250 research outputs found
Subtracting and Fitting Histograms using Profile Likelihood
It is known that many interesting signals expected at LHC are of unknown shape and strongly contaminated by background events. These signals will be dif cult to detect during the rst years of LHC operation due to the initial low luminosity. In this work, one presents a method of subtracting histograms based on the pro le likelihood function when the background is previously estimated by Monte Carlo events and one has low statistics. Estimators for the signal in each bin of the histogram difference are calculated so as limits for the signals with 68.3% of Con dence Level in a low statistics case when one has a exponential background and a Gaussian signal. The method can also be used to t histograms when the signal shape is known. Our results show a good performance and avoid the problem of negative values when subtracting histograms
Two singularity subtraction schemes for a class of nonlinear weakly singular integral equations
Singularity subtraction for linear weakly singular Fredholm integral equations of the second kind
is generalized to nonlinear integral equations. Two approaches are presented: The Classical Ap proach discretizes the nonlinear problem, and uses some finite dimensional linearization process
to solve numerically the discrete problem. Its convergence is proved under mild hypotheses
on the nonlinearity and the quadrature rule of the singularity subtraction scheme. The New
Approach is based on linearization of the problem in its infinite dimensional setting, and dis cretization of the sequence of linear problems by singularity subtraction. It is more efficient than
the former, as two numerical experiments confirm.The second and fourth authors were partially supported by CMUP, which is financed by national funds through FCT -Fundacao para a Ciencia e Tecnologia, I.P., under the project with reference UIDB/00144/2020. The research of the third author was partially financed by Portuguese Funds through FCT (Fundacao para a Ciencia e a Tecnologia) within the Projects UIDB/00013/2020 and UIDP/00013/2020
Much or More? Experiments of Rationality and Spite with School Children
Copyright © 2014 North American Journal of Pyschology.In a competitive environment the maximization of self-interest and the minimization of the other's interest can be seen as the two faces of the same coin. However, these motivations can lead to very different behaviors. In order to understand how these are expressed, we designed an experiment to measure the ability of children and teenagers to react to stimuli that induce behavior to act as a rational player (maximization of self interest) or as a spiteful player (minimization of other's interest). Each player faced the following dilemma: maximizing pay-off and incurring the risk of having a lower pay-off; or alternatively guaranteeing one’s own pay-off was not smaller than the opponent’s pay-off. A prize was attributed proportionally to the pay-off (Treatment 1) or to the player with highest pay-off (Treatment 2), which meant that the optimal behavior was different for each treatment. We performed experiments with 398 Portuguese children and teenagers and found evidence that younger children tended to be maximizers (in both variants) and that teenagers tended towards rational behavior when it was best for them and towards spiteful behavior when the latter was more advantageous
Subchronical treatment with Fluoxetine modifies the activity of the MCHergic and hypocretinergic systems. Evidences from peptide CSF concentration and gene expression
In the postero-lateral hypothalamus are located two neuronal systems that utilize the neuropeptides melanin-concentrating hormone (MCH) and hypocretins (also called orexins) as neuromodulators. These systems have reciprocal connections between them, and project throughout the central nervous system. MCH has been involved in the generation of sleep, mainly REM sleep, while hypocretins have a critical role in the generation of wakefulness. MCHergic activity is also involved in the pathophysiology of major depressive disorder (MD). In this regards, intracerebral administration of MCH promotes pro-depressive behaviors (i.e., immobility in the forced swimming test) and REM sleep hypersomnia, which is an important trait of depression. Furthermore, the antagonism of the MCHR-1 receptor has a reliable antidepressant effect, suggesting that MCH is a pro-depressive factor. Hypocretins have been also involved in mood regulation; however, their role in depression is still on debate. Taking these data into account, we explored whether systemic subchronical treatment with Fluoxetine (FLX), a serotonergic antidepressant, modifies the concentration of MCH in the cerebrospinal fluid (CSF), as well as the preproMCH mRNA expression. We also evaluated the hypocretinergic system by quantifying the hypocretin-levels in the CSF and the preprohypocretin mRNA expression. Compared to control, FLX increased the levels of preprohypocretin mRNA without affecting the hypocretin-1 CSF levels. On the contrary, FLX significantly decreased the MCH CSF concentration without affecting the preproMCH gene expression. This result is in agreement with the fact that MCH serum level diminishes during the antidepressant treatment in MD, and supports the hypothesis that an increase in the MCHergic activity could have pro-depressive consequences. (C) 2016 Brazilian Association of Sleep. Production and Hosting by Elsevier B.V.Proyecto de Cooperacion Bilateral Uruguay- Brasil, Dicyt-CNPqPrograma de Desarrollo de Ciencias Basicas (PEDECIBA)Associacao Fundo de Incentivo a Pesquisa (AFIP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Univ Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilUniv Republica, Dept Physiol, Sch Med, Montevideo, UruguayUniv Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilProyecto de Cooperacion Bilateral Uruguay- Brasil, Dicyt-CNPq: ANII-FCE-1-2011-1-5997Web of Scienc
Lidar temperature series in the middle atmosphere as a reference data set – Part 1: Improved retrievals and a 20-year cross-validation of two co-located French lidars
The objective of this paper and its companion (Wing et al., 2018) is to show
that ground-based lidar temperatures are a stable, accurate, and precise
data set for use in validating satellite temperatures at high vertical
resolution. Long-term lidar observations of the middle atmosphere have been
conducted at the Observatoire de Haute-Provence (OHP), located in southern
France (43.93° N, 5.71° E), since 1978. Making use of
20 years of high-quality co-located lidar measurements, we have shown that
lidar temperatures calculated using the Rayleigh technique at 532 nm are
statistically identical to lidar temperatures calculated from the
non-absorbing 355 nm channel of a differential absorption lidar (DIAL)
system. This result is of interest to members of the Network for the
Detection of Atmospheric Composition Change (NDACC) ozone lidar community
seeking to produce validated temperature products. Additionally, we have
addressed previously published concerns of lidar–satellite relative warm bias
in comparisons of upper-mesospheric and lower-thermospheric (UMLT)
temperature profiles. We detail a data treatment algorithm which minimizes
known errors due to data selection procedures, a priori choices, and
initialization parameters inherent in the lidar retrieval. Our algorithm
results in a median cooling of the lidar-calculated absolute temperature
profile by 20 K at 90 km altitude with respect to the standard OHP
NDACC lidar temperature algorithm. The confidence engendered by the long-term
cross-validation of two independent lidars and the improved lidar temperature
data set is exploited in Wing et al. (2018) for use in multi-year satellite
validations.</p
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