Liftable derivations for generically separably algebraic morphisms of schemes

We consider dominant, generically algebraic, and tamely ramified (if the characteristic is positive) morphisms $\pi: X/S \to Y/S$, where Y,S are Noetherian and integral and X is a Krull scheme (e.g. normal Noetherian), and study the sheaf of tangent vector fields on Y that lift to tangent vector fields on X. We give an easily computable description of these vector fields using valuations along the critical locus. We generalise to positive characteristic Seidenberg's theorem on lifting tangent vector fields to the normalisation. If $\pi$ is a blow-up of a coherent ideal I we show that tangent vector fields that preserve the Ratliff-Rush hull of I are liftable, and that all liftable tangent vector fields preserve the integral closure of I.Comment: 27 pages. Imrproved introduction, corrections of small errors. Accepted Trans. American Math So

Spin-Flavour Symmetry and Contractions Towards Classical Space-Time Symmetry

A classification scheme of hadrons is proposed on the basis of the division algebra H of quaternions and an appropriate geometry. This scheme suggests strongly to understand flavour symmetry in another manner than from standard symmetry schemes. In our approach, we do not start from `exact' symmetry groups like SU(2) \times SU(2) chiral symmetry and impose various symmetry breaking mechanisms which collide with theorems wellknown from quantum field theory. On the contrary, the approximate symmetry properties of the hadron spectrum at low energies, usually classified by `appropriately' broken compact flavour groups, emerge very naturally as a low energy reduction of the noncompact (dynamical) symmetry group Sl(2,H). This quaternionic approach not only avoids most of the wellknown conceptual problems of Chiral Dynamics but it also allows for a general treatment of relativistic flavour symmetries as well as it yields a direct connection towards classical relativistic symmetry.Comment: 6 pages, LaTeX (style file included). Talk given at the IWCQIS 1996, Dubna, Russia. To appear in the proceeding

Strongly confined fluids: Diverging time scales and slowing down of equilibration

The Newtonian dynamics of strongly confined fluids exhibits a rich behavior. Its confined and unconfined degrees of freedom decouple for confinement length $L \to 0$. In that case and for a slit geometry the intermediate scattering functions $S_{\mu\nu}(q,t)$ simplify, resulting for $(\mu,\nu) \neq (0,0)$ in a Knudsen-gas like behavior of the confined degrees of freedom, and otherwise in $S_{\parallel}(q,t)$, describing the structural relaxation of the unconfined ones. Taking the coupling into account we prove that the energy fluctuations relax exponentially. For smooth potentials the relaxation times diverge as $L^{-3}$ and $L^{-4}$, respectively, for the confined and unconfined degrees of freedom. The strength of the $L^{-3}$ divergence can be calculated analytically. It depends on the pair potential and the two-dimensional pair distribution function. Experimental setups are suggested to test these predictions.Comment: no figure

The impact of European integration on the German system of pharmaceutical product authorization

The European Union has evolved since 1965 into an influential political player in the regulation of pharmaceutical safety standards. The objective of establishing a single European market for pharmaceuticals makes it necessary for member-states to adopt uniform safety standards and marketing authorization procedures. This article investigates the impact of the European integration process on the German marketing authorization system for pharmaceuticals. The analysis shows that the main focal points and objectives of European regulation of pharmaceutical safety have shifted since 1965. The initial phase saw the introduction of uniform European safety standards as a result of which Germany was obliged to undertake “catch-up” modernization. From the mid-1970s, these standards were extended and specified in greater detail. Since the mid-1990s, a process of reorientation has been under way. The formation of the European Agency for the Evaluation of Medicinal Products (EMEA) and the growing importance of the European authorization procedure, combined with intensified global competition on pharmaceutical markets, are exerting indirect pressure for EU member-states to adjust their medicines policies. Consequently, over the past few years Germany has been engaged in a competition-oriented reorganization of its pharmaceutical product authorization system the outcome of which will be to give higher priority to economic interests.Die Europäische Gemeinschaft ist in der Regulierung der Arzneimittelsicherheit seit 1965 zu einem einflussreichen politischen Akteur geworden. Das Ziel eines einheitlichen europäischen Marktes für Arzneimittel erfordert eine Vereinheitlichung der Sicherheitsstandards und Zulassungsverfahren in den Mitgliedstaaten. Im folgenden Beitrag wird der Frage nachgegangen, welche Auswirkungen der Prozess der Europäischen Integration auf das System der Arzneimittelzulassung in Deutschland hat. Es wird deutlich, dass sich die Schwerpunkte und Zielsetzungen der europäischen Regulierung der Arzneimittelsicherheit seit 1965 verschoben haben. Nach einer ersten Phase der Etablierung einheitlicher europäischer Sicherheitsstandards, die in Deutschland eine nachholende Modernisierung erforderlich machten, wurden diese Standards seit Mitte der 1970er Jahre ausgebaut und präzisiert. Seit Mitte der 1990er Jahre kommt es zu einer Neuausrichtung. Die Errichtung der europäischen Arzneimittelagentur EMEA und der Bedeutungsgewinn der europäischen Zulassungsverfahren erzeugen in Verbindung mit dem verschärften globalen Wettbewerb auf den Arzneimittelmärkten einen mittelbaren Anpassungsdruck auf die nationalen Arzneimittelpolitiken. In der Konsequenz wird in Deutschland seit einigen Jahren eine wettbewerbsorientierte Umgestaltung der Arzneimittelzulassung betrieben, die zu einer Aufwertung ökonomischer Interessen im Zulassungssystem führt