3,026 research outputs found
The valuation of clean spread options: linking electricity, emissions and fuels
The purpose of the paper is to present a new pricing method for clean spread options, and to illustrate its main features on a set of numerical examples produced by a dedicated computer code. The novelty of the approach is embedded in the use of a structural model as opposed to reduced-form models which fail to capture properly the fundamental dependencies between the economic factors entering the production process
Influence of the kind of wood (chestnut and Limousin oak) in the extractives and Klason lignin contents of wood fragments used in the ageing of wine brandies
Só está disponível o resumo da comunicação.Influence of the kind of wood (chestnut and Limousin oak) in the extractives and Klason lignin contents of wood fragments used in the ageing of wine brandie
Generalized commutation relations and Non linear momenta theories, a close relationship
A revision of generalized commutation relations is performed, besides a
description of Non linear momenta realization included in some DSR theories. It
is shown that these propositions are closely related, specially we focus on
Magueijo Smolin momenta and Kempf et al. and L.N. Chang generalized
commutators. Due to this, a new algebra arises with its own features that is
also analyzed.Comment: accepted version in IJMP
Instantaneous frequency and amplitude identification using wavelets: Application to glass structure
This paper describes a method for extracting rapidly varying, superimposed
amplitude- and frequency-modulated signal components. The method is based upon
the continuous wavelet transform (CWT) and uses a new wavelet which is a
modification to the well-known Morlet wavelet to allow analysis at high
resolution. In order to interpret the CWT of a signal correctly, an approximate
analytic expression for the CWT of an oscillatory signal is examined via a
stationary-phase approximation. This analysis is specialized for the new
wavelet and the results are used to construct expressions for the amplitude and
frequency modulations of the components in a signal from the transform of the
signal. The method is tested on a representative, variable-frequency signal as
an example before being applied to a function of interest in our subject area -
a structural correlation function of a disordered material - which immediately
reveals previously undetected features.Comment: 9 pages, 19 figures; v1.04 higher quality diagrams, removed
mathematica font requirement
Pseudoscalar mesons and their radial excitations from the Effective Chiral Lagrangian
Effective Chiral Lagrangian is derived from QCD in the framework of Field
Correlator Method. It contains the effects of both confinement and chiral
symmetry breaking due to a special structure of the resulting quark mass
operator. It is shown that this Lagrangian describes light pseudoscalar mesons,
and Gell-Mann-Oakes-Renner relations for pions, eta and K mesons are
reproduced. Spectrum of radial excitations of pions and K mesons is found and
compared to experimentally known masses.Comment: 6 pages; v3: minor corrections, references adde
Neutron background at the Canfranc Underground Laboratory and its contribution to the IGEX-DM dark matter experiment
A quantitative study of the neutron environment in the Canfranc Underground
Laboratory has been performed. The analysis is based on a complete set of
simulations and, particularly, it is focused on the IGEX-DM dark matter
experiment. The simulations are compared to the IGEX-DM low energy data
obtained with different shielding conditions. The results of the study allow us
to conclude, with respect to the IGEX-DM background, that the main neutron
population, coming from radioactivity from the surrounding rock, is practically
eliminated after the implementation of a suitable neutron shielding. The
remaining neutron background (muon-induced neutrons in the shielding and in the
rock) is substantially below the present background level thanks to the muon
veto system. In addition, the present analysis gives us a further insight on
the effect of neutrons in other current and future experiments at the Canfranc
Underground Laboratory. The comparison of simulations with the body of data
available has allowed to set the flux of neutrons from radioactivity of the
Canfranc rock, (3.82 +- 0.44) x 10^{-6} cm^{-2} s^{-1}, as well as the flux of
muon-induced neutrons in the rock, (1.73 +- 0.22(stat) \+- 0.69(syst)) x
10^{-9} cm^{-2} s^{-1}, or the rate of neutron production by muons in the lead
shielding, (4.8 +- 0.6 (stat) +- 1.9 (syst)) x 10^{-9} cm^{-3} s^{-1}.Comment: 17 pages, 8 figures, elsart document class; final version to appear
in Astroparticle Physic
Wavelets: mathematics and applications
The notion of wavelets is defined. It is briefly described {\it what} are
wavelets, {\it how} to use them, {\it when} we do need them, {\it why} they are
preferred and {\it where} they have been applied. Then one proceeds to the
multiresolution analysis and fast wavelet transform as a standard procedure for
dealing with discrete wavelets. It is shown which specific features of signals
(functions) can be revealed by this analysis, but can not be found by other
methods (e.g., by the Fourier expansion). Finally, some examples of practical
application are given (in particular, to analysis of multiparticle production}.
Rigorous proofs of mathematical statements are omitted, and the reader is
referred to the corresponding literature.Comment: 16 pages, 5 figures, Latex, Phys. Atom. Nuc
Corrigendum to "The influence of vegetation, fire spread and fire behaviour on biomass burning and trace gas emissions: results from a process-based model" published in Biogeosciences, 7, 1991-2011, doi:10.5194/bg-7-1991-2010, 2010
No abstract available
Methamphetamine abstinence induces changes in μ-opioid receptor, oxytocin and CRF systems: Association with an anxiogenic phenotype
The major challenge in treating methamphetamine addicts is the maintenance of a drug free-state since they experience negative emotional symptoms during abstinence, which may trigger relapse. The neuronal mechanisms underlying long-term withdrawal and relapse are currently not well-understood. There is evidence suggesting a role of the oxytocin (OTR), μ-opioid receptor (MOPr), dopamine D2 receptor (D2R), corticotropin-releasing factor (CRF) systems and the hypothalamic-pituitary-adrenal (HPA)-axis in the different stages of methamphetamine addiction. In this study, we aimed to characterize the behavioral effects of methamphetamine withdrawal in mice and to assess the modulation of the OTR, MOPr, D2R, CRF and HPA-axis following chronic methamphetamine administration and withdrawal. Ten-day methamphetamine administration (2 mg/kg) increased OTR binding in the amygdala, whilst 7 days of withdrawal induced an upregulation of this receptor in the lateral septum. Chronic methamphetamine treatment increased plasma OT levels that returned to control levels following withdrawal. In addition, methamphetamine administration and withdrawal increased striatal MOPr binding, as well as c-Fos+/CRF+ neuronal expression in the amygdala, whereas an increase in plasma corticosterone levels was observed following METH administration, but not withdrawal. No differences were observed in the D2R binding following METH administration and withdrawal. The alterations in the OTR, MOPr and CRF systems occurred concomitantly with the emergence of anxiety-related symptoms and the development of psychomotor sensitization during withdrawal. Collectively, our findings indicate that chronic methamphetamine use and abstinence can induce brain-region specific neuroadaptations of the OTR, MOPr and CRF systems, which may, at least, partly explain the withdrawal-related anxiogenic effects
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