The global circulation of seasonal influenza A (H3N2) viruses

Antigenic and genetic analysis of the hemagglutinin of approximately 13,000 human influenza A (H3N2) viruses from six continents during 2002-2007 revealed that there was continuous circulation in east and Southeast Asia (E-SE Asia) via a region-wide network of temporally overlapping epidemics and that epidemics in the temperate regions were seeded from this network each year. Seed strains generally first reached Oceania, North America, and Europe, and later South America. This evidence suggests that once A (H3N2) viruses leave E-SE Asia, they are unlikely to contribute to long-term viral evolution. If the trends observed during this period are an accurate representation of overall patterns of spread, then the antigenic characteristics of A (H3N2) viruses outside E-SE Asia may be forecast each year based on surveillance within E-SE Asia, with consequent improvements to vaccine strain selection.     

Electronic origin of the inhomogeneous pairing interaction in the high-Tc superconductor Bi2Sr2CaCu2O8+delta

Identifying the mechanism of superconductivity in the high-temperature cuprate superconductors is one of the major outstanding problems in physics. We report local measurements of the onset of superconducting pairing in the high-transition temperature (Tc) superconductor Bi2Sr2CaCu2O8+delta using a lattice-tracking spectroscopy technique with a scanning tunneling microscope. We can determine the temperature dependence of the pairing energy gaps, the electronic excitations in the absence of pairing, and the effect of the local coupling of electrons to bosonic excitations. Our measurements reveal that the strength of pairing is determined by the unusual electronic excitations of the normal state, suggesting that strong electron-electron interactions rather than low-energy (<0.1 volts) electron-boson interactions are responsible for superconductivity in the cuprates.     

Chloride methylation by plant pectin: an efficient environmentally significant process

Atmospheric chloromethane (CH3Cl) plays an important role in stratospheric ozone destruction, but many uncertainties exist regarding the strengths of its sources and sinks and particularly regarding the processes generating this naturally occurring gas. Evidence is presented here that CH3Cl is produced in many terrestrial environments by a common mechanism. Abiotic conversion of chloride to CH3Cl occurs readily in plant material, with the widespread plant component pectin acting as a methyl donor. Significant CH3Cl emissions from senescent and dead leaves were observed at ambient temperatures; those emissions rose dramatically when temperatures increased. This ubiquitous process acting in terrestrial ecosystems and during biomass burning could contribute the bulk of atmospheric CH3Cl.     

Agricultural genetics goes to court

A coalition of environmental groups headed by activist Jeremy Rifkin has filed lawsuits to halt experiments that would release genetically engineered organisms into the environment. One suit, filed against the National Institutes of Health on 14 September 1983, would block tests by researchers at the University of California, Berkeley. A second suit, filed 16 September 1983 against Cetus Madison and BioTechnica, seeks to halt field tests that had been approved by NIH's Recombinant DNA Advisory Committee. At issue are NIH's role in evaluating the risks of genetic experimentation, and the public's right of access to proprietary information.     

Forced unfolding of proteins within cells

To identify cytoskeletal proteins that change conformation or assembly within stressed cells, in situ labeling of sterically shielded cysteines with fluorophores was analyzed by fluorescence imaging, quantitative mass spectrometry, and sequential two-dye labeling. Within red blood cells, shotgun labeling showed that shielded cysteines in the two isoforms of the cytoskeletal protein spectrin were increasingly labeled as a function of shear stress and time, indicative of forced unfolding of specific domains. Within mesenchymal stem cells-as a prototypical adherent cell-nonmuscle myosin IIA and vimentin are just two of the cytoskeletal proteins identified that show differential labeling in tensed versus drug-relaxed cells. Cysteine labeling of proteins within live cells can thus be used to fluorescently map out sites of molecular-scale deformation, and the results also suggest means to colocalize signaling events such as phosphorylation with forced unfolding.     

Genetically engineered plants get a green light

The National Institutes of Health's Recombinant DNA Advisory Committee has given conditional approval to a proposal by the Cetus Madison Corporation to field test plants that have been genetically manipulated to resist some diseases. The committee made no recommendation, however, on another field test proposed by BioTechnica International Inc. Both proposals had been challenged by a coalition of environmental groups led by Jeremy Rifkin, who has now filed a freedom of information request to NIH asking for documents pertaining to their health and safety aspects.     

Ethics panel faces the ax

The President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research, scheduled to go out of business on 31 December 1982, requested a three-month extension of its life to complete several reports. This brief news item reports that the requested extension was added as an amendment to a budget bill by the Senate but then stripped from the bill by a House-Senate conference committee.