50 research outputs found

    Detectability of shape deformation in short-period exoplanets

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    Context Short-period planets are influenced by the extreme tidal forces of their parent stars. These forces deform the planets causing them to attain nonspherical shapes. The nonspherical shapes, modeled here as triaxial ellipsoids, can have an impact on the observed transit light-curves and the parameters derived for these planets. Aims We investigate the detectability of tidal deformation in short-period planets from their transit light curves and the instrumental precision needed. We also aim to show how detecting planet deformation allows us to obtain an observational estimate of the second fluid Love number from the light curve, which provides valuable information about the internal structure of the planet. Methods We adopted a model to calculate the shape of a planet due to the external potentials acting on it and used this model to modify the ellc transit tool. We used the modified ellc to generate the transit light curve for a deformed planet. Our model is parameterized by the Love number; therefore, for a given light curve we can derive the value of the Love number that best matches the observations. Results We simulated the known cases of WASP-103b and WASP-121b which are expected to be highly deformed. Our analyses show that instrumental precision ≤50 ppm min−1 is required to reliably estimate the Love number and detect tidal deformation. This precision can be achieved for WASP-103b in ∼40 transits using the Hubble Space Telescope and in ∼300 transits using the forthcoming CHEOPS instrument. However, fewer transits will be required for short-period planets that may be found around bright stars in the TESS and PLATO survey missions. The unprecedented precisions expected from PLATO and JWST will permit the detection of shape deformation with a single transit observation. However, the effects of instrumental and astrophysical noise must be considered as they can increase the number of transits required to reach the 50 ppm min−1 detection limit. We also show that improper modeling of limb darkening can act to bury signals related to the shape of the planet, thereby leading us to infer sphericity for a deformed planet. Accurate determination of the limb darkening coefficients is therefore required to confirm planet deformation

    TOI-4860 b, a short-period giant planet transiting an M3.5 dwarf

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    We report the discovery and characterisation of a giant transiting planet orbiting a nearby M3.5V dwarf (d = 80.4pc, G = 15.1 mag, K=11.2mag, R∗ = 0.358 ± 0.015 R, M∗ = 0.340 ± 0.009 M). Using the photometric time series from TESS sectors 10, 36, 46, and 63 and near-infrared spectrophotometry from ExTrA, we measured a planetary radius of 0.77 ± 0.03 RJ and an orbital period of 1.52 days. With high-resolution spectroscopy taken by the CFHT/SPIRou and ESO/ESPRESSO spectrographs, we refined the host star parameters ([Fe/H] = 0.27 ± 0.12) and measured the mass of the planet (0.273 ± 0.006 MJ). Based on these measurements, TOI-4860 b joins the small set of massive planets (>80 ME) found around mid to late M dwarfs (<0.4 R), providing both an interesting challenge to planet formation theory and a favourable target for further atmospheric studies with transmission spectroscopy. We identified an additional signal in the radial velocity data that we attribute to an eccentric planet candidate (e = 0.66 ± 0.09) with an orbital period of 427 ± 7 days and a minimum mass of 1.66 ± 0.26 MJ, but additional data would be needed to confirm this

    In vitro propagation of Cyrtopodium saintlegerianum rchb. f. (orchidaceae), a native orchid of the Brazilian savannah

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    In order to enable production of large quantities of plantlets for reintroduction programs, as well as economic exploration, Cyrtopodium saintlegerianum seeds were sown on Knudson culture medium. After seed germination, the protocorms were inoculated on Knudson culture medium supplemented with 6-benzyladenine (BA) and α-naphthaleneacetic acid (NAA). The obtained shoots were individually inoculated in Knudson supplemented with gibberellic acid (GA3 ) in order to promote elongation. Seedlings were evaluated and then transplanted into trays containing commercial substrate Plantmax®-HT, or crushed Acuri leaf sheath. Auxin/ cytokinin ratio influenced in vitro propagation of C. saintlegerianum, resulting in increased shoot number when 2.0 mg L-1 BA was added to the culture medium in the absence or presence of 0.5 mg L-1 NAA. This species proved to be promising for massal in vitro multiplication. Despite having incremented in vitro shoots elongation, the use of GA3 is unnecessary since it contributed negatively in the acclimatization of plants

