L1 libration point manned space habitat

Second generation stations or Manned Space Habitats (MSHs) are discussed for an Earth-Moon libration point and in lunar orbit. The conceptual design of such a station is outlined. Systems and subsystems described reflect anticipation of moderate technology growth. The evolution of the L1 environments is discussed, several selected subsystems are outlined, and how the L1 MSH will complete some of its activities is described

Metabolomic Characterization of Human Model of Liver Rejection Identifies Aberrancies Linked to Cyclooxygenase (COX) and Nitric Oxide Synthase (NOS)

BACKGROUND Acute liver rejection (ALR), a significant complication of liver transplantation, burdens patients, healthcare payers, and the healthcare providers due to an increase in morbidity, cost, and resources. Despite clinical resolution, ALR is associated with an increased risk of graft loss. A unique protocol of delayed immunosuppression used in our institute provided a model to characterize metabolomic profiles in human ALR. MATERIAL AND METHODS Twenty liver allograft biopsies obtained 48 hours after liver transplantation in the absence of immunosuppression were studied. Hepatic metabolites were quantitated in these biopsies by liquid chromatography and mass spectroscopy (LC/MS). Metabolite profiles were compared among: 1) biopsies with reperfusion injury but no histological evidence of rejection (n=7), 2) biopsies with histological evidence of moderate or severe rejection (n=5), and 3) biopsies with histological evidence of mild rejection (n=8). RESULTS There were 133 metabolites consistently detected by LC/MS and these were prioritized using variable importance to projection (VIP) analysis, comparing moderate or severe rejection vs. no rejection or mild rejection using partial least squares discriminant statistical analysis (PLS-DA). Twenty metabolites were identified as progressively different. Further PLS-DA using these metabolites identified 3 metabolites (linoleic acid, γ-linolenic acid, and citrulline) which are associated with either cyclooxygenase or nitric oxide synthase functionality. CONCLUSIONS Hepatic metabolic aberrancies associated with cyclooxygenase and nitric oxide synthase function occur contemporaneous with ALR. Additional studies are required to better characterize the role of these metabolic pathways to enhance utility of the metabolomics approach in diagnosis and outcomes of ALR

Presolar Grains from Novae: Evidence from Neon and Helium Isotopes in Comet Dust Collections

Presolar grains in meteorites and interplanetary dust particles (IDPs) carry non-solar isotopic signatures pointing to origins in supernovae, giant stars, and possibly other stellar sources. There have been suggestions that some of these grains condensed in the ejecta of classical nova outbursts, but the evidence is ambiguous. We report neon and helium compositions in particles captured on stratospheric collectors flown to sample materials from comets 26P/Grigg-Skjellerup and 55P/Tempel-Tuttle that point to condensation of their gas carriers in the ejecta of a neon (ONe) nova. The absence of detectable 3He in these particles indicates space exposure to solar wind (SW) irradiation of a few decades at most, consistent with origins in cometary dust streams. Measured 4He/20Ne, 20Ne/22Ne, 21Ne/22Ne and 20Ne/21Ne isotope ratios, and a low upper limit on 3He/4He, are in accord with calculations of nucleosynthesis in neon nova outbursts. Of these, the uniquely low 4He/20Ne and high 20Ne/22Ne ratios are the most diagnostic, reflecting the large predicted 20Ne abundances in the ejecta of such novae. The correspondence of measured Ne and He compositions in cometary matter with theoretical predictions is evidence for the presence of presolar grains from novae in the early solar system.Comment: As appeared in the Astrophysical Journa

The 1990 update to strategy for exploration of the inner planets

The Committee on Planetary and Lunar Exploration (COMPLEX) has undertaken to review and revise the 1978 report Strategy for Exploration of the Inner Planets, 1977-1987. The committee has found the 1978 report to be generally still pertinent. COMPLEX therefore issues its new report in the form of an update. The committee reaffirms the basic objectives for exploration of the planets: to determine the present state of the planets and their satellites, to understand the processes active now and at the origin of the solar system, and to understand planetary evolution, including appearance of life and its relation to the chemical history of the solar system

