Crystalline acetates from ‘Croton Resin’

Zusammenfassung Durch Hydrolyse des aus Krotonöl gewonnenen Krotonharzes wurde eine empfindliche, wasserlösliche Polyhydroxyverbindung gewonnen, die teilweise als das bereits bekannte Alkohol-Phorbol abgeschieden werden konnte. Von ihren 4 Hydroxylgruppen scheinen im Krotonharz 2 mit Essigsäure verestert zu sein. Nur eine der Acetylgruppen ist verseifbar. Die dritte Hydroxylgruppe ist mit einer höheren Fettsäure von 10–16 C-Atomen verestert, die vierte scheint frei vorzuliegen. Zwei der Hydroxylgruppen im Verseifungsprodukt sind acetylierbar. Im Grundskelett der Formel C₁₉H₂₆O₆ ist daher eine Sauerstoff-Funktion noch ungeklärt.     

Mutants of Escherichia coli deficient in 4-thiouridine in which growth is insensitive to illumination at 365 nm]

Thirteen different mutants of E coli K12 selected for a reduced near ultra-violet induced growth delay have been isolated. The t-RNAs extracted from these clones have all a depressed content of 4-thiouridine. One of these mutants, called Nop has an almost negligible growth delay and completely lacks 4-thiouridine in its t-RNAs. Thus we provide genetic proofs that 4-thiouridine is the chromophore for growth delay.     

Activation of protein kinase C potentiates isoprenaline-induced cyclic AMP accumulation in rat pinealocytes

The pineal gland has proven to be an excellent model for the study of adrenergic control systems. Noradrenaline, released from sympathetic nerve terminals in the pineal gland, regulates a large nocturnal increase in melatonin synthesis by stimulating the activity of arylalkylamine N-acetyltransferase (NAT, EC 2.3.1.87) 30-70-fold. An essential step in both the induction and maintenance of high NAT activity is an increase in intracellular cyclic AMP. Noradrenaline acts via beta-adrenoceptors to increase pineal cyclic AMP by activating adenylate cyclase, and the activation of pineal alpha 1-adrenoceptors potentiates beta-adrenergic stimulation not only of NAT but of both cyclic AMP and cyclic GMP. Here we describe investigations designed to test whether alpha 1-adrenergic potentiation of beta-adrenergic stimulation of pineal cyclic AMP involves protein kinase C. Our results suggest that kinase activation is involved and the data provide the first demonstration of a synergistic interaction between Ca2+-phospholipid-dependent protein kinase (protein kinase C) and neurotransmitter-dependent stimulation of cyclic AMP.     

THERE IS NO MATHEMATICAL VALIDITY FOR USING FUZZY NUMBER CRUNCHING IN THE ANALYTIC HIERARCHY PROCESS

1. Introduction In this brief note we show that although fuzzy thinking may be useful in some engineering practices where so called crisp numbers are obtained from counting or from using scales of measurement, it is highly controversial and not very useful to use it in decision making where the numbers assigned to judgments are already fuzzy and making them more fuzzy does not help produce more valid outcomes. Not only can this be shown with examples, but what makes our assertion more to the p…     

Neurath's programme for naturalistic epistemology

I examine the thesis that Otto Neurath anticipated the programme of naturalised epistemology already at the time of the Vienna Circle and consider the relation between Neurath's proposals and those of two contemporary theorists whose research programmes he would thus have broadly anticipated. The thesis is confirmed by reference to Neurath's own writings. The connection between Neurath's programme and the programmes of his two successors considered here, however, is found to be highly indirect in one case and nonexistent in the other — despite their undeniable overlap.