66 research outputs found

    Eclipses of the inner satellites of Jupiter observed in 2015

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    During the 2014-2015 campaign of mutual events, we recorded ground-based photometric observations of eclipses of Amalthea (JV) and, for the first time, Thebe (JXIV) by the Galilean moons. We focused on estimating whether the positioning accuracy of the inner satellites determined with photometry is sufficient for dynamical studies. We observed two eclipses of Amalthea and one of Thebe with the 1 m telescope at Pic du Midi Observatory using an IR filter and a mask placed over the planetary image to avoid blooming features. A third observation of Amalthea was taken at Saint-Sulpice Observatory with a 60 cm telescope using a methane filter (890 nm) and a deep absorption band to decrease the contrast between the planet and the satellites. After background removal, we computed a differential aperture photometry to obtain the light flux, and followed with an astrometric reduction. We provide astrometric results with an external precision of 53 mas for the eclipse of Thebe, and 20 mas for that of Amalthea. These observation accuracies largely override standard astrometric measurements. The (O-C)s for the eclipse of Thebe are 75 mas on the X-axis and 120 mas on the Y-axis. The (O-C)s for the total eclipses of Amalthea are 95 mas and 22 mas, along the orbit, for two of the three events. Taking into account the ratio of (O-C) to precision of the astrometric results, we show a significant discrepancy with the theory established by Avdyushev and Ban'shikova in 2008, and the JPL JUP 310 ephemeris.Comment: 7 pages, 10 figures, 4 table

    Postharvest changes of fresh cilantro

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    IX SimpĂłsio IbĂ©rico de Maturação e PĂłs Colheita. SessĂ”es PosterCilantro (Coriandrum sativum L.) has become one of the most widely used fresh herbs worldwide. In addition to its flavorful culinary attributes, cilantro has been promoted by public health authorities as partial replacement of dietary salt intake. The objective of this study was to characterize the postharvest behavior of fresh cilantro to provide recommendations for proper postharvest handling. Freshly harvested cilantro leaves were bunched into 50 g bunches held by a rubber band, wrapped in plastic, cooled to ca. 5 ÂșC and transported to the laboratory within 2 h after harvest. The leaf bunches were placed at 0Âș, 10Âș, and 20 ÂșC, and assessed for mass loss, ethylene production rate, respiration rate, color, and chlorophyll content. Hedonic assessment of appearance and odor were also performed. Under these experimental conditions, fresh mass declined at a rate of 1.1; 1.5; and 6.3% per day, at 0Âș, 10Âș and 20 ÂșC, respectively. Ethylene production rate remained stable during storage at 0Âș or 10 ÂșC, at 0.26 and 1.61 ÎŒL kg-1 h-1, respectively. At 20 ÂșC, the initial ethylene production rate of 4.04 ÎŒL kg-1 h-1 increased sharply after 4 days to reach 25.64 ÎŒL kg-1 h-1 at day 7 due to fungal development. The initial respiration rate, expressed in mL CO2 kg-1 h-1, was 7.7 at 0 ÂșC, 27.8 at 10 ÂșC and 114.1 at 20 ÂșC, and remained relatively stable during storage at 0 and 10 ÂșC. However, respiration rate double during 7 days at 20 ÂșC due to decay. The initial hue angle of cilantro leaflets was 124.7Âș, a value that remained relatively constant during 30 days at 0 ÂșC, but decreased slightly (2 to 3%) after 15 days at 10 ÂșC or 4 days at 20 ÂșC. The initial SPAD index of 42.2 decreased to 37.7 after 4 days at 20 ÂșC, to 35.6 after 15 days at 10 ÂșC and to 39.6 after 30 days at 0 ÂșC. Total chlorophyll content at harvest was 1.92 mg g-1 with a ratio of chlorophyll a to chlorophyll b of 3.2. Chlorophyll content decreased slightly at 10Âș and 20 ÂșC, mainly due to the reduction in chlorophyll b but remained unaltered during 30 days at 0 ÂșC. The duration of postharvest life based on appearance was 1.6; 7.3, and 11 days at 20Âș, 10Âș and 0 ÂșC, respectively. However, odor was judged at the sales limit after 1.0; 2.0; and 9.0 days at 20Âș, 10Âș, and 0 ÂșC, respectively. In conclusion, the main causes of shelf-life termination are odor suppression and fungal development. Wilting can be reduced by packaging and senescence-related chlorophyll loss and yellowing are slower than odor suppression. Freshness is best preserved at 0 ÂșCinfo:eu-repo/semantics/publishedVersio

