16 research outputs found

    ANATOMICAL COMPARISON OF POPULAR BRACATINGA ( Mimosa scabrella Bentham) VARIETIES OF WOOD

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    Esta pesquisa objetivou comparar anatomicamente a madeira das variedades populares de bracatinga ( Mimosa scabrella Bentham): bracatinga-branca, bracatinga-vermelha e bracatinga-argentina. Para a realiza\ue7\ue3o deste trabalho, foram coletadas \ue1rvores com idades entre 6 e 7 anos, provenientes de \ue1reas pertencentes \ue0 Embrapa Florestas, localizadas no munic\uedpio de Colombo-PR, Brasil cujo material bot\ue2nico coletado foi identificado e descrito. Foram obtidas amostras de madeira com casca para a caracteriza\ue7\ue3o. As an\ue1lises evidenciaram que n\ue3o h\ue1 diferen\ue7as estat\uedsticas entre os elementos anat\uf4micos do lenho da bracatingabranca e da bracatinga-vermelha, indicando que as diferencia\ue7\uf5es que tais plantas recebem por causa da a cor da madeira n\ue3o est\ue3o presentes no aspecto anat\uf4mico. As duas variedades populares, tamb\ue9m conhecidas como bracatinga-comum, diferiram estatisticamente entre si com rela\ue7\ue3o \ue0 bracatinga-argentina, quanto ao di\ue3metro tangencial dos poros, quantidade de poros/mm2, comprimento dos elementos vasculares, di\ue2metro das c\ue9lulas par\ueanquimo-axiais, largura dos raios unisseriados e multisseriados. Os resultados podem ser considerados um importante aux\uedlio na distin\ue7\ue3o das variedades populares de bracatinga-comum e bracatingaargentina em variedades bot\ue2nicas.The main objective of this research was to compare anatomical wood characteristics of the popular varieties of Mimosa scabrella Bentham known as bracatinga-branca, bracatinga-vermelha and bracatingaargentina. The material used in this work was collected from 6 to 7 years old trees of the popular varieties from areas located in Colombo municipality, State of Paran\ue1, owned by Embrapa Florestas. Botanic for anatomical characterization of wood material was identified and described. Results did not show differences of anatomical characteristics between the bracatinga-branca and bracatinga-vermelha. The bracatingabranca and bracatinga-vermelha showed statistically differences in relation to bracatinga-argentina to average values in pores tangential diameter, pores quantity per square mm, vessel elements individual length, axial parenchyma cells diameter, unisseriate and multisseriate rays width. In conclusion, the observations contribute to a better understanding of the differences showed by the popular varieties

    Trigger and Aperture of the Surface Detector Array of the Pierre Auger Observatory

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    The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive air showers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidate showers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above 3×10183\times 10^{18} eV, for all zenith angles between 0^\circ and 60^\circ, independently of the position of the impact point and of the mass of the primary particle. In these range of energies and angles, the exposure of the surface array can be determined purely on the basis of the geometrical acceptance.Comment: 29 pages, 12 figure

    Ultrahigh energy neutrinos at the Pierre Auger observatory

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    The observation of ultrahigh energy neutrinos (UHEνs) has become a priority in experimental astroparticle physics. UHEνs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ν) or in the Earth crust (Earth-skimming ν), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEνs in the data collected with the ground array of the Pierre Auger Observatory. This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEνs in the EeV range and above.P. Abreu ... K. B. Barber ... J. A. Bellido ... R. W. Clay ... M. J. Cooper ... B. R. Dawson ... T. A. Harrison ... A. E. Herve ... V. C. Holmes ... J. Sorokin ... P. Wahrlich ... B. J. Whelan ... et al

    Effects of the pollution by petroleum on the tracheids along the stem of Podocarpus lambertii Klotzsch ex Endl., Podocarpaceae

