A large hydrothermal reservoir beneath Taal Volcano (Philippines) revealed by magnetotelluric observations and its implications to the volcanic activity.

Taal Volcano is one of the most active volcanoes in the Philippines. The magnetotelluric 3D forward analyses indicate the existence of a large high resistivity anomaly (∼100 Ω·m) with a volume of at least 3 km×3 km×3 km, which is capped by a conductive layer (∼10 Ω·m), beneath the Main Crater. This high resistivity anomaly is hypothesized to be a large hydrothermal reservoir, consisting of the aggregate of interconnected cracks in rigid and dense host rocks, which are filled with hydrothermal fluids coming from a magma batch below the reservoir. The hydrothermal fluids are considered partly in gas phase and liquid phase. The presence of such a large hydrothermal reservoir and the stagnant magma below may have influences on the volcano's activity. Two possibilities are presented. First, the 30 January 1911 explosion event was a magmatic hydrothermal eruption rather than a base-surge associated with a phreato-magmatic eruption. Second, the earlier proposed four eruption series may be better interpreted by two cycles, each consisting of series of summit and flank eruptions.

Friction on the microscale.

A new method is presented for measurements of friction of microsized particles on surfaces. Specifically in this work, the particles are alumina with diameters between approximately 1 and 50 microm and the surfaces are InP, Si, and Cr. Friction is analyzed, its components are determined, and the friction coefficients are estimated from the experimental results. The technique and the specific instrument allow measurements of coefficients of friction for spherical particles with radii as small as 1 microm. For smaller sizes, the instrument needs to be modified by using a more powerful power supply, actuator with extended frequency and amplitude ranges, cooling of the actuator and the power supply, and the related mechanical modifications of the sample holder.

Isolation of Waddlia malaysiensis, a novel intracellular bacterium, from fruit bat (Eonycteris spelaea).

An obligate intracellular bacterium was isolated from urine samples from 7 (3.5%) of 202 fruit bats (Eonycteris spelaea) in peninsular Malaysia. The bacterium produced large membrane-bound inclusions in human, simian, and rodent cell lines, including epithelial, fibroblastlike, and lymphoid cells. Thin-section electron microscopy showed reticulate bodies dividing by binary fission and elementary bodies in the inclusions; mitochondria surrounded the inclusions. The inclusions were positive for periodic acid-Schiff stain but could not be stained by fluorescein-labeled anti-Chlamydia trachomatis major outer membrane protein monoclonal antibody. The bacterium was resistant to penicillin and streptomycin (MICs > 256 mg/L) but susceptible to tetracycline (MIC = 0.25 mg/L) and chloramphenicol (MIC = 0.5 mg/L). Sequence analysis of the 16SrRNA gene indicated that it was most closely related to 2 isolates of Waddlia chondrophila (94% and 96% identity). The 16S and 23S rRNA gene signatures were only 91% identical. We propose this novel bacterium be called W. malaysiensis.

The Fate of l-Phenylalanine Fed to Germinating Pea Seeds, Pisum sativum (L.) var. Alaska, during Imbibition.

Radioactive l-phenylalanine-l-(14)C or -U-(14)C was fed to pea seeds during imbibition. More than 95% was imbibed. Less than 1% of the radioactivity was respired as CO(2). Of the radioactivity taken into the embryos, 80% was still in the cotyledons by 3 days. About half of this was unchanged phenylalanine: 5% free, 10 to 20% in soluble proteins, 1 to 6% in cell wall proteins, and 14% released by mild acid hydrolysis. No other radioactive amino acid was found. About 0.3% of the radioactivity was identified as free caffeic, ferulic, and coumaric acids or their glycosides, and a further 5% was released by mild acid hydrolysis into a phenolic acid fraction. About half of the radioactivity in the cotyledons was lost in the fractionation procedures.About 20% of the radioactivity was found in the shootroot axes to which it had been translocated. Phenylalanine accounted for nearly all the identifiable radioactivity: about 1% free, 1 to 3% in soluble proteins, 1 to 5% in cell wall proteins, and 1% bound to insoluble fractions from which it was released by mild acid hydrolysis. About 1% was released into a phenolic acid fraction. About half of the radioactivity in the shoot-root axes was lost in the fractionation procedures.