Report of the Terrestrial Bodies Science Working Group. Volume 2: Mercury

The objectives and rationale for scientific investigation of Mercury are explored. Knowledge already obtained by astronomical observations and Mariner 10 spacecraft is reviewed and measurements required for the principal scientific goals are described. The use of low thrust propulsion systems is recommended so that maximum scientific return may be achieved and the reconnaissance phase of Mercury exploration may be completed in a single mission. Accelerated development is recommended on solar electric propulsion, solar sails, passive and active cooling mechanisms, and single rough landers

Mars Observer mission

The Mars Observer mission will extend the exploration and characterization of Mars by providing new and systematic measurements of the atmosphere, surface, and interior of the planet. These measurements will be made from a low-altitude polar orbiter over a period of 1 Martian year, permitting repetitive observations of the surface and of the seasonal variations of the atmosphere. The mission will be conducted in a manner that will provide new and valuable scientific data using a distributed data system that minimizes operational complexity and cost

Living on the Precipice: A Conversation with Edward Albee

An edited version of the Writers Forum interview dated February 5, 1981. Speaking with Edward Albee were Stan Sanvel Rubin, the current director of·the Forum; Adam Lazarre, the former Dean of Fine Arts; and Mark Anderson, who teaches Renaissance and contemporary drama

Titanium and Aluminum in Biotite From High-Grade Archaean Gneisses, Langø, West Greenland

Biotite grains from a variety of gneiss types were analyzed by electron microprobe techniques for Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe, Zn, F & Cl. TiO_2- and Al_2O_3-contents range continuously from < 0.1 to 6.0 and 13.9 to 20.6 wt % respectively. Most occur with ilmenite, but a few coexist with rutile. Biotite in pyribolite contains the least Al, and that in Kfeld-sill gneiss contains the most, suggesting that Al-content of biotite is related to the bulk composition of the host rock. For a given rock type, Ti in biotite tends to decrease as Mg/Fe and Al increase

Intensity of Grazing Effect on Livestock and Forage Production

An intensity of grazing experiment was initiated in 1942 at the Cottonwood Range Field Station to study the effects of heavy, moderate, and light grazing on the vegetation and on cow and calf production. Results of the first 9 years of this study were reported in South Dakota Agricultural Experiment Station Bulletin 412 in 1951. These studies have been continued and intensified. The present publication is a progress report on the effects of the intensity of grazing on cow and calf production since 1953 and on the cumulative effects of different grazing intensities on the native vegetation

Advances in the development of encapsulants for mercuric iodide X-ray detectors

Advances in the development of protective impermeable encapsulants with high transparency to ultra-low-energy X-rays for use on HgI_2 X-ray detectors are reported. Various X-ray fluorescence spectra from coated detectors are presented. The X-ray absorption in the encapsulants has been analyzed using characteristic radiation from various elements. Results suggest that low-energy cutoffs for the detectors are not determined solely by the encapsulating coatings presently employed but are also influenced by the front electrode and surface effects, which can affect the local electric field or the surface recombination velocity. An energy resolution of 182 eV (FWHM) has been achieved for Ni L lines at 850 eV. Improved detector sensitivity to X-ray energies under 700 eV is demonstrated

Processing–structure–property relations of chemically bonded phosphate ceramic composites

ABSTRACT: Mechanical properties and microstructures of a chemically bonded phosphate ceramic (CBPC) and its composite with 1⋅0 wt% graphite nanoplatelets (GNPs) reinforcement have been investigated. Microstructure was identified by using optical and scanning electron microscopes, X-ray tomography, and X-ray diffraction. In addition, weight loss of the resin at room temperature was studied. The microstructure characterization shows that CBPC is itself a composite with several crystalline (wollastonite and brushite) and amorphous phases. SEM and micro tomography show a homogeneous distribution of crystalline phases. Bending and compression strength of the CBPC was improved by reducing bubbles via preparation in vacuum

Lithium Decreases Glial Fibrillary Acidic Protein in a Mouse Model of Alexander Disease.

Alexander disease is a fatal neurodegenerative disease caused by mutations in the astrocyte intermediate filament glial fibrillary acidic protein (GFAP). The disease is characterized by elevated levels of GFAP and the formation of protein aggregates, known as Rosenthal fibers, within astrocytes. Lithium has previously been shown to decrease protein aggregates by increasing the autophagy pathway for protein degradation. In addition, lithium has also been reported to decrease activation of the transcription factor STAT3, which is a regulator of GFAP transcription and astrogliogenesis. Here we tested whether lithium treatment would decrease levels of GFAP in a mouse model of Alexander disease. Mice with the Gfap-R236H point mutation were fed lithium food pellets for 4 to 8 weeks. Four weeks of treatment with LiCl at 0.5% in food pellets decreased GFAP protein and transcripts in several brain regions, although with mild side effects and some mortality. Extending the duration of treatment to 8 weeks resulted in higher mortality, and again with a decrease in GFAP in the surviving animals. Indicators of autophagy, such as LC3, were not increased, suggesting that lithium may decrease levels of GFAP through other pathways. Lithium reduced the levels of phosphorylated STAT3, suggesting this as one pathway mediating the effects on GFAP. In conclusion, lithium has the potential to decrease GFAP levels in Alexander disease, but with a narrow therapeutic window separating efficacy and toxicity