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    Clutter Detection and Surface/Subsurface Slope Determination by Combination of Repeat-Pass Sounder Orbits Applied to SHARAD Data

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    Nadir-looking low-frequency radar sounders cannot easily resolve off-nadir surface returns from the subsurface nadir echoes. Cross-track surface echoes (also named "clutter ") with time delays synchronized with subsurface returns are renowned for being a major challenge for scientists, as they can affect the analysis of orbital radar sounders data. We present a method for clutter discrimination and surface/subsurface slope estimation using data acquired from radar sounders in closely spaced repeated orbits configuration. The method takes advantage of cross-track signal migration to discriminate off-nadir clutter from subsurface signal returns received at the nadir. The migration of the off-nadir signals is also used to determine the clutter direction of arrival (DOA) as well as the surface/subsurface cross-track slopes. The effectiveness of the method has been proven on the Mars Reconnaissance Orbiter (MRO)'s Shallow Radar (SHARAD) dataset and provides a proof-of-concept demonstration for the surface clutter discrimination when radar sounders repeated-passes data are available

    Radiation-induced sarcoma of the skull: Report of two cases

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    The authors describe two cases of sarcomas of the skull following cranial irradiation in patients treated for other neoplasms, acute lymphatic leukemia, and astrocytoma, respectively. The patients (one man and one woman; mean age 24.5 years) developed sarcomas within the irradiated field after a mean latency period of 11.5 years. Histologically, the tumor proved to be a fibrosarcoma. Despite aggressive surgery and other therapy, the survival of the patients was short (10 and 8 months, respectively). The pathological and clinical aspects of this unusual complication are analyzed with reference to 41 cases taken from the world literature

    L'actinomicosi intracranica

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    Actinomycosis is a bacterial infection mainly affecting the cervico-oro-facial area, abdomen and lungs, sometimes spreading to the central nervous system. Extremely rare is the primary cerebral location of the disease
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