The first orbital period of a very bright and fast Nova in M31: M31N 2013-01b

We present the first X-ray and UV/optical observations of a very bright and fast nova in the disc of M31, M31N 2013-01b. The nova reached a peak magnitude $R\sim$15 mag and decayed by 2 magnitudes in only 3 days, making it one of the brightest and fastest novae ever detected in Andromeda. From archival multi-band data we have been able to trace its fast evolution down to $U>21$ mag in less than two weeks and to uncover for the first time the Super-Soft X-ray phase, whose onset occurred 10-30 days from the optical maximum. The X-ray spectrum is consistent with a blackbody with a temperature of $\sim$50 eV and emitting radius of $\sim$4$\times 10^{9}$ cm, larger than a white dwarf radius, indicating an expanded region. Its peak X-ray luminosity, 3.5$\times 10^{37}$ erg s$^{-1}$, locates M31N 2013-01b among the most luminous novae in M31. We also unambiguously detect a short 1.28$\pm$0.02 h X-ray periodicity that we ascribe to the binary orbital period, possibly due to partial eclipses. This makes M31N 2013-01b the first nova in M31 with an orbital period determined. The short period also makes this nova one of the few known below the 2-3 h orbital period gap. All the observed characteristics strongly indicate that M31N 2013-01b harbours a massive white dwarf and a very low-mass companion, consistent with being a nova belonging to the disc population of the Andromeda Galaxy.Comment: 9 pages, 3 figures, 2 tables; accepted by the Astrophysical Journa

Crisis y salud: una ocasión para repensar modelos (y acciones)

La actual crisis sanitaria nos invita a repensar el actual modelo de salud, así como sus implicaciones antropológicas, sociales y económicas. A partir de una breve historia del concepto de salud, en este artı́culo tratamos de evidenciar los cambios que ese mismo concepto ha implicado a nivel de relación médico-paciente y a nivel de relaciones sociales. Un nuevo paradigma de salud, más ajustado a los nuevos fenómenos globales que están aconteciendo, implica también una critica a los enfoques individualistas, reduccionistas, tecnocráticos y economicistas que se encontraban en la raı́z del “antiguo” modelo de salud. Por último, proponemos el modelo One Health como una posible respuesta a los problemas teóricos del “antiguo paradigma” de salud, fuertemente enfatizados por la crisis sanitaria actual

On the sensitivity of the diffusion MRI signal to brain activity in response to a motor cortex paradigm

Diffusion functional MRI (dfMRI) is a promising technique to map functional activations by acquiring diffusion-weighed spin-echo images. In previous studies, dfMRI showed higher spatial accuracy at activation mapping compared to classic functional MRI approaches. However, it remains unclear whether dfMRI measures result from changes in the intra-/extracellular environment, perfusion and/or T2 values. We designed an acquisition/quantification scheme to disentangle such effects in the motor cortex during a finger tapping paradigm. dfMRI was acquired at specific diffusion weightings to selectively suppress perfusion and free-water diffusion, then times series of the apparent diffusion coefficient (ADC-fMRI) and of the perfusion signal fraction (IVIM-fMRI) were derived. ADC-fMRI provided ADC estimates sensitive to changes in perfusion and free-water volume, but not to T2/T2* values. With IVIM-fMRI we isolated the perfusion contribution to ADC, while suppressing T2 effects. Compared to conventional gradient-echo BOLD fMRI, activation maps obtained with dfMRI and ADC-fMRI had smaller clusters, and the spatial overlap between the three techniques was below 50%. Increases of perfusion fractions were observed during task in both dfMRI and ADC-fMRI activations. Perfusion effects were more prominent with ADC-fMRI than with dfMRI but were significant in less than 25% of activation ROIs. Taken together, our results suggest that the sensitivity to task of dfMRI derives from a decrease of hindered diffusion and an increase of the pseudo-diffusion signal fraction, leading to different, more confined spatial activation patterns compared to classic functional MRI.Comment: Submitted to peer-reviewed journa

Construção de um instrumento para avaliar a qualidade da comunicação de más notícias fornecidas por médicos sob a perspectiva dos pacientes

