2,537 research outputs found

    Can the evolution of music be analyzed in a quantitative manner?

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    We propose a methodology to study music development by applying multivariate statistics on composers characteristics. Seven representative composers were considered in terms of eight main musical features. Grades were assigned to each characteristic and their correlations were analyzed. A bootstrap method was applied to simulate hundreds of artificial composers influenced by the seven representatives chosen. Afterwards we quantify non-numeric relations like dialectics, opposition and innovation. Composers differences on style and technique were represented as geometrical distances in the feature space, making it possible to quantify, for example, how much Bach and Stockhausen differ from other composers or how much Beethoven influenced Brahms. In addition, we compared the results with a prior investigation on philosophy. Opposition, strong on philosophy, was not remarkable on music. Supporting an observation already considered by music theorists, strong influences were identified between composers by the quantification of dialectics, implying inheritance and suggesting a stronger master-disciple evolution when compared to the philosophy analysis.Comment: 8 pages, 6 figures, added references for sections 1 and 4.C, better mathematical description on section 2. New values and interpretation, now considering a bootstrap metho

    J-PLUS: A wide-field multi-band study of the M15 globular cluster. Evidence of multiple stellar populations in the RGB

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    The Javalambre Photometric Local Universe Survey (J-PLUS) provides wide field-of-view images in 12 narrow, intermediate and broad-band filters optimized for stellar photometry. Here we have applied J-PLUS data for the first time for the study of Galactic GCs using science verification data obtained for the very metal-poor GC M\,15. Our J-PLUS data provide low-resolution spectral energy distributions covering the near-UV to the near-IR, allowing us to search for MPs based on pseudo-spectral fitting diagnostics. J-PLUS CMDs are found to be particularly useful to search for splits in the sequences formed by the upper red giant branch (RGB) and asymptotic giant branch (AGB) stars. We interpret these split sequences as evidence for the presence of MPs. This demonstrates that the J-PLUS survey will have sufficient spatial coverage and spectral resolution to perform a large statistical study of GCs through multi-band photometry in the coming years.Comment: 11 pages, 11 figures. Accepted for publication @ A&

    Um modelo para seleção de avaliações adaptativas em ambientes computacionais de aprendizagem

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    No sistema tradicional de ensino e também na grande maioria dos Ambientes Computacionais de Aprendizagem todos os estudantes são avaliados de maneira uniforme independente do seu nível de aquisição de conhecimentos e dos conteúdos abordados. O insucesso recorrente nessas avaliações pode ser desestimulante para o aprendiz e torna o processo de avaliação formativa ineficaz uma vez que os resultados não são utilizados para realimentar o próprio processo de avaliação. Este artigo tem por objetivo apresentar um modelo para a seleção de avaliações adaptativas num ambiente computacional de aprendizagem utilizando técnicas de mineração de dados com base no nível de aquisição de conhecimentos do estudante em cada item do domínio em questão e também nos conteúdos abordados nas unidades de Avaliação. A seleção de unidades de avaliação adequadas ao perfil atual do estudante criará condições para avaliações personalizadas de modo a proteger ou desafiar o aprendiz nos seus sucessos ou insucessos.In the traditional system of education and also in the great majority of Computational Environments of Learning all the students are evaluated in an independent uniform way it its level of acquisition of knowledge and them boarded contents. The recurrent failure in these evaluations can be discouraged for the apprentice and becomes the process of inefficacious formative evaluation once that the results are not used to feedback the proper process of evaluation. This article has for objective to present a model for the selection of adaptive evaluations in a computational environment of learning using data mining techniques based on the level of acquisition of knowledge of the student in each item of the domain in question and also in the boarded contents in the units of the Evaluation. The selection of adequate units of evaluation to the current profile of the student will create conditions for personalized evaluations in order to protect or to defy the apprentice in its successes or failures.VI Workshop de Tecnología Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI

    Um modelo para seleção de avaliações adaptativas em ambientes computacionais de aprendizagem

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    No sistema tradicional de ensino e também na grande maioria dos Ambientes Computacionais de Aprendizagem todos os estudantes são avaliados de maneira uniforme independente do seu nível de aquisição de conhecimentos e dos conteúdos abordados. O insucesso recorrente nessas avaliações pode ser desestimulante para o aprendiz e torna o processo de avaliação formativa ineficaz uma vez que os resultados não são utilizados para realimentar o próprio processo de avaliação. Este artigo tem por objetivo apresentar um modelo para a seleção de avaliações adaptativas num ambiente computacional de aprendizagem utilizando técnicas de mineração de dados com base no nível de aquisição de conhecimentos do estudante em cada item do domínio em questão e também nos conteúdos abordados nas unidades de Avaliação. A seleção de unidades de avaliação adequadas ao perfil atual do estudante criará condições para avaliações personalizadas de modo a proteger ou desafiar o aprendiz nos seus sucessos ou insucessos.In the traditional system of education and also in the great majority of Computational Environments of Learning all the students are evaluated in an independent uniform way it its level of acquisition of knowledge and them boarded contents. The recurrent failure in these evaluations can be discouraged for the apprentice and becomes the process of inefficacious formative evaluation once that the results are not used to feedback the proper process of evaluation. This article has for objective to present a model for the selection of adaptive evaluations in a computational environment of learning using data mining techniques based on the level of acquisition of knowledge of the student in each item of the domain in question and also in the boarded contents in the units of the Evaluation. The selection of adequate units of evaluation to the current profile of the student will create conditions for personalized evaluations in order to protect or to defy the apprentice in its successes or failures.VI Workshop de Tecnología Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI

