179 research outputs found

    The red giants in NGC 6633 as seen with CoRoT, HARPS and SOPHIE

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    The open cluster NGC 6633 was observed with CoRoT in 2011 and simultaneous high-resolution spectroscopy was obtained with the SOPHIE and HARPS spectrographs. One of the four targets was not found to be a cluster member. For all stars we provide estimates of the seismic and spectroscopic parameters.Comment: Proc. of the workshop "Asteroseismology of stellar populations in the Milky Way" (Sesto, 22-26 July 2013), Astrophysics and Space Science Proceedings, (eds. A. Miglio, L. Girardi, P. Eggenberger, J. Montalban

    Neurocognitive Functions and Behavior in Joubert Syndrome

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    Investigators from multiple Italian pediatric neurology and neurogenetics departments studied cognitive functions, behavior, and adaptive functioning in large cohort of 54 patients with Joubert syndrome (JS) as part of a prospective, multi-center study

    Gómez-López-Hernández syndrome: reappraisal of the diagnostic criteria

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    Gómez-López-Hernández syndrome (GLHS) is a rare and possibly underdiagnosed condition. So far, 21 patients have been reported and all of them were sporadic observations. We report six additional patients. The hallmark triad of GLHS, also named cerebellotrigeminal dermal dysplasia, consists of rhombencephalosynapsis, trigeminal anesthesia (often giving rise to corneal opacities), and bilateral parietal or parieto-occipital alopecia. Our patients had rhombencephalosynapsis and alopecia, but none had trigeminal dysfunction. In this respect, the term cerebellotrigeminal dermal dysplasia is potentially misleading. In conclusion, only rhombencephalosynapsis and alopecia are consistently present in GLHS and are required diagnostic criteria, while trigeminal anesthesia, dysmorphic features, and ataxia are inconsistent findings. A high index of suspicion is required to diagnose GLHS, particularly as alopecia tends to be hidden by surrounding scalp hai

    Outcome of children with low-grade cerebellar astrocytoma: long-term complications and quality of life

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    Objects: To study the long-term outcome of surgically treated low-grade cerebellar astrocytomas in children. Materials and methods: We followed 31 consecutive patients under 16years of age who were diagnosed between 1980 and 2005 in a single institution. In 21 of 31 survivors (median follow-up time 7.9years; range 5.6-27.4years) who agreed to participate, tumor control, neurological and cognitive complications, and their impact on behavioral and emotional adjustment and health-related quality of life (HRQoL) were comprehensively assessed qualitatively and quantitatively. Results: Neurological sequelae were found in 43%. However, age-appropriate ability to perform daily life activities was normal in all patients. Remarkably, cognitive deficits leading to significant school problems occurred in 19% and behavioral and emotional adjustment disturbances in 27%. In comparison with healthy controls, the survivors rated their HRQoL similarly or even higher. Conclusion: Childhood low-grade cerebellar astrocytomas have an excellent cure rate by tumor surgery alone. When compared with other pediatric brain tumors, the risk of neurological, cognitive, emotional, and behavioral complications is relatively small. HRQoL is similar to that of healthy control

    Activity and rotation of the X-ray emitting Kepler stars

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    The relation between magnetic activity and rotation in late-type stars provides fundamental information on stellar dynamos and angular momentum evolution. Rotation/activity studies found in the literature suffer from inhomogeneity in the measure of activity indexes and rotation periods. We overcome this limitation with a study of the X-ray emitting late-type main-sequence stars observed by XMM-Newton and Kepler. We measure rotation periods from photometric variability in Kepler light curves. As activity indicators, we adopt the X-ray luminosity, the number frequency of white-light flares, the amplitude of the rotational photometric modulation, and the standard deviation in the Kepler light curves. The search for X-ray flares in the light curves provided by the EXTraS (Exploring the X-ray Transient and variable Sky) FP-7 project allows us to identify simultaneous X-ray and white-light flares. A careful selection of the X-ray sources in the Kepler field yields 102 main-sequence stars with spectral types from A to M. We find rotation periods for 74 X-ray emitting main-sequence stars, 22 of which without period reported in the previous literature. In the X-ray activity/rotation relation, we see evidence for the traditional distinction of a saturated and a correlated part, the latter presenting a continuous decrease in activity towards slower rotators. For the optical activity indicators the transition is abrupt and located at a period of ~ 10 d but it can be probed only marginally with this sample which is biased towards fast rotators due to the X-ray selection. We observe 7 bona-fide X-ray flares with evidence for a white-light counterpart in simultaneous Kepler data. We derive an X-ray flare frequency of ~ 0.15 d^{-1} , consistent with the optical flare frequency obtained from the much longer Kepler time-series.Comment: Accepted for publication in A&A. 31 pages, 19 figure

