The N/N ratio for N2 in the atmosphere of Titan was recently measured to be a factor of 2 higher than the corresponding ratio for HCN. Using a one-dimensional photochemical model with transport, we incorporate new isotopic photoabsorption and photodissociation cross sections of N2, computed quantum-mechanically, and show that the difference in the ratio of N/N between N2 and HCN can be explaine...

…upon being put into a solution of nicotine in sea water, the squid, 3 or 4 seconds, falls to bottom dish… Moore, 1919 Nicotine influences physiology organism via CNS.1 As confirmed also subiculum, may directly modulate hyperpolarization-activated cyclic nucleotide–gated (HCN) non-selective cation channel.2 The latter mirrors findings interneurons stratum oriens (SO) with axons terminating with...

[1] We report the first in situ measurements of hydrogen cyanide (HCN) and methyl cyanide (CH3CN, acetonitrile) from the Pacific troposphere (0–12 km) obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission (February–April 2001). Mean HCN and CH3CN mixing ratios of 243 ± 118 (median 218) ppt and 149 ± 56 (median 138) ppt, respectively, were measured...

What are the implications for the existence of subthreshold ion channels, their localization profiles, and plasticity on local field potentials (LFPs)? Here, we assessed the role of hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels in altering hippocampal theta-frequency LFPs and the associated spike phase. We presented spatiotemporally randomized, balanced theta-modulated exci...

Hyperpolarization-activated cation currents (I(h)) are carried by channels encoded by a family of four genes (HCN1-4) that are differentially expressed within the brain in specific cellular and subcellular compartments. HCN1 shows a high level of expression in apical dendrites of cortical pyramidal neurons and in presynaptic terminals of cerebellar basket cells, structures with a high density o...

It has been recently argued that the HCN J=1–0 line emission may not be an unbiased tracer of dense molecular gas (n & 10 cm) in Luminous Infrared Galaxies (LIRGs: LFIR > 10 11 L⊙) and HCO + J=1–0 may constitute a better tracer instead (Graciá-Carpio et al. 2006), casting doubt into earlier claims supporting the former as a good tracer of such gas (Gao & Solomon 2004; Wu et al. 2006). In this p...

Using the Plateau de Bure interferometer, we observed the λ3mm absorption lines of CN, HCN and HNC from some of the diffuse clouds which lie toward our well-studied sample of compact extragalactic mm-wave continuum sources. The column densities of these species all vary by a factor of about fifty and are prominent in only a limited subset of the clouds seen in the most ubiquitous species such a...

BACKGROUND The efficacy of pharmacological interventions to prevent sudden arrhythmic death in patients with chronic heart failure remains limited. Evidence now suggests increased ventricular expression of hyperpolarization-activated cation (HCN) channels in hypertrophied and failing hearts contributes to their arrythmicity. Still, the role of induced HCN channel expression in the enhanced arrh...

An increase in the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel conductance reduces input resistance, whereas the consequent increase in the inward h current depolarizes the membrane. This results in a delicate and unique conductance-current balance triggered by the expression of HCN channels. In this study, we employ experimentally constrained, morphologically realistic, c...