    Transferência de calor através de paineis aglomerados de bagaço de cana, pinus e eucalipto : Heat transfer through against panels of sugar cane, pinus and eucaliptus

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    O objetivo deste trabalho foi determinar a transferência de calor, a temperatura de combustão e o calor específico de painéis de aglomerado feitos de bagaço de cana, pinus e eucalipto. Os painéis foram expostos a uma fonte de calor até a combustão e mantido por 30 minutos o fluxo de calor entre os materiais. Os resultados mostraram que a transferência de energia durante o aquecimento é maior para os painéis feitos de bagaço de cana-de-açúcar em comparação com os demais materiais

    Novel ocellatin peptides mitigate LPS-induced ROS formation and NF-kB activation in microglia and hippocampal neurons

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    © The Author(s) 2020. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Cre-ative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not per-mitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Cutaneous secretions of amphibians have bioactive compounds, such as peptides, with potential for biotechnological applications. Therefore, this study aimed to determine the primary structure and investigate peptides obtained from the cutaneous secretions of the amphibian, Leptodactylus vastus, as a source of bioactive molecules. The peptides obtained possessed the amino acid sequences, GVVDILKGAAKDLAGH and GVVDILKGAAKDLAGHLASKV, with monoisotopic masses of [M + H]± = 1563.8 Da and [M + H]± = 2062.4 Da, respectively. The molecules were characterized as peptides of the class of ocellatins and were named as Ocellatin-K1(1-16) and Ocellatin-K1(1-21). Functional analysis revealed that Ocellatin-K1(1-16) and Ocellatin-K1(1-21) showed weak antibacterial activity. However, treatment of mice with these ocellatins reduced the nitrite and malondialdehyde content. Moreover, superoxide dismutase enzymatic activity and glutathione concentration were increased in the hippocampus of mice. In addition, Ocellatin-K1(1-16) and Ocellatin-K1(1-21) were effective in impairing lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) formation and NF-kB activation in living microglia. We incubated hippocampal neurons with microglial conditioned media treated with LPS and LPS in the presence of Ocellatin-K1(1-16) and Ocellatin-K1(1-21) and observed that both peptides reduced the oxidative stress in hippocampal neurons. Furthermore, these ocellatins demonstrated low cytotoxicity towards erythrocytes. These functional properties suggest possible to neuromodulatory therapeutic applications.Alexandra Plácido is a recipient of a post-doctoral grant from the project FCT (PTDC/BII-BIO/31158/2017). Renato Socodato and Camila Cabral Portugal hold postdoctoral fellowships from FCT (Refs: SFRH/BPD/91833/2012 and FRH/BPD/91962/2012, respectively). This work was funded through project UID/QUI/50006/2013-POCI/01/0145/FEDER/007265 (LAQV/REQUIMTE) with financial support from FCT/MEC through national funds and co-financed by FEDER, under the Partnership Agreement PT 2020info:eu-repo/semantics/publishedVersio

    The mini-JPAS: A study of the wavelength dependence of the photon response nonuniformity of the JPAS-pathfinder camera

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    Understanding the origins of small-scale flats of CCDs and their wavelength-dependent variations plays an important role in high-precision photometric, astrometric, and shape measurements of astronomical objects. Based on the unique flat data of 47 narrowband filters provided by JPAS-Pathfinder, we analyze the variations of small-scale flats as a function of wavelength. We find moderate variations (from about 1.0% at 390 nm to 0.3% at 890 nm) of small-scale flats among different filters, increasing toward shorter wavelengths. Small-scale flats of two filters close in central wavelengths are strongly correlated. We then use a simple physical model to reproduce the observed variations to a precision of about ±0.14% by considering the variations of charge collection efficiencies, effective areas, and thicknesses between CCD pixels. We find that the wavelength-dependent variations of the small-scale flats of the JPAS-Pathfinder camera originate from inhomogeneities of the quantum efficiency (particularly charge collection efficiency), as well as the effective area and thickness of CCD pixels. The former dominates the variations in short wavelengths, while the latter two dominate at longer wavelengths. The effects on proper flat-fielding, as well as on photometric/flux calibrations for photometric/slitless spectroscopic surveys, are discussed, particularly in blue filters/wavelengths. We also find that different model parameters are sensitive to flats of different wavelengths, depending on the relations between the electron absorption depth, photon absorption length, and CCD thickness. In order to model the wavelength-dependent variations of small-scale flats, a small number (around 10) of small-scale flats with well-selected wavelengths are sufficient to reconstruct small-scale flats in other wavelengths. © 2021. The American Astronomical Society. All rights reserved.he PRNU model adopted in this work was developed as part of Mr. Baocun Chen's undergraduate thesis work under the supervision of H.Z. This work is supported by the National Natural Science Foundation of China through projects NSFC 12173007 and 11603002, the National Key Basic R&D Program of China via 2019YFA0405503, and Beijing Normal University grant No. 310232102. We acknowledge the science research grants from the China Manned Space Project with Nos. CMS-CSST-2021-A08 and CMS-CSST2021-A09. Based on observations made with the JST/T250 telescope and JPCam at the Observatorio Astrofisico de Javalambre (OAJ) in Teruel, owned, managed, and operated by the Centro de Estudios de Fisica del Cosmos de Aragon (CEFCA). We acknowledge the OAJ Data Processing and Archiving Unit (UPAD) for reducing and calibrating the OAJ data used in this work. Funding for the JPAS Project has been provided by the Governments of Spain and Aragon through the Fondo de Inversion de Teruel, European FEDER funding, and the Spanish Ministry of Science, Innovation and Universities, as well as by the Brazilian agencies FINEP, FAPESP, and FAPERJ and the National Observatory of Brazil. Additional funding was also provided by the Tartu Observatory and the JPAS Chinese Astronomical Consortium. With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709