    Diagnósticos de enfermagem e proposta de intervenções para pacientes com lesão medular Diagnósticos de enfermería y propuesta de intervenciones para pacientes con lesión medular Nursing diagnoses and interventions proposal al for patients with spinal cord lesion

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    INTRODUÇÃO: As lesões medulares constituem evento grave que acomete principalmente jovens, requerendo um planejamento cuidadoso da assistência de enfermagem Este estudo tem a finalidade de contribuir nesse planejamento, oferecendo subsídios para melhorar a qualidade do cuidado desses pacientes. OBJETIVOS: Identificar os diagnósticos de enfermagem, segundo a NANDA, em portadores de lesão medular internados numa Unidade de Ortopedia e Traumatologia; e propor as intervenções de enfermagem, conforme a NIC. MÉTODOS: Estudo descritivo prospectivo, com 10 casos analisados no período de janeiro/2000 a julho/2002. Os dados foram coletados por meio de um instrumento criado para uso na unidade de estudo, identificando-se os diagnósticos de enfermagem. As intervenções foram propostas pelas autoras e submetidas à avaliação de duas especialistas. RESULTADOS: Foram identificados 15 diagnósticos de enfermagem prevalentes, para os quais foram propostas 26 intervenções de enfermagem. CONCLUSÃO: Os resultados poderão subsidiar as enfermeiras ao cuidado do paciente com lesão medular, auxiliando-o e contribuindo à sua autonomia, através das intervenções propostas.<br>INTRODUCCIÓN: Las lesiones medulares constituyen un evento grave que afecta, en su mayoría, a los jóvenes, las cuales requirien una planificación cuidadosa para la atencion de enfermeria. Este estudio tiene la finalidad de contribuir con subsidios para mejorar la calidad de los cuidados prestados a esos pacientes. OBJETIVOS: Identificar los diagnósticos de enfermería, según la taxonomía de la NANDA, en pacientes con lesión medular, internados en una Unidad de Ortopedia y Traumatología; y proponer las intervenciones de enfermería, conforme el referencial de la NIC. MÉTODOS: Estudio descriptivo prospectivo en el cual fue analizado un total de 10 casos, en el período de enero/2000 a julio/2002. Los datos fueron recolectados por medio de un instrumento creado para uso en la unidad de estudio, con la finalidad de identificar los diagnósticos de enfermería. Las intervenciones fueron propuestas por las autoras y sometidas a la evaluación de dos especialistas. RESULTADOS: Fueron identificados 15 diagnósticos de enfermería prevalentes, para los cuales se propusieron 26 intervenciones de enfermería. CONCLUSIÓN: Los resultados del estudio servirán de subsidio a las enfermeras para el cuidado de pacientes con lesión medular, auxiliándolos y contribuyendo en su autonomía, a través de las intervenciones propuestas.<br>INTRODUCTION: Spinal cord lesions constitute very serious events that occur mostly among young people. Providing care to these patients is a complex task because they are greatly dependent on nursing staff and require a very carefully designed plan of care. The purpose of this study was to contribute ways to design a quality plan of care to attend these patients. OBJECTIVES: To identify nursing diagnoses according to the NANDA for patients with spinal cord lesions from an Orthopedic and Trauma Unit, and to propose appropriate nursing interventions according to the NIC. METHODS: This study used a descriptive and prospective research design. The sample consisted of 10 patients with spinal cord lesions. Data were colleted from January, 2000 to July, 2002 using a specific assessment tool. Data analysis led the researchers to propose nursing diagnoses which were validated by two clinical nursing specialists. RESULTS: Fifteen prevalent nursing diagnoses were identified and 26 nursing interventions were proposed. CONCLUSION: The results can be used to assist nurse to provide quality care for patients with spinal cord lesions, so as to improve the patients independence
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