Requirement of Caprine Arthritis Encephalitis VirusvifGene forin VivoReplication

AbstractReplication ofvif-caprine arthritis encephalitis virus (CAEV) is highly attenuated in primary goat synovial membrane cells and blood-derived macrophages compared to the wild-type (wt) virus. We investigated the requirement for CAEV Vif forin vivoreplication and pathogenicity in goats by intra-articular injection of either infectious proviral DNA or viral supernatants. Wild-type CAEV DNA or virus inoculation induced persistent infection resulting in severe inflammatory arthritic lesions in the joints. We were unable to detect any sign of virus replication invif-CAEV DNA inoculated goats, whilevif-CAEV virus inoculation resulted in the seroconversion of the goats. However, virus isolation and RT-PCR analyses on blood-derived macrophage cultures remained negative throughout the experiment as well as in joint or lymphoid tissues taken at necropsy. No pathologic lesions could be observed in joint tissue sections examined at necropsy. Goats inoculated with thevif-virus demonstrated no protection against a pathogenic virus challenge. These results demonstrate that CAEV Vif is absolutely required for efficientin vivovirus replication and pathogenicity and provide additional evidence that live attenuated lentiviruses have to establish a persistent infection to induce efficient protective immunity

Mass fractionation in hydrodynamic escape

We show that mass fractionation occurs during the course of hydrodynamic escape of gases from the atmosphere of an inner planet. Light gases escape more readily than heavy gases. The resultant fractionation as a function of mass yields a linear or concave downward plot in a graph of logarithm of remaining inventory against atomic mass. An episode of hydrodynamic escape early in the history of Mars could have resulted in the mass-dependent depletion of the noble gases observed in the Martian atmosphere, if Mars was initially hydrogen rich. Similarly, a hydrodynamic escape episode early in Earth's history could have yielded a mass-dependent fractionation of the xenon isotopes. The required hydrodynamic escape fluxes and total amounts of hydrogen lost from the planets in these episodes are large, but not impossibly so. The theory of the mass fractionation process is simple, but more work will be needed to put together an internally consistent scenario that reconciles a range of data from different planets.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26796/1/0000352.pd

Discovery of Brownleeite: a New Manganese Silicide Mineral in an Interplanetary Dust Particle

The Earth accretes approximately 40,000 tons of cosmic dust annually, originating mainly from the disintegration of comets and collisions among asteroids. This cosmic dust, also known as interplanetary dust particles (IDPs), is a subject of intense interest since it is made of the original building blocks of our Solar System. Although the specific parent bodies of IDPs are unknown, the anhydrous chondritic-porous IDPs (CP-IDPs) subset has been potentially linked to a cometary source. The CP-IDPs are extremely primitive materials based on their unequilibrated mineralogy, C-rich chemistry, and anomalous isotopic signatures. In particular, some CP-IDPs escaped the thermal, aqueous and impact shock processing that has modified or destroyed the original mineralogy of meteorites. Thus, the CP-IDPs represent some of the most primitive solar system materials available for laboratory study. Most CP-IDPs are comprised of minerals that are common on Earth. However, in the course of an examination of one of the CP-IDPs, we encountered three sub-micrometer sized grains of manganese silicide (MnSi), a phase that has heretofore not been found in nature. In the seminar, we would like to focus on IDP studies and this manganese silicide phase that has been approved as the first new mineral identified from a comet by the International Mineralogical Association (IMA) in 2008. The mineral is named in honour of Donald E. Brownlee, an American astronomer and a founder of the field of cosmic dust research who is the principal investigator of the NASA Stardust Mission that collected dust samples from Comet 81P/Wild-2 and returned them to Earth. Much of our current view and understanding of the early solar system would not exist without the pioneering work of professor Don Brownlee in the study of IDPs

Geminate recombination of electrons generated by above-the-gap (12.4 eV) photoionization of liquid water

The picosecond geminate recombination kinetics for hydrated electrons generated by 200 nm two photon absorption (12.4 eV total energy) has been measured in both light and heavy water. The geminate kinetics are observed to be almost identical in both H2O and D2O. Kinetic analysis based upon the independent reaction time approximation indicates that the average separation between the electron and its geminate partners in D2O is 13% narrower than in H2O (2.1 nm vs. 2.4 nm). These observations suggest that, even at this high ionization energy, autoionization of water competes with direct ionization.Comment: 10 pages + 2 figures, submitted to Chem. Phys. Letter

F.A.R.O.G. FORUM, Vol. 2 No. 6

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