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Ciências Médicas, Florianópolis, 2019.Introdução: A comunicação de más notícias é uma das tarefas mais difíceis na prática médica. A maneira como ela é realizada pode afetar o grau de sofrimento e o nível de esperança do paciente. A percepção do paciente sobre a qualidade da comunicação de notícias ruins ainda necessita maior aprofundamento. Visando contribuir para preencher esta lacuna, o objetivo deste estudo foi desenvolver um instrumento para a avaliação por pacientes sobre a qualidade da comunicação de más notícias fornecidas por médicos. Método: Este estudo consistiu na construção de instrumento usando abordagem mista, qualitativa tipo exploratória, com entrevistas semiestruturadas com 109 pacientes clínicos e cirúrgicos, seguida de uma análise de conteúdo com codificação e categorização, resultando na geração dos itens do instrumento. Posteriormente, estes itens passaram por avaliação quantitativa de clareza e relevância, para validação conteúdo, com 11 experts e 10 pacientes. Resultados: Foram elaborados 19 itens, relativos ao preparo do médico, à transmissão da má notícia, à atitude do médico durante o encontro e ao compartilhamento de informações para planejamento futuro. A validação de conteúdo por experts revelou que 2 itens não eram relevantes e estes foram retirados do instrumento. A avaliação da clareza pelos experts resultou em algumas modificações nos itens existentes. Um terceiro item foi retirado do instrumento por ter sido considerado controverso pelos experts, gerando-se um instrumento com 16 itens, que foram avaliados quanto a clareza e relevância pelos pacientes. Os pacientes consideraram os itens claros e avaliaram que dois itens apresentavam baixa relevância. Optou-se, entretanto, por manter estes itens até futura avaliação das propriedades psicométricas do instrumento. Conclusão: O instrumento gerado para avaliar a qualidade da comunicação de más notícias é claro na avaliação de experts e pacientes, e teve validade de conteúdo confirmada por experts, sendo dois itens considerados pouco relevantes por pacientes. A próxima etapa é aplicar o instrumento a um número maior de pacientes para avaliação de suas propriedades psicométricas.Abstract : Introduction: Communicating bad news to patients is one of the most difficult tasks in medical practice. The way it is carried out may affect the degree of suffering and the patient's level of hope. Patients' perceptions perception of the quality of bad news communication still require a much deeper analysis. This study aims to fill this gap by developing an evaluation tool so patients can assess how physicians deliver bad news. Method: This study consisted of the construction of an instrument using mixed, qualitative exploratory type approach, with semi-structured interviews with 109 clinical and surgical patients, followed by a content analysis with coding and categorization, which resulted in the generation of items. Subsequently, these items went through quantitative assessment of clarity and relevance, for content validation, with 11 experts and 10 patients. Results: Nineteen items were developed, related to the doctors? preparedness, the communication of bad news, the doctors´ behavior during the meeting and how information is shared for future planning. The content validation provided by the experts revealed that 2 items were not relevant, being withdrawn from the instrument. The clarity evaluation provided by the experts resulted in few modifications to existing items. A third item was withdrawn from the instrument because it was considered controversial by the experts, generating an instrument including 16 items that were evaluated for clarity and relevance by patients. The patients considered the items clear and evaluated that two items had low relevance. However, it was decided to keep these items until further evaluation of the psychometric properties of the instrument. Conclusion: The instrument generated that evaluates the quality of bad news is clear in the evaluation of experts and patients, and had validity of content confirmed by experts, being two items considered not relevant by patients. Future studies including a larger number of participants to evaluate their psychometric properties are still required

Impact of the first COVID-19 lockdown on the relationship with parents and peers in a cohort of adolescents with somatic symptom disorder

