Thermal Structure of Jupiter's Upper Atmosphere Derived from the Galileo Probe

Temperatures in Jupiter's atmosphere derived from Galileo Probe deceleration data increase from 109 kelvin at the 175-millibar level to 900 ± 40 kelvin at 1 nanobar, consistent with Voyager remote sensing data. Wavelike oscillations are present at all levels. Vertical wavelengths are 10 to 25 kilometers in the deep isothermal layer, which extends from 12 to 0.003 millibars. Above the 0.003-millibar level, only 90- to 270- kilometer vertical wavelengths survive, suggesting dissipation of wave energy as the probable source of upper atmosphere heating.     

Monitoring the impact of acid deposition on the soil microbiota,using glucose and vanillin decomposition

Samples of organic (F/H) and mineral soil (to approximately 8 cm depth) were collected from three ‘ecologically analogous’ sites in a boreal forest at intervals of 2.8 km (site 1), 6.0 km (site 2) and 9.6 km (site 3) from a ‘sour gas’ plant emitting S0₂. The organic soil of site 1 was characterized by a lower basal respiration rate, smaller microbial biomass, and a longer time to attain the peak rate of CO₂ efflux following enrichment with glucose or vanillin (0.15 and 0.1 g (15 g soil)^?1, respectively). No significant differences were detected between the mineral soils of the 3 sites in terms of the rate or extent of glucose decomposition (0.1 g (100 g soil)^?1), but there was a significant retardation in vanillin decomposition in the mineral soil of site 1 (0.05 g (100 g soil)^?1). Concentrations of 0.075 and 0.1 g vanillin (100 g soil)^?1 were decomposed in the mineral soil of sites 2 and 3, but not at site 1. Following incubation with vanillin, fewer bacteria were isolated from both the organic and mineral soils of site 1, and a greater proportion of these were spore formers and bisulfite-tolerant isolates compared with those from sites 2 and 3.     

High-Energy Charged Particles in the Innermost Jovian Magnetosphere

The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of Io to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at approximately2.2RJ (where RJ is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (approximately62 megaelectron volts per nucleon) that peaked at approximately1.5RJ inside the bright dust ring. The abundances of all particle species decreased sharply at approximately1.35RJ; this decrease defines the innermost edge of the equatorial jovian radiation.     

Aurintricarboxylic acid and initiation factors of wheat embryo

In extracts of wheat embryo, aurintricarboxylic acid inhibits attachment of ribosomes to messenger RNA and has little effect on aminoacyl transfer to peptide. This specificity of inhibition allows (i) the demonstration that the initial phase of amino acid incorporation dependent on RNA of tobacco mosaic virus involves an "initiation" reaction between ribosome and messenger RNA which requires two soluble factors, (ii) an assay facilitating purification of the initiation factors, and (iii) the demonstration that these factors are distinct from aminoacyl transfer enzymes.     

Structural analysis of the mechanism of adenovirus binding to its human cellular receptor, CAR

Binding of virus particles to specific host cell surface receptors is known to be an obligatory step in infection even though the molecular basis for these interactions is not well characterized. The crystal structure of the adenovirus fiber knob domain in complex with domain I of its human cellular receptor, coxsackie and adenovirus receptor (CAR), is presented here. Surface-exposed loops on knob contact one face of CAR, forming a high-affinity complex. Topology mismatches between interacting surfaces create interfacial solvent-filled cavities and channels that may be targets for antiviral drug therapy. The structure identifies key determinants of binding specificity, which may suggest ways to modify the tropism of adenovirus-based gene therapy vectors.