Nitric oxide and synaptic function

The free radical gas nitric oxide (NO) is a recently identified neuronal messenger that carries out diverse signaling tasks in both the central and peripheral nervous systems. Whereas most neurotransmitters are packaged in synaptic vesicles and secreted in a Ca2+-dependent manner from specialized nerve endings, NO is an unconventional transmitter which is not packaged in vesicles, but rather diffuses from its site of production in the absence of any specialized release machinery. The lack of a requirement for release apparatus raises the possibility that NO can be released from both pre- and postsynaptic neuronal elements. In addition, because NO is gaseous and extremely membrane permeant, it can bypass normal signal transduction routes involving interactions with synaptic membrane receptors. Although the targets of NO have not yet been completely described, it is known that NO can bind to the iron contained in heine groups, leading to conformational changes in associated proteins, such as guanylyl cyclase

Traveling waves of excitation in neural field models

Field models provide an elegant mathematical framework to analyze large-scale patterns of neural activity. On the microscopic level, these models are usually based on either a firing-rate picture or integrate-and-fire dynamics. This article shows that in spite of the large conceptual differences between the two types of dynamics, both generate closely related plane-wave solutions. Furthermore, for a large group of models, estimates about the network connectivity derived from the speed of these plane waves only marginally depend on the assumed class of microscopic dynamics. We derive quantitative results about this phenomenon and discuss consequences for the interpretation of experimental data

use natural gas consumption in 201Scenarios to decarbonize residential water heating in California

This paper presents the first detailed long-term stock turnover model to investigate scenarios to decarbonize the residential water heating sector in California, which is currently dominated by natural gas. We model a mix of water heating (WH) technologies including conventional and on-demand (tank-less) natural gas heating, electric resistance, existing electric heat pumps, advanced heat pumps with low global warming refrigerants and solar thermal water heaters. Technically feasible policy scenarios are developed by considering combinations of WH technologies with efficiency gains within each technology, lowering global warming potential of refrigerants and decreasing grid carbon intensity. We then evaluate energy demand, emissions and equipment replacement costs of the pathways. We develop multiple scenarios by which the annual greenhouse gas emissions from residential water heaters in California can be reduced by over 80% from 1990 levels resulting in an annual savings of over 10 Million Metric Tons by 2050. The overall cost of transition will depend on future cost reductions in heat pump and solar thermal water heating equipment, energy costs, and hot water consumption

ROBUSTNESS OF NON-PARAMETRIC MEASUREMENT OF EFFICIENCY AND RISK AVERSION

This paper examines the performance of a risk-adjusted non-parametric approach to measuring efficiency and risk aversion. Prior work is extended to the case where agent behavior is motivated by expected utility maximization. Results indicate the approach significantly outperforms traditional efficiency measurement methods when applied to risk averse agents.Risk and Uncertainty,

Self-calibrating tomography for multi-dimensional systems

We present a formalism for self-calibrating tomography of arbitrary dimensional systems. Self-calibrating quantum state tomography was first introduced in the context of qubits, and allows the reconstruction of the density matrix of an unknown quantum state despite incomplete knowledge of the unitary operations used to change the measurement basis. We show how this can be generalized to qudits, i.e. d-level systems, and provide a specific example for a V-type three-level atomic system whose transition dipole moments are not known. We show that it is always possible to retrieve the unknown state and process parameters, except for a set of zero measure in the state-parameter space.Comment: Revised version. 9 pages, 3 figure