Observational data needs useful for modeling the coma

A computer model of comet comae is described; results from assumed composition of frozen gases are summarized and compared to coma observations. Restrictions on relative abundance of some frozen constituents are illustrated. Modeling, when tightly coupled to observational data, can be important for comprehensive analysis of observations, for predicting undetected molecular species and for improved understanding of coma and nucleus. To accomplish this, total gas production rates and relative elemental abundances of H:C:N:O:S are needed as a function of heliocentric distance of the comet. Also needed are relative column densitites and column density profiles with well defined diaphragm range and pointing position on the coma. Production rates are less desirable since they are model dependent. Total number (or upper limits) of molecules in the coma and analysis of unidentified spectral lines are needed also

EURECA mission control experience and messages for the future

EURECA is a retrievable space platform which can perform multi-disciplinary scientific and technological experiments in a Low Earth Orbit for a typical mission duration of six to twelve months. It is deployed and retrieved by the NASA Space Shuttle and is designed to support up to five flights. The first mission started at the end of July 1992 and was successfully completed with the retrieval in June 1993. The operations concept and the ground segment for the first EURECA mission are briefly introduced. The experiences in the preparation and the conduction of the mission from the flight control team point of view are described

Transcriptional profiling of Arabidopsis heat shock proteins and transcription factors reveals extensive overlap between heat and non-heat stress response pathways

<p>Abstract</p> <p>Background</p> <p>The heat shock response of <it>Arabidopsis thaliana </it>is dependent upon a complex regulatory network involving twenty-one known transcription factors and four heat shock protein families. It is known that heat shock proteins (Hsps) and transcription factors (Hsfs) are involved in cellular response to various forms of stress besides heat. However, the role of Hsps and Hsfs under cold and non-thermal stress conditions is not well understood, and it is unclear which types of stress interact least and most strongly with Hsp and Hsf response pathways. To address this issue, we have analyzed transcriptional response profiles of <it>Arabidopsis </it>Hsfs and Hsps to a range of abiotic and biotic stress treatments (heat, cold, osmotic stress, salt, drought, genotoxic stress, ultraviolet light, oxidative stress, wounding, and pathogen infection) in both above and below-ground plant tissues.</p> <p>Results</p> <p>All stress treatments interact with Hsf and Hsp response pathways to varying extents, suggesting considerable cross-talk between heat and non-heat stress regulatory networks. In general, Hsf and Hsp expression was strongly induced by heat, cold, salt, and osmotic stress, while other types of stress exhibited family or tissue-specific response patterns. With respect to the Hsp20 protein family, for instance, large expression responses occurred under all types of stress, with striking similarity among expression response profiles. Several genes belonging to the Hsp20, Hsp70 and Hsp100 families were specifically upregulated twelve hours after wounding in root tissue, and exhibited a parallel expression response pattern during recovery from heat stress. Among all Hsf and Hsp families, large expression responses occurred under ultraviolet-B light stress in aerial tissue (shoots) but not subterranean tissue (roots).</p> <p>Conclusion</p> <p>Our findings show that Hsf and Hsp family member genes represent an interaction point between multiple stress response pathways, and therefore warrant functional analysis under conditions apart from heat shock treatment. In addition, our analysis revealed several family and tissue-specific heat shock gene expression patterns that have not been previously described. These results have implications regarding the molecular basis of cross-tolerance in plant species, and raise new questions to be pursued in future experimental studies of the <it>Arabidopsis </it>heat shock response network.</p

The pressure medium as a solid-state oxygen buffer

We present a simple method to buffer oxygen fugacity at high pressures and high temperatures where the traditional 'double capsule' method is inappropriate. The pressure medium is doped with a metal which partially reacts with the free oxygen in the pore spaces of the, cell. The resultant finely intergrown metal-metal oxide assemblage buffers the oxygen fugacity in the sample as long as the capsule and furnace materials are oxygen permeable

Correlation of Wettability and Interfacial Reaction to the Densification and Dielectric Properties of Fluxed-BaTiO₃

Reducing the sintering temperature of BaTiO3 has typically been achieved through the use of a fluxing agent to promote densification by liquid phase sintering. Liquid phase formation in these systems is due either to the melting of the flux or to the formation of a eutectic liquid between the flux and BaTiO3. In this paper, the correlation between the wettability and interfacial reactions between fluxes and BaTiO3 with respect to the densification behavior associated with liquid phase sintering, and the resulting dielectric properties is presented. Fluxes used in this study include 5ZnO*2B2O3, 5CdO*2SiO2, Pb5Ge3O11, CuO*TiO2, 3Bi2O3*B2O3, and LiF