    Reactivation of latent HIV-1 in vitro using an ethanolic extract from Euphorbia umbellata (Euphorbiaceae) latex

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    Euphorbia umbellata (E. umbellata) belongs to Euphorbiaceae family, popularly known as Janauba, and its latex contains a combination of phorbol esters with biological activities described to different cellular protein kinase C (PKC) isoforms. Here, we identified deoxi-phorbol esters present in E. umbellata latex alcoholic extract that are able to increase HIV transcription and reactivate virus from latency models. This activity is probably mediated by NF-kB activation followed by nuclear translocation and binding to the HIV LTR promoter. In addition, E. umbellata latex extract induced the production of pro inflammatory cytokines in vitro in human PBMC cultures. This latex extract also activates latent virus in human PBMCs isolated from HIV positive patients as well as latent SIV in non-human primate primary CD4+ T lymphocytes. Together, these results indicate that the phorbol esters present in E. umbellata latex are promising candidate compounds for future clinical trials for shock and kill therapies to promote HIV cure and eradication.Research and experimental expenses were funded by the grant E26/2015064289 from FAPERJinfo:eu-repo/semantics/publishedVersio

    Strangeness Enhancement in Cu+Cu and Au+Au Collisions at \sqrt{s_{NN}} = 200 GeV

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    We report new STAR measurements of mid-rapidity yields for the Λ\Lambda, Λˉ\bar{\Lambda}, KS0K^{0}_{S}, Ξ\Xi^{-}, Ξˉ+\bar{\Xi}^{+}, Ω\Omega^{-}, Ωˉ+\bar{\Omega}^{+} particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity yields for the Λ\Lambda, Λˉ\bar{\Lambda}, KS0K^{0}_{S} particles in Au+Au at \sNN{200}. We show that at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parameterization based on the fraction of participants that undergo multiple collisions

    Inclusive charged hadron elliptic flow in Au + Au collisions at sNN\sqrt{s_{NN}} = 7.7 - 39 GeV

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    A systematic study is presented for centrality, transverse momentum (pTp_T) and pseudorapidity (η\eta) dependence of the inclusive charged hadron elliptic flow (v2v_2) at midrapidity(η<1.0|\eta| < 1.0) in Au+Au collisions at sNN\sqrt{s_{NN}} = 7.7, 11.5, 19.6, 27 and 39 GeV. The results obtained with different methods, including correlations with the event plane reconstructed in a region separated by a large pseudorapidity gap and 4-particle cumulants (v24v_2{4}), are presented in order to investigate non-flow correlations and v2v_2 fluctuations. We observe that the difference between v22v_2{2} and v24v_2{4} is smaller at the lower collision energies. Values of v2v_2, scaled by the initial coordinate space eccentricity, v2/εv_{2}/\varepsilon, as a function of pTp_T are larger in more central collisions, suggesting stronger collective flow develops in more central collisions, similar to the results at higher collision energies. These results are compared to measurements at higher energies at the Relativistic Heavy Ion Collider (sNN\sqrt{s_{NN}} = 62.4 and 200 GeV) and at the Large Hadron Collider (Pb + Pb collisions at sNN\sqrt{s_{NN}} = 2.76 TeV). The v2(pT)v_2(p_T) values for fixed pTp_T rise with increasing collision energy within the pTp_T range studied (<2GeV/c< 2 {\rm GeV}/c). A comparison to viscous hydrodynamic simulations is made to potentially help understand the energy dependence of v2(pT)v_{2}(p_{T}). We also compare the v2v_2 results to UrQMD and AMPT transport model calculations, and physics implications on the dominance of partonic versus hadronic phases in the system created at Beam Energy Scan (BES) energies are discussed.Comment: 20 pages, 12 figures. Version accepted by PR
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