Use of famciclovir for the treatment of endotheliotrophic herpesvirus infections in Asian elephants (Elephas maximus).

Two juvenile Asian elephants (Elephas maximus) presented with an acute onset of facial edema and lethargy. Examination of the oral cavity of each animal revealed cyanosis of the tip and distal margins of the tongue suggestive of endothelial inclusion body disease (EIBD) of elephants. Whole-blood samples were obtained, and polymerase chain reaction tests confirmed the presence of elephant herpesvirus. The animals were administered famciclovir (Famvir, SmithKline Beecham Pharmaceuticals, Philadelphia, Pennsylvania 19101, USA), a potent human anti-herpesvirus drug, in the course of their disease, and recovery followed a treatment regime of 3-4 wk. These are the first known cases of elephants surviving EIBD.     

Improved Methods for High-Throughput Extraction and Assay of Green Barley Malt Proteinase Activity Facilitating Examination of Proteinase Activity Across Large-Scale Barley Populations

We report efficient sample extraction and assay methods allowing quantitative determinations of proteinase activities from barley malt. The improved methods are used to assay >2,200 developmental lines of malting barley for two subsets of proteinase activity. The distributions of the resulting activities suggest differences in population structures between the two types of proteinases. Comparison of the activities of the green malt proteinases with standard malting quality measurements show highly significant correlations that differ between the proteinase subsets. The pH 4.5 hydrolysis of the artificial substrate Z-Phe-Arg-AMC correlates well with the traditional malting quality measurements, supporting the role of cysteine-class proteinases in mobilization of grain reserves during malting and mashing. Results from assays of gelatin hydrolysis at pH 6.0 suggest that these proteolytic activities may be involved in other aspects of seed C and N dynamics also linked to malting quality measurements. The differences between the pH 4.5 and 6.0 activities assayed here and their association with malting quality measurements suggest different physiological roles for the two proteinase activities in several aspects of seed germination. Either assay could be useful for population surveys, depending on the particular facet of seed metabolism under study.     

Microscopic Particle Motions in Strongly Coupled Dusty Plasmas

The microscopic particle motions from the crystal to the disordered state of a dusty plasma with micrometer-sized silicon dioxide particle suspensions in a radio-frequency glow discharge system were studied through an optical microimaging system. Small-amplitude random motion around the lattice sites of the crystal state, relative domain motion with varying boundaries, cooperative hopping in the liquid state, and highly disordered motion with increasing radio-frequency power were observed. Chaotic states with different spatial scales under the coherent and stochastic coupling between dust particles and self-organized background plasma fluctuations were also demonstrated.     

Equatorial X-ray Emissions: Implications for Jupiter's High Exospheric Temperatures

Observations with the High Resolution Imager on the Rontgensatellit reveal x-ray emissions from Jupiter's equatorial latitudes. The observed emissions probably result from the precipitation of energetic (>300 kiloelectron volts per atomic mass unit) sulfur and oxygen ions out of Jupiter's inner radiation belt. Model calculations of the energy deposition by such heavy ion precipitation and of the resulting atmospheric heating rates indicate that this energy source can contribute to the high exospheric temperatures(>800 kelvin at 0.01 microbar) measured by the Galileo probe's Atmospheric Structure Instrument. Low-latitude energetic particle precipitation must therefore be considered, in addition to other proposed mechanisms such as gravity waves and soft electron precipitation, as an important source of heat for Jupiter's thermosphere.     

Neutron activation for distinguishing cascade range pyroclastics

Neutron activation of glassy separates of volcanic ash resulted in 21 nuclides measurable with instrumental techniques. The relative activities of most of the nuclides distinguish samples from Mount Mazama, Newberry Crater, and Glacier Peak. The usefulness of the technique was assessed by comparing the values for known sources with those from fine ash of uncertain origin. The data strongly suggest Mount Mazama as the source.     

