We report the discovery of water vapour toward the carbon star V Cygni. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 1(11) - 0(00) para-water transition at ...1113.3430 GHz in the upper sideband of the Band 4b receiver. The observed spectral line profile is nearly parabolic, but with a slight asymmetry associated with blueshifted absorption, and the integrated antenna temperature is 1.69 \pm 0.17 K km/s. This detection of thermal water vapour emission, carried out as part of a small survey of water in carbon-rich stars, is only the second such detection toward a carbon-rich AGB star, the first having been obtained by the Submillimeter Wave Astronomy Satellite toward IRC+10216. For an assumed ortho-to-para ratio of 3 for water, the observed line intensity implies a water outflow rate ~ (3 - 6) E-5 Earth masses per year and a water abundance relative to H2 of ~ (2-5) E-6. This value is a factor of at least 1E+4 larger than the expected photospheric abundance in a carbon-rich environment, and - as in IRC+10216 - raises the intriguing possibility that the observed water is produced by the vapourisation of orbiting comets or dwarf planets. However, observations of the single line observed to date do not permit us to place strong constraints upon the spatial distribution or origin of the observed water, but future observations of additional transitions will allow us to determine the inner radius of the H2O-emitting zone, and the H2O ortho-to-para ratio, and thereby to place important constraints upon the origin of the observed water emission.
Ovalbumin-antiovalbumin IgG immune aggregates were incubated with normal human serum in the presence of iodo1-14Cacetamide, in conditions in which only the alternative pathway of complement was ...activated. The 14CC3b-IgG covalent complexes formed were digested with pepsin, and analysed by SDS/polyacrylamide-gel electrophoresis and fluorography. Covalent complexes of 14CC3-Fd and 14CC3-pFc' were visualized, demonstrating that, during complement activation by the alternative pathway, C3 is covalently incorporated into the C gamma 3 domain of IgG, as well as into the Fd region. The C gamma 2 domain becomes protected from pepsin action by the bound C3b. All the covalent linkages between C3 and the IgG were sensitive to hydroxylamine. When 14CC3-pFc' covalent complexes were treated with 1 M-NH2OH and loaded onto a Bio-Gel P-4 column, a radioactive peak of 3 kDa was obtained. The material released from 14CC3-pFc' and 14CC3-F(ab')2 complexes after treatment with 1 M-NH2OH was mixed and analysed in the Bio-Gel P-4 column. A similar radioactive peak of 3 kDa was obtained. When this peak, either from 14CC3-pFc' alone or from the mixture of 14CC3-F(ab')2 and 14CC3-pFc', was fractionated by h.p.l.c., virtually the same radioactive peptide profile was obtained, indicating that very similar C3 peptides remained covalently bound to both regions (Fab and C gamma 3) of the antibody molecule. It is suggested that C3 bound to the C gamma 3 domain of IgG may interfere with the Fc-Fc interactions of immune aggregates and thus may be involved in several biological properties displayed by these complement-activating aggregates.
CONTEXT: Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser ...transitions may ultimately lead to greater insight. AIMS: We have aimed to elucidate the nature and structure of the VY CMa water vapour masers in part by observationally testing a theoretical prediction of the relative strengths of the 620.701 GHz and the 22.235 GHz maser components of ortho water vapour. METHODS: In its high-resolution mode (HRS) the Herschel Heterodyne Instrument for the Infrared (HIFI) offers a frequency resolution of 0.125 MHz, corresponding to a line-of-sight velocity of 0.06 km/s, which we employed to obtain the strength and linear polarisation of maser spikes in the spectrum of VY CMa at 620.701 GHz. Simultaneous ground based observations of the 22.235 GHz maser with the Max-Planck-Institut f\"ur Radioastronomie 100-meter telescope at Effelsberg, provided a ratio of 620.701 GHz to 22.235 GHz emission. RESULTS:We report the first astronomical detection to date of water vapour maser emission at 620.701 GHz. In VY CMa both the 620.701 and the 22.235 GHz polarisation are weak. At 620.701 GHz the maser peaks are superposed on what appears to be a broad emission component, jointly ejected asymmetrically from the star. We observed the 620.701 GHz emission at two epochs 21 days apart, both to measure the potential direction of linearly polarised maser components and to obtain a measure of the longevity of these components. Although we do not detect significant polarisation levels in the core of the line, they rise up to approximately 6% in its wings.
C1q has 12 binding sites for 1-anilino-8-naphthalene sulphonate (ANS), two per peripheral subunit. This number increases to 18 upon weak-acid-induced conformational transition in the globular heads. ...One ANS binding site is present in each C gamma 2 domain of human IgG. ANS is bound by C1q with a higher affinity (Ka = 2.07 X 10(6) M-1) than by the Fc fragment (Ka = 9.07 X 10(4) M-1) of human IgGl. Hence the inhibitory capacity of C1q binding to IgG immune complexes of ANS probably reflects its preferential binding to the globular heads of C1q. The characteristics of ANS-C1q binding may in part explain the hydrophobic component of the C1q-IgG interaction. It is suggested that an ionic-hydrophobic two-step process is involved in the contact between C1q and IgG.
