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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
Manipulating the torsion of molecules by strong laser pulses
A proof-of-principle experiment is reported, where torsional motion of a
molecule, consisting of a pair of phenyl rings, is induced by strong laser
pulses. A nanosecond laser pulse spatially aligns the carbon-carbon bond axis,
connecting the two phenyl rings, allowing a perpendicularly polarized, intense
femtosecond pulse to initiate torsional motion accompanied by an overall
rotation about the fixed axis. The induced motion is monitored by femtosecond
time-resolved Coulomb explosion imaging. Our theoretical analysis accounts for
and generalizes the experimental findings.Comment: 4 pages, 4 figures, submitted to PRL; Major revision of the
presentation of the material; Correction of ion labels in Fig. 2(a
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
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
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
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
Sensitizing properties of proteins:executive summary
The scope of allergy risk is diverse considering the myriad ways in which protein allergenicity is affected by physiochemical characteristics of proteins. The complexity created by the matrices of foods and the variability of the human immune system add additional challenges to understanding the relationship between sensitization potential and allergy disease. To address these and other issues, an April 2012 international symposium was held in Prague, Czech Republic, to review and discuss the state-of-the-science of sensitizing properties of protein allergens. The symposium, organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute, featured presentations on current methods, test systems, research trends, and unanswered questions in the field of protein sensitization. A diverse group of over 70 interdisciplinary scientists from academia, government, and industry participated in the symposium. Experts provided overviews on known mechanisms by which proteins in food may cause sensitization, discussed experimental models to predict protein sensitizing potential, and explored whether such experimental techniques may be applicable in regulatory settings. Three accompanying reviews address critical factors and methods for assessing allergic sensitization: 1) food-and protein-related factors; 2) host-specific factors and 3) screening methods, i.e., the ability of experimental models to predict the sensitizing potential of proteins and whether such models are applicable within regulatory settings
Dose Optimization for Using the Contrast Agent Gadofosveset in Magnetic Resonance Imaging (MRI) of Domestic Pig Brain
Pigs are useful models in stroke research, and Magnetic Resonance Imaging (MRI) is a useful tool for measurements of brain pathophysiology. Perfusion Weighed Imaging (PWI) with standard Gd-based chelates (i.e. gadobutrol) provides crucial information about breakdown of the Blood-Brain-Barrier (BBB) in patients. Gadofosveset is also a Gd-based contrast agent, but with a higher binding to serum albumin. The prolonged plasma-half life of gadofosveset allows the acquisition of steady state angiographies, which may increase the sensitivity for detection of BBB leakage. We hypothesize that the contrast dosage with gadofosveset can be optimized for PWI and subsequent steady-state Magnetic Resonance Angiography (MRA) in pigs. Anesthetized domestic pigs (females; N=6) were MRI scanned four times in one day: they were initially imaged during a standard gadobutrol bolus injection (0.1 mmol/kg). Then they received three successive gadofosveset bolus injections of varying dosages (0.015-0.09 mmol/kg). Based on projection from our data, we suggest that a bolus injection of 0.0916 mmol/kg gadofosveset would yield contrast similar to that of a standard dose of 0.1 mmol/kg gadobutrol in dynamic susceptibility contrast MRI at 3 T. In conclusion, our results demonstrate the feasibility of gadofosveset based PWI in pig brain research. The relaxation and plasma half-life properties allow detailed steady-state MRA angiographies and may prove useful in detecting subtle BBB disruption of significance in stroke models and human patients
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