We report a sensitive search for the HCN(J=2→1) emission line towards SDSS J114816.64+525150.3 (hereafter: J1148+5251) at z=6.42 with the Very Large Array (VLA). HCN emission is a star formation indicator, tracing dense molecular hydrogen gas (n(H2) ≥ 10 4 cm) within star-forming molecular clouds. No emission was detected in the deep interferometer maps of J1148+5251. We derive a limit for the ...

Hyperpolarization-activated, cyclic nucleotide-gated ion channels (HCN) mediate an inward cation current that contributes to spontaneous rhythmic firing activity in the heart and the brain. HCN channels share sequence homology with depolarization-activated Kv channels, including six transmembrane domains and a positively charged S4 segment. S4 has been shown to function as the voltage sensor an...

Dendritically placed, voltage-sensitive ion channels are key regulators of neuronal synaptic integration. In several cell types, hyperpolarization/cyclic nucleotide gated (HCN) cation channels figure prominently in dendritic mechanisms controlling the temporal summation of excitatory synaptic events. In prefrontal cortex, the sustained activity of pyramidal neurons in working memory tasks is th...

BACKGROUND It is poorly understood how hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) function. RESULTS We have identified a leucine zipper in the S5 segment of HCNs, regulating hyperpolarization-activated and instantaneous current components. CONCLUSION The leucine zipper is essential for HCN channel gating. SIGNIFICANCE The identification and functional characteriza...

It is suggested that the incorporation of HCN in Titan’s atmospheric haze may be an important process affecting the HCN profile and the C/N ratio in Titan’s haze. By introducing a loss to the haze term for HCN (i.e. a production term of “poly-HCN”) in the photochemical model of Lara et al. (1996), we have improved the model’s ability to simultaneously reproduce the observed HCN and C2 hydrocarb...

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are activated by membrane hyperpolarization that creates time-dependent, inward rectifying currents, gated by the movement of the intrinsic voltage sensor S4. However, inward rectification of the HCN currents is not only observed in the time-dependent HCN currents, but also in the instantaneous HCN tail currents. Inward rectific...

[1] The U.S. Historical Climatology Network (HCN) database contains statistical adjustments that address historical changes in observation time at each observing station in the network. A paper in 2002 suggested that these adjustments cause HCN temperature trends to be ''spuriously'' warm relative to other datasets for the United States. To test this hypothesis, this paper evaluates the reliabi...

Ghose and Desai [1] introduced a new interconnection for large-scale distributed memory multiprocessors called the Hierarchical Cubic Network (HCN). The HCN is topologically superior to a comparable hypercube. They also proposed optimal routing algorithms for the HCN and obtained its diameter, which is about three-fourths the diameter of a comparable hypercube. However, their routing algorithm ...

Results of the J = 1 − 0 HCN observations toward 34 bright far-infrared sources selected from the IRAS Point Source Catalog are reported. Together with 17 sources observed in this line earlier (Pirogov et al., 1996) they form a complete sample of the sources with flux densities S(100μm) > 500 Jy and δ > 0◦ in the outer Galaxy. The HCN data are compared with the HCO+, NH3, CS and CO data taken f...

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels comprise a small subfamily of proteins within the superfamily of pore-loop cation channels. In mammals, the HCN channel family comprises four members (HCN1-4) that are expressed in heart and nervous system. The current produced by HCN channels has been known as I(h) (or I(f) or I(q)). I(h) has also been designated as pacemaker c...