Assessment of Vessel Density on Non-Contrast Computed Tomography to Detect Basilar Artery Occlusion

Introduction: Basilar artery occlusion (BAO) may be clinically occult due to variable and non-specific symptomatology. We evaluated the qualitative and quantitative determination of a hyperdense basilar artery (HDBA) on non-contrast computed tomography (NCCT) brain for the diagnosis of BAO.Methods: We conducted a case control study of patients with confirmed acute BAO vs a control group of suspected acute stroke patients without BAO. Two EM attending physicians, one third-year EM resident, and one medical student performed qualitative and quantitative assessments for the presence of a HDBA on axial NCCT images. Our primary outcome measures were sensitivity and specificity for BAO. Our secondary outcomes were inter-rater and intra-rater reliability of the qualitative and quantitative assessments.Results: We included 60 BAO and 65 control patients in our analysis. Qualitative assessment of the hyperdense basilar artery sign was poorly sensitive (54%–72%) and specific (55%–89%). Quantitative measurement improved the specificity of hyperdense basilar artery assessment for diagnosing BAO, with a threshold of 61.0–63.8 Hounsfield units demonstrating relatively high specificity of 85%–94%. There was moderate inter-rater agreement for the qualitative assessment of HDBA (Fleiss’ kappa statistic 0.508, 95% confidence interval: 0.435–0.581). Agreement improved for quantitative assessments, but still fell in the moderate range (Shrout-Fleiss intraclass correlation coefficient: 0.635). Intra-rater reliability for the quantitative assessments of the two attending physician reviewers demonstrated substantial consistency.Conclusion: Our results highlight the importance of carefully examining basilar artery density when interpreting the NCCT of patients with altered consciousness or other signs and symptoms concerning for an acute basilar artery occlusion. If the Hounsfield unit density of the basilar artery exceeds 61 Hounsfield units, BAO should be highly suspected

Optimization of an ih-cavity based high energy heavy-ion LINAC at GSI

A new high energy heavy-ion injector (HE-Linac) for the FAIR project was proposedas replacement for the existing post-stripper linac at the GSI UNILAC. Six 108 MHz IH-type drift-tube linac cavities within a total length of about 24m accelerate the ions (up to U28+) from1.4 MeV/u up to 11.4 MeV/u. Fast pulsed quadrupole triplet lenses are used for transverse focusing in between the IH cavities. The optimization of the HE linac with respect to the emittance growth reductionis investigated

Urban Water Pricing: The Metro Manila and Metro Cebu Cases

Water is a critical commodity for human survival and a scarce resource that must be appropriately priced to ensure that it is not wastefully and unsuitably consumed. This Notes offers an optimal pricing scheme, together with suggestions on the improvement of the overall water resource management that could provide the proper environment by which such pricing scheme can succeed.urban management, water sector, water demand

Towards a definition of quantum integrability

We briefly review the most relevant aspects of complete integrability for classical systems and identify those aspects which should be present in a definition of quantum integrability. We show that a naive extension of classical concepts to the quantum framework would not work because all infinite dimensional Hilbert spaces are unitarily isomorphic and, as a consequence, it would not be easy to define degrees of freedom. We argue that a geometrical formulation of quantum mechanics might provide a way out.Comment: 37 pages, AmsLatex, 1 figur

Cómo valoran y usan las Tecnologías de la Información y la Comunicación (TIC) los profesores de alumnos con Necesidades Educativas Especiales (NEE)

La introducción paulatina de las (TIC) en todos lo ámbitos de la actividad humana está transformando la sociedad y, en consecuencia, emergen directamente dentro del escenario educativo.; por ello, en los diferentes tipos de centros de las diversas etapas educativas se están desarrollando experiencias muy interesantes, pero paulatinas y analíticas, que reflejan el aprovechamiento en las diversas áreas de la enseñanza-aprendizaje.Y desde aquí ya adelantamos que este trabajo ha pretendido abrir un foro de debate y reflexión sobre la articulación de las TIC en las aulas dando a conocer opiniones docentes con la finalidad de enriquecer formación para profesionales del diferente alumnado, contemplando, plenamente, sus nee de éste cuando las presenta