User roles in asynchronous distributed collaborative idea generation

This paper presents the findings of an exploratory study within a real-life context that investigates participant behaviour and emergent user roles in asynchronous distributed collaborative idea generation by a defined community of users. In the study, a high-fidelity prototype of an online virtual ideas room was built and used by a Community of Interest consisting of representatives from 10 different voluntary organisations spread across Denmark. The study revealed five user roles, which the authors propose that future asynchronous distributed collaborative idea generation platforms should consider

Correlations in local measurements on a quantum state, and complementarity as an explanation of nonclassicality

We consider the classical correlations that two observers can extract by measurements on a bipartite quantum state, and we discuss how they are related to the quantum mutual information of the state. We show with several examples how complementarity gives rise to a gap between the quantum and the classical correlations, and we relate our quantitative finding to the so-called classical correlation locked in a quantum state. We derive upper bounds for the sum of classical correlation obtained by measurements in different mutually unbiased bases and we show that the complementarity gap is also present in the deterministic quantum computation with one quantum bit.Comment: 15 pages, 4 figures, references adde

A quantum beam splitter for atoms

An interferometric method is proposed to controllably split an atomic condensate in two spatial components with strongly reduced population fluctuations. All steps in our proposal are in current use in cold atom laboratories, and we show with a theoretical calculation that our proposal is very robust against imperfections of the interferometer.Comment: 6 pages, 3 figures, revtex

Electrical manipulation of spin states in a single electrostatically gated transition-metal complex

We demonstrate an electrically controlled high-spin (S=5/2) to low-spin (S=1/2) transition in a three-terminal device incorporating a single Mn2+ ion coordinated by two terpyridine ligands. By adjusting the gate-voltage we reduce the terpyridine moiety and thereby strengthen the ligand-field on the Mn-atom. Adding a single electron thus stabilizes the low-spin configuration and the corresponding sequential tunnelling current is suppressed by spin-blockade. From low-temperature inelastic cotunneling spectroscopy, we infer the magnetic excitation spectrum of the molecule and uncover also a strongly gate-dependent singlet-triplet splitting on the low-spin side. The measured bias-spectroscopy is shown to be consistent with an exact diagonalization of the Mn-complex, and an interpretation of the data is given in terms of a simplified effective model.Comment: Will appear soon in Nanoletter

Lapex: A Phoswich balloon experiment for hard X-ray astronomy

Satellite and balloon observations have shown that several classes of celestial objects are hard ( 15 keV) energy band with a sensitivity of approx 10 mCrab has been performed with the UCSD/MIT instrument (A4) on board the HEAO 1 satellite. About 70 X-ray sources were detected, including galactic and extragalactic objects. Hard X-ray emission has been detected in the Galaxy from X-ray pulsars. Extragalactic sources of hard X-ray emission include clusters of galaxies, QSOs, BL Lac objects, Seyfert galaxies. The essential characteristics of the Large Area Phoswich Experiment (LAPEX) for crowded sky field observations are described. It has: (1) a broad energy band of operation (20-300 keV); (2) a 3 sigma sensitivity of about 1 mCrab in 10,000 s of live observing time; and (3) imaging capabilities with an angular resolution of about 20'

Unitary representations of nilpotent super Lie groups

We show that irreducible unitary representations of nilpotent super Lie groups can be obtained by induction from a distinguished class of sub super Lie groups. These sub super Lie groups are natural analogues of polarizing subgroups that appear in classical Kirillov theory. We obtain a concrete geometric parametrization of irreducible unitary representations by nonnegative definite coadjoint orbits. As an application, we prove an analytic generalization of the Stone-von Neumann theorem for Heisenberg-Clifford super Lie groups

Natural product coumarins that inhibit human carbonic anhydrases.

Natural products (NPs) have proven to be an invaluable source of new chemotherapies yet very few have been explored to source small molecule carbonic anhydrase (CA) inhibitors. CA enzymes underpin physiological pH and are critical to the progression of several diseases including cancer. The present study is the first to more widely investigate NP coumarins for CA inhibition following the recent discovery of a NP coumarin CA inhibitor. We assembled a NP library comprising 24 plant coumarins (compounds 4-27) and three ascidian coumarins (compounds 28-30) that together provide a diverse collection of structures containing the coumarin pharmacophore. This library was then evaluated for inhibition of six human CA isozymes (CAs I, II, VII, IX, XII and XIII) and a broad range of inhibition and isozyme selectivity profiles were evident. Our findings provide a platform to support further evaluation of NPs for the discovery of new chemotypes that inhibit disease relevant CA enzymes.Full Tex

Influence of oxygen ordering kinetics on Raman and optical response in YBa_2Cu_3O_{6.4}

Kinetics of the optical and Raman response in YBa_2Cu_3O_{6.4} were studied during room temperature annealing following heat treatment. The superconducting T_c, dc resistivity, and low-energy optical conductivity recover slowly, implying a long relaxation time for the carrier density. Short relaxation times are observed for the B_{1g} Raman scattering -- magnetic, continuum, and phonon -- and the charge transfer band. Monte Carlo simulations suggest that these two relaxation rates are related to two length scales corresponding to local oxygen ordering (fast) and long chain and twin formation (slow).Comment: REVTeX, 3 pages + 4 PostScript (compressed) figure