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Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994–95 are presented. The broad-band fluxes (B, V , R, and I), the spectrophotometric optical continuum flux F λ (5177Å), and the integrated emission-line fluxes of Hα, Hβ, Hγ, He i λ5876, and He ii λ4686 all show a nearly monotonic increase with episodes of milder short-term variations(More)
Hydrogenation processes leading from biomolecules to fossil biomarkers in anoxic sediments are crucial for the preservation of organic matter. However, these processes are still poorly understood. The present identification of several reduced carotenoids in recent sediments attests that these processes operate at the earliest stages of diagenesis without(More)
Glycerol tetraethers with head-to-head isoprenoid 40-carbon chains that are typical of archaebacteria, in particular of methanogens, were identified in the polar lipids of sediments and petroleums. These structures are at least partially preserved in the subsurface beyond the stage of petroleum formation. Their identification provides further evidence that(More)
Measles virus isolated from the brain of a 12-year-old boy with subacute sclerosing panencephalitis caused a chronic, progressive encephalitis in experimentally infected rhesus monkeys. The infection was eventually fatal in spite of pre-existing measles immunity and a vigorous secondary antibody response in serum and cerebrospinal fluid of the infected(More)
The organic matter found in sedimentary rocks must derive from many sources; not only from ancient primary producers but also from consumers and secondary producers. In all of these organisms, isotope effects can affect the abundance and distribution of 13C in metabolites. Here, by using an improved form of a previously described technique in which the(More)
The sediments that now comprise the Messel shale accumulated 47 +/- 2 million years ago in anaerobic waters at the bottom of a lake. Subsequent depths of burial have not exceeded 300 m, nor has the temperature of the shale exceeded 40 degrees C. Contents of organic carbon reach 25%, and preservation of molecular structures has been excellent. Sixteen(More)
1.5/1.3 /spl mu/m transceiver-photonic integrated circuits (PICs) with in-line and Y-junction architecture including a 1.3-/spl mu/m wavelength-selective photodetector building block have been fabricated. The characterization of a first Y-junction module in a test bed is presented.
Plastic tearing occurs in compact tension (C(T)) specimens fabricated from ductile steels. This tearing, however, is not an elastic fracture problem governed by a crack tip singularity parameter. The current application of the J-integral and the J-R curve to plastic fracture mechanics is misleading. This dissertation reviews the existing energy rate and(More)
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