745 research outputs found

    NASA follow-on to the Bangladesh Agro-Climatic Environmental Monitoring Project

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    The NASA responsibility and activities for the follow-on to the original Agro-Climatic Environmental Monitoring Project (ACEMP) which was completed during 1987 is described. Five training sessions which comprise the NASA ACEMP follow-on are: Agrometeorology, Meteorology of Severe Storms Using GEMPAK, Satellite Oceanography, Hydrology, and Meteorology with TOVS. The objective of the follow-on is to train Bangladesh Government staff in the use of satellite data for remote sensing applications. This activity also encourages the scientific connection between NASA/Goddard Space Flight Center and The Bangladesh Space and Remote Sensing Organization (SPARRSO)

    HCl Vapour Pressures and Reaction Probabilities for ClONO2 + HCl on Liquid H2SO4-HNO3-HCl-H20 Solutions

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    Henry's Law solubility constants for HCl have been measured for liquid H2SO4-HNO3-HCl-H2O solutions; the results are in good agreement with predictions from published semiempirical models. The ClONO2 + HCl reaction on the surfaces of such solutions with compositions simulating those of stratospheric aerosols has been investigated; as the composition changes following the temperature drop characteristic of the high-latitude stratosphere the reaction probability gamma increases rapidly. Furthermore, the gamma values remain essentially unchanged when HN03 uptake is neglected; the controlling factor appears to be the solubility of HCl. These results corroborate our earlier suggestion that supercooled liquid sulfate aerosols promote chlorine activation at low temperatures as efficiently as solid polar stratospheric cloud particles

    ISM In-Space Manufacturing

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    Develop and enable the technologies, materials, and processes required to provide affordable, sustainable on-demand manufacturing, recycling, and repair during Exploration Missions

    Structural and Compositional Changes in the Upper Atmosphere Related to the PEDE‐2018 Dust Event on Mars as Observed by MAVEN NGIMS

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    The onset of the planet encircling dust event (PEDE‐2018) started around 1 June 2018 as observed by Mars Reconnaissance Orbiter/Mars Color Imager, peaking around 7–10 July and persisting through mid‐October 2018. After the onset of the event, the upper atmosphere underwent significant changes in density and thermal structures. Mars Atmosphere and Volatile Evolution‐Neutral Gas and Ion Mass Spectrometer (MAVEN NGIMS) had a good opportunity to observe these changes from the first detection in the upper atmosphere and throughout the duration of the PEDE. The compositional changes included increased density at a constant altitude for CO2 and Ar, while the O decreased from the peak throughout the decay of the bulk of the PEDE.Plain Language SummaryFrom June through October 2018 Mars experienced a planet encircling dust event (PEDE‐2018), a fairly rare event last observed in 2007. The dust storm grew from a local event to cover the entire planet and was opaque enough that so little sunlight reached the surface that the solar‐powered opportunity rover ceased operations and all attempts to re‐establish contact with it were unsuccessful. Meanwhile, the orbiter Mars Atmosphere and Volatile Evolution (MAVEN) was able to observe changes in the upper atmosphere in the composition as a result of this globally extensive PEDE. MAVEN observed increases in both the CO2 and Ar while also observing an unexpected reduction in the O densities.Key PointsMAVEN/NGIMS observed increased of CO2 and Ar densities observed in the upper atmosphere corresponding to the peak of the dust eventUnexpected decrease in O densities in the upper atmosphere (160–250 km) was simultaneously observedComparisons between model and data results show good agreement with scale height and temperatures, further M‐GITM model revisions needed to capture circulation effectsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154472/1/grl59716_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154472/2/grl59716.pd

    Repositioning An Academic Department To Stimulate Growth

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    The complexity of the market in higher education, and the lack of literature regarding marketing, particularly branding, at the academic department level, presented an opportunity to establish a systematic process for evaluating an academic department’s brand meaning. A process for evaluating a brand’s meaning for an academic department is developed in this paper using Keller’s Customer Base Brand Equity model. This process will aid academic departments experiencing perception problems or wishing to improve their brand to better understand their existing brand meaning and assess the alignment between the student market perception and the industry market perception. This systematic process for evaluating a brand’s meaning is presented as applied to a case study.

    He bulge revealed: He and CO2 diurnal and seasonal variations in the upper atmosphere of Mars as detected by MAVEN NGIMS

