beside ziegler-natta and phillips catalysts the development of methylaluminoxane (mao) as cocatalyst incombination with metallocenes or other transition metal complexes for the polymerization of olefins haswidely increased the possibilities in controlling the polymer composition, polymer structure, tacticity and special properties with high precision. these catalysts allow the synthesis of isot...

1 I n t r o d u c t i o n . This work appl ies some l inear a lgebra ideas in an o rd ina ry differential equa t ion (ODE) context . We begin by summar i s ing the a p p r o p r i a t e l inear a lgebra , and then we in t roduce the O D E problem. *Received July 1995. Revised July 1996. tThis work was supported by Engineering and Physical Sciences Research Council grants GR/H94634 and GR/KS0228...

During Drosophila oogenesis, border cells perform a stereotypic migration. Slbo, a C/EBP transcription factor, is required for this migration. Here we identify Drosophila Stat92E (signal transducer and activator of transcription) in a screen for gain-of-function suppressors of the slbo mutant phenotype. By clonal analysis for Stat92E and hop (Drosophila JAK) mutants we find that the JAK/STAT pa...

Each cell division in Caulobacter crescentus is asymmetric, yielding a swarmer cell with several polar pili and a non-piliated stalked cell. To identify factors contributing to the asymmetric biogenesis of polar pili, cytological studies of pilus assembly components were performed. We show here that the CpaC protein, which is thought to form the outer membrane pilus secretion channel, and its a...

Rho factor has been purified from a strain of E. coli containing the Su78 mutation in the suA gene and assayed in another strain with an amber mutation in the suA gene. The rho from the Su78 mutant strain is present in normal amounts but has altered termination function; it does not terminate transcription at some sites that are recognized effectively by the rho factor from the isogenic wild-ty...

Background: Morphology and presence of Polar body in the oocyte are denoting oocyte quality and is used as a criterion for prognosis of embryo quality. However, little is known about ICSI result of oocytes with two polar bodies. The present study reports the result of ICSI in a case having several oocytes with two polar bodies. Materials and Methods: A 34 years old patient (K.H.) with history o...

Objective: The genus Marrubium is used for treatment of joint pain, gout, stomach-ache and colic in Iranian Traditional Medicine. Marrubium astracanicum Jacq. (M. astracanicum) is a native species in the flora of Iran. The aim of this study was to evaluate the antinociceptive properties of various extracts of aerial parts of M. astracanicum.Materials and Methods: Antinociceptive activities of t...

A variety of single observations has suggested a systematic and detailed study of the physiological properties of the large group of non-polar-polar organic electrolytes, which as detergents, as wetting and dispersing agents, play an ever increasing r61e not only in technical processes, but also in microbiological research as bacteriostatic and bactericidal agents, the nature of which draws to ...

Introduction: In this study, Antibacterial and antioxidant activities of the essential oil and methanolic extract of the endemic plant, Zataria multiflora Boiss. have been studied. Method: The antioxidant potential of the samples was evaluated using two separate methods of inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ammonium thiocyanate systems. Antibacterial activity wa...

By “polar cliff” we mean the steep increase in the ionization density observed in the morning sector of the polar ionosphere. Here the properties of this remarkable feature are investigated. The data set consists of electron density and temperature measurements obtained by the Dynamics Explorer 2 satellite. Only data recorded in the Northern Hemisphere winter are considered (solar zenith angle≥...