The binding properties of activated C4 to immune complexes (ovalbumin-rabbit IgG antiovalbumin) were studied by using 125I-IgG in the immune complexes or performing the C4 binding assays in the ...presence of 14C-iodoacetamide. High molecular weight complexes formed between C4 and IgG could be detected by the incorporation of 14C-iodoacetamide in the -SH group generated in the nascent C4b during the activation process. The same complexes with an apparent molecular weight of 180,000 daltons were detected when the immune aggregates contained 125I-IgG. Two-dimensional SDS-PAGE analysis of the C4b-IgG covalent complexes indicated: In the absence of control proteins, the complexes are formed by the alpha'-chain of C4b and the H chain of the antibody. The alpha'-H complexes are 36% sensitive to hydroxylamine and 64% resistant. This is consistent with the presence of two populations of C4, which are not equivalent in their covalent binding with immune complexes. Covalent complexes C4-C4b or C4b(like)-C4b(like) are generated during the C4 activation and they are detected as alpha-alpha' or alpha-alpha complexes, respectively. Interaction of C4b with the L chain of the antibody molecule also seems to occur, but to a lesser extent than with the H chain.
Gap junctional channels which couple myocytes mediate conduction phenomena in the heart. These channels are dodecamers of transmembrane proteins belonging to the connexin family (Cx). Three Cxs, ...Cx43, -40 and -45, have been found to be expressed in cardiomyocytes. Each of them has a distinct spatiotemporal pattern of expression, which is regulated during development. In the adult mouse heart, Cx43 is expressed in all the working myocytes and most of the conductive myocytes; Cx45 is weakly expressed in all conductive myocytes, including those of the nodal tissues; Cx40 expression is restricted to the atria and ventricular conduction system. Analysis of mice with deletions of Cx genes has provided evidence that Cx43, -40 and -45, and consequently the gap junctional channels they form, are involved in both heart function and development. For example, Cx40 deficiency results in sinoatrial conduction impairments, a significant decrease of the conduction velocity in the atria, and a delay of the propagation of impulse in the His bundle. Transgenic mouse lines with modified Cx40 genes are now being used to draw up a detailed map of the conduction system in the adult and developing heart, and to identify the regulatory elements involved in the transcriptional regulation of the Cx40 gene. Some preliminary results of these studies are described.
The activation and subsequent degradation of C3 covalently bound to immune complexes (IC) has been studied by using immune aggregates antiovalbumin-125I-F(ab')2-ovalbumin or 125I-C3 in the presence ...of serum. Kinetic experiments were performed in order to establish the physiological sequence of C3 degradation as a function of time. The results indicated: The interaction C3-IC, as analyzed in SDS-PAGE, results in bands of high molecular weight corresponding to C3 alpha-65-Fd and C3 alpha-41-Fd covalent complexes. In the first 7 min only C3 alpha-65-Fd complexes were detected. From 7 to 15 min a progressive increase in the C3 alpha-41-Fd complexes occurs. After this time the ratio C3 alpha-65-Fd/C3 alpha-41-Fd was kept constant for at least 45 min. Hence, C3b covalently bound to F(ab')2 IC is degraded in serum much faster than when it is bound to IgG IC. The spatial distribution of the Fab arms in the IC appears to be a critical feature in providing a protective environment for C3b. The orientation of the Fab arms was dependent on the presence of the Fc regions.
Adding a memory sink-source term to the Advection Dispersion Equation (ADE) helps in alleviating many of the discrepancies between ADE predictions and field observations. Specifically, such a term ...can explain the scale dependence of apparent dispersivity, the time dependence of cinematic porosity, asymmetry in the spatial distribution of concentrations and, specially, tailing in breakthrough curves. This memory sink-source term can be quite easily incorporated in conventional ADE simulators as the convolution of a memory function times the concentration history. The resulting approach is equivalent to the Multi Rate Mass Transfer models and can be viewed as a special case of Continuous Time Random Walk. The big question is whether the memory function should be viewed as just a toolbox full of additional fitting parameters or one can assign it a physical meaning. And, in the latter case, whether could one predict the evolution of solutes on the sole basis of flow information (e.g., statistics of hydraulic conductivity, and the like). Here, we summarize the efforts we have made in developing a positive response to those questions. We find that neither simple matrix diffusion nor transport through stationary random log conductivity fields lead to satisfactory results. These can be obtained either when diffusion into immobile zones is treated as spatially variable or when transport is simulated over fields resulting from the superposition of an evolving range of scales (i.e., Neuman's Universal Scaling approach).
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