Salicylic Acid: a likely endogenous signal in the resistance response of tobacco to viral infection

Some cultivars of tobacco are resistant to tobacco mosaic virus (TMV) and synthesize pathogenesis-related (PR) proteins upon infection. In a search for the signal or signals that induce resistance or PR genes, it was found that the endogenous salicylic acid levels in resistant, but not susceptible, cultivars increased at least 20-fold in infected leaves and 5-fold in uninfected leaves after TMV inoculation. Induction of PRl genes paralleled the rise in salicylic acid levels. Since earlier work has demonstrated that treatment with exogenous salicylic acid induces PR genes and resistance, these findings suggest that salicylic acid functions as the natural transduction signal.     

Voyager 2 radio observations of uranus

Within distances to Uranus of about 6 x 10(6) kilometers (inbound) and 35 x 10(6) kilometers (outbound), the planetary radio astronomy experiment aboard Voyager 2 detected a wide variety of radio emissions. The emission was modulated in a period of 17.24 +/- 0.01 hours, which is identified as the rotation period of Uranus' magnetic field. Of the two poles where the axis of the off-center magnetic dipole (measured by the magnetometer experiment aboard Voyager 2) meets the planetary surface, the one closer to dipole center is now located on the nightside of the planet. The radio emission generally had maximum power and bandwidth when this pole was tipped toward the spacecraft. When the spacecraft entered the nightside hemisphere, which contains the stronger surface magnetic pole, the bandwidth increased dramatically and thereafter remained large. Dynamically evolving radio events of various kinds embedded in these emissions suggest a Uranian magnetosphere rich in magnetohydrodynamic phenomena.     

Antibodies to polynucleotides: distribution in human serums

Hemagglutination procedures were used to determine the distribution of antibodies to native DNA, single-stranded DNA, and double-stranded RNA. Antibodies to all three polynucleotides were found in a high percentage of the serums of patients with systemic lupus erythematosus. Antibodies to native DNA occurred almost exclusively in serums of patients in the active stages of systemic lupus erythematosus, whereas antibodies to single-stranded DNA were observed in the serums of patients with several diseases and of some normal individuals.     

How biotechnology regulation sets a risk/ethics boundary

In public debate over agricultural biotechnology, at issue hasbeen its self-proclaimed aim of further industrializingagriculture. Using languages of risk, critics and proponentshave engaged in an implicit ethics debate on the direction oftechnoscientific development. Critics have challenged thebiotechnological R&D agenda for attributing socio-agronomicproblems to genetic deficiencies, while perpetuating the hazardsof intensive monoculture. They diagnosed ominous links betweentechnological dependency and tangible harm from biotechnologyproducts.In response to scientific and public concerns, theEuropean Community enacted precautionary legislation for theintentional release of genetically modified organisms (GMOs). Inits implementation, choices for managing and investigatingbiotechnological risk involve an implicit environmental ethics.Yet the official policy language downplays the inherent valuejudgments, by portraying risk regulation as a matter ofobjective science.In parallel with safety regulation, thestate has devised an official bioethics that judges where todraw the line in applying biotechnological knowledge, as ifthe science itself were value-free. Bioethics may also judge howto balance risks and benefits, as if their definition were notan issue. This form of ethics serves to compensate for theunacknowledged value-choices and institutional commitmentsalready embedded in R&D priorities.Thus the state separatesrisk and ethics, while assigning both realms to specialists.The risk/ethics boundary encourages public deference to theexpert assessments of both safety regulators and professionalethicists. Biotechnology embodies a contentious model of controlover nature and society, yet this issue becomes displaced andfragmented into various administrative controls. At stake arethe prospects for democratizing the problem-definitions thatguide R&D priorities.     

Enhanced c2 yields from methane oxidative coupling by means of a separative chemical reactor

Of the processes for converting natural gas into a more useful chemical feedstock, the oxidative coupling of methane to form ethane and ethylene (C(2)) has perhaps been the most intensively investigated in recent years, but it has proved extremely difficult to obtain C(2) yields in excess of 20 to 25%. Methane oxidative coupling was carried out in a separative chemical reactor that simulated a countercurrent chromatographic moving-bed. This reaction gives 65% methane conversion, 80% C(2) selectivity, and a C(2) yield slightly better than 50% with Sm(2)O(3) catalyst at approximately 1000 K.     

Planetary radio astronomy observations from voyager 1 near saturn

The Voyager 1 planetary radio astronomy experiment detected two distinct kinds of radio emissions from Saturn. The first, Saturn kilometric radiation, is strongly polarized, bursty, tightly correlated with Saturn's rotation, and exhibits complex dynamic spectral features somewhat reminiscent of those in Jupiter's radio emission. It appears in radio frequencies below about 1.2 megahertz. The second kind of radio emission, Saturn electrostatic discharge, is unpolarized, extremely impulsive, loosely correlated with Saturn's rotation, and very broadband, appearing throughout the observing range of the experiment (20.4 kilohertz to 40.2 megahertz). Its sources appear to lie in the planetary rings.     

Nitrogen uptake in riparian plant communities across a sharp ecological boundary of salmon density

Background

Recent studies of anadromous salmon (Oncorhynchus spp.) on the Pacific Coast of North America indicate an important and previously unrecognized role of salmonid nutrients to terrestrial biota. However, the extent of this uptake by primary producers and consumers and the influences on community structure remain poorly described. We examine here the contribution of salmon nutrients to multiple taxa of riparian vegetation (Blechnum spicant, Menziesii ferruginea, Oplopanax horridus, Rubus spectabilis, Vaccinium alaskaense, V. parvifolium, Tsuga heterophylla) and measure foliar δ¹⁵N, total %N and plant community structure at two geographically separated watersheds in coastal British Columbia. To reduce potentially confounding effects of precipitation, substrate and other abiotic variables, we made comparisons across a sharp ecological boundary of salmon density that resulted from a waterfall barrier to salmon migration.

Results

δ¹⁵N and %N in foliage, and %cover of soil nitrogen indicators differed across the waterfall barrier to salmon at each watershed. δ¹⁵N values were enriched by 1.4‰ to 9.0‰ below the falls depending on species and watershed, providing a relative contribution of marine-derived nitrogen (MDN) to vegetation of 10% to 60%. %N in foliar tissues was slightly higher below the falls, with the majority of variance occurring between vegetation species. Community structure also differed with higher incidence of nitrogen-rich soil indicator species below the waterfalls.

Conclusions

Measures of δ¹⁵N, %N and vegetation cover indicate a consistent difference in the riparian community across a sharp ecological boundary of salmon density. The additional N source that salmon provide to nitrogen-limited habitats appears to have significant impacts on the N budget of riparian vegetation, which may increase primary productivity, and result in community shifts between sites with and without salmon access. This, in turn, may have cascading ecosystem effects in forests adjacent to salmon streams.

     

The Connectivity Map: using gene-expression signatures to connect small molecules, genes, and disease

To pursue a systematic approach to the discovery of functional connections among diseases, genetic perturbation, and drug action, we have created the first installment of a reference collection of gene-expression profiles from cultured human cells treated with bioactive small molecules, together with pattern-matching software to mine these data. We demonstrate that this "Connectivity Map" resource can be used to find connections among small molecules sharing a mechanism of action, chemicals and physiological processes, and diseases and drugs. These results indicate the feasibility of the approach and suggest the value of a large-scale community Connectivity Map project.