Pegaptanib sodium treatment in neovascular age-related macular degeneration: clinical experience in Germany

Nikolaus Feucht, Huebner Matthias, Chris P Lohmann, Mathias MaierAugenklinik rechts der Isar, Technical University Munich, GermanyBackground: The VEGF Inhibition Study In Ocular Neovascularisation (VISION) reported the efficacy of intravitreal (ITV) vascular endothelial growth factor (VEGF) inhibition with pegaptanib sodium (Macugen&amp;reg;) for the treatment of neovascular age-related macular degeneration (AMD). This paper reports clinical experience with pegaptanib sodium for the treatment of occult or minimally classic choroidal neovascularization (CNV) due to AMD.Material and methods: The study included 50 eyes (in 49 patients) with either occult CNV or minimally classic CNV secondary to neovascular AMD who were not eligible for photodynamic therapy (PDT). Study data were analyzed retrospectively. During the 6-month study, patients were administered an average 2.74 injections of 0.3 mg ITV pegaptanib sodium. Angiography and optical coherence tomography (OCT) examinations were carried out and intraocular pressure (IOP) and visual acuity (VA) were measured at baseline, at 3 months and at 6 months. An eye examination was performed and VA was measured the 2 days following treatment and then again at weeks 4&amp;ndash;6, and at 3 and 6 months. OCT, VA, and IOP were also assessed at 1 month.Results: ITV pegaptanib sodium was well tolerated and no treatment complications arose. Mean VA was measured as: 0.37 &amp;plusmn; 0.24 at baseline; 0.37 &amp;plusmn; 0.25 at 1 month; 0.37 &amp;plusmn; 0.25 at 3 months and 0.40 &amp;plusmn; 0.26 at 6 months. VA was stabilized in approximately 90% of eyes treated with pegaptanib sodium. OCT examination showed a minimal change in central retinal thickness (CRT) during the course of the study, from 251.19 &amp;micro;m at baseline to 251.63 &amp;micro;m at 6 months. No elevation in IOP was measured during treatment at 4&amp;ndash;6 months in patients receiving pegaptanib sodium.Conclusions: ITV therapy with pegaptanib sodium for occult and minimally classic CNV secondary to neovascular AMD offered good efficacy with a favorable adverse events profile. The majority of patients showed stabilization in all assessed parameters. In clinical practice, careful consideration should be given to the use of nonselective VEGF inhibition in patients with a high cardiovascular risk profile or in those with a history of thromboembolic events.Keywords: Intravitreal (ITV) injection, age-related macular degeneration (AMD), choroidal neovascularization (CNV), anti-VEGF therapy, pegaptanib sodiu

MSFC's Advanced Space Propulsion Formulation Task

In NASA s Fiscal Year 2012, a small project was undertaken to provide additional substance, depth, and activity knowledge to the technology areas identified in the In-Space Propulsion Systems Roadmap, Technology Area 02 (TA-02), as created under the auspices of the NASA Office of the Chief Technologist (OCT). This roadmap was divided into four basic groups: (1) Chemical Propulsion, (2) Non-chemical Propulsion, (3) Advanced (TRL<3) Propulsion Technologies, and (4) Supporting Technologies. The first two were grouped according to the governing physics. The third group captured technologies and physic concepts that are at a lower TRL level. The fourth group identified pertinent technical areas that are strongly coupled with these related areas which could allow significant improvements in performance. There were a total of 45 technologies identified in TA-02, and 25 of these were studied in this formulation task. The goal of this task was to provide OCT with a knowledge-base for decisionmaking on advanced space propulsion technologies and not waste money by unintentionally repeating past projects or funding the technologies with minor impacts. This formulation task developed the next level of detail for technologies described and provides context to OCT where investments should be made. The presentation will begin with the list of technologies from TA-02, how they were prioritized for this study, and details on what additional data was captured for the technologies studied. Following this, some samples of the documentation will be provided, followed by plans on how the data will be made accessible

Genesis II: Advanced Lunar Outpost

Sponsored by NASA/Universities Space Research Association, this study investigated advanced lunar habitats for 11 astronauts and mission specialists for durations of 20 months. Design recommendations are based on environmental response to the harsh lunar environment, human habitability, transportability, constructability, resilience and suitability for NASA lunar research missions in the early 21st century. Drawings include master plans, construction sequencing, detailed floor plans, sections, interior perspectives and construction details.https://dc.uwm.edu/caupr_mono/1051/thumbnail.jp