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    Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae) is native and a member of the Pinophyta (Gymnosperm) of southern Brazil, locally known as "pinheiro-bravo". The present work aims to investigate the effects of petroleum on the tracheids dimensions. Wood samples from twenty individuals were studied along the stem, ten being exposed to pollution and ten used as a control set. The wood samples were collected from incisions at three levels: at the ground level, and one and two metres above the ground level. From these samples, sub-samples were selected at the border of the growth layers in the vascular cambium-medulla direction. The methodology followed that traditionally recommended for plant anatomy studies, with analyses done by light microscopy (OLYMPUS - BX41) assisted by the software Image Pro-plus for measurements. Comparison of the individuals exposed to petroleum with the control set, showed that the length, diameter and cell wall width of the tracheids of the former were smaller, a trend which was statistically significant according to the Student's t-test. These traits were observed mainly on the tracheids of the last growth layer, corresponding to the year in which the individuals were exposed to petroleum

    Analysis of 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia.

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    Pregnancy in women with inherited thrombocytopenias is a major matter of concern as both the mothers and the newborns are potentially at risk of bleeding. However, medical management of this condition cannot be based on evidence because of the lack of consistent information in the literature. To advance knowledge on this matter, we performed a multicentric, retrospective study evaluating 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia. Neither the degree of thrombocytopenia nor the severity of bleeding tendency worsened during pregnancy and the course of pregnancy did not differ from that of healthy subjects in terms of miscarriages, fetal bleeding and pre-term births. The degree of thrombocytopenia in the babies was similar to that in the mother. Only 7 of 156 affected newborns had delivery-related bleeding, but 2 of them died of cerebral hemorrhage. The frequency of delivery-related maternal bleeding ranged from 6.8% to 14.2% depending on the definition of abnormal blood loss, suggesting that the risk of abnormal blood loss was increased with respect to the general population. However, no mother died or had to undergo hysterectomy to arrest bleeding. The search for parameters predicting delivery-related bleeding in the mother suggested that hemorrhages requiring blood transfusion were more frequent in women with history of severe bleedings before pregnancy and with platelet count at delivery below 50 7 10(9)/L

    La famiglia nella societ\ue0 contemporanea

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    Il volume raccoglie, rielaborati, gli Atti del Convegno internazionale \u201cLa famiglia nella societ\ue0 contemporanea\u201d, svoltosi a Verona presso il Dipartimento di Scienze giuridiche, nei giorni 14-15 novembre 2014, con il contributo dell\u2019Universidad Nacional de Educaci\uf3n a Distancia de Madrid (UNED), dell\u2019Instituto de Desarrollo y An\ue1lisis del Derecho de Familia en Espa\uf1a (IDADFE) e dell\u2019Osservatorio Nazionale sul Diritto di Famigli

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8\ub10.7(stat)\ub16.7(syst)\u2009\u2009MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory

    Search for photons with energies above 1018eV using the hybrid detector of the Pierre Auger Observatory

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    A search for ultra-high energy photons with energies above 1EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1\u20132EeV are found, which is compatible with the expected hadron induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km 122 sr 121 yr 121 are derived at 95% C.L. for energy thresholds of 1, 2, 3, 5 and 10EeV. These limits bound the fractions of photons in the all-particle integral flux below 0.1%, 0.15%, 0.33%, 0.85% and 2.7%. For the first time the photon fraction at EeV energies is constrained at the sub-percent level. The improved limits are below the flux of diffuse photons predicted by some astrophysical scenarios for cosmogenic photon production. The new results rule-out the early top-down models 12 in which ultra-high energy cosmic rays are produced by, e.g., the decay of super-massive particles 12 and challenge the most recent super-heavy dark matter model

    Search for ultrarelativistic magnetic monopoles with the Pierre Auger Observatory

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    We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from 10^ 1219(cm2 sr s)^ 121 for a Lorentz factor \u3b3 = 10^9 to 2.5 7 10 1221(cm2 sr s)^ 121 for \u3b3 = 10^12. These results\u2014the first obtained with a UHECR detector\u2014improve previously published limits by up to an order of magnitude
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