    Composición química y dinámica poblacional de Hyalella curvispina en el arroyo Las Flores (cuenca del río Luján)

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    Se estudió la dinámica poblacional del anfípodo Hyalella curvispina en un manchón de macrofitas sumergidas del arroyo Las Flores. Se tomaron muestras mensuales durante un período de 15 meses (septiembre de 2000 a noviembre de 2001), registrando abundancias por estadíos (juveniles, machos adultos, hembras adultas y hembras ovígeras) y obteniendo el contenido corporal de proteínas y lípidos de los ejemplares. Los resultados son coherentes con investigaciones anteriores en el mismo arroyo. La mayor abundancia de estos anfípodos tiene lugar entre octubre y diciembre, en asociación con la mayor biomasa de fitobentos en el arroyo. La máxima proporción de lípidos coincide con los meses de mayor reproducción (septiembre y octubre), mientras que el mayor porcentaje de proteínas se da en julio para todos los estadíos. El porcentaje de proteínas en el cuerpo de este anfípodo varía entre un 17,7 % de promedio anual para los machos y un 74,2 % de promedio anual para los juveniles. Las proporciones de lípidos son mucho menores y van desde 0.5 mg/gPS en juveniles a 340 mg/gPS en machos. Se puede concluir que un mayor porcentaje de lípidos está directamente asociado con la reproducción y que estos invertebrados acumulan lípidos en primavera perdiendo esas reservas a medida que avanza el año y llegando a un mínimo de lípidos (y por lo tanto un máximo de proteínas) en el invierno. No parece haber diferencias importantes entre los dos sexos para la acumulación de lípidos, aunque el muestreo de hembras ovígeras fue algo pobre y no arroja resultados concluyentes para ese estadío

    Magnetic resonance imaging findings in children with spasmus nutans

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    Background Spasmus nutans (SN) is a rare pediatric ophthalmologic syndrome characterized by nystagmus, head bobbing, and abnormal head positioning. Historically, SN has been associated with underlying optic pathway gliomas (OPG); however, evidence of this association is based primarily on a small number of isolated case reports. Prior retrospective analyses have found the rate of OPG to be <2%, but these studies only intermittently used neuroimaging with computed tomography, which has limited sensitivity for detection of small lesions in the optic pathway. The purpose of this study was to investigate the association of SN with intracranial abnormalities, particularly OPG, using magnetic resonance imaging of the brain and orbits. Methods Neuroradiology databases at three institutions spanning January 2010 to May 2016 were queried for examinations ordered for evaluation of SN; MRI examinations of the brain and/or orbits were included and evaluated for OPG and other structural abnormalities. Medical records were reviewed to confirm a diagnosis of SN, presence of other underlying neurological disease, or preexisting diagnoses. Results A total of 40 patients with eligible MRI examinations were identified. None had optic nerve pathway gliomas. Two children had optic nerve hypoplasia; no other patients had optic pathway abnormalities. None had intracranial or orbital masses. MRI examinations were normal in 25 patients. Conclusions This series represents the largest collection of MRI examinations for SN in the literature to date and shows no association between OPG and SN. In children presenting with SN but no other findings suggesting OPG or neurological abnormalities, neuroimaging may not be required

    Pluralism, Community and Civil Society at Regional Level : An Analysis from a Viewpoint of Historical Research

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    textabstractOBJECTIVE. The purpose of this article is to present and discuss the susceptibilityweighted imaging signal characteristics of the normal pediatric brain and those of a variety of pediatric brain pathologic abnormalities. CONCLUSION. Its high susceptibility for blood products, iron depositions, and calcifications makes susceptibility-weighted imaging an important additional sequence for the diagnostic workup of pediatric brain pathologic abnormalities. Compared with conventional MRI sequences, susceptibility-weighted imaging may show lesions in better detail or with higher sensitivity. Familiarity with the pediatric susceptibility-weighted imaging signal variance is essential to prevent misdiagnosis
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