238 research outputs found

    Astrometry of the main satellites of Uranus: 18 years of observations

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    We determine accurate positions of the main satellites of Uranus: Miranda, Ariel, Umbriel, Titania, and Oberon. Positions of Uranus, as derived from those of these satellites, are also determined. The observational period spans from 1992 to 2011. All runs were made at the Pico dos Dias Observatory, Brazil. We used the software called Platform for Reduction of Astronomical Images Automatically (PRAIA) to minimise (digital coronography) the influence of the scattered light of Uranus on the astrometric measurements and to determine accurate positions of the main satellites. The positions of Uranus were then indirectly determined by computing the mean differences between the observed and ephemeris positions of these satellites. A series of numerical filters was applied to filter out spurious data. These filters are mostly based on the comparison between the positions of Oberon with those of the other satellites and on the offsets as given by the differences between the observed and ephemeris positions of all satellites. We have, for the overall offsets of the five satellites, -29 (+/-63) mas in right ascension and -27 (+/-46) mas in declination. For the overall difference between the offsets of Oberon and those of the other satellites, we have +3 (+/-30) mas in right ascension and -2 (+/-28) mas in declination. Ephemeris positions for the satellites were determined from DE432+ura111. Comparisons using other modern ephemerides for the solar system -INPOP13c- and for the motion of the satellites -NOE-7-2013- were also made. They confirm that the largest contribution to the offsets we find comes from the motion of the barycenter of the Uranus system around the barycenter of the solar system, as given by the planetary ephemerides. Catalogues with the observed positions are provided.Comment: 13 pages, 21 figure

    Alterações nas características químicas de um Cambissolo Háplico cultivado com melão

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    O presente trabalho avaliou alterações nas propriedades químicas em Cambissolo, em função do tempo de cultivo com melão, em Baraúna-RN. Selecionaram-se 4 áreas: mata nativa e áreas com um, dois e três anos de cultivo, com amostras coletadas nas camadas de 0-20 e 20-40 cm de profundidade. Foram determinados os teores de carbono orgânico, nitrogênio total, nitrato, fósforo disponível e bases trocáveis, a acidez potencial, pH, condutividade elétrica, soma de bases, capacidade de troca de cátions, saturação por bases e sódio e atividade da fração argila. Os dados foram submetidos à análise de variância e ajustados à equação de regressão com médias comparadas por Tukey a 5% de probabilidade. O tempo de cultivo influenciou todas as características químicas, exceto nitrogênio total. Os teores de cálcio e a CTC reduziram com o tempo de cultivo, tendo as demais características químicas apresentado tendência ao incremento. A camada superficial apresentou valores mais elevados para a maioria das características químicas, exceto nitrato e magnésio

    Fluorescence image analyzer - FLIMA: Software for quantitative analysis of fluorescence in situ hybridization

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    The Fluorescence Image Analyzer (FLIMA) software was developed for the quantitative analysis of images generated by fluorescence in situ hybridization (FISH). Currently, the images of FISH are examined without a coefficient that enables a comparison between them. Through GD Graphics Library, the FLIMA software calculates the amount of pixels on image and recognizes each present color. The coefficient generated by the algorithm shows the percentage of marks (probes) hybridized on the chromosomes. This software can be used for any type of image generated by a fluorescence microscope and is able to quantify digoxigenin probes exhibiting a red color, biotin probes exhibiting a green color, and double-FISH probes (digoxigenin and biotin used together), where the white color is displayed. © 2017 The Authors

    Irrigação na cultura do chuchu.

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    A presente publicação tem por objetivo orientar produtores e técnicos ligados à produção de chuchu sobre procedimentos e informações técnicas simples e atuais sobre os principais sistemas de irrigação e métodos de manejo da água que podem ser usados com sucesso na cultura.bitstream/item/127635/1/CT-139X.pd

    Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations

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    The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how they were captured. The best way to obtain these parameters are observations in situ by spacecrafts or from stellar occultations by the objects. Both techniques demand that the orbits are well known. We aimed to obtain good astrometric positions of irregular satellites to improve their orbits and ephemeris. We identified and reduced observations of several irregular satellites from three databases containing more than 8000 images obtained between 1992 and 2014 at three sites (Observat\'orio do Pico dos Dias, Observatoire de Haute-Provence, and European Southern Observatory - La Silla). We used the software PRAIA (Platform for Reduction of Astronomical Images Automatically) to make the astrometric reduction of the CCD frames. The UCAC4 catalog represented the International Celestial Reference System in the reductions. Identification of the satellites in the frames was done through their ephemerides as determined from the SPICE/NAIF kernels. Some procedures were followed to overcome missing or incomplete information (coordinates, date), mostly for the older images. We managed to obtain more than 6000 positions for 18 irregular satellites: 12 of Jupiter, 4 of Saturn, 1 of Uranus (Sycorax), and 1 of Neptune (Nereid). For some satellites the number of obtained positions is more than 50\% of what was used in earlier orbital numerical integrations. Comparison of our positions with recent JPL ephemeris suggests there are systematic errors in the orbits for some of the irregular satellites. The most evident case was an error in the inclination of Carme.Comment: 9 pages, with 3 being online materia

