Untersuchung der Atmung einzelner Gewebekulturen mit Radiokohlenstoff

Zusammenfassung In Embryonalextrakt gehaltenen Kulturen von Hühnchenfibroblasten wurde radioaktive Glukose zugeführt und die Aktivität des erzeugten Kohlendioxyds bestimmt. Aus dieser Aktivität wurde auf die veratmete Glukosemenge geschlossen. Deckglaskulturen veratmeten bei Zufuhr von 6 oder mehr Glukose 1 . Nach einigen Stunden wurde ein Maximum der Atmung erreicht, nach wenigen Tagen kam die Atmung praktisch zum Stillstand. Auch Embryonalextrakt allein (ohne Kultur) entwickelt eine geringe Menge Radiokohlendioxyd.Roller-Kulturen veratmen viel mehr (unter Umständen hundertemal mehr) Glukose als Deckglaskulturen; auch in diesem Falle ist die Kohlendioxydentwicklung der Kultur viel größer als die des Nährmediums. Deckglas- undRoller-Kulturen veratmen Glukose auch in isotoner Salzlösung ohne Zusatz von Embryonalextrakt.     

Operational Research and the Universities

University staff may contribute to operational research by developing and refining its special techniques, or by becoming involved in operational research projects; they may investigate practice to guide them in their research, or in the training of operation analysts. The universities are, in many ways, ideally equipped for operational research work, but involvement in long-term consulting activities is not without serious problems of its own.     

Correlation of the elastic characteristics of Arimid PM with the elasticity modulus of its crystal lattice

Studies were made of the elastic characteristics (longitudinal elasticity modulus, elastic recovery) of Arimid PM fibers and of the longitudinal elasticity modulus of the crystal lattice of these samples. The elasticity modulus of the crystallites was determined by x-ray diffraction studies of loaded fibers. It is shown that the studied samples practically instanteneously recover their starting length after removing the load; the sample and its crystal lattice have comparatively low elasticity moduli with nearly identical values. Based on this data, reasons are discussed for the high elastic recovery of Arimid fibers and for the low elasticity modulus of its crystal lattice.Leningrad Branch, All-Union Scientific-Research Institute of Synthetic Fibers. Translated from Mekhanika Polimerov, No. 5, pp. 771–773, September–October, 1972.     

Freezing and melting of a colloidal adsorbate on a 1D quasicrystalline substrate

Using Monte Carlo simulations and an extended Landau-Alexander-McTague theory, we demonstrate that colloids in a one-dimensional quasicrystalline potential order in triangular and rhombic-alpha crystalline phases. Increasing the strength of the potential further, a new type of light-induced melting is discovered that has its origin in the nonperiodicity of the potential. In contrast to reentrant melting in periodic potentials, the quasicrystalline potential melts the crystalline phases even when they already exist at zero potential.     

Total synthesis of cis-solamin: exploiting the RuO4-catalyzed oxidative cyclization of dienes

[structure: see text] An enantioselective total synthesis of cis-solamin has been accomplished using a highly diastereoselective ruthenium tetroxide catalyzed oxidative cyclization as a crucial transformation. Further key steps involved an enzymatic desymmetrization, a TPAP-catalyzed oxidative termini differentiation, and a ruthenium-catalyzed Alder-ene reaction. Thus, the total synthesis of cis-solamin was achieved in 11 steps with an overall yield of 7.5%.     

Raman spectroscopy of laser‐induced oxidation of titanomagnetites

Titanomagnetites are important carriers of magnetic remanence in nature and can track redox conditions in magma. The titanium concentration in magnetite bears heavily on its magnetic properties, such as saturation moment and Curie temperature. On land and in the deep ocean, however, these minerals are prone to alteration which can mask the primary magnetic signals they once recorded. Thus, it is essential to characterize the cation composition and oxidation state of titanomagnetites that record the paleomagnetic field. Raman spectroscopy provides a unique tool for both purposes. Nonetheless, the heat generated by the excitation laser can itself induce oxidation. We show that the laser power threshold to produce oxidation decreases with increasing titanium content. With confocal Raman spectroscopy and magnetic force microscopy (MFM) on natural and synthetic titanomagnetites, a non‐destructive Raman imaging protocol was established. We applied this protocol to map out the composition and magnetization state within a single ex‐solved titanomagnetite grain in a deep‐sea basalt. Copyright © 2011 John Wiley & Sons, Ltd.     

On the interaction between the input signal and the singularity expansion method

For transient excitation, it is well known that the Singularity Expansion Method (SEM) is a late time technique that is not in general suitable for early time. Lossy dielectric slab studies, with bounded integrable finite-duration input signal, have shown that the SEM representation for early time requires an additional branch cut contribution and a modification of the SEM series for completeness. Other researchers indicated that the SEM representation is not complete for most cases of practical interest and that it may not converge for early time. In this paper, we present an approach, using the input signal, to obtain a convergent SEM series that is valid for early as well as for late time. In this approach the branch cut contribution is not needed and instead we have pole contributions form the input signal and a modified SEM series. In addition, two forms of SEM representations will be presented, the traditional form and the time varying coupling coefficient form. Furthermore, the interaction and the effect of the input signal choice on the SEM representation will be clarified. This will be done for a dielectric slab backed by a perfect conductor.     

Relative deprivation as a cause of risky behaviors

ABSTRACT

Combining a standard measure of concern about low relative wealth and a standard measure of relative risk aversion leads to a novel explanation of variation in risk-taking behavior identified and documented by social psychologists and economists. We obtain two results: (1) Holding individual i’s wealth and his rank in the wealth distribution constant, the individual’s relative risk aversion decreases when he becomes more relatively deprived as a result of an increase in the average wealth of the individuals who are wealthier than he is. (2) If relative deprivation enters the individual’s utility function approximately linearly then, holding constant individual i’s wealth and the average wealth of the individuals who are wealthier than he is, the individual’s relative risk aversion decreases when he becomes more relatively deprived as a result of a decline in his rank. Our findings provide a theoretical support for evidence about the propensity of relatively deprived individuals to gamble and resort to other risky behaviors.