672 research outputs found
Observing Culture: Differences in U.S.-American and German Team Meeting Behaviors
Although previous research has theorized about team interaction differences between the German and U.S. cultures, actual behavioral observations of such differences are sparse. This study explores team meetings as a context for examining intercultural differences. We analyzed a total of 5,188 meeting behaviors in German and U.S. student teams. All teams discussed the same task to consensus. Results from behavioral process analyses showed that German teams focused significantly more on problem analysis, whereas U.S. teams focused more on solution production. Moreover, U.S. teams showed significantly more positive socioemotional meeting behavior than German teams. Finally, German teams showed significantly more counteractive behavior such as complaining than U.S. teams. We discuss theoretical and pragmatic implications for understanding these observable differences and for improving interaction in intercultural teams
Coherent Time Evolution and Boundary Conditions of Two-Photon Quantum Walks
Multi-photon quantum walks in integrated optics are an attractive controlled
quantum system, that can mimic less readily accessible quantum systems and
exhibit behavior that cannot in general be accurately replicated by classical
light without an exponential overhead in resources. The ability to observe time
evolution of such systems is important for characterising multi-particle
quantum dynamics---notably this includes the effects of boundary conditions for
walks in spaces of finite size. Here we demonstrate the coherent evolution of
quantum walks of two indistinguishable photons using planar arrays of 21
evanescently coupled waveguides fabricated in silicon oxynitride technology. We
compare three time evolutions, that follow closely a model assuming unitary
evolution, corresponding to three different lengths of the array---in each case
we observe quantum interference features that violate classical predictions.
The longest array includes reflecting boundary conditions.Comment: 7 pages,7 figure
The nonrelativistic limit of the Majorana equation and its simulation in trapped ions
We analyze the Majorana equation in the limit where the particle is at rest.
We show that several counterintuitive features, absent in the rest limit of the
Dirac equation, do appear. Among them, Dirac-like positive energy solutions
that turn into negative energy ones by free evolution, or nonstandard
oscillations and interference between real and imaginary spinor components for
complex solutions. We also study the ultrarelativistic limit, showing that the
Majorana and Dirac equations mutually converge. Furthermore, we propose a
physical implementation in trapped ions.Comment: 7 pages, 1 figure. Proceedings of 18th Central European Workshop on
Quantum Optics (CEWQO 2011), Madrid, Spai
Quantum walks of correlated photon pairs in two-dimensional waveguide arrays
We demonstrate quantum walks of correlated photons in a 2D network of
directly laser written waveguides coupled in a 'swiss cross' arrangement. The
correlated detection events show high-visibility quantum interference and
unique composite behaviour: strong correlation and independence of the quantum
walkers, between and within the planes of the cross. Violations of a
classically defined inequality, for photons injected in the same plane and in
orthogonal planes, reveal non-classical behaviour in a non-planar structure.Comment: 5 pages, 5 figure
Cation selectivity of the presequence translocase channel Tim23 is crucial for efficient protein import.
Virtually all mitochondrial matrix proteins and a considerable number of inner membrane proteins carry a positively charged, N-terminal presequence and are imported by the TIM23 complex (presequence translocase) located in the inner mitochondrial membrane. The voltage-regulated Tim23 channel constitutes the actual protein-import pore wide enough to allow the passage of polypeptides with a secondary structure. In this study, we identify amino acids important for the cation selectivity of Tim23. Structure based mutants show that selectivity is provided by highly conserved, pore-lining amino acids. Mutations of these amino acid residues lead to reduced selectivity properties, reduced protein import capacity and they render the Tim23 channel insensitive to substrates. We thus show that the cation selectivity of the Tim23 channel is a key feature for substrate recognition and efficient protein import
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