The first synthetic receptor for the RGD sequence

[structure: see text] The combination of an optimized arginine receptor unit with a semirigid linker carrying a strategically placed primary ammonium group leads to the first synthetic RGD receptor. It binds to the free RGD peptide as well as to cyclo(RGDfV) in water with association constants around 1000 M(-1). RGD mimetics such as benzamidine 6 are not recognized, rendering the new host a prototype of a new class of receptors selective for the true RGD sequence in peptides.     

Tracking elementary particles near their primary vertex: A combinatorial approach

Colliding beams experiments in High Energy Physics rely on solid state detectors to track the flight paths of charged elementary particles near their primary point of interaction. Reconstructing tracks in this region requires, per collision, a partitioning of up to 10³ highly correlated observations into an unknown number of tracks. We report on the successful implementation of a combinatorial track finding algorithm to solve this pattern recognition problem in the context of the ALEPH experiment at CERN. Central to the implementation is a 5-dimensional axial assignment model (AP5) encompassing noise and inefficiencies of the detector, whose weights of assignments are obtained by means of an extended Kalman filter. A preprocessing step, involving the clustering and geometric partitioning of the observations, ensures reasonable bounds on the size of the problems, which are solved using a branch & bound algorithm with LP relaxation. Convergence is reached within one second of CPU time on a RISC workstation in average.     

Modelltheoretische Analyse des Einstufungssystems zur Berücksichtigung des Schadenverlaufs in der Kraftfahrzeug-Haftpflichtversicherung

Zusammenfassung Die Höhe der Prämie für die Kraftfahrzeug-Haftpflichtversicherung richtet sich unter anderem nach der Schaden(freiheits)klasse, in die der Versicherungsvertrag eingestuft ist. Für das System der Einstufung wird auf der Grundlage der Theorie stochastischer Prozesse (insb. Poissonprozesse und Markoffketten) ein Analysemodell entwickelt. Bei gegebenem Erwartungswert für die Schadenhäufigkeit werden Wahrscheinlichkeiten für zukünftige Klassenzugehörigkeiten sowie Erwartungswerte und Standardabweichungen für die Beitragssätze errechnet. Außerdem werden der Einfluß einer Variation des Erwartungswertes für die Schadenhäufigkeit auf die Modellergebnisse untersucht und Hinweise auf Modellverfeinerungsmöglichkeiten gegeben.

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Summary In the Federal Republic of Germany the third-party automobile insurance premium depends on a classification of the insurance contract, taking into account the number of claimfree years. For the classification system, an analytic model, based on the theory of stochastic processes (especially Poisson processes and Markov chains), has been developed. Assuming a given expectation of loss frequency, probabilities for future classification as well as expected values and standard deviations of the premiums can be computed. Additionally the influence of a variation of the expected loss frequency on the results of the model has been analysed and possibilities of improving the model are indicated.

     

Multiple forms of aldolase in organ extracts of the rat. On aldolases, 8

The aldolase activities of crude rat tissue extracts were separated by starch gel electrophoresis. Aldolase was located on the gel by a specific staining method. Nine bands of different electrophoretic mobility were stainable by this technique. Organ specific isoenzyme patterns could be demonstrated.     

PRESSURE-VELOCITY EQUILIBRIUM HYDRODYNAMIC MODELS

This article describes mathematical models for phase separated mixtures of materials that are in pressure and velocity equilibrium but not necessarily temperature equilibrium. General conditions for constitutive models for such mixtures that exhibit a single mixture sound speed are discussed and specific examples are described.     

Correlation between biological activity and energies of electronic transitions in benzodiazepines. Negative ion mass spectrometry and ultraviolet absorption spectroscopy study of some derivatives

A correlation between the energies of electronic singlet transitions in benzodiazepines and their biological activity, which was revealed earlier by means of negative ion mass spectrometry with resonance electron capture, has been verified with a UV absorption spectroscopy investigation. Also, it has been noted that the energies of electronic singlet transitions in benzodiazepines are close in value to the ionization energies of atoms Cs, Rb, K, Na, Li and Tl, the cations of which are known to play an important role in nerve cell excitation processes. Copyright 1999 John Wiley & Sons, Ltd.