The first total synthesis of N1999-A2: absolute stereochemistry and stereochemical implications into DNA cleavage

Enediyne antitumor antibiotics have attracted immense attention among chemists and biologists alike because of their unique chemical structures, potent antitumor activities, and fascinating biological modes of action. As a novel addition to this family, the nonprotein and extremely strained nine-membered enediyne antibiotic N1999-A2 strongly inhibits the growth of various tumor cell lines and bacteria, and cleaves DNA in a base-specific manner. The attractive features of this molecule lie not only within the chemical structure being analogous to the neocarzinostatin chromophore, itself a potent anticancer agent, but also in that it can invoke remarkably strong biological activities even without a stabilizing apoprotein carrier and a glycoside functionality that can accelerate the rate of DNA cleavage. In this regard, N1999-A2 serves as a leading enediyne-based antitumor agent with minimal functionality that is able to act on DNA selectively. We therefore focused on this unique, unstable, and stereochemically unknown compound and undertook the formidable challenge of devising an efficient strategy that would be flexible enough to ultimately construct a series of related highly strained systems

Unperformed Rituals in an Unread Book

What is the significance of an unperformed ritual? And what is the meaning of an unread text? The intuitive answer, that unperformed rituals and unread texts have no meaning, is clearly wrong in the case of Leviticus. The rituals depicted in its text mean a great deal, because Jews, Samaritans and Christians continue to ritualize Leviticus as part of their scriptures. Leviticus’s status as the third book of scripture has remained virtually uncontested throughout the histories of these three religions, despite the fact that people do not observe many of its offering instructions or, among Christians, even read much of its text. It retains its place among the sacred scrolls and books reproduced by each religion. Therefore if the job of commentary is to explain the meaning of Leviticus, it cannot stop with the book’s words, much less their original referents. The meanings of Leviticus have been broadcast by the sounds of its words and the sight of the books and scrolls that contain it as much as by semantic interpretations of its contents, which have themselves been manifested in ritual and legal performances as well as in sermons and commentaries. Out of all this emerges the phenomenon of scripture, of which Leviticus is an original and integral part

Phase-wise enhanced voltage support from electric vehicles in a Danish low-voltage distribution grid

High deployment of electric vehicles (EVs) imposes great challenges for the distribution grids, especially in unbalanced systems with notable voltage variations which detrimentally affect security of supply. On the other hand, with development of Vehicle-to-Grid technology, EVs may be able to provide numerous services for grid support, e.g., voltage control. Implemented electronic equipment will allow them to exchange reactive power for autonomous voltage support without communicating with the distribution system operator or influencing the available active power for primary transportation function. This paper proposes a voltage dependent EV reactive power control and quantifies its impact on a real Danish low-voltage grid. The observed network is a heavily unbalanced three-phase four-wire grid modeled in Matlab SimPowerSystems based on real hourly measurement data. Simulations are performed in order to evaluate phase-to-neutral voltage support benefits as well as to address neutral-to-ground values, active power losses and the unbalances at the same time. The analysis shows that reactive power supportboth raises minimum phase-to-neutral voltage magnitudes and improves voltage dispersion while the energy losses are not notably increased. Further on, since the control is voltage dependent, provided reactive power is unequal among the phases leading to greater support on heavily loaded phases and decreased unbalances caused by residential consumption. Hence, implementation of such a phase-wise enhanced voltage support could defer the need for grid reinforcement in case of large EV penetration rates, especially in highly unbalanced networks

Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice

Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales