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Presents Hubble Space Telescope WFPC2 imaging of slow nova HR Del in filters centered on the lines of Hα, [N II] and [O III], with corresponding William Herschel Telescope ISIS slit spectroscopy for the lines of Hα, Hβ, [N II] and [O III]. Data showing the ejected shell of HR Del is composed of many small bright knots; Distribution of the knots in a bipolar structure with an equatorial ring, and polar rings or caps; Evidence for a fast wind from the central binary system.

CA 125 is found in body fluids in a variety of molecular weight forms. The largest species are found in normal abdominal fluid and cervical mucus. The present study therefore incorporated CA 125 derived from these sources as well as ascites fluid to investigate if the source of CA 125 influenced epitope characterization. Ascites-derived CA 125 varied in size from about 190 to about 2,700 kD. Cervical mucus-derived CA 125 treated with ultrasound changed its apparent size from more than 20,000 to 700 kD. Epitope mapping of antibodies was not grossly influenced by the size or source of CA 125 used as target. However, low-molecular-weight CA 125, i.e. ascites fractions CA 17/E, CA 17/F and CA 10/7, did show differences in certain assay combinations and cross-inhibition patterns which probably can be explained by steric effects due to the smaller size compared with the most abundant forms of CA 125 present in serum and other body fluids. The specificity of six new monoclonal antibodies to CA 125 was tested by cross-inhibition and immunometric assay combinations and compared to reference antibodies. One antibody, X306, belonged to the OC125-like antibodies. Four antibodies, X52, X75, X325 and VK8, were M11-like. The sixth antibody, 7C12, reacted with an epitope which was difficult to define. This antibody was inhibited by M11-like antibodies and OV197. However, used as an inhibitor, 7C12 inhibited only itself. We grouped it as an OV197-like antibody, but clearly different from OV197. The topography of epitopes was studied by analyzing all antibody pairs in immunoradiometric assays. These results confirmed the grouping of antibodies described above and are in accordance with previous findings that the highest signal is obtained using an OC125-like antibody or OV197 on the solid phase and an M11-like antibody as tracer. The composition of the sample in terms of high- and low-molecular-weight species of CA 125 was measured, with different responses depending on the antibody pair used. This might be one reason for discrepancies between assay results for CA 125 using different assays. Copyright © 2002 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We have detected radio emission from the remnant of V705 Cas, beginning 221 d after visual maximum. We follow the remnant from first detection while still optically thick through the turn-over to optically thin emission, and finally confirming the absence of emission due to expansion and fading by the end of 1998. While the emission is consistent with thermal bremsstrahlung, as seen in most previous novae, the small-scale structure shows two ridge-like features, which develop significantly from day 585 until our last detection on day 1544. While the development is fairly rapid, it is also much smoother than that seen in V1974 Cyg, in that we can follow individual features as they change over almost 1000 d. Our optical spectra unequivocally indicate some form of axial symmetry, as derived from the velocity structure. This is difficult to reconcile with the observed development in the radio images. We suggest a number of possible explanations. [ABSTRACT FROM AUTHOR]

In this paper we report on the first five out of eleven observations in our programme of Hubble Space Telescope (HST) imaging of old nova shells. We present new WFPC2 images of the shells around FH Ser and V533 Her taken in the F656N (Hα+[N ii]) filter. We also show long-slit spectra taken using the William Herschel Telescope on La Palma for these objects in the same spectral range. The shell around FH Ser is found to be a prolate ellipsoid of ellipticity 1.3±0.1 inclined at 62°±4° to the line of sight. The shell has an equatorial ring which is found to be due to increased emission in the two [N ii] lines rather than Hα. The expansion velocity is best modelled by a true equatorial expansion rate of 490±20 km s[sup -1]. The best-fitting systemic velocity is -45 km s[sup -1]. A synthetic image and synthetic spectra are also presented for this model for comparison with our observations. We derive a distance to FH Ser of 950±50 pc. The origin of the [N ii] equatorial ring is discussed in the context of a photoionization feature resulting from aspherical illumination by the central source rather than a simple density enhancement. It is possible, however, that the ring is also in part due to an extremely localized increase in the nitrogen abundance. The brightest part of the shell is found to have a surface brightness of 9.1×10[sup -15] erg cm[sup -2] s[sup -1] arcsec[sup -2]. Similar imaging and spectroscopy of the nova V533 Her reveal a shell of radius 5±0.7 arcsec with an axial ratio of 1.2±0.2 and peak surface brightness of 1.3×10[sup -15] erg cm[sup -2] s[sup -1] arcsec[sup -2]. The expansion velocity of this shell is 850±150 km s[sup -1] and the distance is estimated to be 1250±300 pc. The shells around BT Mon, DK Lac and V476 Cyg were not detected with HST, implying 3σ upper limits to the surface brightness in Hα+[N ii] of 5.3–6.3×10[sup -16] erg cm[sup -2] s[sup -1] arcsec[sup -2]. [ABSTRACT FROM AUTHOR]

We investigate how several parameters can affect the results of a collision between an extragalactic jet and a dense, intergalactic cloud, through a series of hydrodynamic simulations. Such collisions are often suggested to explain the distorted structures of some radio jets. However, theoretical studies of this mechanism are in conflict over whether it can actually reproduce the observations. The parameters are the Mach number, and the relative densities of the jet and the cloud to the ambient medium. Using a simple prescription, we have produced synthetic radio images for comparison with observations. These show that a variety of structures may be produced from simple jet–cloud collisions. We illustrate this with a few examples, and examine the details in one case. In most cases we do not see a clear, sustained deflection. Lighter jets are completely disrupted. The most powerful jets produce a hotspot at the impact which outshines any jet emission, and erode the cloud too quickly to develop a deflected arm. It appears that moderate Mach numbers and density contrasts are needed to produce bends in the radio structure. This explains the apparent conflict between theoretical studies, as conclusions were based on different values of these parameters. Shocks are produced in the ambient medium that might plausibly reproduce the observed alignment of the extended emission-line regions with the radio axis. [ABSTRACT FROM AUTHOR]

We have calculated optically thin emission-line profiles for various models of classical-nova shells. These models range from simple geometries incorporating expanding ellipsoidal shells encircled by equatorial and tropical rings or polar caps to the results of previously published hydrodynamical modelling. The effects on the profiles of different inclinations to the line of sight are also considered. A recent set of line profiles of the classical nova V705 Cas is also shown for comparison. The modelling of classical-nova shells by ellipsoids with enhanced equatorial and tropical rings is discussed. [ABSTRACT FROM AUTHOR]

The specificity of 26 monoclonal antibodies against the CA 125 antigen was investigated in two phases of the ISOBM TD-1 workshop. The binding specificity was studied using CA 125 immunoextracted by specific antibodies immobilized on various solid phases, or on the surface of human cell lines. Immunometric assays using all possible antibody combinations were used to study the topography of antibody binding sites on the antigen. We conclude that the CA 125 antigen carries only two major anti-genic domains, which classifies the antibodies as OC125-like (group A) or Mil-like (group B). One antibody, OV 197, showed binding specificity related to some of the OC125-like antibododies, but was classified into a separate group C. The OC125-like group of antibodies has four subgroups with different binding specificities. These are A1 = OC 125 and K 95, A2 = K 93, A3 = B43.13, and A4 = ZS 33, B27.1 and CCD 247. Binding of nonlabelled OC 125 or K 95 to CA 125 caused a marked increase in binding of labelled OV 197 to the complex. This conformational change was not observed with any other antibody combinations. Antibody B43.13 could form immunometric assay combinations particularly with antibodies of subgroup A4, indicating that the B43.13 epitope is in the periphery of the binding area of OC125-like antibodies. The M11 -like group of antibodies is more homogenous with strong cross-inhibition between most antibodies. Only one antibody, ZR 38, would form an immunoassay combination with other M11 -like antibodies and thus represents a distinct subgroup. The main group of M11-like antibodies are M 11, ZR 45, MA602-6, K 91, OV 185, K 101, K 90, K 96, K 97, K 102, CCD 242, 145-9, and 130-22. Antibody OV 197 binds to a domain designated C and is unique, as stated above. Antibody pairs from any two of the three groups may be used in immunometric assays. Three antibodies were not studied by complete cross-inhibition due to low affinity (OV 198 and K 100) or lack of material (MA602-1). OV 198 and K 100 are most likely OC125-like and MA602-1 is Ml 1-like. Antibody affinity was estimated with labelled antigen in solution or with antigen adsorbed on microtiter wells. Western blot analysis showed staining both in the stacking gel and corresponding to a molecule of 200 kDa. There was a marked difference between the antibodies in their ability to bind to CA 125 immobilized on a membrane. Strongest binding was observed with the M11-like antibodies, particularly M 11, K 96, K 97, MA602-6, 145-9. Antibodies belonging to the subgroup A4 were the only OC 125-like antibodies which reacted well with CA 125 in Western analysis. Digestion of CA 125 with proteolytic enzymes showed it to be particularly sensitive to trypsin cleavage. However, no low molecular weight fragments with preserved immunoreactivity were found. Copyright © 1996 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]