The AGN 1ES1959+650 has been observed with the MAGIC telescope in September and October 2004, at the end of the commissioning phase. The MAGIC Telescope is currently the IACT with the lowest energy threshold, which is well suited for observations of weak γ-ray sources with soft spectra, like AGNs in a quiescent state. During the first observations by MAGIC, 1ES1959+650 was in a low state of act...

In a recent letter [1] the PVLAS collaboration reported the observation of optical rotation induced in vacuum by an external magnetic field. More recently [2] the same group reported also the observation of vaccuum birefringence under similar conditions. In this comment I wish to point out that the reported results are excluded at the 95% confidence level by a previous experiment [3] carried ou...

Micellar aggregates have been prepared from chloro­ phyll a. Whereas most detergents including non-ionic, zwitterionic and anionic ones, produce aggregates with long-wavelength shifted and enhanced Q Y absorption, the cationic detergents hexadecyl-trimethylammoniumbromide and hexadecyl-pyridiniumchloride produce complexes with opposite traits: The Q Y absorption is shifted to shorter wavelength...

Sergey Prosandeev,1,2 Andrei Malashevich,3 Zhigang Gui,1 Lydie Louis,1 Raymond Walter,1 Ivo Souza,4 and L. Bellaiche1 1Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA 2Institute of Physics, South Federal University, Rostov on Don 344090, Russia 3Department of Applied Physics, Yale University, New Haven, Connecticut 0651...

In addition to the dielectric and magnetic permeability constants, another constant is generally needed to describe the electrodynamic properties of a linear isotropic medium. We discuss why the need for the third constant arises and what sort of physical situations can give rise to a non-zero value for it. This additional constant, which we call the “Activity Constant” and denote by ζ, can exp...

Many sustainable agronomical practices can be adopted to contain environmental risks of crop production and, at the same time, sustain yield and quality. In this framework, the aim of this research was to study the effects of continuous cropping (CC) and crop rotation, tillage and fertilization strategies on durum wheat (Triticum durum Desf.) production. The responses of soil properties we...

T he fundamentals of structure and stereochemistry have been considered in previous chapters in some detail. There are, however, practical aspects of stereochemistry that have not yet been mentioned, particularly with regard to chiral compounds. How, for instance, can a racemic mixture be separated into its component enantiomers (resolution); what methods can be used to establish the configurat...

H. Liu,1 D. A. Genov,1 D. M. Wu,1 Y. M. Liu,1 Z. W. Liu,1 C. Sun,1 S. N. Zhu,2 and X. Zhang1,* 15130 Etcheverry Hall, Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720-1740, USA 2Department of Physics, National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, People’s Republic of China Received 30 June 2007; published 14...

We introduce chiral rotational spectroscopy, a technique that enables the determination of the orientated optical activity pseudotensor components BXX , BYY , and BZZ of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample and provides an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules tha...