2,052 research outputs found

    Magnetic field fluctuations in the shocked umbral chromosphere

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    Several studies have reported magnetic field fluctuations associated with umbral shock waves. We aim to study the properties and origin of magnetic field fluctuations in the umbral chromosphere. Temporal series of spectropolarimetric observations were acquired with the GREGOR telescope. The chromospheric and photospheric conditions were derived from simultaneous inversions of the He I 10830 \AA\ triplet and the Si I 10827 \AA\ line using HAZEL2. The oscillations are interpreted using wavelet analysis and context information from UV observations acquired with SDO/AIA and IRIS. The chromospheric magnetic field shows strong fluctuations in the sunspot umbra, with peak field strengths up to 2900 G. Magnetic field and velocity umbral oscillations exhibit a strong coherence, with the magnetic field lagging the shock fronts detected in the velocity fluctuations. This points to a common origin of the fluctuations in both parameters, whereas the analysis of the phase shift between photospheric and chromospheric velocity is consistent with upwards wave propagation. These results suggest that the strong inferred magnetic field fluctuations are caused by changes in the response height of the He I 10830 \AA\ line to the magnetic field, which is sensitive to high photospheric layers after the shock fronts. The coronal activity seen in EUV data could possibly have some impact on the inferred fluctuations, but it is not the main driver of the magnetic field oscillations since they are found before EUV events take place. Chromospheric magnetic field fluctuations measured with the He I 10830 \AA\ triplet arise due to variations in the opacity of the line. After shocks produced by slow magnetoacoustic waves, the response of the line to the magnetic field can be shifted down to the upper photosphere. This is seen as remarkably large fluctuations in the line of sight magnetic field strength.Comment: Accepted for publication in A&A. Abstract abridged due to arXiv's 1920 character limi

    Incidence Patterns and Trends of non-Central Nervous System Solid Tumours in Children and Adolescents. A Collaborative Study of the Spanish Population Based Cancer Registries

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    Objective: To describe incidence patterns and trends in children (0-14 years) and adolescents (15-19 age-range) with solid tumours, except those of central nervous system (CNS), in Spain. Methods: Cases were drawn from eleven Spanish population-based cancer registries. Incidence was estimated for the period 1983-2007 and trends were evaluated using Joinpoint regression analysis. Results: The studied tumour groups accounted for 36% of total childhood cancers and 47.6% of those diagnosed in adolescence with annual rates per million of 53.5 and 89.3 respectively. In children 0 to 14 years of age, Neuroblastoma (NB) was the commonest (7.8%) followed by Soft-tissue sarcomas (STS) (6.3%), bone tumours (BT) (6.2%) and renal tumours (RT) (4.5%). NB was the most frequently diagnosed tumour before the 5th birthday, while STS and BT were the commonest at 5-9 years of age, and BT and Carcinoma and other epithelial tumours (COET) at 10-14. COET presented the highest incidence in adolescents, followed by germ-cell tumours (GCT), BT and STS. These four diagnostic groups accounted for 94% of total non-CNS solid tumours, in adolescents. Overall incidence rates increased significantly in children up to 1996 with an annual percentage change (APC) of 2.6% (95% CI: 1.7; 3.6). NB and COET showed significant time trend (APCs: 1.4% and 3.8% respectively) while other tumour groups such as RT, STS, BT or GCT had no significant changes over time. A significant increase was present in NB under the age of 5 and in BT and STS in children aged 10-14 years. In adolescents there were significant increases for all tumours combined (APC=2.7; 95% CI: 1.8-3.6) and for STS, GCT and COET (APCs: 3.2%, 4.4% and 3.5% respectively), while other tumour groups such as hepatic tumours, BT or thyroid carcinomas showed a decreasing trend or no increase. Conclusions: Overall, the incidence of the studied cancers in children increased along the period 1983-1996 with no posterior significant rise, while the incidence in adolescents increased significantly over the whole period 1983-2007. Several specific tumour groups showed significant rises or decrements in childhood or adolescence, although the small number of cases precludes showing significant trends or inflexion points

    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

    Unified Topological Inference for Brain Networks in Temporal Lobe Epilepsy Using the Wasserstein Distance

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    Persistent homology can extract hidden topological signals present in brain networks. Persistent homology summarizes the changes of topological structures over multiple different scales called filtrations. Doing so detect hidden topological signals that persist over multiple scales. However, a key obstacle of applying persistent homology to brain network studies has always been the lack of coherent statistical inference framework. To address this problem, we present a unified topological inference framework based on the Wasserstein distance. Our approach has no explicit models and distributional assumptions. The inference is performed in a completely data driven fashion. The method is applied to the resting-state functional magnetic resonance images (rs-fMRI) of the temporal lobe epilepsy patients collected at two different sites: University of Wisconsin-Madison and the Medical College of Wisconsin. However, the topological method is robust to variations due to sex and acquisition, and thus there is no need to account for sex and site as categorical nuisance covariates. We are able to localize brain regions that contribute the most to topological differences. We made MATLAB package available at https://github.com/laplcebeltrami/dynamicTDA that was used to perform all the analysis in this study

    Actividades corporales de aventura en la escuela: la carrera de orientación como propuesta en el desarrollo de habilidades socioemocionales