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    Analysis of the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmosphere Volatiles and EvolutioN (MAVEN) spacecraft closed source data from all orbits with good pointing revealed an enhanced Helium [He] density on the nightside orbits and a depressed He density on the dayside by about a factor of 10–20. He was also found to be larger in the polar regions than in the equatorial regions. The northern polar winter nightside He bulge was approximately twice that of the northern polar summer nightside bulge. The first 6 weeks of the MAVEN prime mission had periapsis at high latitudes on the nightside during northern winter, followed by the midlatitudes on the dayside moving to low latitudes on the nightside returning to the high latitudes during northern summer. In this study we examined the NGIMS data not only in the different latitudes but sorted by solar longitude (Ls) in order to separate the diurnal or local solar time (LST) effects from the seasonal effects. The Mars Global Ionosphere‐Thermosphere Model (M‐GITM) has predicted the formation of a He bulge in the upper atmosphere of Mars on the nightside early morning hours (Ls = 2–5 h) with more He collecting around the poles. Taking a slice at constant altitude across all orbits indicates corresponding variations in He and CO2 with respect to LST and Ls and a diurnal and seasonal dependence.Key PointsData using MAVEN NGIMS for 1 Martian year reveal diurnal and seasonal variations in He and CO2 indicating a changing He bulge in upper atmosphereObserved He bulge is found to agree preliminarily with M‐GITM modeling effortsHe bulge found at Mars is similar to those found at Earth and VenusPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136361/1/jgra53312_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136361/2/jgra53312.pd

    In vitro culture with gemcitabine augments death receptor and NKG2D ligand expression on tumour cells

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    Much effort has been made to try to understand the relationship between chemotherapeutic treatment of cancer and the immune system. Whereas much of that focus has been on the direct effect of chemotherapy drugs on immune cells and the release of antigens and danger signals by malignant cells killed by chemotherapy, the effect of chemotherapy on cells surviving treatment has often been overlooked. In the present study, tumour cell lines: A549 (lung), HCT116 (colon) and MCF-7 (breast), were treated with various concentrations of the chemotherapeutic drugs cyclophosphamide, gemcitabine (GEM) and oxaliplatin (OXP) for 24 hours in vitro. In line with other reports, GEM and OXP upregulated expression of the death receptor CD95 (fas) on live cells even at sub-cytotoxic concentrations. Further investigation revealed that the increase in CD95 in response to GEM sensitised the cells to fas ligand treatment, was associated with increased phosphorylation of stress activated protein kinase/c-Jun N-terminal kinase and that other death receptors and activatory immune receptors were co-ordinately upregulated with CD95 in certain cell lines. The upregulation of death receptors and NKG2D ligands together on cells after chemotherapy suggest that although the cells have survived preliminary treatment with chemotherapy they may now be more susceptible to immune cell-mediated challenge. This re-enforces the idea that chemotherapy-immunotherapy combinations may be useful clinically and has implications for the make-up and scheduling of such treatments

    Photoacoustic Experimental System To Confirm Infrared Absorption Due to Greenhouse Gases

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    An experimental system for detecting infrared absorption using the photoacoustic (PA) effect is described. It is aimed for use at high-school level to illustrate the difference in infrared (IR) absorption among the gases contained in the atmosphere in connection with the greenhouse effect. The experimental system can be built with readily available components and is suitable for small-group experiments. The PA signal from a greenhouse gas (GHG), such as CO2, H2O, and CH4, can be detected down to a concentration of 0.1%. Since the basic theory of the PA effect in gases due to IR absorption is straightforward, the experiments with this PA system are accessible to students. It can be shown that there is a significant difference in IR absorption between GHGs and the major components of the atmosphere, N2, O2, and Ar, which helps students understand that the minor components, that is, the GHGs, determine the IR absorptivity of the atmosphere

    Inferring Market Structure from Customer Response to Competing and Complementary Products

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    We consider customer influences on market structure, arguing that market structure should explain the extent to which any given set of market offerings are substitutes or complements. We describe recent additions to the market structure analysis literature and identify promising directions for new research in market structure analysis. Impressive advances in data collection, statistical methodology and information technology provide unique opportunities for researchers to build market structure tools that can assist “real-time” marketing decision-making.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46981/1/11002_2004_Article_5088105.pd

    The Orbiting Astrophysical Spectrometer In Space (OASIS)

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    The Orbiting Astrophysical Observatory In Space (OASIS) is an Advanced Concept currently under study at NASA as a mission for the next decade. The goal of the OASIS mission is to identify a local site or sites where galactic cosmic rays (GCR) originate and are accelerated. The mission will also allow GCR data to be used to investigate how elements are made and distributed in the galaxy and to improve our understanding of supernovae and the nucleosynthesis of the heavy elements. OASIS consists of two instruments that provide complementary data on the location and nature of the source(s) through investigating the composition of ultra-heavy nuclei ( ) and the energy spectrum of electrons. In particular OASIS will measure the relative abundances in the actinide group ( ) to determine the age of the -process material in GCRs. The presence of young r-process material would indicate that GCRs are a sample of the interstellar medium in OB associations. OASIS will measure the electron spectrum to 10 TeV. The energy where this spectrum ends will tell us the distance to the nearest GCR source(s). OASIS will look for spectral features and anisotropy in the high energy electron spectrum that are expected to appear when only a few of the nearest astrophysical sources can contribute to the electron flux. Spectral features may also suggest dark matter decay products. We anticipate that these measurements will lead to the identification of the nearest cosmic ray electron source and provide a crucial test of the OB association model for the origin of GCR nuclei
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