Mouse models of tumor development in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a prevalent familial cancer syndrome resulting from germ line mutations in the NF1 tumor suppressor gene. Hallmark features of the disease are the development of benign peripheral nerve sheath tumors (neurofibromas), which can progress to malignancy. Unlike humans, mice that are heterozygous for a mutation in Nf1 do not develop neurofibromas. However, as described here, chimeric mice composed in part of Nf1-/- cells do, which demonstrates that loss of the wild-type Nf1 allele is rate-limiting in tumor formation. In addition, mice that carry linked germ line mutations in Nf1 and p53 develop malignant peripheral nerve sheath tumors (MPNSTs), which supports a cooperative and causal role for p53 mutations in MPNST development. These two mouse models provide the means to address fundamental aspects of disease development and to test therapeutic strategies.     

Origin of the West Nile virus responsible for an outbreak of encephalitis in the northeastern United States

In late summer 1999, an outbreak of human encephalitis occurred in the northeastern United States that was concurrent with extensive mortality in crows (Corvus species) as well as the deaths of several exotic birds at a zoological park in the same area. Complete genome sequencing of a flavivirus isolated from the brain of a dead Chilean flamingo (Phoenicopterus chilensis), together with partial sequence analysis of envelope glycoprotein (E-glycoprotein) genes amplified from several other species including mosquitoes and two fatal human cases, revealed that West Nile (WN) virus circulated in natural transmission cycles and was responsible for the human disease. Antigenic mapping with E-glycoprotein-specific monoclonal antibodies and E-glycoprotein phylogenetic analysis confirmed these viruses as WN. This North American WN virus was most closely related to a WN virus isolated from a dead goose in Israel in 1998.     

The respiratory sinus arrhythmia: a measure of cardiac age

A method developed for quantifying respiratory sinus arrhythmia (RSA) during voluntary cardiorespiratory synchronization relies on computer-assisted rhythmometric cosinor analysis of instantaneous heart rate data. The RSA was present in all subjects tested, even those at advanced ages. The amplitude of the RSA falls approximately 10 percent per decade. An individual with a transplanted heart and one with severe diabetic neuropathy each had resting RSA values that were normal for their ages. The shape and amplitude of the RSA during voluntary cardiorespiratory synchronization may reflect the suppleness of the heart and its response to rhythmically changing intrathoracic pressure and the subsequent ebb-and-flow of venous return. Our technology allows objective quantitative assessment of the biologic age of the heart and also the effect of any drug, disease, or behavior that affects the RSA.     

Enhanced diapycnal mixing by salt fingers in the thermocline of the tropical Atlantic

Diapycnal mixing plays a significant role in the ocean's circulation and uptake of heat and carbon dioxide, but has not been quantified in salt finger-driven thermohaline staircases. We recently performed a tracer release experiment in the western tropical Atlantic staircase at approximately 400 m depth. The observed dispersion implies an effective diapycnal diffusivity for tracer and salt of 0.8 to 0.9 x 10(-4) m2/s. Temperature microstructure data interpreted in terms of a vertical production-dissipation balance yields a smaller effective diffusivity for heat of 0.45 (+/- 0.2) x 10(-4) m2/s, consistent with salt fingers and well above the mixing ascribable to mechanical turbulence.     

Evidence from numerical experiments for a feedback dynamo generating Mercury's magnetic field

The observed weakness of Mercury's magnetic field poses a long-standing puzzle to dynamo theory. Using numerical dynamo simulations, we show that it could be explained by a negative feedback between the magnetospheric and the internal magnetic fields. Without feedback, a small internal field was amplified by the dynamo process up to Earth-like values. With feedback, the field strength saturated at a much lower level, compatible with the observations at Mercury. The classical saturation mechanism via the Lorentz force was replaced by the external field impact. The resulting surface field was dominated by uneven harmonic components. This will allow the feedback model to be distinguished from other models once a more accurate field model is constructed from MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) and BepiColombo data.