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    Os esportes de aventura quando tematizados nas aulas de Educação Física têm o potencial de despertar fortes emoções, principalmente pelas experiências de risco e aventura, no contexto escolar, a Base Nacional Comum Curricular-BNCC, existe há necessidade de se trabalhar a educação emocional. O objetivo deste estudo foi analisar o comportamento socioemocional dos alunos diante de uma intervenção de corrida de orientação. 39 escolares do ensino médio participaram do estudo. Foi aplicado o questionário Big Five Inventory (BFI) após uma intervenção de corrida de orientação para a avaliação do perfil socioemocional. Foi constado que as maiores médias entre os perfis foram: Abertura (34,59), amabilidade (30,44), conscienciosidade (28,23) (tabela 1). A corrida de orientação, se mostra eficaz no desempenho emocional dos escolares pois os perfis de maior as maiores medias foram para os perfis de: Abertura, amabilidade e conscienciosidade. Está intervenção também atende aos requisitos presentes no BNCC sobre o desenvolvimento emocional como também sobre a necessidade de práticas de aventura para a Educação Física.Adventure sports when thematized in Physical Education classes have the potential to arouse strong emotions, mainly through risk and adventure experiences, in the school context, the National Common Curricular Base-BNCC, there is a need to work on emotional education. The objective of this study was to analyze the socio-emotional behavior of students in the face of an orienteering race intervention. 39 high school students participated in the study. The Big Five Inventory (BFI) questionnaire was applied after an orienteering race intervention to assess the socio-emotional profile. It was found that the highest averages among the profiles were: Openness (34.59), kindness (30.44), conscientiousness (28.23) (Table 1). The orienteering race proves to be effective in the emotional performance of the students because the profiles of the highest the highest averages were for the profiles of: Openness, kindness and conscientiousness. This intervention also meets the requirements present in the BNCC on emotional development as well as on the need for adventure practices for Physical Education.Los deportes de aventura cuando son tematizados en las clases de Educación Física tienen el potencial de despertar emociones fuertes, principalmente a través de experiencias de riesgo y aventura, en el contexto escolar, Base Curricular Común NacionalBNCC, existe la necesidad de trabajar la educación emocional. El objetivo de este estudio fue analizar el comportamiento socioemocional de los estudiantes ante una intervención de carrera de orientación. 39 estudiantes de secundaria participaron en el estudio. Se aplicó el cuestionario Big Five Inventory (BFI) después de una intervención de carrera de orientación para evaluar el perfil socioemocional. Se encontró que los promedios más altos entre los perfiles fueron: Apertura (34,59), amabilidad (30,44), escrupulosidad (28,23) (Tabla 1). La carrera de orientación demuestra ser efectiva en el desempeño emocional de los estudiantes debido a que los perfiles de los más altos los promedios más altos fueron para los perfiles de: Apertura, amabilidad y escrupulosidad. Esta intervención también cumple con los requisitos presentes en el BNCC sobre el desarrollo emocional, así como sobre la necesidad de prácticas de aventura para la Educación Física.Facultad de Humanidades y Ciencias de la Educació

    Semantic Segmentation under Adverse Conditions:A Weather and Nighttime-aware Synthetic Data-based Approach

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    Recent semantic segmentation models perform well under standard weather conditions and sufficient illumination but struggle with adverse weather conditions and nighttime. Collecting and annotating training data under these conditions is expensive, timeconsuming, error-prone, and not always practical. Usually, synthetic data is used as a feasible data source to increase the amount of training data. However, just directly using synthetic data may actually harm the model’s performance under normal weather conditions while getting only small gains in adverse situations. Therefore, we present a novel architecture specifically designed for using synthetic training data for domain adaptation. We propose a simple yet powerful addition to DeepLabV3+ by using weather and time-of-the-day supervisors trained with multi-task learning, making it both weather and nighttime aware, which improves its mIoU accuracy by 14 percentage points on the ACDC dataset while maintaining a score of 75% mIoU on the Cityscapes dataset. Our code is available at https://github.com/lsmcolab/Semantic-Segmentation-under-Adverse-Conditions

    MPK6, sphinganine and the \u3ci\u3eLCB2a\u3c/i\u3e gene from serine palmitoyltransferase are required in the signaling pathway that mediates cell death induced by long chain bases in \u3ci\u3eArabidopsis\u3c/i\u3e

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    • Long chain bases (LCBs) are sphingolipid intermediates acting as second messengers in programmed cell death (PCD) in plants. Most of the molecular and cellular features of this signaling function remain unknown. • We induced PCD conditions in Arabidopsis thaliana seedlings and analyzed LCB accumulation kinetics, cell ultrastructure and phenotypes in serine palmitoyltransferase (spt), mitogen-activated protein kinase (mpk), mitogenactivated protein phosphatase (mkp1) and lcb-hydroxylase (sbh) mutants. • The lcb2a-1 mutant was unable to mount an effective PCD in response to fumonisin B1 (FB1), revealing that the LCB2a gene is essential for the induction of PCD. The accumulation kinetics of LCBs in wild-type (WT) and lcb2a-1 plants and reconstitution experiments with sphinganine indicated that this LCB was primarily responsible for PCD elicitation. The resistance of the null mpk6 mutant to manifest PCD on FB1 and sphinganine addition and the failure to show resistance on pathogen infection and MPK6 activation by FB1 and LCBs indicated that MPK6 mediates PCD downstream of LCBs. • This work describes MPK6 as a novel transducer in the pathway leading to LCBinduced PCD in Arabidopsis, and reveals that sphinganine and the LCB2a gene are required in a PCD process that operates as one of the more effective strategies used as defense against pathogens in plants
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