    On the formation and decay of a molecular ultracold plasma

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    Double-resonant photoexcitation of nitric oxide in a molecular beam creates a dense ensemble of 50f(2)50f(2) Rydberg states, which evolves to form a plasma of free electrons trapped in the potential well of an NO+^+ spacecharge. The plasma travels at the velocity of the molecular beam, and, on passing through a grounded grid, yields an electron time-of-flight signal that gauges the plasma size and quantity of trapped electrons. This plasma expands at a rate that fits with an electron temperature as low as 5 K, colder that typically observed for atomic ultracold plasmas. The recombination of molecular NO+^+ cations with electrons forms neutral molecules excited by more than twice the energy of the NO chemical bond, and the question arises whether neutral fragmentation plays a role in shaping the redistribution of energy and particle density that directs the short-time evolution from Rydberg gas to plasma. To explore this question, we adapt a coupled rate-equations model established for atomic ultracold plasmas to describe the energy-grained avalanche of electron-Rydberg and electron-ion collisions in our system. Adding channels of Rydberg predissociation and two-body, electron- cation dissociative recombination to the atomic formalism, we investigate the kinetics by which this relaxation distributes particle density and energy over Rydberg states, free electrons and neutral fragments. The results of this investigation suggest some mechanisms by which molecular fragmentation channels can affect the state of the plasma

    TerritĂłrio e territorialidade no contexto hospitalar: uma abordagem interdisciplinar

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    Este artigo trata o hospital como territĂłrio de organização complexa, atravessado por mĂșltiplos interesses, que ocupa lugar crĂ­tico na prestação de serviços de saĂșde, lugar de construção de identidades profissionais, com grande reconhecimento social. O objetivo diz respeito a compreender o hospital na perspectiva interdisciplinar. Para tanto, buscou-se o referencial teĂłrico referente Ă s concepçÔes de territĂłrio e territorialidade, oriundas da geografia e de outros campos do conhecimento, como a ciĂȘncia da saĂșde e a filosofia. A partir da interação entre estas disciplinas aborda-se o hospital como territĂłrio de produção de atos de saĂșde formado por segmentos e superfĂ­cies, agenciamentos entre profissionais e usuĂĄrios que se entrecortam em um emaranhado de linhas de segmentaridade; nĂłs, redes e malhas que revelam a produção territorial; poder e disciplinamento e o saber-poder que revelam as relaçÔes sociais, efetivadas entre os sujeitos e o objeto, ou seja, as relaçÔes que se concretizam no territĂłrio e significam territorialidade. Concluiu-se, entĂŁo, que o territĂłrio hospitalar, como os demais territĂłrios, Ă© a expressĂŁo concreta e abstrata do espaço apropriado, produzido, formado em sua multidimensionalidade, pelos atores sociais que o (re)definem constantemente em suas cotidianidades, num campo de forças relacionalmente emaranhado por poderes nas mais variadas intensidades

    Antikinetoplastid SAR study in 3-nitroimidazopyridine series: identification of a novel non-genotoxic and potent anti-T. b. brucei hit-compound with improved pharmacokinetic properties

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    To study the antikinetoplastid 3-nitroimidazo[1,2-a]pyridine pharmacophore, a structure-activity relationship study was conducted through the synthesis of 26 original derivatives and their in vitro evaluation on both Leishmania spp and Trypanosoma brucei brucei. This SAR study showed that the antitrypanosomal pharmacophore was less restrictive than the antileishmanial one and highlighted positions 2, 6 and 8 of the imidazopyridine ring as key modulation points. None of the synthesized compounds allowed improvement in antileishmanial activity, compared to previous hit molecules in the series. Nevertheless, compound 8, the best antitrypanosomal molecule in this series (EC50 = 17 nM, SI = 2650 & E° = -0.6 V), was not only more active than all reference drugs and previous hit molecules in the series but also displayed improved aqueous solubility and better in vitro pharmacokinetic characteristics: good microsomal stability (T1/2 > 40 min), moderate albumin binding (77%) and moderate permeability across the blood brain barrier according to a PAMPA assay. Moreover, both micronucleus and comet assays showed that nitroaromatic molecule 8 was not genotoxic in vitro. It was evidenced that bioactivation of molecule 8 was operated by T. b. brucei type 1 nitroreductase, in the same manner as fexinidazole. Finally, a mouse pharmacokinetic study showed that 8 displayed good systemic exposure after both single and repeated oral administrations at 100 mg/kg (NOAEL) and satisfying plasmatic half-life (T1/2 = 7.7 h). Thus, molecule 8 appears as a good candidate for initiating a hit to lead drug discovery program
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