Replication of immune RNA by human lymphoblastoid cells]

Animal immune RNA used for the induction of the human lymphoblastoid cell line LDV/7, induces the appearance of receptor sites on the surface of these cells and the synthesis of specific immunoglobulins which are liberated into the culture medium. Furthermore, RNA has been extracted from these cells, which possesses the same properties of specific cytotoxicity as the RNA used for induction. It is supposed that the immune RNA derepresses specific genes on the genome of the induced cells.     

A novel explosive process is required for the gamma-ray burst GRB 060614

Over the past decade, our physical understanding of gamma-ray bursts (GRBs) has progressed rapidly, thanks to the discovery and observation of their long-lived afterglow emission. Long-duration (> 2 s) GRBs are associated with the explosive deaths of massive stars ('collapsars', ref. 1), which produce accompanying supernovae; the short-duration (< or = 2 s) GRBs have a different origin, which has been argued to be the merger of two compact objects. Here we report optical observations of GRB 060614 (duration approximately 100 s, ref. 10) that rule out the presence of an associated supernova. This would seem to require a new explosive process: either a massive collapsar that powers a GRB without any associated supernova, or a new type of 'engine', as long-lived as the collapsar but without a massive star. We also show that the properties of the host galaxy (redshift z = 0.125) distinguish it from other long-duration GRB hosts and suggest that an entirely new type of GRB progenitor may be required.     

A measurement of the cosmological mass density from clustering in the 2dF Galaxy Redshift Survey

The large-scale structure in the distribution of galaxies is thought to arise from the gravitational instability of small fluctuations in the initial density field of the Universe. A key test of this hypothesis is that forming superclusters of galaxies should generate a systematic infall of other galaxies. This would be evident in the pattern of recessional velocities, causing an anisotropy in the inferred spatial clustering of galaxies. Here we report a precise measurement of this clustering, using the redshifts of more than 141,000 galaxies from the two-degree-field (2dF) galaxy redshift survey. We determine the parameter beta = Omega0.6/b = 0.43 +/- 0.07, where Omega is the total mass-density parameter of the Universe and b is a measure of the 'bias' of the luminous galaxies in the survey. (Bias is the difference between the clustering of visible galaxies and of the total mass, most of which is dark.) Combined with the anisotropy of the cosmic microwave background, our results favour a low-density Universe with Omega approximately 0.3.     

A larger pool of ozone-forming carbon compounds in urban atmospheres

Volatile organic compounds play a central role in the processes that generate both urban photochemical smog and tropospheric ozone. For successful and accurate prediction of these pollution episodes, identification of the dominant reactive species within the volatile organic carbon pool is needed. At present, lack of resolution inherent in single-column chromatographic analysis limits such a detailed chemical characterization of the complex urban atmosphere. Here we present an improved method of peak deconvolution from double-column (orthogonal) gas chromatography. This has enabled us to isolate and classify more than 500 chemical species of volatile organic compounds in urban air, including over 100 multi-substituted monoaromatic and volatile oxygenated hydrocarbons. We suggest that previous assessments of reactive carbon species may therefore have underestimated the contribution made by volatile organic compounds to urban pollution, particularly for compounds with more than six carbon atoms. Incorporating these species in predictive models should greatly improve our understanding of photochemical ozone yields and the formation of harmful secondary organic aerosols.