8,351 research outputs found
The Super-Cooling Agent Icilin Reveals a Mechanism of Coincidence Detection by a Temperature-Sensitive TRP Channel
AbstractTRPM8, a member of the transient receptor potential family of ion channels, depolarizes somatosensory neurons in response to cold. TRPM8 is also activated by the cooling agents menthol and icilin. When exposed to menthol or cold, TRPM8 behaves like many ligand-gated channels, exhibiting rapid activation followed by moderate Ca2+-dependent adaptation. In contrast, icilin activates TRPM8 with extremely variable latency followed by extensive desensitization, provided that calcium is present. Here, we show that, to achieve full efficacy, icilin requires simultaneous elevation of cytosolic Ca2+, either via permeation through TRPM8 channels or by release from intracellular stores. Thus, two stimuli must be paired to elicit full channel activation, illustrating the potential for coincidence detection by TRP channels. Determinants of icilin sensitivity map to a region of TRPM8 that corresponds to the capsaicin binding site on the noxious heat receptor TRPV1, suggesting a conserved molecular logic for gating of these thermosensitive channels by chemical agonists
Removing Barriers, Integrating Research, Spreading Excellence: The European Satellite Communications Network of Excellence "SatNEx"
Within the recently launched 6th Research Framework Programme of the European Commission, 21 major players in satellite communications research have joined forces to implement the European Satellite Communications Network of Excellence (SatNEx). The primary goal of SatNEx is to achieve long-lasting integration of the European research in satellite communication and to develop a common base of knowledge, thus contributing to the realization of the European Research Area.
This paper discusses the background and motivation for implementation of the network and highlights the SatNEx mission and key objectives. A top-level overview is then provided including a description of the consortium, the Joint Programme of Activities (JPA) and the time schedule with deliverables and milestones. Finally, an update of ongoing work is presented
Relations between entanglement, Bell-inequality violation and teleportation fidelity for the two-qubit X states
Based on the assumption that the receiver Bob can apply any unitary
transformation, Horodecki {\it et al.} [Phys. Lett. A {\bf 222}, 21 (1996)]
proved that any mixed two spin-1/2 state which violates the Bell-CHSH
inequality is useful for teleportation. Here, we further show that any X state
which violates the Bell-CHSH inequality can also be used for nonclassical
teleportation even if Bob can only perform the identity or the Pauli rotation
operations. Moreover, we showed that the maximal difference between the two
average fidelities achievable via Bob's arbitrary transformations and via the
sole identity or the Pauli rotation is 1/9.Comment: 5 pages, to be published in "Quantum Information Processing
New Affine Isoperimetric Inequalities
We prove new affine isoperimetric inequalities for all . We establish, for all , a duality formula which shows
that affine surface area of a convex body equals
affine surface area of the polar body
Bifurcation analysis of dynamic systems with continuously piecewise linearity
The periodic response and associated bifurcations of a harmonically driven oscillator with continuously piecewise linearity has received great attention during the past decade. The oscillator serves as a widely used model to describe various mechanical systems with clearances, elastic constraints etc. Even if the 'corners' of the piecewise-linear restoring force in the oscillator make the system non-smooth on the interface between two linear regions, the bifurcation analysis published up to now is still based on the theory of smooth dynamic systems. The validity of such an extention is an open problem
Exotic d-wave superconductivity in strongly hole doped K(x)Ba(1-x)Fe2As2
We investigate the superconducting phase in the K(x)Ba(1-x)Fe2As2 122
compounds from moderate to strong hole-doping regimes. Using functional
renormalization group, we show that while the system develops a nodeless
anisotropic s+- order parameter in the moderately doped regime, gapping out the
electron pockets at strong hole doping drives the system into a nodal cos (kx)
cos (ky) d-wave superconducting state. This is in agreement with recent
experimental evidence from measurements on KFe2As2 which see a nodal order
parameter in the extreme doping regime. The magnetic instability is strongly
suppressed. The case of only hole pockets present is argued to be structurally
similar to the case of only electron pockets present as indicated for KxFe2Se2.Comment: 4.2 pages, 4 figures; version as published in PR
Detection of C60 in the proto-planetary nebula IRAS 01005+7910
We report the first detection of buckminsterfullerene (C60) in a
proto-planetary nebula (PPN). The vibrational transitions of C60 at 7.0, 17.4,
and 18.9um are detected in the Spitzer/IRS spectrum of IRAS 01005+7910. This
detection suggests that fullerenes are formed shortly after the asymptotic
giant branch but before the planetary nebulae stage. A comparison with the
observations of C60 in other sources is made and the implication on
circumstellar chemistry is discussed.Comment: 14 pages, 4 figures, accepted for publication in Ap
A Knotted Meta-molecule with 2-D Isotropic Optical Activity Rotating the Incident Polarization by 90{\deg}
Optical activity is the ability of chiral materials to rotate
linearly-polarized (LP) electromagnetic waves. Because of their intrinsic
asymmetry, traditional chiral molecules usually lack isotropic performance, or
at best only possess a weak form of chirality. Here we introduce a knotted
chiral meta-molecule that exhibits optical activity corresponding to a 90{\deg}
polarization rotation of the incident waves. More importantly, arising from the
continuous multi-fold rotational symmetry of the chiral torus knot structure,
the observed polarization rotation behavior is found to be independent of how
the incident wave is polarized. In other words, the proposed chiral knot
structure possesses two-dimensional (2-D) isotropic optical activity as
illustrated in Fig. 1, which has been experimentally validated in the microwave
spectrum. The proposed chiral torus knot represents the most optically active
meta-molecule reported to date that is intrinsically isotropic to the incident
polarization
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