reveals a widening gap in affluence between urban and rural areas, as well as between women and men. Vietnamese women employed in agriculture still must be regarded as the weakest group within this process of change. Despite their extensive participation in the rural economy, women are partially excluded from the benefits of the reforms.Especially in rural areas women suffer more than men from an increased burden of work, decline in their level of education, the deterioration of the health system as well as their limited access to financial and material resources. The re-orientation of the household economy as basic productive unit causes a revival of traditional attitudes and behaviour, mainly conditioned by Confucianism, which promotes the discrimination against women
The Role of Paladin in Endothelial Cell Signaling and Angiogenesis
No full textAngiogenesis, the formation of new blood vessels from a pre-existing vasculature, is crucial during development and for many diseases including cancer. Despite tremendous progress in the understanding of the angiogenic process, many aspects are still not fully elucidated. Several attempts have been made to identify novel genes involved in endothelial cell biology and angiogenesis. Here we focused on Pald1, a recently identified, vascular-enriched gene encoding paladin. Our in vitro studies indicate that paladin is a lipid phosphatase catalyzing dephosphorylation of phosphatidylinositol phosphates, a process essential for endocytosis and intracellular vesicle trafficking. We confirmed paladin’s vascular expression pattern and revealed a shift from a broad endothelial cell expression during development to an arterial mural cell-restricted expression in several vascular beds in adult mice. Paladin expression in the lung, however, was not restricted to the vasculature, but was also observed in pneumocytes and myofibroblasts. Lungs of female, but not male, Pald1 null mice displayed an obstructive lung phenotype with increased alveolar air sacs that were already apparent early in the alveolarization process. Only endothelial cells, but not other main lung cell types, were affected by loss of paladin. Endothelial cell number was reduced in 4-week old mice, possibly due to increased endothelial turnover in Pald1 deficient lungs. Vascular defects were also found in the retina. Loss of paladin led to reduced retinal vascular outgrowth accompanied by a hyperdense and hypersprouting vascular front. Downstream signaling of the major angiogenic driver, vascular endothelial growth factor receptor 2 (VEGFR2) was sustained in Pald1 null mice, and VEGFR2 degradation was impaired. Furthermore, paladin inhibited endothelial cell junction stability and loss of paladin led to reduced vascular permeability. Whether the differences in VEGFR2 signaling and adherens junction stability are connected remains to be fully explored. The newly identified lipid phosphatase activity of paladin and its specific effects on VEGFR2 signaling and adherens junction stability indicate that paladin may be controlling the endocytic pathway
Engaging Visitors at Depot Boijmans Van Beuningen: The design of an interactive guided experience which invites visitors to contribute and feel a sense of ownership of the collection stored in Depot Boijmans Van Beuningen
No full textA design was developed to introduce and invite visitors to take ownership of the collection stored in Depot Boijmans Van Beuningen. The Double Diamond process formed the basis of the design methodology. This iterative process resulted into the design of an interactive guided experience. Extensive research resulted in the selection of four overarching themes defining the needs of visitors, staff and scientists: perspectives, belonging, recognition and relevance. The final design is based on these overarching themes. It was first prototyped and tested online and after on site in the depot. The results of the tests were positive, the design made visitors aware of the function of the depot: the storing, preserving and collecting activities. It also personalized the visitors’ journey. Once interaction was established, it was found that visitors are also willing to add personal information to the collection. It is suggested that this system can be applied in other museum depots in general, but for that more needs to be done.Design for Interactio
Localized physical vapor deposition via focused laser spike dewetting of gold thin films for nanoscale patterning
No full textFocused laser spike (FLaSk) excitation has been demonstrated as a reliable technique for the patterning of micro-to-nanoscale features locally by thermocapillary shear of thin films. Recent work on polymer thin films has revealed that overlapping laser scans can leverage coupled thermal and fluid effects to create subwavelength patterns. Compared to polymeric films, metallic thin films possess both a lower melt viscosity and higher surface tension. Here we investigate overlapping effects in the dewetting of ~15 nm gold thin films on borosilicate and quartz glass substrates with a 532 nm continuous wave laser. During this process, FLaSk initiates capillary and thermocapillary dewetting simultaneously. Further, the low oxidation potential and high vapor pressure of gold lead to non-equilibrium vaporization during heating. Since the parameters of overlapping scans control the amount of material that is heated and to what temperature it is heated, selection of laser power, scanning distance, writing speed, and numerical aperture results in particles with different sizes and spacing deposited on the writing substrates or a positioned superstrate through a laser-induced localized physical vapor deposition (LILPVD) process. If the laser parameters are selected within a specific working range, uniform or periodic particle distributions can be repeatably deposited in this fashion, which can then be used as seeds for nanomaterial growth. In addition, if the substrate melts during FLaSk, the viscous forces of the liquid-on-liquid dewetting broadens the range of patterning conditions by resisting the motion of the gold leading to more uniform particles over a large range of parameters.Peer reviewe
Thermocapillary Multidewetting of Thin Films
No full textThermocapillary dewetting of liquids and molten films has recently emerged as a viable alternative to conventional microprocessing methods. As this thermal gradient-induced mechanism is universal, it can be applied to any material. This work explores the sequential dewetting of materials with varying melting points, including polymers and metals, to create aligned morphologies. The variation in melting point allows for the dewetting of single layers at a time or mobility-limited simultaneous dewetting. As a result, a variety of multimaterial structures can be produced with built-in alignment, such as arrays of concentric circles, lines with periodic segmentation, or islands on holes. This approach employs photothermal methods to induce the necessary thermal gradient, manipulating several variables in order to influence the consequent structures. Adjusting laser power and light intensity allows for the control of temperature for selective dewetting of films; altering beam size and exposure time affects the extent of dewetting in terms of diameter size; overlap effects and simultaneous dewetting can result in complex architectures. This controlled writing of patterns also presents a technique to create both masks at low temperatures for conductive multilayers as well as templates for electrospray deposition.Peer reviewe
Potential below the poverty line
No full textA squeeze bottle that enables children to purify their own drinking water. A bicycle that disabled unemployed people can use to sell ice cream. In Africa, inventions from Delft can make a world of difference.Industrial Design Engineerin
Rolling Recap: E2FLIGHT
No full textThis rolling recap conference presentation gave the participants of the AIAA/IEEE Electric Aircraft Technologies Symposium (EATS) 2020 an overview on all the sessions of the E2Flight 2020. The rolling recap presentation is supported by one-page summary slides delivered by following presenters of the E2Flight: Amy Jankovsky, Christoph Schäper, Robin Ladous, Maximilian Nitzsche, Markus Neubert on behalf of Prof. Dr. ir. Dr. h. c. Rik W. De Doncker, Dirk Grossmann, Philipp Schildt, Leo Veldhuis, Carsten Döll, Georgi Atanasov, Vincenzo Palladino and Julian Renz. The author expresses his gratitude and appreciation to all the presenters of the E2Flight for the excellent presentations given
ANJA NITZSCHE: Frauen, Marktwirtschaft und Patriarchat - Auswirkungen der gesellschaftlichen Erneuerung auf die Situation von Frauen in Vietnam
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