After discussing numerous models for exudation from the xylem of roots, we present a new biphasic exudation model based on osmoregulation of the root symplast by stretch‐activated ion channels (SA channels). We tested some features of the model in maize roots. (1) Using a microdrop recorder we showed that bathing the roots in 50 mmol m−3 gadolinium ions, known to inhibit some SA channels, inhibited xylem exudation by over 80% after 24h application. (2) Measuring xylem exudation from single roots into an attached micropipette revealed the capacity of the roots to perform strong autonomous exudation pulses. (3) In partially encased roots, the rhizodermis exuded water concurrently to xylem exudation. These results were regarded as supporting our model. An interesting observation with the microdrop recorder, which does not address the theory, is that addition of a variety of inorganic ions to distilled water as the roots' bathing medium instantaneously and reversibly increases xylem exudation, evidently nonosmotically.

The legal version of post-modernism has not failed to challenge comparative law. It points out that, traditionally, comparatists have participated in a project of objectivity, universalism and neutrality of law, of which the “new” approach to comparative law is altogether sceptical.1 In the era of globalisation, both the discipline and its critique have gained relevance. What the transition of post-socialist countries and the unification of Europe have effected regionally, globalisation now accomplishes on a global scale: it creates desires for harmonisation and, as a pre-requisite, legal comparison. However, not only the technical function of comparative law is needed, but also its critical potential. In the process of globalisation, different legal systems and different cultures are confronted with each other and must interact. This provokes new questions about the options and limits of comparative law and legal unification, regarding, for instance, the applicability of specific moral and legal standards to other cultures by comparatists and law-makers. These questions are all the more pressing as we begin to realise that governing globalisation, in particular economic globalisation, with the help of global law perhaps requires a concept of a global legal order which is based on a “global legal pluralism”.2

The review summarizes some of our current knowledge on the phenomenon of exudation from the cut surface of detached roots with emphasis on results that were mostly established over the last fifty years. The phenomenon is quantitatively documented in the 18th century (by Hales in 1727). By the 19th century, theories mainly ascribed exudation to the secretion of living root cells. The 20th century favored the osmometer model of root exudation. Nevertheless, growing insights into the mechanisms of water transport and new or rediscovered observations stimulated the quest for a more adequate exudation model. The historical overview shows how understanding of exudation changed with time following experimental opportunities and novel ideas from different areas of knowledge. Later theories included cytoskeleton-dependent micro-pulsations of turgor in root cells to explain the observed water exudation. Recent progress in experimental biomedicine led to detailed study of channels and transporters for ion transport via cellular membranes and to the discovery of aquaporins. These universal molecular entities have been incorporated to the more complex models of water transport via plant roots. A new set of ideas and explanations was based on cellular osmoregulation by mechanosensitive ion channels. Thermodynamic calculations predicted the possibility of water transport against osmotic forces based on co-transport of water with ions via cation-chloride cotransporters. Recent observations of rhizodermis exudation, exudation of roots without an external aqueous medium, segments cut from roots, pulses of exudation, a phase shifting of water uptake and exudation, and of effects of physiologically active compounds (like ion channel blockers, metabolic agents, and cytoskeletal agents) will likely refine our understanding of the phenomenon. So far, it seems that more than one mechanism is responsible for root pressure and root exudation, processes which are important for refilling of embolized xylem vessels. However, recent advances in ion and water transport research at the molecular level suggest potential future directions to understanding of root exudation and new models awaiting experimental testing.

Die Vorstellung der Auferstehung des physischen Körpers und des ewigen Fortlebens mit diesem Körper in einem zukünftigen paradiesischen Reich Gottes auf Erden gehört zu den rätselhaftesten religiösen Ideen. Sie widerspricht gänzlich unserem Wissen von der Vergänglichkeit aller Dinge dieses Kosmos. Nach der Hypothese des Autors liegen dieser Idee bestimmte Formen von Jenseitserfahrungen zugrunde, wie sie beispielsweise von Menschen mit Nahtoderfahrungen häufig berichtet werden: Begegnungen mit Verstorbenen in strahlend- schönen Körpern und Erlebnisse paradiesischer, irdisch anmutender Landschaften. Derartige Jenseitserfahrungen seien in Kulturen mit einer prämodernen Kosmologie mitunter ins Diesseits, an entlegene, unbekannte Orte der Erde projiziert worden. Sie hätten auch die Vorlage für eine – notwendig vergebliche und potenziell tragische – Erwartung jenseitiger Verhältnisse auf Erden geliefert. Der Autor weist Parallelen zwischen den Berichten über Jenseitserfahrungen und eschatologischen Vorstellungen des Zoroastrismus, des Judentums und des Christentums nach, wobei er besonders ausführlich auf Jesus von Nazareth eingeht. An der Geistertanz-Bewegung der Lakota von 1890 zeigt er, dass Jenseitserfahrungen tatsächlich die Erwartung jenseitiger Verhältnisse auf Erden fördern können. Er vermutet, dass die Verwechslung der Welten nicht nur den Lakota, sondern auch Jesus von Nazareth zum Verhängnis wurde.

No abstract