2,140 research outputs found
Effective extraction and filtering of frequency components in physiological signals using sum-of-sinusoids modelling
In biological signal processing, modelling and extraction of specific frequency components constitute an important procedure for filtering signal components of interest as well as artefact removal. Under some interference scenarios, a satisfactory elimination of artefacts from the signal must be even performed by subtraction of an artefact waveform model or template, rather than the use of linear band-pass filters. That is the case of the gradient artefact induced in the EEG within the fMRI scanner, which cannot be characterized by a specific bandwidth or spectral content. This paper presents a simple and accurate approach based upon sum-of-sinusoids modelling for signal and artefact frequency components representation in physiological signals. According to the proposed method, each signal frequency component is approximated as a sinusoid, whose amplitude and phase parameters are estimated by making use of the Discrete Fourier Transform (DFT). The proposed approach reveals to perform an effective modelling and extraction of ECG signal components as well as underlying gradient artefacts in the EEG signal
Orthogonal basis with a conicoid first mode for shape specification of optical surfaces: Reply
We present some comments to the paper “Orthogonal basis with a conicoid first mode for shape specification of optical surfaces: comment.
Credible Equilibria in Games with Utilities Changing During the Play
Whenever one deals with an interactive decision situation of long duration, one has to take into account that priorities of the participants may change during the conflict. In this paper we propose an extensive-form game model to handle such situations and suggest and study a solution concept, called credible equilibrium, which generalizes the concept of the Nash equilibrium. We also discuss possible variants to this concept and applications of the model to other types of games.
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Ultra-high sensitive strain sensor based on post-processed optical fiber Bragg grating
An ultra-high sensitive strain sensor is proposed. The sensing head, based on the post-processing of a fiber Bragg grating, is used to perform passive and active strain measurements. Both wavelength and full width half maximum dependences with the applied strain are studied for the passive sensor, where maximum sensitivities of 104.1 pm/με and 61.6 pm/με are respectively obtained. When combining the high performance of this sensor with a ring laser cavity configuration, the Bragg grating will act as a filter and high resolution measurements can be performed. With the proposed sensor, a resolution of 700 nε is achieved
Finite-size investigation of scaling corrections in the square-lattice three-state Potts antiferromagnet square-lattice three-state Potts antiferromagnet
We investigate the finite-temperature corrections to scaling in the
three-state square-lattice Potts antiferromagnet, close to the critical point
at T=0. Numerical diagonalization of the transfer matrix on semi-infinite
strips of width sites, , yields finite-size estimates of
the corresponding scaled gaps, which are extrapolated to . Owing to
the characteristics of the quantities under study, we argue that the natural
variable to consider is x\eta_3=2.00(1)\eta_{{\bf P}_{\rm
stagg}}=3$, corresponding to the staggered polarization.Comment: RevTex4, 5 pages, 2 .eps figures include
Population Structure Of Jatropha And Its Implication For The Breeding Program
Jatropha (Jatropha curcas L.) has potential as an oilseed crop that requires the development of technology for its exploitation. The objective of this study was to assess the population structure and the genetic diversity in jatropha accessions at a global level using simple sequence repeat (SSR) molecular markers. Jatropha accessions (N = 109) from 10 countries were genotyped using 10 SSR markers. The results showed a low level of genetic diversity among 92 accessions originating from India, Mozambique, Ethiopia, Tanzania, Brazil, Honduras, and Indonesia, which were grouped in one cluster. In contrast, accessions from Mexico and Costa Rica showed high level of genetic variability. These accessions may be used to increase the genetic diversity of jatropha in the breeding populations. The study also showed the need of collecting activity from the center of diversity (Mexico and Costa Rica) to aggregate the genetic diversity in the international collections of jatropha. © FUNPEC-RP.15
DOIS ANOS (LETIVOS) DE PANDEMIA: EXPECTATIVAS E RECEIOS DE NOVOS ESTUDANTES DO ENSINO SUPERIOR
A pandemia exacerbou os desafios enfrentados pelos estudantes que ingressam no ensino superior. Este estudo, de natureza qualitativa e cariz exploratório, teve como objetivo contribuir para o conhecimento das expectativas e dos receios de dois grupos de estudantes (n=90) que ingressaram no ensino superior durante a pandemia. Os dados foram recolhidos com recurso à versão portuguesa do Hopes and Fears Questionnaire. A análise dos resultados identificou diferenças ao nível das expectativas e dos receios dos estudantes inquiridos, nomeadamente nos domínios educação, global/coletivo e realização pessoal. Concluiu‐se que os estudantes expressaram mais receios do que expectativas em relação ao seu futuro. Este estudo contribui para um melhor conhecimento sobre a transição e adaptação ao Ensino Superior em contexto de pandemia COVID‐19.info:eu-repo/semantics/publishedVersio
Pristine Multi-walled carbon nanotubes for a rapid and efficient plasmid DNA clarification
Therapeutic approaches based on nucleic acids to modulate cell activity have recently gained attention. These molecules arise from complex biotechnological processes, requiring effective manufacturing strategies, high purity, and precise quality control to be used as biopharmaceuticals. One of the most critical and time-consuming steps for nucleic acids-based biotherapeutics manufacturing is their purification, mainly due to the complexity of the extracts. In this study, a simple, efficient, and reliable method to isolate and clarify plasmid DNA (pDNA) from complex samples is described. The method is based on the selective capture of RNA and other impurities, using pristine carbon nanotubes (CNTs). Multi-walled CNTs (MWCNTs) with different diameters were studied to determine their adsorption capacity and to address their ability to interact and distinguish between nucleic acids. The results revealed that MWCNTs preferentially interact with RNA and that smaller MWCNTs present a higher adsorption capacity, as expected by the higher specific surface area. Overall, this study showed that MWCNTs significantly reduce the levels of impurities, namely RNA, gDNA, and proteins, by approximately 83.6 % compared to their initial level, enabling the recovery of clarified pDNA in solution while maintaining its stability throughout the recovery process. This method facilitates the pre-purification of pDNA for therapeutic applications.publishe
Predicted Planck Extragalactic Point Source Catalogue
An estimation of the number and amplitude (in flux) of the extragalactic
point sources that will be observed by the Planck Mission is presented in this
paper. The study is based on the Mexican Hat wavelet formalism introduced by
Cayon et al. 2000. Simulations at Planck observing frequencies are analysed,
taking into account all the possible cosmological, Galactic and Extragalactic
emissions together with noise. With the technique used in this work the Planck
Mission will produce a catalogue of extragalactic point sources above fluxes:
1.03 Jy (857 GHz), 0.53 Jy (545 GHz), 0.28 Jy (353 GHz), 0.24 Jy (217 GHz),
0.32 Jy (143 GHz), 0.41 Jy (100 GHz HFI), 0.34 Jy (100 GHz LFI), 0.57 Jy (70
GHz), 0.54 Jy (44 GHz) and 0.54 Jy (30 GHz), which are only slightly model
dependent (see text). Amplitudes of these sources are estimated with errors
below 15%. Moreover, we also provide a complete catalogue (for the point
sources simulation analysed) with errors in the estimation of the amplitude
below 10%. In addition we discuss the possibility of identifying different
point source populations in the Planck catalogue by estimating their spectral
indices.Comment: 13 pages, 2 figures, submitted to MNRA
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