Microbial Oxidation of (-)-α-pinene to Verbenol Production by Newly Isolated Strains

Verbenol is a bicyclicbicycle secondary allylic alcohol, with pronounced camphor and mint flavor notes, mainly used as food flavoring. This compound is also used to control harmful insects, and hence has potential for using in agriculture, and is an intermediate in the synthesis of valuable perfume and medicinal substances. This work is focused on the microbial oxidation of (-)-α-pinene to verbenol production. To carry out the present study, 405 microorganisms were tested for their ability to bioconvert the substrate. From the isolated microorganisms, 193 were selected in the pre-screening using mineral medium for limonene degradation. At the screening step, 31 strains were able to convert (-)-α-pinene in verbenol. The highest concentration in verbenol from (-)-α-pinene was about 125.6 mg/L for yeast isolated from orange juice industrial residue.     

Transfer reaction and molecular weight distribution in the anionic polymerization of formaldehyde

The anhydrous formaldehyde polymerization is examined. The influence of initiator and monomer concentration on the molecular weight and molecular weight distribution are emphasized. A mechanism for the transfer to the monomer is introduced. This mechanism is confirmed by experimental results and leads to the formation of formyl end groups. The influence of various initiators on the transfer reaction also is evaluated.     

Linear Sections of the Finite Veronese Varieties and Authentication Systems Defined Using Geometry

In this paper we deal with authentication systems in which one key is used to authenticate many source states. We answer a related question on the cardinalities of the intersections of quadrics in PG (d,q). We first generalize a class of geometric authentication systems, which has been introduced by Beutelspacher, Tallini and Zanella4. The source states are the lines through a special point N of PG (d,q) (the d-dimensional projective space over GF (q)). The keys are some hypersurfaces which have N as a nucleus ( N is a nucleus of if every line through N meets in exactly one point). The message belonging to a source state and a key is the unique point of intersection of the line with the hypersurface . We give the values of s for which the constructed authentication systems have a security which is comparable to the best allowed by a theoretical bound. In case the hypersurfaces are quadrics, we give further results on the security. To this end, we determine the greatest cardinality for the intersections of the finite Veronese varieties with the projective subspaces of any given dimension. Finally, we discuss a possible implementation.     

On flags in a topological projective plane

In this paper we study some properties of the flag space () of a topological projective plane . The line set, sayL, of (), splits into two subfamiliesL ₀ andL ₁ which an non-trivial partitions of the point set of (). For any two distinct lines , ' belonging to one of the two subfamilies, there is exactly one line in the other subfamily meeting botl and '; turns out to be a continuous mapping of (-,'–. Further, the intersection o: two lines, having exactly one point in common, is a continuous and open mapping. Conversely, every irreducible semilinear space, satisfying the above properties, is isomor phic to the flag space of a topological projective plane.This paper has been prepared from some results of a research project supported by N.A.T.O.     

Synthesis and characterization of bis(indenyl) zirconium aryloxide derivatives and their use in α‐olefin polymerization

A series of new bis(indenyl) zirconium diaryloxides of general formula Ind₂Zr(OL)₂ (L = C₆H₅, 2 ; C₆F₅, 3 ; 2,6‐Me₂C₆H₃, 4; 2,4,6‐Me₃C₆H₂, 5 ; 4‐^tBuC₆H₄, 6 ) were synthesized by a metathesis reaction of Ind₂ZrCl₂ ( 1 ) with the appropriate thallium aryloxide salt, TlOL. The complexes 1–6 were characterized by ¹H and ¹³C NMR techniques. They were also examined as catalysts for ethene and 1‐hexene polymerization with methylalumoxane as co‐catalyst, and a trend of the polymerization activity as a function of aryloxide ligands was observed. An interpretation of this trend, considering both the electronic and steric effects of the substituents on the aryloxide rings, was proposed. Copyright © 2001 John Wiley & Sons, Ltd.     

Incidence and Combinatorial Properties of Linear Complexes

In this paper a generalisation of the notion of polarity is exhibited which allows to completely describe, in an incidence-geometric way, the linear complexes of h-subspaces. A generalised polarity is defined to be a partial map which maps (h−1)-subspaces to hyperplanes, satisfying suitable linearity and reciprocity properties. Generalised polarities with the null property give rise to linear complexes and vice versa. Given that there exists for h > 1 a linear complex of h-subspaces which contains no star – this seems to be an open problem over an arbitrary ground field – the combinatorial structure of a partition of the line set of the projective space into non-geometric spreads of its hyperplanes can be obtained. This line partition has an additional linearity property which turns out to be characteristic. Received: December 3, 2007. Revised: December 13, 2007.     

Brønsted Base Catalyzed One‐Pot Synthesis of Stereodefined Six‐Member Carbocycles Featuring Transient Trienolates and a Key Intramolecular 1,6‐Addition

A catalyst‐driven one‐pot reaction sequence is developed for the enantio‐ and diastereoselective synthesis of tetrasubstituted cyclohexenes from simple unsaturated ketones or thioesters. The method involves a tertiary amine/squaramide‐catalyzed α‐selective addition of transiently generated trienolates to nitroolefins, subsequent base‐catalyzed double bond isomerization, and an intramolecular (vinylogous) 1,6‐addition reaction, a rare key carbocyclization step that proceeded with essentially perfect stereocontrol.     

Boltzmann Games in Heterogeneous Consensus Dynamics

Journal of Statistical Physics - We consider a constrained hierarchical opinion dynamics in the case of leaders’ competition and with complete information among leaders. Each leaders’...