To investigate the coping strategies of a group of adolescents with somatic symptom disorder compared to non-somatic symptom disorder peers during the COVID-19 related lockdown.This cross-sectional study is the second part of a previously published study showing an improved trend in depression and anxiety in a group of patients with somatic symptom disorder compared to non-somatic symptom disorder peers. An anonymous semi-structured survey was distributed to two groups of Italian adolescents to measure the impact of quarantine on their daily life and coping strategies.We recruited 115 adolescents, 58 (50.4%) mean age 15.3, with a recent diagnosis of somatic symptom disorder and 57 (49.6%) mean age 15.8, control peers.The aim of this study was to detect differences in coping strategies and relationships with parents and peers, during the lockdown period in a group of adolescents with somatic symptom disorder and low disease burden when compared with a non-somatic symptom disorder group.The relationship with parents significantly worsened in 4 (6.9%) of adolescents with somatic symptom disorder compared to 12 (21.1%) adolescents in the non-somatic symptom disorder group (p = 0.048). The relationship with peers significantly improved in 13 (22.4%) of adolescents with symptom disorder versus 3 (5.3%) of peers of the non- somatic symptom disorder group (p = 0.013).Adolescents with somatic symptom disorder with a low burden of physical symptoms experienced less deterioration in their relationships with parents and peers than the non-somatic symptom disorder group

Star formation in clusters: early sub-clustering in the Serpens core

We present high resolution interferometric and single dish observations of molecular gas in the Serpens cluster-forming core. Star formation does not appear to be homogeneous throughout the core, but is localised in spatially- and kinematically-separated sub-clusters. The stellar (or proto-stellar) density in each of the sub-clusters is much higher than the mean for the entire Serpens cluster. This is the first observational evidence for the hierarchical fragmentation of proto-cluster cores suggested by cluster formation models.Comment: 11 pages, 3 Figures, ApJ Letters in pres

EXTraS discovery of a peculiar flaring X-ray source in the Galactic globular cluster NGC 6540

We report the discovery of a flaring X-ray source in the globular cluster NGC 6540, obtained during the EXTraS project devoted to a systematic search for variability in archival data of the XMM-Newton satellite. The source had a quiescent X-ray luminosity of the order of ~10^32 erg/s in the 0.5-10 keV range (for a distance of NGC 6540 of 4 kpc) and showed a flare lasting about 300 s. During the flare, the X-ray luminosity increased by more than a factor 40, with a total emitted energy of ~10^36 erg. These properties, as well as Hubble Space Telescope photometry of the possible optical counterparts, suggest the identification with a chromospherically active binary. However, the flare luminosity is significantly higher than what commonly observed in stellar flares of such a short duration, leaving open the possibility of other interpretations.Comment: To appear in Astronomy and Astrophysic

Safety issues in nutraceutical exploitation of Chlorella vulgaris, Arthrospira Platensis and Scenedesmus sp. microalgae

Microalgae contain many bioactive compounds, which may be exploited in food and nutraceutical fields. Bisphenol A (BPA) is a contaminant in microalgae that may be released from polymeric plastics. Since it is responsible for toxic effects on humans, the European legislation set the legal BPA limit within foods at 50 µg kg−1 of food weight. In this work, a fast ultrasounds solid-liquid extraction of BPA from commercial microalgal powders of Chlorella vulgaris, Arthrospira Platensis and Scenedesmus sp. was optimized. To increase selectivity, BPA was derivatized by using N,O-bis(trimethylsilyl)trifluoroacetamide/trimethylchlorosilane (BSTFA-TMCS) and it was analysed by GC-MS in selected ion monitoring mode. A design of experiment (DOE) optimization study of the reaction conditions was performed. The analytical method was validated by determining selectivity, linearity (R2= 0.99999 ± 3.3165E-07), precision, accuracy (99.92 ± 9.83E-02 %), recovery (99.65 ± 3.61E-02 %) and sensitivity (LoD= 0.547 ± 9.94E-02 µg kg−1; LoQ= 1.823 ± 3.31E-1 µg kg−1). The overall method proved to be fast, with high recovery and suitable to selectively and sensitively determine the content of BPA, eliminating the interferences from extraction and allowing to control the safety profile of microalgae. Dried microalgae cultivated in a polycarbonate reactor, were found to contain an amount of BPA 6 times exceeding the legal limit