    The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period

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    peer reviewedWe report six stellar occultations by Phoebe (Saturn IX), an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 6 event was the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision compared to the currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single- chord stellar occultations, we can identify the best solution for Phoebe's rotational period as 9.27365 ± 0.00002 h. From the stellar occultations, we also obtained six geocentric astrometric positions in the ICRS as realized by the Gaia DR2 with uncertainties at the 1-mas level

    The new nitric oxide donor cyclohexane nitrate induces vasorelaxation, hypotension, and antihypertensive effects via NO/cGMP/PKG pathway

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    We investigated the cardiovascular effects induced by the nitric oxide donor Cyclohexane Nitrate (HEX). Vasodilatation, NO release and the effects of acute or sub-chronic treatment with HEX on cardiovascular parameters were evaluated. HEX induced endothelium-independent vasodilatation (Maximum effect- [efficacy, ME] = 100.4±4.1%; potency [pD2] = 5.1±0.1). Relaxation was attenuated by scavenging nitric oxide (ME = 44.9±9.4% vs. 100.4±4.1%) or by inhibiting the soluble guanylyl cyclase (ME = 38.5±9.7% vs. 100.4±4.1%). In addition, pD2 was decreased after non-selective blockade of K+ channels (pD2 = 3.6±0.1 vs. 5.1±0.1) or by inhibiting KATP channels (pD2 = 4.3±0.1 vs. 5.1±0.1). HEX increased NO levels in mesenteric arteries (33.2±2.3 au vs. 10.7±0.2 au, p<0.0001). Intravenous acute administration of HEX (1-20 mg/kg) induced hypotension and bradycardia in normotensive and hypertensive rats. Furthermore, starting at six weeks after the induction of 2K1C hypertension, oral treatment with the HEX (10 mg/Kg/day) for seven days reduced blood pressure in hypertensive animals (134±6 vs 170±4 mmHg, respectively). Our data demonstrate that HEX is a NO donor able to produce vasodilatation via NO/cGMP/PKG pathway and activation of the ATP-sensitive K+ channels. Furthermore, HEX acutely reduces blood pressure and heart rate as well as produces antihypertensive effect in renovascular hypertensive rats

    Results of two multi-chord stellar occultations by dwarf planet (1) Ceres

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    We report the results of two multi-chord stellar occultations by the dwarf planet (1) Ceres that were observed from Brazil on 2010 August 17, and from the USA on 2013 October 25. Four positive detections were obtained for the 2010 occultation, and nine for the 2013 occultation. Elliptical models were adjusted to the observed chords to obtain Ceres' size and shape. Two limb fitting solutions were studied for each event. The first one is a nominal solution with an indeterminate polar aspect angle. The second one was constrained by the pole coordinates as given by Drummond et al. Assuming a Maclaurin spheroid, we determine an equatorial diameter of 972 ±\pm 6 km and an apparent oblateness of 0.08 ±\pm 0.03 as our best solution. These results are compared to all available size and shape determinations for Ceres made so far, and shall be confirmed by the NASA's Dawn space mission.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

    Indicadores para Centros de Referência em Saúde do Trabalhador: proposição de um sistema de acompanhamento de serviços de saúde

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    Os Centros de Referência em Saúde do Trabalhador (CEREST) são eixos estruturantes da Rede Nacional de Atenção Integral à Saúde do Trabalhador (RENAST), coordenados pela Coordenação Geral de Saúde do Trabalhador (CGSAT) do Ministério da Saúde. O instrumento apresentado no artigo visa contribuir para o acompanhamento e a futura avaliação da implantação e implementação da RENAST. Com o objetivo de construir um sistema de indicadores para monitoramento dos CEREST, elaborou-se uma primeira listagem de indicadores com base nas determinações previstas pela Portaria GM/MS nº 2.437/2005. A listagem foi enviada a 173 coordenadores dos CEREST para avaliação, com base em uma escala do tipo Likert. Retornaram 48,6% das avaliações, cuja análise foi realizada globalmente e segundo a abrangência, a data de habilitação e a localização dos CEREST. Consideraram-se aprovados os indicadores com 75% ou mais de aceitação, resultando um instrumento final com 12 indicadores para os CEREST estaduais e 13 indicadores para os CEREST regionais. A descrição dos procedimentos para a construção do instrumento e sua formatação final poderá ser útil no estímulo à construção de indicadores de monitoramento/avaliação de serviços de saúde em geral.This research proposes a framework of indicators to monitor the activities of the Occupational Health Reference Centers (CEREST). CEREST are structural elements of the National Network of Comprehensive Attention to Workers' Health (RENAST) and are coordinated by the General Coordination of Occupational Health of the Ministry of Health (CGSAT). In order to build this framework, we first elaborated a list of indicators based on the norms that govern CEREST's responsibilities. As a strategy to build a participative approach, a Likert scale questionnaire was sent to 173 CEREST coordinators, who were asked to evaluate this preliminary list of indicators. After the return of the questionnaires (48,6%), the answers were analyzed, considering the CEREST scope (State or Regional), date of accreditation and location. Indicators with approval rate higher than 75% were included in the proposed framework. This instrument consisted in 12 indicators for State CEREST and 13 indicators for Regional CEREST. It is expected that the procedures proposed in this research and the framework itself might encourage the government to create a monitoring system for RENAST as well as for health services in general
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