On the Weakening of Chromospheric Magnetic Field in Active Regions

Simultaneous measurement of line-of-sight (LOS) magnetic and velocity fields at the photosphere and chromosphere are presented. Fe I line at $\lambda6569$ and $H_{\alpha}$ at $\lambda6563$ are used respectively for deriving the physical parameters at photospheric and chromospheric heights. The LOS magnetic field obtained through the center-of-gravity method show a linear relation between photospheric and chromospheric field for field strengths less than 700 G. But in strong field regions, the LOS magnetic field values derived from $H_{\alpha}$ are much weaker than what one gets from the linear relationship and also from those expected from the extrapolation of the photospheric magnetic field. We discuss in detail the properties of magnetic field observed in $H_{\alpha}$ from the point of view of observed velocity gradients. The bisector analysis of $H_{\alpha}$ Stokes $I$ profiles show larger velocity gradients in those places where strong photospheric magnetic fields are observed. These observations may support the view that the stronger fields diverge faster with height compared to weaker fields.Comment: accepted for publication in Ap

Characterization of tumour cell aggregation promoting factor from rat ascites hepatoma cells: Separation of two factors with different antigenic property.

The previously described glycoprotein that promotes tumour cell aggregation, derived from rat ascites hepatoma cells and capable of partial purification by chromatography, was found to be a mixture of 2 factors with different antigenic property. One was not absorbed by immunoadsorbent chromatography with anti-rat serum antibody and the other was. The action of the unabsorbed factor was clearly more potent than that of the absorbed factor. Both the factors were found in the serum of tumour bearing rats and the action of the unabsorbed factor was also more potent than that of the absorbed factor; its amount increased with time after i.p. inoculation of the cells. The serum of healthy rats contained the absorbed factor but not the unabsorbed factor. It was thus assumed that the unabsorbed factor was associated with the hepatoma cell surface itself and released into the serum, while the absorbed factor was associated with serum protein coating the cell

Reduced lung uptake of iodine-123 metaiodobenzylguanidine in high-altitude pulmonary oedema

The definitive version is available at www.blackwell-synergy.com.ArticleRESPIROLOGY. 13(6):897-902(2008)journal articl